RESUMO
The cytokine TWEAK and its cognate receptor Fn14 are members of the TNF/TNFR superfamily and are upregulated in tumors. We found that Fn14, when expressed in tumors, causes cachexia and that antibodies against Fn14 dramatically extended lifespan by inhibiting tumor-induced weight loss although having only moderate inhibitory effects on tumor growth. Anti-Fn14 antibodies prevented tumor-induced inflammation and loss of fat and muscle mass. Fn14 signaling in the tumor, rather than host, is responsible for inducing this cachexia because tumors in Fn14- and TWEAK-deficient hosts developed cachexia that was comparable to that of wild-type mice. These results extend the role of Fn14 in wound repair and muscle development to involvement in the etiology of cachexia and indicate that Fn14 antibodies may be a promising approach to treat cachexia, thereby extending lifespan and improving quality of life for cancer patients.
Assuntos
Caquexia/tratamento farmacológico , Neoplasias/patologia , Receptores do Fator de Necrose Tumoral/antagonistas & inibidores , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/administração & dosagem , Atrofia/tratamento farmacológico , Caquexia/patologia , Morte Celular , Neoplasias do Colo/tratamento farmacológico , Citocina TWEAK , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Desenvolvimento Muscular , Neoplasias/metabolismo , Receptores do Fator de Necrose Tumoral/química , Receptores do Fator de Necrose Tumoral/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Receptor de TWEAK , Fatores de Necrose Tumoral/metabolismoRESUMO
Identifying molecular mediators of neural circuit development and/or function that contribute to circuit dysfunction when aberrantly reengaged in neurological disorders is of high importance. The role of the TWEAK/Fn14 pathway, which was recently reported to be a microglial/neuronal axis mediating synaptic refinement in experience-dependent visual development, has not been explored in synaptic function within the mature central nervous system. By combining electrophysiological and phosphoproteomic approaches, we show that TWEAK acutely dampens basal synaptic transmission and plasticity through neuronal Fn14 and impacts the phosphorylation state of pre- and postsynaptic proteins in adult mouse hippocampal slices. Importantly, this is relevant in two models featuring synaptic deficits. Blocking TWEAK/Fn14 signaling augments synaptic function in hippocampal slices from amyloid-beta-overexpressing mice. After stroke, genetic or pharmacological inhibition of TWEAK/Fn14 signaling augments basal synaptic transmission and normalizes plasticity. Our data support a glial/neuronal axis that critically modifies synaptic physiology and pathophysiology in different contexts in the mature brain and may be a therapeutic target for improving neurophysiological outcomes.
Assuntos
Degeneração Neural/metabolismo , Transdução de Sinais , Acidente Vascular Cerebral/metabolismo , Sinapses/metabolismo , Receptor de TWEAK/metabolismo , Animais , Citocina TWEAK/metabolismo , Modelos Animais de Doenças , Feminino , Hipocampo/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Degeneração Neural/fisiopatologia , Plasticidade Neuronal/fisiologia , Terminações Pré-Sinápticas/metabolismo , Acidente Vascular Cerebral/fisiopatologia , Transmissão Sináptica/fisiologiaRESUMO
Novel therapies and biomarkers are needed for the treatment of acute ischemic stroke (AIS). This study aimed to provide comprehensive insights into the dynamic proteome changes and underlying molecular mechanisms post-ischemic stroke. TMT-coupled proteomic analysis was conducted on mouse brain cortex tissue from five time points up to 4 weeks poststroke in the distal hypoxic-middle cerebral artery occlusion (DH-MCAO) model. We found that nearly half of the detected proteome was altered following stroke, but only â¼8.6% of the changes were at relatively large scales. Clustering on the changed proteome defined four distinct expression patterns characterized by temporal and quantitative changes in innate and adaptive immune response pathways and cytoskeletal and neuronal remodeling. Further analysis on a subset of 309 "top hits", which temporally responded to stroke with relatively large and sustained changes, revealed that they were mostly secreted proteins, highly correlated to different cortical cytokines, and thereby potential pharmacodynamic biomarker candidates for inflammation-targeting therapies. Closer examination of the top enriched neurophysiologic pathways identified 57 proteins potentially associated with poststroke recovery. Altogether, our study generated a rich dataset with candidate proteins worthy of further validation as biomarkers and/or therapeutic targets for stroke. The proteomics data are available in the PRIDE Archive with identifier PXD025077.
Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Camundongos , Proteoma/genética , ProteômicaRESUMO
Germinal center kinase-like kinase (GLK, also known as MAP4K3) has been hypothesized to have an effect on key cellular activities, including inflammatory responses. GLK is required for activation of protein kinase C-θ (PKCθ) in T cells. Controlling the activity of T helper cell responses could be valuable for the treatment of autoimmune diseases. This approach circumvents previous unsuccessful approaches to target PKCθ directly. The use of structure based drug design, aided by the first crystal structure of GLK, led to the discovery of several inhibitors that demonstrate potent inhibition of GLK biochemically and in relevant cell lines.
