Role of melatonin receptor 1B gene polymorphism and its effect on the regulation of glucose transport in gestational diabetes mellitus / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Melatonin receptor 1B (MT2, encoded by the MTNR1B gene), a high-affinity receptor for melatonin, is associated with glucose homeostasis including glucose uptake and transport. The rs10830963 variant in the MTNR1B gene is linked to glucose metabolism disorders including gestational diabetes mellitus (GDM); however, the relationship between MT2-mediated melatonin signaling and a high birth weight of GDM infants from maternal glucose abnormality remains poorly understood. This article aims to investigate the relationship between rs10830963 variants and GDM development, as well as the effects of MT2 receptor on glucose uptake and transport in trophoblasts. TaqMan-MGB (minor groove binder) probe quantitative real-time polymerase chain reaction (qPCR) assays were used for rs10930963 genotyping. MT2 expression in the placenta of GDM and normal pregnant women was detected by immunofluorescence, western blot, and qPCR. The relationship between MT2 and glucose transporters (GLUTs) or peroxisome proliferator-activated receptor γ (PPARγ) was established by western blot, and glucose consumption of trophoblasts was measured by a glucose assay kit. The results showed that the genotype and allele frequencies of rs10830963 were significantly different between GDM and normal pregnant women (P<0.05). The fasting, 1-h and 2-h plasma glucose levels of G-allele carriers were significantly higher than those of C-allele carriers (P<0.05). Besides, the protein and messenger RNA (mRNA) expression of MT2 in the placenta of GDM was significantly higher than that of normal pregnant women (P<0.05). Melatonin could stimulate glucose uptake and GLUT4 and PPARγ protein expression in trophoblasts, which could be attenuated by MT2 receptor knockdown. In conclusion, the rs10830963 variant was associated with an increased risk of GDM. The MT2 receptor is essential for melatonin to raise glucose uptake and transport, which may be mediated by PPARγ.

The effects and mechanisms of trimethylamine-N-oxide on insulin sensitivity in insulin target cells / 药学学报

Gut microbial metabolite trimethylamine-N-oxide (TMAO) is associated with type 2 diabetes (T2DM). Decreased insulin sensitivity is a significant etiological factor of T2DM. Adipocytes, myocytes, and hepatocytes are the three major target cells for insulin. This study aims to investigate the effects and mechanisms of TMAO on the insulin sensitivity of these target cells. Research results indicate that in different ages of db/db diabetic mice, plasma TMAO levels were increased. TMAO significantly inhibits the insulin signaling pathways in these three major insulin target cells, reduces glucose uptake in 3T3-L1 adipocytes and L6 myocytes and downregulates genes related to gluconeogenesis in primary mouse hepatocytes. Furthermore, in mice with normal insulin sensitivity, elevating plasma TMAO levels to those seen in db/db mice using a minipump results in impaired glucose tolerance and hyperinsulinemia. All animal experiments were carried out with approval of the Experimental Animal Welfare Ethics Committee of the Institute of Materia Medica (Chinese Academy of Medical Sciences and Peking Union Medical College). Mechanistic studies suggest that TMAO exposure increases the levels of endoplasmic reticulum stress-related proteins in these three major insulin target cells. In summary, TMAO directly attenuates insulin sensitivity in insulin target cells, and its mechanism of action may involve enhancing endoplasmic reticulum stress.

A new polycyclic polyprenylated acylphloroglucinols from Hypericum lagarocladum N. Robson / 药学学报

Silica gel column chromatography, reversed phase C18 column chromatography, Sephadex LH-20 gel column chromatography, high performance liquid chromatography and medium performance semi preparative liquid chromatography were performed to separate and purify the chemical constituents of Hypericum lagarocladum N. Robson. Spectroscopic methods such as MS and NMR combined with physicochemical properties were applied in identifying the structures of the isolated compounds. A total of 11 compounds were isolated and identified as hyperlagarone A (1), hyperpatulone E (2), hyperbeanol G (3), uralione D (4), tomoeone F (5), pyramidatone A (6), tomoeone A (7), tomoeone B (8), hyperbeanol C (9), hyperbeanol A (10), and hypercohone G (11), respectively. Compound 1 is a new polycyclic polyprenylated acylphloroglucinol derivative, and compounds 2-11 are isolated from this plant for the first time. 11 compounds were tested for glucose uptake in L6 cells, and the results showed that compounds 7 and 8 had significant effect on glucose uptake.

