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1.
Int J Mol Sci ; 22(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34445223

RESUMO

Increasing evidence suggests that systemic inflammation triggers a neuroinflammatory response that involves sustained microglia activation. This response has deleterious consequences on memory and learning capability in experimental animal models and in patients. However, the mechanisms connecting systemic inflammation and microglia activation remain poorly understood. Here, we identify the autotaxin (ATX)/lysophosphatidic acid (LPA)/LPA-receptor axis as a potential pharmacological target to modulate the LPS-mediated neuroinflammatory response in vitro (the murine BV-2 microglia cell line) and in vivo (C57BL/6J mice receiving a single i.p. LPS injection). In LPS-stimulated (20 ng/mL) BV-2 cells, we observed increased phosphorylation of transcription factors (STAT1, p65, and c-Jun) that are known to induce a proinflammatory microglia phenotype. LPS upregulated ATX, TLR4, and COX2 expression, amplified NO production, increased neurotoxicity of microglia conditioned medium, and augmented cyto-/chemokine concentrations in the cellular supernatants. PF8380 (a type I ATX inhibitor, used at 10 and 1 µM) and AS2717638 (an LPA5 antagonist, used at 1 and 0.1 µM) attenuated these proinflammatory responses, at non-toxic concentrations, in BV-2 cells. In vivo, we demonstrate accumulation of PF8380 in the mouse brain and an accompanying decrease in LPA concentrations. In vivo, co-injection of LPS (5 mg/kg body weight) and PF8380 (30 mg/kg body weight), or LPS/AS2717638 (10 mg/kg body weight), significantly attenuated LPS-induced iNOS, TNFα, IL-1ß, IL-6, and CXCL2 mRNA expression in the mouse brain. On the protein level, PF8380 and AS2717638 significantly reduced TLR4, Iba1, GFAP and COX2 expression, as compared to LPS-only injected animals. In terms of the communication between systemic inflammation and neuroinflammation, both inhibitors significantly attenuated LPS-mediated systemic TNFα and IL-6 synthesis, while IL-1ß was only reduced by PF8380. Inhibition of ATX and LPA5 may thus provide an opportunity to protect the brain from the toxic effects that are provoked by systemic endotoxemia.


Assuntos
Benzoxazóis/farmacologia , Encéfalo/metabolismo , Endotoxemia , Isoquinolinas/farmacologia , Lipopolissacarídeos/toxicidade , Microglia/metabolismo , Diester Fosfórico Hidrolases/metabolismo , Piperazinas/farmacologia , Piperidinas/farmacologia , Receptores de Ácidos Lisofosfatídicos , Animais , Encéfalo/patologia , Linhagem Celular , Modelos Animais de Doenças , Endotoxemia/induzido quimicamente , Endotoxemia/metabolismo , Endotoxemia/patologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Microglia/patologia , Receptores de Ácidos Lisofosfatídicos/antagonistas & inibidores , Receptores de Ácidos Lisofosfatídicos/metabolismo
2.
Molecules ; 26(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34443679

RESUMO

Alcohol consumption is associated with gut dysbiosis, increased intestinal permeability, endotoxemia, and a cascade that leads to persistent systemic inflammation, alcoholic liver disease, and other ailments. Craving for alcohol and its consequences depends, among other things, on the endocannabinoid system. We have analyzed the relative role of central vs. peripheral cannabinoid CB1 receptors (CB1R) using a "two-bottle" as well as a "drinking in the dark" paradigm in mice. The globally acting CB1R antagonist rimonabant and the non-brain penetrant CB1R antagonist JD5037 inhibited voluntary alcohol intake upon systemic but not upon intracerebroventricular administration in doses that elicited anxiogenic-like behavior and blocked CB1R-induced hypothermia and catalepsy. The peripherally restricted hybrid CB1R antagonist/iNOS inhibitor S-MRI-1867 was also effective in reducing alcohol consumption after oral gavage, while its R enantiomer (CB1R inactive/iNOS inhibitor) was not. The two MRI-1867 enantiomers were equally effective in inhibiting an alcohol-induced increase in portal blood endotoxin concentration that was caused by increased gut permeability. We conclude that (i) activation of peripheral CB1R plays a dominant role in promoting alcohol intake and (ii) the iNOS inhibitory function of MRI-1867 helps in mitigating the alcohol-induced increase in endotoxemia.


Assuntos
Consumo de Bebidas Alcoólicas/patologia , Antagonistas de Receptores de Canabinoides/farmacologia , Endotoxemia/patologia , Etanol/efeitos adversos , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Receptor CB1 de Canabinoide/antagonistas & inibidores , Consumo de Bebidas Alcoólicas/sangue , Animais , Ansiedade/sangue , Ansiedade/complicações , Comportamento Animal/efeitos dos fármacos , Catalepsia/induzido quimicamente , Catalepsia/complicações , Cicloexanóis/administração & dosagem , Teste de Labirinto em Cruz Elevado , Endotoxemia/sangue , Endotoxemia/complicações , Endotoxinas/sangue , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Hipotermia Induzida , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo II/metabolismo , Pirazóis/administração & dosagem , Receptor CB1 de Canabinoide/metabolismo , Rimonabanto/administração & dosagem , Rimonabanto/farmacologia , Estereoisomerismo , Sulfonamidas/administração & dosagem
3.
Int J Mol Sci ; 22(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200709

