title: Effect of p38 Mitogen Activated Protein Kinase Inhibitor on Temporomandibular Joint Synovitis Induced by Occlusal Alteration.
abstract: OBJECTIVE
  To investigate the alteration in rat temporomandibular joint (TMJ) synovial membrane induced by increased occlusal vertical dimension (iOVD) and to determine whether the p38 mitogen activated protein kinase (MAPK) signaling cascade is involved.
  
  
  METHODS
  Thirty-six rats were randomly divided into 3 groups: control + normal saline (NS; controls), iOVD + NS, and iOVD + SB203580 (a potent p38 MAPK inhibitor). Morphologic changes of synovial tissues were observed and scored. Activation levels of p38 MAPK and activating transcription factor-2 (ATF2) were detected by immunohistochemistry. Expression levels of interleukin-1β (IL-1β) and matrix metalloproteinase-3 (MMP-3) were measured by quantitative real-time polymerase chain reaction and immunohistochemistry.
  
  
  RESULTS
  Obvious synovitis was found in the iOVD group. P38 and ATF2 were activated, and mRNA and protein expression levels of IL-1β and MMP-3 were upregulated after iOVD. However, decreased synovial tissue inflammation and lower mRNA and protein levels of IL-1β and MMP-3 were observed in the iOVD + SB203580 group.
  
  
  CONCLUSIONS
  iOVD can induce temporomandibular joint synovitis, and the p38 MAPK signaling cascade might participate in and aggravate the process of articular inflammation.
authors: Dental student, Stomatological Hospital of Shandong University and the Shandong Province Key Laboratory of Oral Tissue Regeneration, Jinan City, Shandong Province, China.
authors: Linhong
authors: L
authors: Jiang
authors: Resident, Stomatological Hospital of Shandong University and the Shandong Province Key Laboratory of Oral Tissue Regeneration, Jinan City, Shandong Province, China.
authors: Xuefen
authors: X
authors: Lin
authors: Professor, Stomatological Hospital of Shandong University and the Shandong Province Key Laboratory of Oral Tissue Regeneration, Jinan City, Shandong Province, China. Electronic address: jiping@mail.sdu.edu.cn.
authors: Ping
authors: P
authors: Ji
mesh_terms: D000818:Animals; D007093:Imidazoles / Q000494:pharmacology; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D008310:Malocclusion / Q000150:complications* / Q000503:physiopathology; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D013585:Synovitis / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors*
chemical_list: D007093:Imidazoles; D053583:Interleukin-1beta; D011725:Pyridines; D048051:p38 Mitogen-Activated Protein Kinases; D019278:Matrix Metalloproteinase 3; C093642:SB 203580