Simiao Wan alleviates obesity-associated insulin resistance via PKCε/IRS-1/PI3K/Akt signaling pathway based on network pharmacology analysis and experimental validation

Background:The purpose of the study was to investigatethe active ingredients and potential biochemicalmechanisms of Simiao Wan(SMW)in obesity-associated insulin resistance.Methods:An integrated network pharmacology method to screen the active compoundsand candidate targets,construct the protein-protein-interaction network,and ingredients-targets-pathways network was constructed for topological analysis to identify core targets and main ingredients.To find the possible signaling pathways,enrichment analysis was performed.Further,a model of insulin resistance in HL-7702 cells was established to verify the impact of SMW and the regulatory processes.Results:An overall of 63 active components and 151 candidate targets were obtained,in which flavonoids were the main ingredients.Enrichment analysis indicated that the PI3K-Akt signaling pathway was the potential pathway regulated by SMW in obesity-associated insulin resistance treatment.The result showed that SMW could significantly ameliorate insulin sensitivity,increase glucose synthesis and glucose utilization and reduce intracellular lipids accumulation in hepatocytes.Also,SMW inhibited diacylglycerols accumulation-induced PKCεactivity and decreased its translocation to the membrane.Conclusion:SMW ameliorated obesity-associated insulin resistance through PKCε/IRS-1/PI3K/Akt signaling axis in hepatocytes,providing a new strategy for metabolic disease treatment.

Characterization of Wnt1-inducible Signaling Pathway Protein-1 in Obese Children and Adolescents

Wnt1-inducible signaling pathway protein-1(WISP1),a member of the CCN family,is increasingly being recognized as a potential target for obesity and type 2 diabetes mellitus.Recent studies have shown that WISP1 can regulate low-grade inflammation in obese mice,and circulating WISP1 levels are associated with obesity and type 2 diabetes mellitus in adults.Herein,we measured serum WISP1 levels in obese youth and explored its relationships with pro-inflammatory cytokine interleukin 18(IL-18)and other metabolic indexes.Totally,44 normal-weight and 44 obese children and adolescents were enrolled.Physical and laboratory data were recorded,and then serum levels of WISP1 and IL-18 were determined by enzyme-linked immunosorbent assays.Results showed that serum levels of WISP1 were significantly higher in obese children and adolescents than in normal-weight healthy controls (1735.444-15.29 vs. 1364.084-18.69 pg/mL).WISP1 levels were significantly positively correlated with body mass index (BMI)and BMI z-score (r=0.392,P=0.008;r=0.474,P=0.001,respectively) in obese group;circulating IL-18 was increased in obese individuals (1229.064-29.42 vs. 295.874-13.30 pg/mL).Circulating WISP1 levels were significantly correlated with IL-18 (r=0.542,P<0.001),adiponectin (r=0.585,P<0.001)and leptin (r=0.592,P<0.001).The multivariate stepwise regression analysis showed that higher IL-18 levels represented the main determinant of increased WISP1 levels after adjusting for BMI,waist circumference, fasting insulin,homeostatic model assessment of insulin resistance (HOMA-IR)and HbAlc in obese individuals (β=0.542,P=0.000).WISP1 can be involved in glucose/lipid metabolism in obese youth,which may be modulated by IL-18.Increased WISP1 levels may be a risk factor of obesity and insulin resistance,and WISP1 has a potential therapeutic effect on insulin resistance in obese children and adolescents.

AT1 receptor downregulation:A mechanism for improving glucose homeostasis

There is a pathophysiological correlation between arterial hypertension and diabetes mellitus, established since the pre-diabetic state in the entity known as insulin resistance. It is known that high concentrations of angiotensin-Ⅱ enable chronic activation of the AT1 receptor, promoting sustained vasoconstriction and the consequent development of high blood pressure. Furthermore, the chronic activation of the AT1 receptor has been associated with the development of insulin resistance. From a molecular outlook, the AT1 receptor signaling pathway can activate the JNK kinase. Once activated, this kinase can block the insulin signaling pathway, favoring the resistance to this hormone. In accordance with the previously mentioned mechanisms, the negative regulation of the AT1receptor could have beneficial effects in treating metabolic syndrome and type 2diabetes mellitus. This review explains the clinical correlation of the metabolic response that diabetic patients present when receiving negatively regulatory drugs of the AT1 receptor.

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.

