Cyclosporine-A mimicked the ischemic pre- and postconditioning-mediated cardioprotection in hypertensive rats: Role of PKCε

LF GONZÁLEZ ARBELÁEZ; CIOCCI PARDO A; FANTINELLI JC; MARÍA S MOSCA

EXPERIMENTAL AND MOLECULAR PATHOLOGY.

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2016

0014-4800

Our aim was to assess the action of cyclosporine-A (CsA) against reperfusion injury in spontaneously hypertensiverats (SHR) compared to the effects of ischemic pre- (IP) and postconditioning (IPC), examining the roleplayed by PKCε. Isolated hearts were submitted to the following protocols: IC: 45 min global ischemia (GI) and1 h reperfusion (R); IP: a cycle of 5 min GI and 10 min of R prior to 45 min-GI; and IPC: three cycles of 30 s-GI/30 s-R at the start of R. Other hearts of the IC, IP and IPC groups received CsA (mitochondrial permeability transitionpore inhibitor) or chelerythrine (Che, non-selective PKC inhibitor). Infarct size (IS) was assessed. TBARSand reduced glutathione (GSH) content ? as parameters of oxidative damage, the expression of P-Akt, P-GSK-3β, P-PKCε and cytochrome c (Cyc) release ? as an index of mitochondrial permeability and the response of isolatedmitochondria to Ca2+ were also measured. IS similarly decreased in preconditioned, postconditioned andCsA treated heart showing the highest values in the combinations IP + CsA and IPC + CsA. TBARS decreasedand GSH was partially preserved after all interventions. The content of P-Akt, P-GSK-3β and P-PKCε increasedin cytosol and decreased in mitochondria after IP and IPC. In CsA treated hearts these enzymes increased inboth fractions reaching the highest values. Cyc release was attenuated and the response of mitochondria toCa2+ was improved by the interventions. The beneficial effects of IP and IPC were annulled when PKC wasinhibitedwith Che. A PKCε/VDAC association was also detected. These data show that, in SHR, the CsA treatmentmimicked and reinforced the cardioprotective action afforded by IP and IPC inwhich PKCε-mediated attenuationof mitochondrial permeability appears as the main mechanism involved.