Abstract
Disclosure: I. Chowdhury: None. S. Banerjee: None. A. Rodriguez: None. Neuregulin 1 (NRG1) is a member of the EGF-like factor family and has recognized pro-survival and anti-inflammatory roles in neurodevelopmental and cardiac function, neurological and psychiatric disorders, cancer, and development. However, the physiological role of NRG1 in the human ovary and uterus has not been well documented. Therefore, we assessed the expression pattern of NRG1 and its receptor ErbB3 in normal human ovary and uterus tissue samples by immunohistochemistry (IHC). ErbB3 is one of the bona fide receptors for NRG1. NRG1 and ErbB3 were colocalized with steroidogenic acute regulatory protein (StAR) in normal human ovarian tissue samples, whereas NRG1 and ErBB3 were colocalized with CD105 (Endoglin) and epithelial cadherin (E-cadherin) in human uterine tissue samples. Our results showed strong immunoreactive signals of NRG1, ErbB3, and StAR in antral follicles, whereas weak or lack of immunoreactive signals in preantral follicles. The strong immunoreactive signals of NRG1 and ErbB3 were observed in granulosa cells and theca interstitial cells of antral follicles. In the uterus, a differential pattern of NRG1, ErbB3, CD105, and E-cadherin expressions were noticed. Interestingly, strong immunoreactive signals of NRG1, ErbB3, CD105, and E-cadherin in the luminal epithelium, and superficial and deep glands of endometrium were observed, whereas weak immunostaining in myometrium was noticed. These findings suggest that NRG1 and ErbB3 are important intracellular autocrine-paracrine anti-inflammatory factors that may govern antral follicular development and uterine implantation. Nothing to Disclose: SB; AR; IC. Sources of Research Support: This study was supported in part by National Institutes of Health Grants 1SC1 GM130544, G12-RR03034, and P50-HD28934. This investigation was conducted in a facility constructed with support from Research Facilities Improvement Grant #C06 RR18386 from NIH/NCRR. Presentation: Friday, June 16, 2023