Effect of glucagon-like peptide-1 agonist on insulin signaling pathway in skeletal muscle of mice with insulin resistance

Objective To study the effect of glucagon-like peptide-1 agonist(exendin-4)on insulin signaling pathway in skeletal muscle of mice with insulin resistance(IR).Methods Thirty male KM mice were divided into normal control group(NC group,n=10)and IR group(n=20).The mice in NC group and IR group were fed

CD26 upregulates proliferation and invasion in keloid fibroblasts through an IGF-1-induced PI3K/AKT/mTOR pathway

Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs);however,because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism.Our previous studies revealed that the expansion of CD26+KFs was responsible for increased keloid proliferation and invasion capabilities;the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation.The aim of this studywas to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities,and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.Methods:Flow cytometry was performed to isolate CD26+/CD26−fibroblasts from KFs and normal fibroblasts.To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor(IGF-1R),lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection.Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2-deoxyuridine(EdU)incorporation assay.Scratching assay and transwell assay were used to assess cell migration and invasion abilities.To further quantify the regulatory role of CD26 expression in the relevant signalling pathway,RT-qPCR,western blot,ELISA,PI3K activity assay and immunofluorescence were used.Results:Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs.Furthermore,the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion.The PI3K/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.Conclusions:CD26 can be the effective biomarker for KFs,and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway.This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.

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.

Effects of (–)-5-hydroxy-equol on the lifespan and stress resistance of Caenorhabditis elegans

Caenorhabditis elegans （C. elegans） was used as an animal model to study the effect of （-）-5-hydroxy-equol, a microbialmetabolite of isoflavone genistein, on the lifespan, fecundity and resistance against thermal and oxidative stress. The resultsshowed that （-）-5-hydroxy-equol not only significantly increased the lifespan of C. elegans but also significantly enhancedthe resistance against thermal and oxidative stress at the concentrations of 0.1 mmol/L and 0.2 mmol/L. However, the fecundityof C. elegans was not obviously influenced after being exposed to the same concentrations of （-）-5-hydroxy-equol. Further studieson comparative transcriptome analyses and the lifespan ofdaf-16 （mu86） mutant and daf-2 （e1370） mutant indicated that（-）-5-hydroxy-equol prolonged the lifespan of C. elegans through DAF-2/DAF-16 Insulin/IGF-1 signaling pathway. This isthe first report that （-）-5-hydroxy-equol was able to increase the lifespan and improve the thermal and oxidative stress toleranceof C. elegans.

Molecular mechanisms of dietary restriction in aging—insights from Caenorhabditis elegans research

Dietary restriction(DR) is one of the most robust environmental manipulations that not only extend life span but also delay the onset of age-related diseases in almost every species examined. Caenorhabditis elegans plays an important role in aging studies due to its simple life cycle, easy genetic manipulations and highly conserved genome. Recent studies have demonstrated that the beneficial effects of DR are mediated by the highly conserved transcription factors and signaling pathways in C. elegans. Here we review recent progress in the methodology and molecular mechanisms of DR using C. elegans as a model, as well as prospects for future research.

Linsitinib (OSI‑906) modulates brain energy metabolism and seizure activity in the lithium‑pilocarpine rat model

Background:Epileptic seizure is a process of energy accumulation,bursting,and depletion accompanied by the production,spread,and termination of epileptic discharges.The energy required for a seizure is mainly provided through mitochondrial production of ATP.Mitochondrial diseases often lead to epileptic seizures,and energy depletion caused by seizures can lead to mitochondrial dysfunction.The energy metabolism has become a key target for treatment of epileptic diseases.Method:The effect of OSI-906,an insulin receptor(IR)/insulin-like growth factor 1 receptor(IGF-1R)inhibitor,on behaviors and electroencephalographic activity in the lithium-pilocarpine rats were tested.18F-FDG positron emission tomography(PET)/computed tomography(CT)was performed to detect the relative whole-brain glucose uptake values.Electron microscopy was performed to observe the ultrastructure of neuronal and mitochondrial damage.The changes in blood glucose at different time points before and after the intervention were tested and the effects of OSI-906 on IR/IGF-1R and downstream Akt signaling in the context of seizures were evaluated.Results:The OSI-906 treatment applied 3 days before the pilocarpine-induced seizures significantly reduced the seizure severity,prolonged the seizure latency and decreased the EEG energy density.MicroPET/CT revealed that 50 mg/kg of OSI-906 inhibited the 18F-FDG glucose uptake after epileptic seizures,suggesting that OSI-906,through inhibiting IR/IGF-1R and the downstream AKT signaling,may regulate the excessive energy consumption of the epileptic brain.The OSI-906 treatment also reduced the mitochondrial damage caused by epileptic seizures.Conclusion:The IR/IGF-1R inhibitor OSI-906 can significantly reduce the sensitivity and severity of pilocarpineinduced seizures by inhibiting the IR/IGF-1R and the downstream Akt signaling pathway.