Cross-talk between calpain and caspase-3 in penumbra and core during focal cerebral ischemia-reperfusion.
OBJECTIVE
Some data have shown the functional connection between calpain and caspase-3. Here, we investigated the cross-talk between calpain and caspase-3 in penumbra and core during focal cerebral ischemia-reperfusion.


METHODS
The activities of calpain and the levels of calpastatin, microtubule-associated protein-2 (MAP-2), and spectrin in penumbra and core at 3 or 23 h of reperfusion (R 3 h or R 23 h) after 1-h focal cerebral ischemia in rats were determined in sham- or caspase-3 inhibitor z-DEVD-CHO-treated rats.On the other hand, the determination of the activities of caspase-3 and the levels of MAP-2 and spectrin was done in sham- or calpain-inhibitor I-treated rats.


RESULTS
z-DEVD-CHO (600 ng/rat, i.c.v.) markedly reduced the mu- and m-calpain activities in penumbra and the m-calpain activities in core at R 3 h and R 23 h, and enhanced the calpastatin levels in penumbra at R 3 h and in core at R 3 h and R 23 h significantly; however, it had no significant effects on the mu-calpain activities in core and the calpastatin levels in penumbra at R 23 h. Calpain inhibitor I (0.8 mg/rat, i.c.v.) markedly reduced the caspase-3 activities in core at R 3 h and R 23 h, but not in penumbra. Both calpain and caspase-3 inhibitors increased the levels of MAP-2 and spectrin in penumbra and core significantly after focal cerebral ischemia-reperfusion.


CONCLUSIONS
Our data provide direct evidence to demonstrate the cross-talk between calpain and caspase-3 in penumbra and core during focal cerebral ischemia-reperfusion.
D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism*; D061945:Caspase Inhibitors; D006023:Glycoproteins / Q000494:pharmacology; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008954:Models, Biological; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion; D013049:Spectrin / Q000378:metabolism
D002135:Calcium-Binding Proteins; D061945:Caspase Inhibitors; D006023:Glycoproteins; D008869:Microtubule-Associated Proteins; D011480:Protease Inhibitors; C039304:calpain inhibitors; D013049:Spectrin; C033668:calpastatin; D002154:Calpain; D053148:Caspase 3; C449000:m-calpain; C449002:mu-calpain