Transmembrane Glucose Transport Research Articles

Effect of Ca2+ signal on the activity of key enzymes of carbon metabolism and related gene expression in yeast under high sugar fermentation.

Saccharomyces cerevisiae is a fungus widely used in the food industry and biofuel industry, whereas it is usually exposed to high sugar stress during the fermentation process. Ca2+ is a key second messenger of the cell, it can regulate cell metabolism. The present study investigated the effect of the Ca2+ signal on the activity of key enzymes of carbon metabolism and related gene expression in yeast under high sugar fermentation. The expression of genes encoding hexokinase was up-regulated in the high sugar environment, the activity of hexokinase was increased, glucose transmembrane transport capacity was enhanced, the ability of glucose to enter into glycolytic metabolism was increased, and the expression of genes related to pentose phosphate metabolism, glycerol metabolism and trehalose metabolism was up-regulated in the high glucose with Ca2+ group. Ca2+ signal regulates the cellular metabolism of glycerol and trehalose and optimizes the allocation of carbon flow by regulating the key enzymes and related gene expression to enhance the resistance of yeast to high sugar stress. © 2024 Society of Chemical Industry.

Myricetin Oligomer Triggers Multi-Receptor Mediated Penetration and Autophagic Restoration of Blood-Brain Barrier for Ischemic Stroke Treatment.

Restoration of blood-brain barrier (BBB) dysfunction, which drives worse outcomes of ischemic stroke, is a potential target for therapeutic opportunities, whereas a sealed BBB blocks the therapeutics entrance into the brain, making the BBB protection strategy paradoxical. Post ischemic stroke, hypoxia/hypoglycemia provokes the up-regulation of transmembrane glucose transporters and iron transporters due to multiple metabolic disorders, especially in brain endothelial cells. Herein, we develop a myricetin oligomer-derived nanostructure doped with Ce to bypass the BBB which is cointermediated by glucose transporters and iron transporters such as glucose transporters 1 (GLUT1), sodium/glucose cotransporters 1 (SGLT1), and transferrin(Tf) reporter (TfR). Moreover, it exhibits BBB restoration capacity by regulating the expression of tight junctions (TJs) through the activation of protective autophagy. The myricetin oligomers scaffold not only acts as targeting moiety but is the prominent active entity that inherits all diverse pharmacological activities of myricetin. The suppression of oxidative damage, M1 microglia activation, and inflammatory factors makes it a multitasking nanoagent with a single component as the scaffold, targeting domain and curative components.

Hydrolysates of hemp (Cannabis sativa L.) seed meal: Characterization and their inhibitory effect on α-glucosidase activity and glucose transport in Caco-2 cells

Due to the lack of high value-added products and the rough utilization of hemp protein, which has the effect of regulating blood glucose, as well as the adverse effects of glucose-lowering drugs currently on the market, it is urgent to develop new safe and effective α-glucosidase inhibitors as substitutes for existing hypoglycemic drugs. Therefore, this study explored the physical and chemical properties, antioxidant activity, and inhibitory mechanism of α-glucosidase activity of non-dehulled hemp seed meal hydrolysate prepared by controlled enzymatic hydrolysis technology, as well as its inhibitory of α-glucosidase and glucose transmembrane transport in Caco-2 cells. Kinetic experiments indicated that the inhibition of α-glucosidase by hemp seed meal hydrolysate was reversible mixed inhibition. Cell experiments revealed that the hydrolysate inhibited both intracellular disaccharidase and the transport of glucose at different concentrations. In conclusion, the hemp seed meal hydrolysate can inhibit the activity of α-glucosidase and has potential value and application prospects in hypoglycemic effect.

SGLT2 inhibitor empagliflozin alleviates cardiac remodeling and contractile anomalies in a FUNDC1-dependent manner in experimental Parkinson's disease.

