摘要
Background:Mesenchymal stem or stromal cells(MSCs)derived from the induced pluripotent stem cells(iPSCs)have uniform biological activity,which makes the clinical application of MSCs in bone repair possible.Culturing the iPSC-MSCs onto osteoconductive materials is a promising tissue engineering-based strategy in bone regeneration.The aim of this work was to evaluate the effects of semaphorin 3A(Sema3A)and hypoxia inducible factor 1 subunit alpha(HIF1α)co-overexpression on the survival and osteogenic differentiation of iPSC-MSCs.Methods:Sema3A and HIF1αwere linked together with the three(GGGGS;G,glycine;S,serine)peptide fragment,and their co-expression in iPSC-MSCs was mediated by a lentiviral vector.The fusion protein retained the immune reactivity for both Sema3A and HIF1αas determined with Western blotting.iPSC-MSCs were infected with overexpression lentivirus(oeLenti)as negative control,oeLenti-Sema3A,oeLenti-HIF1αor oeLenti-Sema3A-HIF1αlentiviruses.Results:Sema3A overexpression alone promoted the osteogenic differentiation of iPSC-MSCs(the activity and/or expression of osteoblast markers,such as alkaline phosphatase,osteopontin,and osteocalcin,were upregulated),and suppressed cell survival.The Sema3A-HIF1αfusion protein showed a comparable osteoconductive effect to that of Sema3A without reducing cell survival.We further seeded iPSC-MSCs modified by SemaA-HIF1αoverexpression onto hydroxyapatite(HA)scaffolds,and evaluated their growth and differentiation on this three-dimensional material.Additional data indicated that,as compared to iPSC-MSCs cultured in ordinary two-dimensional dishes,cells cultured in HA scaffolds grew(blank vs.HA scaffolds:0.83 vs.1.39 for survival)and differentiated better(blank vs.HA scaffolds:11.29 vs.16.62 for alkaline phosphatase activity).Conclusion:Modifying iPSC-MSCs with pro-osteogenic(Sema3A)and pro-survival(HIF1α)factors may represent a promising strategy to optimize tissue engineering-based strategy in bone repair.
基金
This work was supported by a grant from the National Natural Science Foundation of China(No.81601726).
