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Nature Reviews. Molecular Cell Biology Jul 2020'Reactive oxygen species' (ROS) is an umbrella term for an array of derivatives of molecular oxygen that occur as a normal attribute of aerobic life. Elevated formation... (Review)
Review
'Reactive oxygen species' (ROS) is an umbrella term for an array of derivatives of molecular oxygen that occur as a normal attribute of aerobic life. Elevated formation of the different ROS leads to molecular damage, denoted as 'oxidative distress'. Here we focus on ROS at physiological levels and their central role in redox signalling via different post-translational modifications, denoted as 'oxidative eustress'. Two species, hydrogen peroxide (HO) and the superoxide anion radical (O), are key redox signalling agents generated under the control of growth factors and cytokines by more than 40 enzymes, prominently including NADPH oxidases and the mitochondrial electron transport chain. At the low physiological levels in the nanomolar range, HO is the major agent signalling through specific protein targets, which engage in metabolic regulation and stress responses to support cellular adaptation to a changing environment and stress. In addition, several other reactive species are involved in redox signalling, for instance nitric oxide, hydrogen sulfide and oxidized lipids. Recent methodological advances permit the assessment of molecular interactions of specific ROS molecules with specific targets in redox signalling pathways. Accordingly, major advances have occurred in understanding the role of these oxidants in physiology and disease, including the nervous, cardiovascular and immune systems, skeletal muscle and metabolic regulation as well as ageing and cancer. In the past, unspecific elimination of ROS by use of low molecular mass antioxidant compounds was not successful in counteracting disease initiation and progression in clinical trials. However, controlling specific ROS-mediated signalling pathways by selective targeting offers a perspective for a future of more refined redox medicine. This includes enzymatic defence systems such as those controlled by the stress-response transcription factors NRF2 and nuclear factor-κB, the role of trace elements such as selenium, the use of redox drugs and the modulation of environmental factors collectively known as the exposome (for example, nutrition, lifestyle and irradiation).
Topics: Aging; Animals; Antioxidants; Humans; Neoplasms; Oxidation-Reduction; Oxidative Stress; Protein Processing, Post-Translational; Reactive Oxygen Species; Signal Transduction
PubMed: 32231263
DOI: 10.1038/s41580-020-0230-3 -
The Journal of Clinical Investigation Jul 2019Development of novel and effective therapeutics for treating various cancers is probably the most congested and challenging enterprise of pharmaceutical companies.... (Review)
Review
Development of novel and effective therapeutics for treating various cancers is probably the most congested and challenging enterprise of pharmaceutical companies. Diverse drugs targeting malignant and nonmalignant cells receive clinical approval each year from the FDA. Targeting cancer cells and nonmalignant cells unavoidably changes the tumor microenvironment, and cellular and molecular components relentlessly alter in response to drugs. Cancer cells often reprogram their metabolic pathways to adapt to environmental challenges and facilitate survival, proliferation, and metastasis. While cancer cells' dependence on glycolysis for energy production is well studied, the roles of adipocytes and lipid metabolic reprogramming in supporting cancer growth, metastasis, and drug responses are less understood. This Review focuses on emerging mechanisms involving adipocytes and lipid metabolism in altering the response to cancer treatment. In particular, we discuss mechanisms underlying cancer-associated adipocytes and lipid metabolic reprogramming in cancer drug resistance.
