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1.
Commun Biol ; 7(1): 791, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951588

RESUMO

According to single-molecule localisation microscopy almost all plasma membrane proteins are clustered. We demonstrate that clusters can arise from variations in membrane topography where the local density of a randomly distributed membrane molecule to a degree matches the variations in the local amount of membrane. Further, we demonstrate that this false clustering can be differentiated from genuine clustering by using a membrane marker to report on local variations in the amount of membrane. In dual colour live cell single molecule localisation microscopy using the membrane probe DiI alongside either the transferrin receptor or the GPI-anchored protein CD59, we found that pair correlation analysis reported both proteins and DiI as being clustered, as did its derivative pair correlation-photoactivation localisation microscopy and nearest neighbour analyses. After converting the localisations into images and using the DiI image to factor out topography variations, no CD59 clusters were visible, suggesting that the clustering reported by the other methods is an artefact. However, the TfR clusters persisted after topography variations were factored out. We demonstrate that membrane topography variations can make membrane molecules appear clustered and present a straightforward remedy suitable as the first step in the cluster analysis pipeline.


Assuntos
Antígenos CD59 , Membrana Celular , Receptores da Transferrina , Imagem Individual de Molécula , Imagem Individual de Molécula/métodos , Membrana Celular/metabolismo , Antígenos CD59/metabolismo , Receptores da Transferrina/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Análise por Conglomerados , Microscopia de Fluorescência/métodos
2.
Commun Biol ; 7(1): 795, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38951640

RESUMO

The peroxisome is a versatile organelle that performs diverse metabolic functions. PEX3, a critical regulator of the peroxisome, participates in various biological processes associated with the peroxisome. Whether PEX3 is involved in peroxisome-related redox homeostasis and myocardial regenerative repair remains elusive. We investigate that cardiomyocyte-specific PEX3 knockout (Pex3-KO) results in an imbalance of redox homeostasis and disrupts the endogenous proliferation/development at different times and spatial locations. Using Pex3-KO mice and myocardium-targeted intervention approaches, the effects of PEX3 on myocardial regenerative repair during both physiological and pathological stages are explored. Mechanistically, lipid metabolomics reveals that PEX3 promotes myocardial regenerative repair by affecting plasmalogen metabolism. Further, we find that PEX3-regulated plasmalogen activates the AKT/GSK3ß signaling pathway via the plasma membrane localization of ITGB3. Our study indicates that PEX3 may represent a novel therapeutic target for myocardial regenerative repair following injury.


Assuntos
Membrana Celular , Integrina beta3 , Camundongos Knockout , Regeneração , Animais , Camundongos , Integrina beta3/metabolismo , Integrina beta3/genética , Membrana Celular/metabolismo , Miócitos Cardíacos/metabolismo , Masculino , Plasmalogênios/metabolismo , Transdução de Sinais , Miocárdio/metabolismo , Miocárdio/patologia , Camundongos Endogâmicos C57BL , Traumatismos Cardíacos/metabolismo , Traumatismos Cardíacos/patologia , Traumatismos Cardíacos/genética , Proliferação de Células , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética
3.
J Gen Physiol ; 156(9)2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-38990175

RESUMO

L-type CaV1.2 current (ICa,L) links electrical excitation to contraction in cardiac myocytes. ICa,L is tightly regulated to control cardiac output. Rad is a Ras-related, monomeric protein that binds to L-type calcium channel ß subunits (CaVß) to promote inhibition of ICa,L. In addition to CaVß interaction conferred by the Rad core motif, the highly conserved Rad C-terminus can direct membrane association in vitro and inhibition of ICa,L in immortalized cell lines. In this work, we test the hypothesis that in cardiomyocytes the polybasic C-terminus of Rad confers t-tubular localization, and that membrane targeting is required for Rad-dependent ICa,L regulation. We introduced a 3xFlag epitope to the N-terminus of the endogenous mouse Rrad gene to facilitate analysis of subcellular localization. Full-length 3xFlag-Rad (Flag-Rad) mice were compared with a second transgenic mouse model, in which the extended polybasic C-termini of 3xFlag-Rad was truncated at alanine 277 (Flag-RadΔCT). Ventricular cardiomyocytes were isolated for anti-Flag-Rad immunocytochemistry and ex vivo electrophysiology. Full-length Flag-Rad showed a repeating t-tubular pattern whereas Flag-RadΔCT failed to display membrane association. ICa,L in Flag-RadΔCT cardiomyocytes showed a hyperpolarized activation midpoint and an increase in maximal conductance. Additionally, current decay was faster in Flag-RadΔCT cells. Myocardial ICa,L in a Rad C-terminal deletion model phenocopies ICa,L modulated in response to ß-AR stimulation. Mechanistically, the polybasic Rad C-terminus confers CaV1.2 regulation via membrane association. Interfering with Rad membrane association constitutes a specific target for boosting heart function as a treatment for heart failure with reduced ejection fraction.


