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1.
PLoS Pathog ; 15(8): e1007990, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31425553

RESUMO

The granulomatous lesion resulting from infection with the fungus Paracoccidioides brasiliensis is characterized by a compact aggregate of mature cells, surrounded by a fibroblast- and collagen-rich content. Granuloma formation requires signaling elicited by inflammatory molecules such as members of the interleukin-1 family. Two members of this family have been thoroughly studied, namely IL-1α and IL-1ß. In this study, we addressed the mechanisms underlying IL-1α secretion and its functional role on the host resistance to fungal infection. We found that, the expression of caspase-11 triggered by P. brasiliensis infection of macrophages depends on IFN-ß production, because its inhibition reduced procaspase-11 levels. Curiously, caspase-11 deficiency did not impair IL-1ß production, however caspase-11 was required for a rapid pore-mediated cell lysis. The plasma membrane rupture facilitated the release of IL-1α, which was necessary to induce NO production and restrict fungal replication. Furthermore, P. brasiliensis-infected macrophages required IL-1α to produce optimal levels of IL-6, a major component of Th17 lymphocyte differentiation. Indeed, IL-1α deficiency accounted for a significant reduction of Th17 lymphocytes in lungs of infected mice, correlating with diminished neutrophil infiltration in the lungs. Strikingly, we identified that IL-1α directly reprograms the transcriptional profile of Th17-committed lymphocytes, increasing cellular proliferation, as for boosting IL-17 production by these cells. Beyond neutrophil chemotaxis in vivo, IL-17 also amplified IL-1α production by infected macrophages in vitro, endorsing a critical amplification loop of the inflammatory response. Therefore, our data suggest that the IFN-ß/caspase-11/IL-1α pathway shapes a protective antifungal Th17 immunity, revealing a molecular mechanism underlying the cross-talk between innate and adaptive immunity.


Assuntos
Caspases/fisiologia , Imunidade Inata/imunologia , Interleucina-1alfa/metabolismo , Macrófagos/imunologia , Paracoccidioides/imunologia , Paracoccidioidomicose/imunologia , Células Th17/imunologia , Animais , Inflamassomos , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Paracoccidioidomicose/metabolismo , Paracoccidioidomicose/microbiologia , Células Th17/metabolismo , Células Th17/microbiologia
3.
Infect Immun ; 87(8)2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31160363

RESUMO

It has been shown that caspase-1, but not its upstream activator, ASC, contributes to oviduct pathology during mouse genital Chlamydia muridarum infection. We hypothesized that this dichotomy is due to the inadvertent absence of caspase-11 in previously used caspase-1-deficient mice. To address this, we studied the independent contributions of caspase-1 and -11 during genital Chlamydia infection. Our results show that caspase-11 deficiency was sufficient to recapitulate the effect of the combined absence of both caspase-1 and caspase-11 on oviduct pathology. Further, mice that were deficient for both caspase-1 and -11 but that expressed caspase-11 as a transgene (essentially, caspase-1-deficient mice) had no significant difference in oviduct pathology from control mice. Caspase-11-deficient mice showed reduced dilation in both the oviducts and uterus. To determine the mechanism by which caspase-11-deficient mice developed reduced pathology, the chlamydial burden and immune cell infiltration were determined in the oviducts. In the caspase-11-deficient mice, we observed increased chlamydial burdens in the upper genital tract, which correlated with increased CD4 T cell recruitment, suggesting a contribution of caspase-11 in infection control. Additionally, there were significantly fewer neutrophils in the oviducts of caspase-11-deficient mice, supporting the observed decrease in the incidence of oviduct pathology. Therefore, caspase-11 activation contributes to pathogen control and oviduct disease independently of caspase-1 activation.


