GLUT, SGLT, and SWEET: Structural and mechanistic investigations of the glucose transporters

Role of glucose metabolism in amelogenesis

BACKGROUND

Cell energy metabolism plays a pivotal role in organ development and function by regulating cell behavior in pathophysiological conditions. Glucose metabolism is the central cascade for obtaining energy in mammalian cells, and cells alter the glucose metabolic pathway depending on intra- and extracellular environments. Therefore, glucose metabolism is closely associated with cell differentiation stages, and cell energy metabolism plays a vital role not only in energy production but also in cell fate regulation in organogenesis.

HIGHLIGHT

During enamel formation, the timing of the expression of passive and active glucose transporters, glycogen synthesis, and glycogen degradation is strictly regulated according to the energy demand of ameloblast-lineage cells. These glucose metabolic reactions are particularly active in the maturation stage of ameloblasts. Furthermore, autophagy, a key regulator of cellular energy homeostasis that modulates glucose metabolism, occurs during both the secretory and maturation stages of ameloblasts. Disruption of glucose metabolism cascade and autophagy induces enamel hypoplasia, as demonstrated in both in vitro and in vivo models.

CONCLUSION

Adequate energy supply via glucose metabolism is essential for enamel matrix secretion and maturation. A thorough understanding of the precise regulation of energy metabolism in amelogenesis facilitates comprehension of the normal enamel formation process and pathological conditions affecting it. This review summarizes glucose metabolic processes during amelogenesis, focusing on glucose uptake, glycogenesis, and glycogenolysis.

Molecular characterization and function of sodium-dependent glucose transporter 1 in postprandial glucose homeostasis in Macrobrachium rosenbergii

Aquatic animals often exhibit glucose intolerance following a glucose load, and understanding the mechanisms of glucose uptake is crucial for elucidating the underlying processes. Sodium-dependent glucose transporter 1 (SGLT1) plays a crucial role in the process of intestinal glucose absorption and transport in vertebrates, but there is limited information about its function in crustaceans. This study identified the SGLT1 gene (named MrSGLT1) from Macrobrachium rosenbergii. The full cDNA sequence is 3764 bp, encoding 903 amino acids. Unlike SGLT1 in most teleost fish, which have 14 transmembrane domains, MrSGLT1 protein has only 12. MrSGLT1 was predominantly expressed in the intestine, with its expression increasing after feeding. This was accompanied by elevated levels of glucose and trehalose in the hemolymph, and increased glycogen levels in the hepatopancreas. Silencing MrSGLT1 in vivo resulted in decreased glucose and trehalose levels in the hemolymph and reduced glycogen levels in the hepatopancreas, although muscle glycogen levels were unaffected. Moreover, knockdown of MrSGLT1 led to increased expression of genes involved in glycogenolysis and decreased expression of genes associated with glycogenesis, inhibiting postprandial glycogen accumulation in the hepatopancreas. Feeding-induced glycolysis was also inhibited following MrSGLT1 silencing, while no significant changes were observed in gluconeogenesis-related genes. These findings highlight the critical role of MrSGLT1 in regulating postprandial glucose homeostasis in crustaceans.

Steam explosion improved the physicochemical properties, hypoglycemic effects of polysaccharides from Clerodendranthus spicatus leaf via regulating IRS1/PI3K/AKT/GSK-3β signaling pathway in IR-HepG2 cells

Clerodendranthus spicatus (C. spicatus) leaf is a kind of functional tea and traditional Chinese folk medicine and it is famous for hypoglycemic value. The effects of steam explosion (SE) pretreatment on structural characteristics, α-glucosidase inhibition activity and hypoglycemic effects of C. spicatus leaf polysaccharides (CSP) were investigated. Two polysaccharides fractions from the untreated C. spicatus leaf (NTCSP-A) and SE treated C. spicatus leaf (SECSP-C) were obtained after the purification by DEAE Sepharose Fast Flow column chromatography. Results showed that SE pretreatment obviously increased the yields of CSP from 10.17 % to 13.43 % and decreased the molecular weight distribution. Monosaccharide composition analysis indicated that the main compositional modification by SE pretreatment was the increase in the proportion of mannose, glucuronic acid and arabinose. And SE pretreatment changed the inhibition type against α-glucosidase from competitive inhibition (NTCSP-A) to uncompetitive inhibition (SECSP-C). In addition, SE pretreatment increased the anti-diabetic activity on IR-HepG2 cells by increasing the glucose consumption and glycogen synthesis and regulating IRS1/PI3K/AKT/GSK-3β signaling pathway. This study indicated that SE technology modified the physiochemical properties and increased the hypoglycemic activity of CSP. It also provided helpful information on the application of SE in the efficient preparation and utilization of bioactive polysaccharides.

Synthesis, radiolabeling, and biological evaluation of methyl 6-deoxy-6-[18F]fluoro-4-thio-α-d-maltotrioside as a positron emission tomography bacterial imaging agent

We developed fluorine-18 ([18F]) labeled methyl 6-deoxy-6-fluoro-4-thio-α-d-maltotrioside ([18F]MFTMT) for bacterial imaging and evaluated its stability and efficacy in vitro and in vivo. We found that Staphylococcus aureus (S. aureus) internalized [18F]MFTMT whereas Escherichia coli (E. coli) and CHO-K1 cells did not, in in vitro. Positron emission tomography imaging with [18F]MFTMT revealed that radioactivity accumulated not only in the S. aureus-infected group but also in the E. coli-infected and non-infectious inflammation groups. Further studies revealed that rat serum digested [18F]MFTMT into [18F]-methyl 6-deoxy-6-fluoro-4-thio-α-d-maltoside ([18F]MFTM), while [18F]MFTMT was stable in human serum for 210 min. [18F]MFTM was identified as the only radioactive metabolite in vivo. Similar to [18F]MFTMT, [18F]MFTM was internalized only by S. aureus. [18F]MFTM was identified as the only radioactive metabolite in vivo. We found that the sodium-glucose co-transporter 1 (SGLT1) is expressed in inflammatory tissue, and SGLT1 overexpressing cells showed increased retention of [18F]MFTMT and [18F]MFTM in vitro. Our study showed that the thio-glycosyl bond is stable against enzymatic digestion, and maltotetraose or a longer maltodextrin backbone is desirable for bacteria-specific imaging to avoid nonspecific uptake by SGLT1.

mCNN-glucose: Identifying families of glucose transporters using a deep convolutional neural network based on multiple-scanning windows

Glucose transporters are essential carrier proteins that function on the phospholipid bilayer to facilitate glucose diffusion across cell membranes. The transporters play many physiological and pathological roles in addition to absorption and metabolism of fructose in food and the pathogenesis of gastrointestinal diseases. These carrier proteins play an important role in diseases of the nervous system, cardiovascular system, digestive system, and urinary system. These essential transporters have been extensively studied as potential therapeutic targets for cancers such as pancreatic, prostate, and hepatocellular carcinoma, which serve as diagnostic and prognostic indicators. The method uses position-specific scoring metrics (PSSM) with multiple-scanning windows-based convolutional neural networks to classify glucose transport proteins based on their functional significance and crucial role in therapy. Convolutional neural networks with multiple window scanning are employed to capture biologically meaningful, significant, and meaningful features from PSSM evolutionary profiles. Our proposed Method obtained Matthews correlation coefficients (MCC) of 0.99, Accuracy (AC) of 99.46, for Glucose facilitative transporters (GLUT), 0.99, 99.46, for Sodium Coupled glucose transporters (SGLT), and 0.92, and 97.3 for Sugars will eventually be exported transporters (SWEET) respectively. This study shows significantly higher performance than our previous study, which could be used to accurately classify novel glucose transporters.

Insight into the Mechanism of d-Glucose Accelerated Exchange in GLUT1 from Molecular Dynamics Simulations

Transmembrane glucose transport, facilitated by glucose transporters (GLUTs), is commonly understood through the simple mobile carrier model (SMCM), which suggests that the central binding site alternates exposure between the inside and outside of the cell, facilitating glucose exchange. An alternative "multisite model" posits that glucose transport is a stochastic diffusion process between ligand-operated gates within the transporter's central channel. This study aims to test these models by conducting atomistic molecular dynamics simulations of multiple glucose molecules docked along the central cleft of GLUT1 at temperatures both above and below the lipid bilayer melting point. Our results show that glucose exchanges occur on a nanosecond time-scale as glucopyranose rings slide past each other within the channel cavities, with minimal protein conformational movement. While bilayer gelation slows net glucose transit, the frequency of positional exchanges remains consistent across both temperatures. This supports the observation that glucose exchange at 0 °C is much faster than net flux, aligning with experimental data that show approximately 100 times the rate of exchange flux relative to net flux at 0 °C compared to 37 °C.

