Search Results (223)

Glucose transport across biological membranes in mammals depends primarily on two transporter families: the facilitative glucose transporters of the SLC2 family and the sodium-dependent cotransporters of the SLC5 family. Together, these proteins mediate tissue-specific glucose uptake, epithelial absorption and reabsorption, nutrient sensing, and adaptive responses to metabolic stress. This review summarizes current knowledge of transporter classification, structural mechanism, tissue distribution, intracellular trafficking, and disease associations, with emphasis on GLUT1, GLUT2, GLUT3, GLUT4, SGLT1, and SGLT2. It also discusses less well-characterized members of the extended GLUT family, the therapeutic implications of SGLT inhibition, and unresolved questions regarding transporter specificity. Furthermore, the review integrates emerging evidence on CAR-T cell engineering, Alport syndrome, lupus nephritis, erythropoietic responses, and the reduction in dementia risk associated with transporter modulation. Full article

Breast cancer cells exhibit a reversed pH gradient and metabolic plasticity that promote proliferation, invasion, and resistance to therapy. Natural products such as chlorogenic acid (CGA) and cinnamaldehyde (CA) have shown emerging anticancer potential. However, their effects on intracellular pH and metabolic transport systems remain undefined. Therefore, the aim of this study was to characterize these parameters in breast cancer and non-tumorigenic breast cells. This study evaluated the physiochemical properties of CGA and CA using LC–MS, under pH conditions (pH 1.2, 7.4, and 9.0) mimicking the gastrointestinal track (GIT). Additionally, LC–MS-based human liver microsome (HLM) assays with NADPH were used to evaluate susceptibility to CYP-mediated metabolism to evaluate first-pass metabolic stability. Intracellular uptake kinetics were quantified at multiple time points using LC–MS. Following CGA:CA treatment, intracellular pH (pH_i) was measured in cancerous MDA-MB-231 and non-tumorigenic MCF-10A breast cell lines using SNARF-1 targeted ratio-metric fluorescence approach. Expression of OATP1B1, GLUT1, and MCT1 were analyzed by Western and immunofluorescence respectively, to assess potential cellular uptake of CGA:CA through OATP1B1 and their effects on glucose uptake and lactate and proton transport. Physiochemical results demonstrated that the compounds ranged from fully stable (pH 1.2 and 7.4) to completely unstable (pH 9.0). HLM incubation indicated no CYP-mediated hepatic metabolism. Treatment results showed that there was rapid intracellular uptake of CGA and CA in cancer cells and that CGA:CA lowered pH_i in both MDA-MB-231 and MCF-7 cells, while pH_i remained mostly unchanged in MCF-10A cells. Protein analysis revealed that CGA:CA treatment downregulated GLUT1 and MCT1 expression in cancer cells, suggesting impaired glycolytic activity and lactate shuttling. OATP1B1 expression was significantly suppressed in cancer cells, suggesting feedback inhibition of the solute carrier protein. Collectively, these findings indicate that CGA and CA exhibit favorable biochemical stability and disrupt intracellular pH regulation and metabolic transporter expression in breast cancer cells. Importantly, normal cells are not significantly affected. Thus, CGA:CA demonstrates therapeutic potential for breast cancer through pH_i and metabolic modulation. Full article

Pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC) are aggressive malignancies frequently driven by oncogenic Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations associated with metabolic reprogramming and resistance to apoptosis. In this study, we evaluated the antitumor and anti-inflammatory activity of a Lepidium latifolium L.-derived formulation (CTP) enriched in glucosinolate hydrolysis products in KRAS-mutant colorectal and pancreatic cancer models. The formulation was designed to promote the generation of the epithionitrile 1-cyano-2,3-epithiopropane (CETP) through iron-dependent myrosinase-mediated sinigrin hydrolysis. CTP induced dose-dependent cytotoxicity and morphological alterations consistent with apoptosis in KRAS-mutant cancer cell lines. Treatment significantly reduced mitochondrial membrane potential, ATP production, oxygen consumption rate (OCR), and extracellular acidification rate (ECAR), indicating severe bioenergetic impairment. In parallel, CTP downregulated the metabolic and proliferative regulators C-myc, PKM2, GLUT1, and Cyclin E1. RNA-seq analysis revealed extensive transcriptional reprogramming associated with oxidative stress, metabolic adaptation, and cell-cycle regulation. In addition, CTP significantly suppressed nitric oxide, IL-6, and IL-8 production in LPS-stimulated RAW 264.7 macrophages. These findings demonstrate that glucosinolate-derived metabolites from L. latifolium interfere with metabolic and inflammatory pathways critical for KRAS-driven tumor survival and support the therapeutic potential of Brassicaceae-derived epithionitriles as multitarget anticancer agents. Full article

