交泰丸组分配伍改善小鼠胰岛素瘤B细胞脂质沉积的机制研究

目的：研究交泰丸中主要活性成分小檗碱（BBR）、肉桂酸（CA）及其配伍（BBR/CA）对软脂酸（PA）诱导的NIT-1胰岛B细胞内脂质沉积的影响。方法：将细胞在PA的培养基中培养24 h,建立高脂诱导的细胞内脂肪沉积模型。分为模型组、BBR组、CA组、BBR/CA组、二甲双胍（Met）组,分别给予相应药物干预,另设对照组。油红O染色法评估细胞内脂肪沉积情况;酶法检测细胞内三酰甘油（TG）含量;使用Western Blotting和实时荧光定量PCR（RT-PCR）法检测细胞腺苷酸活化蛋白激酶（AMPK）及其下游脂肪生成和脂肪酸氧化基因的表达水平,包括脂肪酸合成酶（FAS）、乙酰辅酶A羧化酶（ACC）、磷酸化乙酰辅酶A羧化酶（p-ACC）、肉碱酰转移酶-1（CPT-1）、固醇调节元件结合蛋白（SREBP-1c）。结果：PA诱导使NIT-1胰岛B细胞中脂肪沉积明显增加,TG含量显著升高,AMPK蛋白及其下游靶标（如p-ACC、CPT-1等）表达显著降低。同时,AMPK下游脂肪生成基因包括SREBP-1c mRNA、FAS和ACC蛋白表达显著增加。BBR单药和BBR/CA配伍处理优于CA单药,可显著逆转NIT-1胰岛B细胞中上述基因表达水平的变化。结论：在体外,交泰丸活性组分配伍可减少高脂诱导的NIT-1胰岛B细胞内脂肪沉积,其机制可能与减少脂肪合成和增加脂肪氧化有关。     

Hypolipogenic effects of Icariside E4 via phosphorylation of AMPK and inhibition of MID1IP1 in HepG2 cells

Though icariside E4 (IE4) is known to have anti-noceptive, anti-oxidant, anti-Alzheimer and anti-inflammatory effects, there was no evidence on the effect of IE4 on lipid metabolism so far. Hence, the hypolipogenic mechanism of IE4 was investigated in HepG2 hepatocellular carcinoma cells (HCCs) in association with MID1 Interacting Protein 1(MID1IP1) and AMPK signaling. Here, IE4 did not show any toxicity in HepG2 cells, but reduced lipid accumulation in HepG2 cells by Oil Red O staining. MID1IP1 depletion decreased the expression of SREBP-1c and fatty acid synthase (FASN) and induced phosphorylation of ACC in HepG2 cells. Indeed, IE4 activated phosphorylation of AMPK and ACC and inhibited the expression of MID1IP1 in HepG2 cells. Furthermore, IE4 suppressed the expression of SREBP-1c, liver X receptor-α (LXR), and FASN for de novo lipogenesis in HepG2 cells. Interestingly, AMPK inhibitor compound C reversed the ability of IE4 to reduce MID1IP1, SREBP-1c, and FASN and activate phosphorylation of AMPK/ACC in HepG2 cells, indicating the important role of AMPK/ACC signaling in IE4-induced hypolipogenic effect. Taken together, these findings suggest that IE4 has hypolipogenic potential in HepG2 cells via activation of AMPK and inhibition of MID1IP1 as a potent candidate for treatment of fatty liver disease.     

