Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 388
Filtrar
1.
J Immunol ; 207(7): 1785-1797, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470858

RESUMO

Our previous work has revealed the ability of CD11b to regulate BCR signaling and control autoimmune disease in mice. However, how CD11b regulates the immune response under normal conditions remains unknown. Through the use of a CD11b knockout model on a nonautoimmune background, we demonstrated that CD11b-deficient mice have an elevated Ag-specific humoral response on immunization. Deletion of CD11b resulted in elevated low-affinity and high-affinity IgG Ab and increases in Ag-specific germinal center B cells and plasma cells (PCs). Examination of BCR signaling in CD11b-deficient mice revealed defects in association of negative regulators pLyn and CD22 with the BCR, but increases in colocalizations between positive regulator pSyk and BCR after stimulation. Using a CD11b-reporter mouse model, we identified multiple novel CD11b-expressing B cell subsets that are dynamically altered during immunization. Subsequent experiments using a cell-specific CD11b deletion model revealed this effect to be B cell intrinsic and not altered by myeloid cell CD11b expression. Importantly, CD11b expression on PCs also impacts on BCR repertoire selection and diversity in autoimmunity. These studies describe a novel role for CD11b in regulation of the healthy humoral response and autoimmunity, and reveal previously unknown populations of CD11b-expressing B cell subsets, suggesting a complex function for CD11b in B cells during development and activation.


Assuntos
Linfócitos B/imunologia , Antígeno CD11b/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Animais , Autoimunidade , Antígeno CD11b/genética , Células Cultivadas , Humanos , Imunidade Humoral , Imunização , Imunomodulação , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação , Receptores de Antígenos de Linfócitos B/genética , Transdução de Sinais , Quinase Syk/metabolismo
2.
Biochem Biophys Res Commun ; 572: 49-56, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34343834

RESUMO

BACKGROUND: Osteosarcoma is a multiple malignant tumor in adolescents. MicroRNAs (MiRNAs) have been found to express abnormally in OS tissues and are considered as potential targets for OS prognosis and treatment. METHODS: MiR-96-5p and SYK expression in clinical samples, osteoblast and OS cell lines were detected. The changes of cell proliferation, apoptosis, adhesion and metastasis of OS cells were detected by CCK-8, BrdU, caspase-3 activity and transwell assay. Dual luciferase report analysis and RNA pull-down were used to confirm binding relation of miR-96-5p and SYK. RESULTS: MiR-96-5p was increased in OS tissue and cells. Moreover, miR-96-5p inhibits proliferation, adhesion and migration of HOS and Saos-2 cells, and promotes cell apoptosis. SYK has been identified to be targeted by miR-96-5p. Overexpressed SYK inhibits the suppressive impact of miR-96-5 on OS cells. CONCLUSION: MiR-96-5p may function as an effective target in OS treatment.


Assuntos
Neoplasias Ósseas/metabolismo , MicroRNAs/metabolismo , Osteossarcoma/metabolismo , Quinase Syk/metabolismo , Adolescente , Neoplasias Ósseas/patologia , Adesão Celular , Proliferação de Células , Criança , Pré-Escolar , Humanos , MicroRNAs/genética , Osteossarcoma/patologia , Quinase Syk/genética , Células Tumorais Cultivadas
3.
Clin Immunol ; 229: 108795, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34252574

RESUMO

Acute and chronic kidney failure is common in hospitalized patients with COVID-19, yet the mechanism of injury and predisposing factors remain poorly understood. We investigated the role of complement activation by determining the levels of deposited complement components (C1q, C3, FH, C5b-9) and immunoglobulin along with the expression levels of the injury-associated molecules spleen tyrosine kinase (Syk), mucin-1 (MUC1) and calcium/calmodulin-dependent protein kinase IV (CaMK4) in the kidney tissues of people who succumbed to COVID-19. We report increased deposition of C1q, C3, C5b-9, total immunoglobulin, and high expression levels of Syk, MUC1 and CaMK4 in the kidneys of COVID-19 patients. Our study provides strong rationale for the expansion of trials involving the use of inhibitors of these molecules, in particular C1q, C3, Syk, MUC1 and CaMK4 to treat patients with COVID-19.


