Effects of interleukin-10 in epithelial-mesenchymal transition and endoplasmic reticulum stress on intestinal fibrosis / 中华消化杂志

ABSTRACT

Objective To investigate the effects of interleukin-10 on mice intestinal fibrosis and epithelial-mesenchymal transition(EMT),and the relation between these effects and endoplasmic reticulum stress(ERS).Methods Forty-two IL-10 knockout(IL-10-/-)mice were divided into fibrosis model group(n=18),IL-10 treatment group(n=12)and solvent control group(n =12),another 18 wild-type mice were taken as negative control group.IL-10 and 0.9％ NaCl were intraperitonealy injected in IL-10 treatment group and solvent control group respectively since 12th week,and mice were sacrificed at week 14th and 16th,and no treatment to fibrosis model group and negative control group.The injury and fibrosis in mice colon tissue were detected with HE staining and Masson collagen staining.The expressions of collagen Ⅰ,glucose-regulated protein78(GRP78),C/EBP homologous protein(CHOP)and a-smooth muscle actin(α-SMA)and E-cadherin(E-cad)at mRNA level were determined by realtime PCR.The expression of α-SMA and E-cad in mice colon tissue was examined by immunohistochemical staining.Results At 16th week,the colonic tissue injury scores(7.00±0.90,7.17±1.17)and collagen area ratio(17.78％±4.15％,18.56％±3.81％)of fibrosis model group and solvent control group significantly increased compared with negative control group(1.50±1.38 and 9.11％±2.99％)and IL-10 treatment qroup(4.33±0.82 and 12.56％±1.39％)(F=36.150,F=11.280； P=0.000).At week 12th,14th and 16th,the expressions of GRP78,α-SMA,collagen Ⅰ in fibrosis model group and solvent control group significantly increased compared with negative control group(all P＜0.05),however the expression of E-cad significantly decreased(P＜0.05).The expression of CHOP mRNA in fibrosis model group(0.95％ ±0.12％)significantly increased compared with negative control group(0.21％ ± 0.12％)at week 12th(t=5.188,P=0.000),however there was no statistical significant difference in groups at week 14th and 16th(P＞0.05).At week 14th and 16th,the expressions of GRP78,α-SMA and collagen Ⅰ(at week 14th0.73％±0.31％,1.18％±0.11％ and 1.10％±0.49％； at week 16th0.57％±0.16％,0.81％ ±0.50 ％ and 0.76 ％ ± 0.25 ％)in IL-10 treatment group were significantly lower than that of fibrosis model group(P＜0.05).The expression of E-cad(at week 14th0.73％ ±0.29％ ； at week 16th0.97％ ±0.25％)significantly increased compared with fibrosis model group(at week 14th0.37％±0.17％； at week 16th0.35％±0.20％)(F=6.524,P=0.003； F=17.493,P=0.000).However at week 16th,the expression of α-SMA in IL-10 treatment group was lower than that of solvent control group(1.82±0.22)％(F=9.842,P=0.000),and the expression of E-cad significantly increased than in solvent control group(0.47 ± 0.25)％(F=17.493,P =0.000).Conclusion IL-10 may have a role in inhibiting EMT and reducing intestinal fibrosis in mice,which may be related to the regulation of ERS by IL-10.