汉黄芩素缓解高脂饮食喂养ApoE~(-/-)小鼠的动脉粥样硬化和NF-κB介导的动脉炎症反应

为探究汉黄芩素对高脂饮食喂养ApoE~(-/-)小鼠的动脉粥样硬化和炎症的影响,本研究将ApoE~(-/-)小鼠分为正常饮食组、高脂饮食组、高脂饮食+汉黄芩素10 mg/kg组、高脂饮食+汉黄芩素20 mg/kg组,高脂饮食和药物同时给予,12周后收集动脉组织。采用RT-qPCR法检测IL-6、TNF-α、ICAM-1和VCAM-1的mRNA表达;油红O染色和HE染色检测主动脉根部油脂变化和病理变化;免疫荧光染色检测Moma-2和VCAM-1表达;生化试剂盒检测血液中的血脂水平;Western blot法检测动脉的NF-κB的磷酸化和IκB-α的表达变化。结果显示,与高脂饮食组比较,汉黄芩素治疗组动脉粥样硬化斑块面积减少(P0.05),但血脂水平无变化;汉黄芩素治疗组动脉中单核/单核巨噬细胞浸润,TNF-α、IL-6、ICAM-1和VCAM-1的mRNA表达水平,VCAM-1的蛋白表达水平和NF-κB信号通路的激活均显著降低(P0.05)。提示汉黄芩素有效缓解高脂饮食喂养诱导的小鼠动脉粥样硬化,并伴随抑制NF-κB介导的动脉炎症。     

乳酸调控大鼠肠黏膜微血管内皮细胞的NF-κB信号通路

目的探讨内毒素（LPS）刺激大鼠肠黏膜微血管内皮细胞（RIMMVECs）后,乳酸（LA）调控NF-κB信号通路中磷酸化IκBα和NF-κB p65蛋白表达情况,肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）mRNA表达情况,阐明乳酸发挥作用的最佳时间及其调控NF-κB信号通路的部位。方法提取RIMMVECs总蛋白和总RNA,用Western blotting检测NF-κB p65、IκBα及p-IκBα蛋白表达水平,用real-time PCR对TNF-α和IL-6 mRNA进行定量检测。结果乳酸能降低LPS诱导RIMMVECs分泌的TNF-α和IL-6 mRNA表达水平,并分别于24 h和3 h下调效果最明显;乳酸能抑制IκBα磷酸化及NF-κB转录活性,并于4～8 h达到最佳效果;乳酸发挥作用部位是抑制信号通路中IκBα磷酸化。结论乳酸通过抑制IκBα磷酸化而阻断NF-κB的激活,抑制下游炎性因子表达,进而发挥出很好的预防炎症效果。     

当归对阴虚哮喘小鼠气道黏液高分泌及TNF-α/NF-κB信号通路的影响*

目的: 探讨当归对阴虚哮喘小鼠气道黏液高分泌及TNF-α/NF-κB信号通路的影响。方法: 取KM小鼠随机分为空白对照组、模型对照组、氨溴索组、当归低、中、高剂量(2、4、8 g/kg)组(n=12),采用卵蛋白与甲状腺片复制阴虚哮喘模型,观测当归对小鼠哮喘症状、IgE、TNF-α以及肺组织Muc5ac与NF-κB表达的影响。结果: 2、4、8 g/kg当归能明显缓解阴虚哮喘小鼠的哮喘症状,降低血清IgE与BALF中TNF-α水平,抑制肺组织Muc5ac与NF-κB的过度表达。结论: 当归具有明显的平喘作用,抑制TNF-α/NF-κB信号通路而缓解气道黏液高分泌是其平喘的作用机制之一。     

