Oral Presentation ESA-SRB-ANZBMS 2024 in conjunction with ENSA

Normal and endometriotic stromal cell responses to steroid hormones and 5-hmC inhibition (#49)

Abbey C Lissaman 1 , Anna Ponnampalam 1 2 , Jane E Girling 3 , Lynsey Cree 4
  1. Department of Physiology, University of Auckland, Auckland, New Zealand
  2. Manaaki Manawa - The Center for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
  3. Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
  4. Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand

The endometrial stroma plays a crucial role in supporting endometrial epithelial cells throughout the menstrual cycle. Outside the context of decidualization, our understanding of how cycling steroid hormones and their receptors are regulated in stromal cells of the healthy uterus, and dysregulated in endometriosis, is limited.  Furthermore, the regulation of menstrual cycle-related genes by epigenetic modifications, particularly hydroxymethylation (5hmC), mediated by Ten-Eleven Translocase proteins (TETs), is largely unexplored in endometrial biology.

This study characterizes and compares endometrial stromal cells (ESCs) and endometriotic stromal cells (eESCs) responses to steroid hormone signalling and 5hmC modulation pathways.

ESCs and eESCs were treated for 21 days with control, estrogen (β-estradiol), or combined estrogen and progesterone with or without estrogen priming. Cells were also treated for 3 days with various concentrations of the TET inhibitor Bobcat339, with or without estrogen. Samples were collected at multiple time points for proliferation, gene and protein expression analysis.

The findings showed that eESCs expressed higher baseline levels of steroid hormone receptors and TETs compared to ESCs. Preliminary data indicated that estrogen, alone and with progesterone, had a more inductive effect on estrogen receptor alpha expression and inhibitory effect on estrogen receptor beta in eESCs compared to ESCs. 14 days of estrogen treatment increased progesterone receptor, androgen receptor, and TET1 expression in ESCs but not eESCs. While neither cell line showed differences in proliferation rates with hormone treatment, eESC proliferation was significantly reduced compared to ESCs at multiple time points with control and estrogen treatment. Proliferation of ESCs and eESCs was reduced by TET inhibition in a dose-dependent manner; interestingly, estrogen in combination with Bobcat339 had an even more anti-proliferative effect.

This study highlights hormonal and proliferative differences between ESCs and eESCs, and the possibility of targeting epigenetic pathways in the search for therapeutic interventions for endometriosis.