RESUMO
Mitochondria are perhaps best known as the "powerhouse of the cell" for their role in ATP production required for numerous cellular activities. Mitochondria have emerged as an important signaling organelle. Here, we first focus on signaling pathways mediated by mitochondria-nuclear communication that promote protein homeostasis (proteostasis). We examine the mitochondrial unfolded protein response (UPRmt) in C. elegans, which is regulated by a transcription factor harboring both a mitochondrial- and nuclear-targeting sequence, the integrated stress response in mammals, as well as the regulation of chromatin by mitochondrial metabolites. In the second section, we explore the role of mitochondria-to-nuclear communication in the regulation of innate immunity and inflammation. Perhaps related to their prokaryotic origin, mitochondria harbor molecules also found in viruses and bacteria. If these molecules accumulate in the cytosol, they elicit the same innate immune responses as viral or bacterial infection.
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Caenorhabditis elegans , Núcleo Celular , Imunidade Inata , Mitocôndrias , Proteostase , Animais , Caenorhabditis elegans/genética , Mamíferos , Mitocôndrias/metabolismo , Núcleo Celular/metabolismo , Resposta a Proteínas não Dobradas , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Inflamassomos , DNA MitocondrialRESUMO
Severe forms of malaria are associated with systemic inflammation and host metabolism disorders; however, the interplay between these outcomes is poorly understood. Using a Plasmodium chabaudi model of malaria, we demonstrate that interferon (IFN) γ boosts glycolysis in splenic monocyte-derived dendritic cells (MODCs), leading to itaconate accumulation and disruption in the TCA cycle. Increased itaconate levels reduce mitochondrial functionality, which associates with organellar nucleic acid release and MODC restraint. We hypothesize that dysfunctional mitochondria release degraded DNA into the cytosol. Once mitochondrial DNA is sensitized, the activation of IRF3 and IRF7 promotes the expression of IFN-stimulated genes and checkpoint markers. Indeed, depletion of the STING-IRF3/IRF7 axis reduces PD-L1 expression, enabling activation of CD8+ T cells that control parasite proliferation. In summary, mitochondrial disruption caused by itaconate in MODCs leads to a suppressive effect in CD8+ T cells, which enhances parasitemia. We provide evidence that ACOD1 and itaconate are potential targets for adjunct antimalarial therapy.
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Malária , Plasmodium , Succinatos , Humanos , Monócitos , DNA Mitocondrial/metabolismo , Antígeno B7-H1/genética , Plasmodium/genética , Plasmodium/metabolismo , Malária/metabolismo , Mitocôndrias/metabolismo , Células DendríticasRESUMO
Activation of endosomal Toll-like receptor (TLR) 7, TLR9, and TLR11/12 is a key event in the resistance against the parasite Toxoplasma gondii. Endosomal TLR engagement leads to expression of interleukin (IL)-12 via the myddosome, a protein complex containing MyD88 and IL-1 receptor-associated kinase (IRAK) 4 in addition to IRAK1 or IRAK2. In murine macrophages, IRAK2 is essential for IL-12 production via endosomal TLRs but, surprisingly, Irak2-/- mice are only slightly susceptible to T. gondii infection, similar to Irak1-/- mice. Here, we report that upon T. gondii infection IL-12 production by different cell populations requires either IRAK1 or IRAK2, with conventional dendritic cells (DCs) requiring IRAK1 and monocyte-derived DCs (MO-DCs) requiring IRAK2. In both populations, we identify interferon regulatory factor 5 as the main transcription factor driving the myddosome-dependent IL-12 production during T. gondii infection. Consistent with a redundant role of DCs and MO-DCs, mutations that affect IL-12 production in both cell populations show high susceptibility to infection in vivo.
