G Protein–Coupled Receptor and S-Nitrosylation in Cardiac Ischemia
Curators: Larry H. Bernstein, MD, FCAP and Aviva Lev-Ari, PhD, RN
This recently published article delineates a role of G-protein-coupled receptor with S-nitrosylation in outcomes for acute coronary syndrome.
Convergence of G Protein–Coupled Receptor and S-Nitrosylation Signaling Determines the Outcome to Cardiac Ischemic Injury
Sci. Signal., 29 Oct 2013; 6(299), p. ra95 http:dx.doi.org/10.1126/scisignal.2004225
Abstract
Heart failure caused by ischemic heart disease is a leading cause of death in the developed world. Treatment is currently centered on regimens involving
- G protein–coupled receptors (GPCRs) or nitric oxide (NO).
These regimens are thought to target distinct molecular pathways. We showed that
- these pathways are interdependent and converge on the effector GRK2 (GPCR kinase 2) to regulate myocyte survival and function.
Ischemic injury coupled to
- GPCR activation, including GPCR desensitization and myocyte loss,
- required GRK2 activation,
and we found that cardioprotection mediated by inhibition of GRK2 depended on
- endothelial nitric oxide synthase (eNOS) and
- was associated with S-nitrosylation of GRK2.
Conversely, the cardioprotective effects of NO bioactivity were absent in a knock-in mouse with a form of GRK2 that cannot be S-nitrosylated. Because GRK2 and eNOS inhibit each other,
the balance of the activities of these enzymes in the myocardium determined the outcome to ischemic injury. Our findings suggest new insights into
- the mechanism of action of classic drugs used to treat heart failure and
- new therapeutic approaches to ischemic heart disease.
* Corresponding author. E-mail: walter.koch@temple.edu
Citation: Z. M. Huang, E. Gao, F. V. Fonseca, H. Hayashi, X. Shang, N. E. Hoffman, J. K. Chuprun, X. Tian, D. G. Tilley, M. Madesh, D. J. Lefer, J. S. Stamler, W. J. Koch, Convergence of G Protein–Coupled Receptor and S-Nitrosylation Signaling Determines the Outcome t
Editor’s Summary
Sci. Signal., 29 Oct 2013; 6(299), p. ra95 [DOI: 10.1126/scisignal.2004225]
NO More Heart Damage
Damage caused by the lack of oxygen and nutrients that occurs during myocardial ischemia can result in heart failure. A therapeutic strategy that helps to limit the effects of heart failure is to
- increase signaling through G protein–coupled receptors (GPCRs)
- by inhibiting GRK2 (GPCR kinase 2), a kinase that
- desensitizes GPCRs.
Another therapeutic strategy provides S-nitrosothiols, such as nitric oxide, which can be
- added to proteins in a posttranslational modification called S-nitrosylation.
Huang et al. found that the ability of S-nitrosothiols to enhance cardiomyocyte survival after ischemic injury required the S-nitrosylation of GRK2, a modification that inhibits this kinase. Mice bearing a form of GRK2 that could not be S-nitrosylated
- were more susceptible to cardiac damage after ischemia.
These results suggest that therapeutic strategies that promote the S-nitrosylation of GRK2 could be used to treat heart failure after myocardial ischemia.
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