Relationship Between Brain Insulin Resistance, Carbohydrate Consumption, and Protein Carbonyls, and the Link Between Peripheral Insulin Resistance, Fat Consumption, and Malondialdehyde

The consumption of a high-fat (HFD) or high-carbohydrate/low-fat (LFD) diet is related to insulin resistance; however, central and peripheral alterations can occur independently. In this study, the timeline of insulin resistance was determined while taking into consideration the role of diet in oxidative damage. Background/Objectives: The aim of this study was to ascertain whether a HFD or LFD induces peripheral insulin resistance (PIR) before brain insulin resistance (BIR), and whether the timing of these alterations correlates with heightened oxidative damage markers in plasma, adipose tissue, and the cerebral cortex. Methodology and Results: Three-month-old C57BL/6 male mice were fed with a HFD, LFD, or standard diet for 1, 2, or 3 months. Glucose and insulin tolerance tests were performed to determine PIR, and the hypothalamic thermogenic response to insulin was used to determine their BIR status. For oxidative damage, the levels of malondialdehyde (MDA) and the protein carbonyl group (PCO) and the enzymatic activity of glutathione peroxidase (GSH-Px) were evaluated in plasma, white adipose tissue, brown adipose tissue, and the cerebral cortex. PIR occurred at 3 months of the HFD, but MDA levels in the white adipose tissue increased at 2 months. BIR occurred at 1 and 2 months of the LFD, but the enzymatic activity of GSH-Px was lower at 1 month and the amount of the PCO increased at 2 months. Conclusions: The intake of a HFD or LFD of different durations can influence the establishment of PIR or BIR, and oxidative damage in the fat tissue and cerebral cortex can play an important role.

Metabolic gatekeepers: Dynamic roles of sugar transporters in insect metabolism and physiology

Sugars play multiple critical roles in insects, serving as energy sources, carbon skeletons, osmolytes and signalling molecules. The transport of sugars from source to sink via membrane proteins is essential for the uptake, distribution and utilization of sugars across various tissues. Sugar supply and distribution are crucial for insect development, flight, diapause and reproduction. Insect sugar transporters (STs) share significant structural and functional similarities with those in mammals and other higher eukaryotes. However, they exhibit unique characteristics, including differential regulation, substrate selectivity and kinetics. Here, we have discussed structural diversity, evolutionary trends, expression dynamics, mechanisms of action and functional significance of insect STs. The sequence and structural diversity of insect STs, highlighted by the analysis of conserved domains and evolutionary patterns, underpins their functional differentiation and divergence. The review emphasizes the importance of STs in insect metabolism, physiology and stress tolerance. It also discusses how variations in transporter regulation, expression, selectivity and activity contribute to functional differences. Furthermore, we have underlined the potential and necessity of studying these mechanisms and roles to gain a deeper understanding of insect glycobiology. Understanding the regulation and function of sugar transporters is vital for comprehending insect metabolism and physiological potential. This review provides valuable insights into the diverse functionalities of insect STs and their significant roles in metabolism and physiology.

Downregulation of glucose-energy metabolism via AMPK signaling pathway in granulosa cells of diminished ovarian reserve patients

Glucose metabolism plays a crucial role in the function of granulosa cells (GCs) and the development of follicles. In cases of diminished ovarian reserve (DOR), alterations in these processes can impact female fertility. This study aims to investigate changes in glucose-energy metabolism in GCs of young DOR patients aged 20 to 35 years and their correlation with the onset and progression of DOR. 72 DOR cases and 75 women with normal ovarian reserve (NOR) as controls were included based on the POSEIDON and Bologna criteria. Samples of GCs and follicular fluid (FF) were collected for a comprehensive analysis involving transcriptomics, metabolomics, RT-qPCR, JC-1 staining, and flow cytometry. The study identified differentially expressed genes and metabolites in GCs of DOR and NOR groups, revealing 7 common pathways related to glucose-energy metabolism, along with 11 downregulated genes and 14 metabolites. Key substances in the glucose-energy metabolism pathway, such as succinate, lactate, NADP, ATP, and ADP, showed decreased levels, with the DOR group exhibiting a reduced ADP/ATP ratio. Downregulation of genes involved in glycolysis (HK, PGK, LDH1), the TCA cycle (CS), and gluconeogenesis (PCK) was observed, along with reduced glucose content and expression of glucose transporter genes (GLUT1 and GLUT3) in DOR GCs. Additionally, decreased AMPK pathway activity and impaired mitochondrial function in DOR suggest a connection between mitochondrial dysfunction and disrupted energy metabolism. Above all, the decline in glucose-energy metabolism in DOR is closely associated with its onset and progression. Reduced glucose uptake and impaired mitochondrial function in DOR GCs lead to internal energy imbalances, hindering the AMPK signaling pathway, limiting energy production and supply, and ultimately impacting follicle development and maturation.

Cryo-EM structure of the human glucose transporter GLUT7

GLUT7 is a Class II glucose transporter predominantly expressed at the apical membrane of enterocytes in the small intestine. Here, we report the cryo-EM structure of nanodisc-reconstituted human GLUT7 in the apo state at 3.3 Å resolution. Our atomic model reveals a typical major facilitator superfamily fold, with the substrate-binding site open to the extracellular side of the membrane. Despite the nearly identical conformation to its closest family member, rat GLUT5, our structure unveils distinct features of the substrate-binding cavity that may influence substrate specificity and binding mode. A homology model of the inward-open human GLUT7 indicates that similar to other members of the GLUT family, it may undergo a global rocker-switch-like reorientation of the transmembrane bundles to facilitate substrate translocation across the membrane. Our work enhances the current structural understanding of the GLUT family, and lays a foundation for rational design of regulators of GLUTs and other sugar transporters.

Research progress and considerations on oral rehydration therapy for the prevention and treatment of severe burn shock: A narrative review

Severe burns are a significant cause of life-threatening conditions in both peacetime and wartime. Shock is a critical complication during the early stages of burn injury, contributing substantially to mortality and long-term disability. Effective fluid resuscitation is crucial for preventing and treating shock, with prompt administration being vital. However, timely intravenous fluid resuscitation is often challenging, and errors in resuscitation significantly contribute to mortality. Therefore, exploring a more rapid and effective non-invasive method of fluid resuscitation is necessary. Oral rehydration therapy (ORT) has shown considerable potential in this regard. This paper reviews ORT's historical development and current research progress, discussing its application in early anti-shock treatment for burns. While ORT is generally safe, potential complications like diarrhoea, vomiting, and abdominal discomfort must be noted, particularly if the rehydration rate is too rapid or if gastrointestinal issues exist. Careful patient assessment and monitoring are essential during ORT administration. Based on a comprehensive review of relevant research, we present provisional guidelines for ORT in burn patients. These guidelines aim to inform clinical practice but should be applied cautiously due to limited clinical evidence. Implementation must be tailored to the patient's condition under healthcare supervision, with adjustments according to evolving circumstances: ① Initiation timing: Start as soon as possible, and the ideal start time is usually within 6 h after injury. ② Rate of application: Employing a fractional administration approach, wherein small quantities of approximately 150-250 millilitres are provided for each instance and the initial fluid rate of oral rehydration can be simplified to 100 mL/kg/24 h. ③ Composition combination: In addition to essential salts and glucose, the oral rehydration solution can incorporate various anti-inflammatory and cellular protection constituents.

Progress in Lactate Metabolism and Its Regulation via Small Molecule Drugs

Lactate, once viewed as a byproduct of glycolysis and a metabolic "waste", is now recognized as an energy-providing substrate and a signaling molecule that modulates cellular functions under pathological conditions. The discovery of histone lactylation in 2019 marked a paradigm shift, with subsequent studies revealing that lactate can undergo lactylation with both histone and non-histone proteins, implicating it in the pathogenesis of various diseases, including cancer, liver fibrosis, sepsis, ischemic stroke, and acute kidney injury. Aberrant lactate metabolism is associated with disease onset, and its levels can predict disease outcomes. Targeting lactate production, transport, and lactylation may offer therapeutic potential for multiple diseases, yet a systematic summary of the small molecules modulating lactate and its metabolism in various diseases is lacking. This review outlines the sources and clearance of lactate, as well as its roles in cancer, liver fibrosis, sepsis, ischemic stroke, myocardial infarction, and acute kidney injury, and summarizes the effects of small molecules on lactate regulation. It aims to provide a reference and direction for future research.