银杏黄酮对非酒精性脂肪肝模型小鼠的作用及NF-κB在其机制中的相关性分析

本文观察银杏黄酮对非酒精性脂肪性肝(NAFLD)模型小鼠的作用,并分析NF-κB与小鼠肝脏脂肪变性及血清丙氨酸氨基转移酶(ALT)的相关性。170只昆明小鼠随机分为正常对照组、模型组、银杏黄酮高[300mg/(kg·d)]、中[150 mg/(kg·d)]、低[75 mg/(kg·d)]剂量组。采用高脂饲料构建非酒精性脂肪肝小鼠动物模型,分别于给药后4周、8周和12周末处死,观察肝脏病理变化,计算肝指数,检测血清总胆固醇(TC)、ALT、TNF-α以及肝组织NF-κB的表达。各剂量银杏黄酮组小鼠肝指数,血清TC、ALT和TNF-α水平,肝组织NF-κBp65的表达量比模型组显著降低,肝脏脂肪变性明显减轻(P0.05或P0.01);肝组织NF-κBp65相对表达量与肝脏脂肪变性程度及血清ALT含量呈正相关(r0、P0.01或P0.05)。实验结果表明:银杏黄酮可降低NAFLD小鼠血脂、减轻肝脏脂肪变性、改善肝功能指标及肝脏大体形态,且有一定的剂量和时间依赖性;NF-κB上游炎症通路可能是其作用的主要机制。     

敲除Nrf2促进高脂饮食诱导小鼠肝脏NF-kB的活化

目的：氧化应激和炎症反应是NASH进展的关键因素,同时二者之间存在着密切关系,而转录因子Nrf2和NF-kB分别是氧化应激和炎症信号通路的关键调控靶点,因此,研究Nrf2对高脂饮食诱导小鼠肝脏NF-kB信号通路的影响,对探讨NASH进展具有重要的意义。方法：雄性野生型（WT）和Nrf2基因敲除（Nrf2-/-）ICR小鼠各10只,随机分为WT对照组（Control）、Nrf2-/-对照组（KO）、WT高脂饮食组（HFD）和Nrf2-/-高脂饮食组（KOHFD）（n=5）。喂养8周后,观察肝脏光镜下改变,检测肝脏GSH、MDA、TNFα和IL-6水平。Western-Blot检测肝脏NF-kB蛋白表达水平,观察敲除Nrf2对肝脏NF-kB活性作用的影响。结果：1.光镜下观察,Control组与KO组小鼠肝脏结构无明显变化,HFD组小鼠肝脏呈现大片脂肪沉积和炎症细胞浸润,KOHFD组小鼠肝脏则呈现明显的大泡性变性,且炎症细胞浸润较HFD组明显加重;2.与Control组相比,KO组小鼠肝脏MDA轻度升高,GSH轻度降低,但无明显差异,而HFD组和KOHFD组小鼠肝脏MDA显著升高（P〈0.05）,GSH显著降低（P〈0.05）,且KOHFD组MDA明显高于HFD组（P〈0.05）,GSH明显低于HFD组（P〈0.05）。3.ELISA结果显示,与Control组相比,KO组小鼠肝脏TNFα和IL-6分泌轻度增加,而HFD组和KOHFD组小鼠肝脏TNFα与IL-6水平显著升高（P〈0.05）,且KOHFD组小鼠肝脏TNFα与IL-6显著高于HFD组（P〈0.05）;4.Western-Blot结果显示,Control组和KO组之间无明显差异,而KOHFD组和HFD组小鼠肝脏胞核NF-kB蛋白表达水平显著升高,且KOHFD组高于HFD组。结论：敲除Nrf2可以显著加重高脂饮食诱导的小鼠肝脏氧化应激水平,进而促进NF-kB的活化,从而为通过以Nrf2为靶点治疗NASH提供重要的实验依据。     

