Clinical and Experimental Reproductive Medicine

The Korean Society for Reproductive Medicine (대한생식의학회)
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Gonadotropin Regulation of Regulator of G Protein Signaling 2 (RGS-2) Expression in the Rat Ovary

백서 난소에서 성선자극호르몬에 의한 RGS-2의 발현 조절

  • Lee, Yu-Il (Department of Obstetrics and Gynecology, Chonnam National University Medical School) ;
  • Lee, Eun-Suk (Department of Obstetrics and Gynecology, Chonnam National University Medical School) ;
  • Kim, Sun-Ae (Hormone Research Center, Chonnam National University Medical School) ;
  • Kim, Mi-Young (Department of Obstetrics and Gynecology, Chonnam National University Medical School) ;
  • Cho, Moon-Kyoung (Department of Obstetrics and Gynecology, Chonnam National University Medical School) ;
  • Chun, Sang-Young (Hormone Research Center, Chonnam National University Medical School)
  • 이여일 (전남대학교 의과대학 산부인과학교실) ;
  • 이은숙 (전남대학교 의과대학 산부인과학교실) ;
  • 김선애 (전남대학교 의과대학 호르몬연구센타) ;
  • 김미영 (전남대학교 의과대학 산부인과학교실) ;
  • 조문경 (전남대학교 의과대학 산부인과학교실) ;
  • 전상영 (전남대학교 의과대학 호르몬연구센타)
  • Published : 2008.06.30
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Abstract

Objective: The purpose of the present study was to examine the hormonal regulation of RGS-2 in the rat ovary. Methods: Immature rats were injected with 10 IU of PMSG to induce multiple growth of preovulatory follicles and 10 IU of hCG to induce ovulation. Northern blot analysis performed for gene expression and in situ hybridization performed for mRNA localization. Results: Northern blot analysis revealed that pregnant mare's serum gonadotropin (PMSG) treatment did not affect RGS-2 mRNA levels. In contrast, human chorionic gonadotropin (hCG) treatment of PMSG-primed rats resulted in an increase in RGS-2 expression within $1{\sim}3\;h$. The major cell-types expressing RGS-2 mRNA were oocytes regardless of follicle size. Interestingly, hCG treatment caused the stimulation of RGS-2 gene expression in granulosa cells of preovulatory and growing follicles. In contrast, cell types expressing RGS-2 protein were theca cells regardless of hCG treatment. Like in vivo, treatment of preovulatory granulosa cells with LH in vitro stimulated RGS-2 levels within 1 h. Interestingly, GnRH antagonist II enhanced the stimulatory action of LH. Conclusion: The present study demonstrates the LH/hCG induction of RGS-2 in preovulatory granulosa cells and suggests a role of RGS-2 in Gq protein signaling pathway during ovulation.

연구방법: 미성숙 백서 난소의 과배란 유도를 위해 PMSG를 주사하고, 배란을 위해서 hCG를 주입하였다. RGS-2의 유전자 발현양상을 조사하기 위하여는 Northern blot 분석과 in situ hybridization 분석을 시행하였다. 결 과: 미성숙 백서에 성선자극호르몬인 PMSG를 복강내 주사했을 때 RGS-2 mRNA 발현에 영향을 미치지 않음을 Northern blot analysis로 확인할 수 있었으나, hCG를 주입했을 때는 1시간에서 3시간 내에 발현이 증가됨을 알 수 있었다. In situ hybridization으로 살펴본 RGS-2 mRNA의 발현세포는 난포의 크기에 관계없이 난자였으나, hCG로 처리한 후에는 배란 전 난포와 성장중인 난포의 과립막 세포이었다. 그러나, RGS-2 단백의 발현은 hCG 처치와 관계없이 난포막 세포이었다. 상기 생체 실험과 마찬가지로 시험관에서도 배란 전 난포의 과립막 세포에 대한 LH 처리는 RGS-2 유전자 발현을 1시간 내에 촉진하였다. 또한, 성선자극호르몬 분비호르몬 2 길항제도 이러한 LH의 촉진작용을 증진시켰다. 결 론: 본 연구로 배란 전 과립막 세포에서 성선자극호르몬인 LH/hCG와 성선자극호르몬 분비호르몬 길항제에 의해 RGS-2의 발현이 증진되는 양상으로 보아 RGS-2가 배란과정 동안에 Gq protein 신호전달을 조절할 것으로 추정된다.

Keywords

References

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