Recent evidence shows a close link between Parkinson's disease (PD) and cardiac dysfunction with limited treatment options. Mitophagy plays a crucial role in the control of mitochondrial quantity, metabolic reprogramming and cell differentiation. Mutation of the mitophagy protein Parkin is directly associated with the onset of PD. Parkin-independent receptor-mediated mitophagy is also documented such as BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) and FUN14 domain containing 1 (FUNDC1) for receptor-mediated mitophagy. In this study we investigated cardiac function and mitophagy including FUNDC1 in PD patients and mouse models, and evaluated the therapeutic potential of a SGLT2 inhibitor empagliflozin. MPTP-induced PD model was established. PD patients and MPTP mice not only displayed pronounced motor defects, but also low plasma FUNDC1 levels, as well as cardiac ultrastructural and geometric anomalies (cardiac atrophy, interstitial fibrosis), functional anomalies (reduced E/A ratio, fractional shortening, ejection fraction, cardiomyocyte contraction) and mitochondrial injury (ultrastructural damage, UCP2, PGC1α, elevated mitochondrial Ca2+ uptake proteins MCU and VDAC1, and mitochondrial apoptotic protein calpain), dampened autophagy, FUNDC1 mitophagy and apoptosis. By Gene set enrichment analysis (GSEA), we found overtly altered glucose transmembrane transport in the midbrains of MPTP-treated mice. Intriguingly, administration of SGLT2 inhibitor empagliflozin (10 mg/kg, i.p., twice per week for 2 weeks) in MPTP-treated mice significantly ameliorated myocardial anomalies (with exception of VDAC1), but did not reconcile the motor defects or plasma FUNDC1. FUNDC1 global knockout (FUNDC1-/- mice) did not elicit any phenotype on cardiac geometry or function in the absence or presence of MPTP insult, but it nullified empagliflozin-caused cardioprotection against MPTP-induced cardiac anomalies including remodeling (atrophy and fibrosis), contractile dysfunction, Ca2+ homeostasis, mitochondrial (including MCU, mitochondrial Ca2+ overload, calpain, PARP1) and apoptotic anomalies. In neonatal and adult cardiomyocytes, treatment with PD neurotoxin preformed fibrils of α-synuclein (PFF) caused cytochrome c release and cardiomyocyte mechanical defects. These effects were mitigated by empagliflozin (10 μM) or MCU inhibitor Ru360 (10 μM). MCU activator kaempferol (10 μM) or calpain activator dibucaine (500 μM) nullified the empagliflozin-induced beneficial effects. These results suggest that empagliflozin protects against PD-induced cardiac anomalies, likely through FUNDC1-mediated regulation of mitochondrial integrity.

MicroRNA-17-5p and MicroRNA-130b-3p Promote Radioresistance of Glioma Stem Cells by Targeting PTEN/AKT/HIF-1α Pathway-Controlled Phosphopentose Metabolism

Background. The radioresistance of glioma stem cells (GSCs) is related to some microRNAs (miRs) generated by radiation. This study aimed to investigate the effects of miR-17-5p and miR-130b-3p on the radiosensitivity of GSCs. Methods. miR-17-5p and miR-130b-3p expressions in SU3 and SU3-5R cells were determined. SU3 cells transfected with miR-17-5p or miR-130b-3p mimics or inhibitors were used to determine cell viability after irradiation as well as to examine changes of supernatant glucose, intracellular glucose 6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6-PGDH), reduced nicotinamide adenine dinucleotide phosphate (NADPH), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), phosphatase and tensin homolog (PTEN), hypoxia-inducible factor-1α (HIF-1α), glucose transporter (GLUT)-1/3, protein kinase B (AKT), and p-AKT levels. The target gene of the two miRs was verified by luciferase reporter gene assay. Results. miR-17-5p and miR-130b-3p expressions in the radiation-resistant SU3-5R cells or 8 Gy irradiation-treated SU3 cells were high. After transfection of SU3 cells with miR-17-5p or miR-130b-3p mimics, cell viability, intracellular HIF-1α, GLUT-1/3, AKT, and p-AKT protein expressions, and intracellular G6PDH, 6-PGDH, NADPH, GSH-Px, and GSH levels were high, whereas intracellular PTEN expression and supernatant glucose were low. The opposite effects were also observed in the two miR inhibitors-transfected SU3 cells. Further study confirmed that miR-17-5p or miR-130b-3p could directly bind with the PTEN. Conclusion. Radiation-induced miR-17-5p and miR-130b-3p might cause the radioresistance of GSCs, and the mechanisms were associated with the enhancement of antioxidant production, which was from the increments of AKT/HIF-1α signaling pathway-controlled glucose transmembrane transport and phosphopentose metabolism by targeting PTEN.

