Development of Fibrosis in Nonalcoholic Steatosis through Combination of a Synthetic Diet Rich in Disaccharide and Low-Dose Lipopolysaccharides in the Livers of Zucker (fa/fa) Rats

Nonalcoholic steatohepatitis (NASH) can develop into end-stage disease such as cryptogenic cirrhosis and hepatocellular carcinoma. Hence, it is important to understand the pathogenesis of NASH. In general, the “two-hit theory” has prevailed as a pathogenic mechanism of NASH. According to this theory, lipopolysaccharides (LPS) contained in normal portal blood are the “second hit,” but their role is not completely understood. Based on this theory, we evaluated the role of LPS in NASH pathogenesis. For the first hit to develop metabolic abnormalities, a synthetic diet rich in disaccharide (synthetic diet: 12.1 cal% disaccharide) was fed to Zucker (fa/fa) rats for 12 weeks. For the second hit, 100 µg/kg LPS was injected intraperitoneally once daily for 2 weeks. Synthetic diet-fed rats treated with LPS showed an increase in the triglyceride content and higher expression of profibrogenic mRNAs in the liver. Plasma alanine aminotransferase levels were significantly elevated using this protocol. Furthermore, histological examination demonstrated that this protocol induced mild hepatic fibrosis and focal necrosis in the livers of all rats. Synthetic diet-fed Zucker (fa/fa) rats treated with LPS could be useful for understanding the development of hepatic fibrosis in the two-hit theory.     

Effect of atorvastatin and diet on non-alcoholic fatty liver disease activity score in hyperlipidemic chickens

Non-alcoholic steatohepatitis (NASH) is part of the spectrum of non-alcoholic fatty liver disease (NAFLD), which includes from simple steatosis and steatohepatitis, to the most severe cirrhosis and carcinoma, which develops in the absence of excessive alcohol intake. NAFLD is the most common liver disorder in affluent societies. There is no proven treatment for NAFLD/NASH. One of the most frequent adverse effects of statins is an increase in hepatic aminotransferases. Studies that evaluate if the benefits of statins overcome the risks in NASH are lacking. The present study was conceived to explore the effect of both atorvastatin and diet on regression of steatohepatitis, using a chicken experimental model induced by a hyperlipidemic diet (HD). Plasma lipid levels, liver enzymes and hepatic histopathology, as well as image analysis were performed to determine changes in liver lipid deposits and inflammatory infiltration. Features of steatosis, cell-ballooning, and inflammation were scored to obtain the NAFLD activity score (NAS). A severe level of steatosis was found in animals fed on HD. Atorvastatin treated groups showed smaller size of lipid deposits and a lower level of inflammation than non-treated groups. Atorvastatin therapy induced a significant reduction of hepatocellular damage, even though in the animals which continuously received a hyperlipidemic diet. The combination of atorvastatin therapy and a standard diet produced the lowest decrease of NAS. Our results show that atorvastatin therapy not only decreased plasmatic levels of cholesterol and triglycerides, but also induced a reduction of liver steatosis, inflammation and hepatocellular damage, without increasing plasmatic amynotransferase levels.     

运动对高脂饮食诱导非酒精性脂肪肝的治疗作用

目的 观察运动对高脂饮食诱导非酒精性脂肪肝的治疗作用,并初步探讨其相关机制.方法 将30只Wistar大鼠分为对照组及高脂组,分别给予基础饲料和高脂饲料喂养;高脂组大鼠经喂养18周后制成胰岛素抵抗(IR)模型,并进一步细分为静息组和运动组,继续给予高脂饲料喂养,运动组同时进行游泳训练,共持续6周.于实验进行24周后处死各组大鼠,计算肝指数,观察肝脏病理学改变,检测各组大鼠肝脏甘油三酯(TG)含量,同时应用蛋白免疫印迹法检测肝脏组织一磷酸腺苷活化蛋白激酶(AMPK)磷酸化水平.结果 实验进行24周后,与对照组比较,静息组大鼠胰岛素敏感性显著降低,肝脏TG含量、肝指数明显增高,光镜下肝脏出现明显脂肪变性,肝脏内AMPK磷酸化水平降至对照组水平的50.8%;与静息组比较,运动组大鼠胰岛素敏感性明显提高,肝指数及肝脏TG含量均显著降低,光镜下可见肝脏脂肪变性程度明显改善,肝组织内AMPK磷酸化水平亦显著提高.结论 运动干预对高脂饮食诱导的非酒精性脂肪肝具有治疗作用,其机制可能与运动上调肝脏组织中AMPK磷酸化水平,从而改善IR及减少肝脏内TG含量有关.     

