title: Knockdown Epithelial Membrane Protein 1 Suppresses Human Degenerative Intervertebral Disc-Derived Nucleus Pulposus Cell Proliferation.
abstract: OBJECTIVE
  Our previous work showed that epithelial membrane protein 1 (EMP1) is highly expressed in nucleus pulposus of the human degenerative intervertebral disc. The present study was designed to investigate the role of EMP1 in nucleus pulposus cells in intervertebral disc degeneration (IDD).
  
  
  METHODS
  Human nucleus pulposus cells derived from degenerative intervertebral discs were cultured. EMP1 expression was knocked down by lentivirus-mediated specific interfering RNA. Cell morphology was observed, and cell proliferation, apoptosis, and cycle were evaluated.
  
  
  RESULTS
  Knockdown of EMP1 inhibited cell proliferation, caused cells to shrink, and accelerated the apoptosis induced by serum deprivation or addition of cycloheximide but did not evoke apoptosis in normal culture conditions.
  
  
  CONCLUSIONS
  These findings suggest that EMP1 promoted chondrocyte proliferation, survival, and morphological change of cells during IDD, implying that EMP1 may be a target for biological therapy for IDD.
authors.affiliation: Department of Anatomy, Second Military Medical University, Shanghai, China.
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Li
authors.affiliation: Department of Anatomy, Second Military Medical University, Shanghai, China.
authors.forename: Shao-Hu
authors.initials: SH
authors.lastname: Xiong
authors.affiliation: Department of Orthopedics, Second Affiliated Hospital of the General Hospital of the Chinese People's Liberation Army, Beijing, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Hu
authors.affiliation: Department of Anatomy, Second Military Medical University, Shanghai, China.
authors.forename: Chuan-Sen
authors.initials: CS
authors.lastname: Zhang
keywords: cell proliferation; cell survival; epithelial membrane protein 1; intervertebral disc degeneration; nucleus pulposus cells