The Relationship Between TGF-β And Notch Signaling Pathway And Epithelial To Mesenchymal Transition In Endometriosis

Objective:To explore the relationship between epithelial-to-mesenchymal transition(EMT)which endows cells with migratory and invasive properties and endometriosis,and the regulation of Notch and TGF-P signal pathways involved in regulating EMT to further clarify the pathogenesis of endometriosis.Materials and Methods:Women with or without endometriosis visiting and undergoing surgery in the department of gynaecology and obstetrics of Zhongda Hospital affiliated to Southeast University from October 2014 to April 2015 were recruited for this study.They were categorized into 3 groups according to the sources of endometrial tissue:(1)ectopic endometrial tissue in the endometriosis group;(2)eutopic endometrial tissue in the endometriosis group;(3)endometrial tissue in the control non-endometriosis group.Endometrial tissue was obtained after diagnosis and signing a written informed consent.The epidemiological data such as age,BMI,age of menarche,menstrual cycle,menstrual period,parity,number of cesarean delivery,number of abortion and age at first delivery and other correlated factors were collected.We investigated the relative expression levels of related markers for EMT:E-cadherin(E-cad),N-cadherin(N-cad),Vimentin(Vim);Notchl,Hesl related with the Notch signal pathway;TGF-β1 and Smad3 related with TGF-(3 signal pathway for the three specific groups;Ectopic(n=30),Eutopic(n=30)or control(n=30)using immunohistochemical staining method(Immunohisto chemistry,IHC).We used real-time qPCR to investigate expression levels of four recognized markers for EMT:E-cadherin(E-cad),N-cadherin(N-cad),Vimentin(Vim)and Snail1,three TGF-β signal components:TGF-β1,TGF-βR1 and Smad3 and three Notch signal components:Notch1,Jagged1 and Hes1 in the ectopic(n=16),eutopic(n=8)or control(n=9)endometrium of women with or without endometriosis.(GAPDH was used as a reference gene).Results:1.Clinical epidemiological data analysis showed that age,BMI,age of menarche,menstrual cycle,menstrual period,parity,number of cesarean delivery,number of abortion and age at first delivery and other correlated factors comparison in the ectopic,eutopic and control groups had no statistical significance(P>0.05).2.EMT markers:(1)IHC:Compared with the control group,E-cad was significantly decreased in the eutopic and ectopic groups(P<0.05)but showed no statistical difference between the eutopic and ectopic groups(P>0.05),Vim showed no statistical difference in all three groups(P>0.05).(2)Real-time qPCR:Compared with the control group,E-cad was significantly decreased(P<0.001),Vim and Snail1 were upregulated(Vim:P=0.001,Snail1:P=0.014),N-cad showed an increasing trend in the ectopic group.In the eutopic group,E-cad was downregulated(P<0.001),Vim,Snaill and N-ca were significantly upregulated as with the control group.In the ectopic group Snail1was significantly increased(P-0.023),E-cad,Vim and N-cad expressions showed no statistical difference(P>0.05).3.Notch signaling components:(1)IHC:Compared with the control group,Notchl,Hesl were lower in both the ectopic and eutopic groups(Notchl:H=36.455,P<0.05;Hes 1:H=13.451,P<0.05)and both showed no statistical difference between the ectopic and eutopic groups.(2)Real-time qPCR:Compared with the control group,Notchl,Jagged1 and Hes1 were significantly downregulated in the eutopic and ectopic groups(Notch1:P=0.003,P=0.001;Jaggedl:P=0.024,P=0.068;Hes1:P<0.001,P<0.001).There was so significant statistical difference between the eutopic and ectopic groups.4.TGF-β signaling components:Using IHC and real-time qPCR,the expression levels of TGF-β1 TGF-βR1 and Smad3 did not seem to show any statistical significance between these three groups.Conclusions:1.EMT was excessively activated in ectopic and eutopic endometrium of women with endometriosis.It indicates that abnormal activation of EMT might be involved in the pathogenesis of endometriosis2.Decreased Notch signaling components(Notchl,Jaggedl and Hesl)might be involved in regulating the formation of EMT in endometriosis.It indicates a correlation between the Notch signaling pathway and the formation of EMT.3.The expression of TGF-β/Smad signaling components(TGF-β1,TGF-βR1 and Smad3)showed no significant difference between the three groups,indicating no significant correlation between TGF-β/Smad signaling pathway and regulation of the formation of EMT.