Mitochondrial @entity37372 opens the mitochondrial permeability transition pore in XXXX -reperfusion.

@entity71295 @entity462 @entity71296 @entity35 @entity63 @entity46404 @entity1563 @entity37372 @entity141 @entity583 @entity2383
BACKGROUND/OBJECTIVES: Opening of the mitochondrial permeability transition pore (mPTP) is involved in @entity63 -reperfusion injury. Isoforms of @entity141 -activated @entity462 proteases, calpains, are implicated in the development of @entity583 in @entity63 -reperfusion. Growing evidence has revealed the presence of @entity2383 . We aimed to characterize mitochondrial calpains in the @entity35 heart and to investigate the roles of calpains in mPTP opening after @entity63 -reperfusion. METHODS AND RESULTS: Western blotting analysis showed the expression of  -calpain, @entity37372 and @entity71295 in mitochondria isolated from male @entity35 , but casein zymography detected only @entity37372 activity. Subcellular fractionation of mitochondria demonstrated the distribution of @entity37372 to the matrix fraction. Addition of >500 M of @entity141 to isolated mitochondria induced @entity2383 , reflecting mPTP opening, and calpain activation. @entity141 -induced @entity2383 was inhibited partially by the calpain inhibitor @entity46404 . These results support a partial contribution of calpain in the opening of the mPTP. The addition of @entity141 to the mitochondria induced inactivation of complex I of the electron transport chain, and cleavage of the @entity71296 complex I subunit, which were inhibited by calpeptin. Mitochondria isolated from @entity35 hearts that underwent 30min of @entity1563 followed by 30min of reperfusion showed activation of mitochondrial calpains, @entity71296 cleavage, complex I inactivation, and mPTP opening, which were inhibited by pretreatment with calpain inhibitor 1. CONCLUSIONS: We demonstrated for the first time the presence of mitochondrial matrix @entity37372 , and its contribution to complex I inactivation and mPTP opening after postischemic reperfusion in the @entity35 heart.
