Effect and Mechanism of Dicliptera chinensis Polysaccharide on miR-141/AMPK/SIRT1 Signaling Pathway in Rats with NAFLD

[Objectives]Non-alcoholic fatty liver disease(NAFLD)rat model was established by feeding high-fat and high-sugar fodder to rats,and the protective effect of Dicliptera chinensis polysaccharide(DCP)on NAFLD rats was studied to explore its potential mechanism.[Methods]45 SD rats were randomly divided into 4 groups:normal control group,model control group and DCP treatment groups(100 and 300 mg/kg).The rats in the normal control group were fed with ordinary fodder,and the rats in other groups were fed with high-fat and high-sugar diet for 14 weeks to establish NAFLD model.From the 9^(th)week,the rats in the DCP treatment groups were given different doses of DCP by intragastric administration(5 mL/kg)for 6 weeks.After the last intragastric administration,the rats fasted for 16 h,and the serum and liver of rats were collected for detection.Hematoxylin-eosin(HE)staining was conducted to observe the histopathological changes of rat liver,and alanine aminotransferase(ALT),aspartate aminotransferase(AST),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),malondialdehyde(MDA),triglyceride(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C),and high density lipoprotein cholesterol(HDL-C)were detected by biochemical method.Interleukin-6(IL-6),interleukin-1β(IL-1β),tumor necrosis factor(TNF-α)and micrornA-141(micro RNA-141)were detected by reverse transcription-polymerase chain reaction(RT-PCR).The expression of SIRT1 and adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)in rat liver was detected by western blot.[Results]Compared with the model control group,the inflammatory damage and steatodegeneration of rats in the DCP groups were relieved to varying degrees,and the number of lipid vacuoles significantly reduced.The ALT,AST,TC,TG and LDL-C content in the serum and MDA content in the liver tissue decreased to varying degrees,while the HDL-C,SOD and GSH-Px content increased.The expression of SIRT1 and AMPK increased,while the expression of miR-141,TNF-α,IL-6 and IL-1βdeclined,and the DCP 300 mg/kg treatment group had better improvement effect.[Conclusions]DCP had a certain protective effect on NAFLD rats,which may be related to the regulation of miR-141/AMPK/SIRT1 signaling pathway.

二陈汤对肥胖小鼠肝脏脂代谢及AMPK/ACC/SREBP1信号通路作用机制研究

目的:观察二陈汤对肥胖小鼠肝组织AMPK/ACC/SREBP1信号通路的作用,并探讨其改善肝脏脂质代谢及炎性病变的作用机制。方法:将小鼠随机分为空白(Control)组、模型(Model)组、奥利司他(Orlistat)组和二陈汤(ECD)组。除Control组外,其他各组小鼠通过高脂饲料建立肥胖模型。Orlistat组和ECD组小鼠分别给予奥利司他胶囊和二陈汤,Control组和Model组小鼠给予等体积的生理盐水。计算小鼠体重、肝脏湿重和肝体比值;检测小鼠血清ALT、AST、TC、TG、LDL-C、HDL-C水平;HE染色和油红O染色分别用于观察肝组织病理形态及肝组织脂滴的变化;ELISA检测肝组织中IL-1β、IL-6、IL-8、TNF-α水平;Western bolt检测肝组织中AMPK、ACC、SREBP1及其磷酸化的蛋白表达水平。结果:与Model组比较,Orlistat组和ECD组小鼠体重、肝脏湿重及肝体比值都有所降低(P<0.01,P<0.05),且肝组织病理结构和脂滴沉积得到明显改善。与Control组比较,Model组小鼠血清ALT、AST、TC、TG、LDL-C水平升高(P<0.01),而HDL-C水平下降(P<0.01)。与Model组比较,Orlistat组和ECD组小鼠血清ALT、AST、TC、TG、LDL-C水平下降(P<0.01,P<0.05),而HDL-C水平升高(P<0.01,P<0.05)。与Control组比较,Model组小鼠肝组织中p-AMPKα/AMPKα、p-ACC/ACC的表达水平显著降低(P<0.01),而IL-1β、IL-6、IL-8、TNF-α、SREBP1的表达水平显著升高(P<0.01)。与Model组比较,Orlistat组和ECD组小鼠肝组织中p-AMPKα/AMPKα、p-ACC/ACC表达水平升高(P<0.01,P<0.05),而IL-1β、IL-6、IL-8、TNF-α、SREBP1表达水平降低(P<0.01,P<0.05)。结论:二陈汤可通过调节AMPK/ACC/SREBP1信号通路改善肥胖小鼠肝脏脂代谢紊乱。

