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International Journal of Molecular... Mar 2019Lysophosphatidylcholine (LPC) is increasingly recognized as a key marker/factor positively associated with cardiovascular and neurodegenerative diseases. However,... (Review)
Review
Lysophosphatidylcholine (LPC) is increasingly recognized as a key marker/factor positively associated with cardiovascular and neurodegenerative diseases. However, findings from recent clinical lipidomic studies of LPC have been controversial. A key issue is the complexity of the enzymatic cascade involved in LPC metabolism. Here, we address the coordination of these enzymes and the derangement that may disrupt LPC homeostasis, leading to metabolic disorders. LPC is mainly derived from the turnover of phosphatidylcholine (PC) in the circulation by phospholipase A₂ (PLA₂). In the presence of Acyl-CoA, lysophosphatidylcholine acyltransferase (LPCAT) converts LPC to PC, which rapidly gets recycled by the Lands cycle. However, overexpression or enhanced activity of PLA₂ increases the LPC content in modified low-density lipoprotein (LDL) and oxidized LDL, which play significant roles in the development of atherosclerotic plaques and endothelial dysfunction. The intracellular enzyme LPCAT cannot directly remove LPC from circulation. Hydrolysis of LPC by autotaxin, an enzyme with lysophospholipase D activity, generates lysophosphatidic acid, which is highly associated with cancers. Although enzymes with lysophospholipase A₁ activity could theoretically degrade LPC into harmless metabolites, they have not been found in the circulation. In conclusion, understanding enzyme kinetics and LPC metabolism may help identify novel therapeutic targets in LPC-associated diseases.
Topics: 1-Acylglycerophosphocholine O-Acyltransferase; Homeostasis; Humans; Hydrolysis; Lipoproteins, LDL; Lysophosphatidylcholines; Metabolic Diseases; Phosphatidylcholines; Phospholipases A2; Phosphoric Diester Hydrolases
PubMed: 30845751
DOI: 10.3390/ijms20051149 -
Gastroenterology Apr 2016Hepatocyte cellular dysfunction and death induced by lipids and macrophage-associated inflammation are characteristics of nonalcoholic steatohepatitis (NASH). The fatty...
BACKGROUND & AIMS
Hepatocyte cellular dysfunction and death induced by lipids and macrophage-associated inflammation are characteristics of nonalcoholic steatohepatitis (NASH). The fatty acid palmitate can activate death receptor 5 (DR5) on hepatocytes, leading to their death, but little is known about how this process contributes to macrophage-associated inflammation. We investigated whether lipid-induced DR5 signaling results in the release of extracellular vesicles (EVs) from hepatocytes, and whether these can induce an inflammatory macrophage phenotype.
METHODS
Primary mouse and human hepatocytes and Huh7 cells were incubated with palmitate, its metabolite lysophosphatidylcholine, or diluent (control). The released EV were isolated, characterized, quantified, and applied to macrophages. C57BL/6 mice were placed on chow or a diet high in fat, fructose, and cholesterol to induce NASH. Some mice also were given the ROCK1 inhibitor fasudil; 2 weeks later, serum EVs were isolated and characterized by immunoblot and nanoparticle-tracking analyses. Livers were collected and analyzed by histology, immunohistochemistry, and quantitative polymerase chain reaction.
RESULTS
Incubation of primary hepatocytes and Huh7 cells with palmitate or lysophosphatidylcholine increased their release of EVs, compared with control cells. This release was reduced by inactivating mediators of the DR5 signaling pathway or rho-associated, coiled-coil-containing protein kinase 1 (ROCK1) inhibition. Hepatocyte-derived EVs contained tumor necrosis factor-related apoptosis-inducing ligand and induced expression of interleukin 1β and interleukin 6 messenger RNAs in mouse bone marrow-derived macrophages. Activation of macrophages required DR5 and receptor-interacting protein kinase 1. Administration of the ROCK1 inhibitor fasudil to mice with NASH reduced serum levels of EVs; this reduction was associated with decreased liver injury, inflammation, and fibrosis.