Assuntos
Quinases Associadas a Receptores de Interleucina-1 , Toxoplasmose , Animais , Camundongos , Células Dendríticas , Fatores Reguladores de Interferon/genética , Interleucina-12RESUMO
T1D can be associated with metabolic disorders and several impaired pathways, including insulin signaling, and development of insulin resistance through the renin-angiotensin system (RAS). The main precursor of RAS is angiotensinogen (Agt) and this system is often linked to autophagy dysregulation. Dysregulated autophagy has been described in T1D and linked to impairments in both glucose metabolism, and leukotrienes (LTs) production. Here, we have investigated the role of RAS and LTs in both muscle and liver from T1D mice, and its effects on insulin and autophagy pathways. We have chemically induced T1D in 129sve and 129sve 5LO-/- mice (lacking LTs) with streptozotocin (STZ). To further inhibit ACE activity, mice were treated with captopril (Cap). In muscle of T1D mice, treatment with Cap increased the expression of RAS (angiotensinogen and angiotensin II receptor), insulin signaling, and autophagy markers, regardless of the genotype. In the liver of T1D mice, the treatment with Cap increased the expression of RAS and insulin signaling markers, mostly when LTs were absent. 5LO-/- T1D mice showed increased insulin sensitivity, and decreased NEFA, after the Cap treatment. Cap treatment impacted both insulin signaling and autophagy pathways at the mRNA levels in muscle and liver, indicating the potential role of ACE inhibition on insulin sensitivity and autophagy in T1D.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Resistência à Insulina , Camundongos , Animais , Captopril/farmacologia , Angiotensinogênio/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Experimental/metabolismo , Sistema Renina-Angiotensina , Insulina/metabolismo , Leucotrienos/metabolismoRESUMO
Introduction: This study provides evidence of how Th1 cell metabolism is modulated by the purinergic receptor P2X7 (P2RX7), a cation cannel activated by high extracellular concentrations of adenosine triphosphate (ATP). Methods: In vivo analysis was performed in the Plasmodium chabaudi model of malaria in view of the great relevance of this infectious disease for human health, as well as the availability of data concerning Th1/Tfh differentiation. Results: We show that P2RX7 induces T-bet expression and aerobic glycolysis in splenic CD4+ T cells that respond to malaria, at a time prior to Th1/Tfh polarization. Cell-intrinsic P2RX7 signaling sustains the glycolytic pathway and causes bioenergetic mitochondrial stress in activated CD4+ T cells. We also show in vitro the phenotypic similarities of Th1-conditioned CD4+ T cells that do not express P2RX7 and those in which the glycolytic pathway is pharmacologically inhibited. In addition, in vitro ATP synthase blockade and the consequent inhibition of oxidative phosphorylation, which drives cellular metabolism for aerobic glycolysis, is sufficient to promote rapid CD4+ T cell proliferation and polarization to the Th1 profile in the absence of P2RX7. Conclusion: These data demonstrate that P2RX7-mediated metabolic reprograming for aerobic glycolysis is a key event for Th1 differentiation and suggest that ATP synthase inhibition is a downstream effect of P2RX7 signaling that potentiates the Th1 response.
Assuntos
Glicólise , Malária , Receptores Purinérgicos P2X7 , Células Th1 , Animais , Camundongos , Camundongos Endogâmicos C57BL , Receptores Purinérgicos P2X7/metabolismo , Células Th1/citologia , Células Th1/metabolismo , Diferenciação Celular , Plasmodium chabaudi , Malária/imunologia , Trifosfato de Adenosina , Adenosina Trifosfatases , Mitocôndrias/metabolismo , Proteínas com Domínio T/metabolismo , Fosforilação Oxidativa , Transdução de Sinais , Células CultivadasRESUMO
Disorders of carbohydrate metabolism, including hypoglycemia and lactic acidosis, are common features of malaria. In this issue of Cell Metabolism, Ramos et al. report that regulation of gluconeogenesis and glycemia by the host glucose-6-phosphatase catalytic subunit 1 (G6Pc1) is a key metabolic step that affects both Plasmodium replication and clinical outcome of disease.