RESUMO

Sepsis is characterized by multiple-organ dysfunction caused by the dysregulated host response to infection. Until now, however, the role of the Wnt signaling has not been fully characterized in multiple organs during sepsis. This study assessed the suppressive effect of a Wnt signaling inhibitor, Wnt-C59, in the kidney, lung, and liver of lipopolysaccharide-induced endotoxemic mice, serving as an animal model of sepsis. We found that Wnt-C59 elevated the survival rate of these mice and decreased their plasma levels of proinflammatory cytokines and organ-damage biomarkers, such as BUN, ALT, and AST. The Wnt/ß-catenin and NF-κB pathways were stimulated and proinflammatory cytokines were upregulated in the kidney, lung, and liver of endotoxemic mice. Wnt-C59, as a Wnt signaling inhibitor, inhibited the Wnt/ß-catenin pathway, and its interaction with the NF-κB pathway, which resulted in the inhibition of NF-κB activity and proinflammatory cytokine expression. In multiple organs of endotoxemic mice, Wnt-C59 significantly reduced the ß-catenin level and interaction with NF-κB. Our findings suggest that the anti-endotoxemic effect of Wnt-C59 is mediated via reducing the interaction between ß-catenin and NF-κB, consequently suppressing the associated cytokine upregulation in multiple organs. Thus, Wnt-C59 may be useful for the suppression of the multiple-organ dysfunction during sepsis.


Assuntos
Benzenoacetamidas/farmacologia , Citocinas/metabolismo , Endotoxemia/tratamento farmacológico , Lipopolissacarídeos/toxicidade , NF-kappa B/antagonistas & inibidores , Piridinas/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/antagonistas & inibidores , Animais , Citocinas/genética , Endotoxemia/induzido quimicamente , Endotoxemia/metabolismo , Endotoxemia/patologia , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Domínios e Motivos de Interação entre Proteínas , beta Catenina/metabolismo
4.
Front Immunol ; 12: 637845, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995355

RESUMO

Baroreflex and chemoreflex act through the autonomic nervous system, which is involved with the neural regulation of inflammation. The present study reports the effects of reflex physiological sympathetic activation in endotoxemic rats using bilateral carotid occlusion (BCO), a physiological approach involving the baroreflex and chemoreflex mechanisms and the influence of the baroreceptors and peripheral chemoreceptors in the cardiovascular and systemic inflammatory responses. After lipopolysaccharide (LPS) administration, the arterial pressure was recorded during 360 min in unanesthetized rats, and serial blood samples were collected to analyze the plasma cytokine levels. BCO elicited the reflex activation of the sympathetic nervous system, providing the following outcomes: (I) increased the power of the low-frequency band in the spectrum of the systolic arterial pressure during the BCO period; (II) reduced the levels of pro-inflammatory cytokines in plasma, including the tumor necrosis factor (TNF) and the interleukin (IL)-1ß; (III) increased the plasma levels of anti-inflammatory cytokine IL-10, 90 min after LPS administration. Moreover, selective baroreceptor or chemoreceptor denervation deactivated mechanosensitive and chemical sensors, respectively, and decreased the release of the LPS-induced cytokine but did not alter the BCO modulatory effects. These results show, for the first time, that physiological reflex activation of the sympathetic circuit decreases the inflammatory response in endotoxemic rats and suggest a novel function for the baroreceptors as immunosensors during the systemic inflammation.


Assuntos
Barorreflexo/fisiologia , Endotoxemia/patologia , Inflamação/fisiopatologia , Pressorreceptores/fisiologia , Sistema Nervoso Simpático/fisiologia , Animais , Sistema Nervoso Autônomo/fisiologia , Pressão Sanguínea/fisiologia , Células Quimiorreceptoras/fisiologia , Interleucina-10/sangue , Interleucina-1beta/sangue , Lipopolissacarídeos , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/sangue
5.
Arch Biochem Biophys ; 705: 108900, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33964247

RESUMO

Mitochondria play an essential role in inflammatory processes such as sepsis or endotoxemia, contributing to organ-cellular redox metabolism, emerging as the energy hub of the cell, and as an important center of action of second messengers. In this work, we aimed to elucidate the energy state, redox balance, and mitochondrial remodeling status in cerebral cortex in an experimental model of endotoxemia. Female Sprague-Dawley rats were subjected to a single dose of LPS (ip 8 mg kg-1 body weight) for 6 h. State 3 O2 consumption was observed increased, ATP production and P/O ratio were observed decreased, probably indicating an inefficient oxidative phosphorylation process. O2- production and both systemic and tissue NO markers were observed increased in treated animals. The existence of nitrated proteins suggests an alteration in the local redox balance and possible harmful effects over energetic processes. Increases in PGC-1α and mtTFA expression, and in OPA-1 expression, suggest an increase in de novo formation of mitochondria and fusion of pre-existing mitochondria. The observed elongation of mitochondria correlates with the occurrence of mild mitochondrial dysfunction and increased levels of systemic NO. Our work presents novel results that contribute to unravel the mechanism by which the triad endotoxemia-redox homeostasis-energy management interact in the cerebral cortex, leading to propose a relevant mechanism for future developing therapeutics with the aim of preserving this organ from inflammatory and oxidative damage.


