transforming-growth-factor-beta and Aortic-Diseases

Many patients with congenital cardiac disease are at risk for progressive aortic dilation. The mechanisms underlying aortic dilation in this patient cohort are described, and the similarities to the pathophysiologic alterations seen in Marfan syndrome are highlighted. Indications for treatment are discussed.

Topics: Aortic Diseases; Dilatation, Pathologic; Heart Defects, Congenital; Humans; Marfan Syndrome; Transforming Growth Factor beta

To explore the mechanism of CircANKRD36 regulating cell heterogeneity and endothelial mesenchymal transition in aortic valve stromal cells by regulating miR-599 and TGF-β signaling pathway.. Human tissue specimens were divided into Control group (n = 25) and CAVD group (n = 25). The mRNA expressions of CircANKRD36 and miR-599 in tissue samples were analyzed by qRT-PCR. Western blot was used to analyze the protein expression of osteogenic differentiation related factors induced by OM.The expressions of ALP, osteocalcin, osteopontin, Runx2 and Cadherin11 were detected by Western blot.. The expression of CircANKRD36mRNA in CAVD tissue was lower than that in Control tissue (P < 0.05), and the expression of miR-599mRNA in CAVD tissue was higher than that in Control tissue (P < 0.05). CircANKRD36 was negatively correlated with ALP, osteocalcin, osteopontin, Runx2, Cadherin11 expression level after OM induced osteogenic differentiation. The expression level of miR-599 was positively correlated with ALP, osteocalcin, osteopontin, Runx2 and Cadherin11 after OM induced osteogenic differentiation.The expression of ALP, osteocalcin, osteopontin, Runx2 and Cadherin11 protein in circ+miR-599 group was lower than that in circ+miR-NC group (P < 0.05). Compared with Vector+miR-NC group, the protein expressions of TGF-β1, TGF-β2 and SMAD4 in circ+miR-NC group decreased (P < 0.05), while the protein expressions of TGF-β1, TGF-β2 and SMAD4 in circ+miR-599 group increased (P < 0.05).. CircANKRD36 can inhibit the expression of miR-599 and the activation of TGF-β signaling pathway, thus inhibiting the expression of differentiation-related factors of VIC osteogenesis and the formation of calcified nodules. Therefore, circANKRD36-miR-599-TGF-β axis can be a new theoretical basis for treating CAVD.

Topics: Aortic Diseases; Aortic Valve; Calcinosis; Cell Differentiation; Cells, Cultured; Humans; MicroRNAs; Nuclear Proteins; Osteogenesis; RNA, Circular; Signal Transduction; Stromal Cells; Transforming Growth Factor beta

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

We sought to determine whether there are differences in transforming growth factor-beta (TGFß) signaling in aneurysms associated with bicuspid (BAV) and unicuspid (UAV) aortic valves versus normal aortic valves. Ascending aortic aneurysms are frequently associated with BAV and UAV. The mechanisms are not yet clearly defined, but similarities to transforming growth factor-beta TGFß vasculopathies (i.e. Marfan, Loeys-Dietz syndromes) are reported. Non-dilated (ND) and aneurysmal (D) ascending aortic tissue was collected intra-operatively from individuals with a TAV (N = 10ND, 10D), BAV (N = 7ND, 8D) or UAV (N = 7ND, 8D). TGFß signaling and aortic remodeling were assessed through immuno-assays and histological analyses. TGFß1 was increased in BAV/UAV-ND aortas versus TAV (P = 0.02 and 0.04, respectively). Interestingly, TGFß1 increased with dilatation in TAV (P = 0.03) and decreased in BAV/UAV (P = 0.001). In TAV, SMAD2 and SMAD3 phosphorylation (pSMAD2, pSMAD3) increased with dilatation (all P = 0.04) and with TGFß1 concentration (P = 0.04 and 0.03). No relationship between TGFß1 and pSMAD2 or pSMAD3 was observed for BAV/UAV (all P > 0.05). pSMAD3 increased with dilatation in BAV/UAV aortas (P = 0.01), whereas no relationship with pSMAD2 was observed (P = 0.56). Elastin breaks increased with dilatation in all groups (all P < 0.05). In TAV, elastin degradation correlated with TGFß1, pSMAD2 and pSMAD3 (all P < 0.05), whereas in BAV and UAV aortas, elastin degradation correlated only with pSMAD3 (P = 0.0007). TGFß signaling through SMAD2/SMAD3 contributes to aortic remodeling in TAV, whereas TGFß-independent activation of SMAD3 may underlie aneurysm formation in BAV/UAV aortas. Therefore, SMAD3 should be further investigated as a therapeutic target against ascending aortic dilatation in general, and particularly in BAV/UAV patients.

Topics: Aortic Diseases; Dilatation; Dilatation, Pathologic; Elastin; Heart Valve Diseases; Humans; Smad3 Protein; Transforming Growth Factor beta; Transforming Growth Factors

Thoracic aortic aneurysm is a potentially life-threatening disease with a strong genetic contribution. Despite identification of multiple genes involved in aneurysm formation, little is known about the specific underlying mechanisms that drive the pathological changes in the aortic wall. The aim of our study was to unravel the molecular mechanisms underlying aneurysm formation in Marfan syndrome (MFS). We collected aortic wall samples from

Topics: Adult; Animals; Aorta; Aortic Diseases; Cell Respiration; Female; Fibrillin-1; Gene Expression Profiling; Gene Expression Regulation; Genomics; Humans; Male; Marfan Syndrome; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Signal Transduction; Transforming Growth Factor beta

Mutations in lysyl oxidase (LOX) genes cause severe vascular anomalies in mice and humans. LOX activity can be irreversibly inhibited by the administration of β-aminoproprionitrile (BAPN). We investigated the mechanisms underlying the damage to the ascending thoracic aorta induced by LOX deficiency and evaluated whether 6-propylthiouracil (PTU) can afford protection in rats. BAPN administration caused disruption of the ascending aortic wall, increased the number of apoptotic cells, stimulated TGF-β signaling (increase of nuclear p-SMAD2 staining), and up-regulated the expression of metalloproteinases-2 and -9. In BAPN-treated animals, PTU reduced apoptosis, p-SMAD2 staining, MMP-2, and -9 expression, and markedly decreased the damage to the aortic wall. Our results suggest that, as in some heritable vascular diseases, enhanced TGF-β signaling and upregulation of MMP-2 and -9 can contribute to the pathogenesis of ascending aorta damage caused by LOX deficiency. We have also shown that PTU, a drug already in clinical use, protects against the effects of LOX inhibition. MMP-2 and -9 might be potential targets of new therapeutic strategies for the treatment of vascular diseases caused by LOX deficiency.

