title: Effects of low-intensity pulsed ultrasound on the expression of cyclooxygenase-2 in mandibular condylar chondrocytes.
abstract: OBJECTIVE
  To determine the effect of low-intensity pulsed ultrasound (LIPUS) on cyclooxygenase-2 (COX-2) expression and related mechanisms by using cultured articular chondrocytes derived from porcine mandibular condyles after treatment with interleukin-1 beta (IL-1β).
  
  
  METHODS
  Chondrocytes were derived from porcine mandibular condylar cartilage and cultured. The cells were treated with or without 10 ng/mL IL-1β. At the same time, the cells were exposed to LIPUS for 20 minutes. After LIPUS exposure, the conditioned medium was changed to a fresh one without IL-1β, and the cells were incubated for 0 to 24 hours. The effects of LIPUS on IL-1β-treated chondrocytes were examined in terms of the expression of p-integrin β1, COX-2, and phosphorylated extracellular signal-related kinase (p-ERK) 1/2 by real-time polymerase chain reaction (PCR) and Western blot analyses. Differences in the means among multiple groups were examined by one-way analysis of variance (ANOVA) for all groups at each time point, followed by a Scheffé multiple comparison test as a post-hoc test; Student t test was also used.
  
  
  RESULTS
  COX-2 mRNA level was upregulated by the treatment with IL-1β and was suppressed significantly (P < .01) by LIPUS exposure. Furthermore, LIPUS enhanced gene expression and phosphorylation of integrin β, and it inhibited the expression of p-ERK 1/2.
  
  
  CONCLUSIONS
  LIPUS exposure inhibited IL-1β-induced COX-2 expression through the integrin β1 receptor followed by the phosphorylation of ERK 1/2. Despite the restricted duration of its effect, LIPUS is suggested to be a potential candidate as a preventive and auxiliary treatment to suppress the degradation of articular chondrocytes in temporomandibular joint osteoarthritis.
authors: Yasunori
authors: Y
authors: Iwabuchi
authors: Kotaro
authors: K
authors: Tanimoto
authors: Yuki
authors: Y
authors: Tanne
authors: Toshihiro
authors: T
authors: Inubushi
authors: Takashi
authors: T
authors: Kamiya
authors: Ryo
authors: R
authors: Kunimatsu
authors: Naoto
authors: N
authors: Hirose
authors: Tomomi
authors: T
authors: Mitsuyoshi
authors: Shaoching
authors: S
authors: Su
authors: Eiji
authors: E
authors: Tanaka
authors: Kazuo
authors: K
authors: Tanne
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D018929:Cell Culture Techniques; D002469:Cell Separation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000201:enzymology*; D017077:Culture Media, Conditioned; D051546:Cyclooxygenase 2 / Q000032:analysis* / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000032:analysis / Q000187:drug effects; D005260:Female; D019012:Integrin beta1 / Q000032:analysis / Q000187:drug effects; D053583:Interleukin-1beta / Q000494:pharmacology; D008335:Mandibular Condyle / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D010766:Phosphorylation; D060888:Real-Time Polymerase Chain Reaction; D013552:Swine; D013997:Time Factors; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D017077:Culture Media, Conditioned; D019012:Integrin beta1; D053583:Interleukin-1beta; D051546:Cyclooxygenase 2; D048049:Extracellular Signal-Regulated MAP Kinases