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1.
Nat Commun ; 11(1): 4891, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994417

RESUMO

Peripheral sensory neurons regenerate their axon after nerve injury to enable functional recovery. Intrinsic mechanisms operating in sensory neurons are known to regulate nerve repair, but whether satellite glial cells (SGC), which completely envelop the neuronal soma, contribute to nerve regeneration remains unexplored. Using a single cell RNAseq approach, we reveal that SGC are distinct from Schwann cells and share similarities with astrocytes. Nerve injury elicits changes in the expression of genes related to fatty acid synthesis and peroxisome proliferator-activated receptor (PPARα) signaling. Conditional deletion of fatty acid synthase (Fasn) in SGC impairs axon regeneration. The PPARα agonist fenofibrate rescues the impaired axon regeneration in mice lacking Fasn in SGC. These results indicate that PPARα activity downstream of FASN in SGC contributes to promote axon regeneration in adult peripheral nerves and highlight that the sensory neuron and its surrounding glial coat form a functional unit that orchestrates nerve repair.


Assuntos
Regeneração Nervosa , Neuroglia/citologia , Células Receptoras Sensoriais/citologia , Animais , Axônios/fisiologia , Proliferação de Células , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuroglia/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Traumatismos dos Nervos Periféricos/genética , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/fisiopatologia , Nervos Periféricos/crescimento & desenvolvimento , Nervos Periféricos/metabolismo , Nervos Periféricos/fisiopatologia , Células Receptoras Sensoriais/metabolismo , Transdução de Sinais
2.
Proc Natl Acad Sci U S A ; 117(28): 16492-16499, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601222

RESUMO

Metabolic stress causes activation of the cJun NH2-terminal kinase (JNK) signal transduction pathway. It is established that one consequence of JNK activation is the development of insulin resistance and hepatic steatosis through inhibition of the transcription factor PPARα. Indeed, JNK1/2 deficiency in hepatocytes protects against the development of steatosis, suggesting that JNK inhibition represents a possible treatment for this disease. However, the long-term consequences of JNK inhibition have not been evaluated. Here we demonstrate that hepatic JNK controls bile acid production. We found that hepatic JNK deficiency alters cholesterol metabolism and bile acid synthesis, conjugation, and transport, resulting in cholestasis, increased cholangiocyte proliferation, and intrahepatic cholangiocarcinoma. Gene ablation studies confirmed that PPARα mediated these effects of JNK in hepatocytes. This analysis highlights potential consequences of long-term use of JNK inhibitors for the treatment of metabolic syndrome.


Assuntos
Ácidos e Sais Biliares/metabolismo , Colangiocarcinoma/enzimologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Animais , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colangiocarcinoma/fisiopatologia , Homeostase , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 9 Ativada por Mitógeno/genética , PPAR alfa/genética , PPAR alfa/metabolismo
3.
Life Sci ; 257: 118021, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32621919

RESUMO

AIMS: Tribbles homolog 3 (TRIB3) is emerging as a multifunctional oncoprotein associated with various cellular events in different tumors. However, the regulatory mechanism of TRIB3 in acute myeloid leukemia (AML) remains unknown. This study aims to investigate the molecular mechanisms and uncover the functions of TRIB3 in AML. METHODS: Western blotting and quantitative real-time PCR were used to analyze the expression levels of TRIB3, peroxisome proliferator-activated receptor α (PPARα), apoptosis markers and autophagy markers in AML cells. Flow cytometry was used to assess cell apoptosis. The interaction of TRIB3 and PPARα was evaluated by immunofluorescence, coimmunoprecipitation, and in vivo ubiquitination assays. KEY FINDINGS: We demonstrated that downregulating TRIB3 in leukemic cells effectively induced apoptosis and autophagy by regulating the degradation of PPARα. Mechanistically, TRIB3 interacted with PPARα and contributed to its destabilization by promoting its ubiquitination. When PPARα was activated by its specific agonist clofibrate, the apoptosis and autophagy of AML cells were significantly enhanced. These results were confirmed by rescue experiments. Blocking PPARα expression using the PPARα inhibitor GW6471 reversed the functional influence of TRIB3 on AML cells. SIGNIFICANCE: The aim of this study is to provide evidence of the degradation of PPARα by TRIB3 via ubiquitin-dependent proteasomal degradation. This process meditates the progression of AML and prolongs the survival of leukemic cells. As a result, these data indicate that TRIB3 is a novel and promising therapeutic target for AML treatment.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Leucemia Mieloide Aguda/genética , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Apoptose/fisiologia , Autofagia/fisiologia , Bases de Dados Genéticas , Humanos , Leucemia Mieloide Aguda/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteostase/fisiologia , Transdução de Sinais/fisiologia , Ubiquitina/metabolismo , Ubiquitinação
4.
Proc Natl Acad Sci U S A ; 117(27): 15789-15798, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32581129

