Extracellular nucleotides and adenosine independently activate AMP-activated protein kinase in endothelial cells: involvement of P2 receptors and adenosine transporters.

ABSTRACT: AMP-activated protein kinase (AMPK) plays a key role in the regulation of energy homeostasis and is activated in response to cellular stress, including hypoxia/ischemia and hyperglycemia. The stress events are accompanied by rapid release of extracellular nucleotides from damaged tissues or activated endothelial cells (EC) and platelets. We demonstrate that extracellular nucleotides (ATP, ADP, and UTP, but not UDP) and adenosine independently induce phosphorylation and activation of AMPK in human umbilical vein EC (HUVEC) by the mechanism that is not linked to changes in AMP:ATP ratio. HUVEC express NTPDases, as well as 5'-nucleotidase; hence, nucleotides can be metabolized to adenosine. However, inhibition of 5'-nucleotidase had no effect on ATP/ADP/UTP-induced phospho- rylation of AMPK,

SUBMITTER: da Silva CG 

PROVIDER: S-EPMC2830086 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature