Abstract 14312: Hexokinase 1 Cellular Localization Regulates the Metabolic Fate of Glucose

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Adam DEJESUS
Keyword(s):  
Inflammatory Response ◽  
Subcellular Localization ◽  
Cellular Localization ◽  
Cytokine Production ◽  
Pentose Phosphate ◽  
Binding Domain ◽  
Low Grade ◽  
Alternative Pathways ◽  
Gapdh Activity ◽  
Glucose Flux

Introduction: The product of hexokinase (HK) enzymes, glucose-6-phosphate (G6P), can be metabolized through glycolysis or directed to alternative pathways, such as the pentose-phosphate-pathway (PPP) for anabolism. However, it is not known what determines the fate of G6P. HK1 contains an N-terminal mitochondrial-binding domain, but its physiologic significance remains unclear. Inflammation is a tightly controlled process sensitive to dynamic changes in the tissue environment and the intrinsic state of immune cells, both contributing to the initiation and resolution of inflammation. The loss of HK1 attenuates glycolytic reprogramming and inflammatory cytokine production in LPS stimulated macrophages. Given the importance of HK1 in the innate immune response, we used myeloid cells as a model system to study the effect of HK1 subcellular localization on cellular metabolism and inflammation. Results: We overexpressed full-length and truncated HK1 in tissue culture and generated mice lacking the HK1 mitochondrial-binding domain (ΔE1HK1). Although ΔE1HK1 mice displayed no overt phenotype, HK1 dislocation from the mitochondria increased glucose flux through the PPP, decreased flux below the level of GAPDH, and induced a hyper-inflammatory response to lipopolysaccharide. The mechanism for the increased PPP flux is through a glycolytic block at GAPDH, which is mediated by binding of cytosolic HK1 with S100A8/A9 and increased GAPDH nitrosylation through iNOS. Human and mouse macrophages from conditions of low-grade inflammation, such as aging and diabetes, displayed an increase in cytosolic HK1 and cytokine production, along with reduced GAPDH activity. Conclusions: Our data indicate that HK1 subcellular localization is a critical regulator of glucose metabolism and determines whether glucose is shuttled into PPP at the expense of glycolysis, and regulates the inflammatory response in macrophages (Figure).

scholarly journals Adipocyte death triggers a pro-inflammatory response and induces metabolic activation of resident macrophages

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Andreas Lindhorst ◽  
Nora Raulien ◽  
Peter Wieghofer ◽  
Jens Eilers ◽  
Fabio M. V. Rossi ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Metabolic Activation ◽  
Degradation Process ◽  
Critical Threshold ◽  
Low Grade ◽  
Blood Monocytes ◽  
Threshold Size ◽  
Laser Injury ◽  
Reporter Mice

AbstractA chronic low-grade inflammation within adipose tissue (AT) seems to be the link between obesity and some of its associated diseases. One hallmark of this AT inflammation is the accumulation of AT macrophages (ATMs) around dead or dying adipocytes, forming so-called crown-like structures (CLS). To investigate the dynamics of CLS and their direct impact on the activation state of ATMs, we established a laser injury model to deplete individual adipocytes in living AT from double reporter mice (GFP-labeled ATMs and tdTomato-labeled adipocytes). Hence, we were able to detect early ATM-adipocyte interactions by live imaging and to determine a precise timeline for CLS formation after adipocyte death. Further, our data indicate metabolic activation and increased lipid metabolism in ATMs upon forming CLS. Most importantly, adipocyte death, even in lean animals under homeostatic conditions, leads to a locally confined inflammation, which is in sharp contrast to other tissues. We identified cell size as cause for the described pro-inflammatory response, as the size of adipocytes is above a critical threshold size for efferocytosis, a process for anti-inflammatory removal of dead cells during tissue homeostasis. Finally, experiments on parabiotic mice verified that adipocyte death leads to a pro-inflammatory response of resident ATMs in vivo, without significant recruitment of blood monocytes. Our data indicate that adipocyte death triggers a unique degradation process and locally induces a metabolically activated ATM phenotype that is globally observed with obesity.

