Hypoglycemic mechanism of Tegillarca granosa polysaccharides on type 2 diabetic mice by altering gut microbiota and regulating the PI3K-akt signaling pathwaye

Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin.TGP(5.1×10^(3) Da)was composed of mannose,glucosamine,rhamnose,glucuronic acid,galactosamine,glucose,galactose,xylose,and fucose.It could significantly alleviate weight loss,reduce fasting blood glucose levels,reverse dyslipidemia,reduce liver damage from oxidative stress,and improve insulin sensitivity.RT-PCR and Western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance.TGP increased the abundance of Allobaculum,Akkermansia,and Bifidobacterium,restored the microbiota abundance in the intestinal tracts of mice with T2DM,and promoted short-chain fatty acid production.This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.

miR-152-3p通过AKT/GSK-3β/Nrf2信号通路促进脑出血大鼠神经元铁死亡

目的:探讨miR-152-3p通过AKT/GSK-3β/Nrf2信号通路促进脑出血(ICH)大鼠神经元铁死亡的机制。方法:使用大鼠神经元细胞为研究对象,采用氧合血红蛋白(oxyHb)刺激神经元细胞构建ICH体外细胞模型,分别将miR-152-3p inhibitor和(或)PIK3CA抑制剂分别处理细胞,采用流式细胞术观察细胞凋亡情况,RT-qPCR、Western blot检测相关基因和蛋白表达情况;并用细胞免疫荧光观察Nrf2蛋白的入核率;用双荧光素酶靶标实验验证miR-152-3p与PIK3CA的关系。结果:将miR-152-3p inhibitor转染的细胞构建ICH细胞模型后,细胞凋亡率明显降低(P<0.01);SLC7A11、GPx4、PIK3CA、Nrf2蛋白表达水平以及p-AKT/AKT比率显著升高而GSK-3β蛋白表达水平显著降低(P<0.01);同时,Nrf2蛋白入核量也显著升高(P<0.01);而此作用在使用PIK3CA抑制剂干预后,miR-152-3p inhibitor的改善效果消失;荧光素酶靶标实验证实,miR-152-3p可靶向调控PIK3CA。结论:miR-152-3p通过AKT/GSK-3β/Nrf2信号通路促进ICH大鼠神经元铁死亡。

Liqi Huoxue dripping pill protects against myocardial ischemia-reperfusion injury via the PI3K/Akt/GSK-3β signaling pathway in rats

Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;however,its mechanism of action remains unclear.The purpose of this study was to investigate the protective mechanism of LQHXDP on MIRI in rats and its relationship with the PI3K/Akt signaling pathway.Methods:In this study,Sprague-Dawley rats were pre-infused with LQHXDP(175 mg/kg/d)for 10 days.PI3K inhibitor LY294002(0.3 mg/kg)was intravenously injected 15 minutes before ischemia.The rat model of MIRI was established by ligating the left anterior descending coronary artery.Subsequently,cardiac hemodynamics,serum myocardial injury markers,inflammatory factors,myocardial infarct size,antioxidant indexes,myocardial histopathology,and phosphorylation levels of key proteins of PI3K/Akt signaling pathway were assessed in rats.Results:LQHXDP was found to improve cardiac hemodynamic indexes,reduce serum creatine kinase MB isoenzyme activity and cardiac troponin and heart-type fatty acid binding protein levels,lower serum interleukin-1 beta,interleukin-6 and tumour necrosis factorαlevels,reduce the myocardial infarct size and enhance the antioxidant capacity of myocardial tissue in MIRI rats.Pathological analysis revealed that LQHXDP attenuated the extent of myocardial injury and protected mitochondria from damage in MIRI rats.Immunoblot analysis revealed that LQHXDP increased the expression levels of p-Akt and p-GSK-3βin MIRI rat cardiomyocytes.PI3K inhibitor LY294002 could impair these effects of LQHXDP.Conclusion:LQHXDP attenuated myocardial injury,attenuated oxidative stress injury and reduced inflammatory response in MIRI rats,and its protective effects were mediated by activating of PI3K/Akt/GSK-3βsignaling pathway.