运动对高脂饮食诱导非酒精性脂肪肝的治疗作用

目的 观察运动对高脂饮食诱导非酒精性脂肪肝的治疗作用,并初步探讨其相关机制.方法 将30只Wistar大鼠分为对照组及高脂组,分别给予基础饲料和高脂饲料喂养;高脂组大鼠经喂养18周后制成胰岛素抵抗(IR)模型,并进一步细分为静息组和运动组,继续给予高脂饲料喂养,运动组同时进行游泳训练,共持续6周.于实验进行24周后处死各组大鼠,计算肝指数,观察肝脏病理学改变,检测各组大鼠肝脏甘油三酯(TG)含量,同时应用蛋白免疫印迹法检测肝脏组织一磷酸腺苷活化蛋白激酶(AMPK)磷酸化水平.结果 实验进行24周后,与对照组比较,静息组大鼠胰岛素敏感性显著降低,肝脏TG含量、肝指数明显增高,光镜下肝脏出现明显脂肪变性,肝脏内AMPK磷酸化水平降至对照组水平的50.8%;与静息组比较,运动组大鼠胰岛素敏感性明显提高,肝指数及肝脏TG含量均显著降低,光镜下可见肝脏脂肪变性程度明显改善,肝组织内AMPK磷酸化水平亦显著提高.结论 运动干预对高脂饮食诱导的非酒精性脂肪肝具有治疗作用,其机制可能与运动上调肝脏组织中AMPK磷酸化水平,从而改善IR及减少肝脏内TG含量有关.     

Comparative effectiveness of phosphodiesterase 3, 4, and 5 inhibitors in amelioration of high-fat diet-induced nonalcoholic fatty liver in rats

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent disease linked to insulin resistance, oxidative stress, and cytokine imbalance. Phosphodiesterase (PDE) inhibitors have shown remarkable antioxidant and anti-inflammatory potential in different disease sets including liver diseases. This study aimed to compare the ameliorative effect of different PDE inhibitors on a high-fat diet (HFD)-induced NAFLD. Male Wistar rats were fed a HFD for 16 weeks to induce NAFLD, and then, oral treatments of a vehicle or different PDE inhibitors (pentoxifylline (50 mg/kg), cilostazol (20 mg/kg), or sildenafil (5 mg/kg)) were started in the last four weeks and given on a daily basis. Rats’ body composition and liver indices were recorded. Serum levels of liver enzymes, glucose, insulin, bilirubin, total cholesterol, triglycerides, and nitric oxide were measured. Liver tissues were used for histopathological examination and detecting oxidative stress and inflammatory markers. Results showed that different PDE inhibitors exhibited different efficacy against liver injury and metabolic disorders associated with HFD-induced NAFLD in rodents evident by different strength-ameliorated effects on the aforementioned parameters. Compared to cilostazol and sildenafil, insulin resistance, hepatic oxidative stress, and inflammatory markers were significantly reduced by pentoxifylline treatment. Furthermore, pentoxifylline nearly completely reversed hepatocyte steatosis and exhibited superior rectifying effect on the rats’ liver status compared with other PDE inhibitors. This investigation highlighted the potential role of PDE inhibitors in NAFLD treatment. Pentoxifylline had the most remarkable ameliorative effects against NAFLD, while sildenafil was the least effective.     