Assuntos
Caspases/fisiologia , Infecções por Chlamydia/patologia , Oviductos/patologia , Infecções do Sistema Genital/patologia , Animais , Caspase 1/fisiologia , Caspases/genética , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos
4.
Infect Immun ; 87(8)2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31109948

RESUMO

Leukotoxin (LtxA) (trade name, Leukothera) is a protein secreted by the oral bacterium Aggregatibacter actinomycetemcomitans A. actinomycetemcomitans is an oral pathogen strongly associated with development of localized aggressive periodontitis. LtxA acts as a virulence factor for A. actinomycetemcomitans by binding to the ß2 integrin lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18) on white blood cells (WBCs) and causing cell death. In addition, because of its specificity for malignant and activated WBCs, LtxA is being investigated as a therapeutic agent for treatment of hematological malignancies and autoimmune diseases. Here, we report the successful generation and characterization of Jurkat T lymphocytes with deletions in CD18, CD11a, and Fas that were engineered using CRISPR/Cas9 gene editing. Using these clones, we demonstrate the specificity of LtxA for cells expressing LFA-1. We also demonstrate the requirement of the cell death receptor Fas for LtxA-mediated cell death in T lymphocytes. We show that LFA-1 and Fas are early events in the LtxA-mediated cell death cascade as caspase activation and mitochondrial perturbation do not occur in the absence of either receptor. To our knowledge, LtxA is the first molecule, other than FasL, known to require the Fas death receptor to initiate cell death. Knowledge of the mechanism of cell death induced by LtxA will facilitate the understanding of LtxA as a bacterial virulence factor and development of it as a potential therapeutic agent.


Assuntos
Exotoxinas/fisiologia , Antígeno-1 Associado à Função Linfocitária/fisiologia , Linfócitos T/fisiologia , Receptor fas/fisiologia , Antígeno CD11a/fisiologia , Antígenos CD18/fisiologia , Caspases/fisiologia , Morte Celular , Humanos , Células Jurkat , Fatores de Virulência/fisiologia
5.
J Leukoc Biol ; 106(1): 27-34, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30748031

RESUMO

Brucellosis, caused by the intracellular bacterial pathogen Brucella, is a globally important zoonotic disease for which arthritis is the most common focal complication in humans. Wild-type mice infected systemically with Brucella typically do not exhibit arthritis, but mice lacking IFN-γ develop arthritis regardless of the route of Brucella infection. Here, we investigated mechanisms by which IFN-γ suppresses Brucella-induced arthritis. Several cell types, including innate lymphoid cells, contributed to IFN-γ production and suppression of joint swelling. IFN-γ deficiency resulted in elevated joint IL-1ß levels, and severe joint inflammation that was entirely inflammasome dependent, and in particular, reliant on the NLRP3 inflammasome. IFN-γ was vital for induction of the nitric oxide producing enzyme, iNOS, in infected joints, and nitric oxide directly inhibited IL-1ß production and inflammasome activation in Brucella-infected macrophages in vitro. During in vivo infection, iNOS deficiency resulted in an increase in IL-1ß and inflammation in Brucella-infected joints. Collectively, this data indicate that IFN-γ prevents arthritis both by limiting Brucella infection, and by inhibiting excessive inflammasome activation through the induction of nitric oxide.


Assuntos
Artrite Infecciosa/prevenção & controle , Brucelose/complicações , Inflamassomos/fisiologia , Interferon gama/fisiologia , Óxido Nítrico/fisiologia , Animais , Caspases/fisiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Óxido Nítrico Sintase Tipo II/fisiologia , S-Nitroso-N-Acetilpenicilamina/farmacologia
6.
J Leukoc Biol ; 106(1): 127-132, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30694581

RESUMO

Proinflammatory immune responses to Gram-negative bacterial lipopolysaccharides (LPS) are crucial to innate host defenses but can also contribute to pathology. How host cells sensitively detect structural features of LPS was a mystery for years, especially given that a portion of the molecule essential for its potent proinflammatory properties-lipid A-is buried in the bacterial membrane. Studies of responses to extracellular and vacuolar LPS revealed a crucial role for accessory proteins that specifically bind LPS-rich membranes and extract LPS monomers to generate a complex of LPS, MD-2, and TLR4. These insights provided means to understand better both the remarkable host sensitivity to LPS and the means whereby specific LPS structural features are discerned. More recently, the noncanonical inflammasome, consisting of caspases-4/5 in humans and caspase-11 in mice, has been demonstrated to mediate responses to LPS that has reached the host cytosol. Precisely how LPS gains access to cytosolic caspases-and in what form-is not well characterized, and understanding this process will provide crucial insights into how the noncanonical inflammasome is regulated during infection. Herein, we briefly review what is known about LPS detection by cytosolic caspases-4/5/11, focusing on lessons derived from studies of the better-characterized TLR4 system that might direct future mechanistic questions.