Modified Lactoperoxidase System as a Promising Anticaries Agent: In Vitro Studies on Streptococcus mutans Biofilms.

The lactoperoxidase (LPO) system shows promise in the prevention of dental caries, a common chronic disease. This system has antimicrobial properties and is part of the non-specific antimicrobial immune system. Understanding the efficacy of the LPO system in the fight against biofilms could provide information on alternative strategies for the prevention and treatment of caries. In this study, the enzymatic system was modified using four different (pseudo)halide substrates (thiocyanate, thiocyanate-iodide mixture, selenocyanate, and iodide). The study evaluated the metabolic effects of applying such modifications to Streptococcus mutans; in particular: (1) biofilm formation, (2) synthesis of insoluble polysaccharides, (3) lactate synthesis, (4) glucose and sucrose consumption, (5) intracellular NAD+ and NADH concentrations, and (6) transmembrane glucose transport efficiency (PTS activity). The results showed that the LPO-iodide system had the strongest inhibitory effect on biofilm growth and lactate synthesis (complete inhibition). This was associated with an increase in the NAD+/NADH ratio and an inhibition of glucose PTS activity. The LPO-selenocyanate system showed a moderate inhibitory effect on biofilm biomass growth and lactate synthesis. The other systems showed relatively small inhibition of lactate synthesis and glucose PTS but no effect on the growth of biofilm biomass. This study provides a basis for further research on the use of alternative substrates with the LPO system, particularly the LPO-iodide system, in the prevention and control of biofilm-related diseases.

Lian-Qu formula treats metabolic syndrome via reducing fat synthesis, insulin resistance and inflammation.

Metabolic syndrome (MetS) is a pathological condition characterized by obesity, hyperglycemia, hypertension and hyperlipidemia that increases the risk of cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease. The traditional Chinese medicine Lian-Qu formula (LQF) is modified from Xiaoxianxiong decoction, which has been used for coronary heart disease or metabolic disease in clinical for a long time. However, the pharmacological mechanism of LQF on MetS is unclear. Here, we explored the actions of LQF on MetS via network pharmacology and validated the mechanism in the MetS mice. The chemical components of LQF were searched in the traditional Chinese medicine systems pharmacology database and the natural product activity & species source database. The related targets of MetS disease were gathered from genes cluster with literature profiles database. The protein-protein interaction network was constructed to obtain the key target genes. The Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment of the key targets were performed to predict the potential mechanisms of LQF action on MetS. And then, the high-fat diet-induced MetS mice were used to validate its therapeutic effect and molecular targets. Insulin tolerance test and oral glucose tolerance test were used to assess insulin sensitivity. Body weight and visceral fat index were measured to assess obesity. Liver metabolism was detected by H&E section, oil red O staining and untargeted lipid metabolomics experiments. Finally, the key targets of LQF action on MetS were verified by PCR and ELISA kits. A total of 466 components in LQF were obtained, among which 71 were active. These components correspond to 74 targets associated with MetS. The predicted targets of LQF worked on MetS were AKT1, INSR, PPARs, FASN, LDLR, TNF, CRP, IL-6, IL-1β and so on. Furthermore, these targets were related to pathways in cellular response to lipid, inflammatory response, glucose transmembrane transport and insulin resistance. Finally, the animal experiments validated that LQF inhibited lipids accumulation by inhibiting the gene expression of FASN and increasing ADPN, and it relieved insulin resistance by increasing GLUT-4 expression. Moreover, LQF alleviated inflammation by reducing IL-6 and CRP levels. LQF exerted anti-MetS effects through improving insulin sensitivity, ameliorating hyperlipidemia and obesity, reducing liver injury, and inhibiting inflammatory response.

Co-conversion of lignocellulose-derived glucose, xylose, and aromatics to polyhydroxybutyrate by metabolically engineered Cupriavidus necator

Utilization of all major components of lignocellulose is essential for biomass biorefining. Glucose, xylose, and lignin-derived aromatics can be generated from cellulose, hemicellulose, and lignin of lignocellulose degradation through pretreatment and hydrolysis. In present work, Cupriavidus necator H16 was engineered to utilize glucose, xylose, p-coumaric acid, and ferulic acid simultaneously by multi-step genetic engineering. Firstly, genetic modification and adaptive laboratory evolution were performed to promote glucose transmembrane transport and metabolism. Xylose metabolism was then engineered by integrating genes xylAB (xylose isomerase and xylulokinase) and xylE (proton-coupled symporter) in the locus of ldh (lactate dehydrogenase) and ackA (acetate kinase) on the genome, respectively. Thirdly, p-coumaric acid and ferulic acid metabolism was achieved by constructing an exogenous CoA-dependent non-β-oxidation pathway. Using corn stover hydrolysates as carbon sources, the resulting engineered strain Reh06 simultaneously converted all components of glucose, xylose, p-coumaric acid, and ferulic acid to produce 11.51 g/L polyhydroxybutyrate.

