Increase In Aerobic Glycolysis Research Articles

Immunometabolic rewiring in macrophages for periodontitis treatment via nanoquercetin-mediated leverage of glycolysis and OXPHOS

Periodontitis is a chronic inflammatory disease marked by a dysregulated immune microenvironment, posing formidable challenges for effective treatment. The disease is characterized by an altered glucose metabolism in macrophages, specifically an increase in aerobic glycolysis, which is linked to heightened inflammatory responses. This suggests that targeting macrophage metabolism could offer a new therapeutic avenue. In this study, we developed an immunometabolic intervention using quercetin (Q) encapsulated in bioadhesive mesoporous polydopamine (Q@MPDA) to treat periodontitis. Our results demonstrated that Q@MPDA could reprogram inflammatory macrophages to an anti-inflammatory phenotype (i.e., from-M1-to-M2 repolarization). In a murine periodontitis model, locally administered Q@MPDA reduced the presence of inflammatory macrophages, and decreased the levels of inflammatory cytokines (IL-1β and TNF-α) and reactive oxygen species (ROS) in the periodontium. Consequently, it alleviated periodontitis symptoms, reduced alveolar bone loss, and promoted tissue repair. Furthermore, our study revealed that Q@MPDA could inhibit the glycolysis of inflammatory macrophages while enhancing oxidative phosphorylation (OXPHOS), facilitating the shift from M1 to M2 macrophage subtype. Our findings suggest that Q@MPDA is a promising treatment for periodontitis via immunometabolic rewiring.

Characterization of an in vitro model to study CD4+ T cells metabolism in dairy cows

Dairy cows are susceptible to several health disorders throughout their lactation. Objectives were to characterize an in vitro model to study bioenergetic measures in CD4+ T lymphocytes in dairy cows. Twenty-four healthy mid-lactating multiparous Holstein dairy cows were enrolled at a mean (±standard deviation) of 234 ± 22 d in milk (DIM). Cows were blocked according to DIM and blood was collected to isolate peripheral blood mononuclear cells followed by magnetic separation of CD4+ T lymphocytes using bovine specific monoclonal antibodies. The isolated CD4+ T lymphocytes from each cow were split into 2 tubes and randomly assigned to incubate in an assay medium as control (CON) or with a combination of phorbol myristate acetate and ionomycin (PMA+IMY) to evaluate metabolic function under resting and activated state. Mitochondrial and glycolytic functional kinetics were recorded in CD4+ T lymphocytes based on real-time measurement of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) under basal conditions and in response to complex V inhibitor (oligomycin), a protonophore uncoupler (BAM 15), and complex I and complex III inhibitors (rotenone and antimycin A). The mean (±SD) viability and purity of CD4+ T lymphocytes was 92.5 ± 2.9% and 95.2 ± 2.9%, respectively. The basal OCR in CD4+ T lymphocytes treated with PMA+IMY was greater than CON; nevertheless, the maximal respiration rate (CON = 58.0 vs. PMA+IMY = 47.3 ± 5.7 pmol/min) and sparing respiratory capacity rate (CON = 42.0 vs. PMA+IMY = 28.7 ± 4.2 pmol/min) were decreased in activated CD4+ T lymphocytes. The ECAR in CD4+ T lymphocytes increased progressively over time in PMA+IMY compared with CON, which indicated an increase in aerobic glycolysis in PMA+IMY compared with CON (CON = 46.9 vs. PMA+IMY = 86.4 ± 7.0 pmol/min). Activated CD4+ T lymphocytes exhibit a metabolic switch from oxidative phosphorylation to aerobic glycolysis, which may support rapid cell proliferation. The results observed in this experiment demonstrate the sensitivity of the technique to detect changes in metabolic function under different cellular conditions, providing a robust framework to study immuno-metabolism in dairy cattle.