非酒精性脂肪性肝病模型大鼠饮食或二甲双胍干预后肝视黄醇结合蛋白4表达

背景：目前关于血清视黄醇结合蛋白4在非酒精性脂肪性肝病中的表达水平仍存在争议。目的：研究饮食或二甲双胍干预对非酒精性脂肪性肝病大鼠肝脏视黄醇结合蛋白4表达的影响。方法：将50只SD大鼠随机分为6组,8周对照组,正常饮食8周后处死;8周高脂组,高脂饮食8周制作非酒精性脂肪性肝病模型,随后处死;16周对照组,正常饮食16周后处死;16周高脂组,高脂饮食16周后处死;饮食干预组,8周高脂饮食后再正常饮食8周,随后处死;二甲双胍治疗组,8周高脂饮食后,继续8周高脂饮食,同时给予二甲双胍灌胃治疗,随后处死。采用ELISA法检测血清视黄醇结合蛋白4水平及生化指标,免疫组织化学法、Western blotting法、RT-PCR法检测肝脏组织视黄醇结合蛋白4表达。结果与结论：高脂饮食成功建立非酒精性脂肪性肝病大鼠模型,随造模时间延长,大鼠肝脏由单纯性脂肪肝逐渐进展成为脂肪性肝炎。饮食干预可改善高脂饮食引发的肝组织视黄醇结合蛋白4表达下降、肝功能异常、脂代谢紊乱和胰岛素抵抗,二甲双胍治疗仅改善了高脂饮食引发的肝脂肪变。结果表明肝组织视黄醇结合蛋白4表达的改变可能在非酒精性脂肪性肝病发病中起一定作用,饮食干预应作为防治非酒精性脂肪性肝病的基本措施,二甲双胍可以改善非酒精性脂肪性肝病的肝脂肪变。     

Cardiovascular disease is associated with high-fat-diet-induced liver damage and up-regulation of the hepatic expression of hypoxia-inducible factor 1α in a rat model

CVD (cardiovascular disease) is associated with abnormal liver enzymes, and NAFLD (non-alcoholic fatty liver disease) is independently associated with cardiovascular risk. To gain insights into the molecular events underlying the association between liver enzymes and CVD, we developed an HFD (high-fat diet)-induced NAFLD in the SHR (spontaneously hypertensive rat) and its control WKY (Wistar-Kyoto) rat strain. We hypothesized that hepatic induction of Hif1a (hypoxia-inducible factor 1α) might be the link between CVD and liver injury. Male SHRs (n=13) and WKY rats (n=14) at 16?weeks of age were divided into two experimental groups: standard chow diet and HFD (10?weeks). HFD-fed rats, irrespective of the strain, developed NAFLD; however, only HFD-SHRs had focus of lobular inflammation and high levels of hepatic TNFα (tumour necrosis factor α). SHRs had significantly higher liver weight and ALT (alanine aminotransferase) levels, irrespective of NAFLD. Liver abundance of Hif1a mRNA and Hif1α protein were overexpressed in SHRs (P<0.04) and were significantly correlated with ALT levels (R=0.50, P<0.006). This effect was not reverted by a direct acting splanchnic vasodilator (hydralazine). Angiogenesis may be induced by the HFD, but the disease model showed significantly higher hepatic Vegf (vascular endothelial growth factor) levels (P<0.025) even in absence of dietary insult. Hif1a mRNA overexpression was not observed in other tissues. Liver mRNA of Nr1d1 (nuclear receptor subfamily 1, group D, member 1; P<0.04), Ppara [Ppar (peroxisome-proliferatoractivated receptor) α; P<0.05], Pparg (Pparγ; P<0.001) and Sirt1 (Sirtuin 1; P<0.001) were significantly upregulated in SHRs, irrespective of NAFLD. Sirt1 and Hif1a mRNAs were significantly correlated (R=0.71, P<0.00002). In conclusion, CVD is associated with Hif1a-related liver damage, hepatomegaly and reprogramming of liver metabolism, probably to compensate metabolic demands.     

