elastin and Ischemia

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

WBS is a rare disorder caused by mutations in the chromosomal sub-band 7q11.23 involving the elastin gene. The clinical features (craniofacial, developmental, and cardiovascular abnormalities) are variable. The association with cardiac anomalies is a well-recognized feature, and SVAS is the most common cardiac defect found. End-stage ischemic heart disease is unusual in this setting but when it occurs, OHT remains the final therapeutic option. This decision can be difficult to determine, and it must be tailored to the individual patient based on the clinical status and concomitant cardiovascular and multisystem lesions. To date, no cases of OHT in patients with WBS have been described. We present a 14-month-old patient with WBS who developed severe LV dysfunction secondary to ischemia following a complex staged surgery for SVAS repair. He underwent successful OHT with no post-operative complications, and at three-month follow-up, he remains asymptomatic on standard immunosuppressive therapy. This case constitutes the first demonstration that OHT may be indicated for extended survival in selected children with WBS and we discuss the basic principles for extending the indication for OHT to this scenario as well as the particularities for post-transplant care.

Topics: Cardiac Catheterization; Chromosomes, Human, Pair 7; Elastin; Heart Defects, Congenital; Heart Failure; Heart Transplantation; Hemodynamics; Humans; Hypothyroidism; Immunosuppressive Agents; Infant; Ischemia; Magnetic Resonance Imaging; Male; Treatment Outcome; Ventricular Dysfunction, Left; Williams Syndrome

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

Diabetes is a risk factor for the development of cardiovascular diseases associated with impaired angiogenesis or increased endothelial cell apoptosis.. Here it is shown that angiogenic repair of ischemic hindlimbs was impaired in Lepr(db/db) mice, a leptin receptor-deficient model of diabetes, compared with wild-type (WT) C57BL/6 mice, as evaluated by laser Doppler flow and capillary density analyses. To identify molecular targets associated with this disease process, hindlimb cDNA expression profiles were created from adductor muscle of Lepr(db/db) and WT mice before and after hindlimb ischemia using Affymetrix GeneChip Mouse Expression Set microarrays. The expression patterns of numerous angiogenesis-related proteins were altered in Lepr(db/db) versus WT mice after ischemic injury. These transcripts included neuropilin-1, vascular endothelial growth factor-A, placental growth factor, elastin, and matrix metalloproteinases implicated in blood vessel growth and maintenance of vessel wall integrity.. These data illustrate that impaired ischemia-induced neovascularization in type 2 diabetes is associated with the dysregulation of a complex angiogenesis-regulatory network.

Topics: Animals; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Disease Models, Animal; Elastin; Gene Expression Profiling; Hindlimb; Ischemia; Leptin; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Microcirculation; Muscle, Skeletal; Neovascularization, Physiologic; Neuropilin-1; Oligonucleotide Array Sequence Analysis; Reverse Transcriptase Polymerase Chain Reaction; Transcription, Genetic

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

To test the hypothesis that atherosclerosis may be initiated by hypoperfusion or thrombotic occlusion of the adventitial vasa vasonum.. In a new model of atherogenesis, an early atherosclerotic lesion may be initiated by removal of the adventitia from the carotid artery of the New Zealand White rabbit, wherein lie the vasa vasorum.. Animal laboratory, University Department of Surgery and Medicine.. Immunocytochemistry was undertaken to demonstrate the presence of smooth muscle cells and macrophages within the intimal lesions. Smooth muscle cells were labelled with a monoclonal antibody designated HHF35 and macrophages were labelled with a rabbit specific, macrophage specific antibody, RAM11. CHIEF RESULTS: In rabbits fed a normal diet, at day 14, the intimal lesion was composed exclusively of smooth muscle cells. By day 28, such lesions had regressed. In rabbits fed a high cholesterol diet, at day 14, the intimal lesion was composed of a mixture of macrophages and smooth muscle cells. By day 42, the pattern of cellular distribution was such that macrophages (present as foam cells) were predominant. In the presence of persistent hypercholesterolaemia these lesions did not regress.. This new model can produce two different cellular responses that may mimic the intimal lesions seen with re-stenosis after angioplasty or in hypercholesterolaemic man and as such, might be useful in separating out these two different pathophysiologies.

Topics: Animals; Arteriosclerosis; Carotid Arteries; Carotid Artery Diseases; Collagen; Elastic Tissue; Elastin; Endothelium, Vascular; Foam Cells; Hypercholesterolemia; Immunohistochemistry; Ischemia; Macrophages; Male; Microscopy, Electron; Muscle, Smooth, Vascular; Rabbits; Thrombosis; Tunica Intima

Topics: Animals; Autoantibodies; Elastin; Fluorescent Antibody Technique; Hindlimb; Ischemia; Muscle, Smooth, Vascular; Necrosis; Peptides; Rabbits; Thromboangiitis Obliterans

Topics: Aging; Animals; Antigen-Antibody Reactions; Antigens; Aorta; Aortic Diseases; Arteriosclerosis; Cattle; Chickens; Complement Fixation Tests; Connective Tissue; Connective Tissue Cells; Cross Reactions; Dogs; Elastic Tissue; Elastin; Geese; Glycoproteins; Graft Rejection; Hemagglutination Tests; Horses; Humans; Hypersensitivity, Delayed; Hypertension; Immune Sera; Ischemia; Muscle, Smooth; Rabbits; Rats; Swine; Transplantation, Homologous

Topics: Animals; Aorta, Abdominal; Elastic Tissue; Elastin; Epithelium; Female; Histocytochemistry; Ischemia; Rats; Transplantation, Autologous; Vasa Vasorum