The skeleton: an overlooked regulator of systemic glucose metabolism in cancer?

Recent discoveries demonstrated the skeleton's role as an endocrine organ regulating whole-body glucose homeostasis. Glucose metabolism is critical for rapid cell proliferation and tumour growth through increasing glucose uptake and fermentation of glucose to lactate despite being in an aerobic environment. This hypothesis paper discusses emerging evidence on how bones can regulate whole-body glucose homeostasis with potential to impact on tumour growth and proliferation. Moreover, it proposes a clinical link between bone glucose metabolism and prognosis of cancer based on recent clinical trial data. Targeting metabolic pathways related with classic glucose metabolism and also bone metabolism, novel methods of cancer therapy and treatment could be developed. This paper objective is to highlight the need for future research on this altered metabolism with potential to change future management of cancer patients.

Selenium polysaccharide form sweet corn cob mediated hypoglycemic effects in vitro and untargeted metabolomics study on type 2 diabetes

Type 2 diabetes mellitus (T2D) causes complications due to metabolic disorders besides increasing blood glucose. Sweet corn cob selenium polysaccharide (SeSCP) is a complex of Se with Sweet corn cob polysaccharide that has good hypoglycemic efficacy, but its effect on T2D metabolism has not been determined. In this study, the hypoglycemic effect of SeSCP was investigated by in vitro and in vivo experiments, and the levels of metabolites in feces were analyzed in a high-fat diet and STZ-induced T2D mouse model by Liquid chromatography-mass spectrometry (LC-MS). The results indicated that SeSCP regulates α-amylase and α-glucosidase through competitive reversible inhibition, and the reaction is spontaneous, driven by van der Waals forces and hydrogen bonding. In vivo, SeSCP modulates glucose transport decreasing glucose entry into the bloodstream. The metabolites mainly affected by SeSCP-MC were adenine, LysoPA (0:0/18:2(9Z, 12Z)), cysteine-S-sulfate, and demeclocycline (hydrochloride) metabolites. SeSCP interfered with β-alanine metabolism, starch and sucrose metabolism, ether lipid metabolism, glycerophospholipid metabolism, glyoxylate and dicarboxylate metabolism, pantothenate and CoA biosynthesis, etc. Additionally, SeSCP exhibited more effective metabolic interventions than metformin and SCP. Therefore, SeSCP can reduce complications while improving T2D blood glucose.

GLUT1 mediates bronchial epithelial E-cadherin disruption in TDI-induced steroid-insensitive asthma

OBJECTIVE

Down-regulation of bronchial epithelial E-cadherin is an important of feature of severe asthma, including steroid-insensitive asthma. Yet, the mechanisms involved in E-cadherin disruption are not fully understood. This study was aimed to investigate the role of glucose transporter 1 (GLUT1) in dysregulation of E-cadherin in toluene diisocyanate (TDI)-induced steroid-insensitive asthma.

METHODS

A murine model of steroid-insensitive asthma was established by TDI sensitization and aerosol inhalation. Selective GLUT1 antagonists WZB117 and BAY876 were given to BALB/c mice after airway challenge. In vitro, primary human bronchial epithelial cells (HBECs) cultured in an airway-liquid interface (ALI) were exposed to TDI.

RESULTS

TDI exposure markedly up-regulated GLUT1 in murine lungs and HBECs. Pharmacological inhibition of GLUT1 with BAY876 decreased airway hyperresponsiveness, neutrophil and eosinophil accumulation, as well as type 2 inflammation in vivo. Besides, the TDI-induced down-regulated expression of full-length E-cadherin was also partly recovered, accompanied by inhibited secretion of soluble E-cadherin (sE-cadherin). WZB117 also exhibited mild therapeutic effects, though not significant. In vitro, treatment with GLUT1 inhibitor relieved the TDI-induced disruption of E-cadherin in HBECs.

CONCLUSIONS

Taken together, our data demonstrated that GLUT1 modulates bronchial epithelial E-cadherin dysfunction production in TDI-induced steroid-insensitive asthma.

Design, synthesis and biological evaluation of glucose metabolism inhibitors as anticancer agents

Compared to normal cells, tumour cells exhibit an upregulation of glucose transporters and an increased rate of glycolytic activity. In previous research, we successfully identified a promising hit compound BH10 through a rigorous screening process, which demonstrates a potent capacity for inhibiting cancer cell proliferation by targeting glucose metabolism. In the current study, we identify Kelch-like ECH-associated protein 1 (Keap1) as a potential protein target of BH10via avidin pull-down assays with biotinylated-BH10. Subsequently, we present a comprehensive analysis of a series of BH10 analogues characterized by the incorporation of a naphthoimidazole scaffold and the introduction of a triazole ring with diverse terminal functional groups. Notably, compound 4d has emerged as the most potent candidate, exhibiting better anti-cancer activities against HEC1A cancer cells with an IC50 of 2.60 μM, an extended biological half-life, and an improved pharmacokinetic profile (compared to BH10) in mice.

Hypoxia-inducible factor-driven glycolytic adaptations in host-microbe interactions

Mammalian cells utilize glucose as a primary carbon source to produce energy for most cellular functions. However, the bioenergetic homeostasis of cells can be perturbed by environmental alterations, such as changes in oxygen levels which can be associated with bacterial infection. Reduction in oxygen availability leads to a state of hypoxia, inducing numerous cellular responses that aim to combat this stress. Importantly, hypoxia strongly augments cellular glycolysis in most cell types to compensate for the loss of aerobic respiration. Understanding how this host cell metabolic adaptation to hypoxia impacts the course of bacterial infection will identify new anti-microbial targets. This review will highlight developments in our understanding of glycolytic substrate channeling and spatiotemporal enzymatic organization in response to hypoxia, shedding light on the integral role of the hypoxia-inducible factor (HIF) during host-pathogen interactions. Furthermore, the ability of intracellular and extracellular bacteria (pathogens and commensals alike) to modulate host cellular glucose metabolism will be discussed.

Lipid Metabolism in Relation to Carbohydrate Metabolism

Carbohydrates and lipids integrate into a complex metabolic network that is essential to maintain homeostasis. In insects, as in most metazoans, dietary carbohydrates are taken up as monosaccharides whose excess is toxic, even at relatively low concentrations. To cope with this toxicity, monosaccharides are stored either as glycogen or neutral lipids, the latter constituting a quasi-unlimited energy store. Breakdown of these stores in response to energy demand depends on insect species and on several physiological parameters. In this chapter, we review the multiple metabolic pathways and strategies linking carbohydrates and lipids that insects utilize to respond to nutrient availability, food scarcity or physiological activities.

The novel family of Warbicin® compounds inhibits glucose uptake both in yeast and human cells and restrains cancer cell proliferation

Many cancer cells share with yeast a preference for fermentation over respiration, which is associated with overactive glucose uptake and breakdown, a phenomenon called the Warburg effect in cancer cells. The yeast tps1Δ mutant shows even more pronounced hyperactive glucose uptake and phosphorylation causing glycolysis to stall at GAPDH, initiation of apoptosis through overactivation of Ras and absence of growth on glucose. The goal of the present work was to use the yeast tps1Δ strain to screen for novel compounds that would preferentially inhibit overactive glucose influx into glycolysis, while maintaining basal glucose catabolism. This is based on the assumption that the overactive glucose catabolism of the tps1Δ strain might have a similar molecular cause as the Warburg effect in cancer cells. We have isolated Warbicin ® A as a compound restoring growth on glucose of the yeast tps1Δ mutant, showed that it inhibits the proliferation of cancer cells and isolated structural analogs by screening directly for cancer cell inhibition. The Warbicin ® compounds are the first drugs that inhibit glucose uptake by both yeast Hxt and mammalian GLUT carriers. Specific concentrations did not evoke any major toxicity in mice but increase the amount of adipose tissue likely due to reduced systemic glucose uptake. Surprisingly, Warbicin ® A inhibition of yeast sugar uptake depends on sugar phosphorylation, suggesting transport-associated phosphorylation as a target. In vivo and in vitro evidence confirms physical interaction between yeast Hxt7 and hexokinase. We suggest that reversible transport-associated phosphorylation by hexokinase controls the rate of glucose uptake through hydrolysis of the inhibitory ATP molecule in the cytosolic domain of glucose carriers and that in yeast tps1Δ cells and cancer cells reversibility is compromised, causing constitutively hyperactive glucose uptake and phosphorylation. Based on their chemical structure and properties, we suggest that Warbicin ® compounds replace the inhibitory ATP molecule in the cytosolic domain of the glucose carriers, preventing hexokinase to cause hyperactive glucose uptake and catabolism.

