elastin and Inflammation

Platelets are essential mediators of inflammation and thrombosis. Chronic obstructive pulmonary disease (COPD) is a heterogeneous multisystem disease, causing significant morbidity and mortality worldwide. Recent evidence suggests that the lung is an important organ for platelet biogenesis. Cigarette smoking has been shown to induce platelet aggregation and decrease the capacity of mitochondrial electron transport system in platelets. Preclinical and clinical studies have suggested that platelets may contribute to the development of COPD through the breakdown of lung elastin by platelet factor 4, platelet activation and formation of platelet aggregates, and modulation of hypoxia signaling pathways. Recent large population studies have produced encouraging results indicating a potential role for aspirin in preventing exacerbations and delaying disease progression in patients with COPD. This review summarizes the information about the lung as an organ for platelet production, pathophysiological functions of platelets and platelet mediators in the development of COPD, and the most updated evidence on the utility of aspirin in patients with COPD.

Topics: Aspirin; Blood Platelets; Disease Progression; Elastin; Electron Transport; Humans; Inflammation; Lung; Megakaryocytes; Mitochondria; Mitochondrial Diseases; Platelet Activation; Platelet Aggregation; Platelet Aggregation Inhibitors; Platelet Factor 4; Pulmonary Disease, Chronic Obstructive; Smoking; Thrombosis

It is now well accepted that aging is associated with the occurrence of a low-grade inflammation called Inflamm-aging. This leads to the imbalance between the various mediators of the inflammatory response in favour of the pro-inflammatory response represented by pro-inflammatory cytokines and oxidative stress. The question that arises, and is still under investigation, what is the origin of the driving force leading to these changes. One of the current hypotheses is that chronic stimulation of the immune system contributes to the pro-inflammatory shift. The chronic stimulation can be of viral origin such as cytomegalovirus, from tumor antigens or from other sources such as the extracellular matrix, especially from elastin fibres and collagens. Aging and various inflammatory diseases such as atherosclerosis, abdominal aortic aneurysms, chronic obstructive pulmonary diseases (COPD), cancer and type 2 diabetes are characterized by the destruction of elastin fibers and the consequent generation of elastin peptides which are biologically active. This review will describe the putative contribution of elastin peptides to inflamm-aging and extend on their role on immunosenescence, as well as on age-associated chronic inflammatory diseases.

Topics: Adaptive Immunity; Aging; Animals; Disease; Elastin; Humans; Immunity, Innate; Inflammation; Models, Biological; Peptides

The transforming growth factor β (TGFβ) superfamily consists of multipotential secreting cytokines that mediate many key events in normal cellular growth and development, including differentiation, proliferation, motility, organization and death. TGFβs act as ligand for 3 classes of cell surface receptors, the transmembrane serine-threonine kinase receptors, TGFβ receptor type I (TGFβRI) and type 2 (TGFβRII), and TGFβRIII receptors which include an ubiquitous extracellular β-glycan and the membrane glycoprotein endoglin (CD105). Binding of TGFβs to their receptors initiates diverse cellular responses resulting in the phosphorilation of Smad proteins, which then translocate to the nucleus and regulate the transcription of target genes. Perturbation of TGFβ signaling has been implicated in various human disorders including cancer, fibrosis and auto-immune diseases. Recently, mutations in TGFβR1 and TGFβR2 genes have been found in association with a continuum of clinical features with widespread vascular involvement. The extreme of clinical severity is represented by the Loeys-Dietz syndrome (LDS), an autosomal dominant disorder characterized by hypertelorism, bifid uvula, and/or cleft palate, and aggressive arteriopathy causing arterial tortuosity as well as life-threatening complications such as vascular aneurysms and dissections. Elastin disarray, loss of elastic fibre architecture and increased collagen expression in the arterial wall are the pathologic hallmark of LDS. In the present review article we will provide details on the activation of TGFβ cascade, on the clinical features of LDS, as well as on the mechanisms of TGFβ signaling perturbation leading to this condition and the potential role of the antagonism of TGFβ activity in disease management.

Topics: Elastin; Endothelial Cells; Extracellular Matrix; Humans; Inflammation; Loeys-Dietz Syndrome; Receptors, Transforming Growth Factor beta; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

Extracellular matrix is generally increased in asthma, causing thickening of the airways which may either increase or decrease airway responsiveness, depending on the mechanical requirements of the deposited matrix. However, in vitro studies have shown that the altered extracellular matrix produced by asthmatic airway smooth muscle cells is able to induce increased proliferation of non-asthmatic smooth muscle cells, which is a process believed to contribute to airway hyper-responsiveness in asthma. Elastin is an extracellular matrix protein that is altered in asthmatic airways, but there has been no systematic investigation of the functional effect of these changes. This review reveals divergent reports of the state of elastin in the airway wall in asthma. In some layers of the airway it has been described as increased, decreased and/or fragmented, or unchanged. There is also considerable evidence for an imbalance of matrix metalloproteinases, which degrade elastin, and their respective inhibitors the tissue inhibitors of metalloproteinases, which collectively help to explain observations of both increased elastin and elastin fragments. A loss of lung elastic recoil in asthma suggests a mechanical role for disordered elastin in the aetiology of the disease, but extensive studies of elastin in other tissues show that elastin fragments elicit cellular effects such as increased proliferation and inflammation. This review summarises the current understanding of the role of elastin in the asthmatic airway.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Cell Proliferation; Elastin; Extracellular Matrix; Humans; Inflammation; Matrix Metalloproteinases; Myocytes, Smooth Muscle

Inflammation, proteolysis, smooth muscle cell apoptosis, and angiogenesis have been implicated in the pathogenesis of abdominal aortic aneurysms (AAAs), although the well-defined initiating mechanism is not fully understood. Matrix metalloproteinases (MMPs) such as MMP-2 and -9 and other proteinases degrading elastin and extracellular matrix are the critical pathogenesis of AAAs. Among the risk factors of AAAs, cigarette smoking is an irrefutable one. Cigarette smoke is practically involved in various aspects of the AAA pathogenesis. Nicotine, a major alkaloid in tobacco leaves and a primary component in cigarette smoke, can stimulate the MMPs expression by vascular SMCs, endothelial cells, and inflammatory cells in vascular wall and induce angiogenesis in the aneurysmal tissues. However, for the inflammatory and apoptotic processes in the pathogenesis of AAAs, nicotine seems to be moving in just the opposite direction. Additionally, the effects of nicotine are probably dose dependent or associated with the exposure duration and may be partly exerted by its receptors--nicotinic acetylcholine receptors (nAChRs). In this paper, we will mainly discuss the pathogenesis of AAAs involving inflammation, proteolysis, smooth muscle cell apoptosis and angiogenesis, and the roles of nicotine and nAChRs.

Topics: Aged; Aged, 80 and over; Animals; Aortic Aneurysm, Abdominal; Apoptosis; Elastin; Extracellular Matrix; Female; Humans; Hypertension; Inflammation; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Neovascularization, Pathologic; Nicotine; Receptors, Nicotinic; Risk Factors; Sex Factors; Smoking

Calcific aortic stenosis is a progressive disease characterized by massive fibrosis andmineralization of the valve leaflets. The aim of this study was to determine whether the onset of native calcific aortic stenosis is associated primarily with matrix remodelling events, and particularly with elastin degradation.. The immunohistochemical expression profile of matrix degradating enzymes and tenascin-C was investigated in both healthy and native calcified aortic valves. Collagen and elastic tissue were studied by light microscopy and electron microscopy. Immunophenotypic analysis of inflammatory cells was carried out by using monoclonal antibodies to macrophages, T and B lymphocytes. Immunoreactivity for tenascin-C and matrix metalloproteinase-12 (MMP-12) was associated with areas of dense mineralization, which were characterized by fibrosis, fragmentation and calcification of elastic fibres a positive reaction was also found around small islands of calcification. MMP-11 was not detected in the diseased valves. Osteopontin and osteonectin were also found at sites of mineralization. All calcified valves examined showed inflammatory cell infiltration.. Our results demonstrate the direct involvement of MMP-12 in native aortic valve stenosis. MMP-mediated degradation of elastic fibres might contribute actively to valve mineralization by inducing calcium deposition onto fragmented elastin.

Topics: Aged; Aged, 80 and over; Aortic Valve; Aortic Valve Stenosis; Calcinosis; Elastin; Female; Humans; Immunohistochemistry; Inflammation; Male; Matrix Metalloproteinase 12; Microscopy, Electron, Transmission; Middle Aged; Osteonectin; Osteopontin; Tenascin

Chemoattractant properties of matrix proteins, like collagen and elastin, for neutrophils and monocytes in vitro have long been recognized. This activity often resides in fragments of these proteins. These peptides may play a role in diseases of the lung matrix, such as chronic obstructive pulmonary disease. Recent advances include the elucidation of the structure of chemotactic collagen fragments and the demonstration that their activity may reside in a structural relatedness to CXC chemokines. Collagen and elastin fragments have been demonstrated to have a role in in vivo lung pathophysiology and have been quantified in patients with chronic lung diseases where they may activate autoimmune pathways. Elucidation of these pathways may provide novel biomarkers and therapeutic targets for chronic lung diseases.

Topics: Animals; Chemokines, CXC; Chemotactic Factors; Collagen; Elastin; Extracellular Matrix Proteins; Humans; Inflammation; Lung; Lung Diseases; Matrix Metalloproteinase 9; Oligopeptides; Peptide Fragments; Peptide Hydrolases; Pulmonary Disease, Chronic Obstructive

Within the last several years, research scientists and clinicians have been intrigued with the potential use of an active form of vitamin A, retinoic acid (RA), for the treatment and prevention of emphysema. The interest in this area can be largely attributed to the work of Massaro and Massaro (1996, 1997, 2000) in which they presented evidence that RA partially protects against and to some degree restores elastase-induced emphysema in rats. The mechanism for this protective effect of RA is in part related to elastin metabolism. RA also inhibits inflammation, an upstream event that may lead to the development of emphysema. Although there is evidence of this protective effect in young rats and a mechanistic explanation, more studies are needed in humans in order to establish a role for vitamin A in protecting against emphysema. Too many unanswered questions remain to definitively state that vitamin A protects against this disease in humans. Nevertheless, the potential for this novel approach in prevention and treatment of emphysema is an exciting area of research.

Topics: Animals; Elastin; Humans; Inflammation; Lung; Pulmonary Emphysema; Smoking; Tretinoin; Vitamin A; Vitamin A Deficiency; Vitamins

Degradation of elastin, the main amorphous component of elastic fibers, by elastases belonging to the serine, metallo, or cysteine families leads to the generation of elastin fragments, designated as elastokines in keeping with their cytokine-like properties. Generation of elastokines from one of the longest lived protein in human might represent a strong tissue repair signal. Indeed, they (1) exhibit potent chemotactic activity for leukocytes, (2) stimulate fibroblast and smooth muscle cell proliferation, and (3) display proangiogenic activity as potent as VEGF. However, continuous exposure of cells to these matrikines, through increased elastase(s) expression with age, can contribute to the formation of a chronic inflammatory state, that is, inflamm-aging. Importantly, binding of elastokines to S-Gal, their cognate receptor, proved to stimulate matrix metalloproteinase expression in normal and cancer cells. Besides, these elastin fragments can polarize lymphocytes toward a Th-1 response or induce an osteogenic response in smooth muscle cells, and arterial wall calcification. In this chapter, emphasis will be made on the contribution of elastokines on the genesis of age-related arterial wall diseases, particularly abdominal aortic aneurysms (AAAs). An elastokine theory of AAAs progression will be proposed. Age is one main risk factor of cancer incidence and development. The myriad of biological effects exerted by elastokines on stromal and inflammatory cells led us to hypothesize that they might be main actors in elaborating a favorable cancerization field in melanoma; for instance these peptides could catalyze the vertical growth phase transition in melanoma through increased expression of gelatinase A and membrane-type 1 matrix metalloproteinase.

Topics: Aging; Amino Acid Motifs; Animals; Arteries; Disease Progression; Elastic Tissue; Elastin; Humans; Inflammation; Matrix Metalloproteinases; Melanoma; Neovascularization, Physiologic; Pancreatic Elastase; Peptides; Receptors, Cell Surface; Signal Transduction; T-Lymphocytes; Vascular Diseases

Biomaterials, including non-biodegradable and biodegradable polymers, and collagen and fibrin matrices, have been used in experimental and clinical arterial reconstruction. While these biomaterials exhibit various characteristics suitable for arterial reconstruction, the patency of biomaterial-based arterial substitutes remains problematic because of inflammation and thrombogenesis. Endothelial cell seeding of biomaterials has been proposed and used for reducing the thrombogenicity of biomaterials. However, difficulties in cell retention hamper the application of such an approach. Although autogenous vein grafts offer satisfactory results, not all patients possess veins available for arterial replacements. Thus, a critical issue in arterial reconstruction is developing arterial substitutes that are inflammation/thrombosis-resistant while possessing the characteristics of natural arteries. Here we show that allogenic vascular elastic laminae exhibit anti-inflammatory properties and may be considered a potential material for arterial reconstruction. In this article, we briefly review the composition, structure, and function of vascular elastic laminae, summarize recent discoveries on the role of elastic laminae in regulating leukocyte adhesion and vascular smooth muscle cell proliferation and migration, and discuss potential applications of allogenic elastic laminae to arterial reconstruction.

Topics: Angioplasty; Animals; Biocompatible Materials; Blood Vessel Prosthesis; Blood Vessels; Cell Adhesion; Cell Movement; Cell Proliferation; Elastin; Endothelium, Vascular; Gene Expression Regulation; Humans; Inflammation; Leukocytes; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Polymers; Thrombosis

The pathogenesis of abdominal aortic aneurysm involves many factors acting over time. However, destruction of elastin in the aortic wall is a key event that shifts the load produced by blood pressure on to collagen. This is exacerbated in the presence of hypertension. Smoking and age are further important factors, as is the site; elastic lamellae are relatively less common in the abdominal aorta. Once the shielding effect of elastin is lost, further dilatation and rupture of the aorta depend on the physical properties of the collagen present.

Topics: Age Factors; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Arteriosclerosis; Collagen; Elastin; Humans; Hypertension; Inflammation; Smoking

Topics: Autoantigens; Autoimmune Diseases; Collagen; Elastin; Eye Proteins; Glycosaminoglycans; Humans; Inflammation; Lens Diseases; Lens, Crystalline

Topics: Aging; Amino Acids; Aneurysm; Animals; Arteriosclerosis; Brain Diseases; Copper; Deficiency Diseases; Elastic Tissue; Elastin; Endocardial Fibroelastosis; Growth Disorders; Hair; Humans; Inflammation; Lathyrism; Marfan Syndrome; Metabolic Diseases; Respiratory Tract Diseases; Skin Diseases

Topics: Cell Nucleus; Chromatography, Ion Exchange; Connective Tissue; Cytoplasmic Granules; Elastin; Enzyme Inhibitors; Humans; Hydrolysis; Immune Sera; Inflammation; Isoelectric Focusing; Leukocytes; Lysosomes; Microbial Collagenase; Microsomes; Pancreatic Elastase; Subcellular Fractions; Trypsin Inhibitors

As oxygen is essential for wound healing and there is limited diffusion across the stratum corneum into the epidermis, we wanted to evaluate whether the topical delivery of a total dissolved oxygen in dressing form on intact human subject skin would improve clinical and histologic skin functioning.. Fifty normal, healthy subjects completed a pilot clinical evaluation to assess the efficacy and tolerability of a dissolved oxygen dressing (OxygeneSys™-Continuous) to improve the health and appearance of intact skin.. Clinical analysis was performed on 50 subjects; histological and gene expression analysis was performed on 12 of the 50 subjects to assess the effect of the dissolved oxygen dressing.. Clinical data demonstrate that the dressing is well tolerated, and several measures of skin health and integrity showed improvements compared with a control dressing site. Skin hydration measurements showed a statistically significant increase in skin hydration at 0-4, 4-8, and 0-8 weeks (P < 0.05 at each time point). The blinded clinical investigator's grading of desquamation, roughness, and skin texture show significant decreases from baseline to the 8-week time point (P < 0.05). The dressings were removed prior to the blinded clinical investigator's grading. These data were supported by the histological and gene expression studies, which showed a general reduction in inflammatory response markers and transcription products (IL-6, IL-8, TNF-alpha, MMP-1, and MMP-12), while facilitating a general increase in structural skin proteins (collagen I, elastin, and filaggrin). Additionally, p53 signals from biopsy samples support the clinical investigator's observations of no safety concerns.. The data from this study demonstrate that the dressing has no deleterious effects and stimulates beneficial effects on intact, nonwounded skin.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Cutaneous; Aged; Aquaporin 3; Collagen Type I; Deoxyguanosine; Elastin; Female; Filaggrin Proteins; Gene Expression; Humans; Inflammation; Interleukin-1; Interleukin-6; Intermediate Filament Proteins; Male; Matrix Metalloproteinase 1; Matrix Metalloproteinase 12; Middle Aged; Oxygen; Single-Blind Method; Skin; Skin Physiological Phenomena; Tumor Necrosis Factor-alpha

Topics: Aging; Animals; Aorta; Elastin; Female; Humans; Inflammation; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Pulse Wave Analysis; Vascular Stiffness

The Ponseti method corrects a clubfoot by manipulation and casting which causes stress relaxation on the tendons. Here, we examined the effect of long-term stress relaxation on tendon extracellular matrix (ECM) by (1) an

Topics: Animals; Clubfoot; Elastin; Extracellular Matrix; Inflammation; Rabbits; Tendons; Treatment Outcome

Inflammatory processes are activated following ischemic stroke that lead to increased tissue damage for weeks following the ischemic insult, but there are no approved therapies that target this inflammation-induced secondary injury. Here, we report that SynB1-ELP-p50i, a novel protein inhibitor of the nuclear factor kappa B (NF-κB) inflammatory cascade bound to the drug carrier elastin-like polypeptide (ELP), decreases NF-κB induced inflammatory cytokine production in cultured macrophages, crosses the plasma membrane and accumulates in the cytoplasm of both neurons and microglia in vitro, and accumulates at the infarct site where the blood-brain barrier (BBB) is compromised following middle cerebral artery occlusion (MCAO) in rats. Additionally, SynB1-ELP-p50i treatment reduces infarct volume by 11.86% compared to saline-treated controls 24 h following MCAO. Longitudinally, SynB1-ELP-p50i treatment improves survival for 14 days following stroke with no effects of toxicity or peripheral organ dysfunction. These results show high potential for ELP-delivered biologics for therapy of ischemic stroke and other central nervous system disorders and further support targeting inflammation in ischemic stroke.

Topics: Animals; Anti-Inflammatory Agents; Brain; Brain Ischemia; Elastin; Infarction, Middle Cerebral Artery; Inflammation; Ischemic Stroke; Microglia; NF-kappa B; Peptides; Rats; Stroke

Acute lung injury (ALI) is a life-threatening disease that has received considerable critical attention in the field of intensive care. This study aimed to explore the role and mechanism of vitamin K2 (VK2) in ALI. Intraperitoneal injection of 7 mg/kg LPS was used to induce ALI in mice, and VK2 injection was intragastrically administered with the dose of 0.2 and 15 mg/kg. We found that VK2 improved the pulmonary pathology, reduced myeloperoxidase (MPO) activity and levels of TNF-α and IL-6, and boosted the level of IL-10 of mice with ALI. Moreover, VK2 played a significant part in apoptosis by downregulating and upregulating Caspase-3 and Bcl-2 expressions, respectively. As for further mechanism exploration, we found that VK2 inhibited P38 MAPK signaling. Our results also showed that VK2 inhibited ferroptosis, which manifested by reducing malondialdehyde (MDA) and iron levels, increasing glutathione (GSH) level, and upregulated and downregulated glutathione peroxidase 4 (GPX4) and heme oxygenase-1 (HO-1) expressions, respectively. In addition, VK2 also inhibited elastin degradation by reducing levels of uncarboxylated matrix Gla protein (uc-MGP) and desmosine (DES). Overall, VK2 robustly alleviated ALI by inhibiting LPS-induced inflammation, apoptosis, ferroptosis, and elastin degradation, making it a potential novel therapeutic candidate for ALI.

Topics: Acute Lung Injury; Animals; Apoptosis; Elastin; Ferroptosis; Inflammation; Lipopolysaccharides; Lung; Mice; Vitamin K 2

The airway structures and messenger RNA expression of genes that regulate airway inflammation and remodeling may be altered in the trachea of patients with tracheobronchomalacia (TBM).. Fourteen tracheal specimens obtained from 2005 to 2018 were used in this study. Surgical resection specimens from patients with TBM and tracheal stenosis (TS) were compared with control tracheal specimens obtained from autopsy cases. We investigated the messenger RNA expression of genes encoding fibroblast growth factor (FGF) binding protein 2 (FGFBP2), FGF receptor R3 (FGFR3), interleukin-1β (IL1β), tumor growth factor-β1 (TGFβ1), tissue inhibitor of metalloproteinases 1 (TIMP1), and intercellular adhesion molecule 1 (ICAM1) as well as established markers of airway inflammation including interferon-γ (IFNγ) and tumor necrosis factor (TNF). The relative expression of target transcripts was assessed by quantitative real-time polymerase chain reaction. A histologic examination of the same resected airway specimens was performed on formalin-fixed paraffin-embedded tissue sections.. FGFBP2 and FGFR3 showed higher expression in TBM compared with TS and control groups (P < .05 and P < .01, respectively). Furthermore, both TGFβ1 and TIMP1 were elevated in TBM patients compared with control subjects (P < .05). Conversely ICAM1 was downregulated in TBM versus TS and control subjects (P < .05). IL1β, IFNγ, and TNF were increased in TBM, although it did not achieve statistical significance. Histologically compared with control airways both TBM and TS demonstrated submucosal fibrotic changes, with TBM additionally demonstrating alterations in elastin fiber quality and density in the posterior membrane.. Significant changes in gene expression are observed in the tracheal walls of patients with TBM and TS compared with control subjects.

Topics: Elastin; Fibroblast Growth Factors; Formaldehyde; Gene Expression; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interferon-gamma; Interleukin-1beta; Receptors, Fibroblast Growth Factor; RNA, Messenger; Tissue Inhibitor of Metalloproteinases; Tracheal Stenosis; Tracheobronchomalacia; Tumor Necrosis Factors

Interferon-stimulated gene 15 (ISG15) encodes a ubiquitin-like protein that induces a reversible post-translational modification (ISGylation) and can also be secreted as a free form. ISG15 plays an essential role as host-defence response to microbial infection; however, its contribution to vascular damage associated with hypertension is unknown.. Bioinformatics identified ISG15 as a mediator of hypertension-associated vascular damage. ISG15 expression positively correlated with systolic and diastolic blood pressure and carotid intima-media thickness in human peripheral blood mononuclear cells. Consistently, Isg15 expression was enhanced in aorta from hypertension models and in angiotensin II (AngII)-treated vascular cells and macrophages. Proteomics revealed differential expression of proteins implicated in cardiovascular function, extracellular matrix and remodelling, and vascular redox state in aorta from AngII-infused ISG15-/- mice. Moreover, ISG15-/- mice were protected against AngII-induced hypertension, vascular stiffness, elastin remodelling, endothelial dysfunction, and expression of inflammatory and oxidative stress markers. Conversely, mice with excessive ISGylation (USP18C61A) show enhanced AngII-induced hypertension, vascular fibrosis, inflammation and reactive oxygen species (ROS) generation along with elastin breaks, aortic dilation, and rupture. Accordingly, human and murine abdominal aortic aneurysms showed augmented ISG15 expression. Mechanistically, ISG15 induces vascular ROS production, while antioxidant treatment prevented ISG15-induced endothelial dysfunction and vascular remodelling.. ISG15 is a novel mediator of vascular damage in hypertension through oxidative stress and inflammation.

Topics: Angiotensin II; Animals; Aortic Aneurysm, Abdominal; Carotid Intima-Media Thickness; Elastin; Humans; Hypertension; Inflammation; Interferons; Leukocytes, Mononuclear; Mice; Mice, Inbred C57BL; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species

Marfan syndrome (MFS) is associated with TGF (transforming growth factor) β-stimulated ERK (extracellular signal-regulated kinase) activity in vascular smooth muscle cells (VSMCs), which adopt a mixed synthetic/contractile phenotype. In VSMCs, TGFβ induces IL (interleukin) 11) that stimulates ERK-dependent secretion of collagens and MMPs (matrix metalloproteinases). Here, we examined the role of IL11 in the MFS aorta.. We used echocardiography, histology, immunostaining, and biochemical methods to study aortic anatomy, physiology, and molecular endophenotypes in. In MFS, IL11 is upregulated in aortic VSMCs to cause ERK-related thoracic aortic dilatation, inflammation, and fibrosis. Therapeutic inhibition of IL11, imminent in clinical trials, might be considered as a new approach in MFS.