Assuntos
Citosol/química , Lipopolissacarídeos/análise , Antígeno 96 de Linfócito/fisiologia , Receptor 4 Toll-Like/fisiologia , Animais , Caspases/fisiologia , Humanos , Inflamassomos/fisiologia , Lipopolissacarídeos/química , Lipopolissacarídeos/farmacologia
7.
Appl Physiol Nutr Metab ; 44(2): 153-163, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30058356

RESUMO

The aim of this study was to explain the possible mechanisms by which melatonin deficiency results in cardiovascular injury and to investigate the effects of melatonin administration on important signalling pathways and element equilibrium in the thoracic aorta (TA). For this purpose, we analysed the cellular and molecular effects of melatonin deficiency or administration on oxidative stress, DNA damage, molecular chaperone response, and apoptosis induction in TA tissues of pinealectomised rats using ELISA, RAPD, qRT-PCR, and Western blot assays. The results showed that melatonin deficiency led to an imbalance in essential element levels, unfolded or misfolded proteins, increased lipid peroxidation, and selectively induced caspase-dependent apoptosis in TA tissues without significantly affecting the Bcl-2/BAX ratio (2.28 in pinealectomised rats, 2.73 in pinealectomised rats treated with melatonin). In pinealectomised rats, the genomic template stability (80.22%) was disrupted by the significantly increased oxidative stress, and heat shock protein 70 (20.96-fold), TNF-α (1.73-fold), caspase-8 (2.03-fold), and caspase-3 (2.87-fold) were markedly overexpressed compared with the sham group. Melatonin treatment was protective against apoptosis and inhibited oxidative damage. In addition, melatonin increased the survivin level and improved the regulation of element equilibrium in TA tissues. The results of the study indicate that melatonin deficiency induces TNF-α-related extrinsic apoptosis signals and that the administration of pharmacological doses of melatonin attenuates cardiovascular toxicity by regulating the increase in the rate of apoptosis caused by melatonin deficiency in TA tissue of Sprague-Dawley rats.


Assuntos
Aorta Torácica/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Caspases/fisiologia , Melatonina/deficiência , Melatonina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Glândula Pineal/fisiologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Animais , Aorta Torácica/fisiologia , Genômica , Proteínas de Choque Térmico HSP70/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Deficiências na Proteostase , Ratos , Ratos Sprague-Dawley
8.
Inflamm Bowel Dis ; 24(11): 2394-2403, 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30312415

RESUMO

Background: Human and mouse studies implicate the inflammasome in the pathogenesis of inflammatory bowel diseases, though the effects in mice are variable. The noncanonical inflammasome activator caspase-11 (Casp11) reportedly attenuates acute dextran sodium sulfate (DSS) colitis in mice. However, the effects of Casp11 on chronic experimental colitis and factors that influence the impact of Casp11 on acute DSS colitis are unknown. Methods: We studied the role of Casp11 in Il10-/- mice and acute and chronic DSS colitis mouse models. We quantified colonic Casp11 mRNA using quantative polymerase chain reaction and colitis using weight loss, blinded histological scoring, IL-12/23p40 secretion by colonic explants, and fecal lipocalin-2. We determined fecal microbial composition using 16S amplicon sequencing. Results: We detected increased colonic Casp11 mRNA in Il10-/- mice with chronic colitis, but not in mice with DSS colitis. The presence of Casp11 did not alter the severity of chronic colitis in DSS-treated or Il10-/- mice. Contrary to prior reports, we initially observed that Casp11 exacerbates acute DSS colitis. Subsequent experiments in the same animal facility revealed no effect of Casp11 on acute DSS colitis. There were pronounced stochastic changes in the fecal microbiome over this time. The majority of bacterial taxa that changed over time in wild-type vs Casp11-/- mice belong to the Clostridiales. Conclusions: Casp11 does not impact chronic experimental colitis, and its effects on acute DSS colitis vary with environmental factors including the microbiota, particularly Clostridiales. Stochastic drifts in intestinal microbiota composition, even in mice in the same housing facility, should be considered when interpreting studies of acute DSS colitis models.