Assuntos
Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Endotoxemia/metabolismo , Endotoxemia/patologia , Metabolismo Energético , Dinâmica Mitocondrial , Animais , Feminino , Fosforilação Oxidativa , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley
6.
Int J Mol Sci ; 22(4)2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33567713

RESUMO

Mechanical ventilation (MV) is required to maintain life for patients with sepsis-related acute lung injury but can cause diaphragmatic myotrauma with muscle damage and weakness, known as ventilator-induced diaphragm dysfunction (VIDD). Hypoxia-inducible factor 1α (HIF-1α) plays a crucial role in inducing inflammation and apoptosis. Low-molecular-weight heparin (LMWH) was proven to have anti-inflammatory properties. However, HIF-1α and LMWH affect sepsis-related diaphragm injury has not been investigated. We hypothesized that LMWH would reduce endotoxin-augmented VIDD through HIF-1α. C57BL/6 mice, either wild-type or HIF-1α-deficient, were exposed to MV with or without endotoxemia for 8 h. Enoxaparin (4 mg/kg) was administered subcutaneously 30 min before MV. MV with endotoxemia aggravated VIDD, as demonstrated by increased interleukin-6 and macrophage inflammatory protein-2 levels, oxidative loads, and the expression of HIF-1α, calpain, caspase-3, atrogin-1, muscle ring finger-1, and microtubule-associated protein light chain 3-II. Disorganized myofibrils, disrupted mitochondria, increased numbers of autophagic and apoptotic mediators, substantial apoptosis of diaphragm muscle fibers, and decreased diaphragm function were also observed (p < 0.05). Endotoxin-exacerbated VIDD and myonuclear apoptosis were attenuated by pharmacologic inhibition by LMWH and in HIF-1α-deficient mice (p < 0.05). Our data indicate that enoxaparin reduces endotoxin-augmented MV-induced diaphragmatic injury, partially through HIF-1α pathway inhibition.


Assuntos
Diafragma/efeitos dos fármacos , Modelos Animais de Doenças , Endotoxemia/complicações , Heparina de Baixo Peso Molecular/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Lesão Pulmonar Induzida por Ventilação Mecânica/tratamento farmacológico , Animais , Endotoxemia/induzido quimicamente , Endotoxemia/patologia , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Lesão Pulmonar Induzida por Ventilação Mecânica/etiologia , Lesão Pulmonar Induzida por Ventilação Mecânica/metabolismo , Lesão Pulmonar Induzida por Ventilação Mecânica/patologia
7.
Nat Immunol ; 22(2): 154-165, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33398185

RESUMO

Inflammatory caspase sensing of cytosolic lipopolysaccharide (LPS) triggers pyroptosis and the concurrent release of damage-associated molecular patterns (DAMPs). Collectively, DAMPs are key determinants that shape the aftermath of inflammatory cell death. However, the identity and function of the individual DAMPs released are poorly defined. Our proteomics study revealed that cytosolic LPS sensing triggered the release of galectin-1, a ß-galactoside-binding lectin. Galectin-1 release is a common feature of inflammatory cell death, including necroptosis. In vivo studies using galectin-1-deficient mice, recombinant galectin-1 and galectin-1-neutralizing antibody showed that galectin-1 promotes inflammation and plays a detrimental role in LPS-induced lethality. Mechanistically, galectin-1 inhibition of CD45 (Ptprc) underlies its unfavorable role in endotoxin shock. Finally, we found increased galectin-1 in sera from human patients with sepsis. Overall, we uncovered galectin-1 as a bona fide DAMP released as a consequence of cytosolic LPS sensing, identifying a new outcome of inflammatory cell death.


Assuntos
Alarminas/metabolismo , Endotoxemia/imunologia , Galectina 1/metabolismo , Mediadores da Inflamação/metabolismo , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Alarminas/deficiência , Alarminas/genética , Animais , Estudos de Casos e Controles , Modelos Animais de Doenças , Endotoxemia/induzido quimicamente , Endotoxemia/metabolismo , Endotoxemia/patologia , Feminino , Galectina 1/sangue , Galectina 1/deficiência , Galectina 1/genética , Células HeLa , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Antígenos Comuns de Leucócito/metabolismo , Lipopolissacarídeos , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Necroptose , Proteínas de Ligação a Fosfato/deficiência , Proteínas de Ligação a Fosfato/genética , Células RAW 264.7 , Sepse/sangue , Sepse/diagnóstico , Transdução de Sinais , Regulação para Cima
8.
Am J Respir Crit Care Med ; 203(11): 1419-1430, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33320799