Assuntos
COVID-19/metabolismo , Proteínas do Sistema Complemento/metabolismo , Rim/metabolismo , Mucina-1/metabolismo , SARS-CoV-2 , Quinase Syk/metabolismo , Idoso , Idoso de 80 Anos ou mais , COVID-19/patologia , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , Proteínas do Sistema Complemento/genética , Evolução Fatal , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mucina-1/genética , Quinase Syk/genética
4.
Front Immunol ; 12: 669162, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248948

RESUMO

Renal ischemia is the most common cause of acute kidney injury (AKI) that might be exacerbate lupus activity through neutrophil extracellular traps (NETs) and apoptosis. Here, the renal ischemia reperfusion injury (I/R) was performed in Fc gamma receptor 2b deficient (Fcgr2b-/-) lupus mice and the in vitro experiments. At 24 h post-renal I/R injury, NETs in peripheral blood neutrophils and in kidneys were detected using myeloperoxidase (MPO), neutrophil elastase (NE) and citrullinated histone H3 (CitH3), as well as kidney apoptosis (activating caspase-3), which were prominent in Fcgr2b-/- mice more compared to wild-type (WT). After 120 h renal-I/R injury, renal NETs (using MPO and NE) were non-detectable, whereas glomerular immunoglobulin (Ig) deposition and serum anti-dsDNA were increased in Fcgr2b-/- mice. These results imply that renal NETs at 24 h post-renal I/R exacerbated the lupus nephritis at 120 h post-renal I/R injury in Fcgr2b-/- lupus mice. Furthermore, a Syk inhibitor attenuated NETs, that activated by phorbol myristate acetate (PMA; a NETs activator) or lipopolysaccharide (LPS; a potent inflammatory stimulator), more prominently in Fcgr2b-/- neutrophils than the WT cells as determined by dsDNA, PAD4 and MPO. In addition, the inhibitors against Syk and PAD4 attenuated lupus characteristics (serum creatinine, proteinuria, and anti-dsDNA) in Fcgr2b-/- mice at 120 h post-renal I/R injury. In conclusion, renal I/R in Fcgr2b-/- mice induced lupus exacerbation at 120 h post-I/R injury partly because Syk-enhanced renal NETs led to apoptosis-induced anti-dsDNA, which was attenuated by a Syk inhibitor.


Assuntos
Injúria Renal Aguda/metabolismo , Apoptose , Armadilhas Extracelulares/metabolismo , Rim/metabolismo , Nefrite Lúpica/metabolismo , Neutrófilos/metabolismo , Receptores de IgG/deficiência , Traumatismo por Reperfusão/metabolismo , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/imunologia , Injúria Renal Aguda/patologia , Animais , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Progressão da Doença , Feminino , Rim/efeitos dos fármacos , Rim/imunologia , Rim/patologia , Nefrite Lúpica/tratamento farmacológico , Nefrite Lúpica/imunologia , Nefrite Lúpica/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Neutrófilos/patologia , Inibidores da Fosfodiesterase 4/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Receptores de IgG/genética , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/patologia , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Fatores de Tempo
5.
Eur J Immunol ; 51(9): 2251-2265, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34323286

RESUMO

Bruton's tyrosine kinase (Btk) is a crucial signaling molecule in BCR signaling and a key regulator of B- cell differentiation and function. Btk inhibition has shown impressive clinical efficacy in various B-cell malignancies. However, it remains unknown whether inhibition additionally induces changes in BCR signaling due to feedback mechanisms, a phenomenon referred to as BCR rewiring. In this report, we studied the impact of Btk activity on major components of the BCR signaling pathway in mice. As expected, NF-κB and Akt/S6 signaling was decreased in Btk-deficient B cells. Unexpectedly, phosphorylation of several proximal signaling molecules, including CD79a, Syk, and PI3K, as well as the key Btk-effector PLCγ2 and the more downstream kinase Erk, were significantly increased. This pattern of BCR rewiring was essentially opposite in B cells from transgenic mice overexpressing Btk. Importantly, prolonged Btk inhibitor treatment of WT mice or mice engrafted with leukemic B cells also resulted in increased phosho-CD79a and phospho-PLCγ2 in B cells. Our findings show that Btk enzymatic function determines phosphorylation of proximal and distal BCR signaling molecules in B cells. We conclude that Btk inhibitor treatment results in rewiring of BCR signaling, which may affect both malignant and healthy B cells.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Linfócitos B/imunologia , Antígenos CD79/metabolismo , Fosfolipase C gama/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Tirosina Quinase da Agamaglobulinemia/genética , Animais , Antineoplásicos/farmacologia , Linfócitos B/citologia , Benzamidas/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Imunoglobulina M/imunologia , Linfoma de Células B/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirazinas/farmacologia , Transdução de Sinais/imunologia , Quinase Syk/metabolismo
6.
Hamostaseologie ; 41(3): 206-216, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34192779