Synthetic Monosaccharide Channels: Size-Selective Transmembrane Transport of Glucose and Fructose Mediated by Porphyrin Boxes.

Here we report synthetic monosaccharide channels built with shape-persistent organic cages, porphyrin boxes (PBs), that allow facile transmembrane transport of glucose and fructose through their windows. PBs show a much higher transport rate for glucose and fructose over disaccharides such as sucrose, as evidenced by intravesicular enzyme assays and molecular dynamics simulations. The transport rate can be modulated by changing the length of the alkyl chains decorating the cage windows. Insertion of a linear pillar ligand into the cavity of PBs blocks the monosaccharide transport. In vitro cell experiment shows that PBs transport glucose across the living-cell membrane and enhance cell viability when the natural glucose transporter GLUT1 is blocked. Time-dependent live-cell imaging and MTT assays confirm the cyto-compatibility of PBs. The monosaccharide-selective transport ability of PBs is reminiscent of natural glucose transporters (GLUTs), which are crucial for numerous biological functions.

Synthetic Monosaccharide Channels: Size‐Selective Transmembrane Transport of Glucose and Fructose Mediated by Porphyrin Boxes

AbstractHere we report synthetic monosaccharide channels built with shape‐persistent organic cages, porphyrin boxes (PBs), that allow facile transmembrane transport of glucose and fructose through their windows. PBs show a much higher transport rate for glucose and fructose over disaccharides such as sucrose, as evidenced by intravesicular enzyme assays and molecular dynamics simulations. The transport rate can be modulated by changing the length of the alkyl chains decorating the cage windows. Insertion of a linear pillar ligand into the cavity of PBs blocks the monosaccharide transport. In vitro cell experiment shows that PBs transport glucose across the living‐cell membrane and enhance cell viability when the natural glucose transporter GLUT1 is blocked. Time‐dependent live‐cell imaging and MTT assays confirm the cyto‐compatibility of PBs. The monosaccharide‐selective transport ability of PBs is reminiscent of natural glucose transporters (GLUTs), which are crucial for numerous biological functions.

Transcriptomic analysis reveals the antibacterial mechanism of phenolic compounds from kefir fermented soy whey against Escherichia coli 0157:H7 and Listeria monocytogenes

Transcriptomic analysis was used to investigate the antibacterial mechanism of phenolic compounds from kefir fermented soy whey (FSP) against Escherichia coli 0157:H7 and Listeria monocytogenes. The kefir fermentation increased the concentration of several phenolic aglycones with proven antibacterial efficacy in the FSP. The time-kill curve showed that 2× MICs of the FSP killed >99.9 % of the strains within 2 h of exposure. The checkerboard fractional inhibition concentration (FIC) assay proved that phenolics were the sole antibacterial agent in the FSP. The transmission electron microscope (TEM) photomicrograph corroborated the propidium iodide (PI) uptake, protein, and nucleic acid leakage assays. They demonstrated that the phenolics permeated the cell membrane, disrupted the cytoplasm, and caused cell lysis in the treated cells leading to protein and nucleic acid leakage. The transcriptome analysis revealed that exposure of the cells to MICs of the phenolics induced molecular responses leading to differential expression of 1850 genes in E. coli 0157:H7 and 2090 in L. monocytogenes. The phenolics suppressed the expression of genes crucial for carbohydrate utilization, transmembrane glucose transport, tricarboxylic acid (TCA), and ATP synthesis. The phenolic-induced stress also downregulated the expression of quorum sensing and virulence-related genes, peptidoglycan and phospholipid synthases, and ABC transporters. The cells initiated a resistance response by stimulating the two-component signal transduction systems to trigger the over-expression of a cascade of genes involved in stress resistance, gluconeogenesis, ATPase activity and proton transmembrane transport. Nonetheless, the data indicated that the phenolics suppressed the expression of translational proteins that would have facilitated the resistance and repair of the cell damage caused by the phenolics. The study provides discrete data evidence that FSP could be used to control the pathogenicity and the proliferation of E. coli 0157:H7 and L. monocytogenes in our foods and food systems.

