Lysophosphatidylcholine (LPC) is a bioactive lipid present at high concentrations in inflamed and injured tissues where it contributes to the initiation and maintenance of pain. One of its important molecular effectors is the transient receptor potential canonical 5 (TRPC5), but the explicit mechanism of the activation is unknown. Using electrophysiology, mutagenesis and molecular dynamics simulations, we show that LPC-induced activation of TRPC5 is modulated by xanthine ligands and depolarizing voltage, and involves conserved residues within the lateral fenestration of the pore domain. Replacement of W577 with alanine (W577A) rendered the channel insensitive to strong depolarizing voltage, but LPC still activated this mutant at highly depolarizing potentials. Substitution of G606 located directly opposite position 577 with tryptophan rescued the sensitivity of W577A to depolarization. Molecular simulations showed that depolarization widens the lower gate of the channel and this conformational change is prevented by the W577A mutation or removal of resident lipids. We propose a gating scheme in which depolarizing voltage and lipid-pore helix interactions act together to promote TRPC5 channel opening.
- MeSH
- gating iontového kanálu účinky léků MeSH
- HEK293 buňky MeSH
- kationtové kanály TRPC * metabolismus genetika chemie MeSH
- lidé MeSH
- lysofosfatidylcholiny * metabolismus farmakologie MeSH
- lysofosfolipidy metabolismus farmakologie MeSH
- membránové potenciály účinky léků MeSH
- mutace MeSH
- simulace molekulární dynamiky * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Autotaxin, also known as ecto-nucleotide pyrophosphatase/phosphodiesterase family member 2, is a secreted glycoprotein that plays multiple roles in human physiology and cancer pathology. This protein, by converting lysophosphatidylcholine into lysophosphatidic acid, initiates a complex signalling cascade with significant biological implications. The article outlines the autotaxin gene and protein structure, expression regulation and physiological functions, but focuses mainly on the role of autotaxin in cancer development and progression. Autotaxin and lysophosphatidic acid signalling influence several aspects of cancer, including cell proliferation, migration, metastasis, therapy resistance, and interactions with the immune system. The potential of autotaxin as a diagnostic biomarker and promising drug target is also examined.
- MeSH
- fosfodiesterasy * genetika chemie metabolismus MeSH
- lidé MeSH
- lysofosfolipidy metabolismus MeSH
- nádory * MeSH
- signální transdukce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Bis(monoacylglycero)phosphates (BMPs), a class of lipids highly enriched within endolysosomal organelles, are key components of the lysosomal intraluminal vesicles responsible for activating sphingolipid catabolic enzymes. While BMPs are understudied relative to other phospholipids, recent reports associate BMP dysregulation with a variety of pathological states including neurodegenerative diseases and lysosomal storage disorders. Since the dramatic lysosomal remodeling characteristic of cellular transformation could impact BMP abundance and function, we employed untargeted lipidomics approaches to identify and quantify BMP species in several in vitro and in vivo models of breast cancer and comparative non-transformed cells and tissues. We observed lower BMP levels within transformed cells relative to normal cells, and consistent enrichment of docosahexaenoic acid (22:6) fatty acyl chain-containing BMP species in both human- and mouse-derived mammary tumorigenesis models. Our functional analysis points to a working model whereby 22:6 BMPs serve as reactive oxygen species scavengers in tumor cells, protecting lysosomes from oxidant-induced lysosomal membrane permeabilization. Our findings suggest that breast tumor cells might divert polyunsaturated fatty acids into BMP lipids as part of an adaptive response to protect their lysosomes from elevated reactive oxygen species levels, and raise the possibility that BMP-mediated lysosomal protection is a tumor-specific vulnerability that may be exploited therapeutically.
- MeSH
- fosfáty metabolismus MeSH
- kyseliny dokosahexaenové * MeSH
- lidé MeSH
- lysofosfolipidy metabolismus MeSH
- lyzozomy metabolismus MeSH
- myši MeSH
- nádory prsu * patologie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Research Support, N.I.H., Extramural MeSH
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.
