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The oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) is activated constitutively in a wide array of human cancers. It is an appealing molecular target for novel therapy as it directly regulates expression of genes involved in cell proliferation, survival, angiogenesis, chemoresistance and immune responsiveness. In addition to these well-established oncogenic roles, STAT3 has also been found to mediate a wide array of functions in modulating cellular behavior. The transcriptional function of STAT3 is canonically regulated through tyrosine phosphorylation. However, STAT3 phosphorylated at a single serine residue can allow incorporation of this protein into the inner mitochondrial membrane to support oxidative phosphorylation (OXPHOS) and maximize the utility of glucose sources. Conflictingly, its canonical transcriptional activity suppresses OXPHOS and favors aerobic glycolysis to promote oncogenic behavior. Apart from mediating the energy metabolism and controversial effects on ATP production, STAT3 signaling modulates lipid metabolism of cancer cells. By mediating fatty acid synthesis and beta oxidation, STAT3 promotes employment of available resources and supports survival in the conditions of metabolic stress. Thus, the functions of STAT3 extend beyond regulation of oncogenic genes expression to pleiotropic effects on a spectrum of essential cellular processes. In this review, we dissect the current knowledge on activity and mechanisms of STAT3 involvement in transcriptional regulation, mitochondrial function, energy production and lipid metabolism of malignant cells, and its implications to cancer pathogenesis and therapy.

Highlights • Aging affects the metabolic profile of fibroblasts derived from ALS cases • Increased NADH metabolism with age is observed in the presence of a specific set of catabolic energy substrates in healthy individuals • Reduced NADH metabolism with age is observed in the presence of glycogen in the ALS cohort • Disease progression rates in ALS cases correlate with fibroblast NADH production in the presence of a number of energy substrates including inosine, Aging is a major risk factor for neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). As metabolic alterations are a hallmark of aging and have previously been observed in ALS, it is important to examine the effect of aging in the context of ALS metabolic function. Here, using a newly established phenotypic metabolic approach, we examined the effect of aging on the metabolic profile of fibroblasts derived from ALS cases compared to controls. We found that ALS fibroblasts have an altered metabolic profile, which is influenced by age. In control cases, we found significant increases with age in NADH metabolism in the presence of several metabolites including lactic acid, trehalose, uridine and fructose, which was not recapitulated in ALS cases. Conversely, we found a reduction of NADH metabolism with age of biopsy, age of onset and age of death in the presence of glycogen in the ALS cohort. Furthermore, we found that NADH production correlated with disease progression rates in relation to a number of metabolites including inosine and α-ketoglutaric acid. Inosine or α-ketoglutaric acid supplementation in ALS fibroblasts was bioenergetically favourable. Overall, we found aging related defects in energy substrates that feed carbon into glycolysis at various points as well as the tricarboxylic acid (TCA) cycle in ALS fibroblasts, which was validated in induced neuronal progenitor cell derived iAstrocytes. Our results suggest that supplementing those pathways may protect against age related metabolic dysfunction in ALS.

Hypoxia exerts profound effects on cell physiology, but its effect on colonic uptake of the microbiota-generated forms of vitamin B1 (i.e., thiamin pyrophosphate [TPP] and free thiamine) has not been described. Here, we used human colonic epithelial NCM460cells and human differentiated colonoid monolayers as invitro and exvivo models, respectively, and were subjected to either chamber (1% O2, 5% CO2, and 94% N2) or chemically (desferrioxamine; 250μM)-induced hypoxia followed by determination of different physiological-molecular parameters. We showed that hypoxia causes significant inhibition in TPP and free thiamin uptake by colonic NCM460cells and colonoid monolayers; it also caused a significant reduction in the expression of TPP (SLC44A4) and free thiamin (SLC19A2 and SLC19A3) transporters and in activity of their gene promoters. Furthermore, hypoxia caused a significant induction in levels of hypoxia-inducible transcription factor (HIF)-1α but not HIF-2α. Knocking down HIF-1α using gene-specific siRNAs in NCM460cells maintained under hypoxic conditions, on the other hand, led to a significant reversal in the inhibitory effect of hypoxia on TPP and free thiamin uptake as well as on the expression of their transporters. Finally, a marked reduction in level of expression of the nuclear factors cAMP responsive element-binding protein 1 and gut-enriched Krüppel-like factor 4 (required for activity of SLC44A4 and SLC19A2 promoters, respectively) was observedunder hypoxic conditions. In summary, hypoxia causes severe inhibition in colonic TPP and free thiamin uptake that is mediated at least in part via HIF-1α-mediated transcriptional mechanisms affecting their respective transporters.

