Fanlian Huazhuo Formula alleviates high-fat diet-induced nonalcoholic fatty liver disease by modulating autophagy and lipid synthesis signaling pathway

BACKGROUND Fanlian Huazhuo Formula(FLHZF)has the functions of invigorating spleen and resolving phlegm,clearing heat and purging turbidity.It has been identified to have therapeutic effects on type 2 diabetes mellitus(T2DM)in clinical application.Non-alcoholic fatty liver disease(NAFLD)is frequently diagnosed in patients with T2DM.However,the therapeutic potential of FLHZF on NAFLD and the underlying mechanisms need further investigation.AIM To elucidate the effects of FLHZF on NAFLD and explore the underlying hepatoprotective mechanisms in vivo and in vitro.METHODS HepG2 cells were treated with free fatty acid for 24 hours to induce lipid accumulation cell model.Subsequently,experiments were conducted with the different concentrations of freeze-dried powder of FLHZF for 24 hours.C57BL/6 mice were fed a high-fat diet for 8-week to establish a mouse model of NAFLD,and then treated with the different concentrations of FLHZF for 10 weeks.RESULTS FLHZF had therapeutic potential against lipid accumulation and abnormal changes in biochemical indicators in vivo and in vitro.Further experiments verified that FLHZF alleviated abnormal lipid metabolism might by reducing oxidative stress,regulating the AMPKα/SREBP-1C signaling pathway,activating autophagy,and inhibiting hepatocyte apoptosis.CONCLUSION FLHZF alleviates abnormal lipid metabolism in NAFLD models by regulating reactive oxygen species,autophagy,apoptosis,and lipid synthesis signaling pathways,indicating its potential for clinical application in NAFLD.

MIR-448 Regulates MAGEA6/AMPK Signaling Pathway in Hepatocellular Carcinoma Tumor Stem Cells

Objective: To explore the role of miR-448 in regulating MAGEA6/AMPK signaling pathway in the biological study of hepatocellular carcinoma (HCC) tumor stem cells. Methods: Using the database, the hepatocellular carcinoma related expression chips were obtained and the regulatory mirnas of candidate genes were predicted, and the predicted results were analyzed. The effects of miR-448 and MAGEA6 on the pellet formation rate and clone formation rate of hepatocellular carcinoma stem cells were detected by immunofluorescence identification of stem cell markers and light microscope counting method. The effects of miR-448 and MAGEA6 on migration and invasion of hepatocellular carcinoma stem cells were detected by scratch and Transwell assay. Dual luciferase reporter assay to verify whether miR-448 targets MAGEA6. The expression and influence of miR-448 on MAGEA6 and AMPK pathway were detected by qRT-PCR and Western blot. Results: It was found that miR-448 may directly regulate the expression of MAGEA6. Overexpression of miR-448 inhibited the characteristics, proliferation, migration, and invasion of hepatocellular carcinoma stem cells in vitro, as well as the ability of xenograft tumor formation in vivo. However, inhibition of miR-448 showed opposite results. In addition, miR-448 directly targets MAGEA6 and regulates AMPK signaling. Silencing MAGEA6 and adding AMPK activator further verified that miR-448 activated AMPK signaling pathway by targeting MAGEA6, thus affecting characteristics, proliferation, migration and invasion of hepatoma stem cells. Conclusions: Our results reveal that miR-448 activates AMPK signaling pathway by targeting MAGEA6, thereby affecting characteristics, proliferation, migration and invasion of hepatoma stem cells. It is suggested that overexpression of miR-448 may be a new therapeutic strategy for hepatocellular carcinoma.

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.

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.

Effect of Platelet-rich Plasma in Stimulating Macrophage Transformation into M2 Type under AMPK Signaling Pathway

