The development of metastasis is a leading cause of cancer-related death that involves specific changes in the plasma membrane (PM) and nucleus of cancer cells. Elevated levels of membrane lipids, including sphingomyelin, cholesterol, and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), in the PM, contribute to changes in membrane rigidity, lipid raft formation, and actin polymerisation dynamics, processes that drive cell invasion. This review discusses the relationship between well-studied cytoplasmic phosphoinositides and their lesser-known nuclear counterparts, highlighting their functional role in metastatic progression. Nuclear phosphoinositides, particularly PI(4,5)P2, are essential for regulating transcription factors and chromatin organisation, thereby shaping gene expression patterns. We also explore the role of PI(4,5)P2 and its metabolism in cancer cell invasiveness and metastasis, proposing a model in which the dysregulation of cytosolic and/or nuclear PI(4,5)P2 pool triggers malignant transformation. Understanding the PI(4,5)P2-related mechanisms underlying metastasis may provide insights into potential therapeutic targets, paving the way for more effective therapies and improved patient outcomes.
- MeSH
- Cell Membrane * metabolism MeSH
- Cell Nucleus * metabolism MeSH
- Phosphatidylinositol 4,5-Diphosphate * metabolism MeSH
- Humans MeSH
- Membrane Microdomains metabolism MeSH
- Neoplasm Metastasis MeSH
- Neoplasms * metabolism pathology genetics MeSH
- Signal Transduction * MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
The thermo- and pain-sensitive Transient Receptor Potential Melastatin 3 and 8 (TRPM3 and TRPM8) ion channels are functionally associated in the lipid rafts of the plasma membrane. We have already described that cholesterol and sphingomyelin depletion, or inhibition of sphingolipid biosynthesis decreased the TRPM8 but not the TRPM3 channel opening on cultured sensory neurons. We aimed to test the effects of lipid raft disruptors on channel activation on TRPM3- and TRPM8-expressing HEK293T cells in vitro, as well as their potential analgesic actions in TRPM3 and TRPM8 channel activation involving acute pain models in mice. CHO cell viability was examined after lipid raft disruptor treatments and their effects on channel activation on channel expressing HEK293T cells by measurement of cytoplasmic Ca2+ concentration were monitored. The effects of treatments were investigated in Pregnenolone-Sulphate-CIM-0216-evoked and icilin-induced acute nocifensive pain models in mice. Cholesterol depletion decreased CHO cell viability. Sphingomyelinase and methyl-beta-cyclodextrin reduced the duration of icilin-evoked nocifensive behavior, while lipid raft disruptors did not inhibit the activity of recombinant TRPM3 and TRPM8. We conclude that depletion of sphingomyelin or cholesterol from rafts can modulate the function of native TRPM8 receptors. Furthermore, sphingolipid cleavage provided superiority over cholesterol depletion, and this method can open novel possibilities in the management of different pain conditions.
- MeSH
- Analgesics pharmacology therapeutic use MeSH
- beta-Cyclodextrins * pharmacology MeSH
- Pain chemically induced drug therapy metabolism MeSH
- CHO Cells MeSH
- Cholesterol metabolism MeSH
- Cricetulus MeSH
- HEK293 Cells MeSH
- TRPM Cation Channels * metabolism genetics MeSH
- Humans MeSH
- Membrane Microdomains metabolism drug effects MeSH
- Disease Models, Animal MeSH
- Mice MeSH
- Pregnenolone pharmacology MeSH
- Pyrimidinones pharmacology MeSH
- Sphingomyelin Phosphodiesterase * metabolism pharmacology MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Styrene-maleic acid (SMA) and similar amphiphilic copolymers are known to cut biological membranes into lipid nanoparticles/nanodiscs containing membrane proteins apparently in their relatively native membrane lipid environment. Our previous work demonstrated that membrane raft microdomains resist such disintegration by SMA. The use of SMA in studying membrane proteins is limited by its heterogeneity and the inability to prepare defined derivatives. In the present paper, we demonstrate that some amphiphilic peptides structurally mimicking SMA also similarly disintegrate cell membranes. In contrast to the previously used copolymers, the simple peptides are structurally homogeneous. We found that their membrane-disintegrating activity increases with their length (reaching optimum at 24 amino acids) and requires a basic primary structure, that is, (XXD)n, where X represents a hydrophobic amino acid (optimally phenylalanine), D aspartic acid, and n is the number of repeats of these triplets. These peptides may provide opportunities for various well-defined potentially useful modifications in the study of membrane protein biochemistry. Our present results confirm a specific character of membrane raft microdomains.
