Expression Of GRIM-19 In Adenomyosis And Its Possible Role In Pathogenesis

ObjectiveAdenomyosis is a commonly encountered,benign gynecologic disease that typically occurs in women of reproductive age characterized by the benign invasion of endometrium into the myometrium and diffuse growth.Adenomyosis is generally considered a variant of endometriosis,referred to as internal endometriosis.Although endometriosis is referred to as benign disease,it has the characteristics of decreasing apoptosis,increasing proliferation,new blood vessel formation,increased adhesion and invasion ability and other characteristics of malignant tumors.Our study aim to investigate the potential roles of GRIM-19(gene associated with retinoid-interferon-induced mortality-19)in the development of adenomyosis by detecting the expression of GRIM-19 and apoptosis and vascular changes in normal endometrium,eutopic and ectopic endometrium.Vitro experiments were conducted to study the effect of GRIM-19 expression on cell apoptosis and angiogenesis.and to explore the possible mechanism of GRIM-19 in the development of adenomyosisMethodsIn vivo study:Normal endometrial biopsy tissues were collected from 10 patients(n?4,secretory phase;n=6,proliferative phase).Eutopic and ectopic samples were then collected from these patients with adenomyosis(n=13,secretory phase;n=17,proliferative phase).Immunohistochemistry(IHC)was performed to evaluate the expression of GRIM-19,phospho-STAT3(Y705)(pSTAT3(Y705)),and VEGF in endometrial tissue samples.IHC with an antibody directed against CD34 was performed to detect new blood vessels in the endometrial tissue.Apoptosis in endometrial specimens was assayed by TUNEL.The protein levels of GRIM-19,pSTAT3(Y705),STAT3 and VEGF were detected by Western blot.In vitro study:High expression and low expression of GRIM-19 in Ishikawa cells were expressed by GRIM-19 pEGFP plasmid and GRIM-19-siRNA technique.The protein levels of pSTAT3(Y705),STAT3 and VEGF were detected by Western blot.Results1.GRIM-19 positivity in endometrial glandular cells in the ectopic endometrium and paired eutopic endometrium in patients with adenomyosis and in the endometria of healthy patients.There was no significant difference(P>0.05)in the expression of GRIM-19 protein between proliferative phase and secretory phase of normal control group and the endometrium in patients with adenomyosis.The protein levels of GRIM-19 were significantly lower in the eutopic endometria of the adenomyosis group than in the normal endometria of the control group(P<0.01).2.Fewer apoptotic cells were significantly seen in the endometria of patients with adenomyosis relative to the endometria of the normal control group(P<0.01),and a further decrease in the number of apoptotic cells was noted in adenomyotic lesions(P<0.05).The number of apoptotic cells did not vary with menstrual cycle phase(P>0.05).3.pSTAT3(Y705)protein was localized to glandular epithelial cell nuclei in control and the eutopic and ectopic groups.There was no significant difference(P>0.05)in the expression of p-STAT3(Y705)protein in the normal control group and the endometrium during the menstrual cycle.pSTAT3(Y705)was more highly expressed in the adenomyosis group than in the control group(P<0.05).The expression levels of total STAT3 did not differ in the presence of adenomyosis(P>0.05).4.VEGF immunoreactivity was primarily localized in glandular epithelial cells both control and adenomyotic groups.VEGF was significantly upregulated in eutopic endometria with adenomyosis compared with tissues from the control group(P<0.01).No statistically significant difference was observed between the 2 phases in any of the groups(P>0.05)5.A significantly increased MVD was observed in the endometria of patients with adenomyosis compared with the corresponding normal endometria(P<0.05)Microvessel density(MVD)was significantly higher in the ectopic endometrial tissue of the patients with adenomyosis than in the control group(P<0.05)6.Upregulation of GRIM-19 caused a decrease in the expression of pSTAT3(Y705)and VEGF protein(P<0.05).Downregulation of GRIM-19 stimulated a significantly higher expreesion of pSTAT3(Y705)and VEGF protein levels(P<0.05).The overall expression of STAT3 was not significantly different in any of the groups(P>0.05)ConclusionsAberrant expression level of GRIM-19 may promote the genesis of adenomyosis by repressing apoptosis and accelerating angiogenesis through the GRIM-19-STAT3-VEGF axis.