摘要目的 探讨ω-3多不饱和脂肪酸对大鼠炎症性肠病(IBD)模型结肠损伤程度、 炎症反应和内质网应激的影响.方法 采用三硝基苯磺酸灌肠诱导大鼠IBD模型,将100只成年雄性SD大鼠,按随机数字表法分为假手术组(Sham组),大鼠IBD模型组(IBD组),IBD+ω-3多不饱和脂肪酸组(IBD+ω-3组),IBD+5-氨基水杨酸组(IBD+5-ASA组)和IBD+ω-3多不饱和脂肪酸+内质网应激诱导剂2-脱氧葡萄糖组(IBD+ω-3+2-DG组).分别于伤后1、3、7、14 d进行结肠大体形态损伤指数和结肠组织病理学评分;酶联免疫吸附测定法检测血清中炎症因子肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1、IL-6浓度;Western blot方法测定内质网应激相关因子[葡萄糖调节蛋白78(GRP78)、 内质网肌醇需求酶1(IRE-1)、 增强子结合蛋白同源蛋白(CHOP)]蛋白的表达.结果 与Sham组比较,其余4组结肠大体形态损伤指数和组织病理学评分明显升高,血清炎症相关因子(TNF-α、IL-1、IL-6)和内质网相关因子(GRP78、IRE-1、CHOP)蛋白表达上调(P均<0.001);与IBD组比较,IBD+ω-3组结肠大体形态损伤指数明显下降[7 d:3.55±0.29比4.37±0.39,P=0.03;14 d:2.46±0.17比3.86±0.21,P=0.04]和组织病理学评分明显下降[7 d:(2.56±0.27)分比(3.45±0.40)分,P=0.02;14 d:(2.23±0.20)分比(3.06±0.26)分,P=0.04],血清炎症因子TNF-α、IL-1和IL-6表达减少[TNF-α:(43.71±11.39)pg/ml比(84.97±13.81)pg/ml,P=0.02;IL-1:(38.51±10.60)pg/ml比(73.04±12.48)pg/ml,P=0.01;IL-6:(28.91±7.27)pg/ml比(53.45±9.40)pg/ml,P=0.02],同时内质网应激相关因子GRP78、IRE-1和CHOP蛋白表达减少(GRP78:2.41±0.29比1.47±0.21,P=0.01;IRE-1:2.83±0.31比1.23±0.20,P<0.001;CHOP:1.89±0.17比1.32±0.11,P=0.04).内质网应激诱导剂2-脱氧葡萄糖抵消ω-3多不饱和脂肪酸抑制内质网应激的作用,逆转ω-3多不饱和脂肪酸抗炎症反应和保护作用[TNF-α:(72.67±10.37)pg/ml比(43.71±11.39)pg/ml,P=0.02;IL-1:(57.66±13.88)pg/ml比(38.51±10.60)pg/ml,P=0.02;IL-6:(46.10±9.67)pg/ml比(28.91±7.27)pg/ml,P=0.01;GRP78:1.47±0.21比1.82±0.24,P=0.03;IRE-1:1.23±0.20比2.21±0.23,P=0.02;CHOP:1.32±0.11比1.61±0.16,P=0.04].结论 ω-3多不饱和脂肪酸干预能抑制肠壁炎症反应,降低结肠大体形态损伤指数和组织病理学评分,改善IBD病情,其机制可能通过抑制肠壁内质网应激反应实现.

abstractsObjective To investigate the effects and mechanisms of omega-3 polyunsaturated fatty acids (ω-3 PUFA) supplementation on colonic macroscopic and histological score , inflammatory response , and endo-plasmic reticulum stress ( ERS ) response in experimental rat models of colitis .Methods Experimental rat models of colitis were induced by trinitro-benzene-sulfonic acid (TNBS).Totally 100 male SD rats were ran-domly divided into 5 groups according to the random data tables:sham operation group ( Sham group ) , inflam-matory bowel disease group (IBD group),ω-3 PUFA supplementation group (IBD+ω-3 group), 5-aminosali-cylic acid group ( IBD +5-ASA group ) , and ERS activation 2-deoxy-D-glucose group ( IBD +ω-3 +2-DG group).Colonic macroscopic and histological scores were evaluated on days 1, 3, 7 and 14 after modeling.The serum levels of tumor necrosis factor-α(TNF-α), interleukin (IL) -1, and IL-6 were measured using en-zyme-linked immunosorbent assay , whereas ERS cytokines including glucose-regulated protein 78 ( GRP78 ) , inositol-requiring enzyme 1 (IRE-1), and C/EBP homologous protein (CHOP) were tested by Western blot. Results Compared with the Sham group , colonic macroscopic and histological score , the serum levels of in-flammation relatived factors (TNF-α, IL-1, IL-6) and ERS relatived factors (GRP78、 IRE-1, CHOP) were significantly increased on the rest of the four groups ( all P<0.001 ) .Compared with the IBD group , ω-3 PUFA supplementation reduced colonic macroscopic [7 d: 3.55 ±0.29 vs.4.37 ±0.39, P=0.03, 14 d:2.46 ±0.17 vs.3.86 ±0.21, P=0.04] and histological score [7 d: (2.56 ±0.27) scores vs.(3.45 ± 0.40) scores, P=0.02, 14 d: (2.23 ±0.20) scores vs.(3.06 ±0.26) scores, P=0.04].Meanwhile,ω-3 PUFA supplementation suppressed the expressions of inflammation [TNF-α:(43.71 ±11.39) pg/ml vs. (84.97 ±13.81) pg/ml, P=0.02, IL-1:(38.51 ±10.60) pg/ml vs.(73.04 ±12.48) pg/ml, P=0.01, IL-6:(28.91 ±7.27) pg/ml vs.(53.45 ±9.40) pg/ml, P=0.02] and ERS relatived factors (GRP78:2.41 ±0.29 vs.1.47 ±0.21, P=0.01, IRE-1:2.83 ±0.31 vs.1.23 ±0.20, P<0.001, CHOP:1.89 ± 0.17 vs.1.32 ±0.11 , P=0.04 ) .However , the salutary effects of ω-3 PUFA would been reversed by ERS activation 2-deoxy-D-glucose [ TNF-α: (72.67 ±10.37 ) pg/ml vs.(43.71 ±11.39 ) pg/ml, P =0.02, IL-1:(57.66 ±13.88) pg/ml vs.(38.51 ±10.60) pg/ml, P=0.02, IL-6: (46.10 ±9.67) pg/ml vs. (28.91 ±7.27) pg/ml, P=0.01, GRP78:1.47 ±0.21 vs.1.82 ±0.24, P=0.03, IRE-1:1.23 ±0.20 vs.2.21 ±0.23, P=0.02, CHOP:1.32 ±0.11 vs.1.61 ±0.16, P=0.04].Conclusion The salutary effects of ω-3 PUFA supplementation on the colitis induced by TNBS appear to be mediated by inhibited inflam -matory responses , which may suppress the activation of ERS response .