Even with increasing evidence for roles of glycolytic enzymes in controlling cancerous characteristics, the best target of candidate metabolic enzymes for lessening malignancy remains under debate. Pyruvate is a main glycolytic metabolite that could be mainly converted into either lactate by Lactate Dehydrogenase A (LDHA) or acetyl-CoA by Pyruvate Dehydrogenase E1 component α subunit (PDHA1) catalytic complex. In tumor cells, accumulating lactate is produced whereas the conversion of pyruvate into mitochondrial acetyl-CoA is less active compared with their normal counterparts. This reciprocal molecular association makes pyruvate metabolism a potential choice of anti-cancer target. Cellular and molecular changes were herein assayed in Head and Neck Squamous Cell Carcinoma (HNSCC) cells in response to LDHA and PDHA1 loss in vitro, in vivo and in clinic. By using various human cancer databases and clinical samples, LDHA and PDHA1 levels exhibit reversed prognostic roles. In vitro analysis demonstrated that decreased cell growth and motility accompanied by an increased sensitivity to chemotherapeutic agents was found in cells with LDHA loss whereas PDHA1-silencing exhibited opposite phenotypes. At the molecular level, it was found that oncogenic Protein kinase B (PKB/Akt) and Extracellular signal-regulated kinase (ERK) singling pathways contribute to pyruvate metabolism mediated HNSCC cell growth. Furthermore, LDHA/PDHA1 changes in HNSCC cells resulted in a broad metabolic reprogramming while intracellular molecules including polyunsaturated fatty acids and nitrogen metabolism related metabolites underlie the malignant changes. Collectively, our findings reveal the significance of pyruvate metabolic fates in modulating HNSCC tumorigenesis and highlight the impact of metabolic plasticity in HNSCC cells.

Objective Astrocytes actively participate in energy metabolism in the brain, and astrocytic aerobic glycolysis disorder is associated with the pathology of Alzheimer's disease (AD). GLP-1 has been shown to improve cognition in AD; however, the mechanism remains unclear. The objectives of this study were to assess GLP-1's glycolytic regulation effects in AD and reveal its neuroprotective mechanisms. Methods The Morris water maze test was used to evaluate the effects of liraglutide (an analog of GLP-1) on the cognition of 4-month-old 5×FAD mice, and a proteomic analysis and Western blotting were used to assess the proteomic profile changes. We constructed an astrocytic model of AD by treating primary astrocytes with Aβ1-42. The levels of NAD+ and lactate were examined, and the oxidative levels were assessed by a Seahorse examination. Astrocyte-neuron co-culture was performed to evaluate the effects of GLP-1 on astrocytes’ neuronal support. Results GLP-1 improved cognition in 4-month-old 5×FAD mice by enhancing aerobic glycolysis and reducing oxidative phosphorylation (OXPHOS) levels and oxidative stress in the brain. GLP-1 also alleviated Aβ-induced glycolysis declines in astrocytes, which resulted in reduced OXPHOS levels and reactive oxygen species (ROS) production. The mechanism involved the activation of the PI3K/Akt pathway by GLP-1. Elevation in astrocytic glycolysis improved astrocyte cells’ support of neurons and promoted neuronal survival and axon growth. Conclusions Taken together, we revealed GLP-1's capacity to regulate astrocytic glycolysis, providing mechanistic insight into one of its neuroprotective roles in AD and support for the feasibility of energy regulation treatments for AD., Graphical abstract Image 1, Highlights • GLP-1 mediates a metabolic shift from oxidative phosphorylation to aerobic glycolysis in Alzheimer's disease. • GLP-1's mechanism of action involves activation of the PI3K/Akt pathway. • GLP-1 enhances the supportive ability of astrocytes to neurons by promoting aerobic glycolysis.

