title: miR-335 orchestrates cell proliferation, migration and differentiation in human mesenchymal stem cells.
abstract: In spite of the extensive potential of human mesenchymal stem cells (hMSCs) in cell therapy, little is known about the molecular mechanisms that regulate their therapeutic properties. We aimed to identify microRNAs (miRNAs) involved in controlling the transition between the resting and reparative phenotypes of hMSCs, hypothesizing that these miRNAs must be present in the undifferentiated cells and downregulated to allow initiation of distinct activation/differentiation programs. Differential miRNA expression analyses revealed that miR-335 is significantly downregulated upon hMSC differentiation. In addition, hMSCs derived from a variety of tissues express miR-335 at a higher level than human skin fibroblasts, and overexpression of miR-335 in hMSCs inhibited their proliferation and migration, as well as their osteogenic and adipogenic potential. Expression of miR-335 in hMSCs was upregulated by the canonical Wnt signaling pathway, a positive regulator of MSC self-renewal, and downregulated by interferon-γ (IFN-γ), a pro-inflammatory cytokine that has an important role in activating the immunomodulatory properties of hMSCs. Differential gene expression analyses, in combination with computational searches, defined a cluster of 62 putative target genes for miR-335 in hMSCs. Western blot and 3'UTR reporter assays confirmed RUNX2 as a direct target of miR-335 in hMSCs. These results strongly suggest that miR-335 downregulation is critical for the acquisition of reparative MSC phenotypes.
authors.affiliation: Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Tomé
authors.forename: P
authors.initials: P
authors.lastname: López-Romero
authors.forename: C
authors.initials: C
authors.lastname: Albo
authors.forename: J C
authors.initials: JC
authors.lastname: Sepúlveda
authors.forename: B
authors.initials: B
authors.lastname: Fernández-Gutiérrez
authors.forename: A
authors.initials: A
authors.lastname: Dopazo
authors.forename: A
authors.initials: A
authors.lastname: Bernad
authors.forename: M A
authors.initials: MA
authors.lastname: González
mesh_terms: D020413:3' Untranslated Regions / Q000502:physiology; D002454:Cell Differentiation; D002465:Cell Movement / Q000502:physiology*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D057809:HEK293 Cells; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology*; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D050659:Core Binding Factor Alpha 1 Subunit; C556347:MIRN335 microRNA, human; D035683:MicroRNAs; C493709:RUNX2 protein, human; D051153:Wnt Proteins; D007371:Interferon-gamma