CONCLUSIONS
Lipids, which stimulate DR5, induce release of hepatocyte EVs, which activate an inflammatory phenotype in macrophages. Strategies to inhibit ROCK1-dependent release of EVs by hepatocytes might be developed for the treatment of patients with NASH.
Topics: Animals; Caspases; Cell Line, Tumor; Extracellular Vesicles; HEK293 Cells; Hepatitis; Hepatocytes; Humans; Inflammation Mediators; Liver; Liver Cirrhosis, Experimental; Lysophosphatidylcholines; Macrophages; Mice, Inbred C57BL; Mice, Transgenic; Non-alcoholic Fatty Liver Disease; Palmitic Acid; Phenotype; Protein Kinase Inhibitors; RNA Interference; Rats, Sprague-Dawley; Receptors, TNF-Related Apoptosis-Inducing Ligand; Signal Transduction; Transfection; rho-Associated Kinases
PubMed: 26764184
DOI: 10.1053/j.gastro.2015.12.037 -
Kidney International Mar 2022Some patients with diabetic kidney disease (DKD) show a fast progression of kidney dysfunction and are known as a "fast decliner" (FD). Therefore, it is critical to...
Some patients with diabetic kidney disease (DKD) show a fast progression of kidney dysfunction and are known as a "fast decliner" (FD). Therefore, it is critical to understand pathomechanisms specific for fast decline. Here, we performed a comprehensive metabolomic analysis of patients with stage G3 DKD and identified increased urinary lysophosphatidylcholine (LPC) in fast decline. This was confirmed by quantification of urinary LPC using mass spectrometry and identified urinary LPC containing saturated fatty acids palmitic (16:0) and stearic (18:0) acids was increased in FDs. The upsurge in urinary LPC levels was correlated with a decline in estimated glomerular filtration rate after 2.5 years. To clarify a pathogenic role of LPC in FD, we studied an accelerated rat model of DKD and observed an increase in LPC (16:0) and (18:0) levels in the urine and kidney tubulointerstitium as the disease progressed. These findings suggested that local dysregulation of lipid metabolism resulted in excessive accumulation of this LPC species in the kidney. Our in vitro studies also confirmed LPC-mediated lipotoxicity in cultured proximal tubular cells. LPC induced accumulation of lipid droplets via activation of peroxisome proliferator-activated receptor-δ followed by upregulation of the lipid droplet membrane protein perilipin 2 and decreased autophagic flux, thereby inducing organelle stress and subsequent apoptosis. Thus, LPC (16:0) and (18:0) may mediate a fast progression of DKD and may serve as a target for novel therapeutic approaches.
Topics: Animals; Diabetes Mellitus; Diabetic Nephropathies; Glomerular Filtration Rate; Humans; Kidney; Lysophosphatidylcholines; Rats; Renal Insufficiency
PubMed: 34856312
DOI: 10.1016/j.kint.2021.10.039 -
Journal of Biomedical Science Mar 2021Previous study disclosed Fucosyltransferase 2 (Fut2) gene as a IBD risk locus. This study aimed to explore the mechanism of Fut2 in IBD susceptibility and to propose a...
BACKGROUND AND AIMS
Previous study disclosed Fucosyltransferase 2 (Fut2) gene as a IBD risk locus. This study aimed to explore the mechanism of Fut2 in IBD susceptibility and to propose a new strategy for the treatment of IBD.
METHODS
Intestinal epithelium-specific Fut2 knockout (Fut2) mice was used. Colitis was induced by dextran sulfate sodium (DSS). The composition and diversity of gut microbiota were assessed via 16S rRNA analysis and the metabolomic findings was obtained from mice feces via metabolite profiling. The fecal microbiota transplantation (FMT) experiment was performed to confirm the association of gut microbiota and LPC. WT mice were treated with Lysophosphatidylcholine (LPC) to verify its impact on colitis.