黄芪散有效部位群对胰岛素抵抗HepG2细胞SREBP-1c及其靶基因表达的影响

目的:观察黄芪散有效部位群(HQS)对胰岛素抵抗HepG2细胞固醇调控元件结合蛋白-1c(SREBP-1c)及其靶基因表达的影响,并探讨其可能的作用机制。方法:噻唑蓝(MTT)比色法检测HQS对细胞活性的影响,采用高糖高胰岛素诱导HepG2细胞建立胰岛素抵抗模型,造模同时予以不同浓度HQS进行干预,并以二甲双胍(MET)作为阳性药,另设空白组。采用荧光D-葡萄糖同系物2-脱氧-D-葡萄糖(2-NBDG)检测细胞糖摄取量,测定细胞内甘油三酯(TG),游离脂肪酸(FFA)含量,油红O染色法观察细胞脂质沉积情况,实时荧光定量聚合酶链式反应(Real-time PCR)检测细胞内SREBP-1c,乙酰辅酶A羧化酶1(ACC1),脂肪酸合成酶(FAS),硬脂酰辅酶A去饱和酶(SCD1)基因的表达。结果:依据MTT实验结果,选择25,50,100 mg·L-1分别作为HQS低、中、高质量浓度值(HQS-L,HQS-M,HQS-H),处理时间为24 h。与空白组比较,模型组细胞糖摄取显著减少(P0.01),细胞内TG,FFA含量显著升高(P0.01),胞浆内可见大量红色的小泡性脂滴,SREBP-1c,ACC1,FAS,SCD1 mRNA的表达显著上调(P0.01)。与模型组比较,不同质量浓度HQS均可显著升高细胞糖摄取量(P0.05,P0.01),HQS-H,HQS-M可显著降低细胞中TG,FFA含量(P0.01),减少细胞内脂滴数量,HQS-L亦可降低FFA含量(P0.05),此外,HQS-H可显著下调SREBP-1c,ACC1,FAS,SCD1 mRNA的表达(P0.05,P0.01),HQS-M亦可下调SREBP-1c,FAS,SCD1 mRNA的表达(P0.05),对ACC1 mRNA表达具有一定程度的抑制。结论:HQS可能通过抑制SREBP-1c的表达,减少脂质合成,改善HepG2细胞胰岛素抵抗。     

基于LKB1/AMPK/PGC-1α的泽泻汤改善非酒精性脂肪肝作用机制研究

以棕榈酸(palmitic acid,PA)诱导的脂质堆积细胞模型和高脂诱导的非酒精性脂肪肝(nonalcoholic fatty liver disease,NAFLD)动物模型,探讨泽泻汤(Zexie Decoction)体内外改善NAFLD的药效,以LKB1/AMPK/PGC-1α通路为切入点探讨其可能作用机制。MTT结果显示泽泻汤对HepG2细胞活力无影响,泽泻汤剂量依赖性下调PA诱导的肝细胞培养基谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate aminotransferase,AST)的水平,降低高脂饮食(high-fat diet,HFD)小鼠血浆ALT、AST及肝脏总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)水平。尼罗红染色观察PA诱导的细胞内脂质沉积,PA诱导的肝细胞脂质蓄积显著增加,体外细胞脂质堆积模型诱导成功,泽泻汤有效改善PA诱导的肝细胞脂质堆积;小鼠肝脏油红染色结果同样表明,泽泻汤剂量依赖性减少HFD小鼠肝脏脂质堆积。线粒体膜电位染色显示泽泻汤能够逆转PA诱导肝细胞损伤引起的线粒体膜电位的下降;同时泽泻汤激活PGC-1α上调其靶基因ACADS、CPT-1α、CPT-1β、UCP-1、ACSL-1、NRF-1等的表达;Western blot及免疫组化结果显示泽泻汤可体内外上调LKB1、p-AMPK、p-ACC、PGC-1α蛋白表达水平。综上所述,泽泻汤能够有效改善NAFLD,其机制可能与调控LKB1/AMPK/PGC-1α通路相关。     

Hypoglycemic and Hypolipidemic Effects of Lycium barbarum Polysaccharide in Diabetic Rats

Objective To study the antidiabetic effects and the underlying molecular mechanisms of Lycium barbarum polysaccharide(LBP) and its DEAE cellulose elution fraction LBP-IV in diabetic rats induced by high fat diet(HFD) and streptozotocin(STZ). Methods After ig administration of LBP-IV [50, 100, and 200 mg/(kg·d)] and LBP [100 mg/(kg·d)] once daily for consecutive 4 weeks to diabetic rats, the glucose and lipids in blood, m RNA expression of phosphoenolpyruvate carboxykinase(PEPCK), sterol regulatory element binding-protein-1c(SREBP-1c), and fatty acid synthase(FAS) in liver were determined. Results Ig administration of LBP and LBP-IV significantly decreased the levels of blood glucose, Hb A1 c, TC, TG, and LDL-C, as well as the hepatic m RNA expression of PEPCK, SREBP-1c, and FAS, whereas significantly increased the oral glucose tolerance of diabetic rats. Conclusion The findings suggest that the antidiabetic effects of LBP and LBP-IV are associated with the decreased hepatic m RNA expression of PEPCK, SREBP-1c, and FAS in HFD-STZ induced diabetic rats.     