PXR activation impairs hepatic glucose metabolism partly via inhibiting the HNF4α-GLUT2 pathway

Drug-induced hyperglycemia/diabetes is a global issue. Some drugs induce hyperglycemia by activating the pregnane X receptor (PXR), but the mechanism is unclear. Here, we report that PXR activation induces hyperglycemia by impairing hepatic glucose metabolism due to inhibition of the hepatocyte nuclear factor 4-alpha (HNF4α)‒glucose transporter 2 (GLUT2) pathway. The PXR agonists atorvastatin and rifampicin significantly downregulated GLUT2 and HNF4α expression, and impaired glucose uptake and utilization in HepG2 cells. Overexpression of PXR downregulated GLUT2 and HNF4α expression, while silencing PXR upregulated HNF4α and GLUT2 expression. Silencing HNF4α decreased GLUT2 expression, while overexpressing HNF4α increased GLUT2 expression and glucose uptake. Silencing PXR or overexpressing HNF4α reversed the atorvastatin-induced decrease in GLUT2 expression and glucose uptake. In human primary hepatocytes, atorvastatin downregulated GLUT2 and HNF4α mRNA expression, which could be attenuated by silencing PXR. Silencing HNF4α downregulated GLUT2 mRNA expression. These findings were reproduced with mouse primary hepatocytes. Hnf4α plasmid increased Slc2a2 promoter activity. Hnf4α silencing or pregnenolone-16α-carbonitrile (PCN) suppressed the Slc2a2 promoter activity by decreasing HNF4α recruitment to the Slc2a2 promoter. Liver-specific Hnf4α deletion and PCN impaired glucose tolerance and hepatic glucose uptake, and decreased the expression of hepatic HNF4α and GLUT2. In conclusion, PXR activation impaired hepatic glucose metabolism partly by inhibiting the HNF4α‒GLUT2 pathway. These results highlight the molecular mechanisms by which PXR activators induce hyperglycemia/diabetes.

Sesquiterpenes and polyphenols with glucose-uptake stimulatory and antioxidant activities from the medicinal mushroom Sanghuangporus sanghuang / 中国天然药物

A chemical investigation on the fermentation products of Sanghuangporus sanghuang led to the isolation and identification of fourteen secondary metabolites (1-14) including eight sesquiterpenoids (1-8) and six polyphenols (9-14). Compounds 1-3 were sesquiterpenes with new structures which were elucidated based on NMR spectroscopy, high resolution mass spectrometry (HRMS) and electronic circular dichroism (ECD) data. All the isolates were tested for their stimulation effects on glucose uptake in insulin-resistant HepG2 cells, and cellular antioxidant activity. Compounds 9-12 were subjected to molecular docking experiment to primarily evaluate their anti-coronavirus (SARS-CoV-2) activity. As a result, compounds 9-12 were found to increase the glucose uptake of insulin-resistant HepG2 cells by 18.1%, 62.7%, 33.7% and 21.4% at the dose of 50 μmol·L

In Vitro Antidiabetic Activity By Glucose Uptake Of Yeast Cell Assay And Antioxidant Potential Of Annona Reticulata L. Leaf Extracts

The undesirable adverse effects of present available synthetic drugs endorse the modern medicine to search the superior choice for the treatment of metabolic diseases. Herbal medicine turns out to be a hopeful therapy for the effective treatment of diabetes in foreseeable future. In an effort to render a scientific evidence for the antidiabetic potential of Annona reticulata L., the present research, with the objective to evaluate the ability of A. reticulata leaf extracts on antihyperglycemic property under in vitro using yeast cell model was performed. Besides, as the diabetes and its complications are highly associated with the oxidative stress, the current study was also focussed on antioxidant property of A. reticulata leaf extracts. The scavenging ability of plant extracts on free radical 2, 2 – diphenyl- 1- picrylhydrazyl (DPPH), ferric reducing power assay and total antioxidant activity were performed to establish the antioxidant potential of A. reticulata leaf extracts. The in vitro antidiabetic ability of A. reticulata leaves was evaluated by glucose uptake method using yeast cell model. Among the four chosen solvent extracts- aqueous, methanol, ethyl acetate and n-hexane, methanol extract (MeE) exhibited high antioxidant potential. MeE exhibited 62.28% of DPPH inhibition at 200µg/ml, with total antioxidant activity 164.72 ± 2.63µg/ml and higher absorbance in reducing power assay (1.15 ± 0.03). In vitro antidiabetic activity by glucose uptake of yeast cell assay was evaluated and observed dose dependant rise in % of glucose uptake in methanol, ethylacetate and aqueous extracts of A. reticulata. MeE showed 48.55% of glucose uptake at 500µg/ml concentration. Hence the present study could be concluded as A.reticulata leaves possess potent antioxidant activity and antidiabetic activity under in vitro conditions. With the outcome of the present initial study, research work could be extended further; thereby the exact pharmacological action of the plant compounds could be discovered.

