Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 33
Filtrer
1.
Nat Commun ; 15(1): 5170, 2024 Jun 17.
Article de Anglais | MEDLINE | ID: mdl-38886341

RÉSUMÉ

The spatiotemporal regulation of inflammasome activation remains unclear. To examine the mechanism underlying the assembly and regulation of the inflammasome response, here we perform an immunoprecipitation-mass spectrometry analysis of apoptosis-associated speck-like protein containing a CARD (ASC) and identify NCF4/1/2 as ASC-binding proteins. Reduced NCF4 expression is associated with colorectal cancer development and decreased five-year survival rate in patients with colorectal cancer. NCF4 cooperates with NCF1 and NCF2 to promote NLRP3 and AIM2 inflammasome activation. Mechanistically, NCF4 phosphorylation and puncta distribution switches from the NADPH complex to the perinuclear region, mediating ASC oligomerization, speck formation and inflammasome activation. NCF4 functions as a sensor of ROS levels, to establish a balance between ROS production and inflammasome activation. NCF4 deficiency causes severe colorectal cancer in mice, increases transit-amplifying and precancerous cells, reduces the frequency and activation of CD8+ T and NK cells, and impairs the inflammasome-IL-18-IFN-γ axis during the early phase of colorectal tumorigenesis. Our study implicates NCF4 in determining the spatial positioning of inflammasome assembly and contributing to inflammasome-mediated anti-tumor responses.


Sujet(s)
Protéines adaptatrices de signalisation CARD , Tumeurs colorectales , Surveillance immunologique , Inflammasomes , Espèces réactives de l'oxygène , Tumeurs colorectales/immunologie , Tumeurs colorectales/anatomopathologie , Tumeurs colorectales/génétique , Tumeurs colorectales/métabolisme , Inflammasomes/métabolisme , Animaux , Humains , Souris , Protéines adaptatrices de signalisation CARD/métabolisme , Protéines adaptatrices de signalisation CARD/génétique , Espèces réactives de l'oxygène/métabolisme , Évolution de la maladie , Protéine-3 de la famille des NLR contenant un domaine pyrine/métabolisme , Protéine-3 de la famille des NLR contenant un domaine pyrine/génétique , NADPH oxidase/métabolisme , NADPH oxidase/génétique , Souris knockout , Interleukine-18/métabolisme , Souris de lignée C57BL , Mâle , Lymphocytes T CD8+/immunologie , Lymphocytes T CD8+/métabolisme , Cellules tueuses naturelles/immunologie , Cellules tueuses naturelles/métabolisme , Femelle , Phosphorylation , Lignée cellulaire tumorale
2.
Platelets ; 35(1): 2308635, 2024 Dec.
Article de Anglais | MEDLINE | ID: mdl-38345065

RÉSUMÉ

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) restricts platelet activation via platelet collagen receptor GPVI/FcRγ-chain. In this study, screening against collagen-induced platelet aggregation was performed to identify functional CEACAM1 extracellular domain fragments. CEACAM1 fragments, including Ala-substituted peptides, were synthesized. Platelet assays were conducted on healthy donor samples for aggregation, cytotoxicity, adhesion, spreading, and secretion. Mice were used for tail bleeding and FeCl3-induced thrombosis experiments. Clot retraction was assessed using platelet-rich plasma. Extracellular segments of CEACAM1 and A1 domain-derived peptide QDTT were identified, while N, A2, and B domains showed no involvement. QDTT inhibited platelet aggregation. Ala substitution for essential amino acids (Asp139, Thr141, Tyr142, Trp144, and Trp145) in the QDTT sequence abrogated collagen-induced aggregation inhibition. QDTT also suppressed platelet secretion and "inside-out" GP IIb/IIIa activation by convulxin, along with inhibiting PI3K/Akt pathways. QDTT curtailed FeCl3-induced mesenteric thrombosis without significantly prolonging bleeding time, implying the potential of CEACAM1 A1 domain against platelet activation without raising bleeding risk, thus paving the way for novel antiplatelet drugs.


What is the context? The study focuses on Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) and its role in platelet activation, particularly through the GPVI/FcRγ-chain pathway.The research aims to identify specific fragments of CEACAM1's extracellular domain that could restrict platelet activation, without increasing bleeding risk.What is new? The researchers identified a peptide called QDTT derived from the A1 domain of CEACAM1's extracellular segment. This peptide demonstrated the ability to inhibit platelet aggregation, secretion, and GP IIb/IIIa activation.The study also revealed that specific amino acids within the QDTT sequence were essential for its inhibitory effects on collagen-induced aggregation.What is the impact? The findings suggest that the A1 domain-derived peptide QDTT from CEACAM1 could serve as a potential basis for developing novel antiplatelet drugs. This peptide effectively limits platelet activation and aggregation without significantly prolonging bleeding time, indicating a promising approach to managing thrombosis and related disorders while minimizing bleeding risks.


