lysophosphatidylserine and lysophosphatidic-acid

Topics: Animals; Cell Physiological Phenomena; Drug Design; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Inflammation; Insulin; Insulin Secretion; Lysophospholipids; Neurotransmitter Agents; Propylene Glycols; Receptors, G-Protein-Coupled; Sphingosine

Lipids play important roles in inflammation and may be involved in the pathophysiology of inflammatory bowel disease (IBD). Here, we evaluated the characteristics of the plasma lipid profile in patients with IBD.. Plasma samples were collected from 20 patients with Crohn's disease (CD), 20 patients with ulcerative colitis (UC), and 10 healthy volunteers (HVs) after overnight fasting. The subjects were men between 20 and 49 years of age with no history of hyperlipidemia. A total of 698 molecular species in 22 lipid classes were analyzed by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.. Lipid classes of lysophosphatidic acid, lysophosphatidylserine (LPS), phosphatidylserine (PS), and shingosine-1-phosphate (S1P) were significantly increased in UC patients compared with the HV. The LPS, PS, and S1P levels were significantly increased, while those of lysophosphatidylinositol and phosphatidylcholine were significantly decreased in CD patients compared with HV. Among PS species, the levels of PSacyl (PSa) 40:3, PSa 38:3, and PSa 42:4 were significantly higher in CD patients, both active and remissive stage, than in HV. The LPS 18:0 level was significantly higher in CD and UC patients compared with HV. PSa 40:3 and PSa 38:3 levels positively correlated with the Crohn's Disease Activity Index, erythrocyte sedimentation rate, and platelet count and negatively correlated with hemoglobin, hematocrit, and albumin levels in CD patients.. The lipid profile in IBD patients exhibits significant alterations, and PS levels are associated with clinical disease activity in CD patients.

Topics: Adult; Biomarkers; Chromatography, High Pressure Liquid; Colitis, Ulcerative; Crohn Disease; Female; Humans; Inflammatory Bowel Diseases; Lipidomics; Lysophospholipids; Male; Middle Aged; Phosphatidylserines; Spectrometry, Mass, Electrospray Ionization; Young Adult

Although lysophospholipids are known to play an important role in the development and progression of several kinds of cancers, their role in human colorectal cancer is as yet unclear. In this study, we aim to investigate lysophospholipid levels in colorectal cancer tissues to identify lysophospholipids, the levels of which change specifically in colorectal cancers. We used liquid chromatography-tandem mass spectrometry to measure lysophospholipid levels in cancerous and normal tissues from 11 surgical specimens of sigmoid colon cancers, since recent advances in this field have improved detection sensitivities for lysophospholipids. Our results indicate that, in colon cancer tissues, levels of lysophosphatidylinositol and lysophosphatidylserine were significantly higher ( p = 0.025 and p = 0.01, respectively), whereas levels of lysophosphatidic acid were significantly lower ( p = 0.0019) than in normal tissues. Although levels of lysophosphatidylglycerol were higher in colon cancer tissues than in normal tissues, this difference was not found to be significant ( p = 0.11). Fatty acid analysis further showed that 18:0 lysophosphatidylinositol and 18:0 lysophosphatidylserine were the predominant species of lysophospholipids in colon cancer tissues. These components may be potentially involved in colorectal carcinogenesis.

Topics: Aged; Aged, 80 and over; Biomarkers, Tumor; Case-Control Studies; Colorectal Neoplasms; Female; Humans; Lysophospholipids; Male; Middle Aged; Prognosis

Lysophosphatidic acid (LysoPA) has been proposed to be involved in the pathogenesis of various cancers. Moreover, glycero-lysophospholipids (glycero-LysoPLs) other than LysoPA are now emerging as novel lipid mediators. Therefore, we aimed to elucidate the possible involvement of glycero-LysoPLs in the pathogenesis of gastric cancer by measuring glycero-LysoPLs, autotaxin (ATX), and phosphatidylserine-specific phospholipase A1 (PS-PLA

Topics: Animals; Ascites; Female; Fibrosis; Humans; Lysophospholipids; Male; Mice; Phospholipases A1; Phosphoric Diester Hydrolases; Stomach Neoplasms

