Abstract
AMP-activated protein kinase (AMPK) activation plays a central role in cellular metabolic homeostasis. Although AMPK is known for its roles in energy homeostasis, numerous recent studies have suggested broader protective roles in inflammation and hypertension. Chemokine CCL5 has shown down-regulatory effects on angiotensin II (Ang II)-induced hypertensive mediators as well as VSMCs proliferation in spontaneously hypertensive rats (SHR) VSMCs. In the present study, we investigated the relationship between CCL5 and AMPK in the anti-hypertensive effects of CCL5 in SHR VSMCs. CCL5 increased AMPK phosphorylation and attenuated Ang II-induced AMPK inhibition. AMPK activation induced by CCL5 was mediated mainly through the AT2 R pathway. Activation of dimethylarginine dimethylaminohydrolase (DDAH)-1 by CCL5 resulted in AMPK activation as well as attenuation of Ang II-induced AMPK inhibition. In addition, AMPK activation induced by CCL5 was partially responsible for the inhibitory effects of CCL5 on Ang II-induced 12-lipoxygenase (12-LO) and endothelin (ET)-1 expression, and the inhibitory effect of CCL5 on Ang II-induced VSMCs proliferation was also mediated via AMPK activation in SHR VSMCs. In conclusion, CCL5 induces activation of AMPK via DDAH-1 activity in SHR VSMCs, and activation of AMPK is partially responsible for the inhibitory effects of CCL5 on Ang II-induced hypertensive mediators. These results suggest that activation of AMPK by CCL5 potentially expands the anti-hypertensive role of CCL5 in SHR VSMCs.