Bone morphogenetic protein 15 expression in human ovaries from fetuses, girls, and women

Objective: To investigate, for the first time, the protein expression of bone morphogenetic protein (BMP) 15 in human ovaries from fetuses, girls/women as well as its mRNA transcripts in ovaries from fetuses and girls. Design: Controlled immunohistochemical and in situ hybridization study of expression of BMP-15 protein and mRNA transcripts in human ovaries. Setting: Major tertiary care academic center. Patient(s): Nine patients that underwent pregnancy terminations at 21-33 gestational weeks and 18 girls and women aged 5-39 years that underwent ovarian laparoscopies. Intervention(s): None. Main Outcome Measure(s): Immunohistochemistry (protein detection) in all specimens and in situ hybridization (mRNA detection) in specimens from fetuses and girls. Both procedures were conducted on paraffin sections. Result(s): The expression of the BMP-15 protein and its mRNA was identified already from primordial stages. Protein expression was detected in all oocytes and stroma cells from both ovarian sources, and in granulosa cells of specimens from girls and women. The mRNA transcripts were detected in the oocyte, granulosa, and stroma cells from fetuses and girls. Conclusion(s): The BMP-15 protein is expressed already at primordial stages in fetuses, girls, and women, and its mRNA transcripts in fetuses and girls. Further studies should be conducted to elucidate if indeed BMP-15 is involved in the activation of human primordial follicles.