- MeSH
- Cell Membrane metabolism chemistry MeSH
- Cell Line MeSH
- Humans MeSH
- Maleates chemistry MeSH
- Membrane Microdomains metabolism chemistry MeSH
- Membrane Proteins * chemistry metabolism MeSH
- Peptides * chemistry MeSH
- Polystyrenes chemistry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
An advantageous alternative to the use of detergents in biochemical studies on membrane proteins are the recently developed styrene-maleic acid (SMA) amphipathic copolymers. In our recent study [1] we demonstrated that using this approach, most T cell membrane proteins were fully solubilized (presumably in small nanodiscs), while two types of raft proteins, GPI-anchored proteins and Src family kinases, were mostly present in much larger (>250 nm) membrane fragments markedly enriched in typical raft lipids, cholesterol and lipids containing saturated fatty acid residues. In the present study we demonstrate that disintegration of membranes of several other cell types by means of SMA copolymer follows a similar pattern and we provide a detailed proteomic and lipidomic characterization of these SMA-resistant membrane fragments (SRMs).
Membrane cholesterol is essential for cell membrane properties, just as serum cholesterol is important for the transport of molecules between organs. This review focuses on cholesterol transport between lipoproteins and lipid rafts on the surface of macrophages. Recent studies exploring this mechanism and recognition of the central dogma-the key role of macrophages in cardiovascular disease-have led to the notion that this transport mechanism plays a major role in the pathogenesis of atherosclerosis. The exact molecular mechanism of this transport remains unclear. Future research will improve our understanding of the molecular and cellular bases of lipid raft-associated cholesterol transport.
- MeSH
- Atherosclerosis * MeSH
- Biological Transport MeSH
- Cell Membrane chemistry metabolism MeSH
- Cholesterol chemistry metabolism MeSH
- Homeostasis MeSH
- Humans MeSH
- Lipoproteins metabolism MeSH
- Macrophages metabolism MeSH
- Membrane Microdomains chemistry metabolism MeSH
- Lipid Metabolism MeSH
- Protein Binding MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Rotaviruses infect cells by binding to specific cell surface molecules including gangliosides, heat shock protein cognate protein 70 (Hsc70), and some integrins. The characterization of cell surface receptors defining viral tropism is crucial for inhibiting entry into the normal cells or the cancer cells. In the present work, several tumor cell-adapted rotavirus isolates were tested for their interaction with some heat shock proteins (HSPs) present in the U-937 cells, derived from a human pleural effusion (histiocytic lymphoma monocyte). This interaction was examined by virus overlay protein-binding (VOPB), immunochemistry, immuno-dot blot assays, and flow cytometry. The results indicated that the rotavirus isolates studied were able to infect U937 cells by interacting with Hsp90, Hsp70, Hsp60, Hsp40, Hsc70, protein disulfide isomerase (PDI), and integrin β3, which are implicated in cellular proliferation, differentiation, and cancer development. Interestingly, these cellular proteins were found to be associated in lipid microdomains (rafts), facilitating in this way eventual sequential interactions of the rotavirus particles with the cell surface receptors. The rotavirus tropism for U937 cells through the use of these cell surface proteins made this rotavirus isolates an attractive target for the development of oncolytic strategies in the context of alternative and complementary treatment of cancer.
The respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica employ a type III secretion system (T3SS) to inject a 69-kDa BteA effector protein into host cells. This effector is known to contain two functional domains, including an N-terminal lipid raft targeting (LRT) domain and a cytotoxic C-terminal domain that induces nonapoptotic and caspase-1-independent host cell death. However, the exact molecular mechanisms underlying the interaction of BteA with plasma membrane (PM) as well as its cytotoxic activity in the course of Bordetella infections remain poorly understood. Using a protein-lipid overlay assay and surface plasmon resonance, we show here that the recombinant LRT domain binds negatively charged membrane phospholipids. Specifically, we determined that the dissociation constants of the LRT domain-binding liposomes containing phosphatidylinositol 4,5-bisphosphate, phosphatidic acid, and phosphatidylserine were ∼450 nM, ∼490 nM, and ∼1.2 μM, respectively. Both phosphatidylserine and phosphatidylinositol 4,5-bisphosphate were required to target the LRT domain and/or full-length BteA to the PM of yeast cells. The membrane association further involved electrostatic and hydrophobic interactions of LRT and depended on a leucine residue in the L1 loop between the first two helices of the four-helix bundle. Importantly, charge-reversal substitutions within the L1 region disrupted PM localization of the BteA effector without hampering its cytotoxic activity during B. bronchiseptica infection of HeLa cells. The LRT-mediated targeting of BteA to the cytosolic leaflet of the PM of host cells is, therefore, dispensable for effector cytotoxicity.
- MeSH
- Bacterial Proteins genetics metabolism MeSH
- Bordetella bronchiseptica genetics growth & development metabolism MeSH
- Cell Membrane metabolism MeSH
- Phagocytosis MeSH
- Phospholipids metabolism MeSH
- HeLa Cells MeSH
- Humans MeSH
- Lipid Bilayers metabolism MeSH
- Membrane Microdomains metabolism MeSH
- Protein Domains MeSH
- Protein Binding MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
T cells communicate with the environment via surface receptors. Cooperation of surface receptors regulates T-cell responses to diverse stimuli. Recently, finger-like membrane protrusions, microvilli, have been demonstrated to play a role in the organization of receptors and, hence, T-cell activation. However, little is known about the morphogenesis of dynamic microvilli, especially in the cells of immune system. In this review, I focus on the potential role of lipids and lipid domains in morphogenesis of microvilli. Discussed is the option that clustering of sphingolipids with phosphoinositides at the plasma membrane results in dimpling (curved) domains. Such domains can attract phosphoinositide-binding proteins and stimulate actin cytoskeleton reorganization. This process triggers cortical actin opening and bundling of actin fibres to support the growing of microvilli. Critical regulators of microvilli morphogenesis in T cells are unknown. At the end, I suggest several candidates with a potential to organize proteins and lipids in these structures.
- MeSH
- Cell Membrane chemistry metabolism MeSH
- Phosphatidylinositols metabolism MeSH
- Immunomodulation MeSH
- Humans MeSH
- Membrane Microdomains chemistry metabolism MeSH
- Lipid Metabolism * MeSH
- Microvilli metabolism ultrastructure MeSH
- Morphogenesis MeSH
- Sphingolipids metabolism MeSH
- Signal Transduction MeSH
- T-Lymphocytes cytology physiology ultrastructure MeSH
- Protein Binding MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
COVID-19 je ochorenie zapríčinené koronavírusom SARS-CoV-2 (Severe Acute Respiratory Syndrome COronaVirus 2), ktoré vyústilo do celosvetovej pandémie. SARS-CoV-2 je veľmi nákazlivý, priebeh ochorenia je veľmi variabilný a miera úmrtnosti nepredvídateľná. U približne 80 % pacientov s COVID-19 sa vyvinú mierne až stredne závažné príznaky, u 15 % závažné a u 5 % život ohrozujúce klinické komplikácie. Zahŕňajú zápal pľúc, ťažký akútny respiračný syndróm (SARS), septický šok a komplikácie vírusovej infekcie pri liečbe ischemickej choroby srdca, infarktu myokardu, srdcového zlyhania, myokarditídy a arytmií. Niekoľko pozorovacích štúdií a metaanalýz ukázalo, že kardiovaskulárne ochorenia, diabetes mellitus, artériová hypertenzia a obezita tiež zreteľne zvyšujú závažnosť a úmrtnosť na COVID-19. Väčšina pacientov s uvedenými rizikovými faktormi má však prítomnú aj dyslipidémiu a užíva hypolipidemickú farmakologickú liečbu. Doteraz bolo publikovaných niekoľko systematických prehľadov a metaanalýz rozoberajúcich potenciálnu súvislosť medzi prítomnosťou dyslipidémie (jedného z najdôležitejších rizikových faktorov aterosklerózou podmieneného kardiovaskulárneho ochorenia a závažnosťou priebehu ochorenia COVID-19). Do popredia sa dostávajú najmä otázky týkajúce sa bezpečnosti pokračovania v hypolipidemickej liečbe ako u pacientov s vyšším rizikom rozvoja COVID-19, tak aj u pacientov infikovaných koronavírusom SARS-CoV-2. Práve u týchto pacientov musíme veľmi dôsledne zvažovať známe interakcie hypolipidemík s terapiou špecifickou pre COVID-19
