Human fallopian tube expresses transforming growth factor (TGF beta) isoforms, TGF beta type I-III receptor messenger ribonucleic acid and protein, and contains [125I]TGF beta-binding sites

Abstract

Reverse transcription-polymerase chain reaction analysis of total ribonucleic acid (RNA) from human fallopian tubes revealed that transforming growth factor-beta 1 (TGF beta 1), TGF beta 2, and TGF beta 3 as well as TGF beta type I-III messenger RNA (mRNA) are expressed in this tissue. In situ hybridization and immunohistochemical observations using TGF beta isoform-specific [35S]40-mer oligonucleotide probes and polyclonal antibodies indicate that all the tubal cell types express TGF beta isoforms and TGF beta type II receptor mRNA and protein. The tubal epithelial cells appeared to express more TGF beta 1 mRNA and TGF beta 1-3 proteins than other cell types, whereas TGF beta 2 and TGF beta 3 mRNA appeared to be equally expressed in the epithelial and other tubal cell types. In the epithelial lining, both ciliated and nonciliated cells in the ampullary and isthmus regions appeared to express mRNA and protein for TGF beta s and TGF beta type II receptor at a similar level. The intensity of immunostaining of TGF beta s in tubal epithelial cells was lower during the early proliferative and late secretory than the mid- to late proliferative and early to midsecretory phases of the menstrual cycle and reduced during the postmenopausal period. However, the intensity of immunoreactive TGF beta type II receptor in these cells did not vary during the cycle as much as that seen with TGF beta s. Quantitative autoradiography of [125I]TGF beta 1 indicates that fallopian tubes contain specific binding sites for TGF beta 1. Net grain density per 100 microns 2, calculated for different cell types, indicates that the epithelial cells had a significantly higher grain density than other tubal cell types (P < 0.05), with similar densities in the late proliferative and early secretory phases of the cycle. These results provide the first evidence that human fallopian tubes express mRNA and protein and contain specific binding sites for TGF beta system, suggesting an autocrine/paracrine role for TGF beta in a variety of tubal functions.