Gut bacteria are essential for development of an invasive bark beetle by regulating glucose transport.

Insects and their gut bacteria form a tight and beneficial relationship, especially in utilization of host nutrients. The red turpentine beetle (RTB), a destructive and invasive pine pest, employs mutualistic microbes to facilitate its invasion success. However, the molecular mechanism underlying the utilization of nutrients remains unknown. In this study, we found that gut bacteria are crucial for the utilization of D-glucose, a main carbon source for RTB development. Downstream assays revealed that gut bacteria-induced gut hypoxia and the secretion of riboflavin are responsible for RTB development by regulating D-glucose transport via the activation of a hypoxia-induced transcription factor 1 (Hif-1α). Further functional investigations confirmed that Hif-1α mediates glucose transport by direct upregulation of two glucose transporters (ST10 and ST27), thereby promoting RTB development. Our findings reveal how gut bacteria regulate the development of RTB, and promote our understanding of the mutualistic relationship of animals and their gut bacteria.

Unmasking the silent culprit: recurrent exercise-induced acute kidney injury in a Chinese adolescent with renal hypouricemia.

Primary renal hypouricemia (RHUC) is a rare autosomal recessive disorder with a mean duration of end-stage acute kidney injury (EIAKI) of 14 days. The pathogenesis of EIAKI in patients with RHUC remains unclear. Several hypotheses have been proposed, including those related to the renal vasoconvulsive effect and the elevating effect of xanthine oxidase (XO). The effect of xanthine oxidase (XO) is most often observed following strenuous anaerobic exercise, which is frequently accompanied by low back pain, nausea, and acute kidney injury (AKI). Consequently, we postulate that EIAKI could be prevented by avoiding strenuous exercise, thus preventing the onset and recurrence of EIAKI. In this paper, we present a case of recurrent EIAKI in a patient with RHUC and a mutation in the SLC2A9 gene.

Effects of Commonly used Surfactants, Poloxamer 188 and Tween 80, on the Drug Transport Capacity of Intestinal Glucose Transporters.

Some glycoside drugs can be transported through intestinal glucose transporters (IGTs). The surfactants used in oral drug preparations can affect the function of transporter proteins. This study aimed to investigate the effect of commonly used surfactants, Poloxamer 188 and Tween 80, on the drug transport capacity of IGTs. Previous studies have shown that gastrodin is the optimal drug substrate for IGTs. Gastrodin was used as a probe drug to evaluate the effect of these two surfactants on intestinal absorption in SD rats through pharmacokinetic and in situ single-pass intestinal perfusion. Then, the effects of the two surfactants on the expression of glucose transporters and tight-junction proteins were examined using RT-PCR and western blotting. Additionally, the effect of surfactants on intestinal permeability was evaluated through hematoxylin-eosin staining. The results found that all experimental for Poloxamer 188 (0.5%, 2.0% and 8.0%) and Tween 80 (0.1% and 2.0%) were not significantly different from those of the blank group. However, the AUC(0-∞) of gastrodin increased by approximately 32% when 0.5% Tween 80 was used. The changes in IGT expression correlated with the intestinal absorption of gastrodin. A significant increase in the expression of IGTs was observed at 0.5% Tween 80. In conclusion, Poloxamer 188 had minimal effect on the drug transport capacity of IGTs within the recommended limits of use. However, the expression of IGTs increased in response to 0.5% Tween 80, which significantly enhanced the drug transport capacity of IGTs. However, 0.1% and 2.0% Tween 80 had no significant effect.

[Glucose transporters in lymphocytes: expression and effects on lymphocyte functions].