Under a quiescent state, microglia exhibit a ramified shape, rather than the amoeboid-like morphology following injury or inflammation. The manipulation of microglial morphology in vitro has not been very successful, which has impeded the progress of microglial studies. We demonstrate that lysophosphatidylserine (LysoPS), a kind of lysophospholipids, rapidly and substantially alters the morphology of primary cultured microglia to an in vivo-like ramified shape in a receptor independent manner. This mechanism is mediated by Cdc42 activity. LysoPS is incorporated into the plasma membrane and converted to phosphatidylserine (PS) via the Lands' cycle. The accumulated PS on the membrane recruits Cdc42. Both Cdc42 and PS colocalize predominantly in primary and secondary processes, but not in peripheral branches or tips of microglia. Along with the morphological changes LysoPS suppresses inflammatory cytokine production and NF-kB activity. The present study provides a tool to manipulate a microglial phenotype from an amoeboid to a fully ramified in vitro, which certainly contributes to studies exploring microglial physiology and pathology.

Topics: Animals; Animals, Newborn; cdc42 GTP-Binding Protein; Cell Membrane; Cells, Cultured; Inflammation; Lysophospholipids; Mice, Knockout; Microglia; NF-kappa B; Phenotype

Members of the pancreatic lipase family exhibit both lipase activity toward triacylglycerol and/or phospholipase A(1) (PLA(1)) activity toward certain phospholipids. Some members of the pancreatic lipase family exhibit lysophospholipase activity in addition to their lipase and PLA(1) activities. Two such enzymes, phosphatidylserine (PS)-specific PLA(1) (PS-PLA(1)) and phosphatidic acid (PA)-selective PLA(1)α (PA-PLA(1)α, also known as LIPH) specifically hydrolyze PS and PA, respectively. However, little is known about the mechanisms that determine their substrate specificities. Crystal structures of lipases and mutagenesis studies have suggested that three surface loops, namely, β5, β9, and lid, have roles in determining substrate specificity. To determine roles of these loop structures in the substrate recognition of these PLA(1) enzymes, we constructed a number of PS-PLA(1) mutants in which the three surface loops are replaced with those of PA-PLA(1)α. The results indicate that the surface loops, especially the β5 loop, of PA-PLA(1)α play important roles in the recognition of PA, whereas other structure(s) in PS-PLA(1) is responsible for PS preference. In addition, β5 loop of PS-PLA(1) has a crucial role in lysophospholipase activity toward lysophosphatidylserine. The present study revealed the critical role of lipase surface loops, especially the β5 loop, in determining substrate specificities of PLA(1) enzymes.

Topics: Blotting, Western; Cell Line; Enzyme-Linked Immunosorbent Assay; Humans; Lysophospholipids; Phosphatidic Acids; Phosphatidylserines; Phospholipases A1; Protein Structure, Secondary; Substrate Specificity

In the studies of lipid metabolomics, liquid chromatography electrospray ionization mass spectrometry (LC/MS) is a robust and popular technique. Although effective reverse-phase LC methods enabling the separation of phospholipid molecular species have been developed, there are still problems with the separation of phosphatidic acid (PA) and phosphatidylserine (PS). These acidic phospholipids often elute as extensively broad peaks, causing inferior separation, detection, and quantification-a severe limitation of the method. In this study, we have developed reverse-phase LC conditions that reduce the undesired peak tailings in the elution profiles of both PA and PS, by using a starting mobile phase containing a low concentration of phosphoric acid (5 microM) and a high percentage of water (40%). Our method sensitively analyzes PA, PS, and their lysoforms, as well as the other phospholipids within a biological sample, in a single chromatographic step by an LC/MS method and, thus, is suitable for lipidomics.

