RESUMEN
Genetic studies have highlighted microglia as pivotal in orchestrating Alzheimer's disease (AD). Microglia that adhere to Aß plaques acquire a transcriptional signature, "disease-associated microglia" (DAM), which largely emanates from the TREM2-DAP12 receptor complex that transmits intracellular signals through the protein tyrosine kinase SYK. The human TREM2R47H variant associated with high AD risk fails to activate microglia via SYK. We found that SYK-deficient microglia cannot encase Aß plaques, accelerating brain pathology and behavioral deficits. SYK deficiency impaired the PI3K-AKT-GSK-3ß-mTOR pathway, incapacitating anabolic support required for attaining the DAM profile. However, SYK-deficient microglia proliferated and advanced to an Apoe-expressing prodromal stage of DAM; this pathway relied on the adapter DAP10, which also binds TREM2. Thus, microglial responses to Aß involve non-redundant SYK- and DAP10-pathways. Systemic administration of an antibody against CLEC7A, a receptor that directly activates SYK, rescued microglia activation in mice expressing the TREM2R47H allele, unveiling new options for AD immunotherapy.
Asunto(s)
Enfermedad de Alzheimer , Microglía , Animales , Ratones , Humanos , Microglía/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Péptidos beta-Amiloides/metabolismo , Enfermedad de Alzheimer/patología , Placa Amiloide/metabolismo , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Quinasa Syk/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Receptores Inmunológicos/metabolismoRESUMEN
Recent studies have begun to reveal critical roles for the brain's professional phagocytes, microglia, and their receptors in the control of neurotoxic amyloid beta (Aß) and myelin debris accumulation in neurodegenerative disease. However, the critical intracellular molecules that orchestrate neuroprotective functions of microglia remain poorly understood. In our studies, we find that targeted deletion of SYK in microglia leads to exacerbated Aß deposition, aggravated neuropathology, and cognitive defects in the 5xFAD mouse model of Alzheimer's disease (AD). Disruption of SYK signaling in this AD model was further shown to impede the development of disease-associated microglia (DAM), alter AKT/GSK3ß-signaling, and restrict Aß phagocytosis by microglia. Conversely, receptor-mediated activation of SYK limits Aß load. We also found that SYK critically regulates microglial phagocytosis and DAM acquisition in demyelinating disease. Collectively, these results broaden our understanding of the key innate immune signaling molecules that instruct beneficial microglial functions in response to neurotoxic material.
Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Animales , Ratones , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides , Modelos Animales de Enfermedad , Ratones Transgénicos , Microglía/patología , FagocitosisRESUMEN
STING (stimulator of interferon genes) exerts protective cellular responses to viral infection via induction of interferon production and autophagy. Here, we report the role of STING in modulating the immune responses toward fungal infection. Upon Candida albicans stimulation, STING transited alongside the endoplasmic reticulum (ER) to the phagosomes. In phagosomes, STING directly bound with Src via the N-terminal 18 amino acids of STING, and this binding prevented Src from recruiting and phosphorylating Syk. Consistently, Syk-associated signaling and production of pro-inflammatory cytokines and chemokines were increased in mouse BMDCs (bone-marrow-derived dendritic cells) lacking STING with fungal treatment. STING deficiency improved anti-fungal immunity in systemic C. albicans infection. Importantly, administration of the N-terminal 18-aa (amino acid) peptide of STING improved host outcomes in disseminated fungal infection. Overall, our study identifies a previously unrecognized function of STING in negatively regulating anti-fungal immune responses and offers a potential therapeutic strategy for controlling C. albicans infection.
