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Nature Reviews. Molecular Cell Biology Mar 2018Studies of bioactive lipids in general and sphingolipids in particular have intensified over the past several years, revealing an unprecedented and unanticipated... (Review)
Review
Studies of bioactive lipids in general and sphingolipids in particular have intensified over the past several years, revealing an unprecedented and unanticipated complexity of the lipidome and its many functions, which rivals, if not exceeds, that of the genome or proteome. These results highlight critical roles for bioactive sphingolipids in most, if not all, major cell biological responses, including all major cell signalling pathways, and they link sphingolipid metabolism to key human diseases. Nevertheless, the fairly nascent field of bioactive sphingolipids still faces challenges in its biochemical and molecular underpinnings, including defining the molecular mechanisms of pathway and enzyme regulation, the study of lipid-protein interactions and the development of cellular probes, suitable biomarkers and therapeutic approaches.
Topics: Aging; Animals; Apoptosis; Autophagy; Biological Transport, Active; Cell Adhesion; Cell Compartmentation; Cell Movement; DNA Damage; Enzymes; Humans; Immune System; Inflammation; Lipid Metabolism; Metabolic Diseases; Metabolic Networks and Pathways; Models, Biological; Neoplasms; Signal Transduction; Sphingolipids
PubMed: 29165427
DOI: 10.1038/nrm.2017.107 -
Nature Reviews. Cancer Jan 2018Sphingolipids, including the two central bioactive lipids ceramide and sphingosine-1-phosphate (S1P), have opposing roles in regulating cancer cell death and survival,... (Review)
Review
Sphingolipids, including the two central bioactive lipids ceramide and sphingosine-1-phosphate (S1P), have opposing roles in regulating cancer cell death and survival, respectively, and there have been exciting developments in understanding how sphingolipid metabolism and signalling regulate these processes in response to anticancer therapy. Recent studies have provided mechanistic details of the roles of sphingolipids and their downstream targets in the regulation of tumour growth and response to chemotherapy, radiotherapy and/or immunotherapy using innovative molecular, genetic and pharmacological tools to target sphingolipid signalling nodes in cancer cells. For example, structure-function-based studies have provided innovative opportunities to develop mechanism-based anticancer therapeutic strategies to restore anti-proliferative ceramide signalling and/or inhibit pro-survival S1P-S1P receptor (S1PR) signalling. This Review summarizes how ceramide-induced cellular stress mediates cancer cell death through various mechanisms involving the induction of apoptosis, necroptosis and/or mitophagy. Moreover, the metabolism of ceramide for S1P biosynthesis, which is mediated by sphingosine kinase 1 and 2, and its role in influencing cancer cell growth, drug resistance and tumour metastasis through S1PR-dependent or receptor-independent signalling are highlighted. Finally, studies targeting enzymes involved in sphingolipid metabolism and/or signalling and their clinical implications for improving cancer therapeutics are also presented.
Topics: Animals; Apoptosis; Ceramides; Drug Resistance, Neoplasm; Humans; Lysophospholipids; Neoplasms; Signal Transduction; Sphingolipids; Sphingosine
PubMed: 29147025
DOI: 10.1038/nrc.2017.96 -
British Journal of Pharmacology Dec 2021Macrophage activation in response to stimulation of Toll-like receptor 4 (TLR4) provides a paradigm for investigating energy metabolism that regulates the inflammatory... (Review)
Review
Macrophage activation in response to stimulation of Toll-like receptor 4 (TLR4) provides a paradigm for investigating energy metabolism that regulates the inflammatory response. TLR4-mediated pro-inflammatory macrophage activation is characterized by increased glycolysis and altered mitochondrial metabolism, supported by selective amino acid uptake and/or usage. Fatty acid metabolism remains as a highly complex rewiring that accompanies classical macrophage activation. TLR4 activation leads to de novo synthesis of fatty acids, which flux into sphingolipids, complex lipids that form the building blocks of eukaryotic cell membranes and regulate cell function. Here, we review the importance of TLR4-mediated de novo synthesis of membrane sphingolipids in macrophages. We first highlight fatty acid metabolism during TLR4-driven macrophage immunometabolism. We then focus on the temporal dynamics of sphingolipid biosynthesis and emphasize the modulatory role of some sphingolipid species (i.e. sphingomyelins, ceramides and glycosphingolipids) on the pro-inflammatory and pro-resolution phases of LPS/TLR4 activation in macrophages.