Obesity is a global metabolic disease closely associated with dyslipidemia, insulin resistance, hepatic steatosis, and chronic oxidative stress. Cydonia oblonga Miller (COM, Quince) from Xinjiang Uygur Autonomous Region of China is a traditional medicinal and edible plant rich in polyphenols, flavonoids, polysaccharides, and other bioactive constituents. Our previous studies suggested that total polyphenols of Cydonia oblonga Miller (TPCOM) may exert promising anti-obesity effects. Objective: This study aimed to investigate the therapeutic effects of TPCOM on high-fat diet-induced obese C57BL/6 mice and to explore its underlying molecular mechanisms related to glycolipid metabolism. Methods: TPCOM was extracted and purified from Xinjiang Cydonia oblonga fruits, and its total polyphenol content was determined using the Folin–Ciocalteu method. C57 mice were randomly divided into normal diet, model, and TPCOM intervention groups. After 12 weeks of high-fat diet feeding and 6 weeks of TPCOM treatment, body weight was monitored continuously. Serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total antioxidant capacity (T-AOC) were measured using commercial kits. Hepatic pathological changes were observed by hematoxylin–eosin (HE) staining. Bioinformatics analyses including GO and KEGG were performed to predict key targets and pathways related to lipid metabolism. The protein expression levels of PPARGC1A, FFAR1, KLF15, Adipolin, GLUT4, and phosphorylated p38 MAPK in liver tissues were detected by Western blotting. Results: TPCOM intervention significantly reduced body weight gain in obese mice in a dose-dependent manner. Serum biochemical assays showed that TPCOM decreased TC, TG, and LDL-C levels, increased HDL-C levels, and markedly enhanced total antioxidant capacity (T-AOC). Bioinformatics analysis suggested that PPARG and FFAR1 were highly expressed in liver tissue and may participate in glucose and lipid metabolism regulation. Western blot results confirmed that TPCOM significantly upregulated the expression of PPARGC1A, FFAR1, KLF15, Adipolin, GLUT4, and phosphorylated p38 MAPK in the liver of obese mice. Conclusions: TPCOM effectively ameliorates obesity, dyslipidemia, hepatic steatosis, and oxidative stress in high-fat diet-induced obese mice. The underlying mechanism may be related to the regulation of glycolipid metabolism, mitochondrial function, insulin sensitivity, and antioxidant signaling via activating the FFAR1–PPARG–p38 MAPK axis and downstream targets including PPARGC1A, KLF15, Adipolin, and GLUT4. This study provides a scientific basis and theoretical support for the development and application of TPCOM as a natural functional ingredient in the prevention and adjuvant treatment of obesity and related metabolic disorders. Full article

Background: Acute kidney injury (AKI) remains a condition with limited effective therapeutic options, partly due to challenges in early diagnosis and timely intervention. While lactate accumulation is a hallmark of ischemic and septic AKI, the underlying mechanisms remain unclear. Methods: This study integrated single-cell RNA sequencing data from AKI patients (GEO database) with lactate metabolism-related genes (LMRGs) to identify key therapeutic targets. Results: Collecting duct (CD) cells exhibited the highest LMRG expression. Machine learning algorithms and validation in bilateral ischemia/reperfusion injury (bIRI) and lipopolysaccharide (LPS)-induced AKI mouse models, as well as hypoxia/reoxygenation (H/R)-stimulated renal cells, identified Ldhb as a core gene. Disruption of lactate metabolism via BAY876 (selective GLUT1 inhibitor) or siRNA-mediated Ldhb knockdown significantly attenuated kidney injury, reduced inflammatory cytokines (IL-1β, IL-6, TNF-α), and decreased reactive oxygen species in vitro and in vivo. Conclusions: These findings reveal that lactate metabolism is reprogrammed in AKI, particularly in CD cells, and identify LDHB as a novel potential therapeutic target for this condition, though further mechanistic studies are required to establish causality. Full article

