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Cell Metabolism Jan 2020Exercise is an effective strategy for diabetes management but is limited by the phenomenon of exercise resistance (i.e., the lack of or the adverse response to exercise... (Randomized Controlled Trial)
Randomized Controlled Trial
Exercise is an effective strategy for diabetes management but is limited by the phenomenon of exercise resistance (i.e., the lack of or the adverse response to exercise on metabolic health). Here, in 39 medication-naive men with prediabetes, we found that exercise-induced alterations in the gut microbiota correlated closely with improvements in glucose homeostasis and insulin sensitivity (clinicaltrials.gov entry NCT03240978). The microbiome of responders exhibited an enhanced capacity for biosynthesis of short-chain fatty acids and catabolism of branched-chain amino acids, whereas those of non-responders were characterized by increased production of metabolically detrimental compounds. Fecal microbial transplantation from responders, but not non-responders, mimicked the effects of exercise on alleviation of insulin resistance in obese mice. Furthermore, a machine-learning algorithm integrating baseline microbial signatures accurately predicted personalized glycemic response to exercise in an additional 30 subjects. These findings raise the possibility of maximizing the benefits of exercise by targeting the gut microbiota.
Topics: Adult; Algorithms; Animals; Bacteria; Diet; Fecal Microbiota Transplantation; Feces; Gastrointestinal Microbiome; Glucose; High-Intensity Interval Training; Humans; Insulin Resistance; Machine Learning; Male; Metabolome; Mice; Mice, Inbred C57BL; Middle Aged; Prediabetic State
PubMed: 31786155
DOI: 10.1016/j.cmet.2019.11.001 -
Medicine and Science in Sports and... Nov 2016: The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise, and individual muscles/muscle groups. For... (Review)
Review
: The hyperbolic form of the power-duration relationship is rigorous and highly conserved across species, forms of exercise, and individual muscles/muscle groups. For modalities such as cycling, the relationship resolves to two parameters, the asymptote for power (critical power [CP]) and the so-called W' (work doable above CP), which together predict the tolerable duration of exercise above CP. Crucially, the CP concept integrates sentinel physiological profiles-respiratory, metabolic, and contractile-within a coherent framework that has great scientific and practical utility. Rather than calibrating equivalent exercise intensities relative to metabolically distant parameters such as the lactate threshold or V˙O2max, setting the exercise intensity relative to CP unifies the profile of systemic and intramuscular responses and, if greater than CP, predicts the tolerable duration of exercise until W' is expended, V˙O2max is attained, and intolerance is manifested. CP may be regarded as a "fatigue threshold" in the sense that it separates exercise intensity domains within which the physiological responses to exercise can (
CP) be stabilized. The CP concept therefore enables important insights into 1) the principal loci of fatigue development (central vs. peripheral) at different intensities of exercise and 2) mechanisms of cardiovascular and metabolic control and their modulation by factors such as O2 delivery. Practically, the CP concept has great potential application in optimizing athletic training programs and performance as well as improving the life quality for individuals enduring chronic disease. Topics: Energy Metabolism; Exercise; Humans; Isometric Contraction; Lactic Acid; Muscle Fatigue; Muscle, Skeletal; Oxygen Consumption
PubMed: 27031742
DOI: 10.1249/MSS.0000000000000939 -
EBioMedicine Nov 2021Disordered metabolic states, which are characterised by hypoxia and elevated levels of metabolites, particularly lactate, contribute to the immunosuppression in the... (Review)
Review
Disordered metabolic states, which are characterised by hypoxia and elevated levels of metabolites, particularly lactate, contribute to the immunosuppression in the tumour microenvironment (TME). Excessive lactate secreted by metabolism-reprogrammed cancer cells regulates immune responses via causing extracellular acidification, acting as an energy source by shuttling between different cell populations, and inhibiting the mechanistic (previously 'mammalian') target of rapamycin (mTOR) pathway in immune cells. This review focuses on recent advances in the regulation of immune responses by lactate, as well as therapeutic strategies targeting lactate anabolism and transport in the TME, such as those involving glycolytic enzymes and monocarboxylate transporter inhibitors. Considering the multifaceted roles of lactate in cancer metabolism, a comprehensive understanding of how lactate and lactate-targeting therapies regulate immune responses in the TME will provide insights into the complex relationships between metabolism and antitumour immunity.
