Abstract 17681: Hydrogen Sulfide Attenuates Inflammasome Formation Following Myocardial Ischemia/Reperfusion Injury
Background: The infarct-sparing and anti-inflammatory effects of hydrogen sulfide (H2S) following ischemic injury have been demonstrated in the heart and other organs. Whether H2S attenuates inflammasome formation which is responsible for amplification of the inflammatory response and further loss of functional myocardium through caspase-1 activation following ischemia/reperfusion injury (I/R) is unknown.
Methods and Results: To study the effect of H2S on the classical pathway of inflammasome formation, adult primary rat cardiomyocytes were challenged with lipopolysaccharide (LPS; 100 ηg/ml, for 2 h) and ATP (5 mM, for 1 h) in the presence or absence of the H2S donor, Na2S (10 µM). The expression of apoptosis speck-like protein containing a caspase-recruitment domain (ASC) aggregates was measured using immunofluorescence whereas caspase-1 activity was measured using a fluorescent substrate. Cell death was assessed by trypan blue staining. To examine the effect of H2S in vivo, adult male CD-1 mice were treated with Na2S (100 µg/kg, ip) or vehicle (saline) 1 h prior to 30 min of regional ischemia followed by reperfusion for 24 h. The hearts were then harvested for assessment of ASC aggregates (immunofluorescence) and caspase-1 activity (enzymatic assay). Na2S attenuated the formation of ASC aggregates (47% reduction, P<0.01), caspase-1 activity (Fig. A) and cell death (53% reduction, P<0.01) in cardiomyocytes challenged with LPS+ATP as compared to control cells. Similarly, Na2S blunted inflammasome formation in the heart [ASC aggregates in the zone bordering the infarct (by 74%) and caspase-1 activity (Fig. B)] following regional myocardial I/R.
Conclusion: Na2S, a H2S donor, inhibits inflammasome formation in cardiomyocytes in vitro and in vivo. We propose that, in addition to its infarct-limiting capacity, H2S possesses an anti-inflammatory effect preventing caspase-1 activation and inflammatory complications following I/R injury. .
- © 2012 by American Heart Association, Inc.