Anti-diabetic potential of apigenin,luteolin,and baicalein via partially activating PI3K/Akt/GLUT-4 signaling pathways in insulin-resistant HepG2 cells

Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.

Elevated retinol binding protein 4 levels are associated with atherosclerosis in diabetic rats via JAK2/STAT3 signaling pathway

BACKGROUND Atherosclerosis is a major cause of mortality worldwide and is driven by multiple risk factors,including diabetes,which results in an increased atherosclerotic burden,but the precise mechanisms for the occurrence and development of diabetic atheroscerosis have not been fully elucidated.AIM To summarize the potential role of retinol binding protein 4(RBP4) in the pathogenesis of diabetic atheroscerosis,particularly in relation to the RBP4-Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3)signaling pathway.METHODS Male Wistar rats were randomly divided into three groups,including a control group(NC group),diabetic rat group(DM group),and diabetic atherosclerotic rat group(DA group).The contents of total cholesterol(TC), high-density lipoprotein cholesterol(HDL-c), triglycerides(TG), low-density lipoprotein cholesterol(LDLc), fasting insulin(FINS),fasting plasma glucose,and hemoglobin A1 c(HbA1 c)were measured.Moreover,the adipose and serum levels of RBP4,along with the expression levels of JAK2, phosphorylated JAK2(p-JAK2), STAT3,phosphorylated STAT3(p-STAT3), B-cell lymphoma-2(Bcl-2), and Cyclin D1 in aortic tissues were also measured.Besides,homeostasis model assessment of insulin resistance(HOMA-IR) and atherogenic indexes(AI) were calculated.RESULTS Compared with the NC and DM groups,the levels LDL-c,TG,TC,FINS,HOMAIR,RBP4,and AI were upregulated,whereas that of HDL-c was downregulated in the DA group(P <0.05);the mRNA levels of JAK2,STAT3,Cyclin D1,and Bcl-2 in the DA group were significantly increased compared with the NC group and the DM group;P-JAK2,p-JAK2/JAK2 ratio,p-STAT3,p-STAT3/STAT3 ratio,Cyclin D1,and Bcl-2 at protein levels were significantly upregulated in the DA group compared with the NC group and DM group.In addition,as shown by Pearson analysis,serum RBP4 had a positive correlation with TG,TC,LDL-c,FINS,HbA1 C,p-JAK2,p-STAT3,Bcl-2,Cyclin D1,AI,and HOMA-IR but a negative correlation with HDL-c.In addition,multivariable logistic regression analysis showed that serum RBP4,p-JAK2,p-STAT3,and LDL-c were predictors of the presence of diabetic atherosclerosis.CONCLUSION RBP4 could be involved in the initiation or progression of diabetic atherosclerosis by regulating the JAK2/STAT3 signaling pathway.

Melatonin improves synapse development by PI3K/Akt signaling in a mouse model of autism spectrum disorder

Autism spectrum disorders are a group of neurodevelopmental disorders involving more than 1100 genes,including Ctnnd2 as a candidate gene.Ctnnd2knockout mice,serving as an animal model of autis m,have been demonstrated to exhibit decreased density of dendritic spines.The role of melatonin,as a neuro hormone capable of effectively alleviating social interaction deficits and regulating the development of dendritic spines,in Ctnnd2 deletion-induced nerve injury remains unclea r.In the present study,we discove red that the deletion of exon 2 of the Ctnnd2 gene was linked to social interaction deficits,spine loss,impaired inhibitory neurons,and suppressed phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt) signal pathway in the prefrontal cortex.Our findings demonstrated that the long-term oral administration of melatonin for 28 days effectively alleviated the aforementioned abnormalities in Ctnnd2 gene-knockout mice.Furthermore,the administration of melatonin in the prefro ntal cortex was found to improve synaptic function and activate the PI3K/Akt signal pathway in this region.The pharmacological blockade of the PI3K/Akt signal pathway with a PI3K/Akt inhibitor,wo rtmannin,and melatonin receptor antagonists,luzindole and 4-phenyl-2-propionamidotetralin,prevented the melatonin-induced enhancement of GABAergic synaptic function.These findings suggest that melatonin treatment can ameliorate GABAe rgic synaptic function by activating the PI3K/Akt signal pathway,which may contribute to the improvement of dendritic spine abnormalities in autism spectrum disorders.