Background/Objectives: Diabetic cardiomyopathy (DCM) is largely driven by severe oxidative stress and calcium dyshomeostasis. We examined the targeted antioxidant and therapeutic effects of zinc sulfate (ZnSO₄) on contractile dynamics, oxidative damage, calcium turnover, and apoptosis/fibrosis in aged female rats with type 2 diabetes. Methods: Thirty-two aged female Wistar rats were divided into Control, Control + ZnSO₄, Diabetes (DM), and DM + ZnSO₄ groups. DM was induced via high-fat diet and 30 mg/kg streptozotocin. After a 4-week complication period, treatment groups received 10 mg/kg/day ZnSO₄ (i.p.) for 6 weeks. Left ventricular papillary muscle contraction, oxidative/antioxidant markers (MDA/GSH), and gene expressions (SIRT1, GLUT4, SERCA2a, RyR2, Cav1.2, PLN) were evaluated. Myocardial architecture, fibrosis, and apoptosis were analyzed immunohistochemically. In DM rats, contractile force (CF) and velocities (±dF/dtmax) significantly declined. Results: Concurrently, SIRT1, GLUT4, SERCA2a, RyR2, Cav1.2, and antioxidant GSH decreased, while oxidative lipid damage (MDA), PLN, Caspase-3 activity, Collagen I, and fibrosis increased (p < 0.001). ZnSO₄ treatment in diabetic rats acted as a potent antioxidant modulator; it restored redox balance, activated the SIRT1/GLUT4 pathway, protected calcium-handling proteins from oxidative degradation, and significantly improved contractile dynamics. It also preserved myocardial architecture by reducing apoptosis and fibrosis. In healthy rats, ZnSO₄ caused mild stress and early fibrosis. Conclusions: In conclusion, while inducing mild stress in healthy myocardium, zinc supplementation provides robust antioxidant protection in diabetic hearts. It activates SIRT1, suppresses oxidative damage, maintains calcium homeostasis, and restores contractile dynamics, demonstrating strong antioxidant therapeutic potential against DCM. Full article

Gastric adenocarcinoma (STAD) exhibits extensive intratumoral heterogeneity that contributes to tumor progression and therapeutic resistance. In this study, we integrated single-cell RNA sequencing and bulk transcriptomic analyses to characterize malignant epithelial subtypes in STAD. Among seven identified tumor subtypes, the OLFM4-associated C3 subtype exhibited enriched palmitoylation-related signatures and altered metabolic activities, particularly glycolysis-related pathways. Functional enrichment analyses further supported the enrichment of multiple energy metabolism pathways. To evaluate the association between OLFM4 and metabolic regulation, recombinant OLFM4 treatment and siRNA-mediated OLFM4 knockdown were performed in gastric cancer cell lines. OLFM4 upregulation increased the expression of ZDHHC2 and GLUT1, accompanied by enhanced glucose uptake and elevated ATP production, whereas OLFM4 silencing reduced ZDHHC2 and GLUT1 expression. In addition, a prognostic risk model derived from C3 subtype-associated genes (MUC16, RALA, and PCBD1) effectively stratified STAD patients and was associated with immune checkpoint expression and immune infiltration. Collectively, our findings identify an OLFM4-associated gastric cancer cell state with palmitoylation-related signatures and altered metabolic activities, highlighting its potential relevance to metabolic heterogeneity in gastric adenocarcinoma. Full article