Glucose uptake by lymphocytes is dependent on the facilitative glucose transporters (GLUT1, GLUT3, GLUT4, and GLUT6) of the GLUT family and the Na+-coupled glucose transporter SGLT1. GLUTs and SGLTs are widely expressed in mammals, and their expression and functions may affect cell development, homeostasis, activation, and differentiation. This article details the important functions of several GLUTs and SGLTs in lymphocytes and points out that glucose transporters play a key role in supplying energy for lymphocytes, maintaining intracellular glucose homeostasis, and improving the efficiency of immune responses, which reflect their key roles in signal transduction. Probing into the effects of glucose transporters on lymphocyte functions will help to decipher the functioning mechanisms of lymphocytes in diseases. Furthermore, this paper prospects the application values of glucose transporters in lymphocytes from molecular biology, aiming to provide better strategies for the clinical treatment of lymphocyte-related diseases and promote the research and development of targeted therapeutic drugs.

Glucose transporters and sodium glucose co-transporters cooperatively import glucose into energy-demanding organs in carcinogenic liver fluke Clonorchis sinensis.

BACKGROUND: The liver fluke Clonorchis sinensis imports large amounts of glucose to generate energy and metabolic intermediates through glycolysis. We hypothesized that C. sinensis absorbs glucose through glucose transporters and identified four subtypes of glucose transporter (CsGTP) and one sodium glucose co-transporter (CsSGLT) in C. sinensis. METHODOLOGY/PRINCIPAL FINDINGS: Expressed sequence tags encoding CsGTPs were retrieved from the C. sinensis transcriptome database, and their full-length cDNA sequences were obtained by rapid amplification of cDNA ends (RACE). The tissue distribution of glucose transporters in C. sinensis adults was determined using immunohistochemical staining. Developmental expression was measured using RT-qPCR. The transport and distribution of glucose into living C. sinensis were monitored using confocal microscopy. Membrane topology and key functional residues of CsGTPs were homologous to their counterparts in animals and humans. CsGTP1, 2, and 4 were transcribed 2.4-5.5 times higher in the adults than metacercariae, while CsGTP3 was transcribed 2.1 times higher in the metacercariae than adults. CsSGLT transcription was 163.6 times higher in adults than in metacercariae. In adults, CsSGLT was most abundant in the tegument; CsGTP3 and CsSGLT were localized in the vitelline gland, uterine wall, eggs, mesenchymal tissue, and testes; CsGTP4 was found in sperm and mesenchymal tissue; and CsGTP1 was mainly in the sperm and testes. In C. sinensis adults, exogenous glucose is imported in a short time and is present mainly in the middle and posterior body, in which the somatic and reproductive organs are located. Of the exogenous glucose, 53.6% was imported through CsSGLT and 46.4% through CsGTPs. Exogenous glucose import was effectively inhibited by cytochalasin B and phlorizin. CONCLUSIONS/SIGNIFICANCE: We propose that CsSGLT cooperates with CsGTPs to import exogenous glucose from the environmental bile, transport glucose across mesenchymal tissue cells, and finally supply energy-demanding organs in C. sinensis adults. Studies on glucose transporters may pave the way for the development of new anthelmintic drugs.

[Uric Acid Metabolism, Uric Acid Transporters and Dysuricemia].

Serum urate levels are determined by the balance between uric acid production and uric acid excretion capacity from the kidneys and intestinal tract. Dysuricemia, including hyperuricemia and hypouricemia, develops when the balance shifts towards an increase or a decrease in the uric acid pool. Hyperuricemia is mostly a multifactorial genetic disorder involving several disease susceptibility genes and environmental factors. Hypouricemia, on the other hand, is caused by genetic abnormalities. The main genes involved in dysuricemia are xanthine oxidoreductase, an enzyme that produces uric acid, and the urate transporters urate transporter 1/solute carrier family 22 member 12 (URAT1/SLC22A12), glucose transporter 9/solute carrier family 2 member 9 (GLUT9/SLC2A9) and ATP binding cassette subfamily G member 2 (ABCG2). Deficiency of xanthine oxidoreductase results in xanthinuria, a rare disease with marked hypouricemia. Xanthinuria can be due to a single deficiency of xanthine oxidoreductase or in combination with aldehyde oxidase deficiency as well. The latter is caused by a deficiency in molybdenum cofactor sulfurase, which is responsible for adding sulphur atoms to the molybdenum cofactor required for xanthine oxidoreductase and aldehyde oxidase to exert their action. URAT1/SLC22A12 and GLUT9/SLC2A9 are involved in urate reabsorption and their deficiency leads to renal hypouricemia, a condition that is common in Japanese due to URAT1/SLC22A12 deficiency. On the other hand, ABCG2 is involved in the secretion of urate, and many Japanese have single nucleotide polymorphisms that result in its reduced function, leading to hyperuricemia. In particular, severe dysfunction of ABCG2 leads to hyperuricemia with reduced extrarenal excretion.