RESUMO

Patients infected with influenza are at high risk of secondary bacterial infection, which is a major proximate cause of morbidity and mortality. We have shown that in mice, prior infection with influenza results in increased inflammation and mortality upon Staphylococcus aureus infection, recapitulating the human disease. Lipidomic profiling of the lungs of superinfected mice revealed an increase in CYP450 metabolites during lethal superinfection. These lipids are endogenous ligands for the nuclear receptor PPARα, and we demonstrate that Ppara -/- mice are less susceptible to superinfection than wild-type mice. PPARα is an inhibitor of NFκB activation, and transcriptional profiling of cells isolated by bronchoalveolar lavage confirmed that influenza infection inhibits NFκB, thereby dampening proinflammatory and prosurvival signals. Furthermore, network analysis indicated an increase in necrotic cell death in the lungs of superinfected mice compared to mice infected with S. aureus alone. Consistent with this, we observed reduced NFκB-mediated inflammation and cell survival signaling in cells isolated from the lungs of superinfected mice. The kinase RIPK3 is required to induce necrotic cell death and is strongly induced in cells isolated from the lungs of superinfected mice compared to mice infected with S. aureus alone. Genetic and pharmacological perturbations demonstrated that PPARα mediates RIPK3-dependent necroptosis and that this pathway plays a central role in mortality following superinfection. Thus, we have identified a molecular circuit in which infection with influenza induces CYP450 metabolites that activate PPARα, leading to increased necrotic cell death in the lung which correlates with the excess mortality observed in superinfection.


Assuntos
Inflamação/genética , Influenza Humana/genética , PPAR alfa/genética , Infecções Estafilocócicas/genética , Superinfecção/genética , Animais , Lavagem Broncoalveolar/métodos , Coinfecção/genética , Coinfecção/microbiologia , Coinfecção/mortalidade , Sistema Enzimático do Citocromo P-450/genética , Modelos Animais de Doenças , Suscetibilidade a Doenças , Humanos , Inflamação/microbiologia , Inflamação/mortalidade , Influenza Humana/microbiologia , Influenza Humana/mortalidade , Pulmão/microbiologia , Pulmão/patologia , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Camundongos , Camundongos Knockout , Necroptose/genética , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/mortalidade , Superinfecção/mortalidade
5.
J Food Sci ; 85(6): 1915-1923, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32460375

RESUMO

Polar components (PCs) are produced during the frying of oil, affecting the quality of edible oil and posing a hazard to human health. In this study, C57 mice were fed a high-fat (HF) diet containing purified PCs for nine weeks. Their effects on lipid metabolism and liver function in animals were analyzed. Our results indicated that the contents of total PCs and saturated fatty acid increased from 6.07 ± 0.6% and 58.27 ± 0.35% to 19.17 ± 1.8% and 69.91 ± 0.51%, respectively (P < 0.01). PC intake resulted an 18.56% higher liver index in mice than that in the HF group. The PC group had the highest malondialdehyde (MDA) content (1.94 ± 0.11 nmol/mg protein) and the liver nonalcoholic fatty liver disease (NAFLD) activity score (NAS) was 4, which already showed NAFLD characteristics. In addition, the expression levels of lipid metabolism-related genes, including sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthetase (FAS), peroxisome proliferator-activated receptor-alpha, and peroxisome acyl-CoA oxidase 1, indicated that PC increased hepatic lipid accumulation by upregulating the transcriptional level of fat synthesis genes and further leads to liver damage by affecting mitochondrial function. Our results provided important information about the effects of PCs produced in the frying process of PO on animal health, which is critical for assessing the biosafety of fried products. PRACTICAL APPLICATION: The research will help promote the industrial upgrading of fried foods and help consumers build healthy lifestyles.


