title: Matrix stiffness promotes cartilage endplate chondrocyte calcification in disc degeneration via miR-20a targeting ANKH expression.
abstract: The mechanical environment is crucial for intervertebral disc degeneration (IDD). However, the mechanisms underlying the regulation of cartilage endplate (CEP) calcification by altered matrix stiffness remain unclear. In this study, we found that matrix stiffness of CEP was positively correlated with the degree of IDD, and stiff matrix, which mimicked the severe degeneration of CEP, promoted inorganic phosphate-induced calcification in CEP chondrocytes. Co-expression analysis of the miRNA and mRNA profiles showed that increasing stiffness resulted in up-regulation of miR-20a and down-regulation of decreased ankylosis protein homolog (ANKH) during inorganic phosphate-induced calcification in CEP chondrocytes. Through a dual luciferase reporter assay, we confirmed that miR-20a directly targets 3'-untranslated regions of ANKH. The inhibition of miR-20a attenuated the calcium deposition and calcification-related gene expression, whereas the overexpression of miR-20a enhanced calcification in CEP chondrocytes on stiff matrix. The rescue of ANKH expression restored the decreased pyrophosphate efflux and inhibited calcification. In clinical samples, the levels of ANKH expression were inversely associated with the degeneration degree of CEP. Thus, our findings demonstrate that the miR-20a/ANKH axis mediates the stiff matrix- promoted CEP calcification, suggesting that miR-20a and ANKH are potential targets in restraining the progression of IDD.
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Ming-Han
authors.initials: MH
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China.|Key Laboratory of Tumor Immunopathology of Ministry of Education of China, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: You-Hong
authors.initials: YH
authors.lastname: Cui
authors.affiliation: Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China.|Key Laboratory of Tumor Immunopathology of Ministry of Education of China, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Xiu-Wu
authors.initials: XW
authors.lastname: Bian
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D020413:3' Untranslated Regions; D000293:Adolescent; D000328:Adult; D000368:Aged; D002114:Calcinosis / Q000235:genetics* / Q000378:metabolism*; D002356:Cartilage / Q000378:metabolism* / Q000473:pathology; D049109:Cell Proliferation; D019902:Chondrocytes / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D055119:Elastic Modulus; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D028061:Phosphate Transport Proteins / Q000235:genetics*; D034622:RNA Interference; D055815:Young Adult
chemical_list: D020413:3' Untranslated Regions; C498770:ANKH protein, human; C534451:MIRN20a microRNA, human; D035683:MicroRNAs; D028061:Phosphate Transport Proteins; D003094:Collagen