Electroacupuncture preconditioning attenuates ischemic brain injury by activation of the adenosine monophosphate-activated protein kinase signaling pathway

Electroacupuncture has therapeutic effects on ischemic brain injury, but its mechanism is still poorly understood. In this study, mice were stimulated by electroacupuncture at the Baihui（GV20） acupoint for 30 minutes at 1 m A and 2/15 Hz for 5 consecutive days. A cerebral ischemia model was established by ligating the bilateral common carotid artery for 15 minutes. At 72 hours after injury, neuronal injury in the mouse hippocampus had lessened, and the number of terminal deoxynucleotide transferase-mediated d UTP nick-end labeling-positive cells reduced after electroacupuncture treatment. Moreover, expression of adenosine monophosphate-activated protein kinase α（AMPKα） and phosphorylated AMPKα was up-regulated. Intraperitoneal injection of the AMPK antagonist, compound C, suppressed this phenomenon. Our findings suggest that electroacupuncture preconditioning alleviates ischemic brain injury via AMPK activation.

Metformin attenuates motility,contraction,and fibrogenic response of hepatic stellate cells in vivo and in vitro by activating AMP-activated protein kinase

AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.

Amino acids regulate energy utilization through mammalian target of rapamycin complex 1 and adenosine monophosphate activated protein kinase pathway in porcine enterocytes

As major fuels for the small intestinal mucosa,dietary amino acids(AA)are catabolized in the mitochondria and serve as sources of energy production.The present study was conducted to investigate AA metabolism that supply cell energy and the underlying signaling pathways in porcine enterocytes.Intestinal porcine epithelial cells(IPEC-J2)were treated with different concentrations of AA,inhibitor,or agonist of mammalian target of rapamycin complex 1(mTORCl)and adenosine monophosphate activated protein kinase(AMPK),and mitochondrial respiration was monitored.The results showed that AA treatments resulted in enhanced mitochondrial respiration,increased intracellular content of pyruvic acid and lactic acid,and increased hormone-sensitive lipase mRNA expression.Meanwhile,decreased citrate synthase,isocitrate dehydrogenase alpha,and carnitine palmitoyltransferase 1 mRNA expression were also observed.We found that AA treatments increased the protein levels of phosphorylated mammalian target of rapamycin(p-mTOR),phosphorylated-p70 ribosomal protein S6 kinase,and phosphorylated-4 E-binding protein 1.What is more,the protein levels of phosphorylated AMPKα(pAMPKa)and nicotinamide adenine dinucleotide(NAD)-dependent protein deacetylase sirtuin-1(SIRT1)were decreased by AA treatments in a time depending manner.Mitochondrial bioenergetics and the production of tricarboxylic acid cycle intermediates were decreased upon inhibition of mTORCl or AMPK.Moreover,AMPK activation could up-regulate the mRNA expressions of inhibitor of nuclear factor kappa-B kinase subunit beta(Ikbk(3),integrin-linked protein kinase(ILK),unconventional myosin-Ic(Myolc),ribosomal protein S6 kinase beta-2(RPS6 Kβ2),and vascular endothelial growth factor(VEGF)-β,which are downstream effectors of mammalian target of rapamycin(mTOR).The mRNA expressions of phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform(PIK3 CD)and5’-AMP-activated protein kinase subunit gamma-1(PRKAG1),which are upstream regulators of mTOR,were also up-regulated by AMPK activation.On the other hand,AMPK activation also down-regulated FK506-binding protein 1 A(FKBP1 A),serine/threonine-protein phosphatase 2 A 55 kDa regulatory subunit B beta isoform,phosphatase and tensin homolog(PTEN),and unc-51 like autophagy activating kinase 1(Ulkl),which are up-stream regulators of mTORCl.Taken together,these data indicated that AA regulated cellular energy metabolism through mTOR and AMPK pathway in porcine enterocytes.These results demonstrated interactions of AMPK and mTORCl pathways in AA catabolism and energy metabolism in intestinal mucosa cells of piglets,and also provided reference for using AA to remedy human intestinal diseases.

Beneficial effects of metformin on primary cardiomyocytes via activation of adenosine monophosphate-activated protein kinase

Background Metformin has become a cornerstone in the treatment of patients with type-2 diabetes. Accumulated evidence suggests that metformin supports direct cardiovascular effects. The present study aimed to investigate if metformin has beneficial effects on primary cardiomyocytes damaged by H2O2, and reveal the potential mechanism of action of metformin. Methods Cardiomyocytes were incubated in the presence of 100μmol/L H2O2 for 12 hours. Cardiomyocytes were pretreated with metformin at different concentrations and time and with aminoimidazole carboxamide ribonucleotide （AICAR） （500μmol/L）, an adenosine monophophate （AMP）-activated protein kinase （AMPK） agonist for 60 minutes before the addition of H2O2. Other cells were preincubated with compound C （an AMPK antagonist, 20μmol/L） for 4 hours. The viability and apoptosis of cells were analyzed. AMPK, endothelial nitric oxide synthase （eNOS）, and transforming growth factor （TGF）-β1 were analyzed using immunblotting. Results Metformin had antagonistic effects on the influences of H2O2 on cell viability and attenuated oxidative stress-induced apoptosis. Metformin also increased phosphorylation of AMPK and eNOS, and reduced the expression of TGF-β1, basic fibroblast growth factor （bFGF）, and tumor necrosis factor （TNF）-α. Conclusions Metformin has beneficial effects on cardiomyocytes, and this effect involves activation of the AMPK-eNOS pathway. Metformin may be potentially beneficial for the treatment of heart disease.