RESUMO

Rationale: Pulmonary endothelial permeability contributes to the high-permeability pulmonary edema that characterizes acute respiratory distress syndrome. Circulating BMP9 (bone morphogenetic protein 9) is emerging as an important regulator of pulmonary vascular homeostasis. Objectives:To determine whether endogenous BMP9 plays a role in preserving pulmonary endothelial integrity and whether loss of endogenous BMP9 occurs during LPS challenge. Methods: A BMP9-neutralizing antibody was administrated to healthy adult mice, and lung vasculature was examined. Potential mechanisms were delineated by transcript analysis in human lung endothelial cells. The impact of BMP9 administration was evaluated in a murine acute lung injury model induced by inhaled LPS. Levels of BMP9 were measured in plasma from patients with sepsis and from endotoxemic mice. Measurements and Main Results: Subacute neutralization of endogenous BMP9 in mice (N = 12) resulted in increased lung vascular permeability (P = 0.022), interstitial edema (P = 0.0047), and neutrophil extravasation (P = 0.029) compared with IgG control treatment (N = 6). In pulmonary endothelial cells, BMP9 regulated transcriptome pathways implicated in vascular permeability and cell-membrane integrity. Augmentation of BMP9 signaling in mice (N = 8) prevented inhaled LPS-induced lung injury (P = 0.0027) and edema (P < 0.0001). In endotoxemic mice (N = 12), endogenous circulating BMP9 concentrations were markedly reduced, the causes of which include a transient reduction in hepatic BMP9 mRNA expression and increased elastase activity in plasma. In human patients with sepsis (N = 10), circulating concentratons of BMP9 were also markedly reduced (P < 0.0001). Conclusions: Endogenous circulating BMP9 is a pulmonary endothelial-protective factor, downregulated during inflammation. Exogenous BMP9 offers a potential therapy to prevent increased pulmonary endothelial permeability in lung injury.


Assuntos
Lesão Pulmonar Aguda/sangue , Lesão Pulmonar Aguda/patologia , Endotélio/patologia , Endotoxemia/sangue , Fator 2 de Diferenciação de Crescimento/sangue , Sepse/sangue , Lesão Pulmonar Aguda/etiologia , Animais , Estudos de Casos e Controles , Células Endoteliais/metabolismo , Endotoxemia/etiologia , Endotoxemia/patologia , Feminino , Humanos , Masculino , Camundongos , Edema Pulmonar/sangue , Edema Pulmonar/etiologia , Edema Pulmonar/patologia , Sepse/etiologia , Sepse/patologia
9.
Biochem Pharmacol ; 184: 114399, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33382969

RESUMO

Dedicator of cytokinesis 2 (DOCK2), an atypical Rac activator, has important anti-inflammatory properties in blepharitis, enteric bacterial infection and colitis. However, the roles of DOCK2 in macrophage activation and acute lung injury (ALI) are still poorly elucidated. In vitro studies demonstrated that DOCK2 was essential for the nucleotide-sensing Toll-like receptor (TLR) 4-mediated inflammatory response in macrophages. We also confirmed that exposure of macrophages to LPS induced Rac activation through a TLR4-independent, DOCK2-dependent mechanism. Phosphorylation of IκB kinase (IKK) ß and nuclear translocation of transcription factor nuclear factor kappa B (NF-κB) were impaired in Ad-shDOCK2-expressing macrophages, resulting in a decreased inflammatory response. Similar results were obtained when EHop-016 (a Rac inhibitor) was used to treat uninfected macrophages. In summary, these data indicate that the DOCK2-Rac signaling pathway acts in parallel with TLR4 engagement to control IKKß activation for inflammatory cytokine release. Next, we investigated whether pharmacological inhibition of DOCK2 protects against endotoxemia-induced lung injury in mice. Treatment with 4-[3'-(2″-chlorophenyl)-2'-propen-1'-ylidene]-1-phenyl-3,5-pyrazolidinedione (CPYPP), a small-molecule inhibitor of DOCK2, reduced the severity of lung injury, as indicated by decreases in the lung injury score and myeloperoxidase (MPO) activity. Moreover, CPYPP attenuated LPS-induced proinflammatory cytokine release in mice. Our studies suggest that inhibition of DOCK2 may suppress LPS-induced macrophage activation and that DOCK2 may be a novel target for treating endotoxemia-related ALI.


Assuntos
Lesão Pulmonar Aguda/etiologia , Endotoxemia/complicações , Proteínas Ativadoras de GTPase/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Macrófagos/metabolismo , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/patologia , Animais , Citocinas/metabolismo , Endotoxemia/patologia , Proteínas Ativadoras de GTPase/antagonistas & inibidores , Proteínas Ativadoras de GTPase/genética , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Fatores de Troca do Nucleotídeo Guanina/genética , Quinase I-kappa B/metabolismo , Lipopolissacarídeos/toxicidade , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/metabolismo , Pirazóis/farmacologia , Células RAW 264.7 , Receptor 4 Toll-Like/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo
10.
PLoS One ; 15(10): e0240164, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33048962

RESUMO

Acute inflammation begins with leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) binding to P-selectin on inflamed endothelium and platelets. In pathologic conditions, this process may contribute to secondary organ damage, like sepsis-induced liver injury. Therefore, developing novel therapies to attenuate inflammation may be beneficial. We previously reported that recombinant human vimentin (rhVim) binds P-selectin to block leukocyte adhesion to endothelium and platelets. In this study, we used SPOT-peptide arrays to identify the rod domain as the active region within rhVim that interacts with P-selectin. Indeed, recombinant human rod domain of vimentin (rhRod) binds to P-selectin with high affinity, with in silico modeling suggesting that rhRod binds P-selectin at or near the PSGL-1 binding site. Using bio-layer interferometry, rhRod decreases PSGL-1 binding to immobilized P-selectin, corroborating the in silico data. Under parallel-plate flow, rhRod blocks leukocyte adhesion to fibrin(ogen)-captured platelets, P-selectin/Fc-coated channels, and IL-1ß/IL-4-co-stimulated human umbilical vein endothelial cells. Finally, using intravital microscopy in endotoxemic C57Bl/6 mice, rhRod co-localizes with P-selectin in the hepatic sinusoids and decreases neutrophil adhesion to hepatic sinusoids. These data suggest a potential role for rhRod in attenuating inflammation through directly blocking P-selectin-PSGL-1 interactions.