- MeSH
- antigen CA-19-9 krev MeSH
- ceramidy krev MeSH
- lidé MeSH
- lipidomika metody MeSH
- lysofosfatidylcholiny krev MeSH
- metabolismus lipidů genetika MeSH
- multivariační analýza MeSH
- nádorové biomarkery krev genetika MeSH
- nádory slinivky břišní krev diagnóza mortalita patologie MeSH
- proporcionální rizikové modely MeSH
- senzitivita a specificita MeSH
- sfingomyeliny krev MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lipid catabolism and anabolism changes play a role in stemness acquisition by cancer cells, and cancer stem cells (CSCs) are particularly dependent on the activity of the enzymes involved in these processes. Lipidomic changes could play a role in CSCs' ability to cause disease relapse and chemoresistance. The exploration of lipid composition and metabolism changes in CSCs in the context of hepatocellular cancer (HCC) is still incomplete and their lipidomic scenario continues to be elusive. We aimed to evaluate through high-throughput mass spectrometry (MS)-based lipidomics the levels of the members of the six major classes of sphingolipids and phospholipids in two HCC cell lines (HepG2 and Huh-7) silenced for the expression of histone variant macroH2A1 (favoring stemness acquisition), or silenced for the expression of focal adhesion tyrosine kinase (FAK) (hindering aggressiveness and stemness). Transcriptomic changes were evaluated by RNA sequencing as well. We found definite lipidomic and transcriptomic changes in the HCC lines upon knockdown (KD) of macroH2A1 or FAK, in line with the acquisition or loss of stemness features. In particular, macroH2A1 KD increased total sphingomyelin (SM) levels and decreased total lysophosphatidylcholine (LPC) levels, while FAK KD decreased total phosphatidylcholine (PC) levels. In conclusion, in HCC cell lines knocked down for specific signaling/epigenetic processes driving opposite stemness potential, we defined a lipidomic signature that hallmarks hepatic CSCs to be exploited for therapeutic strategies.
- MeSH
- buňky Hep G2 MeSH
- fokální adhezní kinasa 1 antagonisté a inhibitory nedostatek genetika MeSH
- fosfatidylcholiny metabolismus MeSH
- genový knockdown MeSH
- hepatocelulární karcinom genetika metabolismus patologie MeSH
- histony antagonisté a inhibitory nedostatek genetika MeSH
- lidé MeSH
- lipidomika MeSH
- lysofosfatidylcholiny metabolismus MeSH
- metabolismus lipidů * genetika MeSH
- nádorové biomarkery genetika metabolismus MeSH
- nádorové buněčné linie MeSH
- nádorové kmenové buňky metabolismus patologie MeSH
- nádory jater genetika metabolismus patologie MeSH
- regulace genové exprese u nádorů MeSH
- sekvenování transkriptomu MeSH
- sfingomyeliny metabolismus MeSH
- stanovení celkové genové exprese MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The systemic anaphylactic reaction is a life-threatening allergic response initiated by activated mast cells. Sphingolipids are an essential player in the development and attenuation of this response. De novo synthesis of sphingolipids in mammalian cells is inhibited by the family of three ORMDL proteins (ORMDL1, 2, and 3). However, the cell and tissue-specific functions of ORMDL proteins in mast cell signaling are poorly understood. This study aimed to determine cross-talk of ORMDL2 and ORMDL3 proteins in IgE-mediated responses. To this end, we prepared mice with whole-body knockout (KO) of Ormdl2 and/or Ormdl3 genes and studied their role in mast cell-dependent activation events in vitro and in vivo. We found that the absence of ORMDL3 in bone marrow-derived mast cells (BMMCs) increased the levels of cellular sphingolipids. Such an increase was further raised by simultaneous ORMDL2 deficiency, which alone had no effect on sphingolipid levels. Cells with double ORMDL2 and ORMDL3 KO exhibited increased intracellular levels of sphingosine-1-phosphate (S1P). Furthermore, we found that concurrent ORMDL2 and ORMDL3 deficiency increased IκB-α phosphorylation, degranulation, and production of IL-4, IL-6, and TNF-α cytokines in antigen-activated mast cells. Interestingly, the chemotaxis towards antigen was increased in all mutant cell types analyzed. Experiments in vivo showed that passive cutaneous anaphylaxis (PCA), which is initiated by mast cell activation, was increased only in ORMDL2,3 double KO mice, supporting our in vitro observations with mast cells. On the other hand, ORMDL3 KO and ORMDL2,3 double KO mice showed faster recovery from passive systemic anaphylaxis, which could be mediated by increased levels of blood S1P presented in such mice. Our findings demonstrate that Ormdl2 deficiency potentiates the ORMDL3-dependent changes in mast cell signaling.