Dan-gua Fang (丹瓜方) Improves Glycolipid Metabolic Disorders by Promoting Hepatic Adenosine 5'-monophosphate Activated Protein Kinase Expression in Diabetic Goto-kakizaki Rats

Objective：To investigate the effect of Dan-gua Fang（丹瓜方） on adenosine 5’-monophosphate（AMP） activated protein kinase（AMPK） α expression in liver and subsequent improvement of glucose and lipid metabolism.Methods：Forty 13-week-old diabetic Goto-Kakizaki（GK） rats were randomly divided into model,Dan-gua Fang,metformin and simvastatin groups（n=10 for each）,and fed high-fat diet ad libitum.Ten Wistar rats were used as normal group and fed normal diet.After 24 weeks,liver expression of AMPK α mRNA was assessed by real-time PCR.AMPK α and phospho-AMPK α protein expression in liver was evaluated by Western blot.Liver histomorphology was carried out after hematoxylin-eosin staining,and blood glucose（BG）,glycosylated hemoglobin A1c（HbA1c）,food intake and body weight recorded.Results：Similar AMPK α mRNA levels were found in the Dan-gua Fang group and normal group,slightly higher than the values obtained for the remaining groups（P〈0.05）.AMPK α protein expression in the Dan-gua Fang group animals was similar to other diabetic rats,whereas phospho-AMPK α（Thr-172） protein levels were markedly higher than in the metformin group and simvastatin group（P〈0.05）,respectively.However,phosphor-AMPKa/AMPK α ratios were similar in all groups.Dan-gua Fang reduced fasting blood glucose with similar strength to metformin,and was superior in reducing cholesterol,triglycerides,high-density lipoprotein cholesterol as well as improving low-density lipoprotein cholesterol in comparison with simvastatin and metformin.Dan-gua Fang decreases plasma alanine aminotransferase（ALT） significantly.Conclusion：Dan-gua Fang,while treating phlegm-stasis,could decrease BG and lipid in type 2 diabetic GK rats fed with high-fat diet,and effectively protect liver histomorphology and function.This may be partly explained by increased AMPK expression in liver.Therefore,Dan-gua Fang might be an ideal drug for comprehensive Intervention for glucose and lipid metabolism disorders in type 2 diabetes mellitus.

Metformin inhibits nuclear factor-κB activation and inflammatory cytokines expression induced by high glucose via adenosine monophosphate-activated protein kinase activation in rat glomerular mesangial cells in vitro

Background The renoprotective mechanisms of adenosine monophosphate （AMP）-activated protein kinase （AMPK） agonist-metformin have not been stated clearly.We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB （NF-κB）,monocyte chemoattractant protein-1 （MCP-1）,intercellular adhesion molecule-1 （ICAM-1） and transforming growth factor-beta 1 （TGF-β1） induced by high glucose （HG） in cultured rat glomerular mesangial cells （MCs）.Methods MCs were cultured in the medium with normal concentration glucose （group NG,5.6 mmol/L）,high concentration glucose （group HG,25 mmol/L） and different concentrations of metformin （group M1,M2,M3）.After 48-hour exposure,the supernatants and MCs were collected.The expression of NF-κB,MCP-1,ICAM-1,and TGF-β1 mRNA was analyzed by real time polymerase chain reaction.Westem blotting was used to detect the expression of AMPK,phospho-Thr-172 AMPK （p-AMPK）,NF-κB p65,MCP-1,ICAM-1,and TGF-β1 protein.Results After stimulated by HG,the expression of NF-κB,MCP-1,ICAM-1,TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG （P ＜0.05）.Both genes and protein expression of NF-κB,MCP-1,ICAM-1,TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner （P ＜0.05）.The expression of p-AMPK increased with the rising of metformin concentration,presenting the opposite trend,while the level of total-AMPK protein was unchanged with exposure to HG or metformin.Conlusion Metformin can suppress the expression of NF-κB,MCP-1,ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation,which may partlv contribute to its reno-protection.

