Li-promoted C_(3)N_(4) catalyst for efficient isomerization of glucose into fructose at 50℃ in water

Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous catalyst.However,high yield and selectivity of fructose cannot be simultaneously obtained under mild conditions which hamper the scale of application compared with enzymatic catalysis.Herein,a Li-promoted C_(3)N_(4) catalyst was exploited which afforded an excellent fructose yield(40.3 wt%)and selectivity(99.5%)from glucose in water at 50℃,attributed to the formation of stable Li–N bond to strengthen the basic sites of catalysts.Furthermore,the so-formed N_(6)–Li–H_(2)O active site on Li–C_(3)N_(4) catalyst in aqueous phase changes the local electronic structure and strengthens the deprotonation process during glucose isomerization into fructose.The superior catalytic performance which is comparable to biological pathway suggests promising applications of lithium containing heterogeneous catalyst in biomass refinery.

Synaptotagmins family affect glucose transport in retinal pigment epithelial cells through their ubiquitination-mediated degradation and glucose transporter-1 regulation

BACKGROUND Synaptotagmins(SYTs)are a family of 17 membrane transporters that function as calcium ion sensors during the release of Ca2+-dependent neurotransmitters and hormones.However,few studies have reported whether members of the SYT family play a role in glucose uptake in diabetic retinopathy(DR)through Ca2+/glucose transporter-1(GLUT1)and the possible regulatory mechanism of SYTs.AIM To elucidate the role of the SYT family in the regulation of glucose transport in retinal pigment epithelial cells and explore its potential as a therapeutic target for the clinical management of DR.METHODS DR was induced by streptozotocin in C57BL/6J mice and by high glucose medium in human retinal pigment epithelial cells(ARPE-19).Bioinformatics analysis,reverse transcriptase-polymerase chain reaction,Western blot,flow cytometry,ELISA,HE staining,and TUNEL staining were used for analysis.RESULTS Six differentially expressed proteins(SYT2,SYT3,SYT4,SYT7,SYT11,and SYT13)were found between the DR and control groups,and SYT4 was highly expressed.Hyperglycemia induces SYT4 overexpression,manipulates Ca2+influx to induce GLUT1 fusion with the plasma membrane,promotes abnormal expression of the glucose transporter GLUT1 and excessive glucose uptake,induces ARPE-19 cell apoptosis,and promotes DR progression.Parkin deficiency inhibits the proteasomal degradation of SYT4 in DR,resulting in SYT4 accumulation and enhanced GLUT1 fusion with the plasma membrane,and these effects were blocked by oe-Parkin treatment.Moreover,dysregulation of the myelin transcription factor 1(Myt1)-induced transcription of SYT4 in DR further activated the SYT4-mediated stimulus-secretion coupling process,and this process was inhibited in the oe-MYT1-treated group.CONCLUSION Our study reveals the key role of SYT4 in regulating glucose transport in retinal pigment epithelial cells during the pathogenesis of DR and the underlying mechanism and suggests potential therapeutic targets for clinical DR.

Low glucose metabolism in hepatocellular carcinoma with GPC3 expression

AIM To investigate the relationship between glucose metabolism and glypican-3(GPc3)expression in hepatocellular carcinoma(Hcc).METHODSImmunohistochemical staining of pathological samples for GPc3 and glucose transporter 1(GLUT1),and whole-body ^(18)F-FDG PET/c T for measuring tumour glucose uptake were performed in 55 newly diagnosed Hcc patients.The maximum standard uptake value(s UVmax)and tumour-to-non-tumourous liver uptake(T/NT)ratio were used to quantify ^(18)F-FDG uptake.In vitro ^(18)F-FDG uptake assay of GPc3-expressing Hep G2 and non-GPc3-expressing RH7777 cel ls was used to examine the effect of GPc3 in cellular glucose metabolism.The relationships between GPc3 expression and ^(18)F-FDG uptake,GLUT1 expression,tumour differentiation,and other clinical indicators were analysed using spearman rank correlation,univariateand multiple logistic regression analyses.RESULTSPositive GPc3 expression was observed in 67.3%of Hcc patients,including 75.0%of those with well or moderately differentiated Hcc and 36.4%of those with poorly differentiated Hcc.There was an inverse relationship between GPc3 expression and s UVmax(Spearman correlation coefficient=-0.281,P=0.038)and a positive relationship between GLUT1 expression and sU Vmax(Spearman correlation coefficient=0.681,P<0.001)in patients with Hcc.Univariate analysis showed that two glucose metabolic parameters(sU Vmax and T/NT ratio),tumour differentiation,lymph node metastasis,and TNM stage were all significantly associated with GPc3 expression(P<0.05),whereas GLUT1 expression,sex,age,tumour size,intrahepatic lesion number,and distant metastasis showed no statistical association(P>0.05).Further multivariate analysis revealed that only the T/N ratio was significantly correlated with GPC3 expression in patients with Hcc(P<0.05).In vitro assay revealed that the uptake of ^(18)F-FDG in GPc3-expressing HepG2 cells was significantly lower than that of non-GPc3-expressing RH7777 cells(t=-20.352,P<0.001).CONCLUSIONThe present study demonstrated that GPc3 expression is inversely associated with glucose metabolism,suggesting that GPc3 may play a role in regulating glucose metabolism in Hcc.

