Lesion of NPY Receptor-expressing Neurons in Perifornical Lateral Hypothalamus Attenuates Glucoprivic Feeding

Glucoprivic feeding is one of several counterregulatory responses (CRRs) that facilitates restoration of euglycemia following acute glucose deficit (glucoprivation). Our previous work established that glucoprivic feeding requires ventrolateral medullary (VLM) catecholamine (CA) neurons that coexpress neuropeptide Y (NPY). However, the connections by which VLM CA/NPY neurons trigger increased feeding are uncertain. We have previously shown that glucoprivation, induced by an anti-glycolygic agent 2-deoxy-D-glucose (2DG), activates perifornical lateral hypothalamus (PeFLH) neurons and that expression of NPY in the VLM CA/NPY neurons is required for glucoprivic feeding. We therefore hypothesized that glucoprivic feeding and possibly other CRRs require NPY-sensitive PeFLH neurons. To test this, we used the ribosomal toxin conjugate NPY-saporin (NPY-SAP) to selectively lesion NPY receptor-expressing neurons in the PeFLH of male rats. We found that NPY-SAP destroyed a significant number of PeFLH neurons, including those expressing orexin, but not those expressing melanin-concentrating hormone. The PeFLH NPY-SAP lesions attenuated 2DG-induced feeding but did not affect 2DG-induced increase in locomotor activity, sympathoadrenal hyperglycemia, or corticosterone release. The 2DG-induced feeding response was also significantly attenuated in NPY-SAP-treated female rats. Interestingly, PeFLH NPY-SAP lesioned male rats had reduced body weights and decreased dark cycle feeding, but this effect was not seen in female rats. We conclude that a NPY projection to the PeFLH is necessary for glucoprivic feeding, but not locomotor activity, hyperglycemia, or corticosterone release, in both male and female rats.

Transcriptome analysis reveals organ-specific effects of 2-deoxyglucose treatment in healthy mice

OBJECTIVE

Glycolytic inhibition via 2-deoxy-D-glucose (2DG) has potential therapeutic benefits for a range of diseases, including cancer, epilepsy, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), and COVID-19, but the systemic effects of 2DG on gene function across different tissues are unclear.

METHODS

This study analyzed the transcriptional profiles of nine tissues from C57BL/6J mice treated with 2DG to understand how it modulates pathways systemically. Principal component analysis (PCA), weighted gene co-network analysis (WGCNA), analysis of variance, and pathway analysis were all performed to identify modules altered by 2DG treatment.

RESULTS

PCA revealed that samples clustered predominantly by tissue, suggesting that 2DG affects each tissue uniquely. Unsupervised clustering and WGCNA revealed six distinct tissue-specific modules significantly affected by 2DG, each with unique key pathways and genes. 2DG predominantly affected mitochondrial metabolism in the heart, while in the small intestine, it affected immunological pathways.

CONCLUSIONS

These findings suggest that 2DG has a systemic impact that varies across organs, potentially affecting multiple pathways and functions. The study provides insights into the potential therapeutic benefits of 2DG across different diseases and highlights the importance of understanding its systemic effects for future research and clinical applications.

Establishment of bone-targeted nano-platform and the study of its combination with 2-deoxy-d-glucose enhanced photodynamic therapy to inhibit bone metastasis

At present, simple anti-tumor drugs are ineffective at targeting bone tissue and are not purposed to treat patients with bone metastasis. In this study, zoledronic acid (ZOL) demonstrated excellent bone-targeting properties as a bone-targeting ligand. The metal-organic framework (MOF) known as ZIF-90 was modified with ZOL to construct a bone-targeting-based drug delivery system. Chlorin e6 (Ce6) was loaded in the bone-targeted drug delivery system and combined with 2-deoxy-D-glucose (2-DG), which successfully treated bone tumors when enhanced photodynamic therapy was applied. The Ce6@ZIF-PEG-ZOL (Ce6@ZPZ) nanoparticles were observed to have uniform morphology, a particle size of approximately 210 nm, and a potential of approximately -30.4 mV. The results of the bone-targeting experiments showed that Ce6@ZPZ exhibited a superior bone-targeted effect when compared to Ce6@ZIF-90-PEG. The Ce6@ZPZ solution was subjected to 660 nm irradiation and the resulting production of reactive oxygen species increased over time, which could be further increased when Ce6@ZPZ was used in combination with 2-DG. Their combination had a stronger inhibitory capacity against tumor cells than either 2-DG or Ce6@ZPZ alone, increasing the rate of tumor cell apoptosis. The apoptosis rate caused by HGC-27 was 61.56% when 2-DG was combined with Ce6@ZPZ. In vivo results also showed that Ce6@ZPZ combined with 2-DG maximally inhibited tumor growth and prolonged mice survival compared to the other experimental groups. Therefore, the combination of PDT and glycolytic inhibitors serves as a potential option for the treatment of cancer.

2-Deoxy-glucose ameliorates the peritoneal mesothelial and endothelial barrier function perturbation occurring due to Peritoneal Dialysis fluids exposure

Peritoneal dialysis (PD) and prolonged exposure to PD fluids (PDF) induce peritoneal membrane (PM) fibrosis and hypervascularity, leading to functional PM degeneration. 2-deoxy-glucose (2-DG) has shown potential as PM antifibrotic by inhibiting hyper-glycolysis induced mesothelial-to-mesenchymal transition (MMT). We investigated whether administration of 2-DG with several PDF affects the permeability of mesothelial and endothelial barrier of the PM. The antifibrotic effect of 2-DG was confirmed by the gel contraction assay with embedded mesothelial (MeT-5A) or endothelial (EA.hy926) cells cultured in Dianeal® 2.5 % (CPDF), BicaVera® 2.3 % (BPDF), Balance® 2.3 % (LPDF) with/without 2-DG addition (0.2 mM), and qPCR for αSMA, CDH2 genes. Moreover, 2-DG effect was tested on the permeability of monolayers of mesothelial and endothelial cells by monitoring the transmembrane resistance (RTM), FITC-dextran (10, 70 kDa) diffusion and mRNA expression levels of CLDN-1 to -5, ZO1, SGLT1, and SGLT2 genes. Contractility of MeT-5A cells in CPDF/2-DG was decreased, accompanied by αSMA (0.17 ± 0.03) and CDH2 (2.92 ± 0.29) gene expression fold changes. Changes in αSMA, CDH2 were found in EA.hy926 cells, though αSMA also decreased under LPDF/2-DG incubation (0.42 ± 0.02). Overall, 2-DG mitigated the PDF-induced alterations in mesothelial and endothelial barrier function as shown by RTM, dextran transport and expression levels of the CLDN-1 to -5, ZO1, and SGLT2. Thus, supplementation of PDF with 2-DG not only reduces MMT but also improves functional permeability characteristics of the PM mesothelial and endothelial barrier.

2-Deoxy-D-glucose ameliorates inflammation and fibrosis in a silicosis mouse model by inhibiting hypoxia-inducible factor-1α in alveolar macrophages

Inhaling silica causes the occupational illness silicosis, which mostly results in the gradual fibrosis of lung tissue. Previous research has demonstrated that hypoxia-inducible factor-1α (HIF-1α) and glycolysis-related genes are up-regulated in silicosis. The role of 2-deoxy-D-glucose (2-DG) as an inhibitor of glycolysis in silicosis mouse models and its molecular mechanisms remain unclear. Therefore, we used 2-DG to observe its effect on pulmonary inflammation and fibrosis in a silicosis mouse model. Furthermore, in vitro cell experiments were conducted to explore the specific mechanisms of HIF-1α. Our study found that 2-DG down-regulated HIF-1α levels in alveolar macrophages induced by silica exposure and reduced the interleukin-1β (IL-1β) level in pulmonary inflammation. Additionally, 2-DG reduced silica-induced pulmonary fibrosis. From these findings, we hypothesize that 2-DG reduced glucose transporter 1 (GLUT1) expression by inhibiting glycolysis, which inhibits the expression of HIF-1α and ultimately reduces transcription of the inflammatory cytokine, IL-1β, thus alleviating lung damage. Therefore, we elucidated the important regulatory role of HIF-1α in an experimental silicosis model and the potential defense mechanisms of 2-DG. These results provide a possible effective strategy for 2-DG in the treatment of silicosis.

2-Deoxyglucose drives plasticity via an adaptive ER stress-ATF4 pathway and elicits stroke recovery and Alzheimer's resilience

Intermittent fasting (IF) is a diet with salutary effects on cognitive aging, Alzheimer's disease (AD), and stroke. IF restricts a number of nutrient components, including glucose. 2-deoxyglucose (2-DG), a glucose analog, can be used to mimic glucose restriction. 2-DG induced transcription of the pro-plasticity factor, Bdnf, in the brain without ketosis. Accordingly, 2-DG enhanced memory in an AD model (5xFAD) and functional recovery in an ischemic stroke model. 2-DG increased Bdnf transcription via reduced N-linked glycosylation, consequent ER stress, and activity of ATF4 at an enhancer of the Bdnf gene, as well as other regulatory regions of plasticity/regeneration (e.g., Creb5, Cdc42bpa, Ppp3cc, and Atf3) genes. These findings demonstrate an unrecognized role for N-linked glycosylation as an adaptive sensor to reduced glucose availability. They further demonstrate that ER stress induced by 2-DG can, in the absence of ketosis, lead to the transcription of genes involved in plasticity and cognitive resilience as well as proteostasis.