Background/Objectives: Exploiting the metabolic properties of postbiotics is a novel strategy for managing metabolic disorders, including diabetes. Inactivated microorganisms, a major class of postbiotics, improve glycemic control in preclinical and clinical studies. Here, we examined whether heat-killed (HK) Mycobacterium aurum (M. aurum) exerts prophylactic or therapeutic anti-hyperglycemic effects in diabetic mice. Methods: Diabetes was induced in male BALB/c mice by streptozotocin (STZ; 150 mg/kg) injection. HK M. aurum (1 mg) was given orally (three prophylactic doses before STZ) or intradermally (six weekly therapeutic doses after STZ). We assessed glycemic parameters, serum C-peptide/insulin (ELISA), and tissue protein expression (Western blot). Results: Neither route altered body weight or glucose homeostasis in non-diabetic mice. In STZ-diabetic mice, oral prophylactic treatment significantly attenuated hyperglycemia (39–60% reduction weeks 5–8 post-STZ) and showed a trend toward improved serum C-peptide, but did not affect dysregulated expression of skeletal muscle (SM), hepatic, pancreatic and renal proteins involved in glucose transport (GLUT2, GLUT4, and SGLT2), glycolysis (α-LDH), mitochondrial uncoupling (UCP2 and UCP3), and antioxidant defense (CAT). Therapeutic intradermal administration significantly decreased blood glucose (~30% at week 5, ~40% at week 6) and modestly enhanced insulin secretion. Hepatic UCP2 and α-LDH and SM UCP3 protein levels were normalized toward non-diabetic levels, whereas hepatic GLUT2 and SM GLUT4 remained largely unchanged. These correlative findings suggest effects independent of insulin-dependent glucose transport, but do not demonstrate direct functional improvement in mitochondrial or redox status. Conclusions: HK M. aurum exerts partial anti-hyperglycemic effects in STZ-induced diabetic mice, but the associated protein changes require functional validation before its role as a postbiotic in β-cell dysfunction can be established. Full article

Background/Objectives: Hepatocellular carcinoma (HCC) exhibits enhanced glycolytic activity, primarily facilitated by Class I glucose transporters (GLUTs), particularly GLUT-2. Phloretin, a natural polyphenol, is known to modulate glucose transport; however, its isoform-specific interactions and functional impact on HCC metabolism remain unclear. This study compared phloretin’s inhibitory effects on glucose uptake in HCC cells versus normal liver cell models and assessed its binding affinity across Class I GLUTs using molecular docking. Methods: Cytotoxicity was evaluated in HepG2 (HCC) and THLE-2 (normal hepatocyte) cells using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays to determine biologically relevant concentrations. Glucose uptake at sub-cytotoxic levels was quantified using the fluorescent analog 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)Amino)-2-Deoxyglucose. To elucidate the molecular mechanism, in silico docking simulations were performed to compare the binding affinities of phloretin, glucose, and reference inhibitors (glutor and cytochalasin B) with the outward-facing conformations of GLUT-1 through GLUT-4. Results: Phloretin induced dose- and time-dependent cytotoxicity, with HepG2 cells exhibiting significantly higher sensitivity than THLE-2 cells. Functionally, phloretin markedly reduced glucose uptake in HepG2 cells, whereas THLE-2 cells showed minimal inhibition. Molecular docking revealed that phloretin occupies the central substrate-binding cavity of Class I GLUTs, forming its most stable interaction network with GLUT-2. Conclusions: These results demonstrate that phloretin selectively inhibits glucose uptake in liver cancer cells, likely through its high-affinity interaction with GLUT-2. Collectively, these findings highlight phloretin’s potential as a metabolic therapeutic agent and support GLUT-2 as a viable target for HCC intervention. Full article