Topics: Animals; Antibodies, Neutralizing; Aorta; Aortic Diseases; Disease Models, Animal; Elastin; Fibrosis; Immunoglobulin G; Inflammation; Interleukin-11; Interleukin-11 Receptor alpha Subunit; Marfan Syndrome; Matrix Metalloproteinase 2; Mice; Muscle, Smooth, Vascular; Receptors, Interleukin-11; Transforming Growth Factor beta

Inflammatory disorders of the skin are major public health concerns due to constant exposure to external stimuli. Skin cells are associated with prominent immune mechanisms to defend against adverse reactions. In the present study, the anti‑inflammatory properties of membrane‑free stem cell components (MFSCC) from adipose tissue‑derived stem cells (ADSCs) and their basic preventive effects on skin wrinkle formation using human keratinocytes (HaCaT) and fibroblast (Detroit 551) cells, were investigated. Initially, a human inflammation antibody array was used on tumor necrosis factor‑α (TNF‑α)/interferon‑γ (IFN‑γ)‑induced and MFSCC‑treated HaCaT cells. Array spots revealed three differential proteins, interleukin (IL)‑1 F1 (IL‑1α), IL‑6, and TIMP2. Of these three proteins, IL‑6 was significantly downregulated by MFSCC treatment. Western blot analysis revealed that IL‑6 and its key downstream proteins JAK2 and STAT3 were suppressed in MFSCC‑treated HaCaT cells. Further analysis revealed that MFSCC decreased the expression of TNF‑α/IFN‑γ‑induced phosphorylated (p)‑IκB‑α, p‑p65, p‑JNK, p‑ERK, and p‑p38 by inhibiting the activation of MAPK and NF‑κB pathways. Treatment of Detroit 551 cells with MFSCC increased COL1A1 and elastin but suppressed matrix metalloproteinase (MMP)‑1 and MMP‑8 protein expression levels. Collectively, these data indicated that MFSCC exhibited a primary inhibitory effect on inflammation and wrinkle formation in skin. These results provide a basis for further extensive studies and application of MFSCC in treating skin inflammatory disorders.

Topics: Adipose Tissue; Cell Line; Cell Survival; Collagen; Elastin; Fibroblasts; Humans; Inflammation; Interferon-gamma; Interleukin-6; Janus Kinase 2; Keratinocytes; Mitogen-Activated Protein Kinases; NF-kappa B; Phosphorylation; Signal Transduction; Skin; STAT3 Transcription Factor; Stem Cells; Tumor Necrosis Factor-alpha

Elastin-derived peptides (EDPs) contain replications of the Val-Gly-Val-Ala-Pro-Gly (VGVAPG) hexapeptide. It has been described that the VGVAPG peptide induces reactive oxygen species (ROS) production in murine monocytes and astrocytes, human fibroblasts, and the human neuroblastoma (SH-SY5Y) cell line. To date, there is growing evidence that calcium channel blockers (CCBs) reduce oxidative stress and development of inflammation in the nervous system. Therefore, the aim of the present study was to evaluate the impact of such CCBs as Nifedipine, Verapamil, and MK-801 on the expression of peroxisome proliferator-activated receptor (Pparγ), i.e. ROS-related and inflammation-related proteins, in mouse astrocytes exposed in vitro to the VGVAPG peptide. The experiments showed that Nifedipine or MK-801 used in co-treatment with the VGVAPG peptide potentiated the effect of this peptide on the Pparγ level after the 24-h and 48-h treatment. Moreover, all studied compounds decreased the VGVAPG-induced caspase-1 activity in both time intervals. The data also showed that the VGVAPG peptide decreased the interleukin 1 beta (IL-1β) level in both studied time intervals. Upon a short-time exposure, the use of CCBs intensified the decrease in IL-1β stimulated by the VGVAPG peptide, opposite to the longer treatment. Moreover, the VGVAPG peptide decreased the IL-1βR1 level in both studied time intervals. After 24 h, Nifedipine and Verapamil potentiated the effect of the VGVAPG peptide. The VGVAPG peptide decreased the catalase (Cat) protein expression only after 24 h, whereas CCBs did not affect the expression of Cat induced by the VGVAPG peptide. The VGVAPG peptide increased the expression of the superoxide dismutase 1 (Sod1) protein. After 24 h of exposure, Nifedipine and Verapamil potentiated the increase in the Sod1 protein expression. Finally, our data showed that VGVAPG did not change the level of estradiol (E

Topics: Animals; Astrocytes; Calcium Channel Blockers; Dizocilpine Maleate; Elastin; Humans; Inflammation; Mice; Neuroblastoma; Nifedipine; Oligopeptides; Peptides; PPAR gamma; Reactive Oxygen Species; Superoxide Dismutase-1; Verapamil

Abdominal aortic aneurysm (AAA) represents the serious vascular degenerative disorder, which causes high incidence and mortality. Alpha-ketoglutarate (AKG), a crucial metabolite in the tricarboxylic acid (TCA) cycle, has been reported to exert significant actions on the oxidative stress and inflammation. However, its role in AAA still remains elusive. Herein, we examined the effects of AKG on the formation of AAA. The study established an elastase-induced mouse abdominal aortic aneurysms model as well as a TNF-α-mediated vascular smooth muscle cells (VSMCs) model, respectively. We displayed that AKG pre-treatment remarkably prevented aneurysmal dilation assessed by diameter and volume and reduced aortic rupture. In addition, it was also observed that AKG treatment suppressed the development of AAA by attenuating the macrophage infiltration, elastin degradation and collagen fibers remodeling. In vitro, AKG potently decreased TNF-α-induced inflammatory cytokines overproduction, more apoptotic cells and excessive superoxide. Mechanistically, we discovered that upregulation of vpo1 in AAA was significantly suppressed by AKG treatment. By exploring the RNA-seq data, we found that AKG ameliorates AAA mostly though inhibiting oxidative stress and the inflammatory response. PXDN overexpression neutralized the inhibitory effects of AKG on ROS generation and inflammatory reaction in MOVAS. Furthermore, AKG treatment suppressed the expression of p-ERK1/2, 3-Cl Tyr in vivo and in vitro. ERK activator disrupted the protective of AKG on TNF-α-induced VSMCs phenotypic switch. Conclusively, AKG can serve as a beneficial therapy for AAA through regulating PXDN/HOCL/ERK signaling pathways.

Topics: Animals; Aortic Aneurysm, Abdominal; Collagen; Cytokines; Deoxyribonucleosides; Disease Models, Animal; Elastin; Inflammation; Ketoglutaric Acids; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Pancreatic Elastase; Purine Nucleosides; Reactive Oxygen Species; Signal Transduction; Superoxides; Tricarboxylic Acids; Tumor Necrosis Factor-alpha

A previous study has found an association between chronic inflammatory disorders e.g. psoriasis, rheumatoid arthritis, and inflammatory bowel disease and increased vascular stiffness(1). Psoriasis and hidradenitis suppurativa (HS) are believed to have shared comorbidities and pathophysiology despite their morphologically different manifestations in the skin. In order to evaluate a putative association between the chronic inflammatory skin disease HS and arterial stiffness, an observational cross-sectional retrospective study was carried out as part of the Danish General Suburban Population Study (GESUS) (1), in which 430 patients with HS from the general population (representing mild HS; Table 1), 32 patients with HS from a hospital-based out-patient clinic (representing severe HS, Table 1), and 20,780 controls underwent measurements of arterial vascular tone and stiffness using photoplethysmography (Pulse Trace PCA2®; Micro Medical Ltd, Kent, UK). The method of Pulse Trace has been validated by correlation with intra-arterial sensing techniques, and is a simple cost-effective screening method[2]. All analyses were performed using SAS 9.3. This study was accepted by the ethics committee of Region Zealand (project number SJ-191, SJ-113, SJ-114) in Denmark (2,3). RESULTS Reflection index (RI) is an expression of arterial vascular tone and stiffness of small arteries. The raw data showed a significantly lower RI for both HS groups groups, compared to controls. The results remained significant when adjusting for confounders (age, sex, smoking and metabolic syndrome) in the out-patient clinic HS group (-11.26 (-17.75- -4.76), P=0.0002*), but not in the population HS group (Table 2). Stiffness index (SI) expresses arterial stiffness in large arteries. Both HS groups showed no significant difference in either SI or vascular age in multivariate analysis, when compared with controls (Table 2). DISCUSSION This study suggests that decreased vascular tone and stiffness of small arteries may be associated with severe HS, and at the same time found no difference in arterial stiffness in large arteries. The significance for the out-patient clinic HS group, but not the population HS group may reflect a dose-response relationship. Vascular tone in vascular smooth muscle cells of small arteries depends on competing vasodilators and vasoconstrictors. We speculate that the inflammation of HS may induce a dysfunctional balance e.g. through increased TNF-alpha with subsequent

Topics: Arteries; Cicatrix; Cross-Sectional Studies; Elastin; Hidradenitis Suppurativa; Histamine; Humans; Hydrocortisone; Inflammation; Myocardial Infarction; Nitric Oxide; Psoriasis; Retrospective Studies; Stroke; Tumor Necrosis Factor-alpha; Vasoconstrictor Agents; Vasodilator Agents

Aortic dissection (AD) is a lethal aortic pathology without effective medical treatments since the underlying pathological mechanisms responsible for AD remain elusive. Matrix metalloproteinase-8 (MMP8) has been previously identified as a key player in atherosclerosis and arterial remodeling. However, the functional role of MMP8 in AD remains largely unknown. Here, we report that an increased level of MMP8 was observed in 3-aminopropionitrile fumarate (BAPN)-induced murine AD. AD incidence and aortic elastin fragmentation were markedly reduced in MMP8-knockout mice. Importantly, pharmacologic inhibition of MMP8 significantly reduced the AD incidence and aortic elastin fragmentation. We observed less inflammatory cell accumulation, a lower level of aortic inflammation, and decreased smooth muscle cell (SMC) apoptosis in MMP8-knockout mice. In line with our previous observation that MMP8 cleaves Ang I to generate Ang II, BAPN-treated MMP8-knockout mice had increased levels of Ang I, but decreased levels of Ang II and lower blood pressure. Additionally, we observed a decreased expression level of vascular cell adhesion molecule-1 (VCAM1) and a reduced level of reactive oxygen species (ROS) in MMP8-knockout aortas. Mechanistically, our data show that the Ang II/VCAM1 signal axis is responsible for MMP8-mediated inflammatory cell invasion and transendothelial migration, while MMP8-mediated SMC inflammation and apoptosis are attributed to Ang II/ROS signaling. Finally, we observed higher levels of aortic and serum MMP8 in patients with AD. We therefore provide new insights into the molecular mechanisms underlying AD and identify MMP8 as a potential therapeutic target for this life-threatening aortic disease.

Topics: Aminopropionitrile; Angiotensin II; Animals; Aortic Dissection; Disease Models, Animal; Elastin; Humans; Inflammation; Matrix Metalloproteinase 8; Mice; Mice, Knockout; Reactive Oxygen Species; Vascular Cell Adhesion Molecule-1

Emerging evidence indicates that early life events can increase the risk for developing chronic obstructive pulmonary disease (COPD). Using an inducible transgenic mouse model for NF-κB activation in the airway epithelium, we found that a brief period of inflammation during the saccular stage (P3-P5) but not alveolar stage (P10-P12) of lung development disrupted elastic fiber assembly, resulting in permanent reduction in lung function and development of a COPD-like lung phenotype that progressed through 24 months of age. Neutrophil depletion prevented disruption of elastic fiber assembly and restored normal lung development. Mechanistic studies uncovered a role for neutrophil elastase (NE) in downregulating expression of critical elastic fiber assembly components, particularly fibulin-5 and elastin. Further, purified human NE and NE-containing exosomes from tracheal aspirates of premature infants with lung inflammation downregulated elastin and fibulin-5 expression by saccular-stage mouse lung fibroblasts. Together, our studies define a critical developmental window for assembling the elastin scaffold in the distal lung, which is required to support lung structure and function throughout the lifespan. Although neutrophils play a well-recognized role in COPD development in adults, neutrophilic inflammation may also contribute to early-life predisposition to COPD.

Topics: Animals; Elastin; Inflammation; Leukocyte Elastase; Mice; Mice, Transgenic; Neutrophils; Pulmonary Alveoli; Pulmonary Disease, Chronic Obstructive

Topics: Aneurysm; Angiotensin II; Animals; Disease Models, Animal; DNA-Binding Proteins; Elastin; Inflammation; Matrix Metalloproteinases; Mice; Mice, Transgenic; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Nerve Tissue Proteins; Oxidative Stress; Receptors, Steroid; Receptors, Thyroid Hormone; Signal Transduction

Critical limb ischemia (CLI) is characterized by the impairment of microcirculation, necrosis and inflammation of the muscular tissue. Although the role of glycans in mediating inflammation has been reported, changes in the glycosylation following muscle ischemia remains poorly understood. Here, a murine CLI model was used to show the increase of high mannose, α-(2, 6)-sialic acid and the decrease of hybrid and bisected N-glycans as glycosylation associated with the ischemic environment. Using this model, the efficacy of an elastin-like recombinamers (ELR) hydrogel was assessed. The hydrogel modulates key angiogenic signaling pathways, resulting in capillary formation, and ECM remodeling. Arterioles formation, reduction of fibrosis and anti-inflammatory macrophage polarization wa also induced by the hydrogel administration. Modulation of glycosylation was observed, suggesting, in particular, a role for mannosylation and sialylation in the mediation of tissue repair. Our study elucidates the angiogenic potential of the ELR hydrogel for CLI applications and identifies glycosylation alterations as potential new therapeutic targets.

Topics: Animals; Elastin; Glycosylation; Hydrogels; Inflammation; Ischemia; Mice; Neovascularization, Physiologic

[Figure: see text].

Topics: Animals; Antineoplastic Agents; Aorta; Collagen; Doxorubicin; Elastin; Extracellular Matrix; Inflammation; Male; Mice; Pulse Wave Analysis; Tumor Necrosis Factor-alpha; Vascular Stiffness

Hidradenitis suppurativa (HS) is a dermatological condition characterized by ruptured hair follicles inducing a localized, but massive chronic inflammatory response. Analysis of 104 HS lesions in formalin-fixed paraffin-embedded tissues identified the most common histologic features found associated with HS were migrating epithelial sheets, acute and chronic inflammation, perivascular chronic inflammation in regions adjacent to active lesions, and granulation tissue. Additionally, using a modified Masson's trichrome stain principally for collagen, Verhoeff van Gieson elastic stain, and CD34 immunohistochemistry assay for endothelium, lesional areas in the dermis with chronic inflammation exhibited a significant decrease in collagen and elastin, and an increase in neovascularization.

Topics: Collagen; Elastin; Hair Follicle; Hidradenitis Suppurativa; Humans; Inflammation; Neovascularization, Pathologic

Background Abdominal aortic aneurysm (AAA) is a life-threatening vascular disorder characterized by chronic inflammation of the aortic wall, which lacks effective pharmacotherapeutic remedies and has an extremely high mortality. Nuclear receptor NR4A1 (Nur77) functions in various chronic inflammatory diseases. However, the influence of Nur77 on AAA has remained unclear. Herein, we sought to determine the effects of Nur77 on the development of AAA. Methods and Results We observed that Nur77 expression decreased significantly in human and mice AAA lesions. Deletion of Nur77 accelerated the development of AAA in mice, as evidenced by increased AAA incidence, abdominal aortic diameters, elastin fragmentation, and collagen content. Consistent with genetic manipulation, pharmacological activation of Nur77 by celastrol showed beneficial effects against AAA. Microscopic and molecular analyses indicated that the detrimental effects of Nur77 deficiency were associated with aggravated macrophage infiltration in AAA lesions and increased pro-inflammatory cytokines secretion and matrix metalloproteinase (MMP-9) expression. Bioinformatics analyses further revealed that LOX-1 was upregulated by Nur77 deficiency and consequently increased the expression of cytokines and MMP-9. Moreover, rescue experiments verified that LOX-1 notably aggravated inflammatory response, an effect that was blunted by Nur77. Conclusions This study firstly demonstrated a crucial role of Nur77 in the formation of AAA by targeting LOX-1, which implicated Nur77 might be a potential therapeutic target for AAA.

Topics: Animals; Aorta; Aortic Aneurysm, Abdominal; Cytokines; Drug Discovery; Elastin; Humans; Inflammation; Matrix Metalloproteinase 9; Mice; Mice, Knockout; Nuclear Receptor Subfamily 4, Group A, Member 1; Organ Size; Scavenger Receptors, Class E; Signal Transduction; Vascular Remodeling

During vascular aging or in pathological conditions in humans, elastin is degraded and its by-products, the elastin-derived peptides (EDPs), enter the blood circulation. EDPs may be detected in the serum of healthy subjects or people who suffered a stroke. Moreover, recent evidence suggests a potential role of inflammatory mechanisms in neurological conditions, which are usually not categorized as inflammatory. Therefore, the present in vitro study was conducted to investigate the impact of the VGVAPG peptide on the activation of inflammatory process in mouse primary astrocytes, which were maintained in phenol red-free DMEM/F12 supplemented with 10% fetal bovine serum. The cells were exposed to VGVAPG or VVGPGA peptides for 24 and 48 h; this was followed by the determination of the activity of caspase-1 and levels of SOD, CAT, PPARγ, NF-κB, IL-1β, and IL-1βR1. Furthermore, rosiglitazone-a PPARγ agonist-was applied. Our study pioneered the finding that the VGVAPG peptide increases caspase-1 activity in astrocytes in vitro. The VGVAPG peptide simultaneously decreases the release of IL-1β into the cell-culture medium from astrocytes. The ELISA method revealed that the VGVAPG peptide increases the protein expression of SOD1 whereas it decreases the expression of IL-1βR1, CAT, and NF-κB. Therefore, the available data suggest that the VGVAPG peptide (concentration 10 nM) synergistically acts with agonists of PPARγ in mouse astrocytes. However, given the lack of sufficient data to explain the molecular mechanism of action of the VGVAPG peptide in the nervous system, more studies in this area are necessary.

Topics: Animals; Astrocytes; Elastin; Gene Expression; Inflammation; Inflammation Mediators; Mice; Oligopeptides; Peptides; Primary Cell Culture; Rosiglitazone

The autoimmune disorder, Sjögren's syndrome (SS), is characterized by lymphocytic infiltration and loss of function of exocrine glands such as the lacrimal gland (LG) and salivary gland. SS-associated changes in the LG are associated with the development of autoimmune-mediated dry eye disease. We have previously reported the accumulation of intercellular adhesion molecule 1 (ICAM-1) in the LG of Non-Obese Diabetic (NOD) mice, a murine model of autoimmune-mediated dry eye in SS, in both LG acinar cells and infiltrating lymphocytes. ICAM-1 initiates T-cell activation and can trigger T-cell migration through binding to lymphocyte function-associated 1 antigen (LFA). To modulate this interaction, this study introduces a new tool, a multivalent biopolymeric nanoparticle assembled from a diblock elastin-like polypeptide (ELP) using the S48I48 (SI) ELP scaffold fused with a mouse ICAM-1 targeting peptide to form IBP-SI. IBP-SI forms a multivalent, monodisperse nanoparticle with a radius of 21.9 nm. Unlike the parent SI, IBP-SI binds mouse ICAM-1 and is internalized by endocytosis into transfected HeLa cells before it accumulates in lysosomes. In vitro assays measuring lymphocyte adhesion to Tumor Necrosis Factor TNF-α-treated bEnd.3 cells, which express high levels of ICAM-1, show that adhesion is inhibited by IBP-SI but not by SI, with IC

Topics: Animals; Autoimmune Diseases; Biopolymers; Cell Proliferation; Dry Eye Syndromes; Elastin; Endocytosis; HeLa Cells; Humans; Inflammation; Inhibitory Concentration 50; Intercellular Adhesion Molecule-1; Lacrimal Apparatus; Lymphocyte Function-Associated Antigen-1; Lymphocytes; Lysosomes; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred NOD; Nanoparticles; Peptides; Sjogren's Syndrome; T-Lymphocytes; Tumor Necrosis Factor-alpha

Surgical intervention is currently the only option for an abdominal aortic aneurysm (AAA), preventing its rupture and sudden death of a patient. Therefore, it is crucial to determine the pathogenic mechanisms of this disease for the development of effective pharmacological therapies. Oxidative stress is said to be one of the pivotal factors in the pathogenesis of AAAs. Thus, we aimed to evaluate the significance of nuclear factor erythroid 2-related factor 2 (Nrf2) transcriptional activity in the development of AAA and to verify if simvastatin, administered as pre- and cotreatment, may counteract this structural malformation. Experiments were performed on mice with inhibited transcriptional activity of Nrf2 (tKO) and wild-type (WT) counterparts. We used a model of angiotensin II- (AngII-) induced AAA, combined with a fat-enriched diet. Mice were administered with AngII or saline for up to 28 days

Topics: Angiotensin II; Animals; Aorta; Aortic Aneurysm, Abdominal; Blood Pressure; Collagen; Elastin; Humans; Inflammation; Mice, Inbred C57BL; Mice, Knockout; NF-E2-Related Factor 2; Oxidative Stress; Reactive Oxygen Species; Receptor, Angiotensin, Type 1; Signal Transduction; Simvastatin; Transcription, Genetic; Vascular Cell Adhesion Molecule-1

Abdominal aortic aneurysm (AAA), commonly occurring in the aged population, is a degenerative disease that dilate and weaken infrarenal aorta due to progressive degeneration of aortic wall integrity. Vinpocetine, a derivative of alkaloid vincamine, has long been used for cerebrovascular disorders and cognitive impairment in the aged population. Recent studies have indicated that vinpocetine antagonizes occlusive vascular disorders such as intimal hyperplasia and atherosclerosis. However, its role in vascular degenerative disease AAA remains unexplored. Herein, we determined the effect of vinpocetine on the formation of AAA as well as the intervention of pre-existing moderate AAA. AAA was induced by periaortic elastase application in C57BL/6J mice. Systemic vinpocetine treatment was applied daily via intraperitoneal injection. We showed that vinpocetine pre-treatment remarkably attenuated aneurysmal dilation assessed by diameter and volume. More importantly, vinpocetine also significantly suppressed the progression of pre-existing moderate AAA in a post-intervention model. Vinpocetine improved multiple cellular and molecular changes associated with AAA, such as elastin degradation, media smooth muscle cell depletion, collagen fibers remodeling and macrophage infiltration in aneurysmal tissues. Vinpocetine potently suppressed tumor necrosis factor-α-induced nuclear factor kappa-light-chain-enhancer of activated B cells activation and proinflammatory mediator expression in primary cultured macrophages in vitro, as well as in the aorta wall in vivo, suggesting vinpocetine conferred anti-AAA effect at least partially via the inhibition of inflammation. Taken together, our findings reveal a novel role of vinpocetine in AAA formation, development and progression. Given the excellent safety profile of vinpocetine, the present study suggests vinpocetine may be a novel therapeutic agent for AAA prevention and treatment.

Topics: Animals; Aortic Aneurysm, Abdominal; Cells, Cultured; Dilatation, Pathologic; Disease Progression; Elastin; Inflammation; Macrophages; Mice, Inbred C57BL; Myocytes, Smooth Muscle; NF-kappa B; Protective Agents; Proteoglycans; Proteolysis; Vinca Alkaloids

Extracellular matrix (ECM) based bioscaffolds prepared by decellularization has increasingly emerged in tissue engineering application because it has structural, biochemical, and biomechanical cues that have dramatic effects upon cell behaviors. Therefore, we developed a closed sonication decellularization system to prepare ideal bioscaffolds with minimal adverse effects on the ECM. The decellularization was achieved at 170 kHz of ultrasound frequency in 0.1% and 2% Sodium Dodecyl Sulphate (SDS) solution for 10 hours. The immersion treatment as control was performed to compare the decellularization efficiency with our system. Cell removal and ECM structure were determined by histological staining and biochemical assay. Biomechanical properties were investigated by the indentation testing to test the stiffness, a residual force and compression of bioscaffolds. Additionally, in vivo implantation was performed in rat to investigate host tissue response. Compared to native tissues, histological staining and biochemical assay confirm the absence of cellularity with preservation of ECM structure. Moreover, sonication treatment has not affected the stiffness [N/mm] and a residual force [N] of the aortic scaffolds except for compression [%] which 2% SDS significantly decreased compared to native tissues showing higher SDS has a detrimental effect on ECM structure. Finally, minimal inflammatory response was observed after 1 and 5 weeks of implantation. This study reported that the novelty of our developed closed sonication system to prepare ideal bioscaffolds for tissue engineering applications.