Chemogenetic activation of ventral medullary astrocytes enhances feeding and corticosterone release in response to mild glucoprivation

To investigate the role of glial cells in the regulation of glucoprivic responses in rats, a chemogenetic approach was used to activate astrocytes neighboring catecholamine (CA) neurons in the ventromedial medulla (VLM) where A1 and C1 CA cell groups overlap (A1/C1). Previous results indicate that activation of CA neurons in this region is necessary and sufficient for feeding and corticosterone release in response to glucoprivation. However, it is not known whether astrocyte neighbors of CA neurons contribute to glucoregulatory responses. Hence, we made nanoinjections of AAV5-GFAP-hM3D(Gq)-mCherry to selectively transfect astrocytes in the A1/C1 region with the excitatory designer receptor exclusively activated by designer drugs (DREADDs), hM3D(Gq). After allowing time for DREADD expression, we evaluated the rats for increased food intake and corticosterone release in response to low systemic doses of the antiglycolytic agent, 2-deoxy-d-glucose (2DG), alone and in combination with the hM3D(Gq) activator clozapine-n-oxide (CNO). We found that DREADD-transfected rats ate significantly more food when 2DG and CNO were coadministered than when either 2DG or CNO was injected alone. We also found that CNO significantly enhanced 2DG-induced FOS expression in the A1/C1 CA neurons, and that corticosterone release also was enhanced when CNO and 2DG were administered together. Importantly, CNO-induced activation of astrocytes in the absence of 2DG did not trigger food intake or corticosterone release. Our results indicate that during glucoprivation, activation of VLM astrocytes cells markedly increases the sensitivity or responsiveness of neighboring A1/C1 CA neurons to glucose deficit, suggesting a potentially important role for VLM astrocytes in glucoregulation.

Effect of 2-deoxyglucose-mediated inhibition of glycolysis on migration and invasion of HTR-8/SVneo trophoblast cells

The proper invasion of trophoblasts is crucial for embryo implantation and placental development, which is helpful to establish a correct maternal-fetal relationship. Trophoblasts can produce a large amount of lactate through aerobic glycolysis during early pregnancy. Lactate creates a low pH microenvironment around the embryo to help uterine tissue decompose and promote the invasion of trophoblasts. The purpose of this study is to reveal the the potential mechanism of aerobic glycolysis regulating the invasiveness of trophoblasts by investigating the effect of 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor, on the biological function of HTR-8/SVneo trophoblast cells, the expressions of epithelial mesenchymal transformation (EMT) markers and invasion-related factors. 2-DG could inhibit the aerobic glycolysis of trophoblasts and decrease the activity of trophoblasts in a dose-dependent manner. Moreover, 2-DG inhibited the EMT of HTR-8/SVneo cells, down-regulated the expression of invasion-related factors matrix metalloproteinase 2/9 (MMP2/9) and up-regulated the expression of tissue inhibitor of matrix metalloproteinases 1/2 (TIMP1/2), thus inhibiting cell migration and invasion. This paper provides a foundation in the significance of aerobic glycolysis of trophoblasts in the process of invasion, and also provides ideas and insights for the promotion of embryo implantation.

Glycolytic stress deteriorates 229E virulence to improve host defense response

Viral infection treatment is a difficult task due to its complex structure and metabolism. Additionally, viruses can alter the metabolism of host cells, mutate, and readily adjust to harsh environments. Coronavirus stimulates glycolysis, weakens mitochondrial activity, and impairs infected cells. In this study, we investigated the efficacy of 2-DG in inhibiting coronavirus-induced metabolic processes and antiviral host defense systems, which have not been explored so far. 2-Deoxy-d-glucose (2-DG), a molecule restricting substrate availability, has recently gained attention as a potential antiviral drug. The results revealed that 229E human coronavirus promoted glycolysis, producing a significant increase in the concentration of fluorescent 2-NBDG, a glucose analog, particularly in the infected host cells. The addition of 2-DG decreased its viral replication and suppressed infection-induced cell death and cytopathic effects, thereby improving the antiviral host defense response. It was also observed that administration of low doses of 2-DG inhibited glucose uptake, indicating that 2-DG consumption in virus-infected host cells was mediated by high-affinity glucose transporters, whose levels were amplified upon coronavirus infection. Our findings indicated that 2-DG could be a potential drug to improve the host defense system in coronavirus-infected cells.

The Combined Metabolically Oriented Effect of Fucoidan from the Brown Alga Saccharina cichorioides and Its Carboxymethylated Derivative with 2-Deoxy-D-Glucose on Human Melanoma Cells

Melanoma is the most aggressive and treatment-resistant form of skin cancer. It is phenotypically characterized by aerobic glycolysis that provides higher proliferative rates and resistance to cell death. The glycolysis regulation in melanoma cells by means of effective metabolic modifiers represents a promising therapeutic opportunity. This work aimed to assess the metabolically oriented effect and mechanism of action of fucoidan from the brown alga Saccharina cichorioides (ScF) and its carboxymethylated derivative (ScFCM) in combination with 2-deoxy-D-glucose (2-DG) on the proliferation and colony formation of human melanoma cell lines SK-MEL-28, SK-MEL-5, and RPMI-7951. The metabolic profile of melanoma cells was determined by the glucose uptake and Lactate-GloTM assays. The effect of 2-DG, ScF, ScFCM, and their combination on the proliferation, colony formation, and activity of glycolytic enzymes was assessed by the MTS, soft agar, and Western blot methods, respectively. When applied separately, 2-DG (IC50 at 72 h = 8.7 mM), ScF (IC50 at 72 h > 800 µg/mL), and ScFCM (IC50 at 72 h = 573.9 μg/mL) inhibited the proliferation and colony formation of SK-MEL-28 cells to varying degrees. ScF or ScFCM enhanced the inhibiting effect of 2-DG at low, non-toxic concentrations via the downregulation of Glut 1, Hexokinase II, PKM2, LDHA, and pyruvate dehydrogenase activities. The obtained results emphasize the potential of the use of 2-DG in combination with algal fucoidan or its derivative as metabolic modifiers for inhibition of melanoma SK-MEL-28 cell proliferation.

2DG and glycolysis as therapeutic targets for status epilepticus

2-deoxy-D-glucose (2DG) is a glucose analog differing from glucose only by removal of an oxygen atom at the 2 position, which prevents the isomerization of glucose-6-phosphate to fructose-6-phosphate, and thereby reversibly inhibits glycolysis. PET studies of regional brain glucose utilization positron-emitting 18F-2DG demonstrate that brain regions generating seizures have diminished glucose utilization during interictal conditions, but rapidly transition to markedly increased glucose delivery and utilization during seizures, particularly in status epilepticus (SE). 2-deoxy-D-glucose has acute antiseizure actions in multiple in vivo and in vitro seizure models, including models of SE induced by the chemo convulsants pilocarpine and kainic acid, suggesting that focal enhanced delivery of 2DG to ictal brain circuits is a potential novel anticonvulsant intervention for the treatment of SE.

The Glycolysis Inhibitor 2-Deoxy-D-Glucose Exerts Different Neuronal Effects at Circuit and Cellular Levels, Partially Reverses Behavioral Alterations and does not Prevent NADPH Diaphorase Activity Reduction in the Intrahippocampal Kainic Acid Model of Temporal Lobe Epilepsy

Temporal lobe epilepsy is the most drug-resistant type with the highest incidence among the other focal epilepsies. Metabolic manipulations are of great interest among others, glycolysis inhibitors like 2-deoxy D-glucose (2-DG) being the most promising intervention. Here, we sought to investigate the effects of 2-DG treatment on cellular and circuit level electrophysiological properties using patch-clamp and local field potentials recordings and behavioral alterations such as depression and anxiety behaviors, and changes in nitric oxide signaling in the intrahippocampal kainic acid model. We found that epileptic animals were less anxious, more depressed, with more locomotion activity. Interestingly, by masking the effect of increased locomotor activity on the parameters of the zero-maze test, no altered anxiety behavior was noted in epileptic animals. However, 2-DG could partially reverse the behavioral changes induced by kainic acid. The findings also showed that 2-DG treatment partially suppresses cellular level alterations while failing to reverse circuit-level changes resulting from kainic acid injection. Analysis of NADPH-diaphorase positive neurons in the CA1 area of the hippocampus revealed that the number of positive neurons was significantly reduced in dorsal CA1 of the epileptic animals and 2-DG treatment did not affect the diminishing effect of kainic acid on NADPH-d+ neurons in the CA1 area. In the control group receiving 2-DG, however, an augmented NADPH-d+ cell number was noted. These data suggest that 2-DG cannot suppress epileptiform activity at the circuit-level in this model of epilepsy and therefore, may fail to control the seizures in temporal lobe epilepsy cases.