Assuntos
Metabolismo dos Lipídeos , Fígado/metabolismo , Óleo de Palmeira/química , Óleo de Palmeira/metabolismo , Animais , Culinária , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Ácidos Graxos/metabolismo , Temperatura Alta , Humanos , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Óleo de Palmeira/efeitos adversos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
6.
Invest Ophthalmol Vis Sci ; 61(4): 15, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32298438

RESUMO

Purpose: Pathological neovascularization and fibrosis are common pathological changes of many retinal diseases, such as proliferative retinopathy (PR) and age-related macular degeneration (AMD). Treatment modalities for these pathological changes are limited. The purpose of the present study was to test the effects of palmitoylethanolamide (PEA), an endocannabinoid mimetic amide, on retinal neovascularization and fibrosis and to determine its molecular mechanism of action. Methods: A rat Müller cell line (rMC-1), a mouse model of oxygen-induced retinopathy (OIR), and the very-low-density lipoprotein receptor (VLDLR) knockout mouse model were used. PEA was intraperitoneally injected or orally administrated in animal models. Inflammation and profibrotic changes were evaluated by western blot analysis. Glial fibrillary acidic protein (GFAP) and peroxisome proliferator-activated receptor alpha (PPARα) were measured by RT-PCR and western blot analysis. Results: Profibrotic changes were present in OIR and Vldlr-/- retinas. PEA significantly alleviated inflammation and inhibited neovascularization in OIR and Vldlr-/- retinas and suppressed profibrotic changes in OIR and Vldlr-/- retinas. Moreover, PEA potently suppressed Müller gliosis in these retinas. In rMC-1 cells, PEA suppressed Müller gliosis, reduced inflammatory cytokines, and attenuated profibrotic changes. Further, both mRNA and protein levels of PPARα were elevated in the retina under PEA treatment, and the effects of PEA were abolished in Pparα-/- OIR mice. Conclusions: PEA reduced retinal neovascularization and fibrotic changes and suppressed Müller gliosis in experimental PR and neovascular AMD by activating PPARα. PEA may be a potential treatment for retinopathies with pathological neovascularization and fibrosis.


Assuntos
Agonistas de Receptores de Canabinoides/uso terapêutico , Etanolaminas/uso terapêutico , Gliose/tratamento farmacológico , PPAR alfa/metabolismo , Ácidos Palmíticos/uso terapêutico , Retina/patologia , Neovascularização Retiniana/tratamento farmacológico , Administração Oral , Animais , Western Blotting , Linhagem Celular , Modelos Animais de Doenças , Células Ependimogliais/efeitos dos fármacos , Fibrose/tratamento farmacológico , Fibrose/metabolismo , Fibrose/patologia , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/metabolismo , Gliose/patologia , Marcação In Situ das Extremidades Cortadas , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxigênio/toxicidade , PPAR alfa/genética , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Receptores de LDL/genética , Retina/metabolismo , Neovascularização Retiniana/induzido quimicamente , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia
7.
Diabetes ; 69(6): 1279-1291, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32213513