Effects of suppressing glucose transporter-1 by an antisense oligodeoxynucleotide on the growth of human hepatocellular carcinoma cells

BACKGROUND:The glucose transporter-1(Glut-1),a key ratelimiting factor in the transport and metabolism of glucose in cancer cells,is over-expressed in many human cancer cells and this overexpression is correlated with poor biological behavior. The increased levels of Glut-1 expression in hepatocellular carcinoma(HCC)cells functionally affect tumorigenicity.This study was undertaken to investigate effects of suppressing Glut-1 by an antisense oligodeoxynucleotide(AS-ODN)on the growth of human hepatocellular carcinoma(HepG-2)cells. METHODS:We used AS-ODN targeting against the Glut-1 gene in a HepG-2 cell line.There were four experimental groups: empty pcDNA3.1 vector(mock transfection),pcDNA3.1-anti-Glut(+),pcDNA3.1-Glut(+),and non-transfected HepG-2 cells. The Glut-1 mRNA expression was detected by RT-PCR and the Glut-1 protein expression by Western blotting after cell culture, and the glucose uptake was detected after glucose stimulation in each group. RESULTS:Compared with non-transfected HepG-2 or Glut-1 pcDNA3.1,a down-regulation of Glut-1 mRNA in HepG-2 cells transfected with anti-Glut-1 pcDNA3.1 was noted(P<0.05).Glut-1 protein in HepG-2 cells transfected with Glut-1 AS-ODN was decreased compared with non-transfected HepG-2,Glut-1 pcDNA3.1,or empty vectors. Glucose uptake by the HepG-2 cells transfected with AS-ODN was decreased at 1 hour after glucose stimulation.CONCLUSIONS:The application of Glut-1 AS-ODN can down-regulate the expression of Glut-1 at mRNA and protein,and inhibit glucose uptake partially in HepG-2 cells.The Glut-1 gene maybe a potential therapeutic target for HCC.

Effects of Na2S2O3 and Glucose on the Compositions of Glycerolipids and Their Fatty Acids in Synechocystis sp. PCC 6803 Cells

Compositions of glycerolipids and fatty acid compositions of glycerolipids were compared among Synechocystis sp. PCC 6803 cells grown in the BG-11 medium containing different concentrations of glucose and Na2S2O3 in this study. It was found that Na2S2O3 can effectively increase the percentage of sulphoquinovosyl diacylglycerol (SQDG) and phosphatidylglycerol (PG) to total membrane lipids and the simultaneous application of glucose with Na2S2O3 can counteract the effect of Na2S2O3. In addition, Na2S2O3 can significantly increase the percentage of palmitic acid (C, 16:0) in fatty acid composition of monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) and decrease the fatty acid unsaturation degree accordingly, and these effects can also be eliminated by glucose. These results indicate that Na2S2O3 can take as a reductant to make membrane lipids in a low unsaturated state, and the simultaneous application of glucose can decrease the reducing power of Na2S2O3. In addition, Na2S2O3 can take as a sulfur donor for the synthesis of SQDG.