Role of Glycolysis and Fatty Acid Synthesis in the Activation and T Cell-Modulating Potential of Dendritic Cells Stimulated with a TLR5-Ligand Allergen Fusion Protein

Trained immune responses, based on metabolic and epigenetic changes in innate immune cells, are de facto innate immune memory and, therefore, are of great interest in vaccine development. In previous studies, the recombinant fusion protein rFlaA:Betv1, combining the adjuvant and toll-like receptor (TLR)5-ligand flagellin (FlaA) and the major birch pollen allergen Bet v 1 into a single molecule, significantly suppressed allergic sensitization in vivo while also changing the metabolism of myeloid dendritic cells (mDCs). Within this study, the immune-metabolic effects of rFlaA:Betv1 during mDC activation were elucidated. In line with results for other well-characterized TLR-ligands, rFlaA:Betv1 increased glycolysis while suppressing oxidative phosphorylation to different extents, making rFlaA:Betv1 a suitable model to study the immune-metabolic effects of TLR-adjuvanted vaccines. In vitro pretreatment of mDCs with cerulenin (inhibitor of fatty acid biosynthesis) led to a decrease in both rFlaA:Betv1-induced anti-inflammatory cytokine Interleukin (IL) 10 and T helper cell type (TH) 1-related cytokine IL-12p70, while the pro-inflammatory cytokine IL 1β was unaffected. Interestingly, pretreatment with the glutaminase inhibitor BPTES resulted in an increase in IL-1β, but decreased IL-12p70 secretion while leaving IL-10 unchanged. Inhibition of the glycolytic enzyme hexokinase-2 by 2-deoxyglucose led to a decrease in all investigated cytokines (IL-10, IL-12p70, and IL-1β). Inhibitors of mitochondrial respiration had no effect on rFlaA:Betv1-induced IL-10 level, but either enhanced the secretion of IL-1β (oligomycin) or decreased IL-12p70 (antimycin A). In extracellular flux measurements, mDCs showed a strongly enhanced glycolysis after rFlaA:Betv1 stimulation, which was slightly increased after respiratory shutdown using antimycin A. rFlaA:Betv1-stimulated mDCs secreted directly antimicrobial substances in a mTOR- and fatty acid metabolism-dependent manner. In co-cultures of rFlaA:Betv1-stimulated mDCs with CD4+ T cells, the suppression of Bet v 1-specific TH2 responses was shown to depend on fatty acid synthesis. The effector function of rFlaA:Betv1-activated mDCs mainly relies on glycolysis, with fatty acid synthesis also significantly contributing to rFlaA:Betv1-mediated cytokine secretion, the production of antimicrobial molecules, and the modulation of T cell responses.

2-Deoxy-D-glucose Alleviates Cancer Cachexia-Induced Muscle Wasting by Enhancing Ketone Metabolism and Inhibiting the Cori Cycle

Cachexia is characterized by progressive weight loss accompanied by the loss of specific skeletal muscle and adipose tissue. Increased lactate production, either due to the Warburg effect from tumors or accelerated glycolysis effects from cachectic muscle, is the most dangerous factor for cancer cachexia. This study aimed to explore the efficiency of 2-deoxy-D-glucose (2-DG) in blocking Cori cycle activity and its therapeutic effect on cachexia-associated muscle wasting. A C26 adenocarcinoma xenograft model was used to study cancer cachectic metabolic derangements. Tumor-free lean mass, hindlimb muscle morphology, and fiber-type composition were measured after in vivo 2-DG administration. Activation of the ubiquitin-dependent proteasome pathway (UPS) and autophagic–lysosomal pathway (ALP) was further assessed. The cachectic skeletal muscles of tumor-bearing mice exhibited altered glucose and lipid metabolism, decreased carbohydrate utilization, and increased lipid β-oxidation. Significantly increased gluconeogenesis and decreased ketogenesis were observed in cachectic mouse livers. 2-DG significantly ameliorated cancer cachexia-associated muscle wasting and decreased cachectic-associated lean mass levels and fiber cross-sectional areas. 2-DG inhibited protein degradation-associated UPS and ALP, increased ketogenesis in the liver, and promoted ketone metabolism in skeletal muscle, thus enhancing mitochondrial bioenergetic capacity. 2-DG effectively prevents muscle wasting by increasing ATP synthesis efficiency via the ketone metabolic pathway and blocking the abnormal Cori cycle.

The Antiviral Effects of 2-Deoxy-D-glucose (2-DG), a Dual D-Glucose and D-Mannose Mimetic, against SARS-CoV-2 and Other Highly Pathogenic Viruses

Viral infection almost invariably causes metabolic changes in the infected cell and several types of host cells that respond to the infection. Among metabolic changes, the most prominent is the upregulated glycolysis process as the main pathway of glucose utilization. Glycolysis activation is a common mechanism of cell adaptation to several viral infections, including noroviruses, rhinoviruses, influenza virus, Zika virus, cytomegalovirus, coronaviruses and others. Such metabolic changes provide potential targets for therapeutic approaches that could reduce the impact of infection. Glycolysis inhibitors, especially 2-deoxy-D-glucose (2-DG), have been intensively studied as antiviral agents. However, 2-DG’s poor pharmacokinetic properties limit its wide clinical application. Herein, we discuss the potential of 2-DG and its novel analogs as potent promising antiviral drugs with special emphasis on targeted intracellular processes.

Antiepileptic effect of 2deoxyDglucose by activation of miR194/KATP signaling pathway

OBJECTIVES

Epilepsy is a syndrome of central nervous system dysfunction caused by many reasons, which is mainly characterized by abnormal discharge of neurons in the brain. Therefore, finding new targets for epilepsy therapy has always been the focus and hotspot in neurological research field. Studies have found that 2-deoxy-D-glucose (2-DG) exerts anti-epileptic effect by up-regulation of KATP channel subunit Kir6.1, Kir6.2 mRNA and protein. By using the database of TargetScan and miRBase to perform complementary pairing analysis on the sequences of miRNA and related target genes, it predicted that miR-194 might be the upstream signaling molecule of KATP channel. This study aims to explore the mechanism by which 2-DG exerts its anti-epileptic effect by regulating KATP channel subunits Kir6.1 and Kir6.2 via miR-194.

METHODS

A magnesium-free epilepsy model was established and randomly divided into a control group, an epilepsy group (EP group), an EP+2-DG group, and miR-194 groups (including EP+miR-194 mimic, EP+miR-194 mimic+2-DG, EP+miR-194 mimic control, EP+miR-194 inhibitor, EP+miR-194 inhibitor+2-DG, and EP+miR-194 inhibitor control groups). The 2-DG was used to intervene miR-194 mimics, patch-clamp method was used to detect the spontaneous recurrent epileptiform discharges, real-time PCR was used to detect neuronal miR-194, Kir6.1, and Kir6.2 expressions, and the protein levels of Kir6.1 and Kir6.2were detected by Western blotting.

RESULTS

Compared with the control group, there was no significant difference in the amplitude of spontaneous discharge potential in the EP group (P>0.05), but the frequency of spontaneous discharge was increased (P<0.05). Compared with the EP group, the frequency of spontaneous discharge was decreased (P<0.05). Compared with the EP+miR-194 mimic control group, the mRNA and protein expressions of Kir6.1 and Kir6.2 in the EP+miR-194 mimic group were down-regulated (all P<0.05). Compared with the EP+miR-194 inhibitor control group, the mRNA and protein expressions of Kir6.1 and Kir6.2 in the EP+miR-194 inhibitor group were up-regulated (all P<0.05). After pretreatment with miR-194 mimics, the mRNA and protein expression levels of KATP channel subunits Kir6.1 and Kir6.2 were decreased (all P<0.05). Compared with the EP+2-DG group, the mRNA and protein expression levels of Kir6.1 and Kir6.2 in the EP+miR-194 mimic+2-DG group were down-regulated (all P<0.05) and the mRNA and protein expression levels of Kir6.1 and Kir6.2 in the EP+miR-194 inhibitor+2-DG group were up-regulated (all P<0.05).

CONCLUSIONS

The 2-DG might play an anti-epilepsy effect by up-regulating KATP channel subunits Kir6.1 and Kir6.2via miR-194.

Mass Spectrometric Metabolic Fingerprinting of 2-Deoxy-D-Glucose (2-DG)-Induced Inhibition of Glycolysis and Comparative Analysis of Methionine Restriction versus Glucose Restriction under Perfusion Culture in the Murine L929 Model System

All forms of restriction, from caloric to amino acid to glucose restriction, have been established in recent years as therapeutic options for various diseases, including cancer. However, usually there is no direct comparison between the different restriction forms. Additionally, many cell culture experiments take place under static conditions. In this work, we used a closed perfusion culture in murine L929 cells over a period of 7 days to compare methionine restriction (MetR) and glucose restriction (LowCarb) in the same system and analysed the metabolome by liquid chromatography mass spectrometry (LC-MS). In addition, we analysed the inhibition of glycolysis by 2-deoxy-D-glucose (2-DG) over a period of 72 h. 2-DG induced very fast a low-energy situation by a reduced glycolysis metabolite flow rate resulting in pyruvate, lactate, and ATP depletion. Under perfusion culture, both MetR and LowCarb were established on the metabolic level. Interestingly, over the period of 7 days, the metabolome of MetR and LowCarb showed more similarities than differences. This leads to the conclusion that the conditioned medium, in addition to the different restriction forms, substantially reprogramm the cells on the metabolic level.

In Vivo Photometry Reveals Insulin and 2-Deoxyglucose Maintain Prolonged Inhibition of VMH Vglut2 Neurons in Male Mice

The ventromedial hypothalamic (VMH) nucleus is a well-established hub for energy and glucose homeostasis. In particular, VMH neurons are thought to be important for initiating the counterregulatory response to hypoglycemia, and ex vivo electrophysiology and immunohistochemistry data indicate a clear role for VMH neurons in sensing glucose concentration. However, the temporal response of VMH neurons to physiologically relevant changes in glucose availability in vivo has been hampered by a lack of available tools for measuring neuronal activity over time. Since the majority of neurons within the VMH are glutamatergic and can be targeted using the vesicular glutamate transporter Vglut2, we expressed cre-dependent GCaMP7s in Vglut2 cre mice and examined the response profile of VMH to intraperitoneal injections of glucose, insulin, and 2-deoxyglucose (2DG). We show that reduced available glucose via insulin-induced hypoglycemia and 2DG-induced glucoprivation, but not hyperglycemia induced by glucose injection, inhibits VMH Vglut2 neuronal population activity in vivo. Surprisingly, this inhibition was maintained for at least 45 minutes despite prolonged hypoglycemia and initiation of a counterregulatory response. Thus, although VMH stimulation, via pharmacological, electrical, or optogenetic approaches, is sufficient to drive a counterregulatory response, our data suggest VMH Vglut2 neurons are not the main drivers required to do so, since VMH Vglut2 neuronal population activity remains suppressed during hypoglycemia and glucoprivation.