The impact of chrysanthemi indici flos-enriched flavonoid part on the model of hyperuricemia based on inhibiting synthesis and promoting excretion of uric acid.

ETHNOPHARMACOLOGICAL RELEVANCE: In recent years, in addition to hypertension, hyperglycemia, and hyperlipidemia, the prevalence of hyperuricemia (HUA) has increased considerably. Being the fourth major health risk factor, HUA can affect the kidneys and cardiovascular system. Chrysanthemi Indici Flos is a flavonoid-containing traditional Chinese patent medicine that exhibits a uric acid (UA)-lowering effect. However, the mechanisms underlying Chrysanthemi Indici Flos-enriched flavonoid part (CYM.E) mediated alleviation of HUA remain unelucidated. AIM OF THE STUDY: This study aimed to elucidate the efficacy of CYM.E in preventing and treating HUA and its specific effects on UA-related transport proteins, to explore possible mechanism. METHODS: The buddleoside content in CYM.E was determined through high-performance liquid chromatography. HUA was induced in mice models using adenine and potassium oxonate. Subsequently, mice were administered 10 mg/kg allopurinol, and 30, 60, and 90 mg/kg CYM.E to evaluate the effects of CYM.E on the of HUA mice model. Herein, plasma uric acid (UA), creatinine (CR), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c) contents, along with serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities were measured. Additionally, xanthine oxidase (XOD) and adenosine deaminase (ADA) activities in the liver were determined. The histomorphologies of the liver and kidney tissues were examined through hematoxylin and eosin staining. The messenger RNA (mRNA) expression of facilitated glucose transporter 9 (GLUT9), organic anion transporter (OAT)1, OAT3, and adenosine triphosphate binding cassette subfamily G2 (ABCG2) in the kidney was assessed by real-time quantitative polymerase chain reaction. Furthermore, the expression of urate transporter 1 (URAT1), GLUT9, OAT1, and OAT3 in the kidney, OAT4, and ABCG2 proteins was determined by immunohistochemistry and western blotting. RESULTS: The buddleoside content in CYM.E was approximately 32.77%. CYM.E improved body weight and autonomous activity in HUA mice. Additionally, it reduced plasma UA, BUN, and CR levels and serum ALT and AST activities, thus improving hepatic and renal functions, which further reduced the plasma UA content. CYM.E reduced histopathological damage to the kidneys. Furthermore, it lowered plasma TC, TG, and LDL-c levels, thereby improving lipid metabolism disorder. CYM.E administration inhibited hepatic XOD and ADA activities and reduced the mRNA expression of renal GLUT9. CYM.E inhibited the protein expression of renal URAT1, GLUT9, and OAT4, and increased the mRNA and protein expression of renal OAT1, OAT3, and ABCG2. Altogether, these results show that CYM.E could inhibit the production and promote reabsorption of UA and its excretion.

Effects of allopurinol and febuxostat on uric acid transport and transporter expression in human umbilical vein endothelial cells.