Embryonic liver fordin is involved in glucose glycolysis of hepatic stellate cell by regulating PI3K/Akt signaling

AIM To investigate the role of embryonic liver fordin(ELF) in liver fibrosis by regulating hepatic stellate cells(HSCs) glucose glycolysis.METHODS The expression of ELF and the glucose glycolysisrelated proteins were evaluated in activated HSCs. si RNA was used to silence ELF expression in activated HSCs in vitro and the subsequent changes in PI3K/Akt signaling and glucose glycolysis-related proteins were observed.RESULTS The expression of ELF increased remarkably in HSCs of the fibrosis mouse model and HSCs that were cultured for 3 wk in vitro. Glucose glycolysis-related proteins showed an obvious increase in the activated HSCs, such as phosphofructokinase, platelet and glucose transporter 1. ELF-si RNA, which perfectly silenced the expression of ELF in activated HSCs, led to the induction of glucose glycolysis-related proteins and extracellular matrix(ECM) components. Moreover, p Akt, which is an important downstream factor in PI3K/Akt signaling, showed a significant change in response to the ELF silencing. The expression of glucose glycolysisrelated proteins and ECM components decreased remarkably when the PI3K/Akt signaling was blocked by Ly294002 in the activated HSCs. CONCLUSION ELF is involved in HSC glucose glycolysis by regulating PI3K/Akt signaling.

Adenovirus-mediated transfection with glucose transporter 3 suppresses PC12 cell apoptosis following ischemic injury

In this study, we investigated the effects of adenovirus-mediated transfection of PC12 cells with glucose transporter 3 after ischemic injury. The results of flow cytometry and TUNEL showed that exogenous glucose transporter 3 significantly suppressed PC12 cell apoptosis induced by ischemic injury. The results of isotopic scintiscan and western blot assays showed that, the glucose uptake rate was significantly increased and nuclear factor kappaB expression was significantly decreased after adenovirus-mediated transfection of ischemic PC12 cells with glucose transporter 3. These results suggest that adenovirus-mediated transfection of cells with glucose transporter 3 elevates the energy metabolism of PC12 cells with ischemic injury, and inhibits cell apoptosis.

Heterogeneous Cu_(x)O Nano‑Skeletons from Waste Electronics for Enhanced Glucose Detection

Electronic waste(e-waste)and diabetes are global challenges to modern societies.However,solving these two challenges together has been challenging until now.Herein,we propose a laser-induced transfer method to fabricate portable glucose sensors by recycling copper from e-waste.We bring up a laser-induced full-automatic fabrication method for synthesizing continuous heterogeneous Cu_(x)O(h-Cu_(x)O)nano-skeletons electrode for glucose sensing,offering rapid(<1 min),clean,air-compatible,and continuous fabrication,applicable to a wide range of Cu-containing substrates.Leveraging this approach,h-Cu_(x)O nanoskeletons,with an inner core predominantly composed of Cu_(2)O with lower oxygen content,juxtaposed with an outer layer rich in amorphous Cu_(x)O(a-Cu_(x)O)with higher oxygen content,are derived from discarded printed circuit boards.When employed in glucose detection,the h-Cu_(x)O nano-skeletons undergo a structural evolution process,transitioning into rigid Cu_(2)O@CuO nano-skeletons prompted by electrochemical activation.This transformation yields exceptional glucose-sensing performance(sensitivity:9.893 mA mM^(-1) cm^(-2);detection limit:0.34μM),outperforming most previously reported glucose sensors.Density functional theory analysis elucidates that the heterogeneous structure facilitates gluconolactone desorption.This glucose detection device has also been downsized to optimize its scalability and portability for convenient integration into people’s everyday lives.

