title: Oestrogen receptor beta mediates decreased occlusal loading induced inhibition of chondrocyte maturation in female mice.
abstract: OBJECTIVE
  Temporomandibular joint (TMJ) disorders predominantly afflict women, suggesting that estrogen may play a role in the disease process. Defects in mechanical loading-induced TMJ remodelling are believed to be a major etiological factor in TMJ degenerative disease. Previously, we found that, decreased occlusal loading caused a significant decrease in early chondrocyte maturation markers (Sox9 and Col 2) in female, but not male, C57BL/6 wild type mice (1). The goal of this study was to examine the role of Estrogen Receptor (ER) beta in mediating these effects.
  
  
  METHODS
  21-day-old male (n = 24) and female (n = 25) ER beta KO mice were exposed to decreased occlusal loading (soft diet administration and incisor trimming) for 4 weeks. At 49 days of age the mice were sacrificed. Proliferation, gene expression, Col 2 immunohistochemistry and micro-CT analysis were performed on the mandibular condyles.
  
  
  RESULTS
  Decreased occlusal loading triggered similar effects in male and female ER beta KO mice; specifically, significant decreases in Col 10 expression, subchondral total volume, bone volume, and trabecular number.
  
  
  CONCLUSIONS
  Decreased occlusal loading induced inhibition of chondrocyte maturation markers (Sox9 and Col 2) did not occur in female ER beta deficient mice.
authors: Division of Orthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: ip2162@columbia.edu.
authors: Ilona
authors: I
authors: Polur
authors: Division of Orthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: kamisuke816@gmail.com.
authors: Yosuke
authors: Y
authors: Kamiya
authors: Division of Orthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: mx2137@cumc.columbia.edu.
authors: Manshan
authors: M
authors: Xu
authors: Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: bsc2126@cumc.columbia.edu.
authors: Bianca S
authors: BS
authors: Cabri
authors: Division of Orthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: ma3315@columbia.edu.
authors: Marwa
authors: M
authors: Alshabeeb
authors: Division of Orthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: sw2680@cumc.columbia.edu.
authors: Sunil
authors: S
authors: Wadhwa
authors: Division of Orthodontics, Columbia University College of Dental Medicine, New York, NY 10032, USA. Electronic address: jc3835@cumc.columbia.edu.
authors: Jing
authors: J
authors: Chen
mesh_terms: D000818:Animals; D001732:Bite Force; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D019902:Chondrocytes / Q000378:metabolism*; D020219:Chondrogenesis / Q000502:physiology*; D004032:Diet; D004195:Disease Models, Animal; D047629:Estrogen Receptor beta / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D007150:Immunohistochemistry; D008297:Male; D008335:Mandibular Condyle / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013704:Temporomandibular Joint / Q000378:metabolism; D013705:Temporomandibular Joint Disorders / Q000378:metabolism; D016474:Weight-Bearing / Q000502:physiology; D055114:X-Ray Microtomography
chemical_list: D047629:Estrogen Receptor beta
keywords: Estrogen receptor beta; Mechanical loading; Mouse; Temporomandibular joint