Triterpene-Based Prodrug for Self-Boosted Drug Release and Targeted Oral Squamous Cell Carcinoma Chemotherapy

Chemotherapy is one of the main treatments for oral squamous cell carcinoma (OSCC), especially as a combined modality approach with and after surgery or radiotherapy. Limited therapeutic efficiency and serious side effects greatly restrict the clinical performance of chemotherapeutic drugs. The development of smart nanomedicines has provided new research directions, to some extent. However, the involvement of complex carrier compositions inevitably brings biosafety concerns and greatly limits the "bench-to-bed" translation of most nanomedicines reported. In this study, a carrier-free self-assembled prodrug was fabricated by two triterpenes (glycyrrhetinic acid, GA and ginsenoside Rh2, Rh2) isolated from medicinal plants, licorice, and ginseng, for the targeted and highly effective treatment of OSCC. Reactive oxygen species (ROS) self-supplied molecule TK-GA2 was synthesized with ROS-responsive thioketal linker and prodrug was prepared by a rapid-solvent-exchange method with TK-GA2 and Rh2. After administration, oral tumor cells transported large amounts of prodrugs with glucose ligands competitively. Endogenous ROS in oral tumor cells then promoted the release of GA and Rh2. GA further evoked the generation of a large number of ROS to help self-boosted drug release and increase oxidative stress, synergistically causing tumor cell apoptosis with Rh2. Overall, this carrier-free triterpene-based prodrug might provide a preeminent opinion on the design of effective chemotherapeutics with low systemic toxicity against OSCC.

The maize sugar transporters ZmSWEET15a and ZmSWEET15b positively regulate salt tolerance in plants

The SWEETs (sugars will eventually be exported transporter) family comprises a class of recently identified sugar transporters that play diverse roles in regulating plant development. Beyond those fundamental functions, emerging evidence suggests that SWEETs may also be involved in plant stress responses, such as salt tolerance. However, the specific role of maize SWEETs in regulating salt tolerance remains unexplored. In this study, we demonstrate that two maize SWEET family members, ZmSWEET15a and ZmSWEET15b, are typical sugar transporters with seven transmembrane helices localized in the cell membrane. The heterologous expression of ZmSWEET15a and ZmSWEET15b in the yeast mutant strain confirms their role as sucrose transporters. Overexpression of ZmSWEET15a and ZmSWEET15b in Arabidopsis resulted in improved NaCl resistance and significant increase in seed germination rate compared to the wild type. Furthermore, by generating maize knockout mutants, we observe that the absence of ZmSWEET15a and ZmSWEET15b affects both plant growth and grain development. The salt treatment results indicate that the knockout mutants of these two genes are more sensitive to salt stress. Comparative analyses revealed that wild-type maize plants outperformed the knockout mutants in terms of growth parameters and physiological indices. Our findings unravel a novel function of ZmSWEET15a and ZmSWEET15b in the salt stress response, offering a theoretical foundation for enhancing maize salt resistance.

Controlling diurnal flower-opening time by manipulating the jasmonate pathway accelerates development of indica-japonica hybrid rice breeding

Inter-subspecific indica-japonica hybrid rice (Oryza sativa) has the potential for increased yields over traditional indica intra-subspecies hybrid rice, but limited yield of F1 hybrid seed production (FHSP) hinders the development of indica-japonica hybrid rice breeding. Diurnal flower-opening time (DFOT) divergence between indica and japonica rice has been a major contributing factor to this issue, but few DFOT genes have been cloned. Here, we found that manipulating the expression of jasmonate (JA) pathway genes can effectively modulate DFOT to improve the yield of FHSP in rice. Treating japonica cultivar Zhonghua 11 (ZH11) with methyl jasmonate (MeJA) substantially advanced DFOT. Furthermore, overexpressing the JA biosynthesis gene OPDA REDUCTASE 7 (OsOPR7) and knocking out the JA inactivation gene CHILLING TOLERANCE 1 (OsHAN1) in ZH11 advanced DFOT by 1- and 2-h respectively; and knockout of the JA signal suppressor genes JASMONATE ZIM-DOMAIN PROTEIN 7 (OsJAZ7) and OsJAZ9 resulted in 50-min and 1.5-h earlier DFOT respectively. The yields of FHSP using japonica male-sterile lines GAZS with manipulated JA pathway genes were significantly higher than that of GAZS wildtype. Transcriptome analysis, cytological observations, measurements of elastic modulus and determination of cell wall components indicated that the JA pathway could affect the loosening of the lodicule cell walls by regulating their composition through controlling sugar metabolism, which in turn influences DFOT. This research has vital implications for breeding japonica rice cultivars with early DFOT to facilitate indica-japonica hybrid rice breeding.

Alterations of the blood-brain barrier during aging

The blood-brain barrier (BBB) is a complex and dynamic interface that regulates the exchange of molecules and cells between the blood and the central nervous system. It undergoes structural and functional changes during aging, which may compromise its integrity and contribute to the pathogenesis of neurodegenerative diseases. In recent years, advances in microscopy and high-throughput bioinformatics have allowed a more in-depth investigation of the aging mechanisms of BBB. This review summarizes age-related alterations of the BBB structure and function from six perspectives: endothelial cells, astrocytes, pericytes, basement membrane, microglia and perivascular macrophages, and fibroblasts, ranging from the molecular level to the human multi-system level. These basic components are essential for the proper functioning of the BBB. Recent imaging methods of BBB were also reviewed. Elucidation of age-associated BBB changes may offer insights into BBB homeostasis and may provide effective therapeutic strategies to protect it during aging.

Glucose uptake in trophoblasts of GDM mice is regulated by the AMPK-CLUT3 signaling pathway

GDM, as a metabolic disease during pregnancy, regulates GLUT3 translocation by AMPK, thereby affecting glucose uptake in trophoblasts. It provides a new research idea and therapeutic target for alleviating intrauterine hyperglycemia in GDM. STZ was used to construct GDM mice, inject AICAR into pregnant mice, and observe fetal and placental weight; flow cytometry was employed for the detection of glucose uptake by primary trophoblast cells; immunofluorescence was applied to detect the localization of GLUT3 and AMPK in placental tissue; Cocofal microscope was used to detect the localization of GLUT3 in trophoblast cells;qRT-PCR and Western blot experiments were carried out to detect the expression levels of GLUT3 and AMPK in placental tissue; CO-IP was utilized to detect the interaction of GLUT3 and AMPK. Compared with the normal pregnancy group, the weight of the fetus and placenta of GDM mice increased (P < 0.001), and the ability of trophoblasts to take up glucose decreased (P < 0.001). In addition, AMPK activity in trophoblasts and membrane localization of GLUT3 in GDM mice were down-regulated compared with normal pregnant mice (P < 0.05). There is an interaction between GLUT3 and AMPK. Activating AMPK in trophoblasts can up-regulate the expression of GLUT3 membrane protein in trophoblasts of mice (P < 0.05) and increase the glucose uptake of trophoblasts (P < 0.05). We speculate that inhibition of AMPK activity in GDM mice results in aberrant localization of GLUT3, which in turn attenuates glucose uptake by placental trophoblast cells. AICAR activates AMPK to increase the membrane localization of GLUT3 and improve the glucose uptake capacity of trophoblasts.

