title: MicroRNA-99a regulates early chondrogenic differentiation of rat mesenchymal stem cells by targeting the BMPR2 gene.
abstract: Mesenchymal stem cells (MSCs) are candidates for the regeneration of articular cartilage as they possess the potential for chondrogenic differentiation. MSCs are easily obtained and expanded in vitro. Specific microRNAs (miRNAs) that regulate chondrogenesis have yet to be identified and the mechanisms involved remain to be defined. The miRNAs regulate biological processes by binding target mRNA to reduce protein synthesis. In this study, we show that expression of miR-99a and miR-125b-3p were increased during early chondrogenic differentiation of MSCs (rMSCs) derived from the Norwegian brown rat (Rattus norvegicus). MiR-99a knockdown promoted proteoglycan deposition and increased the expression of ACAN and COL2A1 during early chondrogenic differentiation. MiR-99a knockdown promoted early chondrogenic differentiation of rMSCs. A dual-luciferase reporter gene assay showed that miR-99a targeted a putative binding site in the 3'-UTR of bone morphogenetic protein (BMP) receptor type 2 (BMPR2). Overexpression of miR-99a reduced the expression levels of BMPR2 protein. The expression of total p38 and p-p38 increased at 7 and 14 days during early chondrogenic differentiation of rMSCs. Reduction in levels of total p38 and p-p38 protein followed miR-99a overexpression during early chondrogenic differentiation of rMSCs. BMPR2 silencing reversed the effects of miR-99a inhibition on proteoglycan deposition and protein expression of ACAN, COL2A1, total p38 and p-p38 during early chondrogenic differentiation of rMSCs. In conclusion, the findings of these in vitro studies in rat MSCs support a role for miR-99a as a negative regulator of early chondrogenic differentiation by directly targeting the BMPR2 gene at an early stage.
authors.affiliation: University of South China, Hengyang, Hunan, 421001, China.
authors.forename: Xiaozhong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Zhongshan Torch Development Zone Hospital, Zhongshan, Guangdong, 528437, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Sun
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Wangyang
authors.initials: W
authors.lastname: Xu
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Dixin
authors.initials: D
authors.lastname: Luo
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Xunjie
authors.initials: X
authors.lastname: Jin
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Weijian
authors.initials: W
authors.lastname: Chen
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Zhousheng
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Feimeng
authors.initials: F
authors.lastname: Li
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Guangdong No.2 Provincial People's Hospital, Guanzhou, Guangdong, 510317, China. xiaozhongzhou2015@yeah.net.
authors.forename: Guitao
authors.initials: G
authors.lastname: Li
mesh_terms: D000818:Animals; D001483:Base Sequence; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics; D020219:Chondrogenesis / Q000235:genetics; D024043:Collagen Type II / Q000378:metabolism; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D008156:Luciferases / Q000378:metabolism; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism; D011914:Rats, Inbred BN
chemical_list: D024043:Collagen Type II; D035683:MicroRNAs; C000618872:Mirn99 microRNA, rat; D011509:Proteoglycans; D008156:Luciferases; D052006:Bone Morphogenetic Protein Receptors, Type II
keywords: BMPR2; Bone morphogenetic protein receptor 2; Chondrogenic differentiation; Mesenchymal stem cells; MicroRNA-99a