Antidiabetic effect of Chrysophyllum albidum is mediated by enzyme inhibition and enhancement of glucose uptake via 3T3-L1 adipocytes and C2C12 myotubes

Objective: To investigate the in vivo and in vitro antidiabetic potential of Chrysophyllum albidum. Methods: The effects of oral treatment with hydro-ethanolic extract (125, 250 and 500 mg/kg) of the stem bark of Chrysophyllum albidum and glibenclamide for 21 d on glucose level, serum enzyme markers for liver function, lipid profile, total protein, serum urea, serum creatinine, and body weight were evaluated in experimental diabetic rats administered with 45 mg/kg of streptozotocin. In vitro assays including glucose uptake in C2C12 cells and 3T3-L1 adipose tissues, α-glucosidase and α-amylase inhibition were employed to evaluate the possible mechanism of hypoglycemic action of the extract. DPPH and nitric oxide radical antioxidant activity of the extract was also measured. Results: The increased levels of blood glucose, triglycerides, low-density lipoprotein, total cholesterol, serum aspartate, and alanine transaminases, creatinine, and urea in the diabetic animals were reduced significantly (P<0.01) after treatment with Chrysophyllum albidum extract. The decreased total protein and high-density lipoprotein concentrations were normalized after treatment. In addition, the extract significantly (P<0.01) increased the transport of glucose in 3T3-L1 cells and C2C12 myotubes and exhibited considerable potential to inhibit α-amylase and α-glucosidase. It also demonstrated potent antioxidant action by scavenging considerably DPPH and nitric oxide radicals. Conclusions: Chrysophyllum albidum stem bark extract exhibits considerable antidiabetic effect by stimulating glucose uptake and utilization in C2C12 myotubes and 3T3-L1 adipocytes as well as inhibiting the activities of α-amylase and α-glucosidase.

Effect of recombinant adenovirus Ad-mir-22 on glucose uptake in HepG2 cells / 生物工程学报

The recombinant adenoviruses expressing miR-22 (Ad-miR-22) was constructed and the effect of Ad-miR-22 on insulin signal pathway and glucose uptake in HepG2 cells was analyzed. MiR-22 gene was amplified by PCR from human hepatocytes and cloned into the pAdTrack-CMV vector to generate the shuttle plasmid pAdT-22. The positive colonies were confirmed by PCR and sequencing. The resultant shuttle plasmid was linearized with Pme I, followed by co-transformation into competent BJ5183 cells containing an adenoviral backbone plasmid (pAdEasy-1) to create the recombinant plasmid pAd-miR-22. After digested with Pac I, the linearized pAd-miR-22 was transfected into 293A packaging cell line to generate recombinant adenoviruses Ad-miR-22. HepG2 cells were infected with Ad-miR-22 or control Ad-GFP (adenoviruses expressing green fluorescent protein), and then the miR-22 expression levels were analyzed by qPCR. The result shows that adenovirus-mediated overexpression of miR-22 significantly decreased insulin-induced glucose uptake in HepG2 cells. Moreover, overexpression of miR-22 markedly decreased insulin-induced phosphorylation of GSK-3β. miR-22 also increased the mRNA levels of gluconeogenic genes in HepG2 cells. Furthermore, Western blotting results indicate that the protein expression of SIRT1 decreased in Ad-miR-22 infected HepG2 cells as compared with Ad-GFP infected HepG2 cells. In summary, overexpressing of miR-22 significantly increased gluconeogenesis while decreased glucose uptake in HepG2 cells. The effect of miR-22 on glucose metabolism may be mediated by SIRT1.