RESUMO

Comprehensive proteomic analyses of human and murine platelets established an extraordinary intracellular repertoire of signaling components, which control crucial functions. The spectrum of platelet serine/threonine protein kinases (more than 100) includes the AGC family (protein kinase A, G, C [PKA, PKG, PKC]), the mitogen-activated protein kinases (MAPKs), and others. PKA and PKG have multiple significantly overlapping substrates in human platelets, which possibly affect functions with clear "signaling nodes" of regulation by multiple protein kinases/phosphatases. Signaling nodes are intracellular Ca2+ stores, the contractile system (myosin light chains), and other signaling components such as G-proteins, protein kinases, and protein phosphatases. An example for this fine-tuning is the tyrosine kinase Syk, a crucial component of platelet activation, which is controlled by several serine/threonine and tyrosine protein kinases as well as phosphatases. Other protein kinases including PKA/PKG modulate protein phosphatase 2A, which may be a master regulator of MAPK signaling in human platelets. Protein kinases and in particular MAPKs are targeted by an increasing number of clinically used inhibitors. However, the precise regulation and fine-tuning of these protein kinases and their effects on other signaling components in platelets are only superficially understood-just the beginning. However, promising future approaches are in sight.


Assuntos
Plaquetas/efeitos dos fármacos , Fosfoproteínas Fosfatases/farmacologia , Proteínas Quinases/farmacologia , Serina/metabolismo , Treonina/metabolismo , Animais , Plaquetas/metabolismo , Humanos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Animais , Cadeias Leves de Miosina/metabolismo , Ativação Plaquetária/efeitos dos fármacos , Ativação Plaquetária/genética , Proteômica , Transdução de Sinais , Quinase Syk/metabolismo
7.
Front Immunol ; 12: 667991, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968071

RESUMO

B- and T-lymphocyte attenuator (BTLA/CD272) is an inhibitory checkpoint molecule expressed on T and B cells. Prior studies reported defective function of BTLA by T cells in patients with systemic lupus erythematosus (SLE), whereas nothing is known about its role on B cells in SLE, a disease with various B cell abnormalities. Peripheral blood mononuclear cells (PBMCs) from 23 healthy donors (HD) and 34 SLE patients were stained for BTLA and its expression on B cells was assessed. PBMCs or CD27-IgD+ naive B cells were stimulated together with an activating anti-BTLA antibody or an inhibitor of spleen tyrosine kinase (SYK) and differentiation as well as the expression of activation markers CD71, PD-1 and CD86 were analyzed. Our phenotypic and functional studies revealed reduced BTLA expression on CD27-IgD+ naïve B cells from SLE patients (p=0.0017) related to anti-dsDNA antibody titers (p=0.0394) and SIGLEC-1/CD169 expression on monocytes (p=0.0196), a type I interferon marker related to disease activity. BTLA engagement was found to control CpG/TLR9 activation limiting plasmablast (p=0.0156) and B cell memory induction (p=0.0078) in normal B cells in contrast to other B cell activation pathways (CD40, BCR). These BTLA functions were impaired in SLE B cells. Inhibition of SYK was found to mimic the effects of BTLA activity in vitro. Thus, is it possible that reduced BTLA expression and function of CD27-IgD+ antigen- and T cell-inexperienced SLE B cells could be overcome by SYK inhibition which should be tested in future studies as potential therapeutic principle.


