title: miR-21 modulates the ERK-MAPK signaling pathway by regulating SPRY2 expression during human mesenchymal stem cell differentiation.
abstract: The ERK-MAPK signaling pathway plays a pivotal role during mesenchymal stem cell (MSC) differentiation. Studies have demonstrated that ERK-MAPK promotes adipogenesis and osteogenesis through the phosphorylation of differentiation-associated transcription factors and that it is the only active signaling in all three lineages (adipogenic, chondrogenic, and osteogenic) during MSC differentiation. Recent studies pointed to the significant roles of microRNA-21 (miR-21) during several physiological and pathological processes, especially stem cell fate determination. The miR-21 expression pattern is also correlated with ERK-MAPK activity. Here, we found that miR-21 expression is elevated and associated with an increased differentiation potential in MSCs during adipogenesis and osteogenesis. The overexpression of miR-21 elevated the expression level of the differentiation-associated genes PPARγ and Cbfa-1 during MSC differentiation, whereas miR-21 knockdown reduced the expression level of both genes. The ERK-MAPK signaling pathway activity had an increasing tendency to respond to miR-21 upregulation and a decreasing tendency to respond to miR-21 down-regulation during the first 4 days of adipogenesis and osteogenesis. Our data indicate that miR-21 modulated ERK-MAPK signaling activity by repressing SPRY2 expression, a known regulator of the receptor tyrosine kinase (RTK) signaling pathway, to affect the duration and magnitude of ERK-MAPK activity. The ERK-MAPK signaling pathway was regulated by Sprouty2 (SPRY2) expression via a miR-21-mediated mechanism during MSC differentiation.
authors.affiliation: Center of Excellence in Tissue Engineering, Department of Cell Biology, Institute of Basic Medical Sciences, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Mei
authors.forename: Chunjing
authors.initials: C
authors.lastname: Bian
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Du
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Yang
authors.forename: Robert C H
authors.initials: RC
authors.lastname: Zhao
mesh_terms: D020413:3' Untranslated Regions; D050156:Adipogenesis; D000273:Adipose Tissue / Q000166:cytology; D000328:Adult; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D002469:Cell Separation; D002478:Cells, Cultured; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D035683:MicroRNAs / Q000502:physiology*; D010012:Osteogenesis; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; C524940:MIRN21 microRNA, human; D008565:Membrane Proteins; D035683:MicroRNAs; C114487:PDCD4 protein, human; D016601:RNA-Binding Proteins; C485561:SPRY2 protein, human