Topics: Animals; Antimetabolites; Aorta, Thoracic; Aortic Diseases; Biomarkers; Disease Models, Animal; Immunohistochemistry; In Situ Nick-End Labeling; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Pilot Projects; Propylthiouracil; Protein-Lysine 6-Oxidase; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta

Small-molecule inhibitors of transforming growth factor beta receptor 1 (TGFβRI) have a history of significant class-based toxicities (eg, cardiac valvulopathy) in preclinical species that have limited their development as new medicines. Nevertheless, some TGFβRI inhibitors have entered into clinical trials using intermittent-dosing schedules and exposure limits in an attempt to avoid these toxicities. This report describes the toxicity profile of the small-molecule TGFβRI inhibitor, BMS-986260, in rats and dogs. Daily oral dosing for 10 days resulted in valvulopathy and/or aortic pathology at systemic exposures that would have been targeted clinically, preventing further development with this dosing schedule. These toxicities were not observed in either species in 1-month studies using the same doses on an intermittent-dosing schedule of 3 days on and 4 days off (QDx3 once weekly). Subsequently, 3-month studies were conducted (QDx3 once weekly), and while there were no cardiovascular findings in dogs, valvulopathy and mortality occurred early in rats. The only difference compared to the 1-month study was that the rats in the 3-month study were 2 weeks younger at the start of dosing. Therefore, a follow-up 1-month study was conducted to evaluate whether the age of rats influences sensitivity to target-mediated toxicity. Using the same dosing schedule and similar doses as in the 3-month study, there was no difference in the toxicity of BMS-986260 in young (8 weeks) or adult (8 months) rats. In summary, an intermittent-dosing schedule mitigated target-based cardiovascular toxicity in dogs but did not prevent valvulopathy in rats, and thus the development of BMS-986260 was terminated.

Topics: Animals; Aortic Diseases; Dogs; Dose-Response Relationship, Drug; Drug Administration Schedule; Enzyme Inhibitors; Female; Humans; Male; Models, Animal; Rats; Receptor, Transforming Growth Factor-beta Type I; Transforming Growth Factor beta

Vascular biglycan contributes to atherosclerosis development and increased biglycan expression correlates with increased atherosclerosis. However, mice deficient in biglycan have either no reduction in atherosclerosis or an unexpected increase in atherosclerosis. Biglycan deficient mice have systemically elevated TGF-β, likely due to lack of sequestration of TGF-β in the extracellular matrix. The purpose of this study was to determine if prevention of TGF-β elevations in biglycan deficient mice affected atherosclerosis development.. Biglycan deficient mice were crossed to Ldlr deficient mice. Diabetes was induced via streptozotocin and all mice were fed a high cholesterol diet. Diabetic biglycan wild type and biglycan deficient Ldlr deficient mice were injected with the TGF-β neutralizing antibody 1D11 or the irrelevant control antibody 13C4.. Biglycan deficient mice had significantly elevated plasma TGF-β levels, which was further increased by diabetes, and significantly increased atherosclerosis. There was a significant correlation between TGF-β concentrations and atherosclerosis. However, despite nearly complete suppression of plasma TGF-β levels in mice treated with the TGF-β neutralizing antibody 1D11, there was no significant difference in atherosclerosis between mice with elevated TGF-β levels and mice with suppressed TGF-β levels.. The increased atherosclerosis in biglycan deficient mice does not appear to be due to elevations in TGF-β.

Topics: Animals; Antibodies, Neutralizing; Aortic Diseases; Atherosclerosis; Biglycan; Diabetes Mellitus, Experimental; Diet, High-Fat; Disease Models, Animal; Male; Mice, Inbred C57BL; Mice, Knockout; Plaque, Atherosclerotic; Receptors, LDL; Streptozocin; Transforming Growth Factor beta; Up-Regulation

Genetic aortic syndromes (GAS) include Marfan, Loeys-Dietz, vascular Ehlers-Danlos, and Turner syndrome as well as congenital bicuspid aortic valve. The clinical management of these diseases has certain similarities and differences. We employed medical strategy analysis to test the utility of genetic diagnostics in the management of GAS. We chose the standpoint of the cardiologist for our analysis. In the first step, the medical goals in the management of GAS are specified. In the second step, the accuracy of genetic diagnostics for GAS is examined. Finally, conclusions can be drawn about the utility of genetic diagnostics in managing GAS. We found that genetic diagnostics is necessary to exclude GAS, to diagnose GAS, and to specify disease types. Second, combining phenotype with genotype information maximizes the predictability of the course of disease. Third, with genetic diagnostics it is possible to predict the birth of children with causative mutations for GAS and to initiate drug therapy to prevent the onset of aortic dilatation or to slow down its progression to aortic aneurysm. Finally, genetic diagnostics improves prognostic predictions and thereby contributes to a better timing of elective surgery and to a better choice of procedures. The findings of our medical strategy analysis indicate the high utility of genetic diagnostics for managing GAS.

Topics: Aortic Diseases; DNA Mutational Analysis; Female; Genetic Predisposition to Disease; Genetic Testing; Genotype; Humans; Infant, Newborn; Marfan Syndrome; Microfibrils; Phenotype; Pregnancy; Prenatal Diagnosis; Transforming Growth Factor beta

Marfan syndrome (MFS) is caused by mutations in the gene encoding fibrillin-1 (FBN1); however, the mechanisms through which fibrillin-1 deficiency causes MFS-associated aortopathy are uncertain. Recently, attention was focused on the hypothesis that MFS-associated aortopathy is caused by increased transforming growth factor-β (TGF-β) signaling in aortic medial smooth muscle cells (SMC). However, there are many reasons to doubt that TGF-β signaling drives MFS-associated aortopathy. We used a mouse model to test whether SMC TGF-β signaling is perturbed by a fibrillin-1 variant that causes MFS and whether blockade of SMC TGF-β signaling prevents MFS-associated aortopathy.. MFS mice (Fbn1. In young Fbn1

Topics: Animals; Aorta; Aortic Aneurysm, Thoracic; Aortic Diseases; Disease Models, Animal; Fibrillin-1; Marfan Syndrome; Mice; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; Transforming Growth Factor beta