Asunto(s)
Nucleótidos , Transducción de Señal , Animales , Ratones , Citocinas/metabolismo , Inmunidad Innata , Interferones/metabolismo , Nucleótidos/metabolismo , Fagosomas/metabolismo , Fagosomas/microbiologíaRESUMEN
Production of interleukin-17 (IL-17) and IL-22 by T helper 17 (Th17) cells and group 3 innate lymphoid cells (ILC3s) in response to the gut microbiota ensures maintenance of intestinal barrier function. Here, we examined the mechanisms whereby the immune system detects microbiota in the steady state. A Syk-kinase-coupled signaling pathway in dendritic cells (DCs) was critical for commensal-dependent production of IL-17 and IL-22 by CD4+ T cells. The Syk-coupled C-type lectin receptor Mincle detected mucosal-resident commensals in the Peyer's patches (PPs), triggered IL-6 and IL-23p19 expression, and thereby regulated function of intestinal Th17- and IL-17-secreting ILCs. Mice deficient in Mincle or with selective depletion of Syk in CD11c+ cells had impaired production of intestinal RegIIIγ and IgA and increased systemic translocation of gut microbiota. Consequently, Mincle deficiency led to liver inflammation and deregulated lipid metabolism. Thus, sensing of commensals by Mincle and Syk signaling in CD11c+ cells reinforces intestinal immune barrier and promotes host-microbiota mutualism, preventing systemic inflammation.
Asunto(s)
Células Dendríticas/inmunología , Microbioma Gastrointestinal/inmunología , Interleucina-17/inmunología , Interleucinas/inmunología , Lectinas Tipo C/inmunología , Proteínas de la Membrana/inmunología , Quinasa Syk/inmunología , Animales , Células Dendríticas/metabolismo , Microbioma Gastrointestinal/fisiología , Humanos , Interleucina-17/metabolismo , Interleucinas/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Ganglios Linfáticos Agregados/inmunología , Ganglios Linfáticos Agregados/metabolismo , Ganglios Linfáticos Agregados/microbiología , Transducción de Señal/inmunología , Quinasa Syk/genética , Quinasa Syk/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Interleucina-22RESUMEN
Fungi represent a significant proportion of the gut microbiota. Aberrant immune responses to fungi are frequently observed in inflammatory bowel diseases (IBD) and colorectal cancer (CRC), and mutations in the fungal-sensing pathways are associated with the pathogenesis of IBD. Fungal recognition receptors trigger downstream signaling via the common adaptor protein CARD9 and the kinase SYK. Here we found that commensal gut fungi promoted inflammasome activation during AOM-DSS-induced colitis. Myeloid cell-specific deletion of Card9 or Syk reduced inflammasome activation and interleukin (IL)-18 maturation and increased susceptibility to colitis and CRC. IL-18 promoted epithelial barrier restitution and interferon-γ production by intestinal CD8+ T cells. Supplementation of IL-18 or transfer of wild-type myeloid cells reduced tumor burden in AOM-DSS-treated Card9-/- and Sykfl/flLysMCre/+ mice, whereas treatment with anti-fungal agents exacerbated colitis and CRC. CARD9 deletion changes the gut microbial landscape, suggesting that SYK-CARD9 signaling maintains a microbial ecology that promotes inflammasome activation and thereby restrains colitis and colon tumorigenesis.
Asunto(s)
Proteínas Adaptadoras de Señalización CARD/metabolismo , Colitis/inmunología , Neoplasias del Colon/inmunología , Hongos/inmunología , Microbioma Gastrointestinal/inmunología , Inflamasomas/metabolismo , Enfermedades Inflamatorias del Intestino/inmunología , Mucosa Intestinal/fisiología , Células Mieloides/fisiología , Quinasa Syk/metabolismo , Animales , Proteínas Adaptadoras de Señalización CARD/genética , Células Cultivadas , Colitis/inducido químicamente , Modelos Animales de Enfermedad , Humanos , Interleucina-18/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal , Dodecil Sulfato de Sodio , Quinasa Syk/genéticaRESUMEN
Positive selection of germinal center (GC) B cells is driven by B cell receptor (BCR) affinity and requires help from follicular T helper cells. The transcription factors c-Myc and Foxo1 are critical for GC B cell selection and survival. However, how different affinity-related signaling events control these transcription factors in a manner that links to selection is unknown. Here we showed that GC B cells reprogram CD40 and BCR signaling to transduce via NF-κB and Foxo1, respectively, whereas naive B cells propagate both signals downstream of either receptor. Although either BCR or CD40 ligation induced c-Myc in naive B cells, both signals were required to highly induce c-Myc, a critical mediator of GC B cell survival and cell cycle reentry. Thus, GC B cells rewire their signaling to enhance selection stringency via a requirement for both antigen receptor- and T cell-mediated signals to induce mediators of positive selection.