Puerarin protects rat brain against ischemia/reperfusion injury by suppressing autophagy via the AMPK-mT OR-ULK1 signaling pathway

Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-m TOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, m TOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin（50 or 100 mg/kg） reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and p S317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-m TOR and p S757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-m TOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury.

丹红注射液对高脂血症大鼠肝脏AMPK/SREBP-1/ACC通路的影响

目的探讨丹红注射液(Danhong injection,DHI)对大鼠高脂血症的作用及机制。方法采用高脂饲料制备大鼠高脂血症模型,检测各组大鼠肝脏腺苷酸激活蛋白激酶(AMPK)、p-AMPK、胆固醇调节元件结合蛋白(SREBP-1)、乙酰辅酶A羧化酶(ACC)、p-ACC的蛋白表达水平。结果给予丹红注射液后,肝脏AMPK、SREBP-1和ACC的蛋白表达水平明显降低(P<0.05),p-ACC和p-AMPK的蛋白表达水平明显升高(P<0.05)。结论丹红注射液通过增强AMPK的活化,抑制SREBP-1和ACC的活性,促进脂肪酸氧化,减少脂质沉积,有效降低了高脂血症大鼠的血脂水平。

Yiqi Yangyin and Huatan Quyu granule can improve skeletal muscle energy metabolism in a type 2 diabetic rat model by promoting the AMPK/SIRT/PGC-1α signalling pathway

Objective:To investigate how Yiqi Yangyin and Huatan Quyu granule (YYHO) improves skeletal muscle insulin resistance in a type 2 diabetic rat model and to discover whether the molecular mechanism is related to the promotion of the AMPK/SIRT/PGC-1α signalling pathway.Methods:Rats were randomly divided into 4 groups:the normal group,the model group,the YYHQ granule group,and the pioglitazone group.The type 2 diabetic rat model was established by feeding a high-fat diet for 5 weeks along with a single intraperitoneal injection of 30 mg/kg streptozotocin (STZ).After modelling successfully,the appropriate drug was intragastrically administered to diabetic rats for 2 weeks,once per day.The YYHQ granule group was given a dose of 4.8 g/kg body weight per day,the pioglitazone group was given a dose of 1.35 mg/kg body weight per day.The doses for both groups were equivalent to the clinical equivalent dose based on a previous study.Other groups were gavaged with the same amount of saline water.Body weight,food intake,water intake,urine volume and grip strength were recorded weekly.The fasting blood glucose(FBG) was determined weekly using blood glucose test strips.The related glucose and lipid metabolism indexes,e.g.,fasting insulin (Fins),glycated haemoglobin (GHb),HOMA-IR,ISI,triglycerides (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C) and free fatty acid (FFA),were determined using biochemical method.The mRNA expression levels of adenosine monophosphate-activated protein kinase (AMPK),peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α),carnitine palmitoyl transterase-1 (CPT-1),Sirtuin 1 (SIRT1),and Sirtuin 3 (SIRT3) were assessed using quantitative real-time PCR (qRT-PCR).The protein expression levels of creatine kinase (CK),Ca2+ ATPase,α-Actin,AMPK,PGC-1α and CPT-1 were determined using enzyme-linked immunosorbent assay method (ELISA).Results:Body weight decreased significantly (P <.01),food intake,water intake and urine volume increased significantly (P <.01),and grip strength decreased significantly (P <.01) in the model group compared with the normal group.The levels of FBG,Fins,GHb and HOMA-IR increased significantly (P <.01),and the ISI decreased significantly (P <.01) in the model group.The levels of TG,TC,LDL-C and FFA increased significantly (P <.05 or P <.01),and the level of HDL-C decreased significantly (P <.05) in the model group.These changes were reversed after treatment with YYHQ granule or pioglitazone.Compared with the model group,the YYHQ granule and pioglitazone groups significantly improve body weight,water intake and urine volume (P <.05 or P <.01),however,both treatments had no significant effect on food intake (P >.05).The levels of FBG,Fins,GHb,HOMA-IR and ISI were improved significantly (P <.01) and the levels of TG,TC and LDL-C were improved significantly (P <.05 or P <.01),however,both treatments had no significant effect on the levels of HDL-C and FFA (P >.05).Further results indicated that YYHQ granule significantly decreased the mRNA expression of AMPK,PGC-1α,CPT-1,SIRT1 and SIRT3 in skeletal muscle (P <.01) and the pioglitazone group showed similar effects;moreover,the protein expression levels of CK,Ca2+ATPase,α-Actin,AMPK,PGC-1α and CPT-1 in skeletal muscle significantly decreased (P <.01),however,pioglitazone had no significant effect on CK and α-Actin (P >.05).Conclusion:The possible molecular mechanism of YYHQ granule improving skeletal muscle insulin resistance in a type 2 diabetic rat model may be related to the stimulation of energy metabolism in skeletal muscle via the AMPK/SIRT/PGC-1α signalling pathway.