Assuntos
Canais de Cálcio Tipo L , Miócitos Cardíacos , Animais , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/genética , Camundongos , Miócitos Cardíacos/metabolismo , Membrana Celular/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Proteínas Monoméricas de Ligação ao GTP/genética , Camundongos Transgênicos , Proteínas ras
4.
Commun Biol ; 7(1): 826, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38972875

RESUMO

Classically, G protein-coupled receptors (GPCRs) promote signaling at the plasma membrane through activation of heterotrimeric Gαßγ proteins, followed by the recruitment of GPCR kinases and ßarrestin (ßarr) to initiate receptor desensitization and internalization. However, studies demonstrated that some GPCRs continue to signal from internalized compartments, with distinct cellular responses. Both ßarr and Gßγ contribute to such non-canonical endosomal G protein signaling, but their specific roles and contributions remain poorly understood. Here, we demonstrate that the vasopressin V2 receptor (V2R)-ßarr complex scaffolds Gßγ at the plasma membrane through a direct interaction with ßarr, enabling its transport to endosomes. Gßγ subsequently potentiates Gαs endosomal translocation, presumably to regenerate an endosomal pool of heterotrimeric Gs. This work shines light on the mechanism underlying G protein subunits translocation from the plasma membrane to the endosomes and provides a basis for understanding the role of ßarr in mediating sustained G protein signaling.


Assuntos
Endossomos , Subunidades beta da Proteína de Ligação ao GTP , Subunidades gama da Proteína de Ligação ao GTP , Transporte Proteico , Receptores de Vasopressinas , beta-Arrestinas , Endossomos/metabolismo , Humanos , beta-Arrestinas/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/genética , Receptores de Vasopressinas/metabolismo , Receptores de Vasopressinas/genética , Células HEK293 , Transdução de Sinais , Membrana Celular/metabolismo , Animais
5.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(6): 1059-1069, 2024 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-38977335

RESUMO

OBJECTIVE: To investigate the cell membrane-penetrating capacity of human cell-penetrating peptide hPP10 carrying human antioxidant protein Cu-Zn superoxide dismutase (Cu, Zn-SOD) and assess the antioxidant and anti-inflammatory activity of these fusion proteins. METHODS: The fusion protein hPP10-Cu, Zn-SOD was obtained by genetic engineering and identified by Western blotting. The membrane-penetrating ability of the fusion protein was evaluated by immunofluorescence assay, fluorescence colocalization assay and Western blotting, its SOD enzyme activity was detected using a commercial kit, and its effect on cell viability was assessed with MTT assay. In a HEK293 cell model of H2O2-induced oxidative stress, the effect of hPP10-Cu, Zn-SOD on cell apoptosis was analyzed with flow cytometry and RT-qPCR, and its antioxidant effect was assessed using reactive oxygen species (ROS) assay; its anti-inflammatory effect was evaluated in mouse model of TPA-induced ear inflammation by detecting expression of the inflammatory factors using RT-qPCR, Western blotting and immunohistochemistry. RESULTS: The fusion protein hPP10-Cu, Zn-SOD was successfully obtained. Immunofluorescence assay confirmed obvious membrane penetration of this fusion protein in HEK293 cells, localized both in the cell membrane and the cell nuclei after cell entry. hPP10-Cu, Zn-SOD at the concentration of 5 µmol/L exhibited strong antioxidant activity with minimal impact on cell viability at the concentration up to 10 µmol/L. The fusion protein obviously inhibited apoptosis and decreased intracellular ROS level in the oxidative stress cell model and significantly reduced mRNA and protein expression of the inflammatory factors in the mouse model of ear inflammation. CONCLUSION: The fusion protein hPP10-Cu, Zn-SOD capable of penetrating the cell membrane possesses strong antioxidant and anti-inflammatory activities with only minimal cytotoxicity, demonstrating the value of hPP10 as an efficient drug delivery vector and the potential of hPP10-Cu, Zn-SOD in the development of skincare products.