Asunto(s)
Antígenos CD40/fisiología , Centro Germinal/inmunología , Proteínas Proto-Oncogénicas c-myc/biosíntesis , Receptores de Antígenos de Linfocitos B/fisiología , Transducción de Señal/fisiología , Animales , Proteína Forkhead Box O1/fisiología , Sistema de Señalización de MAP Quinasas/fisiología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , FN-kappa B/fisiología , Fosfatidilinositol 3-Quinasas/fisiología , Proteínas Proto-Oncogénicas c-akt/fisiología , Quinasa Syk/fisiologíaRESUMEN
Mice carrying a hypomorphic point mutation in the Ptpn6 gene (Ptpn6spin mice) develop an inflammatory skin disease that resembles neutrophilic dermatosis in humans. Here, we demonstrated that interleukin-1α (IL-1α) signaling through IL-1R and MyD88 in both stromal and immune cells drive inflammation in Ptpn6spin mice. We further identified SYK as a critical kinase that phosphorylates MyD88, promoted MyD88-dependent signaling and mediates dermatosis in Ptpn6spin mice. Our studies further demonstrated that SHP1 encoded by Ptpn6 binds and suppresses SYK activation to inhibit MyD88 phosphorylation. Downstream of SHP1 and SYK-dependent counterregulation of MyD88 tyrosine phosphorylation, we have demonstrated that the scaffolding function of receptor interacting protein kinase 1 (RIPK1) and tumor growth factor-ß activated kinase 1 (TAK1)-mediating signaling were required to spur inflammatory disease. Overall, these studies identify SHP1 and SYK crosstalk as a critical regulator of MyD88 post-translational modifications and IL-1-driven inflammation.
Asunto(s)
Inflamación/inmunología , Interleucina-1alfa/inmunología , Factor 88 de Diferenciación Mieloide/inmunología , Enfermedades de la Piel/inmunología , Quinasa Syk/inmunología , Animales , Citometría de Flujo , Células HEK293 , Humanos , Immunoblotting , Inflamación/genética , Inflamación/metabolismo , Interleucina-1alfa/genética , Interleucina-1alfa/metabolismo , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/inmunología , Quinasas Quinasa Quinasa PAM/metabolismo , Ratones Noqueados , Modelos Inmunológicos , Mutación , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 6/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 6/inmunología , Proteína Tirosina Fosfatasa no Receptora Tipo 6/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Proteína Serina-Treonina Quinasas de Interacción con Receptores/inmunología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Receptores de Interleucina-1/inmunología , Receptores de Interleucina-1/metabolismo , Transducción de Señal/genética , Transducción de Señal/inmunología , Enfermedades de la Piel/genética , Enfermedades de la Piel/metabolismo , Quinasa Syk/genética , Quinasa Syk/metabolismoRESUMEN
Lignin valorization is being intensely pursued via tandem catalytic depolymerization and biological funneling to produce single products. In many lignin depolymerization processes, aromatic dimers and oligomers linked by carbon-carbon bonds remain intact, necessitating the development of enzymes capable of cleaving these compounds to monomers. Recently, the catabolism of erythro-1,2-diguaiacylpropane-1,3-diol (erythro-DGPD), a ring-opened lignin-derived ß-1 dimer, was reported in Novosphingobium aromaticivorans. The first enzyme in this pathway, LdpA (formerly LsdE), is a member of the nuclear transport factor 2 (NTF-2)-like structural superfamily that converts erythro-DGPD to lignostilbene through a heretofore unknown mechanism. In this study, we performed biochemical, structural, and mechanistic characterization of the N. aromaticivorans LdpA and another homolog identified in Sphingobium sp. SYK-6, for which activity was confirmed in vivo. For both enzymes, we first demonstrated that formaldehyde is the C1 reaction product, and we further demonstrated that both enantiomers of erythro-DGPD were transformed simultaneously, suggesting that LdpA, while diastereomerically specific, lacks enantioselectivity. We also show that LdpA is subject to a severe competitive product inhibition by lignostilbene. Three-dimensional structures of LdpA were determined using X-ray crystallography, including substrate-bound complexes, revealing several residues that were shown to be catalytically essential. We used density functional theory to validate a proposed mechanism that proceeds via dehydroxylation and formation of a quinone methide intermediate that serves as an electron sink for the ensuing deformylation. Overall, this study expands the range of chemistry catalyzed by the NTF-2-like protein family to a prevalent lignin dimer through a cofactorless deformylation reaction.
