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The goal of this work was to investigate the effect of fermentation pH and time on the acid tolerance, glycolytic activity, and survival during freeze drying of L. delbrueckii subsp. bulgaricus WDCM 00102 strains during cultivation in the medium, based on pretreated biomass of Spirulina platensis. During the study, when the fermentation process is carried out at a constant pH, a higher value of glycolytic activity is established in the cells of the probiotic culture, which decreases when the pH is lowered. The survival rate of cells of L. delbrueckii subsp. bulgaricus WDCM 00102 after lyophilization shows similar values after cultivation for 25 and 37 h (p < 0.05), while the opposite dependence is established in experiments related to changes in the pH of the cultivation medium. pH and fermentation time significantly influence the glycolytic activity of L. delbrueckii subsp. bulgaricus WDCM 00102 and on the resistance of its cells to acid stress and lyophilization conditions. [ABSTRACT FROM AUTHOR]

Ischemic heart disease (IHD) is the leading cause of death, with age range being the primary factor for development. The mechanisms by which aging increases vulnerability to ischemic insult are not well understood. We aim to use single‐cell RNA sequencing to discover transcriptional differences in various cell types between aged and young mice, which may contribute to aged‐related vulnerability to ischemic insult. Utilizing 10× Genomics Single‐Cell RNA sequencing, we were able to complete bioinformatic analysis to identity novel differential gene expression. During the analysis of our collected samples, we detected Pyruvate Dehydrogenase Kinase 4 (Pdk4) expression to be remarkably differentially expressed. Particularly in cardiomyocyte cell populations, Pdk4 was found to be significantly upregulated in the young mouse population compared to the aged mice under ischemic/reperfusion conditions. Pdk4 is responsible for inhibiting the enzyme pyruvate dehydrogenase, resulting in the regulation of glucose metabolism. Due to decreased Pdk4 expression in aged cardiomyocytes, there may be an increased reliance on glucose oxidization for energy. Through biochemical metabolomics analysis, it was observed that there is a greater abundance of pyruvate in young hearts in contrast to their aged counterparts, indicating less glycolytic activity. We believe that Pdk4 response provides valuable insight towards mechanisms that allow for the young heart to handle ischemic insult stress more effectively than the aged heart. [ABSTRACT FROM AUTHOR]

Macrophages differentiated into a classically activated (M1) or alternatively activated phenotype (M2) in infection and tumor, but the precise effects of glycolysis and oxidative phosphorylation (OXPHOS) metabolic pathway remain unclear. Herein, the effects of glycolysis or OXPHOS on macrophage polarizations were investigated using a pharmacological approach in mice. 2-Deoxy-D-glucose (2-DG) treatments, which blocks the key enzyme hexokinase of glycolysis, efficiently inhibits a specific switch to M1 lineage, decreasing the secretion of pro-inflammatory cytokines and expressions of co-stimulatory molecules associated with relieving infectious inflammation in vitro and in vivo. Glycolytic activation through the hypoxia-inducible factor-1α (HIF-1α) pathway was required for differentiation to the M1 phenotype, which conferred protection against infection. Dimethyl malonate (DMM) treatment, which blocks the key element succinate of OXPHOS, efficiently inhibits a specific switch to M2 lineage when macrophages receiving M2 stimulation, decreasing the secretion of anti-inflammatory cytokine and CD206 expressions. Mitochondrial dynamic alterations including mitochondrial mass, mitochondrial membrane potential (Dym) and ROS productions were critically for differentiation to the M2 phenotype, which conferred protection against anti-tumor immunity. Glycolysis is also required for macrophage M2 differentiation. Thus, these data provide a basis for a comprehensively understanding the role of glycolysis and OXPHOS in macrophage differentiation during anti-infection and anti-tumor inflammation.

