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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
- buněčná membrána * metabolismus MeSH
- buněčné jádro * metabolismus MeSH
- fosfatidylinositol-4,5-difosfát * metabolismus MeSH
- lidé MeSH
- membránové mikrodomény metabolismus MeSH
- metastázy nádorů MeSH
- nádory * metabolismus patologie genetika MeSH
- signální transdukce * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Today, it would be difficult for us to live a full life without polymers, especially in medicine, where its applicability is constantly expanding, giving satisfactory results without any harm effects on health. This study focused on the formation of hexagonal domains doped with AgNPs using a KrF excimer laser (λ=248 nm) on the polyetheretherketone (PEEK) surface that acts as an unfailing source of the antibacterial agent - silver. The hexagonal structure was formed with a grid placed in front of the incident laser beam. Surfaces with immobilized silver nanoparticles (AgNPs) were observed by AFM and SEM. Changes in surface chemistry were studied by XPS. To determine the concentration of released Ag+ ions, ICP-MS analysis was used. The antibacterial tests proved the antibacterial efficacy of Ag-doped PEEK composites against Escherichia coli and Staphylococcus aureus as the most common pathogens. Because AgNPs are also known for their strong toxicity, we also included cytotoxicity tests in this study. The findings presented here contribute to the advancement of materials design in the biomedical field, offering a novel starting point for combating bacterial infections through the innovative integration of AgNPs into inert synthetic polymers.
- MeSH
- antibakteriální látky * farmakologie chemie MeSH
- benzofenony * chemie farmakologie MeSH
- biokompatibilní potahované materiály chemie farmakologie MeSH
- Escherichia coli * účinky léků MeSH
- ketony chemie farmakologie MeSH
- kovové nanočástice * chemie MeSH
- lidé MeSH
- mikrobiální testy citlivosti * MeSH
- polyethylenglykoly * chemie farmakologie MeSH
- polymery * chemie farmakologie MeSH
- povrchové vlastnosti MeSH
- Staphylococcus aureus * účinky léků MeSH
- stříbro * chemie farmakologie MeSH
- velikost částic MeSH
- zdravotnické prostředky mikrobiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články 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
- analgetika farmakologie terapeutické užití MeSH
- beta-cyklodextriny * farmakologie MeSH
- bolest chemicky indukované farmakoterapie metabolismus MeSH
- CHO buňky MeSH
- cholesterol metabolismus MeSH
- Cricetulus MeSH
- HEK293 buňky MeSH
- kationtové kanály TRPM * metabolismus genetika MeSH
- lidé MeSH
- membránové mikrodomény metabolismus účinky léků MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- pregnenolon farmakologie MeSH
- pyrimidinony farmakologie MeSH
- sfingomyelinfosfodiesterasa * metabolismus farmakologie MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články 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
- buněčná membrána metabolismus chemie MeSH
- buněčné linie MeSH
- lidé MeSH
- maleáty chemie MeSH
- membránové mikrodomény metabolismus chemie MeSH
- membránové proteiny * chemie metabolismus MeSH
- peptidy * chemie MeSH
- polystyreny chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lamins, the nuclear intermediate filaments, are important regulators of nuclear structural integrity as well as nuclear functional processes such as DNA transcription, replication and repair, and epigenetic regulations. A portion of phosphorylated lamin A/C localizes to the nuclear interior in interphase, forming a lamin A/C pool with specific properties and distinct functions. Nucleoplasmic lamin A/C molecular functions are mainly dependent on its binding partners; therefore, revealing new interactions could give us new clues on the lamin A/C mechanism of action. In the present study, we show that lamin A/C interacts with nuclear phosphoinositides (PIPs), and with nuclear myosin I (NM1). Both NM1 and nuclear PIPs have been previously reported as important regulators of gene expression and DNA damage/repair. Furthermore, phosphorylated lamin A/C forms a complex with NM1 in a phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2)-dependent manner in the nuclear interior. Taken together, our study reveals a previously unidentified interaction between phosphorylated lamin A/C, NM1, and PI(4,5)P2 and suggests new possible ways of nucleoplasmic lamin A/C regulation, function, and importance for the formation of functional nuclear microdomains.
- MeSH
- buněčné jádro * metabolismus MeSH
- interfáze MeSH
- intermediární filamenta metabolismus MeSH
- lamin typ A * metabolismus MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články 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
- ateroskleróza * MeSH
- biologický transport MeSH
- buněčná membrána chemie metabolismus MeSH
- cholesterol chemie metabolismus MeSH
- homeostáza MeSH
- lidé MeSH
- lipoproteiny metabolismus MeSH
- makrofágy metabolismus MeSH
- membránové mikrodomény chemie metabolismus MeSH
- metabolismus lipidů MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Light plays an essential role in photosynthesis; however, its excess can cause damage to cellular components. Photosynthetic organisms thus developed a set of photoprotective mechanisms (e.g., non-photochemical quenching, photoinhibition) that can be studied by a classic biochemical and biophysical methods in cell suspension. Here, we combined these bulk methods with single-cell identification of microdomains in thylakoid membrane during high-light (HL) stress. We used Synechocystis sp. PCC 6803 cells with YFP tagged photosystem I. The single-cell data pointed to a three-phase response of cells to acute HL stress. We defined: (1) fast response phase (0-30 min), (2) intermediate phase (30-120 min), and (3) slow acclimation phase (120-360 min). During the first phase, cyanobacterial cells activated photoprotective mechanisms such as photoinhibition and non-photochemical quenching. Later on (during the second phase), we temporarily observed functional decoupling of phycobilisomes and sustained monomerization of photosystem II dimer. Simultaneously, cells also initiated accumulation of carotenoids, especially ɣ-carotene, the main precursor of all carotenoids. In the last phase, in addition to ɣ-carotene, we also observed accumulation of myxoxanthophyll and more even spatial distribution of photosystems and phycobilisomes between microdomains. We suggest that the overall carotenoid increase during HL stress could be involved either in the direct photoprotection (e.g., in ROS scavenging) and/or could play an additional role in maintaining optimal distribution of photosystems in thylakoid membrane to attain efficient photoprotection.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- fotosystém I (proteinový komplex) genetika metabolismus MeSH
- fotosystém II (proteinový komplex) genetika metabolismus MeSH
- karotenoidy metabolismus MeSH
- světlo * MeSH
- Synechocystis metabolismus účinky záření MeSH
- tylakoidy metabolismus účinky záření MeSH
- velikost buňky účinky záření MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem 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.
- MeSH
- internalizace viru * MeSH
- lidé MeSH
- membránové proteiny metabolismus MeSH
- nádorové buněčné linie MeSH
- proteiny tepelného šoku HSC70 MeSH
- proteiny tepelného šoku HSP70 genetika MeSH
- proteiny teplotního šoku * metabolismus MeSH
- Rotavirus * metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
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
- bakteriální proteiny genetika metabolismus MeSH
- Bordetella bronchiseptica genetika růst a vývoj metabolismus MeSH
- buněčná membrána metabolismus MeSH
- fagocytóza MeSH
- fosfolipidy metabolismus MeSH
- HeLa buňky MeSH
- lidé MeSH
- lipidové dvojvrstvy metabolismus MeSH
- membránové mikrodomény metabolismus MeSH
- proteinové domény MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