GO-CoA-Tat改善脂肪肝小鼠脂质代谢和氧化应激

目的 非酒精性脂肪性肝病(NAFLD)是目前最常见的肝病之一,既往研究提示GO-CoA-Tat在减轻小鼠体重和调节血糖方面发挥作用,本研究探讨GO-CoA-Tat对高脂饮食诱导的NAFLD小鼠脂质代谢和氧化应激的影响。方法 实验动物分为:对照组、高脂饮食(HFD)组和GO-CoA-Tat组。对照组给予标准饮食,HFD组和GO-CoA-Tat组均给予HFD。此外,GO-CoA-Tat组接受皮下注射GO-CoA-Tat。肝细胞油红Ｏ染色检测脂肪滴形成情况。相关检测试剂盒对各组小鼠血清生化指标进行检测。相关检测试剂盒检测氧化应激产物浓度变化。正态分布的计量资料多组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。结果 给予HFD 8周后小鼠出现明显的肝脏脂肪变性,GO-CoA-Tat干预后脂肪变性明显缓解。GO-CoA-Tat组(5.455±0.186)食物摄入量较HFD组(7.672±0.268)明显下降(P=0.004)。GO-CoA-Tat组(1.165±0.038)小鼠肝脏重量较HFD组(1.392±0.051)明显下降(P=0.005)。GO-CoA-Tat组(74.791±3.857)小鼠肝脏TG含量与HFD组(96.891±2.708)相比明显下降(P=0.009)。GO-CoA-Tat组(1.441±0.044)血清TG浓度较HFD组(1.821±0.071)明显下降(P=0.01)。GO-CoA-Tat组(4.207±0.204)血清TC浓度较HFD组(5.897±0.151)明显下降(P=0.007)。GO-CoA-Tat组(6.820±0.296)GSH浓度较HFD组(5.073±0.331)明显升高(P=0.009)。GO-CoA-Tat组(223.1±7.188)SOD浓度较HFD组(178.1±8.234)明显升高(P=0.008)。GO-CoA-Tat组(12.381±0.481)MDA浓度较HFD组(16.621±0.521)明显下降(P=0.005)。结论 GO-CoA-Tat可改善NAFLD小鼠肝脏的脂质代谢和氧化应激,从而发挥肝脏保护作用。     

吡格列酮对大鼠非酒精性脂肪肝病的治疗作用及其机制

【目的】探讨吡格列酮对SD大鼠非酒精性脂肪肝病（NAFLD ）的治疗作用及其机制。【方法】36只雄性SD大鼠随机分为正常对照组（NG组）、吡格列酮治疗组（PIOG组）及高脂饮食组（FG组）,均饲养12周;NG组喂饲普通饲料,剩余两组喂饲高脂饲料;PIOG组于实验第8～12周予吡格列酮灌胃,其余两组同期予蒸馏水灌胃;比较三组空腹血清丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、三酰甘油（TG）、总胆固醇（TC）、空腹血糖（FPG）、空腹胰岛素（FINS）、空腹胰岛素抵抗指数（FIRI）、肿瘤坏死因子-α（TNF-α）及一氧化氮（NO）的水平;HE染色分析肝组织切片病理学改变;观察Kupffer细胞（KCs）形态变化。【结果】FG组大鼠FIRI、TG、TC均高于NG组,其差异均有统计学意义（ P ＜0．05）,肝组织呈大泡性脂肪变性并出现炎症细胞浸润及点状坏死,肝脏KCs发生形态改变,其产生的TNF、NO水平与肝组织病理学改变呈正相关（ P ＜0．05）;PIOG组大鼠 FIRI、TG、TC均低于FG组,其差异均有统计学意义（ P ＜0．05）,肝组织脂肪变性程度减轻,仍可见炎症细胞浸润和肝细胞气球样变性,肝脏KCs形态及功能仍存在异常。【结论】吡格列酮可部分延缓高脂饮食诱导的NAFLD的进展;其机制可能与改善胰岛素抵抗、降低血脂有关,与调节KCs功能无关。     

