Sphingosine-1-phosphate에 의한 중간엽 줄기세포의 이동과 평활근세포로의 분화

Abstract

Migration and differentiation of mesenchymal stem cells are crucial for tissue regeneration in response to injury. Sphingosine-1-phosphate (S1P) is a bioactive lipid that regulates a variety of biological processes, including proliferation, survival, differentiation and motility. In the present study, we determined the role of S1P in migration and differentiation of human bone marrow-derived mesenchymal stem cells (BMSCs). S1P stimulated migration of BMSCs in a dose- and time-dependent manner, and pre-incubation of the cells with pertussis toxin completely abrogated S1P-induced migration, suggesting involvement of Gi-coupled receptors in S1P-induced cell migration. S1P elicited elevation of intracellular concentration of Ca 2+ ([Ca 2+ ]i) and pretreatment with VPC23019, an antagonist of S1P₁/S1P₃, blocked S1P-induced migration and increase of [Ca 2+ ]i. Small interfering RNA-mediated knockdown of endogenous S1P1 attenuated S1P-induced migration of BMSCs. Furthermore, S1P treatment induced expression of α-smooth muscle actin (α-SMA), a smooth muscle marker, and pretreatment with VPC23019 abrogated S1P-induced α-SMA expression. S1P induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), and pretreatment of cells with SB202190, an inhibitor of p38 MAPK, or adenoviral overexpression of a dominant-negative mutant of the p38 MAPK blocked S1P-induced cell migration and α-SMA expression. Taken together, these results suggest that S1P stimulates migration and smooth muscle differentiation of BMSCs through an S1P1-p38 MAPK-dependent mechanism.