title: Notch signaling pathways in human thoracic ossification of the ligamentum flavum.
abstract: This study investigated the pathological process of Notch signaling in the osteogenesis of ligamentum flavum tissues and cells, and the associated regulatory mechanisms. Notch receptors, ligands, and target genes were identified by quantitative polymerase chain reaction (qPCR) in ligamentum flavum cells and immunohistochemistry in ligamentum flavum sections from ossification of the ligamentum flavum (OLF) patients and controls. The temporospatial expression patterns of JAG1/Notch2/HES1 in human ligamentum flavum cells during osteogenic differentiation were determined by qPCR. Lentiviral vectors for Notch2 overexpression and knockdown were constructed and transfected into ligamentum flavum cells before osteogenic differentiation to examine the function of Notch signaling pathways in the osteogenic differentiation of ligamentum flavum cells. Alkaline phosphatase, Runx2, Osterix, osteocalcin, and osteopontin mRNA levels, alkaline phosphatase activity, and Alizarin Red staining were used as indicators of osteogenic differentiation. JAG1/Notch2/HES1 mRNA levels were up-regulated in ligamentum flavum cells from OLF patients, which increased during osteogenic differentiation. Immunohistochemical analysis suggested positive Notch2 expression at the ossification front. Down-regulation of Notch2 expression decelerated osteogenic differentiation of ligamentum flavum cells, and Notch2 overexpression promoted osteogenic differentiation of ligamentum flavum cells. Expression of Runx2 and Osterix increased in a manner similar to that of Notch2 during osteogenic differentiation of ligamentum flavum cells, and Notch2 knockdown and overexpression influenced their expression levels. Notch signaling plays an important role in OLF, and Notch may affect the osteogenic differentiation of ligamentum flavum cells via interactions with Runx2 and Osterix.© 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1481-1491, 2016.
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Qu
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Zhongqiang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Dongwei
authors.initials: D
authors.lastname: Fan
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Chuiguo
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Hou
authors.affiliation: Department of Orthopaedics, Peking University Third Hospital, 49 North Garden Road, Haidian District, Beijing 100191, China.
authors.forename: Shanglong
authors.initials: S
authors.lastname: Ning
mesh_terms: D000328:Adult; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D000072100:Jagged-1 Protein / Q000378:metabolism; D017843:Ligamentum Flavum / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000378:metabolism*; D010012:Osteogenesis; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013122:Spinal Diseases / Q000378:metabolism*; D013904:Thoracic Vertebrae; D000072056:Transcription Factor HES-1 / Q000378:metabolism
chemical_list: C000606273:JAG1 protein, human; D000072100:Jagged-1 Protein; D051880:Receptors, Notch; D000072056:Transcription Factor HES-1; C078493:HES1 protein, human
keywords: Notch signaling pathways; ossification of ligamentum flavum; osteogenic differentiation; thoracic spinal stenosis