GLUT1 regulates the release of VEGF-A in the alveolar epithelium of lipopolysaccharide-induced acute lung injury

Acute lung injury (ALI) is a severe disease with high mortality and poor prognosis, characterized by excessive and uncontrolled inflammatory response. Vascular endothelial growth factor A (VEGF-A) contributes to the development and progression of ALI. The aim of this study was to evaluate the role of glucose transporter 1 (GLUT1) in alveolar epithelial VEGF-A production in lipopolysaccharide (LPS)-induced ALI. An ALI mouse model was induced by LPS oropharyngeal instillation. Mice were challenged with LPS and then treated with WZB117, a specific antagonist of GLUT1. For the vitro experiments, cultured A549 cells (airway epithelial cell line) were exposed to LPS, with or without the GLUT1 inhibitors WZB117 or BAY876. LPS significantly upregulated of GLUT1 and VEGF-A both in the lung from ALI mice and in cultured A549. In vivo, treatment with WZB117 not only markedly decreased LPS-induced pulmonary edema, injury, neutrophilia, as well as levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF), but also reduced VEGF-A production. Yet, the maximum tolerated concentration of WZB117 failed to suppress LPS-induced VEGF-A overexpression in vitro. While administration of BAY876 inhibited gene and protein expression as well as secretion of VEGF-A in response to LPS in A549. These results illustrated that GLUT1 upregulates VEGF-A production in alveolar epithelia from LPS-induced ALI, and inhibition of GLUT1 alleviates ALI.

Differences in time-intensity sensory profiles of sweet taste intensity of glucose between older and young adults

Background

To understand age-related changes in sweet taste perception in daily life, it is important to understand taste intensity at the suprathreshold level. Previous studies have attempted to characterize the temporal aspects of human taste perception in terms of time-intensity evaluations. The perception of dynamic taste intensity in older adults increases slowly for salty taste; however, there have been no previous studies on time-intensity sensory evaluation of sweet taste in older adults. We hypothesized that older adults perceive sweet taste intensity more slowly than young adults.

Methods

Fifty young and 40 older adults participated in the study and glucose solutions of 0.6 M and 1.5 M were used as stimuli. The study comprised two experiments: (1) a cup tasting test (static taste perception in the mouth), and (2) a time-intensity sensory evaluation, in which the solutions were presented using a custom-made delivery system. The intra-oral device was made to fit each participant's dentition. Further, the level of gag reflex was taken into consideration for each participant in the design of the intra-oral device. A suction tube was placed across the posterior tongue near the throat to remove solution and saliva. The solution delivery system was controlled by an original computer program.

Results

Older adults presented significantly different maximum intensity timing and slope for both concentrations compared with young adults (slope for 1.5 M, p < 0.01; others, p < 0.05). No significant differences were found between the older and young adults for reaction timing and maximum intensity.

Conclusion

We conclude that older adults perceived sweetness more slowly than young adults, and ultimately perceived almost the same intensity as young adults. This is the first reported characterization of the time-intensity profile of sweet taste intensity of glucose in older adults. Using a standardized system enabled us to assess and compare feedback on taste intensities among different age groups in real-time. Based on this, we recommend older adults "savor" to perceive sweet tastes at the same level experienced by young adults.

Glucose transport, transporters and metabolism in diabetic retinopathy

Diabetic retinopathy (DR) is the most common reason for blindness in working-age individuals globally. Prolonged high blood glucose is a main causative factor for DR development, and glucose transport is prerequisite for the disturbances in DR caused by hyperglycemia. Glucose transport is mediated by its transporters, including the facilitated transporters (glucose transporter, GLUTs), the "active" glucose transporters (sodium-dependent glucose transporters, SGLTs), and the SLC50 family of uniporters (sugars will eventually be exported transporters, SWEETs). Glucose transport across the blood-retinal barrier (BRB) is crucial for nourishing the neuronal retina in the context of retinal physiology. This physiological process primarily relies on GLUTs and SGLTs, which mediate the glucose transportation across both the cell membrane of retinal capillary endothelial cells and the retinal pigment epithelium (RPE). Under diabetic conditions, increased accumulation of extracellular glucose enhances the retinal cellular glucose uptake and metabolism via both glycolysis and glycolytic side branches, which activates several biochemical pathways, including the protein kinase C (PKC), advanced glycation end-products (AGEs), polyol pathway and hexosamine biosynthetic pathway (HBP). These activated biochemical pathways further increase the production of reactive oxygen species (ROS), leading to oxidative stress and activation of Poly (ADP-ribose) polymerase (PARP). The activated PARP further affects all the cellular components in the retina, and finally resulting in microangiopathy, neurodegeneration and low-to-moderate grade inflammation in DR. This review aims to discuss the changes of glucose transport, glucose transporters, as well as its metabolism in DR, which influences the retinal neurovascular unit (NVU) and implies the possible therapeutic strategies for treating DR.

Natural Sweetener Glycyrrhetinic Acid Monoglucuronide Improves Glucose Homeostasis in Healthy Mice

Noncaloric or low-caloric sweeteners have become popular worldwide, although debates persist regarding their impact on health. To investigate whether the sweeteners are favorable for glucose homeostasis, our study assessed the effects of glycyrrhetinic acid monoglucuronide (GAMG) and several commonly used sweeteners [glycyrrhetinic acid (GA), stevioside, erythritol, sucralose, and aspartame] on glycometabolism and elucidated the underlying mechanisms. The C57BL/6J male mice were exposed to different sweeteners for 10 weeks, and our results showed that GAMG significantly reduced fasting blood glucose (FBG) levels (FBG-control: 3.81 ± 0.42 mmol/L; FBG-GAMG: 3.37 ± 0.38 mmol/L; p < 0.05) and the blood glucose levels 15 and 30 min after sucrose or maltose loading (p < 0.05). Furthermore, it improved glucose tolerance (p = 0.028) and enhanced insulin sensitivity (p = 0.044), while the other sweeteners had negligible or adverse effects on glucose homeostasis. Subsequent experiments showed that GAMG inhibited α-glucosidases potently (IC50 = 0.879 mg·mL-1), increased three SCFA-producing bacteria and SCFAs levels (p < 0.05), and promoted the gene expression of SCFA receptor GPR43 (p = 0.018). These results suggest that GAMG may regulate blood glucose by inhibiting α-glucosidases and modulating gut microbial SCFAs. Our findings prove that GAMG, beneficial to blood glucose regulation, is a promising natural sweetener for future utilization.

Parkinson's disease risk enhancers in microglia

Genome-wide association studies have identified thousands of single nucleotide polymorphisms that associate with increased risk for Parkinson's disease (PD), but the functions of most of them are unknown. Using assay for transposase-accessible chromatin (ATAC) and H3K27ac chromatin immunoprecipitation (ChIP) sequencing data, we identified 73 regulatory elements in microglia that overlap PD risk SNPs. To determine the target genes of a "risk enhancer" within intron two of SNCA, we used CRISPR-Cas9 to delete the open chromatin region where two PD risk SNPs reside. The loss of the enhancer led to reduced expression of multiple genes including SNCA and the adjacent gene MMRN1. It also led to expression changes of genes involved in glucose metabolism, a process that is known to be altered in PD patients. Our work expands the role of SNCA in PD and provides a connection between PD-associated genetic variants and underlying biology that points to a risk mechanism in microglia.

GSK3β: A ray of hope for the treatment of diabetic kidney disease

Diabetic kidney disease (DKD), a major microvascular complication of diabetes, is characterized by its complex pathogenesis, high risk of chronic renal failure, and lack of effective diagnosis and treatment methods. GSK3β (glycogen synthase kinase 3β), a highly conserved threonine/serine kinase, was found to activate glycogen synthase. As a key molecule of the glucose metabolism pathway, GSK3β participates in a variety of cellular activities and plays a pivotal role in multiple diseases. However, these effects are not only mediated by affecting glucose metabolism. This review elaborates on the role of GSK3β in DKD and its damage mechanism in different intrinsic renal cells. GSK3β is also a biomarker indicating the progression of DKD. Finally, the protective effects of GSK3β inhibitors on DKD are also discussed.

Bridging the gap: glucose transporters, Alzheimer's, and future therapeutic prospects

Glucose is the major source of chemical energy for cell functions in living organisms. The aim of this mini-review is to provide a clearer and simpler picture of the fundamentals of glucose transporters as well as the relationship of these transporters to Alzheimer's disease. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Electronic databases (PubMed and ScienceDirect) were used to search for relevant studies mainly published during the period 2018-2023. This mini-review covers the two main types of glucose transporters, facilitated glucose transporters (GLUTs) and sodium-glucose linked transporters (SGLTs). The main difference between these two types is that the first type works through passive transport across the glucose concentration gradient. The second type works through active co-transportation to transport glucose against its chemical gradient. Fluctuation in glucose transporters translates into a disturbance of normal functioning, such as Alzheimer's disease, which may be caused by a significant downregulation of GLUTs most closely associated with insulin resistance in the brain. The first sign of Alzheimer's is a lack of GLUT4 translocation. The second sign is tau hyperphosphorylation, which is caused by GLUT1 and 3 being strongly upregulated. The current study focuses on the use of glucose transporters in treating diseases because of their proven therapeutic potential. Despite this, studies remain insufficient and inconclusive due to the complex and intertwined nature of glucose transport processes. This study recommends further understanding of the mechanisms related to these vectors for promising future therapies.

