title: Fluid-induced, shear stress-regulated extracellular matrix and matrix metalloproteinase genes expression on human annulus fibrosus cells.
abstract: BACKGROUND
  Mechanical loading plays an important role in the regulation of extracellular matrix (ECM) homeostasis as well as pathogenesis of intervertebral disc (IVD) degeneration. The human annulus fibrosus (hAF) in the IVD is subjected to contact shear stress during body motion. However, the effects of shear stress on hAF cells remain unclear. This aim of the study was to investigate the expression of the ECM (COLI, COLIII and aggrecan) and matrix metalloproteinase (MMP-1, MMP-3 and ADAMTS-4) genes in hAF cells following fluid-induced shear stress in a custom-fabricated bio-microfluidic device.
  
  
  METHODS
  hAF cells were harvested from degenerated disc tissues in routine spine surgery, staged by magnetic resonance imaging, expanded in monolayers and then seeded onto the bio-microfluidic device. The experimental groups were subjected to 1 and 10 dyne/cm(2) shear stress for 4 h, and no shear stress was applied to the control group. We used real time polymerase chain reaction for gene expression.
  
  
  RESULTS
  Shear stress of 1 dyne/cm(2) exerted an anabolic effect on COLI and COLIII genes and catabolic effects on the aggrecan gene, while 10 dyne/cm(2) had an anabolic effect on the COLI gene and a catabolic effect on COLIII and aggrecan genes. The COLI gene was upregulated in a stress-dependent manner. Expression of MMP-1 was significantly higher in the 10 dyne/cm(2) group compared to the control group (P < 0.05), but was similar in the control and 1 dyne/cm(2) groups. Expression of MMP-3 and ADAMTS-4 were similar in all three groups.
  
  
  CONCLUSIONS
  Taken together, hAF cells responded to shear stress. The findings help us understand and clarify the effects of shear stress on IVD degeneration as well as the development of a new therapeutic strategy for IVD degeneration.
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Po-Hsin
authors.initials: PH
authors.lastname: Chou
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Shih-Tien
authors.initials: ST
authors.lastname: Wang
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University and Academia Sinica Taipei, Taipei, Taiwan.
authors.forename: Meng-Hua
authors.initials: MH
authors.lastname: Yen
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Chien-Lin
authors.initials: CL
authors.lastname: Liu
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Ming-Chau
authors.initials: MC
authors.lastname: Chang
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University and Academia Sinica Taipei, Taipei, Taiwan. kslee@vghtpe.gov.tw.|Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan. kslee@vghtpe.gov.tw.|Taipei City General Hospital, No.145, Zhengzhou Rd., Datong Dist., Taipei City, 10341, Taiwan (R.O.C.). kslee@vghtpe.gov.tw.
authors.forename: Oscar Kuang-Sheng
authors.initials: OK
authors.lastname: Lee
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism; D000071121:ADAMTS4 Protein; D001696:Biomechanical Phenomena; D002478:Cells, Cultured; D004790:Enzyme Induction; D005109:Extracellular Matrix / Q000201:enzymology* / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D007403:Intervertebral Disc / Q000201:enzymology / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000201:enzymology / Q000473:pathology; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D011348:Procollagen N-Endopeptidase / Q000235:genetics / Q000378:metabolism
chemical_list: D051722:ADAM Proteins; D011348:Procollagen N-Endopeptidase; C511768:MMP3 protein, human; D019278:Matrix Metalloproteinase 3; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1; D000071121:ADAMTS4 Protein; C000603918:ADAMTS4 protein, human