Assuntos
Caspases/fisiologia , Colite/patologia , Microbioma Gastrointestinal , Inflamassomos/toxicidade , Índice de Gravidade de Doença , Doença Aguda , Animais , Colite/induzido quimicamente , Colite/microbiologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
Autophagy ; 14(11): 1928-1942, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30165781

RESUMO

CASP4/caspase-11-dependent inflammasome activation is important for the clearance of various Gram-negative bacteria entering the host cytosol. Additionally, CASP4 modulates the actin cytoskeleton to promote the maturation of phagosomes harboring intracellular pathogens such as Legionella pneumophila but not those enclosing nonpathogenic bacteria. Nevertheless, this non-inflammatory role of CASP4 regarding the trafficking of vacuolar bacteria remains poorly understood. Macroautophagy/autophagy, a catabolic process within eukaryotic cells, is also implicated in the elimination of intracellular pathogens such as Burkholderia cenocepacia. Here we show that CASP4-deficient macrophages exhibit a defect in autophagosome formation in response to B. cenocepacia infection. The absence of CASP4 causes an accumulation of the small GTPase RAB7, reduced colocalization of B. cenocepacia with LC3 and acidic compartments accompanied by increased bacterial replication in vitro and in vivo. Together, our data reveal a novel role of CASP4 in regulating autophagy in response to B. cenocepacia infection.


Assuntos
Autofagossomos/metabolismo , Autofagia/genética , Infecções Bacterianas/imunologia , Burkholderia cenocepacia/imunologia , Caspases/fisiologia , Animais , Autofagossomos/microbiologia , Autofagia/imunologia , Infecções Bacterianas/genética , Infecções Bacterianas/metabolismo , Infecções por Burkholderia/genética , Infecções por Burkholderia/imunologia , Infecções por Burkholderia/metabolismo , Burkholderia cenocepacia/metabolismo , Caspases/genética , Células Cultivadas , Escherichia coli/imunologia , Escherichia coli/metabolismo , Inflamassomos/genética , Inflamassomos/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fagossomos/genética , Fagossomos/metabolismo , Fagossomos/microbiologia , Fagossomos/patologia
10.
Sci Rep ; 8(1): 12199, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30111833

RESUMO

The cleavage of nuclear proteins by caspases promotes nuclear breakdown and, therefore, plays a key role in apoptosis execution. However, the detailed molecular mechanisms of these events remain unclear. To get more insights into the mechanisms of nuclear events during apoptosis we set up a rapid fractionation protocol for the separation of the cytoplasmic and nuclear fractions of cells undergoing cisplatin-induced apoptosis. Importantly, nuclear accumulation of effector caspase-3 as well as initiator caspase-2, -8 and -9 was observed using the developed protocol and immunofluorescence microscopy. The detection of caspases and their cleavage products in the nucleus occurred within the same time interval after cisplatin treatment and took place shortly before nuclear fragmentation. The entry of initiator caspases to the nucleus was independent of caspase-3. Given that all three initiator caspases had catalytic activity in the nuclei, our findings indicate that initiator caspases might participate in the proteolysis of nuclear components during apoptosis, promoting its disintegration and apoptotic cell death.


Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Caspases/fisiologia , Caspase 2/metabolismo , Caspase 3/metabolismo , Caspase 8/metabolismo , Fracionamento Celular/métodos , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Cisplatino/farmacologia , Cisteína Endopeptidases/metabolismo , Citoplasma/metabolismo , Fragmentação do DNA , Células HeLa , Humanos , Células MCF-7 , Proteínas Nucleares/metabolismo , Frações Subcelulares/fisiologia
11.
J Leukoc Biol ; 104(4): 729-735, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30020539

RESUMO

Guanylate-binding proteins (GBPs) are conserved family of IFN-inducible GTPases that play an important role in the host immunity against bacterial, viral, and protozoan pathogens. GBPs protect the host by associating with intracellular microbes, their vacuolar niche or, in the case of viruses, with their replication complex. This association results in a restriction of the respective pathogen, yet the exact molecular mechanisms of the antimicrobial functions of GBPs are still unclear. Recent work has linked the GBPs with the activation of inflammasomes, multi-protein complexes that assemble upon recognition of pathogen- or host-derived signals and that drive the release of cytokines and host cell death. Here, we will focus on the most recent findings that have started to unravel the manifold restriction mechanism controlled by GBPs in mouse and human cells, and that shed light on the molecular cues that control GBP recruitment to bacterial membranes.


Assuntos
Proteínas de Ligação ao GTP/fisiologia , Imunidade Inata , Infecções/imunologia , Animais , Infecções Bacterianas/enzimologia , Infecções Bacterianas/imunologia , Caspases/fisiologia , Membrana Celular/metabolismo , Citocinas/metabolismo , Humanos , Infecções/enzimologia , Inflamassomos/imunologia , Lipopolissacarídeos/metabolismo , Mamíferos/imunologia , Camundongos , Doenças Parasitárias/enzimologia , Doenças Parasitárias/imunologia , Transporte Proteico , Infecções por Protozoários/enzimologia , Infecções por Protozoários/imunologia , Viroses/enzimologia , Viroses/imunologia
12.
Infect Immun ; 86(9)2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29941463

RESUMO

Brucellosis, caused by the intracellular bacterial pathogen Brucella, is a zoonotic disease for which arthritis is the most common focal complication in humans. Here we investigated the role of inflammasomes and their effectors, including interleukin-1 (IL-1), IL-18, and pyroptosis, on inflammation and control of infection during Brucella-induced arthritis. Early in infection, both caspase-1 and caspase-11 were found to initiate joint inflammation and proinflammatory cytokine production. However, by 1 week postinfection, caspase-1 and caspase-11 also contributed to control of Brucella joint infection. Inflammasome-dependent restriction of Brucella joint burdens did not require AIM2 (absent in melanoma 2) or NLRP3 (NLR family, pyrin domain containing 3). IL-1R had a modest effect on Brucella-induced joint swelling, but mice lacking IL-1R were not impaired in their ability to control infection of the joint by Brucella In contrast, IL-18 contributed to the initiation of joint swelling and control of joint Brucella infection. Caspase1/11-dependent cell death was observed in vivo, and in vitro studies demonstrated that both caspase-1 and caspase-11 induce pyroptosis, which limited Brucella infection in macrophages. Brucella lipopolysaccharide alone was also able to induce caspase-11-dependent pyroptosis. Collectively, these data demonstrate that inflammasomes induce inflammation in an IL-18-dependent manner and that inflammasome-dependent IL-18 and pyroptosis restrict Brucella infection.


Assuntos
Brucelose/imunologia , Caspase 1/fisiologia , Caspases/fisiologia , Inflamassomos/fisiologia , Inflamação/imunologia , Artropatias/imunologia , Piroptose/fisiologia , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Camundongos , Camundongos Transgênicos
13.
PLoS Pathog ; 14(5): e1007105, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29791511

RESUMO

Infection with Burkholderia pseudomallei or B. thailandensis triggers activation of the NLRP3 and NLRC4 inflammasomes leading to release of IL-1ß and IL-18 and death of infected macrophages by pyroptosis, respectively. The non-canonical inflammasome composed of caspase-11 is also activated by these bacteria and provides protection through induction of pyroptosis. The recent generation of bona fide caspase-1-deficient mice allowed us to reexamine in a mouse model of pneumonic melioidosis the role of caspase-1 independently of caspase-11 (that was also absent in previously generated Casp1-/- mice). Mice lacking either caspase-1 or caspase-11 were significantly more susceptible than wild type mice to intranasal infection with B. thailandensis. Absence of caspase-1 completely abolished production of IL-1ß and IL-18 as well as pyroptosis of infected macrophages. In contrast, in mice lacking caspase-11 IL-1ß and IL-18 were produced at normal level and macrophages pyroptosis was only marginally affected. Adoptive transfer of bone marrow indicated that caspase-11 exerted its protective action both in myeloid cells and in radio-resistant cell types. B. thailandensis was shown to readily infect mouse lung epithelial cells triggering pyroptosis in a caspase-11-dependent way in vitro and in vivo. Importantly, we show that lung epithelial cells do not express inflammasomes components or caspase-1 suggesting that this cell type relies exclusively on caspase-11 for undergoing cell death in response to bacterial infection. Finally, we show that IL-18's protective action in melioidosis was completely dependent on its ability to induce IFNγ production. In turn, protection conferred by IFNγ against melioidosis was dependent on generation of ROS through the NADPH oxidase but independent of induction of caspase-11. Altogether, our results identify two non-redundant protective roles for caspase-1 and caspase-11 in melioidosis: Caspase-1 primarily controls pyroptosis of infected macrophages and production of IL-18. In contrast, caspase-11 mediates pyroptosis of infected lung epithelial cells.


