HSPA5 enhances the survival rate of human cells by protecting mesenchymal stem cells from heat stress

Xenotransplantation of human cells into pigs holds great promise for the development of humanized animal models, large-scale production of human cells, and regeneration of humanized organs. However, the low efficiency of human cell transplantation severely hampers its clinical translation. There exists a temperature difference of 2–2.5 °C in core body temperature between humans and pigs; however, the impact of this interspecies temperature difference on the growth and function of human cells remains unclear. This study utilized human mesenchymal stem cells (hMSCs) and porcine embryos as experimental models to investigate the effects of interspecies temperature differences on the survival and function of human-derived cells, as well as the underlying mechanisms. The results showed that hMSCs cultured under conditions simulating porcine body temperature exhibited phenotypic changes, including accelerated cellular senescence, inhibited proliferation, elevated oxidative stress levels, increased apoptosis, and reduced multipotent differentiation capacity. Molecular mechanism studies identified and validated HSPA5 as a key gene regulating hMSC function under heat stress. Overexpression of HSPA5 can alleviate heat stress-induced cellular damage and this protective effect is accompanied by a reduction in the activation of the PERK-eIF2α-ATF4 pathway. Concurrently, HSPA5 overexpression was associated with enhanced hMSC survival in porcine preimplantation embryos. This study reveals that interspecies temperature differences between human and porcine are a key environmental factor affecting the survival of human cells within the porcine host. Importantly, HSPA5 may serve as a potential functional target for enhancing cellular heat tolerance, thereby providing new insights into improving the survival and engraftment of human cells under heat stress conditions. The physiological temperature of pigs induces heat stress in hMSCs. HSPA5 plays a crucial role in maintaining short-term cellular homeostasis under heat stress conditions. Overexpression of HSPA5 partially alleviates heat stress-induced cellular damage, which is accompanied by a reduction in the activation of the PERK-eIF2α-ATF4 pathway. HSPA5 overexpression enhances the survival of hMSCs under in vitro culture conditions.