6-姜烯酚通过抑制SCD1 表达改善db/db 小鼠肝脏脂肪变性的研究

目的探讨6-姜烯酚对db/db小鼠肝脏脂质代谢的影响及机制。方法将24只db/db小鼠随机分为模型组、6-姜烯酚低剂量组(10 mg·kg^-1)和6-姜烯酚高剂量组(40 mg·kg^-1),每组8只,雌雄各半;另取8只BKS小鼠(雌雄各半)作为正常对照组;灌胃给药,每日1次,连续21 d。采用酶法检测肝脏组织甘油三酯(TG)含量;采用油红O染色法检测肝脏组织脂质沉积情况;采用实时荧光定量聚合酶链式反应(qPCR)法检测碳水化合物反应元件结合蛋白(ChREBP)、固醇调节元件结合蛋白-1c(SREBP-1c)、脂肪酸合酶(FAS)、乙酰辅酶A羧化酶(ACC)、二酰基甘油酰基转移酶2(DGAT2)、硬脂酰辅酶A去饱和酶1(SCD1)、酰基辅酶A氧化酶(ACOX)及肉碱棕榈酰基转移酶1a(CPT1a)的mRNA表达;采用Western Blot法和免疫荧光染色法检测肝脏组织SCD1蛋白的表达情况。结果与正常对照组比较,模型组小鼠肝脏组织的TG含量和油红O染色面积以及SREBP-1c、ACC、FAS、DGAT2、SCD1 mRNA表达显著上调(P<0.05,P<0.01),ACOX、CPT1a mRNA表达显著下调(P<0.05)。与模型组比较,6-姜烯酚高剂量组的小鼠肝脏组织TG含量和油红O染色面积明显减少(P<0.01),SCD1在mRNA水平和蛋白水平的表达均显著下调(P<0.05,P<0.01),与免疫荧光染色法检测结果一致。结论6-姜烯酚能够改善db/db小鼠的肝脏脂质沉积,其机制可能与下调SCD1的表达有关。     

Thymoquinone attenuates hepatic lipid accumulation by inducing autophagy via AMPK/mTOR/ULK1-dependent pathway in nonalcoholic fatty liver disease

Thymoquinone (TQ) has been proved to exert wide-ranging pharmacological activities, with anti-inflammatory, antioxidant, anticonvulsant, antimicrobial, anti-tumor, and antidiabetic properties. In this study, we investigated the beneficial effects of TQ on a high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) in C57BL/6 N mice in vivo and free fatty acid (FFA)-induced human hepatocellular carcinoma HepG2 cells in vitro. Further, the underlying mechanisms of TQ to promote hepatic autophagy were also discovered. Data showed that TQ caused (p < 0.01) body weight reduction, improved glucose homeostasis, alleviated hepatosteatosis, and decreased hepatic lipid accumulation related to the induction of autophagy in HFD-fed mice. In vitro, TQ obviously increased (p < 0.01) autophagic flux in FFA-induced HepG2 cells and consequently reduced the lipid accumulation in combination with activation of AMPK/mTOR/ULK1 signaling pathways. Moreover, pharmacological inhibition of the AMPK pathway by addition with AMPK inhibitor Compound C (CC) or silence of ULK1 by transfection with siRNA(ULK1) into HepG2 cells reversed these beneficial effects of TQ on triggering hepatic autophagy and reducing lipid accumulation (p < 0.01). Taken together, these results suggested that TQ alleviated hepatic lipid accumulation by triggering autophagy through the AMPK/mTOR/ULK1-dependent signaling pathway. Our study supports a potential role for TQ in ameliorating NAFLD.     