Effects of Ginsenoside Rb1 on Skeletal Muscle Insulin Resistance and Adenosine Monophosphate?activated Protein Kinase Signaling Pathway in Obese Mice

Objectives: The objective of the study is to observe the effects of ginsenoside Rb1 on indexes of body weight, body composition, blood lipid, skeletal muscle endurance, and insulin sensitivity in obese mice, probe into its pharmacological action, and further explore its effects on adenosine monophosphate-activated protein kinase(AMPK) signaling pathway in skeletal muscle. Materials and Methods: Eight-week-old C57 BL/6 J mice were fed with high-fat diet for 12 weeks to establish obese mouse model. The model-establishment obese mice were randomly divided into three groups including model control group, metformin group, and ginsenoside Rb1 group. In the normal control group, normal diet was administered. The intervention period was 8 weeks. Body weight and food intake of the mice were measured regularly every week. The treadmill test was performed at weeks 3 and 7, and the oral glucose tolerance test was carried out at weeks 4 and 8. Body composition of the mice was detected by applying NMR Animal Body Composition Analyzer at week 8. Four parameters of blood lipids and free fatty acid(FFA)levels were detected. The m RNA expression of AMPKα and proliferator-activated receptor gamma coactivator-1α(PGC-1α) in skeletal muscle was examined by real-time fluorescence quantitative polymerase chain reaction, and the influence of ginsenoside Rb1 on protein expression of AMPKα, p-AMPKα, and PGC-1α was observed by western blotting. Results: The body weight(since the 5 th week of drug administration)and food intake of the mice in the ginsenoside Rb1 group were significantly lower than those in the model control group(P < 0.05) in a time-dependent manner. Ginsenoside Rb1 could significantly reduce the levels of triglyceride and low-density lipoprotein cholesterol, while increase the high-density lipoprotein cholesterol level(P < 0.05). In addition, ginsenoside Rb1 could reduce the serum FFA level(P < 0.05).After the administration of ginsenoside Rb1 for 8 weeks, the body fat mass of obese mice decreased and the lean mass increased(P < 0.05).The skeletal muscle endurance and the oral glucose tolerance of the obese mice improved using ginsenoside Rb1. At the molecular level,ginsenoside Rb1 could up-regulate the mRNA and protein expression of AMPKα in skeletal muscle, and increase the content of p-AMPK protein significantly(P < 0.01). At the same time, the mRNA and protein level of PGC-1α was also un-regulated, correspondingly(P < 0.01).Conclusion: Ginsenoside Rb1 exerts effects on reducing body weight, decreasing blood lipid levels, enhancing the skeletal muscle endurance,and increasing the insulin sensitivity in obese mice by activating the related proteins in AMPK signaling pathway in skeletal muscle.

肠道菌群通过去乙酰化酶3激活单磷酸腺苷活化的蛋白激酶/雷帕霉素信号通路对脓毒症心肌炎和心肌细胞线粒体损伤的影响

目的探讨正常肠道粪菌移植(FMT)对脓毒症心肌炎和心肌细胞线粒体损伤的改善作用与机制。方法将40只SD大鼠随机分为盲肠结扎穿孔术(CLP)建立的脓毒症模型组(CLP组)、假手术对照组(sham组)、FMT治疗组(CLP+FMT组)及FMT联合去乙酰化酶3(SIRT3)抑制剂(3-TYP)治疗组(CLP+FMT+3-TYP组),每组各10只。采用HE染色观察大鼠心肌组织的病理变化,采用ELISA检测大鼠血液中IL-1β、IL-6、肿瘤坏死因子(TNF)-α的表达水平,采用Western blot检测大鼠心肌组织中IL-1β、NOD样受体热蛋白结构域相关蛋白3(NLRP3)、去乙酰化酶3(SIRT3)、单磷酸腺苷活化的蛋白激酶(AMPK)、磷酸化AMPK(p-AMPK)、雷帕霉素(mTOR)及p-mTOR表达水平,采用透射电镜观察大鼠心肌细胞线粒体形态,采用流式细胞术分析大鼠心肌细胞的线粒体膜电位变化。结果与sham组比较,CLP组、CLP+FMT组、CLP+FMT+3-TYP组心肌组织SIRT3和p-mTOR表达水平均显著降低,而心肌组织p-AMPK和血液中IL-1β、IL-6及TNF-α的表达水平均显著增加;与CLP组比较,CLP+FMT组心肌组织SIRT3和p-mTOR的表达水平均显著增加,而心肌组织p-AMPK和血液中IL-1β、IL-6及TNF-α的表达水平均显著降低;与CLP+FMT组比较,CLP+FMT+3-TYP组心肌组织SIRT3和p-mTOR的表达水平均显著降低,而心肌组织中p-AMPK和血液中IL-1β、IL-6及TNF-α的表达水平均显著增加;与sham组比较,CLP组线粒体膜电位的红/绿荧光强度比值显著下降;与CLP组比较,CLP+FMT组线粒体膜电位的红/绿荧光强度比值显著增加;与CLP+FMT组比较,CLP+FMT+3-TYP组线粒体膜电位的红/绿荧光强度比值显著下降(P<0.05)。结论肠道菌群通过SIRT3激活AMPK/mTOR信号通路对脓毒症心肌炎和心肌细胞线粒体损伤均有改善作用。