- MeSH
- anafylaxe etiologie metabolismus MeSH
- biologické markery MeSH
- chemotaxe imunologie MeSH
- cytokiny metabolismus MeSH
- exprese genu MeSH
- lysofosfolipidy krev metabolismus MeSH
- mastocyty imunologie metabolismus MeSH
- membránové proteiny chemie nedostatek genetika metabolismus MeSH
- multigenová rodina MeSH
- myši knockoutované MeSH
- myši MeSH
- náchylnost k nemoci MeSH
- pasivní kožní anafylaxe genetika imunologie MeSH
- sekvence aminokyselin MeSH
- sfingolipidy krev metabolismus MeSH
- sfingosin analogy a deriváty krev metabolismus MeSH
- signální transdukce * MeSH
- vápník metabolismus MeSH
- vápníková signalizace MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Ultrahigh-performance supercritical fluid chromatography - mass spectrometry (UHPSFC/MS), ultrahigh-performance liquid chromatography - mass spectrometry (UHPLC/MS), and matrix-assisted laser desorption/ionization (MALDI) - MS techniques were used for the lipidomic characterization of exosomes isolated from human plasma. The high-throughput methods UHPSFC/MS and UHPLC/MS using a silica-based column containing sub-2 μm particles enabled the lipid class separation and the quantitation based on exogenous class internal standards in <7 minute run time. MALDI provided the complementary information on anionic lipid classes, such as sulfatides. The nontargeted analysis of 12 healthy volunteers was performed, and absolute molar concentration of 244 lipids in exosomes and 191 lipids in plasma belonging to 10 lipid classes were quantified. The statistical evaluation of data included principal component analysis, orthogonal partial least square discriminant analysis, S-plots, p-values, T-values, fold changes, false discovery rate, box plots, and correlation plots, which resulted in the information on lipid changes in exosomes in comparison to plasma. The major changes were detected in the composition of triacylglycerols, diacylglycerols, phosphatidylcholines, and lysophosphatidylcholines, whereby sphingomyelins, phosphatidylinositols, and sulfatides showed rather similar profiles in both biological matrices.
- MeSH
- diglyceridy krev izolace a purifikace metabolismus MeSH
- dospělí MeSH
- exozómy chemie metabolismus MeSH
- fosfatidylcholiny krev izolace a purifikace metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- lipidomika metody MeSH
- lysofosfatidylcholiny krev izolace a purifikace metabolismus MeSH
- metabolismus lipidů * MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- superkritická fluidní chromatografie metody MeSH
- triglyceridy krev izolace a purifikace metabolismus MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Background: It is clear that in developed countries more women die annually from ovarian cancer than from all other gynecologic malignancies combined. Objective: The aim of this article is to analyze current possibilities and propose adequate measures which can help the development of effective screening methods/assays for the early detection of epithelial ovarian cancer. Results and Discussion: This article updates the status of ovarian cancer screening and addresses most relevant studies published during the last five years. The developments that followed the review are best summarized in reference to the screening tests, target populations and newly published trials. The possible role of 3D ultrasound technology, especially 3D power Doppler imaging, in early and accurate detection of ovarian malignancy is discussed. We described our new ovarian cancer screening trial, which started in January 2001. Improvements in ultrasound technology such as 3D volume acquisition and 3D power Doppler imaging may have clinical utility in a more reliable identification of an abnormal ovarian vascularity and architecture. 3D volume acquisition allows for careful evaluation of the internal surfaces of cyst walls for excrescences otherwise not appreciated by 2D ultrasound. Conclusion: While the addition of 3D power Doppler provides a new tool for measuring the quality of ovarian tumor angiogenesis, improving accurate diagnosis of ovarian malignancies, its clinical value for the early detection of ovarian carcinoma has yet to be determined.