C1QTNF6 participates in the pathogenesis of PCOS by affecting the inflammatory response of granulosa cells

2021 ◽  
Author(s):  
Sisi Yan ◽  
Jinli Ding ◽  
Yi Zhang ◽  
Jiayu Wang ◽  
Sainan Zhang ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Mouse Models ◽  
Granulosa Cells ◽  
Polycystic Ovary ◽  
Serum Levels ◽  
Inflammatory Factors ◽  
Low Grade ◽  
Reactive Protein ◽  
Reproductive Endocrine ◽  
Factor Α

Abstract Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disease. It has been reported that chronic low-grade inflammation might participate in its pathogenesis. C1q and TNF related 6 (C1QTNF6) is a newly identified adiponectin paralog associated with inflammation. The aim of the present study was to investigate the role of C1QTNF6 in the development of chronic inflammation in PCOS and the underlying molecular mechanism. After analyzing the expression of C1QTNF6 in the serum and granulosa cells (GCs) of PCOS patients and healthy controls, we verified the roles of C1QTNF6 in inflammation through dehydroepiandrosterone-induced PCOS mouse models and cell models of lipopolysaccharide (LPS)-induced inflammation. The results demonstrated that C1QTNF6 expression in the serum and GCs of patients with PCOS was significantly elevated compared with those of the controls, and similar results were observed in the serum and ovary of PCOS mouse models. In PCOS mice and C1QTNF6-overexpressing PCOS mice, serum levels of pro-inflammatory factors including C-reactive protein (CRP), interleukin 6 (IL6) and tumor necrosis factor-α (TNFα) were increased, while the opposite effects were observed when C1QTNF6 was downregulated in PCOS mice. Furthermore, C1QTNF6 overexpression upregulated the levels of TNFα, IL6, and CRP and activated the AKT/NF-κB pathway in LPS-treated KGN cells, whereas C1QTNF6 knockdown and BAY-117082 (an NF-κB inhibitor) treatment resulted in the opposite effects. Taken together, our results indicate that C1QTNF6 is involved in the pathogenesis of PCOS by affecting the inflammatory response via the AKT/NF-κB signaling pathway.

scholarly journals Inflammatory Mediators and Insulin Resistance in Obesity: Role of Nuclear Receptor Signaling in Macrophages

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Lucía Fuentes ◽  
Tamás Rőszer ◽  
Mercedes Ricote
Keyword(s):  
Insulin Resistance ◽  
Nuclear Receptor ◽  
Cytokine Production ◽  
Current Knowledge ◽  
Liver Steatosis ◽  
Visceral Obesity ◽  
M2 Macrophage ◽  
Low Grade ◽  
The Impact

Visceral obesity is coupled to a general low-grade chronic inflammatory state characterized by macrophage activation and inflammatory cytokine production, leading to insulin resistance (IR). The balance between proinflammatory M1 and antiinflammatory M2 macrophage phenotypes within visceral adipose tissue appears to be crucially involved in the development of obesity-associated IR and consequent metabolic abnormalities. The ligand-dependent transcription factors peroxisome proliferator activated receptors (PPARs) have recently been implicated in the determination of the M1/M2 phenotype. Liver X receptors (LXRs), which form another subgroup of the nuclear receptor superfamily, are also important regulators of proinflammatory cytokine production in macrophages. Disregulation of macrophage-mediated inflammation by PPARs and LXRs therefore underlies the development of IR. This review summarizes the role of PPAR and LXR signaling in macrophages and current knowledge about the impact of these actions in the manifestation of IR and obesity comorbidities such as liver steatosis and diabetic osteopenia.