2-Deoxy-D-glucose and combined 2-Deoxy-D-glucose/albendazole exhibit therapeutic efficacy against Echinococcus granulosus protoscoleces and experimental alveolar echinococcosis

2-Deoxy-D-glucose (2-DG) is a glucose analog used as a promising anticancer agent. It exerts its effects by inhibiting the glycolytic energy metabolism to deplete cells of energy. The larval stage of Echinococcus relies on glycolysis for energy production. Therefore, in this study, we investigated the in vitro and in vivo efficacy of 2-DG against the larval stage of Echinococcus granulosus and E. multilocularis. 2-DG exhibited significant time- and dose-dependent effects against in vitro cultured E. granulosus protoscoleces and E. multilocularis metacestodes. A daily oral administration of 500 mg/kg 2-DG in E. multilocularis-infected mice effectively reduced the weight of metacestodes. Notably, the combination treatment, either 2-DG (500 mg/kg/day) + albendazole (ABZ) (200 mg/kg/day) or 2-DG (500 mg/kg/day) + half-dose of ABZ (100 mg/kg/day), exhibited a potent therapeutic effect against E. multilocularis, significantly promoting the reduction of metacestodes weight compared with the administration of 2-DG or ABZ alone. Furthermore, the combination significantly promoted apoptosis of the cells of metacestodes and inhibited glycolysis in metacestodes, compared with the administration of 2-DG or ABZ alone. In conclusion, 2-DG exerts an effective activity against the larval stage of Echinococcus. Thus, it may be a promising anti-Echinococcus drug, and its combination with ABZ may provide a new strategy for the treatment of echinococcosis in humans.

Echinococcosis is a serious but neglected helminthic zoonosis caused by the larval stage of Echinococcus granulosus and E. multilocularis. At present, clinical pharmacotherapy of echinococcosis, such as albendazole (ABZ) and mebendazole, has limited effectiveness. Thus, the development of novel therapeutic drugs for human echinococcosis is urgently needed. 2-Deoxy-D-glucose (2-DG) is a glucose analog used as a promising anticancer agent, and it exerts its effects by inhibiting the glycolytic energy metabolism to deplete cells of energy. Echinococcus in the host depends on glycolysis for energy production and glycolysis intermediates for other metabolic processes. Therefore, in this study, we investigated the efficacy of 2-DG against Echinococcus. 2-DG exerted an effective in vitro and in vivo activity against E. granulosus protoscoleces and E. multilocularis metacestodes, and the combination of this drug with ABZ further improved the therapeutic effect. Therefore, 2-DG can be developed as a promising anti-Echinococcus drug, and its combination with ABZ may provide a new strategy for the treatment of human echinococcosis in the future.

Blood-based untargeted metabolomics in relapsing-remitting multiple sclerosis revealed the testable therapeutic target

Metabolic aberrations impact the pathogenesis of multiple sclerosis (MS) and possibly can provide clues for new treatment strategies. Using untargeted metabolomics, we measured serum metabolites from 35 patients with relapsing-remitting multiple sclerosis (RRMS) and 14 healthy age-matched controls. Of 632 known metabolites detected, 60 were significantly altered in RRMS. Bioinformatics analysis identified an altered metabotype in patients with RRMS, represented by four changed metabolic pathways of glycerophospholipid, citrate cycle, sphingolipid, and pyruvate metabolism. Interestingly, the common upstream metabolic pathway feeding these four pathways is the glycolysis pathway. Real-time bioenergetic analysis of the patient-derived peripheral blood mononuclear cells showed enhanced glycolysis, supporting the altered metabolic state of immune cells. Experimental autoimmune encephalomyelitis mice treated with the glycolytic inhibitor 2-deoxy-D-glucose ameliorated the disease progression and inhibited the disease pathology significantly by promoting the antiinflammatory phenotype of monocytes/macrophage in the central nervous system. Our study provided a proof of principle for how a blood-based metabolomic approach using patient samples could lead to the identification of a therapeutic target for developing potential therapy.

A novel property of hexokinase inhibition by Favipiravir and proposed advantages over Molnupiravir and 2 Deoxy D glucose in treating COVID-19

PURPOSE

In the wake of SARS-CoV-2's global spread, human activities from health to social life to education have been affected. Favipiravir and Molnupiravir exhibited novel hexokinase inhibition and we discuss advantages of this property in their COVID-19 inhibition potential.

METHODS

This paper describes molecular docking data of human hexokinase II with Favipiravir, Cyan 20, Remdesivir, 2DG, and Molnupiravir along with hexokinase inhibition assays.

RESULTS

Favipiravir, an antiviral drug previously cleared for treating the flu and ebola, has shown some promise in early trials to treat COVID-19. We observed potent human hexokinase inhibiting potential of Favipiravir (50%) as against 4% and merely 0.3% hexokinase inhibition with Molnupiravir and 2 Deoxy D glucose at 0.1 mM concentration supported by molecular docking studies.

CONCLUSION

Favipiravir could continue to be part of the COVID-19 treatment regimen due to its resistance to host esterases, hexokinase inhibition potential and proven safety through human trials.

2 deoxy-D-glucose augments the mitochondrial respiratory chain in heart

2-Deoxy-D-glucose (2DG) has recently received emergency approval for the treatment of COVID-19 in India, after a successful clinical trial. SARS-CoV-2 infection of cultured cells is accompanied by elevated glycolysis and decreased mitochondrial function, whereas 2DG represses glycolysis and stimulates respiration, and restricts viral replication. While 2DG has pleiotropic effects on cell metabolism in cultured cells it is not known which of these manifests in vivo. On the other hand, it is known that 2DG given continuously can have severe detrimental effects on the rodent heart. Here, we show that the principal effect of an extended, intermittent 2DG treatment on mice is to augment the mitochondrial respiratory chain proteome in the heart; importantly, this occurs without vacuolization, hypertrophy or fibrosis. The increase in the heart respiratory chain proteome suggests an increase in mitochondrial oxidative capacity, which could compensate for the energy deficit caused by the inhibition of glycolysis. Thus, 2DG in the murine heart appears to induce a metabolic configuration that is the opposite of SARS-CoV-2 infected cells, which could explain the compound's ability to restrict the propagation of the virus to the benefit of patients with COVID-19 disease.

Cholinergic anti-inflammatory pathway ameliorates murine experimental Th2-type colitis by suppressing the migration of plasmacytoid dendritic cells

Ulcerative colitis (UC) is a chronic inflammatory bowel disease. Several studies have demonstrated that α7 nicotinic acetylcholine receptors (α7nAChRs) exert anti-inflammatory effects on immune cells and nicotine suppress UC onset and relapse. Plasmacytoid dendritic cells (pDCs) reportedly accumulate in the colon of UC patients. Therefore, we investigated the pathophysiological roles of α7nAChRs on pDCs in the pathology of UC using oxazolone (OXZ)-induced Th2-type colitis with BALB/c mice. 2-deoxy-D-glucose, a central vagal stimulant suppressed OXZ colitis, and nicotine also ameliorated OXZ colitis with suppressing Th2 cytokines, which was reversed by α7nAChR antagonist methyllycaconitine. Additionally, α7nAChRs were expressed on pDCs, which were located very close to cholinergic nerve fibers in the colon of OXZ mice. Furthermore, nicotine suppressed CCL21-induced bone marrow-derived pDC migration due to Rac 1 inactivation, which was reversed by methyllycaconitine, a JAK2 inhibitor AG490 or caspase-3 inhibitor AZ-10417808. CCL21 was mainly expressed in the isolated lymphoid follicles (ILFs) of the colon during OXZ colitis. The therapeutic effect of cholinergic pathway on OXZ colitis probably through α7nAChRs on pDCs were attributed to the suppression of pDC migration toward the ILFs. Therefore, the activation of α7nAChRs has innovative therapeutic potential for the treatment of UC.

Diet-induced obesity in mice impairs host defense against Klebsiella pneumonia in vivo and glucose transport and bactericidal functions in neutrophils in vitro

Obesity impairs host defense against Klebsiella pneumoniae, but responsible mechanisms are incompletely understood. To determine the impact of diet-induced obesity on pulmonary host defense against K. pneumoniae, we fed 6-wk-old male C57BL/6j mice a normal diet (ND) or high-fat diet (HFD) (13% vs. 60% fat, respectively) for 16 wk. Mice were intratracheally infected with Klebsiella, assayed at 24 or 48 h for bacterial colony-forming units, lung cytokines, and leukocytes from alveolar spaces, lung parenchyma, and gonadal adipose tissue were assessed using flow cytometry. Neutrophils from uninfected mice were cultured with and without 2-deoxy-d-glucose (2-DG) and assessed for phagocytosis, killing, reactive oxygen intermediates (ROI), transport of 2-DG, and glucose transporter (GLUT1-4) transcripts, and protein expression of GLUT1 and GLUT3. HFD mice had higher lung and splenic bacterial burdens. In HFD mice, baseline lung homogenate concentrations of IL-1β, IL-6, IL-17, IFN-γ, CXCL2, and TNF-α were reduced relative to ND mice, but following infection were greater for IL-6, CCL2, CXCL2, and IL-1β (24 h only). Despite equivalent lung homogenate leukocytes, HFD mice had fewer intraalveolar neutrophils. HFD neutrophils exhibited decreased Klebsiella phagocytosis and killing and reduced ROI to heat-killed Klebsiella in vitro. 2-DG transport was lower in HFD neutrophils, with reduced GLUT1 and GLUT3 transcripts and protein (GLUT3 only). Blocking glycolysis with 2-DG impaired bacterial killing and ROI production in neutrophils from mice fed ND but not HFD. Diet-induced obesity impairs pulmonary Klebsiella clearance and augments blood dissemination by reducing neutrophil killing and ROI due to impaired glucose transport.