PDK4-dependent hypercatabolism and lactate production of senescent cells promotes cancer malignancy

Senescent cells remain metabolically active, but their metabolic landscape and resulting implications remain underexplored. Here, we report upregulation of pyruvate dehydrogenase kinase 4 (PDK4) upon senescence, particularly in some stromal cell lines. Senescent cells display a PDK4-dependent increase in aerobic glycolysis and enhanced lactate production but maintain mitochondrial respiration and redox activity, thus adopting a special form of metabolic reprogramming. Medium from PDK4+ stromal cells promotes the malignancy of recipient cancer cells in vitro, whereas inhibition of PDK4 causes tumor regression in vivo. We find that lactate promotes reactive oxygen species production via NOX1 to drive the senescence-associated secretory phenotype, whereas PDK4 suppression reduces DNA damage severity and restrains the senescence-associated secretory phenotype. In preclinical trials, PDK4 inhibition alleviates physical dysfunction and prevents age-associated frailty. Together, our study confirms the hypercatabolic nature of senescent cells and reveals a metabolic link between cellular senescence, lactate production, and possibly, age-related pathologies, including but not limited to cancer.

Особенности изменения взаимосвязей ключевых метаболических процессов у молодняка кур при трансовариальном введении глутатиона

It is known that the intensity of metabolic processes largely depends on the realization of their interrelationships, with a positive correlation with the growth, development and realization of productive qualities of the individual. It is important to note that it is impossible to increase the metabolic intensity against the background of depletion of antioxidant resources. Thus, the transovarian use of glutathione at optimal concentrations led to an increase in aerobic glycolysis and a tendency to activation of transamination enzymes, within reference values, intensification of mineral metabolism, which plays an important role in the maintenance of homeostasis. The fixed changes obviously were more positive for dynamically developing organism, as the received youngsters had not only higher viability during all period of embryogenesis, but also quality on a number of indicators. At the same time, it is important to note a fixed tendency to a certain depletion of protein and lipid metabolism in the absence of differences in body weight of the chickens from the experimental and control groups, which obviously points to the need for additional administration of glutathione at a later period of embryogenesis and requires further investigation. It is an important fact that the same trend was recorded when using the biostimulant in the embryogenesis of quail.

Aerobic glycolysis and tumor progression of hepatocellular carcinoma are mediated by ubiquitin of P53 K48-linked regulated by TRIM37

BackgroundHepatocellular carcinoma (HCC) is the most common primary liver cancer in the world. In malignant liver cancer, the increase of aerobic glycolysis indicates that the possibility of tumorigenesis is greatly enhanced. TRIM37 is a member of the TRIM family of proteins that possesses E3 ubiquitin ligase activity and has been implicated in the occurrence and prognosis of many different tumors. However, the stability of P53 plays an important role in preventing tumorigenesis. The mechanism by which TRIM37 regulates the stability of P53 through ubiquitin in the progression of hepatocellular carcinoma is still unclear. Materials and methodsReal-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were used to detect the expression of mRNA and protein in HCC cells. Lactic acid production, glucose uptake, and ATP levels were measured by BioVision kit. The following were used to assess the in vitro function of TRIM37 in HCC cells: cell counting kit-8 (CCK-8), colony formation assay, cell migration and invasion assay, and flow cytometry. We observed the effect of TRIM37 on the growth of transplanted tumors in nude mice. Co-Immunoprecipitation (Co-IP) revealed a binding relationship between TRIM37 and P53. ResultsThe expression of TRIM37 in hepatocellular carcinoma (HCC) tissues was higher than that of normal tissues according to an analysis of The Cancer Genome Atlas (TCGA) database.Loss-of-function assays indicated that TRIM37 inhibited the proliferation, colony formation, migration, and invasion of liver cancer cells. The mechanism is as follows: TRIM37 interacts with the P53 protein to induce E3 ligase activity, ubiquitination, and degradation, further promoting the malignant characteristics of hepatocellular carcinoma, thus promoting the process of glycolysis. Genetic knockdown of P53 reversed the promoting function of TRIM37 on the growth and metastasis of hepatocellular carcinoma cells. ConclusionsOur study showed that the TRIM37-P53 axis plays a role in the progression of liver cancer, and thus is a potential target for the treatment of liver cancer.