Immunotherapy by inducing oral tolerance to atherogenic self-antigens is gaining importance as an alternative treatment modality for atherosclerosis. The use of live bacterial vectors to express the recombinant antigen in vivo will obviate the need for large-scale purification of recombinant protein and may also augment the efficacy of oral tolerance induction.. The objective of the study was to explore the use of recombinant Mycobacterium smegmatis as a live vector for oral delivery of antigens to induce immune tolerance.. We developed a M. smegmatis vector to secrete a recombinant tripeptide construct (AHC; peptides from Apolipoprotein B, Heat-shock protein 60 and Chlamydia pneumoniae outer membrane protein) expressed in a dendroaspin protein scaffold in pJH154 background. Immune response and oral tolerance to the cloned peptides were studied in C57/BL6 mice. The efficacy of this live vaccine to control atherosclerosis was studied in ApoE(-/-) knockout mice in C57/BL6 background. Oral administration of M. smegmatis secreting the cloned AHC antigen was found to induce tolerance to cloned protein and reduce the development of atherosclerosis by 24.0% compared to control. Protection against atherosclerosis was associated with increase in expression of regulatory T cell-associated markers including CTLA4 (1.8-fold), Foxp3 (2.6-fold), TGF-β (2.8-fold), IL10 (2.9-fold), and reduction in lipids, macrophage infiltration, and expression of inflammatory mediators in aorta.. Our results suggest that M. smegmatis can be developed as an oral carrier of recombinant proteins to treat inflammatory autoimmune diseases.

Topics: Administration, Oral; Animals; Antigens; Aortic Diseases; Apolipoproteins E; Atherosclerosis; CTLA-4 Antigen; Disease Models, Animal; Female; Forkhead Transcription Factors; Genetic Predisposition to Disease; Genetic Vectors; Immune Tolerance; Immunization; Immunotherapy; Inflammation Mediators; Interleukin-10; Lipid Metabolism; Macrophages; Male; Mice, Inbred C57BL; Mice, Knockout; Mycobacterium smegmatis; Oligopeptides; Phenotype; T-Lymphocytes, Regulatory; Time Factors; Transforming Growth Factor beta; Vaccines, Synthetic

Individuals with bicuspid aortic valves (BAV) are at a higher risk of developing thoracic aortic aneurysms (TAA) than patients with trileaflet aortic valves (TAV). The aneurysms associated with BAV most commonly involve the ascending aorta and spare the descending aorta. Smooth muscle cells (SMCs) in the ascending and descending aorta arise from neural crest (NC) and paraxial mesoderm (PM), respectively. We hypothesized defective differentiation of the neural crest stem cells (NCSCs)-derived SMCs but not paraxial mesoderm cells (PMCs)-derived SMCs contributes to the aortopathy associated with BAV. When induced pluripotent stem cells (iPSCs) from BAV/TAA patients were differentiated into NCSC-derived SMCs, these cells demonstrated significantly decreased expression of marker of SMC differentiation (MYH11) and impaired contraction compared to normal control. In contrast, the PMC-derived SMCs were similar to control cells in these aspects. The NCSC-SMCs from the BAV/TAA also showed decreased TGF-β signaling based on phosphorylation of SMAD2, and increased mTOR signaling. Inhibition of mTOR pathway using rapamycin rescued the aberrant differentiation. Our data demonstrates that decreased differentiation and contraction of patient's NCSC-derived SMCs may contribute to that aortopathy associated with BAV.

Topics: Aortic Diseases; Aortic Valve; Bicuspid Aortic Valve Disease; Biomarkers; Cell Culture Techniques; Cell Differentiation; Heart Valve Diseases; Humans; Immunophenotyping; Induced Pluripotent Stem Cells; Muscle Contraction; Myocytes, Smooth Muscle; Myosin Heavy Chains; Neural Crest; Phenotype; Signal Transduction; TOR Serine-Threonine Kinases; Transforming Growth Factor beta

Fibroblast growth factor 21 (FGF21) is an important regulator in glucose and lipid metabolism, and has been considered as a potential therapy for diabetes. The effect of FGF21 on the development and progression of diabetes-induced pathogenic changes in the aorta has not currently been addressed. To characterize these effects, type 1 diabetes was induced in both FGF21 knockout (FGF21KO) and C57BL/6 J wild type (WT) mice via multiple-dose streptozotocin injection. FGF21KO diabetic mice showed both earlier and more severe aortic remodeling indicated by aortic thickening, collagen accumulation and fibrotic mediator connective tissue growth factor expression. This was accompanied by significant aortic cell apoptosis than in WT diabetic mice. Further investigation found that FGF21 deletion exacerbated aortic inflammation and oxidative stress reflected by elevated expression of tumor necrosis factor α and transforming growth factor β, and the accumulation of 3-nitrotyrocine and 4-Hydroxynonenal. FGF21 administration can reverse the pathologic changes in FGF21KO diabetic mice. These findings demonstrate that FGF21 deletion aggravates aortic remodeling and cell death probably via exacerbation of aortic inflammation and oxidative stress. This marks FGF21 as a potential therapy for the treatment of aortic damage due to diabetes.

Topics: Aldehydes; Animals; Aorta; Aortic Diseases; Apoptosis; Collagen; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Fibroblast Growth Factors; Fibrosis; Gene Deletion; Genetic Predisposition to Disease; Male; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase Type III; Oxidative Stress; Phenotype; Signal Transduction; Time Factors; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Tyrosine; Vascular Remodeling

The clinical course of many patients with a bicuspid aortic valve (BAV) is complicated by ascending aortic dilatation. Currently, the indication for aortic surgery is solely based on the aortic diameter and subsequently only a small proportion of BAV patients undergoing valve surgery require concomitant ascending aortic replacement based on these recommendations. Unfortunately, a substantial number of BAV patients still develop aortic dilatation in the future and would potentially benefit from a more aggressive approach towards ascending aortic replacement. We, therefore, designed this study to identify molecular biological markers in the aortic wall predictive of aortopathy in BAV.. Ascending aortic wall specimen of BAV (n = 36) and tricuspid aortic valve (TAV) (n = 23), both without and with (>44 mm) dilatation were investigated histologically and immunohistochemically for the expression of markers for vascular remodelling [transforming growth factor (TGF)-β, phosphorylated Smad2, matrix metalloproteinase 9 (MMP9)], cellular differentiation [c-Kit, phosphorylated-c-Kit, hypoxia-inducable factor-1 alpha (HIF1α)] and haemodynamic influences on the aortic wall [endothelial nitric oxide (eNOS)].. All BAV patients showed significantly less inflammation (P < 0.001) and an altered intima/media ratio when compared with TAV patients. The expression of markers of a signalling pathway characteristic for cellular dedifferentiation, as exemplified by the marked expression of c-Kit, phosphorylated c-Kit and HIF1α; in the dilated BAV group was however completely comparable with only a subgroup of the non-dilated BAV (BAb), whereas the remainder of the non-dilated BAV group (BAa) was significantly distinct. This difference between the dilated BAV and BAa was further confirmed in the expression of TGF-β, phosphorylated Smad2, MMP9 and eNOS. Besides the expression pattern, similarity in the dilated BAV and BAb was also noted clinically in the most common variant of commissure position and conjoined raphe of the BAV. Based on these observations, we consider the BAb group a likely candidate for future dilatation as opposed to the BAa group.. Using a panel of molecular tissue markers, the non-dilated BAV patients can be divided into groups susceptible and non-susceptible to aortopathy.