柚皮素对口腔鳞状细胞癌细胞的干预作用研究

目的:探究柚皮素(NRG)对口腔鳞状细胞癌(OSCC)细胞增殖、凋亡、迁移与侵袭的影响。方法:采用浓度(μmol/L)为0、5、10、15、20、25、30的NRG处理OSCC CAL-27细胞,CCK-8法检测细胞活力;将CAL-27细胞分为低、中、高剂量NRG组(NRG-L、NRG-M组、NRG-H组)、Compound C(AMPK抑制剂)组、NRG-H+Compound C组、对照组(NC组,正常培养),CCK-8与EdU染色、流式细胞术、划痕实验、Transwell分别检测细胞增殖、凋亡、迁移、侵袭;Western blot检测天冬氨酸特异性半胱氨酸蛋白酶-3(Caspase-3)、增殖细胞核抗原(PCNA)、基质金属蛋白酶(MMP)-2、MMP-9、磷酸化腺苷酸活化蛋白激酶(p-AMPK)、沉默信息调节蛋白1(SIRT1)、乙酰化核因子κB p65(Ac-NF-κB p65)蛋白表达。结果:选取5、10、20μmol/L NRG分别作为后续处理CAL-27细胞的低、中、高剂量;与NC组比较,NRG-L组、NRG-M组、NRG-H组EdU阳性率、划痕愈合率、A 450值、侵袭细胞数及MMP-2、PCNA、MMP-9、Ac-NF-κB p65蛋白下调,细胞凋亡率及p-AMPK、Caspase-3、SIRT1蛋白上调(P<0.05);与NC组相比,Compound C组EdU阳性率、划痕愈合率、A 450值、侵袭细胞数及MMP-2、PCNA、MMP-9、Ac-NF-κB p65蛋白升高,细胞凋亡率及p-AMPK、Caspase-3、SIRT1蛋白表达下调(P<0.05);Compound C逆转了高剂量NRG对CAL-27细胞增殖、迁移、凋亡及侵袭的影响。结论:NRG抑制CAL-27细胞增殖、迁移与侵袭,并诱导细胞凋亡,其机制可能与激活AMPK进而抑制NF-κB通路有关。

青藤碱调节AMPK/mTOR/ULK1信号通路对IL-1β诱导的关节软骨细胞自噬和凋亡的影响

目的探讨青藤碱(SN)调节单磷酸腺苷活化蛋白激酶(AMPK)/雷帕霉素靶蛋白(mTOR)/UNC-51样激酶1(ULK1)信号通路对白介素-1β(IL-1β)诱导的关节软骨细胞自噬和凋亡的影响。方法将关节软骨细胞分为Control组(正常培养)、IL-1β组(10μg/L的IL-1β诱导12 h)、L-SN、M-SN、H-SN组(在IL-1β诱导的基础上添加25、50、100μmol/L的SN)、SN+Compound C组(在H-SN组的基础上添加10μmol/L AMPK抑制剂Compound C)。MTT法、透射电子显微镜(TEM)、流式细胞仪分别检测SN对各组关节软骨细胞增殖、自噬、凋亡的影响;ELISA试剂盒检测各组细胞中COX-2、TNF-α、MMP-3、MMP-13的表达;蛋白印迹实验(WB)检测各组细胞中p-AMPK、AMPK、p-mTOR、mTOR、p-ULK1、ULK1蛋白水平。结果与Control组比较,IL-1β组关节软骨细胞的A 490值、p-AMPK/AMPK、p-ULK1/ULK1蛋白水平降低,自噬空泡数、凋亡率、COX-2、TNF-α、MMP-3、MMP-13、p-mTOR/mTOR蛋白水平升高(P<0.05);与IL-1β组比较,L-SN组、M-SN组、H-SN组A 490值、自噬空泡数、p-AMPK/AMPK、p-ULK1/ULK1蛋白水平升高,凋亡率、COX-2、TNF-α、MMP-3、MMP-13、p-mTOR/mTOR蛋白水平降低(P<0.05);与H-SN组比较,SN+Compound C组A 490值、自噬空泡数、p-AMPK/AMPK、p-ULK1/ULK1蛋白水平降低,凋亡率、COX-2、TNF-α、MMP-3、MMP-13、p-mTOR/mTOR蛋白水平升高(P<0.05)。结论SN可以通过促进IL-1β诱导的关节软骨细胞自噬,抑制细胞凋亡,其机制可能是通过激活AMPK/mTOR/ULK1信号通路实现的。