Sujet(s)
, Chlorures , Composés du fer III , Thrombose , Souris , Animaux , Glycoprotéines de membrane plaquettaire/métabolisme , Phosphatidylinositol 3-kinases/métabolisme , Agrégation plaquettaire , Plaquettes/métabolisme , Antiagrégants plaquettaires/pharmacologie , Antiagrégants plaquettaires/métabolisme , Peptides/pharmacologie , Collagène/pharmacologie , Thrombose/métabolisme
3.
Cardiovasc Toxicol ; 24(2): 133-145, 2024 Feb.
Article de Anglais | MEDLINE | ID: mdl-38180639

RÉSUMÉ

Cardiac Vascular disease particularly myocardial infarction (MI) is a threat to health worldwide. microRNAs (miRNAs) have been shown to regulate myocardial fibrosis. Therefore, it is potential to investigate the mechanism of miRNA and fibrosis following myocardial infarction. Hypoxia human cardiac microvascular endothelial cells (HCMECs) were selected for the vitro experimental model. The miR-146a-5p expression was tested via RT-qPCR. The level of endothelial-to-mesenchymal transition (EndMT) and fibrosis markers were detected by Western blotting and immunofluorescence. Then, the inflammation, cell viability and apoptosis were investigated. The target was predicted by an online database and verified by a dual-luciferase activity assay. An MI mouse model was created to validate that miR-146a-5p regulates cardiac fibrosis in vivo. MI mouse was transfected with miR-146a-5p lentivirus. Subsequently, its effect on cardiac fibrosis of infarcted hearts was assessed by In situ hybridization (ISH), Immunohistochemistry (IHC), Triphenylterazolium chloride (TTC) staining and Masson staining. Herein, we confirmed that miR-146a-5p was down-regulated in hypoxia HCMECs. Overexpression of miR-146a-5p inhibited hypoxia-induced cardiac fibrosis following myocardial infarction by inhibiting EndMT in HCMECs. Thioredoxin-interacting protein (TXNIP) was a target that was negatively regulated by miR-146a-5p. Up-regulation of miR-146a-5p inhibited cardiac fibrosis via regulating EndMT by targeting TXNIP, and it also regulated EndMT to inhibit cardiac fibrosis in vivo.


Sujet(s)
Cardiomyopathies , microARN , Infarctus du myocarde , Animaux , Humains , Souris , Apoptose , Cardiomyopathies/métabolisme , Cellules endothéliales , , Fibrose , Hypoxie/complications , Hypoxie/génétique , microARN/génétique , microARN/métabolisme , Infarctus du myocarde/génétique , Infarctus du myocarde/prévention et contrôle , Infarctus du myocarde/métabolisme
4.
Cereb Cortex ; 34(2)2024 01 31.
Article de Anglais | MEDLINE | ID: mdl-38216542

RÉSUMÉ

The mutual interaction between bone characteristics and brain had been reported previously, yet whether the cortical structure has any relevance to osteoporosis is questionable. Therefore, we applied a two-sample bidirectional Mendelian randomization analysis to investigate this relationship. We utilized the bone mineral density measurements of femoral neck (n = 32,735) and lumbar spine (n = 28,498) and data on osteoporosis (7300 cases and 358,014 controls). The global surficial area and thickness and 34 specific functional regions of 51,665 patients were screened by magnetic resonance imaging. For the primary estimate, we utilized the inverse-variance weighted method. The Mendelian randomization-Egger intercept test, MR-PRESSO, Cochran's Q test, and "leave-one-out" sensitivity analysis were conducted to assess heterogeneity and pleiotropy. We observed suggestive associations between decreased thickness in the precentral region (OR = 0.034, P = 0.003) and increased chance of having osteoporosis. The results also revealed suggestive causality of decreased bone mineral density in femoral neck to declined total cortical surface area (ß = 1400.230 mm2, P = 0.003), as well as the vulnerability to osteoporosis and reduced thickness in the Parstriangularis region (ß = -0.006 mm, P = 0.002). Our study supports that the brain and skeleton exhibit bidirectional crosstalk, indicating the presence of a mutual brain-bone interaction.


Sujet(s)
Analyse de randomisation mendélienne , Ostéoporose , Humains , Ostéoporose/imagerie diagnostique , Ostéoporose/génétique , Encéphale , Nonoxinol , Radiopharmaceutiques , Étude d'association pangénomique
5.
Front Pharmacol ; 14: 1255069, 2023.
Article de Anglais | MEDLINE | ID: mdl-38026984

RÉSUMÉ

Introduction: Luteolin inhibits platelet activation and thrombus formation, but the mechanisms are unclear. This study investigated the effects of luteolin on GPVI-mediated platelet activation in vitro and explored the effect of luteolin on thrombosis, coagulation, and platelet production in vivo. Methods: Washed human platelets were used for aggregation, membrane protein expression, ATP, Ca2+, and LDH release, platelet adhesion/spreading, and clot retraction experiments. Washed human platelets were used to detect collagen and convulxin-induced reactive oxygen species production and endogenous antioxidant effects. C57BL/6 male mice were used for ferric chloride-induced mesenteric thrombosis, collagen-epinephrine induced acute pulmonary embolism, tail bleeding, coagulation function, and luteolin toxicity experiments. The interaction between luteolin and GPVI was analyzed using solid phase binding assay and surface plasmon resonance (SPR). Results: Luteolin inhibited collagen- and convulxin-mediated platelet aggregation, adhesion, and release. Luteolin inhibited collagen- and convulxin-induced platelet ROS production and increased platelet endogenous antioxidant capacity. Luteolin reduced convulxin-induced activation of ITAM and MAPK signaling molecules. Molecular docking simulation showed that luteolin forms hydrogen bonds with GPVI. The solid phase binding assay showed that luteolin inhibited the interaction between collagen and GPVI. Surface plasmon resonance showed that luteolin bonded GPVI. Luteolin inhibited integrin αIIbß3-mediated platelet activation. Luteolin inhibited mesenteric artery thrombosis and collagen- adrenergic-induced pulmonary thrombosis in mice. Luteolin decreased oxidative stress in vivo. Luteolin did not affect coagulation, hemostasis, or platelet production in mice. Discussion: Luteolin may be an effective and safe antiplatelet agent target for GPVI. A new mechanism (decreased oxidative stress) for the anti-platelet activity of luteolin has been identified.