Topics: Lipopolysaccharides; Macrophage Activation; Macrophages; Sphingolipids; Toll-Like Receptor 4
PubMed: 34363204
DOI: 10.1111/bph.15642 -
FEBS Letters Nov 2020
Topics: Animals; Cryptococcus neoformans; Gene Expression Regulation; Gene Regulatory Networks; Humans; Plants; Saccharomyces cerevisiae; Signal Transduction; Sphingolipids
PubMed: 33241880
DOI: 10.1002/1873-3468.13979 -
Cell Metabolism Jul 2021The bioactive sphingolipid metabolites ceramide and sphingosine-1-phosphate (S1P) are a recent addition to the lipids accumulated in obesity and have emerged as... (Review)
Review
The bioactive sphingolipid metabolites ceramide and sphingosine-1-phosphate (S1P) are a recent addition to the lipids accumulated in obesity and have emerged as important molecular players in metabolic diseases. Here we summarize evidence that dysregulation of sphingolipid metabolism correlates with pathogenesis of metabolic diseases in humans. This review discusses the current understanding of how ceramide regulates signaling and metabolic pathways to exacerbate metabolic diseases and the Janus faces for its further metabolite S1P, the kinases that produce it, and the multifaceted and at times opposing actions of S1P receptors in various tissues. Gaps and limitations in current knowledge are highlighted together with the need to further decipher the full array of their actions in tissue dysfunction underlying metabolic pathologies, pointing out prospects to move this young field of research toward the development of effective therapeutics.
Topics: Animals; Humans; Lipid Metabolism; Metabolic Diseases; Metabolic Networks and Pathways; Obesity; Sphingolipids
PubMed: 34233172
DOI: 10.1016/j.cmet.2021.06.006 -
International Journal of Molecular... Feb 2023Sphingolipidoses are defined as a group of rare hereditary diseases resulting from mutations in the genes encoding lysosomal enzymes. This group of lysosomal storage... (Review)
Review
Sphingolipidoses are defined as a group of rare hereditary diseases resulting from mutations in the genes encoding lysosomal enzymes. This group of lysosomal storage diseases includes more than 10 genetic disorders, including GM1-gangliosidosis, Tay-Sachs disease, Sandhoff disease, the AB variant of GM2-gangliosidosis, Fabry disease, Gaucher disease, metachromatic leukodystrophy, Krabbe disease, Niemann-Pick disease, Farber disease, etc. Enzyme deficiency results in accumulation of sphingolipids in various cell types, and the nervous system is also usually affected. There are currently no known effective methods for the treatment of sphingolipidoses; however, gene therapy seems to be a promising therapeutic variant for this group of diseases. In this review, we discuss gene therapy approaches for sphingolipidoses that are currently being investigated in clinical trials, among which adeno-associated viral vector-based approaches and transplantation of hematopoietic stem cells genetically modified with lentiviral vectors seem to be the most effective.
Topics: Humans; Sphingolipids; Sphingolipidoses; Gaucher Disease; Tay-Sachs Disease; Genetic Therapy
PubMed: 36835039
DOI: 10.3390/ijms24043627 -
Bacteroides-Derived Sphingolipids Are Critical for Maintaining Intestinal Homeostasis and Symbiosis.Cell Host & Microbe May 2019Sphingolipids are structural membrane components and important eukaryotic signaling molecules. Sphingolipids regulate inflammation and immunity and were recently...
Sphingolipids are structural membrane components and important eukaryotic signaling molecules. Sphingolipids regulate inflammation and immunity and were recently identified as the most differentially abundant metabolite in stool from inflammatory bowel disease (IBD) patients. Commensal bacteria from the Bacteroidetes phylum also produce sphingolipids, but the impact of these metabolites on host pathways is largely uncharacterized. To determine whether bacterial sphingolipids modulate intestinal health, we colonized germ-free mice with a sphingolipid-deficient Bacteroides thetaiotaomicron strain. A lack of Bacteroides-derived sphingolipids resulted in intestinal inflammation and altered host ceramide pools in mice. Using lipidomic analysis, we described a sphingolipid biosynthesis pathway and revealed a variety of Bacteroides-derived sphingolipids including ceramide phosphoinositol and deoxy-sphingolipids. Annotating Bacteroides sphingolipids in an IBD metabolomic dataset revealed lower abundances in IBD and negative correlations with inflammation and host sphingolipid production. These data highlight the role of bacterial sphingolipids in maintaining homeostasis and symbiosis in the gut.
Topics: Animals; Bacteroides thetaiotaomicron; Germ-Free Life; Homeostasis; Host Microbial Interactions; Inflammatory Bowel Diseases; Intestines; Mice; Sphingolipids; Symbiosis
PubMed: 31071294
DOI: 10.1016/j.chom.2019.04.002 -
Cell Host & Microbe Jun 2022Microbially-derived gut metabolites are important contributors to host phenotypes, many of which may link microbiome composition to metabolic disease. However,...