The glycolysis inhibitor 2-deoxyglucose ameliorates adjuvant-induced arthritis by regulating macrophage polarization in an AMPK-dependent manner

Macrophages are highly plastic cells critical for the development of rheumatoid arthritis (RA). Macrophages exhibit a high degree of pro-inflammatory plasticity in RA, accompanied by a metabolic reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis. 2-deoxyglucose (2-DG), a glycolysis inhibitor, has previously been shown to exhibit anti-inflammatory and anti-arthritic properties. However, the specific mechanisms of inflammatory modulation by 2-DG remain unclear. This study used 2-DG to treat rats with adjuvant arthritis (AA) and investigated its specific anti-arthritic mechanisms in the murine-derived macrophage cell line RAW264.7 in vitro. 2-DG reduced the arthritis index as well as alleviated cellular infiltration, synovial hyperplasia, and bone erosion in AA rats. Moreover, 2-DG treatment modulated peritoneal macrophage polarization, increasing levels of the arginase1 (Arg1) and decreasing expression of the inducible nitric oxide synthase (iNOS). 2-DG activated AMP-activated protein kinase (AMPK) via phosphorylation and reduced activation of the nuclear factor κB (NF-κB) in peritoneal macrophages of AA rats. In vitro, we verified that 2-DG promoted macrophage transition from M1 to M2-type by upregulating the expression of p-AMPKα and suppressing NF-κB activation in LPS-stimulated RAW264.7 cells. LPS-induced macrophages exhibited a metabolic shift from glycolysis to OXPHOS following 2-DG treatment, as observed by reduced extracellular acidification rate (ECAR), lactate export, glucose consumption, as well as an elevated oxygen consumption rate (OCR) and intracellular ATP concentration. Importantly, changes in polarization and metabolism in response to 2-DG were dampened after AMPKα knockdown. These findings indicate that the anti-arthritic 2-DG effect is mediated by a modulation of macrophage polarization in an AMPK-dependent manner.

Metabolic regulation of RA macrophages is distinct from RA fibroblasts and blockade of glycolysis alleviates inflammatory phenotype in both cell types

Recent studies have shown the significance of metabolic reprogramming in immune and stromal cell function. Yet, the metabolic reconfiguration of RA macrophages (MΦs) is incompletely understood during active disease and in crosstalk with other cell types in experimental arthritis. This study elucidates a distinct regulation of glycolysis and oxidative phosphorylation in RA MΦs compared to fibroblast (FLS), although PPP (Pentose Phosphate pathway) is similarly reconfigured in both cell types. 2-DG treatment showed a more robust impact on impairing the RA M1 MΦ-mediated inflammatory phenotype than IACS-010759 (IACS, complexli), by reversing ERK, AKT and STAT1 signaling, IRF8/3 transcription and CCL2 or CCL5 secretion. This broader inhibitory effect of 2-DG therapy on RA M1 MΦs was linked to dysregulation of glycolysis (GLUT1, PFKFB3, LDHA, lactate) and oxidative PPP (NADP conversion to NADPH), while both compounds were ineffective on oxidative phosphorylation. Distinctly, in RA FLS, 2-DG and IACS therapies constrained LPS/IFNγ-induced AKT and JNK signaling, IRF5/7 and fibrokine expression. Disruption of RA FLS metabolic rewiring by 2-DG or IACS therapy was accompanied by a reduction of glycolysis (HIF1α, PFKFB3) and suppression of citrate or succinate buildup. We found that 2-DG therapy mitigated CIA pathology by intercepting joint F480+iNOS+MΦ, Vimentin+ fibroblast and CD3+T cell trafficking along with downregulation of IRFs and glycolytic intermediates. Surprisingly, IACS treatment was inconsequential on CIA swelling, cell infiltration, M1 and Th1/Th17 cytokines (IFN-γ/IL-17) and joint glycolytic mediators. Collectively, our results indicate that blockade of glycolysis is more effective than inhibition of complex 1 in CIA, in part due to its effectiveness on the MΦ inflammatory phenotype.

2-Deoxy-d-glucose exploits increased glucose metabolism in cancer and viral-infected cells: Relevance to its use in India against SARS-CoV-2

Mechanisms discovered to drive increased glucose metabolism in cancer cells are found to be similar to those in viral-infected cells. In this mini review, we summarize the major pathways by which the sugar analog, 2-Deoxy-d-glucose, has been shown to exploit increased glucose metabolism in cancer and how this information applies to viral-infected cells. Moreover, we highlight the relevance of these findings to the emergency approval of 2-Deoxy-d-glucose in India to be used against SARS-CoV-2, the virus responsible for COVID-19.

3-Methyladenine prevents energy stress-induced necrotic death of melanoma cells through autophagy-independent mechanisms

We investigated the effect of 3-methyladenine (3MA), a class III phosphatidylinositol 3-kinase (PI3K)-blocking autophagy inhibitor, on cancer cell death induced by simultaneous inhibition of glycolysis by 2-deoxyglucose (2DG) and mitochondrial respiration by rotenone. 2DG/rotenone reduced ATP levels and increased mitochondrial superoxide production, causing mitochondrial swelling and necrotic death in various cancer cell lines. 2DG/rotenone failed to increase proautophagic beclin-1 and autophagic flux in melanoma cells despite the activation of AMP-activated protein kinase (AMPK) and inhibition of mechanistic target of rapamycin complex 1 (mTORC1). 3MA, but not autophagy inhibition with other PI3K and lysosomal inhibitors, attenuated 2DG/rotenone-induced mitochondrial damage, oxidative stress, ATP depletion, and cell death, while antioxidant treatment mimicked its protective action. The protection was not mediated by autophagy upregulation via class I PI3K/Akt inhibition, as it was preserved in cells with genetically inhibited autophagy. 3MA increased AMPK and mTORC1 activation in energy-stressed cells, but neither AMPK nor mTORC1 inhibition reduced its cytoprotective effect. 3MA reduced JNK activation, and JNK pharmacological/genetic suppression mimicked its mitochondria-preserving and cytoprotective activity. Therefore, 3MA prevents energy stress-triggered cancer cell death through autophagy-independent mechanisms possibly involving JNK suppression and decrease of oxidative stress. Our results warrant caution when using 3MA as an autophagy inhibitor.

3-Deoxyglucosone reduces glucagon-like peptide-1 secretion at low glucose levels through down-regulation of SGLT1 expression in STC-1 cells

CONTEXT

Sodium glucose co-transporter 1 (SGLT1) triggers low glucose-induced glucagon-like peptide-1 (GLP-1) secretion. We reported that a two-week administration of 3-deoxyglucosone (3DG), an independent factor associated with the development of pre-diabetes, reduces basal GLP-1 secretion in rats.

OBJECTIVE

This study investigated the effects of 3DG on GLP-1 secretion and SGLT1 pathway under low-glucose conditions in STC-1 cells.

METHODS

STC-1 cells were incubated with phloridzin or 3DG at 5.6 mM glucose. SGLT1 expression (by western blotting), GLP-1 and cyclic adenosine monophosphate (cAMP) levels (by ELISA), and intracellular Ca²⁺ concentration (by Fluo-3/AM) were measured.

RESULTS

Phloridzin inhibited GLP-1 secretion. SGLT1 protein expression in STC-1 cells cultured in 5.6 mM glucose is higher than that in 25 mM glucose. Exposure to 3DG for 6 h reduced GLP-1 secretion, SGLT1 protein expression, and intracellular concentrations of cAMP and Ca²⁺.

CONCLUSIONS

3DG reduces low glucose-induced GLP-1 secretion in part through reduction of SGLT1 expression.

Effect of biochanin A on the rumen microbial community of Holstein steers consuming a high fiber diet and subjected to a subacute acidosis challenge

Subacute rumen acidosis (SARA) occurs when highly fermentable carbohydrates are introduced into the diet, decreasing pH and disturbing the microbial ecology of the rumen. Rumen amylolytic bacteria rapidly catabolize starch, fermentation acids accumulate in the rumen and reduce environmental pH. Historically, antibiotics (e.g., monensin, MON) have been used in the prevention and treatment of SARA. Biochanin A (BCA), an isoflavone produced by red clover (Trifolium pratense), mitigates changes associated with starch fermentation ex vivo. The objective of the study was to determine the effect of BCA on amylolytic bacteria and rumen pH during a SARA challenge. Twelve rumen fistulated steers were assigned to 1 of 4 treatments: HF CON (high fiber control), SARA CON, MON (200 mg d^-1), or BCA (6 g d^-1). The basal diet consisted of corn silage and dried distiller’s grains ad libitum. The study consisted of a 2-wk adaptation, a 1-wk HF period, and an 8-d SARA challenge (d 1–4: 40% corn; d 5–8: 70% cracked corn). Samples for pH and enumeration were taken on the last day of each period (4 h). Amylolytic, cellulolytic, and amino acid/peptide-fermenting bacteria (APB) were enumerated. Enumeration data were normalized by log transformation and data were analyzed by repeated measures ANOVA using the MIXED procedure of SAS. The SARA challenge increased total amylolytics and APB, but decreased pH, cellulolytics, and in situ DMD of hay (P < 0.05). BCA treatment counteracted the pH, microbiological, and fermentative changes associated with SARA challenge (P < 0.05). Similar results were also observed with MON (P < 0.05). These results indicate that BCA may be an effective alternative to antibiotics for mitigating SARA in cattle production systems.

