title: MicroRNA-33 suppresses CCL2 expression in chondrocytes.
abstract: CCL2-mediated macrophage infiltration in articular tissues plays a pivotal role in the development of the osteoarthritis (OA). miRNAs regulate the onset and progression of diseases via controlling the expression of a series of genes. How the CCL2 gene was regulated by miRNAs was still not fully elucidated. In the present study, we demonstrated that the binding sites of miR-33 in the 3'UTR of CCL2 gene were conserved in human, mouse and rat species. By performing gain- or loss-of-function studies, we verified that miR-33 suppressed CCL2 expression in the mRNA and protein levels. We also found that miR-33 suppressed the CCL2 levels in the supernatant of cultured primary mouse chondrocytes. With reporter gene assay, we demonstrated that miR-33 targeted at AAUGCA in the 3'UTR of CCL2 gene. In transwell migration assays, we demonstrated that the conditional medium (CM) from miR-33 deficient chondrocytes potentiated the monocyte chemotaxis in a CCL2 dependent manner. Finally, we demonstrated that the level of miR-33 was decreased, whereas the CCL2 level was increased in the articular cartilage from the OA patients compared with the control group. In summary, we identified miR-33 as a novel suppressor of CCL2 in chondrocytes. The miR-33/CCL2 axis in chondrocytes regulates monocyte chemotaxis, providing a potential mechanism of macrophage infiltration in OA.
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wei
authors.affiliation: Department of Orthopaedics, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China qingyunxie123@tom.com.
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Dongyang
authors.initials: D
authors.lastname: Guo
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Liweng
authors.initials: L
authors.lastname: Mo
authors.affiliation: Department of Nephrology and Rheumatology, Chengdu Military General Hospital. No. 270, Rongdu Avenue, Jinniu District, Chengdu, Sichuan, 610083, P.R. China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics*; D019902:Chondrocytes / Q000378:metabolism* / Q000473:pathology; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D010003:Osteoarthritis / Q000235:genetics* / Q000473:pathology; D051381:Rats
chemical_list: D020413:3' Untranslated Regions; C111835:CCL2 protein, human; C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; C550416:MIRN33a microRNA, human; D035683:MicroRNAs; C550417:Mirn33 microRNA, mouse
keywords: CCL2; chemotaxis; microRNA-124 (miR-124); microRNA-33 (miR-33); osteoarthritis; reporter gene