Topics: Adipocytes; Animals; Drug Resistance, Neoplasm; Glycolysis; Humans; Lipid Metabolism; Neoplasms; Tumor Microenvironment
PubMed: 31264969
DOI: 10.1172/JCI127201 -
Frontiers in Immunology 2019Macrophages are a heterogeneous population of immune cells playing several and diverse functions in homeostatic and immune responses. The broad spectrum of macrophage... (Review)
Review
Macrophages are a heterogeneous population of immune cells playing several and diverse functions in homeostatic and immune responses. The broad spectrum of macrophage functions depends on both heterogeneity and plasticity of these cells, which are highly specialized in sensing the microenvironment and modify their properties accordingly. Although it is clear that macrophage phenotypes are difficult to categorize and should be seen as plastic and adaptable, they can be simplified into two extremes: a pro-inflammatory (M1) and an anti-inflammatory/pro-resolving (M2) profile. Based on this definition, M1 macrophages are able to start and sustain inflammatory responses, secreting pro-inflammatory cytokines, activating endothelial cells, and inducing the recruitment of other immune cells into the inflamed tissue; on the other hand, M2 macrophages promote the resolution of inflammation, phagocytose apoptotic cells, drive collagen deposition, coordinate tissue integrity, and release anti-inflammatory mediators. Dramatic switches in cell metabolism accompany these phenotypic and functional changes of macrophages. In particular, M1 macrophages rely mainly on glycolysis and present two breaks on the TCA cycle that result in accumulation of itaconate (a microbicide compound) and succinate. Excess of succinate leads to Hypoxia Inducible Factor 1α (HIF1α) stabilization that, in turn, activates the transcription of glycolytic genes, thus sustaining the glycolytic metabolism of M1 macrophages. On the contrary, M2 cells are more dependent on oxidative phosphorylation (OXPHOS), their TCA cycle is intact and provides the substrates for the complexes of the electron transport chain (ETC). Moreover, pro- and anti-inflammatory macrophages are characterized by specific pathways that regulate the metabolism of lipids and amino acids and affect their responses. All these metabolic adaptations are functional to support macrophage activities as well as to sustain their polarization in specific contexts. The aim of this review is to discuss recent findings linking macrophage functions and metabolism.
Topics: Citric Acid Cycle; Glycolysis; Humans; Inflammation; Macrophage Activation; Macrophages; Oxidation-Reduction; Oxidative Phosphorylation
PubMed: 31333642
DOI: 10.3389/fimmu.2019.01462 -
Cell Metabolism Dec 2020Energetic metabolism reprogramming is critical for cancer and immune responses. Current methods to functionally profile the global metabolic capacities and dependencies...
Energetic metabolism reprogramming is critical for cancer and immune responses. Current methods to functionally profile the global metabolic capacities and dependencies of cells are performed in bulk. We designed a simple method for complex metabolic profiling called SCENITH, for single-cell energetic metabolism by profiling translation inhibition. SCENITH allows for the study of metabolic responses in multiple cell types in parallel by flow cytometry. SCENITH is designed to perform metabolic studies ex vivo, particularly for rare cells in whole blood samples, avoiding metabolic biases introduced by culture media. We analyzed myeloid cells in solid tumors from patients and identified variable metabolic profiles, in ways that are not linked to their lineage or their activation phenotype. SCENITH's ability to reveal global metabolic functions and determine complex and linked immune-phenotypes in rare cell subpopulations will contribute to the information needed for evaluating therapeutic responses or patient stratification.
Topics: Adult; Animals; Cells, Cultured; Energy Metabolism; Female; Fibroblasts; Humans; Male; Metabolome; Mice, Inbred C57BL; Middle Aged; Neoplasms; Single-Cell Analysis
PubMed: 33264598
DOI: 10.1016/j.cmet.2020.11.007 -
Mitochondrion May 2023Pathogenesis and salugenesis are the first and second stages of the two-stage problem of disease production and health recovery. Salugenesis is the automatic,... (Review)
Review
Pathogenesis and salugenesis are the first and second stages of the two-stage problem of disease production and health recovery. Salugenesis is the automatic, evolutionarily conserved, ontogenetic sequence of molecular, cellular, organ system, and behavioral changes that is used by living systems to heal. It is a whole-body process that begins with mitochondria and the cell. The stages of salugenesis define a circle that is energy- and resource-consuming, genetically programmed, and environmentally responsive. Energy and metabolic resources are provided by mitochondrial and metabolic transformations that drive the cell danger response (CDR) and create the three phases of the healing cycle: Phase 1-Inflammation, Phase 2-Proliferation, and Phase 3-Differentiation. Each phase requires a different mitochondrial phenotype. Without different mitochondria there can be no healing. The rise and fall of extracellular ATP (eATP) signaling is a key driver of the mitochondrial and metabolic reprogramming required to progress through the healing cycle. Sphingolipid and cholesterol-enriched membrane lipid rafts act as rheostats for tuning cellular sensitivity to purinergic signaling. Abnormal persistence of any phase of the CDR inhibits the healing cycle, creates dysfunctional cellular mosaics, causes the symptoms of chronic disease, and accelerates the process of aging. New research reframes the rising tide of chronic disease around the world as a systems problem caused by the combined action of pathogenic triggers and anthropogenic factors that interfere with the mitochondrial functions needed for healing. Once chronic pain, disability, or disease is established, salugenesis-based therapies will start where pathogenesis-based therapies end.