Assuntos
Proteína Quinase C-theta/metabolismo , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Humanos , Concentração Inibidora 50 , Interleucina-2/metabolismo , Camundongos , Camundongos Knockout , Simulação de Acoplamento Molecular , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Estrutura Terciária de Proteína , Piridinas/química , Piridinas/metabolismo , Piridinas/farmacologia , Relação Estrutura-Atividade , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
TNF-like cytokine 1A (TL1A) is expressed on APCs and provides costimulatory signals to activated lymphocytes that bear its functional receptor, death receptor 3 (DR3). TL1A/DR3 signaling is involved in the pathogenesis of human and experimental inflammatory bowel disease. In the current study, we investigated the role of this cytokine/receptor pair in acute intestinal injury/repair pathways. We demonstrate that intact DR3 signaling protected mice from acute dextran sodium sulfate colitis because DR3(-/-) mice showed more severe mucosal inflammation and increased mortality. DR3(-/-) mice were compromised in their ability to maintain adequate numbers of CD4(+)CD25(+)Foxp3(+) regulatory T cells in response to acute mucosal damage. This defect in immune regulation led to a nonspecific upregulation of effector proinflammatory pathways, which was most prominent for the Th17 immunophenotype. TL1A(-/-) mice were similarly more susceptible to dextran sodium sulfate colitis, although without mortality and with delayed kinetics compared with DR3(-/-) mice, and also displayed significantly reduced numbers of regulatory T cells. Infection of DR3(-/-) mice with Salmonella typhimurium was associated with defective microbial clearance and elevated bacterial load. Taken together, our findings indicate a novel protective role for the TL1A/DR3 axis in the regulation of mucosal homeostasis during acute intestinal injury/repair, which contrasts with its known pathogenic function during chronic intestinal inflammation.
Assuntos
Colite/imunologia , Intestinos/patologia , Membro 25 de Receptores de Fatores de Necrose Tumoral/metabolismo , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Membro 15 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo , Animais , Células Cultivadas , Sulfato de Dextrana , Fatores de Transcrição Forkhead/metabolismo , Humanos , Intestinos/microbiologia , Camundongos , Camundongos Knockout , Camundongos SCID , Membro 25 de Receptores de Fatores de Necrose Tumoral/genética , Transdução de Sinais/genética , Membro 15 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genéticaRESUMO
TNF-like weak inducer of apoptosis (TWEAK), a TNF family ligand, and its only known signaling receptor, FGF-inducible molecule-14 (Fn14), have emerged as a key molecular pathway regulating tissue responses after acute tissue injury and in contexts of chronic injury and disease, including autoimmunity, chronic inflammation, fibrosis, and malignancy. Usually dormant due to the low level of Fn14 expression in healthy tissues, this axis is specifically activated by the upregulation of Fn14 expression locally within injured tissues, thereby triggering a wide range of activities in tissue parenchymal and stromal cells as well as tissue progenitor cells. Current evidence supports that although transient TWEAK/Fn14 pathway activation may be beneficial for tissue repair after acute injury, excessive or sustained TWEAK/Fn14 activation due to repeated injury or chronic disease mediates significant tissue damage and pathological tissue remodeling. This paradigm for the dichotomous function of the TWEAK/Fn14 pathway is discussed, highlighting emerging findings, complexities, and implications for the treatment of tissue damage-associated pathologies and cancer.
Assuntos
Inflamação/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Transdução de Sinais , Fatores de Necrose Tumoral/metabolismo , Animais , Citocina TWEAK , Fibrose/imunologia , Fibrose/metabolismo , Humanos , Inflamação/imunologia , Neoplasias/imunologia , Neoplasias/metabolismo , Receptor de TWEAKRESUMO
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder that primarily affects motoneurons in the brain and spinal cord. Astrocyte and microglia activation as well as skeletal muscle atrophy are also typical hallmarks of the disease. However, the functional relationship between astrocytes, microglia and skeletal muscle in the pathogenic process remains unclear. Here, we report that the tumor necrosis factor-like weak inducer of apoptosis (Tweak) and its receptor Fn14 are aberrantly expressed in spinal astrocytes and skeletal muscle of SOD1(G93A) mice. We show that Tweak induces motoneuron death, stimulates astrocytic interleukin-6 release and astrocytic proliferation in vitro. The genetic ablation of Tweak in SOD1(G93A) mice significantly reduces astrocytosis, microgliosis and ameliorates skeletal muscle atrophy. The peripheral neutralization of Tweak through antagonistic anti-Tweak antibody ameliorates muscle pathology and notably, decreases microglial activation in SOD1(G93A) mice. Unexpectedly, none of these approaches improved motor function, lifespan and motoneuron survival. Our work emphasizes the multi-systemic aspect of ALS, and suggests that a combinatorial therapy targeting multiple cell types will be instrumental to halt the neurodegenerative process.
Assuntos
Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Gliose/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/genética , Fatores de Necrose Tumoral/genética , Esclerose Lateral Amiotrófica/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Astrócitos/metabolismo , Astrócitos/patologia , Morte Celular , Proliferação de Células , Citocina TWEAK , Modelos Animais de Doenças , Deleção de Genes , Regulação da Expressão Gênica , Interleucina-6/biossíntese , Expectativa de Vida , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Microglia/metabolismo , Microglia/patologia , Placa Motora/genética , Placa Motora/metabolismo , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Mutação , Receptores de Superfície Celular/metabolismo , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/metabolismo , Transdução de Sinais , Medula Espinal/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase-1 , Receptor de TWEAK , Fatores de Necrose Tumoral/metabolismo , Regulação para CimaRESUMO
OBJECTIVES: Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease associated with diffuse immune cell dysfunction. CD40-CD40 ligand (CD40L) interaction activates B cells, antigen-presenting cells and platelets. CD40L blockade might provide an innovative treatment for systemic autoimmune disorders. We investigated the safety and clinical activity of dapirolizumab pegol, a polyethylene glycol conjugated anti-CD40L Fab' fragment, in patients with SLE. METHODS: This 32-week randomised, double-blind, multicentre study (NCT01764594) evaluated repeated intravenous administration of dapirolizumab pegol in patients with SLE who were positive for/had history of antidouble stranded DNA/antinuclear antibodies and were on stable doses of immunomodulatory therapies (if applicable). Sixteen patients were randomised to 30 mg/kg dapirolizumab pegol followed by 15 mg/kg every 2 weeks for 10 weeks; eight patients received a matched placebo regimen. Randomisation was stratified by evidence of antiphospholipid antibodies. Patients were followed for 18 weeks after the final dose. RESULTS: No serious treatment-emergent adverse events, thromboembolic events or deaths occurred. Adverse events were mild or moderate, transient and resolved without intervention. One patient withdrew due to infection.Efficacy assessments were conducted only in patients with high disease activity at baseline. Five of 11 (46%) dapirolizumab pegol-treated patients achieved British Isles Lupus Assessment Group-based Composite Lupus Assessment response (vs 1/7; 14% placebo) and 5/12 (42%) evaluable for SLE Responder Index-4 responded by week 12 (vs 1/7; 14% placebo). Mechanism-related gene expression changes were observed in blood RNA samples. CONCLUSIONS: Dapirolizumab pegol could be an effective biological treatment for SLE. Further studies are required to address efficacy and safety. TRIAL REGISTRATION NUMBER: NCT01764594.
Assuntos
Fragmentos Fab das Imunoglobulinas/administração & dosagem , Fatores Imunológicos/administração & dosagem , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Polietilenoglicóis/administração & dosagem , Transcriptoma/efeitos dos fármacos , Administração Intravenosa , Adolescente , Adulto , Idoso , Ligante de CD40/efeitos dos fármacos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Lúpus Eritematoso Sistêmico/sangue , Masculino , Pessoa de Meia-Idade , RNA/sangue , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: The excessive accumulation of extracellular matrix (ECM) in the renal tubulointerstitium is a key component of chronic renal damage in lupus nephritis (LN) and a critical determinant of the disease progression to renal failure. Detection of fibrosis requires renal biopsy and is therefore limited by high risks associated with an invasive procedure. This study explores whether a unique LN urinary peptidome can be identified and whether LN-specific alteration reflects the underlying fibrogenic process of altered ECM turnover. METHOD: Urinary peptides were analyzed for 36 LN and 35 nonrenal systemic lupus erythematosus (SLE) subjects and 58 healthy volunteers (HVs). RESULTS: In total, 70 collagen and 230 noncollagen peptides were significantly changed between LN and nonrenal SLE and between LN and HV and defined as 'LN peptides'; 14 proteases associated with observed LN collagen peptides were identified and activities in 9 proteases were significantly different between LN and nonrenal SLE; 28 collagen peptides were correlated with at least one parameter of clinical renal dysfunction or histolopathology. CONCLUSION: Urinary peptidomic alterations likely reflect pathogenic pathways involving ECM turnover in LN kidneys and potentially could be developed as biomarkers to monitor renal disease progression.