Antidiabetic effect of Chrysophyllum albidum is mediated by enzyme inhibition and enhancement of glucose uptake via 3T3-L1 adipocytes and C2C12 myotubes

Objective: To investigate the in vivo and in vitro antidiabetic potential of Chrysophyllum albidum. Methods: The effects of oral treatment with hydro-ethanolic extract (125, 250 and 500 mg/kg) of the stem bark of Chrysophyllum albidum and glibenclamide for 21 d on glucose level, serum enzyme markers for liver function, lipid profile, total protein, serum urea, serum creatinine, and body weight were evaluated in experimental diabetic rats administered with 45 mg/kg of streptozotocin. In vitro assays including glucose uptake in C2C12 cells and 3T3-L1 adipose tissues, α-glucosidase and α-amylase inhibition were employed to evaluate the possible mechanism of hypoglycemic action of the extract. DPPH and nitric oxide radical antioxidant activity of the extract was also measured. Results: The increased levels of blood glucose, triglycerides, low-density lipoprotein, total cholesterol, serum aspartate, and alanine transaminases, creatinine, and urea in the diabetic animals were reduced significantly (P<0.01) after treatment with Chrysophyllum albidum extract. The decreased total protein and high-density lipoprotein concentrations were normalized after treatment. In addition, the extract significantly (P<0.01) increased the transport of glucose in 3T3-L1 cells and C2C12 myotubes and exhibited considerable potential to inhibit α-amylase and α-glucosidase. It also demonstrated potent antioxidant action by scavenging considerably DPPH and nitric oxide radicals. Conclusions: Chrysophyllum albidum stem bark extract exhibits considerable antidiabetic effect by stimulating glucose uptake and utilization in C2C12 myotubes and 3T3-L1 adipocytes as well as inhibiting the activities of α-amylase and α-glucosidase.

Screening Ethanolic Extract Of Aerva Lanata For Α-Amylase Inhibition And In Vitro Uptake Of Glucose In Adipose Tissue And Psoas Muscle Of Male Sprague Dawley Rats

The study was intended to investigate anti-diabetic efficacy of Aerva lanata by determining its α-amylase inhibition activity and in vitro uptake of glucose in adipose tissue and psoas muscle isolated from male Sprague Dawley (SD) rats. Aerva lanata is reported to have many traditional and Ayurvedic uses. Male SD rats (n=3) of 150 g were sacrificed and 250 mg of respective tissues were isolated for the study. Aerva lanata ethanolic extract (ALE) (5-20 mg/mL) showed 13.30 to 54.08% α-amylase inhibition activity. Glucose uptake studies in in vitro conditions were carried out in both adipose tissue and psoas muscle in different sets - tissue alone, tissue along with (Aerva lanata extract: 50µg, 100µg, 150µg, insulin: 25 mU/L, insulin: 50 mU/L and Aerva lanata extract: 50µg + insulin: 25 mU/L, Aerva lanata extract: 100µg + insulin: 25 mU/L, Aerva lanata extract: 150µg + insulin: 25 mU/L, Aerva lanata extract: 50µg + insulin: 50 mU/L, Aerva lanata extract: 100µg + insulin: 50 mU/L, Aerva lanata extract: 150µg + insulin: 50 mU/L). The rate of glucose uptake by insulin action in these tissues was stabilized by ethanolic extract of Aerva lanata and this shows synergetic activity of insulin and Aerva lanata.

Antidiabetic effect of free amino acids supplementation in human visceral adipocytes through adiponectin-dependent mechanism