The effects of 1,25(OH)2D3 treatment on metabolic reprogramming and maturation in bone marrow-derived dendritic cells from control and diabetic mice

Activated dendritic cells (DCs) undergo significant metabolic reprogramming, which is characterized by an increase in aerobic glycolysis and a concurrent progressive loss of oxidative phosphorylation. The modulation of metabolic reprogramming is believed to be closely related to the function of DCs. Vitamin D has been reported to inhibit the maturation of DCs. DC dysfunction has been reported in diabetic patients, and hyperglycemia is associated with impaired glycolytic metabolism in immune cells. Therefore, vitamin D and diabetes may affect intracellular metabolism, thereby regulating the activity of DCs. We investigated the effect of in vitro treatment of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on metabolic reprogramming and maturation of bone marrow-derived dendritic cells (BMDCs) from diabetic mouse. Six-week-old male C57BLKS/J-m+/m+ mice (CON) and C57BLKS/J-db/db mice (db/db) were fed with a 10% kcal fat diet for seven weeks. BMDCs were generated by culturing bone marrow cells from the mice with rmGM-CSF (20 ng/mL) in the absence or presence of 10 nM 1,25(OH)2D3. The maturation of BMDCs was induced via lipopolysaccharide (LPS, 50 ng/mL) stimulation for 24 h. LPS stimulation induced iNOS protein expression and decreased the mitochondrial respiration, while increased lactate production and the expression of glycolytic pathway-related genes (Glut1 and Pfkfb3) in BMDCs from both CON and db/db groups. In LPS-stimulated mature BMDCs, 1,25(OH)2D3 treatment decreased the expression of surface markers related to immunostimulatory functions (MHC class II, CD80, CD86, and CD40) and production of IL-12p70 in both CON and db/db groups. While the mRNA level of the gene related to glucose uptake (Glut1) was increased in both groups, lactate production was decreased by 1,25(OH)2D3 treatment. mTORC1 activity was suppressed following 1,25(OH)2D3 treatment. Collectively, our findings confirmed that metabolic reprogramming occurred in BMDCs following LPS stimulation. In vitro 1,25(OH)2D3 treatment induced tolerogenic phenotypes by reducing the expression of surface markers, as well as cytokine production. However, no significant difference was observed regarding the effects of 1,25(OH)2D3 treatment on metabolic conversion and maturation of BMDCs between the control and diabetic mice. Additionally, the decreased aerobic glycolysis induced by the 1,25(OH)2D3 treatment appeared to be associated with the diminished maturation of BMDCs, and mTORC1 appears to play a key role in the 1,25(OH)2D3-mediated regulation of glycolysis.

Chronic Alcohol Exposure Promotes Cancer Stemness and Glycolysis in Oral/Oropharyngeal Squamous Cell Carcinoma Cell Lines by Activating NFAT Signaling.

Alcohol consumption is associated with an increased risk of several cancers, including oral/oropharyngeal squamous cell carcinoma (OSCC). Alcohol also enhances the progression and aggressiveness of existing cancers; however, its underlying molecular mechanism remains elusive. Especially, the local carcinogenic effects of alcohol on OSCC in closest contact with ingestion of alcohol are poorly understood. We demonstrated that chronic ethanol exposure to OSCC increased cancer stem cell (CSC) populations and their stemness features, including self-renewal capacity, expression of stem cell markers, ALDH activity, and migration ability. The ethanol exposure also led to a significant increase in aerobic glycolysis. Moreover, increased aerobic glycolytic activity was required to support the stemness phenotype of ethanol-exposed OSCC, suggesting a molecular coupling between cancer stemness and metabolic reprogramming. We further demonstrated that chronic ethanol exposure activated NFAT (nuclear factor of activated T cells) signaling in OSCC. Functional studies revealed that pharmacological and genetic inhibition of NFAT suppressed CSC phenotype and aerobic glycolysis in ethanol-exposed OSCC. Collectively, chronic ethanol exposure promotes cancer stemness and aerobic glycolysis via activation of NFAT signaling. Our study provides a novel insight into the roles of cancer stemness and metabolic reprogramming in the molecular mechanism of alcohol-mediated carcinogenesis.