Inhibition of AXL enhances chemosensitivity of human ovarian cancer cells to cisplatin via decreasing glycolysis

Anexelekto (AXL), a member of the TYRO3-AXL-MER (TAM) family of receptor tyrosine kinases (RTK), is overexpressed in varieties of tumor tissues and promotes tumor development by regulating cell proliferation, migration and invasion. In this study, we investigated the role of AXL in regulating glycolysis in human ovarian cancer (OvCa) cells. We showed that the expression of AXL mRNA and protein was significantly higher in OvCa tissue than that in normal ovarian epithelial tissue. In human OvCa cell lines suppression of AXL significantly inhibited cell proliferation, and increased the sensitivity of OvCa cells to cisplatin, which also proved by nude mice tumor formation experiment. KEGG analysis showed that AXL was significantly enriched in the glycolysis pathways of cancer. Changes in AXL expression in OvCa cells affect tumor glycolysis. We demonstrated that the promotion effect of AXL on glycolysis was mediated by phosphorylating the M2 isoform of pyruvate kinase (PKM2) at Y105. AXL expression was significantly higher in cisplatin-resistant OvCa cells A2780/DDP compared with the parental A2780 cells. Inhibition of AXL decreased the level of glycolysis in A2780/DDP cells, and increased the cytotoxicity of cisplatin against A2780/DDP cells, suggesting that AXL-mediated glycolysis was associated with cisplatin resistance in OvCa. In conclusion, this study demonstrates for the first time that AXL is involved in the regulation of the Warburg effect. Our results not only highlight the clinical value of targeting AXL, but also provide theoretical basis for the combination of AXL inhibitor and cisplatin in the treatment of OvCa.

Inhibiting glycolysis rescues memory impairment in an intellectual disability Gdi1-null mouse

OBJECTIVES

GDI1 gene encodes for αGDI, a protein controlling the cycling of small GTPases, reputed to orchestrate vesicle trafficking. Mutations in human GDI1 are responsible for intellectual disability (ID). In mice with ablated Gdi1, a model of ID, impaired working and associative short-term memory was recorded. This cognitive phenotype worsens if the deletion of αGDI expression is restricted to neurons. However, whether astrocytes, key homeostasis providing neuroglial cells, supporting neurons via aerobic glycolysis, contribute to this cognitive impairment is unclear.

METHODS

We carried out proteomic analysis and monitored [¹⁸F]-fluoro-2-deoxy-d-glucose uptake into brain slices of Gdi1 knockout and wild type control mice. d-Glucose utilization at single astrocyte level was measured by the Förster Resonance Energy Transfer (FRET)-based measurements of cytosolic cyclic AMP, d-glucose and L-lactate, evoked by agonists selective for noradrenaline and L-lactate receptors. To test the role of astrocyte-resident processes in disease phenotype, we generated an inducible Gdi1 knockout mouse carrying the Gdi1 deletion only in adult astrocytes and conducted behavioural tests.

RESULTS

Proteomic analysis revealed significant changes in astrocyte-resident glycolytic enzymes. Imaging [¹⁸F]-fluoro-2-deoxy-d-glucose revealed an increased d-glucose uptake in Gdi1 knockout tissue versus wild type control mice, consistent with the facilitated d-glucose uptake determined by FRET measurements. In mice with Gdi1 deletion restricted to astrocytes, a selective and significant impairment in working memory was recorded, which was rescued by inhibiting glycolysis by 2-deoxy-d-glucose injection.

CONCLUSIONS

These results reveal a new astrocyte-based mechanism in neurodevelopmental disorders and open a novel therapeutic opportunity of targeting aerobic glycolysis, advocating a change in clinical practice.

A Multi-Omics Study Revealing the Metabolic Effects of Estrogen in Liver Cancer Cells HepG2

Hepatocellular carcinoma (HCC) that is triggered by metabolic defects is one of the most malignant liver cancers. A much higher incidence of HCC among men than women suggests the protective roles of estrogen in HCC development and progression. To begin to understand the mechanisms involving estrogenic metabolic effects, we compared cell number, viability, cytotoxicity, and apoptosis among HCC-derived HepG2 cells that were treated with different concentrations of 2-deoxy-d-glucose (2-DG) that blocks glucose metabolism, oxamate that inhibits lactate dehydrogenase and glycolysis, or oligomycin that blocks ATP synthesis and mitochondrial oxidative phosphorylation. We confirmed that HepG2 cells primarily utilized glycolysis followed by lactate fermentation, instead of mitochondrial oxidative phosphorylation, for cell growth. We hypothesized that estrogen altered energy metabolism via its receptors to carry out its anticancer effects in HepG2 cells. We treated cells with 17β-estradiol (E2), 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT) an estrogen receptor (ER) α (ERα) agonist, or 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), an ERβ agonist. We then used transcriptomic and metabolomic analyses and identified differentially expressed genes and unique metabolite fingerprints that are produced by each treatment. We further performed integrated multi-omics analysis, and identified key genes and metabolites in the gene–metabolite interaction contributed by E2 and ER agonists. This integrated transcriptomic and metabolomic study suggested that estrogen acts on estrogen receptors to suppress liver cancer cell growth via altering metabolism. This is the first exploratory study that comprehensively investigated estrogen and its receptors, and their roles in regulating gene expression, metabolites, metabolic pathways, and gene–metabolite interaction in HCC cells using bioinformatic tools. Overall, this study provides potential therapeutic targets for future HCC treatment.

Structural and functional remodeling of mitochondria as an adaptive response to energy deprivation

Cancer cells bioenergetics is more dependent on glycolysis than mitochondrial oxidative phosphorylation, a phenomenon known as the Warburg Effect. It has been proposed that inhibition of glycolysis may selectively affect cancer cells. However, the effects of glycolysis inhibition on mitochondrial function and structure in cancer cells are not completely understood. Here, we investigated the comparative effects of 2-deoxy-d-glucose (2-DG, a glucose analogue, which suppresses cellular glycolysis) on cellular bioenergetics in human colon cancer DLD-1 cells, smooth muscle cells, human umbilical vein endothelial cells and HL-1 cardiomyocytes. In all cells, 2-DG treatment resulted in significant ATP depletion, however, the cell viability remained unchanged. Also, we did not observe the synergistic effects of 2-DG with anticancer drugs doxorubicin and 5-fluorouracil. Instead, after 2-DG treatment and ATP depletion, mitochondrial respiration and membrane potential were significantly enhanced and mitochondrial morphology changed in the direction of more network organization. Analysis of protein expression demonstrated that 2-DG treatment induced an activation of AMPK (elevated pAMPK/AMPK ratio), increased mitochondrial fusion (mitofusins 1 and 2) and decreased fission (Drp1) proteins. In conclusion, this study suggests a strong link between respiratory function and structural organization of mitochondria in the cell. We propose that the functionality of the mitochondrial network is enhanced compared to disconnected mitochondria.

Neuromodulation or energy failure? Metabolic limitations silence network output in the hypoxic amphibian brainstem

Hypoxia tolerance in the vertebrate brain often involves chemical modulators that arrest neuronal activity to conserve energy. However, in intact networks, it can be difficult to determine whether hypoxia triggers modulators to stop activity in a protective manner or whether activity stops because rates of ATP synthesis are insufficient to support network function. Here, we assessed the extent to which neuromodulation or metabolic limitations arrest activity in the respiratory network of bullfrogs-a circuit that survives moderate periods of oxygen deprivation, presumably, by activating an inhibitory noradrenergic pathway. We confirmed that hypoxia and norepinephrine (NE) reduce network output, consistent with the view that hypoxia may cause the release of NE to inhibit activity. However, these responses differed qualitatively; hypoxia, but not NE, elicited a large motor burst and silenced the network. The stereotyped response to hypoxia persisted in the presence of both NE and an adrenergic receptor blocker that eliminates sensitivity to NE, indicating that noradrenergic signaling does not cause the arrest. Pharmacological inhibition of glycolysis and mitochondrial respiration recapitulated all features of hypoxia on network activity, implying that reduced ATP synthesis underlies the effects of hypoxia. Finally, activating modulatory mechanisms that dampen neuronal excitability when ATP levels fall, KATP channels and AMP-dependent protein kinase, did not resemble the hypoxic response. These results suggest that energy failure-rather than inhibitory modulation-silences the respiratory network during hypoxia and emphasize the need to account for metabolic limitations before concluding that modulators arrest activity as an adaptation for energy conservation in the nervous system.

Effect of 2-deoxyglucose-mediated inhibition of glycolysis on the regulation of mTOR signaling and protein synthesis before and after high-intensity muscle contraction

BACKGROUND

Glycolysis controls mTORC1 signaling and protein synthesis. In skeletal muscle, glucose metabolism increases with both exercise/contraction intensity and volume, and therefore, high-intensity muscle contraction (HiMC) such as resistance exercise facilitates glycolysis including glucose uptake and glycogen breakdown. However, it is unknown whether glycolysis regulates HiMC-induced mTORC1 activation and increase in protein synthesis.

METHODS

To determine whether glycolysis regulates basal and HiMC-induced mTORC1 signaling and protein synthesis, we employed 2-deoxyglucose (2-DG) to inhibit glycolysis and isometrically contracted the gastrocnemius muscle of Sprague Dawley rats using percutaneous electrical stimulation.

