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1.
Mol Cell ; 80(2): 296-310.e6, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32979304

RESUMO

Necroptosis induction in vitro often requires caspase-8 (Casp8) inhibition by zVAD because pro-Casp8 cleaves RIP1 to disintegrate the necrosome. It has been unclear how the Casp8 blockade of necroptosis is eliminated naturally. Here, we show that pro-Casp8 within the necrosome can be inactivated by phosphorylation at Thr265 (pC8T265). pC8T265 occurs in vitro in various necroptotic cells and in the cecum of TNF-treated mice. p90 RSK is the kinase of pro-Casp8. It is activated by a mechanism that does not need ERK but PDK1, which is recruited to the RIP1-RIP3-MLKL-containing necrosome. Phosphorylation of pro-Casp8 at Thr265 can substitute for zVAD to permit necroptosis in vitro. pC8T265 mimic T265E knockin mice are embryonic lethal due to unconstrained necroptosis, and the pharmaceutical inhibition of RSK-mediated pC8T265 diminishes TNF-induced cecum damage and lethality in mice by halting necroptosis. Thus, phosphorylation of pro-Casp8 at Thr265 by RSK is an intrinsic mechanism for passing the Casp8 checkpoint of necroptosis.


Assuntos
Proteínas Quinases Dependentes de 3-Fosfoinositídeo/metabolismo , Caspase 8/metabolismo , Necroptose , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Transdução de Sinais , Animais , Ceco/lesões , Ceco/patologia , Linhagem Celular , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Mutação/genética , Necroptose/efeitos dos fármacos , Especificidade de Órgãos , Fosforilação/efeitos dos fármacos , Fosfotreonina/metabolismo , Proteínas Quinases/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
2.
Nat Commun ; 11(1): 4596, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929083

RESUMO

Earlier studies indicate that either the canonical or non-canonical pathways of inflammasome activation have a limited role on malaria pathogenesis. Here, we report that caspase-8 is a central mediator of systemic inflammation, septic shock in the Plasmodium chabaudi-infected mice and the P. berghei-induced experimental cerebral malaria (ECM). Importantly, our results indicate that the combined deficiencies of caspases-8/1/11 or caspase-8/gasdermin-D (GSDM-D) renders mice impaired to produce both TNFα and IL-1ß and highly resistant to lethality in these models, disclosing a complementary, but independent role of caspase-8 and caspases-1/11/GSDM-D in the pathogenesis of malaria. Further, we find that monocytes from malaria patients express active caspases-1, -4 and -8 suggesting that these inflammatory caspases may also play a role in the pathogenesis of human disease.


Assuntos
Caspase 8/metabolismo , Inflamação/patologia , Malária Cerebral/enzimologia , Animais , Encéfalo/patologia , Caspase 1/metabolismo , Células Dendríticas/metabolismo , Ativação Enzimática , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Interferon gama/metabolismo , Interleucina-1beta/metabolismo , Lipopolissacarídeos , Malária Cerebral/genética , Camundongos Endogâmicos C57BL , Monócitos/metabolismo , Plasmodium chabaudi/fisiologia , Baço/metabolismo , Receptores Toll-Like/metabolismo
3.
Nat Commun ; 11(1): 4071, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792491

RESUMO

Arrest of oligodendrocyte (OL) differentiation and remyelination following myelin damage in multiple sclerosis (MS) is associated with neurodegeneration and clinical worsening. We show that Glutathione S-transferase 4α (Gsta4) is highly expressed during adult OL differentiation and that Gsta4 loss impairs differentiation into myelinating OLs in vitro. In addition, we identify Gsta4 as a target of both dimethyl fumarate, an existing MS therapy, and clemastine fumarate, a candidate remyelinating agent in MS. Overexpression of Gsta4 reduces expression of Fas and activity of the mitochondria-associated Casp8-Bid-axis in adult oligodendrocyte precursor cells, leading to improved OL survival during differentiation. The Gsta4 effect on apoptosis during adult OL differentiation was corroborated in vivo in both lysolecithin-induced demyelination and experimental autoimmune encephalomyelitis models, where Casp8 activity was reduced in Gsta4-overexpressing OLs. Our results identify Gsta4 as an intrinsic regulator of OL differentiation, survival and remyelination, as well as a potential target for future reparative MS therapies.


