Thyroid-stimulating hormone receptor and thyroid hormone receptors are involved in human endometrial physiology

Abstract

To study the expression, distribution, and function of thyroid-stimulating hormone receptor (TSHR) and thyroid hormone receptors (TR) α1, α2, and β1 in human endometrium. Experimental clinical study. University hospital. 31 fertile women. Endometrial biopsy samples obtained throughout the menstrual cycle. Real-time reverse transcriptase polymerase chain reaction, immunohistochemistry and Western blot to study the expression of TSHR, TRα1, TRα2, and TRβ1 messenger RNA (mRNA) and proteins in human endometrium. We found TSHR, TRα1, TRα2 and TRβ1 mRNA and proteins expressed in human endometrium. Immunostaining for TSHR in the luminal epithelium and TRα1 and β1 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. Thyroid hormones are directly involved in endometrial physiology.