title: Increased periostin gene expression in degenerative intervertebral disc cells.
abstract: BACKGROUND
  Disc degeneration is a multifactorial disease that may cause clinical symptoms such as chronic back pain or radiculopathy in the extremities. Periostin, an extracellular matrix protein involved in the process of fibrosis, expressed in tissues subjected to mechanical stress such as intervertebral disc. However, the expression of periostin during disc degeneration has not yet been studied.
  
  
  OBJECTIVE
  The aim of this study is to elucidate the difference in gene expression profiles between degenerative and nondegenerative intervertebral discs for a better understanding of disc degeneration.
  
  
  METHODS
  Degenerative and nondegenerative nucleus pulposus cells were isolated from elderly patients with degenerative disc disease and younger patients with adolescent idiopathic scoliosis, respectively.
  
  
  METHODS
  Affymetrix GeneChip Human arrays were used to derive gene expression profiles for disc degeneration, and gene expressions of periostin and other degeneration-related markers were confirmed by reverse transcription-polymerase chain reaction (RT-PCR), real-time RT-PCR, and western blot analysis. Immunohistochemical analysis of periostin and Gomori trichrome stain was performed to show the relationship of periostin, fibrosis, and disc degeneration. The mechanical stress experiment was designed to demonstrate the relationship of periostin, stress, and disc degeneration.
  
  
  RESULTS
  Fourteen genes were identified to express at significantly different levels between degenerative and nondegenerative groups. An increase of periostin gene expression was observed in human degenerative nucleus pulposus cells for the messenger RNA and protein levels. Histological examination demonstrated an increased positive staining of periostin in degenerative discs from human tissues and rat needle-punctured tails and more fibrosis with architectural disorder and fragmentation in human degenerative disc as compared with nondegenerative discs. The expression of periostin was significantly induced by stress in human degenerative nucleus pulposus cells but not in nondegenerative cells.
  
  
  CONCLUSIONS
  This study demonstrates for the first time an upregulation of periostin in addition to the expression levels of Type I collagen and matrix metalloproteinase-2 in human disc degeneration. It suggests that periostin may be a candidate gene that shows promise as a new prognostic marker and a therapeutic target that is worth further study to expand our knowledge of its role in disc degeneration.
authors: Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Rd, Kwei-Shan, Tao-Yuan, Taiwan, Republic of China.
authors: Tsung-Ting
authors: TT
authors: Tsai
authors: Po-Liang
authors: PL
authors: Lai
authors: Jen-Chung
authors: JC
authors: Liao
authors: Tsai-Sheng
authors: TS
authors: Fu
authors: Chi-Chien
authors: CC
authors: Niu
authors: Lih-Huei
authors: LH
authors: Chen
authors: Mel S
authors: MS
authors: Lee
authors: Wen-Jer
authors: WJ
authors: Chen
authors: Hung-Chen
authors: HC
authors: Fang
authors: Natalie Y J
authors: NY
authors: Ho
authors: Jong-Hwei S
authors: JH
authors: Pang
mesh_terms: D000293:Adolescent; D000368:Aged; D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D007403:Intervertebral Disc / Q000378:metabolism* / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012600:Scoliosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D013314:Stress, Mechanical; D015854:Up-Regulation / Q000235:genetics
chemical_list: D015815:Cell Adhesion Molecules; D024042:Collagen Type I; C512835:POSTN protein, human; D020778:Matrix Metalloproteinase 2