ABSTRACT
Estrogen receptor beta (ERß/ESR2) has a central role in mouse ovaries, as ERß knockout (BERKO) mice are subfertile due to an increase in fibrosis around the maturing follicle and a decrease in blood supply. This has a consequence that these follicles rarely rupture to release the mature oocyte. Matrix metalloproteinases (MMPs) are modulators of the extracellular matrix, and the expression of one specific MMP, MMP-19, is normally increased in granulosa cells during their maturation until ovulation. In this study, we demonstrate that MMP-19 levels are downregulated in BERKO mouse ovaries. Using human MCF-7 cells that overexpress ERß, we could identify MMP-19 to be a transcriptional target of ligand-bound activated ERß acting on a specificity protein-1 binding site. These data provide a molecular explanation for the observed follicle rupture defect that contributes to the subfertility of female BERKO mice.
Subject(s)
Estrogen Receptor beta/metabolism , Matrix Metalloproteinases, Secreted/metabolism , Ovary/metabolism , Animals , Chorionic Gonadotropin , Down-Regulation , Estrogen Receptor alpha/metabolism , Female , Humans , MCF-7 Cells , Matrix Metalloproteinases, Secreted/genetics , Mice, Inbred C57BL , Mice, Knockout , Ovulation , Sp1 Transcription Factor/metabolismABSTRACT
OBJECTIVE: To study the expression, distribution, and function of thyroid-stimulating hormone receptor (TSHR) and thyroid hormone receptors (TR) α1, α2, and ß1 in human endometrium. DESIGN: Experimental clinical study. SETTING: University hospital. PATIENT(S): 31 fertile women. INTERVENTION(S): Endometrial biopsy samples obtained throughout the menstrual cycle. MAIN OUTCOME MEASURE(S): Real-time reverse transcriptase polymerase chain reaction, immunohistochemistry and Western blot to study the expression of TSHR, TRα1, TRα2, and TRß1 messenger RNA (mRNA) and proteins in human endometrium. RESULT(S): We found TSHR, TRα1, TRα2 and TRß1 mRNA and proteins expressed in human endometrium. Immunostaining for TSHR in the luminal epithelium and TRα1 and ß1 in the glandular and luminal epithelium increased statistically significantly on luteinizing hormone (LH) days 6 to 9, coinciding with appearance of pinopodes. Endometrial stromal and Ishikawa cells expressed mRNA for TSHR, TR, and iodothyronine deiodinases 1-3. After 48 hours, TSH significantly increased leukemia inhibitory factor (LIF) and LIF receptor (LIFR) messenger RNA (mRNA) in endometrial stromal cells, but decreased their expression in Ishikawa cells. Glucose transporter 1 mRNA was up-regulated by TSH in Ishikawa cells. We found that TSH statistically significantly increased secretion of free triiodothyronine (T3) and total thyroxin (T4) by Ishikawa cells compared with nonstimulated cells. CONCLUSION(S): Thyroid hormones are directly involved in endometrial physiology.
Subject(s)
Endometrium/physiology , Receptors, Thyrotropin/genetics , Thyroid Hormone Receptors alpha/genetics , Thyroid Hormone Receptors beta/genetics , Biopsy , Cells, Cultured , Culture Media, Conditioned/pharmacology , Endometrium/cytology , Endometrium/ultrastructure , Female , Gene Expression/physiology , Glucose Transporter Type 1/genetics , Humans , Immunohistochemistry , Leukemia Inhibitory Factor/genetics , Leukemia Inhibitory Factor Receptor alpha Subunit/genetics , Microscopy, Electron, Scanning , RNA, Messenger/metabolism , Receptors, Thyrotropin/metabolism , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Thyroid Hormone Receptors alpha/metabolism , Thyroid Hormone Receptors beta/metabolismABSTRACT
Dysfunction in thyroid regulation can cause menstrual and ovulatory disturbances, the mechanism of which is not clear. The distribution and activity of the thyroid-stimulating hormone (TSHR), and the thyroid hormone receptors (TR) alpha1, alpha2 and beta1 in human ovarian tissue and in granulosa cells was studied using immunohistochemistry, reverse-transcriptase polymerase chain reaction (RT-PCR), quantitative PCR and immunoassays. Strong immunostaining of TSHR, TRalpha1 and TRbeta1 was observed in ovarian surface epithelium and in oocytes of primordial, primary and secondary follicles, with minimal staining in granulosa cells of secondary follicles. Granulosa cells of antral follicles expressed TSHR, TRalpha1 and TRbeta1 proteins. Messenger RNA for all receptors was present in ovarian tissue. Mature human granulosa cells expressed transcripts for 5' deiodinases types 2 and 3, but not type 1, indicating the possibility of conversion of peripheral thyroid hormone thyroxin (T(4)). Granulosa cells stimulated with TSH showed a significant increase in cAMP concentrations after 2 h of culture (P = 0.047), indicating activation through TSHR. Stimulation with T(4) resulted in increased extracellular signal-regulated kinase 1 and 2 activation after 10, 30, 60 min and 24 h. These data demonstrate that TSH and thyroid hormone receptors may participate in the regulation of ovarian function.