银杏叶提取物对内毒素诱导巨噬细胞核因子-κB活化及炎性细胞因子表达的调节

探讨银杏叶提取物（EGb761）对内毒素（LPS）诱导RAW264．7细胞核因子-κB（NF-κB）活化及炎性细胞因子基因表达的调节,为银杏叶提取物的临床运用提供理论依据．分别用LPS或EGb761＋LPS处理体外培养的小鼠巨噬细胞系RAW264．7细胞,采用蛋白质印迹分析检测细胞中NF-κB活性,用逆转录-聚合酶链反应（RT-PCR）和酶联免疫吸附法（ELISA）检测细胞中TNF-α、IL-1β、IL-6 mRNA和蛋白的表达．研究结果表明LPS组NF-κB活性和TNF-α、IL-1β、IL-6含量在刺激后2～12h明显高于正常对照组,而EGb761＋LPS组NF-κB活性和TNF-α、IL-1β、IL-6含量均显著低于LPS组．结果提示LPS可诱导RAW264．7细胞NF-κB活化,导致TNF-α、IL-1β、IL-6基因表达增强,而EGb761能抑制NF-κB活化而调节TNF-α、IL-1β、IL-6基因的表达．     

基于抗炎及抗氧化作用探讨微生态制剂在非酒精性脂肪肝模型大鼠中的应用价值

目的研究基于抗炎及抗氧化作用探讨微生态制剂在非酒精性脂肪肝(NAFLD)模型大鼠中的应用价值。方法选择成年雄性SD大鼠并随机分为对照组、NAFLD组、蓝莓益生菌(BP)组。后2组采用复合高脂饲料建立NAFLD模型,BP组给予蓝莓联合益生菌干预。比较3组间血清肝功能指标、炎症指标、氧化应激指标含量及肝脏组织中炎症及氧化应激信号分子表达的差异。结果 NAFLD组大鼠血清中ALT、AST、TNF-α、IL-1、IL-6、IL-18、MDA的含量及肝脏中p-p38MAPK、NF-κB的表达量明显高于对照组,血清中SOD、GPX的含量及肝脏中p-AMPK、Nrf-2的表达量明显低于对照组;BP组大鼠血清中ALT、AST、TNF-α、IL-1、IL-6、IL-18、MDA的含量及肝脏中p-p38MAPK、NF-κB的表达量明显低于NALFD组,血清中SOD、GPX的含量及肝脏中p-AMPK、Nrf-2的表达量明显高于NALFD组。结论蓝莓益生菌用于NALFD模型大鼠的干预能够改善肝功能并抑制炎症反应、氧化应激反应。     

齐墩果酸抑制肿瘤坏死因子-α诱导的成纤维细胞样滑膜细胞炎症因子表达及其机制研究

探讨齐墩果酸(Oleanolic acid,OA)对肿瘤坏死因子-α(TNF-α)诱导成纤维细胞样滑膜细胞的炎症因子表达的影响及其机制。首先复苏培养人成纤维细胞样滑膜细胞(FLS),通过RT-PCR检测细胞IL-6及IL-1βmRNA表达,采用Western blot方法检测p38MAPK及NF-κB蛋白表达变化,通过ELISA法检测细胞上清液中IL-6及IL-1β浓度。与对照组比较,TNF-α明显诱导FLS细胞IL-6及IL-1βmRNA的表达及上清液中IL-6及IL-1β的分泌(P0.05),同时磷酸化p38蛋白和核NF-κB明显增加(P0.05),且p38MAPK阻断剂SB203580能抑制TNF-α诱导的核NF-κB增加。OA呈浓度依赖性抑制TNF-α诱导的FLS细胞p38蛋白磷酸化和核NF-κB增加(P0.05)。且OA、p38MAPK通路抑制剂SB203580或NF-κB阻断剂BAY 11-7082均能抑制TNF-α诱导的IL-6及IL-1β分泌增加(P0.05)。综上所述,OA能抑制TNF-α诱导的FLS细胞炎症因子IL-6及IL-1β的产生,其机制可能与抑制p38MAPK/NF-κB信号通路有关。     