Assuntos
Caspase 1/fisiologia , Caspases/fisiologia , Interleucina-18/metabolismo , Pulmão/citologia , Melioidose/prevenção & controle , Piroptose/fisiologia , Animais , Burkholderia/fisiologia , Linhagem Celular , Modelos Animais de Doenças , Feminino , Interferon gama/fisiologia , Macrófagos/microbiologia , Macrófagos/fisiologia , Masculino , Melioidose/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Mucosa Respiratória/citologia
14.
Biochim Biophys Acta Gen Subj ; 1862(7): 1527-1536, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29704527

RESUMO

Glioblastoma is the most common and aggressive glioma, characterized by brain invasion capability. Being very resistant to the current therapies, since even under treatment, surgery, and chemotherapy with temozolomide (TMZ), patients achieve a median survival of one year. In the search for more effective therapies, new molecules have been designed. For nervous system cancers, molecules able to cross the blood-brain barrier are handled with priority. Accordingly, tacrine was chosen for this study and the inclusion of spiro-heterocyclic rings was done in its structure resulting in new compounds. Cytotoxic activity of tacrine derivatives was assayed using glioblastoma cell line (SF295) as well as analyzing cell death mechanism. Increased caspases activities were observed, confirming apoptosis as cell death type. Some derivatives also increased reactive oxygen species formation and decreased the mitochondrial membrane potential. Moreover, compounds acted on several glioblastoma-related proteins including p53, HLA-DR, beta-catenin, Iba-1, MAP2c, Olig-2, and IDH1. Therefore, tacrine derivatives presented promising results for the development of new glioblastoma therapy, particularly to treat those patients resistant to TMZ.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/patologia , Proteínas de Neoplasias/fisiologia , Tacrina/farmacologia , Apoptose/efeitos dos fármacos , Caspases/fisiologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitose/efeitos dos fármacos , Estrutura Molecular , Terapia de Alvo Molecular , Necrose , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Espécies Reativas de Oxigênio/metabolismo , Tacrina/análogos & derivados , Temozolomida
15.
Sheng Li Xue Bao ; 70(1): 93-98, 2018 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-29492520

RESUMO

Pyroptosis is a form of inflammatory programmed cell death activated by caspase-1 and caspase-4/5/11, and involves in the pathogenesis of infectious diseases and nervous system diseases. Pyroptosis is mediated by canonical inflammasome pathway and non-canonical inflammasome pathway. The canonical inflammasome pathway is activated in stroke and aggravates brain injury. Inhibition of inflammasome, caspase-1, IL-1ß and IL-18 ameliorates brain injury. These studies indicate that canonical inflammasome pathway contributes to post-stroke brain injury, therefore, pyroptosis has become a potential therapeutic target for preventing excessive cell death during stroke. We reviewed the relationship between pyroptosis and stroke to provide some perspectives on future researches in this field.