Assuntos
Anti-Inflamatórios , Antioxidantes , Apoptose , Peptídeos Penetradores de Células , Estresse Oxidativo , Superóxido Dismutase , Humanos , Camundongos , Antioxidantes/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Células HEK293 , Estresse Oxidativo/efeitos dos fármacos , Peptídeos Penetradores de Células/farmacologia , Apoptose/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Proteínas Recombinantes de Fusão/farmacologia , Inflamação/metabolismo , Peróxido de Hidrogênio
6.
Sci Rep ; 14(1): 15831, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982188

RESUMO

2-Hydroxyoleic acid (2-OHOA) has gained attention as a membrane lipid therapy (MLT) anti-cancer drug. However, in the viewpoint of anti-cancer drug, 2-OHOA shows poor water solubility and its effectiveness still has space for improvement. Thus, this study aimed to overcome the problems by formulating 2-OHOA into liposome dosage form. Furthermore, in the context of MLT reagents, the influence of 2-OHOA on the biophysical properties of the cytoplasmic membrane remains largely unexplored. To bridge this gap, our study specifically focused the alterations in cancer cell membrane fluidity and lipid packing characteristics before and after treatment. By using a two-photon microscope and the Laurdan fluorescence probe, we noted that liposomes incorporating 2-OHOA induced a more significant reduction in cancer cell membrane fluidity, accompanied by a heightened rate of cellular apoptosis when compared to the non-formulated 2-OHOA. Importantly, the enhanced efficacy of 2-OHOA within the liposomal formulation demonstrated a correlation with its endocytic uptake mechanism. In conclusion, our findings underscore the significant influence of 2-OHOA on the biophysical properties of cancer plasma membranes, emphasizing the potential of liposomes as an optimized delivery system for 2-OHOA in anti-cancer therapy.


Assuntos
Membrana Celular , Lipossomos , Fluidez de Membrana , Lipossomos/química , Humanos , Membrana Celular/metabolismo , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , 2-Naftilamina/análogos & derivados , 2-Naftilamina/química , Apoptose/efeitos dos fármacos , Lauratos/química , Microscopia de Fluorescência por Excitação Multifotônica , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Ácidos Oleicos/química , Corantes Fluorescentes/química
7.
Proc Natl Acad Sci U S A ; 121(29): e2409334121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38985763

RESUMO

In this study, we used cryoelectron microscopy to determine the structures of the Flotillin protein complex, part of the Stomatin, Prohibitin, Flotillin, and HflK/C (SPFH) superfamily, from cell-derived vesicles without detergents. It forms a right-handed helical barrel consisting of 22 pairs of Flotillin1 and Flotillin2 subunits, with a diameter of 32 nm at its wider end and 19 nm at its narrower end. Oligomerization is stabilized by the C terminus, which forms two helical layers linked by a ß-strand, and coiled-coil domains that enable strong charge-charge intersubunit interactions. Flotillin interacts with membranes at both ends; through its SPFH1 domains at the wide end and the C terminus at the narrow end, facilitated by hydrophobic interactions and lipidation. The inward tilting of the SPFH domain, likely triggered by phosphorylation, suggests its role in membrane curvature induction, which could be connected to its proposed role in clathrin-independent endocytosis. The structure suggests a shared architecture across the family of SPFH proteins and will promote further research into Flotillin's roles in cell biology.