基于HMGB1/TLR4/NF-κB信号通路探讨忍冬苷对脓毒症肝损伤大鼠的影响

摘要 目的：基于高迁移率族蛋白B1（HMGB1）/Toll样受体4（TLR4）/核因子κB（NF-κB）信号通路探讨忍冬苷对脓毒症肝损伤大鼠的影响。方法：60只雄性SD大鼠随机分为模型组、对照组、阳性对照组（地塞米松10 mg/kg）、忍冬苷低剂量（7.5 mg/kg）、忍冬苷中剂量（15 mg/kg）、忍冬苷高剂量（30 mg/kg）组,每组10只。采用盲肠结扎穿刺法建立大鼠脓毒症模型。实验结束后麻醉大鼠取血制备血清,检测血清中超氧化物歧化酶（SOD）活性和丙二醛（MDA）、白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、白介素-10（IL-10）含量;分离肝组织称重,计算肝脏指数,一部分用于HE染色观察肝组织病理变化,一部分用于制备组织匀浆检测组织中肝功能指标谷丙转氨酶（ALT）、天冬氨酸转氨酶（AST）活性及HMGB1、TLR4、NF-κB蛋白表达。结果：与对照组比较,模型组大鼠血清中MDA、TNF-α、IL-6含量、肝脏指数以及肝组织中AST、ALT活性、HMGB1、TLR4、NF-κB蛋白表达显著增加（P＜0.05）,SOD活性与IL-10含量显著下降（P＜0.05）;且肝组织出现明显病灶,肝细胞水肿变性,大量炎性细胞浸润。与模型组比较,阳性对照组与忍冬苷各剂量组大鼠血清中MDA、TNF-α、IL-6含量、肝脏指数以及肝组织中AST、ALT活性、HMGB1、TLR4、NF-κB蛋白表达显著降低（P＜0.05）,SOD活性与IL-10含量显著升高（P＜0.05）;忍冬苷低、中剂量组仍可见病灶和水肿,但病变减轻;地塞米松组与忍冬苷高剂量组肝细胞结构趋于正常,未发现病灶。与阳性对照组比较,忍冬苷低、中剂量组大鼠血清中MDA、TNF-α、IL-6含量、肝脏指数以及肝组织中AST、ALT活性、HMGB1、TLR4、NF-κB蛋白表达显著升高（P＜0.05）,SOD活性与IL-10含量显著降低（P＜0.05）;忍冬苷高剂量组上述指标无显著差异（P＞0.05）。结论：忍冬苷通过下调HMGB1/TLR4/NF-κB信号通路的表达,抑制氧化应激,减轻炎症反应,改善肝功能,发挥对脓毒症肝损伤的保护作用。     

清血消脂片对代谢性炎症小鼠的干预作用及炎症机制研究

目的:研究清血消脂片对代谢性炎症小鼠血脂和血清炎症因子IL-6、MIP-1a以及NF-κB和PPARγm RNA表达的影响。方法:60只雄性C57小鼠,随机分为正常组、模型组、立普妥组、清血消脂片组(n=15)。采用高脂饮食联合脂多糖注射造成小鼠代谢性炎症模型。造模5周后,按成人临床等效剂量换算成小鼠剂量灌胃给药,每天两次,连续灌胃5周。处死后采血和取肝脏,检测各组小鼠血清胆固醇(TC)、甘油三酯(TG)和低密度脂蛋白胆固醇(LDL-C)水平,并采用流式细胞术检测血清炎症因子IL-6和MIP-1a水平。反转录聚合酶链式反应(RT-PCR)法测定肝脏NF-κB和PPARγm RNA的表达。结果:与模型组相比,清血消脂片组小鼠血清TC和LDL-C水平明显降低(P0.01),血清炎症因子IL-6和MIP-1a水平明显降低(P0.01),清血消脂片组小鼠肝脏组织中NF-κB m RNA的表达显著降低(P0.05),PPARγm RNA的表达显著提高(P0.05)。结论:清血消脂片可降低代谢性炎症小鼠血脂和血清炎症因子IL-6和MIP-1a水平,并可通过调控核转录因子NF-κB和PPARγ受体,抑制小鼠体内代谢性炎症,从而可能对早期动脉粥样硬化起到干预作用。     