Background & objectives: Amino acids are general nutrients having anti-diabetic property. The present study was undertaken to investigate the mechanism of anti-diabetic effects of amino acids in human visceral adipocyte cells in high glucose environment. Methods: Experiments were carried out in human visceral adipocytes. Adiponectin (APN) siRNAs were designed using Ambion tools. APN mRNA expression was quantified using real-time polymerase chain reaction, and protein level was studied using ELISA. AMP-activated kinase (AMPK) activity was measured and glucose uptake by 2-deoxyglucose uptake method. Results: Amino acids (proline and phenylalanine) exposure to adipocytes significantly (P <0.01) increased APN mRNA by 1.5-folds when compared to control whereas proline increased APN secretion by 10.6-folds (P <0.01), phenylalanine by 12.7-folds (P <0.001) and alanine by 6.3-folds (P <0.01). Free amino acid-induced AMPK activity and glucose uptake were decreased with the transient knockdown of APN. Interpretation & conclusions: Antidiabetic effect of the tested amino acids was exhibited by increased glucose uptake through the AMPK pathway by an APN-dependent mechanism in human visceral adipocytes. This should be tested and confirmed in in vivo system. Newer treatment modalities with amino acids which can enhance glucose uptake and APN secretion can be developed as drug for treating both diabetes and obesity.

Regulatory effects of glabridin and quercetin on energy metabolism of breast cancer cells / 中国中药杂志

It is reported that energy metabolism is the core feature of tumor cells. This study is aimed to investigate the regulatory effect of two flavonoids( glabridin and quercetin) on energy supply and glycolysis of breast cancer cells,and provide reference for developing some anticancer herbal drugs with the function of regulating tumor energy metabolism. Based on the characteristics of each pathway during energy metabolism,in the present study,the triple negative breast cancer tumor cells( MDA-MB-231) were selected to investigate the effects of glabridin and quercetin on the energy metabolism of breast cancer cells and discuss the possible mechanisms from the following five potential targets: glucose uptake,protein expression of glucose transporter 1( GLUT1),adenosine triphosphate( ATP) level,lactate dehydrogenase( LDH) activity,and lactic acid( LD) concentration. The results showed that both quercetin and glabridin could decrease the glucose uptake capacity of breast cancer cells by down-regulating the protein expression of GLUT1. Quercetin had no significant effect on LDH activity and LD concentration; it did not affect the glycolysis process,but increased the intracellular ATP level. Glabridin decreased the activity of LDH and reduced LD concentration,thereby inhibiting the glycolysis metabolism of breast cancer cells. Therefore,both quercetin and glabridin can regulate the energy metabolism of breast cancer cells and can be used as potential anticancer agents or anti-cancer adjuvants.

Comparison of isothermic and cold cardioplegia in cardiac surgery in Salem District

Background: Perioperative myocardial damage is one of the most common causes of morbidity and mortality after heart surgery. The improvement of the technique of myocardial preservation has contributed greatly to significant advances in cardiac surgery. However, serious questions remain regarding the use of warm versus cold cardioplegia, blood versus crystalloid cardioplegia, antegrade versus retrograde delivery and intermittent versus continuous perfusion. Cardioplegic solution is the means by which the ischemic myocardium is protected from cell death. This is achieved by reducing myocardial metabolism through a reduction in cardiac workload and by the use of hypothermia. Chemically, the high potassium concentration present in most cardioplegic solutions decreases the membrane resting potential of cardiac cells. The normal resting potential of ventricular myocytes is about -90 mV. Materials and methods: The study was conducted in the Department of Cardiothoracic Surgery, Government Mohan Kumaramangalam Medical College Hospital from 2016-2017. Thirty patients were selected and divided into two equal groups. Group I, Isothermic blood cardioplegia, patients were cooled to 30˚C, and cardioplegia given at the same temperature as circulating blood in cardiopulmonary bypass and repeated at 20 minutes. The cardioplegic heat exchanger was not utilized in the cardiopulmonary bypass circuit. In group II, conventional cold cardioplegia, patients were cooled to 28-30˚C. Cardioplegia was given at 7-10˚C and was repeated every 30 minutes. To assess myocardial metabolic activity, myocardial oxygen consumption (MVO2), myocardial glucose uptake, myocardial lactate, and acidosis were measured, using arterial and coronary venous blood samples. Results: Mean cardiopulmonary bypass time was significantly shorter receiving isothermic blood cardioplegia (69 v/s 96 minutes). Serum lactate after cardiopulmonary bypass in isothermic blood Pon. A. Rajarajan. Comparison of isothermic and cold cardioplegia in cardiac surgery in Salem District. IAIM, 2019; 6(3): 266-271. Page 267 cardioplegia was lower (1.9 v/s 2.9). There was less metabolic acidosis in the isothermic group (pH 7.37 v/s 7.34). Glucose uptake was higher in the isothermic group. Myocardial contractile function was slightly better in the isothermic group (Ejection Fraction -62 v/s 60 %). Conclusion: The aim of myocardial protection during heart surgery was to preserve myocardial function while providing a bloodless and motionless operating field. In the early stage, myocardial protection was obtained by decreasing myocardial oxygen demand as a consequence of hypothermia. Although intermittent cold cardioplegia perfusion is associated with excellent clinical outcomes in cardiac surgery, this standard technique results in myocardial hypothermia, ischemia and a delay in the recovery of postoperative myocardial metabolism and function. Myocardium utilizes more oxygen and glucose after isothermic cardioplegia, but lactate and acid production were less.

