P-343 Progesterone resistance related Renin-angiotensin system activation is involved in endometriosis

Study question Whether renin-angiotensin system activation could be involved in endometriosis development and act as the key linking hypertension with endometriosis. Summary answer We proved that progesterone resistance related AGT-HEY1-GATA4 regulatory axis is involved in endometriosis. Intraperitoneal injection of AGT may promote the growth of peritoneal endometriosis lesions. What is known already Patients with endometriosis may be more susceptible to hypertension, and there is currently no research exploring the molecular mechanisms underlying the association between endometriosis and hypertension. Previous studies have shown AGT’s important role in hypertension, however, it is still unknown whether the activation of the AGT pathway is involved in the occurrence and development of endometriosis, whether it is a key molecular mechanism linking endometriosis with the risk of hypertension, and whether it can serve as a potential intervention target for the progression of endometriosis. Study design, size, duration Cross-analysis of the differently expressed genes by RNA-sequencing (n = 4) and potential target genes for ERa and PR by Cut-tag (n = 1) in paired eutopic and ectopic endometrium was conducted to explore the dysregulated targets in endometriosis. Dysregulation of several AGT related markers were further confirmed by IHC, q-PCR or Western blot on tissue microarrays (n = 30) or frozen tissue (n = 10). Serum levels of AGT, MME and Progesterone were measured by ELISA in endometriosis patients and controls (n = 28). Participants/materials, setting, methods 50 endometriosis patients identified by laparoscopy and 50 controls were enrolled. A human endometrial cell line (THESC) was used as in vitro model and an endometriosis mouse model were established by the peritoneal suture and fixation of endometrium. Each experiment included at least three independent samples and was repeated at least three times. Comparisons of the two groups were made by Student’s t-tests. Differences among multiple groups were compared using a one-way analysis of variance. Main results and the role of chance AGT was found upregulated in ectopic endometrium, which was predicted to be one of the up regulators for differentially expressed genes based on IPA analysis. As AGT pathway molecules, dysregulation of AGT, AGTR1, MME, CPA3, CTSG, REN and so on were confirmed between eu-and ectopic endometrial tissues by qPCR or western blot. The cross analysis showed most of the genes differentially expressed in endometriosis lesions were regulated by ERa or PR. AGT-HEY1-GATA4 regulatory axis, which carried PR binding sites, was predicted to play a role in the development of endometriosis by IPA analysis. In vivo, we further confirmed upregulation of AGT and GATA4, downregulation of HEY1 in endometriosis lesions based on the IHC analysis of tissue microarrays of eutopic endometrium and ectopic lesions, as well as the q-PCR and western blot analysis of fresh frozen tissues. In vitro, progesterone treatment can upregulate MME and down-regulate HEY1 respectively in THESC cell at a concentration dependent mode. A higher serum level of AGT while a lower serum levels of MME in endometriosis patient were also determined by ELISA. Similarly, continuous intraperitoneal injection of AGT at 30ug/d for 2 weeks in endometriosis mouse model can significantly increase sizes of peritoneal endometriosis lesions. Limitations, reasons for caution The present study has found renin-angiotensin system activation was involved in endometriosis development and acted as the key linking hypertension with endometriosis, but further study is warranted to verify deeper mechanism. Wider implications of the findings Our study provides a common pathogenesis for exploring hypertension and endometriosis, which have been found to be associated in previous epidemiological investigations. Our study has great potential to identify biomarkers for the early diagnosis of endometriosis and to unlock treatment opportunities with more permanent efficacy and with fewer adverse effects. Trial registration number No