title: [Expression of PDCD5 and caspase 3 in the cochlea of different age of C57BL/6J mice].
abstract: OBJECTIVE
  To investigate the age related changes of the expression of programmed cell death 5 (PDCD5) and caspase 3 in the cochlea of the different age of C57BL/6J mice. The relationship of PDCD5 and caspase 3 and the possible roles in the pathogenesis of presbycusis were also discussed.
  
  
  METHODS
  C57 mice of 3, 6, 9 and 12 months old were selected and divided into 4 groups, with 15 mice in each group. Auditory function of C57BL/6J mice was measured by auditory brainstem response (ABR) respectively. The changes of PDCD5 and Caspase 3 protein in the cochlea were detected by immunohistochemistry and Western blotting, the changes of PDCD5 mRNA and caspase 3 mRNA were detected using RT-PCR.
  
  
  RESULTS
  With the increase of age, the mean value for ABR thresholds in response to click, 4 kHz and 8 kHz sound stimulus of C57 mice gradually increased, the expression of PDCD5 and caspase 3 were increased also. At 3 months and 6 months of age in the cochlea of C57, all sorts of expression of PDCD5 and caspase 3 and the expression were enhanced with age. There was an evident expression at 9 months age, but the highest expression was detected at 12 months age. The PDCD5 and Caspase 3 expression were statistically different in each group (P < 0.05). The changes of PDCD5 and caspase 3 mRNA expression were in accordance with that of PDCD5 and Caspase 3 protein expression by the real-time PCR.
  
  
  CONCLUSIONS
  The expression levels of PDCD5 and caspase 3 in the cochlea of C57 mice increase with age, the results suggested that the expression of PDCD5 and caspase 3 might play an important role in the pathogenic mechanism of presbycusis.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Han-qi
authors.initials: HQ
authors.lastname: Chu
authors.forename: Liang-qiang
authors.initials: LQ
authors.lastname: Zhou
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.forename: Zhi-yong
authors.initials: ZY
authors.lastname: Li
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Xiao-wen
authors.initials: XW
authors.lastname: Huang
authors.forename: Yong-hua
authors.initials: YH
authors.lastname: Cui
mesh_terms: D000375:Aging; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D001309:Auditory Threshold; D053148:Caspase 3 / Q000378:metabolism*; D003051:Cochlea / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000378:metabolism*; D011304:Presbycusis / Q000378:metabolism* / Q000473:pathology
chemical_list: D051017:Apoptosis Regulatory Proteins; D009363:Neoplasm Proteins; C486488:Pdcd5 protein, mouse; C505409:Casp3 protein, mouse; D053148:Caspase 3