Asunto(s)
Liasas , Lignina/metabolismo , Proteínas Bacterianas/metabolismo , Oxidorreductasas/metabolismo , EstereoisomerismoRESUMEN
Acute respiratory distress syndrome (ARDS) is a deadly clinical presentation in sepsis, COVID, and other lung disorders where vascular fluid leakage is a severe problem. Recent findings by Shadab et al. in the JBC show that a well-known player in immune function, Syk, also regulates vascular leakage in response to sepsis. An existing FDA-approved inhibitor of Syk, fostamatinib, prevents the vascular leakage and improves survival in a mouse sepsis model, providing promise for ARDS treatment in the clinic.
Asunto(s)
Aminopiridinas , Morfolinas , Inhibidores de Proteínas Quinasas , Pirimidinas , Síndrome de Dificultad Respiratoria , Quinasa Syk , Humanos , Aminopiridinas/uso terapéutico , Morfolinas/uso terapéutico , Pirimidinas/uso terapéutico , Quinasa Syk/antagonistas & inhibidores , Quinasa Syk/metabolismo , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Animales , Ratones , Inhibidores de Proteínas Quinasas/uso terapéutico , Sepsis/tratamiento farmacológicoRESUMEN
Chemical compounds have recently been introduced as alternative and non-integrating inducers of pluripotent stem cell fate. However, chemical reprogramming is hampered by low efficiency and the molecular mechanisms remain poorly characterized. Here, we show that inhibition of spleen tyrosine kinase (Syk) by R406 significantly promotes mouse chemical reprogramming. Mechanistically, R406 alleviates Syk / calcineurin (Cn) / nuclear factor of activated T cells (NFAT) signaling-mediated suppression of glycine, serine, and threonine metabolic genes and dependent metabolites. Syk inhibition upregulates glycine level and downstream transsulfuration cysteine biosynthesis, promoting cysteine metabolism and cellular hydrogen sulfide (H2 S) production. This metabolic rewiring decreased oxidative phosphorylation and ROS levels, enhancing chemical reprogramming. In sum, our study identifies Syk-Cn-NFAT signaling axis as a new barrier of chemical reprogramming and suggests metabolic rewiring and redox homeostasis as important opportunities for controlling cell fates.
Asunto(s)
Fibroblastos/metabolismo , Sulfuro de Hidrógeno/metabolismo , Quinasa Syk/antagonistas & inhibidores , Animales , Calcineurina/metabolismo , Células Cultivadas , Cisteína/metabolismo , Fibroblastos/efectos de los fármacos , Glicina/metabolismo , Ratones , Factores de Transcripción NFATC/metabolismo , Oxazinas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Transducción de SeñalRESUMEN
Epigenetic alterations, especially DNA methylation, have been shown to play a role in the pathogenesis of diabetes mellitus (DM) and its complications, including diabetic kidney disease (DKD). Spleen tyrosine kinase (Syk) is known to be involved in immune and inflammatory disorders. We, therefore, investigated the possible involvement of Syk promoter methylation in DKD, and the mechanisms underlying this process. Kidney tissues were obtained from renal biopsies of patients with early and advanced DKD. A diabetic mouse model (ApoE-/- DM) was generated from ApoE knockout (ApoE-/-) mice using a high-fat and high-glucose diet combined with low-dose streptozocin intraperitoneal injection. We also established an in vitro model using HK2 cells. A marked elevation in the expression levels of Syk, PKCß, and P66shc in renal tubules was observed in patients with DKD. In ApoE-/- DM mice, Syk expression and the binding of Sp1 to the Syk gene promoter were both increased in the kidney. In addition, the promoter region of the Syk gene exhibited hypomethylation. Syk inhibitor (R788) intervention improved renal function and alleviated pathologic changes in ApoE-/- DM mice. Moreover, R788 intervention alleviated oxidative stress and apoptosis and downregulated the expression of PKCß/P66shc signaling pathway proteins. In HK2 cells, oxLDL combined with high-glucose stimulation upregulated Sp1 expression in the nucleus (compared with control and oxLDL groups), and this was accompanied by an increase in the binding of Sp1 to the Syk gene promoter. SP1 silencing downregulated the expression of Syk and inhibited the production of reactive oxygen species and cell apoptosis. Finally, PKC agonist intervention reversed the oxidative stress and apoptosis induced by Syk inhibitor (R406). In DKD, hypomethylation at the Syk gene promoter was accompanied by an increase in Sp1 binding at the promoter. As a consequence of this enhanced Sp1 binding, Syk gene expression was upregulated. Syk inhibitors could attenuate DKD-associated oxidative stress and apoptosis via downregulation of PKCß/P66shc signaling pathway proteins. Together, our results identify Syk as a promising target for intervention in DKD.