Assuntos
Linfócitos B/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Receptores Imunológicos/metabolismo , Adulto , Anticorpos Antinucleares/sangue , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Estudos de Casos e Controles , Diferenciação Celular , Células Cultivadas , DNA/imunologia , Feminino , Humanos , Memória Imunológica , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Monócitos/metabolismo , Fenótipo , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Adulto Jovem
8.
J Clin Invest ; 131(13)2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34043588

RESUMO

Peripheral T cell lymphomas (PTCLs) represent a significant unmet medical need with dismal clinical outcomes. The T cell receptor (TCR) is emerging as a key driver of T lymphocyte transformation. However, the role of chronic TCR activation in lymphomagenesis and in lymphoma cell survival is still poorly understood. Using a mouse model, we report that chronic TCR stimulation drove T cell lymphomagenesis, whereas TCR signaling did not contribute to PTCL survival. The combination of kinome, transcriptome, and epigenome analyses of mouse PTCLs revealed a NK cell-like reprogramming of PTCL cells with expression of NK receptors (NKRs) and downstream signaling molecules such as Tyrobp and SYK. Activating NKRs were functional in PTCLs and dependent on SYK activity. In vivo blockade of NKR signaling prolonged mouse survival, demonstrating the addiction of PTCLs to NKRs and downstream SYK/mTOR activity for their survival. We studied a large collection of human primary samples and identified several PTCLs recapitulating the phenotype described in this model by their expression of SYK and the NKR, suggesting a similar mechanism of lymphomagenesis and establishing a rationale for clinical studies targeting such molecules.


Assuntos
Linfoma de Células T Periférico/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Células Matadoras Naturais/imunologia , Animais , Carcinogênese/genética , Carcinogênese/imunologia , Reprogramação Celular/genética , Reprogramação Celular/imunologia , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Genes p53 , Humanos , Células Matadoras Naturais/imunologia , Linfoma de Células T Periférico/genética , Linfoma de Células T Periférico/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neoplasias Experimentais/genética , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Células Matadoras Naturais/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Quinase Syk/metabolismo , Linfócitos T/imunologia
9.
J Biol Chem ; 296: 100256, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33839682

RESUMO

A long-standing hypothesis is that complement receptors (CRs), especially CR3, mediate sinking phagocytosis, but evidence is lacking. Alternatively, CRs have been reported to induce membrane ruffles or phagocytic cups, akin to those induced by Fcγ receptors (FcγRs), but the details of these events are unclear. Here we used real-time 3D imaging and KO mouse models to clarify how particles (human red blood cells) are internalized by resident peritoneal F4/80+ cells (macrophages) via CRs and/or FcγRs. We first show that FcγRs mediate highly efficient, rapid (2-3 min) phagocytic cup formation, which is completely abolished by deletion or mutation of the FcR γ chain or conditional deletion of the signal transducer Syk. FcγR-mediated phagocytic cups robustly arise from any point of cell-particle contact, including filopodia. In the absence of CR3, FcγR-mediated phagocytic cups exhibit delayed closure and become aberrantly elongated. Independent of FcγRs, CR3 mediates sporadic ingestion of complement-opsonized particles by rapid phagocytic cup-like structures, typically emanating from membrane ruffles and largely prevented by deletion of the immunoreceptor tyrosine-based activation motif (ITAM) adaptors FcR γ chain and DAP12 or Syk. Deletion of ITAM adaptors or Syk clearly revealed that there is a slow (10-25 min) sinking mode of phagocytosis via a restricted orifice. In summary, we show that (1) CR3 indeed mediates a slow sinking mode of phagocytosis, which is accentuated by deletion of ITAM adaptors or Syk, (2) CR3 induces phagocytic cup-like structures, driven by ITAM adaptors and Syk, and (3) CR3 is involved in forming and closing FcγR-mediated phagocytic cups.


Assuntos
Membrana Celular/metabolismo , Antígeno de Macrófago 1/metabolismo , Macrófagos/metabolismo , Pseudópodes/metabolismo , Quinase Syk/metabolismo , Animais , Células Cultivadas , Humanos , Motivo de Ativação do Imunorreceptor Baseado em Tirosina , Camundongos , Camundongos Knockout , Fagocitose , Transdução de Sinais
10.
Eur J Med Chem ; 219: 113393, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-33845236

RESUMO

ZAP-70 (zeta-chain associated protein kinase 70 kDa) signaling pathway and its functions have been involved in the development and adaptive immune signaling of T cell. It thus represents a promising target for autoimmune diseases. Although reversible ZAP-70 kinase domain inhibitors have been developed, they are either weak or nonselective. We report herein the structure-guided development of the first potent and covalent inhibitor of ZAP-70 kinase domain. In particular, compound 18 (RDN009) showed good selectivity for ZAP-70 over structurally related Syk, and displayed potent inhibitory effects on T cell proliferation, activation, and inflammatory cytokine production. A mass spectrometry analysis further confirmed the covalent linkage between the inhibitor and ZAP-70 protein at C346. Overall, the covalent inhibitor RDN009 represents a potent and selective probe of ZAP-70 for further development for treatment of autoimmune diseases.