Uric acid induces radical oxygen species formation, endothelial inflammation, and endothelial dysfunction which contributes to the progression of atherosclerosis. Febuxostat inhibits BCRP- and allopurinol stimulates MRP4-mediated uric acid efflux in human embryonic kidney cells. We hypothesized that endothelial cells express uric acid transporters that regulate intracellular uric acid concentration and that modulation of these transporters by febuxostat and allopurinol contributes to their different impact on cardiovascular mortality. The aim of this study was to explore a potential difference between the effect of febuxostat and allopurinol on uric acid uptake by human umbilical vein endothelial cells. Febuxostat increased intracellular uric acid concentrations compared with control. In contrast, allopurinol did not affect intracellular uric acid concentration. In line with this observation, febuxostat increased mRNA expression of GLUT9 and reduced MRP4 expression, while allopurinol did not affect mRNA expression of these uric acid transporters. These findings provide a possible pathophysiological pathway which could explain the higher cardiovascular mortality for febuxostat compared to allopurinol but should be explored further.

Structural basis for urate recognition and apigenin inhibition of human GLUT9.

Urate, the physiological form of uric acid and a potent antioxidant in serum, plays a pivotal role in scavenging reactive oxygen species. Yet excessive accumulation of urate, known as hyperuricemia, is the primary risk factor for the development of gout. The high-capacity urate transporter GLUT9 represents a promising target for gout treatment. Here, we present cryo-electron microscopy structures of human GLUT9 in complex with urate or its inhibitor apigenin at overall resolutions of 3.5 Å and 3.3 Å, respectively. In both structures, GLUT9 exhibits an inward open conformation, wherein the substrate binding pocket faces the intracellular side. These structures unveil the molecular basis for GLUT9's substrate preference of urate over glucose, and show that apigenin acts as a competitive inhibitor by occupying the substrate binding site. Our findings provide critical information for the development of specific inhibitors targeting GLUT9 as potential therapeutics for gout and hyperuricemia.

Mechanisms of epigallocatechin gallate (EGCG) in ameliorating hyperuricemia: insights into gut microbiota and intestinal function in a mouse model.

Epigallocatechin gallate (EGCG), a prominent bioactive compound found in tea, offers numerous health benefits. Previous studies have highlighted its potential in mitigating hyperuricemia. In this study, hyperuricemic mice induced by potassium oxonate (PO) were treated with EGCG or the anti-hyperuricemia medication allopurinol (AP) to investigate the mechanisms underlying their anti-hyperuricemic effects. The results demonstrated that both EGCG and AP significantly reduced serum uric acid (UA) levels. Further analysis revealed that EGCG promoted the expression of UA secretion transporter genes (Oat1 and Oct1) while inhibiting the expression of UA reabsorption transporter genes (Urat1 and Glut9) in the kidney. By 16S rDNA sequencing, EGCG, but not AP, was found to alter the composition of the gut microbiota. Notably, EGCG induced significant changes in the relative abundance of specific bacteria such as Lactobacillus, Faecalibaculum, and Bifidobacterium, which displayed high correlations with serum UA levels and UA-related gene expression. Metabolomic analysis suggested that EGCG-induced modifications in bacterial metabolites might contribute to the alleviation of hyperuricemia. Transcriptomic analysis of the intestinal epithelium identifies 191 differentially expressed genes (DEGs) in EGCG-treated mice, including 8 purine-related genes. This study elucidates the anti-hyperuricemic mechanisms of EGCG, particularly its influence on the gut microbiota and gene expression in the intestinal epithelium.

Saturated fatty acids inhibit unsaturated fatty acid induced glucose uptake involving GLUT10 and aerobic glycolysis in bovine granulosa cells.

Fatty acids have been shown to modulate glucose metabolism in vitro and in vivo. However, there is still a need for substantial evidence and mechanistic understanding in many cell types whether both saturated and unsaturated fatty acids (SFAs and UFAs) pose a similar effect and, if not, what determines the net effect of fatty acid mixes on glucose metabolism. In the present study, we asked these questions by treating granulosa cells (GCs) with the most abundant non-esterified fatty acid species in bovine follicular fluid. Results revealed that oleic and alpha-linolenic acids (UFAs) significantly increased glucose consumption compared to palmitic and stearic acids (SFAs). A significant increase in lactate production, extracellular acidification rate, and decreased mitochondrial activity indicate glucose channeling through aerobic glycolysis in UFA treated GCs. We show that insulin independent glucose transporter GLUT10 is essential for UFA driven glucose consumption, and the induction of AKT and ERK signaling pathways necessary for GLUT10 expression. To mimic the physiological conditions, we co-treated GCs with mixes of SFAs and UFAs. Interestingly, co-treatments abolished the UFA induced glucose uptake and metabolism by inhibiting AKT and ERK phosphorylation and GLUT10 expression. These data suggest that the net effect of fatty acid induced glucose uptake in GCs is determined by SFAs under physiological conditions.

