Zhenghong Zhang

Publications (2)3.94 Total impact

• Article: Regulatory Effect of Hypoxia-Inducible Factor-1α on hCG-Stimulated Endothelin-2 Expression in Granulosa Cells from the PMSG-Treated Rat Ovary.

  Jisen Zhang, Zhenghong Zhang, Yanqing Wu, Liyun Chen, Qianping Luo, Jiajie Chen, Xiaohong Huang, Yong Cheng, Zhengchao Wang
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  ABSTRACT: Endothelin (ET)-2 plays a crucial role in ovarian ovulation in mammals. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1α-mediated transcriptional activation contributes to the increased expression of ET-2 gene in response to hCG in rat ovarian granulosa cells (GCs) during gonadotropin-induced superovulation. By real-time RT-PCR analysis, ET-2 mRNA expression was found to significantly increase in cultured ovarian GCs after treatment with hCG, or even N-carbobenzoxyl-L-leucinyl-L-leucinyl-L-norvalinal (MG-132), while this increased ET-2 mRNA expression could also be blocked by ferrous ammonium sulfate (FAS) under human chorionic gonadotropin (hCG) treatment. Further analysis also found that these changes of ET-2 mRNA were consistent with HIF-1α expression or HIF-1 activity, and HIF-1α inhibitor echinomycin inhibited ovulation in rats. Taken together, these results indicate that ET-2 is transcriptionally activated by hCG through HIF-1α-mediated mechanism in GCs. This HIF-1α-induced transcriptional activation may be one of the important mechanisms mediating the increase of ET-2 expression in GCs during the gonadotropin-induced mammalian ovulatory process in vivo.
  Journal of Reproduction and Development 08/2012; · 1.46 Impact Factor
• Article: Effects of Echinomycin on Endothelin-2 Expression and Ovulation in Immature Rats Primed with Gonadotropins.

  Zhengchao Wang, Zhenghong Zhang, Yanqing Wu, Liyun Chen, Qianping Luo, Jisen Zhang, Jiajie Chen, Zimiao Luo, Xiaohong Huang, Yong Chen
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  ABSTRACT: Echinomycin is a small-molecule inhibitor of hypoxia-inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1alpha-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to hCG during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after echinomycin treatment, while HIF-1alpha mRNA and protein expression was no obviously changes. Further analysis also found that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1alpha and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1alpha and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1alpha directly mediated the transcriptional activation of ET-2 during gonadotropin-induced superuvulation. Taken together, these results demonstrated this HIF-1alpha-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo.
  Experimental and Molecular Medicine 08/2012; · 2.48 Impact Factor