A polysaccharide, MDG-1, induces S1P1 and bFGF expression and augments survival and angiogenesis in the ischemic
Shuo Wang1, Zhang Zhang, Xiao Lin
1Engineering Research Center of Modern Preparation Technology of TCM, Shanghai University of Traditional Chinese Medicine, Pudong, Shanghai, 201203, People's Republic of China.
Abstract:
Ophiopogon japonicus is a traditional Chinese medicine used to treat cardiovascular disease. Recent studies have confirmed its beneficial properties, but not the mechanism of action. Herein, we investigate the anti-ischemic properties of a water-soluble beta-d-fructan (MDG-1) from Ophiopogon japonicus, and assess the cytoprotective and proangiogenic effects of MDG-1. MDG-1 protects cardiomyocyte and microvascular endothelial cells (HMEC-1) against oxygen glucose deprivation (OGD)-induced cell death, as well as protect myocardial cells from ischemia-induced death occurring after coronary artery ligation in rats. Meanwhile, MDG-1 stimulates the differentiation of HMEC-1 cells into capillary-like structures in vitro and functions as a chemoattractant in migration assays, and promotes neovascularization in ischemic myocardium. In addition, MDG-1 upregulates sphingosine kinase 1 and sphingosine-1-phosphate (S1P) receptor 1 expression. Both MDG-1 and S1P induce basic fibroblast growth factor (bFGF) expression in HMEC-1 cells. Further study revealed that both MDG-1 and S1P induce Akt and ERK phosphorylation in a dose- and time-dependent manner, an effect that is attenuated by pre-treatment with either the Akt inhibitor wortmannin or the ERK inhibitor PD98059, and MDG-1 can also induce eNOS phosphorylation and increases in production of NO. These data indicate that MDG-1 presented remarkable anti-ischemic activity and protects cardiomyocyte and HMEC-1 cells from ischemia-induced cell damage by inducing S1P1 and bFGF cytoprotective and proangiogenic effects via the S1P/bFGF/Akt/ERK/eNOS signaling pathway.