Vitamin B3 inhibits apoptosis and promotes autophagy of isletβcells under high glucose stress

Background:Hyperglycemia is a typical symptom of diabetes.High glucose induces apoptosis of isletβcells.While autophagy functions in cytoprotection and autophagic cell death.The interaction between autophagy and apoptosis is important in the modulation of the function of isletβcells.Vitamin B3 can induce autophagy and inhibit isletβapoptosis.Method:The mechanism of vitamin B3-mediated protective effect on the function of isletβcells was explored by the method of western blot,immunofluorescence and flow cytometry.Results:In the present study,high glucose stress increased the apoptosis rate,while vitamin B3 reduced the apoptosis rate.The effect of vitamin B3 on autophagy flux under normal and high glucose stress was also investigated.Vitamin B3 increased the number of autophagosomes and increased the light chain(LC)3-II/LC3-I ratio.In contrast,vitamin B3 decreased sequestosome 1(SQSTM1)/p62 protein expression and inhibited the phosphorylation of mammalian ribosomal protein S6 kinaseβ-1(p70S6K/S6K1),which was a substrate of mammalian target of rapamycin(mTOR)under normal and high glucose stress.To further verify the protective effect of vitamin B3 on apoptosis,we treated isletβcell RIN-m5F with autophagy inhibitor 3-methyladenine(3-MA).Vitamin B3 decreased the apoptosis rate under high glucose stress,while the inhibition of apoptosis by vitamin B3 was blocked after adding 3-MA.Conclusion:Our data suggested that vitamin B3 reduced the apoptosis rate ofβcells,possibly through inducing autophagy under high glucose stress.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Enhance the Osteoblastic Differentiation of Periodontal Ligament Stem Cells Under High Glucose Conditions Through the PI3K/AKT Signaling Pathway

Objective High glucose(HG)can influence the osteogenic differentiation ability of periodontal ligament stem cells(PDLSCs).Human umbilical cord mesenchymal stem cell-derived exosomes(hUCMSC-exo)have broad application prospects in tissue healing.The current study aimed to explore whether hUCMSC-exo could promote the osteogenic differentiation of hPDLSCs under HG conditions and the underlying mechanism.Methods We used a 30 mmol/L glucose concentration to simulate HG conditions.CCK-8 assay was performed to evaluate the effect of hUCMSC-exo on the proliferation of hPDLSCs.Alkaline phosphatase(ALP)staining,ALP activity,and qRT-PCR were performed to evaluate the pro-osteogenic effect of hUCMSC-exo on hPDLSCs.Western blot analysis was conducted to evaluate the underlying mechanism.Results The results of the CCK-8 assay,ALP staining,ALP activity,and qRT-PCR assay showed that hUCMSC-exo significantly promoted cell proliferation and osteogenic differentiation in a dosedependent manner.The Western blot results revealed that hUCMSC-exo significantly increased the levels of p-PI3K and p-AKT in cells,and the effect was inhibited by LY294002(PI3K inhibitor)or MK2206(AKT inhibitor),respectively.Moreover,the increases in osteogenic indicators induced by hUCMSC-exo were significantly suppressed by LY294002 and MK2206.Conclusion hUCMSC-exo promote the osteogenic differentiation of hPDLSCs under HG conditions through the PI3K/AKT signaling pathway.

Free fatty acids receptors 2 and 3 control cell proliferation by regulating cellular glucose uptake

BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.

IcarisideⅡ alleviates oxygen-glucose deprivation and reoxygenation-induced PC12 celloxidative injury by activating Nrf2 / SIRT3signaling pathway