Asunto(s)
Diabetes Mellitus , Nefropatías Diabéticas , Quinasa Syk , Animales , Humanos , Ratones , Apoptosis , Nefropatías Diabéticas/genética , Metilación de ADN , Glucosa , Estrés Oxidativo , Transducción de Señal , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src/genética , Ratones Noqueados para ApoE , Quinasa Syk/genéticaRESUMEN
Enhanced DNA repair is an important mechanism of inherent and acquired resistance to DNA targeted therapies, including poly ADP ribose polymerase (PARP) inhibition. Spleen associated tyrosine kinase (Syk) is a non-receptor tyrosine kinase acknowledged for its regulatory roles in immune cell function, cell adhesion, and vascular development. This study presents evidence indicating that Syk expression in high-grade serous ovarian cancer and triple-negative breast cancers promotes DNA double-strand break resection, homologous recombination (HR), and subsequent therapeutic resistance. Our investigations reveal that Syk is activated by ATM following DNA damage and is recruited to DNA double-strand breaks by NBS1. Once localized to the break site, Syk phosphorylates CtIP, a pivotal mediator of resection and HR, at Thr-847 to promote repair activity, particularly in Syk-expressing cancer cells. Inhibition of Syk or its genetic deletion impedes CtIP Thr-847 phosphorylation and overcomes the resistant phenotype. Collectively, our findings suggest a model wherein Syk fosters therapeutic resistance by promoting DNA resection and HR through a hitherto uncharacterized ATM-Syk-CtIP pathway. Moreover, Syk emerges as a promising tumor-specific target to sensitize Syk-expressing tumors to PARP inhibitors, radiation and other DNA-targeted therapies.
Asunto(s)
Roturas del ADN de Doble Cadena , Resistencia a Antineoplásicos , Recombinación Homóloga , Quinasa Syk , Quinasa Syk/metabolismo , Quinasa Syk/genética , Quinasa Syk/antagonistas & inhibidores , Humanos , Roturas del ADN de Doble Cadena/efectos de los fármacos , Femenino , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/efectos de los fármacos , Fosforilación , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Reparación del ADN/efectos de los fármacos , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteínas de la Ataxia Telangiectasia Mutada/antagonistas & inhibidores , Proteínas de la Ataxia Telangiectasia Mutada/genética , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/patología , Animales , Línea Celular Tumoral , Daño del ADN/efectos de los fármacosRESUMEN
Prostate cancer (PCa), a prevalent malignancy among elderly males, exhibits a notable rate of advancement, even when subjected to conventional androgen deprivation therapy or chemotherapy. An effective progression prediction model would prove invaluable in identifying patients with a higher progression risk. Using bioinformatics strategies, we integrated diverse data sets of PCa to construct a novel risk model predicated on gene expression and progression-free survival (PFS). The accuracy of the model was assessed through validation using an independent data set. Eight genes were discerned as independent prognostic factors and included in the prediction model. Patients assigned to the high-risk cohort demonstrated a diminished PFS, and the areas under the curve of our model in the validation set for 1-year, 3-year, and 5-year PFS were 0.9325, 0.9041 and 0.9070, respectively. Additionally, through the application of single-cell RNA sequencing to two castration-related prostate cancer (CRPC) samples and two hormone-related prostate cancer (HSPC) samples, we discovered that luminal cells within CRPC exhibited an elevated risk score. Subsequent molecular biology experiments corroborated our findings, illustrating heightened SYK expression levels within tumour tissues and its contribution to cancer cell migration. We found that the knockdown of SYK could inhibit migration in PCa cells. Our progression-related risk model demonstrated the potential prognostic value of SYK and indicated its potential as a target for future diagnosis and treatment strategies in PCa management.