Assuntos
Glutationa Transferase/metabolismo , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Caspase 8/genética , Caspase 8/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Glutationa Transferase/genética , Homeostase/genética , Homeostase/fisiologia , Imuno-Histoquímica , Masculino , Microglia/citologia , Microglia/metabolismo , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo , Esclerose Múltipla/genética , Esclerose Múltipla/metabolismo , Fagocitose/genética , Fagocitose/fisiologia , Processamento de Proteína Pós-Traducional , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Remielinização/genética , Remielinização/fisiologia
4.
J Biol Chem ; 295(41): 14040-14052, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32763970

RESUMO

Coronaviruses have caused several zoonotic infections in the past two decades, leading to significant morbidity and mortality globally. Balanced regulation of cell death and inflammatory immune responses is essential to promote protection against coronavirus infection; however, the underlying mechanisms that control these processes remain to be resolved. Here we demonstrate that infection with the murine coronavirus mouse hepatitis virus (MHV) activated the NLRP3 inflammasome and inflammatory cell death in the form of PANoptosis. Deleting NLRP3 inflammasome components or the downstream cell death executioner gasdermin D (GSDMD) led to an initial reduction in cell death followed by a robust increase in the incidence of caspase-8- and receptor-interacting serine/threonine-protein kinase 3 (RIPK3)-mediated inflammatory cell deathafter coronavirus infection. Additionally, loss of GSDMD promoted robust NLRP3 inflammasome activation. Moreover, the amounts of some cytokines released during coronavirus infection were significantly altered in the absence of GSDMD. Altogether, our findings show that inflammatory cell death, PANoptosis, is induced by coronavirus infection and that impaired NLRP3 inflammasome function or pyroptosis can lead to negative consequences for the host. These findings may have important implications for studies of coronavirus-induced disease.


Assuntos
Caspase 8/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Animais , Células Cultivadas , Coronavirus/fisiologia , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/patologia , Infecções por Coronavirus/veterinária , Citocinas/metabolismo , Inflamassomos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Necroptose , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(30): 17808-17819, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32661168

RESUMO

p53 is the most frequently mutated, well-studied tumor-suppressor gene, yet the molecular basis of the switch from p53-induced cell-cycle arrest to apoptosis remains poorly understood. Using a combination of transcriptomics and functional genomics, we unexpectedly identified a nodal role for the caspase-8 paralog and only human pseudo-caspase, FLIP(L), in regulating this switch. Moreover, we identify FLIP(L) as a direct p53 transcriptional target gene that is rapidly up-regulated in response to Nutlin-3A, an MDM2 inhibitor that potently activates p53. Genetically or pharmacologically inhibiting expression of FLIP(L) using siRNA or entinostat (a clinically relevant class-I HDAC inhibitor) efficiently promoted apoptosis in colorectal cancer cells in response to Nutlin-3A, which otherwise predominantly induced cell-cycle arrest. Enhanced apoptosis was also observed when entinostat was combined with clinically relevant, p53-activating chemotherapy in vitro, and this translated into enhanced in vivo efficacy. Mechanistically, FLIP(L) inhibited p53-induced apoptosis by blocking activation of caspase-8 by the TRAIL-R2/DR5 death receptor; notably, this activation was not dependent on receptor engagement by its ligand, TRAIL. In the absence of caspase-8, another of its paralogs, caspase-10 (also transcriptionally up-regulated by p53), induced apoptosis in Nutlin-3A-treated, FLIP(L)-depleted cells, albeit to a lesser extent than in caspase-8-proficient cells. FLIP(L) depletion also modulated transcription of canonical p53 target genes, suppressing p53-induced expression of the cell-cycle regulator p21 and enhancing p53-induced up-regulation of proapoptotic PUMA. Thus, even in the absence of caspase-8/10, FLIP(L) silencing promoted p53-induced apoptosis by enhancing PUMA expression. Thus, we report unexpected, therapeutically relevant roles for FLIP(L) in determining cell fate following p53 activation.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acetilação , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Benzamidas/farmacologia , Caspase 8/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Sinergismo Farmacológico , Regulação da Expressão Gênica , Humanos , Imidazóis/metabolismo , Modelos Biológicos , Piperazinas/metabolismo , Ligação Proteica , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Piridinas/farmacologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Proteína Supressora de Tumor p53/genética
6.
Anticancer Res ; 40(5): 2613-2625, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32366406