Highlights • Succinic acid was produced from Cocos nucifera water. • E. coli M6PM was constructed using metabolic engineering strategy. • E. coli M6PM utilized Cocos nucifera water effectively to produce succinic acid., Succinic acid is an important acid which is used in medicine and pharmaceutical companies. Metabolically engineered Escherichia coli strain was used for the effective production of succinic acid using Cocos nucifera water, which contained 5.00 ± 0.02 g/L glucose, 6.10 ± 0.01 g /L fructose and 6.70 ± 0.02 g /L sucrose. Fermentation of C. nucifera water with E. coli M6PM produced a final concentration of 11.78 ± 0.02 g/L succinic acid and yield of 1.23 ± 0.01 mol/mol, 0.66 ± 0.01 g/g total sugars after 72 h dual-phase fermentation in M9 medium while modeled sugar was 0.38 ± 0.02 mol/mol total sugars. It resulted in 72% of the maximum theoretical yield of succinic acid. Here we show that novel substrate of C. nucifera water resulted in effective production of succinic acid. These investigations unveil the importance of C. nucifera water as a substrate for the production of biochemicals.

Solute carrier (SLC) transporters meditate many essential physiological functions, including nutrient uptake, ion influx/efflux, and waste disposal. In its protective role against tumors and infections, the mammalian immune system coordinates complex signals to support the proliferation, differentiation, and effector function of individual cell subsets. Recent research in this area has yielded surprising findings on the roles of solute carrier transporters, which were discovered to regulate lymphocyte signaling and control their differentiation, function, and fate by modulating diverse metabolic pathways and balanced levels of different metabolites. In this review, we present current information mainly on glucose transporters, amino-acid transporters, and metal ion transporters, which are critically important for mediating immune cell homeostasis in many different pathological conditions., Graphical abstract Solute carrier (SLC) transporters meditate many essential physiological functions. In this review, we present current information mainly on glucose transporters, amino-acid transporters, and metal ion transporters, which are critically important for mediating immune cell homeostasis in many different pathological conditions.Image 1

Clear cell renal cell carcinoma (ccRCC) is the most lethal neoplasm of the urologic system. Clinical therapeutic effect varies greatly between individual ccRCC patients, so there is an urgent need to develop prognostic molecular biomarkers to help clinicians identify patients in need of early aggressive management. In this study, samples from primary ccRCC tumor and their corresponding nontumor adjacent tissues (n = 18) were analyzed by quantitative proteomic assay. Proteins downregulated in tumors were studied by GO and KEGG pathways enrichment analyses. Six proteins were found both downregulated and annotated with cell proliferation in ccRCC patients. Of these proteins, PDZK1 and FABP1 were also involved in the lipid metabolism pathway. The downregulation of PDZK1 was further validated in TCGA_KIRC dataset (n = 532) and independent set (n = 202). PDZK1 could discriminate recurrence, metastasis and prognosis between ccRCC patients. Low level of PDZK1 in both mRNA and protein was associated with reduced overall survival (OS) and disease–free survival (DFS) in two independent sets. In univariate and multivariate analyses, PDZK1 was defined as an independent prognostic factor for both OS and DFS. These findings indicated that low level of PDZK1 could predict poor clinical outcome in patients with ccRCC., Highlights • PDZK1, which was involved in cell proliferation and lipid metabolism pathway, was significantly downregulated in ccRCC. • PDZK1 was defined as an independent prognostic factor for OS and DFS in univariate and multivariate cox analyses. • Low level of PDZK1 could predict poor clinical outcome in patients with ccRCC. Clinical therapeutic effect varies greatly between individuals of clear cell renal cell carcinoma (ccRCC). Development of prognostic molecular biomarkers can help clinicians identify patients in need of early aggressive management. Differentially expressed proteins between tumor and adjacent normal tissues were analyzed by proteomics. Subsequently, bioinformatics assay was combined to screen for prognostic markers in ccRCC. PDZ domain containing 1 (PDZK1), involved in cell proliferation and lipid metabolism pathway, was significantly downregulated in ccRCC and defined as an independent prognostic factor for poor clinical outcome in ccRCC patients. Our findings will facilitate patient counseling and individualize management of patients with ccRCC.