Topics: Animals; Biological Transport; Biomarkers; Disease Management; Disease Susceptibility; Energy Metabolism; Glycolysis; Humans; Immunomodulation; Immunotherapy; Lactic Acid; Metabolic Networks and Pathways; Neoplasms; Tumor Microenvironment
PubMed: 34656878
DOI: 10.1016/j.ebiom.2021.103627 -
Nature Reviews. Neurology Nov 2019Migraine can be regarded as a conserved, adaptive response that occurs in genetically predisposed individuals with a mismatch between the brain's energy reserve and... (Review)
Review
Migraine can be regarded as a conserved, adaptive response that occurs in genetically predisposed individuals with a mismatch between the brain's energy reserve and workload. Given the high prevalence of migraine, genotypes associated with the condition seem likely to have conferred an evolutionary advantage. Technological advances have enabled the examination of different aspects of cerebral metabolism in patients with migraine, and complementary animal research has highlighted possible metabolic mechanisms in migraine pathophysiology. An increasing amount of evidence - much of it clinical - suggests that migraine is a response to cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity and that the attack itself helps to restore brain energy homeostasis and reduces harmful oxidative stress levels. Greater understanding of metabolism in migraine offers novel therapeutic opportunities. In this Review, we describe the evidence for abnormalities in energy metabolism and mitochondrial function in migraine, with a focus on clinical data (including neuroimaging, biochemical, genetic and therapeutic studies), and consider the relationship of these abnormalities with the abnormal sensory processing and cerebral hyper-responsivity observed in migraine. We discuss experimental data to consider potential mechanisms by which metabolic abnormalities could generate attacks. Finally, we highlight potential treatments that target cerebral metabolism, such as nutraceuticals, ketone bodies and dietary interventions.
Topics: Animals; Brain; Energy Metabolism; Humans; Migraine Disorders; Mitochondria; Oxidative Stress; Treatment Outcome
PubMed: 31586135
DOI: 10.1038/s41582-019-0255-4 -
Cell Host & Microbe Aug 2016Antibody production is a metabolically demanding process that is regulated by gut microbiota, but the microbial products supporting B cell responses remain incompletely...
Antibody production is a metabolically demanding process that is regulated by gut microbiota, but the microbial products supporting B cell responses remain incompletely identified. We report that short-chain fatty acids (SCFAs), produced by gut microbiota as fermentation products of dietary fiber, support host antibody responses. In B cells, SCFAs increase acetyl-CoA and regulate metabolic sensors to increase oxidative phosphorylation, glycolysis, and fatty acid synthesis, which produce energy and building blocks supporting antibody production. In parallel, SCFAs control gene expression to express molecules necessary for plasma B cell differentiation. Mice with low SCFA production due to reduced dietary fiber consumption or microbial insufficiency are defective in homeostatic and pathogen-specific antibody responses, resulting in greater pathogen susceptibility. However, SCFA or dietary fiber intake restores this immune deficiency. This B cell-helping function of SCFAs is detected from the intestines to systemic tissues and conserved among mouse and human B cells, highlighting its importance.
Topics: Animals; Antibody Formation; B-Lymphocytes; Cell Differentiation; Dietary Fiber; Fatty Acids, Volatile; Fermentation; Gastrointestinal Microbiome; Gastrointestinal Tract; Gene Expression Regulation; Metabolic Networks and Pathways; Mice, Inbred C57BL
PubMed: 27476413
DOI: 10.1016/j.chom.2016.07.001 -
Immunological Reviews May 2021While the existence of a special relationship between Mycobacterium tuberculosis (Mtb) and host lipids has long been known, it remains a challenging enigma. It was... (Review)
Review
While the existence of a special relationship between Mycobacterium tuberculosis (Mtb) and host lipids has long been known, it remains a challenging enigma. It was clearly established that Mtb requires host fatty acids (FAs) and cholesterol to produce energy, build its distinctive lipid-rich cell wall, and produce lipid virulence factors. It was also observed that in infected hosts, Mtb constantly resides in a FA-rich environment that the pathogen contributes to generate by inducing a lipid-laden "foamy" phenotype in host macrophages. These observations and the proximity between lipid droplets and phagosomes containing bacteria within infected macrophages gave rise to the hypothesis that Mtb reprograms host cell lipid metabolism to ensure a continuous supply of essential nutrients and its long-term persistence in vivo. However, recent studies question this principle by indicating that in Mtb-infected macrophages, lipid droplet formation prevents bacterial acquisition of host FAs while supporting the production of FA-derived protective lipid mediators. Further, in vivo investigations reveal discrete macrophage phenotypes linking the FA metabolisms of host cell and intracellular pathogen. Notably, FA storage within lipid droplets characterizes both macrophages controlling Mtb infection and dormant intracellular Mtb. In this review, we integrate findings from immunological and microbiological studies illustrating the new concept that cytoplasmic accumulation of FAs is a metabolic adaptation of macrophages to Mtb infection, which potentiates their antimycobacterial responses and forces the intracellular pathogen to shift into fat-saving, survival mode.
Topics: Fatty Acids; Host-Pathogen Interactions; Humans; Lipid Metabolism; Macrophages; Mycobacterium tuberculosis; Tuberculosis
PubMed: 33559209
DOI: 10.1111/imr.12952 -
Open Biology Nov 2022Neutrophils are front line cells in immunity that quickly recognize and eliminate pathogens, relying mainly on glycolysis to exert their killing functions. Even though... (Review)
Review
Neutrophils are front line cells in immunity that quickly recognize and eliminate pathogens, relying mainly on glycolysis to exert their killing functions. Even though investigations into the influence of metabolic pathways in neutrophil function started in the 1930s, the knowledge of how neutrophils metabolically adapt during a bacterial infection remains poorly understood. In this review, we discuss the current knowledge about the metabolic regulation underlying neutrophils response to bacterial infection. Glycogen metabolism has been shown to be important for multiple neutrophil functions. The potential contribution of metabolic pathways other than glycolysis, such as mitochondrial metabolism, for neutrophil function has recently been explored, including fatty acid oxidation in neutrophil differentiation. Complex III in the mitochondria might also control glycolysis via glycerol-3-phosphate oxidation. Future studies should yield new insights into the role of metabolic change in the anti-bacterial response in neutrophils.