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.

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.

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.

Rosmarinic acid elicits neuroprotection in ischemic stroke via Nrf2 and heme oxygenase 1 signaling

Rosmarinic acid（RA） can elicit a neuroprotective effect against ischemic stroke, but the precise molecular mechanism remains poorly understood. In this study, an experimental ischemic stroke model was established in CD-1 mice（Beijing Vital River Laboratory Animal Technology, Beijing, China） by occluding the right middle cerebral artery for 1 hour and allowing reperfusion for 24 hours. After intraperitoneally injecting model mice with 10, 20, or 40 mg/kg RA, functional neurological deficits were evaluated using modified Longa scores. Subsequently, cerebral infarct volume was measured using TTC staining and ischemic brain tissue was examined for cell apoptosis with TUNEL staining. Superoxide dismutase activity and malondialdehyde levels were measured by spectrophometry. Expression of heme oxygenase-1（HO-1）, nuclear factor erythroid 2-related factor 2（Nrf2）, Bcl-2, Bax, Akt, and phospho-Ser473 Akt proteins in ischemic brain tissue was detected by western blot, while mRNA levels of Nrf2, HO-1, Bcl-2, and Bax were analyzed using real time quantitative PCR. In addition, HO-1 enzyme activity was measured spectrophotometrically. RA（20 and 40 mg/kg） greatly improved neurological function, reduced infarct volume, decreased cell apoptosis, upregulated Bcl-2 protein and mRNA expression, downregulated Bax protein and mRNA expression, increased HO-1 and Nrf2 protein and mRNA expression, increased superoxide dismutase activity, and decreased malondialdehyde levels in ischemic brain tissue of model mice. However, intraperitoneal injection of a HO-1 inhibitor（10 mg/kg zinc protoporphyrin IX） reversed the neuroprotective effects of RA on HO-1 enzyme activity and Bcl-2 and Bax protein expression. The PI3 K/Akt signaling pathway inhibitor LY294002（10 mM） inhibited Akt phosphorylation, as well as Nrf2 and HO-1 expression. Our findings suggest that RA has anti-oxidative and anti-apoptotic properties that protect against ischemic stroke by a mechanism involving upregulation of Nrf2 and HO-1 expression via the PI3 K/Akt signaling pathway.

PTEN and AKT/GSK-3β/CRMP-2 signaling pathway are involved in neuronal apoptosis and axonal injury in early brain injury after SAH in rats

In early brain injury(EBI)after subarachnoid hemorrhage(SAH),white matter(WM)axonal injury plays a key role in the prognosis of the disease.The purpose of this study was to investigate the effects of phosphatase and tensin homolog deleted on chromosome ten(PTEN)on axonal injury and neuronal apoptosis post-SAH in rats and to find its underlying mechanism.Adeno-associated virus was injected into the lateral ventricle to suppress or promote PTEN.Neural function post-SAH in animals was determined by the modified Garcia score,beam balance,and Rotarod test,and the blood–brain barrier disruption was assessed by the brain water content.Axonal injury post-SAH was observed by TEM and determined by IF,and neuron apoptosis was measured by TUNEL staining.The mechanism was analyzed by Western blot to detect p-PTEN/PTEN,p-AKT/AKT,p-GSK-3β/GSK-3β,p-CRMP-2/CRMP-2,axonal injury markerβ-APP and pro-and anti-apoptosis proteins,including Bax and Bcl-2,expression.We found 1.After knocking down PTEN,neuronal apoptosis and axonal injury were alleviated,and nerve function and blood–brain barrier were protected;accordingly,after overexpression of PTEN,neuronal apoptosis and axon damage were aggravated,and nerve function damage and blood–brain barrier damage were increased.2.PTEN and AKT/GSK-3β/CRMP-2 pathway were jointly involved in regulating neuronal apoptosis and WM axon injury after SAH.According to our research,PTEN was a negative factor of EBI,and together with the AKT/GSK-3β/CRMP-2 signaling pathway aggravates neuronal apoptosis and WM axon damage after SAH.Inhibition of PTEN expression may become a new target for SAH treatment.