Topics: Adult; Aged; Aorta; Aortic Diseases; Aortic Valve; Bicuspid Aortic Valve Disease; Biomarkers; Cohort Studies; Female; Heart Valve Diseases; Humans; Immunohistochemistry; Male; Middle Aged; Muscle, Smooth, Vascular; Nitric Oxide; Phosphorylation; Prognosis; Proto-Oncogene Proteins c-kit; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta

Patients with Marfan syndrome (MFS) are at risk for cardiovascular disease. Marfan associated mutations in the FBN1 gene lead to increased transforming growth factor-β (TGF-β) activation. The aim of this study was to investigate the role of plasma TGF-β as a biomarker for progressive aortic root dilatation and dissection.. Plasma TGF-β level and aortic root diameter by means of echocardiography were assessed in 99 MFS patients. After 38 months of follow-up measurement of the aortic root was repeated and individual aortic root growth curves were constructed. Clinical events were evaluated. The primary composite endpoint was defined as aortic dissection and prophylactic aortic root replacement.. TGF-β levels were higher in MFS patients as compared to healthy controls (109 pg/ml versus 54 pg/ml, p<0.001). Higher plasma TGF-β levels correlated with larger aortic root dimensions (r=0.26, p=0.027), previous aortic root surgery (161 pg/ml versus 88 pg/ml, p=0.007) and faster aortic root growth rate (r=0.42, p<0.001). During 38 months of follow-up, 17 events were observed (four type B dissections and 13 aortic root replacements). Patients with TGF-β levels above 140 pg/ml had a 6.5 times higher risk of experiencing the composite endpoint compared to patients with TGF-β levels below 140 pg/ml (95% CI: 2.1 to 20.1, p=0.001) with 65% sensitivity and 78% specificity.. Elevated TGF-β level in patients with Marfan syndrome is correlated with larger aortic root diameters and faster aortic root growth. Level of plasma TGF-β predicts cardiovascular events and might serve as a prognostic biomarker in MFS.

Topics: Adolescent; Adult; Aortic Diseases; Biomarkers; Disease Progression; Female; Follow-Up Studies; Humans; Male; Marfan Syndrome; Middle Aged; Prognosis; Transforming Growth Factor beta; Young Adult

Marfan syndrome (MFS) is an inherited disorder of connective tissue caused by mutations in the gene for fibrillin-1 (FBN1). The complex pathogenesis of MFS involves changes in transforming growth factor beta (TGF-β) signaling and increased matrix metalloproteinase (MMP) expression. Fibrillin-1 and elastin have repeated Gly-x-x- Pro-Gly (GxxPG) motifs that can induce a number of effects including macrophage chemotaxis and increased MMP activity by induction of signaling through the elastin-binding protein (EBP). In this work, we test the hypothesis that antagonism of GxxPG fragments can suppress disease progression in the Marfan aorta. Fibrillin-1 underexpressing mgR/mgR Marfan mice were treated with weekly intraperitoneal (i.p.) injections of an antibody directed against GxxPG fragments. The treatment was started at 3 weeks of age and continued for 8 weeks. The treatment significantly reduced MMP-2, MMP-9 and pSmad2 activity, as well as fragmentation and macrophage infiltration in the aorta of the mgR/mgR mice. Additionally, airspace enlargement and increased pSmad2 activity in the lungs of mgR/mgR animals were prevented by the treatment. Our findings demonstrate the important role of secondary cellular events caused by GxxPG-containing fragments and matrix-induced inflammatory activity in the pathogenesis of thoracic aortic aneurysm (TAA) in mgR/mgR mice. Moreover, the results of the current study suggest that antagonism of the effects of GxxPG fragments may be a fruitful therapeutic strategy in MFS.

Topics: Amino Acid Motifs; Animals; Antibodies, Monoclonal; Aortic Aneurysm, Thoracic; Aortic Diseases; Blotting, Western; Disease Models, Animal; Elastin; Enzyme-Linked Immunosorbent Assay; Fibrillin-1; Fibrillins; Immunohistochemistry; Latent TGF-beta Binding Proteins; Macrophages; Marfan Syndrome; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Microfilament Proteins; Mutation; Peptides; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta; Up-Regulation

The TGF-β superfamily members transforming growth factor-β (TGF-β/Activin) and bone morphogenetic proteins (BMP) have been implicated in the pathogenesis of atherosclerosis. However, their role in human disease remains controversial. In this study we used Smad phosphorylation as a read out for TGF-β and BMP signaling during the initiation, progression and (de)stabilization of human atherosclerotic disease.. A systematic analysis was performed in 114 peri-renal aortic patches (stained with Movat Pentachrome, H&E, pSmad2, pSmad1,5,8 and PAI-1) covering the entire atherosclerotic spectrum (van Dijk, 2010). Immunostaining against T-cells (CD3) and monocytes and macrophages (CD68) was used to explore a putative association between TGF-β and BMP signaling and vascular inflammation.. Smad phosphorylation was present within the normal arterial wall in approximately 10% of the endothelial cells and intimal smooth muscle cells. A significant increase in pSmad2 and pSmad1,5,8 positivity was found in non-progressive lesions (>50% positivity). No further increase or decrease was found in the progressive atherosclerotic lesions, vulnerable and stabilized lesions. No association was found between TGF-β and BMP signaling and CD3 and CD68 expression, nor cap thickness.. Activation of the TGF-β and BMP pathways is an early event in atherosclerotic lesion formation. No significant relationships were found between Smad phosphorylation and vessel wall inflammation or plaque vulnerability.