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Acidose Láctica , Hipoglicemia , Malária , Glicemia/metabolismo , Gluconeogênese , Humanos , Hipoglicemia/metabolismoRESUMO
Impaired metabolic functions underlie the pathophysiology of diabetes and obesity. The renin-angiotensin system (RAS) is one pathway related to the pathophysiology of both diseases. RAS activation in metabolically active tissues exerts pro-inflammatory effects via angiotensin II (Ang II), linked to dysfunction in cellular processes such as autophagy, which is associated with obesity and diabetes. Here, we determined whether RAS is involved in metabolic dysregulations in a Type 1 Diabetes (T1D) mouse model, treated with captopril, and in an obesity mouse model (Agt-Tg) that overexpresses angiotensinogen (Agt) in adipose tissue. T1D mice had lower plasma leptin, resistin and higher non-esterified fatty acids (NEFA) compared to wild type (Wt) mice, even under captopril treatment. Further, mRNA levels for Agt, At1, Insr, and Beclin1 were upregulated in muscle and liver of T1D mice with captopril compared to Wt. Moreover, autophagy markers LC3 and p62 proteins were decreased, regardless of captopril treatment in the liver from T1D mice. In obese Wt mice, captopril increased muscle Irs1 gene levels. Further, captopril reduced mRNA levels of At1, Insr, Ampk, Beclin1, Atg12, and Lc3 in the liver from both Wt and Agt-Tg mice, while Agt, At1, Insr, and Atg12 expression was reduced in Agt-Tg mice without captopril treatment. Irs1 expression was decreased in the liver from obese Wt mice treated with captopril. Our results suggest that captopril treatment upregulates components of RAS, insulin signaling, and autophagy in both muscle and liver, indicating potential utility of captopril in targeting both insulin sensitivity and autophagy in diabetes and obesity.
Assuntos
Captopril , Diabetes Mellitus Tipo 1 , Animais , Autofagia , Proteína Beclina-1/metabolismo , Captopril/farmacologia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Dieta , Glucose/metabolismo , Fígado/metabolismo , Camundongos , Camundongos Obesos , Músculos/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo , RNA Mensageiro/metabolismoRESUMO
Natural killer T (NKT) cells are an innate-like T cell subset that recognize lipid antigens presented by CD1d-expressing antigen presenting cells (APCs), such as dendritic cells, macrophages, and B cells. They can be subdivided into two different subsets according to the variation in αß TCR chains: type I and type II NKT cells. Type I, also called invariant NKT cells (iNKT), express restricted TCRs with an invariant α-chain (Vα24-Jα18 in humans and Vα14-Jα18 in mice) and limited ß-chains. Here we have established a protocol in which iNKT cells are isolated from a donor wild-type mouse and transferred into iNKT KO (Jα18-/-) mouse. Below we will explore the methods for cell sorting of splenic iNKTs, iNKT cells transfer, and detection of transferred cells into the liver using flow cytometry technique.
Assuntos
Células T Matadoras Naturais , Animais , Células Apresentadoras de Antígenos , Antígenos CD1d , Citometria de Fluxo , Camundongos , Receptores de Antígenos de Linfócitos T , Subpopulações de Linfócitos TRESUMO
Cholesterol-ester transfer protein (CETP) plays a role in atherosclerosis, the inflammatory response to endotoxemia and in experimental and human sepsis. Functional alterations in lipoprotein (LP) metabolism and immune cell populations, including macrophages, occur during sepsis and may be related to comorbidities such as chronic obstructive pulmonary disease (COPD). Macrophages are significantly associated with pulmonary emphysema, and depending on the microenvironment, might exhibit an M1 or M2 phenotype. Macrophages derived from the peritoneum and bone marrow reveal CETP that contributes to its plasma concentration. Here, we evaluated the role of CETP in macrophage polarization and elastase-induced pulmonary emphysema (ELA) in human CETP-expressing transgenic (huCETP) (line 5203, C57BL6/J background) male mice and compared it to their wild type littermates. We showed that bone marrow-derived macrophages from huCETP mice reduce polarization toward the M1 phenotype, but with increased IL-10. Compared to WT, huCETP mice exposed to elastase showed worsened lung function with an increased mean linear intercept (Lm), reflecting airspace enlargement resulting from parenchymal destruction with increased expression of arginase-1 and IL-10, which are M2 markers. The cytokine profile revealed increased IL-6 in plasma and TNF, and IL-10 in bronchoalveolar lavage (BAL), corroborating with the lung immunohistochemistry in the huCETP-ELA group compared to WT-ELA. Elastase treatment in the huCETP group increased VLDL-C and reduced HDL-C. Elastase-induced pulmonary emphysema in huCETP mice promotes lung M2-like phenotype with a deleterious effect in experimental COPD, corroborating the in vitro result in which CETP promoted M2 macrophage polarization. Our results suggest that CETP is associated with inflammatory response and influences the role of macrophages in COPD.
