title: Cyclooxygenase-2 inhibitor decreases extracellular matrix synthesis in stretched renal fibroblasts.
abstract: OBJECTIVE
  Both TGF-beta and cyclooxygenase-2 have been implicated in the pathogenesis of interstitial fibrosis in unilateral ureteral obstruction (UUO). Cyclic tensile stretch has been used in vitro to mimic the changes in intrarenal pressure in UUO. We sought to determine the effect of meloxicam (a selective cyclooxygenase-2 inhibitor) on extracellular matrix and TGF-beta synthesis in stretched renal fibroblasts (NRK-49F).
  
  
  METHODS
  NRK-49F cells were subject to cyclic stretch (6 cycles/min, 15% elongation) using a Flexcell apparatus. Cells were stretched in the absence or presence of meloxicam for 48 h, and then cells and supernatants were isolated. Collagen was quantified by the Sircol assay; fibronectin and laminin were visualized using immunofluorescence. TGF-beta was quantified by ELISA, and protease activity determined by a colorimetric assay.
  
  
  RESULTS
  Both collagen and TGF-beta synthesis were increased following a 48-hour stretch of NRK-49F. Meloxicam significantly decreased the collagen and TGF-beta response to stretch. Stretch-induced fibronectin and laminin synthesis was also decreased by meloxicam. NRK-49F protease activity was decreased by stretch; this was unaffected by meloxicam.
  
  
  CONCLUSIONS
  Stretch of NRK-49F results in extracellular matrix synthesis, a process which may be activated in UUO and contribute to interstitial fibrosis. Inhibition of cyclooxygenase-2 may reduce fibrosis through a TGF-beta-dependent process.
authors.affiliation: Department of Urology, Institute for Pediatric Urology, New York Presbyterian Children's Hospital, New York, NY, USA.
authors.forename: Maher
authors.initials: M
authors.lastname: El Chaar
authors.forename: Erik
authors.initials: E
authors.lastname: Attia
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Jo
authors.initials: J
authors.lastname: Hannafin
authors.forename: Dix P
authors.initials: DP
authors.lastname: Poppas
authors.forename: Diane
authors.initials: D
authors.lastname: Felsen
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D003094:Collagen / Q000096:biosynthesis; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000502:physiology*; D005355:Fibrosis; D007668:Kidney / Q000473:pathology*; D000077239:Meloxicam; D011312:Pressure; D051381:Rats; D013718:Tensile Strength; D013843:Thiazines / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000502:physiology; D014517:Ureteral Obstruction / Q000150:complications*
chemical_list: D016861:Cyclooxygenase Inhibitors; D013843:Thiazines; D013844:Thiazoles; D016212:Transforming Growth Factor beta; D003094:Collagen; D000077239:Meloxicam