慢性丙型肝炎发生肝脂肪变与脂联素的关系

目的探讨慢性丙型肝炎(chronic hepatitis C,CHC)患者发生肝脂肪变与脂联素的关系。方法 80例CHC患者分为有肝脂肪变组8例与无肝脂肪变组72例,单纯非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)26例为对照组,比较各组血清脂联素等生化指标。结果 2组CHC患者糖代谢及脂代谢指标、丙型肝炎病毒核糖核酸水平、血清脂联素水平、肝脏炎症程度比较差异均无统计学意义(P>0.05),CHC组血清脂联素水平高于NAFLD组(P<0.01);脂联素与年龄、谷丙转氨酶、谷草转氨酶和丙型肝炎病毒核糖核酸水平呈正相关(P<0.05),与低密度脂蛋白胆固醇、载脂蛋白-B、三酰甘油和空腹血糖水平呈负相关(P<0.05)。结论 CHC患者发生肝脂肪变与血清脂联素无关;血清脂联素与年龄、肝脏炎症程度和丙型肝炎病毒核糖核酸水平呈正相关,与血糖、血脂水平呈负相关。     

Targeting hepatic kisspeptin receptor ameliorates nonalcoholic fatty liver disease in a mouse model

Nonalcoholic fatty liver disease (NAFLD), the most common liver disease, has become a silent worldwide pandemic. The incidence of NAFLD correlates with the rise in obesity, type 2 diabetes, and metabolic syndrome. A hallmark featureof NAFLD is excessive hepatic fat accumulation or steatosis, due to dysregulated hepatic fat metabolism, which can progress to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Currently, there are no approved pharmacotherapies to treat this disease. Here, we have found that activation of the kisspeptin 1 receptor (KISS1R) signaling pathway has therapeutic effects in NAFLD. Using high-fat diet–fed mice, we demonstrated that a deletion of hepatic Kiss1r exacerbated hepatic steatosis. In contrast, enhanced stimulation of KISS1R protected against steatosis in wild-type C57BL/6J mice and decreased fibrosis using a diet-induced mouse model of NASH. Mechanistically, we found that hepatic KISS1R signaling activates the master energy regulator, AMPK, to thereby decrease lipogenesis and progression to NASH. In patients with NAFLD and in high-fat diet–fed mice, hepatic KISS1/KISS1R expression and plasma kisspeptin levels were elevated, suggesting a compensatory mechanism to reduce triglyceride synthesis. These findings establish KISS1R as a therapeutic target to treat NASH.     

Enhanced expression of pro-inflammatory mediators and liver X-receptor-regulated lipogenic genes in non-alcoholic fatty liver disease and hepatitis C

NAFLD (non-alcoholic fatty liver disease) is one of the most frequent chronic liver diseases worldwide. The metabolic factors associated with NAFLD are also determinants of liver disease progression in chronic HCV (hepatitis C virus) infection. It has been reported that, besides inducing hepatic fatty acid biosynthesis, LXR (liver X receptor) regulates a set of inflammatory genes. We aimed to evaluate the hepatic expression of LXRα and its lipogenic and inflammatory targets in 43 patients with NAFLD, 44 with chronic HCV infection and in 22 with histologically normal liver. Real-time PCR and Western blot analysis were used to determine hepatic expression levels of LXRα and related lipogenic and inflammatory mediators in the study population. We found that the LXRα gene and its lipogenic targets PPAR-γ (peroxisome-proliferator-activated receptor-γ), SREBP (sterol-regulatory-element-binding protein)-1c, SREBP-2 and FAS (fatty acid synthase) were overexpressed in the liver of NAFLD and HCV patients who had steatosis. Moreover, up-regulation of inflammatory genes, such as TNF (tumour necrosis factor)-α, IL (interleukin)-6, OPN (osteopontin), iNOS (inducible NO synthase), COX (cyclo-oxygenase)-2 and SOCS (suppressors of cytokine signalling)-3, was observed in NAFLD and HCV patients. Interestingly, TNF-α, IL-6 and osteopontin gene expression was lower in patients with steatohepatitis than in those with steatosis. In conclusion, hepatic expression of LXRα and its related lipogenic and inflammatory genes is abnormally increased in NAFLD and HCV patients with steatosis, suggesting a potential role of LXRα in the pathogenesis of hepatic steatosis in these chronic liver diseases.     