6.
Biomed Res Int ; 2022: 4893859, 2022.
Article de Anglais | MEDLINE | ID: mdl-35937403

RÉSUMÉ

Evodia rutaecarpa has multiple pharmacological effects and is widely used in the prevention and treatment of migraine, diabetes, cardiovascular disease, cancer, and other chronic diseases; however, the pharmacological effects of its active compound evodiamine (Evo) have not been thoroughly investigated. The purpose of this study was to investigate the effects of Evo on antiplatelet activation and thrombosis. We discovered that Evo effectively inhibited collagen-induced platelet activation but had no effect on platelet aggregation caused by activators such as thrombin, ADP, and U46619. Second, we found that Evo effectively inhibited the release of platelet granules induced by collagen. Finally, evodiamine inhibits the transduction of the SFKs/Syk/Akt/PLCγ2 activation pathway in platelets. According to in vivo studies, Evo significantly prolonged the mesenteric thromboembolism induced by ferric chloride and had no discernible effect on the coagulation function of mice. In conclusion, the antiplatelet and thrombotic effects of Evo discovered in this study provide an experimental basis for the investigation of the pharmacological mechanisms of Evo and the development of antiplatelet drugs.


Sujet(s)
Activation plaquettaire , Thrombose , Animaux , Plaquettes/métabolisme , Collagène/métabolisme , Souris , Agrégation plaquettaire , Antiagrégants plaquettaires/pharmacologie , Antiagrégants plaquettaires/usage thérapeutique , Quinazolines , Thrombose/étiologie
7.
FASEB J ; 35(12): e22037, 2021 12.
Article de Anglais | MEDLINE | ID: mdl-34762761

RÉSUMÉ

Complement component C3, mainly synthesized by hepatocytes, acts as the convergence point of three different pathways in activating the complement cascade. Besides its well-established roles in the extracellular milieu, C3 performs various intracellular functions such as immunomodulation and pathogen recognition. Although C3 is present at extremely high concentrations in hepatocytes, little is known about its intrahepatic function. In this study, we found that C3 knockout (C3-/- ) mice displayed accelerated hepatic triglyceride (TG) accumulation compared with C57BL/6J wild type mice. Mechanistically, C3 deficiency impaired lipophagy in hepatocytes, owing to the disrupted interaction between C3 and autophagy-related 16 like 1, which is essential for autolysosome assembly. Furthermore, lipophagy deficiency affected the function of the endoplasmic reticulum in C3-/- mice, subsequently affecting the expression of protein disulfide isomerase and activity of microsomal TG transfer protein, and ultimately impairing the production of hepatic very-low-density lipoproteins (VLDLs). Rapamycin and thapsigargin treatment accelerated VLDL secretion and alleviated hepatic lipid accumulation in C3-/- mice. Our study demonstrates that C3 promotes lipophagy to facilitate VLDL secretion in hepatocytes, thus playing an essential role in balancing TG levels in the liver.


Sujet(s)
Protéines associées à l'autophagie/métabolisme , Autophagie , Complément C3/physiologie , Lipoprotéines VLDL/métabolisme , Stéatose hépatique non alcoolique/prévention et contrôle , Sirolimus/pharmacologie , Animaux , Protéines associées à l'autophagie/génétique , Immunosuppresseurs/pharmacologie , Mâle , Souris , Souris de lignée C57BL , Souris knockout , Stéatose hépatique non alcoolique/étiologie , Stéatose hépatique non alcoolique/métabolisme , Stéatose hépatique non alcoolique/anatomopathologie
8.
Bio Protoc ; 11(17): e4151, 2021 Sep 05.
Article de Anglais | MEDLINE | ID: mdl-34604456

RÉSUMÉ

An inflammasome is an intracellular multiprotein complex that plays important roles in host defense and inflammatory responses. Inflammasomes are typically composed of the adaptor protein apoptosis-associated speck-like protein containing a CARD (ASC), cytoplasmic sensor protein, and the effector protein pro-caspase-1. ASC assembly into a protein complex termed ASC speck is a readout for inflammasome activation. Here, we provide a step-by-step protocol for the detection of ASC speck by confocal microscopy in Bone marrow derived macrophages (BMBDs) triggered by chemical stimuli and bacterial pathogens. We also describe the detailed procedure for the generation of BMDMs, stimulating conditions for inflammasome activation, immunofluorescence cell staining of ASC protein, and microscopic examination. Thus far, this method is a simple and reliable manner to visualize and quantify the intracellular localization of ASC speck. Graphic abstract: Figure 1. Confocal microscopy detection of ASC speck formation in untreated WT BMDMs and WT BMDMs stimulated with LPS and ATP, transfected with dsDNA, and infected with F. novicida or Salmonella as indicated. Arrow indicates the ASC speck. Scale bars: 10 µm.