Mass isotopomer study of the nonoxidative pathways of the pentose cycle with [1,2-13C2]glucose

1998 ◽  
Vol 274 (5) ◽  
pp. E843-E851 ◽  
Author(s):  
Wai-Nang Paul Lee ◽  
Laszlo G. Boros ◽  
Joaquim Puigjaner ◽  
Sara Bassilian ◽  
Shu Lim ◽  
...  
Keyword(s):  
Pentose Phosphate ◽  
Gas Chromatography Mass Spectrometry ◽  
Hep G2 ◽  
Tracer Method ◽  
Human Hepatoma Cells ◽  
Glucose Flux ◽  
Isotopomer Analysis ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Mass Isotopomer

We present a single-tracer method for the study of the pentose phosphate pathway (PPP) using [1,2-13C2]glucose and mass isotopomer analysis. The metabolism of [1,2-13C2]glucose by the glucose-6-phosphate dehydrogenase, transketolase (TK), and transaldolase (TA) reactions results in unique pentose and lactate isotopomers with either one or two13C substitutions. The distribution of these isotopomers was used to estimate parameters of the PPP using the model of Katz and Rognstad (J. Katz and R. Rognstad. Biochemistry 6: 2227–2247, 1967). Mass and position isotopomers of ribose, and lactate and palmitate (products from triose phosphate) from human hepatoma cells (Hep G2) incubated with 30% enriched [1,2-13C2]glucose were determined using gas chromatography-mass spectrometry. After 24–72 h incubation, 1.9% of lactate molecules in the medium contained one 13C substitution ( m 1) and 10% contained two 13C substitutions ( m 2). A similar m 1-to- m 2ratio was found in palmitate as expected. Pentose cycle (PC) activity determined from incubation with [1,2-13C2]glucose was 5.73 ± 0.52% of the glucose flux, which was identical to the value of PC (5.55 ± 0.73%) determined by separate incubations with [1-13C] and [6-13C]glucose.13C was found to be distributed in four ribose isotopomers ([1-13C]-, [5-13C]-, [1,2-13C2]-, and [4,5-13C2]ribose). The observed ribose isotopomer distribution was best matched with that provided from simulation by substituting 0.032 for TK and 0.85 for TA activity relative to glucose uptake into the model of Katz and Rognstad. The use of [1,2-13C2]glucose not only permits the determination of PC but also allows estimation of relative rates through the TK and TA reactions.

Cyane-carvone, a Synthetic Derivative of Carvone, Inhibits Inflammatory Response by Reducing Cytokine Production and Oxidative Stress and Shows Antinociceptive Effect in Mice

Inflammation ◽  
2014 ◽  
Author(s):  
Thiago Henrique Costa Marques ◽  
Maria Leonildes Boavista Gomes Cast Marques ◽  
Jand-Venes R. Medeiros ◽  
Renan Oliveira Silva ◽  
André Luiz dos Reis Barbosa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Response ◽  
Cytokine Production ◽  
Antinociceptive Effect ◽  
Synthetic Derivative ◽  
And Oxidative Stress

scholarly journals Effect of pregnancy hormone mixtures on cytokine production and surface marker expression in naïve and LPS-activated THP-1 differentiated monocytes/macrophages

2019 ◽  
Vol 26 (2) ◽  
pp. 84-96
Author(s):  
María Isabel Mendoza-Cabrera ◽  
Rosa-Elena Navarro-Hernández ◽  
Anne Santerre ◽  
Pablo Cesar Ortiz-Lazareno ◽  
Ana Laura Pereira-Suárez ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Cytokine Production ◽  
Immune Cell ◽  
Surface Marker ◽  
Independent Manner ◽  
Surface Marker Expression ◽  
Monocytes And Macrophages ◽  
Marker Expression ◽  
Activated Monocytes ◽  
In Pregnancy

In pregnancy, maternal monocytes and macrophages acquire a specific phenotype that enables them to maintain immune tolerance and facilitate hormone–immune cell interactions, which are necessary for gestational progression. The aim of this study was to determine the effect of pregnancy hormone mixtures of the first and third trimesters on both resting and activated monocytes and macrophages. Pregnancy hormone levels (cortisol, estradiol, progesterone, and prolactin) were quantified at the first and third trimesters. The average of the levels obtained was used to prepare two mixtures of synthetic hormones: low and high. These mixtures were then used to stimulate THP-1 monocytes and macrophages, resting or activated with LPS. Cytokine production in the culture supernatants and surface marker expression (CD14, CD86, and CD163) were evaluated by ELISA and flow cytometry, respectively. We found that the hormones modulated the pro-inflammatory response of THP-1 cells, LPS-activated monocytes, and macrophages, inducing high levels of IL-10 and low levels of IL-8, IL-1-β, and IL-6. All hormone stimulation increased the CD163 receptor in both resting and LPS-activated monocytes and macrophages in a dose-independent manner, unlike CD14 and CD86. Pregnancy hormones promote the expression of the markers associated with the M2-like phenotype, modulating their pro-inflammatory response. This phenotype regulation by hormones could be a determinant in pregnancy.

