RESUMO

Cholesterol is essential for the ability of cytotoxic T cells to eliminate cancer cells. In this issue of Cancer Cell, Yan et al. reveal how intra-tumoral cholesterol deficiency contributes to T cell exhaustion by inhibiting mTORC1 signaling. Moreover, they demonstrate that increasing cholesterol levels in chimeric antigen receptor (CAR)-T cells by blocking liver X receptor (LXR) leads to improved anti-tumor function.

Assuntos

Neoplasias , Receptores de Antígenos Quiméricos , Humanos , Microambiente Tumoral , Imunoterapia Adotiva , Neoplasias/terapia , Linfócitos T Citotóxicos

RESUMO

Cardiovascular manifestations account for marked morbi-mortality in autosomal dominant polycystic kidney disease (ADPKD). Pkd1- and Pkd2-deficient mice develop cardiac dysfunction, however the underlying mechanisms remain largely unclear. It is unknown whether impairment of polycystin-1 cleavage at the G-protein-coupled receptor proteolysis site, a significant ADPKD mutational mechanism, is involved in this process. We analyzed the impact of polycystin-1 cleavage on heart metabolism using Pkd1V/V mice, a model unable to cleave this protein and with early cardiac dysfunction. Pkd1V/V hearts showed lower levels of glucose and amino acids and higher lipid levels than wild-types, as well as downregulation of p-AMPK, p-ACCß, CPT1B-Cpt1b, Ppara, Nppa and Acta1. These findings suggested decreased fatty acid ß-oxidation, which was confirmed by lower oxygen consumption by Pkd1V/V isolated mitochondria using palmitoyl-CoA. Pkd1V/V hearts also presented increased oxygen consumption in response to glucose, suggesting that alternative substrates may be used to generate energy. Pkd1V/V hearts displayed a higher density of decreased-size mitochondria, a finding associated with lower MFN1, Parkin and BNIP3 expression. These derangements were correlated with increased apoptosis and inflammation but not hypertrophy. Notably, Pkd1V/V neonate cardiomyocytes also displayed shifts in oxygen consumption and p-AMPK downregulation, suggesting that, at least partially, the metabolic alterations are not induced by kidney dysfunction. Our findings reveal that disruption of polycystin-1 cleavage leads to cardiac metabolic rewiring in mice, expanding the understanding of heart dysfunction associated with Pkd1 deficiency and likely with human ADPKD.

Assuntos

Rim Policístico Autossômico Dominante , Canais de Cátion TRPP , Animais , Coração , Camundongos , Mitocôndrias/metabolismo , Mutação , Rim Policístico Autossômico Dominante/genética , Rim Policístico Autossômico Dominante/metabolismo , Canais de Cátion TRPP/genética , Canais de Cátion TRPP/metabolismo

RESUMO

Hancornia speciosa Gomes (HS) is a Brazilian fruit tree used in inflammatory disorders by folk medicine. Here we sought to investigate the antioxidant and hepatoprotective properties of HS fruit juice in acetaminophen-induced hepatoxicity model in rats, as well as to perform a comprehensive chemical characterization of phenolics and metals by mass spectrometry. HS showed hepatoprotective and antioxidant activity by decreasing MDA and liver injury markers at healthy control levels. In addition, liver histopathological analysis revealed that HS decreases hepatocellular degeneration. Chemical characterization revealed 16 different phenolics, being chlorogenic acid (150 ± 5 µg/g) and rutin (120 ± 8 µg/g) the major phenolics in HS. Among the 14 micronutrients we identified, zinc and boron were the most abundant metals detected in HS. In line with previous studies involving liver diseases, our data supports evidence that such phenolics and metals present in HS may prevent liver injury induced by acetaminophen.

Assuntos

Apocynaceae , Doença Hepática Induzida por Substâncias e Drogas , Acetaminofen/toxicidade , Animais , Antioxidantes/farmacologia , Apocynaceae/química , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Sucos de Frutas e Vegetais , Fígado , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos

Assuntos

Síndrome Coronariana Aguda , Doenças Cardiovasculares , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Ceramidas , Fatores de Risco de Doenças Cardíacas , Humanos , Fosfatidilcolinas , Fosfolipídeos , Fatores de Risco

