Fig. 2

Enrichment of Neutrophils to Ectopic Lesions. A Representative MPO immunohistochemistry of ectopic ovarian endometriosis (EMs-Ectopic), matched eutopic endometrium (EMs-Eutopic), and control endometrium (Ctrl-Eutopic). The scale bar is 100 μm. B The number of MPO⁺ neutrophils per field in ectopic ovarian endometriosis, matched eutopic endometrium, and control endometrium. N = 6 per group. Data are given as the average number of neutrophils in 4 different fields. C Schematic illustration of the procedure for the endometriosis model. Estradiol benzoate-treated female mice were sacrificed and uteri were removed and split. Endometrial tissue was isolated and mechanically disrupted before intraperitoneal injection into recipient mice. D Images showing fluid-filled endometriotic lesions (circle and arrow) at day 14 after lesion establishment. E–G Flow cytometric measurements E and corresponding quantitative analysis F and G of the percentage of neutrophils (CD11b⁺Ly6G⁺) in CD45⁺ leukocytes of peritoneal fluid (PF), eutopic endometrium and ectopic lesion at the indicated time points after lesion establishment. N = 5 to 9 per time point. Data were shown as mean ± SEM and were analyzed by one-way ANOVA with Turkey’s post hoc test. ***P < 0.001; n.s., not significant