Mitochondrial Unfolded Protein Response and Its Roles in Stem Cells.

The mitochondrial unfolded protein response (UPR) is a mitochondrial protein quality control mechanism that is involved in many pathophysiological activities and maintains cellular homeostasis. The UPR signaling pathway in both and mammals has gained much attention in recent years. Many studies have reported the general function of UPR, including the relationship between UPR and longevity, survival, apoptosis, innate immunity, cancer growth, and neurodegenerative diseases. Stem cells are capable of self-renewing and differentiating, thus playing an important role in maintaining tissue homeostasis and tissue regeneration. Although the role and regulation of UPR in somatic cells have been widely studied, the regulatory mechanism of UPR in stem cells is not fully known. Thus, in this article, the regulatory role of UPR in stem cell proliferation, cellular differentiation, and aging is reviewed. This review aims to provide novel insights for UPR promoting stem cell rejuvenation and improving life span in mammals.