Prognostic value of the ferroptosis-related gene SLC2A3 in gastric cancer and related immune mechanisms.

SLC2A3 is a ferroptosis marker engaged in transmembrane glucose transport. However, the effect of SLC2A3 on the prognosis of patients with cancer remains unclear. This study aimed to explore the prognostic implications of SLC2A3 and its underlying immune mechanisms in gastric cancer. The mRNA expression profiles and corresponding clinical data of patients with gastric cancer were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus databases. Differentially expressed genes related to SLC2A3 were identified using the R package “limma.” Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, gene set enrichment analysis, and gene set variation analysis were used to explore the underlying mechanisms. The protein–protein and miRNA interaction networks were analyzed using Cytoscape software. Immune cell infiltration was assessed using single-sample gene set enrichment analysis. Univariate and multivariate Cox regression analyses revealed the relationship between SLC2A3 expression and prognosis. SLC2A3 was found to be highly expressed in tumor tissues and was associated with an unfavorable prognosis in patients with gastric cancer. Functional enrichment analysis showed that SLC2A3 is related to cytokine–cytokine receptor interaction, epithelial–mesenchymal transition, T cell receptor signaling pathway, B cell receptor signaling pathway, and immune checkpoints. SLC2A3 is also involved in immune response regulation and is regulated by multiple miRNAs, including miR-195-5p, miR-106a-5p, miR-424-5p, and miR-16-5p. Univariate and multivariate Cox regression analyses indicated that SLC2A3 can be used as an independent prognostic factor for predicting the outcome in patients with gastric cancer. SLC2A3 and related miRNAs are potential prognostic biomarkers and therapeutic targets.

Abstract 2387: The impact of beta 1,6-GlcNAc branched N-glycan synthesis on hexosamine pathway and UDP-GlcNAc demands in colorectal cancer cells

Abstract Metabolic changes are commonly seen in cancer. Tumor cells present a high rate of glucose and glutamine uptake and part of these nutrients supplies the hexosamine biosynthesis pathway (HBP), whose exacerbation has been related to solid tumors progression, including colorectal cancer. Uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), the end product of HBP, serves as the donor for several enzymes involved in glycan biosynthesis. Aberrant glycosylation is known to affect cellular and molecular mechanisms related to the malignant phenotype. Beta 1,6-GlcNAc branches on N-glycans (products of the MGAT5 enzyme) are associated with greater stability of transmembrane glycoproteins, as glutamine and glucose transporters, and growth factor receptors. Furthermore, changes in the availability of UDP-GlcNAc can affect the levels of hyaluronic acid (HA) and O-GlcNAc-modified proteins. The interplay between different direct demands for UDP-GlcNAc is not well understood and may help to better understand tumor metabolism. Therefore, we intend to evaluate in colorectal cancer cells how changes in levels of branched beta1,6-GlcNAc N-glycans can affect both the hexosamine pathway and the different processes which demand UDP-GlcNAc (such as O-GlcNAcylation and hyaluronic acid synthesis). For this, two experimental strategies were performed. The first focused on the inhibition of complex N-glycans using swainsonine, and the second focused on the MGAT5 inactivation using CRISPR-Cas9. The levels of UDP-GlcNAc were also manipulated using DON, an inhibitor of the GFAT enzyme. Initially, it was found that both the pharmacological inhibition of complex N-glycan biosynthesis and the specific inactivation of MGAT5 lead to significantly reduced levels of hexosamine pathway intermediates, activated monosaccharides, and proteins modified by O-GlcNAc. Furthermore, it was also observed that MGAT5 inactivation enhances the expression of genes encoding HA synthases (HAS2 and HAS3). Upon detection of metabolites by LC-MS, a multivariate analysis was performed using the statistical method of Partial Least-Squares Discriminant Analysis (PLS-DA), and it was observed that KO MGAT5 cells formed a metabolically distinct population from MOCK cells. Interestingly, after pharmacological inhibition of GFAT, an increase in the levels of beta 1,6-GlcNAc branched N-glycans and a reduction in O-GlcNAcylation were observed. Treatment with DON was also able to reduce HAS2 expression however an increased in HAS3 expression was observed. These data suggest that there is a relationship among different demands for UDP-GlcNAc in tumor cells and a possible regulatory role played by beta 1,6-GlcNAc branched N-glycans in this issue. This work contributes to a better understanding of interconnections between biochemical processes that demand UDP-GlcNAc in the context of colorectal cancer. Citation Format: Érika Elias Ferreira, Isadora de Araújo Oliveira, Adriane Regina Todeschini, Julio Cesar de Freitas-Junior. The impact of beta 1,6-GlcNAc branched N-glycan synthesis on hexosamine pathway and UDP-GlcNAc demands in colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2387.

