Changes in the expression of integrin α9 in the differentiation of adipose-derived stem cells to lymphatic endothelial cells

Abstract:

Objective：To isolate and culture adipose-derived stem cells（ADSCs） from human adipose tissues，to induce the differentiation of ADSCs to lymphatic endothelial cells（LECs），to explore the changes in the expression of integrin α9 in the differentiation pro－cess so as to find a molecular target and to make contribution to the molecular treatment of lymphedema with ADSCs. Methods：①ADSCs were isolated and cultured from human adipose tissue which derived from the liposuction surgery.Morphological characteristics were observed with inverted phase contrast microscope.②Expression of CD90，CD29，CD34 and CD45 in the cell membrane was as－sayed by using flow cytometry（FCM）. Growth curve was drawn with MTT assay. ③Lymphendothelial differentiation of ADSCs was induced with human vascular endothelial growth factor C（VEGF-C），human vascular endothelial growth factor A（VEGF-A） and platelet-derived growth factor BB（PBGF BB） in vitro.Human LECs were taken as positive control group. ④Expression of lymphatic endothelial hyaluronan receptor-1（LYVE-1），integrin α9 and CD34 was detected by Western blot. ⑤Cell cycles of the three groups were determined with FCM. Then the data were ana－lyzed with SPSS 17.0. Results：①ADSCs was in spindle shape and adherent growth.Growth curves of 1th，3th and 5th passage of ADSCs all presented S shape. The expression of CD90+ was positive，and the expression of CD34+ and CD45+ was negative. ②LYVE-1 expressed positively in experiment group and posi－tive control group；CD34 expressed negatively in experiment group and positive control group；expression of integrin α9 was similar to LYVE-1 and expression of integrin α9 and LYVE-1 were lower in experiment group than in positive control group；integrin α9，LYVE-1 and CD34 expressed negatively in negative control group. ③There were differences in proportion of cells at G0/G1 stage，higher in negative control group than in experiment group and positive control group（P<0.01）. There was no difference in proportion of cells at G0/G1 stage between experiment group and positive control group（P=0.083）. Conclusions：Human ADSCs can differentiate into LECs but not vascular endothelial cells when culture in vitro with VEGF-C，VEGF-A and PDGF-BB. Cell cycle will change and the expression of integrin α9 will elevate during this process. Integrin α9 may make an important role in the formation of LECs and may obtain the opportunity to become a molecular target in the treatment of lymphedema.