Telomere shortening as a hallmark of stem cell senescence. Author: Fathi E1, Charoudeh HN2, Sanaat Z3, Farahzadi R3 Affiliation: <sup>1</sup>Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran. <sup>2</sup>Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. <sup>3</sup>Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Conference/Journal: Stem Cell Investig. Date published: 2019 Mar 6 Other: Volume ID: 6 , Pages: 7 , Special Notes: doi: 10.21037/sci.2019.02.04. eCollection 2019. , Word Count: 147 Stem cells, especially mesenchymal stem cells (MSCs)-based therapies have been greatly attentioned in regenerative medicine through multi-lineage differentiation, self-renewal properties, etc. Despite the above advantages of MSCs, the defined properties of these cells are strongly affected by aging. Thus, the use of MSCs from older donors is lower than younger one, which limits clinical applications in cell therapy. According to the theories of aging, it is determined that aging is most likely caused by telomere shortening and telomere shortening is considered hallmarks of aging. Finding out the most mechanisms of these changes will probably reveal novel therapeutic targets for prolonging human health and for ameliorating age-associated phenotypes. This review focuses on prevalent knowledge about the mechanisms of stem cell senescence by telomere shortening and the molecular mechanism details involved in it. KEYWORDS: Telomere length; cell therapy; regenerative medicine; stem cell senescence PMID: 31019963 PMCID: PMC6458335 DOI: 10.21037/sci.2019.02.04