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 14th:0.73％±0.31％,1.18％±0.11％ and 1.10％±0.49％； at week 16th:0.57％±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 14th:0.73％ ±0.29％ ； at week 16th:0.97％ ±0.25％)significantly increased compared with fibrosis model group(at week 14th:0.37％±0.17％； at week 16th:0.35％±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.
ABSTRACT
Objective To investigate the anti-fibrotic effects of curcumin in trinitrobenzene sulphonic acid (TNBS) induced intestinal fibrosis in rats and its mechanism. Methods Forty SD rats were randomly divided into model group, treatment group, control group and normal group with 10each. Except the normal group, the other three groups were given 10, 15, 20, 25 and 30 mg of TNBS enema on the 1st, 8 th, 15th, 22nd and 29th days,respectively. The rats in treatment group were intraperitonealy injected with 30 mg/kg of curcumin daily. Control group was injected with 0. 9%NaCl solution and normal group received an equal volume of 50% ethanol enema without any treatment. The damage and fibrosis of colon were detected with HE staining and Masson collagen staining, respectively. The contents of interleukin (IL) -2, tumor necrosis factor (TNF) -α, IL-4 and IL-17 in colon were measured by enzyme-link immunosorbent analysis (ELISA). The expressions of intestinal fibrosis related cytokines such as transforming growth factor (TGF) -β1, connective tissue growth factor (CTGF), Smad3, collagen Ⅰ and collagen Ⅲ mRNA were determined by FQ-PCR.Results The macroscopic and micrpscopic colonic damage scores and collagen area were significantly higher in model group (6.14 ± 1.07, 8. 42 ± 1.40 and 36. 59% ± 4.07%, respectively) and control group (6.17 ± 1.47, 8. 17 ±1.47 and 37.18 %±4.05 %, respectively) than those in normal group (2.13±0.64, 2.25±1.28 and 25.43%±5.39% ,respectively)(P＜0.05). Contents of IL2, TNF-α, IL-17, as well as expressions of intestinal fibrosis related cytokines including TGF-β1, CTGF,Smad3, collagen Ⅰ and Ⅲ mRNA were also higher in model group [(378. 25±29. 90) ng/L,(87.11±23.85) ng/L, (47.80±5.62) ng/L, 4.71%±2.71%,10.33%±6.99%,9.35%±7.32%,1.52% ± 1.11% and 3.04% ±1.33%, respectively] and control group [(410. 06 ± 64.74) ng/L,(100.41±12.59) ng/L, (41.45±2. 12) ng/L, 4. 12%±3.01%,11.46%±4.72%,10. 11%±3.80%,1. 57% ± 1. 35% and 3. 03% ± 3. 53%, respectively] in comparision with normal group [(179.74±20. 73) ng/L, (35. 47±7. 13) ng/L, (14. 48±7. 52) ng/L and 0. 90%± 1. 13%,0.53%±0.47%, 0. 62%±0. 44%, 0. 16%±0. 09% and 0. 18%±0. 10%, respectively] (P＜0.05). While in treatment group, the macroscopic (4.00 ± 1.07 ) and micrpscopic (5. 13 ± 1.46)colonic damage scores, collagen area (30.01%±7.56%), contents of IL-2 [(223.91±28.04) ng/L],TNF-α [(44.19±4. 77) ng/L] and IL-17 [(14.89±4. 31) ng/L], expressions of TGF-β1 (0.85%±0.76%), CTGF (1.56%±1.13%), Smad3 (3.62%±3.03%), collagen Ⅰ (0.40%±0.31%) and Ⅲ (0.60 % ± 1.02 % ) mRNA were much lower than those in model group and control group (P＜0.05 ), but similar to those in normal group (P＞ 0.05 ). Conclusions Curcumin can inhibit intestinal fibrosis caused by excessive "wound-healing" reaction via reducing the overexpression of cytokines in colonic mucosa and attenuating the inflammation of colon.