Hesperetin induces glyoxalase 1 enhancement in SH-SY5Y cells cultured with high glucose via Nrf2/ARE activation

OBJECTIVE To investigate the neuroprotective effects of hesperetin on central neurons under chronic high glucose,and the relationship to glyoxalase 1(Glo-1),a cytoprotective enzyme.METHODS The human neuroblas⁃toma SH-SY5Y cells were divided into 5 groups:normal glucose,high glucose(HG),HG plus low,middle,or high concentra⁃tion of hesperetin(1,5,25μmol·L^-1).After treatment for 72 h,neuron damages,Glo-1 expressions and functions,as well as Nrf2/ARE pathway and its regulating mechanisms were examined.RESULTS Hesperetin increased cell viability and decreased lactate dehydrogenase release,which was accompanied by the elevated activity,protein,and mRNA levels of Glo-1 as well as the enhanced Glo-1 functions in SH-SY5Y cells cultured with HG.Moreover,hesperetin activated Nrf2/ARE pathway as evidenced by the raised Nrf2 and p-Nrf2 levels in nucleus and up-regulation of γ-glutamycysteine synthase(γ-GCS),a well-known target gene of Nrf2/ARE pathway.Nevertheless,pretreatment with a PKC inhibitor(Go 6983)or an Akt inhibitor(MK-22062HCl,reflecting GSK-3β activation)abolished the effect of hesperetin on protein expressions of Glo-1 and γ-GCS.CONCLUSION Hesperetin exerted the neuroprotection by promoting Glo-1 function in central neurons in long-term HG condition,which was mediated by activation of Nrf2/ARE pathway;moreover,the increased Nrf2 phosphorylation and nuclear translocation mediated by PKC activation and/or GSK-3β inhibition were involved in the activation of Nrf2/ARE pathway by hesperetin.

Macrophage-derived exosomal miR-342-3p promotes the progression of renal cell carcinoma through the NEDD4L/CEP55 axis

Due to its difficulty in early diagnosis and lack of sensitivity to chemotherapy and radiotherapy,renal cell carcinoma(RCC)remains to be a frequent cause of cancer-related death.Here,we probed into new targets for its early diagnosis and treatment for RCC.microRNA(miRNA)data of M2-EVs and RCC were searched on the Gene Expression Omnibus database,followed by the prediction of the potential downstream target.Expression of target genes was measured via RT-qPCR and Western blot,respectively.M2 macrophage was obtained viaflow cytometry with M2-EVs extracted.The binding ability of miR-342-3p to NEDD4L and to CEP55 ubiquitination was studied with their roles in the physical abilities of RCC cells assayed.Subcutaneous tumor-bearing mouse models and lung metastasis models were prepared to observe in vivo role of target genes.M2-EVs induced RCC growth and metastasis.miR-342-3p showed high expression in both M2-EVs and RCC cells.M2-EVs carrying miR-342-3p promoted RCC cell abilities to proliferate,invade and migrate.In RCC cells,M2-EV-derived miR-342-3p could specifically bind to NEDD4L and consequently elevate CEP55 protein expression via suppressing NEDD4L,thereby exerting tumor-promoting effects.CEP55 could be degraded by ubiquitination under the function of NEDD4L,and miR-342-3p delivered by M2-EVs facilitated the RCC occurrence and development by activating the PI3K/AKT/mTOR signaling pathway.In conclusion,M2-EVs promote RCC growth and metastasis by delivering miR-342-3p to suppress NEDD4L and subsequently inhibit CEP55 ubiquitination and degradation via activation of the PI3K/AKT/mTOR signaling pathway,strongly driving the proliferative,migratory and invasive of RCC cells.