Research Progress on the Effect and Mechanism of Tea Products with Different Fermentation Degrees in Regulating Type 2 Diabetes Mellitus

A popular non-alcoholic beverage worldwide, tea can regulate blood glucose levels, lipid levels, and blood pressure, and may even prevent type 2 diabetes mellitus (T2DM). Different tea fermentation levels impact these effects. Tea products with different fermentation degrees containing different functional ingredients can lower post-meal blood glucose levels and may prevent T2DM. There are seven critical factors that shed light on how teas with different fermentation levels affect blood glucose regulation in humans. These factors include the inhibition of digestive enzymes, enhancement of cellular glucose uptake, suppression of gluconeogenesis-related enzymes, reduction in the formation of advanced glycation end products (AGEs), inhibition of dipeptidyl peptidase-4 (DPP-4) activity, modulation of gut flora, and the alleviation of inflammation associated with oxidative stress. Fermented teas can be used to lower post-meal blood glucose levels and can help consumers make more informed tea selections.

Evidential support for garlic supplements against diabetic kidney disease: a preclinical meta-analysis and systematic review

Garlic (Allium sativum L.) is a popular spice that is widely used for food and medicinal purposes and has shown potential effects on diabetic kidney disease (DKD). Nevertheless, systematic preclinical studies are still lacking. In this meta-analysis and systematic review, we evaluated the role and potential mechanisms of action of garlic and its derived components in animal models of DKD. We searched eight databases for relevant studies from the establishment of the databases to December 2022 and updated in April 2023 before the completion of this review. A total of 24 trials were included in the meta-analysis. It provided preliminary evidence that supplementing with garlic could improve the indicators of renal function (BUN, Scr, 24 h urine volume, proteinuria, and KI) and metabolic disorders (BG, insulin, and body weight). Meanwhile, the beneficial effects of garlic and its components in DKD could be related to alleviating oxidative stress, suppressing inflammatory reactions, delaying renal fibrosis, and improving glucose metabolism. Furthermore, time-dose interval analysis exhibited relatively greater effectiveness when garlic products were supplied at doses of 500 mg kg-1 with interventions lasting 8-10 weeks, and garlic components were administered at doses of 45-150 mg kg-1 with interventions lasting 4-10 weeks. This meta-analysis and systematic review highlights for the first time the therapeutic potential of garlic supplementation in animal models of DKD and offers a more thorough evaluation of its effects and mechanisms to establish an evidence-based basis for designing future clinical trials.

Deletion of the Sodium Glucose Cotransporter 1 (Sglt-1) impairs mouse sperm movement

The Sodium Glucose Cotransporter Isoform 1 (Sglt-1) is a symporter that moves Na+ and glucose into the cell. While most studies have focused on the role of Sglt-1 in the small intestine and kidney, little is known about this transporter's expression and function in other tissues. We have previously shown that Sglt-1 is expressed in the mouse sperm flagellum and that its inhibition interferes with sperm metabolism and function. Here, we further investigated the importance of Sglt-1 in sperm, using a Sglt-1 knockout mouse (Sglt-1 KO). RNA, immunocytochemistry, and glucose uptake analysis confirmed the ablation of Sglt-1 in sperm. Sglt-1 KO male mice are fertile and exhibit normal sperm counts and morphology. However, Sglt-1 null sperm displayed a significant reduction in total, progressive and other parameters of sperm motility compared to wild type (WT) sperm. The reduction in motility was exacerbated when sperm were challenged to swim in media with higher viscosity. Parameters of capacitation, namely protein tyrosine phosphorylation and acrosomal reaction, were similar in Sglt-1 KO and WT sperm. However, Sglt-1 KO sperm displayed a significant decrease in hyperactivation. The impaired motility of Sglt-1 null sperm was observed in media containing glucose as the only energy substrate. Interestingly, the addition of pyruvate and lactate to the media partially recovered sperm motility of Sglt-1 KO sperm, both in the low and high viscosity media. Altogether, these results support an important role for Sglt-1 in sperm energetics and function, providing sperm with a higher capacity for glucose uptake.

GLUT1 contributes to impaired epithelial tight junction in the late phase of acute lung injury

Dysfunction of epithelial barrier is crucial for the development of acute lung injury (ALI). This study was aimed to evaluate the role of glucose transporter 1 (GLUT1) in dysregulation of epithelial tight junction in ALI. GLUT1 was inhibited with specific antagonists WZB117 or BAY876 to see the effects on epithelial tight junction in a well-established LPS-induced mouse ALI model as well as in vitro cultured epithelial cells. Pharmacological inhibition of GLUT1 with WZB117 at either a low or high dose had no effects on lung injury and inflammation 24 h after LPS challenge, but significantly decreased the pulmonary inflammatory responses induced by LPS at 72 h with a high dose, which was verified by treatment with BAY876. WZB117 or BAY876 also recovered the expression of epithelial tight junction proteins ZO-1 and occludin. In cultured BEAS-2B and A549 cells, LPS induced increased GLUT1 expression, accompanied by decreased expression of tight junction protein ZO-1 and occludin. Blockade of GLUT1 restored LPS-induced disruption of ZO-1 and occludin in BEAS-2B rather than A549. Taken together, our results showed that GLUT1 is responsible for dysfunction of epithelial tight junctions in the late phase of LPS-induced ALI.

Sphingosine-1-phosphate suppresses GLUT activity through PP2A and counteracts hyperglycemia in diabetic red blood cells

Red blood cells (RBC) are the major carriers of sphingosine-1-phosphate (S1P) in blood. Here we show that variations in RBC S1P content achieved by altering S1P synthesis and transport by genetic and pharmacological means regulate glucose uptake and metabolic flux. This is due to S1P-mediated activation of the catalytic protein phosphatase 2 (PP2A) subunit leading to reduction of cell-surface glucose transporters (GLUTs). The mechanism dynamically responds to metabolic cues from the environment by increasing S1P synthesis, enhancing PP2A activity, reducing GLUT phosphorylation and localization, and diminishing glucose uptake in RBC from diabetic mice and humans. Functionally, it protects RBC against lipid peroxidation in hyperglycemia and diabetes by activating the pentose phosphate pathway. Proof of concept is provided by the resistance of mice lacking the S1P exporter MFSD2B to diabetes-induced HbA1c elevation and thiobarbituric acid reactive substances (TBARS) generation in diabetic RBC. This mechanism responds to pharmacological S1P analogues such as fingolimod and may be functional in other insulin-independent tissues making it a promising therapeutic target.

Identification of SLC2A3 as a prognostic indicator correlated with the NF-κB/EMT axis and immune response in head and neck squamous cell carcinoma

SLC2A3 is an important member of the glucose transporter superfamily. It has been recently suggested that upregulation of SLC2A3 is associated with poor survival and acts as a prognostic marker in a variety of tumors. Unfortunately, the prognostic role of SLC2A3 in head and neck squamous cell carcinoma (HNSC) is less known. In the present study, we analyzed SLC2A3 expression in HNSC and its correlation with prognosis using TCGA and GEO databases. The results showed that SLC2A3 mRNA expression was higher in HNSC compared with adjacent normal tissues, which was validated with our 9 pairs of HNSC specimens. Moreover, high SLC2A3 expression predicted poor prognosis in HNSC patients. Mechanistically, GSEA revealed that high expression of SLC2A3 was enriched in epithelial-mesenchymal transition (EMT) and NF-κB signaling. In HNSC cell lines, SLC2A3 knockdown inhibited cell proliferation and migration. In addition, NF-κB P65 and EMT-related gene expression was suppressed upon SLC2A3 knockdown, indicating that SLC2A3 may play a preeminent role in the progression of HNSC through the NF-κB/EMT axis. Meanwhile, the expression of SLC2A3 was negatively correlated with immune cells, suggesting that SLC2A3 may be involved in the immune response in HNSC. The correlation between SLC2A3 expression and drug sensitivity was further assessed. In conclusion, our study demonstrated that SLC2A3 could predict the prognosis of HNSC patients and mediate the progression of HNSC via the NF-κB/EMT axis and immune responses.

