AMP-activated protein kinase mediates erythropoietin-induced activation of endothelial nitric oxide synthase.
We investigated whether AMP-activated protein kinase (AMPK), a multi-functional regulator of energy homeostasis, participates in the regulation of erythropoietin (EPO)-mediated activation of endothelial nitric oxide synthase (eNOS) in endothelial cells (ECs) and mice. In ECs, treatment with EPO increased the phosphorylation of AMPK, acetyl-CoA carboxylase (ACC), and eNOS, as revealed by Western blot analysis. Inhibition of AMPK activation by compound C or dominant-negative AMPK mutant abrogated the EPO-induced increase in the phosphorylation of AMPK, ACC, and eNOS, as well as nitric oxide (NO) production. Additionally, suppression of AMPK activation abolished EPO-induced EC proliferation, migration and tube formation. Immunoprecipitation analysis demonstrated that AMPK mediated the EPO-induced increase in the phosphorylation of β common receptor (βCR) and the formation of a βCR-AMPK-eNOS complex. In mice, inhibition of AMPK activation by compound C markedly decreased EPO-elicited angiogenesis in Matrigel plugs. Furthermore, the phosphorylation of AMPK and eNOS was significantly higher in aortas from EPO transgenic mice than wild-type mice. Moreover, treatment with EPO neutralizing antibody greatly reduced the exercise training-induced increase in phosphorylation of AMPK and eNOS in aortas of wild-type mice. Taken together, EPO may trigger AMPK-dependent signaling, which leads to enhanced phosphorylation of βCR and eNOS, increased βCR-AMPK-eNOS complex formation, NO production, and, ultimately, angiogenesis.
Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. skshyue@ibms.sinica.edu.tw
Kuo-Hui
KH
Su
Yuan-Bin
YB
Yu
Hsin-Han
HH
Hou
Jin-Feng
JF
Zhao
Yu Ru
YR
Kou
Li-Ching
LC
Cheng
Song-Kun
SK
Shyue
Tzong-Shyuan
TS
Lee
D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000103:Acetyl-CoA Carboxylase / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D004921:Erythropoietin / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018919:Neovascularization, Physiologic / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D015398:Signal Transduction
D011720:Pyrazoles; D011743:Pyrimidines; C516138:dorsomorphin; D004921:Erythropoietin; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D055372:AMP-Activated Protein Kinases; D000103:Acetyl-CoA Carboxylase