电针对肥胖大鼠骨骼肌AMPK/ACC/CPT-1信号通路的影响

目的观察电针对肥胖大鼠骨骼肌腺苷酸活化蛋白激酶(AMPK)信号通路的影响,探讨电针治疗肥胖的机制。方法30只刚断乳(3周龄)的SPF级SD雄性大鼠,随机挑选6只普通饲料喂养并设为正常组,另24只高脂饲料喂养造模12周,将造模成功的12只随机分为模型组和电针组。测定各组大鼠体质量、脂肪质量、血脂等相关指标,qPCR检测各组大鼠骨骼肌中AMPKα1、乙酰辅酶A羧化酶(ACC)、肉毒碱棕榈酰转移酶1(CPT-1)的mRNA表达变化,Western blot法检测骨骼肌AMPK、ACC磷酸化水平和CPT-1蛋白水平。结果与正常组比较,模型组体质量显著升高(P<0.01),显示肥胖大鼠造模成功。与模型组相比,电针组大鼠的体质量、内脏脂肪质量和血脂均显著降低(P<0.05~0.01);骨骼肌AMPKα1、ACC、CPT-1 mRNA的表达量显著上升(P<0.05~0.01)。电针使AMPK磷酸化水平显著提高(P<0.01),激活AMPK的活性;ACC磷酸化水平显著提高,抑制ACC活性;同时提高CPT-1蛋白水平。结论电针可以降低肥胖大鼠的体质量并改善其脂肪代谢的紊乱,其机制可能通过调节骨骼肌组织AMPK/ACC/CPT-1信号通路实现的。

萆薢总皂苷调控AMPK/SREBP-1c/ACC信号通路改善小鼠非酒精性脂肪性肝炎

目的:研究萆薢总皂苷(TSD)改善小鼠非酒精性脂肪性肝炎(NASH)的作用及机制。方法:将48只C57BL/6J小鼠随机分为正常组和造模组,采用高脂高胆固醇饲料+20%果糖水喂养16周,将造模组小鼠随机分为模型组、阿托伐他汀组(4 mg·kg^(-1)·d^(-1))、TSD高、中、低剂量组(200、60、20 mg·kg^(-1)·d^(-1)),灌胃给药,连续8周。测定小鼠活动度、肝脏系数、肝脏总胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)及血清TC、TG、天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)、γ-谷氨酰转移酶(GGT)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)水平;苏木素-伊红(HE)染色、Masson染色、油红O染色和透射电子显微镜观察肝组织和肝细胞病理变化、脂质蓄积情况和肝脏超微结构形态学变化;蛋白免疫印迹法(Western blot)检测肝脏组织AMP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(ACC)及其磷酸化形式的蛋白表达。结果:与正常组比较,模型组小鼠活动度明显降低(P<0.05,P<0.01),小鼠肝脏TC、TG、FFA和血清TC、TG、ALT、AST、GGT、IL-1β、TNF-α水平、肝脏系数、肝脏病理评分均明显升高,肝脏组织p-AMPK/AMPK、p-ACC蛋白表达明显降低,SREBP-1c、ACC蛋白表达明显升高(P<0.05,P<0.01)。与模型组比较,阿托伐他汀组小鼠活动度明显增加(P<0.05),TSD各剂量组小鼠活动度无明显改变;TSD及阿托伐他汀组小鼠肝脏TC、TG、FFA和血清TC、TG、ALT、AST、GGT、IL-1β、TNF-α水平、肝脏系数、肝脏病理评分均明显降低,肝脏组织p-AMPK/AMPK、p-ACC蛋白表达明显升高,SREBP-1c、ACC蛋白表达明显降低(P<0.05,P<0.01)。结论:TSD可能通过调控AMPK/SREBP-1c/ACC信号通路减少脂质合成,从而改善小鼠NASH。