Advances of relationship between protein O-GlcNAcylation and glucose metabolism in tumors / 中国药科大学学报

@#O-GlcNAcylation is the addition of a single N-acetylglucosamine(GlcNAc)moiety to the hydroxyl groups of serine or threonine residues of nuclear and cytoplasmic proteins. The transcription factors, kinases of the metabolic pathways and some cytoplasmic enzymes can be O-GlcNAcylated to affect cell transcription, signal transduction, cell metabolism and other biological functions. Abnormal glucose metabolism of tumors has been a hotspot in the research field of tumor pathogenesis and therapeutic targets recently. O-GlcNAclation regulates the glucose metabolism of tumor by affecting the activity of kinases in the metabolic pathway, which is closely associated with the abnormal glucose metabolism of tumor. The abnormal O-GlcNAcylation is one of the potential reasons of cancer. In this review, in order to provide a theoretical reference for developing anti-tumor targets and drugs targeting O-GlcNAc modification, we briefly summarized how O-GlcNAcylation regulated glucose metabolism on glucose metabolism, glucose uptake, glycolysis, pentose phosphate pathway and tricarboxylic acid cycle in cancer cell.

Effects of oxygen glucose deprivation and reperfusion on gap junction and glucose uptake of astrocytes / 中华行为医学与脑科学杂志

Objective@#To explore the relationship between gap junction and glucose uptake of astrocytes under oxygen-glucose deprivation(OGD) and reperfusion.@*Methods@#Cerebral cortical astrocyte from 1 day newborn SD rats were undergone the primary culture. The ischemia cell model was established by OGD. This experiment were divided into control group, OGD group and OGD+ CBX group.After different reperfusion time (0 h, 12 h 24 h and 48 h), the glucose uptake of astrocyte was measured by 2-NBDG through flow cytometry analysis and connexin 43(Cx43) gap junction plaques was detected using immunofluorescene.@*Results@#Compared with the control group, the glucose uptake of astrocyte was up-regulated induced by OGD following different reperfusion time.The glucose uptake of OGD group was (2.32±0.43)nmol/μgDNA in 24 hours reperfusion time and was (0.95±0.28)nmol/μgDNA in control group. The up-regulation was up to 2.63-fold increase (t=13.99, P=0.0024) in 24 hours after reperfusion.Compared with the control group, the Cx43 gap junction number was up to 2.5- fold increase(t=11.34, P=0.003) and the size was 1.85-fold increase (t=10.27, P=0.004) in 24 h reperfusion. The glucose uptake of astrocyte after OGD was reduced by CBX and the decrease was 42% in 48 h after reperfusion.@*Conclusion@#Those results urges us consider the clinical treatment for interfering with Cx43 gap junction.

Research progress of oxytocin and diabetes / 中华内分泌代谢杂志

Oxytocin is a classic neuropeptide hormone. In recent years, basic and clinical researches have shown that oxytocin is involved in the regulation of blood glucose homeostasis by protecting islet β cells, promoting insulin secretion and peripheral tissue glucose uptake. This article reviews the recent evidence of the linkage between oxytocin and diabetes mellitus.