Topics: Animals; Aorta; Biomechanical Phenomena; Collagen; Elastin; Extracellular Matrix; Inflammation; Rats; Sonication; Stress, Mechanical; Swine; Tissue Engineering; Tissue Scaffolds; Ultrasonics

Deterioration of lung functions and degradation of elastin fibers with age are accelerated during chronic obstructive pulmonary disease (COPD). Excessive genesis of soluble elastin peptides (EP) is a key factor in the pathophysiology of COPD. We have previously demonstrated that 6-wk-old mice exhibited emphysematous structural changes associated with proinflammatory immune response after EP instillation. In this study, we investigated the consequences of aging on inflammatory, immune, and histological criteria associated with murine emphysema progression after EP exposure. Young (6 wk old) and elderly (15 mo old) C57BL/6J mice were endotracheally instilled with EP, and, at various time points after treatment, the inflammatory cell profiles from bronchoalveolar lavage fluids (BALF) and the T-lymphocyte phenotypes, at local and systemic levels, were analyzed by flow cytometry. Lungs were also prepared to allow morphological and histological analysis by confocal microscopy. Elderly mice exhibited an earlier development of pulmonary emphysema, characterized by an increase of the inflammatory and lymphocytic infiltrates, extracellular matrix breakdown, and airspace enlargement compared with young mice. This age-dependent parenchymal tissue remodeling was associated with an increase of the matrix metalloproteinase expressions and desmosine levels in BALF and/or sera of EP-treated mice. In addition, both the proportion of CD4

Topics: Aging; Animals; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Desmosine; Disease Models, Animal; Elastin; Female; Inflammation; Lung; Macrophages, Alveolar; Matrix Metalloproteinases; Mice; Mice, Inbred C57BL; Neutrophils; Proteolysis; Pulmonary Emphysema

The use of biomaterials for circumferential esophageal repair is technically challenging in a rat model, and an optimal scaffold implantation technique with nutritional support is essential. The purpose of this study was to investigate the effects of three-dimensional printed esophageal grafts and bioreactor cultivation on muscle regeneration and reepithelialization from circumferential esophageal defects in a rat model. Here, we designed an artificial esophagus that can enhance the regeneration of esophageal mucosa and muscle through the optimal combination of a two-layered tubular scaffold and mesenchymal stem cell-based bioreactor system. The graft was verified by the performance comparison with an omentum-cultured esophageal scaffold. We also applied a new surgical anastomosis technique and a thyroid gland flap over the implanted scaffold to improve graft survival. Although no regenerated mucosal layer was observed around the implants of the control group, histological examination of the regenerative esophagi along the scaffold revealed that the bioreactor system and omentum-cultured groups showed more than 80% of the mucosal regeneration without a fistula. The regenerated tissues showed that the integration of the esophageal scaffold and its native esophageal tissue was intact and were covered with layers of stratified squamous epithelium with several newly developed blood vessels. Therefore, this study describes a novel approach for circumferential esophageal reconstruction. Impact Statement

Topics: Animals; Bioreactors; Cell Tracking; Cells, Cultured; Collagen; Elastin; Esophagus; Humans; Implants, Experimental; Inflammation; Macrophages; Neovascularization, Physiologic; Polyesters; Polyurethanes; Printing, Three-Dimensional; Rats, Sprague-Dawley; Re-Epithelialization; Tissue Engineering; Tissue Scaffolds

Mechanical and inflammatory signals in the fetal membrane play an important role in extracellular matrix (ECM) remodelling in order to dictate the timing of birth. We developed a mechanical model that mimics repetitive stretching of the amniotic membrane (AM) isolated from regions over the placenta (PAM) or cervix (CAM) and examined the effect of cyclic tensile strain (CTS) on mediators involved in mechanotransduction (Cx43, AKT), tissue remodelling (GAGs, elastin, collagen) and inflammation (PGE

Topics: Amnion; Cervix Uteri; Collagen; Connexin 43; Dinoprostone; Elastin; Female; Gene Expression Regulation, Developmental; Humans; Inflammation; Matrix Metalloproteinases; Mechanotransduction, Cellular; Placenta; Pregnancy; Proto-Oncogene Proteins c-akt

Vascular malformations are characterized by anomalous vascular channels with fragile walls and a propensity to bleed. Arteriovenous malformations (AVMs) in particular have disorganized vascular spaces with intervening fibrosis. Characterization of the structural abnormalities of these vessels has not been comprehensively evaluated. We hypothesize that AVMs are likely to demonstrate altered elastic and collagen fiber organization and distribution, reflecting their fragility, vascular instability, and abnormal development.. Fifteen AVMs were histologically evaluated by H&E, elastin and trichrome staining. To identify potential differences between extracranial and intracranial AVMs, 5 AVMs were harvested from the brain (n=5) and 10 from extracranial sites involving the skin and deep soft tissue (n=10).. The elastin staining demonstrated reduplication, fragmentation and disruption of internal elastic lamina as well as irregular thickness, and inconsistent vascular density of all AVM specimens. Trichrome staining revealed thickening of the intimal layers of AVM arteries and demonstrated an irregular thickness of venous walls within the malformation and some areas of medial degeneration. Intracranial AVMs are characterized by more intramural inflammation with predominant neutrophil and lymphocyte infiltration. In contrast, extracranial AVMs display more extravascular inflammation with mast cell and neutrophil infiltration. Microvascular proliferations intervening between larger blood vessels were also noted in both types of AVMs, but more obvious in extracranial AVMs.. These observed histologic anomalies of AVMs demonstrate disorganized deposition of elastin and collagen that point to the clinically observed vascular instability and fragility of these lesions.

Topics: Arteriovenous Malformations; Brain; Cell Proliferation; Collagen; Elastic Tissue; Elastin; Fibrosis; Humans; Inflammation; Intracranial Arteriovenous Malformations; Microcirculation; Pilot Projects

Loss of immune tolerance to self-antigens can promote chronic inflammation and disrupt the normal function of multiple organs, including the lungs. Degradation of elastin, a highly insoluble protein and a significant component of the lung structural matrix, generates proinflammatory molecules. Elastin fragments (EFs) have been detected in the serum of smokers with emphysema, and elastin-specific T cells have also been detected in the peripheral blood of smokers with emphysema. However, an animal model that could recapitulate T cell-specific autoimmune responses by initiating and sustaining inflammation in the lungs is lacking. In this study, we report an animal model of autoimmune emphysema mediated by the loss of tolerance to elastin. Mice immunized with a combination of human EFs plus rat EFs but not mouse EFs showed increased infiltration of innate and adaptive immune cells to the lungs and developed emphysema. We cloned and expanded mouse elastin-specific CD4

Topics: Adaptive Immunity; Animals; Autoimmunity; Cell Line; Disease Models, Animal; Elastin; Female; HEK293 Cells; Humans; Immune Tolerance; Immunity, Innate; Inflammation; Lung; Mice; Mice, Inbred C57BL; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Smoking

Cyanogenic glycosides are found in a diverse group of plants and are metabolized into thiocyanate by the intestines and liver. Conversion of plant derived thiocyanates into cyanide and isocyanic acid occurs by the activity of neutrophil-derived enzyme myeloperoxidase. Therefore, increased intake of cyanogenic glycoside rich plant based diet may lead to increased isocyanic acid induced protein carbamylation in chronic inflammatory states (increased myeloperoxidase activity). As there is a close relationship between non-enzymatic post-translational modification and protein function, carbamylation induced structural changes also affect the functions of proteins. Carbamylation induced structural alterations of proteins have recently drawn a great attention in the current literature, especially regarding the alterations of proteins with long half-life such as type I collagen, elastin, α-crystallin. We hypothesize that a plant-based natural diet, rich in cyanogenic glycosides, may have unintended consequences on native protein structure/function in individuals with chronic inflammatory diseases such as chronic kidney and rheumatological diseases because of the higher rate of transformation of plant derived thiocyanates into isocyanic acid by the increased activity of neutrophil-derived enzyme myeloperoxidase. Regulation of myeloperoxidase activity or moderation of cyanogenic glycoside rich diet might be important in the prevention/modulation of dangerous protein carbamylation process, especially in this patient group.

Topics: Chronic Disease; Collagen; Cyanates; Cyanides; Diet; Elastin; Glycosides; Humans; Inflammation; Intestines; Liver; Models, Theoretical; Neutrophils; Peroxidase; Protein Carbamylation; Proteins; Risk; Up-Regulation

Biocompatibility studies, especially innate immunity induction, in vitro and in vivo cytotoxicity, and fibrosis, are often lacking for many novel biomaterials including recombinant protein-based ones, such as elastin-like recombinamers (ELRs), and has not been extensively explored in the scientific literature, in contrast to traditional biomaterials. Herein, we present the results from a set of experiments designed to elucidate the preliminary biocompatibility of 2 types of ELRs that are able to form extracellular matrix-like hydrogels through either physical or chemical cross-linking both of which are intended for different applications in tissue engineering and regenerative medicine. Initially, we present in vitro cytocompatibility results obtained upon culturing human umbilical vein endothelial cells on ELR substrates, showing optimal proliferation up to 9 days. Regarding in vivo cytocompatibility, luciferase-expressing hMSCs were viable for at least 4 weeks in terms of bioluminescence emission when embedded in ELR hydrogels and injected subcutaneously into immunosuppressed mice. Furthermore, both types of ELR-based hydrogels were injected subcutaneously in immunocompetent mice and serum TNFα, IL-1β, IL-4, IL-6, and IL-10 concentrations were measured by enzyme-linked immunosorbent assay, confirming the lack of inflammatory response, as also observed upon macroscopic and histological evaluation. All these findings suggest that both types of ELRs possess broad biocompatibility, thus making them very promising for tissue engineering and regenerative medicine-related applications.

Topics: Animals; Biocompatible Materials; Cell Count; Cell Proliferation; Cell Survival; Cell Tracking; Cross-Linking Reagents; Cytokines; Elastin; Human Umbilical Vein Endothelial Cells; Humans; Hydrogels; Inflammation; Injections, Subcutaneous; Male; Mesenchymal Stem Cells; Mice; Recombinant Proteins; Regenerative Medicine; Tissue Engineering

Aortic stiffening is a major independent risk factor for cardiovascular diseases, cognitive dysfunction, and other chronic disorders of aging. Mitochondria-derived reactive oxygen species are a key source of arterial oxidative stress, which may contribute to arterial stiffening by promoting adverse structural changes-including collagen overabundance and elastin degradation-and enhancing inflammation, but the potential for mitochondria-targeted therapeutic strategies to ameliorate aortic stiffening with primary aging is unknown. We assessed aortic stiffness [pulse-wave velocity (aPWV)], ex vivo aortic intrinsic mechanical properties [elastic modulus (EM) of collagen and elastin regions], and aortic protein expression in young (~6 mo) and old (~27 mo) male C57BL/6 mice consuming normal drinking water (YC and OC) or water containing mitochondria-targeted antioxidant MitoQ (250 µM; YMQ and OMQ) for 4 wk. Both baseline and postintervention aPWV values were higher in OC vs. YC (post: 482 ± 21 vs. 420 ± 5 cm/s, P < 0.05). MitoQ had no effect in young mice but decreased aPWV in old mice (OMQ, 426 ± 20, P < 0.05 vs. OC). MitoQ did not affect age-associated increases in aortic collagen-region EM, collagen expression, or proinflammatory cytokine expression, but partially attenuated age-associated decreases in elastin region EM and elastin expression. Our results demonstrate that MitoQ reverses in vivo aortic stiffness in old mice and suggest that mitochondria-targeted antioxidants may represent a novel, promising therapeutic strategy for decreasing aortic stiffness with primary aging and, possibly, age-related clinical disorders in humans. The destiffening effects of MitoQ treatment may be at least partially mediated by attenuation/reversal of age-related aortic elastin degradation. NEW & NOTEWORTHY We show that 4 wk of treatment with the mitochondria-specific antioxidant MitoQ in mice completely reverses the age-associated elevation in aortic stiffness, assessed as aortic pulse-wave velocity. The destiffening effects of MitoQ treatment may be at least partially mediated by attenuation of age-related aortic elastin degradation. Our results suggest that mitochondria-targeted therapeutic strategies may hold promise for decreasing arterial stiffening with aging in humans, possibly decreasing the risk of many chronic age-related clinical disorders.

Topics: Animals; Antioxidants; Aorta; Cytokines; Elastin; Endothelium, Vascular; Inflammation; Male; Mice; Mice, Inbred C57BL; Mitochondria; Oxidative Stress; Pulse Wave Analysis; Reactive Oxygen Species; Superoxides; Vascular Stiffness; Vasodilation

Novel thermo-sensitive elastin-like recombinamers (ELRs) containing bioactive molecules were created for use as a biomimetic biomaterial for tissue regeneration. For effective use for in vivo applications, it is essential to ensure that they do not induce adverse inflammatory, immune, or allergic responses that inhibit tissue repair. Therefore, we sought to establish a pre-clinical approach to evaluate biocompatibility in experimental mice using ELRs as a prototype biomaterial. First, we measured in vitro proliferation and cytokine production from BALB/c and C57BL/6 mouse splenocytes incubated with ELRs. Second, we used a rapid, high throughput in vivo approach in which inflammatory cells and cytokines were measured following an intraperitoneal implantation. Lastly, a subchronic in vivo approach was used in which ELRs or positive controls were subcutaneously implanted and the implantation sites were assessed for inflammation and gene expression. We found that ELRs induced mild inflammation and minimal fibrosis compared to the intense response to Vitoss. Additionally, implantation increased antigen-specific antibody titers for both groups and gene expression profiling of the implantation sites revealed the upregulation of inflammation, fibrosis, and wound healing-related genes in ELR and positive control-implanted mice compared to sham controls. These data demonstrate that ELRs appear safe for use in tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 924-934, 2018.

Topics: Animals; Antigens; Biocompatible Materials; Cell Proliferation; Cytokines; Elastin; Female; Fibrosis; Gene Expression Regulation; Inflammation; Mice, Inbred BALB C; Mice, Inbred C57BL; Models, Animal; Prosthesis Implantation

Elastin is an abundant extracellular matrix protein in elastic tissues, including the lungs, skin and arteries, and comprises 30-57% of the aorta by dry mass. The monomeric precursor, tropoelastin (TE), undergoes complex processing during elastogenesis to form mature elastic fibres. Peroxynitrous acid (ONOOH), a potent oxidising and nitrating agent, is formed in vivo from superoxide and nitric oxide radicals. Considerable evidence supports ONOOH formation in the inflamed artery wall, and a role for this species in the development of human atherosclerotic lesions, with ONOOH-damaged extracellular matrix implicated in lesion rupture. We demonstrate that TE is highly sensitive to ONOOH, with this resulting in extensive dimerization, fragmentation and nitration of Tyr residues to give 3-nitrotyrosine (3-nitroTyr). This occurs with equimolar or greater levels of oxidant and increases in a dose-dependent manner. Quantification of Tyr loss and 3-nitroTyr formation indicates extensive Tyr modification with up to two modified Tyr per protein molecule, and up to 8% conversion of initial ONOOH to 3-nitroTyr. These effects were modulated by bicarbonate, an alternative target for ONOOH. Inter- and intra-protein di-tyrosine cross-links have been characterized by mass spectrometry. Examination of human atherosclerotic lesions shows colocalization of 3-nitroTyr with elastin epitopes, consistent with TE or elastin modification in vivo, and also an association of 3-nitroTyr containing proteins and elastin with lipid deposits. These data suggest that exposure of TE to ONOOH gives marked chemical and structural changes to TE and altered matrix assembly, and that such damage accumulates in human arterial tissue during the development of atherosclerosis.

Topics: Arteries; Atherosclerosis; Cadaver; Elastin; Extracellular Matrix; Humans; Immunohistochemistry; Inflammation; Macrophages; Nitro Compounds; Oxidation-Reduction; Peroxynitrous Acid; Protein Conformation; Tropoelastin; Tyrosine; Unfolded Protein Response

Obesity results in decreased lung function and increased inflammation. Moderate aerobic exercise (AE) reduced lung inflammation and remodeling in a variety of respiratory disease models. Therefore, this study investigated whether AE can attenuate a diet-induced obesity respiratory phenotype; including airway hyper-responsiveness (AHR), remodeling and inflammation.. Sixty C57Bl/6 male mice were distributed into four groups: control lean (CL), exercise lean (EL), obese (O) and obese exercise (OE) groups (2 sets of 7 and 8 mice per group; n = 15). A classical model of diet-induced obesity (DIO) over 12 weeks was used. AE was performed 60 min/day, 5 days/week for 5 weeks. Airway hyperresponsiveness (AHR), lung inflammation and remodeling, adipokines and cytokines in bronchoalveolar lavage (BAL) was determined.. A high fat diet over 18 weeks significantly increased body weight (p < .0001). Five weeks of AE significantly reduced both AHR and pulmonary inflammation. AHR in obese mice that exercised was reduced at the basal level (p < .05), vehicle (PBS) (p < .05), 6.25 MCh mg/mL (p < .05), 12.5 MCh mg/mL (p < .01), 25 MCh mg/mL (p < .01) and 50 MCh mg/mL (p < .05). Collagen (p < .001) and elastic (p < .001) fiber deposition in airway wall and also smooth muscle thickness (p < .001) were reduced. The number of neutrophils (p < .001), macrophages (p < .001) and lymphocytes (p < .01) were reduced in the peribronchial space as well as in the BAL: lymphocytes (p < .01), macrophages (p < .01), neutrophils (p < .001). AE reduced obesity markers leptin (p < .001), IGF-1 (p < .01) and VEGF (p < .001), while increased adiponectin (p < .01) in BAL. AE also reduced pro-inflammatory cytokines in the BAL: IL-1β (p < .001), IL-12p40 (p < .001), IL-13 (p < .01), IL-17 (p < .001, IL-23 (p < .05) and TNF-alpha (p < .05), and increased anti-inflammatory cytokine IL-10 (p < .05).. Aerobic exercise reduces high fat diet-induced obese lung phenotype (AHR, pulmonary remodeling and inflammation), involving anti-inflammatory cytokine IL-10 and adiponectin.

Topics: Animals; Biomarkers; Collagen; Diet, High-Fat; Elastin; Inflammation; Male; Mice, Inbred C57BL; Obesity; Phenotype; Physical Conditioning, Animal; Respiratory Hypersensitivity

Emphysema is characterized by degradation of lung alveoli that leads to poor airflow in lungs. Irreversible elastic fiber degradation by matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) activity leads to loss of elasticity and drives the progression of this disease. We investigated if a polyphenol, pentagalloyl glucose (PGG) can increase elastin production in pulmonary fibroblasts. We also studied the effect of PGG treatment in reducing MMP activity and ROS levels in cells. We exposed rat pulmonary fibroblasts to two different types of inflammatory environments i.e., tumor necrosis factor-α (TNF-α) and cigarette smoke extract (CSE) to mimic the disease. Parameters like lysyl oxidase (LOX) and elastin gene expression, MMP-9 activity in the medium, lysyl oxidase (LOX) activity and ROS levels were studied to assess the effect of PGG on pulmonary fibroblasts. CSE inhibited lysyl oxidase (LOX) enzyme activity that resulted in a decreased elastin formation. Similarly, TNF-α treated cells showed less elastin in the cell layers. Both these agents caused increase in MMP activity and ROS levels in cells. However, when supplemented with PGG treatment along with these two inflammatory agents, we saw a significant increase in elastin deposition, reduction in both MMP activity and ROS levels. Thus PGG, which has anti-inflammatory, anti-oxidant properties coupled with its ability to aid in elastic fiber formation, can be a multifunctional drug to potentially arrest the progression of emphysema.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Complex Mixtures; Elastin; Fibroblasts; Gene Expression Regulation; Hydrolyzable Tannins; Inflammation; Lung; Matrix Metalloproteinase 9; Primary Cell Culture; Protein-Lysine 6-Oxidase; Rats; Reactive Oxygen Species; Signal Transduction; Tobacco Smoke Pollution; Tumor Necrosis Factor-alpha

Uncontrolled hypertension is a primary risk factor for diverse cardiovascular diseases and thus remains responsible for significant morbidity and mortality. Hypertension leads to marked changes in the composition, structure, properties, and function of central arteries; hence, there has long been interest in quantifying the associated wall mechanics. Indeed, over the past 20 years there has been increasing interest in formulating mathematical models of the evolving geometry and biomechanical behavior of central arteries that occur during hypertension. In this paper, we introduce a new mathematical model of growth (changes in mass) and remodeling (changes in microstructure) of the aortic wall for an animal model of induced hypertension that exhibits both mechano-driven and immuno-mediated matrix turnover. In particular, we present a bilayered model of the aortic wall to account for differences in medial versus adventitial growth and remodeling and we include mechanical stress and inflammatory cell density as determinants of matrix turnover. Using this approach, we can capture results from a recent report of adventitial fibrosis that resulted in marked aortic maladaptation in hypertension. We submit that this model can also be used to identify novel hypotheses to guide future experimentation.

Topics: Adventitia; Animals; Aorta; Aorta, Thoracic; Arteries; Biomechanical Phenomena; Collagen; Computer Simulation; Disease Models, Animal; Elastin; Homeostasis; Humans; Hypertension; Immune System; Inflammation; Male; Mice; Models, Cardiovascular; Nonlinear Dynamics; Regression Analysis; Stress, Mechanical; Tunica Media; Vascular Stiffness

Particulate matter smaller than 2.5 μm (PM2.5) is a continuing challenge to pulmonary health. Here, we investigated the mechanisms involved in PM2.5 exposure-induced acute lung injury in rats. We analyzed biochemical and morphological changes following a 2-week "real-world" exposure. And then we found that PM2.5 exposure increased the concentrations of total protein, malondialdehyde, hydrogen peroxide, nitric oxide, and soluble elastin in bronchoalveolar lavage fluid, levels of cytokines in blood, and expression of MMP-9 in airways. Further, alveolar macrophage and neutrophil counts increased following PM2.5 exposure, and edema and lung lesions were observed. Our results suggest that PM2.5 exposure can induce oxidative stress and acute inflammatory responses, which can damage the micro-environment and decrease the repair ability of the lung, resulting in tissue damage.

Topics: Air Pollutants; Animals; Bronchoalveolar Lavage Fluid; Cytokines; Elastin; Environmental Exposure; Hydrogen Peroxide; Inflammation; Lung; Lung Injury; Malondialdehyde; Matrix Metalloproteinase 9; Nitric Oxide; Oxidative Stress; Particulate Matter; Rats; Rats, Wistar; Reactive Oxygen Species

A single administration of mesenchymal stromal cells (MSCs) has been shown to reduce lung inflammation in experimental elastase-induced emphysema; however, effects were limited in terms of lung-tissue repair and cardiac function improvement. We hypothesized that two doses of MSCs could induce further lung and cardiovascular repair by mitigating inflammation and remodeling in a model of emphysema induced by multiple elastase instillations. We aimed to comparatively investigate the effects of one versus two doses of MSCs, administered 1 week apart, in a murine model of elastase-induced emphysema.. C57BL/6 mice were randomly divided into control (CTRL) and emphysema (E) groups. Mice in the E group received porcine pancreatic elastase (0.2 IU, 50 μL) intratracheally once weekly for four consecutive weeks; the CTRL animals received sterile saline (50 μL) using the same protocol. Three hours after the last instillation, the E group was further randomized to receive either saline (SAL) or murine MSCs (10. Both one and two doses of MSCs improved lung mechanics, reducing keratinocyte-derived chemokine and transforming growth factor-β levels in lung homogenates, total cell and macrophage counts in bronchoalveolar lavage fluid (BALF), and collagen fiber content in airways and blood vessels, as well as increasing vascular endothelial growth factor in lung homogenates and elastic fiber content in lung parenchyma. However, only the two-dose group exhibited reductions in tumor necrosis factor-α in lung tissue, BALF neutrophil and lymphocyte count, thymus weight, and total cellularity, as well as CD8. Two doses of MSCs enhanced lung repair and improvement in cardiac function, while inducing T cell immunosuppression, mainly of CD8

Topics: Animals; Bronchoalveolar Lavage Fluid; Cardiovascular System; Collagen; Elastin; Female; Immunosuppression Therapy; Inflammation; Inflammation Mediators; Lung; Lymphoid Tissue; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice, Inbred C57BL; Pulmonary Emphysema; Wound Healing

Arteriovenous fistulae (AVF) remain the optimal conduit for hemodialysis access but continue to demonstrate poor patency and poor rates of maturation. We hypothesized that CD44, a widely expressed cellular adhesion molecule that serves as a major receptor for extracellular matrix components, promotes wall thickening and extracellular matrix deposition during AVF maturation.. CD44 promotes accumulation of M2 macrophages, extracellular matrix deposition, and wall thickening during AVF maturation. These data show the association of M2 macrophages with wall thickening during AVF maturation and suggest that enhancing CD44 activity may be a strategy to increase AVF maturation.

