Clinical and Experimental Reproductive Medicine

The Korean Society for Reproductive Medicine (대한생식의학회)
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Expression of Immortalization-upregulated Proteins-2 (IMUP-2) in Placenta

태반 내 Immortalization-upregulated Proteins-2 (IMUP-2) 발현

  • 전수연 (차의과학대학교 의생명과학과) ;
  • 이현정 (차바이오텍 CHA 줄기세포연구소) ;
  • 정현민 (차의과학대학교 의생명과학과) ;
  • 김진경 (차의과학대학교 의생명과학과) ;
  • 김기진 (차의과학대학교 의생명과학과)
  • Published : 2009.09.30
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Abstract

Objectives: Members of the immortalization-upregulated protein (IMUP) family are nuclear proteins implicated in SV40-mediated immortalization and cellular proliferation, but the mechanisms by which their expression is regulated are still unknown in placenta. To investigate to expression and functions of IMUPs in placenta, we conducted to compare IMUPs expression in normal and preeclamptic placenta tissues and analyzed the function of IMUP-2 in HTR-8/SVneo trophoblast cells after IMUP-2 gene transfection. Methods: The expression of IMUPs was analyzed in placental tissues from the following groups of patients (none underwent labor): 1) term normal placenta (n=15); 2) term with preeclamptic placeneta (n=15); and 3) pre-term with preeclamptic placenta (n=11) using semi-quantitative RT-PCR, RNA in situ hybiridization, immunohistochemistry, and Western blot. In order to evaluate the function of IMUP-2 in HTR-8/SVneo trophoblast cells, IMUP-2 plasmids were transfected into HTR-8/SVneo trophoblast cells for 24 hours. Results: We observed that IMUPs are mainly expressed in the syncytiotrophoblasts and syncytial knot of placental villi. The expression of IMUP-1 was not differences between normal and preeclamptic placenta tissues. However, IMUP-2 expression was significantly higher in preterm preeclamptic placenta tissues than in normal placenta tissues without labor (p<0.001). Furthermore, we confirmed overexpression of IMUP-2 induced apoptosis in HTR-8/SVneo trophoblast cells through up-regulation of pro-apoptotic proteins. Conclusions: These results suggest that the expression of IMUP-2 is involved in placental development as well as increased IMUP-2 expression is associated with preeclampsia through the inducing of trophoblast apoptosis.

목 적: Immortalization-upregulated proteins (IMUPs) family는 SV40의 유전자 도입을 통한 불사화된 인간 섬유아세포에서 새로이 분리 동정된 핵 내 단백질로써, 세포의 증식과 종양형성에 관여하는 것으로 알려져 있으나, 태반 발달과정에 따른 발현 양상과 기능에 대해서는 알려져 있지 않은 실정이다. 본 연구의 목적은 정상 태반과 자간전증 태반조직에서의 IMUPs 유전자의 발현을 분석하고, IMUPs 유전자의 HTR-8/SVneo trophoblast cells 내로 도입 후 IMUPs의 기능을 분석하고자 하였다. 연구방법: IMUPs 발현을 분석하고자, 정상 태반 (n=15), 중기 자간전증 태반 (n=11), 그리고 말기 자간전증 태반 (n=15)조직을 수집하여 RT-PCR, RNA in situ hybridization, 면역조직화학법, 그리고 Western blot 등을 실시하였다. IMUP-2의 기능을 확인하고자 HTR-8/SVneo trophoblast cells에 IMUP-2 plasmids를 transfection한 뒤 24시간 후에 각 그룹간의 세포 수를 계수하였으며, 세포사멸 관련 유전자들의 발현을 분석하고자 RT-PCR, 그리고 Western blot 분석 등을 실시하였다. 결 과: IMUPs는 주로 태반 내 합포영양막세포와 포합체결절에서 주로 발현되었다. IMUP-1의 경우 정상과 자간전증 태반에서의 발현의 차이가 관찰되지 않았으나, IMUP-2의 경우 정상 태반에서 매우 약한 발현을 보였으며, 자간전증에서는 발현의 증가가 통계학적으로 유의하게 관찰되었으며 (p<0.001), 특히, 중기 자간전증의 태반조직 내에서는 강한 발현이 관찰되었다. 또한, IMUP-2의 유전자 도입에 의해 과발현된 HTR-8/SVneo trophoblast cells에서는 세포사멸 관련 유전자들의 증가로 영양막세포의 수가 감소됨이 관찰되었다. 결 론: 이러한 결과들은 IMUP-2의 발현이 정상 태반의 발달에 관여할 뿐 아니라 증가된 IMUP-2는 영양막세포의 세포사멸을 증가시킴으로써 자간전증과도 상관성이 있음이 관찰되었다. 따라서, IMUP-2는 자간전증을 예측 및 진단 할 수 있는 마커로 유용하게 활용 가능하다고 사료된다.

Keywords

References

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