OBJECTIVE To investigate icariside(ICS)Ⅱ protects against PC12 cel damage induced by oxygen-glucose deprivation and reoxygenation and explore its mechanism.METHODS The oxidative stress injury model was induced by oxygen-glucose deprivation/reoxygenation(OGD/R) 2 h/24 h in PC12 cells.N-acetyl-lcysteine(NAC),a classical anti-oxidant,was used as positive control.Pharmacodynamic experimental study groups as follows:control,control+ICS Ⅱ50 μmol·L^(-1),OGD/R,OGD/R+ICSⅡ 12.5 μmol·L^(-1),OGD/R + ICS Ⅱ 25 μmol·L^(-1),OGD/R + ICS Ⅱ50 μmol·L^(-1),and OGD/R+NAC 100 μmol·L^(-1) groups.Cell viability and lactate dehydrogenase(LDH) leakage rate were measured by MTT assay and LDH ELISA kit,respectively.Moreover,reactive oxygen species(ROS) ELISA kit was used for detection of intracellular ROS generation,Mito-SOX fluorescence staining was used for detecting production of ROS in mitochondria and mitochondrial membrane potential(MMP)was detected by rhodamine 123 dye.In addition,PC12 cells apoptosis was detected by one-step TUNEL assay.Furthermore,the expressions of nuclear factor erythroid 2-related factors(Nrf2),Keap1,HO^(-1),NQO^(-1),silent information regulator 3(SIRT3),IDH2,Bax,Bcl-2 and caspase 3 were detected by Western blotting analysis.RESULTS The results of MTT and LDH assay showed that OGD/R reduced the cell viability and improved LDH release compared with the control or ICSⅡ 50 μmol·L^(-1) alone(P<0.01).Meanwhile,OGD/R not only increased intracellular and mitochondrial ROS generation,but also elevated the fluorescence intensity of TUNEL staining,at the same time,the MMP was declined when challenged by OGD/R.Furthermore,the Western blotting results showed that OGD/R induced the increase in the expression of cytoplasm-Nrf2,Keap1,Bax and cleaved-caspase 3 level,while the decrease in the expression of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).However,ICS Ⅱ significantly increased the viability of PC12 cells and reduced LDH leakage(P<0.01).Notably,ICS Ⅱ also suppressed ROS generation both in the intracellular and mitochondria,as well as restored MMP.It was also worthy to note that ICS Ⅱ decreased the expressions of cytoplasmNrf2,Keap1,Bax and the level of cleaved-caspase3,whereas,it increased the expressions of nucleus-Nrf2,HO^(-1),NQO^(-1),SIRT3,IDH2 and Bcl-2(P<0.05).CONCLUSION ICSⅡ reduced OGD/Rinduced oxidative damage in PC12 cells under the laboratory conditions,and its underlying mechanism may be related to the regulation of Nrf2/SIRT3 signaling pathway.

Proprotein convertase 1/3-mediated down-regulation of brain-derived neurotrophic factor in cortical neurons induced by oxygen-glucose deprivation

Brain-derived neurotrophic factor(BDNF)has robust effects on synaptogenesis,neuronal differentiation and synaptic transmission and plasticity.The maturation of BDNF is a complex process.Proprotein convertase 1/3(PC1/3)has a key role in the cleavage of protein precursors that are directed to regulated secretory pathways;however,it is not clear whether PC1/3 mediates the change in BDNF levels caused by ischemia.To clarify the role of PC1/3 in BDNF maturation in ischemic cortical neurons,primary cortical neurons from fetal rats were cultured in a humidified environment of 95%N_2 and 5%CO_2 in a glucose-free Dulbecco's modified Eagle's medium at 37℃for3 hours.Enzyme-linked immunosorbent assays and western blotting showed that after oxygen-glucose deprivation,the secreted and intracellular levels of BDNF were significantly reduced and the intracellular level of PC1/3 was decreased.Transient transfection of cortical neurons with a PC1/3 overexpression plasmid followed by oxygen-glucose deprivation resulted in increased PC1/3 levels and increased BDNF levels.When levels of the BDNF precursor protein were reduced,the concentration of BDNF in the culture medium was increased.These results indicate that PC 1/3 cleavage of BDNF is critical for the conversion of pro-BDNF in rat cortical neurons during ischemia.The study was approved by the Animal Ethics Committee of Wuhan University School of Basic Medical Sciences.

IDENTIFICATION OF GLUCOSE TRANSPORTER- 1 AND ITS FUNCTIONAL ASSAY IN MOUSE GLOMERULAR MESANGIAL CELLS CULTURED IN VITRO

To evaluate the role of glucose transporter- l (GLUT1) in the glucose uptake of glomerular mesangial cells. Methods. Cultured C57/SJL mouse mesangial cells were used in the study. The expression of GLUT1 mRNA was detected by RT- PCR. The expression of GLUT1 protein was detected by immunofluorescence and flow cytometry. The uptake of glucose and its kinetics were determined by 2- deoxy- [3H]- D- glucose uptake. Results. Both GLUT1 mRNA and protein were found in mouse glomerular mesangial cells. 2- deoxy- D- glucose uptake and kinetics assay showed that this glucose transporter had high affinity for glucose and the glucose uptake specificity was further confirmed by phloretin. Conclusion. Functional GLUT1 did present in mouse mesangial cells cultured in vitro and it might be the predominant transporter mediated the uptake of glucose into mesangial cells.