RESUMO

The nutrient sensors peroxisome proliferator-activated receptor γ (PPARγ) and mechanistic target of rapamycin complex 1 (mTORC1) closely interact in the regulation of adipocyte lipid storage. The precise mechanisms underlying this interaction and whether this extends to other metabolic processes and the endocrine function of adipocytes are still unknown. We investigated herein the involvement of mTORC1 as a mediator of the actions of the PPARγ ligand rosiglitazone in subcutaneous inguinal white adipose tissue (iWAT) mass, endocrine function, lipidome, transcriptome and branched-chain amino acid (BCAA) metabolism. Mice bearing regulatory associated protein of mTOR (Raptor) deletion and therefore mTORC1 deficiency exclusively in adipocytes and littermate controls were fed a high-fat diet supplemented or not with the PPARγ agonist rosiglitazone (30 mg/kg/day) for 8 weeks and evaluated for iWAT mass, lipidome, transcriptome (Rnaseq), respiration and BCAA metabolism. Adipocyte mTORC1 deficiency not only impaired iWAT adiponectin transcription, synthesis and secretion, PEPCK mRNA levels, triacylglycerol synthesis and BCAA oxidation and mRNA levels of related proteins but also completely blocked the upregulation in these processes induced by pharmacological PPARγ activation with rosiglitazone. Mechanistically, adipocyte mTORC1 deficiency impairs PPARγ transcriptional activity by reducing PPARγ protein content, as well as by downregulating C/EBPα, a co-partner and facilitator of PPARγ. In conclusion, mTORC1 and PPARγ are essential partners involved in the regulation of subcutaneous adipose tissue adiponectin production and secretion and BCAA oxidative metabolism.

Assuntos

Adiponectina/metabolismo , Aminoácidos de Cadeia Ramificada/metabolismo , Glicerol/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , PPAR gama/metabolismo , Gordura Subcutânea/metabolismo , Regulação para Cima , Animais , Camundongos , Oxirredução

RESUMO

Two commercial exogenous pulmonary surfactants, Curosurf and Survanta, are investigated. Their thermotropic behavior and associated structural changes for the samples in bulk are characterized and described. For Survanta, the obtained results of differential scanning calorimetry showed a thermogram with three peaks on heating and only a single peak on cooling. Curosurf on the other hand, presents calorimetric thermograms with only one peak in both the heating and cooling scans. This distinct thermotropic behavior between the two pulmonary surfactants, a consequence of their particular compositions, is associated with structural changes that were evaluated by simultaneous small- and wide-angle X-ray scattering experiments with in situ temperature variation. Interestingly, for temperatures below ∼35 °C for Curosurf and ∼53 °C for Survanta, the scattering data indicated the coexistence of two lamellar phases with different carbon chain organizations. For temperatures above these limits, the coexistence of phases disappears, giving rise to a fluid phase in both pulmonary surfactants, with multilamelar vesicles for Curosurf and unilamellar vesicles for Survanta. This process is quasi-reversible under cooling, and advanced data analysis for the scattering data indicated differences in the structural and elastic properties of the pulmonary surfactants. The detailed and systematic investigation shown in this work expands on the knowledge of the structure and thermodynamic behavior of Curosurf and Survanta, being relevant from both physiological and biophysical perspectives and also providing a basis for further studies on other types of pulmonary surfactants.

Assuntos

Surfactantes Pulmonares , Animais , Varredura Diferencial de Calorimetria , Bovinos , Pulmão , Tensoativos , Suínos , Termodinâmica

RESUMO

Palmitoleic acid (POA, 16:1n-7) is a lipokine that has potential nutraceutical use to treat non-alcoholic fatty liver disease. We tested the effects of POA supplementation (daily oral gavage, 300 mg/Kg, 15 days) on murine liver inflammation induced by a high fat diet (HFD, 59% fat, 12 weeks). In HFD-fed mice, POA supplementation reduced serum insulin and improved insulin tolerance compared with oleic acid (OA, 300 mg/Kg). The livers of POA-treated mice exhibited less steatosis and inflammation than those of OA-treated mice with lower inflammatory cytokine levels and reduced toll-like receptor 4 protein content. The anti-inflammatory effects of POA in the liver were accompanied by a reduction in liver macrophages (LM, CD11c+; F4/80+; CD86+), an effect that could be triggered by peroxisome proliferator activated receptor (PPAR)-γ, a lipogenic transcription factor upregulated in livers of POA-treated mice. We also used HFD-fed mice with selective deletion of PPAR-γ in myeloid cells (PPAR-γ KOLyzCre+) to test whether the beneficial anti-inflammatory effects of POA are dependent on macrophages PPAR-γ. POA-mediated improvement of insulin tolerance was tightly dependent on myeloid PPAR-γ, while POA anti-inflammatory actions including the reduction in liver inflammatory cytokines were preserved in mice bearing myeloid cells deficient in PPAR-γ. This overlapped with increased CD206+ (M2a) cells and downregulation of CD86+ and CD11c+ liver macrophages. Moreover, POA supplementation increased hepatic AMPK activity and decreased expression of the fatty acid binding scavenger receptor, CD36. We conclude that POA controls liver inflammation triggered by fat accumulation through induction of M2a macrophages independently of myeloid cell PPAR-γ.