The lipogenic transcription factor ChREBP dissociates hepatic steatosis from insulin resistance in mice and humans

Nonalcoholic fatty liver disease (NAFLD) is associated with all features of the metabolic syndrome. Although deposition of excess triglycerides within liver cells, a hallmark of NAFLD, is associated with a loss of insulin sensitivity, it is not clear which cellular abnormality arises first. We have explored this in mice overexpressing carbohydrate responsive element-binding protein (ChREBP). On a standard diet, mice overexpressing ChREBP remained insulin sensitive, despite increased expression of genes involved in lipogenesis/fatty acid esterification and resultant hepatic steatosis (simple fatty liver). Lipidomic analysis revealed that the steatosis was associated with increased accumulation of monounsaturated fatty acids (MUFAs). In primary cultures of mouse hepatocytes, ChREBP overexpression induced expression of stearoyl-CoA desaturase 1 (Scd1), the enzyme responsible for the conversion of saturated fatty acids (SFAs) into MUFAs. SFA impairment of insulin-responsive Akt phosphorylation was therefore rescued by the elevation of Scd1 levels upon ChREBP overexpression, whereas pharmacological or shRNA-mediated reduction of Scd1 activity decreased the beneficial effect of ChREBP on Akt phosphorylation. Importantly, ChREBP-overexpressing mice fed a high-fat diet showed normal insulin levels and improved insulin signaling and glucose tolerance compared with controls, despite having greater hepatic steatosis. Finally, ChREBP expression in liver biopsies from patients with nonalcoholic steatohepatitis was increased when steatosis was greater than 50% and decreased in the presence of severe insulin resistance. Together, these results demonstrate that increased ChREBP can dissociate hepatic steatosis from insulin resistance, with beneficial effects on both glucose and lipid metabolism.     

慢性丙型肝炎肝组织学改变与肝脏瘦素表达的关系

目的研究慢性丙型肝炎(CHC)肝组织学改变与肝脏瘦素表达的关系。方法未经治疗的53例成年CHC患者分为肝脏瘦素阳性组26例和阴性组27例,以单纯非酒精性脂肪性肝病(NAFLD)15例作为对照组,比较各组肝脏瘦素阳性率、肝脏炎症分级、纤维化分期和脂肪变分级有无差异。结果 CHC组脂肪变分级程度轻于NAFLD组(χ2=13.20,P<0.05),但两组分别在脂肪变1级和2级的肝脏瘦素阳性率差异无统计学意义(χ2=2.57,0.04,P均>0.05);两组在轻度炎症和轻度纤维化的瘦素表达阳性率差异有统计学意义,CHC组肝脏瘦素阳性率低于NAFLD组(χ2=4.54,6.86,P均<0.05)。两组CHC的肝脏瘦素阳性率在不同肝脏炎症分级、纤维化分期和是否发生肝脂肪变差异无统计学意义(χ2=0.106,0.846,0.000,P均>0.05),CHC的肝脏瘦素阳性率与肝脏炎症分级、纤维化分期、脂肪变分级和血清HCVRNA水平无明显相关性(P均>0.05)。结论 CHC发生肝脂肪变、肝脏炎症和纤维化程度均与肝脏瘦素表达无明显相关。     

S-adenosyl-L-methionine attenuates oxidative stress and hepatic stellate cell activation in an ethanol-LPS-induced fibrotic rat model

Previous studies report S-adenosyl-L-methionine (SAMe) can exert hepatoprotective effects. At present, the role of SAMe in affecting the activation and/or proliferation of hepatic stellate cells (HSCs) during alcohol-induced fibrotic disease progression is poorly understood. In the human disease state, chronic ethanol intake increases hepatic exposure to LPS and magnifies the hepatic insult leading to fibrosis and cirrhosis. In this study, we developed a "2-hit" ethanol-LPS fibrotic liver rat model with which to investigate the effects of SAMe as a hepatic antifibrotic treatment. Male rats were maintained on liquid diets containing either ethanol or isocalorically matched controls for 8 weeks. Animals received ethanol alone (E), ethanol concomitant with twice weekly LPS injections (EL), or ethanol, LPS, and daily SAMe injections. When using this model, SAMe-treated animals demonstrated significantly decreased fibrosis, oxidative stress, steatosis, and improved liver function versus the EL group. In addition, the EL group showed increased HSC activation, an effect that was abrogated by the addition of SAMe. Analysis of the transforming growth factor-beta (TGF-beta) signaling pathways demonstrated increased hepatic TGF-beta and Smad3 messenger RNA expression in the E and EL groups, which was inhibited in the presence of SAMe. Conversely, SAMe led to increased Smad7 (an inhibitor of TGF-beta signaling) messenger RNA expression. These data demonstrate chronic ethanol feeding combined with LPS induces liver fibrosis, and the addition of SAMe significantly reduces hepatic injury and fibrosis through inhibition of oxidative stress and HSC activation.     

