Inhibition of histone deacetylases triggers pharmacologic preconditioning effects against myocardial ischemic injury.
OBJECTIVE
Recent evidence has demonstrated the importance of histone deacetylases (HDAC) in the control of hypertrophic responses in the heart. However, it remains unknown whether inhibition of HDACs plays a role in myocardial ischemia and reperfusion (I/R) injury. We hypothesize that HDAC inhibition triggers preconditioning-like effects against I/R injury.


RESULTS
Isolated mouse hearts were perfused with 3 cycles of 5-minute infusion and 5-minute washout of 50 nM of trichostatin A (TSA), a potent inhibitor of HDACs to mimic early pharmacologic preconditioning. This was followed by 30 min of ischemia and 30 min of reperfusion. In addition, mice were treated with saline or TSA (0.1 mg/kg, i.p.) to investigate delayed pharmacologic preconditioning. Twenty-four hours later, the hearts were subjected to I/R. Ventricular function and infarct size were measured, and HDAC 3, 4 and 5 were assessed by Western blot and immunofluorescence. HDAC and p38 mitogen-activated protein kinase activities were determined. TSA produced marked improvements in post-ischemic ventricular function recovery and a reduction in infarct size in both early and delayed preconditioning. Cardioprotection elicited by TSA was abrogated by SB203580, an inhibitor of p38. HDAC 3, 4 and 5 proteins were detected in mouse myocardium. TSA treatments resulted in a significant inhibition of HDAC activity. HDAC inhibition caused a dramatic increase in phosphorylation of p38 and p38 activity. Notably, HDAC inhibition also resulted in remarkable acetylation of p38 at lysine residues.


CONCLUSIONS
These results suggest that inhibition of HDACs triggers pharmacologic preconditioning to protect the ischemic heart, which involves p38 activation.
Zhao
Ting C
TC
Department of Pediatrics, Women & Infants Hospital, The Warren Alpert Brown Medical School, Brown University, Providence, RI 02905, USA. Tzhao@wihri.org
Cheng
Guangmao
G
Zhang
Ling X
LX
Tseng
Yi T
YT
Padbury
James F
JF
D000818:Animals; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000378:metabolism; D006877:Hydroxamic Acids / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009203:Myocardial Infarction / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000517:prevention & control*; D009206:Myocardium / Q000201:enzymology; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D007093:Imidazoles; D011725:Pyridines; C012589:trichostatin A; D048051:p38 Mitogen-Activated Protein Kinases; D006655:Histone Deacetylases; C093642:SB 203580