9.
J Thorac Dis ; 13(5): 3105-3114, 2021 May.
Article de Anglais | MEDLINE | ID: mdl-34164201

RÉSUMÉ

BACKGROUND: Circulating microRNAs (miRNAs) have emerged as potential biomarkers for cardiovascular diseases. However, few studies have focused on the role of exosomal miRNAs in acute coronary syndrome (ACS). The purpose of this study was to explore weather serum exosomal microRNA-146a (exo-miR-146a) could be used as a novel diagnostic biomarker for ACS and to investigate its relationship with inflammatory response. METHODS: A total of 63 ACS patients and 25 patients with normal coronary arteries (Control) were enrolled respectively. The serum exosomes were isolated and then identified by transmission electron microscopy (TEM), western blot, and nanoparticle tracking analysis (NTA). The expression levels of exo-miR-146a in serum were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and the expression levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in serum were assessed by enzyme-linked immunosorbent assay (ELISA). Spearman's correlation analysis was used to appraise the potential factors related to serum exo-miR-146a and receiver operating characteristic (ROC) curve analysis was applied for predicting the accuracy of ACS via the area under curve (AUC). RESULTS: Exosomes isolated from serum were of typical cup-like shape, with 50-150 nm diameter, and expressed CD9, CD63, CD81, and HSP70. The expression levels of serum exo-miR-146a, IL-1ß, IL-6, and TNF-α were significantly increased in ACS patients compared with the control group, Spearman's correlation analysis indicated that exo-miR-146a expression was markedly positively correlated with IL-1ß, IL-6, and TNF-α. The ROC curve analyses revealed that exo-miR-146a could distinguish ACS patients from their normal controls. CONCLUSIONS: The serum exo-miR-146a may be used as a novel diagnostic biomarker for ACS patients, and it is also associated with inflammatory response.

10.
Theranostics ; 11(5): 2149-2169, 2021.
Article de Anglais | MEDLINE | ID: mdl-33500717

RÉSUMÉ

Rationale: Invariant natural killer T (iNKT) cells and Kupffer cells represent major hepatic populations of innate immune cells. However, their roles in steatohepatitis remain poorly understood. To elucidate their functions in steatohepatitis development, real-time, in vivo analysis is necessary to understand the pathophysiological events in the dynamic interactions between them during diet-induced steatohepatitis. Methods: We used a steatohepatitis animal model induced by a methionine-choline-deficient (MCD) diet. Multi-photon confocal live imaging and conventional experimental techniques were employed to investigate the hepatic pathological microenvironment of iNKT and Kupffer cells, interactions between them, and the biological effects of these interactions in steatohepatitis. Results: We found that iNKT cells were recruited and aggregated into small clusters and interacted dynamically with Kupffer cells in the early stage of steatohepatitis. Most significantly, the iNKT cells in the cluster cleared free lipids released by necrotic hepatocytes and presented a non-classical activation state with high IFN-γ expression. Furthermore, the Kupffer cells in the cell cluster were polarized to type M1. The transcriptome sequencing of iNKT cells showed upregulation of genes related to phagocytosis and lipid processing. Adoptive transfer of iNKT cells to Jα18-/- mice showed that iNKT and Kupffer cell clusters were essential for balancing the liver and peripheral lipid levels and inhibiting liver fibrosis development. Conclusions: Our study identified an essential role for dynamic interactions between iNKT cells and Kupffer cells in promoting lipid phagocytosis and clearance by iNKT cells during early liver steatohepatitis. Therefore, modulating iNKT cells is a potential therapeutic strategy for early steatohepatitis.


Sujet(s)
Modèles animaux de maladie humaine , Microscopie intravitale/méthodes , Cellules de Küpffer/anatomopathologie , Lipides/composition chimique , Cellules T tueuses naturelles/anatomopathologie , Stéatose hépatique non alcoolique/anatomopathologie , Animaux , Cellules de Küpffer/métabolisme , Mâle , Souris , Souris de lignée C57BL , Souris knockout , Cellules T tueuses naturelles/métabolisme , Stéatose hépatique non alcoolique/étiologie , Stéatose hépatique non alcoolique/métabolisme
11.
J Clin Invest ; 130(12): 6301-6316, 2020 12 01.
Article de Anglais | MEDLINE | ID: mdl-33104527

RÉSUMÉ

The mechanism by which inflammasome activation is modulated remains unclear. In this study, we identified an AIM2-interacting protein, the E3 ubiquitin ligase HUWE1, which was also found to interact with NLRP3 and NLRC4 through the HIN domain of AIM2 and the NACHT domains of NLRP3 and NLRC4. The BH3 domain of HUWE1 was important for its interaction with NLRP3, AIM2, and NLRC4. Caspase-1 maturation, IL-1ß release, and pyroptosis were reduced in Huwe1-deficient bone marrow-derived macrophages (BMDMs) compared with WT BMDMs in response to stimuli to induce NLRP3, NLRC4, and AIM2 inflammasome activation. Furthermore, the activation of NLRP3, NLRC4, and AIM2 inflammasomes in both mouse and human cells was remarkably reduced by treatment with the HUWE1 inhibitor BI8622. HUWE1 mediated the K27-linked polyubiquitination of AIM2, NLRP3, and NLRC4, which led to inflammasome assembly, ASC speck formation, and sustained caspase-1 activation. Huwe1-deficient mice had an increased bacterial burden and decreased caspase-1 activation and IL-1ß production upon Salmonella, Francisella, or Acinetobacter baumannii infection. Our study provides insights into the mechanisms of inflammasome activation as well as a potential therapeutic target against bacterial infection.