Topics: Animals; Aorta, Abdominal; Arteriovenous Shunt, Surgical; Chemokine CCL2; Collagen; Elastin; Extracellular Matrix; Genotype; Hyaluronan Receptors; Hyaluronic Acid; Inflammation; Macrophages; Male; Mice, Inbred C57BL; Mice, Knockout; Phenotype; Signal Transduction; Time Factors; Vena Cava, Inferior

Temporomandibular joint dysfunction (TMD) is a collection of clinical symptoms that involve masticatory muscles and the temporomandibular joint (TMJ). Common symptoms include limited jaw motion and joint sound/pain, along with TMJ disc displacement. TMD is frequently associated with synovitis, a chronic inflammation of the synovium. Fibroblast‑like synovial cells have been identified to produce several inflammatory mediators and may have an important role in the progression of TMJ inflammation. Degradation of the extracellular matrix molecule elastin may lead to the release of bioactive peptides. The present study aimed to explore the role of elastin‑derived peptides (EDPs) in human temporomandibular disorders. Therefore, interleukin‑6 (IL‑6) expression in the synovial fluid obtained from patients with TMD correlated significantly with two clinical parameters, specifically TMJ locking and pain/jaw function on a visual analog scale (VAS). To the best of our knowledge, this is the first study to determine that the concentration of EDPs in synovial fluid from patients with TMD may also be significantly correlated with the duration of TMJ locking, the VAS score and IL‑6 expression. In vitro, EDPs act on human TMJ synovial cells to promote upregulation of IL‑6 and the elastin‑degrading enzyme matrix metalloproteinase‑12 (MMP‑12). The upregulation of IL‑6 and MMP‑12 expression by EDPs may be mediated through elastin‑binding proteins (EBP) and a protein kinase A signalling cascade. These findings suggest a model for inflammation in the TMJ where EDPs are generated by harmful mechanical stimuli, induce both a pro‑inflammatory cascade and increase expression of MMP‑12 through activation of the EBP signalling cascade. This may lead to further increases in EDP levels, establishing a positive feedback loop leading to chronic inflammation in the TMJ. Therefore, significantly elevated levels of EDPs and IL‑6 in the synovial fluid of the TMJ may be indicators of the pathological conditions of the joint.

Topics: Adolescent; Adult; Aged; Cytokines; Elastin; Female; Fibroblasts; Humans; Inflammation; Male; Matrix Metalloproteinases; Middle Aged; Pain Measurement; Receptors, Cell Surface; Synovial Fluid; Synovial Membrane; Temporomandibular Joint Disorders; Young Adult

Bronchiectasis is a long-neglected disease currently experiencing a surge in interest. It is a highly complex condition with numerous aetiologies, co-morbidities and a heterogeneous disease presentation and clinical course. The past few years have seen major advances in our understanding of the disease, primarily through large real-life cohort studies. The main outcomes of interest in bronchiectasis are symptoms, exacerbations, treatment response, disease progression and death. We are now more able to identify clearly the radiological, clinical, microbiological and inflammatory contributors to these outcomes. Over the past couple of years, multidimensional scoring systems such as the Bronchiectasis Severity Index have been introduced to predict disease severity and mortality. Although there are currently no licensed therapies for bronchiectasis, an increasing number of clinical trials are planned or ongoing. While this emerging evidence is awaited, bronchiectasis guidelines will continue to be informed largely by real-life evidence from observational studies and patient registries. Key developments in the bronchiectasis field include the establishment of international disease registries and characterisation of disease phenotypes using cluster analysis and biological data.

Topics: Bronchiectasis; Cluster Analysis; Comorbidity; Elastin; Humans; Inflammation; Leukocyte Elastase; Phenotype; Prognosis; Radiography; Severity of Illness Index

Antenatal inflammation and preterm birth are associated with the development of airway diseases such as wheezing and asthma. Utilizing a newborn mouse model, we assessed the effects of maternal inflammation and postnatal hyperoxia on the neonatal airway.. Pregnant C57/Bl6 dams were injected with lipopolysaccharide (LPS) or saline on embryonic day 16. Offspring were placed in room air or hyperoxia (50% O2) for 7 d and then returned to normoxia. Airway mechanics, histology, and laser capture micro-dissection (LCM) were performed.. At postnatal day 21, maternal LPS- and 50% O2-exposed pups exhibited increased resistance and decreased compliance compared to 21% O2 pups; however their effects were not synergistic. LPS and hyperoxia each increased the thickness of airway smooth muscle (ASM), but not the airway epithelial layer. Structural changes were largely limited to the conducting airways. Upregulation of inflammatory markers in the lung was observed at birth. LCM revealed increased collagen-3, transforming growth factor β, and connective tissue growth factor expression with LPS and hyperoxia within the ASM layer.. These novel studies provide functional, structural, and molecular evidence that antenatal inflammation is detrimental to the developing airway. Exposure to moderate hyperoxia does not exacerbate LPS effects on the airway.

Topics: Airway Remodeling; Animals; Animals, Newborn; Body Weight; Collagen; Disease Models, Animal; Dose-Response Relationship, Drug; Elastin; Female; Hyperoxia; Inflammation; Lipopolysaccharides; Lung; Methacholine Chloride; Mice; Mice, Inbred C57BL; Oxygen; Pregnancy; Pregnancy, Animal; Respiration; Respiratory System

Marfan syndrome is an autosomal dominant inherited disorder of connective tissue. The vascular complications of Marfan syndrome have the biggest impact on life expectancy. The aorta of Marfan patients reveals degradation of elastin layers caused by increased proteolytic activity of matrix metalloproteinases (MMPs). In this study we performed adenoviral gene transfer of human tissue inhibitor of matrix metalloproteinases-1 (hTIMP-1) in aortic grafts of fibrillin-1 deficient Marfan mice (mgR/mgR) in order to reduce elastolysis.. We performed heterotopic infrarenal transplantation of the thoracic aorta in female mice (n = 7 per group). Before implantation, mgR/mgR and wild-type aortas (WT, C57BL/6) were transduced ex vivo with an adenoviral vector coding for human TIMP-1 (Ad.hTIMP-1) or β-galactosidase (Ad.β-Gal). As control mgR/mgR and wild-type aortas received no gene therapy. Thirty days after surgery, overexpression of the transgene was assessed by immunohistochemistry (IHC) and collagen in situ zymography. Histologic staining was performed to investigate inflammation, the neointimal index (NI), and elastin breaks. Endothelial barrier function of native not virus-exposed aortas was evaluated by perfusion of fluorescent albumin and examinations of virus-exposed tissue were performed by transmission electron microscopy (TEM).. IHC and ISZ revealed sufficient expression of the transgene. Severe cellular inflammation and intima hyperplasia were seen only in adenovirus treated mgR/mgR aortas (Ad.β-Gal, Ad.hTIMP-1 NI: 0.23; 0.43), but not in native and Ad.hTIMP-1 treated WT (NI: 0.01; 0.00). Compared to native mgR/mgR and Ad.hTIMP-1 treated WT aorta, the NI is highly significant greater in Ad.hTIMP-1 transduced mgR/mgR aorta (p = 0.001; p = 0.001). As expected, untreated Marfan grafts showed significant more elastolysis compared to WT (p = 0.001). However, elastolysis in Marfan aortas was not reduced by adenoviral overexpression of hTIMP-1 (compared to untreated Marfan aorta: Ad.hTIMP-1 p = 0.902; control Ad.β-Gal. p = 0.165). The virus-untreated and not transplanted mgR/mgR aorta revealed a significant increase of albumin diffusion through the endothelial barrier (p = 0.037). TEM analysis of adenovirus-exposed mgR/mgR aortas displayed disruption of the basement membrane and basolateral space.. Murine Marfan aortic grafts developed severe inflammation after adenoviral contact. We demonstrated that fibrillin-1 deficiency is associated with relevant dysfunction of the endothelial barrier that enables adenovirus to induce vessel-harming inflammation. Endothelial dysfunction may play a pivotal role in the development of the vascular phenotype of Marfan syndrome.

Topics: Adenoviridae; Animals; Aorta; beta-Galactosidase; Cells, Cultured; Elastin; Endothelium, Vascular; Female; Fibrillin-1; Fibrillins; Genetic Therapy; Inflammation; Marfan Syndrome; Mice; Mice, Inbred C57BL; Microfilament Proteins; Neointima; Tight Junctions; Tissue Inhibitor of Metalloproteinase-1

Chronic inflammation and degradation of elastin are the main processes in the development of abdominal aortic aneurysm (AAA). Recent studies show that zinc has an anti-inflammatory effect. Based on these, zinc may render effective therapy for the treatment of the AAA. Currently, we want to investigate the effects of zinc on AAA progression and its related molecular mechanism. Rat AAA models were induced by periaortic application of CaCl2. AAA rats were treated by daily intraperitoneal injection of ZnSO4 or vehicle alone. The aorta segments were collected at 4 weeks after surgery. The primary rat aortic vascular smooth muscle cells (VSMCs) were stimulated with TNF-α alone or with ZnSO4 for 3 weeks. The results showed that zinc supplementation significantly suppressed the CaCl2-induced expansion of the abdominal aortic diameter, as well as a preservation of medial elastin fibers in the aortas. Zinc supplementation also obviously attenuated infiltration of the macrophages and lymphocytes in the aortas. In addition, zinc reduced MMP-2 and MMP-9 production in the aortas. Most importantly, zinc treatment significantly induced A20 expression, along with inhibition of the NF-κB canonical signaling pathway in vitro in VSMCs and in vivo in rat AAA. This study demonstrated, for the first time, that zinc supplementation could prevent the development of rat experimental AAA by induction of A20-mediated inhibition of the NF-κB canonical signaling pathway.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Cells, Cultured; Disease Models, Animal; DNA-Binding Proteins; Elastin; I-kappa B Kinase; I-kappa B Proteins; Inflammation; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Myocytes, Smooth Muscle; NF-kappa B; NF-KappaB Inhibitor alpha; Rats; Rats, Wistar; Signal Transduction; Tumor Necrosis Factor alpha-Induced Protein 3; Zinc Sulfate

Clinical management of abdominal aortic aneurysm (AAA) is currently limited to elective surgical repair because an effective pharmacotherapy is still awaited. Inhibition of histone deacetylase (HDAC) activity could be a promising therapeutic option in cardiovascular diseases. We aimed to characterise HDAC expression in human AAA and to evaluate the therapeutic potential of class I and IIa HDAC inhibitors in the AAA model of angiotensin II (Ang II)-infused apolipoprotein-E-deficient (ApoE(-/-)) mice. Real-time PCR, western blot and immunohistochemistry evidenced an increased expression of HDACs 1, 2 (both class I), 4 and 7 (both class IIa) in abdominal aorta samples from patients undergoing AAA open repair (n=22) compared with those from donors (n=14). Aortic aneurysms from Ang-II-infused ApoE(-/-) mice exhibited a similar HDAC expression profile. In these animals, treatment with a class I HDAC inhibitor (MS-275) or a class IIa inhibitor (MC-1568) improved survival, reduced the incidence and severity of AAA and limited aneurysmal expansion evaluated by Doppler ultrasonography. These beneficial effects were more potent in MC-1568-treated mice. The disorganisation of elastin and collagen fibres and lymphocyte and macrophage infiltration were effectively reduced by both inhibitors. Additionally, HDAC inhibition attenuated the exacerbated expression of pro-inflammatory markers and the increase in metalloproteinase-2 and -9 activity induced by Ang II in this model. Therefore, our data evidence that HDAC expression is deregulated in human AAA and that class-selective HDAC inhibitors limit aneurysm expansion in an AAA mouse model. New-generation HDAC inhibitors represent a promising therapeutic approach to overcome human aneurysm progression.

Topics: Angiotensin II; Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Apolipoproteins E; Biomarkers; Collagen; Disease Models, Animal; Disease Progression; Elastin; Enzyme Induction; Female; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Inflammation; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Middle Aged; Severity of Illness Index; Up-Regulation

Elastin degradation is a key feature of emphysema and may have a role in the pathogenesis of atherosclerosis associated with chronic obstructive pulmonary disease (COPD). Circulating desmosine is a specific biomarker of elastin degradation. We investigated the association between plasma desmosine (pDES) and emphysema severity/progression, coronary artery calcium score (CACS) and mortality.pDES was measured in 1177 COPD patients and 110 healthy control subjects from two independent cohorts. Emphysema was assessed on chest computed tomography scans. Aortic arterial stiffness was measured as the aortic-femoral pulse wave velocity.pDES was elevated in patients with cardiovascular disease (p<0.005) and correlated with age (rho=0.39, p<0.0005), CACS (rho=0.19, p<0.0005) modified Medical Research Council dyspnoea score (rho=0.15, p<0.0005), 6-min walking distance (rho=-0.17, p<0.0005) and body mass index, airflow obstruction, dyspnoea, exercise capacity index (rho=0.10, p<0.01), but not with emphysema, emphysema progression or forced expiratory volume in 1 s decline. pDES predicted all-cause mortality independently of several confounding factors (p<0.005). In an independent cohort of 186 patients with COPD and 110 control subjects, pDES levels were higher in COPD patients with cardiovascular disease and correlated with arterial stiffness (p<0.05).In COPD, excess elastin degradation relates to cardiovascular comorbidities, atherosclerosis, arterial stiffness, systemic inflammation and mortality, but not to emphysema or emphysema progression. pDES is a good biomarker of cardiovascular risk and mortality in COPD.

Topics: Adult; Aged; Biomarkers; Body Composition; Bronchodilator Agents; Calcinosis; Cardiovascular Diseases; Case-Control Studies; Coronary Vessels; Desmosine; Disease Progression; Elastin; Emphysema; Female; Forced Expiratory Volume; Humans; Inflammation; Male; Middle Aged; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Pulse Wave Analysis; Respiratory Function Tests; Risk Factors; Smoking; Vascular Stiffness

Loss of integrity and massive disruption of elastic fibers are key features of abdominal aortic aneurysm (AAA). Peroxisome proliferator-activated receptor γ (PPARγ) has been shown to attenuate AAA through inhibition of inflammation and proteolytic degradation. However, its involvement in elastogenesis during AAA remains unclear. PPARγ was highly expressed in human AAA within all vascular cells, including inflammatory cells and fibroblasts. In the aortas of transgenic mice expressing PPARγ at 25% normal levels (Pparg(C) (/-) mice), we observed the fragmentation of elastic fibers and reduced expression of vital elastic fiber components of elastin and fibulin-5. These were not observed in mice with 50% normal PPARγ expression (Pparg(+/-) mice). Infusion of a moderate dose of angiotensin II (500 ng/kg per minute) did not induce AAA but Pparg(+/-) aorta developed flattened elastic lamellae, whereas Pparg(C/-) aorta showed severe destruction of elastic fibers. After infusion of angiotensin II at 1000 ng/kg per minute, 73% of Pparg(C/-) mice developed atypical suprarenal aortic aneurysms: superior mesenteric arteries were dilated with extensive collagen deposition in adventitia and infiltrations of inflammatory cells. Although matrix metalloproteinase inhibition by doxycycline somewhat attenuated the dilation of aneurysm, it did not reduce the incidence nor elastic lamella deterioration in angiotensin II-infused Pparg(C/-) mice. Furthermore, PPARγ antagonism downregulated elastin and fibulin-5 in fibroblasts, but not in vascular smooth muscle cells. Chromatin immunoprecipitation assay demonstrated PPARγ binding in the genomic sequence of fibulin-5 in fibroblasts. Our results underscore the importance of PPARγ in AAA development though orchestrating proper elastogenesis and preserving elastic fiber integrity.

Topics: Analysis of Variance; Angiotensin II; Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Cells, Cultured; Disease Models, Animal; Elastin; Gene Expression Regulation; Humans; Inflammation; Male; Matrix Metalloproteinases; Mice; Mice, Knockout; Middle Aged; Muscle, Smooth, Vascular; PPAR gamma

The highly orchestrated interactions between the epithelium and mesenchyme required for normal lung development can be disrupted by perinatal inflammation in preterm infants, although the mechanisms are incompletely understood. We used transgenic (inhibitory κB kinase β transactivated) mice that conditionally express an activator of the NF-κB pathway in airway epithelium to investigate the impact of epithelial-derived inflammation during lung development. Epithelial NF-κB activation selectively impaired saccular stage lung development, with a phenotype comprising rapidly progressive distal airspace dilation, impaired gas exchange, and perinatal lethality. Epithelial-derived inflammation resulted in disrupted elastic fiber organization and down-regulation of elastin assembly components, including fibulins 4 and 5, lysyl oxidase like-1, and fibrillin-1. Fibulin-5 expression by saccular stage lung fibroblasts was consistently inhibited by treatment with bronchoalveolar lavage fluid from inhibitory κB kinase β transactivated mice, Escherichia coli lipopolysaccharide, or tracheal aspirates from preterm infants exposed to chorioamnionitis. Expression of a dominant NF-κB inhibitor in fibroblasts restored fibulin-5 expression after lipopolysaccharide treatment, whereas reconstitution of fibulin-5 rescued extracellular elastin assembly by saccular stage lung fibroblasts. Elastin organization was disrupted in saccular stage lungs of preterm infants exposed to systemic inflammation. Our study reveals a critical window for elastin assembly during the saccular stage that is disrupted by inflammatory signaling and could be amenable to interventions that restore elastic fiber assembly in the developing lung.

Topics: Animals; Blotting, Western; Elastin; Epithelium; Fetal Development; Humans; Immunohistochemistry; Infant, Newborn; Infant, Premature; Inflammation; Lung; Mice; Mice, Transgenic; Microscopy, Electron, Transmission; Models, Animal; NF-kappa B; Real-Time Polymerase Chain Reaction

Aneurysm-osteoarthritis syndrome characterized by unpredictable aortic aneurysm formation, is caused by SMAD3 mutations. SMAD3 is part of the SMAD2/3/4 transcription factor, essential for TGF-β-activated transcription. Although TGF-β-related gene mutations result in aneurysms, the underlying mechanism is unknown. Here, we examined aneurysm formation and progression in Smad3

Topics: Aneurysm; Animals; Aortic Aneurysm; Cell Proliferation; Connective Tissue; Disease Models, Animal; Echocardiography; Elastin; Extracellular Signal-Regulated MAP Kinases; Female; Immunohistochemistry; Inflammation; Male; Matrix Metalloproteinases; Mice; Mice, Knockout; Models, Biological; Molecular Imaging; Mortality; Muscle, Smooth, Vascular; Signal Transduction; Smad2 Protein; Smad3 Protein; Transcriptional Activation; Transforming Growth Factor beta; X-Ray Microtomography

Subjects with type-2 diabetes are typically obese with dysfunctional adipose tissue (AT). Glucagon-like peptide-1 (GLP-1) analogues are routinely used to improve glycaemia. Although, they also aid weight loss that improves AT function, their direct effect on AT function is unclear. To explore GLP-1 analogues' influence on human AT's cytokine and extracellular matrix (ECM) regulation, we therefore obtained and treated omental (OMAT) and subcutaneous (SCAT) AT samples with Exendin-4, an agonist of the GLP-1 receptor (GLP-1R).. OMAT and abdominal SCAT samples obtained from women during elective surgery at the Royal Devon & Exeter Hospital (UK) were treated with increasing doses of Exendin-4. Changes in RNA expression of adipokines, inflammatory cytokines, ECM components and their regulators were assessed and protein secretion analysed by ELISA. GLP-1R protein accumulation was compared in paired AT depot samples.. Exendin-4 induced an increase in OMAT adiponectin (P=0.02) and decrease in elastin expression (P=0.03) in parallel with reduced elastin secretion (P=0.04). In contrast to OMAT, we did not observe an effect on SCAT. There was no change in the expression of inflammatory markers (CD14, TNFA, MCP-1), collagens, TGFB1 or CTGF. GLP-1R accumulation was higher in SCAT.. Independently of weight loss, which may bias findings of in vivo studies, GLP-1 analogues modify human OMAT physiology favourably by increasing the insulin-sensitising cytokine adiponectin. However, the reduction of elastin and no apparent effect on AT's inflammatory cytokines suggest that GLP-1 analogues may be less beneficial to AT function, especially if there is no associated weight loss.

Topics: Adipokines; Adiponectin; Adipose Tissue; Aged; Cytokines; Dose-Response Relationship, Drug; Elastin; Exenatide; Extracellular Matrix; Female; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Inflammation; Middle Aged; Overweight; Peptides; Venoms

The application of cell-derived extracellular matrix (ECM) in tissue engineering has gained increasing interest because it can provide a naturally occurring, complex set of physiologically functional signals for cell growth. The ECM scaffolds produced from decellularized fibroblast cell sheets contain high amounts of ECM substances, such as collagen, elastin, and glycosaminoglycans. They can serve as cell adhesion sites and mechanically strong supports for tissue-engineered constructs. An efficient method that can largely remove cellular materials while maintaining minimal disruption of ECM ultrastructure and content during the decellularization process is critical. In this study, three decellularization methods were investigated: high concentration (0.5 wt%) of sodium dodecyl sulfate (SDS), low concentration (0.05 wt%) of SDS, and freeze-thaw cycling method. They were compared by characterization of ECM preservation, mechanical properties, in vitro immune response, and cell repopulation ability of the resulted ECM scaffolds. The results demonstrated that the high SDS treatment could efficiently remove around 90% of DNA from the cell sheet, but significantly compromised their ECM content and mechanical strength. The elastic and viscous modulus of the ECM decreased around 80% and 62%, respectively, after the high SDS treatment. The freeze-thaw cycling method maintained the ECM structure as well as the mechanical strength, but also preserved a large amount of cellular components in the ECM scaffold. Around 88% of DNA was left in the ECM after the freeze-thaw treatment. In vitro inflammatory tests suggested that the amount of DNA fragments in ECM scaffolds does not cause a significantly different immune response. All three ECM scaffolds showed comparable ability to support in vitro cell repopulation. The ECM scaffolds possess great potential to be selectively used in different tissue engineering applications according to the practical requirement.

Topics: Animals; Cattle; Cell Culture Techniques; Collagen Type I; Cytokines; DNA; Elastin; Extracellular Matrix; Fibroblasts; Fibronectins; Glycosaminoglycans; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Macrophages; Materials Testing; Mesenchymal Stem Cells; Staining and Labeling; Tissue Engineering; Tissue Scaffolds

TGF-β signaling plays critical roles in the pathogenesis of aneurysms; however, it is still unclear whether its role is protective or destructive. In this study, we investigate the role of SMAD3 in the pathogenesis of calcium chloride (CaCl2)-induced abdominal aortic aneurysms (AAA) in Smad3(-/-), Smad3(+/-) and Smad3(+/+) mice. We find that loss of SMAD3 drastically increases wall thickening of the abdominal aorta. Histological analyses show significant vessel wall remodeling with elastic fiber fragmentation. Remarkably, under polarized light, collagen fibers in the hyperplastic adventitia of Smad3(-/-) mice show extensive reorganization accompanied by loosely packed thin and radial collagen fibers. The expressions of matrix metalloproteinases including MMP2, MMP9, and MMP12 and infiltration of macrophage/T cells are drastically enhanced in the vascular wall of Smad3(-/-) mice. We also observe marked increase of NF-κB and ERK1/2 signaling as well as the expression of nuclear Smad2, Smad4 and TGF-β1 in the vessel wall of Smad3(-/-) mice. In addition, we find that SMAD3 expression is reduced in the dedifferentiated medial smooth muscle-like cells of human AAA patients. These findings provide direct in vivo evidence to support the essential roles of SMAD3 in protecting vessel wall integrity and suppressing inflammation in the pathogenesis of AAAs.

Topics: Animals; Aortic Aneurysm, Abdominal; Atrial Remodeling; Calcium Chloride; Collagen; Disease Models, Animal; Elastin; Extracellular Matrix; Gene Expression Regulation; Inflammation; Leukocytes; Matrix Metalloproteinases; Mice; Mice, Knockout; NF-kappa B; Signal Transduction; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta

Abdominal aortic aneurysm (AAA) is characterized by inflammation, loss of smooth muscle cells (SMCs), and degradation of the extracellular matrix in the vessel wall. Innate immune receptors such as Toll-like receptors (TLRs) were recently shown to regulate immunological processes leading to the formation and progression of atherosclerotic plaques as well as to other cardiovascular pathologies. Our aim was to investigate whether blockage of TLR signaling, under the control of TIR domain-containing adaptor protein including IFN-β (TRIF), could inhibit the inflammatory response and AAA development in mice.. In human AAA, an increased TLR3 and TLR4 expression in association with macrophages and T lymphocytes was demonstrated with immunohistochemical analysis. Angiotensin (Ang) II-induced aneurysm formation was significantly reduced by 30% in ApoE(-/-)Trif(-/-) mice compared to ApoE(-/-) mice. Morphologically, AngII-infused ApoE(-/-)Trif(-/-) mice had a more intact cellular and extracellular matrix while ApoE(-/-) mice infused with AngII displayed an increased medial thickness associated with aortic dissection, thrombus formation, and a more disorganized vessel wall. Gene expression analysis of the abdominal aorta revealed a profound decrease of the inflammatory genes CD68 (P < 0.05), CD11b (P < 0.05), and TNF-α (P < 0.05) and the protease gene MMP-12 (P < 0.01) in ApoE(-/-)Trif(-/-) mice compared to ApoE(-/-) mice infused with AngII.. Our results suggest that signaling through TRIF is important for the inflammatory response of AngII-induced AAA and that blockage of the TRIF pathway reduces vascular inflammation and protects against AAA formation.

