Abstract
Purpose :
We here examined here roles of signals derived from sphingosine-1-phosphate (S1P) or its receptor type 3 (S1PR3) on neovascularization activity of human retinal microvascular endothelial cells (HRMECs) and on angiogenic growth factor expression in macrophages. Purpose was to clear the mechanism of suppression of corneal neovascularization in a mouse that lacks sphingosine-1-phosphate receptor type 3 (S1PR3) (reported by us in ARVO 2018) by using cell culture.
Methods :
(1) HRMECs were cultured on matrigel and allowed to form vessel-like structures in three dimension culture. The degree of the formation of the structure was compared in the three groups (S1P+ group, S1P+ and S1PR3 inhibitor+ group, and control group) (2) Peritoneal macrophages were harvested 4 days after i. p. oyster glycogen (5 %, sterilized) in wild-type or S1PR3-null mice. mRNA expression levels of VEGF-A in macrophages were compared and examined using real-time RT-PCR.
Results :
(1) Formation of vessel-like structute by HRMECs was promoted by S1P addition, and inhibited by further addition of S1PR3 inhibitor concentration-dependently. (2) The expression level of VEGF-A in macrophages was significantly suppressed by the loss of S1PR3.
Conclusions :
The mechanisms of inhibition of neovascularization in the absence of S1PR3, reported in ARVO 2018, include both impairment of vascular structure formation by endothelial cells and reduction of VEGF-A in macrophages.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.