Mitochondrial Unfolded Protein Response and Its Roles in Stem Cells

The mitochondrial unfolded protein response (UPR^mt) is a mitochondrial protein quality control mechanism that is involved in many pathophysiological activities and maintains cellular homeostasis. The UPR^mt signaling pathway in both Caenorhabditis elegans and mammals has gained much attention in recent years. Many studies have reported the general function of UPR^mt, including the relationship between UPR^mt 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^mt in somatic cells have been widely studied, the regulatory mechanism of UPR^mt in stem cells is not fully known. Thus, in this article, the regulatory role of UPR^mt in stem cell proliferation, cellular differentiation, and aging is reviewed. This review aims to provide novel insights for UPR^mt promoting stem cell rejuvenation and improving life span in mammals.