高浓度绿原酸对非酒精性肝炎的干预作用及其机制研究

目的：本文通过油酸（oleic acid,OA）处理人肝癌细胞系HepG2体外模拟肝细胞非酒精性脂肪肝（non-alcoholic fatty liver disease ,NAFLD）的病理状态,研究了高浓度绿原酸（chlorogenic acid ,CGA）对NAFLD的干预作用,包括对肝细胞脂堆积、糖摄取和氧化应激的影响。 方法：用0.5 mmol/L OA处理HepG2 细胞24h建立体外非酒精性肝炎的模型。正常组和OA诱导组的细胞用CGA（0, 0.5, 1, and 2 mmol/L）处理24h后有油红O染色和生化分析试剂盒检测胞内的脂堆积情况、活性氧( reactive oxygen species, ROS)含量和糖摄取能力。我们还通过Western blot和RT-qPCR检测了脂合成相关指标（SREBP-1c和PNPLA3）和氧化应激相关蛋白（CYP2E1和CYP4A）的相对表达量。 结果： CGA组相对于OA诱导组其细胞内脂滴含量呈上升趋势,SREBP-1c和PNPLA3的mRNA和蛋白表达量呈上升趋势,CGA还可以促进HepG2对荧光葡萄糖的摄取,降低胞内ROS含量,下调CYP450酶2E1和4A的表达。 结论：本文的研究结果提示,高浓度CGA可以通过上调SREBP-1c和PNPLA3的mRNA和蛋白的表达促进脂合成进而导致细胞内脂滴含量增加;CGA还可以促进HepG2对荧光葡萄糖的摄取,下调CYP450酶2E1和4A的表达进而降低胞内ROS含量,减轻氧化损伤。     

消脂汤对非酒精性脂肪性肝病模型大鼠治疗的作用及机制

目的:观察消脂汤对非酒精性脂肪性肝病(NAFLD)模型大鼠的治疗作用,并探讨其机制。方法:62只雄性SPF级SD大鼠,随机分为造模组(51只)和正常组(11只)。采用高脂饮食法复制大鼠NAFLD模型,造模成功后随机均匀分为模型组、非诺贝特组(0.05 g·kg-1·d-1)、消脂汤高、中、低剂量组(42.5,21.5,10.6 g·kg-1·d-1)。消脂汤组和非诺贝特组灌喂相应药物,正常组和模型组灌喂等体积生理盐水。4周后处死动物,全自动生化仪检测空腹血糖(FBG)、总胆固醇(TG)、甘油三酯(TC)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、谷氨酰胺转肽酶(GGT)、丙二醛(MDA)、超氧化物歧化酶(SOD)、游离脂肪酸(FFA),放射免疫法检测胰岛素(INS),计算胰岛素抵抗指数(HOMAR-IR),HE染色观察肝脏病理变化。RT-PCR方法检测肝组织固醇调节元件结合蛋白(SREBP-1c)mRNA的表达水平;Western blot方法检测肝组织SREBP-1c的蛋白表达水平。结果:与正常组比较,模型组血脂,肝脂,FFA,FINS,HOMAR-IR,MDA,SREBP-1c mRNA及蛋白表达显著升高(P<0.05或P<0.01);SOD含量显著下降(P<0.01)。与模型组比较,各治疗组血脂,肝功,肝脂,FFA,FINS,HOMAR-IR,MDA,SREBP-1c mRNA及蛋白表达水平显著降低(P<0.05或P<0.01),以消脂汤高剂量组尤为显著(P<0.01);SOD含量显著升高(P<0.05或P<0.01)。结论:消脂汤能显著改善NAFLD的胰岛素抵抗和氧化应激,减轻肝脏脂肪蓄积和炎症反应,下调SREBP-1c mRNA和蛋白表达是其减轻肝脏脂肪蓄积的可能机制之一。     

Effects of Soothing Liver and Invigorating Spleen Recipe on Lipid Metabolism Disorders in Kupffer Cells of NAFLD Rats by LXRα/SREBP-1c Signal Pathway