Topics: Adolescent; Adult; Aged; Aorta; Aortic Diseases; Atherosclerosis; Bone Morphogenetic Proteins; Case-Control Studies; Child; Child, Preschool; Disease Progression; Female; Humans; Immunohistochemistry; Macrophages; Male; Middle Aged; Netherlands; Phosphorylation; Signal Transduction; Smad Proteins; T-Lymphocytes; Tissue Banks; Transforming Growth Factor beta; Young Adult

Nicotinic acetylcholine receptor α1 (nAChRα1) was recently identified as a functional cell receptor for urokinase, a potent atherogenic molecule. Here, we test the hypothesis that nAChRα1 plays a role in the pathogenesis of atherosclerosis.. Apolipoprotein E-deficient mice were initially fed a Western diet for 8 wks. Plasmid DNA encoding scramble RNA (pscr) or siRNA (psir2) for nAChRα1 was injected into the mice (n=16) using an aortic hydrodynamic gene transfer protocol. Four mice from each group were sacrificed 7 days after the DNA injection to confirm the nAChRα1 gene silencing. The remaining mice continued on a Western diet for an additional 16 wks.. The nAChRα1 was up-regulated in aortic atherosclerotic lesions. A 78% knockdown of the nAChRα1 gene resulted in remarkably less severe aortic plaque growth and neovascularization at 16 wks (both P<0.05). In addition, significantly fewer macrophages (60% less) and myofibroblasts (80% less) presented in the atherosclerotic lesion of the psir2-treated mice. The protective mechanisms of the nAChRα1 knockdown may involve up-regulating interferon-γ/Y box protein-1 activity and down-regulating transforming growth factor-β expression.. The nAChRα1 gene plays a significant role at the artery wall, and reducing its expression decreases aortic plaque development.

Topics: Actins; Animals; Aorta; Aortic Diseases; Atherosclerosis; Female; Gene Silencing; Interferon-gamma; Macrophages; Mice; Myofibroblasts; Receptors, Nicotinic; Transcription Factors; Transforming Growth Factor beta; Up-Regulation

The multiligand RAGE (receptor for advanced glycation end products) contributes to atherosclerosis in apolipoprotein (Apo)E-null mice.. To delineate the specific mechanisms by which RAGE accelerated atherosclerosis, we performed Affymetrix gene expression arrays on aortas of nondiabetic and diabetic ApoE-null mice expressing RAGE or devoid of RAGE at nine weeks of age, as this reflected a time point at which frank atherosclerotic lesions were not yet present, but that we would be able to identify the genes likely involved in diabetes- and RAGE-dependent atherogenesis.. We report that there is very little overlap of the genes that are differentially expressed both in the onset of diabetes in ApoE-null mice, and in the effect of RAGE deletion in diabetic ApoE-null mice. Pathway-Express analysis revealed that the transforming growth factor-beta pathway and focal adhesion pathways might be expected to play a significant role in both the mechanism by which diabetes facilitates the formation of atherosclerotic plaques in ApoE-null mice, and the mechanism by which deletion of RAGE ameliorates this effect. Quantitative polymerase chain reaction studies, Western blotting, and confocal microscopy in aortic tissue and in primary cultures of murine aortic smooth muscle cells supported these findings.. Taken together, our work suggests that RAGE-dependent acceleration of atherosclerosis in ApoE-null mice is dependent, at least in part, on the action of the ROCK1 (rho-associated protein kinase 1) branch of the transforming growth factor-beta pathway.

Topics: Animals; Aorta; Aortic Diseases; Apolipoproteins E; Atherosclerosis; Blotting, Western; Cell Movement; Cell Proliferation; Cells, Cultured; Diabetes Mellitus, Experimental; Diabetic Angiopathies; Disease Progression; Enzyme Activation; Focal Adhesions; Gene Expression Profiling; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Confocal; Muscle, Smooth, Vascular; Oligonucleotide Array Sequence Analysis; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Reverse Transcriptase Polymerase Chain Reaction; rho-Associated Kinases; Signal Transduction; Thrombospondin 1; Time Factors; Transforming Growth Factor beta

Fibulin-4 is a member of the fibulin family, a group of extracellular matrix proteins prominently expressed in medial layers of large veins and arteries. Involvement of the FBLN4 gene in cardiovascular pathology was shown in a murine model and in three patients affected with cutis laxa in association with systemic involvement. To elucidate the contribution of FBLN4 in human disease, we investigated two cohorts of patients. Direct sequencing of 17 patients with cutis laxa revealed no FBLN4 mutations. In a second group of 22 patients presenting with arterial tortuosity, stenosis and aneurysms, FBLN4 mutations were identified in three patients, two homozygous missense mutations (p.Glu126Lys and p.Ala397Thr) and compound heterozygosity for missense mutation p.Glu126Val and frameshift mutation c.577delC. Immunoblotting analysis showed a decreased amount of fibulin-4 protein in the fibroblast culture media of two patients, a finding sustained by diminished fibulin-4 in the extracellular matrix of the aortic wall on immunohistochemistry. pSmad2 and CTGF immunostaining of aortic and lung tissue revealed an increase in transforming growth factor (TGF)beta signaling. This was confirmed by pSmad2 immunoblotting of fibroblast cultures. In conclusion, patients with recessive FBLN4 mutations are predominantly characterized by aortic aneurysms, arterial tortuosity and stenosis. This confirms the important role of fibulin-4 in vascular elastic fiber assembly. Furthermore, we provide the first evidence for the involvement of altered TGFbeta signaling in the pathogenesis of FBLN4 mutations in humans.

Topics: Aortic Aneurysm; Aortic Diseases; Cardiovascular Diseases; Child; Constriction, Pathologic; Cutis Laxa; Elastic Tissue; Extracellular Matrix Proteins; Female; Frameshift Mutation; Humans; Infant; Infant, Newborn; Male; Mutation, Missense; Signal Transduction; Skin; Transforming Growth Factor beta; Young Adult

Aortic calcification is prevalent in type II diabetes (T2DM), enhancing morbidity and tracking metabolic syndrome parameters. Ldlr(-/-) mice fed high-fat "Westernized" diets (HFD) accumulate aortic calcium primarily in the tunica media, mediated via osteogenic morphogens and transcriptional programs that induce aortic alkaline phosphatase (ALP). Because elevated TNF-alpha is characteristic of obesity with T2DM, we examined contributions of this inflammatory cytokine.. HFD promoted obesity, hyperglycemia, and hyperlipidemia, and upregulated serum TNF-alpha in Ldlr(-/-) mice. Serum haptoglobin (inflammatory marker) was increased along with aortic expression of BMP2, Msx2, Wnt3a, and Wnt7a. Dosing with the TNF-alpha neutralizing antibody infliximab did not reduce obesity, hypercholesterolemia, or hyperglycemia; however, haptoglobin, aortic BMP2, Msx2, Wnt3a, and Wnt7a and aortic calcium accumulation were downregulated by infliximab. Mice with vascular TNF-alpha augmented by a transgene (SM22-TNFalphaTg) driven from the SM22 promoter upregulated aortic Msx2, Wnt3a, and Wnt7a. Furthermore, SM22-TNFalphaTg;TOPGAL mice exhibited greater aortic beta-galactosidase reporter staining versus TOPGAL sibs, indicating enhanced mural Wnt signaling. In aortic myofibroblast cultures, TNF-alpha upregulated Msx2, Wnt3a, Wnt7a, and ALP. ALP induction was inhibited by Dkk1, an antagonist of paracrine Wnt actions.. TNF-alpha promote aortic Msx2-Wnt programs that contribute to aortic calcium accumulation in T2DM.

