Human uterine tissue throughout the menstrual cycle expresses transforming growth factor-beta 1 (TGF beta 1), TGF beta 2, TGF beta 3, and TGF beta type II receptor messenger ribonucleic acid and protein and contains [125I]TGF beta 1-binding sites.

Abstract

The use of isoform-specific transforming growth factor-beta (TGF beta) primers, 35S-labeled 40-mer oligonucleotide probes and polyclonal antibodies, reverse transcription-polymerase chain reaction, in situ hybridization, and immunohistochemical observations has revealed that human uterine tissue at various reproductive stages expresses TGF beta s and TGF beta type II receptor messenger RNAs (mRNAs) and proteins. The reverse transcription-polymerase chain reaction revealed the predicted 443-, 310-, 524-, and 431-basepair fragments for TGF beta 1, TGF beta 2, TGF beta 3, and TGF beta type II receptor, respectively, in both endometrial and myometrial tissues, which were further verified by restriction enzyme analysis. In situ hybridization and immunohistochemical observations indicated that all uterine cell types express TGF beta s mRNAs and proteins. In the functionalis region, endometrial luminal and glandular epithelial cells are the primary cell types expressing TGF beta s mRNAs and proteins, with lesser expression in stromal cells, whereas in the basalis region, they are equally expressed in both cell types. In myometrium, TGF beta mRNA and protein expression in smooth muscle cells occurs at a substantially lower level than in endometrial tissue. In endometrial tissue, the highest level of TGF beta mRNA and protein expression appeared in the late proliferative and early to midsecretory phases of the menstrual cycle, with a considerable reduction during the late secretory and postmenopausal periods. The pattern and cellular distribution of TGF beta type II receptor protein were similar to those seen with TGF beta isoforms in both endometrial and myometrial tissues. Quantitative autoradiography (net grain density per 100 microns 2) of specific binding of [125I]TGF beta 1 for different uterine cell types indicated that the stromal cells contain a higher grain density than other uterine cell types (P < 0.05), without a significantly different density in the proliferative, compared with the secretory, phase of the menstrual cycle. These data suggest that TGF beta s acting through their specific receptors may play an important role in a variety of uterine functions in an autocrine/paracrine manner, and ovarian steroids may also regulate their expression in endometrial tissue.