Assuntos
Inibidores de Proteínas Quinases/química , Proteína-Tirosina Quinase ZAP-70/antagonistas & inibidores , Animais , Sítios de Ligação , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Proliferação de Células/efeitos dos fármacos , Citocinas/análise , Citocinas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Relação Estrutura-Atividade , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Proteína-Tirosina Quinase ZAP-70/metabolismo
11.
Mol Cell ; 81(10): 2094-2111.e9, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33878293

RESUMO

Even though SYK and ZAP70 kinases share high sequence homology and serve analogous functions, their expression in B and T cells is strictly segregated throughout evolution. Here, we identified aberrant ZAP70 expression as a common feature in a broad range of B cell malignancies. We validated SYK as the kinase that sets the thresholds for negative selection of autoreactive and premalignant clones. When aberrantly expressed in B cells, ZAP70 competes with SYK at the BCR signalosome and redirects SYK from negative selection to tonic PI3K signaling, thereby promoting B cell survival. In genetic mouse models for B-ALL and B-CLL, conditional expression of Zap70 accelerated disease onset, while genetic deletion impaired malignant transformation. Inducible activation of Zap70 during B cell development compromised negative selection of autoreactive B cells, resulting in pervasive autoantibody production. Strict segregation of the two kinases is critical for normal B cell selection and represents a central safeguard against the development of autoimmune disease and B cell malignancies.


Assuntos
Autoimunidade , Neoplasias/enzimologia , Neoplasias/prevenção & controle , Quinase Syk/metabolismo , Proteína-Tirosina Quinase ZAP-70/metabolismo , Animais , Antígenos CD19/metabolismo , Linfócitos B , Cálcio/metabolismo , Diferenciação Celular , Transformação Celular Neoplásica , Ativação Enzimática , Humanos , Tolerância Imunológica , Linfoma de Células B/enzimologia , Linfoma de Células B/patologia , Camundongos , Modelos Genéticos , Fatores de Transcrição NFATC/metabolismo , Proteínas de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Ligação Proteica , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais
12.
Cells ; 10(4)2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33917019

RESUMO

CD40-activated CD40L-mediated reverse signalling is a major physiological regulator of neurite growth from excitatory and inhibitory neurons in the developing central nervous system (CNS). Whereas in excitatory pyramidal neurons, CD40L reverse signalling promotes the growth and elaboration of dendrites and axons, in inhibitory GABAergic striatal medium spiny neurons (MSNs), it restricts neurite growth and branching. In pyramidal neurons, we previously reported that CD40L reverse signalling activates an interconnected and interdependent signalling network involving protein kinase C (PKC), extracellular regulated kinases 1 and 2 (ERK1/2), and c-Jun N-terminal kinase (JNK) signalling pathways that regulates dendrite and axon growth. Here, we have studied whether these signalling pathways also influence neurite growth from striatal inhibitory MSNs. To unequivocally activate CD40L reverse signalling, we treated MSN cultures from CD40-deficient mice with CD40-Fc. Here, we report that activation of CD40L reverse signalling in these cultures also increased the phosphorylation of PKC, ERK1/2, and JNK. Using pharmacological activators and inhibitors of these signalling pathways singularly and in combination, we have shown that, as in pyramidal neurons, these signalling pathways work in an interconnected and interdependent network to regulate the neurite growth, but their functions, relationships, and interdependencies are different from those observed in pyramidal neurons. Furthermore, immunoprecipitation studies showed that stimulation of CD40L reverse signalling recruits the catalytic fragment of Syk tyrosine kinase, but in contrast to pyramidal neurons, PKC does not participate in this recruitment. Our findings show that distinctive networks of three signalling pathways mediate the opposite effects of CD40L reverse signalling on neurite growth in excitatory and inhibitory neurons.