Objective:To explore the effect of platelet-rich plasma(RPR)in stimulating the transformation of pro-inflammatory(M1)macrophages into antiinflammatory(M2)under the adenosine-monophosphate-dependent protein kinase(AMPK)signaling pathway.Methods:Rat peritoneal macrophages(RAW264.7)were cultured and randomly divided into 8 groups:blank control group,LPS group,RPR group A,RPR group B,LPS+RPR(12 h)group,LPS+RPR(24 h)group A,LPS+RPR(24 h)group B,LPS+RPR(24 h)group C.RPR was prepared based on blood donors.The expressions of AMPK signaling pathway-related proteins(AMPK,ULK1,m TOR)and macrophage markers(i NOS,Arg-1)in the blank control group,LPS group,LPS+RPR(12 h)group and LPS+RPR(24 h)group were observed and compared.The expressions of macrophage markers in LPS+RPR(24 h)B and C groups were compared,and the expressions of AMPK and TGF-βin RPR A and B groups were compared.Results:The gray values of AMPK and ULK1 in LPS cells decreased significantly,while those in LPS+RPR(12 h)and LPS+RPR(24 h)A cells increased significantly.The gray values of AMPK and ULK1 in LPS+RPR(24 h)A cells were higher than those in LPS+RPR(12 h)cells(P<0.05).The m TOR gray value of LPS cells was significantly higher than that of LPS+RPR(24 h)A cells,and the m TOR gray value of LPS+RPR(24 h)A cells was significantly lower than that of LPS+RPR(12 h)cells(P<0.05).The expression of i NOS in LPS cells was significantly decreased,the expression of i NOS in LPS+RPR(12 h)and LPS+RPR(24 h)cells was significantly increased,and the expression of i NOS in LPS+RPR(24 h)cells was higher than that in LPS+RPR(12 h)cells(P<0.05).The expression of Arg-1 in LPS cells was significantly decreased,the expression of Arg-1 in LPS+RPR(12 h)and LPS+RPR(24 h)A cells was significantly increased,and the expression of Arg-1 in LPS+RPR(24 h)A cells was higher than that in LPS+RPR(12 h)cells(P<0.05).The i NOS expression level of LPS+PRP(24 h)C cells was significantly higher than that of LPS+PRP(24 h)B cells,and the Arg-1 expression level was significantly lower than that of LPS+PRP(24 h)B cells(P<0.05).The gray values of AMPK and TGF-βin PRP B cells were significantly lower than those in PRP A cells(P<0.05).Conclusion:RPR can stimulate macrophage transformation from M1 to M2 by up-regulating AMPK signaling pathway.

Loganin regulates glycolipid metabolism by influencing intestinal microbiota and AMPK signaling in obese mice

Objective: We aimed to observe the effects of loganin(Log) on serum glycolipid levels and probe the mechanisms focusing on intestinal flora and AMP-activated protein kinase(AMPK) signaling in obese mice.Methods: A high-fat diet was given for 12 consecutive weeks to generate the obesity model in institute of cancer research(ICR) mice. Body weight was measured weekly and fasting blood glucose(FBG) was determined every 2 weeks. Both the oral glucose tolerance test and the intraperitoneal insulin tolerance test were performed. The serum levels of total cholesterol(TC), triglyceride, high-density lipoproteincholesterol, low-density lipoprotein-cholesterol(LDL-C), and free fatty acids(FFA) were measured. The expression of key proteins in the AMPK signaling pathway in skeletal muscle tissue was detected by immunoblotting, and gut microbiota were characterized using 16S rDNA sequencing.Results: Log significantly decreased the body weight and the FBG in obese mice(P <.05), and it could restore FBG to normal levels. The total cholesterol, LDL-C, and FFA levels were significantly reduced by Log compared with the obese controls(TC: P =.0020;LDL-C: P =.0233;FFA: P =.0127), and the glucose tolerance of animals was significantly improved(P =.0477). The western blot results showed that Log could upregulate the protein expression of Adenosine 5‘-monophosphate(AMP)-activated protein kinase(AMPKa), Sirtuin 1(SIRT1), and peroxisome proliferator-activated receptor-gamma coactivator-1 alpha(PGC1a) in skeletal muscle tissue of obese mice. 16S rDNA sequencing indicated that Log reduced the diversity of the gut flora in feces and altered the floral composition of obese mice.Conclusions: Log was effective in reducing body weight and improving glucolipid metabolism in obese mice, probably through activating AMPK signaling and regulating intestinal microbial diversity.

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.