Effects of curcuminoids on inflammatory status in patients with non-alcoholic fatty liver disease: A randomized controlled trial

BackgroundNonalcoholic fatty liver diseases (NAFLD) is a highly prevalent disease that is closely associated with several cardiometabolic complications. The potential anti-inflammatory role of curcuminoids that have already been reported to reduce hepatic steatosis, in patients with NAFLD was explored in this study.MethodsThis double-blind, randomized placebo-controlled trial was conducted for a period of 8 weeks in patients with NAFLD. Subjects (n = 55) were randomly allocated to receive either curcuminoids or placebo. The curcuminoids group received one capsule containing 500 mg curcuminoids (plus 5 mg piperine to increase intestinal absorption) per day for 8 weeks and the control group received matched placebo capsules for the same period. Liver ultrasonography was performed to assess the severity of hepatic steatosis at baseline and the study end. Serum levels of cytokines including interleukin-1α, interleukin-1β, interleukin-2, interleukin-4, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-α, monocyte chemoattractant protein-1, interferon γ, vascular endothelial growth factor and epidermal growth factor were measured before and after the intervention.ResultsThe two groups were comparable in demographic features at baseline. The results showed that supplementation with curcuminoids could decrease weight compared to the placebo group (p = 0.016) in patients with NAFLD. Curcuminoids supplementation improved the severity of NAFLD according to the ultrasound results (p = 0.002). Moreover, serum concentrations of TNF-α (p = 0.024), MCP-1 (p = 0.008) and EGF (p = 0.0001) were improved by curcuminoids in NAFLD patients.ConclusionsThe results of our study showed that curcumin supplementation can improve serum levels of inflammatory cytokines in subjects with NAFLD and this might be at least partly responsible for the anti-steatotic effects of curcuminoids.     

Effect of branched-chain amino acid supplementation on the oxidized/reduced state of plasma albumin in rats with chronic liver disease

We examined whether continuous supplementation with branched-chain amino acids phosphorylates ribosomal protein S6, a downstream effector of mammalian target of rapamycin, and improves hypoalbuminemia of rats with chronic liver disease. Sprague-Dawley rats were fed a casein diet (control group) or a branched-chain amino acid-supplemented casein diet (branched-chain amino acid group) for 11 weeks with repeated injections of carbon tetrachloride. Throughout this experimental period, no significant difference in plasma albumin concentration was seen between groups. The percentage of reduced albumin within total plasma albumin gradually decreased in both control and branched-chain amino acid groups. After 11 weeks with supplementation, phosphorylation of ribosomal protein S6 was significantly increased in the liver of rats in the branched-chain amino acid group compared with the control group. Furthermore, the percentage of reduced albumin within total albumin was significantly higher in the branched-chain amino acid group than in the control group. These results indicate that continuous supplementation with branched-chain amino acids in rats with chronic liver disease induces phosphorylation of hepatic ribosomal protein S6 and attenuates decreases in the percentage of reduced albumin, although levels of plasma albumin are not increased.     