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Biología Computacional , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Neoplasias de la Próstata , Masculino , Humanos , Biología Computacional/métodos , Pronóstico , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/diagnóstico , Perfilación de la Expresión Génica , Biomarcadores de Tumor/genética , Factores de Riesgo , Línea Celular TumoralRESUMEN
Increased endothelial cell (EC) permeability is a cardinal feature of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Tyrosine phosphorylation of VE-cadherin is a key determinant of EC barrier disruption. However, the identity and role of tyrosine kinases in this context are incompletely understood. Here we report that Spleen Tyrosine Kinase (Syk) is a key mediator of EC barrier disruption and lung vascular leak in sepsis. Inhibition of Syk by pharmacological or genetic approaches, each reduced thrombin-induced EC permeability. Mechanistically, Syk associates with and phosphorylates VE-cadherin to cause EC permeability. To study the causal role of endothelial Syk in sepsis-induced ALI, we used a remarkably efficient and cost-effective approach based on gene transfer to generate EC-ablated Syk mice. These mice were protected against sepsis-induced loss of VE-cadherin and inflammatory lung injury. Notably, the administration of Syk inhibitor R788 (fostamatinib); currently in phase II clinical trial for the treatment of COVID-19, mitigated lung injury and mortality in mice with sepsis. These data identify Syk as a novel kinase for VE-cadherin and a druggable target against ALI in sepsis.
Asunto(s)
Lesión Pulmonar Aguda , Antígenos CD , Cadherinas , Síndrome de Dificultad Respiratoria , Sepsis , Quinasa Syk , Animales , Ratones , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/patología , Antígenos CD/metabolismo , Cadherinas/metabolismo , Permeabilidad Capilar , Pulmón/metabolismo , Sepsis/complicaciones , Quinasa Syk/metabolismo , FosforilaciónRESUMEN
Spleen tyrosine kinase (Syk), a non-receptor-type tyrosine kinase, has a wide range of physiological functions. A possible role of Syk in Alzheimer's disease (AD) has been proposed. We evaluated the localization of Syk in the brains of patients with AD and control participants. Human neuroblastoma M1C cells harboring wild-type tau (4R0N) were used with the tetracycline off (TetOff) induction system. In this model of neuronal tauopathy, the effects of the Syk inhibitors-BAY 61-3606 and R406-on tau phosphorylation and oligomerization were explored using several phosphorylated tau-specific antibodies and an oligomeric tau antibody, and the effects of these Syk inhibitors on autophagy were examined using western blot analyses. Moreover, the effects of the Syk inhibitor R406 were evaluated in vivo using wild-type mice. In AD brains, Syk and phosphorylated tau colocalized in the cytosol. In M1C cells, Syk protein (72â¯kDa) was detected using western blot analysis. Syk inhibitors decreased the expression levels of several tau phosphoepitopes including PHF-1, CP13, AT180, and AT270. Syk inhibitors also decreased the levels of caspase-cleaved tau (TauC3), a pathological tau form. Syk inhibitors increased inactivated glycogen synthase kinase 3ß expression and decreased active p38 mitogen-activated protein kinase expression and demethylated protein phosphatase 2â¯A levels, indicating that Syk inhibitors inactivate tau kinases and activate tau phosphatases. Syk inhibitors also activated autophagy, as indicated by increased LC3II and decreased p62 levels. In vivo, the Syk inhibitor R406 decreased phosphorylated tau levels in wild-type mice. These findings suggest that Syk inhibitors offer novel therapeutic strategies for tauopathies, including AD.
RESUMEN
Immune thrombocytopenia (ITP) refractory to multiple therapies may require a combination of drugs targeting different mechanisms and targets. In this retrospective, multicentre, international study, we report the safety and effectiveness of avatrombopag and fostamatininb in combination administered to 18 patients with multirefractory ITP. Overall, the combination response was achieved in 15 patients (83.3%), with a median time from combination start to best response of 15 days (IQR: 8-35 days). After a median follow-up of 256 days (IQR: 142.8-319), 5 patients relapsed (26.7%), all during tapering or stopping one drug. Adverse events were described in 6 of 18 patients (33%).