Topics: Humans; Neutrophils; Glycolysis; Bacterial Infections; Mitochondria; Oxidation-Reduction
PubMed: 36416011
DOI: 10.1098/rsob.220248 -
Molecular Metabolism Aug 2020Organisms can be primed by metabolic exposures to continue expressing response genes even once the metabolite is no longer available, and can affect the speed and... (Review)
Review
BACKGROUND
Organisms can be primed by metabolic exposures to continue expressing response genes even once the metabolite is no longer available, and can affect the speed and magnitude of responsive gene expression during subsequent exposures. This "metabolic transcriptional memory" can have a profound impact on the survivability of organisms in fluctuating environments.
SCOPE OF REVIEW
Here I present several examples of metabolic transcriptional memory in the microbial world and discuss what is known so far regarding the underlying mechanisms, which mainly focus on chromatin modifications, protein inheritance, and broad changes in metabolic network. From these lessons learned in microbes, some insights into the yet understudied human metabolic memory can be gained. I thus discuss the implications of metabolic memory in disease progression in humans - i.e., the memory of high blood sugar exposure and the resulting effects on diabetic complications.
MAJOR CONCLUSIONS
Carbon source shifts from glucose to other less preferred sugars such as lactose, galactose, and maltose for energy metabolism as well as starvation of a signal transduction precursor sugar inositol are well-studied examples of metabolic transcriptional memory in Escherichia coli and Saccharomyces cerevisiae. Although the specific factors guiding metabolic transcriptional memory are not necessarily conserved from microbes to humans, the same basic mechanisms are in play, as is observed in hyperglycemic memory. Exploration of new metabolic transcriptional memory systems as well as further detailed mechanistic analyses of known memory contexts in microbes is therefore central to understanding metabolic memory in humans, and may be of relevance for the successful treatment of the ever-growing epidemic of diabetes.
Topics: Animals; Escherichia coli; Galactose; Gene Expression; Gene Expression Regulation; Glucose; Humans; Metabolic Networks and Pathways; Metabolism; Saccharomyces cerevisiae; Transcriptional Activation
PubMed: 32240621
DOI: 10.1016/j.molmet.2020.01.019 -
Redox Biology Feb 2023The metabolic associated fatty liver disease (MAFLD) is a public health challenge, leading to a global increase in chronic liver disease. The respiratory exposure of...
The metabolic associated fatty liver disease (MAFLD) is a public health challenge, leading to a global increase in chronic liver disease. The respiratory exposure of silica nanoparticles (SiNPs) has revealed to induce hepatotoxicity. However, its role in the pathogenesis and progression of MAFLD was severely under-studied. In this context, the hepatic impacts of SiNPs were investigated in vivo and in vitro through using ApoE mice and free fatty acid (FFA)-treated L02 hepatocytes. Histopathological examinations and biochemical analysis showed SiNPs exposure via intratracheal instillation aggravated hepatic steatosis, lipid vacuolation, inflammatory infiltration and even collagen deposition in ApoE mice, companied with increased hepatic ALT, AST and LDH levels. The enhanced fatty acid synthesis and inhibited fatty acid β-oxidation and lipid efflux may account for the increased hepatic TC/TG by SiNPs. Consistently, SiNPs induced lipid deposition and elevated TC in FFA-treated L02 cells. Further, the activation of hepatic oxidative stress was detected in vivo and in vitro, as evidenced by ROS accumulation, elevated MDA, declined GSH/GSSG and down-regulated Nrf2 signaling. Endoplasmic reticulum (ER) stress was also triggered in response to SiNPs-induced lipid accumulation, as reflecting by the remarkable ER expansion and increased BIP expression. More importantly, an UPLC-MS-based metabolomics analysis revealed that SiNPs disturbed the hepatic metabolic profile in ApoE mice, prominently on amino acids and lipid metabolisms. In particular, the identified differential metabolites were strongly correlated to the activation of oxidative stress and ensuing hepatic TC/TG accumulation and liver injuries, contributing to the progression of liver diseases. Taken together, our study showed SiNPs promoted hepatic steatosis and liver damage, resulting in the aggravation of MAFLD progression. More importantly, the disturbed amino acids and lipid metabolisms-mediated oxidative stress was a key contributor to this phenomenon from a metabolic perspective.
Topics: Animals; Mice; Lipid Metabolism; Silicon Dioxide; Amino Acids; Chromatography, Liquid; Tandem Mass Spectrometry; Oxidative Stress; Liver; Nanoparticles; Non-alcoholic Fatty Liver Disease; Lipids; Fatty Acids
PubMed: 36512914
DOI: 10.1016/j.redox.2022.102569