Vulvar squamous cell carcinoma (VSCC) and its precursor lesions are relatively rare malignancies of the gynecologic tract. In recent years, international organizations and pathologic reporting guidelines endorse the subdivision of VSCC into human papillomavirus (HPV)-associated and HPV-independent types. There is also growing evidence for the further separation of HPV-independent into p53 abnormal and p53 wild-type cancers. Although the diagnosis and subclassification of VSCC is often straightforward, using immunohistochemical markers such as p16 and p53 as surrogate markers for high-risk HPV infection and TP53 mutation respectively, rare and unusual scenarios exist that can complicate VSCC classification. Herein we discuss these challenging scenarios in VSCC classification, as well as emerging VSCC prognostic biomarkers such as cyclin D1. In addition, the pathologic diagnosis of VSCC precursor lesions, particularly those of HPV-independent type, are frequently challenging to distinguish from benign conditions of the vulva. We discuss the recent literature describing the added diagnostic value of immunohistochemical biomarkers p53, CK17, CK13, SOX2, GATA3, GLUT1 and others, which may be particularly helpful when morphology is inconclusive. It is anticipated that with improved VSCC classification and precursor recognition, avenues for more tailored therapeutic strategies and earlier therapeutic intervention can be achieved. Full article

Type 2 diabetes mellitus (T2DM) is driven by insulin resistance and β-cell dysfunction. While Ras GTPases are known for oncogenic signaling, emerging evidence implicates the Ras–Ral axis as a critical regulator of glucose homeostasis. This review synthesizes the distinct roles of Ras and Ral in metabolism. Ras hyperactivation promotes insulin resistance and inflammation via MAPK/PI3K pathways, whereas RalA supports GLUT4 translocation and insulin granule exocytosis. We propose a dual-pathway hypothesis: T2DM pathophysiology involves an imbalance characterized by excessive Ras signaling and insufficient Ral-mediated metabolic actions. Consequently, we explore the therapeutic potential of rebalancing this axis through combinatorial strategies, that selectively inhibit pathogenic Ras while enhancing protective Ral activity. We critically evaluate current Ras-targeted agents (e.g., farnesyltransferase inhibitors, allele-specific inhibitors) and discuss the emerging frontier of Ral-specific enhancers. Finally, we outline key translational challenges and future directions for validating this axis as a target for precision medicine in T2DM. Full article

Leucine-rich repeat kinase 2 (LRRK2) is a multidomain serine/threonine kinase and a major genetic contributor to Parkinson’s disease (PD). Although LRRK2 has been extensively studied in neurodegeneration, emerging evidence indicates that it also plays a critical role in systemic metabolism. LRRK2 regulates glucose homeostasis through modulation of insulin signaling, vesicle trafficking, mitochondrial function, and inflammatory responses. Studies using LRRK2 knockout and knock-in models, including the pathogenic G2019S mutation, have revealed abnormalities in insulin sensitivity, adipose tissue inflammation, hepatic glucose production, and skeletal muscle metabolism. Mechanistically, LRRK2 phosphorylates Rab GTPases, thereby controlling insulin receptor trafficking and GLUT4 translocation. In addition, LRRK2 influences mitochondrial dynamics and reactive oxygen species production, linking metabolic stress to inflammatory signaling. Importantly, LRRK2 also regulates innate immune pathways, including TLR4–NFκB signaling and inflammasome activation, thereby connecting peripheral metabolic dysfunction to neuroinflammation. Here, we propose an integrated metabolic–neuroinflammatory crosstalk model in which LRRK2 functions as a molecular coordinator linking peripheral metabolic dysfunction to central neurodegeneration. In this framework, systemic metabolic stress—characterized by insulin resistance, chronic inflammation, advanced glycation end product (AGE) accumulation, and blood–brain barrier disruption—drives microglial activation and neurodegenerative processes. Understanding this systemic axis may provide new therapeutic opportunities targeting both metabolic dysfunction and neurodegeneration in PD. Full article