RESUMEN
Death due to severe influenza is usually a fatal complication of a dysregulated immune response more than the acute virulence of an infectious agent. Although spleen tyrosine kinase (SYK) as a critical immune signaling molecule and therapeutic target plays roles in airway inflammation and acute lung injury, the role of SYK in influenza virus infection is not clear. Here, we investigated the antiviral and anti-inflammatory effects of SYK inhibitor R406 on influenza infection through a coculture model of human alveolar epithelial (A549) and macrophage (THP-1) cell lines and mouse model. The results showed that R406 treatment increased the viability of A549 and decreased the pathogenicity and mortality of lethal influenza virus in mice with influenza A infection, decreased levels of intracellular signaling molecules under the condition of inflammation during influenza virus infection. Combination therapy with oseltamivir further ameliorated histopathological damage in the lungs of mice and further delayed the initial time to death compared with R406 treatment alone. This study demonstrated that phosphorylation of SYK is involved in the pathogenesis of influenza, and R406 has antiviral and anti-inflammatory effects on the treatment of the disease, which may be realized through multiple pathways, including the already reported SYK/STAT/IFNs-mediated antiviral pathway, as well as TNF-α/SYK- and SYK/Akt-based immunomodulation pathway.
Asunto(s)
Antiinflamatorios , Antivirales , Modelos Animales de Enfermedad , Infecciones por Orthomyxoviridae , Oxazinas , Quinasa Syk , Animales , Humanos , Quinasa Syk/antagonistas & inhibidores , Ratones , Antivirales/farmacología , Antivirales/uso terapéutico , Infecciones por Orthomyxoviridae/tratamiento farmacológico , Infecciones por Orthomyxoviridae/inmunología , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Oxazinas/farmacología , Oxazinas/uso terapéutico , Piridinas/farmacología , Piridinas/uso terapéutico , Imidazoles/farmacología , Imidazoles/uso terapéutico , Pulmón/patología , Pulmón/virología , Pulmón/efectos de los fármacos , Pulmón/inmunología , Células A549 , Virus de la Influenza A/efectos de los fármacos , Ratones Endogámicos BALB C , Oseltamivir/farmacología , Oseltamivir/uso terapéutico , Gripe Humana/tratamiento farmacológico , Gripe Humana/inmunología , Células THP-1 , Femenino , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéuticoRESUMEN
Isoliquiritigenin (ISL) is a chalcone-type flavonoid derived from the root of licorice with antioxidant, anti-inflammatory, anti-tumour and neuroprotective properties. ISL has been proven to downregulate the productions of IL-1ß, TNF-α and IL-6 by macrophages. However, detailed molecular mechanisms of this modulation remain elusive. Here, ISL suppressed Syk phosphorylation and CD80, CD86, IL-1ß, TNF-α and IL-6 expressions in lipopolysaccharide-stimulated macrophages ex vivo. ApoC3-transgenic (ApoC3TG) mice had more activated macrophages. ISL was also able to downregulate the inflammatory activities of macrophages from ApoC3TG mice. Administration of ISL inhibited Syk activation and inflammatory activities of macrophages in ApoC3TG mice in vivo. The treatment of ISL further alleviated MCD-induced non-alcoholic fatty liver disease (NAFLD) in wild-type and ApoC3TG mice, accompanied by less recruitment and activation of liver macrophages. Due to the inhibition of Syk phosphorylation, ISL-treated macrophages displayed less production of cytoplasmic ROS, NLRP3, cleaved-GSDMD and cleaved-IL-1ß, suggesting less inflammasome activation. Finally, the molecular docking study demonstrated that ISL bound to Syk directly with the Kd of 1.273 × 10-8 M. When the Syk expression was knocked down by its shRNA, the inhibitory effects of ISL on activated macrophages disappeared, indicating that Syk was at least one of key docking-molecules of ISL. Collectively, ISL could alleviate MCD-induced NAFLD in mice involved with the inhibition of macrophage inflammatory activity by the blockade of Syk-induced inflammasome activation.