Dietary choline activates the Ampk/Srebp signaling pathway and decreases lipid levels in Pacific white shrimp(Litopenaeus vannamei)

An 8-week feeding trial was conducted in Pacific white shrimp(Litopenaeus vannamei)to evaluate the effects of dietary choline supplementation on choline transport and metabolism,hepatopancreas histological structure and fatty acid profile,and regulation of lipid metabolism.Six isonitrogenous and isolipidic diets were formulated to contain different choline levels of 2.91(basal diet),3.85,4.67,6.55,10.70 and 18.90 g/kg,respectively.A total of 960 shrimp(initial weight,1.38±0.01 g)were distributed randomly into twenty-four 250-L cylindrical fiber-glass tanks,with each diet assigned randomly to 4replicate tanks.The results indicated that dietary choline significantly promoted the deposition of choline,betaine and carnitine(P<0.05).The diameters and areas of R cells,total lipid and triglyceride contents in hepatopancreas,and triglyceride and non-esterified fatty acid contents in hemolymph were negatively correlated with dietary choline level.The contents of functional fatty acids in hepatopancreas,the activity of acetyl-CoA carboxylase(Acc),and the mRNA expression of fas,srebp and acc were highest in shrimp fed the diet containing 4.67 g/kg choline,and significantly higher than those fed the diet containing 2.91 g/kg,the lowest level of choline(P<0.05).The number of R cells,content of very lowdensity lipoprotein(VLDL),activities of carnitine palmitoyl-transferase(Cpt1),lipoprotein lipase and hepatic lipase,and the mRNA expression levels of cpt1,fabp,fatp,ldlr,and ampk in hepatopancreas increased significantly as dietary choline increased(P<0.05).In addition,hepatopancreas m RNA expression levels of ctl1,ctl2,oct1,badh,bhmt,ck,cept,and cct were generally up-regulated as dietary choline level increased(P<0.01).In conclusion,dietary choline promoted the deposition of choline and its metabolites by up-regulating genes related to choline transport and metabolism.Moreover,appropriate dietary choline level promoted the development of hepatopancreas R cells and maintained the normal accumulation of lipids required for development,while high dietary choline not only promoted hepatopancreas lipid export by enhancing VLDL synthesis,but also promoted fatty acidβ-oxidation and inhibited de novo fatty acid synthesis by activating the Ampk/Srebp signaling pathway.These findings provided further insight and understanding of the mechanisms by which dietary choline regulated lipid metabolism in L.vannamei.

LncRNAs are involved in regulating ageing and age-related disease through the adenosine monophosphate-activated protein kinase signalling pathway

A long noncoding RNA(lncRNA)is longer than 200 bp.It regulates various biological processes mainly by interacting with DNA,RNA,or protein in multiple kinds of biological processes.Adenosine monophosphate-activated protein kinase(AMPK)is activated during nutrient starvation,especially glucose starvation and oxygen deficiency(hypoxia),and exposure to toxins that inhibit mitochondrial respiratory chain complex function.AMPK is an energy switch in organisms that controls cell growth and multiple cellular processes,including lipid and glucose metabolism,thereby maintaining intracellular energy homeostasis by activating catabolism and inhibiting anabolism.The AMPK signalling pathway consists of AMPK and its upstream and downstream targets.AMPK upstream targets include proteins such as the transforming growth factor b-activated kinase 1(TAK1),liver kinase B1(LKB1),and calcium/calmodulindependent protein kinase b(CaMKKb),and its downstream targets include proteins such as the mechanistic/mammalian target of rapamycin(mTOR)complex 1(mTORC1),hepatocyte nuclear factor 4a(HNF4a),and silencing information regulatory 1(SIRT1).In general,proteins function relatively independently and cooperate.In this article,a review of the currently known lncRNAs involved in the AMPK signalling pathway is presented and insights into the regulatory mechanisms involved in human ageing and age-related diseases are provided.

Hypoglycemic effect and the mechanism of action of a polysaccharide from sweet corncob in a high-fat diet and streptozotocin-induced diabetic mice