RESUMO

The purpose of this study was to investigate the protective role of peroxisome proliferator-activated receptor α (PPARα) against diabetic keratopathy and corneal neuropathy. Corneal samples were obtained from human donors with and without diabetes. Streptozotocin-induced diabetic rats and mice were orally treated with PPARα agonist fenofibrate. As shown by immunohistochemistry and Western blotting, PPARα was downregulated in the corneas of humans with diabetes and diabetic rats. Immunostaining of ß-III tubulin demonstrated that corneal nerve fiber metrics were decreased significantly in diabetic rats and mice, which were partially prevented by fenofibrate treatment. As evaluated using a Cochet-Bonnet aesthesiometer, corneal sensitivity was significantly decreased in diabetic mice, which was prevented by fenofibrate. PPARα -/- mice displayed progressive decreases in the corneal nerve fiber density. Consistently, corneal sensitivity was decreased in PPARα -/- mice relative to wild-type mice by 21 months of age. Diabetic mice showed increased incidence of spontaneous corneal epithelial lesion, which was prevented by fenofibrate while exacerbated by PPARα knockout. Western blot analysis revealed significantly altered neurotrophic factor levels in diabetic rat corneas, which were partially restored by fenofibrate treatment. These results indicate that PPARα protects the corneal nerve from degeneration induced by diabetes, and PPARα agonists have therapeutic potential in the treatment of diabetic keratopathy.


Assuntos
Córnea/inervação , Diabetes Mellitus Experimental/patologia , Degeneração Neural/metabolismo , PPAR alfa/metabolismo , Animais , Regulação para Baixo , Fenofibrato/farmacologia , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Hipolipemiantes/farmacologia , Masculino , Degeneração Neural/tratamento farmacológico , PPAR alfa/genética , Ratos , Ratos Sprague-Dawley
8.
J Food Sci ; 85(3): 800-807, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32090345

RESUMO

The aim of this study is to observe the effects of Ninghong black tea extract on fat deposition and high-fat diet-induced nonalcoholic fatty liver disease (NAFLD) and to explore the potential mechanisms of these effect. Under 2% Ninghong black tea extract diet feeding in rat model, the results showed that Ninghong black tea extract decreased the body fat ratio and the number of lipid droplets in the liver and significantly alleviated NAFLD in the rat model. The real-time fluorescence quantitative polymerase chain reaction results showed that Ninghong black tea extract significantly upregulated the expression of peroxisome proliferator-activated receptor α (PPARα), which is important in fatty acid ß-oxidation, and microsomal triglyceride transfer protein (MTP), which plays an important role in the synthesis of very low density lipoprotein (VLDL). By promoting the expression of PPARα and MTP in liver tissue and thereby promoting fatty acid ß-oxidation and VLDL synthesis, Ninghong black tea extract relieves high-fat diet-induced NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Animais , Camellia sinensis/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Dieta Hiperlipídica/efeitos adversos , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Folhas de Planta/química , Ratos , Ratos Sprague-Dawley
9.
Life Sci ; 247: 117414, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32035928

RESUMO

AIMS: Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been reported to significantly reduce body weight. This study investigated whether SGLT2 inhibitors directly affect adipose tissues and the underlying mechanisms in vivo and in vitro. MAIN METHODS: Male C57BL/6 mice were fed a normal diet, high-fat diet (HFD), or HFD with canagliflozin for 14 weeks. 3T3-L1 adipocytes were treated with canagliflozin. Metabolic parameters were measured. KEY FINDINGS: Canagliflozin reduced body weight, fat mass, and white adipose tissue (WAT) weight and inhibited adipocyte hypertrophy. Canagliflozin improved glucose and lipid metabolic disorders induced by HFD. Furthermore, canagliflozin treatment reversed the suppressed mRNA and protein expression of PGC-1α, NRF1, tfam and CPT1b, which are markers of mitochondrial biogenesis, function and fatty acid oxidation in mice with obesity. In vitro, canagliflozin increased mitochondrial DNA to nuclear DNA and upregulated the expression of PGC-1α, NRF1, tfam, COX5b, COX8b, Atp5o, and CPT1b mRNA and PGC-1α, NRF1, tfam, COX5b, CPT1b protein in 3T3-L1 adipocytes in a dose-dependent manner, while these increases were inhibited by GW6471, a PPARα antagonist. SIGNIFICANCE: Our study showed that canagliflozin protected against HFD-induced obesity and obesity-related metabolic disorders by improving mitochondrial function and fatty acid oxidation in adipose tissue and adipocytes. Such energy-dissipating effects of canagliflozin may be mediated by PPARα.