Microbially-derived gut metabolites are important contributors to host phenotypes, many of which may link microbiome composition to metabolic disease. However, relatively few metabolites with known bioactivity have been traced from specific microbes to host tissues. Here, we use a labeling strategy to characterize and trace bacterial sphingolipids from the gut symbiont Bacteroides thetaiotaomicron to mouse colons and livers. We find that bacterial sphingolipid synthesis rescues excess lipid accumulation in a mouse model of hepatic steatosis and observe the transit of a previously uncharacterized bacterial sphingolipid to the liver. The addition of this sphingolipid to hepatocytes improves respiration in response to fatty-acid overload, suggesting that sphingolipid transfer to the liver could potentially contribute to microbiota-mediated liver function. This work establishes a role for bacterial sphingolipids in modulating hepatic phenotypes and defines a workflow that permits the characterization of other microbial metabolites with undefined functions in host health.
Topics: Animals; Bacteroides thetaiotaomicron; Gastrointestinal Microbiome; Liver; Mice; Microbiota; Sphingolipids
PubMed: 35623356
DOI: 10.1016/j.chom.2022.05.002 -
Cell May 2019Ectopic lipid deposition and altered mitochondrial dynamics contribute to the development of obesity and insulin resistance. However, the mechanistic link between these...
Ectopic lipid deposition and altered mitochondrial dynamics contribute to the development of obesity and insulin resistance. However, the mechanistic link between these processes remained unclear. Here we demonstrate that the C sphingolipid synthesizing ceramide synthases, CerS5 and CerS6, affect distinct sphingolipid pools and that abrogation of CerS6 but not of CerS5 protects from obesity and insulin resistance. We identify proteins that specifically interact with C sphingolipids derived from CerS5 or CerS6. Here, only CerS6-derived C sphingolipids bind the mitochondrial fission factor (Mff). CerS6 and Mff deficiency protect from fatty acid-induced mitochondrial fragmentation in vitro, and the two proteins genetically interact in vivo in obesity-induced mitochondrial fragmentation and development of insulin resistance. Our experiments reveal an unprecedented specificity of sphingolipid signaling depending on specific synthesizing enzymes, provide a mechanistic link between hepatic lipid deposition and mitochondrial fragmentation in obesity, and define the CerS6-derived sphingolipid/Mff interaction as a therapeutic target for metabolic diseases.
Topics: Animals; Apoptosis; Cell Line; HeLa Cells; Humans; Insulin Resistance; Liver; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Mitochondrial Proteins; Obesity; Sphingolipids; Sphingosine N-Acyltransferase
PubMed: 31150623
DOI: 10.1016/j.cell.2019.05.008 -
Communications Biology Oct 2022Dysregulation of sphingomyelin and ceramide metabolism have been implicated in Alzheimer's disease. Genome-wide and transcriptome-wide association studies have...
Dysregulation of sphingomyelin and ceramide metabolism have been implicated in Alzheimer's disease. Genome-wide and transcriptome-wide association studies have identified various genes and genetic variants in lipid metabolism that are associated with Alzheimer's disease. However, the molecular mechanisms of sphingomyelin and ceramide disruption remain to be determined. We focus on the sphingolipid pathway and carry out multi-omics analyses to identify central and peripheral metabolic changes in Alzheimer's patients, correlating them to imaging features. Our multi-omics approach is based on (a) 2114 human post-mortem brain transcriptomics to identify differentially expressed genes; (b) in silico metabolic flux analysis on context-specific metabolic networks identified differential reaction fluxes; (c) multimodal neuroimaging analysis on 1576 participants to associate genetic variants in sphingomyelin pathway with Alzheimer's disease pathogenesis; (d) plasma metabolomic and lipidomic analysis to identify associations of lipid species with dysregulation in Alzheimer's; and (e) metabolite genome-wide association studies to define receptors within the pathway as a potential drug target. We validate our hypothesis in amyloidogenic APP/PS1 mice and show prolonged exposure to fingolimod alleviated synaptic plasticity and cognitive impairment in mice. Our integrative multi-omics approach identifies potential targets in the sphingomyelin pathway and suggests modulators of S1P metabolism as possible candidates for Alzheimer's disease treatment.
Topics: Alzheimer Disease; Animals; Ceramides; Fingolimod Hydrochloride; Genome-Wide Association Study; Humans; Mice; Sphingolipids; Sphingomyelins
PubMed: 36209301
DOI: 10.1038/s42003-022-04011-6