Immunocytochemical detection and reverse transcription polymerase chain reaction expression of oncostatin M (OSM) and its receptor (OSM-Rβ) in human fetal and adult ovaries

Objective: To investigate the immunocytochemical expression and presence of mRNA transcripts of oncostatin M (OSM) and its exclusive receptor (OSM-Rβ) in ovaries from human adults and fetuses. Design: Immunocytochemical and reverse transcription polymerase chain reaction (RT-PCR) study. Setting: Major tertiary care and referral academic centers. Patient(s): Ten women and girls undergoing laparoscopic ovarian biopsy and 30 women undergoing second-trimester and third-trimester pregnancy terminations. Intervention(s): None. Main Outcome Measure(s): Microscopic morphometric analysis, immunocytochemistry for OSM and OSM-Rβ, and RT-PCR analyses. Result(s): There was strong to moderate immunocytochemical staining for OSM in both oocytes and granulosa cells of follicles from primordial stages onwards in ovaries from both fetuses and adults/adolescents. OSM-Rβ was detected mainly in the oocytes. Transcripts of OSM and OSM-Rβ RNA were detected by RT-PCR analyses. Conclusion(s): The expression of OSM and its receptor in ovarian tissue from fetuses and women suggests a possible role of OSM in growth initiation of human primordial follicles.