scholarly journals Pentose Phosphate Pathway Regulates Tolerogenic Apoptotic Cell Clearance and Immune Tolerance

2022 ◽  
Vol 12 ◽  
Author(s):  
Dan He ◽  
Qiangdongzi Mao ◽  
Jialin Jia ◽  
Zhiyu Wang ◽  
Yu Liu ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Immune Tolerance ◽  
Lupus Erythematosus ◽  
Pentose Phosphate Pathway ◽  
Apoptotic Cell ◽  
Pentose Phosphate ◽  
Metabolic Reprogramming ◽  
Macrophage Phagocytosis ◽  
Cell Clearance ◽  
Underlying Mechanisms

The efficient removal of apoptotic cells (ACs), a process termed as efferocytosis, is essential for immune homeostasis. While recent work has established an important interplay between efferocytosis and cellular metabolic changing, underlying mechanisms remain poorly known. Here, we discovered that pentose phosphate pathway (PPP) regulates tolerogenic ACs clearance and immune tolerance. ACs decreased levels of PPP-related genes and metabolites in macrophages. AG1, the agonist of PPP, increased the activity of PPP but greatly reduced macrophage phagocytosis of ACs and enhanced the inflammatory response during efferocytosis. miR-323-5p regulated the expression of PPP-related genes and its levels increased during efferocytosis. miR-323-5p inhibitor greatly promoted levels of PPP-related genes, reduced the macrophage phagocytosis of ACs, and increased inflammatory response during efferocytosis, suggesting that miR-323-5p was essential in regulating PPP activity and ACs clearance in macrophages. Correspondingly, the PPP agonist AG1 exacerbated the lupus-like symptoms in the AC-induced systemic lupus erythematosus (SLE) model. Our study reveals that regulating PPP-dependent metabolic reprogramming is critical for tolerogenic ACs phagocytosis and immune tolerance.

Positional information and pattern regulation in hydra: enzyme profiles

Development ◽  
1975 ◽  
Vol 33 (4) ◽  
pp. 853-867
Author(s):  
Najma Zaheer Baquer ◽  
Patricia McLean ◽  
Amata Hornbruch ◽  
L. Wolpert
Keyword(s):  
Pentose Phosphate Pathway ◽  
Citrate Synthase ◽  
Positional Information ◽  
Pentose Phosphate ◽  
Basal Region ◽  
Redox Systems ◽  
Metabolic Pattern ◽  
Alternative Pathways ◽  
Redox States ◽  
Pattern Regulation

Certain key enzymes of alternative pathways of glucose metabolism, of amino acid metabolism and of redox systems have been measured in hydra and this profile compared with mammalian differentiated tissues with a view to locating pathways of specific importance in hydra. There was a marked constant proportionality in the major part of the enzymes investigated, the profile suggested a metabolic pattern geared to utilization of amino acids as a carbon source for biosynthesis and energy production and to the production and conservation of pyruvate. The importance of conversion to ionized forms was noted. The most notable specific proportion changes were the exceptionally low lactate dehydrogenase, malic enzyme and the relatively high citrate synthase. The proximal-distal gradients in hydra were examined and these gradients suggested a switch to a more anaerobic type of metabolism and an elevation of the pentose phosphate pathway as the basal region was approached. Measurements of the formation of 14CO2 from specifically labelled glucose provided additional evidence for the functional activity and polarity of the pentose phosphate pathway in hydra. The effect of oligomycin, which can reverse polarity in hydra, had a significant effect on gradients of enzymes eliminating all except that observed for G6P dehydrogenase. The profile suggested a movement towards a more anaerobic type of metabolism, in keeping with the known biochemical action of this inhibitor. It is suggested that redox states and/or phosphorylation states may be featured in the positional information of cells in hydra.

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