Assuntos
Canagliflozina/uso terapêutico , Ácidos Graxos/metabolismo , Mitocôndrias/metabolismo , Obesidade/tratamento farmacológico , PPAR alfa/metabolismo , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Células 3T3-L1 , Adipócitos/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Canagliflozina/farmacologia , Dieta Hiperlipídica , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/genética , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia
10.
Diabetes ; 69(4): 771-783, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31974142

RESUMO

The cardiovascular benefits of fibrates have been shown to be heterogeneous and to depend on the presence of atherogenic dyslipidemia. We investigated whether genetic variability in the PPARA gene, coding for the pharmacological target of fibrates (PPAR-α), could be used to improve the selection of patients with type 2 diabetes who may derive cardiovascular benefit from addition of this treatment to statins. We identified a common variant at the PPARA locus (rs6008845, C/T) displaying a study-wide significant influence on the effect of fenofibrate on major cardiovascular events (MACE) among 3,065 self-reported white subjects treated with simvastatin and randomized to fenofibrate or placebo in the ACCORD-Lipid trial. T/T homozygotes (36% of participants) experienced a 51% MACE reduction in response to fenofibrate (hazard ratio 0.49; 95% CI 0.34-0.72), whereas no benefit was observed for other genotypes (P interaction = 3.7 × 10-4). The rs6008845-by-fenofibrate interaction on MACE was replicated in African Americans from ACCORD (N = 585, P = 0.02) and in external cohorts (ACCORD-BP, ORIGIN, and TRIUMPH, total N = 3059, P = 0.005). Remarkably, rs6008845 T/T homozygotes experienced a cardiovascular benefit from fibrate even in the absence of atherogenic dyslipidemia. Among these individuals, but not among carriers of other genotypes, fenofibrate treatment was associated with lower circulating levels of CCL11-a proinflammatory and atherogenic chemokine also known as eotaxin (P for rs6008845-by-fenofibrate interaction = 0.003). The GTEx data set revealed regulatory functions of rs6008845 on PPARA expression in many tissues. In summary, we have found a common PPARA regulatory variant that influences the cardiovascular effects of fenofibrate and that could be used to identify patients with type 2 diabetes who would derive benefit from fenofibrate treatment, in addition to those with atherogenic dyslipidemia.


Assuntos
Diabetes Mellitus Tipo 2/genética , Dislipidemias/tratamento farmacológico , Fenofibrato/uso terapêutico , Hipolipemiantes/uso terapêutico , PPAR alfa/genética , Polimorfismo de Nucleotídeo Único , Quimiocinas/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Dislipidemias/sangue , Dislipidemias/complicações , Dislipidemias/genética , Feminino , Genótipo , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Farmacogenética , Resultado do Tratamento
11.
Molecules ; 25(2)2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31963528

RESUMO

Metformin is the first-line drug for type 2 diabetes mellitus control. It is established that this drug traffics through OCT-2 and MATE-1 transporters in kidney tubular cells and is excreted in its unaltered form in the urine. Hereby, we provide evidence that points towards the metformin-dependent upregulation of OCT-2 and MATE-1 in the kidney via the transcription factor proliferator-activated receptor alpha (PPARα). Treatment of wild type mice with metformin led to the upregulation of the expression of OCT-2 and MATE-1 by 34% and 157%, respectively. An analysis in a kidney tubular cell line revealed that metformin upregulated PPARα and OCT-2 expression by 37% and 299% respectively. MK-886, a PPARα antagonist, abrogated the OCT-2 upregulation by metformin and reduced MATE-1 expression. Conversely, gemfibrozil, an agonist of PPARα, elicited the increase of PPARα, OCT-2, and MATE-1 expression by 115%, 144%, and 376%, respectively. PPARα knockout mice failed to upregulate both the expression of OCT-2 and MATE-1 in the kidney upon metformin treatment, supporting the PPARα-dependent metformin upregulation of the transporters in this organ. Taken together, our data sheds light on the metformin-induced mechanism of transporter modulation in the kidney, via PPARα, and this effect may have implications for drug safety and efficacy.