Metabolic influences on T cell in psoriasis: a literature review

Psoriasis is a systemic inflammatory disease that frequently coexists with various other conditions, such as essential hypertension, diabetes, metabolic syndrome, and inflammatory bowel disease. The association between these diseases may be attributed to shared inflammatory pathways and abnormal immunomodulatory mechanisms. Furthermore, metabolites also play a regulatory role in the function of different immune cells involved in psoriasis pathogenesis, particularly T lymphocytes. In this review, we have summarized the current research progress on T cell metabolism in psoriasis, encompassing the regulation of metabolites in glucose metabolism, lipid metabolism, amino acid metabolism, and other pathways within T cells affected by psoriasis. We will also explore the interaction and mechanism between psoriatic metabolites and immune cells. Moreover, we further discussed the research progress of metabolomics in psoriasis to gain a deeper understanding of its pathogenesis and identify potential new therapeutic targets through identification of metabolic biomarkers associated with this condition.

The intracellular helical bundle of human glucose transporter GLUT4 is important for complex formation with ASPL

Glucose transporters (GLUTs) are responsible for transporting hexose molecules across cellular membranes. In adipocytes, insulin stimulates glucose uptake by redistributing GLUT4 to the plasma membrane. In unstimulated adipose-like mouse cell lines, GLUT4 is known to be retained intracellularly by binding to TUG protein, while upon insulin stimulation, GLUT4 dissociates from TUG. Here, we report that the TUG homolog in human, ASPL, exerts similar properties, i.e., forms a complex with GLUT4. We describe the structural details of complex formation by combining biochemical assays with cross-linking mass spectrometry and computational modeling. Combined, the data suggest that the intracellular domain of GLUT4 binds to the helical lariat of ASPL and contributes to the regulation of GLUT4 trafficking by cooperative binding.

The Dawn of a New Era: Tumor-Targeting Boron Agents for Neutron Capture Therapy

Cancer is widely recognized as one of the most devastating diseases, necessitating the development of intelligent diagnostic techniques, targeted treatments, and early prognosis evaluation to ensure effective and personalized therapy. Conventional treatments, unfortunately, suffer from limitations and an increased risk of severe complications. In light of these challenges, boron neutron capture therapy (BNCT) has emerged as a promising approach for cancer treatment with unprecedented precision to selectively eliminate tumor cells. The distinctive and promising characteristics of BNCT hold the potential to revolutionize the field of oncology. However, the clinical application and advancement of BNCT technology face significant hindrance due to the inherent flaws and limited availability of current clinical drugs, which pose substantial obstacles to the practical implementation and continued progress of BNCT. Consequently, there is an urgent need to develop efficient boron agents with higher boron content and specific tumor-targeting properties. Researchers aim to address this need by integrating tumor-targeting strategies with BNCT, with the ultimate goal of establishing BNCT as an effective, readily available, and cutting-edge treatment modality for cancer. This review delves into the recent advancements in integrating tumor-targeting strategies with BNCT, focusing on the progress made in developing boron agents specifically designed for BNCT. By exploring the current state of BNCT and emphasizing the prospects of tumor-targeting boron agents, this review provides a comprehensive overview of the advancements in BNCT and highlights its potential as a transformative treatment option for cancer.

Deciphering the Mysterious Relationship between the Cross-Pathogenetic Mechanisms of Neurodegenerative and Oncological Diseases

The relationship between oncological pathologies and neurodegenerative disorders is extremely complex and is a topic of concern among a growing number of researchers around the world. In recent years, convincing scientific evidence has accumulated that indicates the contribution of a number of etiological factors and pathophysiological processes to the pathogenesis of these two fundamentally different diseases, thus demonstrating an intriguing relationship between oncology and neurodegeneration. In this review, we establish the general links between three intersecting aspects of oncological pathologies and neurodegenerative disorders, i.e., oxidative stress, epigenetic dysregulation, and metabolic dysfunction, examining each process in detail to establish an unusual epidemiological relationship. We also focus on reviewing the current trends in the research and the clinical application of the most promising chemical structures and therapeutic platforms that have a modulating effect on the above processes. Thus, our comprehensive analysis of the set of molecular determinants that have obvious cross-functional pathways in the pathogenesis of oncological and neurodegenerative diseases can help in the creation of advanced diagnostic tools and in the development of innovative pharmacological strategies.

Genetic Variants in Carbohydrate Digestive Enzyme and Transport Genes Associated with Risk of Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is characterized by abdominal pain and alterations in bowel pattern, such as constipation (IBS-C), diarrhea (IBS-D), or mixed (IBS-M). Since malabsorption of ingested carbohydrates (CHO) can cause abdominal symptoms that closely mimic those of IBS, identifying genetic mutations in CHO digestive enzymes associated with IBS symptoms is critical to ascertain IBS pathophysiology. Through candidate gene association studies, we identify several common variants in TREH, SI, SLC5A1 and SLC2A5 that are associated with IBS symptoms. By investigating rare recessive Mendelian or oligogenic inheritance patterns, we identify case-exclusive rare deleterious variation in known disease genes (SI, LCT, ALDOB, and SLC5A1) as well as candidate disease genes (MGAM and SLC5A2), providing potential evidence of monogenic or oligogenic inheritance in a subset of IBS cases. Finally, our data highlight that moderate to severe IBS-associated gastrointestinal symptoms are often observed in IBS cases carrying one or more of deleterious rare variants.

Impact of Lisinopril on Cardiometabolic Risk Factors in Sisters of Women With Polycystic Ovary Syndrome

Women with polycystic ovary syndrome (PCOS), the most common endocrinopathy in reproductive age, are characterized by increased cardiometabolic risk. Similar hormonal and metabolic changes were found in their siblings. The purpose of our study was to compare blood pressure-lowering and pleiotropic effects of lisinopril between sisters of women with PCOS and their unrelated peers. The study included two age-, body mass index-, and blood pressure-matched groups of women with grade 1 hypertension: 26 sisters of PCOS probands (Group 1) and 26 individuals without a family history of PCOS (Group 2), receiving 10-40 mg of lisinopril daily. Blood pressure, glucose homeostasis markers, plasma levels of lipids (androgens, estradiol, high-sensitivity C-reactive protein (hsCRP), homocysteine, fibrinogen, and uric acid), and urinary albumin-to-creatinine ratio (UACR) were measured before lisinopril treatment and 6 months later. At baseline, the study groups differed in insulin sensitivity, testosterone, free androgen index (FAI), hsCRP, homocysteine, and UACR. Blood pressure-lowering properties of lisinopril did not differ between the groups. The decrease in homocysteine and UACR, although observed in both groups, was stronger in Group 2 than in Group 1. Only in women without a family history of PCOS lisinopril improved insulin sensitivity and reduce hsCRP, fibrinogen, and uric acid. The remaining markers did not change throughout the study. Cardiometabolic effects of lisinopril correlated with testosterone, free androgen index, and changes in insulin sensitivity. The obtained results suggest that cardiometabolic effects of lisinopril may be slightly less pronounced in sisters of women with PCOS than in women without a family history of this disorder.

Correlations between class I glucose transporter expression patterns and clinical outcomes in non-small cell lung cancer

BACKGROUND

Glucose transporters (GLUTs) are highly expressed in various cancers. However, the implications of these variable expression patterns are unclear. This study aimed to clarify the correlation between class I GLUT expression patterns and clinical outcomes in non-small cell lung cancer (NSCLC), including their potential role in inflammatory signaling.

METHODS

Biopsy tissues from 132 patients with NSCLC (92 adenocarcinomas [ADC] and 40 squamous cell carcinomas [SQCC]) were analyzed. mRNA expression levels of class I GLUTs (solute carrier 2A [SLC2A]1, SLC2A2, SLC2A3, and SLC2A4) and inflammation-related molecules (toll-like receptors TLR4, RelA/p65, and interleukins IL8 and IL6) were measured. Cellular localization of GLUT3 and GLUT4 was investigated using immunofluorescence.

RESULTS

Single, combined, and negative GLUT (SLC2A) expression were observed in 27/92 (29.3%), 27/92 (29.3%), and 38/92 (41.3%, p < 0.001) of ADC and 8/40 (20.0%), 29/40 (72.5%, p < 0.001), and 3/40 (7.5%) of SQCC, respectively. In ADC, the single SLC2A3-expressed group had a significantly poorer prognosis, whereas the single SLC2A4-expressed group had a significantly better prognosis. The combined expression groups showed no significant difference. SLC2A expression was not correlated with SQCC prognosis. SLC2A4 expression correlated with lower IL8 expression. GLUT3 and GLUT4 expressions were localized in the tumor cytoplasm.