RESULTS
The expression of Fut2 and α-1,2-fucosylation in colonic tissues were decreased in patients with UC (UC vs. control, P = 0.036) and CD (CD vs. control, P = 0.031). When treated with DSS, in comparison to WT mice, more severe intestinal inflammation and destructive barrier functions in Fut2 mice was noted. Lower gut microbiota diversity was observed in Fut2 mice compared with WT mice (p < 0.001). When exposed to DSS, gut bacterial diversity and composition altered obviously in Fut2 mice and the fecal concentration of LPC was increased. FMT experiment revealed that mice received the fecal microbiota from Fut2 mice exhibited more severe colitis and higher fecal LPC concentration. Correlation analysis showed that the concentration of LPC was positively correlated with four bacteria-Escherichia, Bilophila, Enterorhabdus and Gordonibacter. Furthermore, LPC was proved to promote the release of pro-inflammatory cytokines and damage epithelial barrier in vitro and in vivo.
CONCLUSION
Fut2 and α-1,2-fucosylation in colon were decreased not only in CD but also in UC patients. Gut microbiota in Fut2 mice is altered structurally and functionally, promoting generation of LPC which was proved to promote inflammation and damage epithelial barrier.
Topics: Animals; Bacteria; Colitis; Fucosyltransferases; Gastrointestinal Microbiome; Humans; Intestinal Mucosa; Lysophosphatidylcholines; Mice; Mice, Transgenic; Galactoside 2-alpha-L-fucosyltransferase
PubMed: 33722220
DOI: 10.1186/s12929-021-00711-z -
Nature Communications Jan 2022Pancreatic cancer has the worst prognosis among all cancers. Cancer screening of body fluids may improve the survival time prognosis of patients, who are often diagnosed...
Pancreatic cancer has the worst prognosis among all cancers. Cancer screening of body fluids may improve the survival time prognosis of patients, who are often diagnosed too late at an incurable stage. Several studies report the dysregulation of lipid metabolism in tumor cells, suggesting that changes in the blood lipidome may accompany tumor growth. Here we show that the comprehensive mass spectrometric determination of a wide range of serum lipids reveals statistically significant differences between pancreatic cancer patients and healthy controls, as visualized by multivariate data analysis. Three phases of biomarker discovery research (discovery, qualification, and verification) are applied for 830 samples in total, which shows the dysregulation of some very long chain sphingomyelins, ceramides, and (lyso)phosphatidylcholines. The sensitivity and specificity to diagnose pancreatic cancer are over 90%, which outperforms CA 19-9, especially at an early stage, and is comparable to established diagnostic imaging methods. Furthermore, selected lipid species indicate a potential as prognostic biomarkers.
Topics: Biomarkers, Tumor; CA-19-9 Antigen; Case-Control Studies; Ceramides; Female; Humans; Lipid Metabolism; Lipidomics; Lysophosphatidylcholines; Male; Multivariate Analysis; Pancreatic Neoplasms; Proportional Hazards Models; Sensitivity and Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sphingomyelins
PubMed: 35013261
DOI: 10.1038/s41467-021-27765-9 -
EBioMedicine Dec 2021Metabolic syndrome (MetS) is a cluster of multiple cardiometabolic risk factors that increase the risk of type 2 diabetes and cardiovascular diseases. Identifying novel...
BACKGROUND
Metabolic syndrome (MetS) is a cluster of multiple cardiometabolic risk factors that increase the risk of type 2 diabetes and cardiovascular diseases. Identifying novel biomarkers of MetS and their genetic associations could provide insights into the mechanisms of cardiometabolic diseases.
METHODS
Potential MetS-associated metabolites were screened and internally validated by untargeted metabolomics analyses among 693 patients with MetS and 705 controls. External validation was conducted using two well-established targeted metabolomic methods among 149 patients with MetS and 253 controls. The genetic associations of metabolites were determined by linear regression using our previous genome-wide SNP data. Causal relationships were assessed using a one-sample Mendelian Randomization (MR) approach.