Epigenetic inactivation of secreted frizzled-related protein 2 in esophageal squamous cell carcinoma

AIM： To investigate the expression and methylation status of the secreted frizzled-related protein 2 （SFRP2） in esophageal squamous cell carcinoma （ESCC） and ex- plore its role in ESCC carcinogenesis.METHODS： Seven ESCC cell lines （KYSE 30, KYSE150, KYSE410, KYSE510, EC109, EC9706 and TE-1） and one immortalized human esophageal epithelial cell line （Het- 1A）, 20 ESCC tissue samples and 20 paired adjacent non-tumor esophageal epithelial tissues were analyzed in this study. Reverse-transcription polymerase chain reaction （RT-PCR） was employed to investigate the expression of SFRP2 in cell lines, primary ESCC tumor tissue, and paired adjacent normal tissue. Methylation status was evaluated by methylation-specific PCR and bisulfite sequencing. The correlation between expres- sion and promoter methylation of the SFRP2 gene was confirmed with treatment of 5-aza-2＇-deoxycytidine. To assess the potential role of SFRP2 in ESCC, we es-tablished stable SFRP2-transfected cells and examined them with regard to cell proliferation, colony formation, apoptosis and cell cycle in vivo and in vitro.RESULTS： SFRP2 mRNA was expressed in the im- mortalized normal esophageal epithelial cell line but not in seven ESCC cell lines. By methylation-specific PCR, complete methylation was detected in three cell lines with silenced SFRP2 expression, and extensive methylation was observed in the other four ESCC cell lines. 5-aza-2＇-deoxycytidine could restore the expres- sion of SFRP2 mRNA in the three ESCC cell lines lack- ing SFRP2 expression. SFRP2 mRNA expression was obviously lower in primary ESCC tissue than in adjacent normal tissue （0.939 ± 0.398 vs 1.51 ± 0.399, P 〈 0.01）. SFRP2 methylation was higher in tumor tissue than in paired normal tissue （95% vs 65%, P 〈 0.05）. The DNA methylation status of the SFRP2 correlated inversely with the SFRP2 expression. To assess the potential role of SFRP2 in ESCC, we established stable SFRP2 transfectants and control counterparts by in- troducing pcDNA3.1/v5 hisA -SFRP2 or pcDNA3.1/v5 hisA -empty vector into KYSE30 cells lacking SFRP2 expression. After transfection, the forced-expression of SFRP2 was confirmed by the RT-PCR. In comparison with the control groups, stably-expressed SFRP2 in KYSE 30 cells significantly reduced colony formation in vitro （47.17% 4± 15.61% vs 17% ：1： 3.6%, P = 0.031） and tumor growth in nude mice （917.86：1：249.35 mm3 vs 337.23 ± 124.43 mm3, P 〈 0.05）. Using flow cytom- etry analysis, we found a significantly higher number of early apoptotic cells in SFRP2-transfected cells than in the control cells （P = 0.025）. The mean cell number in the S and G2-M phases of the cell cycle was also significantly lower in SFRP2-transfected KYSE30 cells compared with mock transfected counterparts. CONCLUSION： Silencing of SFRP2 expression through promoter hypermethylation may be a factor in ESCC carcinogenesis through loss of its tumor-suppressive activity.

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.

Regulatory Effects of Zuogui Pill on Apoptosis of Follicles in Rats Injured by 60Co-γRays Based on PI3K/Akt/m TOR Signaling Pathway