CONCLUSIONS

In lung ADC, single SLC2A3 expression correlated with poor prognosis, whereas single SLC2A4 expression correlated with better prognosis and lower IL8 expression. GLUT3 expression, which is increased by IL8 overexpression, may be suppressed by increasing the expression of GLUT4 through decreased IL8 expression.

Structural and pharmacological diversity of 1,4-naphthoquinone glycosides in recent 20 years

1,4-naphthoquinones are the most widespread naphthoquinone compounds. Recently, many 1,4-naphthoquinone glycosides with different structural features have been obtained from both nature and synthesis, which has led to an increasing variety of naphthoquinone glycosides. In this paper, the structure variety and biological activity in recent 20 years are reviewed, and classified them according to the source and structure characteristics. Meanwhile the synthetic methods of O-, S-, C- and N-naphthoquinone glycosides and their structure activity relationships are also described. It was referred that the presence of polar groups of C2 and C5 and non-polar groups attached to C3 on the naphthoquinone ring are beneficial for their biological activities. It will provide more comprehensive literature resources for the future research of 1, 4-naphthoquinone glycosides and lay a theoretical foundation.

Adrenal SGLT1 or SGLT2 as predictors of atherosclerosis under chronic stress based on a computer algorithm

Background

Chronic stress promotes the development of atherosclerosis, causing disruptions in the body's hormone levels and changes in the structural function of organs.

Objective

The purpose of this study was to investigate the pathological changes in the adrenal gland in a model of atherosclerosis under chronic stress and to verify the expression levels of Sodium-glucose cotransporter (SGLT) 1 and SGLT2 in the adrenal gland and their significance in the changes of adrenal gland.

Methods

The model mice were constructed by chronic unpredictable stress, high-fat diet, and Apoe-/- knockout, and they were tested behaviorally at 0, 4, 8 and 12 weeks. The state of the abdominal artery was examined by ultrasound, and the pathological changes of the aorta and adrenal glands were observed by histological methods, and the expression levels and distribution of SGLT1 and SGLT2 in the adrenal gland were observed and analyzed by immunofluorescence and immunohistochemistry. The predictive value of SGLT1 and SGLT2 expression levels on intima-media thickness, internal diameter and adrenal abnormalities were verified by receiver operating characteristic (ROC) curves, support vector machine (SVM) and back-propagation (BP) neural network.

Results

The results showed that chronic stress mice had elevated expression levels of SGLT1 and SGLT2. The model mice developed thickening intima-media and smaller internal diameter in the aorta, and edema, reticular fiber rupture, increased adrenal glycogen content in the adrenal glands. More importantly, analysis of ROC, SVM and BP showed that SGLT1 and SGLT2 expression levels in the adrenal glands could predict the above changes in the aorta and were also sensitive and specific predictors of adrenal abnormalities.

Conclusion

SGLT1 and SGLT2 could be potential biomarkers of adrenal injury in atherosclerosis under chronic stress.

SGLT2 Inhibitors in the Treatment of Diabetic Kidney Disease: More than Just Glucose Regulation

Diabetic kidney disease (DKD) is a severe and common complication and affects a quarter of patients with type 2 diabetes mellitus (T2DM). Oxidative stress and inflammation related to hyperglycemia are interlinked and contribute to the occurrence of DKD. It was shown that sodium-glucose cotransporter-2 (SGLT2) inhibitors, a novel yet already widely used therapy, may prevent the development of DKD and alter its natural progression. SGLT2 inhibitors induce systemic and glomerular hemodynamic changes, provide metabolic advantages, and reduce inflammatory and oxidative stress pathways. In T2DM patients, regardless of cardiovascular diseases, SGLT2 inhibitors may reduce albuminuria, progression of DKD, and doubling of serum creatinine levels, thus lowering the need for kidney replacement therapy by over 40%. The molecular mechanisms behind these beneficial effects of SGLT2 inhibitors extend beyond their glucose-lowering effects. The emerging studies are trying to explain these mechanisms at the genetic, epigenetic, transcriptomic, and proteomic levels.

The circadian rhythm: an influential soundtrack in the diabetes story

Type 2 Diabetes Mellitus (T2DM) has been the main category of metabolic diseases in recent years due to changes in lifestyle and environmental conditions such as diet and physical activity. On the other hand, the circadian rhythm is one of the most significant biological pathways in humans and other mammals, which is affected by light, sleep, and human activity. However, this cycle is controlled via complicated cellular pathways with feedback loops. It is widely known that changes in the circadian rhythm can alter some metabolic pathways of body cells and could affect the treatment process, particularly for metabolic diseases like T2DM. The aim of this study is to explore the importance of the circadian rhythm in the occurrence of T2DM via reviewing the metabolic pathways involved, their relationship with the circadian rhythm from two perspectives, lifestyle and molecular pathways, and their effect on T2DM pathophysiology. These impacts have been demonstrated in a variety of studies and led to the development of approaches such as time-restricted feeding, chronotherapy (time-specific therapies), and circadian molecule stabilizers.

Strain differences in the drug transport capacity of intestinal glucose transporters in Sprague-Dawley versus Wistar rats, C57BL/6J versus Kunming mice

Designing oral drug delivery systems using intestinal glucose transporters (IGTs) may be one of the strategies for improving oral bioavailability of drugs. However, little is known about the biological factors affecting the drug transport capacity of IGTs. Gastrodin is a sedative drug with a structure very similar to glucose. It is a highly water-soluble phenolic glucoside. It can hardly enter the intestine through simple diffusion but exhibits good oral bioavailability of over 80%. We confirmed that gastrodin is absorbed via the intestinal glucose transport pathway. It has the highest oral bioavailability among the reported glycosides' active ingredients through this pathway. Thus, gastrodin is the most selective drug substrate of IGTs and can be used to evaluate the drug transport capacity of IGTs. Obviously, strain is one of the main biological factors affecting drug absorption. This study firstly compared the drug transport capacity of IGTs between SD rats and Wistar rats and between C57 mice and KM mice by pharmacokinetic experiments and single-pass intestinal perfusion experiments of gastrodin. Then, the sodium-dependent glucose transporter type 1 (SGLT1) and sodium-independent glucose transporters type 2 (GLUT2) in the duodenum, jejunum, ileum and colon of these animals were quantified using RT-qPCR and Western blot. The results showed that the oral bioavailability of gastrodin in Wistar rats was significantly higher than in SD rats and significantly higher in KM mice than in C57 mice. Gastrodin absorption significantly differed among different intestinal segments in SD rats, C57 mice and KM mice, except Wistar rats. RT-qPCR and Western blot demonstrated that the intestinal expression distribution of SGLT1 and GLUT2 in SD rats and C57 mice was duodenum ≈ jejunum > ileum > colon. SGLT1 expression did not differ among different intestinal segments in KM mice, whereas the intestinal expression distribution of GLUT2 was duodenum ≈ jejunum ≈ ileum > colon. However, the expression of SGLT1 and GLUT2 did not differ among different intestinal segments in Wistar rats. It was reported that the intestinal expression distribution of SGLT1 and GLUT2 in humans is duodenum > jejunum > ileum > colon. Hence, the intestinal expression distribution of SGLT1 and GLUT2 of SD rats and C57 mice was more similar to that in humans. In conclusion, the drug transport capacity of IGTs differs in different strains of rats and mice. SD rats and C57 mice are more suitable for evaluating the pharmacokinetics of glycosides' active ingredients absorbed via the intestinal glucose transport pathway.

Decoding the regulatory roles of non-coding RNAs in cellular metabolism and disease

Non-coding RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), are being studied extensively in a variety of fields. Their roles in metabolism have received increasing attention in recent years but are not yet clear. The regulation of glucose, fatty acid, and amino acid metabolism is an imperative physiological process that occurs in living organisms and takes part in cancer and cardiovascular diseases. Here, we summarize the important roles played by non-coding RNAs in glucose metabolism, fatty acid metabolism, and amino acid metabolism, as well as the mechanisms involved. We also summarize the therapeutic advances for non-coding RNAs in diseases such as obesity, cardiovascular disease, and some metabolic diseases. Overall, non-coding RNAs are indispensable factors in metabolism and have a significant role in the three major metabolisms, which may be exploited as therapeutic targets in the future.