Sujet(s)
Bactéries/immunologie , Infections bactériennes/immunologie , Inflammasomes/immunologie , Macrophages/immunologie , Protéines suppresseurs de tumeurs/immunologie , Ubiquitin-protein ligases/immunologie , Animaux , Protéines régulatrices de l'apoptose/génétique , Protéines régulatrices de l'apoptose/immunologie , Infections bactériennes/génétique , Protéines adaptatrices de signalisation CARD/génétique , Protéines adaptatrices de signalisation CARD/immunologie , Protéines de liaison au calcium/génétique , Protéines de liaison au calcium/immunologie , Caspase-1/génétique , Caspase-1/immunologie , Protéines de liaison à l'ADN/génétique , Protéines de liaison à l'ADN/immunologie , Cellules HEK293 , Humains , Inflammasomes/génétique , Interleukine-1 bêta/génétique , Interleukine-1 bêta/immunologie , Macrophages/microbiologie , Souris , Souris knockout , Protéine-3 de la famille des NLR contenant un domaine pyrine/génétique , Protéine-3 de la famille des NLR contenant un domaine pyrine/immunologie , Protéines suppresseurs de tumeurs/génétique , Ubiquitin-protein ligases/génétique
12.
J Cardiovasc Pharmacol ; 76(3): 329-336, 2020 09.
Article de Anglais | MEDLINE | ID: mdl-32569018

RÉSUMÉ

Atherosclerosis (AS) is the most common and serious complication in type 2 diabetes mellitus (T2DM). Recent studies have emphasized that inflammation is the main cause of atherosclerosis. Studies have shown that carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1) regulates the expression of matrix metallopeptidase 9 (MMP-9) after ischemic stroke to reduce inflammation. The aim of this study was to elucidate potential molecular mechanism of CEACAM1 on the inflammatory response in atherosclerosis. The serum levels of CEACAM1, MMP-9, and tissue inhibitors of metalloproteinase 1 (TIMP-1) in T2DM patients and healthy control was detected. The results showed that the levels of CEACAM1 and TIMP-1 were significantly decreased, and the levels of MMP-9 were significantly higher than those in the control group. Moreover, we also observed the effect of CEACAM1 on atherosclerosis in T2DM rats. Hematoxylin & eosin (HE) staining and oil red staining showed that CEACAM1 recombinant protein reduced intima-media thickness and the area of atherosclerotic plaques. To further explore the molecular mechanism of CEACAM1 regulating MMP-9/TIMP-1, we conducted experiments in rat aorta vascular endothelial cells and rat aorta smooth muscle cells. The result showed that CEACAM1 inhibits inflammatory response via MMP-9/TIMP-1 axis. Taken together, CEACAM1 attenuates diabetic atherosclerosis by inhibition of IκB/NF-κB signal pathway via MMP-9/TIMP-1 axis, which indicate that CEACAM1 is potentially amenable to therapeutic manipulation for clinical application in atherosclerosis in T2DM.


Sujet(s)
Anti-inflammatoires/pharmacologie , Antigènes CD/pharmacologie , Artères/effets des médicaments et des substances chimiques , Athérosclérose/prévention et contrôle , Molécules d'adhérence cellulaire/pharmacologie , Diabète expérimental/traitement médicamenteux , Diabète de type 2/traitement médicamenteux , Angiopathies diabétiques/prévention et contrôle , Protéines I-kappa B/métabolisme , Matrix metalloproteinase 9/métabolisme , Facteur de transcription NF-kappa B/métabolisme , Inhibiteur tissulaire de métalloprotéinase-1/métabolisme , Animaux , Antigènes CD/métabolisme , Artères/enzymologie , Artères/anatomopathologie , Athérosclérose/enzymologie , Athérosclérose/étiologie , Athérosclérose/anatomopathologie , Études cas-témoins , Molécules d'adhérence cellulaire/métabolisme , Diabète expérimental/complications , Diabète expérimental/enzymologie , Diabète de type 2/complications , Diabète de type 2/enzymologie , Angiopathies diabétiques/enzymologie , Angiopathies diabétiques/étiologie , Angiopathies diabétiques/anatomopathologie , Femelle , Humains , Mâle , Adulte d'âge moyen , Plaque d'athérosclérose , Rat Wistar , Transduction du signal
13.
Biosci Biotechnol Biochem ; 84(1): 85-94, 2020 Jan.
Article de Anglais | MEDLINE | ID: mdl-31794329

RÉSUMÉ

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) regulates collagen-mediated platelet activation through its cytoplasmic immunoreceptor tyrosine-based inhibition motifs (ITIMs). However, the function of CEACAM1's extracellular cleavage fragments is currently unknown. In the present study, we used mass spectrometry (MS) to identify 9 cleavage fragments shed by matrix metallopeptidase 12 (MMP-12), and then we synthesized peptides with sequences corresponding to the fragments. QLSNGNRTLT (QLSN), a peptide from the A1-domain of CEACAM1, significantly attenuated collagen-induced platelet aggregation. QLSN also attenuated platelet static adhesion to collagen. Additionally, QLSN reduced human platelet secretion and integrin αIIbß3 activation in response to glycoprotein VI (GPVI)-selective agonist, convulxin. Correspondingly, QLSN treatment significantly decreased convulxin-mediated phosphorylation of Src, protein kinase B (Akt), spleen tyrosine kinase (Syk) and phospholipase Cγ2 (PLCγ2) in human platelets. These data indicate that the CEACAM1-derived peptide QLSN inhibits GPVI-mediated human platelet activation. QLSN could potentially be developed as a novel antiplatelet agent.


