title: Calpain inhibitor PD150606 attenuates glutamate induced spiral ganglion neuron apoptosis through apoptosis inducing factor pathway in vitro.
abstract: OBJECTIVE
  This research aimed to investigate whether glutamate induced spiral ganglion neurons (SGNs) apoptosis through apoptosis inducing factor (AIF) pathway. And verify whether PD150606, a calpain inhibitor could prevent apoptosis by inhibiting cleaving and releasing AIF in mitochondrion.
  
  
  METHODS
  SGNs of postnatal days 0-3 were harvested and cultured in dishes. 20 mM Glu, the caspase inhibitor Z-VAD-FMK and calpain inhibitor PD150606 were added into cultured dishes separately. We used optical microscope and immunofluoresence staining to observe cell morphology and AIF distribution, RT-PCR and Westernblot to analyse AIF and calpain expression in SGNs. TUNEL assay was used to test cell apoptosis.
  
  
  RESULTS
  Cell morphology and nuclear translocation of AIF were altered in SGNs by 20 mM Glu treated in vitro. The axon of SGN shortened, more apoptosis SGN were observed and the expression of AIF and calpain were up-regulated in Glu-treated group than the normal one (P<0.05). The same experiments were conducted in 20 mM+PD150606 treated group and 20 mM+Z-VAD-FMK group. Obviously AIF were located from cytoplasm to the nuclear and the expressions of AIF and calpain were down-regulated by PD150606 (P<0.05). Positive cells in TUNEL staining decreased after PD150606 treating. However, Z-VAD-FMK had no influence on AIF, calpain expression or cell apoptosis.
  
  
  CONCLUSIONS
  The AIF-related apoptosis pathway is involved in the process of Glu-induced SGN injury. Furthermore, the inhibition of calpain can prevent AIF from releasing the nuclear or inducing SGN apoptosis.
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Zhong-Jia
authors: ZJ
authors: Ding
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Xin
authors: X
authors: Chen
authors: Outpatient Department of Logistics Academy, Beijing, China.
authors: Xiao-Xu
authors: XX
authors: Tang
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Xi
authors: X
authors: Wang
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Yong-Li
authors: YL
authors: Song
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Xiao-Dong
authors: XD
authors: Chen
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Wen-Juan
authors: WJ
authors: Mi
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Jian
authors: J
authors: Wang
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Ying
authors: Y
authors: Lin
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Fu-Quan
authors: FQ
authors: Chen
authors: Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Jian-Hua
authors: JH
authors: Qiu
mesh_terms: D000179:Acrylates / Q000494:pharmacology*; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D051033:Apoptosis Inducing Factor / Q000235:genetics* / Q000378:metabolism; D002154:Calpain / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology; D020169:Caspases / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation; D018698:Glutamic Acid / Q000494:pharmacology*; D006023:Glycoproteins / Q000494:pharmacology*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061251:Primary Cell Culture; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013136:Spiral Ganglion / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D000179:Acrylates; C494831:Aifm1 protein, rat; D000590:Amino Acid Chloromethyl Ketones; D051033:Apoptosis Inducing Factor; D061945:Caspase Inhibitors; D006023:Glycoproteins; C100442:PD 150606; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C039304:calpain inhibitors; D018698:Glutamic Acid; D002154:Calpain; D020169:Caspases