[Objectives]To explore the protective effects of Zuogui Pill on ^(60)Co-γ-ray-induced premature aging of rats based on phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/Akt/mTOR)signaling pathway.[Methods]Sixty sexually mature female SD rats were irradiated with ^(60)Co-γ-ray(6.0 Gy,LD 40)for 24 h at one time.These rats were randomly divided into model group,Progynova group[0.18(g·kg)/d],Progynova[0.09(g·kg)/d]+Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill high dose[23.625(g·kg)/d)]group,Zuogui Pill medium dose[9.45(g·kg)/d)]group and Zuogui Pill low dose[4.725(g·kg)/d]group.The administration(once a day)lasted 21 d.The rat serum[follicle-stimulating hormone(FSH),luteinizing hormone(LH)and estradiol(E_(2))]were detected by Enzyme-linked immunosorbent assay(ELISA).The morphological changes of ovary were observed by hematoxylin-eosin(HE)staining.The apoptosis rate of granulosa cells was detected by terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL).The protein expression of phosphorylated(p)-PI3K,p-Akt,p-mTOR,B-cell lymphoma-2(Bcl-2),and Bcl-2-associated X protein(Bax)in ovarian tissues were detected by Western blot.[Results]Compared with the normal group,the model group showed significant increase in the serum FSH(P<0.01),significant decrease in serum E_(2)(P<0.05),and decrease in the number of early follicles and luteum in the ovary(P<0.01).Besides,the apoptosis rate of granulosa cells increased significantly(P<0.01);the expression of p-PI3K,p-Akt,p-mTOR and Bcl-2 in ovarian tissue decreased significantly,while the expression of Bax increased significantly(P<0.01).Compared with the model group,the number of early follicles in the ovary increased and the apoptosis rate of granulosa cells decreased after intervention in each administration group.In addition,the protein expressions of p-PI3K,p-Akt,p-mTOR and Bcl-2 increased,while the expression of Bax decreased,especially in Progynova+Zuogui Pill high dose group,the differences were statistically significant(P<0.05,P<0.01).[Conclusions]Zuogui Pill may protect the radiation-injured ovary through activating the expression of PI3K/Akt/mTOR protein in ovarian tissue,increasing the amount of Bcl-2 protein and inhibiting the expression of Bax protein.

Impaired PI3K/Akt signal pathway and hepatocellular injury in high-fat fed rats

AIM:To determine whether mitochondrial dysfunction resulting from high-fat diet is related to impairment of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt,also known as PKB) pathway. METHODS:Rat models of nonalcoholic fatty liver were established by high-fat diet feeding. The expression of total and phosphorylated P13K and Akt proteins in hepatocytes was determined by Western blotting. Degree of fat accumulation in liver was measured by hepatic triglyceride. Mitochondrial number and size were determined using quantitative morphometric analysis under transmission electron microscope. The permeability of the outer mitochondrial membrane was assessed by determining the potential gradient across this membrane.RESULTS:After Wistar rats were fed with high-fat diet for 16 wk,their hepatocytes displayed an accumulation of fat (103.1 ± 12.6 vs 421.5 ± 19.7,P < 0.01),deformed mitochondria (9.0% ± 4.3% vs 83.0% ± 10.9%,P < 0.05),and a reduction in the mitochondrial membrane potential (389.385% ± 18.612% vs 249.121% ± 13.526%,P < 0.05). In addition,the expression of the phosphorylated P13K and Akt proteins in hepatocytes was reduced,as was the expression of the anti-apoptotic protein Bcl-2,while expression of the pro-apoptotic protein caspase-3 was increased. When animals were treated with pharmacological inhibitors of P13K or Akt,instead of high-fat diet,a similar pattern of hepatocellular fat accumulation,mitochondrial impairment,and change in the levels of PI3K,Akt,Bcl-2 was observed. CONCLUSION:High-fat diet appears to inhibit the PI3K/Akt signaling pathway,which may lead to hepa-tocellular injury through activation of the mitochondrial membrane pathway of apoptosis.

Correlation between receptor-interacting protein 140 expression and directed differentiation of human embryonic stem cells into neural stem cells

Overexpression of receptor-interacting protein 140（RIP140） promotes neuronal differentiation of N2 a cells via extracellular regulated kinase 1/2（ERK1/2） signaling.However,involvement of RIP140 in human neural differentiation remains unclear.We found both RIP140 and ERK1/2 expression increased during neural differentiation of H1 human embryonic stem cells.Moreover,RIP140 negatively correlated with stem cell markers Oct4 and Sox2 during early stages of neural differentiation,and positively correlated with the neural stem cell marker Nestin during later stages.Thus,ERK1/2 signaling may provide the molecular mechanism by which RIP140 takes part in neural differentiation to eventually affect the number of neurons produced.