Sujet(s)
Antigènes CD/métabolisme , Molécules d'adhérence cellulaire/métabolisme , Collagène/métabolisme , Oligopeptides/pharmacologie , Activation plaquettaire/effets des médicaments et des substances chimiques , Glycoprotéines de membrane plaquettaire/métabolisme , Plaquettes/métabolisme , CSK tyrosine-protein kinase/métabolisme , Adhérence cellulaire/effets des médicaments et des substances chimiques , Venins de crotalidé/pharmacologie , Humains , Motif d'inhibition de l'immunorécepteur dépendant de la tyrosine/physiologie , Lectines de type C , Matrix metalloproteinase 12/métabolisme , Oligopeptides/synthèse chimique , Phospholipase C gamma/métabolisme , Phosphorylation/effets des médicaments et des substances chimiques , Agrégation plaquettaire/effets des médicaments et des substances chimiques , Glycoprotéines de membrane plaquettaire/agonistes , Domaines protéiques/physiologie , Protéines proto-oncogènes c-akt/métabolisme , Syk kinase/métabolisme
14.
Cell Death Differ ; 27(6): 1924-1937, 2020 06.
Article de Anglais | MEDLINE | ID: mdl-31827236

RÉSUMÉ

Acetaminophen (APAP) is the leading cause of drug-induced acute liver failure. Sphingosine-1-phosphate (S1P), whose formation is catalyzed by sphingosine kinase (SPHK)-1 or -2, is a bioactive lipid implicated in human health and disease. Here, we show that APAP-treated sphK1-deficient (sphK1-/-) mice exhibited markedly less liver damage and reduced inflammation compared with the wild-type mice. SPHK1 deficiency alleviated APAP-induced endoplasmic reticulum (ER) stress by affecting the phosphorylation of inositol-requiring enzyme 1α (IRE1α) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK)-eukaryotic translation initiation factor 2α (eIF2α), levels of activating transcription factor 4 (ATF4), and activation of activating transcription factor 6 (ATF6). SPHK1 deficiency also inhibited mitochondrial permeability transition (MPT), as evidenced by the impaired phosphorylation of JNK, apoptosis signal-regulated kinase 1 (ASK1), and glycogen synthase kinase 3ß (GSK3ß). In addition, SPHK1 deficiency reduced the levels of histone deacetylase and promoted the acetylation of p65 and STAT1, thereby impairing the transcription of inflammatory genes. Supplementation with exogenous S1P significantly reversed the activation of the PERK-eIF2α-ATF4 pathway and ATF6 during ER stress as well as the activation of GSK3ß, ASK1, and JNK during MPT. Both FTY720, a functional S1P receptor antagonist, and PF543, an SPHK1 inhibitor, significantly ameliorated APAP-induced liver injury and improved animal survival. Our study reveals a critical role for SPHK1 in mediating APAP-induced hepatotoxicity by promoting ER stress and MPT.


Sujet(s)
Acétaminophène/toxicité , Stress du réticulum endoplasmique/effets des médicaments et des substances chimiques , Chlorhydrate de fingolimod/pharmacologie , Nécrose induite par la perméabilité transmembranaire mitochondriale/effets des médicaments et des substances chimiques , Phosphotransferases (Alcohol Group Acceptor)/antagonistes et inhibiteurs , Pyrrolidines/pharmacologie , Sulfones/pharmacologie , Animaux , Antienzymes , Méthanol/pharmacologie , Souris , Souris de lignée C57BL , Souris knockout , Récepteurs de la sphingosine-1-phosphate/antagonistes et inhibiteurs
15.
Med Sci Monit ; 25: 9864-9874, 2019 Dec 22.
Article de Anglais | MEDLINE | ID: mdl-31865362

RÉSUMÉ

BACKGROUND Acute coronary syndrome (ACS) occurs approximately every 40 seconds, and was an underlying cause of death in 1 out of every 7 deaths. More accurate indicators are needed to distinguish patients with ACS from patients manifesting negative changes in electrocardiogram (ECG) and myocardial enzymes. This study aimed to investigate whether the expression of platelet carcinoembryonic antigen cell adhesion molecule-5 (CEACAM5/CEA/CD66e) could help predict ACS. MATERIAL AND METHODS We enrolled 82 participants (mean age 60 years, 33 females and 49 males). The expression of CEA on washed human platelets was assessed using two-color flow cytometry. The CEA levels on platelets and in serum of these 82 consecutive patients were detected using two-color whole-blood flow cytometry analysis and a custom-made Luminex multiplex assay, respectively. RESULTS CEA was expressed on the surface of human platelets. The expression of platelet CEA (P<0.01), but not serum CEA (P=0.30), was significantly higher in patients with ACS compared to patients with normal coronary artery. Increased platelet CEA levels could serve as a new independent indicator for ACS (P=0.0003). Platelet CEA testing (P=0.000002), as well as cardiac troponin I (cTnI) (P=0.0005), can diagnose ACS with high sensitivity and specificity, and, combined with cTnI (P<0.0001), can improve the diagnostic value. CONCLUSIONS Platelet CEA expression was higher in individuals presenting with ACS. Hence, platelet CEA might be a novel and reliable biomarker for ACS. Large-scale studies are needed to confirm this hypothesis.