PD43-03 MCT INHIBITION SYNERGIZES WITH TYROSINE KINASE AND MTOR INHIBITOR TREATMENT IN RENAL CELL CARCINOMA

You have accessJournal of UrologyCME1 May 2022PD43-03 MCT INHIBITION SYNERGIZES WITH TYROSINE KINASE AND MTOR INHIBITOR TREATMENT IN RENAL CELL CARCINOMA Bhaghyasree Jambunathan, Abdo Dergham, Sayani Bhattacharjee, Rebecca Wynn, Puneet Sindhwani, Firas Petros, and Nagalakshmi Nadiminty Bhaghyasree JambunathanBhaghyasree Jambunathan More articles by this author , Abdo DerghamAbdo Dergham More articles by this author , Sayani BhattacharjeeSayani Bhattacharjee More articles by this author , Rebecca WynnRebecca Wynn More articles by this author , Puneet SindhwaniPuneet Sindhwani More articles by this author , Firas PetrosFiras Petros More articles by this author , and Nagalakshmi NadimintyNagalakshmi Nadiminty More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002604.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: RCC has been recognized in recent years as a uniquely metabolic disease. All histologic types of RCC exhibit increase in aerobic glycolysis with disease progression. The TCGA-RCC study showed that high grade, high stage, and low survival are associated with a shift to aerobic glycolysis and a decrease in oxidative phosphorylation. Approaches targeting glucose metabolism in RCC such as GLUT1 inhibitors, hexokinase inhibitors, GAPDH inhibitor, and PKM2 inhibitor showed limited clinical benefit. Monocarboxylate transporters (MCTs) play a major role in the export/import of the glycolytic end-product lactate. Different MCT isoforms are differentially expressed in RCC tissues with an increase in the expression of MCT1 and MCT4 in clear-cell RCC and papillary RCC. Here we hypothesized that MCT inhibition may be an attractive therapeutic strategy against RCC cells. METHODS: We analyzed the expression levels of MCTs in RCC tissues using public datasets from Oncomine. We treated normal renal epithelial and renal cell carcinoma cells with varying concentrations of MCT inhibitors AR-C155858, AZD3965, or syrosingopine either singly or in combination with sunitinib or everolimus and assessed cell survival, cell viability, proliferation, clonogenic ability, survival in 3-D models, and glycolytic activity. We treated xenografts of ccRCC cells in mice with MCT inhibitors, sunitinib, or everolimus singly or in combination and assessed tumor growth. RESULTS: We found that the suppression of MCT activity using the MCT antagonists AR-C155858, AZD3965, or syrosingopine not only diminished the proliferation, survival, and clonogenic ability of RCC cells, but also potentiated the response of RCC cells to treatment with sunitinib or everolimus. MCT inhibitors inhibited the metabolic adaptation of ccRCC cells when treated with sunitinib or everolimus. Tumor growth of ccRCC xenografts was suppressed significantly when treated with a combination of MCT inhibitors with sunitinib or everolimus. These findings imply that MCT inhibition may be an effective strategy to develop combinatorial therapies in renal cell carcinoma. CONCLUSIONS: MCT inhibition may improve the anti-tumor effects of tyrosine kinase or mTOR inhibitors in renal cell carcinoma. Source of Funding: DoD-PCRP PC190332 (W81XWH2010794), University of Toledo College of Medicine and Life Sciences, NIH/NCI 1R21CA202404, NIH/NCI 1R03CA198696 © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e702 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bhaghyasree Jambunathan More articles by this author Abdo Dergham More articles by this author Sayani Bhattacharjee More articles by this author Rebecca Wynn More articles by this author Puneet Sindhwani More articles by this author Firas Petros More articles by this author Nagalakshmi Nadiminty More articles by this author Expand All Advertisement PDF DownloadLoading ...

新生児マウス心筋細胞におけるβアドレナリン受容体刺激による好気的解糖系の亢進

新生児マウス心筋細胞におけるβアドレナリン受容体刺激による好気的解糖系の亢進

Transforming growth factor beta-1 upregulates glucose transporter 1 and glycolysis through canonical and noncanonical pathways in hepatic stellate cells.