Assuntos
Adesão Celular/efeitos dos fármacos , Endotoxemia/tratamento farmacológico , Leucócitos/imunologia , Glicoproteínas de Membrana/metabolismo , Selectina-P/metabolismo , Vimentina/farmacologia , Animais , Adesão Celular/imunologia , Modelos Animais de Doenças , Endotélio/efeitos dos fármacos , Endotélio/imunologia , Endotoxemia/imunologia , Endotoxemia/patologia , Feminino , Voluntários Saudáveis , Células Endoteliais da Veia Umbilical Humana , Humanos , Interferometria , Leucócitos/efeitos dos fármacos , Masculino , Simulação de Acoplamento Molecular , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/imunologia , Domínios Proteicos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Vimentina/genética , Vimentina/uso terapêutico
11.
Am J Physiol Heart Circ Physiol ; 319(6): H1482-H1495, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33064557

RESUMO

Multiple organ perfusion is impaired in sepsis. Clinical studies suggest that persistent perfusion disturbances are prognostic of fatal outcome in sepsis. Pyroptosis occurs upon activation of caspases and their subsequent cleavage of gasdermin D (Gsdmd), resulting in Gsdmd-N (activated NH2-terminal fragment of Gsdmd) that form membrane pores to induce cell death in sepsis. In addition, Gsdmd-/- mice are protected from a lethal dose of lipopolysaccharide (LPS). However, how Gsdmd-mediated pyroptosis occurs in endothelial cells and leads to impaired perfusion remain unexplored in endotoxemia. We used transgenic mice with ablation of Gsdmd and determined that mice lacking Gsdmd exhibited reduced breakdown of endothelial barrier, improved organ perfusion, as well as increased survival in endotoxemia. Phospholipase Cγ1 (PLCγ1) contributed to Gsdmd-mediated endothelial pyroptosis in a calcium-dependent fashion, without affecting Gsdmd-N production. Cytosolic calcium signaling promoted Gsdmd-N translocation to the plasma membrane, enhancing endothelial pyroptosis induced by LPS. We used adeno-associated virus (AAV9) vectors carrying a short hairpin RNA (shRNA) against murine PLCγ1 mRNA under control of the tie1 core promoter (AAV-tie1-sh-PLCγ1) to uniquely downregulate PLCγ1 expression in the endothelial cells. Here, we showed that unique inhibition of endothelial PLCγ1 attenuated breakdown of endothelial barrier, reduced vascular leakage, and improved perfusion disturbances. Moreover, unique downregulate endothelial PLCγ1 expression markedly decreased mortality of mice in endotoxemia. Thus, we establish that endothelial injury as an important trigger of fatal outcome in endotoxemia. Additionally, these findings suggest that interfering with Gsdmd and PLCγ1-calcium pathway may represent a new treatment strategy for critically ill patients sustaining endotoxemia.NEW & NOTEWORTHY Our study newly reveals that Phospholipase Cγ1 (PLCγ1) contributes to gasdermin D (Gsdmd)-mediated endothelial pyroptosis in a calcium-dependent fashion. Cytosolic calcium signaling promotes activated NH2-terminal fragment of Gsdmd (Gsdmd-N) to translocate to the plasma membrane, enhancing endothelial pyroptosis induced by cytoplasmic LPS. Genetic or pharmacologic inhibition of endothelial PLCγ1 attenuated breakdown of endothelial barrier, reduced vascular leakage, improve perfusion disturbances, and decrease mortality of mice in endotoxemia.


Assuntos
Sinalização do Cálcio , Cálcio/metabolismo , Membrana Celular/enzimologia , Células Endoteliais/enzimologia , Endotoxemia/enzimologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Fosfolipase C gama/metabolismo , Piroptose , Animais , Permeabilidade Capilar , Membrana Celular/patologia , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/patologia , Endotoxemia/induzido quimicamente , Endotoxemia/genética , Endotoxemia/patologia , Feminino , Células Endoteliais da Veia Umbilical Humana/enzimologia , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lipopolissacarídeos , Masculino , Camundongos Knockout , Proteínas de Ligação a Fosfato/deficiência , Proteínas de Ligação a Fosfato/genética , Transporte Proteico
12.
Biochem Biophys Res Commun ; 533(1): 83-89, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-32919702

RESUMO

Macrophages are important innate immune cells that play crucial roles in inflammatory responses. Accumulating evidence has demonstrated macrophage heterogeneity based on biomarkers, functions, and localization. Here, we report a novel stem cell antigen-1 (Sca-1)-positive macrophage population induced in the pathological conditions caused by lipopolysaccharide (LPS). Sca-1 is only upregulated in macrophages but not in monocytes and neutrophils upon LPS injection. Sca-1+ macrophages develop from resident peritoneal macrophages. LPS-induced Sca-1+ macrophage generation was partly blocked by anti-IFN-γ antibody, suggesting a role of IFN-γ in the process. LPS-stimulated production of IL-6, TNF-α, and CCL2 is significantly lower in Sca-1+ macrophages compared to their counterpart Sca-1- macrophages. Depletion of Sca-1+ macrophages using anti-Sca-1 antibody significantly increased survival rate and reduced lung and kidney damage in an LPS-induced sepsis model. Taken together, we discovered a novel population of Sca-1+ macrophages in LPS-induced septic conditions.