Assuntos
Proteínas de Transferência de Ésteres de Colesterol/fisiologia , Macrófagos/metabolismo , Enfisema Pulmonar/imunologia , Animais , Arginase/metabolismo , Líquido da Lavagem Broncoalveolar/citologia , Proteínas de Transferência de Ésteres de Colesterol/deficiência , Proteínas de Transferência de Ésteres de Colesterol/genética , Interleucina-10/metabolismo , Contagem de Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Elastase Pancreática/efeitos adversos , Fenótipo , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Enfisema Pulmonar/induzido quimicamente , Enfisema Pulmonar/genéticaRESUMO
Likely as in other viral respiratory diseases, SARS-CoV-2 elicit a local immune response, which includes production and releasing of both cytokines and secretory immunoglobulin (SIgA). Therefore, in this study, we investigated the levels of specific-SIgA for SARS-CoV-2 and cytokines in the airways mucosa 37 patients who were suspected of COVID-19. According to the RT-PCR results, the patients were separated into three groups: negative for COVID-19 and other viruses (NEGS, n = 5); negative for COVID-19 but positive for the presence of other viruses (OTHERS, n = 5); and the positive for COVID-19 (COVID-19, n = 27). Higher specific-SIgA for SARS-CoV-2, IFN-ß, and IFN-γ were found in the COVID-19 group than in the other groups. Increased IL-12p70 levels were observed in OTHERS group as compared to COVID-19 group. When the COVID-19 group was sub stratified according to the illness severity, significant differences and correlations were found for the same parameters described above comparing severe COVID-19 to the mild COVID-19 group and other non-COVID-19 groups. For the first time, significant differences are shown in the airway's mucosa immune responses in different groups of patients with or without respiratory SARS-CoV-2 infection.
Assuntos
Anticorpos Antivirais/metabolismo , COVID-19/imunologia , Imunoglobulina A/metabolismo , Interferons/metabolismo , Pulmão/patologia , Mucosa Nasal/metabolismo , SARS-CoV-2/fisiologia , Adolescente , Adulto , Idoso , Brasil , Criança , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/imunologia , Adulto JovemRESUMO
BACKGROUND AND AIM: A low-grade inflammation is associated with cardiac autonomic neuropathy (CAN) and increased concentration of leukotriene B4 (LTB4) was found in individuals with type 1 diabetes and definitive CAN. This cross-sectional study evaluated plasma concentration of LTB4 and of other inflammatory mediators, namely, tumor necrosis factor (TNF), interleukin (IL)1B, and IL10 in individuals with type 2 diabetes (T2D) and different degrees of CAN, and correlated these inflammatory mediators with the degree of glycemic control and with a surrogate marker of insulin resistance. METHODS: TNF, IL1B, IL10 and LTB4 plasma concentrations were measured in 129 T2D subjects (62% women with [median] age of 63 years, disease duration of 8 years and HbA1c of 7.3%) with or without CAN. The Lipid accumulation product index was used as a surrogate marker of insulin resistance. RESULTS: LTB4 concentration was significantly higher in those presenting incipient CAN (69.7 ± 16.6 pg mL-1) and definitive CAN (71.5 ± 15.7 pg mL-1) versus those without CAN (57.0 ± 13.9 pg mL-1). The groups without CAN and with incipient CAN were pooled (group without definitive CAN) and compared to those with definitive CAN. LTB4 concentration was higher in the latter group, as well as TNF concentration, while IL10 concentration was lower in this group. After adjustment for confounding variables, only LTB4 concentration remained significantly different between the groups with and without definitive CAN. Plasma concentration of LTB4 did not correlate with the degree of glycemic control. After sorting the participants by sex, a borderline weak correlation was found between LTB4 and the Lipid accumulation product index in women. CONCLUSION: In the T2D setting, circulating LTB4 concentration seems to be associated with cardiovascular dysautonomia.
RESUMO
This study aims to investigate the global profiling of genes and miRNAs expression to explore the regulatory effects of eicosapentaenoic acid (EPA) in visceral adipose tissue (VAT) of obese mice. We used male mice, fed either a high-fat diet (HF) or HF supplemented with EPA (HF-EPA), for 11 weeks. RNA, and small RNA profiling, were performed by RNAseq analysis. We conducted analyses using Ingenuity Pathway Analysis software (IPA®) and validated candidate genes and miRNAs related to lipid mediators and inflammatory pathways using qRT-PCR. We identified 153 genes differentially downregulated, and 62 microRNAs differentially expressed in VAT from HF-EPA compared to HF. Genes with a positive association with inflammation, chemotaxis, insulin resistance, and inflammatory cell death, such as Irf5, Alox5ap, Tlrs, Cd84, Ccr5, Ccl9, and Casp1, were downregulated by EPA. Moreover, EPA significantly reduced LTB4 levels, a lipid mediator with a central role in inflammation and insulin resistance in obesity. The pathways and mRNA/microRNA interactions identified in our study corroborated with data validated for inflammatory genes and miRNAs. Together, our results identified key VAT inflammatory targets and pathways, which are regulated by EPA. These targets merit further investigation to better understand the protective mechanisms of EPA in obesity-associated inflammation.