BACKGROUNDHepatic stellate cells (HSCs) are the key effector cells mediating the occurrence and development of liver fibrosis, while aerobic glycolysis is an important metabolic characteristic of HSC activation. Transforming growth factor-β1 (TGF-β1) induces aerobic glycolysis and is a driving factor for metabolic reprogramming. The occurrence of glycolysis depends on a high glucose uptake level. Glucose transporter 1 (GLUT1) is the most widely distributed glucose transporter in the body and mainly participates in the regulation of carbohydrate metabolism, thus affecting cell proliferation and growth. However, little is known about the relationship between TGF-β1 and GLUT1 in the process of liver fibrosis and the molecular mechanism underlying the promotion of aerobic glycolysis in HSCs.AIMTo investigate the mechanisms of action of GLUT1, TGF-β1 and aerobic glycolysis in the process of HSC activation during liver fibrosis.METHODSImmunohistochemical staining and immunofluorescence assays were used to examine GLUT1 expression in fibrotic liver tissue. A Seahorse extracellular flux (XF) analyzer was used to examine changes in aerobic glycolytic flux, lactate production levels and glucose consumption levels in HSCs upon TGF-β1 stimulation. The mechanism by which TGF-β1 induces GLUT1 protein expression in HSCs was further explored by inhibiting/promoting the TGF-β1/mothers-against-decapentaplegic-homolog 2/3 (Smad2/3) signaling pathway and inhibiting the p38 and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. In addition, GLUT1 expression was silenced to observe changes in the growth and proliferation of HSCs. Finally, a GLUT1 inhibitor was used to verify the in vivo effects of GLUT1 on a mouse model of liver fibrosis.RESULTSGLUT1 protein expression was increased in both mouse and human fibrotic liver tissues. In addition, immunofluorescence staining revealed colocalization of GLUT1 and alpha-smooth muscle actin proteins, indicating that GLUT1 expression was related to the development of liver fibrosis. TGF-β1 caused an increase in aerobic glycolysis in HSCs and induced GLUT1 expression in HSCs by activating the Smad, p38 MAPK and P13K/AKT signaling pathways. The p38 MAPK and Smad pathways synergistically affected the induction of GLUT1 expression. GLUT1 inhibition eliminated the effect of TGF-β1 on HSC proliferation and migration. A GLUT1 inhibitor was administered in a mouse model of liver fibrosis, and GLUT1 inhibition reduced the degree of liver inflammation and liver fibrosis.CONCLUSIONTGF-β1 induces GLUT1 expression in HSCs, a process related to liver fibrosis progression. In vitro experiments revealed that TGF-β1-induced GLUT1 expression might be one of the mechanisms mediating the metabolic reprogramming of HSCs. In addition, in vivo experiments also indicated that the GLUT1 protein promotes the occurrence and development of liver fibrosis.

APO\u03954 lowers energy expenditure in females and impairs glucose oxidation by increasing flux through aerobic glycolysis

BackgroundCerebral glucose hypometabolism is consistently observed in individuals with Alzheimer’s disease (AD), as well as in young cognitively normal carriers of the Ε4 allele of Apolipoprotein E (APOE), the strongest genetic predictor of late-onset AD. While this clinical feature has been described for over two decades, the mechanism underlying these changes in cerebral glucose metabolism remains a critical knowledge gap in the field.MethodsHere, we undertook a multi-omic approach by combining single-cell RNA sequencing (scRNAseq) and stable isotope resolved metabolomics (SIRM) to define a metabolic rewiring across astrocytes, brain tissue, mice, and human subjects expressing APOE4.ResultsSingle-cell analysis of brain tissue from mice expressing human APOE revealed E4-associated decreases in genes related to oxidative phosphorylation, particularly in astrocytes. This shift was confirmed on a metabolic level with isotopic tracing of 13C-glucose in E4 mice and astrocytes, which showed decreased pyruvate entry into the TCA cycle and increased lactate synthesis. Metabolic phenotyping of E4 astrocytes showed elevated glycolytic activity, decreased oxygen consumption, blunted oxidative flexibility, and a lower rate of glucose oxidation in the presence of lactate. Together, these cellular findings suggest an E4-associated increase in aerobic glycolysis (i.e. the Warburg effect). To test whether this phenomenon translated to APOE4 humans, we analyzed the plasma metabolome of young and middle-aged human participants with and without the Ε4 allele, and used indirect calorimetry to measure whole body oxygen consumption and energy expenditure. In line with data from E4-expressing female mice, a subgroup analysis revealed that young female E4 carriers showed a striking decrease in energy expenditure compared to non-carriers. This decrease in energy expenditure was primarily driven by a lower rate of oxygen consumption, and was exaggerated following a dietary glucose challenge. Further, the stunted oxygen consumption was accompanied by markedly increased lactate in the plasma of E4 carriers, and a pathway analysis of the plasma metabolome suggested an increase in aerobic glycolysis.ConclusionsTogether, these results suggest astrocyte, brain and system-level metabolic reprogramming in the presence of APOE4, a ‘Warburg like’ endophenotype that is observable in young females decades prior to clinically manifest AD.