Macrophages differentiated into a classically activated (M1) or alternatively activated phenotype (M2) in infection and tumor, but the precise effects of glycolysis and oxidative phosphorylation (OXPHOS) metabolic pathway remain unclear. Herein, the effects of glycolysis or OXPHOS on macrophage polarizations were investigated using a pharmacological approach in mice. 2-Deoxy-D-glucose (2-DG) treatments, which blocks the key enzyme hexokinase of glycolysis, efficiently inhibits a specific switch to M1 lineage, decreasing the secretion of pro-inflammatory cytokines and expressions of co-stimulatory molecules associated with relieving infectious inflammation in vitro and in vivo. Glycolytic activation through the hypoxia-inducible factor-1α (HIF-1α) pathway was required for differentiation to the M1 phenotype, which conferred protection against infection. Dimethyl malonate (DMM) treatment, which blocks the key element succinate of OXPHOS, efficiently inhibits a specific switch to M2 lineage when macrophages receiving M2 stimulation, decreasing the secretion of anti-inflammatory cytokine and CD206 expressions. Mitochondrial dynamic alterations including mitochondrial mass, mitochondrial membrane potential (Dym) and ROS productions were critically for differentiation to the M2 phenotype, which conferred protection against anti-tumor immunity. Glycolysis is also required for macrophage M2 differentiation. Thus, these data provide a basis for a comprehensively understanding the role of glycolysis and OXPHOS in macrophage differentiation during anti-infection and anti-tumor inflammation. [ABSTRACT FROM AUTHOR]

Mitochondria play a key role in metabolic transitions involved in the reprogramming of somatic cells into induced pluripotent stem cells (iPSCs), but the underlying molecular mechanisms remain largely unexplored. To obtain new insight into the mechanisms of cellular reprogramming, we studied the role of FAH domain-containing protein 1 (FAHD1) in the reprogramming of murine embryonic fibroblasts (MEFs) into iPSCs and their subsequent differentiation into neuronal cells. MEFs from wild type (WT) and Fahd1-knock-out (KO) mice were reprogrammed into iPSCs and characterized for alterations in metabolic parameters and the expression of marker genes indicating mitochondrial biogenesis. Fahd1-KO MEFs showed a higher reprogramming efficiency accompanied by a significant increase in glycolytic activity as compared to WT. We also observed a strong increase of mitochondrial DNA copy number and expression of biogenesis marker genes in Fahd1-KO iPSCs relative to WT. Neuronal differentiation of iPSCs was accompanied by increased expression of mitochondrial biogenesis genes in both WT and Fahd1-KO neurons with higher expression in Fahd1-KO neurons. Together these observations establish a role of FAHD1 as a potential negative regulator of reprogramming and add additional insight into mechanisms by which FAHD1 modulates mitochondrial functions.

Purpose: In PIK3CA mutant breast cancer, downstream hyperactivation of the PI3K/AKT/mTOR pathway may be associated with increased glycolysis of cancer cells. The purpose of this study was to investigate the functional association of PIK3CA mutational status and tumor glycolysis in invasive ER+/HER2- early breast cancer.Procedures: This institutional review board-approved retrospective study included a dataset of 67 ER+/HER2- early breast cancer patients. All patients underwent 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/X-ray computed tomography ([18F]FDG PET/CT) and clinico-pathologic assessments as part of a prospective study. For this retrospective analysis, pyrosequencing was used to detect PIK3CA mutations of exons 4, 7, 9, and 20. Tumor glucose metabolism was assessed semi-quantitatively with [18F]FDG PET/CT using maximum standardized uptake values (SUVmax). SUVmax values were corrected for the partial volume effect, and metabolic tumor volume was calculated using the volume of interest automated lesion growing function 2D tumor size, i.e., maximum tumor diameter was assessed on concurrent pre-treatment contrast-enhanced magnetic resonance imaging.Results: PIK3CA mutations were present in 45 % of all tumors. Mutations were associated with a small tumor diameter (p < 0.01) and with low nuclear grade (p = 0.04). Glycolytic activity was positively associated with nuclear grade (p = 0.01), proliferation (p = 0.002), regional lymph node metastasis (p = 0.015), and metabolic tumor volume (p = 0.001) but not with tumor size/T-stage. In invasive ductal carcinomas, median SUVmax was increased in PIK3CA-mutated compared to wild-type tumors; however, this increase did not reach statistical significance (p = 0.05). Multivariate analysis of invasive ductal carcinomas revealed [18F]FDG uptake to be independently associated with PIK3CA status (p = 0.002) and nuclear tumor grade (p = 0.046). Size, volume, and regional nodal status had no influence on glycolytic activity. PIK3CA mutational status did not influence glycolytic metabolism in lobular carcinomas. Glycolytic activity and PIK3CA mutational status had no significant influence on recurrence-free survival or disease-specific survival.Conclusions: In ER+/HER2- invasive ductal carcinomas of the breast, glucose uptake is independently associated with PIK3CA mutations. Initial data suggest that [18F]FDG uptake reflects complex genomic alterations and may have the potential to be used as candidate biomarker for monitoring therapeutic response and resistance mechanisms in emerging therapies that target the PI3K/AKT/mTOR pathway. [ABSTRACT FROM AUTHOR]