Assuntos
Anti-Inflamatórios/farmacologia , Ácido Eicosapentaenoico/farmacologia , Gordura Intra-Abdominal/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Dieta Hiperlipídica/efeitos adversos , Ácido Eicosapentaenoico/uso terapêutico , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Inflamação/metabolismo , Gordura Intra-Abdominal/efeitos dos fármacos , Leucotrieno B4/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Obesos , MicroRNAs/metabolismo , Obesidade/induzido quimicamente , Obesidade/genética , Obesidade/metabolismo , Receptores de Superfície Celular/efeitos dos fármacos , Receptores de Superfície Celular/genética , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , TranscriptomaRESUMO
Leukotrienes (LTs) are potent lipid mediators that exert a variety of functions, ranging from maintaining the tone of the homeostatic immune response to exerting potent proinflammatory effects. Therefore, LTs are essential elements in the development and maintenance of different chronic diseases, such as asthma, arthritis, and atherosclerosis. Due to the pleiotropic effects of LTs in the pathogenesis of inflammatory diseases, studies are needed to discover potent and specific LT synthesis inhibitors and LT receptor antagonists. Even though most clinical trials using LT inhibitors or antagonists have failed due to low efficacy and/or toxicity, new drug development strategies are driving the discovery for LT inhibitors to prevent inflammatory diseases. A newly important detrimental role for LTs in comorbidities associated with metabolic stress has emerged in the last few years and managing LT production and/or actions could represent an exciting new strategy to prevent or treat inflammatory diseases associated with metabolic disorders. This review is intended to shed light on the synthesis and actions of leukotrienes, the most common drugs used in clinical trials, and discuss the therapeutic potential of preventing LT function in obesity, diabetes, and hyperlipidemia.
Assuntos
Comorbidade , Antagonistas de Leucotrienos/uso terapêutico , Leucotrienos/metabolismo , Doenças Metabólicas/complicações , Doenças Metabólicas/prevenção & controle , Estresse Fisiológico , Asma , Aterosclerose , HumanosRESUMO
Serum levels of leukotriene-B4 (LTB4) are increased in type 1 diabetes (T1D) and it mediates systemic inflammation and macrophage reprogramming associated with this condition. Herein, we investigated the involvement of LTB4 in adiposity loss, hyperlipidemia, and changes in macrophage metabolism in a mouse model of streptozotocin-induced T1D. LTB4 receptor (BLT1) antagonist u75302 was employed to block LTB4 effects. As expected, hypoinsulinemia in T1D was associated with hyperglycemia, low levels of glucagon, hyperlipidemia, significant body fat loss, and increased white adipose tissue expression of Fgf21, a marker for lipolysis. With the exception of hyperglycemia and hypoglucagonemia, blockade of LTB4 signaling reverted these parameters in T1D mice. Along with hyperlipidemia, macrophages from T1D mice exhibited higher lipid uptake and accumulation. These cells also had enhanced glycolysis and oxidative metabolism and these parameters were dependent on the mitochondrial uncoupling respiration, as evidenced by elevated expression of oxidation markers carnitine palmitoyltransferase and uncoupling protein 1. Interestingly, all these parameters were at least partially reverted in T1D mice treated with u75302. Altogether, these findings suggest that in T1D mice LTB4/BLT1 is involved in the fat loss, hyperlipidemia, and increased macrophage lipid uptake and metabolism with an important involvement of mitochondrial uncoupling activity. These previously unrecognized LTB4/BLT1 functions may be explored in future to therapeutically alleviate severity of hyperlipidemia and systemic inflammation in T1D.
