Sphingosine-1-phosphate promotes the proliferation and attenuates apoptosis of Endothelial progenitor cells via S1PR1/S1PR3/PI3K/Akt pathway.

Sphingosine-1-phosphate (S1P) is a bioactive lysophospholipid that involves in numerous pathophysiological processes. Endothelial progenitor cells (EPCs) play a crucial role in endothelial repair and tumor angiogenesis. The aim of study was to determine the effects of S1P on proliferation and anti-apoptosis of EPCs and their signaling pathways. In this study, we showed that S1P, SEW2871 (a selective S1P receptor 1 (S1PR1) agonist), or CYM5541 (a selective S1P receptor 3 (S1PR3) allosteric agonist promotes the proliferation and attenuates apoptosis of bone marrow (BM)-derived EPCs. Futhermore, it was showed that S1P could promote EPCs proliferation, which could be significantly inhibited by pretreatment with CAY10444 (an S1PR3 antagonist), VPC23019 (a selective S1PR(1)/S1PR(3) antagonist), or LY294002 (a PI3K inhibitor). Moveover, we discovered that S1P could significantly attenuate H2 O2 -induced apoptosis and activation of caspase-3 in vitro, while W146 (an S1PR1 antagonist), VPC23019, or LY294002 could significantly increase the activation of caspase-3 and subsequent augmented apoptosis. Our results indicated that the protective effect of S1P is mediated by activating the PI3K/Akt pathway. In addition, S1P promotion of EPCs proliferation was observed to be mainly mediated through S1PR3 and attenuation of EPCs apoptosis induced by H2 O2 was mainly mediated through S1PR1; both of these effects are mediated by activating the PI3K/Akt pathway, which provides potentially useful therapeutic targets for coronary artery disease, diabetes mellitus, and cancer treatment.