RESUMO

BACKGROUND/AIM: The occurrence of BRAFV600E mutation causes an up-regulation of the B-raf kinase activity leading to the stabilization of hypoxia-inducible factor 1-alpha (HIF-1α) - the promoter of the 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) enzyme. The aim of the study was to examine the effect of the (2E)-3-(3-Pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO), as an inhibitor of PFKFB3, on human melanoma cells (A375) with endogenous BRAFV600E mutation. MATERIALS AND METHODS: A375 cells were exposed to different concentrations of 3PO and the following tests were performed: docking, cytotoxicity assay, immunocytochemistry staining glucose uptake, clonogenic assay, holotomography imaging, and flow cytometry. RESULTS: Our studies revealed that 3PO presents a dose-dependent and time-independent cytotoxic effect and promotes apoptosis of A375 cells. Furthermore, the obtained data indicate that 3PO induces cell cycle arrest in G1/0 and glucose uptake reduction. CONCLUSION: Taking all together, our research demonstrated a here should be proapoptotic and antiproliferative effect of 3PO on A375 human melanoma cells.


Assuntos
Inibidores Enzimáticos/farmacologia , Melanoma/enzimologia , Fosfofrutoquinase-2/antagonistas & inibidores , Piridinas/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 8/metabolismo , Domínio Catalítico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores Enzimáticos/química , Glucose/metabolismo , Humanos , Melanoma/patologia , Simulação de Acoplamento Molecular , Terapia de Alvo Molecular , Fosfofrutoquinase-2/metabolismo , Piridinas/química , Ensaio Tumoral de Célula-Tronco
7.
Proc Natl Acad Sci U S A ; 117(23): 12961-12968, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32444487

RESUMO

Viral immune evasion is currently understood to focus on deflecting CD8 T cell recognition of infected cells by disrupting antigen presentation pathways. We evaluated viral interference with the ultimate step in cytotoxic T cell function, the death of infected cells. The viral inhibitor of caspase-8 activation (vICA) conserved in human cytomegalovirus (HCMV) and murine CMV (MCMV) prevents the activation of caspase-8 and proapoptotic signaling. We demonstrate the key role of vICA from either virus, in deflecting antigen-specific CD8 T cell-killing of infected cells. vICA-deficient mutants, lacking either UL36 or M36, exhibit greater susceptibility to CD8 T cell control than mutants lacking the set of immunoevasins known to disrupt antigen presentation via MHC class I. This difference is evident during infection in the natural mouse host infected with MCMV, in settings where virus-specific CD8 T cells are adoptively transferred. Finally, we identify the molecular mechanism through which vICA acts, demonstrating the central contribution of caspase-8 signaling at a point of convergence of death receptor-induced apoptosis and perforin/granzyme-dependent cytotoxicity.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Interações entre Hospedeiro e Microrganismos/imunologia , Evasão da Resposta Imune , Linfócitos T Citotóxicos/imunologia , Animais , Apoptose/imunologia , Caspase 8/genética , Caspase 8/metabolismo , Linhagem Celular , Técnicas de Cocultura , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/virologia , Modelos Animais de Doenças , Fibroblastos , Granzimas/metabolismo , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Camundongos , Camundongos Knockout , Muromegalovirus/genética , Muromegalovirus/imunologia , Muromegalovirus/metabolismo , Mutagênese , Perforina/genética , Perforina/metabolismo , Receptores de Morte Celular/metabolismo , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/metabolismo , Imagem com Lapso de Tempo , Proteínas Virais/genética , Proteínas Virais/imunologia , Proteínas Virais/metabolismo
8.
Life Sci ; 252: 117610, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259601