Effects of environmental enrichment on GLUT expression in the visual cortex of amblyopic rats.

OBJECTIVE: To investigate the potential changes of glucose metabolism and glucose transporter protein (GLUT) in the visual cortex of formally deprived amblyopic rats, as well as the effects of enriched environments on the levels of nerve conduction and glucose metabolism in the visual cortex of amblyopic rats. METHODS: 36 rats were randomly divided into three groups: CON + SE (n = 12), MD + SE (n = 12) and MD + EE (n = 12). The right eyelids of both MD + SE and MD + EE groups were sutured. After successful modelling, the MD + EE group was maintained in an enriched environment, and the other two groups were kept in the same environment. Pattern visual evoked potentials (PVEP) was used to confirm models' effect, glucose metabolism was analyzed by Micro-PET/CT (18F-FDG), and the protein as well as mRNA expression levels of GLUT were detected by Western Blot and quantitative RT-PCR (quantitative Reverse Transcription-Polymerase Chain Reaction) analyses, site of GLUT expression by immunofluorescence (IF). RESULTS: After suture modelling, both the MD + EE and MD + SE groups objective visual nerve conduction function decreased, the glucose metabolism in the visual cortex was markedly lower. After the enriched environment intervention, it recovered in the MD + EE group. The expression levels of GLUT1 and GLUT3 were increased in the MD + EE group in comparison with the MD + SE group. GLUT1 was primarily expressed on astrocytes and endothelial cells, but GLUT3 was mainly expressed on neurons. CONCLUSION: Enrichment of the environment exhibited a therapeutic effect on amblyopia, which could be related to the enhancement of glucose metabolism and GLUT expression in the visual cortex.

Metabolites from Aerial Parts of Glycyrrhiza foetida as Modulators of Targets Related to Metabolic Syndrome.

A detailed phytochemical investigation has been carried out on the aerial parts of G. foetida leading to the isolation of 29 pure compounds, mainly belonging to the amorfrutin and polyphenol classes. Among them, the new amorfrutin N (5) and exiguaflavone L (21) were isolated and their structures elucidated by means of HR-ESIMS and NMR. All the isolated compounds were investigated for modulation of mitochondrial activity and stimulation of glucose uptake via GLUT transporters, two metabolic processes involved in intracellular glucose homeostasis, which, therefore, correlate with the incidence of metabolic syndrome. These experiments revealed that amorfrutins were active on both targets, with amorfrutin M (17) and decarboxyamorfrutin A (2) emerging as mitochondrial stimulators, and amorfrutin 2 (12) as a glucose uptake promoter. However, members of the rich chalcone/flavonoid fraction also proved to contribute to this activity.

Analyzing chemical composition of Sargentodoxae caulis water extract and their hypouricemia effect in hyperuricemic mice.

Hyperuricemia (HUA) is a metabolic disease characterized by the increase of serum uric acid (UA) level. Sargentodoxae Caulis (SC) is a commonly used herbal medicine for the treatment of gouty arthritis, traumatic swelling, and rheumatic arthritis in clinic. In this study, a total of fifteen compounds were identified in SC water extract using UHPLC-Q-TOF-MS/MS, including three phenolic acids, seven phenolic glycosides, four organic acids, and one lignan. Then, to study the hypouricemia effect of SC, a HUA mouse model was induced using a combination of PO, HX, and 20% yeast feed. After 14 days of treatment with the SC water extract, the levels of serum UA, creatinine (CRE), blood urea nitrogen (BUN) were reduced significantly, and the organ indexes were restored, the xanthine oxidase (XOD) activity were inhibited as well. Meanwhile, SC water extract could ameliorate the pathological status of kidneys and intestine of HUA mice. Additionally, quantitative real-time PCR (qRT-PCR) and western blotting results showed that SC water extract could increase the expression of ATP binding cassette subfamily G member 2 (ABCG2), organic cation transporter 1 (OCT1), organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3), whereas decrease the expression of glucose transporter 9 (GLUT9). This study provided a data support for the clinical application of SC in the treatment of HUA.