黄芪总皂苷配伍荷叶总生物碱对高脂血症大鼠肝脏AMPK/SREBP-1c/ACC通路的影响

目的 探讨黄芪总皂苷配伍荷叶总生物碱对高脂血症大鼠的防治作用及机制。方法 将60只SD雄性大鼠随机分为正常组、模型组、阳性药(辛伐他汀,2.1 mg·kg^(-1))组和黄芪总皂苷+荷叶总生物碱低(17+40 mg·kg^(-1))、中(34+80 mg·kg^(-1))、高(68+160 mg·kg^(-1))剂量组;采用高脂饲料喂养复制高脂血症大鼠模型,同时给予药物灌胃治疗,每日1次,连续4周。检测大鼠血清总胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)、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)水平;采用HE染色法观察肝脏组织病理形态学变化;qRT-PCR法检测肝组织中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(ACC)、肉碱棕榈酰转移酶1(CPT-1)m RNA表达情况;免疫荧光法检测肝组织中p-AMPK、SREBP-1c、ACC、CPT-1蛋白表达情况;Western Blot法检测肝组织中AMPK、p-AMPK、SREBP-1c、ACC、p-ACC、CPT-1蛋白表达情况。结果 与正常组比较,模型组大鼠血清TG、TC、FFA、LDL-C、AST、ALT水平显著升高(P<0.01),HDL-C水平显著下降(P<0.01);大鼠肝细胞内有大量的脂滴聚集,胞浆疏松,出现了大量脂滴空泡和气球样变,细胞核偏移;大鼠肝组织AMPK、CPT-1 mRNA表达显著下调(P<0.01),ACC、SREBP-1c mRNA表达显著上调(P<0.01);大鼠肝脏中p-AMPK、CPT-1蛋白阳性表达明显减少(P<0.05,P<0.01),SREBP-1c、ACC蛋白阳性表达显著增加(P<0.01);大鼠肝组织中AMPK蛋白表达未见明显变化(P>0.05),p-AMPK、p-ACC、CPT-1蛋白表达水平明显下降(P<0.01),SREBP-1c、ACC蛋白表达水平显著升高(P<0.01)。与模型组比较,各给药组大鼠血清TG、TC、FFA、LDL-C、AST、ALT水平明显下降(P<0.05,P<0.01),HDL-C水平明显升高(P<0.01);大鼠肝细胞内的脂肪沉积均有明显减轻,仅见少量的脂滴空泡;大鼠肝组织AMPK、CPT-1mRNA的表达明显上调(P<0.05,P<0.01),SREBP-1c、ACC mRNA表达明显下调(P<0.05,P<0.01);大鼠肝脏中p-AMPK、CPT-1蛋白阳性表达明显增加(P<0.05,P<0.01),SREBP-1c、ACC蛋白阳性表达显著减少(P<0.01);大鼠肝组织中AMPK蛋白表达未见明显变化(P>0.05),p-AMPK、p-ACC、CPT-1蛋白表达水平均明显升高(P<0.05,P<0.01),SREBP-1c、ACC蛋白表达水平显著降低(P<0.01)。结论 黄芪总皂苷配伍荷叶总生物碱可能通过调节AMPK/SREBP-1c/ACC信号通路,抑制脂肪合成,促进脂肪酸氧化分解来防治高脂血症。

