Expression and selective cellular localization of granulocyte-macrophage colony-stimulating factor (GM-CSF) and GM-CSF α and β receptor messenger ribonucleic acid and protein in human ovarian tissue

Abstract

Reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemical observations revealed that human ovarian tissue expresses granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as GM-CSF α and β receptor (R) mRNA and protein. The RT- PCR products revealed the predicted 286-, 546-, and 380-bp fragments for GM- CSF, GM-CSF αR, and GM-CSF βR, respectively, which were further verified by restriction enzyme digestion analysis. In situ hybridization revealed that the theca interna of the large follicles and luteal cells are the exclusive site of GM-CSF mRNA expression. Furthermore, immunohistochemical studies using specific monoclonal antibodies indicated that the theca interna of the large follicles are the exclusive site of GM-CSF protein, whereas theca externa and to a lesser extent the granulosa cells are the major sites of GM- CSF αR and βR proteins. Atretic follicles and follicular cysts showed very low or no detectable levels of GM-CSF and GM-CSF αR and βR. In the luteal tissue, both the small and large luteal cells of early luteal (Days 14-19) and midluteal (Days 20-25) phase expressed GM-CSF mRNA and protein as well as GM-CSF αR and βR proteins, and their immunostaining intensity was similar to that seen with theca cells. Luteal cells from late luteal phase (Days 26- 28), corpus albicans, and ectopic pregnancy expressed a low level of GM-CSF, GM-CSF αR, and GM-CSF βR mRNA and protein. Ovarian stromal, luteal tissue fibroblast, and arteriole endothelial and smooth muscle cells did not express GM-CSF but showed weak expression of immunoreactive GM-CSF αR and βR. These data provide the first evidence that human ovarian tissue expresses GM-CSF and GM-CSF αR and βR mRNA and protein. Their selective compartmental expression in the follicles and luteal tissue imply an autocrine/paracrine role for theca- and luteal-derived GM-CSF affecting, respectively, the later stages of follicular development and a variety of ovarian biological functions.