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Arg972 Insulin receptor substrate-1 is associated with decreased serum angiotensin-converting enzyme 2 levels in acute myocardial infarction patients: in vivo and in vitro evidence.
- Source :
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Cardiovascular diabetology [Cardiovasc Diabetol] 2013 Oct 17; Vol. 12, pp. 151. Date of Electronic Publication: 2013 Oct 17. - Publication Year :
- 2013
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Abstract
- Background: Activation of the renin-angiotensin system (RAS) plays a critical role in the pathophysiology of myocardial infarction (MI) and the development of heart failure. Both angiotensin-converting enzyme 2 (ACE2) and insulin/insulin receptor substrate-1 (IRS-1) show cardioprotective effects after acute MI. The Arg972 IRS-1 polymorphism is associated with diminished activity of insulin. In the present study, we explored the association among Arg972 IRS-1, acute MI, and serum levels of ACE2.<br />Methods: A total of 711 subjects, including 351 subjects with first-time acute MI and 360 subjects without a history of MI were genotyped for Arg972 IRS-1 polymorphism. Serum levels of ACE2 and MI severity scores were determined. Primary human cardiomyocytes with overexpression of wild type IRS-1 or Arg972 IRS-1 or knockdown of endogenous IRS-1 were exposed to normoxia and hypoxia, and the expression levels of ACE2 were determined.<br />Results: The serum ACE2 level was significantly increased in acute MI patients compared with that of non-MI controls. Compared with wild type IRS-1 carriers, Arg972 IRS-1 carriers exhibited decreased serum ACE2 levels and increased MI severity scores after MI. Our in vitro data demonstrate that impairment of insulin/IRS-1/PI3K signaling by overexpression of Arg972-IRS-1, knockdown of endogenous IRS-1, or PI3K inhibitor can abolish hypoxia-induced IRS-1-associated PI3K activity and ACE2 expression in human cardiomyocytes, which suggests a causal relationship between Arg972-IRS-1 and decreased serum ACE2 levels in acute MI patients. Our in vitro data also indicate that insulin/IRS-1/PI3K signaling is required for ACE2 expression in cardiomyocytes, and that hypoxia can enhance the induction effect of insulin/IRS-1/PI3K signaling on ACE2 expression in cardiomyocytes.<br />Conclusions: This study provides the first evidence of crosstalk between insulin/IRS-1/PI3K signaling and RAS after acute MI, thereby adding fresh insights into the pathophysiology and treatment of acute MI.
- Subjects :
- Adult
Aged
Angiotensin-Converting Enzyme 2
Case-Control Studies
Cells, Cultured
Female
Genetic Predisposition to Disease
Genotype
Humans
Male
Middle Aged
Myocardial Infarction enzymology
Myocardium enzymology
Polymorphism, Single Nucleotide
Renin-Angiotensin System physiology
Severity of Illness Index
Signal Transduction physiology
Hypoxia enzymology
Insulin physiology
Insulin Receptor Substrate Proteins genetics
Myocardial Infarction genetics
Myocytes, Cardiac enzymology
Peptidyl-Dipeptidase A metabolism
Phosphatidylinositol 3-Kinases physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1475-2840
- Volume :
- 12
- Database :
- MEDLINE
- Journal :
- Cardiovascular diabetology
- Publication Type :
- Academic Journal
- Accession number :
- 24134599
- Full Text :
- https://doi.org/10.1186/1475-2840-12-151