Topics: Alkaline Phosphatase; Animals; Anti-Inflammatory Agents; Antibodies, Monoclonal; Aorta; Aortic Diseases; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Calcinosis; Cells, Cultured; Diabetes Mellitus, Type 2; Dietary Fats; Disease Models, Animal; DNA-Binding Proteins; Fibroblasts; Haptoglobins; Homeodomain Proteins; Inflammation; Infliximab; Intercellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Microfilament Proteins; Muscle Proteins; Promoter Regions, Genetic; Receptors, LDL; RNA, Messenger; Signal Transduction; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Wnt Proteins; Wnt3 Protein; Wnt3A Protein

Advanced complicated atherosclerotic lesions have been related to many factors, including inflammation, infectious agents, and growth factors. Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP), inflammation, and growth factors have been associated with severe atherosclerotic lesions in necropsy material in recent work at our lab. The present study intends to clarify the pathogenesis of atherosclerosis, analyzing which of these elements (macrophages, MP, CP, lymphocytes, and growth factors) are associated with initial development of atherosclerotic lesions, discriminating elements related to stabilization of the plaque versus those related to subendothelial active accumulation of macrophages in living patients. Surgical ascending aorta fragments presenting mild atherosclerotic lesions from 30 coronary atherosclerotic patients were immunohistochemically quantified regarding CP, MP, T cells (CD4, CD8), B cells (CD20), macrophages (CD68), and growth factors [platelet-derived growth factor A (PDGF-A), PDGF-B, transforming growth factor-beta (TGF-beta), granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Cases were grouped according to the presence or not of active accumulation of macrophages at the subendothelium that indicates atheroma in development: group I (GI) fragments with <4 CD68+ cells/x400 field, in normal distribution (mean 1.8 +/- 1) representing stable atherosclerotic mild lesion, and GII fragments presenting >or=4 CD68+ cells/x400 field, in a non-normal distribution, mean (8.9 +/- 4.8, atheromas in progress), which was followed by increased number of lymphocytes. The median number in GI was significantly lower than that in GII: CD4 T (2.5 vs. 7.7), CD8 T (1.0 vs. 5.5), and CD20 B (1.5 vs. 5.5) cells/x400 field, p < 0.001. Percentage area positive for CP antigens was significantly lower in GI than in GII: 1.0 vs. 9.2, p < 0.001. There was a higher percentage area occupied by MP than CP in both GI and GII (7.8 vs. 13.8). There was no difference regarding mean number of growth factor-positive cells/x400 field: PDGF-A, 1.4 vs. 3.9; PDGF-B, 3.4 vs. 5.7; TGF-beta, 0.9 vs. 2.2; and GM-CSF, 2.0 vs. 2.2. Considering all cases, a positive correlation was seen between inflammatory cells and CP+ cells (r > 0.5 and p < 0.01). Growth factors did not correlate with inflammatory cells, CP, or MP and were usually seen in smooth muscle cell and fibrotic areas. Study of initial atherosclerotic lesions showed that MP is present in both kinds of lesion

Topics: Adult; Aged; Aged, 80 and over; Antigens, CD; Antigens, CD20; Antigens, Differentiation, Myelomonocytic; Aorta, Thoracic; Aortic Diseases; Atherosclerosis; B-Lymphocytes; Biopsy; Chlamydophila pneumoniae; Cytokines; Disease Progression; Female; Gram-Negative Bacteria; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Inflammation; Intercellular Signaling Peptides and Proteins; Macrophages; Male; Middle Aged; Mycoplasma pneumoniae; Platelet-Derived Growth Factor; T-Lymphocytes; Transforming Growth Factor beta

LDL receptor (LDLR)-null mice fed high-fat/cholesterol diets, a model of the metabolic syndrome, have vascular calcification (VC) worsened by chronic kidney disease (CKD) and ameliorated by bone morphogenetic protein-7 (BMP-7), an efficacious agent in treating animal models of renal osteodystrophy. Here, LDLR-/- high-fat-fed mice without CKD were shown to have significant reductions in bone formation rates, associated with increased VC and hyperphosphatemia. Superimposing CKD resulted in a low turnover osteodystrophy, whereas VC worsened and hyperphosphatemia persisted. BMP-7 treatment corrected the hyperphosphatemia, corrected the osteodystrophy, and prevented VC, compatible with skeletal phosphate deposition leading to reduced plasma phosphate and removal of a major stimulus to VC. A pathologic link between abnormal bone mineralization and VC through the serum phosphorus was supported by the partial effectiveness of directly reducing the serum phosphate by a phosphate binder that had no skeletal action. Thus, in this model of the metabolic syndrome with CKD, a reduction in bone-forming potential of osteogenic cells leads to low bone turnover rates, producing hyperphosphatemia and VC, processes ameliorated by the skeletal anabolic agent BMP-7, in part through deposition of phosphate and increased bone formation.

Topics: Animals; Aorta; Aortic Diseases; Bone and Bones; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Bone Remodeling; Calcinosis; Calcium; Chronic Disease; Chronic Kidney Disease-Mineral and Bone Disorder; Dietary Fats; Dose-Response Relationship, Drug; Female; Kidney Diseases; Male; Metabolic Syndrome; Mice; Mice, Inbred C57BL; Mice, Knockout; Parathyroid Glands; Phosphates; Receptors, LDL; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) has been implicated in the pathogenesis of human atherosclerosis but its actions during lesion progression are poorly understood. Smad2, Smad3, and Smad4 proteins are signaling molecules by which TGF-beta modulates gene transcription. Our objective was to define the actions of TGF-beta during lesion progression in humans by examining the expression of Smads in relation to TGF-beta-mediated responses.. Immunohistochemistry and reverse-transcription polymerase chain reaction demonstrated Smad2, Smad3, and Smad4 expression in macrophages of fibrofatty lesions and their upregulation after differentiation of monocytes to macrophages. The major Smad splice variants expressed by the macrophages were those that are transcriptionally most active. Macrophages also expressed cyclin inhibitors whose expression is induced via Smad proteins. The cytoplasmic location of p21(Waf1) suggests it may protect macrophages from apoptosis. Smooth muscle cells (SMCs) within the fibrofatty lesions did not express the Smad proteins or the cyclin inhibitors. SMCs of fibrous plaques expressed all 3 Smad proteins.. In human atherosclerotic lesions, the actions of TGF-beta appear restricted to SMCs in fibrous plaques and macrophages in fatty streaks/fibrofatty lesions. The lack of key TGF-beta signaling components in SMCs of fibrofatty lesions indicates impaired ability of these cells to initiate TGF-beta-mediated Smad-dependent transcriptional responses.