RESUMO

Hyperammonemia is a serious metabolic disorder associating with hepatic encephalopathy (HE) which occurs secondary to several forms of liver injury ranging from simple acute liver failure (ALF) to its most serious form; cirrhosis. The resent study highlights the possible ameliorative effect of oral nifuroxazide (25 mg/kg) against experimentally induced ALF and the subsequent HE in a well-standardized rat model. ALF and HE were induced in a rat model by I.P. injection of thioacetamide (TAA) (200 mg/kg) for 1 week at alternative days. Nifuroxazide administration for 14 days prior to and for further 7 days alongside TAA injection successfully attenuated TAA-induced ALF and HE; as demonstrated by the significant retraction in both brain and serum hyperammonemia with significant improvement in liver function biomarkers; ALT, AST, ALP, GGT, albumin, and serum total protein. This was associated with a significant restoration of both hepatic and brain oxidative stress incidences; MDA, SOD and catalase activities and GSH concentration. The observed improvement was associated with a significant reduction in liver and brain contents of c-Jun N-terminal kinase (cJNK); as an anti-inflammatory biomarker and a modulator of various pro- and anti-apoptotic proteins, caspase-8, and tumor necrosis factor-related apoptosis ligand (TRAIL); as biomarkers of apoptosis. In conclusion; the modulatory effect of nifuroxazide on cJNK/caspase-8/TRAIL signaling appears to underly its hepatoprotective effect and its ameliorative effect on HE progression.


Assuntos
Encefalopatia Hepática/tratamento farmacológico , Hidroxibenzoatos/farmacologia , Hiperamonemia/prevenção & controle , Falência Hepática Aguda/tratamento farmacológico , Nitrofuranos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Caspase 8/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Encefalopatia Hepática/complicações , Encefalopatia Hepática/fisiopatologia , Hidroxibenzoatos/administração & dosagem , Hiperamonemia/etiologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Falência Hepática Aguda/complicações , Falência Hepática Aguda/fisiopatologia , Masculino , Nitrofuranos/administração & dosagem , Ratos , Ratos Sprague-Dawley , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo
9.
Nature ; 580(7803): 391-395, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32296175

RESUMO

The biological function of Z-DNA and Z-RNA, nucleic acid structures with a left-handed double helix, is poorly understood1-3. Z-DNA-binding protein 1 (ZBP1; also known as DAI or DLM-1) is a nucleic acid sensor that contains two Zα domains that bind Z-DNA4,5 and Z-RNA6-8. ZBP1 mediates host defence against some viruses6,7,9-14 by sensing viral nucleic acids6,7,10. RIPK1 deficiency, or mutation of its RIP homotypic interaction motif (RHIM), triggers ZBP1-dependent necroptosis and inflammation in mice15,16. However, the mechanisms that induce ZBP1 activation in the absence of viral infection remain unknown. Here we show that Zα-dependent sensing of endogenous ligands induces ZBP1-mediated perinatal lethality in mice expressing RIPK1 with mutated RHIM (Ripk1mR/mR), skin inflammation in mice with epidermis-specific RIPK1 deficiency (RIPK1E-KO) and colitis in mice with intestinal epithelial-specific FADD deficiency (FADDIEC-KO). Consistently, functional Zα domains were required for ZBP1-induced necroptosis in fibroblasts that were treated with caspase inhibitors or express RIPK1 with mutated RHIM. Inhibition of nuclear export triggered the Zα-dependent activation of RIPK3 in the nucleus resulting in cell death, which suggests that ZBP1 may recognize nuclear Z-form nucleic acids. We found that ZBP1 constitutively bound cellular double-stranded RNA in a Zα-dependent manner. Complementary reads derived from endogenous retroelements were detected in epidermal RNA, which suggests that double-stranded RNA derived from these retroelements may act as a Zα-domain ligand that triggers the activation of ZBP1. Collectively, our results provide evidence that the sensing of endogenous Z-form nucleic acids by ZBP1 triggers RIPK3-dependent necroptosis and inflammation, which could underlie the development of chronic inflammatory conditions-particularly in individuals with mutations in RIPK1 and CASP817-20.


Assuntos
Inflamação/metabolismo , Necroptose , Proteínas de Ligação a RNA/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Caspase 8/metabolismo , Feminino , Inflamação/genética , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ácidos Nucleicos/metabolismo , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Dermatopatias/genética , Dermatopatias/metabolismo , Dermatopatias/patologia
10.
Biochim Biophys Acta Rev Cancer ; 1873(2): 188357, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32147543