Topics: Humans; Mitochondria; Energy Metabolism; Chronic Disease; Signal Transduction
PubMed: 37120082
DOI: 10.1016/j.mito.2023.04.003 -
Cells Jul 2021Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. HCC progression and metastasis are closely related to altered mitochondrial... (Review)
Review
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. HCC progression and metastasis are closely related to altered mitochondrial metabolism, including mitochondrial stress responses, metabolic reprogramming, and mitoribosomal defects. Mitochondrial oxidative phosphorylation (OXPHOS) defects and reactive oxygen species (ROS) production are attributed to mitochondrial dysfunction. In response to oxidative stress caused by increased ROS production, misfolded or unfolded proteins can accumulate in the mitochondrial matrix, leading to initiation of the mitochondrial unfolded protein response (UPR). The mitokines FGF21 and GDF15 are upregulated during UPR and their levels are positively correlated with liver cancer development, progression, and metastasis. In addition, mitoribosome biogenesis is important for the regulation of mitochondrial respiration, cell viability, and differentiation. Mitoribosomal defects cause OXPHOS impairment, mitochondrial dysfunction, and increased production of ROS, which are associated with HCC progression in mouse models and human HCC patients. In this paper, we focus on the role of mitochondrial metabolic signatures in the development and progression of HCC. Furthermore, we provide a comprehensive review of cell autonomous and cell non-autonomous mitochondrial stress responses during HCC progression and metastasis.
Topics: Animals; Carcinoma, Hepatocellular; Disease Progression; Energy Metabolism; Humans; Liver Neoplasms; Metabolome; Mitochondria, Liver; Mitochondrial Ribosomes; Proteostasis; Reactive Oxygen Species; Signal Transduction; Unfolded Protein Response
PubMed: 34440674
DOI: 10.3390/cells10081901 -
Cell Metabolism Sep 2019Reactive microglia are a major pathological feature of Alzheimer's disease (AD). However, the exact role of microglia in AD pathogenesis is still unclear. Here, using...
Reactive microglia are a major pathological feature of Alzheimer's disease (AD). However, the exact role of microglia in AD pathogenesis is still unclear. Here, using metabolic profiling, we found that exposure to amyloid-β triggers acute microglial inflammation accompanied by metabolic reprogramming from oxidative phosphorylation to glycolysis. It was dependent on the mTOR-HIF-1α pathway. However, once activated, microglia reached a chronic tolerant phase as a result of broad defects in energy metabolisms and subsequently diminished immune responses, including cytokine secretion and phagocytosis. Using genome-wide RNA sequencing and multiphoton microscopy techniques, we further identified metabolically defective microglia in 5XFAD mice, an AD mouse model. Finally, we showed that metabolic boosting with recombinant interferon-γ treatment reversed the defective glycolytic metabolism and inflammatory functions of microglia, thereby mitigating the AD pathology of 5XFAD mice. Collectively, metabolic reprogramming is crucial for microglial functions in AD, and modulating metabolism might be a new therapeutic strategy for AD.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Cell Line; Cytokines; Disease Models, Animal; Female; Gene Expression Regulation; Glycolysis; Hypoxia-Inducible Factor 1, alpha Subunit; Inflammation; Interferon-gamma; Male; Mice; Mice, Inbred ICR; Mice, Transgenic; Microglia; Oxidative Phosphorylation; Phagocytosis; Recombinant Proteins; TOR Serine-Threonine Kinases
PubMed: 31257151
DOI: 10.1016/j.cmet.2019.06.005 -
European Review For Medical and... Sep 2019Gut microbiota has a key role in host metabolic regulation and immune response, and its dysbiosis represents one of the main causes of gastrointestinal diseases. In this... (Review)
Review
OBJECTIVE
Gut microbiota has a key role in host metabolic regulation and immune response, and its dysbiosis represents one of the main causes of gastrointestinal diseases. In this scenario, Akkermansia muciniphila is a crucial player in keeping the integrity of the gastrointestinal tract.
MATERIALS AND METHODS
This review focuses on the correlation between gut microbiota and intestinal homeostasis, primarily exploring A. muciniphila and its involvement in the development of metabolic disorders and gastrointestinal diseases.