Topics: Adult; Aged; Aorta, Thoracic; Aortic Diseases; Arteriosclerosis; Cell Cycle Proteins; Cell Differentiation; Cyclin-Dependent Kinase Inhibitor p15; Cyclin-Dependent Kinase Inhibitor p21; Death, Sudden; DNA-Binding Proteins; Female; Fibrosis; Humans; Lipids; Macrophages; Male; Middle Aged; Monocytes; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; RNA Splicing; Signal Transduction; Smad2 Protein; Smad3 Protein; Smad4 Protein; Trans-Activators; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Suppressor Proteins

Chronic allograft dysfunction, the leading cause of solid-organ transplant failure, is characterised by histological evidence of extracellular matrix (ECM) accumulation (fibrosis). The aim of this study was to compare the effect of combined rapamycin and cyclosporine therapy on fibrosis-associated gene expression and ECM turnover during the development of allograft vasculopathy, compared with either agent alone. Lewis recipients of F344 rat thoracic-to-abdominal aorta transplants were administered rapamycin, cyclosporine, combined rapamycin and cyclosporine or no treatment. F344-to-F344 isografts served as controls. Six grafts in each group were harvested at 16 weeks. Vascular remodelling and ECM accumulation (Sirius red) were measured by computerised histomorphometry of aortic sections. Messenger RNA was extracted from frozen tissue, and expression of fibrosis-associated genes was studied by means of semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Rapamycin (0.5 mg/kg per day) or cyclosporine (5 mg/kg per day) inhibited intimal hyperplasia, medial ECM accumulation and expansive vascular remodelling (increasing vessel circumference) in rat aortic allografts. This was associated with attenuation of the graft inflammatory infiltrate and a reduction in intra-graft gelatinase, collagen III and tissue inhibitor of metalloproteinase (TIMP)-1 mRNA levels. Combined rapamycin and cyclosporine inhibited intimal hyperplasia; however, there was a lesser effect on vascular remodelling and medial ECM accumulation. Combined-treatment aortic allografts were also seen to have a more-severe inflammatory infiltrate and larger amounts of intra-graft matrix metalloproteinase (MMP)-9, transforming growth factor (TGF)-beta and TIMP-1 mRNA than those treated with monotherapy. Rapamycin and cyclosporine act synergistically to inhibit intimal hyperplasia but not the inflammatory infiltrate, allograft fibrosis or vessel remodelling. In the high-responder F344-to-Lewis rat model, effective immunosuppression is required to reduce graft fibrosis.

Topics: Animals; Aorta; Aortic Diseases; Azo Compounds; Cyclosporine; Drug Therapy, Combination; Fibrosis; Gene Expression; Graft Rejection; Immunosuppressive Agents; Matrix Metalloproteinase 9; Rats; Rats, Inbred F344; Rats, Inbred Lew; Reverse Transcriptase Polymerase Chain Reaction; Sirolimus; Transforming Growth Factor beta; Transplantation, Homologous

The vitamin K-dependent protein, matrix Gla protein (MGP) is a binding protein for bone morphogenetic protein-2 (BMP-2). Here we present additional evidence that the Ca2+-induced conformer of the vitamin K-dependent Gla region in MGP is involved in BMP-2 binding. Recombinant BMP-2 binds to the Gla-containing region of MGP in the presence of Ca2+. Immunohistochemistry showed that calcified lesions in the aortic wall of aging rats contained elevated concentrations of MGP that was poorly gamma-carboxylated and did not bind BMP-2. In contrast, we were able to identify glandular structures in the mucosa of the rat nasal septum that gave bright fluorescent signals with both antigens; confocal microscopy confirmed their colocalization. These results demonstrate that the BMP-2/MGP complex exists in vivo, consistent with a role for MGP as a BMP-2 inhibitor. Age-related arterial calcification may be a consequence of under-gamma-carboxylation of MGP, allowing unopposed BMP-2 activity.

Topics: Amino Acid Sequence; Animals; Aortic Diseases; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; Calcinosis; Calcium; Calcium-Binding Proteins; Cattle; Extracellular Matrix Proteins; Female; Fluorescent Antibody Technique; Growth Hormone; Humans; Immunohistochemistry; Matrix Gla Protein; Microscopy, Confocal; Molecular Sequence Data; Nasal Mucosa; Nasal Septum; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Transforming Growth Factor beta; Vitamin K

to compare patients with abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) with regard to risk factors for atherosclerosis, co-morbid conditions and inflammatory activity.. a total of 155 patients undergoing abdominal aortic surgery between January 1993 and October 1997: 82 (53%) had aneurysmal disease and 73 (47%) had occlusive disease. Principal risk factors were compared: age; gender; smoking; hypertension; hyperlipidaemia; diabetes mellitus; severe peripheral vascular disease (PVD) and ischaemic heart disease. Aortic wall tissue samples were obtained during surgery. A prospective blind analysis was performed for the presence of inflammatory cytokines TNF-alpha, IL-1 beta, IL-6 and TGF-beta.. the average age of AAA patients was 74 years (50-88), while that of AOD patients was 61 years (43-82) (p<0.0001). Diabetes mellitus was found to be much more prevalent in the AOD group (p<0.001), while hypertension and severe PVD were more prevalent in the AAA group (p<0.001). No differences were found concerning any of the risk factors. Inflammatory cytokine activity: AAA tissue samples contained significantly higher mean TNF-alpha and IL-6 levels compared to the AOD samples (5.6+/-2.7 x 10 E-4 vs. 4.4+/-2.7 x 10 E-5 atmoles/microl (p=0. 01), and 0.6+/-0.4 vs. 0.01+/-0.006 atmoles/microl (p=0.02) respectively). No differences were found related to IL-1 beta and TGF-beta.. (1) Patients with AAA have fewer atherosclerotic risk factors than do patients with AOD. (2) Patients with AAA and AOD have significantly different inflammatory activity. (3) The data supports the hypothesis that AAA and AOD are probably two different pathological entities.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Aortic Aneurysm, Abdominal; Aortic Diseases; Coronary Disease; Diabetes Complications; Female; Humans; Hyperlipidemias; Hypertension; Interleukin-1; Interleukin-6; Male; Middle Aged; Polymerase Chain Reaction; Prospective Studies; Risk Factors; Sex Factors; Smoking; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vascular Diseases