Discovery of a Novel Thienopyrimidine Compound as a Urate Transporter 1 and Glucose Transporter 9 Dual Inhibitor with Improved Efficacy and Favorable Druggability.

Gout and hyperuricemia are metabolic diseases characterized with high serum uric acid (SUA) levels that significantly impact human health. Lesinurad, a uricosuric agent, is limited to concurrent use with xanthine oxidase inhibitors (XOIs) in clinical practice due to its restricted efficacy and potential nephrotoxicity. Herein, extensive structural modifications of lesinurad were conducted through scaffold hopping and substituent modification strategies, affording 54 novel derivatives containing pyrimidine-fused cyclic structures. Notably, the thienopyrimidine compound 29 demonstrated a remarkable 2-fold increase in SUA-lowering in vivo activity compared to lesinurad, while exhibiting potent inhibitory activity against the urate transporter 1 (URAT1, IC50 = 2.01 µM) and glucose transporter 9 (GLUT9, IC50 = 18.21 µM). Furthermore, it possessed a lower effective dosage of 0.5 mg/kg, favorable safety profile without any apparent acute toxicity at doses of 1000 mg/kg, and improved pharmacokinetic properties. Overall, we have discovered an efficacious URAT1/GLUT9 dual inhibitor for inhibiting urate reabsorption with favorable pharmacokinetic profiles.

Potential Mechanisms of the Protective Effects of the Cardiometabolic Drugs Type-2 Sodium-Glucose Transporter Inhibitors and Glucagon-like Peptide-1 Receptor Agonists in Heart Failure.

Different multifactorial pathophysiological processes are involved in the development of heart failure (HF), including neurohormonal dysfunction, the hypertrophy of cardiomyocytes, interstitial fibrosis, microvascular endothelial inflammation, pro-thrombotic states, oxidative stress, decreased nitric oxide (NO) bioavailability, energetic dysfunction, epicardial coronary artery lesions, coronary microvascular rarefaction and, finally, cardiac remodeling. While different pharmacological strategies have shown significant cardiovascular benefits in HF with reduced ejection fraction (HFrEF), there is a residual unmet need to fill the gap in terms of knowledge of mechanisms and efficacy in the outcomes of neurohormonal agents in HF with preserved ejection fraction (HFpEF). Recently, type-2 sodium-glucose transporter inhibitors (SGLT2i) have been shown to contribute to a significant reduction in the composite outcome of HF hospitalizations and cardiovascular mortality across the entire spectrum of ejection fraction. Moreover, glucagon-like peptide-1 receptor agonists (GLP1-RA) have demonstrated significant benefits in patients with high cardiovascular risk, excess body weight or obesity and HF, in particular HFpEF. In this review, we will discuss the biological pathways potentially involved in the action of SGLT2i and GLP1-RA, which may explain their effective roles in the treatment of HF, as well as the potential implications of the use of these agents, also in combination therapies with neurohormonal agents, in the clinical practice.

Opisthorchis viverrini excretory-secretory products suppress GLUT8 of cholangiocytes.

