Thymosin-β4 prevents cardiac rupture and improves cardiac function in mice with myocardial infarction.

Abstract

Thymosin-β4 (Tβ4) promotes cell survival, angiogenesis, and tissue regeneration and reduces inflammation. Cardiac rupture after myocardial infarction (MI) is mainly the consequence of excessive regional inflammation, whereas cardiac dysfunction after MI results from a massive cardiomyocyte loss and cardiac fibrosis. It is possible that Tβ4 reduces the incidence of cardiac rupture post-MI via anti-inflammatory actions and that it decreases adverse cardiac remodeling and improves cardiac function by promoting cardiac cell survival and cardiac repair. C57BL/6 mice were subjected to MI and treated with either vehicle or Tβ4 (1.6 mg·kg(-1)·day(-1) ip via osmotic minipump) for 7 days or 5 wk. Mice were assessed for 1) cardiac remodeling and function by echocardiography; 2) inflammatory cell infiltration, capillary density, myocyte apoptosis, and interstitial collagen fraction histopathologically; 3) gelatinolytic activity by in situ zymography; and 4) expression of ICAM-1 and p53 by immunoblot analysis. Tβ4 reduced cardiac rupture that was associated with a decrease in the numbers of infiltrating inflammatory cells and apoptotic myocytes, a decrease in gelatinolytic activity and ICAM-1 and p53 expression, and an increase in the numbers of CD31-positive cells. Five-week treatment with Tβ4 ameliorated left ventricular dilation, improved cardiac function, markedly reduced interstitial collagen fraction, and increased capillary density. In a murine model of acute MI, Tβ4 not only decreased mortality rate as a result of cardiac rupture but also significantly improved cardiac function after MI. Thus, the use of Tβ4 could be explored as an alternative therapy in preventing cardiac rupture and restoring cardiac function in patients with MI.

• Authors: Hongmei Peng, Jiang Xu, Xiao-Ping Yang, Xiangguo Dai, Edward L Peterson, Oscar A Carretero, Nour-Eddine Rhaleb
• Journal: American journal of physiology. Heart and circulatory physiology (Am J Physiol Heart Circ Physiol) Vol. 307 Issue 5 Pg. H741-51 (Sep 01 2014) ISSN: 1522-1539 [Electronic] United States
• PMID: 25015963 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 the American Physiological Society.

Chemical References

• Tumor Suppressor Protein p53
• Intercellular Adhesion Molecule-1
• thymosin beta(4)
• Thymosin

Topics

• Animals
• Apoptosis
• Echocardiography
• Heart Rupture, Post-Infarction (metabolism, physiopathology, prevention & control)
• Intercellular Adhesion Molecule-1 (genetics, metabolism)
• Male
• Mice
• Mice, Inbred C57BL
• Myocytes, Cardiac (drug effects, metabolism)
• Thymosin (pharmacology, therapeutic use)
• Tumor Suppressor Protein p53 (genetics, metabolism)
• Ventricular Function, Left