金合欢素调节Sirt1/AMPK/Nrf2信号通路对糖尿病白内障大鼠氧化应激损伤的影响

目的探讨金合欢素对糖尿病白内障(DC)大鼠氧化应激损伤的影响及其对沉默调节蛋白1(Sirt1)/腺苷酸活化蛋白激酶(AMPK)/核因子E2相关因子2(Nrf2)信号通路的调控作用。方法60只SD大鼠随机分为对照组、模型组、金合欢素低剂量组、金合欢素高剂量组、金合欢素+Sirt1抑制剂(EX527)组,除对照组以外均构建DC大鼠模型,其中,金合欢素低剂量组、金合欢素高剂量组大鼠分别经颈部皮下注射10 mg·kg^(-1)、20 mg·kg^(-1)的金合欢素,金合欢素+EX527组大鼠经颈部皮下注射20 mg·kg^(-1)金合欢素,均为每天2次,同时金合欢素+EX527组大鼠经皮下埋入渗透微型泵每天泵入3.5 mg·kg^(-1)EX527,其余组别均泵入等量生理盐水,给药持续4周。给药结束后,测量血压和空腹血糖(FBG),裂隙灯照射法观察大鼠晶状体混浊状况,HE染色观察晶状体组织病理学变化,ELISA测定血清丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、白细胞介素(IL)-6、IL-1β的含量,Western blot检测Sirt1、p-AMPK、AMPK、Nrf2蛋白表达水平。结果与对照组相比,模型组大鼠晶状体上皮细胞呈片状、条索状,发生迁移性聚集,收缩压、FBG、晶状体混浊评分、MDA、IL-6、IL-1β水平均升高,SOD、GSH-Px含量及Sirt1、p-AMPK/AMPK、Nrf2蛋白表达水平均降低(均为P<0.05);与模型组比较,金合欢素低、高剂量组大鼠晶状体上皮细胞迁移性聚集现象改善,收缩压、FBG、晶状体混浊评分、MDA、IL-6、IL-1β水平均降低,SOD、GSH-Px含量及Sirt1、p-AMPK/AMPK、Nrf2蛋白表达水平均升高(均为P<0.05);与金合欢素高剂量组比较,金合欢素+EX527组晶状体上皮细胞形态改变和聚集现象加重,收缩压、FBG、晶状体混浊评分、MDA、IL-6、IL-1β水平均升高,SOD、GSH-Px含量及Sirt1、p-AMPK/AMPK、Nrf2蛋白表达水平均降低(均为P<0.05)。结论金合欢素可能通过激活Sirt1/AMPK/Nrf2通路保护DC大鼠免受氧化应激损伤。

基于“肾脑相济”理论探讨艾灸对阿尔茨海默病大鼠海马AMPK/mTOR信号通路的影响

目的观察艾灸对阿尔茨海默病(Alzheimer’s disease,AD)大鼠腺苷酸活化蛋白激酶(adenosine 5-monophosphate activated protein kinase,AMPK)/雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路相关递质表达的影响,探讨艾灸治疗AD的作用机制。方法将SD大鼠按照随机数字表法分为正常组8只、模型组32只,采取侧脑室注射β淀粉样蛋白(amyloidβ-protein,Aβ)_(25-35)的方法建立大鼠AD模型。将模型复制成功的大鼠随机分为模型组、药物组、艾灸组,每组8只。艾灸组大鼠用艾条灸“百会”“肾俞”“三阴交”,每次15 min,同时按3 mg/kg灌胃蒸馏水;药物组大鼠按3 mg/kg灌胃盐酸多奈哌齐;对照组及模型组大鼠按3 mg/kg灌胃蒸馏水。采用Morris水迷宫法检测大鼠行为学表现,苏木精—伊红染色法观察大鼠海马病理组织改变,Western blot法检测大鼠海马磷酸化雷帕霉素靶蛋白(phosphorylated mammalian target of rapamycin,p-mTOR)、核糖体蛋白S6激酶(ribosomal protein S6 kinase p70,P70S6K)、自噬相关基因5(autophagy-related gene 5,ATG5)、磷酸化腺苷酸活化蛋白激酶(phosphorylated adenosine 5-monophosphate activated protein kinase,p-AMPK)、微管相关蛋白1轻链3B(microtubule associated protein light chain 3B,LC3B)-Ⅱ/LC3B-Ⅰ的表达水平。结果苏木精—伊红染色结果表明,模型组海马神经元萎缩明显,与模型组比较,药物组和艾灸组海马神经元形态及分化程度均有明显改善。与正常组比较,模型组大鼠的逃避潜伏期显著延长(P<0.05),p-mTOR及P70S6K表达水平均显著升高(P<0.05),ATG5、LC3B-Ⅱ/LC3B-Ⅰ、p-AMPK表达水平均显著降低(P<0.05)。与模型组比较,药物组和艾灸组大鼠的逃避潜伏期均显著缩短(P<0.05),p-mTOR及P70S6K表达水平均显著下降(P<0.05),ATG5、LC3B-Ⅱ/LC3B-Ⅰ、p-AMPK表达水平均显著上升(P<0.05)。与药物组比较,艾灸组大鼠逃避潜伏期显著缩短(P<0.05);p-mTOR及P70S6K表达水平显著降低(P<0.05),ATG5、LC3B-Ⅱ/LC3B-Ⅰ、p-AMPK表达水平均显著上升(P<0.05)。结论艾灸能够调控AMPK/mTOR信号通路,诱导细胞自噬,阻断脑内Aβ表达,从而改善认知功能。