Assuntos
Biomarcadores/urina , Colágeno/urina , Nefropatias/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Nefrite Lúpica/complicações , Fragmentos de Peptídeos/urina , Adulto , Estudos de Casos e Controles , Progressão da Doença , Feminino , Humanos , Nefropatias/etiologia , Nefropatias/urina , MasculinoRESUMO
Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) have been associated with liver regeneration in vivo. To further investigate the role of this pathway we examined their expression in human fibrotic liver disease and the effect of pathway deficiency in a murine model of liver fibrosis. The expression of Fn14 and TWEAK in normal and diseased human and mouse liver tissue and primary human hepatic stellate cells (HSCs) were investigated by qPCR, western blotting and immunohistochemistry. In addition, the levels of Fn14 in HSCs following pro-fibrogenic and pro-inflammatory stimuli were assessed and the effects of exogenous TWEAK on HSCs proliferation and activation were studied in vitro. Carbon tetrachloride (CCl4 ) was used to induce acute and chronic liver injury in TWEAK KO mice. Elevated expression of both Fn14 and TWEAK were detected in acute and chronic human liver injury, and co-localized with markers of activated HSCs. Fn14 levels were low in quiescent HSCs but were significantly induced in activated HSCs, which could be further enhanced with the profibrogenic cytokine TGFß in vitro. Stimulation with recombinant TWEAK induced proliferation but not further HSCs activation. Fn14 gene expression was also significantly up-regulated in CCl4 models of hepatic injury whereas TWEAK KO mice showed reduced levels of liver fibrosis following chronic CCl4 injury. In conclusion, TWEAK/Fn14 interaction leads to the progression of fibrotic liver disease via direct modulation of HSCs proliferation, making it a potential therapeutic target for liver fibrosis.
Assuntos
Células Estreladas do Fígado/patologia , Cirrose Hepática/etiologia , Receptores do Fator de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/deficiência , Actinas/metabolismo , Animais , Tetracloreto de Carbono/toxicidade , Proliferação de Células , Doença Hepática Induzida por Substâncias e Drogas , Doença Hepática Crônica Induzida por Substâncias e Drogas , Citocina TWEAK , Progressão da Doença , Fibroblastos/metabolismo , Humanos , Cirrose Hepática/patologia , Masculino , Camundongos Knockout , RNA Mensageiro/metabolismo , Fatores de Transcrição SOX9/metabolismo , Receptor de TWEAK , Fatores de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/farmacologia , Regulação para Cima/fisiologiaRESUMO
The identification of the cellular origins of myofibroblasts has led to the discovery of novel pathways that potentially drive myofibroblast perpetuation in disease. Here, we further investigated the role of innate immune signaling pathways in this process. In mice, renal injury-induced activation of pericytes, which are myofibroblast precursors attached to endothelial cells, led to upregulated expression of TNF receptor superfamily member 12a, also known as fibroblast growth factor-inducible 14 (Fn14), by these cells. In live rat kidney slices, administration of the Fn14 ligand, TNF-related weak inducer of apoptosis (TWEAK), promoted pericyte-dependent vasoconstriction followed by pericyte detachment from capillaries. In vitro, administration of TWEAK activated and differentiated pericytes into cytokine-producing myofibroblasts, and further activated established myofibroblasts in a manner requiring canonical and noncanonical NF-κB signaling pathways. Deficiency of Fn14 protected mouse kidneys from fibrogenesis, inflammation, and associated vascular instability after in vivo injury, and was associated with loss of NF-κB signaling. In a genetic model of spontaneous CKD, therapeutic delivery of anti-TWEAK blocking antibodies attenuated disease progression, preserved organ function, and increased survival. These results identify the TWEAK-Fn14 signaling pathway as an important factor in myofibroblast perpetuation, fibrogenesis, and chronic disease progression.
Assuntos
Nefropatias/etiologia , Rim/patologia , Miofibroblastos/fisiologia , Receptores do Fator de Necrose Tumoral/fisiologia , Transdução de Sinais , Fatores de Necrose Tumoral/fisiologia , Animais , Citocina TWEAK , Progressão da Doença , Fibrose/etiologia , Camundongos , Receptor de TWEAKRESUMO
TNF ligand superfamily member 12, also known as TNF-related weak inducer of apoptosis (TWEAK), acts through its receptor, fibroblast growth factor-inducible 14 (Fn14), to mediate several key pathologic processes involved in tissue injury relating to lupus nephritis. To explore the potential for renal protection in lupus nephritis by targeting this pathway, we introduced the Fn14 null allele into the MRL-lpr/lpr lupus mouse strain. At 26-38 weeks of age, female Fn14-knockout MRL-lpr/lpr mice had significantly lower levels of proteinuria compared with female wild-type MRL-lpr/lpr mice. Furthermore, Fn14-knockout mice had significantly improved renal histopathology accompanied by attenuated glomerular and tubulointerstitial inflammation. There was a significant reduction in glomerular Ig deposition in Fn14-knockout mice, despite no detectable differences in either serum levels of antibodies or splenic immune cell subsets. Notably, we found that the Fn14-knockout mice displayed substantial preservation of podocytes in glomeruli and that TWEAK signaling directly damaged barrier function and increased filtration through podocyte and glomerular endothelial cell monolayers. Our results show that deficiency of the Fn14 receptor significantly improves renal disease in a spontaneous lupus nephritis model through prevention of the direct injurious effects of TWEAK on the filtration barrier and/or modulation of cytokine production by resident kidney cells. Thus, blocking the TWEAK/Fn14 axis may be a novel therapeutic intervention in immune-mediated proliferative GN.
