Knockout of integrin β1 in induced pluripotent stem cells accelerates skin-wound healing by promoting cell migration in extracellular matrix

Background: Induced pluripotent stem cells (iPSCs) have the potential to promote wound healing; however, their adhesion to the extracellular matrix (ECM) might decrease iPSC migration, thereby limiting their therapeutic potential. Integrin beta 1 (Itgb1) is the major integrin subunit that mediates iPSC-ECM adhesion, suggesting that knocking out Itgb1 might be an effective method for enhancing the therapeutic efficacy of iPSCs. Methods: We knocked out Itgb1 in mouse iPSCs and evaluated its effects on the therapeutic potential of topically applied iPSCs, as well as their underlying in vivo and in vitro mechanisms. Results: The Itgb1-knockout (Itgb1-KO) did not change iPSC pluripotency, function, or survival in the absence of embedding in an ECM gel but did accelerate wound healing, angiogenesis, blood perfusion, and survival in skin-wound lesions. However, embedding in an ECM gel inhibited the in vivo effects of wild-type iPSCs but not those of Itgb1-knockout iPSCs. Additionally, in vitro results showed that Itgb1-knockout decreased iPSC-ECM adhesion while increasing ECM-crossing migration. Moreover, ECM coating on the culture surface did not change cell survival, regardless of Itgb1 status; however, the in vivo and in vitro functions of both Itgb1-knockout and wild-type iPSCs were not affected by the presence of agarose gel, which does not contain integrin-binding sites. Knockout of Integrin alpha 4 (Itga4) did not change the above-mentioned cellular and therapeutic functions of iPSCs. Conclusions: Itgb1-knockout increased iPSCs migration and the wound-healing-promoting effect of topically applied iPSCs. These findings suggest the inhibition of Itgb1 expression is a possible strategy for increasing the efficacy of iPSC therapies.