Objective To investigate the mechanism of lipid metabolism disorders in Kupffer cells(KCs) of non-alcoholic fatty liver disease(NAFLD) rats mediated by LXRα-SREBP-1c pathway and the interference of soothing liver and invigorating spleen recipe(SLISR) on it. Methods SD male rats were randomly divided into five groups: normal, model,soothing liver recipe(SLR), invigorating spleen recipe(ISR), and soothing liver and invigorating spleen recipe(SLISR) groups. The rats in treatment groups wereadministered for 8 weeks. The liver tissue was stained with HE and oil red O. The levels of hepatic lipid and blood lipid were measured by biochemical analyzer. KCs were isolated from the livers of rats to evaluate the expression of LXRα, SREBP-1C, and FAS mRNA by real-time fluorescence quantitative PCR tests; LXRα, SREBP-1C, and FAS proteins were measured by Western blotting. Results The HE and oil red O staining results showed that the model rats successfully reproduced typical pathogenetic and histopathological features of NAFLD. The levels of hepatic lipid and blood lipid in the model rats were dramatically increased. Compared with the model group, the values of hepatic lipid and blood lipid in the treatment groups were significantly ameliorated(P 0.05, 0.01). The yields of purified KCs from each rat were 2×107-3×107. The viability ofKCs was higher than 95%, with the purity over 90.18%. Compared with the model group, the expression of LXRα, SREBP-1C, and FAS mRNA and proteins was decreased in all treatment groups, especially in the SLR group(P 0.05). Conclusion SLISR may protect liver against injury included by lipid metabolism disorders in KCs through LXRα/SREBP-1c signaling pathway, which may be an important mechanism for the preventionand treatment of NAFLD.     

Hypolipidemic activity and mechanisms of the total phenylpropanoid glycosides from Ligustrum robustum (Roxb.) Blume by AMPK‐SREBP‐1c pathway in hamsters fed a high‐fat diet

The aim of this study was to evaluate the hypolipidemic effect and mechanisms of total phenylpropanoid glycosides extracted from Ligustrum robustum (Roxb.) Blume (LRTPG) in hamsters fed a high‐fat diet and to discover bioactive components in HepG2 cell model induced by oleic acid. LRTPG of high (1.2 g/kg), medium (0.6 g/kg), and low (0.3 g/kg) doses was administrated daily for 21 consecutive days in hamsters. We found that in hamsters fed a high‐fat diet, LRTPG effectively reduced the concentrations of plasma triglycerides (TG), free fatty acid, total cholesterol, low‐density lipoprotein cholesterol, and hepatic TG and total cholesterol. And the compounds acteoside, ligupurpuroside A, ligupurpuroside C, and ligupurpuroside D significantly inhibited lipid accumulation in HepG2 cell at the concentration of 50 μmol/L. Mechanism research demonstrated that LRTPG increased the levels of phospho–AMP‐activated protein kinase and phospho‐sterol regulatory element binding protein‐1c in liver, further to suppress the downstream lipogenic genes as stearoyl‐CoA desaturase 1, glycerol‐3‐phosphate acyltransferase, 1‐acylglycerol‐3‐phosphate O‐acyltransferase 2, and diacylglycerol acyltransferase 2. In addition, LRTPG increased the hydrolysis of circulating TG by up‐regulating lipoprotein lipase activities. These results indicate that LRTPG prevents hyperlipidemia via activation of hepatic AMP‐activated protein kinase‐sterol regulatory element binding protein‐1c pathway.     

Hovenia Dulcis Extract Reduces Lipid Accumulation in Oleic Acid‐Induced Steatosis of Hep G2 Cells via Activation of AMPK and PPARα/CPT‐1 Pathway and in Acute Hyperlipidemia Mouse Model

Hovenia dulcis Thunb. (HDT) was known to have anti‐fatigue, anti‐diabetes, neuroprotective, and hepatoprotective effects. In the present study, the anti‐fatty liver mechanism of HDT was elucidated in oleic acid (OA)‐treated Hep G2 cells and acute hyperlipidemia mouse model using Triton WR‐1339. Here, HDT activated p‐AMP‐activated protein kinase (p‐AMPK), proliferator activated receptor‐α, carnitine palmitoyltransferase and also inhibited the expression of lipogenesis and cholesterol synthesis proteins, such as 3‐hydroxy‐3‐methylglutaryl‐CoA reductase, sterol regulatory element binding protein‐1c, SREBP‐2, and fatty acid synthase in OA‐treated Hep G2 cells. Conversely, AMPK inhibitor compound C blocked the anti‐fatty liver effect of HDT to induce AMPK phosphorylation and decrease 3‐hydroxy‐3‐methylglutaryl‐CoA reductase and lipid accumulation by oil red O staining in OA‐treated Hep G2 cells. Additionally, HDT pretreatment protected against the increase of serum total cholesterol, triglyceride, low‐density lipoprotein cholesterol and phospholipid in an acute hyperlipidemia mouse model with enhancement of glutathione reductase, glutathione peroxidase, superoxide dismutase, and catalase activities. Taken together, HDT inhibits OA‐induced hepatic lipid accumulation via activation of AMPK and proliferator activated receptor‐α/carnitine palmitoyltransferase signaling and enhancement of antioxidant activity as a potent candidate for nonalcoholic fatty liver disease and hyperlipidemia. Copyright © 2016 John Wiley & Sons, Ltd.     