Assuntos
Microscopia Crioeletrônica , Proteínas de Membrana , Proteínas de Membrana/metabolismo , Proteínas de Membrana/química , Humanos , Membrana Celular/metabolismo , Modelos Moleculares
8.
Proc Natl Acad Sci U S A ; 121(29): e2407744121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38985766

RESUMO

G protein-coupled receptors (GPCRs) control intracellular signaling cascades via agonist-dependent coupling to intracellular transducers including heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. In addition to their critical interactions with the transmembrane core of active GPCRs, all three classes of transducers have also been reported to interact with receptor C-terminal domains (CTDs). An underexplored aspect of GPCR CTDs is their possible role as lipid sensors given their proximity to the membrane. CTD-membrane interactions have the potential to control the accessibility of key regulatory CTD residues to downstream effectors and transducers. Here, we report that the CTDs of two closely related family C GPCRs, metabotropic glutamate receptor 2 (mGluR2) and mGluR3, bind to membranes and that this interaction can regulate receptor function. We first characterize CTD structure with NMR spectroscopy, revealing lipid composition-dependent modes of membrane binding. Using molecular dynamics simulations and structure-guided mutagenesis, we then identify key conserved residues and cancer-associated mutations that modulate CTD-membrane binding. Finally, we provide evidence that mGluR3 transducer coupling is controlled by CTD-membrane interactions in live cells, which may be subject to regulation by CTD phosphorylation and changes in membrane composition. This work reveals an additional mechanism of GPCR modulation, suggesting that CTD-membrane binding may be a general regulatory mode throughout the broad GPCR superfamily.


Assuntos
Membrana Celular , Simulação de Dinâmica Molecular , Receptores de Glutamato Metabotrópico , Humanos , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/genética , Membrana Celular/metabolismo , Domínios Proteicos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Ligação Proteica , Células HEK293 , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/genética , Transdução de Sinais
9.
Proc Natl Acad Sci U S A ; 121(29): e2400569121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38985771

RESUMO

Defects in planar cell polarity (PCP) have been implicated in diverse human pathologies. Vangl2 is one of the core PCP components crucial for PCP signaling. Dysregulation of Vangl2 has been associated with severe neural tube defects and cancers. However, how Vangl2 protein is regulated at the posttranslational level has not been well understood. Using chemical reporters of fatty acylation and biochemical validation, here we present that Vangl2 subcellular localization is regulated by a reversible S-stearoylation cycle. The dynamic process is mainly regulated by acyltransferase ZDHHC9 and deacylase acyl-protein thioesterase 1 (APT1). The stearoylation-deficient mutant of Vangl2 shows decreased plasma membrane localization, resulting in disruption of PCP establishment during cell migration. Genetically or pharmacologically inhibiting ZDHHC9 phenocopies the effects of the stearoylation loss of Vangl2. In addition, loss of Vangl2 stearoylation enhances the activation of oncogenic Yes-associated protein 1 (YAP), serine-threonine kinase AKT, and extracellular signal-regulated protein kinase (ERK) signaling and promotes breast cancer cell growth and HRas G12V mutant (HRasV12)-induced oncogenic transformation. Our results reveal a regulation mechanism of Vangl2, and provide mechanistic insight into how fatty acid metabolism and protein fatty acylation regulate PCP signaling and tumorigenesis by core PCP protein lipidation.


Assuntos
Membrana Celular , Polaridade Celular , Proteínas de Membrana , Humanos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Polaridade Celular/fisiologia , Membrana Celular/metabolismo , Movimento Celular , Tioléster Hidrolases/metabolismo , Tioléster Hidrolases/genética , Aciltransferases/metabolismo , Aciltransferases/genética , Animais , Transdução de Sinais , Processamento de Proteína Pós-Traducional , Peptídeos e Proteínas de Sinalização Intracelular
12.
Nat Commun ; 15(1): 5711, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38977673

RESUMO

The cell cortex is a dynamic assembly formed by the plasma membrane and underlying cytoskeleton. As the main determinant of cell shape, the cortex ensures its integrity during passive and active deformations by adapting cytoskeleton topologies through yet poorly understood mechanisms. The spectrin meshwork ensures such adaptation in erythrocytes and neurons by adopting different organizations. Erythrocytes rely on triangular-like lattices of spectrin tetramers, whereas in neurons they are organized in parallel, periodic arrays. Since spectrin is ubiquitously expressed, we exploited Expansion Microscopy to discover that, in fibroblasts, distinct meshwork densities co-exist. Through biophysical measurements and computational modeling, we show that the non-polarized spectrin meshwork, with the intervention of actomyosin, can dynamically transition into polarized clusters fenced by actin stress fibers that resemble periodic arrays as found in neurons. Clusters experience lower mechanical stress and turnover, despite displaying an extension close to the tetramer contour length. Our study sheds light on the adaptive properties of spectrin, which participates in the protection of the cell cortex by varying its densities in response to key mechanical features.


