title: miR-29c-3p promotes senescence of human mesenchymal stem cells by targeting CNOT6 through p53-p21 and p16-pRB pathways.
abstract: Mesenchymal stem cells (MSCs) are important seed cells for tissue engineering and are promising targets for cell-based therapies. However, the replicative senescence of MSCs during in vitro culture limits their research and clinical applications. The molecular mechanisms underlying the replicative senescence of MSCs are not fully understood. Evidence suggests that miRNAs play important roles in replicative senescence. A microarray analysis found that the miR-29c-3p level was significantly increased during the MSC senescence process. In our study, we investigated the roles of miR-29c-3p in senescence of MSCs. We cultured MSCs for long periods of time, up and down-regulated the miR-29c-3p expression in MSCs, and examined the senescent phenotype changes. The over-expression of miR-29c-3p led to enhanced senescence-associated-β-galactosidase (SA-β-gal) staining, senescence associated secretory phenotype (SASP), senescence associated heterochromatic foci (SAHF), reduced proliferation ability, retarded osteogenic differentiation and corresponding changes in senescence markers, whereas the miR-29c-3p down-regulation had the opposite results. Dual-luciferase reporter assays demonstrated that CNOT6 is the target gene of miR-29c-3p. Knockdown of CNOT6 confirmed its inhibitory effects on the senescence of MSCs. In addition, Western blot results showed that both the p53-p21 and the p16-pRB pathways were activated during the miR-29c-3p-induced senescence of MSCs. In conclusion, our results demonstrate that miR-29c-3p promotes the senescence of MSCs by targeting CNOT6 through p53-p21 and p16-pRB pathways and highlight the contribution of post-transcriptional regulation to stem cell senescence.
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Shang
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shangguan
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. Electronic address: 20016040@163.com.
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. Electronic address: happyzhou@vip.163.com.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D002478:Cells, Cultured; D016922:Cellular Senescence / Q000235:genetics*; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D005095:Exoribonucleases / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D035683:MicroRNAs / Q000502:physiology*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D005095:Exoribonucleases; C534418:cNOT6 protein, human
keywords: Mesenchymal stem cell; MicroRNA; Replicative senescence; Tissue engineering