Cardiovascular diseases remain a leading cause of morbidity and mortality worldwide, underscoring the need to better understand cardiovascular physiology. A key aspect involves identifying regulatory molecules that govern metabolic shifts. Forkhead box protein O1 (FoxO1) has emerged as a potential regulator; however, its role and underlying mechanisms remain unclear. This study investigated FoxO1 in metabolic adaptation using Wistar rats divided into age groups (fetal, postnatal day 1, postnatal day 7, adult) and treatment groups (control, hypoxia, FoxO1 inhibitor, combination). Hypoxia (12–14% O₂) and FoxO1 inhibitor (AS1842856, 10 mg/kgBW/day) were administered accordingly. Parameters assessed included hypoxia inducible factor 1 α (HIF-1α), FoxO1 mRNA and protein, glucose transporter type 1 (GLUT1), glucose transporter type 4 (GLUT4), cluster of differentiation 36 (CD36), hexokinase, pyruvate dehydrogenase kinase isoform 4 (PDK4), phosphoenolpyruvate carboxykinase (PEPCK), lactic acid, malonyl-CoA, carnitine palmitoyltransferase 1 (CPT1), citrate synthase, cytochrome c, and adenosine triphosphate (ATP). ATP production increased with age, associated with higher FoxO1 expression and metabolic shifts. Hypoxia in fetal hearts reduced HIF-1α and FoxO1. FoxO1 inhibition elevated glycolytic and oxidative markers. In conclusion, FoxO1 regulates glycolysis and lipid metabolism, offering insights into cardiac adaptation to hypoxia and potential therapeutic strategies. Full article

Glucose transporter type 4 (GLUT4), encoded by the SLC2A4 gene, is the final effector of insulin-stimulated glucose uptake in insulin-sensitive tissues: skeletal muscle, adipose tissue, and cardiac muscle. Its dynamic localization, retained intracellularly under basal conditions and extensively translocated to the plasma membrane upon stimulation, makes it a master regulator of glycemic homeostasis. While the canonical insulin pathway (PI3K/Akt/TBC1D4) is the most potent and specific mechanism in the postprandial state, its dysfunction is centrally associated with insulin resistance and type 2 diabetes mellitus (T2DM). Crucially, robust alternative signaling networks function completely independently of insulin to regulate GLUT4 synthesis and translocation. Prominent among these are contraction-mediated pathways in skeletal muscle, which employ calcium signaling (via CaMKII), mechanical/metabolic stress sensors (via p38 MAPK γ/δ), and AMP-activated protein kinase (AMPK). This review critically integrates current knowledge, linking the molecular architecture and post-translational modifications of GLUT4 to the complex, tissue-specific signaling networks that govern its vesicular trafficking. We emphasize the hierarchy, redundancy, and interdependence of these pathways, highlighting differences between acute translocation and chronic transcriptional adaptations. Finally, we discuss how deciphering insulin-independent mechanisms offers promising therapeutic opportunities, particularly in identifying pharmacological targets that mimic the metabolic benefits of physical exercise. Full article

Although LRRK2 mutations modulate systemic glucose homeostasis and metabolic dysfunction precedes Parkinson’s disease (PD) motor symptoms; the way in which pathogenic variants of LRRK2 disrupt astrocytic glucose metabolism and organellar homeostasis remains poorly understood. Here, we demonstrate that LRRK2-I1371V mutation causes profound metabolic and organellar dysfunction in LRRK2-I1371V PD-iPSC-derived astrocytes and U87 cells overexpressing I1371V variant. LRRK2-I1371V astrocytes exhibit significantly reduced GLUT1 expression and cell surface localization, resulting in impaired glucose uptake and decreased lactate production. This metabolic insufficiency correlates with cascading mitochondrial dysfunction, characterized by membrane depolarization, elevated reactive oxygen species, enhanced ubiquitination and reduced proteasomal activity. Reduced LAMP1/LAMP2 expression, impaired lysosomal acidification, and selective cathepsin D deficiency were observed. Accumulation of undegraded cargo was confirmed by transmission electron microscopy upon α-synuclein exposure. ER stress was evident by upregulation of GADD34/CHOP, increased phospho-PERK, and reduced nascent protein synthesis. Increased ER–mitochondrial contact via MAMs and enhanced STIM1-ORAI3 clustering reflect compensatory but ultimately insufficient responses to energy stress. Our results reveal that LRRK2-I1371V induces glucose uptake deficits, leading to energy depletion and integrated ER–mitochondria–lysosome dysfunction, thus indicating restoration of astrocytic metabolic capacity as a potential therapeutic strategy for LRRK2-associated PD. Full article