Caloric restriction maintains stem cells through niche and regulates stem cell aging

The functional loss of adult stem cells is a major cause of aging and age-related diseases. Changes in the stem cell niche, increased energy metabolic rate, and accumulation of cell damage severely affect the function and regenerative capacity of stem cells. Reducing the cellular damage and maintaining a pristine stem cell niche by regulating the energy metabolic pathways could be ideal for the proper functioning of stem cells and tissue homeostasis. Numerous studies point out that caloric restriction (CR) has beneficiary effects on stem cell maintenance and tissue regeneration. Recent researches indicate the preventive nature of calorie restriction in stem cells by modulating the stem cell niche through the reduction of energy metabolism and eventually decrease stem cell damage. In this review, we have focused on the general stimuli of stem cell aging, particularly the energy metabolism as an intrinsic influence and stem cell niche as an extrinsic influence in different adult stem cells. Further, we discussed the mechanism behind CR in different adult stem cells and their niche. Finally, we conclude on how CR can enhance the stem cell function and tissue homeostasis through the stem cells niche.