Thymosin β4 peptid szívfejlődésre és szívizomsejtek túlélésére gyakorolt hatásának vizsgálata

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Thymosin ␤4 Is Cardioprotective after Myocardial Infarction

ABSTRACT: Heart disease is a leading cause of death in newborns and in adults. Efforts to promote cardiac repair by introduction or recruitment of exogenous stem cells hold promise but typically involve isolation and introduction of autologous or donor progenitor cells. We have found that the G-actin-sequestering peptide thymosin ␤4 promotes myocardial and endothelial cell migration in the embryonic heart and retains this property in postnatal cardiomyocytes. Survival of embryonic and postnatal cardiomyocytes in culture was also enhanced by thymosin ␤4. We found that thymosin ␤4 formed a functional complex with PINCH and integrin-linked kinase (ILK), resulting in activation of the survival kinase Akt/PKB, which was necessary for thymosin ␤4's effects on cardiomyocytes. After coronary artery ligation in mice, thymosin ␤4 treatment resulted in upregulation of ILK and Akt activity in the heart, enhanced early myocyte survival, and improved cardiac function. These findings suggest that thymosin ␤4 promotes cardiomyocyte and endothelial migration, survival, and repair and may be a novel therapeutic target in the setting of acute myocardial damage

Gene Expression Analysis of Zebrafish Heart Regeneration

Mammalian hearts cannot regenerate. In contrast, zebrafish hearts regenerate even when up to 20% of the ventricle is amputated. The mechanism of zebrafish heart regeneration is not understood. To systematically characterize this process at the molecular level, we generated transcriptional profiles of zebrafish cardiac regeneration by microarray analyses. Distinct gene clusters were identified based on temporal expression patterns. Genes coding for wound response/inflammatory factors, secreted molecules, and matrix metalloproteinases are expressed in regenerating heart in sequential patterns. Comparisons of gene expression profiles between heart and fin regeneration revealed a set of regeneration core molecules as well as tissue-specific factors. The expression patterns of several secreted molecules around the wound suggest that they play important roles in heart regeneration. We found that both platelet-derived growth factor-a and -b (pdgf-a and pdgf-b) are upregulated in regenerating zebrafish hearts. PDGF-B homodimers induce DNA synthesis in adult zebrafish cardiomyocytes. In addition, we demonstrate that a chemical inhibitor of PDGF receptor decreases DNA synthesis of cardiomyocytes both in vitro and in vivo during regeneration. Our data indicate that zebrafish heart regeneration is associated with sequentially upregulated wound healing genes and growth factors and suggest that PDGF signaling is required

β-thymosins and interstitial lung disease: study of a scleroderma cohort with a one-year follow-up

Background: beta-thymosins play roles in cytoskeleton rearrangement, angiogenesis, fibrosis and reparative process, thus suggesting a possible involvement in the pathogenesis of systemic sclerosis. The aim of the study was to investigate the presence of thymosins beta(4), beta(4) sulfoxide, and beta(10) in bronchoalveolar lavage fluid of scleroderma patients with interstitial lung disease and the relation of these factors with pulmonary functional and radiological parameters. Methods: beta-thymosins concentrations were determined by Reverse Phase-High Performance Liquid Chromatography-Electrospray-Mass Spectrometry in the bronchoalveolar lavage fluid of 46 scleroderma patients with lung involvement and of 15 controls. Results: Thymosin beta(4), beta(4) sulfoxide, and beta(10) were detectable in bronchoalveolar lavage fluid of patients and controls. Thymosin beta(4) levels were significantly higher in scleroderma patients than in controls. In addition, analyzing the progression of scleroderma lung disease at one-year follow-up, we have found that higher thymosin beta(4) levels seem to have a protective role against lung tissue damage. Thymosin beta(4) sulfoxide levels were higher in the smokers and in the scleroderma patients with alveolitis. Conclusions: We describe for the first time beta-thymosins in bronchoalveolar lavage fluid and their possible involvement in the pathogenesis of scleroderma lung disease. Thymosin beta(4) seems to have a protective role against lung tissue damage, while its oxidation product mirrors an alveolar inflammatory statu

Increased Expression of Integrin-Linked Kinase Improves Cardiac Function and Decreases Mortality in Dilated Cardiomyopathy Model of Rats

AIMS: Integrin-linked kinase (ILK) is a multifunctional kinase linking the extracellular matrix to intracellular signaling pathways, whose activation in the heart gives rise to a number of functional consequences. The aim of this study is to demonstrate the therapeutic and survival benefit of cardiac ILK overexpression in a rat model of dilated cardiomyopathy. METHODS AND RESULTS: The dilated cardiomyopathy model was generated in rats by intraperitoneal administration of six equal doses of doxorubicin over a 2 week period. Five weeks after the first injection, echocardiographic analysis demonstrated impaired cardiac function and, at that point, recombinant adenoviral vector harboring ILK cDNA or vehicle was injected into the myocardium, and the rats re-studied 4 weeks later. Compared with vehicle injection, ILK treatment ameliorated inflammatory cell infiltration and cardiomyocyte degeneration, as well as left ventricular dilation and dysfunction. ILK treatment was also associated with a reduction in apoptosis and an increase in proliferation of cardiomyocytes, as well as decreased oxidative stress and autophagic vacuole accumulation. Importantly, mortality was lower in rats following ILK treatment than in those following vehicle injection. In cultured neonatal rat cardiomyocytes, we also found that ILK overexpression protected against doxorubicin-induced apoptosis, giving rise to an increase in their proliferation. CONCLUSIONS: These data demonstrate for the first time that ILK gene therapy improves cardiac function and survival in a model of dilated cardiomyopathy, and this may be mediated through suppression of inflammation, prevention of ventricular remodeling, inhibition of cardiomyocyte apoptosis and autophagy, and stimulation of cardiomyocyte proliferation