Assuntos

Ácidos Graxos Monoinsaturados/farmacologia , Inflamação/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , PPAR gama/genética , Quinases Proteína-Quinases Ativadas por AMP , Animais , Antígeno B7-2/genética , Antígeno CD11c/genética , Dieta Hiperlipídica/efeitos adversos , Ácidos Graxos Monoinsaturados/metabolismo , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Resistência à Insulina/genética , Lectinas Tipo C/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Receptor de Manose , Lectinas de Ligação a Manose/genética , Camundongos , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ácido Oleico/metabolismo , Ácido Oleico/farmacologia , Proteínas Quinases/genética , Receptores de Superfície Celular/genética

RESUMO

The Commelina erecta L. (C. erecta) also known as erva-de-santa-luzia is reported by local population to have medical properties against some pathological conditions. In this study, two extracts of C. erecta leaves (aqueous and ethanolic) were phytochemically analysed and evaluated for their in-vitro antioxidant activities by DPPH, TBARS, NO assays and cell viability assays. The ultra-high performance liquid chromatography followed by tandem mass spectrometry analysis showed the presence of rutin and caffeic acid in aqueous and ethanolic extract. The total polyphenols in aqueous and ethanolic extracts found were 142.7 ± 3.0 and 123.1 ± 5.8 µg/mL of GAE, respectively. The ethanolic extract (5 mg/mL) inhibits TBARS by 33.8%, and the aqueous extract (5 mg/mL) exhibited scavenger property against nitric oxide derivatives to an extent of 77.8%. In cell culture, both extracts improved cell survivability under H2O2 induced oxidative stress. Thus, C. erecta extract is a good candidate to become a phytotherapic medicine.

Assuntos

Antioxidantes/farmacologia , Ácidos Cafeicos/análise , Cromatografia Líquida de Alta Pressão/métodos , Commelina/química , Extratos Vegetais/farmacologia , Rutina/análise , Animais , Técnicas de Cultura de Células , Humanos , Peróxido de Hidrogênio/farmacocinética , Estresse Oxidativo/efeitos dos fármacos , Fenóis/análise , Compostos Fitoquímicos/análise , Folhas de Planta/química , Polifenóis/análise , Espectrometria de Massas em Tandem/métodos

RESUMO

SCOPE: Glucose homeostasis and progression of nonalcoholic fatty liver disease (NAFLD) and hepatomegaly in severe lipoatrophic mice and their modulation by intake of a diet rich in omega 3 (n-3) fatty acids (HFO) are evaluated. METHODS AND RESULTS: Severe lipoatrophic mice induced by PPAR-γ deletion exclusively in adipocytes (A-PPARγ KO) and littermate controls (A-PPARγ WT) are evaluated for glucose homeostasis and liver mass, proteomics, lipidomics, inflammation, and fibrosis. Lipoatrophic mice are heavier than controls, severely glucose intolerant, and hyperinsulinemic, and develop NAFLD characterized by increased liver glycogen, triacylglycerol, and diacylglycerol contents, mitotic index, apoptosis, inflammation, steatosis score, fibrosis, and fatty acid synthase (FAS) content and activity. Lipoatrophic mice also display liver enrichment with monounsaturated in detriment of polyunsaturated fatty acids including n-3 fatty acids, and increased content of cardiolipin, a tetracyl phospholipid exclusively found at the mitochondria inner membrane. Administration of a high-fat diet rich in n-3 fatty acids (HFO) to lipoatrophic mice enriches liver with n-3 fatty acids, reduces hepatic steatosis, FAS content and activity, apoptosis, inflammation, and improves glucose homeostasis. CONCLUSION: Diet enrichment with n-3 fatty acids improves glucose homeostasis and reduces liver steatosis and inflammation without affecting hepatomegaly in severe lipoatrophic mice.

Assuntos

Ácidos Graxos Ômega-3/farmacologia , Resistência à Insulina , Lipodistrofia/complicações , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Adipócitos/metabolismo , Animais , Dieta Hiperlipídica , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Masculino , Camundongos Knockout , Camundongos Transgênicos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , PPAR gama/genética

RESUMO

Scope Glucose homeostasis and progression of nonalcoholic fatty liver disease (NAFLD) and hepatomegaly in severe lipoatrophic mice and their modulation by intake of a diet rich in omega 3 (n-3) fatty acids (HFO) are evaluated. Methods and results Severe lipoatrophic mice induced by PPAR-gama deletion exclusively in adipocytes (A-PPARgama KO) and littermate controls (A-PPARgama WT) are evaluated for glucose homeostasis and liver mass, proteomics, lipidomics, inflammation, and fibrosis. Lipoatrophic mice are heavier than controls, severely glucose intolerant, and hyperinsulinemic, and develop NAFLD characterized by increased liver glycogen, triacylglycerol, and diacylglycerol contents, mitotic index, apoptosis, inflammation, steatosis score, fibrosis, and fatty acid synthase (FAS) content and activity. Lipoatrophic mice also display liver enrichment with monounsaturated in detriment of polyunsaturated fatty acids including n-3 fatty acids, and increased content of cardiolipin, a tetracyl phospholipid exclusively found at the mitochondria inner membrane. Administration of a high-fat diet rich in n-3 fatty acids (HFO) to lipoatrophic mice enriches liver with n-3 fatty acids, reduces hepatic steatosis, FAS content and activity, apoptosis, inflammation, and improves glucose homeostasis. Conclusion Diet enrichment with n-3 fatty acids improves glucose homeostasis and reduces liver steatosis and inflammation without affecting hepatomegaly in severe lipoatrophic mice.