FINDINGS
Nine metabolites were ultimately found to be associated with MetS or its components. Five metabolites, including LysoPC(14:0), LysoPC(15:0), propionyl carnitine, phenylalanine, and docosapentaenoic acid (DPA) were selected to construct a metabolite risk score (MRS), which was found to have a dose-response relationship with MetS and metabolic abnormalities. Moreover, MRS displayed a good ability to differentiate MetS and metabolic abnormalities. Three SNPs (rs11635491, rs7067822, and rs1952458) were associated with LysoPC(15:0). Two SNPs, rs1952458 and rs11635491 were found to be marginally correlated with several MetS components. MR analyses showed that a higher LysoPC(15:0) level was causally associated with the risk of overweight/obesity, dyslipidaemia, high uric acid, high insulin and high HOMA-IR.
INTERPRETATION
We identified five metabolite biomarkers of MetS and three SNPs associated with LysoPC(15:0). MR analyses revealed that abnormal LysoPC metabolism may be causally linked the metabolic risk.
FUNDING
This work was supported by grants from the National Key Research and Development Program of China (2017YFC0907004).
Topics: Case-Control Studies; Early Diagnosis; Female; Genome-Wide Association Study; Humans; Linear Models; Lysophosphatidylcholines; Male; Mendelian Randomization Analysis; Metabolic Syndrome; Metabolomics; Middle Aged; Polymorphism, Single Nucleotide
PubMed: 34801968
DOI: 10.1016/j.ebiom.2021.103707 -
International Journal of Biological... 2023Dietary fat intake is positively associated with elevated risk of colorectal cancer (CRC). Currently, clinical treatments remian inadequate bacause of the complex...
Dietary fat intake is positively associated with elevated risk of colorectal cancer (CRC). Currently, clinical treatments remian inadequate bacause of the complex pathogenesis of CRC induced by a high-fat diet (HFD). Mechanistically, imbalances in gut microbiota are associated with HFD-associated colorectal tumourigenesis. Therefore, we investigated the anti-tumor activity of berberine (BBR) in modulating the dysregulated gut microbiota and related metabolites by preforming 16S rDNA sequencing and liquid chromatography/mass spectrometry. As expected, BBR treatment significantly decreased the number of colonic polyps, ameliorated gut barrier disruption, and inhibited colon inflammation and related oncogenic pathways in AOM/DSS-induced CRC model mice fed with an HFD. Furthermore, BBR alleviated gut microbiota dysbiosis and increased the abundance of beneficial gut microorganisms, including and , in HFD-fed CRC mice. In addition, metabolomics analysis demonstrated significantly altered the glycerophospholipid metabolism during the progression of HFD-associated CRC in mice, whereas BBR treatment reverted these changes in glycerophospholipid metabolites, particularly lysophosphatidylcholine (LPC), which was confirmed to promote CRC cell proliferation and ameliorate cell junction impairment. Notably, BBR had no clear anti-tumor effects on HFD-fed CRC model mice with gut microbiota depletion, whereas transplantation of BBR-treated gut microbiota to gut microbiota-depleted CRC mice recapitulated the inhibitory effects of BBR on colorectal tumourigenesis and LPC levels. This study demonstrated that BBR inhibited HFD-associated CRC directly through modulating gut microbiota-regulated LPC levels, thereby providing a promising microbiota-modulating therapeutic strategy for the clinical prevention and treatment of Western diet-associated CRC.
Topics: Animals; Mice; Berberine; Diet, High-Fat; Lysophosphatidylcholines; Gastrointestinal Microbiome; Colorectal Neoplasms; Carcinogenesis; Mice, Inbred C57BL
PubMed: 37151876
DOI: 10.7150/ijbs.81824 -
Proceedings of the National Academy of... Oct 2022The lysosome is central to the degradation of proteins, carbohydrates, and lipids and their salvage back to the cytosol for reutilization. Lysosomal transporters for...