柴芪汤对非酒精性脂肪肝大鼠固醇调节元件结合蛋白-1c表达的影响

目的:观察柴芪汤对非酒精性脂肪性肝病(NAFLD)大鼠肝脏固醇调节元件结合蛋白-1c(SREBP-1c)m RNA及蛋白表达的影响,探讨其防治NAFLD的可能机制。方法:将32只SPF级雄性SD大鼠随机分为正常组、模型组、柴芪汤组和罗格列酮组,每组8只,采用高脂高糖高盐饮食喂养8周复制NAFLD模型,造模第一天开始用药,给予柴芪汤[5.67g/(kg·d)]及罗格列酮混悬液[3 mg/(kg·d)]灌胃干预,8周后检测大鼠血清丙氨酸氨基转移酶(ALT)、天冬氨酸转氨酶(AST)、甘油三酯(TG)、胆固醇(TC)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)及肝组织中TG含量;观察肝组织病理形态改变;Western Blot测定肝SREBP-1c蛋白表达;RT-PCR测定肝SREBP-1c m RNA表达。结果:模型组大鼠血清ALT、AST、TC、TG、HDL-C、LDL-C水平及肝组织中TG含量明显高于正常组(P0.05),2用药组各项指标低于模型组,差异有统计学意义(P0.05);但2组间比较,差异无统计学意义(P0.05)。2用药组SREBP-1c m RNA及蛋白表达水平较模型组降低,差异具有统计学意义(P0.05),但2用药组比较差异无统计学意义(P0.05)。结论:柴芪汤能够改善NAFLD大鼠肝脏脂肪变,其干预效果与西药罗格列酮相似,抑制SREBP-1c m RNA和蛋白表达,从而降低NAFLD大鼠血清ALT、AST、TG、TC、HLD-C、LDL-C,这可能是柴芪汤治疗NAFLD的机制之一。     

Cassiae Semen improves non-alcoholic fatty liver disease through autophagy-related pathway

Objective Cassiae Semen (CS, Juemingzi in Chinese) has been used for thousands of years in ancient Chinese history for relieving constipation, improving liver function as well as preventing myopia. Here we aimed to elucidate the anti-steatosis effect and underlying mechanism of CS against non-alcoholic fatty liver disease (NAFLD). Methods High-performance liquid chromatography (HPLC) was used to identify the major components of CS water extract. Mice were fed with a high-fat and sugar-water (HFSW) diet to induce hepatic steatosis and then treated with CS. The anti-NAFLD effect was determined by measuring serum biomarkers and histopathology staining. Additionally, the effects of CS on cell viability and lipid metabolism in oleic acid and palmitic acid (OAPA)-treated HepG2 cells were measured. The expression of essential genes and proteins involved in lipid metabolism and autophagy signalings were measured to uncover the underlying mechanism. Results Five compounds, including aurantio-obtusin, rubrofusarin gentiobioside, cassiaside C, emodin and rhein were simultaneously identified in CS extract. CS not only improved the diet-induced hepatic steatosis in vivo, as indicated by decreased number and size of lipid droplets, hepatic and serum triglycerides (TG) levels, but also markedly attenuated the OAPA-induced lipid accumulation in hepatocytes. These lipid-lowering effects induced by CS were largely dependent on the inhibition of fatty acid synthase (FASN) and the activation of autophagy-related signaling, including AMP-activated protein kinase (AMPK), light chain 3-II (LC3-II)/ LC3-1 and autophagy-related gene5 (ATG5). Conclusion Our study suggested that CS effectively protected liver steatosis via decreasing FASN-related fatty acid synthesis and activating AMPK-mediated autophagy, which might become a promising therapeutic strategy for relieving NAFLD.     