Asunto(s)
Chalconas , Inflamasomas , Macrófagos , Enfermedad del Hígado Graso no Alcohólico , Quinasa Syk , Animales , Masculino , Ratones , Chalconas/farmacología , Modelos Animales de Enfermedad , Inflamasomas/metabolismo , Inflamasomas/efectos de los fármacos , Activación de Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Transgénicos , Simulación del Acoplamiento Molecular , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/inmunología , Fosforilación , Quinasa Syk/metabolismoRESUMEN
The highly selective Spleen Tyrosine Kinase (SYK) inhibitors entospletinib and lanraplenib disrupt kinase activity and inhibit immune cell functions. They are developed for treatment of B-cell malignancies and autoimmunity diseases. The impact of P-gp/ABCB1 and BCRP/ABCG2 efflux transporters, OATP1a/1b uptake transporters and CYP3A drug-metabolizing enzymes on the oral pharmacokinetics of these drugs was assessed using mouse models. Entospletinib and lanraplenib were orally administered simultaneously at moderate dosages (10 mg/kg each) to female mice to assess the possibility of examining two structurally and mechanistically similar drugs at the same time, while reducing the number of experimental animals and sample-processing workload. The plasma pharmacokinetics of both drugs were not substantially restricted by Abcb1 or Abcg2. The brain-to-plasma ratios of entospletinib in Abcb1a/b-/-, Abcg2-/- and Abcb1a/b;Abcg2-/- mice were 1.7-, 1.8- and 2.9-fold higher, respectively, compared to those in wild-type mice. For lanraplenib these brain-to-plasma ratios were 3.0-, 1.3- and 10.4-fold higher, respectively. This transporter-mediated restriction of brain penetration for both drugs could be almost fully inhibited by coadministration of the dual ABCB1/ABCG2 inhibitor elacridar, without signs of acute toxicity. Oatp1a/b and human CYP3A4 did not seem to affect the pharmacokinetics of entospletinib and lanraplenib, but mouse Cyp3a may limit lanraplenib plasma exposure. Unexpectedly, entospletinib and lanraplenib increased each other's plasma exposure by 2.6- to 2.9-fold, indicating a significant drug-drug interaction. This interaction was, however, unlikely to be mediated through any of the studied transporters or CYP3A. The obtained insights may perhaps help to further improve the safety and efficacy of entospletinib and lanraplenib.
Asunto(s)
Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Encéfalo , Indazoles , Morfolinas , Inhibidores de Proteínas Quinasas , Pirazinas , Animales , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/antagonistas & inhibidores , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2/genética , Femenino , Ratones , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/farmacología , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Quinasa Syk/antagonistas & inhibidores , Quinasa Syk/metabolismo , Ratones Noqueados , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Subfamilia B de Transportador de Casetes de Unión a ATP/metabolismo , Subfamilia B de Transportador de Casetes de Unión a ATP/antagonistas & inhibidores , Ratones Endogámicos C57BL , Pirimidinas/farmacocinética , Pirimidinas/farmacología , Administración OralRESUMEN
Mast cells have traditionally been associated with allergic inflammatory responses; however, they play important roles in cutaneous innate immunity and wound healing. The Hidradenitis Suppurativa tissue transcriptome is associated with alterations in innate immunity and wound healing-associated pathways; however, the role of mast cells in the disease is unexplored. We demonstrate that mast cell-associated gene expression (using whole tissue RNAseq) is upregulated, and in-silico cellular deconvolution identifies activated mast cells upregulated and resting mast cells downregulated in lesional tissue. Tryptase/Chymase positive mast cells (identified using IHC) localize adjacent to epithelialized tunnels, fibrotic regions of the dermis and at perivascular sites associated with Neutrophil Extracellular Trap formation and TNF-alpha production. Treatment with Spleen Tyrosine Kinase antagonist (Fostamatinib) reduces the expression of mast cell-associated gene transcripts, associated biochemical pathways and the number of tryptase/chymase positive mast cells in lesional hidradenitis suppurativa tissue. This data indicates that although mast cells are not the most abundant cell type in Hidradenitis Suppurativa tissue, the dysregulation of mast cells is paralleled with B cell/plasma cell inflammation, inflammatory epithelialized tunnels and epithelial budding. This provides an explanation as to the mixed inflammatory activation signature seen in HS, the correlation with dysregulated wound healing and potential pathways involved in the development of epithelialized tunnels.