Dll4蛋白在高脂饮食喂养大鼠脂肪组织炎症中的作用

目的 探讨Delta-like ligand 4（Dll4）蛋白在高脂饮食喂养大鼠脂肪组织中的表达及其与脂肪组织炎症的关系.方法 将20只SPF级雄性Sprague-Dawley大鼠随机分为正常饮食组（SD,n=10）和高脂饮食组（HFD,n=10）喂养16w后,应用免疫组化及Western blot方法检测脂肪组织中Dll4及炎症通路NF-κB磷酸化、IL-6的表达.结果 免疫组化结果显示,HFD组Dll4表达量显著升高（P〈0.001）;Western blot结果与免疫组化结果相一致,Dll4蛋白表达量是SD组的1.34倍（P〈0.01）;磷酸化核转录因子NF-κB表达水平升高,HFD组为SD组的2.03倍（P〈0.01）;HFD组炎症细胞因子IL-6水平明显升高,为SD组的3.02倍（P〈0.01）.结论 高脂饮食可增加脂肪组织中Dll4蛋白表达,促进了脂肪组织中炎症的发生.     

Short-term high fat feeding increases organ injury and mortality after polymicrobial sepsis

The purpose of this study was to examine the effect of short-term high fat feeding on the inflammatory response in polymicrobial sepsis. Male C57BL/6 mice at 6 weeks of age were randomized to a high-fat diet (HFD) (60% kcal fat) or control diet (CD) (16% kcal fat) for 3 weeks. After 3 weeks of feeding, sepsis was induced by cecal ligation and puncture (CLP) and animals were monitored for survival. In a separate experiment, after 3 weeks of feeding mice underwent CLP and were sacrificed at various time points thereafter. Tissue was collected for biochemical studies. Mice fed a HFD gained more weight and had a greater fat mass compared to CD-fed mice. Mice on a HFD had a lower probability of survival and more severe lung injury compared with CD-fed mice following sepsis. Myeloperoxidase (MPO) activity, an indicator of neutrophil infiltration, was increased in the lung and liver after CLP in HFD-fed mice compared with CD (P < 0.05). The plasma cytokines tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were increased in both groups after CLP, however, TNF-α and IL-6 levels were lower in HFD mice at 3 h after CLP compared with CD and consistent with lung, but not liver, messenger RNA (mRNA) expression. Leptin levels were higher in HFD-fed mice at 18 h after sepsis compared to baseline levels (P < 0.05). Polymicrobial sepsis increased hepatic nuclear factor-κB (NF-κB) activation in HFD-fed mice after CLP vs. CD-fed mice. Short duration high fat feeding increases mortality and organ injury following polymicrobial sepsis. These effects correspond to changes in NF-κB.     

LPSF/GQ-02 Inhibits the Development of Hepatic Steatosis and Inflammation in a Mouse Model of Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) defines a wide spectrum of liver diseases that extends from simple steatosis to non-alcoholic steatohepatitis. Although the pathogenesis of NAFLD remains undefined, it is recognized that insulin resistance is present in almost all patients who develop this disease. Thiazolidinediones (TZDs) act as an insulin sensitizer and have been used in the treatment of patients with type 2 diabetes and other insulin-resistant conditions, including NAFLD. Hence, therapy of NAFLD with insulin-sensitizing drugs should ideally improve the key hepatic histological changes, while also reducing cardiometabolic and cancer risks. Controversially, TZDs are associated with the development of cardiovascular events and liver problems. Therefore, there is a need for the development of new therapeutic strategies to improve liver function in patients with chronic liver diseases. The aim of the present study was to assess the therapeutic effects of LPSF/GQ-02 on the liver of LDLR-/- mice after a high-fat diet. Eighty male mice were divided into 4 groups and two different experiments: 1-received a standard diet; 2-fed with a high-fat diet (HFD); 3–HFD+pioglitazone; 4–HFD+LPSF/GQ-02. The experiments were conducted for 10 or 12 weeks and in the last two or four weeks respectively, the drugs were administered daily by gavage. The results obtained with an NAFLD murine model indicated that LPSF/GQ-02 was effective in improving the hepatic architecture, decreasing fat accumulation, reducing the amount of collagen, decreasing inflammation by reducing IL-6, iNOS, COX-2 and F4 / 80, and increasing the protein expression of IκBα, cytoplasmic NFκB-65, eNOS and IRS-1 in mice LDLR -/-. These results suggest a direct action by LPSF/GQ-02 on the factors that affect inflammation, insulin resistance and fat accumulation in the liver of these animals. Further studies are being conducted in our laboratory to investigate the possible mechanism of action of LPSF/GQ-02 on hepatic lipid metabolism.     