Development of novel parameter for monitoring of malignant melanoma progression

ObjectiveIncreasing HIFs in malignant melanoma, the highly aggressive skin tumour, results in the stimulation of invasiveness. Increased HIF-1α fallouts in inhibition of the activity of some mitochondrial enzymes and leads to preference of cytosol energetic metabolism. Increase of aerobic glycolysis is reflected in an increase of free NADH (Warburg effect) and develops the malignant melanoma.Our goal was to find a link between hypoxia, or hypoxia mimicking factors and the stage of malignant melanoma. Furthermore, we focused on the finding of the experimental parameter which could monitor melanoma patients. Patients and methodsWe targeted HIF-1α gene expression and VDR rs2107301 gene polymorphism by PCR analysis. We detected the level of NADH in blood plasma by fluorescence spectroscopy (excitation and emission spectra). ResultsAnalysis of the obtained data from patient samples has shown an increase in HIF-1α which correlates with the disease stage. Investigation VDR rs2107301 polymorphism of patient samples does not show any significant changes in single nucleotide polymorphism, and the low vitamin D level in blood is not a result of VDR mutation in mitochondria. NADH levels vary under hypoxic and pseudohypoxic conditions and refer to the cancer stage. ConclusionsThe apparent mismatch between HIF-1α expression and NADH fluorescence has become the basis for the design of an algorithm for monitoring malignant melanoma based on the sensing of NADH fluorescence and the determination of HIF-1α.

Neuroinflammatory inhibition of synaptic long-term potentiation requires immunometabolic reprogramming of microglia.

Immunometabolism refers to the rearrangement of metabolic pathways in response to immune stimulation, and the ability of these metabolic pathways themselves to control immune functions. Many aspects of immunometabolism have been revealed through studies of peripheral immune cells. However, immunometabolic reprogramming of microglia, the resident immune cell of the central nervous system, and the consequential outcome on neuronal activity have remained difficult to unravel. Microglia are highly sensitive to subtle changes in their environment, limiting the techniques available to study their metabolic and inflammatory profiles. Here, using fluorescence lifetime imaging of endogenous NAD(P)H, we measure the metabolic activity of individual microglia within acute hippocampal slices. We observed an LPS-induced increase in aerobic glycolysis, which was blocked by the addition of 5 mM 2-deoxyglucose (2DG). This LPS-induced glycolysis in microglia was necessary for the stabilization of hypoxia inducible factor-1α (HIF-1α) and production of the proinflammatory cytokine, interleukin-1β (IL-1β). Upon release, IL-1β acted via the neuronal interleukin-1 receptor to inhibit the formation of synaptic long-term potentiation (LTP) following high frequency stimulation. Remarkably, the addition of 2DG to blunt the microglial glycolytic increase also inhibited HIF-1α accumulation and IL-1β production, and therefore rescued LTP in LPS-stimulated slices. Overall, these data reveal the importance of metabolic reprogramming in regulating microglial immune functions, with appreciable outcomes on cytokine release and neuronal activity.

Mitochondrial Derived Hydrogen Peroxide Results in an Increase in Aerobic Glycolysis in Pulmonary Endothelial Cells via the Activation of HIF-1α Through Disulfide Bond-mediated PHD2 Dimerization

Mitochondrial Derived Hydrogen Peroxide Results in an Increase in Aerobic Glycolysis in Pulmonary Endothelial Cells via the Activation of HIF-1α Through Disulfide Bond-mediated PHD2 Dimerization

B7-H3 promotes aerobic glycolysis and chemoresistance in colorectal cancer cells by regulating HK2

Accumulating evidence suggests that aerobic glycolysis is important for colorectal cancer (CRC) development. However, the underlying mechanisms have yet to be elucidated. B7-H3, an immunoregulatory protein, is broadly overexpressed by multiple tumor types and plays a vital role in tumor progression. In this study, we found that overexpression of B7-H3 effectively increased the rate of glucose consumption and lactate production, whereas knockdown of B7-H3 had the opposite effect. Furthermore, we showed that B7-H3 increased glucose consumption and lactate production by promoting hexokinase 2 (HK2) expression in CRC cells, and we also found that HK2 was a key mediator of B7-H3-induced CRC chemoresistance. Depletion of HK2 expression or treating cells with HK2 inhibitors could reverse the B7-H3-induced increase in aerobic glycolysis and B7-H3-endowed chemoresistance of cancer cells. Moreover, we verified a positive correlation between the expression of B7-H3 and HK2 in tumor tissues of CRC patients. Collectively, our findings suggest that B7-H3 may be a novel regulator of glucose metabolism and chemoresistance via controlling HK2 expression in CRC cells, a result that could help develop B7-H3 as a promising therapeutic target for CRC treatment.