Assuntos
Caspases/fisiologia , Piroptose , Acidente Vascular Cerebral/fisiopatologia , Animais , Apoptose , Proteínas Reguladoras de Apoptose , Morte Celular , Humanos , Inflamassomos , Interleucina-18 , Interleucina-1beta
16.
Int J Radiat Biol ; 94(4): 403-416, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29478373

RESUMO

PURPOSE: The changes in molecular structure and the physiological properties of a gamma-irradiated aloe-emodin were examined. MATERIALS AND METHODS: Aloe-emodin was gamma-irradiated at doses ranging from 0 to 150 kGy, and the molecular structure was then analyzed using high-performance liquid chromatography (HPLC). AGS cells were cultured in RPMI medium and treated gamma irradiated aloe-emodin. Cell viability was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Apoptosis efficiency was investigated by cell cycle arrest, cell morphology, and signaling pathway. The structure of new radiolytic peak was identified by the hydrogen-nuclear magnetic resonance (1H NMR). RESULTS: HPLC results showed that gamma irradiation induced new radiolytic peaks that were distinguishable from the aloe-emodin standard, and the area of new peaks was increased as the radiation dose increased. Gamma-irradiated aloe-emodin treatment significantly increased the cytotoxicity in AGS tumor cells. We also found that 150 kGy aloe-emodin increased the expression of Bax, cytosolic cytochrome c, PARP cleavage, and the activation of caspases-8, -9, -3, Bid, and Bcl-2. Treatment of 150 kGy aloe-emodin induced ROS production, DNA fragmentation, alterations of cell morphology, and the migration in AGS cells. Gamma-irradiated aloe-emodin induced an increase of sub-G1 phase and depolarization of mitochondrial membrane potential in AGS cells. We also confirmed that fractionated AEF1 (new radiolytic peak) induce the cell death, migration, an increase of sub-G1 phase and cytochrome c in a ROS-dependent manner. CONCLUSIONS: The radiolysis product (AEF1) of aloe-emodin transformed by gamma-irradiation strongly induced apoptotic cell death in AGS cells, indicating AEF1 is a potential candidate drug for use in anti-cancer drug.


Assuntos
Antraquinonas/efeitos da radiação , Apoptose/efeitos dos fármacos , Caspases/fisiologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Células 3T3 , Animais , Antraquinonas/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Raios gama , Camundongos , Neoplasias Gástricas/patologia
17.
Mol Immunol ; 94: 190-199, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29331803

RESUMO

Understanding the key regulators which impact the innate immune response during initial phases of tissue injury, can advance the use of therapeutic approaches which aim at attenuating inflammation and organ damage. Recognition of microbial components by TLRs, initiates the transcription of innate immune signal pathways, that induce the expression of key inflammatory mediators: cytokines, chemokines and adhesion molecules. Beside regulating apoptotic cell death, recent studies have revealed distinct roles for caspases in the optimal production of inflammatory cytokines and host defense against injurious infections. Whether caspases can play an immune regulatory role in vivo has not been sufficiently investigated. This study aims to explore whether the pan caspase inhibitor z-VAD-fmk can control inflammation and cytokine production subsequent to challenging the innate immunity of the exocrine secretory tissues in vivo. Submandibular glands (SMGs) of the C57BL/6 mice were challenged with the TLR3 stimulant: polyinosinic-polycytidylic acid (poly (I:C)). Results obtained from the current study provide evidence that caspases can control immune responses downstream of TLR3 ligation. The present work proposes a novel mechanism that can prevent overactivation of the innate immunity, which typically leads to fatal immune disorders.


Assuntos
Inibidores de Caspase/farmacologia , Caspases/fisiologia , Imunidade Inata/efeitos dos fármacos , Mediadores da Inflamação/fisiologia , Inflamação/imunologia , Receptor 3 Toll-Like/fisiologia , Animais , Feminino , Imunidade Inata/imunologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/prevenção & controle , Mediadores da Inflamação/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Poli I-C , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Receptor 3 Toll-Like/metabolismo
18.
Neurobiol Aging ; 62: 130-145, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29149631

RESUMO

Regulation of the amyloid precursor protein (APP) processing by α- and ß-secretases is of special interest to Alzheimer's disease (AD), as these proteases prevent or mediate amyloid beta formation, respectively. Neuroinflammation is also implicated in AD. Our data demonstrate that the endogenous mediator of inflammation prostaglandin J2 (PGJ2) promotes full-length APP (FL-APP) processing by α- and ß-secretases. The decrease in FL-APP was independent of proteasomal, lysosomal, calpain, caspase, and γ-secretase activities. Moreover, PGJ2-treatment promoted cleavage of secreted APP, specifically sAPPα and sAPPß, generated by α and ß-secretase, respectively. Notably, PGJ2-treatment induced caspase-dependent cleavage of sAPPß. Mechanistically, PGJ2-treatment selectively diminished mature (O- and N-glycosylated) but not immature (N-glycosylated only) FL-APP. PGJ2-treatment also increased the overall levels of protein O-GlcNAcylation, which occurs within the nucleocytoplasmic compartment. It is known that APP undergoes O-GlcNAcylation and that the latter protects proteins from proteasomal degradation. Our results suggest that by increasing protein O-GlcNAcylation levels, PGJ2 renders mature APP less prone to proteasomal degradation, thus shunting APP toward processing by α- and ß-secretases.