Assuntos
Antígenos CD40/metabolismo , Ligante de CD40/metabolismo , Neuritos/metabolismo , Transdução de Sinais , Animais , Antígenos CD40/deficiência , Proliferação de Células , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Neurônios GABAérgicos/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos Endogâmicos C57BL , Modelos Biológicos , Fosforilação , Mapas de Interação de Proteínas , Proteína Quinase C/metabolismo , Quinase Syk/metabolismo
13.
Biochem Pharmacol ; 188: 114579, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33895161

RESUMO

Osteolytic diseases, including breast cancer-induced osteolysis and postmenopausal osteoporosis, are attributed to excessive bone resorption by osteoclasts. Spleen tyrosine kinase (SYK) is involved in osteoclastogenesis and bone resorption, whose role in breast cancer though remains controversial. Effects of PRT062607 (PRT), a highly specific inhibitor of SYK, on the osteoclast and breast cancer functionalities are yet to be clarified. This study demonstrated the in vitro inhibitory actions of PRT on the osteoclast-specific gene expression, bone resorption, and osteoclastogenesis caused by receptor activator of nuclear factor kappa B ligand (RANKL), as well as its in vitro suppressive effects on the growth, migration and invasion of breast carcinoma cell line MDA-MB-231, which were achieved through PLCγ2 and PI3K-AKT-mTOR pathways. Further, we proved that PRT could prevent post-ovariectomy (OVX) loss of bone and breast cancer-induced bone destruction in vivo, which agreed with the in vitro outcomes. In conclusion, our findings suggest the potential value of PRT in managing osteolytic diseases mediated by osteoclasts.


Assuntos
Neoplasias da Mama/enzimologia , Cicloexilaminas/uso terapêutico , Osteólise/enzimologia , Ovariectomia/efeitos adversos , Pirimidinas/uso terapêutico , Quinase Syk/antagonistas & inibidores , Quinase Syk/metabolismo , Animais , Reabsorção Óssea/enzimologia , Reabsorção Óssea/patologia , Reabsorção Óssea/prevenção & controle , Neoplasias da Mama/patologia , Neoplasias da Mama/prevenção & controle , Linhagem Celular Tumoral , Cicloexilaminas/farmacologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Osteólise/patologia , Osteólise/prevenção & controle , Pirimidinas/farmacologia
14.
Commun Biol ; 4(1): 329, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33712740

RESUMO

Maternal antibodies (MAbs) protect against infections in immunologically-immature neonates. Maternally transferred immunity may also be harnessed to target diseases associated with endogenous protein misfolding and aggregation, such as Alzheimer's disease (AD) and AD-pathology in Down syndrome (DS). While familial early-onset AD (fEOAD) is associated with autosomal dominant mutations in the APP, PSEN1,2 genes, promoting cerebral Amyloid-ß (Aß) deposition, DS features a life-long overexpression of the APP and DYRK1A genes, leading to a cognitive decline mediated by Aß overproduction and tau hyperphosphorylation. Although no prenatal screening for fEOAD-related mutations is in clinical practice, DS can be diagnosed in utero. We hypothesized that anti-Aß MAbs might promote the removal of early Aß accumulation in the central nervous system of human APP-expressing mice. To this end, a DNA-vaccine expressing Aß1-11 was delivered to wild-type female mice, followed by mating with 5xFAD males, which exhibit early Aß plaque formation. MAbs reduce the offspring's cortical Aß levels 4 months after antibodies were undetectable, along with alleviating short-term memory deficits. MAbs elicit a long-term shift in microglial phenotype in a mechanism involving activation of the FcγR1/Syk/Cofilin pathway. These data suggest that maternal immunization can alleviate cognitive decline mediated by early Aß deposition, as occurs in EOAD and DS.


Assuntos
Doença de Alzheimer/enzimologia , Doença de Alzheimer/prevenção & controle , Vacinas contra Alzheimer/administração & dosagem , Peptídeos beta-Amiloides/metabolismo , Anticorpos/metabolismo , Encéfalo/enzimologia , Fragmentos de Peptídeos/administração & dosagem , Fagocitose , Receptores de IgG/metabolismo , Quinase Syk/metabolismo , Doença de Alzheimer/imunologia , Doença de Alzheimer/patologia , Vacinas contra Alzheimer/imunologia , Peptídeos beta-Amiloides/administração & dosagem , Peptídeos beta-Amiloides/imunologia , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Anticorpos/imunologia , Comportamento Animal , Encéfalo/imunologia , Encéfalo/patologia , Cognição , Modelos Animais de Doenças , Feminino , Imunização , Masculino , Memória , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/enzimologia , Microglia/imunologia , Microglia/patologia , Fragmentos de Peptídeos/imunologia , Fenótipo , Placa Amiloide , Transdução de Sinais , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia
15.
J Immunol ; 206(7): 1419-1423, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33685996

