title: Effects of pulsed electromagnetic fields on cartilage apoptosis signalling pathways in ovariectomised rats.
abstract: OBJECTIVE
  The purpose of this study was to determine the effect of exposure to pulsed electromagnetic fields (PEMF) on modulation of the cartilage apoptosis signalling pathway in ovariectomised rats by monitoring the expression of mRNA of X-linked inhibitor of apoptosis protein (XIAP) and Bax.
  
  
  METHODS
  Forty-eight female Sprague-Dawley rats (250 ± 50 g) were randomly assigned to one of four groups: ovariectomy with PEMF treatment (PEMF group), ovariectomy with oestradiol (E2) treatment (oestrogen group), ovariectomy control (OVX group) and sham group. The ovariectomy model was prepared by surgical resection of the ovaries. After a three-month intermission, animals in the PEMF and oestrogen groups received treatment for 30 days; then serum 17β-oestradiol levels, chondrocyte morphology, and XIAP and Bax mRNA expression in knee joint cartilage were analysed.
  
  
  RESULTS
  The results showed different chondrocyte formation in each group. Serum E2 content in the PEMF and oestrogen groups was significantly higher than in the OVX group (p < 0.05). The expression of XIAP mRNA in the PEMF and oestrogen groups was significantly up-regulated compared to the OVX group, while that of Bax mRNA was significantly down-regulated (p < 0.05). The correlation between E2 level and expression of Bax mRNA was positive (0.506) and statistically significant (p < 0.001).
  
  
  CONCLUSIONS
  These data demonstrate that PEMF can up-regulate XIAP mRNA expression and down-regulate Bax mRNA expression in ovariectomised rats. Changes in XIAP and Bax mRNA expression may be the mechanism by which PEMF therapy affects postmenopausal osteoarthritis.
authors.affiliation: Department of Rehabilitation Medicine, Province Key Laboratory of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Li
authors.forename: Qinglu
authors.initials: Q
authors.lastname: Luo
authors.forename: Liqun
authors.initials: L
authors.lastname: Huang
authors.forename: Yujun
authors.initials: Y
authors.lastname: Hu
authors.forename: Qingjie
authors.initials: Q
authors.lastname: Xia
authors.forename: Chengqi
authors.initials: C
authors.lastname: He
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D004195:Disease Models, Animal; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000528:radiation effects; D010052:Ovariectomy; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000528:radiation effects; D013264:Stifle / Q000378:metabolism / Q000528:radiation effects; D015854:Up-Regulation / Q000528:radiation effects; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: C494828:Bax protein, rat; D004967:Estrogens; D012333:RNA, Messenger; D051636:X-Linked Inhibitor of Apoptosis Protein; D051028:bcl-2-Associated X Protein