高良姜素减轻乙型病毒性肝炎模型大鼠的炎性反应

目的探讨高良姜素(Gal)对乙型病毒性肝炎(乙肝)大鼠炎性反应的影响。方法大鼠随机分为对照组、乙肝组[尾静脉注射乙型肝炎病毒(HBV)]、Gal低(Gal-L)和高剂量(Gal-H)组、阳性药拉米夫定组、Gal-H+AMPK抑制剂(compound C)组,每组12只。造模后进行药物处理,给药1次/d,持续8周。检测血清中谷丙转氨酶(ALT)、总胆红素(TBIL)、谷草转氨酶(AST)水平;HE染色检测肝组织病理变化;TUNEL染色检测细胞凋亡;染色质免疫共沉淀检测HBV病毒载量;ELISA检测肝组织中单核细胞趋化蛋白-1(MCP-1)、白细胞介素(IL-12)、肿瘤坏死因子-α(TNF-α)水平;Western blot检测天冬氨酸特异性半胱氨酸蛋白酶-3(caspase-3)、Bcl-2相关X蛋白(Bax)、p-AMPK、SIRT1蛋白表达。结果与乙肝组比较,Gal-L组、Gal-H组、拉米夫定组肝脏损伤减轻,血清中AST、TBIL、ALT水平降低,肝组织中细胞凋亡率、HBV病毒载量、MCP-1、IL-12、TNF-α水平及caspase-3、Bax蛋白降低,p-AMPK、SIRT1蛋白升高(P<0.05);Compound C减弱了高剂量Gal对乙肝大鼠肝组织中炎性反应、细胞凋亡及HBV病毒载量的抑制作用。结论Gal抑制乙肝大鼠炎性反应的机制可能与上调AMPK/SIRT1通路有关。

利拉鲁肽通过Sirt1/AMPK信号通路改善肝细胞脂肪变性机制研究

目的探讨利拉鲁肽(Lira)干预棕榈酸(PA)诱导的人肝癌细胞对沉默信息调节因子1(Sirt1)/腺苷酸活化蛋白激酶(AMPK)/固醇调节元件结合蛋白(SREBP1c)信号通路的影响。方法取HepG2细胞,分为5组,以PA干预诱导肝细胞脂肪变制备模型,再分别以PA/Lira、PA/Sirt1或PA/Sirt1/Lira干预组。采用油红O染色观察细胞脂滴,采用试剂盒测定肝细胞培养上清液烟酰胺腺嘌呤二核苷酸氧化态/还原态比值(NAD+/NADH)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)和肝细胞甘油三酯(TG)含量,采用RT-qPCR法检测肝激酶B1(LKB1)、游离脂肪酸(FFA)、乙酰辅酶A羧化酶(ACC)和甘油三酯脂肪酶(ATGL)mRNA水平,采用蛋白质印迹法检测细胞p-AMPK、p-Sirt1和p-SREBP1c蛋白表达。结果PA处理组肝细胞内见大量脂滴,PA/Sirt1组脂滴更大,而PA/Lira处理组和PA/Sirt1/Lira处理组细胞脂滴数量显著减少,提示模型制备成功并显示Lira的防治作用;PA组细胞FFA和ACC基因水平显著高于对照组(P均<0.01),PA/Lira处理组LKB1和ATGL基因水平显著高于PA处理组(P均<0.001),而FFA和ACC基因水平显著低于PA组(P均<0.01),PA/Sirt1/Lira组LKB1和ATGL基因水平显著高于(P均<0.01),而FFA基因水平显著低于PA/Sirt1处理组(P<0.05);与对照组比,PA组细胞p-AMPK和p-Sirt1蛋白表达下调,而SREBP1c表达上调;与PA组比,PA/Lira组p-AMPK蛋白表达上调而SREBP1c蛋白表达下调;与PA/Sirt1组比,PA/Sirt1/Lira组细胞p-AMPK表达上调。结论Lira改善HepG2细胞脂肪蓄积可能是通过直接上调Sirt1/AMPK信号通路或部分激活LKB1升高AMPK蛋白表达,抑制SREBP1c蛋白表达,降低了脂质合成分子水平。