Assuntos
Fatores de Crescimento de Fibroblastos/deficiência , Barreira de Filtração Glomerular/metabolismo , Nefrite Lúpica/etiologia , Fatores de Necrose Tumoral/metabolismo , Animais , Citocina TWEAK , Feminino , Imunoglobulina G/metabolismo , Camundongos Knockout , Proteinúria/metabolismoRESUMO
TNF-like weak inducer of apoptosis (TWEAK) is a growth factor for bipotent liver progenitors that express its receptor, fibroblast growth factor-inducible 14 (Fn14), a TNF receptor superfamily member. Accumulation of Fn14(+) progenitors occurs in severe acute alcoholic steatohepatitis (ASH) and correlates with acute mortality. In patients with severe ASH, inhibition of TNF-α increases acute mortality. The aim of this study was to determine whether deletion of Fn14 improves the outcome of liver injury in alcohol-consuming mice. Wild-type (WT) and Fn14 knockout (KO) mice were fed control high-fat Lieber deCarli diet or high-fat Lieber deCarli diet with 2% alcohol (ETOH) and injected intraperitoneally with CCl4 for 2 wk to induce liver injury. Mice were euthanized 3 or 10 days after CCl4 treatment. Survival was assessed. Liver tissues were analyzed for cell death, inflammation, proliferation, progenitor accumulation, and fibrosis by quantitative RT-PCR, immunoblot, hydroxyproline content, and quantitative immunohistochemistry. During liver injury, Fn14 expression, apoptosis, inflammation, hepatocyte replication, progenitor and myofibroblast accumulation, and fibrosis increased in WT mice fed either diet. Mice fed either diet expressed similar TWEAK/Fn14 levels, but ETOH-fed mice had higher TNF-α expression. The ETOH-fed group developed more apoptosis, inflammation, fibrosis, and regenerative responses. Fn14 deletion did not reduce hepatic TNF-α expression but improved all injury parameters in mice fed the control diet. In ETOH-fed mice, Fn14 deletion inhibited TNF-α induction and increased acute mortality, despite improvement in liver injury. Fn14 mediates wound-healing responses that are necessary to survive acute liver injury during alcohol exposure.
Assuntos
Fígado Gorduroso Alcoólico/metabolismo , Fígado/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Doença Aguda , Animais , Apoptose , Tetracloreto de Carbono , Proliferação de Células , Modelos Animais de Doenças , Etanol , Fígado Gorduroso Alcoólico/etiologia , Fígado Gorduroso Alcoólico/genética , Fígado Gorduroso Alcoólico/patologia , Hidroxiprolina/metabolismo , Mediadores da Inflamação/metabolismo , Fígado/patologia , Cirrose Hepática Alcoólica/etiologia , Cirrose Hepática Alcoólica/metabolismo , Cirrose Hepática Alcoólica/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores do Fator de Necrose Tumoral/deficiência , Receptores do Fator de Necrose Tumoral/genética , Transdução de Sinais , Receptor de TWEAK , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismo , CicatrizaçãoRESUMO
Neuropsychiatric disease is one of the most common manifestations of human systemic lupus erythematosus, but the mechanisms remain poorly understood. In human brain microvascular endothelial cells in vitro, TNF-like weak inducer of apoptosis (TWEAK) decreases tight junction ZO-1 expression and increases the permeability of monolayer cell cultures. Furthermore, knockout (KO) of the TWEAK receptor, Fn14, in the MRL/lpr lupus mouse strain markedly attenuates neuropsychiatric disease, as demonstrated by significant reductions in depressive-like behavior and improved cognitive function. The purpose of the present study was to determine the mechanisms by which TWEAK signaling is instrumental in the pathogenesis of neuropsychiatric lupus (NPSLE). Evaluating brain sections of MRL/lpr Fn14WT and Fn14KO mice, we found that Fn14KO mice displayed significantly decreased cellular infiltrates in the choroid plexus. To evaluate the integrity of the blood brain barrier (BBB) in MRL/lpr mice, Western blot for fibronectin, qPCR for iNOS, and immunohistochemical staining for VCAM-1/ICAM-1 were performed. We found preserved BBB permeability in MRL/lpr Fn14KO mice, attributable to reduced brain expression of VCAM-1/ICAM-1 and iNOS. Additionally, administration of Fc-TWEAK intravenously directly increased the leakage of a tracer (dextran-FITC) into brain tissue. Furthermore, MRL/lpr Fn14KO mice displayed reduced antibody (IgG) and complement (C3, C6, and C4a) deposition in the brain. Finally, we found that MRL/lpr Fn14KO mice manifested reduced neuron degeneration and hippocampal gliosis. Our studies indicate that TWEAK/Fn14 interactions play an important role in the pathogenesis of NPSLE by increasing the accumulation of inflammatory cells in the choroid plexus, disrupting BBB integrity, and increasing neuronal damage, suggesting a novel target for therapy in this disease.