Assuntos
Rim/química , Metformina/administração & dosagem , Proteínas de Transporte de Cátions Orgânicos/genética , Transportador 2 de Cátion Orgânico/genética , PPAR alfa/genética , Animais , Linhagem Celular , Genfibrozila/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Indóis/farmacologia , Rim/efeitos dos fármacos , Masculino , Metformina/farmacologia , Camundongos , Regulação para Cima/efeitos dos fármacos
12.
J Enzyme Inhib Med Chem ; 35(1): 524-538, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31939313

RESUMO

A series of nitrogen heterocycles containing α-ethoxyphenylpropionic acid derivatives were designed as dual PPARα/γ agonist ligands for the treatment of type 2 diabetes (T2D) and its complications. 6-Benzoyl-benzothiazol-2-one was the most tolerant of the tested heterocycles in which incorporation of O-methyl oxime ether and trifluoroethoxy group followed by enantiomeric resolution led to the (S)-stereoisomer 44 b displaying the best in vitro pharmacological profile. Compound 44 b acted as a very potent full PPARγ agonist and a weak partial agonist on the PPARα receptor subtype. Compound 44 b showed high efficacy in an ob/ob mice model with significant decreases in serum triglyceride, glucose and insulin levels but mostly with limited body-weight gain and could be considered as a selective PPARγ modulator (SPPARγM).


Assuntos
Benzotiazóis/farmacologia , Hipoglicemiantes/farmacologia , PPAR alfa/agonistas , PPAR gama/agonistas , Fenilpropionatos/farmacologia , Animais , Benzotiazóis/síntese química , Benzotiazóis/química , Células COS , Chlorocebus aethiops , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Relação Dose-Resposta a Droga , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Ligantes , Masculino , Camundongos , Camundongos Obesos , Simulação de Acoplamento Molecular , Estrutura Molecular , PPAR alfa/genética , PPAR gama/genética , Fenilpropionatos/síntese química , Fenilpropionatos/química , Relação Estrutura-Atividade
13.
Toxicol Lett ; 319: 85-94, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31730885

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is a chronic hepatic disease associated with the excessive accumulation of lipids in the liver. Premenopausal women are protected from the liver metabolic complications of obesity compared with body mass index (BMI)-matched men. This protection may be related to estrogen's ability to limit liver fat accumulation. Aryl hydrocarbon receptor (AhR), a novel regulator of NAFLD, may be an important target for regulating estrogen homeostasis. In present study, we used benzo[a]pyrene (BaP), a classic and potent ligand of AhR, to activate AhR pathway causes overexpression of the estrogen-metabolizing enzyme cytochrome P450 1A1 (CYP1A1) and affects the expression of important genes involved in hepatic lipid regulation. BaP induces CYP1A1 expression through AhR signaling and inhibits the protective effect of 17ß-estradiol (E2) on hepatic steatosis, characterized by triglyceride accumulation, and markers of liver damage are significantly elevated. The expression of adipogenic genes involved in the hepatic lipid metabolism of sterol regulatory element-binding protein-1c (SREBP-1c) was increased compared with that in the control group. Furthermore, the mRNA and protein levels of peroxisome proliferator-activated receptor alpha (PPARα), which is involved in fatty acid oxidation, were significantly reduced. Taken together, our results revealed that the steatotic effect of AhR is likely due to overexpression of the E2 metabolic enzyme CYP1A1, which affects the estrogen signaling pathway, leading to the suppression of fatty acid oxidation, inhibition of the hepatic export of triglycerides, and an increase in peripheral fat mobilization. The results from this study may help establish AhR as a novel therapeutic and preventive target for fatty liver disease.


