Quantitative and qualitative analysis of estrogen receptor mRNAs on peripheral mononuclear blood cells from females in different estrogen-endocrine circumstances

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671623
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Obstetrics and gynecology
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: HONJO Hideo Kyoto Prefectural University of Medicine, Dept. of OB/GYN, Professor, 医学部, 教授 (30110852)
• Co-Investigator(Kenkyū-buntansha): TAMURA Takaya Kyoto Prefectural University of Medicine, Dept. of OB/GYN, Assistant, 医学部, 助手 (50271169)
• Project Period (FY): 2000 – 2001
• Keywords: HRT / Peripheral mononuclear cell / estrogen receptor

Research Abstract

Object:
The expression of estrogen receptor (ER) on peripheral mononuclear blood cells (PMBC) was reported. Recent progress in the study of ER revealed the variety of forms and indicated the related functions. But till now, no detailed examination has been made about the expression of ERs and peripheral mononuclear blood cell (PMBC). To see the mechanism of hormone replacement therapy (HRT) through the PMBC, this study was designed to make a quantitative and qualitative analysis about the variant kinds of ERs on mRNA level on PMBC from the women in variant endocrine circumstances.
Material and Method:
With informed consent,2 ml of peripheral whole blood was obtained in EDTA tube from women with regular menstrual cycle (MC ; n=42), menopausal women without HRT (MP ; n40), women with HRT (HR ; n=42) and pregnant women (PR ; n=44). PMBC was isolated and total RNA was extracted. Quantitative RT-PCR was done about Wild type ER α (WtER α), exon 3 alternatively spliced ERα (Δ3ERα),Δ4ERα,Δ5ERα,Δ7 ERα, WtERβ and Δ5ERβ mRNAs using specific primers. All data-was corrected with β actin as Internal control which was measured in the same sample simultaneously.
Result:
WtERα mRNA was detected in all samples. ERα mRNA is dominantly expressed in PMBC and its expression level is influenced with the systemic estrogen levels measured in peripheral blood serum. After menopause it decreased significantly but with 6 month HRT, it was recovered to the level of MC. WtERβ mRNA was detected from 39% to 79% of the cases in each group. But its expression level showed no correlation with individual estrogen level. Δ3ERα mRNA and Δ5ERα mRNA were rarely detected in PMBC. The expression of Δ4ERα mRNA and Δ7ERα mRNA tended to decrease after menopause, but it showed no correlation with serum estrogen level and showed no change with HRT.
Conclusion:
In PMBC, WtERα mRNA is dominantly expressed and it is supposed that serum estrogen level exerted great influence to the expression level. After menopause, it decreases but HRT of more than 6 month can work effectively to recover it to the level of MC, but could not recover the expression level of ΔERα mRNAs.