Background. We evaluated the prognostic significance of standardized uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) in [F-18] FDG PET/CT findings in patients with inoperable non-small-cell lung cancer (NSCLC).

Moderate acute intermittent hypoxia (mAIH) elicits a form of respiratory motor plasticity known as phrenic long-term facilitation (pLTF). Preconditioning with modest protocols of chronic intermittent hypoxia enhances pLTF, demonstrating pLTF metaplasticity. Since "low-dose" protocols of repetitive acute intermittent hypoxia (rAIH) show promise as a therapeutic modality to restore respiratory (and nonrespiratory) motor function in clinical disorders with compromised breathing, we tested 1) whether preconditioning with a mild rAIH protocol enhances pLTF and hypoglossal (XII) LTF and 2) whether the enhancement is regulated by glycolytic flux. In anesthetized, paralyzed, and ventilated adult male Lewis rats, mAIH (three 5-min episodes of 10% O2) elicited pLTF (pLTF at 60 min post-mAIH: 49 ± 5% baseline). rAIH preconditioning (ten 5-min episodes of 11% O2/day with 5-min normoxic intervals, 3 times per week, for 4 wk) significantly enhanced pLTF (100 ± 16% baseline). XII LTF was unaffected by rAIH. When glycolytic flux was inhibited by 2-deoxy-d-glucose (2-DG) administered via drinking water (~80 mg·kg-1·day-1), pLTF returned to normal levels (58 ± 8% baseline); 2-DG had no effect on pLTF in normoxia-pretreated rats (59 ± 7% baseline). In ventral cervical (C4/5) spinal homogenates, rAIH increased inducible nitric oxide synthase mRNA vs. normoxic controls, an effect blocked by 2-DG. However, there were no detectable effects of rAIH or 2-DG on several molecules associated with phrenic motor plasticity, including serotonin 2A, serotonin 7, brain-derived neurotrophic factor, tropomyosin receptor kinase B, or VEGF mRNA. We conclude that modest, but prolonged, rAIH elicits pLTF metaplasticity and that a drug known to inhibit glycolytic flux (2-DG) blocks pLTF enhancement. [ABSTRACT FROM AUTHOR]

Keywords: MSC; metabolism; immunomodulation; extracellular vesicles (EV); miR (microRNA); macrophages; glycolytic activity; mitochondria transfer EN MSC metabolism immunomodulation extracellular vesicles (EV) miR (microRNA) macrophages glycolytic activity mitochondria transfer 1 2 2 08/30/21 20210826 NES 210826 Multipotent mesenchymal stem/stromal cells (MSCs) are progenitor cells and exert several functions including support of hematopoiesis, regeneration, resistance to fibrosis, apoptosis or hypertrophy. MSCs respond to damaged or inflamed tissue through the transfer of Mitochondria (MT) to injured and immune cells, conveying a type of signaling that contributes to the restoration of cell homeostasis and immune function. Therefore, a clearer understanding of how MSC metabolism impacts immunomodulatory function will have a large interest, especially for futures MSC-based therapies, including EVs and mitochondria. [Extracted from the article]