RESULTS

Inhibition of glycolysis by 2-DG inhibited basal phosphorylation of p70S6K and 4E-BP1 (downstream targets of mTORC1) and protein synthesis (all P < 0.05) independent of AMPK phosphorylation. AMPK phosphorylation was comparably increased after HiMC at 0 h post HiMC and returned to basal levels 6 h post HiMC in both vehicle- and 2-DG-treated groups. Glycolysis inhibition attenuated muscle contraction-induced phosphorylation of 4E-BP1 at 6 h post HiMC (P < 0.05) but not p70S6K phosphorylation and protein synthesis.

CONCLUSION

Although glycolysis is involved in basal but not HiMC-induced muscle protein synthesis, it regulates both basal and HiMC-induced mTORC1 signaling, and may play key roles in skeletal muscle adaptation to HiMC.

Profiling and Targeting of Energy and Redox Metabolism in Grade 2 Bladder Cancer Cells with Different Invasiveness Properties

Bladder cancer is one of the most prevalent deadly diseases worldwide. Grade 2 tumors represent a good window of therapeutic intervention, whose optimization requires high resolution biomarker identification. Here we characterize energy metabolism and cellular properties associated with spreading and tumor progression of RT112 and 5637, two Grade 2 cancer cell lines derived from human bladder, representative of luminal-like and basal-like tumors, respectively. The two cell lines have similar proliferation rates, but only 5637 cells show efficient lateral migration. In contrast, RT112 cells are more prone to form spheroids. RT112 cells produce more ATP by glycolysis and OXPHOS, present overall higher metabolic plasticity and are less sensitive than 5637 to nutritional perturbation of cell proliferation and migration induced by treatment with 2-deoxyglucose and metformin. On the contrary, spheroid formation is less sensitive to metabolic perturbations in 5637 than RT112 cells. The ability of metformin to reduce, although with different efficiency, cell proliferation, sphere formation and migration in both cell lines, suggests that OXPHOS targeting could be an effective strategy to reduce the invasiveness of Grade 2 bladder cancer cells.

2-Deoxy-d-glucose Promotes Buforin IIb-Induced Cytotoxicity in Prostate Cancer DU145 Cells and Xenograft Tumors

Inhibition of the glycolytic pathway is a critical strategy in anticancer therapy because of the role of aerobic glycolysis in cancer cells. The glycolytic inhibitor 2-Deoxy-d-glucose (2-DG) has shown potential in combination with other anticancer agents. Buforin IIb is an effective antimicrobial peptide (AMP) with broad-spectrum anticancer activity and selectivity. The efficacy of combination treatment with 2-DG and buforin IIb in prostate cancer remains unknown. Here, we tested the efficacy of buforin IIb as a mitochondria-targeting AMP in the androgen-independent human prostate cancer cell line DU145. Combining 2-DG with buforin IIb had a synergistic toxic effect on DU145 cells and mouse xenograft tumors. Combination treatment with 2-DG and buforin IIb caused stronger proliferation inhibition, greater G1 cell cycle arrest, and higher apoptosis than either treatment alone. Combination treatment dramatically decreased L-lactate production and intracellular ATP levels, indicating severe inhibition of glycolysis and ATP production. Flow cytometry and confocal laser scanning microscopy results indicate that 2-DG may increase buforin IIb uptake by DU145 cells, thereby increasing the mitochondria-targeting capacity of buforin IIb. This may partly explain the effect of combination treatment on enhancing buforin IIb-induced apoptosis. Consistently, 2-DG increased mitochondrial dysfunction and upregulated Bax/Bcl-2, promoting cytochrome c release to initiate procaspase 3 cleavage induced by buforin IIb. These results suggest that 2-DG sensitizes prostate cancer DU145 cells to buforin IIb. Moreover, combination treatment caused minimal hemolysis and cytotoxicity to normal WPMY-1 cells. Collectively, the current study demonstrates that dual targeting of glycolysis and mitochondria by 2-DG and buforin IIb may be an effective anticancer strategy for the treatment of some advanced prostate cancer.

Repeated Pharmacogenetic Catecholamine Neuron Activation in the Ventrolateral Medulla Attenuates Subsequent Glucoregulatory Responses

Hindbrain catecholamine (CA) neurons are essential for elicitation of protective counterregulatory responses (CRRs) to glucose deficit, including increased feeding and elevation of circulating corticosterone, epinephrine, and glucose. Severe or repeated antecedent glucoprivation results in attenuation of these CRRs and failure to correct glucose deficit, constituting a potentially lethal condition known as hypoglycemia-associated autonomic failure (HAAF) that may occur in patients with diabetes on insulin therapy. Recently, we demonstrated that selective pharmacogenetic activation of CA neuron subpopulations in the ventrolateral medulla during normoglycemia elicits these CRRs in a site-specific manner. In the present experiment, we examined the effect of repeated pharmacogenetic activation of CA neurons in the A1/C1 cell group on subsequent elicitation of feeding, corticosterone secretion, and respiratory quotient. We found that this prior treatment attenuated these responses to subsequent pharmacogenetic stimulation, similar to attenuation of these CRRs following repeated antecedent glucoprivation. This suggests that functional impairment of A1/C1 CA neurons resulting from antecedent glucoprivation may account, at least in part, for impairment of specific CRRs critical for restoration of normoglycemia in response to glucose deficit. Thus, a pharmacogenetic approach to selective activation of key neural circuits could provide a means of identifying neuropathogenic mechanisms contributing to HAAF.

Mitochondria-derived ATP participates in the formation of neutrophil extracellular traps induced by platelet-activating factor through purinergic signaling in cows

Neutrophil extracellular trap (NET) formation eliminates/prevents the spread of infectious agents. Platelet activating factor (PAF) is involved in infectious diseases of cattle because it recruits and activates neutrophils. However, its ability to induce NET release and the role of metabolism in this process is not known. We investigated if inhibition of glycolysis, mitochondrial-derived adenosine triphosphate (ATP) synthesis and purinergic signaling though P2X₁ purinoceptors interfered with NET formation induced by PAF. We inhibited bovine neutrophils with 2-deoxy-d-glucose, rotenone, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and NF449 to evaluate PAF-mediated NET extrusion. PAF induced mitochondrial hyperpolarization and triggered extracellular ATP release via pannexin-1. Inhibition of mitochondrial metabolism prevented extracellular ATP release. Inhibition of glycolysis, complex-I activity and oxidative phosphorylation prevented NET formation induced by PAF. Inhibition of P2X₁ purinergic receptors inhibited mitochondrial hyperpolarization and NET formation. We concluded that PAF-induced NET release is dependent upon glycolysis, mitochondrial ATP synthesis and purinergic signaling.

Cisplatin-Induced Giant Cells Formation Is Involved in Chemoresistance of Melanoma Cells

Melanoma is notoriously resistant to current cancer therapy. However, the chemoresistance mechanism of melanoma remains unclear. The present study unveiled that chemotherapy drug cisplatin induced the formation of giant cells, which exhibited enlargement in cell diameter and nucleus in mice and human melanoma cells. Giant cells were positive with melanoma maker S100 and cancer stem cell markers including ABCB5 and CD133 in vitro and in vivo. Moreover, giant cells retained the mitotic ability with expression of proliferation marker Ki-67 and exhibited multiple drug resistance to doxorubicin and actinomycin D. The mitochondria genesis/activities and cellular ATP level were significantly elevated in giant cells, implicating the demand for energy supply. Application of metabolic blockers such as sodium azide or 2-deoxy glucose abolished the cisplatin-induced giant cells formation and expression of cancer stemness markers. The present study unveils a novel chemoresistance mechanism of melanoma cells via size alteration and the anti-neoplastic strategy by targeting giant cells.

Influence of the reporter vector backbone on 2-deoxyglucose dependent promoter activation

Reporter vectors are very often used to investigate mechanisms responsible for regulation of promoter activity. Since their first generation, many new variants were constructed to increase sensitivity and reduce background signal. However, these tools are still imperfect and can generate false results. We have found that depending on the backbone of the reporter vector, pGL3 or pGL2, different results are obtained for a eukaryotic promoter's activation by metabolic changes. These observations were done in the course of investigation of the MMP2 (matrix metalloproteinase-2) promoter regulation in response to inhibition of glycolysis.

Cytoprotective effects of a proprietary red maple leaf extract and its major polyphenol, ginnalin A, against hydrogen peroxide and methylglyoxal induced oxidative stress in human keratinocytes

Phytochemicals from functional foods are common ingredients in dietary supplements and cosmetic products for anti-skin aging effects due to their antioxidant activities. A proprietary red maple (Acer rubrum) leaf extract (Maplifa™) and its major phenolic compound, ginnalin A (GA), have been reported to show antioxidant, anti-melanogenesis, and anti-glycation effects but their protective effects against oxidative stress in human skin cells remain unknown. Herein, we investigated the cytoprotective effects of Maplifa™ and GA against hydrogen peroxide (H2O2) and methylglyoxal (MGO)-induced oxidative stress in human keratinocytes (HaCaT cells). H2O2 and MGO (both at 400 μM) induced toxicity in HaCaT cells and reduced their viability to 59.2 and 61.6%, respectively. Treatment of Maplifa™ (50 μg mL-1) and GA (50 μM) increased the viability of H2O2- and MGO-treated cells by 22.0 and 15.5%, respectively. Maplifa™ and GA also showed cytoprotective effects by reducing H2O2-induced apoptosis in HaCaT cells by 8.0 and 7.2%, respectively. The anti-apoptotic effect of Maplifa™ was further supported by the decreased levels of apoptosis associated enzymes including caspases-3/7 and -8 in HaCaT cells by 49.5 and 19.0%, respectively. In addition, Maplifa™ (50 μg mL-1) and GA (50 μM) reduced H2O2- and MGO-induced reactive oxygen species (ROS) by 84.1 and 56.8%, respectively. Furthermore, flow cytometry analysis showed that Maplifa™ and GA reduced MGO-induced total cellular ROS production while increasing mitochondria-derived ROS production in HaCaT cells. The cytoprotective effects of Maplifa™ and GA in human keratinocytes support their potential utilization for cosmetic and/or dermatological applications.