The role of AMPKα2 in the HFD-induced nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is associated with hepatic steatosis, inflammation and liver fibrosis and has become one of the leading causes of hepatocellular carcinoma and liver failure. However, the underlying molecular mechanism of hepatic steatosis and the progression to nonalcoholic steatohepatitis (NASH) are not fully understood. Herein, we discovered that AMPKα2 catalytic subunit showed reduced expression in the liver following high fat diet (HFD) feeding to mice. Importantly, knockout of AMPKα2 in mice aggravated NAFLD, hepatic steatosis, inflammation and fibrosis. On the other hand, hepatocyte-targeted overexpression of AMPKα2 prevented or reversed NAFLD indications. In vivo mechanistic studies revealed that increased phosphorylation of IKKα/β and NF-κB in HFD-fed AMPKα2^−/− mice compared to WT mice, and treatment of these mouse cohorts with an inhibitor of NF-κB signaling for 4 weeks, effectively attenuated the progression of steatohepatitis and metabolic disorder features. In summary, AMPKα2 provides a protective role in the process of hepatic steatosis to NASH progression through suppression of liver NF-κB signaling.     

动态分析沙鼠非酒精性脂肪肝病形成及生化影响

目的分析高脂饮食导致的沙鼠NAFLD疾病进展中脂质代谢、肝功能、抗氧化等方面的变化,探讨沙鼠NAFLD的形成机理。方法雄性沙鼠120只,随机分为对照组和模型组。对照组给予普通饲料,模型组高脂饮食建立NAFLD模型。分别于1、2、4、6、8、16周每组各处死10只动物,观察肝脏病理变化,计算肝指数,检测血清CHO、TG、LDL-C、HDL-C、GOP、GPT及肝组织的SOD、GSH-PX、CAT活性和FFA含量。结果模型组病理观察2周形成单纯性脂肪肝,6周动物门管区有轻度炎症,8周出现腺泡Ⅲ带局灶性窦周/细胞周纤维化,16周肝脏中度纤维化;模型组第1、2、4、6、8、16周时CHO、HDL-C、LDL-C及FAA波动性升高,但均高于同期对照组（P〈0.05,P〈0.01）,TG在1、2、4周高于同期对照组（P〈0.05,P〈0.01）;16周末GOT、GPT出现了显著性升高（P〈0.01）。抗氧化酶GSH-PX、CAT、SOD活性模型组在第8～16周显著性降低（P〈0.05,P〈0.01）。结论高脂饮食使沙鼠2周形成单纯性脂肪肝模型后,随饲喂时间延长,16周末可发展为中度肝纤维化。脂质代谢紊乱与氧化应激在沙鼠NAFLD进展中的发挥了不同的作用。     

