Expression of steroidogenic acute regulatory protein mRNA in rat placenta during mid-late pregnancy.
The production of a steroid hormone in the placenta is essential for maintaining the pregnancy and developing the fetus during gestation. In various steroidogenic tissues (including gonads and adrenal cortex), the steroidogenic-acute-regulatory protein (StAR) acutely transfers cholesterol from the outer to the inner mitochondrial membrane for rapid steroidogenesis. Although steroid hormones were synthesized in the rat placenta, the developmental expression of StAR has been poorly understood in the rat placenta during mid-late pregnancy. Therefore, the aim of the present study was to establish the expression and localization of StAR mRNA in the rat placenta during mid-late pregnancy using Northern blots and in situ hybridization. The Northern blot analysis showed that the StAR mRNA expression significantly changed as the gestation day (GD) progressed. The placental expression of StAR mRNA increased between GD 11 and 13, and then slightly decreased until term. In situ hybridization showed a strong StAR expression in giant trophoblast cells on GD 11 and 13, and a moderate expression in trophoblast and stroma cells within the villi of the labyrinth zone throughout the pregnancy. In this study, we reveal for the first time the existence of StAR mRNA in steroidogenic cells of the placenta during mid-late pregnancy. In conclusion, our results suggest that StAR may regulate steroidogenesis in the rat placenta to maintain the pregnancy and developing the fetus.
Koh
Phil Ok
PO
Department of Anatomy, College of Medicine, Gyeongsang National University, Jinju 660-751, Korea.
Kim
Yoon Sook
YS
Cheon
Eun Woo
EW
Kang
Sang Soo
SS
Cho
Gyeong Jae
GJ
Choi
Wan Sung
WS
D000818:Animals; D015152:Blotting, Northern; D005314:Embryonic and Fetal Development / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D005865:Gestational Age; D017403:In Situ Hybridization; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013256:Steroids / Q000378:metabolism; D017154:Stromal Cells / Q000378:metabolism; D014327:Trophoblasts / Q000378:metabolism; D000098682:Steroidogenic Acute Regulatory Protein
D010750:Phosphoproteins; D012333:RNA, Messenger; D013256:Steroids; D000098682:Steroidogenic Acute Regulatory Protein