Human herpesvirus 6A promotes glycolysis in infected T cells by activation of mTOR signaling

Human herpesvirus 6 (HHV-6) is an important immunosuppressive and immunomodulatory virus worldwide. However, whether and how HHV-6 infection influences the metabolic machinery of the host cell to provide the energy and biosynthetic resources for virus propagation remains unknown. In this study, we identified that HHV-6A infection promotes glucose metabolism in infected T cells, resulting in elevated glycolytic activity with an increase of glucose uptake, glucose consumption and lactate secretion. Furthermore, we explored the mechanisms involved in HHV-6A-mediated glycolytic activation in the infected T cells. We found increased expressions of the key glucose transporters and glycolytic enzymes in HHV-6A-infected T cells. In addition, HHV-6A infection dramatically activated AKT-mTORC1 signaling in the infected T cells and pharmacological inhibition of mTORC1 blocked HHV-6A-mediated glycolytic activation. We also found that direct inhibition of glycolysis by 2-Deoxy-D-glucose (2-DG) or inhibition of mTORC1 activity in HHV-6A-infected T cells effectively reduced HHV-6 DNA replication, protein synthesis and virion production. These results not only reveal the mechanism of how HHV-6 infection affects host cell metabolism, but also suggest that targeting the metabolic pathway could be a new avenue for HHV-6 therapy.

Targeting Cellular Metabolism in Acute Myeloid Leukemia and The Role of Patient Heterogeneity

Acute myeloid leukemia (AML) is an aggressive blood cancer resulting in accumulation of immature, dysfunctional blood cells in the bone marrow. Changes in cell metabolism are features of many cancers, including AML and this may be exploited as a therapeutic target. In this study we investigated the in vitro antileukemic effects of seven metabolic inhibitors that target different metabolic pathways. The metabolic inhibitors were tested on AML cells derived from 81 patients using proliferation and viability assays; we also compared global gene expression and proteomic profiles for various patient subsets. Metformin, 2DG, 6AN, BPTES and ST1326 had strong antiproliferative and proapoptotic effects for most patients, whereas lonidamine and AZD3965 had an effect only for a minority. Antiproliferative effects on AML cells were additive when combined with the chemotherapeutic agent AraC. Using unsupervised hierarchical clustering, we identified a strong antiproliferative effect on AML cells after treatment with metabolic inhibitors for a subset of 29 patients. Gene expression and proteomic studies suggested that this subset was characterized by altered metabolic and transcriptional regulation. In addition, the Bcl-2 inhibitor venetoclax, in combination with 2DG or 6AN, increased the antiproliferative effects of these metabolic inhibitors on AML cells. Therapeutic targeting of cellular metabolism may have potential in AML, but the optimal strategy will likely differ between patients.

Oleanane Triterpenoids from the Leaves of Gymnema inodorum and Their Insulin Mimetic Activities

During an effort to find insulin mimetic compounds, the leaves of Gymnema inodorum were shown to have a stimulatory effect on glucose uptake in 3T3-L1 adipocyte cells. Bioassay-guided fractionation on a 70% ethanol extract of G. inodorum was applied to yield two new (1 and 2) and two known (8 and 9) oleanane triterpenoids with a methyl anthranilate moiety together with five further new oleanane triterpenoids (3-7). The chemical structures of all isolates were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis. The isolated compounds (1-9) were determined for their stimulatory activities on glucose uptake in differentiated 3T3-L1 adipocyte cells using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a fluorescent-tagged glucose probe. Three compounds (3, 5, and 9) showed stimulatory effects on the uptake of 2-NBDG in 3T3-L1 adipocyte cells. Chemicals with a methyl anthranilate moiety have been considered as crucial contributors of flavor odor in foods, and quantitative analysis showed the content of compound 8 to be 0.90 ± 0.01 mg/g of the total extract. These results suggest that the leaves of G. inodorum have the potential to be used as an antidiabetic functional food or tea.

KMT2D Deficiency Impairs Super-Enhancers to Confer a Glycolytic Vulnerability in Lung Cancer

Epigenetic modifiers frequently harbor loss-of-function mutations in lung cancer, but their tumor-suppressive roles are poorly characterized. Histone methyltransferase KMT2D (a COMPASS-like enzyme, also called MLL4) is among the most highly inactivated epigenetic modifiers in lung cancer. Here, we show that lung-specific loss of Kmt2d promotes lung tumorigenesis in mice and upregulates pro-tumorigenic programs, including glycolysis. Pharmacological inhibition of glycolysis preferentially impedes tumorigenicity of human lung cancer cells bearing KMT2D-inactivating mutations. Mechanistically, Kmt2d loss widely impairs epigenomic signals for super-enhancers/enhancers, including the super-enhancer for the circadian rhythm repressor Per2. Loss of Kmt2d decreases expression of PER2, which regulates multiple glycolytic genes. These findings indicate that KMT2D is a lung tumor suppressor and that KMT2D deficiency confers a therapeutic vulnerability to glycolytic inhibitors.

Dual metabolic reprogramming by ONC201/TIC10 and 2-Deoxyglucose induces energy depletion and synergistic anti-cancer activity in glioblastoma

BACKGROUND

Dysregulation of the metabolome is a hallmark of primary brain malignancies. In this work we examined whether metabolic reprogramming through a multi-targeting approach causes enhanced anti-cancer activity in glioblastoma.

METHODS

Preclinical testing of a combined treatment with ONC201/TIC10 and 2-Deoxyglucose was performed in established and primary-cultured glioblastoma cells. Extracellular flux analysis was used to determine real-time effects on OXPHOS and glycolysis. Respiratory chain complexes were analysed by western blotting. Biological effects on tumour formation were tested on the chorioallantoic membrane (CAM).

RESULTS

ONC201/TIC10 impairs mitochondrial respiration accompanied by an increase of glycolysis. When combined with 2-Deoxyglucose, ONC201/TIC10 induces a state of energy depletion as outlined by a significant decrease in ATP levels and a hypo-phosphorylative state. As a result, synergistic anti-proliferative and anti-migratory effects were observed among a broad panel of different glioblastoma cells. In addition, this combinatorial approach significantly impaired tumour formation on the CAM.

CONCLUSION

Treatment with ONC201/TIC10 and 2-Deoxyglucose results in a dual metabolic reprogramming of glioblastoma cells resulting in a synergistic anti-neoplastic activity. Given, that both agents penetrate the blood-brain barrier and have been used in clinical trials with a good safety profile warrants further clinical evaluation of this therapeutic strategy.

Tributyltin chloride (TBT) induces RXRA down-regulation and lipid accumulation in human liver cells

A subset of environmental chemicals acts as "obesogens" as they increase adipose mass and lipid content in livers of treated rodents. One of the most studied class of obesogens are the tin-containing chemicals that have as a central moiety tributyltin (TBT), which bind and activate two nuclear hormone receptors, Peroxisome Proliferator Activated Receptor Gamma (PPARG) and Retinoid X Receptor Alpha (RXRA), at nanomolar concentrations. Here, we have tested whether TBT chloride at such concentrations may affect the neutral lipid level in two cell line models of human liver. Indeed, using high content image analysis (HCA), TBT significantly increased neutral lipid content in a time- and concentration-dependent manner. Consistent with the observed increased lipid accumulation, RNA fluorescence in situ hybridization (RNA FISH) and RT-qPCR experiments revealed that TBT enhanced the steady-state mRNA levels of two key genes for de novo lipogenesis, the transcription factor SREBF1 and its downstream enzymatic target, FASN. Importantly, pre-treatment of cells with 2-deoxy-D-glucose reduced TBT-mediated lipid accumulation, thereby suggesting a role for active glycolysis during the process of lipid accumulation. As other RXRA binding ligands can promote RXRA protein turnover via the 26S proteasome, TBT was tested for such an effect in the two liver cell lines. We found that TBT, in a time- and dose-dependent manner, significantly reduced steady-state RXRA levels in a proteasome-dependent manner. While TBT promotes both RXRA protein turnover and lipid accumulation, we found no correlation between these two events at the single cell level, thereby suggesting an additional mechanism may be involved in TBT promotion of lipid accumulation, such as glycolysis.

Sonodynamic Therapy Combined to 2-Deoxyglucose Potentiate Cell Metastasis Inhibition of Breast Cancer

Metastasis is a major dilemma of cancer therapy. It frequently occurs in breast cancer, which is the leading form of malignant tumor among females worldwide. Although there are therapies that provide a possible method for this challenge, such as chemotherapy, the tumoral metabolic pathway is unconventional and favors metastasis and proliferation. This magnifies the difficulty of treating breast cancer. In this study, we identified 2-deoxyglucose (2 DG) as an important glycolysis suppressor that can potentiate sonodynamic therapy (SDT) to inhibit migration and invasion. In addition, disruptions of the cell membrane microstructure were captured by a scanning electron microscope in cells treated with the co-therapy. Similarly, we detected blockages of the cell cycle process, using flow cytometry. Of note, we observed that hexokinase II (HK2), the rate-limiting enzyme of glycolysis, was notably uncoupled from the mitochondria in SDT + 2 DG co-therapy group. Furthermore, there was altered expression of HK2 and Glut1, which control glycolysis. Simultaneously, the in vivo results revealed that pulmonary metastasis was also seriously suppressed by SDT + 2 DG co-therapy. These results demonstrate this co-therapy is a promising strategy for breast cancer inhibition through metastasis and proliferation.