Constructing recombinant replication-defective adenoviral vectors that express glucose transporter-1 through in vitro ligation

BACKGROUND： We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter- 1 （GLUT 1） in rats, OBJECTIVE： This study was designed to investigate the feasibility of generating recombinant replication-defective adenoviral vectors that express GLUT1 in rats by in vitro ligation based on the Adeno-X^TM system. DESIGN： An in vitro cell-based experiment. SETTING： This study was performed at the Linbaixin Medical Research Center of the Second Hospital Affiliated to Sun Yat-sen University and Central Laboratory for Prevention and Treatment of Tumor, Sun Yat-sen University between January and August 2004. MATERIALS： Male, adult, Sprague Dawley rats were used to extract total RNA from brain tissue. E. coli DH5 a and human embryonic kidney 293 cells （HEK293 cells） used in the present study were cryo-preserved by the Second Hospital Affiliated to Sun Yat-sen University. Rabbit anti-rat GLUT1 polyclonal antibody （Chemicon, U.S.A.） and primers （Shanghai Boya Bioengineering Co., Ltd） were also used. METHODS： E1/E3-deleted replication-defective adenoviral vectors were used. Using in vitro ligation, the target gene was first sub-cloned into a shuttle vector plasmid to obtain the fragment containing target gene expression cassettes by enzyme digestion. Subsequently, the fragment was co-transformed with linearized adenoviral backbone vector into the E. coli strain. The recombinant adenoviral plasmid was transfected into HEK293 cells to assembly recombinant adenoviral vectors with replication capabilities. The procedure was repeated several times for recombinant adenoviral vectors amplification. MAIN OUTCOME MEASURES： Efficiency of recombinant adenoviral vectors to express the target gene was measured by gene and protein expression through polymerase chain reaction and Western Blot assays, respectively. RESULTS： Results demonstrated that recombinant adenoviral vectors successfully expressed GLUT1 protein, with a relative molecular mass of 55000 in HEK293 cells. These results suggest that recombinant adenoviral vectors obtained by homologous bacterial recombination feature high efficiency, rapidness, and simplicity. CONCLUSION： We successfully amplified the rat GLUT1 gene and constructed replication-defective adenoviral vectors expressing GLUT1. The replication-defective adenoviral vectors proved to successfully express the target gene in HEK293 cells.

Photoactivation of GLUT4 translocation promotes glucose uptake via PI3-K/Akt2 signaling in 3T3-L1 adipocytes

Insulin resistance is a hallmark of the metabolic syndrome and type 2 diabetes.Dysfunction of PI-3K/Akt signaling was involved in insulin resistance.Glucose transporter 4(GLUT4)is a keyfactor for glucose uptake in muscle and adipose tissues,which is closely regulated by Pi-3K/Aktsignaling in response to insulin treatment.Low-power laser irradiation(LPLI)has been shown toregulate various physiological processes and induce the synthesis or release of multiple moleculessuch as growth factors,which(especially red and near infrared light)is mainly through theactivation of mitochondrial respiratory chain and the initiation of intracellular signaling path-ways.Nevertheless,it is unclear whether LPLI could promote glucose uptake through activationof PI-3K/Akt/GLUT4 signaling in 3T3L-1 adipocytes.In this study,we investigated how LPLIpromoted glucose uptake through activation of PI-3K/Akt/GLUT4 signaling path way.Here,we showed that GLUT4 was localized to the Golgi apparatus and translocated from cytoplasm tocytomembrane upon LPLI treatment in 3T3L-1 adipocytes,which enhanced glucose uptake.Moreover,we found that glucose uptake was mediated by the PI3-K/Akt2 signaling,but notAkt1 upon LPLI treatment with Akt isoforms gene silence and PI3-K/Akt inhibitors.Collec-tively,our results indicate that PI3-K/Akt2/GLUT4 signaling act as the key regulators forimprovement of glucose uptake under LPLI treatment in 3T3L-i adipocytes.More importantly,our findings suggest that activation of PI3-K/Akt2/GLUT4 signaling by LPLI may provideguidance in practical applications for promotion of glucose uptake in insulin-resistant adiposetissue.