- MeSH
- antigen CA-125 analýza MeSH
- časná detekce nádoru MeSH
- diagnostické techniky porodnicko-gynekologické MeSH
- lidé MeSH
- lysofosfolipidy analýza MeSH
- míra přežití MeSH
- multimodální zobrazování MeSH
- nádorové biomarkery MeSH
- nádory vaječníků * diagnostické zobrazování MeSH
- randomizované kontrolované studie jako téma MeSH
- staging nádorů MeSH
- ultrasonografie dopplerovská MeSH
- zobrazování trojrozměrné MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
The development and progression of colorectal cancer (CRC), a major cause of cancer-related death in the western world, is accompanied with alterations of sphingolipid (SL) composition in colon tumors. A number of enzymes involved in the SL metabolism have been found to be deregulated in human colon tumors, in experimental rodent studies, and in human colon cancer cells in vitro. Therefore, the enzymatic pathways that modulate SL levels have received a significant attention, due to their possible contribution to CRC development, or as potential therapeutic targets. Many of these enzymes are associated with an increased sphingosine-1-phosphate/ceramide ratio, which is in turn linked with increased colon cancer cell survival, proliferation and cancer progression. Nevertheless, more attention should also be paid to the more complex SLs, including specific glycosphingolipids, such as lactosylceramides, which can be also deregulated during CRC development. In this review, we focus on the potential roles of individual SLs/SL metabolism enzymes in colon cancer, as well as on the pros and cons of employing the current in vitro models of colon cancer cells for lipidomic studies investigating the SL metabolism in CRC.
- MeSH
- alkalická ceramidasa genetika metabolismus MeSH
- ceramidy metabolismus MeSH
- fosfotransferasy s alkoholovou skupinou jako akceptorem genetika metabolismus MeSH
- kyselá ceramidasa genetika metabolismus MeSH
- laktosylceramidy metabolismus MeSH
- lidé MeSH
- lysofosfolipidy metabolismus MeSH
- metabolismus lipidů genetika MeSH
- modely nemocí na zvířatech MeSH
- nádorové buňky kultivované MeSH
- nádory tračníku enzymologie genetika patologie MeSH
- neutrální ceramidasa genetika metabolismus MeSH
- protoonkogenní proteiny c-akt genetika metabolismus MeSH
- regulace genové exprese u nádorů * MeSH
- sfingolipidy metabolismus MeSH
- sfingosin-N-acyltransferasa genetika metabolismus MeSH
- sfingosin analogy a deriváty metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Although the over-expression of angiogenic factors is reported in diffuse large B-cell lymphoma (DLBCL), the poor response to anti-VEGF drugs observed in clinical trials suggests that angiogenesis in these tumours might be driven by VEGF-independent pathways. We show that sphingosine kinase-1 (SPHK1), which generates the potent bioactive sphingolipid sphingosine-1-phosphate (S1P), is over-expressed in DLBCL. A meta-analysis of over 2000 cases revealed that genes correlated with SPHK1 mRNA expression in DLBCL were significantly enriched for tumour angiogenesis meta-signature genes; an effect evident in both major cell of origin (COO) and stromal subtypes. Moreover, we found that S1P induces angiogenic signalling and a gene expression programme that is present within the tumour vasculature of SPHK1-expressing DLBCL. Importantly, S1PR1 functional antagonists, including Siponimod, and the S1P neutralising antibody, Sphingomab, inhibited S1P signalling in DLBCL cells in vitro. Furthermore, Siponimod, also reduced angiogenesis and tumour growth in an S1P-producing mouse model of angiogenic DLBCL. Our data define a potential role for S1P signalling in driving an angiogenic gene expression programme in the tumour vasculature of DLBCL and suggest novel opportunities to target S1P-mediated angiogenesis in patients with DLBCL.
- MeSH
- difúzní velkobuněčný B-lymfom genetika metabolismus patologie MeSH
- endoteliální buňky metabolismus MeSH
- imunohistochemie MeSH
- lidé MeSH
- lysofosfolipidy genetika metabolismus MeSH
- messenger RNA genetika MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- patologická angiogeneze genetika metabolismus MeSH
- regulace genové exprese u nádorů MeSH
- sfingosin analogy a deriváty genetika metabolismus MeSH
- signální transdukce * MeSH
- transkriptom * MeSH
- výpočetní biologie metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH