Contribution of AdipoR1 to CTRP9-induced survival signaling in cardiac myocytes.
A, effect of AdipoR1 ablation on CTRP9-stimulated AMPK signaling. Cardiac myocytes were transfected with siRNAs against AdipoR1 or AdipoR2 or with unrelated siRNAs, followed by stimulation with CTRP9 protein (10 μg/ml) or vehicle for 15 min. The phosphorylation of ACC (P-ACC) and AMPK (P-AMPK) was determined by Western blotting. The relative phosphorylation levels of ACC and AMPK were quantified using ImageJ (mean ± S.E., n = 3). Immunoblots were normalized to the tubulin signal. B, knockdown of AdipoR1 blocks CTRP9-induced survival of cardiac myocytes. After transfection with siRNAs against AdipoR1 or AdipoR2 or with unrelated siRNAs, cardiac myocytes were cultured in the presence of CTRP9 protein (10 μg/ml) or vehicle under conditions of hypoxia/reoxygenation. TUNEL-positive nuclei were counted and quantified (mean ± S.E., n = 3). N.S., not statistically significant.