Aim We evaluated the prognostic significance of standardized uptake value ( SUVmax), metabolic tumor volume ( MTV), and total lesion glycolysis ( TLG) obtained by F-18 FDG PET/ CT ( PET/ CT) in patients with diffuse large B-cell Lymphomas ( DLBCL) presenting intermediate IPI score. Material and Methods Fifty-two patients (61 ± 13 yr) underwent PET/ CT before the first-line chemotherapy. The mean SUVmax value, the summed MTV (cm3; 42% threshold), and the cumulative TLG (g) were registered. The patients were followed up 18 months thereafter (range 3-41 months). The PET/ CT results were compared to the event-free survival ( EFS). Results At univariate analysis, SUVmax and lactate dehydrogenase ( LDH) levels were predictive, but discordantly. The Kaplan- Meier survival analysis for SUVmax showed a significant better EFS in patients presenting higher values as compared to those having lesser ( P = 0.0002, HR 0.13). Summed MTV and cumulative TLG were not suitable for predicting EFS. Conclusion Despite the availability of new tools for the quantitative assessment of disease activity on PET/ CT, the SUVmax rather than MTV and TLG remains the only predictor for EFS in DLBCL patients. The magnitude of glycolytic activity rather than the amount of metabolically active burden holds a predominant value for determining the response to chemotherapy in DLBCL. [ABSTRACT FROM AUTHOR]

Abstract: Rotenone, a widely used pesticide and an environmental risk factor for Parkinson''s disease (PD), induces nigrostriatal injury, Lewy body-like inclusions, and Parkinsonian symptoms in rat models for PD. Our previous data indicated that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) overexpression and glycolytic inhibition were co-current in rotenone-induced PC12 (rat adrenal pheochromocytoma cells) cell death. However, whether GAPDH overexpression plays any role in dopaminergic neurodegeneration in vivo remains unknown. In this study, we have found that GAPDH overexpression and GAPDH-positive Lewy body-like aggregates in nigral dopaminergic neurons while nigral GAPDH glycolytic activity decreases in rotenone-based PD animal models. Furthermore, GAPDH knockdown reduces rotenone toxicity significantly in PC12. These in vitro and in vivo data suggest that GAPDH contributes to the pathogenesis of Parkinson''s disease, possibly representing a new molecular target for neuroprotective strategies and alternative therapies for PD. [Copyright &y& Elsevier]

Abstract: Contractile activity induces a marked increase in glycolytic activity and gene expression of enzymes and transporters involved in glucose metabolism in skeletal muscle. Muscle contraction also increases the production of reactive oxygen species (ROS). In this study, the effects of treatment with N-acetylcysteine (NAC), a potent antioxidant compound, on contraction-stimulated glycolysis were investigated in electrically stimulated primary rat skeletal muscle cells. The following parameters were measured: 2-[3H]deoxyglucose (2-DG) uptake; activities of hexokinase, phosphofructokinase (PFK), and glucose-6-phosphate dehydrogenase (G6PDH); lactate production; and expression of the glucose transporter 4 (GLUT4), hexokinase II (HKII), and PFK genes after one bout of electrical stimulation in primary rat myotubes. NAC treatment decreased ROS signal by 49% in resting muscle cells and abolished the muscle contraction-induced increase in ROS levels. In resting cells, NAC decreased mRNA and protein contents of GLUT4, mRNA content and activity of PFK, and lactate production. NAC treatment suppressed the contraction-mediated increase in 2-DG uptake; lactate production; hexokinase, PFK, and G6PDH activities; and gene expression of GLUT4, HKII, and PFK. Similar to muscle contraction, exogenous H2O2 (500 nM) administration increased 2-DG uptake; lactate production; hexokinase, PFK, and G6PDH activities; and gene expression of GLUT4, HKII, and PFK. These findings support the proposition that ROS endogenously produced play an important role in the changes in glycolytic activity and gene expression of GLUT4, HKII, and PFK induced by contraction in skeletal muscle cells. [Copyright &y& Elsevier]