Type 2 diabetes mellitus(T2DM)is a metabolic disease caused by a glycolipid metabolism disorder and isletβ-cell dysfunction.SCP-80-I is a biologically active water-soluble polysaccharide isolated from sweet corncob,an agricultural byproduct.The hypoglycemic effects of SCP-80-I on T2DM mice and its mechanisms were investigated in this study.SCP-80-I was found to significantly reduce blood glucose and lipid deposition levels in T2DM mice,as well as decrease serum leptin and increase adiponectin secretion.Interestingly,real time-polymerase chain reaction(RT-PCR)and Western blotting results revealed that SCP-80-I could regulate the expression of several glycolipid metabolisms and insulin secretion genes and proteins,including 5'-AMP-activated protein kinase(AMPK),carnitine palmitoyltransferase I(CPTI),and acetyl coenzyme A carboxylase(ACC)in the liver and AMPK,sirtuin1(Sirtl),peroxisome proliferator-activated receptorycoactivator-1(PGC-1α),and uncoupling protein 2(UCP2)in the pancreas.To have a hypoglycemic effect,SCP-80-1 regulated glycolipid metabolism and islet cell function in the liver by regulating the AMPK/AC C/CPT1 signaling pathway and the AMPK/Sirt1/PGC-1αand AMPK/Sirtl/UCP2 signaling pathways.These findings improve our understanding of polysaccharides derived from sweet corncob and the use of SCP-80-I in the production of hypoglycemic foods.

A new peptide,VD11,promotes structural and functional recovery after spinal cord injury

The regenerative capacity of the central nervous system is very limited and few effective treatments are currently available for spinal cord injury.It is therefore a priority to develop new drugs that can promote structural and functional recovery after spinal cord injury.Previous studies have shown that peptides can promote substantial repair and regeneration of injured tissue.While amphibians have a pronounced ability to regenerate the spinal cord,few studies have investigated the effect of amphibian spinal cord-derived peptides on spinal cord injury.Here we report for the first time the successful identification and isolation of a new polypeptide,VD11(amino acid sequence:VDELWPPWLPC),from the spinal cord of an endemic Chinese amphibian(Odorrana schmackeri).In vitro experiments showed that VD11 promoted the secretion of nerve growth factor and brain-derived neurotrophic factor in BV2 cells stimulated with lipopolysaccharide,as well as the proliferation and synaptic elongation of PC12 cells subjected to hypoxia.In vivo experiments showed that intravertebral injection of VD11 markedly promoted recovery of motor function in rats with spinal cord injury,alleviated pathological damage,and promoted axonal regeneration.Furthermore,RNA sequencing and western blotting showed that VD11 may affect spinal cord injury through activation of the AMPK and AKT signaling pathways.In summary,we discovered a novel amphibian-derived peptide that promotes structural and functional recovery after spinal cord injury.

Anti-hyperglycemic effects of dihydromyricetin in streptozotocin-induced diabetic rats

Dihydromyricetin(DHM),as a bioactive flavanonol compound,is mainly found in“Tengcha”(Ampelopsis grossedentata)cultivated in south of China.This study aimed to investigate the anti-hyperglycemic and antidyslipidemic activities of DHM using type 2 diabetes mellitus(T2D)rats,which was induced by feeding with high fat and fructose diet for 42 days and intraperitoneal administration of streptozocin.Forty-eight freshlyweaned rats were randomly assigned into the negative control(Blank),low dose(100 mg/kg),medium dose(200 mg/kg),high dose(400 mg/kg),and positive(40 mg/kg,met)groups.Fasting blood glucose and body weight were measured at weekly interval.Oral glucose tolerance tests were performed on days 42.The results revealed that DHM possessed significant antihyperglycaemic and antihyperinsulinemic effects.Moreover,after the DHM treatment,p-Akt and p-AMPK expression was upregulated,and glycogen synthase kinase-3β(GSK-3β)expression was downregulated,indicating that the potential anti-diabetic mechanism of DHM might be due to the regulation of the AMPK/Akt/GSK-3βsignaling pathway.

cPKCγ Deficiency Exacerbates Autophagy Impairment and Hyperphosphorylated Tau Buildup through the AMPK/mTOR Pathway in Mice with Type 1 Diabetes Mellitus

Type 1 diabetes mellitus(T1DM)-induced cognitive dysfunction is common,but its underlying mechanisms are still poorly understood.In this study,we found that knockout of conventional protein kinase C(cPKC)γsignificantly increased the phosphorylation of Tau at Ser214 and neurofibrillary tangles,but did not affect the activities of GSK-3βand PP2A in the hippocampal neurons of T1DM mice.cPKCγdeficiency significantly decreased the level of autophagy in the hippocampal neurons of T1DM mice.Activation of autophagy greatly alleviated the cognitive impairment induced by cPKCγdeficiency in T1DM mice.Moreover,cPKCγdeficiency reduced the AMPK phosphorylation levels and increased the phosphorylation levels of mTOR in vivo and in vitro.The high glucose-induced Tau phosphorylation at Ser214 was further increased by the autophagy inhibitor and was significantly decreased by an mTOR inhibitor.In conclusion,these results indicated that cPKCγpromotes autophagy through the AMPK/mTOR signaling pathway,thus reducing the level of phosphorylated Tau at Ser214 and neurofibrillary tangles.

