title: Transcriptome-wide gene regulation by gentle treadmill walking during the progression of monoiodoacetate-induced arthritis.
abstract: OBJECTIVE
  Physiotherapies are the most widely recommended conservative treatment for arthritic diseases. The present study was undertaken to examine the molecular mechanisms underlying the effects of gentle treadmill walking (GTW) on various stages of monoiodoacetate-induced arthritis (MIA) to elucidate the basis for the success or failure of such therapies in joint damage.
  
  
  METHODS
  Knees were obtained from untreated control rats, rats with MIA that did not undergo GTW, rats with MIA in which GTW regimens were started 1 day post-MIA induction, and rats with MIA in which GTW regimens were started after cartilage damage had progressed to grade 1 or grade 2. The cartilage was examined macroscopically, microscopically, and by microfocal computed tomography imaging. Transcriptome-wide gene expression analysis was performed, and microarray data were assessed by Ingenuity Pathways Analysis to identify molecular functional networks regulated by GTW.
  
  
  RESULTS
  GTW intervention started on day 1 post-MIA induction significantly prevented the progression of MIA, but its efficacy was reduced when implemented on knees exhibiting close to grade 1 cartilage damage. GTW accelerated cartilage damage in knees with close to grade 2 damage. Transcriptome-wide gene expression analysis revealed that GTW intervention started 1 day post-MIA inception significantly suppressed inflammation-associated genes and up-regulated matrix-associated gene networks. However, delayed GTW intervention after grade 1 damage had occurred was less effective in suppressing proinflammatory genes or up-regulating matrix synthesis.
  
  
  CONCLUSIONS
  The present findings suggest that GTW suppresses proinflammatory gene networks and up-regulates matrix synthesis to prevent progression of cartilage damage in MIA-affected knees. However, the extent of cartilage damage at the initiation of GTW may be an important determinant of the success or failure of such therapies.
authors.affiliation: Department of Oral Biology and Orthopedics, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Nam
authors.forename: Priyangi
authors.initials: P
authors.lastname: Perera
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Lai Chu
authors.initials: LC
authors.lastname: Wu
authors.forename: Björn
authors.initials: B
authors.lastname: Rath
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Butterfield
authors.forename: Sudha
authors.initials: S
authors.lastname: Agarwal
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy*; D002356:Cartilage / Q000378:metabolism / Q000473:pathology; D018450:Disease Progression; D005080:Exercise Test; D005081:Exercise Therapy; D005260:Female; D020869:Gene Expression Profiling; D019807:Iodoacetic Acid / Q000494:pharmacology; D007719:Knee Joint / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D015854:Up-Regulation; D016138:Walking
chemical_list: D019807:Iodoacetic Acid