RESUMO

Caspase-8 is a cysteine - aspartate specific protease that classically triggers the extrinsic apoptotic pathway, in response to the activation of cell surface Death Receptors (DRs) like FAS, TRAIL-R and TNF-R. Besides it's roles in triggering death receptor-mediated apoptosis, Caspase-8 has also been implicated in the onsets of anoikis, autophagy and pyroptosis. Furthermore, Caspase-8 also plays a crucial pro-survival function by inhibiting an alternative form of programmed cell death called necroptosis. Low expression levels of pro-Caspase-8 is therefore associated with the malignant transformation of cancers. However, the long-held notion that pro-Caspase-8 expression/activity is generally lost in most cancers, thereby contributing to apoptotic escape and enhanced resistance to anti-cancer therapeutics, has been found to be true for only a minority of cancers types. In the majority of cases, pro-Caspase-8 expression is maintained and sometimes elevated, while it's apoptotic activity is regulated through different mechanisms. This supports the notion that the non-apoptotic functions of Caspase-8 offer growth advantage in these cancer types and have, therefore, gained renewed interest in the recent years. In light of these reasons, a number of therapeutic approaches have been employed, with the intent of targeting pro-Caspase-8 in cancer cells. In this review, we would attempt to discuss - the classic roles of Caspase-8 in initiating apoptosis; it's non-apoptotic functions; it's the clinical significance in different cancer types; and the therapeutic applications exploiting the ability of pro-Caspase-8 to regulate various cellular functions.


Assuntos
Caspase 8/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias/patologia , Animais , Apoptose/genética , Apoptose/imunologia , Autofagia/genética , Autofagia/imunologia , Caspase 8/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Sobrevivência Celular/genética , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Camundongos , Necroptose/genética , Necroptose/imunologia , Neoplasias/genética , Neoplasias/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Regulação para Cima
11.
Science ; 367(6484): 1379-1384, 2020 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-32193329

RESUMO

Cell death and inflammation are interdependent host responses to infection. During pyroptotic cell death, interleukin-1ß (IL-1ß) release occurs through caspase-1 and caspase-11-mediated gasdermin D pore formation. In vivo, responses to lipopolysaccharide (LPS) result in IL-1ß secretion. In vitro, however, murine macrophages require a second "danger signal" for the inflammasome-driven maturation of IL-1ß. Recent reports have shown caspase-8-mediated pyroptosis in LPS-activated macrophages but have provided conflicting evidence regarding the release of IL-1ß under these conditions. Here, to further characterize the mechanism of LPS-induced secretion in vitro, we reveal an important role for cellular FLICE-like inhibitory protein (cFLIP) in the regulation of the inflammatory response. Specifically, we show that deficiency of the long isoform cFLIPL promotes complex II formation, driving pyroptosis, and the secretion of IL-1ß in response to LPS alone.


Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/fisiologia , Complexo II de Transporte de Elétrons/metabolismo , Inflamassomos/metabolismo , Ativação de Macrófagos , Macrófagos/fisiologia , Piroptose , Animais , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Caspase 1/metabolismo , Caspase 8/metabolismo , Técnicas de Silenciamento de Genes , Interleucina-1beta/metabolismo , Lipopolissacarídeos/imunologia , Macrófagos/imunologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo
12.
Arch Biochem Biophys ; 684: 108327, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32142890

RESUMO

Endometrial carcinoma is a type of gynecological cancer that originates in the endometrial epithelial tissue. Due to its high proliferation and ability to invade muscle tissue, it is one of the most common malignant tumors in the female reproductive system. Fatostatin is a small molecule non-sterol diarylthiazole derivative that acts as a chemical inhibitor of the sterol regulatory-element binding protein (SREBP) pathway. Previous studies have shown that fatostatin has an anti-tumor effect in some cancers. In this study, we investigated the effect of fatostatin on the growth, proliferation, apoptosis, migration and cell cycle of human endometrial carcinoma cells (HEC-1A and AN3 CA cells) using cholecystokinin (CCK) -8 method, clonogenicity assay, wound closure assay, Transwell migration assay and flow cytometer. We also examined its effect on the expression of apoptosis-associated protein (Caspase-3, Caspase-8 and Caspase-9) and level of lipid metabolism-related proteins, free fatty acid, and total cholesterol in cells. The growth of endometrial carcinoma xenografts was measured to confirm the effect of fatostatin in vivo. Our results showed that fatostatin inhibited the growth and proliferation of human endometrial carcinoma cells, changed their cell cycle and induced apoptosis. Based on the preliminary animal experiments, fatostatin also exhibited antitumor activity. The present study adds a new dimension to our understanding of the antitumor effects of fatostatin and provides an experimental basis for its use, and supports its potential value for clinical application.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias do Endométrio/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Piridinas/uso terapêutico , Tiazóis/uso terapêutico , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colesterol/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Feminino , Humanos , Camundongos Endogâmicos BALB C , Piridinas/farmacologia , Tiazóis/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Curr Opin Cell Biol ; 63: 186-193, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32163825