岩藻黄质对高脂饮食诱导的肥胖小鼠胰岛素抵抗的影响

研究岩藻黄质对高脂饮食诱导的肥胖小鼠胰岛素抵抗的作用及其分子机制。将50只C57BL/6J雄性小鼠随机分为正常组(10只)、高脂组(40只),高脂组经高脂饲料喂养12周形成肥胖胰岛素抵抗模型,将其随机分为模型组、岩藻黄质0.2%剂量组、岩藻黄质0.4%剂量组和二甲双胍组,每组10只,连续喂养含有相应药物饲料6周后,测定各组小鼠体质量和附睾脂肪质量;检测血清中空腹血糖(FBG)、空腹胰岛素(FINS)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDLC)、高密度脂蛋白胆固醇(HDL-C)含量,并计算胰岛素抵抗指数(HOMA-IR);HE染色法观察各组小鼠肝脏病理变化;Western blot法检测肝脏组织中胰岛素受体底物1(IRS-1)/磷酸肌醇-3-激酶(PI3K)/苏氨酸蛋白激酶(Akt)和过氧化物酶体增殖剂激活受体-γ(PPARγ)/胆固醇调节元件结合蛋白-1(SREBP-1)/脂肪酸合成酶(FAS)通路相关蛋白的表达。结果显示,与模型组相比,各给药组小鼠的体质量、附睾脂肪质量以及FBG,FINS,TC,TG,LDL-C,HOMA-IR水平,肝组织中PPARγ,SREBP-1和FAS蛋白表达显著降低(P<0.05或P<0.01),同时HDL-C水平及肝组织中p-IRS-1,IRS-1,PI3K,p-Akt的蛋白表达显著升高(P<0.05或P<0.01),且肝组织病理形态明显改善。结果表明,岩藻黄质可明显减轻肥胖小鼠的肥胖及糖脂紊乱,并改善胰岛素抵抗,其作用可能与调控IRS-1/PI3K/Akt和PPARγ/SREBP-1/FAS通路有关。     

痰湿证大鼠模型肝脏脂质合成基因的表达

目的 观察高脂喂养制作的痰湿证大鼠模型肝脏脂质合成相关基因的表达.方法 根据"肥白人多痰湿"的理论,采用高脂饮食喂养法建它痰湿证大鼠模型,采用肝脏HE染色观察模型大鼠肝脏的病理改变,检测血清和肝脏的三酰甘油(TG)和游离脂肪酸(FFA)水平,采用荧光实时定量PCR技术检测肝脏X受体α[(LXRα)、固醇调节元件结合蛋白-1c(SREBP-1c)、脂肪酸合酶(FAS)等与脂质合成相关的基因表达.结果 模型大鼠肝脏出现大量含有脂滴的空泡,血清、肝脏脂质含量与正常组相比显著增高,LXR的表达无显著变化,SREBP-1c和FAS的表达增高.结论 模型大鼠肝脏的脂肪沉积,与脂质合成基因的表达增强有关.     

