Roles of mitochondrial unfolded protein response in mammalian stem cells

The mitochondrial unfolded protein response(UPRmt) is an evolutionarily conserved adaptive mechanism for improving cell survival under mitochondrial stress.Under physiological and pathological conditions,the UPRmtis the key to maintaining intracellular homeostasis and proteostasis.Important roles of the UPRmthave been demonstrated in a variety of cell types and in cell development,metabolism,and immune processes.UPRmtdysfunction leads to a variety of pathologies,including cancer,inflammation,neurodegenerative disease,metabolic disease,and immune disease.Stem cells have a special ability to selfrenew and differentiate into a variety of somatic cells and have been shown to exist in a variety of tissues.These cells are involved in development,tissue renewal,and some disease processes.Although the roles and regulatory mechanisms of the UPRmtin somatic cells have been widely reported,the roles of the UPRmtin stem cells are not fully understood.The roles and functions of the UPRmtdepend on stem cell type.Therefore,this paper summarizes the potential significance of the UPRmtin embryonic stem cells,tissue stem cells,tumor stem cells,and induced pluripotent stem cells.The purpose of this review is to provide new insights into stem cell differentiation and tumor pathogenesis.