title: [Impact of Pax-8 gene interference on mitochondrial function and cardiomyocyte apoptosis].
abstract: OBJECTIVE
  To observe the effects of paired box gene 8 (Pax-8) silencing by RNA interference on mitochondrial function and cardiomyocytes apoptosis.
  
  
  METHODS
  The cultured H9C2 (2-1) myocytes were divided into 3 groups: short interference RNA targeting Pax-8 (Pax-8 siRNA) group, non-specific siRNA group as the negative control (NC siRNA), and blank control group (BC siRNA). Fluorescence spectrophotometry was used to detect the activity of caspase-3. RT-PCR was performed to detect mRNA expression of Bcl2 and Bax. The protein expression of Bcl2, Bax and cytoplasm of Cytochrome was examined by Western blot. Changes of ΔΨm were detected by flow cytometry.ΔΨm with JC-1 monomer/polymer ratio was calculated for measuring mitochondrial depolarization proportion.
  
  
  RESULTS
  Compared to NC siRNA and BC siRNA group (0.075 ± 0.021, 0.072 ± 0.019), the activity of caspase-3 in Pax-8 siRNA group (0.167 ± 0.012) was significantly increased (P < 0.05); Bcl2 mRNA and protein expression in Pax-8 siRNA group (0.61 ± 0.06, 0.94 ± 0.11) were significantly downregulated compared with NC siRNA group (0.90 ± 0.070, 1.39 ± 0.15) and BC siRNA group (0.94 ± 0.087, 1.49 ± 0.20) (P < 0.05); Bax mRNA and protein expression in Pax-8 siRNA group (1.05 ± 0.10, 1.25 ± 0.12) were markedly upregulated compared with NC siRNA group (0.72 ± 0.03, 0.99 ± 0.12) and BC siRNA group (0.64 ± 0.03, 0.92 ± 0.06), P < 0.05; cytosolic cytochrome expression in Pax-8 siRNA group (0.75 ± 0.14) was significantly upregulated compared with NC siRNA group (0.51 ± 0.06) and BC siRNA group (0.48 ± 0.07) (P < 0.05); JC-1 monomer/polymer ratio in Pax-8 siRNA group (0.163 ± 0.011) was significantly increased compared with NC siRNA group (0.092 ± 0.015) and BC siRNA group (0.072 ± 0.025) (P < 0.05) indicating mitochondrial membrane potential was significantly reduced in Pax-8 siRNA group. Above parameters were similar between NC siRNA group and BC siRNA group (P > 0.05).
  
  
  CONCLUSIONS
  Inhibiting Pax-8 results in enhanced cardiomyocytes apoptosis through the mitochondrial pathway.
authors: Department of Cardiology, Institute for Cardiovascular Biology and Gene, Wenzhou, China.
authors: Xiao-chun
authors: XC
authors: Dai
authors: Xi
authors: X
authors: Zhou
authors: Xiao-yan
authors: XY
authors: Huang
authors: Liang-guo
authors: LG
authors: Wang
authors: Su
authors: S
authors: Lin
authors: De-ye
authors: DY
authors: Yang
mesh_terms: D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D008929:Mitochondria, Heart / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D014162:Transfection
chemical_list: D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; C499497:Pax8 protein, rat; D012333:RNA, Messenger