Topics: Adaptor Proteins, Vesicular Transport; Angiotensin II; Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Aorta; Aortic Aneurysm, Abdominal; Apolipoproteins; Apolipoproteins E; CD3 Complex; Elastin; Gene Expression Regulation; Humans; Inflammation; Mice; Mice, Knockout; Signal Transduction; Toll-Like Receptors

Critical limb ischemia is a major clinical problem. Despite rigorous treatment regimes, there has been only modest success in reducing the rate of amputations in affected patients. Reduced level of blood flow and enhanced inflammation are the two major pathophysiological changes that occur in the ischemic tissue. The objective of this study was to develop a controlled dual gene delivery system capable of delivering therapeutic plasmid eNOS and IL-10 in a temporal manner. In order to deliver multiple therapeutic genes, an elastin-like polypeptide (ELP) based injectable system was designed. The injectable system was comprised of hollow spheres and an in situ-forming gel scaffold of elastin-like polypeptide capable of carrying gene complexes, with an extended manner release profile. In addition, the ELP based injectable system was used to deliver human eNOS and IL-10 therapeutic genes in vivo. A subcutaneous dose response study showed enhanced blood vessel density in the treatment groups of eNOS (20 μg) and IL-10 (10 μg)/eNOS (20 μg) and reduced inflammation with IL-10 (10 μg) alone. Next, we carried out a hind-limb ischemia model comparing the efficacy of the following interventions; Saline; IL-10, eNOS and IL-10/eNOS. The selected dose of eNOS, exhibited enhanced angiogenesis. IL-10 treatment groups showed reduction in the level of inflammatory cells. Furthermore, we demonstrated that eNOS up-regulated major proangiogenic growth factors such as vascular endothelial growth factors, platelet derived growth factor B, and fibroblast growth factor 1, which may explain the mechanism of this approach. These factors help in formation of a stable vascular network. Thus, ELP injectable system mediating non-viral delivery of human IL10-eNOS is a promising therapy towards treating limb ischemia.

Topics: Animals; Cell Line; Elastin; Gene Transfer Techniques; Genetic Therapy; Hindlimb; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Interleukin-10; Ischemia; Male; Mice, Inbred C57BL; Neovascularization, Physiologic; Nitric Oxide Synthase Type III; Peptides; Plasmids

Deep venous thrombosis is a common vascular problem with long-term complications including post-thrombotic syndrome. Post-thrombotic syndrome consists of leg pain, swelling and ulceration that is related to incomplete or maladaptive resolution of the venous thrombus as well as loss of compliance of the vein wall. We examine the role of metalloproteinase-9 (MMP-9), a gene important in extracellular remodeling in other vascular diseases, in mediating thrombus resolution and biomechanical changes of the vein wall.. The effects of targeted deletion of MMP-9 were studied in an in vivo murine model of thrombus resolution using the FVB strain of mice. MMP-9 expression and activity significantly increased on day 3 after DVT. The lack of MMP-9 impaired thrombus resolution by 27% and this phenotype was rescued by the transplantation of wildtype bone marrow cells. Using novel biomechanical techniques, we demonstrated that the lack of MMP-9 significantly decreased thrombus-induced loss of vein wall compliance. Biomechanical analysis of the contribution of individual structural components showed that MMP-9 affected the elasticity of the extracellular matrix and collagen-elastin fibers. Biochemical and histological analyses correlated with these biomechanical effects as thrombi of mice lacking MMP-9 had significantly fewer macrophages and collagen as compared to those of wildtype mice.. MMP-9 mediates thrombus-induced loss of vein wall compliance by increasing stiffness of the extracellular matrix and collagen-elastin fibers during thrombus resolution. MMP-9 also mediates macrophage and collagen content of the resolving thrombus and bone-marrow derived MMP-9 plays a role in resolution of thrombus mass. These disparate effects of MMP-9 on various aspects of thrombus illustrate the complexity of individual protease function on biomechanical and morphometric aspects of thrombus resolution.

Topics: Animals; Biomechanical Phenomena; Bone Marrow; Collagen; Disease Models, Animal; Elastin; Extracellular Matrix; Gene Deletion; Immunohistochemistry; Inflammation; Matrix Metalloproteinase 9; Mice; Veins; Venous Thrombosis

The purpose of this study was to analyze the association between morphological characteristics of human carotid plaques and patient's sex, age, and history of neurological symptoms.. The study included 763 atherosclerotic plaques from patients treated surgically for carotid stenosis between 2004 and 2013. Histological analyses of carotid plaques were performed to assess the type of plaque (American Heart Association classification), the stability of the plaque, the extent of calcification, inflammation, and neovascularization, as well as the deposition of collagen and elastin. According to the scale of outcome measurement, logistic regression, ordinal regression, and multinomial regression analyses were applied. All results were adjusted for common risk factors of atherosclerosis.. Male sex was associated with more cellularity (odds ratio [OR], 1.56; P=0.003), more inflammatory infiltrates (OR, 1.75; P<0.001), and more neovascularization (OR, 1.47; P=0.010), but less calcification (OR, 0.78; P=0.090). Symptomatic patients were more likely to have a lower amount of elastin (OR, 0.71; P=0.057). Higher age was associated with increased calcification (OR, 1.23; P=0.009). Unstable plaques were found more frequently in symptomatic patients (OR, 1.60; 95% confidence interval, 1.14-2.25; P=0.007). A multinomial regression model revealed that age, sex, and history of neurological symptoms were significantly associated with specific plaque types (P=0.009, P<0.001, and P=0.017, respectively).. Plaque morphology differed between men and women and varied with age. Certain types of plaques (VI and VI/VII) as well as unstable plaques were significantly associated with a history of neurological symptoms. Thus, individual approaches (eg, in detection of plaque hemorrhage or thin fibrous caps) especially based on sex and age should be considered to identify patients at increased risk of stroke.

Topics: Age Factors; Aged; Aged, 80 and over; Carotid Stenosis; Cohort Studies; Collagen; Cross-Sectional Studies; Elastin; Endarterectomy, Carotid; Female; Humans; Inflammation; Logistic Models; Male; Middle Aged; Neovascularization, Pathologic; Plaque, Atherosclerotic; Sex Factors; Vascular Calcification

Aortic stiffening commonly occurs in hypertension and further elevates systolic pressure. Hypertension is also associated with vascular inflammation and increased mechanical stretch. The interplay between inflammation, mechanical stretch, and aortic stiffening in hypertension remains undefined.. Our aim was to determine the role of inflammation and mechanical stretch in aortic stiffening.. Chronic angiotensin II infusion caused marked aortic adventitial collagen deposition, as quantified by Masson trichrome blue staining and biochemically by hydroxyproline content, in wild-type but not in recombination activating gene-1-deficient mice. Aortic compliance, defined by ex vivo measurements of stress-strain curves, was reduced by chronic angiotensin II infusion in wild-type mice (P<0.01) but not in recombination activating gene-1-deficient mice (P<0.05). Adoptive transfer of T-cells to recombination activating gene-1-deficient mice restored aortic collagen deposition and stiffness to values observed in wild-type mice. Mice lacking the T-cell-derived cytokine interleukin 17a were also protected against aortic stiffening. In additional studies, we found that blood pressure normalization by treatment with hydralazine and hydrochlorothiazide prevented angiotensin II-induced vascular T-cell infiltration, aortic stiffening, and collagen deposition. Finally, we found that mechanical stretch induces the expression of collagen 1α1, 3α1, and 5a1 in cultured aortic fibroblasts in a p38 mitogen-activated protein kinase-dependent fashion, and that inhibition of p38 prevented angiotensin II-induced aortic stiffening in vivo. Interleukin 17a also induced collagen 3a1 expression via the activation of p38 mitogen-activated protein kinase.. Our data define a pathway in which inflammation and mechanical stretch lead to vascular inflammation that promotes collagen deposition. The resultant increase in aortic stiffness likely further worsens systolic hypertension and its attendant end-organ damage.

Topics: Adoptive Transfer; Angiotensin II; Animals; Aortic Diseases; CD4 Antigens; CD8 Antigens; Cells, Cultured; Collagen; Disease Models, Animal; Elastin; Fibroblasts; Homeodomain Proteins; Hypertension; Inflammation; Interleukin-17; Male; Mice; Mice, Knockout; p38 Mitogen-Activated Protein Kinases; Stress, Mechanical; T-Lymphocytes; Vascular Stiffness; Vasculitis; Vasoconstrictor Agents

Adipose tissue in insulin resistant subjects contains inflammatory cells and extracellular matrix components. This study examined adipose pathology of insulin resistant subjects who were treated with pioglitazone or fish oil.. Adipose biopsies were examined from nine insulin resistant subjects before/after treatment with pioglitazone 45 mg/day for 12 weeks and also from 19 subjects who were treated with fish oil (1,860 mg EPA, 1,500 mg DHA daily). These studies were performed in a clinical research center setting.. Pioglitazone treatment increased the cross-sectional area of adipocytes by 18% (p = 0.01), and also increased capillary density without affecting larger vessels. Pioglitazone treatment decreased total adipose macrophage number by 26%, with a 56% decrease in M1 macrophages and an increase in M2 macrophages. Mast cells were more abundant in obese versus lean subjects, and were decreased from 24 to 13 cells/mm(2) (p = 0.02) in patients treated with pioglitazone, but not in subjects treated with FO. Although there were no changes in total collagen protein, pioglitazone increased the amount of elastin protein in adipose by 6-fold.. The PPARγ agonist pioglitazone increased adipocyte size yet improved other features of adipose, increasing capillary number and reducing mast cells and inflammatory macrophages. The increase in elastin may better permit adipocyte expansion without triggering cell necrosis and an inflammatory reaction.

Topics: Adipocytes; Adipose Tissue; Adult; Elastin; Female; Fish Oils; Humans; Inflammation; Insulin Resistance; Macrophages; Male; Mast Cells; Middle Aged; Obesity; Pioglitazone; PPAR gamma; Thiazolidinediones

Most acute cardiovascular events are caused by rupture of an atherosclerotic plaque. The incidence of cardiovascular events increases with age and inflammation is generally considered to be the main cause of increased plaque vulnerability. However, the relationship between age and plaque inflammation has not yet been fully clarified. The aim of our study was to determine if age-dependent plaque vulnerability is associated with increased plaque inflammation.. We collected 200 endarterectomy specimens, 103 of which were from patients 70 years or older. One-hundred and five patients had a recent cerebrovascular event, whereas the rest were asymptomatic despite significant carotid stenosis. Smooth muscle cell, lipid and macrophage content were analyzed by histology. Cytokines, growth factors and extracellular matrix proteins were analyzed in whole plaque homogenates by immunoassays and biochemical methods.. Plaques from elderly patients contained less IFN-γ, TNF-α, fractalkine, sCD40L, and elastin. Lipid and macrophage content was higher in plaques from symptomatic compared to asymptomatic patients in the elderly group, but not in younger patients. The elastin and collagen content was lower in plaques from symptomatic patients in both age groups. Plaques associated with symptoms also contained more TNF-α, IL-1β, IL-6, sCD40L, MIP-1β, MCP-1, RANTES and VEGF, regardless of age.. Our data imply that increased plaque vulnerability in the symptomatic elderly patients is associated with increased lipid accumulation and impaired tissue repair, rather than with increased plaque inflammation, compared to younger individuals.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Aging; Carotid Arteries; Carotid Stenosis; Collagen; Cytokines; Elastin; Endarterectomy, Carotid; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Inflammation; Lipids; Macrophages; Male; Middle Aged; Plaque, Atherosclerotic

Certain photosynthetic marine organisms have evolved mechanisms to counteract UV-radiation by synthesizing UV-absorbing compounds, such as mycosporine-like amino acids (MAAs). In this study, MAAs were separated from the extracts of marine green alga Chlamydomonas hedleyi using HPLC and were identified as porphyra-334, shinorine, and mycosporine-glycine (mycosporine-Gly), based on their retention times and maximum absorption wavelengths. Furthermore, their structures were confirmed by triple quadrupole MS/MS. Their roles as UV-absorbing compounds were investigated in the human fibroblast cell line HaCaT by analyzing the expression levels of genes associated with antioxidant activity, inflammation, and skin aging in response to UV irradiation. The mycosporine-Gly extract, but not the other MAAs, had strong antioxidant activity in the 2,2-diphenyl-1-picryhydrazyl (DPPH) assay. Furthermore, treatment with mycosporine-Gly resulted in a significant decrease in COX-2 mRNA levels, which are typically increased in response to inflammation in the skin, in a concentration-dependent manner. Additionally, in the presence of MAAs, the UV-suppressed genes, procollagen C proteinase enhancer (PCOLCE) and elastin, which are related to skin aging, had increased expression levels equal to those in UV-mock treated cells. Interestingly, the increased expression of involucrin after UV exposure was suppressed by treatment with the MAAs mycosporine-Gly and shinorine, but not porphyra-334. This is the first report investigating the biological activities of microalgae-derived MAAs in human cells.

Topics: Amino Acids; Anti-Inflammatory Agents; Cell Line; Chlamydomonas; Chlorophyta; Cyclohexanols; Cyclohexanones; Cyclohexylamines; Cyclooxygenase 2; Elastin; Extracellular Matrix Proteins; Fibroblasts; Glycine; Glycoproteins; Humans; Inflammation; Skin; Skin Aging; Ultraviolet Rays

Tissue engineering techniques have emerged that allow bioresorbable grafts to be implanted that restore function and transform into biologically active arteries. However, these implants are susceptible to calcification during the remodeling process. The objective of this study was to evaluate the role of pore size of bioabsorbable grafts in the development of calcification.. Two types of grafts were prepared: a large-pore graft constructed of poly(L-lactic acid) (PLA) fibers coated with poly(L-lactide-co-ε-caprolactone) (PLCL) (PLA-PLCL), and a small-pore graft made of electrospun PLA nanofibers (PLA-nano). Twenty-eight PLA-PLCL grafts and twenty-five PLA-nano grafts were implanted as infra-renal aortic interposition conduits in 8-week-old female SCID/Bg mice, and followed for 12 months after implantation.. Large-pore PLA-PLCL grafts induced a well-organized neointima after 12 months, and Alizarin Red S staining showed neointimal calcification only in the thin neointima of small-pore PLA-nano grafts. At 12 months, macrophage infiltration, evaluated by F4/80 staining, was observed in the thin neointima of the PLA-nano graft, and there were few vascular smooth muscle cells (VSMCs) in this layer. On the other hand, the neointima of the PLA-PLCL graft was composed of abundant VSMCs, and a lower density of macrophages (F4/80 positive cells, PLA-PLCL; 68.1 ± 41.4/mm(2) vs PLA-nano; 188.3 ± 41.9/mm(2), p = 0.007). The VSMCs of PLA-PLCL graft expressed transcription factors of both osteoblasts and osteoclasts.. These findings demonstrate that in mouse arterial circulation, large-pore PLA-PLCL grafts created a well-organized neointima and prevented calcific deposition compared to small-pore, electrospun PLA-nano grafts.

Topics: Animals; Arteries; Calcinosis; Collagen; Elastin; Female; Inflammation; Lactic Acid; Macrophages; Mice; Mice, SCID; Microscopy, Electron, Scanning; Models, Animal; Neointima; Osteoblasts; Osteoclasts; Osteogenesis; Polyesters; Polymers; Porosity; Tissue Engineering; Transcription Factors; Vascular Grafting

Bronchopulmonary dysplasia (BPD) is one of the most common complications after preterm birth and is associated with intrauterine exposure to bacteria. Transforming growth factor-β (TGFβ) is implicated in the development of BPD.. We hypothesized that different and/or multiple bacterial signals could elicit divergent TGFβ signaling responses in the developing lung.. Time-mated pregnant Merino ewes received an intra-amniotic injection of lipopolysaccharide (LPS) and/or Ureaplasma parvum serovar 3 (UP) at 117 days' and/or 121/122 days' gestational age (GA). Controls received an equivalent injection of saline and or media. Lambs were euthanized at 124 days' GA (term = 150 days' GA). TGFβ1, TGFβ2, TGFβ3, TGFβ receptor (R)1 and TGFβR2 protein levels, Smad2 phosphorylation and elastin deposition were evaluated in lung tissue.. Total TGFβ1 and TGFβ2 decreased by 24 and 51% after combined UP+LPS exposure, whereas total TGFβ1 increased by 31% after 7 days' LPS exposure but not after double exposures. Alveolar expression of TGFβR2 decreased 75% after UP, but remained unaltered after double exposures. Decreased focal elastin deposition after single LPS exposure was prevented by double exposures.. TGFβ signaling components and elastin responded differently to intrauterine LPS and UP exposure. Multiple bacterial exposures attenuated TGFβ signaling and normalized elastin deposition.

Topics: Amnion; Animals; Chorioamnionitis; Disease Models, Animal; Elastin; Female; Gestational Age; Inflammation; Lipopolysaccharides; Lung; Phosphorylation; Pregnancy; Pregnancy Complications; Receptors, Transforming Growth Factor beta; Sheep; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2; Transforming Growth Factor beta3; Ureaplasma

Plasma phospholipid transfer protein (PLTP) increases the circulating levels of proatherogenic lipoproteins, accelerates blood coagulation, and modulates inflammation. The role of PLTP in the development of abdominal aortic aneurysm (AAA) was investigated by using either a combination of mechanical and elastase injury at one site of mouse aorta (elastase model) or continuous infusion of angiotensin II in hyperlipidemic ApoE-knockout mice (Ang II model). With the elastase model, complete PLTP deficiency was associated with a significantly lower incidence and a lesser degree of AAA expansion. With the Ang II model, findings were consistent with those in the elastase model, with a lower severity grade in PLTP-deficient mice, an intermediate phenotype in PLTP-deficient heterozygotes, and a blunted effect of the PLTP-deficient trait when restricted to bone marrow-derived immune cells. The protective effect of whole-body PLTP deficiency in AAA was illustrated further by a lesser degree of adventitia expansion, reduced elastin degradation, fewer recruited macrophages, and less smooth muscle cell depletion in PLTP-deficient than in wild-type mice, as evident from comparative microscopic analysis of aorta sections. Finally, cumulative evidence supports the association of PLTP deficiency with reduced expression and activity levels of matrix metalloproteinases, known to degrade elastin and collagen. We conclude that PLTP can play a significant role in the pathophysiology of AAA.

Topics: Angiotensin II; Animals; Aorta; Aortic Aneurysm, Abdominal; Apolipoproteins E; CD4-Positive T-Lymphocytes; Cytokines; Elastin; Inflammation; Liver; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Pancreatic Elastase; Phospholipid Transfer Proteins

Radiculopathy, a painful neuroinflammation that can accompany intervertebral disc herniation, is associated with locally increased levels of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα). Systemic administration of TNF antagonists for radiculopathy in the clinic has shown mixed results, and there is growing interest in the local delivery of anti-inflammatory drugs to treat this pathology as well as similar inflammatory events of peripheral nerve injury. Curcumin, a known antagonist of TNFα in multiple cell types and tissues, was chemically modified and conjugated to a thermally responsive elastin-like polypeptide (ELP) to create an injectable depot for sustained, local delivery of curcumin to treat neuroinflammation. ELPs are biopolymers capable of thermally-triggered in situ depot formation that have been successfully employed as drug carriers and biomaterials in several applications. ELP-curcumin conjugates were shown to display high drug loading, rapidly release curcumin in vitro via degradable carbamate bonds, and retain in vitro bioactivity against TNFα-induced cytotoxicity and monocyte activation with IC50 only two-fold higher than curcumin. When injected proximal to the sciatic nerve in mice via intramuscular (i.m.) injection, ELP-curcumin conjugates underwent a thermally triggered soluble-insoluble phase transition, leading to in situ formation of a depot that released curcumin over 4days post-injection and decreased plasma AUC 7-fold.

Topics: Animals; Anti-Inflammatory Agents; Cell Line, Tumor; Curcumin; Delayed-Action Preparations; Drug Delivery Systems; Elastin; Female; Genetic Engineering; Hot Temperature; Humans; Inflammation; Intervertebral Disc Displacement; Mice; Mice, Inbred C57BL; Peptides; Sciatic Nerve; U937 Cells

Mesenchymal stem cells (MSCs) are known to be capable of suppressing inflammatory responses. We previously reported that intra-abdominal implantation of bone marrow-derived MSCs (BM-MSCs) sheet by laparotomy attenuated angiotensin II (AngII)-induced aortic aneurysm (AA) growth in apolipoprotein E-deficient (apoE-/-) mice through anti-inflammation effects. However, cell delivery by laparotomy is invasive; we here demonstrated the effects of multiple intravenous administrations of BM-MSCs on AngII-induced AA formation.. BM-MSCs were isolated from femurs and tibiae of male apoE-/- mice. Experimental AA was induced by AngII infusion for 28 days in apoE-/- mice. Mice received weekly intravenous administration of BM-MSCs (n=12) or saline (n=10). After 4 weeks, AA formation incidence, aortic diameter, macrophage accumulation, matrix metalloproteinase (MMP)' activity, elastin content, and cytokines were evaluated.. AngII induced AA formation in 100% of the mice in the saline group and 50% in the BM-MSCs treatment group (P < 0.05). A significant decrease of aortic diameter was observed in the BM-MSCs treatment group at ascending and infrarenal levels, which was associated with decreased macrophage infiltration and suppressed activities of MMP-2 and MMP-9 in aortic tissues, as well as a preservation of elastin content of aortic tissues. In addition, interleukin (IL)-1β, IL-6, and monocyte chemotactic protein-1 significantly decreased while insulin-like growth factor-1 and tissue inhibitor of metalloproteinases-2 increased in the aortic tissues of BM-MSCs treatment group.. Multiple intravenous administrations of BM-MSCs attenuated the development of AngII-induced AA in apoE-/- mice and may become a promising alternative therapeutic strategy for AA progression.

Topics: Angiotensin II; Animals; Aorta; Aortic Aneurysm; Apolipoproteins E; Bone Marrow Cells; Cytokines; Disease Progression; Elastin; Femur; Inflammation; Injections, Intravenous; Macrophages; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Mice, Knockout

An association of intraluminal thrombus (ILT) with abdominal aortic aneurysm (AAA) growth has been suggested. Previous in vitro experiments have demonstrated that aneurysm-associated thrombus may secrete proteolytic enzymes and may develop local hypoxia that might lead to the formation of tissue-damaging reactive oxygen species. In this study, we assessed the hypothesis that ventral ILT thickness is associated with markers of proteolysis and with lipid oxidation in the underlying AAA vessel wall.. Ventral AAA tissue was collected from asymptomatic patients at the site of maximal diameter during open aneurysm repair. Segments were divided, one part for biochemical measurements and one for histologic analyses. We measured total cathepsin B, cathepsin S levels, and matrix metalloproteinase (MMP)-2 and MMP-9 activity. Myeloperoxidase and thiobarbituric acid reactive substances were determined as measures of lipid oxidation. Histologic segments were analyzed semiquantitatively for the presence of collagen, elastin, vascular smooth muscle cells (VSMCs), and inflammatory cells. Preoperative computed tomography angiography scans of 83 consecutive patients were analyzed. A three-dimensional reconstruction was obtained, and a center lumen line of the aorta was constructed. Ventral ILT thickness was measured in the anteroposterior direction at the level of maximal aneurysm diameter on the orthogonal slices.. Ventral ILT thickness was positively correlated with aortic diameter (r=0.25; P=.02) and with MMP-2 levels (r=0.27; P=.02). No biochemical correlations were observed with MMP-9 activity or cathepsin B and S expression. No correlation between ventral ILT thickness and myeloperoxidase or thiobarbituric acid reactive substances was observed. Ventral ILT thickness was negatively correlated with VSMCs (no staining, 18.5 [interquartile range, 12.0-25.5] mm; minor, 17.6 [10.7-22.1] mm; moderate, 14.5 [4.6-21.7] mm; and heavy, 8.0 [0.0-12.3] mm, respectively; P=.01) and the amount of elastin (no staining, 18.6 [12.2-30.0] mm; minor, 16.5 [9.0-22.1] mm; moderate, 11.7 [2.5-15.3] mm; and heavy 7.7 [0.0-7.7] mm, respectively; P=.01) in the medial aortic layer.. ILT thickness appeared to be associated with VSMCs apoptosis and elastin degradation and was positively associated with MMP-2 concentrations in the underlying wall. This suggests that ILT thickness affects AAA wall stability and might contribute to AAA growth and rupture. ILT thickness was not correlated with markers of lipid oxidation.

