title: miR-335 correlates with senescence/aging in human mesenchymal stem cells and inhibits their therapeutic actions through inhibition of AP-1 activity.
abstract: MicroRNAs, small noncoding RNAs, regulate gene expression primarily at the posttranscriptional level. We previously found that miR-335 is critically involved in the regulation and differentiation capacity of human mesenchymal stem cells (hMSCs) in vitro. In this study, we investigated the significance of miR-335 for the therapeutic potential of hMSCs. Analysis of hMSCs in ex vivo culture demonstrated a significant and progressive increase in miR-335 that is prevented by telomerase. Expression levels of miR-335 were also positively correlated with donor age of hMSCs, and were increased by stimuli that induce cell senescence, such as γ-irradiation and standard O2 concentration. Forced expression of miR-335 resulted in early senescence-like alterations in hMSCs, including: increased SA-β-gal activity and cell size, reduced cell proliferation capacity, augmented levels of p16 protein, and the development of a senescence-associated secretory phenotype. Furthermore, overexpression of miR-335 abolished the in vivo chondro-osseous potential of hMSCs, and disabled their immunomodulatory capacity in a murine experimental model of lethal endotoxemia. These effects were accompanied by a severely reduced capacity for cell migration in response to proinflammatory signals and a marked reduction in Protein Kinase D1 phosphorylation, resulting in a pronounced decrease of AP-1 activity. Our results demonstrate that miR-335 plays a key role in the regulation of reparative activities of hMSCs and suggests that it might be considered a marker for the therapeutic potency of these cells in clinical applications.
authors.affiliation: Department of Cardiovascular Development and Repair, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Tomé
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Sepúlveda
authors.forename: Mario
authors.initials: M
authors.lastname: Delgado
authors.forename: José A
authors.initials: JA
authors.lastname: Andrades
authors.forename: Judith
authors.initials: J
authors.lastname: Campisi
authors.forename: Manuel A
authors.initials: MA
authors.lastname: González
authors.forename: Antonio
authors.initials: A
authors.lastname: Bernad
mesh_terms: D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics*; D002465:Cell Movement / Q000235:genetics; D016922:Cellular Senescence / Q000235:genetics*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D035683:MicroRNAs / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014161:Transduction, Genetic
chemical_list: C556347:MIRN335 microRNA, human; D035683:MicroRNAs; D018808:Transcription Factor AP-1
keywords: Aging; Immunotherapy; Mesenchymal stem cells; MicroRNA