Role of biological markers in stem cell aging and its implications in therapeutic processes

Abstract Stem cell therapy plays a central role in regenerative medicine approach to treat certain diseases, and its success lies in the quantity of stem cells and existing niche in the recipient. Similar to somatic cells, stem cells do age driven by various intrinsic and extrinsic factors. The hallmarks of stem cell aging include oxidative stress, telomere attrition, epigenetic modifications, altered microRNAs, defective RNA splicing, loss of proteostasis, change in cell polarity, mitochondrial dysfunction, deregulated nutrient sensing, niche deterioration, altered circulating factors, defective intercellular communications, and inflammations. Molecules involved in these pathways could serve as biological markers to assess stem cell aging and would help to devise suitable interventions to circumvent cell senescence process. Some of the key biomarkers include altered antioxidant status, DNA strand breaks and mutations, telomere shortening, altered levels of sirtuins, changes in chaperones and protein synthetic mechanisms, modification in intracellular signaling of IGF-I/insulin, Wnt, mTOR, FoxO, AMP-K, tumor suppressor, and cell cycle arrest pathways. Strategies range from simple methods such as use of antioxidants in the stem cell culture system to the treatment with pharmacological agents to delay or ameliorate stem cell aging. As it requires quality stem cells in regenerative medicine, a comprehensive knowledge of underlying mechanisms in stem aging process, potential biomarkers, and possible strategies needs to be accounted to deliver an improved product for a successful stem cell therapy.