RESUMO

Invasive fungal infections have become a leading cause of death among immunocompromised patients, leading to around 1.5 million deaths per year globally. The molecular mechanisms by which hosts defend themselves against fungal infection remain largely unclear, which impedes the development of antifungal drugs and other treatment options. In this article, we show that the tyrosine kinase receptor EPH receptor B2 (EPHB2), together with dectin-1, recognizes ß-glucan and activates downstream signaling pathways. Mechanistically, we found that EPHB2 is a kinase for Syk and is required for Syk phosphorylation and activation after dectin-1 ligand stimulation, whereas dectin-1 is critical for the recruitment of Syk. Ephb2-deficient mice are susceptible to Candida albicans-induced fungemia model, which also supports the role of EPHB2 in antifungal immunity. Overall, we provide evidence that EPHB2 is a coreceptor for the recognition of dectin-1 ligands and plays an essential role in antifungal immunity by phosphorylating Syk.


Assuntos
Candida albicans/fisiologia , Candidíase/imunologia , Receptor EphB2/metabolismo , Animais , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno , Humanos , Lectinas Tipo C/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação , Receptor EphB2/genética , Transdução de Sinais , Quinase Syk/metabolismo , Células THP-1
16.
Biomolecules ; 11(2)2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670716

RESUMO

Spleen tyrosine kinase (SYK) can behave as an oncogene or a tumor suppressor, depending on the cell and tissue type. As pharmacological SYK inhibitors are currently evaluated in clinical trials, it is important to gain more information on the molecular mechanisms underpinning these opposite roles. To this aim, we reconstructed and compared its signaling networks using phosphoproteomic data from breast cancer and Burkitt lymphoma cell lines where SYK behaves as a tumor suppressor and promoter. Bioinformatic analyses allowed for unveiling the main differences in signaling pathways, network topology and signal propagation from SYK to its potential effectors. In breast cancer cells, the SYK target-enriched signaling pathways included intercellular adhesion and Hippo signaling components that are often linked to tumor suppression. In Burkitt lymphoma cells, the SYK target-enriched signaling pathways included molecules that could play a role in SYK pro-oncogenic function in B-cell lymphomas. Several protein interactions were profoundly rewired in the breast cancer network compared with the Burkitt lymphoma network. These data demonstrate that proteomic profiling combined with mathematical network modeling allows untangling complex pathway interplays and revealing difficult to discern interactions among the SYK pathways that positively and negatively affect tumor formation and progression.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patologia , Quinase Syk/metabolismo , Neoplasias da Mama/genética , Linfoma de Burkitt/genética , Linhagem Celular Tumoral , Feminino , Humanos , Células MCF-7 , Modelos Teóricos , Fosfoproteínas/metabolismo , Proteômica , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Quinase Syk/genética
17.
Proc Natl Acad Sci U S A ; 118(12)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33727419

RESUMO

Mature basophils play critical inflammatory roles during helminthic, autoimmune, and allergic diseases through their secretion of histamine and the type 2 cytokines interleukin 4 (IL-4) and IL-13. Basophils are activated typically by allergen-mediated IgE cross-linking but also by endogenous "innate" factors. The aim of this study was to identify the innate stimuli (cytokines, chemokines, growth factors, hormones, neuropeptides, metabolites, and bacterial products) and signaling pathways inducing primary basophil activation. Basophils from naïve mice or helminth-infected mice were cultured with up to 96 distinct stimuli and their influence on basophil survival, activation, degranulation, and IL-4 or IL-13 expression were investigated. Activated basophils show a heterogeneous phenotype and segregate into distinct subsets expressing IL-4, IL-13, activation, or degranulation markers. We find that several innate stimuli including epithelial derived inflammatory cytokines (IL-33, IL-18, TSLP, and GM-CSF), growth factors (IL-3, IL-7, TGFß, and VEGF), eicosanoids, metabolites, TLR ligands, and type I IFN exert significant direct effects on basophils. Basophil activation mediated by distinct upstream signaling pathways is always sensitive to Syk and IκB kinases-specific inhibitors but not necessarily to NFAT, STAT5, adenylate cyclase, or c-fos/AP-1 inhibitors. Thus, basophils are activated by very diverse mediators, but their activation seem controlled by a core checkpoint involving Syk and IκB kinases.