BcSDR1 is involved in regulation of glucose transport and cAMP and MAPK signaling pathways in Botrytis cinerea

Botrytis cinerea is a typical necrotrophic pathogenic fungus that causes severe diseases in a wide range of plant species, leading to significant economic losses. Our previous study showed that BcSDR1 positively regulates growth, development, and pathogenicity of B. cinerea. However, the regulation mechanism of BcSDR1 and the relationship between BcSDR1 and cAMP and MAPK signaling pathways are not well understood. In this study, transcriptome data showed that BcSDR1 is involved in glucose transmembrane transport, signal transduction, secondary metabolism, and other biological processes. BcSDR1 mutant (BCt41) showed remarkably weak sensitivity to cAMP and MAPK signaling pathways specific inhibitors, SQ22536 and U0126, and significantly decreased cAMP content. The key genes of cAMP and MAPK signaling pathways, BcGB1, BcBTP1, BcBOS1, BcRAS1, and BcBMP3 were significantly upregulated, whereas BcPLC1, BcBCG1, BcCDC4, BcSAK1, BcATF1, and BcBAP1 were significantly downregulated (P<0.05). BcSDR1 was obviously upregulated in BcBCG2, BcBCG3, BcPKA1, and BcPKAR RNA interference (RNAi) mutants, but significantly downregulated in BcPKA2, BcBMP1, and BcBMP3 RNAi mutants. Thus, BcBCG2, BcBCG3, BcPKA1, and BcPKAR negatively regulate BcSDR1 expression, whereas BcPKA2, BcBMP1, and BcBMP3 positively regulate BcSDR1 expression.

Unraveling the Gordian knot of insulin resistance in type 2 diabetes mellitus

&lt;abstract&gt; &lt;p&gt;β-cells play an important role in unraveling the Gordian knot of insulin resistance in type 2 diabetes. Firstly, a key feature of the etiology of type 2 diabetes, which appears in the prediabetic phase, is a reduction in the unsaturation index (number of cis carbon-carbon double bonds per 100 acyl chains of membrane phospholipids) compared to healthy controls, which leads to a lower rate of transmembrane glucose transport, and consequently causes reduced glucose effectiveness. Thus, the amount of glucose entering the β-cell via glucose transporter-2 reduces insulin production, leading to reduced insulin sensitivity. Secondly, after synthesis of monomer insulin, six monomer insulin molecules can join together in the presence of zinc ions. The mature hexamers are packed inside mature intracellular vesicles that are transported to the β-cell plasma membrane. Fusion of the intracellular vesicle membrane with the β-cell plasma membrane creates a fusion pore that allows expulsion of monomer insulin molecules into the blood circulation. The large dimensions of the monomer insulin molecule (30 Å wide and 35 Å high) require substantial flexibility of the vesicle membrane and the β-cell plasma membrane. Reduction in the unsaturation indexes leads to a lower rate of insulin transport into the blood circulation, which results in a further decrease in insulin sensitivity.&lt;/p&gt; &lt;p&gt;That brings us to a crucial point. The conceit behind the term “insulin resistance” is wrong. It suggests that cells do not respond well to insulin, but the fact is that this term ignores the essential reduction, compared to the plasma glucose concentration, in the amount of glucose entering the β-cell via glucose transporter-2, resulting in reduced insulin production. We now know that an increase in glucose effectiveness, powered by an increased unsaturation index, reframes fundamentally the mechanisms that participate in the glucose homeostasis during type 2 diabetes mellitus.&lt;/p&gt; &lt;/abstract&gt;

EgGLUT1 Is Crucial for the Viability of Echinococcus granulosus sensu stricto Metacestode: A New Therapeutic Target?