槟榔碱对2型糖尿病大鼠肝脏胰岛素抵抗的作用

目的：探讨槟榔碱对2型糖尿病大鼠肝脏胰岛素抵抗的影响及其机制。方法：采用高果糖饲料饲养Wistar大鼠12周制备2型糖尿病大鼠模型,实验动物随机分为5组（n=8）：对照组、模型组、模型＋不同浓度的槟榔碱（0,0．5,1,5mg／kg）组。4周后通过检测血糖、血脂、胰岛素、RT-PCR检测肝脏组成型雄甾烷受体（CAR）、孕甾烷x受体（PXR）、糖代谢相关基因：葡萄糖-6-磷酸酶（G6Pase）、磷酸烯醇式丙酮酸羧激酶（PEPCK）和炎症相关因子：白细胞介素-6（IL-6）、肿瘤坏死因子α（TNF-α）mRNA表达,Western blot检测大鼠肝内p-AKT和葡萄糖转运体4（GLUT4）蛋白表达。结果：1,5mg／kg槟榔碱显著降低糖尿病大鼠体重、空腹血糖、空腹胰岛素、血脂和糖代谢相关基因及炎症相关因子mRNA水平,提高CAR、PXR mRNA水平及p-AKT、GLUT4蛋白水平。结论：槟榔碱可能通过提高CAR和PXR的表达,导致肝脏糖代谢关键酶PEPCK、G6Pase基因表达或者炎性因子肿瘤坏死因子-α（TNF-α）、白介素-6（n-6）表达降低,改善2型糖尿病大鼠肝脏胰岛素抵抗。     

Hydroxytyrosol prevents metabolic impairment reducing hepatic inflammation and restoring duodenal integrity in a rat model of NAFLD

The potential mechanisms of action of polyphenols in nonalcoholic fatty liver disease (NAFLD) are overlooked. Here, we evaluate the beneficial therapeutic effects of hydroxytyrosol (HT), the major metabolite of the oleuropein, in a nutritional model of insulin resistance (IR) and NAFLD by high-fat diet. Young male rats were divided into three groups receiving (1) standard diet (STD; 10.5% fat), (2) high-fat diet (HFD; 58.0% fat) and (3) HFD + HT (10 mg/kg/day by gavage). After 5 weeks, the oral glucose tolerance test was performed, and at 6th week, blood sample and tissues (liver and duodenum) were collected for following determinations. The HT-treated rats showed a marked reduction in serum AST, ALT and cholesterol and improved glucose tolerance and insulin sensitivity, reducing homeostasis model assessment index. HT significantly corrected the metabolic impairment induced by HFD, increasing hepatic peroxisome proliferator-activated receptor PPAR-α and its downstream-regulated gene fibroblast growth factor 21, the phosphorylation of acetyl-CoA carboxylase and the mRNA carnitine palmitoyltransferase 1a. HT also reduced liver inflammation and nitrosative/oxidative stress decreasing the nitrosylation of proteins, reactive oxygen species production and lipid peroxidation. Moreover, HT restored intestinal barrier integrity and functions (fluorescein isothiocyanate-dextran permeability and mRNA zona occludens ZO-1). Our data demonstrate the beneficial effect of HT in the prevention of early inflammatory events responsible for the onset of IR and steatosis, reducing hepatic inflammation and nitrosative/oxidative stress and restoring glucose homeostasis and intestinal barrier integrity.     

抵抗素对NAFLD肝纤维化的影响及可能的体内外机制

应用高脂饮食饲养Wistar大鼠建立非酒精性脂肪肝病(non-alcoholic fatty liver disease,NAFLD)肝纤维化体内模型,选用重组抵抗素作用于肝星状细胞(hepatic stellate cell-t6,HSC-T6)建立体外模型。观察肝组织纤维化的情况;检测体内体外Ⅲ型前胶原(PCⅢ)、透明质酸(HA)、Ⅳ型胶原(CIV)、层黏蛋白(LN)水平;检测肝组织抵抗素mRNA和蛋白的表达水平;检测HSC-T6中转化生长因子β-1(TGF-β1)mRNA及肿瘤坏死因子α(TNF-α)mRNA表达水平。结果显示,随着高脂喂养时间的延长,大鼠肝组织抵抗表达逐渐增加且纤维化程度逐渐加重;随着抵抗素浓度的增加,HSC-T6上清中纤维化指标升高,细胞中TGF-β1mRNA及TNF-αmRNA表达增加。与对照组比较,各指标差异均有显著性(P<0.05或0.01)。上述结果显示抵抗素通过TNF-α、TGF-β1诱导NAFLD肝纤维的发生和发展。