Assuntos
Apoptose/genética , Barreira Hematoencefálica/fisiopatologia , Neurônios/patologia , Receptores do Fator de Necrose Tumoral/genética , Fatores de Necrose Tumoral/imunologia , Animais , Apoptose/imunologia , Plexo Corióideo/fisiopatologia , Cognição , Complemento C3/imunologia , Complemento C4a/imunologia , Complemento C6/imunologia , Citocina TWEAK , Depressão/genética , Modelos Animais de Doenças , Gliose/genética , Imunoglobulina G/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Camundongos , Camundongos Knockout , Degeneração Neural/genética , Permeabilidade , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor de TWEAK , Molécula 1 de Adesão de Célula Vascular/metabolismo , Proteína da Zônula de Oclusão-1/biossínteseRESUMO
Skeletal muscle wasting attributed to inactivity has significant adverse functional consequences. Accumulating evidence suggests that peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and TNF-like weak inducer of apoptosis (TWEAK)-Fn14 system are key regulators of skeletal muscle mass in various catabolic states. While the activation of TWEAK-Fn14 signaling causes muscle wasting, PGC-1α preserves muscle mass in several conditions, including functional denervation and aging. However, it remains unknown whether there is any regulatory interaction between PGC-1α and TWEAK-Fn14 system during muscle atrophy. Here we demonstrate that TWEAK significantly reduces the levels of PGC-1α and mitochondrial content (â¼50%) in skeletal muscle. Levels of PGC-1α are significantly increased in skeletal muscle of TWEAK-knockout (KO) and Fn14-KO mice compared to wild-type mice on denervation. Transgenic (Tg) overexpression of PGC-1α inhibited progressive muscle wasting in TWEAK-Tg mice. PGC-1α inhibited the TWEAK-induced activation of NF-κB (â¼50%) and dramatically reduced (â¼90%) the expression of atrogenes such as MAFbx and MuRF1. Intriguingly, muscle-specific overexpression of PGC-1α also prevented the inducible expression of Fn14 in denervated skeletal muscle. Collectively, our study demonstrates that TWEAK induces muscle atrophy through repressing the levels of PGC-1α. Overexpression of PGC-1α not only blocks the TWEAK-induced atrophy program but also diminishes the expression of Fn14 in denervated skeletal muscle.
Assuntos
Músculo Esquelético/patologia , Atrofia Muscular/patologia , Receptores do Fator de Necrose Tumoral/fisiologia , Fatores de Transcrição/fisiologia , Fatores de Necrose Tumoral/fisiologia , Animais , Citocina TWEAK , Ensaio de Desvio de Mobilidade Eletroforética , Camundongos , Camundongos Transgênicos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Receptor de TWEAKRESUMO
Our immune system performs the vital function of recognizing and eliminating invading pathogens and malignancies. There is an increasing appreciation that the immune system also actively mediates tissue responses under both physiological and pathological conditions, significantly impacting the inflammatory, fibrogenic, and regenerative components. Likewise, there is a growing understanding of how epithelial, endothelial, and other non-hematopoietic tissue cell types actively contribute to the interplay that shapes tissue responses. While much of the molecular basis underlying the immune regulation of tissue responses remains to be delineated, the tumor necrosis factor (TNF) superfamily ligand/receptor pair of TNF-like weak inducer of apoptosis (TWEAK) and fibroblast growth factor-inducible molecule 14 (Fn14) has now emerged as a key piece of this puzzle. In this review, we first discuss how the usually 'dormant' TWEAK/Fn14 pathway becomes activated specifically in injury and disease contexts. We then summarize how TWEAK-mediated Fn14 signaling triggers a wide range of activities in tissue parenchymal and stromal cells as well as progenitor cells. Finally, we review recent experimental evidence that further supports the functional dichotomy of TWEAK/Fn14 activation in physiological versus pathological tissue responses and its potential therapeutic implications. Whereas transient TWEAK/Fn14 activation promotes productive tissue responses after injury, excessive or persistent TWEAK/Fn14 activation drives pathological tissue responses, leading to progressive damage and degeneration.