Interaction of Hsp40 with influenza virus M2 protein: implications for PKR signaling pathway

Influenza virus contains three integral membrane proteins:haemagglutinin,neuraminidase,and matrix protein(M1 and M2).Among them,M2 protein functions as an ion channel,important for virus uncoating in endosomes of virus-infected cells and essential for virus replication.In an effort to explore potential new functions of M2 in the virus life cycle,we used yeast two-hybrid system to search for M2-associated cellular proteins.One of the positive clones was identified as human Hsp40/Hdj1,a DnaJ/Hsp40 family protein.Here,we report that both BM2(M2 of influenza B virus)and A/M2(M2 of influenza A virus)interacted with Hsp40 in vitro and in vivo.The region of M2-Hsp40 interaction has been mapped to the CTD1 domain of Hsp40.Hsp40 has been reported to be a regulator of PKR signaling pathway by interacting with p58^(IPK) that is a cellular inhibitor of PKR.PKR is a crucial component of the host defense response against virus infection.We therefore attempted to understand the relationship among M2,Hsp40 and p58^(IPK) by further experimentation.The results demonstrated that both A/M2 and BM2 are able to bind to p58^(IPK)in vitro and in vivo and enhance PKR autophosphorylation probably via forming a stable complex with Hsp40 and P58^(IPK),and consequently induce cell death.These results suggest that influenza virus M2 protein is involved in p58^(IPK)mediated PKR regulation during influenza virus infection,therefore affecting infected-cell life cycle and virus replication.

TP53BP2:Roles in suppressing tumorigenesis and therapeutic opportunities

Malignant tumor is still a major problem worldwide.During tumorigenesis or tumor development,tumor suppressor p53-binding protein 2(TP53BP2),also known as apoptosis stimulating protein 2 of p53(ASPP2),plays a critical role in p53 dependent and independent manner.Expression of TP53BP2 is highly correlated with the prognosis and survival rate of malignant tumor patients.TP53BP2 can interact with p53,NF-κB p65,Bcl-2,HCV core protein,PP1,YAP,CagA,RAS,PAR3,and other proteins to regulate cell function.Moreover,TP53BP2 can also regulate the proliferation,apoptosis,autophagy,migration,EMT and drug resistance of tumor cells through downstream signaling pathways,such as NF-κB,RAS/MAPK,mevalonate,TGF-β1,PI3K/AKT,aPKC-ι/GLI1 and autophagy pathways.As a potential therapeutic target,TP53BP2 has been attracted more attention.We review the role of TP53BP2 in tumorigenesis or tumor development and the signal pathway involved in TP53BP2,which may provide more deep insight and strategies for tumor treatment.

Activation of glycine site and GluN2B subunit of NMDA receptors is necessary for ERK/CREB signaling cascade in rostral anterior cingulate cortex in rats:Implications for affective pain

Objective The rostral anterior cingulate cortex （rACC） is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors （NMDARs） are highly expressed in the rACC and mediate painrelated affect by activating a signaling pathway that involves cyclic adenosine monophosphate （cAMP）/protein ki- nase A （PKA） and/or extracellular regulated kinase （ERK）/cAMP-response element-binding protein （CREB）. The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. Methods Immunohistochemistry and Western blot analy- sis were used to separately assess the expression of phospho-ERK （pERK） and phospho-CREB （pCREB） in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. Results Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antago- nist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine- binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up- regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. Conclusion Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.

G protein b_1λ_2 subunits purification and their interaction with adenylyl cyclase

A preliminary study on the interaction of G protein (guanine triphosphate binding pro- tein) b1g2 subunits and their coupled components in cell signal transduction was conducted in vitro. The insect cell lines, Sf9 (Spodoptera frugiperda) and H5 (Trichoplusia ni ) were used to express the recombinant protein Gb1g2. The cell membrane containing Gb1g2 was isolated through affinity chromatography column with Ni-NTA agarose by FPLC method, and the highly purified protein was obtained. The adenylyl cyclase 2 (AC2) activity assay showed that the purified Gb1g2 could signifi-cantly stimulate AC2 activity. The interaction of b1g2 subunits of G protein with the cytoplasmic tail of various mammalian adenylyl cyclases was monitored by BIAcore technology using NTA sensor chip, which relies on the phenomenon of surface plasmon resonance (SPR). The experiments showed the direct binding of Gb1g2 to the cytoplasmic tail C2 domain of AC2. The specific binding domain of AC2 with Gb1g2 was the same as AC2 activity domain which was stimulated by Gb1g2.

