目的探讨活性维生素D3[1,25(0H)2D3,VD]对2型糖尿病大鼠肝脏中C—Jun氨基末端激酶/c-Jun(JNK/C-Jun)炎症通路表达的影响及其发挥肝脏保护作用的可能机制。方法将雄性SD大鼠35只[平均体重(280±10)g]采用随机数字表法随机分为正常对照组(NC)、糖尿病组(DM)、VD治疗组(vD)。VD组以骨化三醇灌胃,DM组和Nc组以花生油灌胃。8周后处死称取体重,分离血清测定空腹血糖(FPG)、谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆固醇(TC)、甘油三酯(TG),留取肝组织,HE染色观察肝组织病理学变化;实时荧光定量PCR检测JNK、C—Jun及其下游肿瘤坏死因子a(TNF-a)和白细胞介素1β(IL-1β)的mRNA表达;免疫组化和Westernblotting检测上述炎症因子蛋白表达。组问两两比较采用t检验,等级资料采用秩和检验。结果与NC组相比,DM组FPG、ALT、AST、TC及TG水平增加,体重下降[分别为(25.7±2.3)比(5.8±0.9)mmol/L、(137±12)比(53±6)U/L、(162±13)比(65±7)U/L、(1.43±0.17)比f1.21±0.08)mmol/L、f1.32±0.15)比(0.73±O.10)mmoUL、(362±12)比(452±16)g,t=29.573、26.142、14.395、10.632、11.746、9.539,均P〈O.05];与DM组相比,VD组仅有ALT、AST及TG下降有统计学意义(分别为(112±10)比(137±12)U/L、(129±11)比(162±13)U/L、(1.06±0.14)比(1.32±0.15)mmol/L,f=5.382、6.043、5.268,均P〈0.05]。Nc组肝细胞排列整齐、形态正常;DM组肝细胞肿胀、脂肪变性,伴有炎细胞浸润;VD组上述病理变化明显减轻。DM组JNK、C—Jun、TNF-a和IL-1B的mRNA和蛋白表达均高于NC组,VD治疗后上述炎症因子的表达低于DM组(x2=19.958、20.710、20.969、21.255,均P〈0.05)。相关分析表明C-Jun、TNF-a、IL-1β与JNK均呈明显的正相关(r=0.857、0.821、0.8
Objective To explore the effect of 1,25-dihydroxy vitamin D3 (VD) on the expression of C-Jun N-terminal kinase/C-Jun (JNK/C-Jun) inflammatory pathway in the liver of type 2 diabetes mellitus (T2DM) rats and the possible mechanisms. Methods Sprague Dawley(SD) rats were divided into normal control group(NC), T2DM group(DM) and calcitriol-treated group(VD) via random number table. Calcitriol was given to VD group by gavage for 8 weeks, while the DM and NC group received peanut oil. After sacrifice, body weight was measured and fasting blood glucose(FBG), alanine transaminase(ALT), asparate transaminase(AST), total cholesterol(TC), triacylglycerol(TG) in serum were tested. Liver histopathology was examined by hematoxylin-eosin (HE) staining. The mRNA levels of JNK, C-Jun and its downstream cytokines tumor necrosis factor(TNF-a and interleukin(IL-1β) were measured by real-time fluorescence quantitative PCR. The protein expression was analyzed by immunohistochemical staining and Western blotting.The t test was performed for pair-wise comparison and wilcoxon rank sum test was used for rankeddata. Results The level of FBG, ALT, AST, TC and TG in DM group increased and body weight decreased compared with those in NC group((25.7±2.3)vs(5.8±0.9) mmol/L, (137± 12)vs(53±6)U/L,(162± 13)vs(65-±7)U/L, (1.4±0.2)vs(1.21 ±0.08)retool/L, (1.32±0.15)vs(0.73±0.10)mmol/L,(362± 12)vs(452± 16) g; t=29.573,26.142, 14.395, 10.632,11.746,9.539, respectively, all P〈0.05). Compared with DM group, ALT,AST and TG decreased significantly in VD group((ll2± 10)vs(137± 12) U/L, (129± ll)vs (162± 13) U/L, (1.06±0.14)vs (1.32 ± 0.15) mmol/L; t=5.382,6.043,5.268, all P〈0.05). HE staining showed that livercells were in alignment and normal in NC group, whereas appeared swelling and fatty degeneration with inflammatory cells infiltration in DM group. VD treatment could alleviate the pathologic c