23 The Role of AMPK and PKCε in the Attenuation of ET-1 Induced Cardiomyocyte Hypertrophy by RIC Human Serum

Abstract

Rationale We have previously shown that serum from healthy volunteers who have undergone Remote Ischaemic Conditioning (RIC) reduces hypertrophy in rat cardiomyoblasts. Here we investigated the roles of AMPK and PKCe in this process. Methodology Blood was taken from healthy volunteers after 3 cycles of 5 min of upper arm cuff inflation/deflation and the serum applied to H9c2 cardiomyoblasts in culture. Cells were treated with endothelin-1 (ET-1) to stimulate hypertrophy, and cell area determined using immunofluorescence at 48 h. The role of AMPK-signalling in the anti-hypertrophic effect of RIC-serum was probed using the AMPK inhibitor compound-C and AMPK phosphorylation and PKCe translocation were analysed using Western blots. Results ET-1 increased cell surface area by >45% from 1.47 x 104 ± 0.08 μm 2 in control cells to 2.14 x 104 ± 0.09 μm 2 in ET-1 treated cells (n = 8, >1000 cells per treatment, p 2 (p 2 (p 2 ; ns). RIC-serum caused a transient translocation of PKCe after 30 min (76.3%), which dissipated after 48 h to be replaced by a significant increase in cytosolic PKCe (3.4 ± 0.5 fold, p Conclusion Our data suggests that PKCe and AMPK-signalling are involved in the anti-hypertrophic action of RIC-serum.