牡荆素调控AMPK/NLRP3途径介导的细胞焦亡对大鼠急性咽炎的作用机制研究

目的:基于AMPK/NLRP3信号通路探究牡荆素对大鼠急性咽炎的影响及其调控机制。方法:60只SD大鼠随机分为对照组、模型组、阿莫西林组和牡荆素低、中、高剂量组,每组各10只。除对照组外,其余各组大鼠均采用咽部定向喷射25%氨水的方法构建急性咽炎模型。牡荆素各剂量组大鼠分别腹腔注射3、6、12 mg/kg牡荆素;阿莫西林组大鼠给予0.36 g/kg阿莫西林灌胃;其余腹腔注射等量0.9%生理盐水。各组大鼠于给药干预7 d后进行行为状态评分、咽部组织病理学染色观察,并进行血清炎症因子IL-6、IL-1β、TNF-α、PGE_(2)检测,筛选出牡荆素最佳给药剂量;同时检测咽部组织焦亡相关蛋白及AMPK/NLRP3表达。随后将40只SD大鼠随机分为对照组、模型组、牡荆素组(腹腔注射12 mg/kg牡荆素)、牡荆素+CC(AMPK抑制剂)组(腹腔注射12 mg/kg牡荆素后,立刻注射20 mg/kgCC),每组各10只。除对照组外,其余各组大鼠均采用咽部定向喷射25%氨水的方法构建急性咽炎,造模后使用相应药物干预,1次/d,共干预7 d。苏木素-伊红(HE)染色观察咽部组织病理学变化;酶联免疫吸附法(ELISA)测定血清IL-6、IL-1β、TNF-α、PGE_(2)水平;Western blot检测咽部组织AMPK/NLRP3通路及细胞焦亡相关蛋白表达。结果:与模型组相比,牡荆素各剂量组大鼠行为状态评分均显著降低(P<0.05),血清IL-6、IL-1β、TNF-α、PGE_(2)水平降低(P<0.05),咽部组织病理性损伤明显减轻,且呈剂量相关性,筛选得出牡荆素12 mg/kg为最佳给药剂量。与模型组相比,牡荆素组大鼠咽部组织p-AMPK蛋白阳性率明显升高,NLRP3蛋白阳性率明显降低,细胞焦亡相关蛋白表达明显降低(P<0.05)。与牡荆素组相比,牡荆素+CC组大鼠咽部组织损伤程度加重,血清IL-6、IL-1β、TNF-α、PGE_(2)水平,细胞焦亡相关蛋白和NLRP3蛋白表达显著升高,p-AMPK/AMPK降低(P<0.05)。结论:牡荆素能够通过调控AMPK/NLRP3信号通路,抑制细胞焦亡,进而改善大鼠急性咽炎。

香菇多糖对ApoE^(-/-)小鼠动脉粥样硬化斑块形成及AMPK信号通路的影响

目的:探讨香菇多糖(LNT)对ApoE^(-/-)小鼠动脉粥样硬化(AS)斑块形成及单磷酸腺苷活化蛋白激酶(AMPK)信号通路的影响。方法:ApoE^(-/-)小鼠分为模型组、立普妥组(5 mg/kg)、LNT低(5 mg/kg)、中(10 mg/kg)、高(20 mg/kg)剂量组,以相似遗传背景的C57BL/6小鼠为对照组。灌胃给药12周后,全自动生化分析仪检测血清甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)水平;ELISA检测血清IL-6、IL-1β水平;油红O染色观察整体主动脉斑块形成情况;HE染色观察主动脉根部斑块形成情况;蛋白免疫印迹检测主动脉AMPK通路蛋白表达。结果:与对照组比较,模型组血清TC、TG、LDL-C、IL-6、IL-1β水平、主动脉斑块面积、主动脉根部斑块面积、主动脉组织NLRP3、IL-6、IL-1β表达显著升高,主动脉组织p-AMPK/AMPK表达和血清HDL-C水平降低(P<0.05);与模型组比较,立普妥组、LNT中、高剂量组TC、TG、LDL-C、IL-6、IL-1β、主动脉斑块面积、主动脉根部斑块面积、主动脉组织NLRP3、IL-6、IL-1β表达显著降低,主动脉组织p-AMPK/AMPK表达和血清HDL-C水平显著升高,且LNT各剂量组间差异有统计学意义(P<0.05);立普妥组与LNT高剂量组差异无统计学意义(P>0.05)。结论:LNT可能通过激活AMPK通路抑制AS小鼠炎症反应和AS斑块形成。

Slit引导配体2通过调控AMPK/SIRT1-FoxO1信号通路影响糖尿病小鼠视网膜血管损伤的机制研究

目的 探讨Slit引导配体2(SLIT2)是否通过调控腺苷单磷酸活化蛋白激酶(AMPK)/转录沉默信息调节因子1(SIRT1)-叉头盒蛋白O1(FoxO1)信号通路通过对糖尿病小鼠视网膜血管损伤的影响。方法 30只db/db小鼠随机分为DR组(db/db小鼠)、DR+阴性对照载体组(DR+sh-NC组)和DR+sh-SLIT2组,每组10只。另选10只db/m小鼠为对照组。DR+sh-NC组和DR+sh-SLIT2组麻醉后分别在双眼玻璃体腔内注射sh-SLIT2的腺相关病毒(AAV)载体。眼底荧光血管造影(FFA)和苏木精伊红染色观察视网膜血管病变;酶联免疫吸附测定检测血清白细胞介素-6(IL-6),肿瘤坏死因子α(TNF-α)和血管内皮生长因子(VEGF)的水平,荧光定量PCR检测SLIT2 mRNA表达;Western blot检测视网膜组织SLIT2、AMPK、SIRT1、FoxO1蛋白水平。结果 与对照组相比,DR组、DR+sh-NC组、DR+sh-SLIT2组血糖、每日饮水量、每日排尿量、食物摄入量及体质量均明显升高(P<0.05);与对照组相比,DR组视网膜存在血管病变及病理损伤,SLIT2 mRNA及蛋白表达、IL-6、TNF-α和VEGF水平,FoxO1蛋白水平均明显升高(P<0.05),AMPK、SIRT1蛋白水平均明显降低(P<0.05);与DR+sh-NC组相比,DR+sh-SLIT2组的视网膜血管病变及病理损伤明显减轻,SLIT2 mRNA及蛋白表达、IL-6、TNF-α和VEGF水平,FoxO1蛋白水平均明显降低(P<0.05),AMPK、SIRT1蛋白水平均明显升高(P<0.05)。结论 沉默SLIT2表达显著改善糖尿病小鼠视网膜血管损伤及炎症水平,这可能是通过调控AMPK/SIRT1-FoxO1信号通路发挥作用的。