The lysosome is central to the degradation of proteins, carbohydrates, and lipids and their salvage back to the cytosol for reutilization. Lysosomal transporters for amino acids, sugars, and cholesterol have been identified, and the metabolic fates of these molecules in the cytoplasm have been elucidated. Remarkably, it is not known whether lysosomal salvage exists for glycerophospholipids, the major constituents of cellular membranes. By using a transport assay screen against orphan lysosomal transporters, we identified the major facilitator superfamily protein Spns1 that is ubiquitously expressed in all tissues as a proton-dependent lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE) transporter, with LPC and LPE being the lysosomal breakdown products of the most abundant eukaryotic phospholipids, phosphatidylcholine and phosphatidylethanolamine, respectively. Spns1 deficiency in cells, zebrafish embryos, and mouse liver resulted in lysosomal accumulation of LPC and LPE species with pathological consequences on lysosomal function. Flux analysis using stable isotope-labeled phospholipid apolipoprotein E nanodiscs targeted to lysosomes showed that LPC was transported out of lysosomes in an Spns1-dependent manner and re-esterified back into the cytoplasmic pools of phosphatidylcholine. Our findings identify a phospholipid salvage pathway from lysosomes to the cytosol that is dependent on Spns1 and critical for maintaining normal lysosomal function.
Topics: Animals; Lysophosphatidylcholines; Lysophospholipids; Lysosomes; Membrane Proteins; Membrane Transport Proteins; Mice; Phosphatidylcholines; Phosphatidylethanolamines; Protons; Zebrafish; Zebrafish Proteins
PubMed: 36161949
DOI: 10.1073/pnas.2210353119 -
Nature Communications May 2023Mfsd2a is the transporter for docosahexaenoic acid (DHA), an omega-3 fatty acid, across the blood brain barrier (BBB). Defects in Mfsd2a are linked to ailments from...
Mfsd2a is the transporter for docosahexaenoic acid (DHA), an omega-3 fatty acid, across the blood brain barrier (BBB). Defects in Mfsd2a are linked to ailments from behavioral and motor dysfunctions to microcephaly. Mfsd2a transports long-chain unsaturated fatty-acids, including DHA and α-linolenic acid (ALA), that are attached to the zwitterionic lysophosphatidylcholine (LPC) headgroup. Even with the recently determined structures of Mfsd2a, the molecular details of how this transporter performs the energetically unfavorable task of translocating and flipping lysolipids across the lipid bilayer remains unclear. Here, we report five single-particle cryo-EM structures of Danio rerio Mfsd2a (drMfsd2a): in the inward-open conformation in the ligand-free state and displaying lipid-like densities modeled as ALA-LPC at four distinct positions. These Mfsd2a snapshots detail the flipping mechanism for lipid-LPC from outer to inner membrane leaflet and release for membrane integration on the cytoplasmic side. These results also map Mfsd2a mutants that disrupt lipid-LPC transport and are associated with disease.
Topics: Fatty Acids, Omega-3; Symporters; Membrane Transport Proteins; Blood-Brain Barrier; Biological Transport; Docosahexaenoic Acids; Lysophosphatidylcholines
PubMed: 37156797
DOI: 10.1038/s41467-023-37702-7 -
Molecules (Basel, Switzerland) Sep 2019Autotaxin (ATX) is an extracellular enzyme that hydrolyses lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), which has a role in the mediation of...
Autotaxin (ATX) is an extracellular enzyme that hydrolyses lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), which has a role in the mediation of inflammation, fibrosis and cancer. ATX is a drug target that has been the focus of many research groups during the last ten years. To date, only one molecule, Ziritaxestat (GLPG1690) has entered the clinic; it is currently in Phase 3 clinical trials for idiopathic pulmonary fibrosis. Other small molecules, with different binding modes, have been investigated as ATX inhibitors for cancer including compounds possessing a boronic acid motif such as HA155. In this work, we targeted new, improved inhibitors of ATX that mimic the important interactions of boronic acid using a benzoxaborole motif as the acidic warhead. Furthermore, we aimed to improve the plasma stability of the new compounds by using a more stable core spacer than that embedded in HA155. Compounds were synthesized, evaluated for their ATX inhibitory activity and ADME properties in vitro, culminating in a new benzoxaborole compound, 37, which retains the ATX inhibition activity of HA155 but has improved ADME properties (plasma protein binding, good kinetic solubility and rat/human plasma stability).
Topics: Animals; Humans; Lysophosphatidylcholines; Lysophospholipids; Neoplasms; Phosphoric Diester Hydrolases; Rats; Structure-Activity Relationship
PubMed: 31547058
DOI: 10.3390/molecules24193419