Assuntos
Adiposidade , Diabetes Mellitus Tipo 1/metabolismo , Leucotrieno B4/farmacologia , Macrófagos Peritoneais/metabolismo , Adiposidade/efeitos dos fármacos , Animais , Biomarcadores/metabolismo , Regulação para Baixo/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Ácidos Graxos/metabolismo , Glicólise/efeitos dos fármacos , Hiperlipidemias/metabolismo , Hiperlipidemias/patologia , Lipogênese/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxirredução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteína Desacopladora 1/metabolismoRESUMO
Type 1 diabetes is associated with systemic low grade inflammation (LGI). We have previously shown that LGI in diabetic mice depends on systemic circulation of leukotriene (LTB4) which potentiates the toll-like/IL1ß receptors response in macrophages. Impaired wound healing is an important co-morbidity in diabetes, and macrophages play a key role in this process. Here, we investigated the role of leukotrienes on monocytes and macrophages phenotype and in the impaired wound healing in diabetic mice. Type 1 diabetes was induced with streptozotocin in 129SvE wild-type (WT) and leukotrienes-deficient 5LO-/- (5-lipoxygenase knockout) mice. In diabetics, the systemic levels of LTB4, TNF-α, IL-6, IL-10, IL-12 and IFNγ were increased as well as the frequency of pro-inflammatory monocytes (CD11b+Ly6ChighLy6G-) compared to healthy mice. In diabetic 5LO-/- mice, these parameters were similar to those in healthy mice. Resident peritoneal macrophages from diabetic WT mice showed a classically activated M1-like phenotype (high Nos2, Stat and Il12 expression, and nitrite levels). Macrophages from diabetic 5LO-/- mice presented alternatively activated M2-macrophages markers (high Arg1 and Chi3l3 expression and arginase activity) and when stimulated with IL4, enhanced phosphorylated-STAT6. Cutaneous wound healing in diabetic WT mice was impaired, which correlated with the decreased frequency of M2-macrophages (CD45+F4/80+CD206+) in the lesions. In diabetic 5LO-/- mice, the frequency of M2-macrophages in the wound was similar to that in healthy mice, suggesting that the impaired healing of diabetic mice depends on 5LO products. The inhibition of leukotrienes or antagonism of its receptors could be a therapeutic alternative for diabetic patients with impaired healing.
Assuntos
Araquidonato 5-Lipoxigenase/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Cicatrização/fisiologia , Animais , Biomarcadores/metabolismo , Diabetes Mellitus Experimental/metabolismo , Inflamação/metabolismo , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Leucotrienos/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Knockout , Monócitos/metabolismo , Fenótipo , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais/fisiologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Obesity is an increasingly costly and widespread epidemic, effecting 1 in 10 adults worldwide. It has been causally linked with both the metabolic syndrome and insulin resistance, both of which are associated with increased chronic inflammation. The exact mechanisms through which inflammation may contribute to both MetS and IR are numerous and their details are still largely unknown. Recently, micro-RNAs (miRNAs) have emerged as potential interventional targets due to their potential preventive roles in the pathogenesis of several diseases, including MetS and obesity. The purpose of this review paper is to discuss some of the known roles of miRNAs as mediators of inflammation-associated obesity and IR and how omega-3 polyunsaturated fatty acids may be used as a nutritional intervention for these disorders.
Assuntos
Tecido Adiposo/patologia , Ácidos Graxos Ômega-3/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/patologia , Resistência à Insulina , Animais , Humanos , Insulina/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Obesidade/patologiaRESUMO
AIMS: To investigate the hypothesis that alteration in histone acetylation/deacetylation triggers aberrant STAT1/MyD88 expression in macrophages from diabetics. Increased STAT1/MyD88 expression is correlated with sterile inflammation in type 1 diabetic (T1D) mice. METHODS: To induce diabetes, we injected low-doses of streptozotocin in C57BL/6 mice. Peritoneal or bone marrow-differentiated macrophages were cultured in 5mM (low) or 25mM (high glucose). ChIP analysis of macrophages from nondiabetic or diabetic mice was performed to determine acetylation of lysine 9 in histone H3 in MyD88 and STAT1 promoter regions. Macrophages from diabetic mice were treated with the histone acetyltransferase inhibitor anacardic acid (AA), followed by determination of mRNA expression by qPCR. RESULTS: Increased STAT1 and MyD88 expression in macrophages from diabetic but not naive mice cultured in low glucose persisted for up to 6days. Macrophages from diabetic mice exhibited increased activity of histone acetyltransferases (HAT) and decreased histone deacetylases (HDAC) activity. We detected increased H3K9Ac binding to Stat1/Myd88 promoters in macrophages from T1D mice and AA in vitro treatment reduced STAT1 and MyD88 mRNA expression. CONCLUSIONS/INTERPRETATION: These results indicate that histone acetylation drives elevated Stat1/Myd88 expression in macrophages from diabetic mice, and this mechanism may be involved in sterile inflammation and diabetes comorbidities.
Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Regulação da Expressão Gênica , Histona Acetiltransferases/metabolismo , Histona Desacetilases/metabolismo , Macrófagos/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Fator de Transcrição STAT1/metabolismo , Acetilação/efeitos dos fármacos , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Células Cultivadas , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Inibidores Enzimáticos/farmacologia , Epigênese Genética/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Histona Acetiltransferases/antagonistas & inibidores , Histonas/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/patologia , Masculino , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/genética , Concentração Osmolar , Regiões Promotoras Genéticas/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Fator de Transcrição STAT1/genética , Estreptozocina/toxicidadeRESUMO
Gamma-terpinene is a monoterpene present in the essential oils of several plants, including those from the Eucalyptus genus. This molecule was recently described as anti-inflammatory and microbiocidal, but little is known about the mechanisms behind its effects. The aim of the present study was to investigate the effect of gamma-terpinene on the lipopolysaccharide-induced production of cytokines by murine peritoneal macrophages. Gamma-terpinene treatment was found to reduce the production of proinflammatory cytokines, such as interleukin-1ß and interleukin-6, and enhance that of the anti-inflammatory cytokine interleukin-10. This was accompanied by increased levels of the enzyme cycloxygenase-2 and its product, the lipid mediator prostaglandin E2. Inhibition of cycloxygenase-2 with nimesulide abolished the potentiating effect of gamma-terpinene on interleukin-10 production. Moreover, nimesulide treatment also abrogated the inhibitory effect of gamma-terpinene on interleukin-1ß and interleukin-6. Furthermore, in macrophages from mice deficient in the interleukin-10 gene, gamma-terpinene failed to inhibit interleukin-1ß and interleukin-6 production. These results suggest that this monoterpene promotes the prostaglandin E2/interleukin-10 axis, which inhibits the production of these proinflammatory cytokines.
Assuntos
Dinoprostona/metabolismo , Interleucina-10/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Monoterpenos/farmacologia , Animais , Células Cultivadas , Monoterpenos Cicloexânicos , Inibidores de Ciclo-Oxigenase/farmacologia , Citocinas/metabolismo , Interleucina-12/metabolismo , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Sulfonamidas/farmacologiaRESUMO
The alkaloid 2-methoxy-4-(7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)phenol (MHTP) was synthesized to prospect new compounds with therapeutic properties. Thus, the goal of this study was to evaluate the MHTP anti-inflammatory effect by in vivo and in vitro assays. The MHTP toxicity was analyzed. We found that MHTP pre-treatment (2.5-10 mg/kg) showed antiedematogenic effect (p < 0.05) in carrageenan-induced paw edema by inhibiting the PGE2 action independently of mast cell degranulation or histamine activity. MHTP also diminished (p < 0.01) total leukocyte migration in 41.5% into peritoneal cavity during carrageenan-induced peritonitis, reducing polymorphonuclear cells (PMNs) (59.6%) and proteins levels (29.4%). MHTP in an experimental model of acute lung injury inhibited (p < 0.001) total inflammatory cell migration into the lungs and PMNs in 58% and 67.5%, respectively. Additionally, MHTP did not present cytotoxicity at concentrations of 10, 25 or 50 µM but decreased (p < 0.001) the NO production in 24%, 47% and 39%, respectively. The alkaloid also reduced (p < 0.001, in lipopolysaccharide (LPS)-stimulated macrophages (1 µg/mL), IL-1ß, IL-6 and IL-10 levels in 35.7%, 31.0% and 33.4%, respectively. The results obtained in this study allow us to conclude that the inedited synthetic alkaloid, MHTP has anti-inflammatory effect by inhibiting PGE2 function as well as inhibiting inflammatory cell migration to the inflamed site and attenuated the acute lung injury disease by inhibiting the migration of neutrophil to the lung. However, further studies will be carried out to demonstrate the mechanisms of action of the molecule and explore its potential as a future drug to treat inflammatory processes.