RESULTS
Akkermansia muciniphila belongs to the Verrucomicrobia phylum, and it colonizes the mucus layer in the gastrointestinal tract, representing 1 to 4% of the fecal microbiota. It stimulates mucosal microbial networks, and it improves intestinal barrier function, providing crucial host immunological responses. Several studies have demonstrated the possible involvement of A. muciniphila in the development of intestinal and metabolic disorders. Indeed, adipose and glucose metabolisms are influenced by A. muciniphila, and its levels inversely correlate to inflammatory conditions, such as inflammatory bowel disease, obesity, and diabetes. Conversely, its therapeutic administration decreases their development.
CONCLUSIONS
A. muciniphila exerts a key role in the maintenance of intestinal health and in host metabolic modulation. Future studies could open new horizons towards its potential therapeutic applications in gastrointestinal and extra-intestinal diseases.
Topics: Akkermansia; Animals; Diabetes Mellitus, Type 2; Dysbiosis; Dyslipidemias; Gastrointestinal Diseases; Gastrointestinal Microbiome; Glucose; Humans; Inflammatory Bowel Diseases; Intestinal Mucosa; Lipid Metabolism; Obesity; Permeability; Verrucomicrobia
PubMed: 31599433
DOI: 10.26355/eurrev_201909_19024 -
Molecular Cell Apr 2022The product of hexokinase (HK) enzymes, glucose-6-phosphate, can be metabolized through glycolysis or directed to alternative metabolic routes, such as the pentose...
The product of hexokinase (HK) enzymes, glucose-6-phosphate, can be metabolized through glycolysis or directed to alternative metabolic routes, such as the pentose phosphate pathway (PPP) to generate anabolic intermediates. HK1 contains an N-terminal mitochondrial binding domain (MBD), but its physiologic significance remains unclear. To elucidate the effect of HK1 mitochondrial dissociation on cellular metabolism, we generated mice lacking the HK1 MBD (ΔE1HK1). These mice produced a hyper-inflammatory response when challenged with lipopolysaccharide. Additionally, there was decreased glucose flux below the level of GAPDH and increased upstream flux through the PPP. The glycolytic block below GAPDH is mediated by the binding of cytosolic HK1 with S100A8/A9, resulting in GAPDH nitrosylation through iNOS. Additionally, human and mouse macrophages from conditions of low-grade inflammation, such as aging and diabetes, displayed increased cytosolic HK1 and reduced GAPDH activity. Our data indicate that HK1 mitochondrial binding alters glucose metabolism through regulation of GAPDH.
Topics: Animals; Glucose; Glycolysis; Hexokinase; Mice; Mitochondria; Pentose Phosphate Pathway
PubMed: 35305311
DOI: 10.1016/j.molcel.2022.02.028 -
Redox Biology Dec 2022Endogenous small molecules are metabolic regulators of cell function. Itaconate is a key molecule that accumulates in cells when the Krebs cycle is disrupted. Itaconate... (Review)
Review
Endogenous small molecules are metabolic regulators of cell function. Itaconate is a key molecule that accumulates in cells when the Krebs cycle is disrupted. Itaconate is derived from cis-aconitate decarboxylation by cis-aconitate decarboxylase (ACOD1) in the mitochondrial matrix and is also known as immune-responsive gene 1 (IRG1). Studies have demonstrated that itaconate plays an important role in regulating signal transduction and posttranslational modification through its immunoregulatory activities. Itaconate is also an important bridge among metabolism, inflammation, oxidative stress, and the immune response. This review summarizes the structural characteristics and classical pathways of itaconate, its derivatives, and the compounds that release itaconate. Here, the mechanisms of itaconate action, including its transcriptional regulation of ATF3/IκBζ axis and type I IFN, its protein modification regulation of KEAP1, inflammasome, JAK1/STAT6 pathway, TET2, and TFEB, and succinate dehydrogenase and glycolytic enzyme metabolic action, are presented. Moreover, the roles of itaconate in diseases related to inflammation and oxidative stress induced by autoimmune responses, viruses, sepsis and IRI are discussed in this review. We hope that the information provided in this review will help increase the understanding of cellular immune metabolism and improve the clinical treatment of diseases related to inflammation and oxidative stress.
Topics: Humans; Kelch-Like ECH-Associated Protein 1; Macrophages; NF-E2-Related Factor 2; Inflammation; Signal Transduction; Oxidative Stress
PubMed: 36459716
DOI: 10.1016/j.redox.2022.102553