Assuntos
Hepatopatia Gordurosa não Alcoólica/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Adipogenia/efeitos dos fármacos , Adipogenia/genética , Animais , Benzo(a)pireno/farmacologia , Citocromo P-450 CYP1A1/biossíntese , Citocromo P-450 CYP1A1/genética , Estradiol/farmacologia , Estrogênios/metabolismo , Feminino , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/biossíntese , PPAR alfa/genética , Receptores de Hidrocarboneto Arílico/agonistas , Transdução de Sinais/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 1/biossíntese , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Triglicerídeos/metabolismo
14.
Int J Mol Sci ; 20(23)2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31783518

RESUMO

In a recent human study, we observed that amoxicillin treatment decreased HDL-C concentration. We hypothesize that antibiotics lower the transcription and secretion of ApoA-I, the responsible protein for HDL production. HepG2 and Caco-2 cells were exposed to increasing dose of amoxicillin, penicillin, and streptomycin. Secreted ApoA-I protein and mRNA transcripts were analyzed using ELISA and qPCR, respectively. To unravel underlying mechanisms, KEAP1, CPT1, and CHOP mRNA expressions were determined as well as PPARα transactivation. In HepG2 and Caco-2, amoxicillin decreased ApoA-I transcription and secretion. Effects on ApoA-I expression were clearly there for amoxicillin while no effects were observed for penicillin or streptomycin. KEAP1, CPT1, and CHOP mRNA expressions were reduced by amoxicillin treatments. Moreover, a significant correlation between ApoA-I and CPT1 mRNA expressions was found. Furthermore, amoxicillin lowered PPARα transactivation. All together, these data suggest that inhibited PPARα transactivation is involved in the effects of amoxicillin on ApoA-I. In conclusion, the direct effect of amoxicillin in treated HepG2 and Caco-2 cells was a lower ApoA-I secretion and transcription. Based on evaluating alterations in KEAP1, CPT1, and CHOP mRNA expressions plus PPARα transactivation, we suggest that a reduced PPARα activation is a potential mechanism behind the observed amoxicillin effects on ApoA-I expression.


Assuntos
Amoxicilina/farmacologia , Apolipoproteína A-I/genética , Apolipoproteína A-I/metabolismo , PPAR alfa/genética , Transcrição Genética/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Células CACO-2 , Carnitina O-Palmitoiltransferase/genética , Linhagem Celular Tumoral , Células Hep G2 , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , RNA Mensageiro/genética , Fator de Transcrição CHOP/genética
15.
J Med Food ; 22(12): 1262-1270, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31834842

RESUMO

The aim of this study was to investigate the potential protective effects of the hot water extract of Eriobotrya japonica (EJW) on EtOH- or free fatty acid (FFA)-induced fatty liver injury in vitro. HepG2/2E1 cells were exposed to EtOH and HepG2 cells were exposed to a mixture of FFAs (oleic acid:palmitic acid, 2:1) to stimulate oxidative stress and to induce lipid accumulation, respectively. Antioxidant activity was significantly increased and lipid accumulation was inhibited in cells pretreated with EJW compared to those in cells exposed to EtOH or FFA only. Also, 5'adenosine monophosphate (AMP)-activated protein kinase (AMPK) and acetyl-coenzyme A carboxylase (ACC) phosphorylations were considerably increased, indicating activation of AMPK. Furthermore, EJW reduced the messenger RNA (mRNA) expression of lipogenesis-associated factors such as ACC, sterol regulatory element binding protein-1c (SREBP-1c), and fatty acid synthase (FAS), and increased mRNA expression related to components of the fatty acid ß-oxidation pathway, such as AMPK, carnitine palmitoyltransferase 1 (CPT-1), and peroxisome proliferator-activated receptor alpha (PPARα). These results suggest that EJW possessed potential preventive effects against both EtOH- and FFA-induced fatty liver disease by alleviation of oxidative stress and lipid accumulation in hepatocytes.


Assuntos
Eriobotrya/química , Fígado Gorduroso Alcoólico/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Extratos Vegetais/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Acetil-CoA Carboxilase/metabolismo , Carnitina O-Palmitoiltransferase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Etanol/efeitos adversos , Ácido Graxo Sintases/metabolismo , Ácidos Graxos não Esterificados/efeitos adversos , Células Hep G2/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Produto da Acumulação Lipídica , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipogênese/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Ácido Oleico/efeitos adversos , Estresse Oxidativo , PPAR alfa/genética , Ácido Palmítico/efeitos adversos , Fosforilação/efeitos dos fármacos , Proteínas Quinases/metabolismo , RNA Mensageiro/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Água
16.
Cell Rep ; 29(12): 4127-4143.e8, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31851938