Sujet(s)
Syndrome coronarien aigu/diagnostic , Antigène carcinoembryonnaire/métabolisme , Syndrome coronarien aigu/sang , Sujet âgé , Marqueurs biologiques/sang , Plaquettes/composition chimique , Antigène carcinoembryonnaire/analyse , Électrocardiographie , Femelle , Cytométrie en flux/méthodes , Protéines liées au GPI/analyse , Protéines liées au GPI/métabolisme , Humains , Mâle , Adulte d'âge moyen , Sérum/composition chimique , Troponine I/métabolisme
16.
Front Pharmacol ; 10: 923, 2019.
Article de Anglais | MEDLINE | ID: mdl-31507419

RÉSUMÉ

Background: Xinmailong (XML), a bioactive composite extracted from Periplaneta americana, has been widely used to treat cardiovascular diseases such as congestive heart failure. However, it is unclear whether XML has antiplatelet and antithrombotic effects. Methods: The effects of XML on agonist-induced platelet aggregation, adhesion and spreading, granule secretion, integrin α II bß3 activation, and thrombus formation were evaluated. Phosphorylation of Syk, PLCγ2, Akt, GSK3ß, and MAPK signaling molecules was also studied on agonist-induced platelets. In addition, the antithrombotic effects of XML were observed in vivo using an acute pulmonary thrombosis mouse model. Results: XML dose-dependently inhibited in vitro platelet aggregation and granule secretion induced by thrombin, collagen, and arachidonic acid (AA). XML also greatly reduced platelet adhesion and spreading on both collagen- and fibrinogen-coated surfaces. Biochemical analysis revealed that XML inhibited thrombin-, collagen-, and AA-induced phosphorylation of Syk, PLCγ2, Akt, GSK3ß, and MAPK. Additionally, XML significantly inhibited in vivo thrombus formation in a collagen-epinephrine-induced acute pulmonary thrombosis mouse model. Conclusions and General Significance: Here, we provide the first report showing that XML inhibits platelet function and that it possesses antithrombotic activity. This suggests that XML could be a potential therapeutic candidate to prevent or treat platelet-related cardiovascular diseases.

17.
J Neuroimmune Pharmacol ; 14(3): 478-492, 2019 09.
Article de Anglais | MEDLINE | ID: mdl-31069623

RÉSUMÉ

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons and excessive microglial activation in the substantia nigra pars compacta (SNpc). In the present study, we aimed to demonstrate the therapeutic effectiveness of the potent sphingosine-1-phosphate receptor antagonist fingolimod (FTY720) in an animal model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and to identify the potential mechanisms underlying these therapeutic effects. C57BL/6J mice were orally administered FTY720 before subcutaneous injection of MPTP. Open-field and rotarod tests were performed to determine the therapeutic effect of FTY720. The damage to dopaminergic neurons and the production of monoamine neurotransmitters were assessed using immunohistochemistry, high-performance liquid chromatography, and flow cytometry. Immunofluorescence (CD68- positive) and enzyme-linked immunosorbent assay were used to analyze the activation of microglia, and the levels of activated signaling molecules were measured using Western blotting. Our findings indicated that FTY720 significantly attenuated MPTP-induced behavioral deficits, reduced the loss of dopaminergic neurons, and increased dopamine release. FTY720 directly inhibited MPTP-induced microglial activation in the SNpc, suppressed the production of interleukin (IL)-6, IL-1ß, and tumor necrosis factor-α in BV-2 microglial cells treated with 1-methyl-4-phenylpyridinium (MPP+), and subsequently decreased apoptosis in SH-SY5Y neuroblastoma cells. Moreover, in MPP+-treated BV-2 cells and primary microglia, FTY720 treatment significantly attenuated the increases in the phosphorylation of PI3K/AKT/GSK-3ß, reduced ROS generation and p65 activation, and also inhibited the activation of NLRP3 inflammasome and caspase-1. In conclusion, FTY720 may reduce PD progression by inhibiting NLRP3 inflammasome activation via its effects on ROS generation and p65 activation in microglia. These findings provide novel insights into the mechanisms underlying the therapeutic effects of FTY720, suggesting its potential as a novel therapeutic strategy against PD. Graphical Abstract FTY720 may reduce ROS production by inhibiting the PI3K/AKT/GSK-3ß signaling pathway, while at the same time reducing p65 phosphorylation, thus decreasing NLRP3 inflammasome activation through these two pathways, ultimately reducing microglia activation-induced neuronal damage.