Assuntos
Espectrina , Espectrina/metabolismo , Animais , Fibroblastos/metabolismo , Actomiosina/metabolismo , Camundongos , Citoesqueleto/metabolismo , Estresse Mecânico , Membrana Celular/metabolismo , Forma Celular , Actinas/metabolismo , Fibras de Estresse/metabolismo , Humanos
13.
J Extracell Vesicles ; 13(7): e12477, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988257

RESUMO

Extracellular vesicles (EVs) are shed from the plasma membrane, but the regulation and function of these EVs remain unclear. We found that oxidative stress induced by H2O2 in Hela cells stimulated filopodia formation and the secretion of EVs. EVs were small (150 nm) and labeled for CD44, indicating that they were derived from filopodia. Filopodia-derived small EVs (sEVs) were enriched with the sphingolipid ceramide, consistent with increased ceramide in the plasma membrane of filopodia. Ceramide was colocalized with neutral sphingomyelinase 2 (nSMase2) and acid sphingomyelinase (ASM), two sphingomyelinases generating ceramide at the plasma membrane. Inhibition of nSMase2 and ASM prevented oxidative stress-induced sEV shedding but only nSMase2 inhibition prevented filopodia formation. nSMase2 was S-palmitoylated and interacted with ASM in filopodia to generate ceramide for sEV shedding. sEVs contained nSMase2 and ASM and decreased the level of these two enzymes in oxidatively stressed Hela cells. A novel metabolic labeling technique for EVs showed that oxidative stress induced secretion of fluorescent sEVs labeled with NBD-ceramide. NBD-ceramide-labeled sEVs transported ceramide to mitochondria, ultimately inducing cell death in a proportion of neuronal (N2a) cells. In conclusion, using Hela cells we provide evidence that oxidative stress induces interaction of nSMase2 and ASM at filopodia, which leads to shedding of ceramide-rich sEVs that target mitochondria and propagate cell death.


Assuntos
Ceramidas , Vesículas Extracelulares , Estresse Oxidativo , Pseudópodes , Esfingomielina Fosfodiesterase , Humanos , Vesículas Extracelulares/metabolismo , Ceramidas/metabolismo , Pseudópodes/metabolismo , Pseudópodes/efeitos dos fármacos , Células HeLa , Esfingomielina Fosfodiesterase/metabolismo , Peróxido de Hidrogênio/metabolismo , Membrana Celular/metabolismo
14.
J Biosci ; 492024.
Artigo em Inglês | MEDLINE | ID: mdl-38973669

RESUMO

Amyloids interact with plasma membranes. Extracellular amyloids cross the plasma membrane barrier. Internalized extracellular amyloids are reported to trigger amyloidogenesis of endogenous proteins in recipient cells. To what extent these extracellular and intracellular amyloids perturb the plasma membrane proteome is not investigated. Using α-synuclein as a model amyloid protein, we performed membrane shaving followed by mass spectrometry experiments to identify the conformational changes in cell surface proteins after extracellular amyloid challenge. We also performed membrane proteomics after the biogenesis of intracellular α-synuclein amyloids. Our results suggest that promiscuous interactions with extracellular amyloids stochastically alter the conformation of plasma membrane proteins. This affects the biological processes through the plasma membrane and results in loss of cell viability. Cells that survive the extracellular amyloid shock can grow normally and gradually develop intracellular amyloids which do not directly impact the plasma membrane proteome and associated biological processes. Thus, our results suggest that α-synuclein amyloids can damage the plasma membrane and related processes during cell-to-cell transfer and not during their intracellular biogenesis.