Isolated hepatocytes from young (4–6 mo) and old (24–26 mo) F344 rats were exposed to increasing concentrations of menadione, a vitamin K derivative and redox cycling agent, to determine whether the age-related decline in Nrf2-mediated detoxification defenses resulted in heightened susceptibility to xenobiotic insult. An LC50 for each age group was established, which showed that aging resulted in a nearly 2-fold increase in susceptibility to menadione (LC50 for young: 405 μM; LC50 for old: 275 μM). Examination of the known Nrf2-regulated pathways associated with menadione detoxification revealed, surprisingly, that NAD(P)H: quinone oxido-reductase 1 (NQO1) protein levels and activity were induced 9-fold and 4-fold with age, respectively (p=0.0019 and p=0.018; N=3), but glutathione peroxidase 4 (GPX4) declined by 70% (p=0.0043; N=3). These results indicate toxicity may stem from vulnerability to lipid peroxidation instead of inadequate reduction of menadione semi-quinone. Lipid peroxidation was 2-fold higher, and GSH declined by a 3-fold greater margin in old versus young rat cells given 300 µM menadione (p2-fold reduction in cell death, suggesting that the age-related increase in menadione susceptibility likely stems from attenuated GSH-dependent defenses. This data identifies cellular targets for intervention in order to limit age-related toxicological insults to menadione and potentially other redox cycling compounds., Graphical abstract fx1, Highlights • Menadione toxicity is nearly two-fold higher with age by LC50 in F344 hepatocytes. • Glutathione (GSH) loss during menadione treatment is accelerated with age. • Age-related loss of GPX4 protein correlates with increased menadione-induced MDA. • NAC maintained GSH mitigates age-related susceptibility to redox cycling menadione.

Almost from all organs, both mesenchymal stromal cells and fibroblasts can be isolated. Mesenchymal stromal cells (MSCs) are the most preferred cellular therapeutic agents with the regenerative potential, and fibroblasts are one of the most abundant cell types with the ability to maintain homeostasis. Because of the promising properties of MSCs, they have been well studied and their differentiation potentials, immunomodulatory potentials, gene expression profiles are identified. It has been observed that fibroblasts and mesenchymal stromal cells have similar morphology, gene expression patterns, surface markers, proliferation, differentiation, and immunomodulatory capacities. Thus, it is hard to distinguish these two cell types. Epigenetic signatures, i.e., methylation patterns of cells, are the only usable promising difference between them. Such significant similarities show that these two cells may be related to each other.

Metabolic imaging of brain tumors using 13C Magnetic Resonance Spectroscopy (MRS) of hyperpolarized [1-13C] pyruvate is a promising neuroimaging strategy which, after a decade of preclinical success in glioblastoma (GBM) models, is now entering clinical trials in multiple centers. Typically, the presence of GBM has been associated with elevated hyperpolarized [1-13C] lactate produced from [1-13C] pyruvate, and response to therapy has been associated with a drop in hyperpolarized [1-13C] lactate. However, to date, lower grade gliomas had not been investigated using this approach. The most prevalent mutation in lower grade gliomas is the isocitrate dehydrogenase 1 (IDH1) mutation, which, in addition to initiating tumor development, also induces metabolic reprogramming. In particular, mutant IDH1 gliomas are associated with low levels of lactate dehydrogenase A (LDHA) and monocarboxylate transporters 1 and 4 (MCT1, MCT4), three proteins involved in pyruvate metabolism to lactate. We therefore investigated the potential of 13C MRS of hyperpolarized [1-13C] pyruvate for detection of mutant IDH1 gliomas and for monitoring of their therapeutic response. We studied patient-derived mutant IDH1 glioma cells that underexpress LDHA, MCT1 and MCT4, and wild-type IDH1 GBM cells that express high levels of these proteins. Mutant IDH1 cells and tumors produced significantly less hyperpolarized [1-13C] lactate compared to GBM, consistent with their metabolic reprogramming. Furthermore, hyperpolarized [1-13C] lactate production was not affected by chemotherapeutic treatment with temozolomide (TMZ) in mutant IDH1 tumors, in contrast to previous reports in GBM. Our results demonstrate the unusual metabolic imaging profile of mutant IDH1 gliomas, which, when combined with other clinically available imaging methods, could be used to detect the presence of the IDH1 mutation in vivo., Graphical abstract Image 1, Highlights • Metabolic imaging of mutant IDH1 gliomas using hyperpolarized 13C MRS is described. • In contrast to GBM, mutant IDH1 gliomas produce no hyperpolarized [1-13C] lactate. • Hyperpolarized [1-13C] lactate is not reduced by treatment in mutant IDH1 tumors. • Mutant IDH1 gliomas present an unusual metabolic imaging profile.