Assuntos
Antígenos Ly/imunologia , Endotoxemia/patologia , Macrófagos Peritoneais/patologia , Proteínas de Membrana/imunologia , Animais , Células Cultivadas , Citocinas/imunologia , Endotoxemia/imunologia , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais/imunologia , Masculino , Camundongos Endogâmicos C57BL , Fagocitose
13.
Int J Mol Sci ; 21(15)2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32717860

RESUMO

Early-life adversity may have programming effects on neuroendocrine and immune adaptation mechanisms in humans and socially living animals. Using a pig model, we investigated the effect of daily 2-h maternal and littermate deprivation from postnatal days 2-15, either alone (DA) or in a group of littermates (DG) on the neuroendocrine, immunological and behavioural responses of piglets challenged with the bacterial endotoxin lipopolysaccharide (LPS) on day 42. LPS increased plasma concentrations of cortisol, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) and induced typical signs of sickness in all piglets. DA+DG piglets showed stronger signs of sickness compared to control (C) piglets. Plasma TNF-α concentrations were significantly lower in DA+DG males. In addition, the TNF-α/IL-10 ratio was significantly lower in DA than in DG and C males. Gene expression analyses showed lower hypothalamic TNF-α mRNA expression and diminished mRNA expression of the mineralocorticoid receptor (MR) and IL-10 in the amygdala of DA+DG piglets in response to LPS. Interestingly, males showed a higher MR- and a lower IL-10 mRNA expression in the amygdala than females. The present data suggest that repeated maternal deprivation during early life may alter neuroendocrine and immune responses to acute endotoxaemia in a sex-specific manner.


Assuntos
Comportamento Animal , Endotoxemia , Comportamento de Doença , Privação Materna , Caracteres Sexuais , Doença Aguda , Animais , Citocinas/imunologia , Modelos Animais de Doenças , Endotoxemia/induzido quimicamente , Endotoxemia/imunologia , Endotoxemia/patologia , Endotoxemia/fisiopatologia , Feminino , Lipopolissacarídeos/toxicidade , Masculino , Receptores de Mineralocorticoides/imunologia , Suínos
14.
Toxicology ; 441: 152527, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32553669

RESUMO

Multidrug resistance-associated protein 2 (Mrp2), expressed at the brush border membrane (BBM) of the enterocyte, is an ABC transporter with relevant intestinal barrier function. Its toxicological relevance lies in preventing absorption and tissue accumulation of dietary contaminants, drugs, and potentially harmful endogenous metabolites. Expression and activity of intestinal Mrp2 is downregulated in LPS-induced endotoxemia. In addition, confocal microscopy studies demonstrated internalization of the transporter to endocytic vesicles. Since IL-1ß plays an important role as early mediator of LPS-inflammatory responses, we evaluated whether IL-1ß mediates LPS-induced impairment of Mrp2 function. Two protocols were used: I) In vivo administration of LPS (5 mg/kg b.wt., i.p., single dose) to rats in simultaneous with administration of anti-IL-1ß (25 µg/kg b.wt., i.p., 4 doses), followed by studies of Mrp2 expression, localization and activity, 24 h after LPS administration; II) In vitro incubation of isolated intestinal sacs with IL-1ß (10 ng/mL) for 30 min, followed by analysis of Mrp2 activity and localization. We found that in vivo immunoneutralization of IL-1ß partially prevented the decrease of Mrp2 protein expression and activity as well as its internalization to intracellular domains induced by LPS. Involvement of IL-1ß in the alteration of Mrp2 localization and activity was more directly demonstrated in isolated intestinal sacs, as incubation with IL-1ß resulted in detection of Mrp2 in intracellular regions of the enterocyte in simultaneous with alteration of transport activity. In conclusion, IL-1ß induces early internalization of intestinal Mrp2, which could partially explain loss of expression at the BBM under conditions of experimental endotoxemia. Concomitant impairment of Mrp2-dependent barrier function may have pathophysiological relevance since IL-1ß mediates the effect of many local and systemic inflammatory processes.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Endotoxemia/metabolismo , Interleucina-1beta/metabolismo , Mucosa Intestinal/metabolismo , Animais , Western Blotting , Endotoxemia/patologia , Feminino , Mucosa Intestinal/ultraestrutura , Microscopia Confocal , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real
15.
Sci Rep ; 10(1): 9918, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555232