HSF1/AMPK信号通路在铁死亡参与糖尿病心肌病发病的机制研究

目的:探讨热休克因子1(heat shock factor 1,HSF1)/5′-单磷酸腺苷活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)信号通路调控铁死亡对糖尿病心肌病(diabetic cardiomyopathy,DCM)发病的影响。方法:本研究为实验研究,采用空白对照与多组实验对照。H9c2细胞随机分为4组:低葡萄糖组(control,Con)、高葡萄糖组(high glucose,HG)、HG+HSF1组、HG+HSF1+化合物C(compound C,CC)组。分别对细胞进行罗丹明胶质蛋白染色、细胞线粒体(reactive oxygen species,ROS)检测和细胞脂质ROS检测,并通过Western blot分析AMPK信号表达。雄性C57/BL6小鼠随机分为4组:NC组、NC+HSF1组、DM组和DM+HSF1组,每组12只。通过超声心动图评估了小鼠心血管功能参数。结果:与Con组相比,HG组HSF1、pAMPK/AMPK水平明显下调(P=0.005、0.002),和相对细胞表面积、线粒体Fe2+水平、线粒体ROS水平、细胞脂质ROS水平明显增加(P=0.001、0.003、0.006、0.002)。与HG组相比,HG+HSF1组明显逆转了这些变化(P=0.001、0.001、0.002、0.006、0.007、0.003),但加入CC时HSF1的逆转作用明显减弱(P<0.05)。与NC组相比,DM组EF%、FS%、E/A、E′/A′和心脏组织中HSF1、pAMPK/AMPK表达明显降低(均P<0.01),和心脏组织中Fe2+、ROS、丙二醛(Malondialdehyde,MDA)水平和4-羟基壬烯酸(4-Hydroxynonenal,4-HNE)蛋白水平明显增加(P=0.004、0.003、0.001、0.004),DM+HSF1组明显逆转了这些变化。结论:HSF1在DCM病理过程中发挥心脏保护作用,其抗铁死亡作用可能与AMPK依赖性的脂质代谢和线粒体稳态调节有关。

基于AMPK/mTOR信号通路探讨人参-黄芪对人胃癌细胞自噬的影响

目的:探究益气扶正药人参-黄芪对人胃癌细胞自噬的影响,并探讨腺苷酸活化蛋白激酶(AMPK)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路在其中的作用机制。方法:将人胃癌细胞株(SGC-7901)随机分为对照组(人参-黄芪0 mg/ml)和人参-黄芪组(1、2、4、8、16、32、64 mg/ml),经药物处理后,CCK-8法观察人胃癌细胞增殖情况;筛选最佳浓度并将其作为后续实验中的实验组;MDC免疫荧光染色观察细胞自噬情况;Western blot法检测人胃癌细胞自噬相关蛋白(Beclin-1、LC3B)及AMPK/mTOR信号通路相关蛋白(AMPK、p-AMPK、mTOR及p-mTOR)的表达情况。结果:CCK-8法结果显示,人参-黄芪组人胃癌细胞增殖作用降低(P<0.01),且呈浓度依赖性;MDC染色荧光检测显示实验组的荧光强度显著增强(P<0.01),表明人参-黄芪可以诱导人胃癌细胞产生自噬;Western blot结果显示,实验组的Beclin-1、LC3B、p-AMPK/AMPK蛋白表达水平上升(P<0.01),p-mTOR/mTOR蛋白表达水平下降(P<0.01)。结论:人参-黄芪配伍能够抑制人胃癌细胞的增殖、促进人胃癌细胞自噬,其机制可能与激活AMPK/mTOR信号通路相关。

腺苷酸活化蛋白激酶-哺乳动物雷帕霉素靶蛋白通路介导线粒体自噬在男性生殖中的研究进展

线粒体自噬是指细胞利用自噬机制选择性地降解受损或多余线粒体的过程。近年来,有证据表明线粒体自噬在男性生殖中至关重要,其可清除异常的线粒体,从而减少氧化应激并维持生殖细胞的能量稳态。作为调控细胞生长代谢的经典通路,腺苷酸活化蛋白激酶(AMPK)-哺乳动物雷帕霉素靶蛋白(mTOR)通路通过产生自噬装置,调控线粒体蛋白,可促进自噬体包裹线粒体等过程,从而介导线粒体自噬。本文对AMPK-mTOR通路在下丘脑-垂体-性腺(HPG)轴中枢水平及性腺水平调节线粒体自噬的机制作一综述,以期为改善精子质量提供新的观点和思路。