Bittersweet tumor development and progression: Emerging roles of epithelial plasticity glycosylations.

Altered metabolism is one of the hallmarks of cancer. The best-known cancer metabolic anomaly is an increase in aerobic glycolysis, which generates ATP and other basic building blocks, such as nucleotides, lipids, and proteins to support tumor cell growth and survival. Epithelial plasticity (EP) programs such as the epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) are evolutionarily conserved processes that are essential for embryonic development. EP also plays an important role during tumor progression toward metastasis and treatment resistance, and new roles in the acceleration of tumorigenesis have been found. Recent evidence has linked EMT-related transcriptomic alterations with metabolic reprogramming in cancer cells, which include increased aerobic glycolysis. More recent studies have revealed a novel connection between EMT and altered glycosylation in tumor cells, in which EMT drives an increase in glucose uptake and flux into the hexosamine biosynthetic pathway (HBP). The HBP is a side-branch pathway from glycolysis which generates the end product uridine-5'-diphosphate-N-acetylglucosamine (UDP-GlcNAc). A key downstream utilization of UDP-GlcNAc is for the post-translational modification O-GlcNAcylation which involves the attachment of the GlcNAc moiety to Ser/Thr/Asn residues of proteins. Global changes in protein O-GlcNAcylation are emerging as a general characteristic of cancer cells. In our recent study, we demonstrated that the EMT-HBP-O-GlcNAcylation axis drives the O-GlcNAcylation of key proteins such as c-Myc, which previous studies have shown to suppress oncogene-induced senescence (OIS) and contribute to accelerated tumorigenesis. Here, we review the HBP and O-GlcNAcylation and their putative roles in driving EMT-related cancer processes with examples to illuminate potential new therapeutic targets for cancer.

31 - Phosphorylation of eNOS at Thr(T)495 induces mitochondrial fission and a hyper-proliferative endothelial cell phenotype in pulmonary arterial hypertension (PAH)

Mitochondrial dysfunction and cell proliferation play an important role in the pathological arterial constriction associated with pulmonary arterial hypertension (PAH). The mechanisms underlying this blood vessel remodeling is unclear. Recent studies have implicated a disruption of mitochondrial network dynamics to favor fission in the attenuation of mitochondrial function in PAH. We found that mitochondrial fission, or fragmentation, enhanced in endothelial cells isolated from IPAH patients. Further, this shift of morphology correlated with an increase of aerobic glycolysis, the Warburg effect. We also identified an increase in mitochondrial generated reactive oxygen species. These changes correlated with an increase in phospho(p)-T495eNOS protein levels Interestingly, high-resolution fluorescent imaging showed an increase in p-T495-eNOS levels on the mitochondria. We also found that the adenoviral-mediated overexpression of a phosphoT495eNOS mimic (T495DeNOS) in normal human pulmonary arterial endothelial cells (HPAEC) was sufficient to induce mitochondrial fission, a glycolytic shift, and stimulate proliferation. Mdivi-1, an inhibitor of the major mitochondrial fission regulator, Drp1 significantly attenuated both mitochondrial fission and cell proliferation. Finally, we found that inhibiting cellular glycolysis using the hexokinase 2 inhibitor, 2-deoxyglucose (2-DG), attenuated the proliferation of EC cultured form IPAH patients and sensitized them to TNF-α mediated apoptosis. Thus, we conclude that the phosphorylation of eNOS at T495 is intimately involved in regulating both mitochondrial morphology and the Warburg effect during PAH and the development of the hyper-proliferative anti-apoptotic EC phenotype associated with the development of PAH.