Purpose: Positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) has been used for various cancers, but reproducibility of common utilized semi-quantitative parameters, such as the maximal single pixel standardized uptake value (SUV) and effective glycolytic volume (EGV), remains unknown. Knowledge of precision is essential for applying these parameters to treatment monitoring. The purpose of this investigation was to assess the precision of PET results obtained by repeated examinations of patients with untreated lung cancer.Patients and Methods: Ten patients with lung cancer underwent two PET examinations within a week with no intervening treatment. The reproducibility of three parameters:((1) maximal SUV of 1 × 1 pixel anywhere in the tumor, calculated on the basis of predicted lean body mass [SULmax]; (2) highest average SUV at 4 × 4 pixels in the tumor adjusted by predicted lean body mass [SULmean]; and (3) EGV calculated by multiplying SUL by tumor volume), using PET images obtained at 50–60 min post-injection, were examined. Plasma glucose, insulin and free fatty acid levels were also monitored.Results: The SULmax, SULmean, and EGV were measured with a mean ± S.D. difference of 11.3% ± 8.0, 10.1% ± 8.2, and 10.1% ± 8.0%, respectively. By multiplying SUL by plasma glucose concentration, the mean differences were slightly reduced to 7.2% ± 5.8, 6.7% ± 6.2, and 9.5% ± 8.2, respectively.Conclusion: These data indicate that commonly used semi-quantitative indices of glucose metabolism on PET show high reproducibly. This supports their use in sequential quantitative analysis in PET, such as in treatment response monitoring. (Mol Imag Biol 2002;4:171–178) [Copyright &y& Elsevier]

Simple Summary: Inside a tumor mass, drug resistant and sensitive cell populations co-exist, leading to a therapeutic challenge in oncology. In this study, we developed 2D and 3D co-culture systems and mathematical modeling to better understand how these different populations impact each other. We demonstrated that drug-sensitive cell populations inhibit the growth of drug-resistant populations. Mathematical modeling predicted that metronomic schedules, using chronic administration of drugs at low doses, could better control intratumor cell dynamics. We validated our in silico data in 3D and in vivo models. Finally, we demonstrated that metabolic cell activity of drug-sensitive cells could play a key role in controlling the proliferation of drug-resistant cells. Altogether, our study reports a new mechanism of action of metronomic therapy and paves the way for using it to better control drug resistance. Despite recent advances in deciphering cancer drug resistance mechanisms, relapse is a widely observed phenomenon in advanced cancers, mainly due to intratumor clonal heterogeneity. How tumor clones progress and impact each other remains elusive. In this study, we developed 2D and 3D non-small cell lung cancer co-culture systems and defined a phenomenological mathematical model to better understand clone dynamics. Our results demonstrated that the drug-sensitive clones inhibit the proliferation of the drug-resistant ones under untreated conditions. Model predictions and their experimental in vitro and in vivo validations indicated that a metronomic schedule leads to a better regulation of tumor cell heterogeneity over time than a maximum-tolerated dose schedule, while achieving control of tumor progression. We finally showed that drug-sensitive and -resistant clones exhibited different metabolic statuses that could be involved in controlling the intratumor heterogeneity dynamics. Our data suggested that the glycolytic activity of drug-sensitive clones could play a major role in inhibiting the drug-resistant clone proliferation. Altogether, these computational and experimental approaches provide foundations for using metronomic therapy to control drug-sensitive and -resistant clone balance and highlight the potential of targeting cell metabolism to manage intratumor heterogeneity. [ABSTRACT FROM AUTHOR]

Dysregulation of retinoic acid signaling is implicated in several human cancer types, including melanoma where the gene encoding retinoic acid receptor beta (RARβ) is frequently silenced by promoter hypermethylation. In this chapter, we describe some of the experimental procedures that we have used to characterize the role of RARβ signaling on the regulation of cellular metabolism in melanoma. Central to these studies is the use of the Seahorse XF Analyzer, which allows real-time assessment of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in cultured cells as readouts for oxidative phosphorylation and glycolysis, respectively. The levels of RARβ signaling can be modulated using RARβ agonists (e.g., all-trans retinoic acid) and antagonists (e.g., LE135). The bioenergetic profiles of melanoma cells in response to RARβ modulators and other metabolic modifiers can be the basis for defining new therapeutic strategies.