Effects of oxygen glucose deprivation and reperfusion on gap junction and glucose uptake of astrocytes / 中华行为医学与脑科学杂志

Objective To explore the relationship between gap junction and glucose uptake of astrocytes under oxygen-glucose deprivation(OGD) and reperfusion.Methods Cerebral cortical astrocyte from 1 day newborn SD rats were undergone the primary culture.The ischemia cell model was established by OGD.This experiment were divided into control group,OGD group and OGD + CBX group.After different reperfusion time (0 h,12 h 24 h and 48 h),the glucose uptake of astrocyte was measured by 2-NBDG through flow cytometry analysis and connexin 43(Cx43) gap junction plaques was detected using immunofluorescene.Results Compared with the control group,the glucose uptake of astrocyte was up-regulated induced by OGD following different reperfusion time.The glucose uptake of OGD group was (2.32 ± 0.43)nmol/μgDNA in 24 hours reperfusion time and was (0.95±0.28)nmol/μgDNA in control group.The upregtulation was up to 2.63-fold increase (t=13.99,P=0.0024) in 24 hours after reperfusion.Compared with the control group,the Cx43 gap junction number was up to 2.5-fold increase(t=11.34,P=0.003) and the size was 1.85-fold increase (t=10.27,P=0.004) in 24 h reperfusion.The glucose uptake of astrocyte after OGD was reduced by CBX and the decrease was 42％ in 48 h after reperfusion.Conclusion Those results urges us consider the clinical treatment for interfering with Cx43 gap junction.

Research progress of oxytocin and diabetes / 中华内分泌代谢杂志

Oxytocin is a classic neuropeptide hormone. In recent years, basic and clinical researches have shown that oxytocin is involved in the regulation of blood glucose homeostasis by protecting islet β cells, promoting insulin secretion and peripheral tissue glucose uptake. This article reviews the recent evidence of the linkage between oxytocin and diabetes mellitus.

The effects of honokiol on lipid synthesis in HepG2 cells with steatosis / 药学学报

In this study, the effects of honokiol (HN) treatment for 24 h on lipid synthesis was examined in HepG2 cells. The parameters include intracellular lipid droplet and the expression of SREBP-1c and PNPLA3, glucose uptake, and oxidative stress including the expression of CYP2E1 and CYP4A in normal, TO901317 (TO)- and oleic acid (OA)-treated HepG2 cells. The lipid droplets were detected by oil red O staining. The glucose uptake was measured by fluorescence spectrophotometry using[2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxyglucose, 2-NBDG] as probe. The expression levels of target genes were detected by quantitative PCR and Western blot. The results showed that:① TO (5 μmol·L−1) and OA (0.5 mmol·L−1) treatment increased the levels of intracellular lipid accumulation and the mRNA and protein expression of SREBP-1c and PNPLA3. After HN (10, 20, 40 μmol·L−1) treatment for 24 h, the lipid accumulation and the expression of SREBP-1c and PNPLA3 were all decreased in the tested cells. ② OA treatment significantly suppressed glucose uptake, while HN treatment dose-dependently increased the glucose uptake in OA-treated cells. ③ Compared with control group, CYP2E1 protein level significantly decreased in the three tested cells, and CYP4A protein level significantly decreased only in OA-treated cells following HN treatment. The above results suggest that HN may attenuate lipid accumulation by suppressing the expression of SREBP-1c and PNPLA3, and reduce lipid peroxidation and insulin resistance by down-regulation of the protein levels of CYP2E1 and CYP4A in HepG2 cells with steatosis.

Acebutolol, a Cardioselective Beta Blocker, Promotes Glucose Uptake in Diabetic Model Cells by Inhibiting JNK-JIP1 Interaction

The phosphorylation of JNK is known to induce insulin resistance in insulin target tissues. The inhibition of JNK-JIP1 interaction, which interferes JNK phosphorylation, becomes a potential target for drug development of type 2 diabetes. To discover the inhibitors of JNK-JIP1 interaction, we screened out 30 candidates from 4320 compound library with In Cell Interaction Trap method. The candidates were further confirmed and narrowed down to five compounds using the FRET method in a model cell. Among those five compounds, Acebutolol showed notable inhibition of JNK phosphorylation and elevation of glucose uptake in diabetic models of adipocyte and liver cell. Structural computation showed that the binding affinity of Acebutolol on the JNK-JIP1 interaction site was comparable to the known inhibitor, BI-78D3. Our results suggest that Acebutolol, an FDA-approved beta blocker for hypertension therapy, could have a new repurposed effect on type 2 diabetes elevating glucose uptake process by inhibiting JNK-JIP1 interaction.