Garcinia xanthochymus extract protects PC12 cells from H2O2-induced apoptosis through modulation of PI3K/AKT and NRF2/HO-1 pathways

The aim of the present study was to investigate the protective effects and underlying mechanisms of Garcinia xanthochymus, a perennial medicinal plant native to Yunnan, China, against H2 O2-induced oxidative damage in rat pheochromacytoma PC12 cells. Preincubation of PC12 cells with fruit Et OAc fraction(fruit-EFr., 12.5–50 μmol·L^(-1)) of G. xanthochymus for 24 h prior to H_2O_2 exposure markedly improved cell viability and increased the activities of antioxidant enzymes(superoxide dismutase, catalase, and heme oxygenase-1 [HO-1]), prevented lactate dehydrogenase release and lipid peroxidation malondialdehyde production, attenuated the decrease of matrix metalloproteinases(MMP), and scavenged reactive oxygen species(ROS). Fruit-EFr. also reduced BAX and cytochrome C expression and improved BCL-2 expression, thereby decreasing the ratio of BAX to BCL-2. Fruit-EFr. activated the nuclear translocation of NRF2 to increase HO-1 and induced the phosphorylation of AKT. Its cytoprotective effect was abolished by LY294002, a specific inhibitor of PI3 K. Taken together, the above findings suggested that fruit-EFr.of G. xanthochymus could enhance cellular antioxidant defense capacity, at least in part, through upregulating HO-1 expression and activating the PI3 K/AKT pathway and that it could suppress H_2O_2-induced oxidative damage via PI3 K/AKT and NRF2/HO-1 signaling pathways.

CD146 promotes malignant progression of breast phyllodes tumor through suppressing DCBLD2 degradation and activating the AKT pathway

Background As a rapid-progressing tumor,breast malignant phyllodes tumors(PTs)are challenged by the lack of effective therapeutic strategies and suitable prognostic markers.This study aimed to clarify the role and mechanism of CD146 on promoting PTs malignant progression,and to identify a novel prognosis marker and treatment target of breast malignant PTs.Methods The expression and prognostic significance of CD146 in PTs was detected through single-cell RNA-sequencing(scRNA-seq),immunostaining,real-time PCR and other methodologies.Functional experiments including proliferation assay,colony formation assay,transwell assay,and collagen contraction assay were conducted to validate the role of CD146 in malignant progression of PTs.The efficacy of anti-CD146 monoclonal antibody AA98 against malignant PTs was corroborated by a malignant PT organoid model and a PT patient-derived xenograft(PDX)model.Transcriptome sequencing,proteomic analysis,co-immunoprecipitation,and pull-down assay was employed to identify the modulating pathway and additional molecular mechanism.Results In this study,the scRNA-seq analysis of PTs disclosed a CD146-positive characteristic in theα-SMA+fibroblast subset.Furthermore,a progressive elevation in the level of CD146 was observed with the malignant progression of PTs.More importantly,CD146 was found to serve as an independent predictor for recurrence in PT patients.Furthermore,CD146 was found to augment the viability and invasion of PTs.Mechanistically,CD146 acted as a protective“shield”to prevent the degradation of Discoidin,CUB,and LCCL domain-containing protein 2(DCBLD2),thereby activating the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway and enhancing malignant behaviors of PT cells.In the malignant PT organoid and PDX model,a significant suppression of malignant PT growth was observed after the application of AA98.Conclusions These findings suggested that CD146 served as an efficacious marker for predicting PT malignant progression and showed promise as a prognosis marker and treatment target of breast malignant PTs.The study further unveiled the essential role of the CD146-DCBLD2/PI3K/AKT axis in the malignant progression of PTs.