Targeting glycometabolic reprogramming to restore the sensitivity of leukemia drug-resistant K562/ADM cells to adriamycin

AimsMounting studies have confirmed that cancer cells reprogram their metabolism during early carcinogenesis to develop many other hallmarks, and demonstrated a relationship between aerobic glycolysis and the occurrence of drug resistance. However, the molecular mechanisms and role in tumor drug resistance of aerobic glycolysis remain unclear. Main methodsWe analyzed differentially expressed genes (DEGs) at the RNA level between the multi-drug resistance (MDR) leukemia cell line K562/adriamycin (ADM) and its parental, drug-sensitive K562 cell line. Clustering and enrichment analysis of DEGs was performed. Oxamate, a lactic dehydrogenase inhibitor were used to assess the effect of glycolysis inhibition on ADM susceptibility and the expression of the enriched DEGs in K562/ADM cells. Key findingsA total of 1742 DEGs were detected between the K562/ADM and K562 cell lines. The differential expression of unigenes encoding enzymes involved in glycometabolism signifies that there was a greater aerobic glycolysis flux in K562/ADM cells. The PI3K-AKT signaling pathway, which is related to glucose metabolism, showed representative differential enrichment and up-regulation in K562/ADM cells. Oxamate improved and re-sensitized the therapeutic effect of ADM in ADM-resistant cells by inhibiting aerobic glycolysis either directly or indirectly by down-regulation of the AKT-mTOR pathway. SignificanceOur findings suggest that ADM resistance mediated by the increase of aerobic glycolysis, which related to the over-activation of the AKT-mTOR-c-Myc pathway in MDR leukemia cells. Inhibition of aerobic glycolysis and down-regulation of signaling pathways involved in aerobic glycolysis represent a potential chemotherapeutic strategy for sensitizing leukemic cells and thereby overcoming MDR.

Metabolic reprogramming of stromal fibroblasts by melanoma exosome microRNA favours a pre-metastatic microenvironment

Local acidification of stroma is proposed to favour pre-metastatic niche formation but the mechanism of initiation is unclear. We investigated whether Human Melanoma-derived exosomes (HMEX) could reprogram human adult dermal fibroblasts (HADF) and cause extracellular acidification. HMEX were isolated from supernatants of six melanoma cell lines (3 BRAF V600E mutant cell lines and 3 BRAF wild-type cell lines) using ultracentrifugation or Size Exclusion Chromatography (SEC). Rapid uptake of exosomes by HADF was demonstrated following 18 hours co-incubation. Exposure of HDAF to HMEX leads to an increase in aerobic glycolysis and decrease in oxidative phosphorylation (OXPHOS) in HADF, consequently increasing extracellular acidification. Using a novel immuno-biochip, exosomal miR-155 and miR-210 were detected in HMEX. These miRNAs were present in HMEX from all six melanoma cell lines and were instrumental in promoting glycolysis and inhibiting OXPHOS in tumour cells. Inhibition of miR-155 and miR-210 activity by transfection of miRNA inhibitors into HMEX reversed the exosome-induced metabolic reprogramming of HADF. The data indicate that melanoma-derived exosomes modulate stromal cell metabolism and may contribute to the creation of a pre-metastatic niche that promotes the development of metastasis.

Abstract B097: Dysregulated mevalonate and cholesterol synthesis is a therapeutic vulnerability in glioblastoma

Abstract A hallmark of cellular transformation is the evasion of contact-dependent inhibition of growth. To find new therapeutic targets for glioblastoma, we looked for pathways that are inhibited by high cell density in normal astrocytes but have lost this regulation in glioblastoma stem-like cells. Here we report that at high cell density, normal astrocytes turn off mevalonate and cholesterol synthesis but glioma cells keep these pathways active. Correspondingly, mevalonate and cholesterol pathway upregulation is associated with poor prognosis in glioblastoma patients. Densely plated glioma cells increase oxygen consumption to synthesize cholesterol, resulting in a decrease in reactive oxygen species, TCA cycle intermediates, and ATP, but without a compensating increase in aerobic glycolysis. This constitutive cholesterol synthesis is controlled by the cell cycle, as it can be turned off by cyclin-dependent kinase inhibitors and it correlates with disabled cell cycle control though loss of p53 and RB. Mevalonate and cholesterol pathway activation promoted aberrant growth through the LXR and Hippo pathways. Finally, glioma cells, but not astrocytes, are sensitive to cholesterol synthesis inhibition downstream of the mevalonate pathway, suggesting that specifically targeting cholesterol synthesis might be an effective treatment for glioblastoma. Citation Format: Diane M. Kambach, Alan S. Halim, A. Gesine Cauer, Qian Sun, Carlos A. Tristan, Aparna H. Kesarwala, Uma Shankavaram, Eric Batchelor, Jayne M. Stommel. Dysregulated mevalonate and cholesterol synthesis is a therapeutic vulnerability in glioblastoma [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B097.