Opisthorchis viverrini infection and the subsequent bile duct cancer it induces remains a significant public health problem in Southeast Asia. Opisthorchiasis has been reported to cause reduced plasma glucose levels among infected patients. The underlying mechanism for this phenomenon is unclear. In the present study, evidence is presented to support the hypothesis that O. viverrini exploits host cholangiocyte glucose transporters (GLUTs) in a similar manner to that of rodent intestinal nematodes, to feed on unabsorbed glucose in the bile for survival. GLUT levels in a cholangiocyte H69 cell line co-cultured with excretory-secretory products of O. viverrini were examined using qPCR and immunoblotting. GLUT 8 mRNA and expressed proteins were found to be downregulated in H69 cells in the presence of O. viverrini. This suggests that O. viverrini alters glucose metabolism in cells within its vicinity by limiting transporter expression resulting in increased bile glucose that it can utilize and potentially explains the previously reported anti-insulin effect of opisthorchiasis.

The determinants of metabolic discrepancies in aerobic glycolysis: Providing potential targets for breast cancer treatment.

Altered aerobic glycolysis is the robust mechanism to support cancer cell survival and proliferation beyond the maintenance of cellular energy metabolism. Several investigators portrayed the important role of deregulated glycolysis in different cancers, including breast cancer. Breast cancer is the most ubiquitous form of cancer and the primary cause of cancer death in women worldwide. Breast cancer with increased glycolytic flux is hampered to eradicate with current therapies and can result in tumor recurrence. In spite of the low order efficiency of ATP production, cancer cells are highly addicted to glycolysis. The glycolytic dependency of cancer cells provides potential therapeutic strategies to preferentially kill cancer cells by inhibiting glycolysis using antiglycolytic agents. The present review emphasizes the most recent research on the implication of glycolytic enzymes, including glucose transporters (GLUTs), hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase-A (LDHA), associated signalling pathways and transcription factors, as well as the antiglycolytic agents that target key glycolytic enzymes in breast cancer. The potential activity of glycolytic inhibitors impinges cancer prevalence and cellular resistance to conventional drugs even under worse physiological conditions such as hypoxia. As a single agent or in combination with other chemotherapeutic drugs, it provides the feasibility of new therapeutic modalities against a wide spectrum of human cancers.

Revisiting the roles of glucose transporters in skeletal muscle physiology: is GLUT10 a novel player?

Skeletal muscle is the largest metabolic tissue responsible for systemic glucose handling. Glucose uptake into skeletal tissue is highly dynamic and delicately regulated, in part through the controlled expression and subcellular trafficking of multiple types of glucose transporters. Although the roles of GLUT4 in skeletal muscle metabolism are well established, the physiological significance of other, seemingly redundant, glucose transporters remain incompletely understood. Nonetheless, recent studies have shed light on the roles of several glucose transporters, such as GLUT1 and GLUT10, in skeletal muscle. Mice experiments suggest that GLUT10 could be a novel player in skeletal muscle metabolism in the context of mechanical overload, which is in line with the meta-analytical results of gene expression changes after resistance exercise in humans. Herein we discuss the knowns, unknowns, and implications of these recent findings.

Intestinal Morphology and Glucose Transporter Gene Expression under a Chronic Intake of High Sucrose.

Sucrose is a disaccharide that is degraded into fructose and glucose in the small intestine. High-sucrose and high-fructose diets have been reported, using two-dimensional imaging, to alter the intestinal morphology and the expression of genes associated with sugar transport, such as sodium glucose co-transporter 1 (SGLT1), glucose transporter 2 (GLUT2), and glucose transporter 5 (GLUT5). However, it remains unclear how high-fructose and high-sucrose diets affect the expression of sugar transporters and the intestinal morphology in the whole intestine. We investigate the influence of a chronic high-sucrose diet on the expression of the genes associated with sugar transport as well as its effects on the intestinal morphology using 3D imaging. High sucrose was found to increase GLUT2 and GLUT5 mRNA levels without significant changes in the intestinal morphology using 3D imaging. On the other hand, the delay in sucrose absorption by an α-glucosidase inhibitor significantly improved the intestinal morphology and the expression levels of SGLT1, GLUT2, and GLUT5 mRNA in the distal small intestine to levels similar to those in the proximal small intestine, thereby improving glycemic control after both glucose and sucrose loading. These results reveal the effects of chronic high-sugar exposure on glucose absorption and changes in the intestinal morphology.