Post-translational modifications (PTM) and protein translocation into mitochondria (MITO) after ischemia-reperfusion (I-R) and indirect (ischemic postconditioning, I-PostC) or direct (pharmacological PostC, P-PostC) targeting of MITO

I-PostC or P-PostC in the early reperfusion phase can limit I-R injury. The I-PostC favors NO and redox signaling with S-nitrosylation (SNO) of proteins and phosphorylation (Phospho) of RISK and SAFE elements, which converge on MITO. Whether P-PostC induces a similar signaling modulation and protein translocation within MITO is unknown. We compared the effects of I-PostC and P-PostC on RISK and SAFE pathways, and markers of apoptosis and autophagy in cytosolic (CF) and mitochondrial (MF) fractions. Isolated rat hearts underwent 1) Sham perfusion; 2) 30-min I plus 2-hours R; 3) I-PostC (5 intermittent cycles of 10-s R and 10-s I immediately after the 30-min I), or 4) P-PostC (infusion of Diazoxide in the first 3-min of 2-h R). Phospho and SNO of proteins were studied by Western blotting and biotin switch assay, respectively. Both I-PostC and P-PostC induced a significant Phospho of elements of RISK and SAFE; in particular Phospho-Akt and Phospho-STAT3 were transolocated into the MITO. On the contrary, Phospho-PKCδ appears mainly located in CF and MF during I-R than after I-PostC or P-PostC. Cleaved caspase-3 (index of apoptosis) and beclin-1 (index of autophagy) levels were reduced by either I-PostC or P-PostC. Both maneuvers increased the levels of SNO of proteins within MF. Indirect (I-PostC) or direct (P-PostC) targeting of MITO activate similar pathways (RISK and SAFE), PTM (Phospho and SNO) and translocation of proteins; thus decreasing apoptosis and autophagic markers.