Nuclear Dbf2-related Kinase 1 functions as tumor suppressor in glioblastoma by phosphorylation of Yes-associated protein

Background:The Nuclear Dbf2-related(NDR1)kinase is a member of the NDR/LATS family,which was a supplementary of Hippo pathway.However,whether NDR1 could inhibit glioblastoma(GBM)growth by phosphorylating Yes-associated protein(YAP)remains unknown.Meanwhile,the role of NDR1 in GBM was not clear.This study aimed to investigate the role of NDR1-YAP pathway in GBM.Methods:Bioinformation analysis and immunohistochemistry(IHC)were performed to identify the expression of NDR1 in GBM.The effect of NDR1 on cell proliferation and cell cycle was analyzed utilizing CCK-8,clone formation,immunofluorescence and flow cytometry,respectively.In addition,the xenograft tumor model was established as well.Protein interaction was examined by Coimmunoprecipitation and immunofluorescence to observe co-localization.Results:Bioinformation analysis and IHC of our patients’tumor tissues showed that expression of NDR1 in tumor tissue was relatively lower than that in normal tissues and was positively related to a lower survival rate.NDR1 could markedly reduce the proliferation and colony formation of U87 and U251.Furthermore,the results of flow cytometry showed that NDR1 led to cell cycle arrest at the G1 phase.Tumor growth was also inhibited in xenograft nude mouse models in NDR1-overexpression group.Western blotting and immunofluorescence showed that NDR1 could integrate with and phosphorylate YAP at S127 site.Meanwhile,NDR1 could mediate apoptosis process.Conclusion:In summary,our findings point out that NDR1 functions as a tumor suppressor in GBM.NDR1 is identified as a novel regulator of YAP,which gives us an in-depth comprehension of the Hippo signaling pathway.

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.

WNT1诱导信号通路蛋白2对肝细胞脂质代谢的影响及其作用机制

目的探讨不同浓度人重组WNT1诱导信号通路蛋白2(WISP2)对人肝癌细胞(HepG2)脂质代谢的影响及相关作用机制。方法分别用不同浓度(0、0.4、1和2 μg/L)人重组WISP2作用于HepG2细胞48 h, Cell-Titer发光法测定细胞活力, 酶法检测各组HepG2细胞内三酰甘油(TG)及总胆固醇(TC)含量, 同时应用实时荧光定量聚合酶链式反应(RT-qPCR)及免疫印迹法(western blot)检测HepG2细胞内脂质合成、分解、转运相关基因mRNA和蛋白表达水平。结果与对照组比较, 各浓度人重组WISP2处理组均未降低HepG2细胞的活性;人重组WISP2处理上调HepG2细胞TG、TC含量, 0.4、1、2 μg/L人重组WISP2处理组TG的含量分别为未处理组的1.254±0.039、1.216±0.028、1.174±0.014倍(F=6.791, P=0.006), TC含量分别为未处理组的1.264±0.057、1.394±0.101、1.392±0.077倍(F=7.045, P=0.005)。进一步研究发现, 与对照组比较, 加入人重组WISP2明显增加HepG2细胞脂质合成蛋白甾醇调节元件结合蛋白1(SREBP1)、羟甲基戊二酸单酰辅酶A还原酶(HMGCR)、乙酰辅酶A羧化酶(ACC)及二酰基甘油酰基转移酶(DGAT2)mRNA表达(均P<0.05), 显著上调SREBP1、ACC及脂肪酸合成酶(FAS)蛋白水平的表达(均P<0.05);但对低密度脂蛋白受体(LDLR)、载脂蛋白B(ApoB)、载脂蛋白E(ApoE)这类脂质转运蛋白及关键的脂质分解蛋白--脂肪三酰甘油脂肪酶(ATGL)的表达无明显影响。结论 rh-WISP2能显著增加肝细胞脂质含量, 促进脂质合成增加可能是其作用的关键机制。

The potential role of metformin in the treatment of Parkinson’s disease

The main treatments for Parkinson’s disease(PD)currently include surgery,rehabilitation,and most commonly,drug therapy.However,the drugs that are currently used to treat PD provide only symptomatic relief and delayed disease progression but have no curative effect and cause many adverse reactions.When considering pathogenic factors and metabolic regulation,PD and type 2 diabetes have a high rate of comorbidity;this provides a theoretical basis for the treatment of PD with first-line antidiabetic drugs.Among these agents,metformin reduces neuronal damage in the brains of PD patients via neuroprotection and the inhibition of oxidative stress and inflammatory responses,thus providing a novel strategy for the clinical treatment of PD.Here,we present the current state of knowledge about the use of metformin to treat PD and discuss its clinical prospects.