Topics: Animals; Calibration; Cell Line; Chromatography, Liquid; DEAE-Cellulose; Liver; Lysophospholipids; Phosphatidic Acids; Phosphatidylserines; Rats; Spectrometry, Mass, Electrospray Ionization

Lysophosphatidylserine (LPS) can be generated following phosphatidylserine-specific phospholipase A2 activation. The effects of LPS on cellular activities and the identities of its target molecules, however, have not been fully elucidated. In this study, we observed that LPS stimulated intracellular calcium increased in mouse bone marrow-derived mast cells (BMMC), and rat C6 glioma and human HCT116 colon cancer cells and compared the LPS-induced Ca2+ increases with the response by lysophosphatidic acid (LPA), a structurally related bioactive lysolipid. In order to test involvement of signaling molecules in the LPS-induced Ca2+ signaling, we used pertussis toxin (PTX), U73122, and 2-APB, which are specific inhibitors for G proteins, phospholipase C (PLC), and IP3 receptors, respectively. The increases due to LPS and LPA were inhibited by PTX, U-73122 and 2-APB, suggesting that both lipids stimulate calcium signaling via G proteins (Gi/o types), PLC activation, and subsequent IP3 production, although the sensitivity to pharmacological inhibitors varied from complete inhibition to partial inhibition depending on cell type and lysolipid. Furthermore, we observed that Ki16425 completely inhibited an LPS-induced Ca2+ response in three cell types, but that the effect of VPC32183 varied from complete inhibition in BMMC and C6 glioma cells to partial inhibition in HCT116 cells. Therefore, we conclude that LPS increases [Ca2+]i through Ki16425/VPC32183-sensitive G protein-coupled receptors (GPCR), G protein, PLC, and IP3 in mouse BMMC, rat C6, and human HCT116 cells.

Topics: Animals; Bone Marrow Cells; Calcium Signaling; Colonic Neoplasms; Dose-Response Relationship, Drug; Enzyme Inhibitors; Estrenes; Glioma; HCT116 Cells; Humans; Inositol 1,4,5-Trisphosphate Receptors; Isoxazoles; Lysophospholipids; Male; Mast Cells; Mice; Mice, Inbred BALB C; Organophosphates; Pertussis Toxin; Propionates; Pyridines; Pyrrolidinones; Rats; Receptors, Lysophosphatidic Acid; Time Factors; Type C Phospholipases

Lysophosphatidylserine (LPS) may be generated after phosphatidylserine-specific phospholipase A2 activation. However, the effects of LPS on cellular activities and the identities of its target molecules have not been fully elucidated. In this study, we observed that LPS stimulates an intracellular calcium increase in L2071 mouse fibroblast cells, and that this increase was inhibited by 1-[6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl]-1H-pyrrole-2,5-dione (U-73122) but not by pertussis toxin, suggesting that LPS stimulates calcium signaling via G-protein coupled receptor-mediated phospholipase C activation. Moreover, LPS-induced calcium mobilization was not inhibited by the lysophosphatidic acid receptor antagonist, (S)-phosphoric acid mono-{2-octadec-9-enoylamino-3-[4-(pyridine-2-ylmethoxy)-phenyl]-propyl} ester (VPC 32183), thus indicating that LPS binds to a receptor other than lysophosphatidic acid receptors. It was also found that LPS stimulates two types of mitogen-activated protein kinase [i.e., extracellular signal-regulated protein kinase (ERK) and p38 kinase] in L2071 cells. Furthermore, these LPS-induced ERK and p38 kinase activations were inhibited by pertussis toxin, which suggests the role of pertussis toxin-sensitive G-proteins in the process. In terms of functional issues, LPS stimulated L2071 cell chemotactic migration, which was completely inhibited by pertussis toxin, indicating the involvement of pertussis toxin-sensitive G(i) protein(s). This chemotaxis of L2071 cells induced by LPS was also dramatically inhibited by 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002) and by 2'-amino-3'-methoxyflavone (PD98059). This study demonstrates that LPS stimulates at least two different signaling cascades, one of which involves a pertussis toxin-insensitive but phospholipase C-dependent intracellular calcium increase, and the other involves a pertussis toxin-sensitive chemotactic migration mediated by phosphoinositide 3-kinase and ERK.

Topics: Animals; Calcium; Calcium-Calmodulin-Dependent Protein Kinases; Chemotaxis; Enzyme Activation; Estrenes; Extracellular Signal-Regulated MAP Kinases; Fibroblasts; Flavonoids; GTP-Binding Protein alpha Subunits, Gi-Go; Lysophospholipids; Mice; p38 Mitogen-Activated Protein Kinases; Pertussis Toxin; Phosphodiesterase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; Pyrrolidinones; Receptors, Lysophosphatidic Acid; Sphingosine