Assuntos
Imunidade Inata , Inflamação/imunologia , Músculo Esquelético/imunologia , Receptores do Fator de Necrose Tumoral/imunologia , Transdução de Sinais/imunologia , Células-Tronco/imunologia , Fatores de Necrose Tumoral/imunologia , Animais , Apoptose/imunologia , Citocina TWEAK , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Expressão Gênica/imunologia , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Camundongos , Camundongos Transgênicos , Músculo Esquelético/citologia , Músculo Esquelético/lesões , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/metabolismo , Células-Tronco/metabolismo , Receptor de TWEAK , Fatores de Necrose Tumoral/genética , Fatores de Necrose Tumoral/metabolismoRESUMO
Clinical complications associated with atherosclerotic plaques arise from luminal obstruction due to plaque growth or destabilization leading to rupture. Tumour necrosis factor ligand superfamily member 12 (TNFSF12) also known as TNF-related weak inducer of apoptosis (TWEAK) is a proinflammatory cytokine that participates in atherosclerotic plaque development, but its role in plaque stability remains unclear. Using two different approaches, genetic deletion of TNFSF12 and treatment with a TWEAK blocking mAb in atherosclerosis-prone mice, we have analysed the effect of TWEAK inhibition on atherosclerotic plaques progression and stability. Mice lacking both TNFSF12 and Apolipoprotein E (TNFSF12(-/-) ApoE(-/-) ) exhibited a diminished atherosclerotic burden and lesion size in their aorta. Advanced atherosclerotic plaques of TNFSF12(-/-) ApoE(-/-) or anti-TWEAK treated mice exhibited an increase collagen/lipid and vascular smooth muscle cell/macrophage ratios compared with TNFSF12(+/+) ApoE(-/-) control mice, reflecting a more stable plaque phenotype. These changes are related with two different mechanisms, reduction of the inflammatory response (chemokines expression and secretion and nuclear factor kappa B activation) and decrease of metalloproteinase activity in atherosclerotic plaques of TNFSF12(-/-) ApoE(-/-) . A similar phenotype was observed with anti-TWEAK mAb treatment in TNFSF12(+/+) ApoE(-/-) mice. Brachiocephalic arteries were also examined since they exhibit additional features akin to human atherosclerotic plaques associated with instability and rupture. Features of greater plaque stability including augmented collagen/lipid ratio, reduced macrophage content, and less presence of lateral xanthomas, buried caps, medial erosion, intraplaque haemorrhage and calcium content were present in TNFSF12(-/-) ApoE(-/-) or anti-TWEAK treatment in TNFSF12(+/+) ApoE(-/-) mice. Overall, our data indicate that anti-TWEAK treatment has the capacity to diminish proinflamatory response associated with atherosclerotic plaque progression and to alter plaque morphology towards a stable phenotype.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Aterosclerose/genética , Placa Aterosclerótica/genética , Fatores de Necrose Tumoral/genética , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/patologia , Apolipoproteínas E/genética , Apoptose/genética , Apoptose/imunologia , Aterosclerose/tratamento farmacológico , Aterosclerose/imunologia , Aterosclerose/patologia , Citocina TWEAK , Humanos , Camundongos , Camundongos Knockout , Miócitos de Músculo Liso/imunologia , Miócitos de Músculo Liso/patologia , Placa Aterosclerótica/tratamento farmacológico , Placa Aterosclerótica/imunologia , Placa Aterosclerótica/patologia , Inibidores do Fator de Necrose Tumoral , Fatores de Necrose Tumoral/imunologiaRESUMO
Non-proliferative proteinuric diseases are the most common primary glomerular disorders causing end-stage renal disease. These disorders may associate low level glomerular inflammation and podocyte expression of inflammatory mediators. However, the factors regulating podocyte expression of inflammatory mediators in vivo in non-immune disorders are poorly understood. We have now explored the regulation and role of TWEAK receptor Fn14 in mediating glomerular inflammation in cultured podocytes and in experimental and human non-immune proteinuria. Transcriptomics disclosed Fn14 and MCP-1 mRNA upregulation in glomeruli from patients with focal segmental glomerulosclerosis, as well as a correlation between the expression of both transcripts. Increased glomerular Fn14 and MCP-1 mRNA was confirmed in a second focal segmental glomerulosclerosis cohort and was also observed in membranous nephropathy. In human non-proliferative proteinuric kidney diseases podocytes displayed Fn14 and MCP-1 expression and NFκB activation. Podocyte Fn14 was increased in murine protein overload-induced proteinuria. In Fn14 knock-out mice with protein overload-induced proteinuria, glomerular and periglomerular macrophage infiltrates were reduced, as were MCP-1 mRNA and podocyte MCP-1 staining and podocyte numbers preserved as compared to wild-type counterparts. Adenovirus-mediated overexpression of TWEAK increased periglomerular macrophage infiltration in mice without prior kidney injury. In cultured podocytes inflammatory cytokines increased Fn14 mRNA and protein levels. TWEAK activated NFκB and increased MCP-1 mRNA and protein, an effect prevented by the NFκB inhibitor parthenolide. In conclusion, Fn14 activation results in NFκB-mediated pro-inflammatory effects on podocytes that may be relevant for the pathogenesis of non-proliferative proteinuric kidney disease of non-immune origin.