The temporal and spatial distribution, and relative levels of the proteoglycan decorin and collagen type I were examined during the progression of atherosclerosis in the dorsal aortas of Japanese quail selected for cholesterol induced atherosclerosis. The quail were placed on either a control or 0.5% added cholesterol diet at approximately 16 weeks of age. Dorsal aortas were collected at 1- or 2-week intervals over a 15-week period after initiating cholesterol feeding. Biochemical analysis for decorin and collagen type I showed that both increased in the cholesterol-fed birds compared to control-fed birds beginning at 9 weeks and continued through the duration of the study. Through immunohistochemical staining for decorin and collagen type I, the spatial localization of decorin and collagen type I in control and less severe plaques in cholesterol-fed birds was most prominent in the arterial adventitia. However, in severe atherosclerotic plaques, decorin was localized in foam cell regions and collagen type I was found surrounding the foam cell regions where decorin accumulated. These results demonstrated a localization of decorin in the core of the atherosclerotic plaque foam cell region with collagen type I being located on the plaque surface.

Topics: Animals; Aorta; Aortic Diseases; Arteriosclerosis; Cholesterol; Cholesterol, Dietary; Collagen; Coturnix; Decorin; Disease Progression; Enzyme-Linked Immunosorbent Assay; Extracellular Matrix; Extracellular Matrix Proteins; Lipoproteins; Male; Proteoglycans; Random Allocation; Transforming Growth Factor beta

The transforming growth factor beta (TGFbeta) superfamily plays an important role in the myocardial response to hypertrophy. We have investigated the protein expression of TGFbeta1, beta2 and beta3 in left ventricular tissue, and determined their subcellular distribution in myocytes by immunoblotting and immunocytochemistry during the development of left ventricular hypertrophy (LVH), using isoform specific antibodies to TGFbeta1, beta2 and beta3. LVH was produced in rats by aortic constriction (AC) and LV tissue was obtained at days (d)0, 1, 3, 7, 14, 21 and 42 following operation. Compared with age matched sham-operated controls (SH), TGFbeta1 levels in LV tissue of AC rats increased significantly from d1-d14 (P<0.03) concomitant with the adaptive growth of LV tissue. In contrast, TGFbeta3 levels decreased in LV tissue of AC rats from d3 post-operation (significant from d14-d42, P<0.03). No significant difference in TGFbeta2 levels were observed from SH and AC rats after operation. Antibodies to TGFbeta1 stained intercalated disks, sarcolemmal membranes and cytoplasm, but not nuclei, of cardiomyocytes on LV sections from untreated and SH rats. However, a trans-localisation of TGFbeta1 to the nuclei of cardiomyocytes was observed in AC hearts. Antibodies to TGFbeta3 stained T tubules, cytoplasm and the nuclei of cardiomyocytes from untreated and SH rats. However, by d7 post-AC operation, TGFbeta3 expression was lost rapidly from nuclei of cardiomyocytes followed by a reduction in total TGFbeta3 immunofluorescence in myocytes. Antibodies to TGFbeta2 stained sarcolemmal membranes of cardiomyocytes from both SH and AC rats without significant difference between groups. Thus, the differential pattern of protein expression and subcellular distribution of TGFbeta1, beta2 and beta3 in myocytes during the development of LVH suggests that these molecules play different roles in the response of cardiomyocytes to LVH.

Topics: Animals; Aorta, Abdominal; Aortic Diseases; Blood Pressure; Gene Expression Regulation; Heart Ventricles; Hypertrophy, Left Ventricular; Male; Myocardium; Rats; Rats, Wistar; Subcellular Fractions; Transforming Growth Factor beta; Ventricular Function, Left

Cytomegalovirus has been implicated in the development of allograft vasculopathy in heart transplant recipients. Given that allograft vasculopathy is a form of chronic rejection, it is conceivable that cytomegalovirus somehow alters the allogeneic response to the vasculature. Prior work has demonstrated that smooth muscle cells (SMCs) are highly permissive for cytomegalovirus and exhibit cytopathologic characteristics and alterations in MHC class I antigens in response to cytomegalovirus at a high multiplicity of infection (MOI).. To determine whether cytomegalovirus at low, more clinically relevant MOI, can alter SMCs phenotypically, human aortic SMCs were infected with approximately 1 plaque forming units/3000 cells of cytomegalovirus strain AD169.. One week after infection, human aortic SMCs (compared with human foreskin fibroblasts) demonstrated no cytopathologic characteristics (n = 6), released reduced amounts of intact virion into the culture media (assessed by exposing naive monolayers of human foreskin fibroblasts to media and staining for cytomegalovirus immediate-early antigen, n = 3), yet had at least, if not greater detectable total cytomegalovirus vital DNA levels. Infected HASMCs uniformly increased their expression of MHC class I antigen by 55% +/- 21% above constitutive levels (assessed by flow cytometry (n = 5, p < 0.0001). Cytomegalovirus infection resulted in an increase in interleukin-6 mRNA expression compared to control (297 +/- 63 vs 188 +/- 50, respectively; p = 0.02, n = 6) and reduced the expression of transforming growth factor-beta mRNA (802 +/- 152 vs 1201 +/- 236, respectively; p = 0.05).. These data suggest that low MOI of cytomegalovirus can infect SMCs without producing cell cytolysis and, in spite of this lack of overt infection, modulate cell surface antigens and cytokine mRNA levels that can influence allogeneic responses.

Topics: Antigens, Viral; Aortic Diseases; Cells, Cultured; Chronic Disease; Coloring Agents; Coronary Disease; Culture Media; Cytokines; Cytomegalovirus; Cytomegalovirus Infections; Cytopathogenic Effect, Viral; DNA, Viral; Fibroblasts; Gene Expression Regulation, Viral; Graft Rejection; Heart Transplantation; Histocompatibility Antigens Class I; Humans; Immediate-Early Proteins; Interleukin-6; Muscle, Smooth, Vascular; Phenotype; RNA, Messenger; Transforming Growth Factor beta; Transplantation, Homologous; Virion; Virus Replication