Effect of miR-27b-3p and Nrf2 in human retinal pigment epithelial cell induced by high-glucose

AIM:To determine whether the microRNA-27b-3p(miR-27b-3p)/NF-E2-related factor 2(Nrf2)pathway plays a role in human retinal pigment epithelial(hRPE)cell response to high glucose,how miR-27b-3p and Nrf2 expression are regulated,and whether this pathway could be specifically targeted.METHODS:hRPE cells were cultured in normal glucose or high glucose for 1,3,or 6d before measuring cellular proliferation rates using cell counting kit-8 and reactive oxygen species(ROS)levels using a dihydroethidium kit.miR-27b-3p,Nrf2,NAD(P)H quinone oxidoreductase 1(NQO1)and heme oxygenase-1(HO-1)mRNA and protein levels were analyzed using reverse transcription quantitative polymerase chain reaction(RT-qPCR)and immunocytofluorescence(ICF),respectively.Western blot analyses were performed to determine nuclear and total Nrf2 protein levels.Nrf2,NQO1,and HO-1 expression levels by RT-qPCR,ICF,or Western blot were further tested after miR-27b-3p overexpression or inhibitor lentiviral transfection.Finally,the expression level of those target genes was analyzed after treating hRPE cells with pyridoxamine.RESULTS:Persistent exposure to high glucose gradually suppressed hRPE Nrf2,NQO1,and HO-1 mRNA and protein levels and increased miR-27b-3p mRNA levels.High glucose also promoted ROS release and inhibited cellular proliferation.Nrf2,NQO1,and HO-1 mRNA levels decreased after miR-27b-3p overexpression and,conversely,both mRNA and protein levels increased after expressing a miR-27b-3p inhibitor.After treating hRPE cells exposed to high glucose with pyridoxamine,ROS levels tended to decreased,proliferation rate increased,Nrf2,NQO1,and HO-1 mRNA and protein levels were upregulated,and miR-27b-3p mRNA levels were suppressed.CONCLUSION:Nrf2 is a downstream target of miR-27b-3p.Furthermore,the miR-27b-3p inhibitor pyridoxamine can alleviate high glucose injury by regulating the miR-27b-3p/Nrf2 axis.

Relationship Between Serum microRNA-372-3p and Glucose Transporter 4 Levels and Insulin Resistance in Gestational Diabetes Mellitus

Objective:To observe the changes in insulin resistance in patients with gestational diabetes mellitus(GDM)based on the detection of serum microRNA-372-3p and glucose transporter protein 4(GLUT4)levels.Methods:We conducted a retrospective cohort study of 42 patients who were diagnosed with GDM and hospitalized in our hospital during the period from January 2017 to December 2021 and another 42 patients who had normal pregnancy during the same period by collecting their clinical data.We analyzed their serum microRNA expression profiles and miR-372-3p levels to study the relationship between GDM and insulin resistance.Results:The relative expression of miR-372-3p in the serum of patients in the GDM group was significantly higher than that of patients in the control group,but the GLUT 4 level of the GDM group was significantly lower than that of the control group(P<0.05).Compared with the control group,the GDM group had significantly higher levels of fasting blood glucose(FBG),fasting insulin(FINS),2-hour postprandial blood glucose(2h-BG),total cholesterol(TC),triglyceride(TG),and homeostatic model assessment for insulin resistance(HOMA-IR)index but significantly lower homeostasis model assessment ofβ-cell function(HOMA-β)index(P<0.05).The relative expression of miR-372-3p in serum was independently and positively correlated with HOMA-IR,while the level of GLUT4 was independently and negatively correlated with HOMA-IR(P<0.05).Conclusion:Glycosylated hemoglobin test in the early stages of pregnancy(12–13 weeks of gestation)is important to ensure the health of pregnant women and fetuses.The screening and intervention for elevated glucose in pregnant women act as a guideline for the treatment of GDM.Patients with insulin resistance and related complications such as hyperinsulinemia and hypoglycemia should be given priority.

