title: Inflammatory cytokines induce NOTCH signaling in nucleus pulposus cells: implications in intervertebral disc degeneration.
abstract: The objective of the study was to investigate how inflammatory cytokines, IL-1β, and TNF-α control NOTCH signaling activity in nucleus pulposus (NP) cells. An increase in expression of selective NOTCH receptors (NOTCH1 and -2), ligand (JAGGED2), and target genes (HES1, HEY1, and HEY2) was observed in NP cells following cytokine treatment. A concomitant increase in NOTCH signaling as evidenced by induction in activity of target gene HES1 and HEY1 promoters and reporter 12xCSL was seen. Moreover, treatment increased activity of a 2-kb NOTCH2 promoter. Treatment of cells with NF-κB and MAPK inhibitors abolished the inductive effect of cytokines on NOTCH2 promoter and its expression. Gain and loss-of-function studies confirmed the inductive effect of p65 on NOTCH2 promoter activity. In contrast, p50 blocked the cytokine induction of promoter activity. Supporting promoter studies, lentiviral delivery of sh-p65, and sh-IKKβ significantly decreased cytokine dependent change in NOTCH2 expression. Interestingly, MAPK signaling showed an isoform-specific control of NOTCH2 promoter; p38α/β2/δ, ERK1, and ERK2 contributed to cytokine dependent induction, whereas p38γ played no role. Analysis of human NP tissues showed that NOTCH1 and -2 and HEY2 expression correlated with each other. Moreover, expression of NOTCH2 and IL-1β as well as the number of cells immunopositive for NOTCH2 significantly increased in histologically degenerate discs compared with non-degenerate discs. Taken together, these results explain the observed dysregulated expression of NOTCH genes in degenerative disc disease. Thus, controlling IL-1β and TNF-α activities during disc disease may restore NOTCH signaling and nucleus pulposus cell function.
authors.affiliation: Department of Orthopaedic Surgery and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107; Department of Orthopaedics, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107; Department of Orthopaedic Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Department of Orthopaedic Surgery and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
authors.forename: Jianru
authors.initials: J
authors.lastname: Wang
authors.affiliation: Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom.
authors.forename: Kate L E
authors.initials: KLE
authors.lastname: Phillips
authors.affiliation: Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom.
authors.forename: Abbie L A
authors.initials: ALA
authors.lastname: Binch
authors.affiliation: Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom.
authors.forename: Sara
authors.initials: S
authors.lastname: Dunn
authors.affiliation: Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Cross
authors.affiliation: Sheffield Teaching Hospitals National Health Services Foundation Trust, Sheffield S5 7AU, United Kingdom.
authors.forename: Neil
authors.initials: N
authors.lastname: Chiverton
authors.affiliation: Department of Orthopaedics, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors.forename: Zhaomin
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Orthopaedic Surgery and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
authors.forename: Irving M
authors.initials: IM
authors.lastname: Shapiro
authors.affiliation: Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, United Kingdom.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Le Maitre
authors.affiliation: Department of Orthopaedic Surgery and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107. Electronic address: makarand.risbud@jefferson.edu.
authors.forename: Makarand V
authors.initials: MV
authors.lastname: Risbud
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D007403:Intervertebral Disc / Q000378:metabolism* / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020935:MAP Kinase Signaling System; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D051883:Receptor, Notch2 / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D000072056:Transcription Factor HES-1; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D018797:Cell Cycle Proteins; D018398:Homeodomain Proteins; D053583:Interleukin-1beta; D051881:Receptor, Notch1; D051883:Receptor, Notch2; D012097:Repressor Proteins; D000072056:Transcription Factor HES-1; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; C485631:HEY1 protein, human; C405693:HEY2 protein, human; C489735:Hes1 protein, rat; C508585:IL1B protein, human; C497761:NOTCH1 protein, human; C497764:NOTCH2 protein, human; C497763:Notch1 protein, rat; C497766:Notch2 protein, rat; C498143:RELA protein, human; C498145:Rela protein, rat; C078493:HES1 protein, human
keywords: Chondrocytes; Cytokine; Intervertebral Disc; NF-kappa B (NF-KB); Notch Pathway; Nucleus Pulposus; Osteoarthritis