益气养阴方对2型糖尿病大鼠脂代谢的影响

目的:观察药食同源益气养阴方对高脂饲料联合链脲佐菌素(STZ)腹腔注射建立的2型糖尿病(T2DM)大鼠模型脂代谢的影响,探讨其在调控脂代谢方面的作用机制。方法:高脂饲料喂养大鼠4周,腹腔注射STZ制备T2DM大鼠模型。糖尿病大鼠随机分为模型组、益气养阴高、中、低剂量组(9.00,4.50,2.25 g·kg^-1)和二甲双胍组(0.20 g·kg^-1),另设正常组。益气养阴方高、中、低剂量组分别给予口服不同剂量的益气养阴方颗粒,二甲双胍组给予二甲双胍,模型组、正常组均给予同体积生理盐水干预。连续灌胃3周,测定体质量、血糖,全自动生化分析仪检测甘油三酯(TG),总胆固醇(TC),低密度脂蛋白胆固醇(LDL-C),高密度脂蛋白胆固醇(HDL-C),天门冬氨酸氨基转移酶(AST),丙氨酸氨基转移酶(ALT),碱性磷酸酶(ALP),总蛋白(TP)的含量;苏木素-伊红(HE)染色观察各组肝脏组织病理变化情况;PAS染色观察肝脏组织肝糖原病理变化情况;油红O染色观察肝脏组织脂质变化情况;蛋白免疫印迹法(Western blot)观察肝脏组织腺苷酸活化蛋白激酶(AMPK)/固醇调节元件结合蛋白1c(SREBP-1c)/乙酰辅酶A羧化酶1(ACC1)/过氧化物酶体增殖激活受体α(PPARα)通路蛋白表达情况。结果:与正常组比较,模型组TG,TC,LDL-C,AST,ALT,ALP含量明显升高,HDL-C含量明显降低(P<0.05,P<0.01),与模型组比较,益气养阴方各组可显著降低大鼠血清中TG,LDL-C含量(P<0.05,P<0.01),显著增加HDL-C含量(P<0.05);组织形态学检测显示,益气养阴方对肝脏中肝细胞胞间空泡、脂肪变性程度显著减轻,肝脏组织脂质区域显著缩小;与正常组比较,模型组肝脏组织中p-AMPKα,PPARα,SREBP-1(浆)蛋白表达显著降低,p-ACC1,SREBP-1(核)蛋白表达显著升高(P<0.01);与模型组比较,益气养阴方对肝脏组织中p-AMPKα,PPARα,SREBP-1(浆)蛋白表达显著升高(P<0.05,P<0.01),p-ACC1,SREBP-1(核)蛋白表达显著降低(P<0.05,P<0.01)。结论:益气养阴方对高脂饲料联合STZ引起的T2DM大鼠血脂升高具有明显的降低作用;T2DM大鼠血脂的降低可能与影响大鼠肝脏AMPK/ACC1/SREBP-1/PPARα通路有关。     

雷公藤红素对非酒精性脂肪肝L02细胞内质网应激的影响及机制

目的:通过雷公藤红素干预非酒精性脂肪肝L02细胞模型来探讨雷公藤红素调节肝L02细胞脂质代谢紊乱及非酒精性脂肪肝L02细胞内质网应激的相关机制。方法:将肝L02细胞分为空白组,模型组,雷公藤红素低剂量组(0. 5 mg·L~(-1)),雷公藤红素高剂量组(1 mg·L~(-1))和辛伐他汀组(SIM,6 mg·L~(-1))进行培养。检测肝L02细胞内胆固醇(TC)和甘油三酯(TG)含量变化;用油红O染色观察肝L02细胞脂质沉积情况;逆转录聚合酶链式反应(RT-PCR)和蛋白免疫印迹法(Western blot)分别检测各组肝L02细胞中内质网应激(ERS)相关信号分子活化转录因子6(ATF6),葡萄糖调节蛋白78(GRP78),肌醇需求酶1(IRE1),固醇调节元件结合蛋白裂解激活蛋白(SCAP),固醇调节元件结合蛋白1c(SREBP-1c)和固醇调节元件结合蛋白-2(SREBP-2)的mRNA转录以及蛋白表达水平。结果:非酒精性脂肪肝病(NAFLD)组肝L02细胞中TC及TG含量均高于空白组(P 0. 05),雷公藤红素低、高剂量组及SIM 6 mg·L~(-1)组肝L02细胞中TC及TG含量较NAFLD组均有不同程度减少(P 0. 05)。油红O染色显示NAFLD组肝L02细胞内含有大量红染脂质颗粒沉积,而雷公藤红素低、高剂量组及SIM 6 mg·L~(-1)组红染脂质颗粒较NAFLD组均有不同程度减少。RT-PCR和Western blot结果显示,NAFLD组肝L02细胞内ERS相关信号分子ATF6,GRP78,IRE1,SCAP,SREBP-1c和SREBP-2的mRNA转录和蛋白表达水平均高于空白组(P 0. 05);雷公藤红素低、高剂量组和SIM 6 mg·L~(-1)组肝L02细胞内ATF6,GRP78,IRE1,SCAP,SREBP-1c和SREBP-2的mRNA转录及蛋白表达水平均低于NAFLD组(P 0. 05)。而雷公藤红素高剂量组与SIM 6 mg·L~(-1)组间肝L02细胞内ATF6,GRP78,IRE1,SCAP,SREBP-1c和SREBP-2 mRNA转录及蛋白表达水平差异不具有统计学意义。结论:雷公藤红素可通过下调肝L02细胞ERS时相关信号分子ATF6,GRP78,IRE1,SCAP,SREBP-1c和SREBP-2的表达来减轻肝L02细胞脂质代谢紊乱,从而改善NAFLD。