四神丸对脾肾阳虚型溃疡性结肠炎模型大鼠结肠组织Toll样受体4及其负性调控因子IRAK-M表达的影响

目的:观察Toll样受体4(TLR4)及其负性调控因子白细胞介素-1受体相关激酶M(IRAK-M)在实验性溃疡性结肠炎(UC)模型大鼠结肠黏膜中的表达,并探讨四神丸干预UC的作用机制。方法:将90只Wistar大鼠随机分成6组,即空白组,模型组,柳氮磺胺嘧啶组(0. 36 g·kg~(-1)),四神丸低、中、高剂量组(2. 5,5,10 g·kg~(-1)),每组15只。以三硝基苯磺酸/乙醇溶液法制备UC大鼠模型,苏木素-伊红(HE)染色观察大鼠结肠组织病理学改变;采用放射免疫法测定血清游离三碘甲腺原氨酸(FT3),血清游离甲状腺素(FT4),免疫球蛋白(Ig) E,白细胞介素(IL)-2的含量;采用黄嘌呤氧化法测定大鼠血清超氧化物歧化酶(SOD)活性;采用硫代巴比妥酸(TBA)比色法测定大鼠血清丙二醛(MDA)的活性。采用实时荧光定量PCR(Real-time PCR),免疫组化和蛋白免疫印迹法(Western blot)分别检测TLR4,IRAK-M的mRNA及蛋白表达。结果:与空白组比较,模型组大鼠肠黏膜损伤评分显著增高(P 0. 01),大鼠血清Ig E,MDA含量显著升高(P 0. 01),FT3,FT4,IL-2,SOD表达水平显著下降(P 0. 01),TLR4 mRNA和蛋白表达显著升高(P 0. 01),IRAK-M mRNA和蛋白表达显著降低(P 0. 01);与模型组比较,各治疗组鼠肠黏膜损伤评分均显著降低(P 0. 01),Ig E,MDA含量明显下降(P 0. 05,P 0. 01),FT3,FT4,IL-2,SOD水平明显升高(P 0. 05,P 0. 01),TLR4 mRNA和蛋白表达明显降低(P 0. 05,P 0. 01),IRAK-M mRNA和蛋白表达水平显著升高(P 0. 01)。结论:UC的发病机制与TLR4及其负性调控因子IRAK-M的表达失衡有关,且四神丸可能通过抑制TLR4mRNA和蛋白的表达,促进其负性调控因子IRAK-M的表达,起到有效治疗UC的作用。

Effect of Sishenwan on Toll-like Receptor 4 and IRAK-M Expression in Colonic Tissue of Rats with Ulcerative Colitis of Spleen-kidney Yang Deficiency Type

Objective:To observe the Toll-like receptor 4(TLR4)and its negative regulating factorInterleukin-1 receptor-associated kinase-M(IRAK-M)in colonic mucosa of rats with experimental ulcerative colitis(UC), and to discuss the mechanism of the Chinese medicine Sishenwan. Method:The 90 Wistar rats were randomly divide into six groups, blank group, model group, sulfasalazine group(0.36 g·kg^-1), Sishenwan low, medium and high-dose group(2.5, 5, 10 g·kg^-1), 15 cases in each group. A rat model of UC was prepared by using a solution of trinitrobenzenesulfonic acid/ethano.The histopathological changes of colon were observed by hematoxylin-eosin (HE) staining. The contents of serum free triiodothyroid acid (FT₃), serum free thyroxine (FT₄), immunoglobulin (Ig) E and interleukin (IL)-2 were determined by radioimmunoassay. The activity of superoxide dismutase (SOD) in rat serum was determined by xanthine oxidation method. The activity of malondialdehyde (MDA) in serum of rats was determined by thiobarbituric acid (TBA) colorimetry. Result:Compared with blank group, intestinal mucosal injury score of rats in model group was significantly increased (P<0.01), serum IgE and MDA contents were significantly increased (P<0.01).The expression levels of FT₃, FT₄, IL-2 and SOD were significantly decreased (P<0.01).The TLR4 mRNA and protein expression in model group increased significantly(P<0.01).The expression of IRAK-M mRNA and protein decreased significantly(P<0.01).Compared with model group, scores of each treatment group were significantly decreased (P<0.01), IgE and MDA contents were significantly decreased (P<0.05, P<0.01), FT₃, FT₄, IL-2, and SOD contents were significantly increased (P<0.05, P<0.01).The expression of TLR4 mRNA and proteinin each treatment group was significantly reduced(P<0.05, P<0.01), IRAK-M mRNA and protein expression level increased(P<0.01). Conclusion:The unbalanced expressions of TLR4 and its negative regulating factor IRAK-M are connected with the pathogenesis of UC.Sishenwan can cure UC and control the expression of TLR4 and promote the expression of IRAK-M.