Restoring Aged Stem Cell Functionality: Current Progress and Future Directions.

Stem cell dysfunction is a hallmark of aging, associated with the decline of physical and cognitive abilities of humans and other mammals. 1 Therefore, it has become an active area of research within the aging and stem cell fields, and various techniques have been employed to mitigate the decline of stem cell function both in vitro and in vivo. While some techniques developed in model organisms are not directly translatable to humans, others show promise in becoming clinically relevant to delay or even mitigate negative phenotypes associated with aging. This review focuses on diet, treatment, and small molecule interventions that provide evidence of functional improvement in at least one type of aged adult stem cell. © AlphaMed Press 2020 SIGNIFICANCE STATEMENT: We present the current status of interventions to improve aging phenotypes, in the context of stem cell aging. By restoring potential to aged stem cells, there will likely be a cascading beneficial effect on the entire system. However, many interventions only have reports in a few tissue-specific stem cell types, and more comprehensive analysis of potential benefits and consequences to all stem cells is necessary. We highlight overlaps between interventions and proposed considerations needed before moving some of these interventions into human trials.