新生大鼠低血糖与非酒精性脂肪性肝病的关系研究

目的本研究通过建立新生大鼠低血糖模型,然后再以此为基础,诱发非酒精性脂肪性肝病（NAFLD）,通过比较不同组间病变程度、胰岛素抵抗强弱、肝功能等指标的差异,了解新生大鼠低血糖和NAFLD易感性之间的关系,为了解NAFLD的发生机制和寻找有效的防治措施提供实验依据。方法购SPF级成熟Wistar雌性大鼠20只和雄性大鼠10只,合笼交配,从所生仔鼠中每窝随机抽取0—1只,总共12只作为正常血糖＋正常饮食组;然后将相同母鼠所生3只新生大鼠,随机分入正常血糖＋高脂饮食组、低血糖＋正常饮食组、低血糖＋高脂饮食组各12只,在第20周末处死,测血清空腹血糖（FBG）、血清空腹胰岛素（FINS）、脂肪酸、总胆固醇（TCH）、三酰甘油（TG）、丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）等指标。肝组织石蜡切片染色判断肝脂变和炎症活动情况。结果20周末大鼠胰岛素抵抗指数（IRI）、脂肪酸、TG、ALT、AST在正常血糖＋高脂饮食组、低血糖＋正常饮食组中明显高于正常血糖＋正常饮食组,低血糖＋高脂饮食组中明显高于正常血糖＋高脂饮食组、低血糖＋正常饮食组;TCH在正常血糖＋高脂饮食组、低血糖＋高脂饮食组中明显高于正常血糖＋正常饮食组、低血糖＋正常饮食组。病理学指标检测中,肝脂变指数及炎症指数在正常血糖＋高脂饮食组、低血糖＋正常饮食组中明显高于正常血糖＋正常饮食组,低血糖＋高脂饮食组中明显高于正常血糖＋高脂饮食组、低血糖＋正常饮食组。结论新生大鼠低血糖所导致的代谢紊乱会导致NAFLD的发生。     

Evaluation of Non-alcoholic Fatty Liver Disease Using Acoustic Radiation Force Impulse Imaging Elastography in Rat Models

The aim of this study is to evaluate the utility of acoustic radiation force impulse (ARFI) elastography for assessing hepatic fibrosis stage and non-alcoholic fatty liver disease (NAFLD) severity, as well as the relationship among hepatic histologic changes using shear wave velocity (SWV). Animal models with various degrees of NAFLD were established in 110 rats. The right liver lobe was processed and embedded in a fabricated gelatin solution (porcine skin). Liver mechanics were measured using SWV induced by acoustic radiation force. Among the histologic findings, liver elasticity could be used to differentiate normal rats from rats with simple steatosis (SS) as well as distinguish SS from non-alcoholic steatohepatitis (NASH), with areas under the receiver operating characteristic curves (AUROC) of 0.963 (95% confidence interval = 0.871–0.973) and 0.882 (95% confidence interval = 0.807–0.956), respectively. For NAFLD rats, the diagnostic performance of ARFI elastography in predicting significant fibrosis (F ≥ 2) had an AUROC of 0.963. For evaluating steatosis severity, we found a progressive increase in ARFI velocity proportional to steatotic severity in NAFLD rat models, but we observed no significant differences for steatotic severity after excluding the rats with fibrosis. ARFI elastography may be used to differentiate among degrees of severity of NAFLD and hepatic fibrotic stages in NAFLD rat models.     

15d-PGJ2对非酒精性脂肪肝大鼠的保护作用

目的 探讨15-脱氧前列腺素J2(15 d-PGJ2)对非酒精性脂肪性肝病(NAFLD)大鼠的保护作用.方法 将50只雄性Wistar大鼠随机分为正常对照组(NC组)和模型组,分别给予普通饲料和高脂饲料喂养,12周末制成NAFLD大鼠模型;再将模型组随机分为4组:15 d-PGJ2低剂量治疗组(LT组),15 d-PGJ2高剂量治疗组(HT组),模型对照组(MC组),饮食疗法组(DT组).治疗2周后处死大鼠,观察各组大鼠的肝组织病理变化,检测血清丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)、碱性磷酸酶(ALP)、空腹血糖(GLU)、甘油三酯(TG)、总胆固醇(TC)的水平.结果 与MC组大鼠相比,LT组、HT组及DT组大鼠血清ALT、AST、ALP、GLU、TG、TC的水平降低,肝细胞脂肪变性及炎症浸润均有减轻,其中以LT组改变最明显(P<0.05).结论 适量的15d-PGJ2对NAFLD大鼠有明显的保护作用,可以改善大鼠的NAFLD.