Apelin-13 Can Promote The Wharton’ Jelly-derived Mesenchymal Stem Cells Differentiating And Forming Vascular Networks

Objective: To explore the role of apelin in regulation of stem cell directional differentiation into vascular net.Method: Human umbilical cord( WJ-MSCs) used by tissue adherence method.The immunophenotypes were endothelial differentiation.Mesenchymal stem cells were isolated from Wharton’jelly of detected by flow cytometry on tissue adherence method. Passage 3 WJ-MSCs were inoculated in 4 flasks, denoted as A1, A2, A3, A4 group.Every day,the three groups of A2, A3, A4 were added to 20 microlitres apelin-13 at concentrations of 1× 1 0- 6, 10 × 1 0- 6and 100 × 1 0- 6mol/L.The group of A1 was joined to the blank DMEM-F12 medium of 20 microlitres.After induced 7 days, cell morphology and growth situation was observed under inverted microscope, and fluorescent staining carries on the v WF and flow cytometric identification on CD31. The inducted endothelial cells were cultured by three dimensional culture medium of hydrogel, which was re numbered with S1, S2, S3, S4 and in accordance with the original A1, A2, A3, A4 groups. Every day the three groups of S2, S3, S4 were treated with 20 microlitres apelin-13 at concentrations of 1× 1 0- 6, 10 × 1 0- 6and 100 × 1 0-6mol/L, adding 20 microliters to S1 of DMEM-F12 as a blank control group. After 7 days, the cell morphology, growth conditions and the structures of the vascule-like networks were observed with microscope.Results: Our study showed that WJ-MSCs, supplementing apelin, can be induced to differentiate into endothelial cells lineage which was positive staining of v WF immunofluorescence. Moreover, the cell numbers of CD31 positive expression increase significantly accompanying with the increase of apelin-13 protein dose. The endothelialcells line formed vascule like networks when grown in three-dimensional culture containing hydrogel observed by microscope.conclusion: This study demonstrated that apelin-13 could promote inducing differentiation of h UC-MSCs into vascular endothelial cell and forming vascular networks, which was significant positive correlated with concentration of apelin dose.