白细胞分化抗原36的棕榈酰化位点突变对HepG2细胞自噬的影响

目的:探讨白细胞分化抗原36(cluster of differentiation 36,CD36)的棕榈酰化位点突变对HepG2细胞自噬的影响。方法:构建过表达野生型CD36(WT-CD36)和棕榈酰化位点突变型CD36(AA-SS)的HepG2细胞系。自噬双标腺病毒(GFP-mRFP-LC3腺病毒)感染细胞,用共聚焦显微镜观察自噬;细胞免疫荧光染色和共聚焦显微镜检测转录因子EB(transcription factor EB,TFEB)核转位;Western blot检测肝激酶B1(liver kinase B1,LKB1)和AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)总蛋白表达及其磷酸化水平;免疫共沉淀检测CD36与蛋白酪氨酸激酶Fyn的共聚体形成。结果:与WT-CD36组相比,AA-SS组细胞内GFP-mRFP-LC3腺病毒绿色荧光明显减弱,红色荧光明显增强,表明AA-SS-HepG2细胞的自噬-溶酶体流增强(P<0.01)。同时,与WT-CD36组相比,AA-SS组CD36与Fyn共聚体的形成显著减少(P<0.01),LKB1蛋白的磷酸化水平降低(P<0.01),而AMPK的磷酸化水平升高(P<0.01)。此外,TFEB在AA-SS组细胞的核内定位也较WT-CD36组显著增多(P<0.05)。结论:CD36的棕榈酰化位点突变能减少CD36/Fyn共聚体形成,抑制LKB1蛋白磷酸化,从而激活AMPK-TFEB通路,促进TFEB核转位,增强HepG2细胞自噬。

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.

Promotion and Mechanism of Acupotomy on Chondrocyte Autophagy in Knee Osteoarthritis Rabbits

Objective:To explore the effect of acupotomy intervention on autophagy of chondrocytes in rabbits with knee osteoarthritis(KOA),and to determine the possible mechanisms of acupotomy to alleviate cartilage degeneration.Methods:The modified Videman method was used to construct a KOA rabbit model.After modeling,40 rabbits were randomly divided into 4 groups by a random number table:control;KOA(model);KOA+acupotomy(acupotomy),and KOA+sham acupotomy(sham),10 in each group.After a 3-week treatment course,the knee joint activity was determined by the modified Lequesne MG index.Hematoxylin-eosin staining staining was used to examine the morphological changes of chondrocytes.Autophagy of chondrocytes was observed by transmission electron microscopy.The surface morphology of cartilage tissue was observed by scanning electron microscope.The mRNA and protein levels of AMP kinase/mammalian target of rapamycin/Unc-51(AMPK/mTOR/ULK1)signal pathway key proteins,autophagy-related factor Beclin-1 and microtubule-associated protein 1A/1B light chain 3(LC3)in rabbit knee cartilage were assessed by real-time fluorescence quantitative polymerase chain reaction and Western blot,respectively.Results:The modified Lequesne MG score of acupotomy group was significantly lower than that of model group(P<0.05).Pathological results showed that chondrocyte autophagy decreased and cartilage surface was rough in the model group,which recovered after acupotomy treatment.The mRNA expressions of AMPK,ULK1,Beclin-1 and the protein levels of p-AMPK,p-ULK1,Beclin-1,and LC3Ⅱ/LC3Ⅰwere decreased in the model group,while the mRNA and protein expressions of mTOR were increased(P<0.01).However,acupotomy treatment reversed these abnormal changes(P<0.05).Conclusions:Acupotomy could effectively up-regulate the expressions of AMPK,ULK1 and Beclin1,reduce the expression of mTOR,promote autophagy,and alleviate joint degeneration.Acupotomy is a promising complementary and alternative therapy for KOA.