Assuntos
Basófilos/imunologia , Basófilos/metabolismo , Quinase I-kappa B/metabolismo , Imunidade Inata , Transdução de Sinais , Quinase Syk/metabolismo , Animais , Basófilos/efeitos dos fármacos , Biomarcadores , Degranulação Celular , Citocinas/metabolismo , Expressão Gênica , Hormônios , Imunidade Inata/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Camundongos , Inibidores de Proteínas Quinases , Transdução de Sinais/efeitos dos fármacos
18.
Biosci Biotechnol Biochem ; 85(4): 931-940, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33686410

RESUMO

Histamine and leukotrienes (LTs), the chemical mediators released from mast cells, play an important role in type-I allergies such as hay fever. Echinacea purpurea (EP) has traditionally been used for herbal tea and has been reported to show biological functions. We evaluated the inhibitory activity of water extracts of EP petals, leaves, and stems against the chemical mediators released from mast cell lines. Petal and leaf extracts exhibited a significant inhibitory effect on histamine release from the stimulated cells, while the stem extract did not exert any effect. Activity of the petal extract was much stronger than that of the leaf extract. All the extracts significantly suppressed LTB4 production in the stimulated cells and displayed similar activities. The petal extract decreased Syk phosphorylation and Ca2+ influx associated with signal transduction in the stimulated cells. These results suggest that EP petal extract may have a relieving effect on allergic symptoms.


Assuntos
Echinacea/química , Mediadores da Inflamação/antagonistas & inibidores , Mastócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Cálcio/metabolismo , Antagonistas dos Receptores Histamínicos/farmacologia , Fosforilação , Folhas de Planta/química , Caules de Planta/química , Transdução de Sinais/efeitos dos fármacos , Quinase Syk/metabolismo
19.
Am J Physiol Cell Physiol ; 320(5): C902-C915, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33689480

RESUMO

Spleen tyrosine kinase (Syk) and Bruton's tyrosine kinase (BTK) play critical roles in platelet physiology, facilitating intracellular immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling downstream of platelet glycoprotein VI (GPVI) and GPIIb/IIIa receptors. Small molecule tyrosine kinase inhibitors (TKIs) targeting Syk and BTK have been developed as antineoplastic and anti-inflammatory therapeutics and have also gained interest as antiplatelet agents. Here, we investigate the effects of 12 different Syk and BTK inhibitors on GPVI-mediated platelet signaling and function. These inhibitors include four Syk inhibitors, Bay 61-3606, R406 (fostamatinib), entospletinib, TAK-659; four irreversible BTK inhibitors, ibrutinib, acalabrutinib, ONO-4059 (tirabrutinib), AVL-292 (spebrutinib); and four reversible BTK inhibitors, CG-806, BMS-935177, BMS-986195, and fenebrutinib. In vitro, TKIs targeting Syk or BTK reduced platelet adhesion to collagen, dense granule secretion, and alpha granule secretion in response to the GPVI agonist cross-linked collagen-related peptide (CRP-XL). Similarly, these TKIs reduced the percentage of activated integrin αIIbß3 on the platelet surface in response to CRP-XL, as determined by PAC-1 binding. Although all TKIs tested inhibited phospholipase C γ2 (PLCγ2) phosphorylation following GPVI-mediated activation, other downstream signaling events proximal to phosphoinositide 3-kinase (PI3K) and PKC were differentially affected. In addition, reversible BTK inhibitors had less pronounced effects on GPIIb/IIIa-mediated platelet spreading on fibrinogen and differentially altered the organization of PI3K around microtubules during platelets spreading on fibrinogen. Select TKIs also inhibited platelet aggregate formation on collagen under physiological flow conditions. Together, our results suggest that TKIs targeting Syk or BTK inhibit central platelet functional responses but may differentially affect protein activities and organization in critical systems downstream of Syk and BTK in platelets.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Plaquetas/efeitos dos fármacos , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Glicoproteínas da Membrana de Plaquetas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Quinase Syk/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia/metabolismo , Plaquetas/enzimologia , Feminino , Humanos , Masculino , Terapia de Alvo Molecular , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Transdução de Sinais , Quinase Syk/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...