Immediate Early Response Gene X-1 (IEX-1) Mediates Ischemic Preconditioning-Induced Cardioprotection in Rats

Figure 8

IEX-1 promotes PKCε phosphorylation. (a) Rat hearts were locally delivered with siRNA or Ad-IEX-1, then underwent I/R (30 min/24 h) or IPC prior to I/R as indicated. Particle location of PKCε was identified by immunofluorescence assay with confocal microscopy; (b) the same heart samples were homogenated for Western blot analysis of phosphor-PKCε. (c) Time course of IEX-1 mRNA expression in neonatal rat cardiomyocytes after hypoxia preconditioning (HPC, 1 cycle of short H/R, 10 min each). (d) Effect of increasing HPC cycles on IEX-1 mRNA expression. (e) Neonatal rat cardiomyocytes were infected with adenovirus at 10 MOI for 36 h, then underwent hypoxia (4 h) and reoxygenation for the indicated time. Phosphor-PKCε were detected. (f) Cardiomyocytes were overexpressed with GFP or IEX-1. Mitochondrial particles were isolated and lysed for Western blot. (g) Cardiomyocytes were overexpressed with GFP or IEX-1 or treated with PKCε inhibitor (PKCεV1–2, 20 μM) and then subjected to H/R. versus the csiR or 0 group or corresponding time points, ^# versus csiR + IPC + I/R.

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