Assuntos
Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/fisiologia , Precursor de Proteína beta-Amiloide/metabolismo , Prostaglandina D2/análogos & derivados , Animais , Caspases/fisiologia , Células Cultivadas , Citoplasma/metabolismo , Feminino , Glicosilação , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Masculino , Prostaglandina D2/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Ratos Sprague-Dawley , Células Tumorais Cultivadas
19.
J Clin Invest ; 127(11): 4124-4135, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28990935

RESUMO

Acute lung injury is a leading cause of death in bacterial sepsis due to the wholesale destruction of the lung endothelial barrier, which results in protein-rich lung edema, influx of proinflammatory leukocytes, and intractable hypoxemia. Pyroptosis is a form of programmed lytic cell death that is triggered by inflammatory caspases, but little is known about its role in EC death and acute lung injury. Here, we show that systemic exposure to the bacterial endotoxin lipopolysaccharide (LPS) causes severe endothelial pyroptosis that is mediated by the inflammatory caspases, human caspases 4/5 in human ECs, or the murine homolog caspase-11 in mice in vivo. In caspase-11-deficient mice, BM transplantation with WT hematopoietic cells did not abrogate endotoxemia-induced acute lung injury, indicating a central role for nonhematopoietic caspase-11 in endotoxemia. Additionally, conditional deletion of caspase-11 in ECs reduced endotoxemia-induced lung edema, neutrophil accumulation, and death. These results establish the requisite role of endothelial pyroptosis in endotoxemic tissue injury and suggest that endothelial inflammatory caspases are an important therapeutic target for acute lung injury.


Assuntos
Caspases/fisiologia , Células Endoteliais/enzimologia , Endotoxemia/enzimologia , Lesão Pulmonar/enzimologia , Piroptose , Animais , Estudos de Casos e Controles , Células Cultivadas , Endotélio Vascular/patologia , Endotoxemia/imunologia , Feminino , Humanos , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Pulmão/enzimologia , Pulmão/imunologia , Pulmão/patologia , Lesão Pulmonar/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor 4 Toll-Like/metabolismo
20.
ACS Infect Dis ; 3(12): 886-897, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-29043768

RESUMO

Human induced pluripotent stem cell (iPSC) lines are a promising model for the early phase of human embryonic development. Here, their contribution to the still incompletely understood pathogenesis of congenital virus infections was evaluated. The infection of iPSC lines with miscarriage-associated coxsackievirus B3 (CVB3) and measles virus (MV) was compared to the efficient teratogen rubella virus (RV). While CVB3 and MV were found to be cytopathogenic on iPSC lines, RV replicated without impairment of iPSC colony morphology and integrity. This so far outstanding course of infection enabled maintenance of RV-infected iPSC cultures over several passages and their subsequent differentiation to ectoderm, endoderm, and mesoderm. A modification of the metabolic profile of infected iPSC lines was the only common aspect for all three viruses. This study points toward two important aspects. First, iPSC lines represent a suitable cell culture model for early embryonic virus infection. Second, metabolic activity represents an important means for evaluation of pathogen-associated alterations in iPSC lines.


Assuntos
Aborto Espontâneo/etiologia , Desenvolvimento Embrionário , Enterovirus Humano B/patogenicidade , Células-Tronco Pluripotentes Induzidas/virologia , Vírus do Sarampo/patogenicidade , Vírus da Rubéola/patogenicidade , Teratogênese , Animais , Caspases/fisiologia , Diferenciação Celular , Sobrevivência Celular , Células Cultivadas , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Replicação Viral
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