WJH 6^(th) Anniversary Special Issues(2): Hepatocellular carcinoma Mammalian target of rapamycin inhibition in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the leading causes of cancer-related death worldwide. It is associated with a poor prognosis and has limited treatment options. Sorafenib, a multi-targeted kinase inhibitor, is the only available systemic agent for treatment of HCC that improves overall survival for patients with advanced stage disease; unfortunately, an effective second-line agent for the treatment of progressive or sorafenib-resistant HCC has yet to be identified. This review focuses on components of the mammalian target of rapamycin(mTOR) pathway, its role in HCC pathogenesis, and dual mTOR inhibition as a therapeutic option with potential efficacy in advanced HCC. There are several important upstream and downstream signals in the mTOR pathway, and alternative tumor-promoting pathways are known to exist beyond mTORC1 inhibition in HCC. This review analyzes the relationships of the upstream and downstream regulators of mTORC1 and mTORC2 signaling; it also provides a comprehensive global picture of the interaction between mTORC1 and mTORC2 which demonstrates the pre-clinical relevance of the mTOR pathway in HCC pathogenesis and progression. Finally, it provides scientific rationale for dual mTORC1 and mTORC2 inhibition in the treatment of HCC. Clinical trials utilizing mTORC1 inhibitors and dual mTOR inhibitors in HCC are discussed as well. The mTOR pathway is comprised of two main components, mTORC1 and mTORC2; each has a unique role in the pathogenesis and progression of HCC. In phase Ⅲ studies, mTORC1 inhibitors demonstrate anti-tumor ac-tivity in advanced HCC, but dual mTOR(mTORC1 and mTORC2) inhibition has greater therapeutic potential in HCC treatment which warrants further clinical investigation.

CircMAN1A2 promotes vasculogenic mimicry of nasopharyngeal carcinoma cells through upregulating ERBB2 via sponging miR-940

Nasopharyngeal carcinoma(NPC)is the most prevalent human primary malignancy of the head and neck,and the presence of vasculogenic mimicry(VM)renders anti-angiogenic therapy ineffective and poorly prognostic.However,the underlying mechanisms are unclear.In the present study,we used miR-940 silencing and overexpression for in vitro NPC cell EdU staining,wound healing assay and 3D cell culture assay,and in vivo xenograft mouse model and VM formation to assess miR-940 function.We found that ectopic miR-940 expression reduced NPC cell proliferation,migration and VM,as well as tumorigenesis in vivo.By bioinformatic analysis,circMAN1A2 was identified as a circRNA that binds to miR-940.Mechanistically,we confirmed that circMAN1A2 acts as a sponge for miR-940,impairs the inhibitory effect of miR-940 on target ERBB2,and then activates the PI3K/AKT/mTOR signaling pathway using RNA-FISH,dual luciferase reporter gene and rescue analysis assays.In addition,upregulation of ERBB2 expression is associated with clinical staging and poor prognosis of NPC.Taken together,the present findings suggest that circMAN1A2 promotes VM formation and progression of NPC through miR-940/ERBB2 axis and further activates the PI3K/AKT/mTOR pathway.Therefore,circMAN1A2 may become a biomarker and therapeutic target for anti-angiogenic therapy in patients with nasopharyngeal carcinoma.

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.

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.