Assuntos
Inflamação/metabolismo , Nefropatias/metabolismo , Glomérulos Renais/metabolismo , Podócitos/metabolismo , Proteinúria/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Receptores do Fator de Necrose Tumoral/fisiologia , Adolescente , Adulto , Animais , Biomarcadores/metabolismo , Southwestern Blotting , Western Blotting , Estudos de Casos e Controles , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Citocina TWEAK , Citocinas/genética , Citocinas/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Imunofluorescência , Perfilação da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Inflamação/genética , Inflamação/patologia , Nefropatias/genética , Nefropatias/patologia , Glomérulos Renais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , NF-kappa B/genética , NF-kappa B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Podócitos/patologia , Proteinúria/genética , Proteinúria/patologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores do Fator de Necrose Tumoral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptor de TWEAK , Fatores de Necrose Tumoral/genética , Fatores de Necrose Tumoral/metabolismoRESUMO
Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) regulates apoptosis, proliferation and inflammation in renal epithelial cells and plays a role in acute kidney injury. However, there is little information on the chronic effects of TWEAK. We hypothesized that TWEAK may influence renal fibrosis and regulate kidney fibroblast biology, in part, through Ras pathway. We studied a chronic model of experimental unilateral ureteral obstruction in wild type and TWEAK deficient mice, and a murine model of systemic TWEAK overexpression. TWEAK actions were also explored in cultured renal and embryonic fibroblasts. TWEAK and TWEAK receptor expression was increased in the obstructed kidneys. The absence of TWEAK decreased early kidney tubular damage, inflammatory infiltrates and myofibroblast number. TWEAK deficient mice had decreased renal fibrosis 21days after obstruction, as assessed by extracellular matrix staining. In mice without prior underlying kidney disease, systemic overexpression of TWEAK induced kidney inflammation and fibrosis. In cultured fibroblasts, TWEAK induced proliferation through activation of the Ras/ERK pathway. TWEAK also activated nuclear factor κB (NFκB)-dependent inflammatory chemokine production in murine renal fibroblasts. In conclusion, lack of TWEAK reduces renal fibrosis in a model of persistent kidney insult and overexpression of TWEAK led to renal fibrosis. TWEAK actions on renal fibroblasts may contribute to the in vivo observations, as TWEAK promotes inflammatory activity and proliferation in fibroblast cultures.
Assuntos
Proliferação de Células , Fibrose/fisiopatologia , Nefropatias/fisiopatologia , Rim/patologia , Fatores de Necrose Tumoral/fisiologia , Proteínas ras/fisiologia , Animais , Linhagem Celular , Citocina TWEAK , Fibroblastos/patologia , CamundongosRESUMO
Progressive loss of skeletal muscle mass and strength (sarcopenia) is a major clinical problem in the elderly. Recently, proinflammatory cytokine TWEAK and its receptor Fn14 were identified as key mediators of muscle wasting in various catabolic states. However, the role of the TWEAK-Fn14 pathway in pathological changes in skeletal muscle during aging remains unknown. In this study, we demonstrate that the levels of Fn14 are increased in skeletal muscle of 18-month old (aged) mice compared with adult mice. Genetic ablation of Fn14 significantly increased the levels of specific muscle proteins and blunted the age-associated fiber atrophy in mice. While gene expression of two prominent muscle-specific E3 ubiquitin ligases MAFBx and MuRF1 remained comparable, levels of ubiquitinated proteins and the expression of autophagy-related molecule Atg12 were significantly reduced in Fn14-knockout (KO) mice compared with wild-type mice during aging. Ablation of Fn14 significantly diminished the DNA-binding activity of transcription factor nuclear factor-kappa B (NF-κB), gene expression of various inflammatory molecules, and interstitial fibrosis in skeletal muscle of aged mice. Collectively, our study suggests that the TWEAK-Fn14 signaling axis contributes to age-associated muscle atrophy and fibrosis potentially through its local activation of proteolytic systems and inflammatory pathways.