The Effect Of Soluble Interleukin-1 Receptor Type Ⅱ On The Endometriosis In A Nude Mouse Model

Objective:Endometriosis is a common gynecological disorder,recent studies have indicated that the mRNA and protein expression of Interleukin-1 receptor typeⅡ(IL-1 RⅡ)in endometrial tissue decreased in women suffering from endometriosis.In endometriotic stromal cells, Interleukin-1β(IL-1β)has been shown to stimulate angiogenic factors such as vascular endothelial growth factor(VEGF)and interleukin-8(IL-8),which is not observed in normal endometrial stromal cells.Our previous study also revealed that IL-1βsignificantly increases the production of IL-8 and this effect can be counteracted by recombinant adenovirus of IL-1RⅡ(rAd-RⅡ).Furthermore,we showed that overexpression of IL- 1RⅡ(rAd-RⅡ)could suppress B-cell lymphoma/leukemia-2(Bcl-2)expression.We aimed to use the endometriosis models to detect the effect of soluble interleukin-1 receptor typeⅡ(sIL-1RⅡ)on the nude mice endometriosis model.We hypothesized that sIL-1RⅡadministration induces a decrease in the implant size,decreases the expression of protein of Bcl-2 and VEGF on the lesions,and decreases the level of VEGF and IL-8 in peripheral fluid (PF)and serum on the nude mouse model of endometriosis.These findings also indicate that the pathogenesis of endometriosis is multifactorial and involves many cellular mediators that warrant further study,and we aimed at to establish a dynamic endometriosis nude mouse model that allows noninvasive assessment of lesion implantation and development,for preclinical testing the efficacy of new drugs targeting endometriosis and understanding the pathophysiology of the disease.Methods:①Nineteen mice,randomly divided into three groups,the sIL-1RⅡtreated group(n=7),IL-1 treated group(n=6),and control group(n=6). Each group of mice were treated with an intraperitoneal iniection of 0.2 ml of their respective treatments every other day for 2 weeks.Human recombinant IL-1(5rig/kg)and human recombinant sIL-1 RⅡ(25ug/kg) aftter 2 weeks,the size of ectopic endometrial lesions were calculated, and the expression of VEGF and Bcl-2 were detected by immunohistochemistry,the IL-8 and VEGF level in the PF and serum were measured via enzyme-linked immuno sorbent assay(ELISA).②Twenty-five female nude mice were devided into subcutaneous group (SC,11 mice)and intraperitoneal group(IP,14 mice),1～2mm~3 whole fragments of human endometrium were infected in vitro by enhanced green fluorescent protein(EGFP)adenovirus before transplantation into nude mouse(5 pieces per animal).Animals were noninvasively and repeatedly imaged by direct visualization of fluorescent tissue before lesion collection. Result(s):①The sizes of ectopic endometrial lesions in the sIL1-RⅡtreated nude mice were smaller compared with the other two groups,but the difference did not reached statistical significance.IL-1 treated group: 23.57±6.7 mm~2,control group:21.14±10.63 mm~2,sIL-1RⅡtreated group:17.6±15.15 mm~2)(p＞0.05).②The expression of VEGF and Bcl-2 significantly lower in the sIL1-RⅡgroup and higher in the IL-1 treated group compared with the control, both the difference reached statistical significance.(VEGF grey value: IL-1 treated group 79.86±1.27,control group 90.57±1.13,sIL-1RⅡtreated group 97.3±1.32;Bcl-2 grey value:IL-1 treated group 90.68±1.87,control group 97.94±0.79,sIL-1RⅡtreated group 110.28±0.98)(p＜0.05).③In the PF and serum,levels of IL-8 were highest in the IL-1 treated group and lowest in the sIL1-RⅡtreated group,and the difference reached statistical significance.(serum IL-8:IL-1 treated group 4.6±0.63ng/ml,control group 4.25±0.57ng/ml,sIL-1RⅡtreated group 3.71±0.49ng/ml,PF IL-8:IL-1 treated group 5.01±0.26ng/ml,control group 4.43±0.35ng/ml,sIL-1RⅡtreated group 4.03±0.25ng/ml)(p＜0.05).④In the PF and serum,levels of VEGF were highest in the IL-1 treated group and lowest in sIL 1-RⅡtreated group,but the difference did not reached statistical significance.(serum VEGF:IL-1 treated group 4.6±0.63ng/ml,control group 4.25±0.57ng/ml,sIL-1RⅡtreated group 3.71±0.49ng/ml;PF VEGF:IL-1 treated group 5.63±0.58ng/ml, control group 5.46±0.5ng/ml,sIL-1RⅡtreated group 5.27±0.85ng/ml)(p＞0.05).⑤EGFP gene transferred into whole endometrial fragments can be performed,fluorescent endometrial fragments implant in nude mouse and form endometriotic-like lesions fluorescence of EGFP expressing in human endometrial fragments can development of endometriotic lesions(average 2 lesions per animal).⑥The lesion can be monitored by the stereo fluorescence microscope from the skin of living animal,the area and intensity of fluorescent decreased with the time went on,which last for 3 weeks.⑦The lesions that were hardly distinguishable by visual examination could be easily located by the EGFP fluorescence.Fluorescence of SC can be easier dynamically monitored than the IP.Conclusion(s):①These results suggest that sIL1-RⅡcan effectively on endometriosis in a nude mouse model,and may provide a new clinical strategy for the treatment of endometriosis,sIL-1RⅡadministration can decrease the size of the implantation may through decrease the angiogenesis of lesions on the mouse model of endometriosis. ②These results suggest that sIL-1RⅡadministration can decrease the size of the implantation may through promote the apoptosis of endometrial fragments to ectopic sites on the mouse model of endometriosis.③This improved SC mouse model allows noninvasive and dynamic studies of lesion implantation and development,and maybe taken as a valuable tool for preclinical testing the efficacy of new drugs targeting endometriosis and understanding the pathophysiology of the disease.