NLRP3 Inflammasome in Relation to Glucose and Lipid Metabolism, and Insulin Resistance in Diabetes and Pre-Diabetes

Aims: To investigate the relationship among NLRP3 inflammasome, glucose and lipid metabolism, and insulin resistance (IR) in the serum of patients with diabetes and pre-diabetes. Methods: A total of 100 patients with abnormal blood glucose divided into the pre-diabetes mellitus (PDM) group (N = 46) and the type 2 diabetes mellitus (T2DM) group (N = 54). 20 normoglycemic subjects (NG, N = 20) were selected as a control group. The serum levels of glucose and lipid metabolism, IR, and the expression of NLRP3, ASC and Caspase-1 were measured. Besides, the correlations of NLRP3 inflammasome with glucose and lipid metabolism, and IR were analyzed. Results: Compared with the NG group, the levels of NLRP3, ASC, Caspase-1, FBG, HbA1C, TG, LDL-C, FINs, and HOMA-IR were higher (P β were lower (P P β were seen (P P β. Regression analysis further showed that blood glucose related indexes, FINs, and NLRP3 have made a decisive contribution to IR. Conclusions: Collectively, this evidence suggested that NLRP3 is closely related to glucose and lipid metabolism, and IR, and activated in PDM and T2DM.

2型糖尿病合并甲状腺功能亢进患者血清Sema 5A、IGFBP-3水平与糖代谢指标的相关性分析

目的分析2型糖尿病合并甲状腺功能亢进(以下简称甲亢)患者血清信号素5A(Sema 5A)、胰岛素样生长因子结合蛋白-3(IGFBP-3)水平与糖代谢指标的相关性。方法选取2021年6月至2022年6月邯郸市中心医院收治的73例2型糖尿病合并甲亢患者作为合并组,56例单纯2型糖尿病患者作为糖尿病组,另选取同期在邯郸市中心医院体检的68例健康者作为对照组。比较对照组、糖尿病组、合并组血清Sema 5A、IGFBP-3水平,比较糖尿病组、合并组临床资料[体质量指数、糖尿病病程、空腹血糖(FBG)、餐后2 h血糖(2 h PG)、胰岛素(FIN)、甘油三酯、总胆固醇、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、糖化血红蛋白(HbA1c)、三碘甲腺原氨酸(T_(3))、甲状腺素(T_(4))、游离三碘甲腺原氨酸(FT_(3))、游离甲状腺素(FT_(4))、促甲状腺素(TSH)、促甲状腺激素受体抗体(TRAB)及甲状腺过氧化物酶抗体(TPOAB)、胰岛素抵抗指数(HOMA-IR)]。采用多因素Logisitic回归分析2型糖尿病并发甲亢的危险因素,采用Pearson相关分析2型糖尿病合并甲亢患者血清Sema 5A、IGFBP-3水平与糖代谢指标的相关性,绘制受试者工作特征(ROC)曲线分析血清Sema 5A、IGFBP-3对2型糖尿病合并甲亢的诊断价值。结果合并组血清Sema 5A、IGFBP-3水平高于对照组和糖尿病组,且糖尿病组高于对照组,差异均有统计学意义(P<0.05)。合并组糖尿病病程长于糖尿病组,血清HOMA-IR、FIN、HbA1c、T_(3)、T_(4)、FT_(3)、FT_(4)、TRAB、TPOAB水平高于糖尿病组,TSH水平低于糖尿病组,差异均有统计学意义(P<0.05)。多因素Logisitic回归分析结果显示,HOMA-IR、TPOAB、Sema 5A、IGFBP-3水平升高,TSH水平降低为2型糖尿病并发甲亢的危险因素(P<0.05)。Pearson相关分析结果显示,2型糖尿病并发甲亢患者血清Sema 5A、IGFBP-3水平与HOMA-IR、FBG、2 h PG、FIN、HbA1c、HDL-C水平均呈正相关(P<0.05)。2型糖尿病并发甲亢患者血清Sema 5A、IGFBP-3水平与LDL-C水平呈负相关(P<0.05)。ROC曲线分析结果显示,血清Sema 5A、IGFBP-3诊断2型糖尿病合并甲亢的曲线下面积(AUC)分别为0.854、0.804,2项指标联合诊断的AUC为0.900,且2项指标联合诊断的AUC高于Sema 5A、IGFBP-3单独诊断的AUC(Z联合-Sema 5A=2.156,P=0.043;Z联合-IGFBP-3=2.873,P=0.004)。结论2型糖尿病合并甲亢患者血清Sema 5A、IGFBP-3水平升高,且二者与糖代谢指标密切相关。