Silencing integrin alpha 6 enhances the pluripotency-differentiation transition in human dental pulp stem cells

Objectives Although integrins have been shown to be associated with proliferation and differentiation in some stem cells, the regulatory effect of integrin alpha 6 (ITG alpha 6) on the human dental pulp stem cells (hDPSCs) has not been reported. Here, we detected the roles of ITG alpha 6 in hDPSCs. Materials and methods Attached to Cytodex 3 microcarriers, hDPSCs grown under stimulated microgravity (SMG) or conventional culture conditions were measured the proliferation and different gene expression. Further, ITG alpha 6 was silenced in hDPSCs, and its effect on proliferation, differentiation, and cytoskeletal organization was analyzed. Results SMG conditions increased the number of Ki67-positive hDPSCs and progression into S phase of cell cycle. WB analysis showed the expression of ITG alpha 6 was upregulated in hDPSCs under SMG conditions. Knockdown of ITG alpha 6 decreased the expression of stemness markers, CD105 and STRO-1 in hDPSCs, but promoted the osteogenic and odontogenic differentiation by increased ALP expression and Alizarin Red nodules. Moreover, RNA-seq demonstrated that RHO/ROCK signaling pathway upregulated silencing ITG alpha 6-hDPSCs. Treatment with Y-27632 inhibited the effect of ITG alpha 6 depletion on hDPSCs stemness, rearranged the cytoskeleton, promoted the pluripotency, proliferation ability, and inhibited the differentiation. Conclusion ITG alpha 6 promotes hDPSCs stemness via inhibiting RHO/ROCK and restoring cytoskeleton.