RESUMO

Patients that suffer from sepsis exhibit an early hyper-inflammatory immune response which can lead to organ failure and death. In our study, we assessed the immune modulation in the human in vivo endotoxemia model and compared it to ex vivo LPS stimulation using 38 transcriptomic markers. Blood was collected before and after 4 hours of LPS challenge and tested with the Immune Profiling Panel (IPP) using the FilmArray system. The use of IPP showed that markers from the innate immunity dominated the response to LPS in vivo, mainly markers related to monocytes and neutrophils. Comparing the two models, in vivo and ex vivo, revealed that most of the markers were modulated in a similar pattern (68%). Some cytokine markers such as TNF, IFN-γ and IL-1ß were under-expressed ex vivo compared to in vivo. T-cell markers were either unchanged or up-modulated ex vivo, compared to a down-modulation in vivo. Interestingly, markers related to neutrophils were expressed in opposite directions, which might be due to the presence of cell recruitment and feedback loops in vivo. The IPP tool was able to capture the early immune response in both the human in vivo endotoxemia model, a translational model mimicking the immune response observed in septic patients.


Assuntos
Biomarcadores/sangue , Endotoxemia/sangue , Endotoxemia/imunologia , Imunidade Inata/imunologia , Lipopolissacarídeos/farmacologia , Monócitos/metabolismo , Transcriptoma/efeitos dos fármacos , Adolescente , Adulto , Endotoxemia/induzido quimicamente , Endotoxemia/patologia , Feminino , Humanos , Imunidade Inata/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Adulto Jovem
16.
Am J Pathol ; 190(4): 791-798, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32035882

RESUMO

Along with the recognition of a crucial role played by endothelial dysfunction secondarily igniting cardiovascular, pulmonary, and renal complications, investigational focus has extended toward endothelial glycocalyx. This delicate coating of cells, including the vascular endothelium, regulates permeability, leukocyte traffic, nitric oxide production, and coagulation, and harbors diverse growth and survival factors. In this brief overview, we discuss the metabolic signatures of sepsis as they relate to the loss of glycocalyx integrity and highlight the contribution of several proteases, heparanase, and hyaluronidase to the shedding of glycocalyx. Clinical manifestations of glycocalyx degradation in unraveling acute respiratory distress syndrome and the cardiovascular, microcirculatory, and renal complications of sepsis are concisely presented. Finally, we list therapeutic strategies for preventing the degradation of, and for restoration of, the glycocalyx.


Assuntos
Endotélio Vascular/patologia , Endotoxemia/patologia , Glicocálix/metabolismo , Sepse/patologia , Animais , Endotélio Vascular/metabolismo , Endotoxemia/metabolismo , Humanos , Sepse/metabolismo
17.
Inflammation ; 43(2): 417-424, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31950323

RESUMO

PNU-282987, the α7 acetylcholine receptor(α7nAchR) agonist, has been repeatedly reported to play a key role in anti-inflammatory action of multiple disease. However, little is known about its effect on LPS-induced intestinal epithelial barrier dysfunction. This study investigated the protective effects and mechanisms of PNU-282987 on intestinal epithelial barrier dysfunction in lipopolysaccharide(LPS)-induced endotoxemic rats. Endotoxemia models were induced by intraperitoneal injection of 10 mg/kg LPS. In the endotoxemic group, results showed increases in ileum mucosal permeability, ultrastructural damage of tight junction and redistribution of zonula occludens-1, apoptosis of intestinal epithelial cells and caspase-3 activation. These changes were significantly improved after PNU-282987 administration(P < 0.05). Pretreatment with α-bungarotoxin before PNU-282987 administration reversed the effects of PNU-282987(P < 0.05). These results indicate that PNU-282987 exerts protective effects on intestinal epithelial barrier dysfunction in LPS-induced endotoxemic rats, and its mechanism may involve the improvement of zonula occludens-1 and inhibition of enterocyte apoptosis in an α7nAchR-dependent manner.


Assuntos
Benzamidas/uso terapêutico , Compostos Bicíclicos com Pontes/uso terapêutico , Endotoxemia/induzido quimicamente , Endotoxemia/tratamento farmacológico , Mucosa Intestinal/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Agonistas Nicotínicos/uso terapêutico , Animais , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Endotoxemia/metabolismo , Endotoxemia/patologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Agonistas Nicotínicos/farmacologia , Ratos , Ratos Sprague-Dawley
18.
J Leukoc Biol ; 108(5): 1665-1671, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-31922294

RESUMO

Acute infection is characterized by eosinopenia. However, the underlying mechanism(s) are poorly understood and it is unclear whether decreased mobilization/production of eosinophils in the bone marrow (BM) and/or increased homing to the tissues play a role. The objective of this study was to investigate the differentiation and activation status of eosinophils in the human BM and blood upon experimental human endotoxemia, a standardized, controlled, and reproducible model of acute systemic inflammation. A BM aspirate and venous blood was obtained from seven healthy volunteers before, 4 h after, and 1 week after intravenous challenge with 2 ng/kg endotoxin. Early progenitors (CD34+/IL-5Rα+), eosinophil promyelocytes, myelocytes, metamyelocytes, and mature eosinophils were identified and quantified in the bone marrow and blood samples using flowcytometry based on specific eosinophil markers (CD193 and IL-5Rα). Activation status was assessed using antibodies against known markers on eosinophils: Alpha-4 (CD49d), CCR3 (CD193), CR1 (CD35), CEACAM-8 (CD66b), CBRM 1/5 (activation epitope of MAC-1), and by plasma cytokine analysis. Four hours after endotoxin administration, numbers of mature eosinophils in the blood and in the BM markedly declined compared with baseline, whereas numbers of all eosinophil progenitors did not change. The remaining eosinophils did not show signs of activation or degranulation despite significantly increased circulating levels of eotaxin-1. Furthermore, the expression of CD49d and CD193 on eosinophils was lower compared to baseline, but normalized after 7 days. Together these data imply that circulatory eosinopenia after an innate immune challenge is mediated by CD49d-mediated homing of eosinophils to the tissues.