Assuntos
Amiloide , Membrana Celular , Proteoma , alfa-Sinucleína , Humanos , alfa-Sinucleína/metabolismo , alfa-Sinucleína/genética , Membrana Celular/metabolismo , Proteoma/metabolismo , Amiloide/metabolismo , Células HEK293 , Proteômica/métodos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Sobrevivência Celular
15.
PLoS One ; 19(7): e0306142, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38954698

RESUMO

Developing T1-weighted magnetic resonance imaging (MRI) contrast agents with enhanced biocompatibility and targeting capabilities is crucial owing to concerns over current agents' potential toxicity and suboptimal performance. Drawing inspiration from "biomimetic camouflage," we isolated cell membranes (CMs) from human glioblastoma (T98G) cell lines via the extrusion method to facilitate homotypic glioma targeting. At an 8:1 mass ratio of ferric chloride hexahydrate to gallic acid (GA), the resulting iron (Fe)-GA nanoparticles (NPs) proved effective as a T1-weighted MRI contrast agent. T98G CM-coated Fe-GA NPs demonstrated improved homotypic glioma targeting, validated through Prussian blue staining and in vitro MRI. This biomimetic camouflage strategy holds promise for the development of targeted theranostic agents in a safe and effective manner.


Assuntos
Meios de Contraste , Ácido Gálico , Imageamento por Ressonância Magnética , Ácido Gálico/química , Humanos , Imageamento por Ressonância Magnética/métodos , Linhagem Celular Tumoral , Meios de Contraste/química , Ferro/química , Materiais Biomiméticos/química , Glioblastoma/tratamento farmacológico , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Nanopartículas/química , Compostos Férricos/química , Membrana Celular/metabolismo
16.
J Phys Chem Lett ; 15(27): 7075-7083, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38950375

RESUMO

The bactericidal potency of ionic liquids (ILs) is well-established, yet their precise mechanism of action remains elusive. Here, we show evidence that the bactericidal action of ILs primarily involves the permeabilization of the bacterial cell membrane. Our findings reveal that ILs exert their effects by directly interacting with the lipid bilayer and enhancing the membrane dynamics. Lateral lipid diffusion is accelerated, which in turn augments membrane permeability, ultimately leading to bacterial death. Furthermore, our results establish a significant connection: an increase in the alkyl chain length of ILs correlates with a notable enhancement in both lipid lateral diffusion and antimicrobial potency. This underscores a compelling correlation between membrane dynamics and antimicrobial effectiveness, providing valuable insights for the rational design and optimization of IL-based antimicrobial agents in healthcare applications.


Assuntos
Líquidos Iônicos , Bicamadas Lipídicas , Líquidos Iônicos/química , Líquidos Iônicos/farmacologia , Bicamadas Lipídicas/química , Antibacterianos/farmacologia , Antibacterianos/química , Difusão , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/química , Testes de Sensibilidade Microbiana
17.
Nat Commun ; 15(1): 5689, 2024 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-38971796

RESUMO

Leukemia is a kind of hematological malignancy originating from bone marrow, which provides essential signals for initiation, progression, and recurrence of leukemia. However, how to specifically deliver drugs to the bone marrow remains elusive. Here, we develop biomimetic vesicles by infusing hematopoietic stem and progenitor cell (HSPC) membrane with liposomes (HSPC liposomes), which migrate to the bone marrow of leukemic mice via hyaluronic acid-CD44 axis. Moreover, the biomimetic vesicles exhibit superior binding affinity to leukemia cells through intercellular cell adhesion molecule-1 (ICAM-1)/integrin ß2 (ITGB2) interaction. Further experiments validate that the vesicles carrying chemotherapy drug cytarabine (Ara-C@HSPC-Lipo) markedly inhibit proliferation, induce apoptosis and differentiation of leukemia cells, and decrease number of leukemia stem cells. Mechanically, RNA-seq reveals that Ara-C@HSPC-Lipo treatment induces apoptosis and differentiation and inhibits the oncogenic pathways. Finally, we verify that HSPC liposomes are safe in mice. This study provides a method for targeting bone marrow and treating leukemia.


Assuntos
Apoptose , Medula Óssea , Citarabina , Sistemas de Liberação de Medicamentos , Células-Tronco Hematopoéticas , Leucemia , Lipossomos , Animais , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Camundongos , Citarabina/farmacologia , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Medula Óssea/metabolismo , Apoptose/efeitos dos fármacos , Leucemia/tratamento farmacológico , Leucemia/patologia , Humanos , Diferenciação Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Antígenos CD18/metabolismo , Proliferação de Células/efeitos dos fármacos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Células-Tronco Neoplásicas/metabolismo
18.
Proc Natl Acad Sci U S A ; 121(29): e2319829121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38976736