BZL方对游离脂肪酸诱导HepG2细胞脂肪沉积和LKB1-AMPK-ACC信号传导通路的影响

目的:研究"祛湿化瘀方"中3种已被认知的、能被分离提取的有效组分(白术多糖、栀子苷、绿原酸)组成的BZL复方对体外肝脂毒性模型脂肪沉积和LKB1-AMPK-ACC信号传导通路的影响,以进一步探讨BZL方防治脂肪肝的作用机制。方法:建立游离脂肪酸诱导的HepG2细胞脂肪变性模型,设正常组、模型组和不同浓度药物血清组分别观察细胞上清液中的细胞内甘油三酯(TG)含量,细胞油红O染色,细胞的P-LKB1、P-AMPKα、P-ACC蛋白表达及LKB1、AMPKα、ACC基因表达。结果:FFA刺激24h后,模型组细胞内脂肪沉积明显,其TG含量明显高于正常组(P<0.01),细胞内P-LKB1、P-AMPK、P-ACC的蛋白表达均减弱,LKB1、AMPK、ACC的mRNA表达均明显减弱,而BZL方高剂量组细胞内TG含量显著低于模型组(P<0.01),其脂肪沉积与模型组相比也明显减轻;与模型组比较,BZL药物血清组细胞内P-LKB1、P-AMPKα、P-ACC的蛋白表达均明显增强(P<0.05,P<0.01),LKB1、AMPKα、ACC的mRNA表达也均明显增强(P<0.05,P<0.01)。结论:BZL方对FFA诱导的HepG2细胞脂肪沉积有显著的抑制作用,且呈剂量依赖关系,激活LKB1-AMPK-ACC信号传导通路可能是BZL方防治非酒精性脂肪性肝病的重要作用机制之一。

金黄地鼠高脂血症模型甘油三酯代谢紊乱的生物标志物的研究

目的建立金黄地鼠高脂血症模型,并研究甘油三酯代谢紊乱的分子机制。方法金黄地鼠随机分为正常组和模型组,正常组饲常规饲料,模型组饲高脂饲料,连续诱导4周。于第2、4周检测血清TG、TC、LDL-C、FFA水平和LPL活性,应用荧光实时定量PCR技术探讨甘油三酯代谢紊乱的分子机制。同时观察阳性药非诺贝特对金黄地鼠高脂血症模型血脂的影响。结果金黄地鼠造模2周时,血清TG、TC、LDL-C、FFA与对照组比较分别升高2.57、1.93、2.49和1.25倍;造模4周时分别升高3.93、1.90、2.27和2.29倍。阳性药对TG和FFA升高有明显的抑制作用。机制研究表明,金黄地鼠造模后,肝脏AMPK、PPARα、CPT-1 mRNA表达降低,SREBP-1c、ACC、SCD-1、AGPAT2、DGAT2 mRNA表达上调。ApoB表达有上调趋势,MTTP和LPL表达有下调趋势,血浆LPL活性明显降低。这些酶、蛋白、受体的表达变化是金黄地鼠甘油三酯代谢紊乱的主要原因。结论金黄地鼠经高脂饲料诱导4周后形成了具有高甘油三酯血症特征的高脂血症模型,AMPK、SREBP-1c、ACC、SCD1、DGAT2、AGPAT2、PPARα、CPT-1、LPL既是金黄地鼠甘油三酯代谢紊乱的生物标志物,也是降甘油三酯药物的作用靶标。

Novel nervous and multi-system regenerative therapeutic strategies for diabetes mellitus with mTOR

Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin（m TOR） is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1（m TORC1） and m TOR Complex 2（m TORC2） and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase（PI 3-K）,protein kinase B（Akt）,AMP activated protein kinase（AMPK）,silent mating type information regulation 2 homolog 1（Saccharomyces cerevisiae）（SIRT1）,Wnt1 inducible signaling pathway protein 1（WISP1）,and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.