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by infection with the larvae of Echinococcus granulosus sensu lato (s.l.) cluster. It is urgent to identify novel drug targets and develop new drug candidates against CE. Glucose transporter 1 (GLUT1) is mainly responsible for the transmembrane transport of glucose to maintain its constant cellular availability and is a recent research hotspot as a drug target in various diseases. However, the role of GLUT1 in E. granulosus s.l. (EgGLUT1) was unknown. In this study, we cloned a conserved GLUT1 homology gene (named EgGLUT1-ss) from E. granulosus sensu stricto (s.s.) and found EgGLUT1-ss was crucial for glucose uptake and viability by the protoscoleces of E. granulosus s.s. WZB117, a GLUT1 inhibitor, inhibited glucose uptake by E. granulosus s.s. and the viability of the metacestode in vitro. In addition, WZB117 showed significant therapeutic activity in E. granulosus s.s.-infected mice: a 10 mg/kg dose of WZB117 significantly reduced the number and weight of parasite cysts (P < 0.05) as efficiently as the reference drug, albendazole. Our results demonstrate that EgGLUT1-ss is crucial for glucose uptake by the protoscoleces of E. granulosus s.s., and its inhibitor WZB117 has a therapeutic effect on CE.

RSPH14 regulates the proliferation, cell cycle progression, and apoptosis of non-small cell lung cancer cells.

Non‐small cell lung cancer (NSCLC) is the most common subtype of lung cancer, and it is characterized by a high incidence. It is important to understand the molecular mechanisms that determine the progression and metastasis of NSCLC in order to develop more effective therapies and identify novel diagnostic indicators of NSCLC. RSPH14 has been reported to be related to multiple human diseases, including duodenal adenocarcinoma and meningiomas, but the role of RSPH14 in NSCLC remains unclear. The present study aimed to investigate the molecular function and clinical significance of RSPH14 in NSCLC. Analyses of public datasets and clinical samples demonstrated that RSPH14 expression was upregulated in NSCLC samples compared with normal samples. In addition, high RSPH14 expression was associated with a shorter overall survival time in patients with NSCLC. Notably, RSPH14 knockdown suppressed the proliferation and cell cycle progression and enhanced the apoptosis of NSCLC cells. Mechanically, tandem mass tag analysis demonstrated that RSPH14 can affect multiple processes, including the AMPK signaling pathway, calcium ion import regulation, glucose transmembrane transporter activity, and glucose transmembrane transport. Taken together, the results of the present study suggest that RSPH14 may be a promising prognostic factor and therapeutic target for NSCLC.

A Prognosis Marker SLC2A3 Correlates With EMT and Immune Signature in Colorectal Cancer.

SLC2A3 is a membrane transporter that belongs to the solute carrier family, whose function includes transmembrane transport and glucose transmembrane transport activity. To clarify the expression and role of SLC2A3 in colorectal cancer (CRC), we analyzed the TCGA and GEO databases and found that SLC2A3 mRNA levels were significantly higher in CRC tissues than that in adjacent non-tumor tissues. Furthermore, high expression of SLC2A3 predicted poor overall survival and disease free survival for CRC patients. For validation, we collected 174 CRC samples and found that SLC2A3 expression was higher in CRC tissues than that in adjacent non-tumor colorectal mucosa tissues by immunohistochemistry staining. Further study showed that high expression of SLC2A3 was enriched in epithelial–mesenchymal transition (EMT) classical pathway, interferon-γ pathway by GSEA analysis enrichment, indicating that SLC2A3 may play a key role in the progression of CRC through EMT and immune response, which also has been validated by the global gene expression profiling of human CRC cell lines. The expression of SLC2A3 was positively correlated with CD4 and CD8+T cells by using TIMER and EPIC algorithm, respectively. SLC2A3 knockdown suppressed migration and inhibited the expression of Vimentin and MMP9 in CRC cell line SW480 and RKO. Meanwhile, PD-L1 expression was also significantly attenuated in SW480 and RKO cells transfected with SLC2A3 siRNA. The result suggests that SLC2A3 may be involved in the immune response of CRC by regulating PD-L1 immune checkpoint. In our series, SLC2A3 and PD-L1 positive expression was 74% (128/174) and 22% (39/174) of CRC, respectively. SLC2A3 expression was significantly associated with perineural invasion in CRC patients. In conclusion, SLC2A3 may play an important role in progression of CRC by regulating EMT and PD-L1 mediated immune responses.