COVID-19 is a disease caused by the coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), which has resulted in a global pandemic. SARS-CoV-2 is highly contagious, the course of the disease is very variable and the mortality rate is unpredictable. Approximately 80 % of patients with COVID-19 develop mild to moderate symptoms, 15 % severe and 5 % life-threatening clinical complications. They include pneumonia, severe acute respiratory syndrome (SARS), septic shock and complications of viral infection in the treatment of ischemic heart disease, myocardial infarction, heart failure, myocarditis and arrhythmias. Several observational studies and meta-analysis have shown that cardiovascular disease, diabetes mellitus, arterial hypertension and obesity also significantly increase the severity and mortality of COVID-19. However, most patients with these risk factors also have dyslipidemia and are receiving lipid lowering therapy. To date, several systematic reviews and meta-analysis have been published analyzing the potential association between the presence of dyslipidemia (one of the most important risk factors for atherosclerosis-related cardiovascular disease and the severity of the course of COVID-19). In particular, questions regarding the safety of continuing lipid lowering therapy are emerging, both in patients at higher risk of developing COVID-19 and in patients infected with the coronavirus SARS-CoV-2. In these patients the known interactions of lipid lowering therapy with COVID-19 specific therapy must be considered very carefully.
- MeSH
- Atherosclerosis drug therapy complications MeSH
- Cholesterol adverse effects MeSH
- COVID-19 * MeSH
- Fibric Acids adverse effects therapeutic use MeSH
- Dyslipidemias * drug therapy MeSH
- Ezetimibe adverse effects therapeutic use MeSH
- Hypolipidemic Agents adverse effects therapeutic use MeSH
- Drug Interactions MeSH
- Humans MeSH
- Membrane Microdomains MeSH
- Fatty Acids, Omega-3 therapeutic use MeSH
- Plasmapheresis MeSH
- Proprotein Convertase 9 adverse effects therapeutic use MeSH
- SARS-CoV-2 MeSH
- Hydroxymethylglutaryl-CoA Reductase Inhibitors adverse effects therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
BACKGROUND INFORMATION: Cellular prion protein (PrPC ) is infamous for its role in prion diseases. The physiological function of PrPC remains enigmatic, but several studies point to its involvement in cell differentiation processes. To test this possibility, we monitored PrPC changes during the differentiation of prion-susceptible CAD 5 cells, and then we analysed the effect of PrPC ablation on the differentiation process. RESULTS: Neuronal CAD 5 cells differentiate within 5 days of serum withdrawal, with the majority of the cells developing long neurites. This process is accompanied by an up to sixfold increase in PrPC expression and enhanced N-terminal β-cleavage of the protein, which suggests a role for the PrPC in the differentiation process. Moreover, the majority of PrPC in differentiated cells is inside the cell, and a large proportion of the protein does not associate with membrane lipid rafts. In contrast, PrPC in proliferating cells is found mostly on the cytoplasmic membrane and is predominantly associated with lipid rafts. To determine the importance of PrPC in cell differentiation, a CAD 5 PrP-/- cell line with ablated PrPC expression was created using the CRISPR/Cas9 system. We observed no considerable difference in morphology, proliferation rate or expression of molecular markers between CAD 5 and CAD 5 PrP-/- cells during the differentiation initiated by serum withdrawal. CONCLUSIONS: PrPC characteristics, such as cell localisation, level of expression and posttranslational modifications, change during CAD 5 cell differentiation, but PrPC ablation does not change the course of the differentiation process. SIGNIFICANCE: Ablation of PrPC expression does not affect CAD 5 cell differentiation, although we observed many intriguing changes in PrPC features during the process. Our study does not support the concept that PrPC is important for neuronal cell differentiation, at least in simple in vitro conditions.