Topics: Aged; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Aortic Rupture; Aortography; Apoptosis; Biopsy; Cathepsin B; Cathepsins; Collagen; Elastin; Female; Humans; Inflammation; Linear Models; Lipid Peroxidation; Logistic Models; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Multivariate Analysis; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Observer Variation; Peroxidase; Predictive Value of Tests; Reproducibility of Results; Thiobarbituric Acid Reactive Substances; Thrombosis; Tomography, X-Ray Computed

Necrotic death of macrophages has long been known to be present in atherosclerotic lesions but has not been studied. We examined the role of receptor interacting protein (RIP) 3, a mediator of necrotic cell death, in atherosclerosis and found that RIP3(-/-);Ldlr(-/-) mice were no different from RIP3(+/+);Ldlr(-/-) mice in early atherosclerosis but had significant reduction in advanced atherosclerotic lesions. Similar results were observed in Apoe(-/-) background mice. Bone marrow transplantation revealed that loss of RIP3 expression from bone-marrow-derived cells is responsible for the reduced disease progression. While no difference was found in apoptosis between RIP3(-/-);Ldlr(-/-) and RIP3(+/+);Ldlr(-/-) mice, electron microscopy revealed a significant reduction of macrophage primary necrosis in the advanced lesions of RIP3(-/-) mice. In vitro cellular studies showed that RIP3 deletion had no effect on oxidized low-density lipoprotein (LDL)-induced macrophage apoptosis, but prevented macrophage primary necrosis occurring in response to oxidized LDL under caspase inhibition or RIP3 overexpression conditions. RIP3-dependent necrosis is not postapoptotic, and the increased primary necrosis in advanced atherosclerotic lesions most likely resulted from the increase of RIP3 expression. Our data demonstrate that primary necrosis of macrophages is proatherogenic during advanced atherosclerosis development.

Topics: Animals; Apolipoproteins E; Apoptosis; Atherosclerosis; Biomarkers; Body Weight; Bone Marrow Cells; Bone Marrow Transplantation; Caspase 8; Caspase Inhibitors; Cell Shape; Cholesterol; Collagen; Cytokines; Elastin; Female; Inflammation; Lipoproteins, LDL; Macrophages; Mice; Microdissection; Necrosis; Receptor-Interacting Protein Serine-Threonine Kinases; Receptors, LDL; RNA, Messenger; Up-Regulation

The formation of fibrotic tissue in the ligamentum flavum (LF) is usually preceded by breakdown of elastic fibers. Elastin-derived peptides (EDPs) from breakdown of elastic fibers display a wide range of biological activities in a variety of cells, but there is minimal information regarding the involvement in the processes of LF hypertrophy. The aim of this study is to elucidate the effects of EDPs on cultured human LF cells and to investigate their molecular and biochemical mechanisms. Human LF cells were obtained from 18 patients who underwent lumbar spine surgery. After treatment with different concentrations of EDPs with or without specific inhibitors in culture medium, the viability and proliferation of LF cells, genes expression, and the signaling pathways were evaluated and analyzed. It was found that 50 μg/ml EDPs significantly increased cell proliferation and synthesis of prostaglandin E(2). The gene expression and protein production of proinflammatory cytokines, including interleukin-1α (IL-1α), IL-1β, and IL-6, were also upregulated. The levels of p-ERK (extracellular signal-regulated kinase) and NF-κB increased immediately following EDP treatment and sustained up to 90 min. It was also found that NF-κB inhibitor, but not ERK1/2 inhibitor, attenuated EDP-dependent induction of IL-1α, IL-1β, and IL-6 expression, indicating that NF-κB pathways are required for EDP-induced IL-1α, IL-1β, and IL-6 gene expression in human LF cells. The results of this in vitro experiment suggest that EDPs do induce inflammatory responses in human LF cells and plays the key role in the development of LF hypertrophy.

Topics: Adult; Aged; Cell Survival; Cytokines; Dinoprostone; Elastin; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Regulation; Humans; Hypertrophy; Inflammation; Inflammation Mediators; Ligamentum Flavum; Male; Middle Aged; Models, Biological; NF-kappa B; Nitric Oxide; Peptides; Signal Transduction

Abdominal aortic aneurysm (AAA) is characterized by extensive aortic wall matrix degradation that contributes to the remodelling and eventual rupture of the arterial wall. Elastinolytic cathepsin S (Cat S) is highly expressed in human aneurysmal lesions, but whether it contributes to the pathogenesis of AAA remains unknown.. AAAs were induced in apolipoprotein E (ApoE) and Cat S compound mutant (Apoe(-/-)Ctss(-/-)) mice and in ApoE-deficient Cat S wild-type littermates (Apoe(-/-)Ctss(+/+)) by chronic angiotensin II infusion, and AAA lesions were analysed after 28 days. We found that Cat S expression increased significantly in mouse AAA lesions. The AAA incidence in Apoe(-/-)Ctss(-/-) mice was much lower than that in Apoe(-/-)Ctss(+/+) mice (10 vs. 80%). Cat S deficiency significantly reduced external and luminal abdominal aortic diameters, medial elastin fragmentation, and adventitia collagen content. Cat S deficiency reduced aortic lesion expression and the activity of matrix metalloproteinase (MMP)-2, MMP-9, and Cat K, but not the activity of other major cathepsins, such as Cat B and Cat L. Absence of Cat S significantly reduced AAA lesion media smooth muscle cell (SMC) apoptosis, lesion adventitia microvessel content, and inflammatory cell accumulation and proliferation. In vitro studies proved that Cat S helps promote SMC apoptosis, angiogenesis, monocyte and T-cell transmigration, and T-cell proliferation--all of which are essential to AAA pathogenesis.. These data provide direct evidence that Cat S plays an important role in AAA formation and suggest that Cat S is a new therapeutic target for human AAA.

Topics: Angiotensin II; Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Apolipoproteins E; Apoptosis; Cathepsin K; Cathepsins; CD3 Complex; Cells, Cultured; Collagen; Disease Models, Animal; Elastin; Inflammation; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Neovascularization, Pathologic; T-Lymphocytes; Time Factors

Apoptosis of smooth muscle cells (SMCs) is a prominent pathological characteristic of abdominal aortic aneurysm (AAA). We have previously shown that SMC apoptosis stimulates proinflammatory signaling in a mouse model of AAA. Here, we test whether protein kinase C-δ (PKCδ), an apoptotic mediator, participates in the pathogenesis of AAA by regulating apoptosis and proinflammatory signals.. Mouse experimental AAA is induced by perivascular administration of CaCl(2). Mice deficient in PKCδ exhibit a profound reduction in aneurysmal expansion, SMC apoptosis, and transmural inflammation as compared with wild-type littermates. Delivery of PKCδ to the aortic wall of PKCδ(-/-) mice restores aneurysm, whereas overexpression of a dominant negative PKCδ mutant in the aorta of wild-type mice attenuates aneurysm. In vitro, PKCδ(-/-) aortic SMCs exhibit significantly impaired monocyte chemoattractant protein-1 production. Ectopic administration of recombinant monocyte chemoattractant protein-1 to the arterial wall of PKCδ(-/-) mice restores inflammatory response and aneurysm development.. PKCδ is an important signaling mediator for SMC apoptosis and inflammation in a mouse model of AAA. By stimulating monocyte chemoattractant protein-1 expression in aortic SMCs, upregulated PKCδ exacerbates the inflammatory process, in turn perpetuating elastin degradation and aneurysmal dilatation. Inhibition of PKCδ may serve as a potential therapeutic strategy for AAA.

Topics: Animals; Aortic Aneurysm, Abdominal; Apoptosis; Calcium Chloride; Cell Movement; Cells, Cultured; Chemokine CCL2; Elastin; In Vitro Techniques; Inflammation; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Models, Animal; Muscle, Smooth, Vascular; Protein Kinase C-delta; Signal Transduction; Up-Regulation

Prior studies on two-dimensional cell cultures suggest that hyaluronic acid (HA) stimulates cell-mediated regeneration of extracellular matrix structures, specifically those containing elastin, though such biologic effects are dependent on HA fragment size. Towards being able to regenerate three-dimensional (3-D) elastic tissue constructs, the present paper studies photo-crosslinked hydrogels containing glycidyl methacrylate (GM)-derivatized bio-inert high molecular weight (HMW) HA (1 × 10(6)Da) and a bioactive HA oligomer mixture (HA-o: MW ∼0.75 kDa). The mechanical (rheology, degradation) and physical (apparent crosslinking density, swelling ratio) properties of the gels varied as a function of incorporated HA oligomer content; however, overall, the mechanics of these hydrogels were too weak for vascular applications as stand-alone materials. Upon in vivo subcutaneous implantation, only a few inflammatory cells were evident around GM-HA gels, however their number increased as HA-o content within the gels increased, and the collagen I distribution was uniform. Smooth muscle cells (SMC) were encapsulated into GM hydrogels, and calcein acetoxymethyl detection revealed that the cells were able to endure twofold the level of UV exposure used to crosslink the gels. After 21 days of culture, SMC elastin production, measured by immunofluorescence quantification, showed HA-o to increase cellular deposition of elastic matrix twofold relative to HA-o-free GM-HA gels. These results demonstrate that cell response to HA/HA-o is not altered by their methacrylation and photo-crosslinking into a hydrogel, and that HA-o incorporation into cell-encapsulating hydrogel scaffolds can be useful for enhancing their production of elastic matrix structures in a 3-D space, important for regenerating elastic tissues.

Topics: Animals; Biocompatible Materials; Cell Survival; Cells, Cultured; Cross-Linking Reagents; Elasticity; Elastin; Epoxy Compounds; Fluorescent Antibody Technique; Hyaluronic Acid; Hydrogel, Polyethylene Glycol Dimethacrylate; Inflammation; Methacrylates; Microscopy, Electron, Scanning; Myocytes, Smooth Muscle; Particle Size; Rats; Rats, Sprague-Dawley; Spectroscopy, Fourier Transform Infrared; Time Factors; Tissue Scaffolds; Viscosity

The latent TGF-β binding proteins (LTBP-1 -3, and -4) assist in the secretion and localization of latent TGF-β molecules. Ltbp3(-/-) and Ltbp4S(-/-) mice have distinct phenotypes and only in the lungs does deficiency of either Ltbp-3 or Ltbp-4 cause developmental abnormalities. To determine if these two LTBPs have additional common functions, we generated mice deficient for both Ltbp-3 and Ltbp-4S. The only novel defect in Ltbp3(-/-);Ltbp4S(-/-) mice was an early lethality compared to mice with single mutations. In addition lung abnormalities were exacerbated and the terminal air sac septation defect was more severe in Ltbp3(-/-);Ltbp4S(-/-) mice than in Ltbp4S(-/-) mice. Decreased cellularity of Ltbp3(-/-);Ltbp4S(-/-) lungs was correlated with higher rate of apoptosis in newborn lungs of Ltbp3(-/-);Ltbp4S(-/-) animals compared to WT, Ltbp3(-/-), and Ltbp4S(-/-) mice. No differences in the maturation of the major lung cell types were discerned between the single and double mutant mice. However, the distribution of type 2 cells and myofibroblasts was abnormal, and myofibroblast segregation in some areas might be an indication of early fibrosis. We also observed differences in ECM composition between Ltbp3(-/-);Ltbp4S(-/-) and Ltbp4S(-/-) lungs after birth, reflected in decreased incorporation of fibrillin-1 and -2 in Ltbp3(-/-);Ltbp4S(-/-) matrix. The function of the lungs of Ltbp3(-/-);Ltbp4S(-/-) mice after the first week of life was potentially further compromised by macrophage infiltration, as proteases secreted from macrophages might exacerbate developmental emphysema. Together these data indicate that LTBP-3 and -4 perform partially overlapping functions only in the lungs.

Topics: Animals; Apoptosis; Cell Differentiation; Elastin; Fibroblasts; Gene Expression Regulation, Developmental; Inflammation; Latent TGF-beta Binding Proteins; Lung; Mice; Microfibrils; Phenotype

To examine whether a lack of prostaglandin E receptor 4 (EP4) on bone marrow-derived cells would increase local inflammation and enhance the formation of abdominal aortic aneurysm (AAA) in vivo.. Prostaglandin E(2) (PGE(2)) through activation of EP4, can mute inflammation. Hypercholesterolemic low-density lipoprotein receptor knockout (LDLR(-/-)) mice transplanted with either EP4(+/+) (EP4(+/+)/LDLR(-/-)) or EP4(-/-) (EP4(-/-)/LDLR(-/-)) bone marrow received infusions of angiotensin II to induce AAA. Deficiency of EP4 on bone marrow-derived cells increased the incidence (50% of male EP4(+/+)/LDLR(-/-) mice versus 88.9% of male EP4(-/-)/LDLR(-/-) mice developed AAA; and 22% of female EP4(+/+)/LDLR(-/-) mice versus 83.3% of female EP4(-/-)/LDLR(-/-) mice developed AAA) and severity of AAA, increased monocyte chemoattractant protein-1 (2.72-fold in males and 1.64-fold in females), and enhanced infiltration of macrophages (3.8-fold in males and 2.44-fold in females) and T cells (1.88-fold in males and 1.66-fold in females) into AAA lesions. Lack of EP4 on bone marrow-derived cells augmented elastin fragmentation, increased apoptotic markers, and decreased smooth muscle cell accumulation within AAA lesions.. Deficiency of EP4 on bone marrow-derived cells boosted inflammation and AAA formation induced by angiotensin II in hyperlipidemic mice. This study affirms the pathophysiologic importance of PGE(2) signaling through EP4 as an endogenous anti-inflammatory pathway involved in experimental aneurysm formation.

Topics: Angiotensin II; Animals; Aortic Aneurysm, Abdominal; Bone Marrow Cells; Bone Marrow Transplantation; Chemokine CCL2; Elastin; Female; Gene Deletion; Hyperlipidemias; Inflammation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Models, Animal; Receptors, LDL; Receptors, Prostaglandin E, EP4 Subtype; Risk Factors

Post-herniation abdominal wall repair can be performed with synthetic or biologic meshes. Synthetics have been associated with complications, so biologics are promising alternatives. The methods used to decellularize biological matrices may affect the extracellular components. This study evaluated the post-implantation biological response of two allogenic acellular dermal matrices (ADMs) in a hernia model.. Testing was conducted with two ADMs from different manufacturers: RTI Biologics (ADM-R) and LifeCell (ADM-L). Samples were evaluated for collagen IV, glycosaminoglycans (GAGs), and elastin before implantation. Samples were also used to repair bilateral full-thickness defects in rat abdominal walls. Pathologist evaluations included explant dimensions, inflammation, neovascularization, mature implant tissue, fibrosis, encapsulation, necrosis, mineralization, adhesions, granulomas, and hemorrhages at four and eight weeks post-implantation.. GAG distribution in ADM-R samples was more consistent with native dermis than that in ADM-L samples. Collagen IV was visible in ADM-R, but not in ADM-L. The four-week ADM-R explants showed primarily lymphocytic infiltrates, and less inflammation at eight weeks. The four-week ADM-L explants showed primarily lymphocytic infiltrates, and sustained inflammation at eight weeks. Fibroplasia at four and eight weeks was higher in ADM-L than in ADM-R. Encapsulation, mature connective tissue, and vascular profile scores were comparable between groups. Picrosirius red image analysis showed no significant differences between groups.. The post-processing matrix characterization and in-vivo response showed notable differences in these ADMs, despite similar allogenic origin. Future investigations into the different matrix composition with regard to fibrosis and inflammation are warranted.

Topics: Abdominal Wall; Animals; Biocompatible Materials; Elastin; Fibrillar Collagens; Glycosaminoglycans; Inflammation; Materials Testing; Models, Animal; Neovascularization, Physiologic; Rats; Rats, Sprague-Dawley; Tissue Scaffolds

Insulin resistance is associated with inflammation, fibrosis, and hypoxia in adipose tissue.. This study was intended to better characterize the extracellular matrix (ECM) and vascularity of insulin-resistant adipose tissue.. Adipose expression of collagens, elastin, and angiogenic factors was assessed using real-time RT-PCR and immunohistochemistry (IHC) in abdominal sc adipose tissue. Adipocyte-macrophage coculture experiments examined the effects of polarized macrophages on adipose ECM gene expression, and the effects of collagens were measured in an angiogenesis assay.. A total of 74 nondiabetic subjects participated at a University Clinical Research Center.. Interventions included baseline adipose biopsy and measurement of insulin sensitivity.. Outcome measures included characterization of vascularity and ECM in adipose tissue.. CD31 (an endothelial marker) mRNA showed no significant correlation with body mass index or insulin sensitivity. In a subgroup of 17 subjects (nine obese, eight lean), CD31-positive capillary number in obese was decreased by 58%, whereas larger vessels were increased by 70%, accounting for the lack of change in CD31 expression with obesity. Using IHC, obese (compared with lean) subjects had decreased elastin and increased collagen V expression, and adipocytes cocultured with M2 macrophages had reduced elastin and increased collagen V expression. In obese subjects, collagen V was colocalized with large blood vessels, and the addition of collagen V to an angiogenesis assay inhibited endothelial budding.. The adipose tissue from obese/insulin-resistant subjects has fewer capillaries and more large vessels as compared with lean subjects. The ECM of adipose tissue may play an important role in regulating the expandability as well as angiogenesis of adipose tissue.

Topics: Adipose Tissue; Adult; Body Composition; Body Mass Index; Capillaries; Collagen; Elastin; Extracellular Matrix; Female; Glucose Tolerance Test; Humans; Inflammation; Insulin Resistance; Male; Obesity; Platelet Endothelial Cell Adhesion Molecule-1

Abdominal aortic aneurysms (AAAs) expand as a consequence of extracellular matrix destruction, and vascular smooth muscle cell (VSMC) depletion. Transforming growth factor (TGF)-beta 1 overexpression stabilizes expanding AAAs in rat. Cyclosporine A (CsA) promotes tissue accumulation and induces TGF -beta1 and, could thereby exert beneficial effects on AAA remodelling and expansion. In this study, we assessed whether a short administration of CsA could durably stabilize AAAs through TGF-beta induction. We showed that CsA induced TGF-beta1 and decreased MMP-9 expression dose-dependently in fragments of human AAAs in vitro, and in animal models of AAA in vivo. CsA prevented AAA formation at 14 days in the rat elastase (diameter increase: CsA: 131.9±44.2%; vehicle: 225.9±57.0%, P = 0.003) and calcium chloride mouse models (diameters: CsA: 0.72±0.14 mm; vehicle: 1.10±0.11 mm, P = .008), preserved elastic fiber network and VSMC content, and decreased inflammation. A seven day administration of CsA stabilized formed AAAs in rats seven weeks after drug withdrawal (diameter increase: CsA: 14.2±15.1%; vehicle: 45.2±13.7%, P = .017), down-regulated wall inflammation, and increased αSMA-positive cell content. Co-administration of a blocking anti-TGF-beta antibody abrogated CsA impact on inflammation, αSMA-positive cell accumulation and diameter control in expanding AAAs. Our study demonstrates that pharmacological induction of TGF-beta1 by a short course of CsA administration represents a new approach to induce aneurysm stabilization by shifting the degradation/repair balance towards healing.

Topics: Animals; Aortic Aneurysm, Abdominal; Calcium Chloride; Cyclosporine; Disease Models, Animal; Elastin; Humans; Inflammation; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Pancreatic Elastase; Rats; Rats, Wistar; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta

In infected lungs of the cystic fibrosis (CF) patients, opportunistic pathogens and mutated cystic fibrosis transmembrane conductance regulator protein (CFTR) contribute to chronic airway inflammation that is characterized by neutrophil/macrophage infiltration, cytokine release and ceramide accumulation. We sought to investigate CF lung inflammation in the alveoli.. Lung tissue from 14 CF patients and four healthy individuals was analyzed for numbers of effector cells, elastin and collagen concentrations, inflammatory markers and density of Pseudomonas aeruginosa. Additionally, desmosine and isodesmosine concentrations were determined in 52 urine specimens from CF patients to estimate the burden of elastase activities in respiratory secretions.. Elastin concentration was significantly decreased and collagen significantly increased in CF alveolar tissues as compared to age-matched, healthy individuals. Elastin split products were significantly increased in urine samples from patients with CF and correlated inversely with age, indicating local tissue remodelling due to elastin degradation by unopposed proteolytic enzymes. Alveolar inflammation was also characterized by a significant cell infiltration of neutrophils, macrophages and T cells, extensive nuclear factor-kappaB and insulin-like growth factor-1 activation in various cell types and increased intercellular adhesion molecule-1 expression, and increased numbers of myofibroblasts. Additionally, ceramide accumulated in type II alveolar epithelial cells, lacking CFTR. P. aeruginosa organisms were rarely present in inflamed alveoli.. Chronic inflammation and remodeling is present in alveolar tissues of the CF lung and needs to be addressed by anti-inflammatory therapies.

Topics: Adolescent; Adult; Case-Control Studies; Ceramides; Collagen; Cystic Fibrosis; Desmosine; Elastin; Female; Humans; Inflammation; Isodesmosine; Male; Pseudomonas aeruginosa; Pulmonary Alveoli; Young Adult

Peroxisome proliferator-activated receptor-γ (PPARγ) plays an important role in the vasculature; however, the role of PPARγ in abdominal aortic aneurysms (AAA) is not well understood. We hypothesized that PPARγ in smooth muscle cells (SMCs) attenuates the development of AAA. We also investigated PPARγ-mediated signaling pathways that may prevent the development of AAA.. We determined whether periaortic application of CaCl(2) renders vascular SMC-selective PPARγ knockout (SMPG KO) mice more susceptible to destruction of normal aortic wall architecture.. There is evidence of increased vessel dilatation in the abdominal aorta 6 weeks after 0.25M periaortic CaCl(2) application in SMPG KO mice compared with littermate controls (1.4 ± 0.3 mm [n = 8] vs 1.1 ± 0.2 mm [n = 7]; P = .000119). Results from SMPG KO mice indicate medial layer elastin degradation was greater 6 weeks after abluminal application of CaCl(2) to the abdominal aorta (P < .01). Activated cathepsin S, a potent elastin-degrading enzyme, was increased in SMPG KO mice vs wild-type controls. To further identify a role of PPARγ signaling in reducing the development of AAA, we demonstrated that adenoviral-mediated PPARγ overexpression in cultured rat aortic SMCs decreases (P = .022) the messenger RNA levels of cathepsin S. In addition, a chromatin immunoprecipitation assay detected PPARγ bound to a peroxisome proliferator-activated receptor response element (PPRE) -141 to -159 bp upstream of the cathepsin S gene sequence in mouse aortic SMCs. Also, adenoviral-mediated PPARγ overexpression and knockdown in cultured rat aortic SMCs decreases (P = .013) and increases (P = .018) expression of activated cathepsin S. Finally, immunohistochemistry demonstrated a greater inflammatory infiltrate in SMPG KO mouse aortas, as evidenced by elevations in F4/80 and tumor necrosis factor-α expression.. In this study, we identify PPARγ as an important contributor in attenuating the development of aortic aneurysms by demonstrating that loss of PPARγ in vascular SMCs promotes aortic dilatation and elastin degradation. Thus, PPARγ activation may be potentially promising medical therapy in reducing the risk of AAA progression and rupture.

Topics: Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Binding Sites; Calcium Chloride; Cathepsins; Cells, Cultured; Dilatation, Pathologic; Disease Models, Animal; Elastin; Enzyme Activation; Inflammation; Mice; Mice, Knockout; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; PPAR gamma; Promoter Regions, Genetic; Rats; RNA Interference; RNA, Messenger; Signal Transduction; Time Factors; Transfection

In the present study, histological aspects were considered in order to evaluate the in vivo photoprotective effect of a w/o microemulsion containing quercetin against UVB irradiation-induced dermal damages. The toxicity in cell culture and the potential skin irritation resulting from topical application of this formulation were also investigated.. Mouse dorsal surfaces were treated topically with 300 mg of the unloaded and quercetin-loaded (0.3%, w/w) microemulsions before and after exposure to UVB (2.87 J/cm2) irradiation. The untreated control groups irradiated and non-irradiated were also evaluated. UVB-induced histopathological changes as well as the photoprotective effect of this formulation were evaluated considering the parameters of infiltration of inflammatory cells, epidermis thickening (basale and spinosum layers) and collagen and elastic fiber contents. The cytotoxicity of the reported formulation was evaluated in L929 mice fibroblasts by MTT assay and the skin irritation was investigated after topical application of both unloaded and quercetin-loaded microemulsions once a day for 15 days.. The results demonstrated that the w/o microemulsion containing quercetin reduced the incidence of histological skin alterations, mainly the connective-tissue damage, induced by exposure to UVB irradiation, this allows the suggestion that protective effects of this formulation against UV-induced responses are not secondary to the interference of UV transmission (i.e., blocking the UVB radiation from being absorbed by the skin), as is usually done with UVB absorbers and sunscreens, but is instead due to different biological effects of this flavonoid. Furthermore, by evaluating the cytotoxic effect on L929 cells and histological aspects such as infiltration of inflammatory cells and epidermis thickness of hairless mice, the present study also demonstrated no toxicity of the proposed system.. Therefore, based on these mouse models, a detailed characterization of the w/o microemulsion incorporating quercetin effects as a photochemoprotective agent on human skin is thus indicated.

Topics: Animals; Antioxidants; Cells, Cultured; Collagen; Elastin; Emulsions; Female; Fibroblasts; Inflammation; Male; Mice; Mice, Hairless; Quercetin; Skin; Ultraviolet Rays

To evaluate the biocompatibility and biodegradability of various hydrogels and choose suitable hydrogels for the coronary arteries angiogenesis in ischemic myocardium, we synthesized six kinds of hyaluronan hydrogels, fibrin hydrogel, poly(vinyl alcohol)-chitosan hydrogel, and obtained elastin hydrogels. We examined their degradation rates and cytotoxicity in vitro. Then, hydrogels were implanted into rat adductor muscles for 1, 2, or 4 weeks. Hydrogels and surrounding tissues were resected, followed by hematoxylin and eosin staining, Masson's trichrome staining, and immunohistochemical staining for measurements of degradation, immune response, and angiogenesis. 2-Iminothiolane grafted hyaluronan hydrogel and periodate oxidated hyaluronan hydrogel presented rapid degradation rates, low quantity of inflammation-mediating cells (12 +/- 3 and 12 +/- 4 per 2.5 x 10(-3) mm(2), respectively, at week 2), thin fibrous capsules (scores were 3.8 +/- 0.1 and 4.0 +/- 0.3 per 0.33 mm(2), respectively, at week 2) with dense blood vessels in the areas surrounding the implanted hydrogels. 2-Iminothiolane grafted hyaluronan and periodate oxidated hyaluronan hydrogels with appropriate degradation rates and low immune responses were suitable for coronary arteries angiogenesis in ischemic myocardium.

Topics: Animals; Biocompatible Materials; Cells, Cultured; Chitosan; Coronary Vessels; Drug Carriers; Elastin; Fibrin; Gene Transfer Techniques; Hyaluronic Acid; Hydrogels; Inflammation; Male; Materials Testing; Muscle, Skeletal; Muscle, Smooth, Vascular; Myocardial Ischemia; Neovascularization, Physiologic; Pilot Projects; Polymers; Polyvinyls; Rats; Rats, Sprague-Dawley

Abdominal aortic aneurysm (AAA) wall is characterized by degradation of extracellular matrix through matrix metalloproteinases (MMPs), chronic inflammatory cell infiltration and extensive neovascularization. So far, MMP expression within AAA wall in association with infiltrates and neovascularization has not yet been studied.. Vessel walls of 15 AAA patients and 8 organ donors were analyzed by immunohistochemistry for expression of various MMPs (MMP-1, -2, -3, -7, -8, -9, -12 and -13) in all cells located within the AAAs and correlated with infiltrates and neovascularization.. Luminal endothelial cells (ECs) were positive for MMP-1, -3 and -9, ECs of mature neovessels were furthermore positive for MMP-2. Immature neovessels expressed all MMPs tested except for MMP-13. Aortic medial smooth muscle cells (SMCs) expressed MMP-1, -2, -3 and -9, SMCs of mature neovessels, only MMP-1, -3 and -9. Inflammatory infiltrates expressed all MMPs tested except for MMP-2, macrophages expressed all MMPs. Infiltrates were composed mainly of B cells (58.5 +/- 10.9%) and T lymphocytes (26.3 +/- 9.5%). Furthermore, significant inverse correlations were found between the amounts of inflammatory cells, neovessels and collagen/elastin content of the aortic vessel wall (r = +0.806/p < 0.001, r = -0.650/p = 0.012, r = -0.63/p < 0.015; respectively).. Inflammatory infiltrates and invading neovessels are relevant sources of MMPs in the AAA wall and may substantially contribute to aneurysm wall instability.

Topics: Aged; Aged, 80 and over; Aortic Aneurysm, Abdominal; Collagen; Elastin; Endothelial Cells; Female; Humans; Immunohistochemistry; Inflammation; Male; Matrix Metalloproteinases; Middle Aged; Myocytes, Smooth Muscle; Neovascularization, Pathologic

The protease-antiprotease imbalance in the lung plays an important role in the pathogenesis of smoke-induced emphysema. The aim of this study was to characterize the proteolytic responses leading to emphysema formation in the guinea pig smoke exposure model. Guinea pigs were exposed to cigarette smoke for 1, 2, 4, 8, and 12 weeks. Age-matched guinea pigs exposed to room air served as controls. Cigarette smoke induced inflammation after 4 weeks and generated emphysematous changes in the guinea pigs after 12 weeks of smoke exposure. Increased phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) mitogen-activated protein (MAP) kinases was demonstrated post cigarette smoke exposure. A decrease in elastin and collagen and the loss of type III collagen were observed in the alveolar wall of smoke-exposed guinea pigs. Interestingly, no change was seen in the expression of collagenolytic matrix metalloproteinases. Furthermore, the authors observed a 3-fold increase in cathepsin K activity in the lungs of smoke-exposed guinea pigs. The significance of this finding was supported by human studies that demonstrate increased expression of cathepsin K in the lungs of patients with emphysema. Elevation of cathepsin K in guinea pig lungs after smoke exposure likely constitutes a critical event leading to the disruption of lung extracellular matrix in this model.

Topics: Animals; Cathepsin K; Collagen; Elastin; Gene Expression Regulation; Guinea Pigs; Inflammation; Mitogen-Activated Protein Kinases; Phosphorylation; Pulmonary Alveoli; Pulmonary Emphysema; Smoke; Time Factors

Topics: Anti-Inflammatory Agents; Creatinine; Elastin; Humans; Inflammation; Interleukin-13; Male; Middle Aged; Pulmonary Emphysema; Tomography, X-Ray Computed; Treatment Outcome; Tretinoin

We hypothesized that the increase in mitochondrial proliferation in hearts from copper-deficient rats is due to an increase in expression of the transcriptional factor peroxisomal-like proliferating related coactivator 1alpha (Ppargc1a), which regulates transcriptional activity for many of the genes that encode for mitochondrial proteins. In addition to several transcriptional factors implicated in mitochondrial biogenesis, we also looked at a number of genes involved in cell cycle regulation and fuel substrate utilization. Long-Evans rats were placed on either a copper-adequate (n=4) or copper-deficient (n=4) diet 3 days post weaning and remained on the diet for 5 weeks; their copper deficiency status was confirmed using previously established assays. Custom oligo arrays spotted with genes pertinent to mitochondrial biogenesis were hybridized with cRNA probes synthesized from the collected heart tissue. Chemiluminescent array images from both groups were analyzed for gene spot intensities and differential gene expression. Our results did not demonstrate any significant increase in Ppargc1a or its implicated targets, as we had predicted. However, consistent with previous data, an up-regulation of genes that encode for collagen type 3, fibronectin and elastin were found. Interestingly, there was also a significant increase in the expression of the transcriptional factor nuclear factor kappaB1 (Nfkappab1) in the copper-deficient treatment animals, compared to the control group, and this was confirmed by real time quantitative polymerase chain reaction. The results of this study merit the further investigation of the role of reactive oxidative species with regard to Nfkappab1 in the copper deficient rat heart.

Topics: Animals; Apoptosis; Collagen Type III; Connective Tissue; Copper; Elastin; Fibronectins; Gene Expression Regulation; Genes, cdc; Inflammation; Male; Mitochondria, Heart; Myocardium; NF-kappa B p50 Subunit; Oligonucleotide Array Sequence Analysis; Rats; Rats, Long-Evans; Transcription Factors; Up-Regulation

We identified a specific interaction between two secreted proteins, thrombospondin-1 and versican, that is induced during a toll-like receptor-3-dependent inflammatory response in vascular smooth muscle cells. Thrombospondin-1 binding to versican is modulated by divalent cations. This interaction is mediated by interaction of the G1 domain of versican with the N-module of thrombospondin-1 but only weakly with the corresponding N-terminal region of thrombospondin-2. The G1 domain of versican contains two Link modules, which are known to mediate TNFalpha-stimulated gene-6 protein binding to thrombospondin-1, and the related G1 domain of aggrecan is also recognized by thrombospondin-1. Therefore, thrombospondin-1 interacts with three members of the Link-containing hyaladherin family. On the surface of poly-I:C-stimulated vascular smooth muscle cells, versican organizes into fibrillar structures that contain elastin but are largely distinct from those formed by hyaluronan. Endogenous and exogenously added thrombospondin-1 incorporates into these structures. Binding of exogenous thrombospondin-1 to these structures, to purified versican and to its G1 domain is potently inhibited by heparin. At higher concentrations, exogenous thrombospondin-1 delays the poly-I:C induced formation of structures containing versican and elastin, suggesting that thrombospondin-1 negatively modulates this component of a vascular smooth muscle inflammatory response.

Topics: Aggrecans; Animals; Aorta; Blood Platelets; Elastin; Fluorescent Antibody Technique; Humans; Immunoassay; In Vitro Techniques; Inflammation; Mice; Microfibrils; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Poly I-C; Protein Binding; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thrombospondin 1; Thrombospondins; Toll-Like Receptor 3; Versicans

The production of the inflammatory cytokine interleukin (IL)-1 is increased in lungs of patients with chronic obstructive pulmonary disease (COPD) or asthma. To characterize the in vivo actions of IL-1 in the lung, transgenic mice were generated in which human IL-1beta was expressed in the lung epithelium with a doxycycline-inducible system controlled by the rat Clara cell secretory protein (CCSP) promoter. Induction of IL-1beta expression in the lungs of adult mice caused pulmonary inflammation characterized by neutrophil and macrophage infiltrates. IL-1beta caused distal airspace enlargement, consistent with emphysema. IL-1beta caused disruption of elastin fibers in alveolar septa and fibrosis in airway walls and in the pleura. IL-1beta increased the thickness of conducting airways, enhanced mucin production, and caused lymphocytic aggregates in the airways. Decreased immunostaining for the winged helix transcription factor FOXA2 was associated with goblet cell hyperplasia in IL-1beta-expressing mice. The production of the neutrophil attractant CXC chemokines KC (CXCL1) and MIP-2 (CXCL2), and of matrix metalloproteases MMP-9 and MMP-12, was increased by IL-1beta. Chronic production of IL-1beta in respiratory epithelial cells of adult mice causes lung inflammation, enlargement of distal airspaces, mucus metaplasia, and airway fibrosis in the adult mouse.

Topics: Animals; Asthma; Base Sequence; Bronchoalveolar Lavage Fluid; Chemokines, CXC; Collagen; Disease Models, Animal; DNA, Complementary; Elastin; Gene Expression; Humans; Inflammation; Interleukin-1; Lymphocytes; Matrix Metalloproteinases; Mice; Mice, Transgenic; Organ Size; Organ Specificity; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema; Respiratory System; RNA, Messenger; Tumor Necrosis Factor-alpha

During carotid endarterectomy (CEA), microemboli may occur, resulting in perioperative adverse cerebral events. The objective of the present study was to investigate the relation between atherosclerotic plaque characteristics and the occurrence of microemboli or adverse events during CEA.. Patients (n=200, 205 procedures) eligible for CEA were monitored by perioperative transcranial Doppler. The following phases were discriminated during CEA: dissection, shunting, release of the clamp, and wound closure. Each carotid plaque was stained for collagen, macrophages, smooth muscle cells, hematoxylin, and elastin. Semiquantitative analyses were performed on all stainings. Plaques were categorized into 3 groups based on overall appearance (fibrous, fibroatheromatous, or atheromatous).. Fibrous plaques were associated with the occurrence of more microemboli during clamp release and wound closure compared with atheromatous plaques (P=0.04 and P=0.02, respectively). Transient ischemic attacks and minor stroke occurred in 5 of 205 (2.4%) and 6 of 205 (2.9%) patients, respectively. Adverse cerebral outcome was significantly related to the number of microembolic events during dissection (P=0.003) but not during shunting, clamp release, or wound closure. More cerebrovascular adverse events occurred in patients with atheromatous plaques (7/69) compared with patients with fibrous or fibroatheromatous plaques (4/138) (P=0.04).. Intraoperatively, a higher number of microemboli were associated with the presence of a fibrous but not an atheromatous plaque. However, atheromatous plaques were more prevalent in patients with subsequent immediate adverse events. In addition, specifically the number of microemboli detected during the dissection phase were related to immediate adverse events.

Topics: Adult; Aged; Atherosclerosis; Carotid Arteries; Carotid Artery Thrombosis; Carotid Stenosis; Collagen; Elastin; Electroencephalography; Embolization, Therapeutic; Endarterectomy, Carotid; Female; Hematoxylin; Humans; Inflammation; Ischemia; Macrophages; Magnetic Resonance Imaging; Male; Microcirculation; Middle Aged; Muscle, Smooth; Phenotype; Prospective Studies; Reverse Transcriptase Polymerase Chain Reaction; Stroke; Tomography, X-Ray Computed; Treatment Outcome; Ultrasonography; Ultrasonography, Doppler, Transcranial; Wound Healing

The tissue response to polyanionic collagen matrices, prepared from bovine pericardium and implanted subperiosteally in rat calvaria, was studied. The materials were implanted in 72 male rats (Rattus norvegicus, albinus, Holtzman), randomly divided into four groups: GI-MBP hydrolyzed for 24 h; GII-MBP hydrolyzed for 36 h; GIII-MBP hydrolyzed for 48 h; GIV-native MBP. The materials were explanted after 15, 30 and 60 days and analyzed by routine histological procedures. Except for group IV (native bovine pericardium), polyanionic collagen from groups GI, GII and GIII showed low inflammatory reaction associated with bone formation, partially or completely integrated to the cranial bone; group GIV was characterized by an intense inflammatory reaction with occasional dystrophic mineralization and with occasional bone formation at 60 days when there was a decrease in the inflammatory reaction. Thus, the MBP from groups I, II and III were biologically compatible, enhancing bone formation with a slight delay at 60 days in GII.

Topics: Animals; Biocompatible Materials; Cattle; Collagen; Elastin; Inflammation; Male; Rats; Rats, Sprague-Dawley; Skull

Matrix metalloproteinase (MMP)-9 secreted by activated polymorphonuclear neutrophils (PMN) may play roles in mediating lung injury by degrading extracellular matrix proteins. However, the mechanisms by which MMP-9 retains activity in the presence of tissue inhibitors of metalloproteinases (TIMPs) are not known. We show that MMP-9 is also expressed on the cell surface of PMN, and proinflammatory mediators induce up to 10-fold increases in cell surface expression of MMP-9. Stimulated human PMN express active forms of cell surface MMP, which cleave the MMP substrate, McaPLGLDpaAR. Loss-of-function studies employing PMN from mice genetically deficient in MMP-9 (MMP-9-/-) demonstrate that membrane-bound MMP-9 contributes substantially to MMP-mediated surface-bound cleavage of McaPLGLDpaAR (approximately 50%) and gelatin (approximately 70%) by stimulated PMN. Like soluble MMP-9, membrane-bound MMP-9 cleaves McaPLGLDpaAR (Kcat/KM = 82,000 M-1s-1), gelatin, type IV collagen, elastin, and alpha1-proteinase inhibitor. However, in contrast to soluble MMP-9, membrane-bound MMP-9 is substantially resistant to inhibition by TIMPs. The IC50 for inhibition of membrane-bound MMP-9 by TIMP-1 and TIMP-2 are approximately 21-fold and approximately 68-fold higher, respectively, than those for inhibition of soluble MMP-9. The binding of MMP-9 to the plasma membrane of PMN enables it to evade inhibition by TIMPs, and thereby may alter the pericellular proteolytic balance in favor of extracellular matrix degradation. Membrane-bound MMP-9 on PMN may play pathogenetic roles in inflammatory lung diseases.

Topics: Animals; Binding Sites; Catalysis; Cell Line; Cell Membrane; Collagen Type IV; Cytokines; Dose-Response Relationship, Drug; Elastin; Gelatin; Humans; Inflammation; Inhibitory Concentration 50; Kinetics; Matrix Metalloproteinase 9; Mice; Mice, Transgenic; Microscopy, Confocal; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Protein Binding; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Tissue Inhibitor of Metalloproteinases

Local overexpression of genes that promote lung defense or repair may be helpful in protecting the immature neonatal lung from injuries, but whether the vectors used to administer these genes affect physiological postnatal lung growth has not been investigated. We explored the effect on alveolarization of E1-deleted Adnull vector (Ad5-LMP-null) given intratracheally to 3-day-old rats. Three Adnull doses were evaluated 10(8), 5 x 10(8), and 10(9) TCID(50). Lung morphometry on day 21 showed significant growth disorders with the two higher doses. With 5 x 10(8) TCID(50), absolute lung volume increased significantly (+16%), as did absolute (+20%) and specific (+32%) alveolar airspace volumes, whereas alveolar surface density decreased by 13% (p < 0.009 for all parameters). Lung inflammation was mild, nonsignificant, and occurred mainly with the highest Adnull dose, indicating that it was unlikely to contribute to our results. Adnull instillation induced a significant#10; decrease in terminal bronchiolar cell proliferation as evaluated by proliferating cell nuclear antigen immunostaining (p = 0.02), as well as a 23% decrease in absolute parenchyma elastic fiber length (p = 0.02). Furthermore, lung tropoelastin mRNA content decreased by 25% (p < 0.02). In conclusion, E1-deleted adenoviral vectors can induce lung growth disorders when instilled into the airways of neonatal rats. Interactions with lung matrix turnover may be the main explanation to these deleterious effects.

Topics: Adenovirus E1A Proteins; Adenoviruses, Human; Animals; Animals, Newborn; beta-Galactosidase; Bronchi; Bronchoalveolar Lavage Fluid; Cell Division; Defective Viruses; Dose-Response Relationship, Drug; Elastic Tissue; Elastin; Epithelial Cells; Gene Expression Regulation, Viral; Genes, Reporter; Genetic Vectors; Inflammation; Instillation, Drug; Lung; Lung Volume Measurements; Rats; Recombinant Fusion Proteins; RNA, Messenger; Trachea; Transfection; Tropoelastin

Inflammation and elastinolysis are observed in the media of abdominal aortic aneurysms (AAAs) where vascular smooth muscle cell (VSMC) density is decreased. In contrast, elastin and VSMCs are preserved in the noninflammatory media of stenotic atherosclerotic lesions. We have tested the hypothesis that VSMCs exert a protective effect against inflammation and proteolysis in a model of AAA in rats, in which medial elastin degradation is driven by inflammation and matrix metalloproteinases.. Decellularized guinea pig aortas (xenografts) were implanted orthotopically into Fischer-344 rats and seeded with a suspension of rat VSMCs syngeneic to the rat recipient, or were infused with culture medium as a control. Diameter and elastin in the media were quantified 8 weeks after implantation. Inflammation, matrix metalloproteinase (MMP) and tissue inhibitor of matrix metalloproteinase (TIMP) expression were analyzed 1 and 2 weeks after implantation.. VSMC addition prevented AAA formation (mean +/- standard deviation diameter increase: 198.2% +/- 106.6% vs 35.3% +/- 17.8%, P =.009), elastin degradation, and decreased infiltration by monocyte-macrophages. Reverse-transcriptase polymerase chain reaction, zymography and reverse zymography for MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 demonstrated a shift of the proteolytic-antiproteolytic balance upon addition of VSMCs. Transcriptional changes were observed in the adventitia, although seeded VSMCs remained located in the intima.. VSMCs exert a paracrine effect on the adventitia that participate in artery wall homeostasis against inflammation and proteolysis. Failure of this protective mechanism results in AAA formation. The understanding of the molecular mechanisms underlying VSMC protective effect may represent a new approach in the treatment of aneurysm and plaque rupture.

Topics: Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Elastin; Guinea Pigs; Inflammation; Male; Matrix Metalloproteinases; Muscle, Smooth, Vascular; Protease Inhibitors; Rats; Rats, Inbred F344; RNA, Messenger; Tissue Inhibitor of Metalloproteinases; Transplantation, Heterologous

To quantitate the pathologic features of carcinoid plaques in a relatively large number of surgical specimens from a single institution.. Medical records, operative reports, and surgical specimens were reviewed from all patients with carcinoid heart disease who underwent cardiac valvular surgery at Mayo Clinic, Rochester, Minn, between 1980 and 2000.. The study group included 75 patients (45 men, 30 women) who ranged in age from 26 to 78 years (mean, 59 years). From these 75 patients, 139 valves had been excised surgically (73 tricuspid, 55 pulmonary, 6 mitral, 5 aortic). Pure regurgitation was the most common dysfunctional state of the tricuspid valve (80% [60/75]), mitral valve (97% [32/33]), and aortic valve (96% [23/24]). The pulmonary valve was more often both stenotic and insufficient (52% [37/71]) than purely regurgitant (30% [21/71]). In all cases, valve dysfunction was attributed to the presence of carcinoid plaques, which caused both thickening and retraction. Thickening was the result of both cellular proliferation and deposition of extracellular matrix. Proliferation of myofibroblasts was observed in all plaques and was mild in 49% (68/139) and moderate or severe in 51% (71/139). Extracellular matrix included collagen (in 99% of the 139 valves), myxoid ground substance (98% [136/139]), and elastin (20% [28/139]). Carcinoid plaques were also involved by neovascularization (94% [131/139]), chronic inflammation (94% [131/139]), and mast cell infiltration (64% [89/139]). Severe thickening was attributable primarily to collagen deposition in tricuspid valves and to myofibroblast proliferation and myxoid matrix in pulmonary valves.. Among patients undergoing valvular surgery for carcinoid heart disease, tricuspid and pulmonary valves represented 92% of the excised valves (128/ 139). Although numerous cellular and extracellular features were common to the carcinoid plaques, variability in their relative expression produced appreciable differences in the histologic appearance among the plaques.

Topics: Adult; Aged; Aortic Valve Insufficiency; Carcinoid Heart Disease; Collagen; Elastin; Female; Fibroblasts; Hemodynamics; Humans; Hyperplasia; Inflammation; Male; Mast Cells; Middle Aged; Mitral Valve Insufficiency; Neovascularization, Pathologic; Pulmonary Valve Insufficiency; Retrospective Studies; Severity of Illness Index; Tricuspid Valve Insufficiency

chemical peelings injure the superficial skin, which is then restored by healing of the wound.. to document the acute and chronic histological changes produced by applying chemical peeling agents used clinically to the UVB-irradiated skin of hairless mice, which served as a model of sun-damaged skin.. three chemical peeling agents, 30% salicylic acid, dissolved in macrogol (a new formulation), 35% trichloroacetic acid (TCA) dissolved in distilled water and 20% glycolic acid dissolved in glycerin were applied to the backs of UVB-irradiated hairless mice. Untreated, irradiated areas of skin served as controls. Specimens were evaluated histologically at 3, 14, 28, and 70 days.. chronic UVB irradiation produced an irregular hypertrophy of the epidermis. The treated areas of irradiated skin recovered by day 70. At 28 days, all skin specimens treated with chemical peeling agents exhibited a unique connective tissue layer composed of fine collagen fibers beneath the epidermis. While 35% TCA produced severe tissue damage marked by inflammation up to day 14, no inflammatory infiltrates were seen with 30% salicylic acid in macrogol at 70 days.. chemical peeling with 30% salicylic acid dissolved in macrogol led to reorganization of the epidermis and a rebuilding of the superficial dermal connective tissue important in reducing wrinkles, and without evidence of inflammatory infiltrates in an animal model of sun-damaged skin. Findings suggest a possible clinical benefit.

Topics: Animals; Elastin; Female; Glycolates; Inflammation; Keratolytic Agents; Mice; Mice, Hairless; Models, Animal; Skin; Skin Aging; Sunlight; Ultraviolet Rays

Intimal hyperplasia is one of the main responses of the vascular wall to injury. In the current study, we tested the hypothesis that endoluminal seeding of host syngeneic vascular cells could limit intimal hyperplasia induced by either mechanical deendothelialization or chronic allograft rejection in rat aorta.. An experimental model of in situ seeding of syngeneic endothelial cells, smooth muscle cells (SMCs), and fibroblasts (FIBs) was used in mechanically deendothelialized and allografted aortas. In a preliminary study, the ability of the three cell types (n = 5 per group) to seed on the deendothelialized luminal surface of the aortic wall was evaluated after 2 days, with the use of fluorescent PKH as marker. In the first model, the abdominal aorta of Lewis rats was deendothelialized (n = 6) or deendothelialized and seeded with either SMCs (n = 6) or FIBs (n = 6) before flow was restored. In the allograft model, aortas were harvested from dark agouti rats and orthotopically grafted in Lewis receivers, directly (n = 6) or after deendothelialization. Deendothelialization was performed alone (n = 6) or associated with the seeding of similar host (Lewis) syngeneic SMCs (n = 6) or FIBs (n = 6). Results were evaluated at 2 months with histologic and morphometric methods.. SMCs and FIBs were able to adhere in situ to the deendothelialized aortic wall, whereas endothelial cells were not. In mechanically deendothelialized aortas, the seeding of syngeneic SMCs led to a significant reduction in intimal thickness compared with deendothelialized aortas or FIB-seeded aortas (26.9 +/- 1.7 microm vs 55.5 +/- 1.7 and 56.7 +/- 1.7 microm, respectively), and a lower nuclear content (382.2 +/- 35.7 microm(2) vs 779.6 +/- 65.9 and 529.6 +/- 24.3 microm(2), respectively) of neointima. After SMC seeding, intimal hyperplasia was richer in elastin, whereas after FIB seeding it was richer in collagen. In allografts, the seeding of syngeneic SMC led to a significant reduction in intimal thickness compared with control aortas, deendothelialized aortas, or FIB-seeded aortas (31.6 +/- 1.1 microm vs 88.55 +/- 2.8, 74.6 +/- 2.9, and 85.7 +/- 2.6 microm, respectively), and a reduced nuclear content of the neointima (444.9 +/- 23.4 microm(2) vs 1529.1 +/- 116, 972.3 +/- 50, and 645.2 +/- 32.4 microm(2), respectively). Differences observed in the extracellular matrix composition were equivalent to those observed in the mechanically deendothelialized model.. Our results suggest that endoluminal seeding of syngeneic SMCs can be effective in reducing intimal hyperplasia both in a deendothelialization model and in arterial allografts. SMC and FIB endoluminal seeding led to a significatively different accumulation of extracellular matrix in the intima.

Topics: Analysis of Variance; Animals; Aorta, Abdominal; Cell Adhesion; Cell Division; Cell Movement; Chronic Disease; Collagen; Disease Models, Animal; Elastin; Fibroblasts; Graft Rejection; Hyperplasia; Inflammation; Male; Muscle, Smooth, Vascular; Rats; Rats, Inbred Lew; Rats, Inbred Strains; Time Factors; Transplantation, Homologous; Transplantation, Isogeneic; Tunica Intima; Wound Healing

Elastolytic matrix metalloproteinases play a central role in the development of chronic atherosclerotic aortic aneurysms, but mycotic aortic aneurysms are a distinct and unusual form of aneurysm disease caused by bacterial infection. Mycotic aortic aneurysms follow a more rapid and unpredictable course than chronic aneurysm disease and they exhibit a predilection for the suprarenal aorta, further implying unique pathophysiologic mechanisms. The purpose of this study was to examine the nature and source of elastin-degrading enzymes in mycotic aortic aneurysm. Bacterial isolates and aortic tissues were obtained from four consecutive patients undergoing surgical repair of suprarenal mycotic aortic aneurysm. Using an in vitro 3H-labeled elastin degradation assay, elastin-degrading enzyme activity was only observed in the bacteria-conditioned medium from an isolate of Pseudomonas aeruginosa. Elastin-degrading enzyme activity in the aortic tissue homogenate of this patient was abolished by the serine protease inhibitor, phenylmethylsulfonyl fluoride, but it was not suppressed by the metalloproteinase inhibitor, ethylenediamine tetraacetic acid (EDTA). In contrast, elastin-degrading enzyme activity in the bacterial-conditioned medium was decreased by about half by both phenylmethylsulfonyl fluoride and EDTA. Elastin substrate zymography revealed two phenylmethylsulfonyl fluoride-inhibitable elastin-degrading enzyme activities in the aortic tissue homogenate that corresponded to human neutrophil elastase (approximately 30 kDa) and its stable complex with alpha 1-proteinase inhibitor (approximately 80 kDa), but no activity attributable to Pseudomonas elastase, a 33-kDa metal-dependent enzyme. Human neutrophil elastase was readily detected throughout mycotic aortic aneurysm tissues by immunohistochemistry, but elastolytic metalloproteinases were only occasionally observed. The results of this study suggest that the elastin-degrading enzyme produced in mycotic aortic aneurysm are largely serine proteases of host neutrophil origin, rather than elastases produced by the infecting microorganisms or the macrophage-derived metalloproteinases typically observed in atherosclerotic aneurysm disease. Further studies will be needed to extend these findings to a larger number of patients with mycotic aortic aneurysm and those caused by additional microorganisms.

Topics: Aged; Aged, 80 and over; Aneurysm, Infected; Aortic Aneurysm, Abdominal; Elastin; Female; Humans; Immunohistochemistry; Inflammation; Leukocyte Elastase; Male; Metalloendopeptidases; Serine Endopeptidases

A neutrophil elastase inhibitor FR901277 was examined for its inhibitory effect on degradation of natural substrate elastin in vitro, and on acute inflammatory states and pulmonary emphysema in vivo.. Elastin-congo red was used as a substrate for elastin degradation assay. Paw edema in male C57BL mice (6 weeks old) and pulmonary hemorrhage in female golden hamsters (5 weeks old) were induced by topical injection of human neutrophil elastase (HNE). Pulmonary emphysema in male golden Syrian hamsters (10 weeks old) was provoked by intratracheal instillation of porcine pancreatic elastase. In all in vivo experiments. FR901277 was administered prior to elastase treatment.. Elastin degradation by HNE was monitored spectrophotometrically with elastin-congo red. Foot swelling was measured by calipers. Pulmonary hemorrhage was assessed by hemoglobin concentration in bronchoalveolar lavage fluid. As emphysematous parameters, quasi-static lung compliance and vital capacity were measured.. FR901277 inhibited HNE-induced elastin degradation. Systemic treatment with FR901277 significantly inhibited paw edema and pulmonary hemorrhage. Intratracheal treatment with FR901277 significantly ameliorated changes in pulmonary function.. These results suggest that FR901277 inhibits the elastase activity potently both in vitro and in vivo, and that elastase may play a role at least in part in pathogenesis of pulmonary emphysema.

Topics: Amides; Animals; Cricetinae; Edema; Elastin; Enzyme Inhibitors; Female; Hemorrhage; Humans; Inflammation; Leukocyte Elastase; Lung Diseases; Male; Mesocricetus; Mice; Mice, Inbred C57BL; Pancreatic Elastase; Pulmonary Emphysema; Swine

To investigate (i) elastin degradation and the possible association between proteolysis and inflammation in abdominal aortic aneurysm disease (AAA), and (ii) the presence of cytomegalovirus (CMV) infection in the walls of AAA.. Specimens from 12 infrarenal AAAs, eight aortas with occlusive disease (AOD) and two normal aortas were studied by conventional light microscopy, immunohistochemistry using a monoclonal anti-elastin antibody BA-4 and anti-CMV antibody and transmission electron microscopy (TEM).. In AAA the decrease in elastin immunoreactivity and the presence of elastin degradation was associated with increased mononuclear inflammatory cell infiltrates (p = 0.004 and p = 0.00002, respectively). The CMV immunostainings of the normal aortic wall and all the AAA and AOD samples were negative, nor could any CMV particles be demonstrated by TEM.. The chronic inflammation and degradation of elastin in AAA suggests a possible immune-mediated mechanism. The inflammation may be induced by the chemotactic properties of elastin-derived peptides.

Topics: Adult; Aged; Antigens, Viral; Aortic Aneurysm, Abdominal; B-Lymphocytes; Chronic Disease; Cytomegalovirus Infections; Elastin; Female; Humans; Immunohistochemistry; Immunophenotyping; Inflammation; Macrophages; Male; Microscopy, Electron; Middle Aged; T-Lymphocytes

The concept that aging impairs wound healing is largely unsubstantiated, the literature being contradictory because of poor experimental design and a failure to adequately characterize animal models. This study tested the hypothesis that aging retards the rate of wound repair using standardized cutaneous incisional wounds in a well-characterized aging mouse colony. Against the background of age-related changes in normal dermal composition, marked differences in healing were observed. Immunostaining for fibronectin was decreased in the wounds of the old mice, with a delay in the inflammatory response, re-epithelialization, and the appearance of extracellular matrix components. Heparan sulfate and blood vessel staining were both unexpectedly increased in the wounds of the old animals at late time points. Despite an overall decrease in collagen I and III deposition in the wounds of old mice, the dermal organization was surprisingly similar to that of normal dermal basket-weave collagen architecture. By contrast, young animals developed abnormal, dense scars. Intriguingly, some of these age-related changes in scar quality and inflammatory cell profile are similar to those seen in fetal wound healing. The rate of healing in young animals appears to be increased at the expense of the scar quality, perhaps resulting from an altered inflammatory response.

Topics: Aging; Animals; Chondroitin Sulfates; Collagen; Elastin; Endothelium; Extracellular Matrix; Heparitin Sulfate; Immunohistochemistry; Inflammation; Male; Mice; Mice, Inbred C57BL; Neovascularization, Physiologic; Skin; Up-Regulation; Wound Healing

The aim of this study was to investigate prospectively the epithelialization process in the healing temporalis myofascial flap (TMF). Eight cats underwent maxillectomy and immediate reconstruction with TMF. They were killed at the determined time and the reconstructed maxillae were processed for examination by light microscopy and scanning electron microscopy. Results revealed that epithelialization of the healing TMF was initiated by hyperplastic changes followed by active migration of epithelial cells deriving from the wound margins. The partial maxillectomy wound was completely covered by a smooth oral mucosa at postoperative week 24. The mucosa had histological and ultrastructural features different from normal palatal mucosa.

Topics: Animals; Cats; Cell Movement; Collagen; Connective Tissue; Edema; Elastin; Epithelium; Fascia; Granulation Tissue; Hyperplasia; Inflammation; Keratins; Lymphocytes; Macrophages; Maxilla; Microscopy, Electron, Scanning; Mouth; Mouth Mucosa; Plasma Cells; Prospective Studies; Regeneration; Surgical Flaps; Temporal Muscle; Wound Healing

It is now accepted that workers with exposure to mineral dusts can develop airflow obstruction. The basis of this process is uncertain, but carefully performed morphologic studies suggest that coal, silica, and perhaps other dusts may produce emphysema in humans. To investigate the mechanisms involved in this process, we administered crystalline silica (quartz) or titanium dioxide (rutile) to rats in a single intratracheal instillation. At varying times after instillation, the animals' lungs were lavaged, the lavageate from one lung was dried and hydrolyzed, and the amounts of desmosine (DES),as a measure of elastin breakdown, and hydroxyproline (HP), as a measure of collagen breakdown, were determined. The lavageate from the other lung was counted for inflammatory cells. Both silica and titanium dioxide caused a dose-dependent increase in DES and HP 24 h after instillation. When an equivalent dose (30 mg) of silica or rutile was administered and animals were sacrificed at various times up to 21 d, a sustained increase in lavage DES and HP was seen in the silica-treated animals, and this was accompanied by a sustained increase in polymorphonuclear leukocytes (PMN); in contrast, both lavage PMN and lavage DES/HP rapidly peaked and then declined in the titanium dioxide-treated animals. Numbers of macrophages remained elevated over the 21-d period of sacrifice with both types of treatment. These data show for the first time that mineral dusts can cause connective-tissue breakdown in the lung, with the release of matrix components into the alveolar spaces. The amount of connective-tissue breakdown appears to parallel the number of PMN but not the number of macrophages in the alveolar spaces, suggesting that PMN-derived proteolytic enzymes are responsible for the breakdown. This process probably plays a role in dust-induced emphysema.

Topics: Animals; Bronchoalveolar Lavage Fluid; Collagen; Desmosine; Dust; Elastin; Hydroxyproline; Inflammation; Lung; Male; Minerals; Pulmonary Emphysema; Quartz; Rats; Rats, Sprague-Dawley; Titanium

Macrophages secrete a variety of proteinases that are thought to participate in remodeling of the extracellular matrix associated with inflammatory processes. We have eliminated expression of the macrophage metalloelastase (MME) gene by targeted disruption to assess the role of this protein in macrophage-mediated proteolysis. We found that the macrophages of MME-deficient (MME-/-) mice have a markedly diminished capacity to degrade extracellular matrix components. In addition, MME-/- macrophages are essentially unable to penetrate reconstituted basement membranes in vitro and in vivo. MME is therefore required for macrophage-mediated extracellular matrix proteolysis and tissue invasion.

Topics: Animals; Base Sequence; Basement Membrane; Cloning, Molecular; DNA Primers; Elastin; Extracellular Matrix; Gene Library; Inflammation; Macrophages, Peritoneal; Matrix Metalloproteinase 12; Metalloendopeptidases; Mice; Mice, Inbred Strains; Molecular Sequence Data; Polymerase Chain Reaction; Recombinant Proteins; Transfection

Factors influencing the in vivo calcification of porcine collagen membranes containing elastic fibres were investigated by light and confocal microscopy. Two glutaraldehyde (GA) cross-linking protocols were used: a new one involving microwaving (NEWGA), and a conventional method using GA treatment at room temperature (OLDGA). We observed that the physical and chemical properties of implanted membranes will influence the acute inflammatory response, which initially checks the calcification process. The NEWGA membranes are superior in cases where rapid calcification is desired. In this context, it is proposed that NEWGA membranes may serve as a useful delivery system for bone morphogenetic protein (BMP).

Topics: Animals; Biocompatible Materials; Bone and Bones; Calcinosis; Collagen; Elastin; Glutaral; Inflammation; Male; Microscopy, Confocal; Microwaves; Prostheses and Implants; Rats; Rats, Wistar; Regeneration; Swine; Time Factors

The maintenance of the mechanical properties of the vessels results from the correct arrangement of smooth muscle cells and extracellular fibrous proteins (elastin and collagen) in their wall. The morphology of extracellular matrix modifications, particularly of elastin, was investigated in inflammatory (IA) and non specific (NSA) abdominal aortic aneurysms by scanning (SEM), transmission (TEM) and immunoelectron microscopy. Both NSAs and IAs were significantly characterized by extensive extracellular matrix remodelling, including different patterns of elastin degradation. Elastic and collagen fibres distribution appeared to be extensively altered in IAs, while it conformed more to a normal pattern in NSAs. With respect to NSAs, the morphology of elastic fibres in IAs was modified to such an extent that their identification by TEM had a rely on immunocytochemical methods and by SEM on back-scattered electron analysis. The observed ultrastructural changes are indicative of the central role of extracellular matrix modifications in the pathogenesis of IAs and NSAs.

Topics: Aortic Aneurysm, Abdominal; Elastin; Extracellular Matrix; Humans; Immunohistochemistry; Inflammation; Microscopy, Electron, Scanning; Muscle, Smooth, Vascular

Reperforation rates of large, surgically closed nasoseptal perforations remain unacceptably high (30% to 70%). With the advent of newer surgical techniques, including external decortication rhinoplasty and midface degloving, excellent exposure of the intranasal anatomy is afforded. The limiting factor of these approaches is the deficiency of local intranasal mucosal lining, which is used to close large septal perforations. The paucity of nasal mucosal lining results in excessive tension on the perforation closure suture line that leads to distal flap ischemia, anastomosis breakdown and, ultimately, reperforation of the septum. Alternatively, using intraoral mucosal flaps of sufficient length and width to close large perforations results in significant and unacceptable donor-site morbidity. We present our technique of harvesting additional local endonasal mucosa using long-term soft-tissue expanders. Long-term nasal mucosal expansion was used in the closure of large septal perforations in five patients. Complications included one case of expander exposure and the morbidity of prefacial expander injections. Total closure of all five septal perforations was documented at the 1-year postsurgical visit. Histologic and electron-microscopic examinations of the expanded nasal floor mucosa are presented.

Topics: Collagen; Elastin; Epithelium; Humans; Inflammation; Microscopy, Electron; Microscopy, Electron, Scanning; Nasal Mucosa; Nasal Septum; Nose; Nose Diseases; Silicone Elastomers; Surgical Flaps; Time Factors; Tissue Expansion; Tissue Expansion Devices

The natural history and the factors determining the expansion of aneurysms have not been elucidated. To study the respective roles of elastolysis, collagenolysis, inflammatory cells, and hypertension in the pathogenesis of aneurysms, two previously described in vivo experimental models were used. An isolated segment of the abdominal aorta was infused with 15 units of pancreatic elastase. The maximal diameter of the aorta was measured before and after infusion and the isolated aorta was excised for classic histologic and immunohistologic studies. Twelve hours after the infusion of elastase the mean diameter of the aorta increased by 30%. The aorta had a cylindric form and only collagen fibers remained. Two and a half days after the infusion the aorta was spherical in shape and the diameter increased by 300% (3.09 +/- 0.08 mm) (p < 0.05). The entire aortic wall was invested by inflammatory cells. Six days after infusion the diameter increased by 421% (4.38 +/- 0.03 mm) (p < 0.05), and immunohistochemical staining showed numerous T lymphocytes and macrophages. Between 6 and 12 days, after perfusion inflammation decreased, the final diameter was 4.23 +/- 0.14 mm (not significant). Sixteen rats had thioglycollate and plasmin infusion, which are nonspecific activators of inflammation. Nine days after infusion the diameter of the aorta had increased by 288%; the elastic fibers of the media were fragmented and rare and the entire aortic wall was invaded by inflammatory cells, predominantly macrophages. The diameter of the aorta increased progressively. Two groups of 17 hypertensive rats (renovascular and spontaneous hypertension) received an aortic infusion of 15 units of pancreatic elastase. Elastolysis overlapped the limits of the infusion and inflammation persisted after 2 weeks. The mean diameter of the aorta (F = 11, p < 0.01) and the mean length of the aneurysms (F = 11.2, p < 0.001) were significantly increased. This study demonstrates that elastolysis and especially collagenolysis are determinants of aneurysmal expansion. Inflammation may be a promoting factor in the degradation of the aortic wall. Hypertension increases the hemodynamic stress to the aorta and activates mural inflammation.

Topics: Animals; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Collagen; Elastin; Fibrinolysin; Hypertension; Inflammation; Male; Pancreatic Elastase; Rats; Rats, Wistar; Thioglycolates

Inflammatory aneurysms (IAs) have peculiar macroscopic and histological aspects which make them very different from nonspecific aneurysms (NSAs). These morphological differences seem to be determined by significant modifications of the extracellular matrix. Extracellular matrix protein component concentrations were determined biochemically in infrarenal aortic biopsies from 10 NSAs, five IAs and five non-aneurysmal aortic controls. The concentration of each wall component was expressed in % w/w (relative concentration) and in mg/wall longitudinal cm (absolute concentration) with reference to total protein recovered after hydrolysis and amino acid analysis. The biochemical results were correlated with the histological and ultrastructural features of the specimens. A significant increase in total collagen was observed in the two groups of aneurysms, with respect to the controls (NSA = 285%, IA = 382%). In contrast the 80-90% decrease in the relative concentration of elastin observed in both types of aneurysm was less marked (NSA = 55%, IA = 39%). This fall was not significant when expressed in mg/cm, although elastin derived peptide (EDP) levels in the plasma of these patients was significantly higher than in age-matched controls. The concentration of the soluble collagen fraction appeared significantly higher (Mann-Whitney, p < 0.05) in the IAs with respect to the NSAs, whilst no differences were observed between the two groups regarding the concentration of insoluble elastin and of wall and plasma EDPs. As well as providing evidence of increased elastin turnover, this study emphasises the conspicuous modifications of collagen deposition in the wall of abdominal aortic aneurysms which appeared more marked in the inflammatory group.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Collagen; Elastin; Extracellular Matrix Proteins; Humans; Inflammation; Microscopy, Electron; Microscopy, Electron, Scanning; Middle Aged

Biocompatibility and biodegradability of a new elastin-fibrin material were investigated in several organs and tissues of the rat. It has been demonstrated that the material was quite well tolerated in all cases, except in bone marrow. Its use is considered in several aspects of reparative or constructive surgery.

Topics: Animals; Biocompatible Materials; Biodegradation, Environmental; Connective Tissue; Elastin; Fibrin; Inflammation; Materials Testing; Prostheses and Implants; Rats; Rats, Inbred Strains

We have recently shown that human neutrophils bind and internalize human eosinophil peroxidase (EPO) but not myeloperoxidase (MPO). In the present work, we studied the interactions of human EPO and MPO with other cells that may be involved in the inflammatory process, i.e., lymphocytes, monocytes, platelets, fibroblasts, and endothelial cells. The results indicate that EPO is bound by all the cell types considered, but is efficiently internalized only by lymphocytes, monocytes, and endothelial cells. Conversely, MPO binds appreciably only to fibroblasts and endothelial cells, although with a lower affinity than EPO, but its internalization by any of the cell types studied is hardly detectable. Furthermore, both peroxidases bind strongly to collagen fibers, whereas only EPO binds to elastin. The results suggest that EPO, owing to its high cytophilia, exerts its biological activity close to the site at which it is released from the eosinophil.

Topics: Blood Platelets; Collagen; Elastin; Endothelium, Vascular; Eosinophils; Fibroblasts; Histocytochemistry; Humans; Inflammation; Lymphocytes; Microscopy, Electron; Monocytes; Peroxidase; Peroxidases

Recent evidence suggests that connective tissue breakdown in the human lung leading to airway obstruction and emphysema involves proteinases expressed by neutrophils and macrophages that traffic to the lungs in response to cigarette smoke. It remains unclear why only a small fraction of all cigarette smokers develop symptomatic airway obstruction. In this study, we examined indexes of inflammation and proteolytic activity in samples of bronchoalveolar lavage from young cigarette smokers and questioned whether there was any correlation between the extent of inflammation or enzymatic activity and lung function. A total of 125 apparently healthy community volunteers who currently smoked at least one pack per day were evaluated by spirometry. Seven subjects with a relatively low FEV1/FVC (% predicted) were identified and further studied by bronchoalveolar lavage. These were compared with a group of 10 smokers of similar age (mean age, 33 yr) and pack-years and higher FEV1/FVC (% predicted). Both groups showed increased accumulation of lung macrophages and neutrophils as compared to nonsmokers, but there were no differences in total cells or cellular differentials between the groups. Similarly, there were no differences in either alveolar fluid phase elastase, antielastase, and plasminogen activator (PA) activities or macrophage elastolytic activity between the groups. In contrast, there was a clear difference in macrophage plasminogen activator activity between the groups, cells from the group with a lower FEV1/FVC (% predicted) having a higher PA activity than that of macrophages from the group with higher FEV1/FVC (% predicted), i.e., 0.50 +/- 0.16 international urokinase units/10(6) cells versus 0.30 +/- 0.10 units/10(6) cells (p less than 0.0007).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Bronchoalveolar Lavage Fluid; Elastin; Forced Expiratory Volume; Forecasting; Humans; Inflammation; Lung; Lung Diseases; Macrophages; Middle Aged; Pancreatic Elastase; Plasminogen Activators; Pulmonary Alveoli; Respiratory Function Tests; Smoking; Vital Capacity

Lung disease may result from a persisting proteinase excess or a depletion of antiproteinase in pulmonary parenchyma. We investigated the in vivo effect of a 48-hr exposure to ozone at 0.5, 1.0, or 1.5 ppm on proteinase and antiproteinase activity of rat lungs. Elastase inhibitory capacities of serum, lung tissue, and airway washings were measured as indicators of antielastase activity. Trypsin inhibitory capacity was measured using an esterolytic procedure. Proteinase was measured as radioactive release from a 14C-globin substrate. The 48-hr exposures to O3 at levels up to 1 ppm produced concentration-dependent decreases of 35-80% of antiproteinase activities in serum and in lung tissue. However, exposure to 1.5 ppm O3 resulted in no decrease in antiproteinase activities. Acid proteinase activities (pH 4.2) were increased 65-120% by exposure to 1 or 1.5 ppm O3, which correlated with inflammatory cells noted histologically. At 1.5 ppm O3, pulmonary edema and hemorrhage were noted in histologic sections. These changes led to a flooding of the alveoli with up to 40 times normal protein levels and a greater than fivefold increase in airway antiproteinase. These data suggest that serum and soluble lung tissue antiproteinase activity decreased upon exposure to low levels of ozone. However, if O3 exposure is high enough to produce pulmonary hemorrhage, antiproteinase may increase following serum exudation. These changes may be important in the development of ozone-induced lung diseases, especially emphysema.

Topics: Animals; Dose-Response Relationship, Drug; Elastin; Female; Inflammation; Lung; Ozone; Pancreatic Elastase; Peptide Hydrolases; Protease Inhibitors; Rats; Trypsin Inhibitors

Topics: Animals; Collagen; Disease Models, Animal; Elastin; Hemorrhage; Inflammation; Intubation, Intratracheal; Lung; Lung Diseases; Papain; Pulmonary Edema; Pulmonary Emphysema; Rabbits

Topics: Animals; Arteritis; Basement Membrane; Chromatography, DEAE-Cellulose; Chromatography, Ion Exchange; Dogs; Edetic Acid; Elastin; Electrophoresis; Hemorrhage; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Inflammation; Leukocytes; Lysosomes; Microbial Collagenase; Pancreatic Elastase; Peptide Hydrolases; Rabbits

Topics: Collagen; Collagen Diseases; Connective Tissue; Elastic Tissue; Elastin; Gastroenterology; Gastrointestinal Tract; Glycoproteins; Glycosaminoglycans; Histocytochemistry; Humans; Inflammation; Mucoproteins; Nasal Mucosa; Pathology; Respiratory Mucosa; Respiratory Tract Diseases