Sujet(s)
Antiparkinsoniens/pharmacologie , Chlorhydrate de fingolimod/pharmacologie , Inflammasomes/effets des médicaments et des substances chimiques , Microglie/effets des médicaments et des substances chimiques , Neuroprotecteurs/pharmacologie , Syndromes parkinsoniens/traitement médicamenteux , Animaux , Apoptose/effets des médicaments et des substances chimiques , Lignée cellulaire , Corps strié/composition chimique , Corps strié/effets des médicaments et des substances chimiques , Cytokines/biosynthèse , Neurones dopaminergiques/effets des médicaments et des substances chimiques , Neurones dopaminergiques/anatomopathologie , Évaluation préclinique de médicament , Comportement d'exploration/effets des médicaments et des substances chimiques , Inflammasomes/métabolisme , Intoxication au MPTP/traitement médicamenteux , Intoxication au MPTP/immunologie , Mâle , Souris , Souris de lignée C57BL , Microglie/métabolisme , Mitochondries/effets des médicaments et des substances chimiques , Protéine-3 de la famille des NLR contenant un domaine pyrine/métabolisme , Syndromes parkinsoniens/immunologie , Pars compacta/composition chimique , Pars compacta/effets des médicaments et des substances chimiques , Pars compacta/anatomopathologie , Espèces réactives de l'oxygène , Test du rotarod , Transduction du signal/effets des médicaments et des substances chimiques
18.
Nano Lett ; 19(2): 1387-1394, 2019 02 13.
Article de Anglais | MEDLINE | ID: mdl-30673293

RÉSUMÉ

To suppress dendrite formation in lithium metal batteries, high cation transference number electrolytes that reduce electrode polarization are highly desirable, but rarely available using conventional liquid electrolytes. Here, we show that liquid electrolytes increase their cation transference numbers (e.g., ∼0.2 to >0.70) when confined to a structurally rigid polymer host whose pores are on a similar length scale (0.5-2 nm) as the Debye screening length in the electrolyte, which results in a diffuse electrolyte double layer at the polymer-electrolyte interface that retains counterions and reject co-ions from the electrolyte due to their larger size. Lithium anodes coated with ∼1 µm thick overlayers of the polymer host exhibit both a low area-specific resistance and clear dendrite-suppressing character, as evident from their performance in Li-Li and Li-Cu cells as well as in post-mortem analysis of the anode's morphology after cycling. High areal capacity Li-S cells (4.9 mg cm-2; 8.2 mAh cm-2) implementing these high transference number polymer-hosted liquid electrolytes were remarkably stable, considering ∼24 µm of lithium was electroreversibly deposited in each cycle at a C-rate of 0.2. We further identified a scalable manufacturing path for these polymer-coated lithium electrodes, which are drop-in components for lithium metal battery manufacturing.

19.
Brain Behav Immun ; 70: 293-304, 2018 05.
Article de Anglais | MEDLINE | ID: mdl-29548997

RÉSUMÉ

Neuropsychiatric (NP) involvement in systemic lupus erythematosus (SLE) severely impacts patients' quality of life and leads to a poor prognosis. The current therapeutic protocol, corticosteroid administration, can also induce neuropsychiatric disorders. FTY720 is an immunomodulator that selectively confines lymphocytes in lymph nodes and reduces autoreactive T cell recruitment to the central nervous system (CNS). This study aimed to identify a novel therapeutic strategy for NPSLE. B6.MRL-lpr mice were treated with oral administration of FTY720 (2 mg/kg) three times per week for 12 weeks, to evaluate its efficacy in a model of NPSLE. FTY720 significantly attenuated the impulsive and depression-like behavior of B6.MRL-lpr mice. Neuronal damage was reduced in the cortex, hippocampus, and amygdala of the FTY720-treated B6.MRL-lpr mice, as well as in TNF-α-treated HT22 cells. Additionally, FTY720 downregulated levels of inflammatory cytokines, and reduced the infiltration of T cells and neutrophils in the brain parenchyma. FTY720 also acted directly on cerebral endothelial cells and reduced the permeability of the blood-brain barrier (BBB) in B6.MRL-lpr mice, as evidenced by reduced central IgG and albumin levels. Finally, FTY720 significantly inhibited activation of PI3K/Akt/GSK3ß/p65 signaling, which further reduced the expression levels of adhesion molecules in bEND.3 cells treated with B6.MRL-lpr mouse serum. Collectively, our data indicate that oral administration of FTY720 at an early stage has beneficial effects in NPSLE-model B6.MRL-lpr mice, suggesting that it may represent an effective new therapeutic strategy for NPSLE.


Sujet(s)
Chlorhydrate de fingolimod/pharmacologie , Lupus érythémateux disséminé/immunologie , Animaux , Encéphale , Cytokines , Dépression , Modèles animaux de maladie humaine , Femelle , Chlorhydrate de fingolimod/usage thérapeutique , Facteurs immunologiques/usage thérapeutique , Lupus érythémateux disséminé/thérapie , Lymphocytes/effets des médicaments et des substances chimiques , Souris , Souris de lignée C57BL , Souris de lignée MRL lpr , Qualité de vie , Transduction du signal , Lymphocytes T
20.
Nat Commun ; 8(1): 2277, 2017 12 22.
Article de Anglais | MEDLINE | ID: mdl-29273748

RÉSUMÉ

Polymer binders in battery electrodes may be either active or passive. This distinction depends on whether the polymer influences charge or mass transport in the electrode. Although it is desirable to understand how to tailor the macromolecular design of a polymer to play a passive or active role, design rules are still lacking, as is a framework to assess the divergence in such behaviors. Here, we reveal the molecular-level underpinnings that distinguish an active polyelectrolyte binder designed for lithium-sulfur batteries from a passive alternative. The binder, a cationic polyelectrolyte, is shown to both facilitate lithium-ion transport through its reconfigurable network of mobile anions and restrict polysulfide diffusion from mesoporous carbon hosts by anion metathesis, which we show is selective for higher oligomers. These attributes allow cells to be operated for >100 cycles with excellent rate capability using cathodes with areal sulfur loadings up to 8.1 mg cm-2.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...