RESUMO

Necroptosis and pyroptosis are inflammatory forms of regulated necrotic cell death as opposed to apoptosis that is generally considered immunologically silent. Recent studies revealed unexpected links in the pathways regulating and executing cell death in response to activation of signaling cascades inducing apoptosis, necroptosis, and pyroptosis. Emerging evidence suggests that receptor interacting protein kinase 1 and caspase-8 control the cross-talk between apoptosis, necroptosis, and pyroptosis and determine the type of cell death induced in response to activation of cell death signaling.


Assuntos
Apoptose/genética , Caspase 8/fisiologia , Necroptose/genética , Piroptose/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/fisiologia , Animais , Caspase 8/genética , Caspase 8/metabolismo , Humanos , Necrose/genética , Necrose/patologia , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais/genética
14.
Am J Chin Med ; 48(2): 373-390, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32138536

RESUMO

The medicinal plant Rhodiola crenulata grows at high altitudes in the Arctic and mountainous regions and is commonly used in phytotherapy in Eastern European and Asian countries. In the present study, we investigated the anti-apoptotic effect of Rhodiola crenulata and its neuroprotective mechanism of action in a rat model of D-galactose-induced aging. Two groups of twelve-week-old male Wistar rats received a daily injection of D-galactose (150mg/kg/day, i.p.) and orally administered Rhodiola crenulata (0, 248mg/kg/day) for eight weeks, while a control group received a saline injection (1ml/kg/day, i.p.). We examined apoptosis in the cortex and hippocampus of three groups of rats based on a terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling (TUNEL) positive assay. The expression levels of apoptotic and anti-apoptotic proteins in excised brains were analyzed by Western blotting. Our findings indicated that D-galactose caused marked neuronal apoptosis via activation of both extrinsic-dependent and mitochondrial-dependent apoptotic pathways. When compared to the control group, the protein levels of Fas receptor, Fas ligand, Fas-associated death domain (FADD), and activated caspase-8 (Fas-dependent apoptotic pathways), as well as those of t-Bid, Bax, cytochrome c, activated caspase-9, and activated caspase-3 (mitochondrial-dependent apoptotic pathways), were significantly increased in the D-galactose treated group. In addition, D-galactose impaired the phosphorylation of PI3K/Akt, an important survival signaling event in neurons. Rhodiola crenulata, however, protected against all these neurotoxicities in aging brains. The present study suggests that neuronal survival promoted by Rhodiola crenulata may be a potentially effective method to enhance the resistance of neurons to age-related disorders.


Assuntos
Envelhecimento , Apoptose/efeitos dos fármacos , Galactose , Fármacos Neuroprotetores , Extratos Vegetais/farmacologia , Rhodiola/química , Administração Oral , Animais , Encéfalo/metabolismo , Caspase 8/metabolismo , Córtex Cerebral/patologia , Proteína Ligante Fas/metabolismo , Hipocampo/patologia , Masculino , Modelos Animais , Fosfatidilinositol 3-Quinases/metabolismo , Fitoterapia , Extratos Vegetais/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Wistar , Receptor fas/metabolismo
15.
Am J Chin Med ; 48(2): 391-406, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32138534

RESUMO

The purpose of this study was to evaluate the effects of diosgenin on the D-galactose-induced cerebral cortical widely dispersed apoptosis. Male 12-week-old Wistar rats were divided into four groups: Control (1mg/kg/day of saline, i.p.), DD0 (150mg/kg/day of D-galactose, i.p.), DD10, and DD50 (D-galactose+10 or 50mg/kg/day of diosgenin orally). After eight weeks, histopathological analysis, positive TUNEL and Western blotting assays were performed on the excised cerebral cortex from all four groups. The TUNEL-positive apoptotic cells, the components of Fas pathway (Fas, FADD, active caspase-8 and active caspase-3), and mitochondria pathway (t-Bid, Bax, cytochrome c, active caspase-9 and active caspase-3) were increased in the DD0 group compared with the control group, whereas they were decreased in the DD50 group. The components of survival pathway (p-Bad, Bcl-2, Bcl-xL, IGF-1, p-PI3K and p-AKT) were increased in the DD50 group compared to the control group, whereas the levels of Bcl-xL, p-PI3K, and p-AKT were also compensatorily increased in the DD0 group compared to the control group. Taken together, diosgenin suppressed D-galactose-induced neuronal Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced the Bcl-2 family associated pro-survival and IGF-1-PI3K-AKT survival pathways, which might provide neuroprotective effects of diosgenin for prevention of the D-galactose-induced aging brain.


