Pigment Eoithelium-derived Factor Expression In Endometriotic Lesions In A Rat Model Of Endometriosis

BackgroundEndometriosis refers to the presence of endometrial tissues outside the uterine cavity. Angiogenesis is a prerequisite for the formation and development of endometriotic lesions. Researches had found that many angiogenic factors were increased in the endometriotic lesions and peritoneal fluid and serum from women with endometriosis, VEGF (Vascular endothelial growth factor) was one of the important factor. Pigment epithelium-derived factor (PEDF) is a potential inhibitor of angiogenesis. We have demonstrated decreased PEDF levels in peritoneal fluid and serum from women suffering from endometriosis, which indicated that PEDF may play a role in the angiogenesis of enometriosis, and may become a new therapy drug in endometriosis. In this experiment, we designed a subcutaneous model of endometriosis in SD rats, to detect the expression of PEDF in endometriotic lesions by immunohistochemistry, and explore the correlation between PEDF and VEGF (Vascular endothelial growth factor) or MVD(Microvessel density, hoping it can offer the laboratory basis for the research of pathogenesis and treatment of endometriosis.ObjectiveTo explore the expression of Pigment epithelium-derived factor in endometriotic lesions in a rat model of endometriosis. Materials and methodsChose healthy female non-pregnant SD rats, weight200-230g; Established the subcutaneous model of endometriosis by auto-transplant; Measured the size of cysts; Confirmed the lesions were endometrium-like tissues by histology and immunohistochemistry; Depicted the growth curve of the subcutaneous lesions according the size of cysts. Then established the same model according to the above method again, when the lesions were in the growth stage、peak stage、stable stage and recession stage, respectively, measured the size of cysts、collected the lesions and uterus tissues. We also set a sham-operated control group. When the rats were on the second operation, we collected uterus tissue as samples. Then detected the expression of PEDF and VEGF and movrovascular density (MVD) by using von Willebrand factor (v-WF) by immunohistochemistry, and explored the correlation.All data were managed with SPSS16.0for windows. One-Way ANOVA and Speraman’rank correlation coefficient analysis were used. Two-tailed test with P<0.05was considered significance.Results1. The success rate was100%. This model had obvious growth stage、peak stage、stable stage and recession stage;2. The expression of PEDF were lowest in the peak stage, were significantly lower than stable stage and recession stage (P<0.05).3. The expression of PEDF has negatively correlation with VEGF and MVD and the size of endometriotic lesions (r=-0.813,P<0.01; r=-0.588,P<0.01; r=-0.578,P<0.01);4.The size of cysts was positive correlated with VEGF and MVD (r=0.761,P<0.01; r=0.522,P<0.05),and negatively correlated with PEDF(r=-0.578,P<0.01)5. The scores of VEGF was positive correlated with MVD (r=0.776,P<0.01)Conclusions1. The success rate of subcutaneous model of endometriosis was100%; and had obvious growth cycle;2. The expression of PEDF in the cysts has negatively correlation with the size of endometriotic lesions and VEGF and MVD, which suggested that PEDF maybe can become a new drug to therapy endometriosis.