Ionic copper strengthens the toxicity of tetrabromobisphenol A (TBBPA) to denitrification by decreasing substrate transport and electron transfer

Increasing electrical and electronic waste have raised concerns about the potential toxicity of brominated flame retardants (BFRs) and heavy metals (HMs). However, few studies have focused on the combined effect of BFRs and HMs on microorganisms, especially denitrifying bacteria, which have an essential role in N cycles and N2O emission. Herein, we investigate the combined effect of tetrabromobisphenol A (TBBPA) and Cu on model denitrifying bacteria. A further 24.5% decline in N removal efficiency was observed when 0.05 mg/L Cu were added into a denitrifying system containing 0.75 mg/L TBBPA. Further study demonstrated that Cu heightened the toxicity of TBBPA to denitrification via following aspects: (1) Cu stimulated EPS secretion induced by TBBPA during denitrification, blocked the transmembrane transport of glucose, which caused insufficient carbon substrate for bacteria growth and electron provision; (2) Cu further suppressed key denitrifying enzymes’ activity and down-regulated genes involving electron transport induced by TBBPA, led to the decrease of electron transport activity. Finally, the decrease of bacterial growth, insufficient electron donor, and lower electron transport activity caused the synergetic toxic effect of TBBPA and Cu on denitrification. Overall, the present study provides new insights into the combined effect of BFRs and HMs on microorganisms.

Continuous Glucose Monitoring Facilitates Diazoxide Use in the Management of Glut1 Deficiency Syndrome

Abstract Background: Glut1 deficiency syndrome (Glut1DS) is caused by mutations in SLC2A1 on chromosome 1p34.2, which impairs transmembrane glucose transport across the blood brain barrier resulting in hypoglycorrhachia and decreased glucose availability for brain metabolism. This causes a drug-resistant, metabolic epilepsy due to energy deficiency. Standard treatment for Glut1DS is the ketogenic diet (KD) but treatment options are limited if patients fail the KD. Diazoxide, which inhibits insulin release, was used sparingly in the past for a few Glut1DS patients to increase blood glucose levels and thus intracerebral glucose levels. Unfortunately, their treatment was complicated by unacceptable persistent hyperglycemia with blood glucoses in the 300s to 500s. We investigated the use of a continuous glucose monitor (CGM) to enable titration of diazoxide therapy in a patient with KD-resistant Glut1DS. Clinical Case: A 14-year-old girl with Glut1DS (c.398_399delGCinsTT:p.Lys133Phe) failed the KD due to severe nausea, vomiting, abdominal pain, and hypertriglyceridemia. Laboratory tests revealed CSF glucose of 36 mg/dL when blood glucose was 93 mg/dL. Over the course of 3 hospitalizations targeting blood glucose levels in the range of 120-180 mg/dL with diazoxide, EEG seizure activity decreased from 3 to 0 absence seizures per hour. CGM placement during the third hospitalization showed an average interstitial glucose of 157 mg/dL with glucose variability of 20.8% on diazoxide dose of 7.3 mg/kg/day. After discharge, CGM has been used to adjust diazoxide doses 2-4 times a week to achieve target interstitial glucoses of 140-180 mg/dL. Repeat laboratory tests revealed CSF glucose of 55 mg/dL when interstitial glucose was 158 mg/dL. Current diazoxide dose is 7.9 mg/kg/day and most recent hemoglobin A1c was 5.4%. Conclusions: This is the first report demonstrating CGM as a tool facilitating the safe initiation and real-time titration of diazoxide in Glut1DS patients who have failed the KD. Diazoxide addresses neuroglycopenia more physiologically by raising blood glucose levels and subsequently intracerebral glucose levels. CGM allows for more accurate titration of blood glucose with diazoxide while avoiding complications of hyperglycemia and thus introduces the possibility of diazoxide becoming a standard of care for Glut1DS. More broadly, CGM provides a valuable tool for the management of other disorders of glucose transport and carbohydrate metabolism.