Assuntos
Envelhecimento , Apoptose/efeitos dos fármacos , Diosgenina/farmacologia , Fármacos Neuroprotetores , Animais , Encéfalo/metabolismo , Caspase 3/metabolismo , Caspase 8/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Mitocôndrias/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Receptor fas/metabolismo
16.
Molecules ; 25(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32069989

RESUMO

The inherent limitations, including serious side-effects and drug resistance, of current chemotherapies necessitate the search for alternative treatments especially for lung cancer. Herein, the anticancer activity of colicin N, bacteria-produced antibiotic peptide, was investigated in various human lung cancer cells. After 24 h of treatment, colicin N at 5-15 µM selectively caused cytotoxicity detected by MTT assay in human lung cancer H460, H292 and H23 cells with no noticeable cell death in human dermal papilla DPCs cells. Flow cytometry analysis of annexin V-FITC/propidium iodide indicated that colicin N primarily induced apoptosis in human lung cancer cells. The activation of extrinsic apoptosis evidenced with the reduction of c-FLIP and caspase-8, as well as the modulation of intrinsic apoptosis signaling proteins including Bax and Mcl-1 were observed via Western blot analysis in lung cancer cells cultured with colicin N (10-15 µM) for 12 h. Moreover, 5-15 µM of colicin N down-regulated the expression of activated Akt (p-Akt) and its upstream survival molecules, integrin ß1 and αV in human lung cancer cells. Taken together, colicin N exhibits selective anticancer activity associated with suppression of integrin-modulated survival which potentiate the development of a novel therapy with high safety profile for treatment of human lung cancer.


Assuntos
Apoptose/efeitos dos fármacos , Colicinas/farmacologia , Neoplasias Pulmonares/metabolismo , Western Blotting , Caspase 8/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citometria de Fluxo , Humanos , Integrinas/metabolismo , Propídio/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismo
17.
Int J Mol Sci ; 21(4)2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32075108

RESUMO

Apoptosis pathways in cells are classified into two pathways: the extrinsic pathway, mediated by binding of the ligand to a death receptor and the intrinsic pathway, mediated by mitochondria. Apoptosis is regulated by various proteins such as Bcl-2 (B-cell lymphoma 2) family and cellular FLICE (Fas-associated Death Domain Protein Interleukin-1ß-converting enzyme)-inhibitory protein (c-FLIP), which have been reported to inhibit caspase-8 activity. In this study, it was found that C5 (3ß-Acetyl-nor-erythrophlamide), a compound of cassaine diterpene amine from Erythrophleum fordii, induced cell apoptosis in a variety of types of cancer cells. Induction of apoptosis in cancer cells by C5 was inversely related to the level of Bcl-2 expression. Overexpression of Bcl-2 into cancer cells significantly decreased C5-induced apoptosis. It was also found that treatment of cancer cells with a caspase-8 inhibitor significantly suppressed C5-induced apoptosis; however, treatment with caspase-9 inhibitors did not affect C5-induced apoptosis, suggesting that C5 may induce apoptosis via the extrinsic pathway by activating caspase-8. It was confirmed that treatment with C5 alone induced an association of FADD with procaspase-8; however, overexpression of c-FLIP decreased C5-induced caspase-8 activation. In conclusion, C5 could be utilized as a new useful lead compound for the development of an anti-cancer agent that has the goal of apoptosis.


Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Alcaloides/química , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/genética , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Caspase 8/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fabaceae/química , Fabaceae/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Linfoma/metabolismo , Linfoma/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
18.
Anticancer Res ; 40(2): 723-731, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32014914

RESUMO

BACKGROUND/AIM: MicroRNAs (miRNAs) play regulatory roles in pancreatic ductal adenocarcinoma (PDAC). However, it is still required to identify the function of miRNA-301-3p in pancreatic cancer cells. MATERIALS AND METHODS: Effects of luteolin on cell growth, TRAIL cytotoxicity, and miR-301-3p levels were evaluated. The role of miRNA-301-3p in regulating cell proliferation, target gene expression, and TRAIL cytotoxicity were studied. RESULTS: The levels of miR-301-3p were down-regulated in PANC-1 cells exposed to luteolin, which inhibits the growth of PANC-1 cells and sensitizes cells to TRAIL. The knockdown of miR-301-3p attenuates cell proliferation and enhances TRAIL cytotoxicity. In addition, caspase-8 was directly targeted by miR-301-3p. CONCLUSION: Our findings unveil a critical biological function of miR-301-3p in regulating cell proliferation and elevating an antiproliferative effect of TRAIL on cancer cells. Our observation of miR-301-3p/caspase-8 relationship can also serve to clarify the role of miR-301-3p in other cancer types and related diseases.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Caspase 8/metabolismo , Luteolina/farmacologia , MicroRNAs/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Carcinoma Ductal Pancreático/genética , Caspase 8/genética , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Técnicas de Silenciamento de Genes , Humanos , Luteolina/administração & dosagem , MicroRNAs/genética , Neoplasias Pancreáticas/genética , Proteínas Recombinantes/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/administração & dosagem , Transfecção
19.
Clin Sci (Lond) ; 134(5): 459-472, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32068238

RESUMO

Antiphospholipid autoantibodies (aPLs), a major maternal risk factor for preeclampsia, are taken into the syncytiotrophoblast where they bind intracellular vesicles and mitochondria. Subsequently, large quantities of extracellular vesicles (EVs) extruded from syncytiotrophoblast into the maternal circulation are altered such that they cause maternal endothelial cell activation. However, the mechanism driving this change is unknown. First trimester placental explants were treated with aPL for 18 h. The EVs were then collected by different centrifugation. The levels of HSP 70, misfolded proteins, caspase 8 activity, and Mixed Lineage Kinase domain-Like (MLKL) were measured in placental explants and EVs. In addition, the levels of TNF-α and CD95 in conditioned medium were also measured. Treating placental explants with aPL caused an increase in levels of HSP 70, misfolded proteins and MLKL in placental explants and EVs. Increased activity of caspase 8 was also seen in placental explants. Higher levels of TNF-α were seen conditioned medium from aPL-treated placental explant cultures. aPLs appear to induce endoplasmic reticulum stress in the syncytiotrophoblast in a manner that involved caspase 8 and TNF-α. To avoid accumulation of the associated misfolded proteins and MLKL, the syncytiotrophoblast exports these potentially dangerous proteins in EVs. It is likely that the dangerous proteins that are loaded into placental EVs in preeclampsia contribute to dysfunction of the maternal cells.


Assuntos
Anticorpos Antifosfolipídeos/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Vesículas Extracelulares/metabolismo , Placenta/efeitos dos fármacos , Trofoblastos/efeitos dos fármacos , Caspase 8/metabolismo , Feminino , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Gravidez , Primeiro Trimestre da Gravidez , Proteínas Quinases/metabolismo , Técnicas de Cultura de Tecidos , Trofoblastos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
20.
J Virol ; 94(9)2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32051270

RESUMO

Influenza A viruses (IAV) are lytic viruses that have recently been found to activate necroptosis in many of the cell types they infect. Necroptotic cell death is potently immunogenic and limits IAV spread by directly eliminating infected cells and by mobilizing both innate and adaptive immune responses. The benefits of necroptosis to the host, however, may sometimes be outweighed by the potentially deleterious hyperinflammatory consequences of activating this death modality in pulmonary and other tissues.


Assuntos
Influenza Humana/metabolismo , Necroptose/fisiologia , Orthomyxoviridae/metabolismo , Animais , Apoptose , Caspase 8/metabolismo , Morte Celular , Humanos , Vírus da Influenza A/metabolismo , Influenza Humana/virologia , Necrose , Orthomyxoviridae/patogenicidade , Infecções por Orthomyxoviridae/metabolismo , Fosforilação , Proteínas Quinases/metabolismo
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