Assuntos
Antígenos de Diferenciação/imunologia , Medula Óssea/imunologia , Diferenciação Celular/imunologia , Endotoxemia/imunologia , Eosinófilos/imunologia , Adulto , Medula Óssea/patologia , Endotoxemia/patologia , Eosinófilos/patologia , Humanos , Masculino
19.
Am J Med Sci ; 359(2): 100-107, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31812215

RESUMO

BACKGROUND: Intestinal barrier dysfunction exerts a pivotal pathophysiological role in the development of multiple organ dysfunction in sepsis. The present study was undertaken to investigate the potential role of serum intestinal fatty acid-binding protein (I-FABP) and zonula occludens-1 (ZO-1) levels as biomarkers of intestinal barrier dysfunction in bacteremic sepsis. METHODS: Seventy-five patients with bacteremic sepsis of abdominal origin (n = 34) or nonabdominal origin (n = 41) and 12 healthy controls were retrospectively studied. Blood samples collected upon sepsis diagnosis were analyzed for serum ZO-1, I-FABP and endotoxin levels. Prognostic scores Sequential Organ Failure Assessment (SOFA), quickSOFA and Acute Physiology and Chronic Health Evaluation (APACHE-II) were determined over the first 24 hours after sepsis diagnosis and patients' outcome in terms of 28-day mortality was recorded. RESULTS: Serum ZO-1 levels were significantly higher in bacteremic septic patients as compared to controls with no difference between patients with abdominal or extra-abdominal source of infection. Serum I-FABP levels were significantly lower in septic patients as compared to control and this reduction was more evident in patients with bacteremic abdominal sepsis. Serum ZO-1 and endotoxin concentrations were found significantly higher in patients who did not survive from sepsis. In receiver operating characteristic curve analysis, both endotoxin and ZO-1 predicted 28-day mortality. In addition, ZO-1 and endotoxin were correlated with the prognostic scores of qSOFA, SOFA and APACHE II. CONCLUSIONS: The results of this study indicate that serum ZO-1 might be a reliable biomarker of gut barrier dysfunction in sepsis, not affected by the abdominal or extra-abdominal site of infection. ZO-1, measured early at sepsis diagnosis, might represent a valuable additional prognostic tool for patients' outcome.


Assuntos
Endotoxemia , Mucosa Intestinal/metabolismo , Proteína da Zônula de Oclusão-1/sangue , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Intervalo Livre de Doença , Endotoxemia/sangue , Endotoxemia/mortalidade , Endotoxemia/patologia , Endotoxinas/sangue , Proteínas de Ligação a Ácido Graxo/sangue , Feminino , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Taxa de Sobrevida , Fatores de Tempo
20.
Int Immunopharmacol ; 78: 106016, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31796383

RESUMO

Ethyl pyruvate exertsa special protectiveeffecton endotoxin-induced endotoxemia and experimental sepsis, but the underlying mechanism remains elusive. Werecently demonstrated that ethyl pyruvate inhibited caspase-11-mediated macrophage pyroptotic cell death. GasderminDis akeymolecule incaspase-11 mediated non-canonical inflammasome-inducedpyroptosis. We proved that ethyl pyruvate significantly decreased caspase-11 and gasdermin D-mediated pyroptosis induced by cytoplasmic lipopolysaccharide (LPS) and bacterial outer membrane vesicles (OMVs). Ethyl pyruvate treatment offered effective protection against lethal endotoxemia and reduced the release of IL-1α and IL-1ß. Similarresults were observed in the mousececal ligation and puncture (CLP)peritonitissepsismodel. These findings identified ethyl pyruvate as an inhibitor against LPS-mediated activation of cytoplasmic caspase-11 and gasdermin D. This mechanism is believed to contribute tothe further explanation of theprotectiveactionof ethyl pyruvate in experimental sepsis and endotoxemia and the potential application of ethyl pyruvate for rescuing sepsis.


Assuntos
Inibidores de Caspase/farmacologia , Caspases Iniciadoras/metabolismo , Endotoxemia/tratamento farmacológico , Piroptose/efeitos dos fármacos , Piruvatos/farmacologia , Animais , Inibidores de Caspase/uso terapêutico , Células Cultivadas , Modelos Animais de Doenças , Endotoxemia/imunologia , Endotoxemia/patologia , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais , Camundongos , Proteínas de Ligação a Fosfato/metabolismo , Cultura Primária de Células , Piroptose/imunologia , Piruvatos/uso terapêutico
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