RESUMO

In the developing human brain, only 53 stochastically expressed clustered protocadherin (cPcdh) isoforms enable neurites from individual neurons to recognize and self-avoid while simultaneously maintaining contact with neurites from other neurons. Cell assays have demonstrated that self-recognition occurs only when all cPcdh isoforms perfectly match across the cell boundary, with a single mismatch in the cPcdh expression profile interfering with recognition. It remains unclear, however, how a single mismatched isoform between neighboring cells is sufficient to block erroneous recognitions. Using systematic cell aggregation experiments, we show that abolishing cPcdh interactions on the same membrane (cis) results in a complete loss of specific combinatorial binding between cells (trans). Our computer simulations demonstrate that the organization of cPcdh in linear array oligomers, composed of cis and trans interactions, enhances self-recognition by increasing the concentration and stability of cPcdh trans complexes between the homotypic membranes. Importantly, we show that the presence of mismatched isoforms between cells drastically diminishes the concentration and stability of the trans complexes. Overall, we provide an explanation for the role of the cPcdh assembly arrangements in neuronal self/non-self-discrimination underlying neuronal self-avoidance.


Assuntos
Caderinas , Neurônios , Isoformas de Proteínas , Humanos , Neurônios/metabolismo , Caderinas/metabolismo , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/genética , Comunicação Celular , Simulação por Computador , Neuritos/metabolismo , Membrana Celular/metabolismo
19.
Cells ; 13(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38994953

RESUMO

The retinal pigment epithelium (RPE) is an essential component of the retina that plays multiple roles required to support visual function. These include light onset- and circadian rhythm-dependent tasks, such as daily phagocytosis of photoreceptor outer segments. Mitochondria provide energy to the highly specialized and energy-dependent RPE. In this study, we examined the positioning of mitochondria and how this is influenced by the onset of light. We identified a population of mitochondria that are tethered to the basal plasma membrane pre- and post-light onset. Following light onset, mitochondria redistributed apically and interacted with melanosomes and phagosomes. In a choroideremia mouse model that has regions of the RPE with disrupted or lost infolding of the plasma membrane, the positionings of only the non-tethered mitochondria were affected. This provides evidence that the tethering of mitochondria to the plasma membrane plays an important role that is maintained under these disease conditions. Our work shows that there are subpopulations of RPE mitochondria based on their positioning after light onset. It is likely they play distinct roles in the RPE that are needed to fulfil the changing cellular demands throughout the day.


Assuntos
Membrana Celular , Luz , Mitocôndrias , Epitélio Pigmentado da Retina , Epitélio Pigmentado da Retina/metabolismo , Animais , Mitocôndrias/metabolismo , Camundongos , Membrana Celular/metabolismo , Camundongos Endogâmicos C57BL , Melanossomas/metabolismo , Ritmo Circadiano/fisiologia , Fagossomos/metabolismo
20.
Commun Biol ; 7(1): 840, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987288

RESUMO

The architecture of the actin cortex determines the generation and transmission of stresses, during key events from cell division to migration. However, its impact on myosin-induced cell shape changes remains unclear. Here, we reconstitute a minimal model of the actomyosin cortex with branched or linear F-actin architecture within giant unilamellar vesicles (GUVs, liposomes). Upon light activation of myosin, neither the branched nor linear F-actin architecture alone induces significant liposome shape changes. The branched F-actin network forms an integrated, membrane-bound "no-slip boundary" -like cortex that attenuates actomyosin contractility. By contrast, the linear F-actin network forms an unintegrated "slip boundary" -like cortex, where actin asters form without inducing membrane deformations. Notably, liposomes undergo significant deformations at an optimized balance of branched and linear F-actin networks. Our findings highlight the pivotal roles of branched F-actin in force transmission and linear F-actin in force generation to yield membrane shape changes.


Assuntos
Actinas , Membrana Celular , Miosinas , Actinas/metabolismo , Membrana Celular/metabolismo , Miosinas/metabolismo , Forma Celular , Animais , Actomiosina/metabolismo , Lipossomas Unilamelares/metabolismo , Lipossomas Unilamelares/química , Biomimética , Lipossomos/metabolismo , Lipossomos/química , Modelos Biológicos , Citoesqueleto de Actina/metabolismo
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