白虎加人参汤加减方对2型糖尿病大鼠骨骼肌GLUT4表达及抗氧化应激作用机制的研究

目的探讨白虎加人参汤加减方对2型糖尿病(T2DM)大鼠骨骼肌葡萄糖转运蛋白4(GLUT4)表达及抗氧化应激作用的影响及机制。方法将SD大鼠随机分为对照组、模型组、阳性药组(二甲双胍,200 mg·kg^(-1))及白虎加人参汤加减方高、低剂量组(37.8、18.9 g·kg^(-1)),每组8只。采用高脂高糖饲料喂养4周后,一次性腹腔注射STZ 40 mg·kg^(-1)复制T2DM大鼠模型;灌胃给药(10 mL·kg^(-1)),每日1次,连续8周,T2DM大鼠继续给予高脂高糖饲料喂养。给药期间每2周测定1次空腹血糖(FBG)值;给药结束后,测定大鼠糖化血红蛋白(HbA1c)、血清胰岛素(INS)水平,计算胰岛素抵抗指数(HOMA-IR);测定大鼠胰腺组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及丙二醛(MDA)水平;qRT-PCR法检测肌肉组织中GLUT4 mRNA表达水平;Western Blot法检测肌肉组织中GLUT4蛋白及胰腺组织中蛋白激酶B(AKT)/糖原合成激酶3β(GSK-3β)/核因子NF-E2相关因子(Nrf2)通路相关蛋白表达水平;免疫组织化学法检测胰腺组织中血红素加氧酶1(HO-1)、n-Nrf2蛋白表达水平。结果与对照组比较,模型组大鼠的FBG、HbA1c及HOMA-IR明显升高(P<0.05),血清INS水平明显降低(P<0.05);胰腺组织的CAT、SOD、GSH-Px水平均明显降低(P<0.05),MDA水平明显升高(P<0.05);肌肉组织中GLUT4蛋白及mRNA表达水平明显降低(P<0.05);胰腺组织中的p-AKT/AKT、p-GSK-3β/GSK-3β蛋白表达水平明显降低(P<0.05),n-Nrf2、n-Fyn、HO-1蛋白表达水平明显升高(P<0.05)。与模型组比较,白虎加人参汤加减方组大鼠第4、6、8周的FBG水平及HbA1c、HOMA-IR均明显降低(P<0.05),血清INS水平明显升高(P<0.05);胰腺组织中CAT、SOD、GSH-Px水平明显升高(P<0.05),MDA水平明显降低(P<0.05);肌肉组织中GLUT4蛋白及mRNA表达水平均明显升高(P<0.05);胰腺组织中p-AKT/AKT、p-GSK-3β/GSK-3β、n-Nrf2、HO-1蛋白表达水平明显升高(P<0.05),n-Fyn蛋白表达水平明显降低(P<0.05)。结论白虎加人参汤加减方可能通过上调骨骼肌GLUT4表达来改善T2DM大鼠的胰岛素抵抗,并可能通过调控AKT/GSK-3β/Nrf2通路发挥抗氧化应激作用。

M2 macrophage-derived exosomes promote diabetic fracture healing by acting as an immunomodulator

Diabetes mellitus is a chronically inflamed disease that predisposes to delayed fracture healing.Macrophages play a key role in the process of fracture healing by undergoing polarization into either M1 or M2 subtypes,which respectively exhibit pro-inflammatory or anti-inflammatory functions.Therefore,modulation of macrophage polarization to the M2 subtype is beneficial for fracture healing.Exosomes perform an important role in improving the osteoimmune microenvironment due to their extremely low immunogenicity and high bioactivity.In this study,we extracted the M2-exosomes and used them to intervene the bone repair in diabetic fractures.The results showed that M2-exosomes significantly modulate the osteoimmune microenvironment by decreasing the proportion of M1 macrophages,thereby accelerating diabetic fracture healing.We further confirmed that M2-exosomes induced the conversion of M1 macrophages into M2 macrophages by stimulating the PI3K/AKT pathway.Our study offers a fresh perspective and a potential therapeutic approach for M2-exosomes to improve diabetic fracture healing.

Mechanism Research of Reducing Obesity-Induced Insulin Resistance in the White Adipose Tissue by Knockdown of Neuropeptide Y Expression in the Dorsomedial Hypothalamus

This study investigated the specific mechanism of knockdown of neuropeptide Y(NPY) in reducing obesity-induced insulin resistance in the white adipose tissue. Adeno-associated virus(AAV)-mediated RNAi was utilized to downregulate NPY expression in rats fed either regular chow or high fat diet. By investigating the differences in rat body weight and food intake, we assessed the effect of knockdown of NPY expression on insulin sensitivity and β-cell proliferation. Glucose consumption and 2-[3 H]DG uptake in 3 T3-L1 adipocytes were assessed to determine the molecular mechanisms. The results showed that knockdown of NPY expression in the dorsomedial hypothalamus(DMH) reduced obesity-induced insulin resistance, increased glucose consumption, and decreased 2-[3 H]DG uptake in 3 T3-L1 adipocytes via the PI3 K/Akt/GSK-3β signaling pathways and the NPY Y5 receptor.