Brain mitochondrial activity is centrally involved in the central control of energy balance. When studying mitochondrial functions in the brain, however, discrepant results might be obtained, depending on the experimental approaches. For instance, immunostaining experiments and biochemical isolation of organelles expose investigators to risks of false positive and/or false negative results. As an example, the functional presence of cannabinoid type 1 (CB1) receptors on brain mitochondrial membranes (mtCB1) was recently reported and rapidly challenged, claiming that the original observation was likely due to artifact results. Here, we addressed this issue by directly comparing the procedures used in the two studies. Our results show that the use of appropriate controls and quantifications allows detecting mtCB1 receptor with CB1 receptor antibodies, and that, if mitochondrial fractions are enriched and purified, CB1 receptor agonists reliably decrease respiration in brain mitochondria. These data further underline the importance of adapted experimental procedures to study brain mitochondrial functions.

The Aim of the study was to reveal if PET-CT analysis of primary and of secondary lung cancer could be related to the onset of lipid peroxidation in cancer and in surrounding non-malignant lung tissue. Methods: Nineteen patients with primary lung cancer and seventeen patients with pulmonary metastasis were involved in the study. Their lungs were analyzed by PET-CT scanning before radical surgical removal of the cancer. Specific immunohistochemistry for the major bioactive marker of lipid peroxidation, 4-hydroxynonenal (HNE), was done for the malignant and surrounding non-malignant lung tissue using genuine monoclonal antibody specific for the HNE-histidine adducts. Results: Both the intensity of the PET-CT analysis and the HNE-immunohistochemistry were in correlation with the size of the tumors analyzed, while primary lung carcinomas were larger than the metastatic tumors. The intensity of the HNE-immunohistochemistry in the surrounding lung tissue was more pronounced in the metastatic than in the primary tumors, but it was negatively correlated with the cancer volume determined by PET-CT. The appearance of HNE was more pronounced in non-malignant surrounding tissue than in cancer or stromal cells, both in case of primary and metastatic tumors. Conclusions: Both PET-CT and HNE-immunohistochemistry reflect the size of the malignant tissue. However, lipid peroxidation of non-malignant lung tissue in the vicinity of cancer is more pronounced in metastatic than in primary malignancies and might represent the mechanism of defense against cancer, as was recently revealed also in case of human liver cancer. Keywords: Lipid peroxidation (LPO), 4-hydroxynonenal (HNE), Positron emission tomography and computed tomography (PET-CT), Cell growth regulation, Inflammation, Immunohistochemistry

HIF1A (hypoxia-inducible factor 1α) is the master regulator of the cellular response to hypoxia and is implicated in cancer progression. Whereas the regulation of HIF1A protein in response to oxygen is well characterized, less is known about the fate of HIF1A mRNA. In the present study, we have identified the pseudo-DUB (deubiquitinating enzyme)/deadenylase USP52 (ubiquitin-specific protease 52)/PAN2 [poly(A) nuclease 2] as an important regulator of the HIF1A-mediated hypoxic response. Depletion of USP52 reduced HIF1A mRNA and protein levels and resulted in reduced expression of HIF1A-regulated hypoxic targets due to a 3′-UTR (untranslated region)-dependent poly(A)-tail-length-independent destabilization in HIF1A mRNA. MS analysis revealed an association of USP52 with several P-body (processing body) components and we confirmed further that USP52 protein and HIF1A mRNA co-localized with cytoplasmic P-bodies. Importantly, P-body dispersal by knockdown of GW182 or LSM1 resulted in a reduction of HIF1A mRNA levels. These data uncover a novel role for P-bodies in regulating HIF1A mRNA stability, and demonstrate that USP52 is a key component of P-bodies required to prevent HIF1A mRNA degradation.