RESUMO

The pro-longevity enzyme SIRT6 regulates various metabolic pathways. Gene expression analyses in SIRT6 heterozygotic mice identify significant decreases in PPARα signaling, known to regulate multiple metabolic pathways. SIRT6 binds PPARα and its response element within promoter regions and activates gene transcription. Sirt6+/- results in significantly reduced PPARα-induced ß-oxidation and its metabolites and reduced alanine and lactate levels, while inducing pyruvate oxidation. Reciprocally, starved SIRT6 transgenic mice show increased pyruvate, acetylcarnitine, and glycerol levels and significantly induce ß-oxidation genes in a PPARα-dependent manner. Furthermore, SIRT6 mediates PPARα inhibition of SREBP-dependent cholesterol and triglyceride synthesis. Mechanistically, SIRT6 binds PPARα coactivator NCOA2 and decreases liver NCOA2 K780 acetylation, which stimulates its activation of PPARα in a SIRT6-dependent manner. These coordinated SIRT6 activities lead to regulation of whole-body respiratory exchange ratio and liver fat content, revealing the interactions whereby SIRT6 synchronizes various metabolic pathways, and suggest a mechanism by which SIRT6 maintains healthy liver.


Assuntos
Fígado/metabolismo , PPAR alfa/metabolismo , Sirtuínas/metabolismo , Acetilação , Animais , Western Blotting , Células Cultivadas , Células HEK293 , Humanos , Imunoprecipitação , Masculino , Camundongos , Camundongos Transgênicos , Coativador 2 de Receptor Nuclear/genética , Coativador 2 de Receptor Nuclear/metabolismo , Oxirredução , PPAR alfa/genética , Sirtuínas/genética
17.
Int J Mol Sci ; 21(1)2019 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-31881714

RESUMO

BACKGROUND: Although the scientific literature regarding sports genomics has grown during the last decade, some genes, such as peroxisome proliferator activated receptors (PPARs), have not been fully described in terms of their role in achieving extraordinary sports performance. Therefore, the purpose of this systematic review was to determine which elite sports performance constraints are positively influenced by PPARs and their coactivators. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used, with a combination of PPAR and sports keywords. RESULTS: In total, 27 studies that referred to PPARs in elite athletes were included, where the Ala allele in PPARG rs1801282 was associated with strength and power elite athlete status in comparison to subelite athlete status. The C allele in PPARA rs4253778 was associated with soccer, and the G allele PPARA rs4253778 was associated with endurance elite athlete status. Other elite status endurance alleles were the Gly allele in PPARGC1A rs8192678 and the C allele PPARD rs2016520. CONCLUSIONS: PPARs can be used for estimating the potential to achieve elite status in human physical performance in strength and power, team, and aerobic sports disciplines. Carrying specific PPAR alleles can provide a partial benefit to achieving elite sports status, but does not preclude achieving elite status if they are absent.


Assuntos
PPAR alfa/genética , PPAR gama/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Alelos , Atletas , Desempenho Atlético , Frequência do Gene , Variação Genética , Humanos , Resistência Física
18.
Open Biol ; 9(12): 190141, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31847785

RESUMO

Endothelial dysfunction caused by endothelial cell injuries is the initiating factor for atherosclerosis (AS), and lipid peroxidative injury is one of a dominant factor for AS pathogenesis. Using RNA-seq, we compared changes in transcriptome expression before and after endothelial cell injury, and found 311 differentially expressed genes (DEGs), of which 258 genes were upregulated and 53 genes were downregulated. The protein-protein interactions (PPIs) between the genes were analysed using the STRING database, and a PPI network of DEGs was constructed. The relationship distributions among these PPIs were analysed by performing network node statistics. We found that in the top 20 DEGs with high connected protein nodes in the PPI network, 16 were upregulated and 4 were downregulated. Gene ontology (GO) functional enrichment analysis and KEGG pathway enrichment analysis on the DEGs were also performed. By comparing the upregulated expressed genes with high connected protein nodes in the PPI network to those related to endothelial cell lipid damage and repair in the GO analysis, we identified seven genes (NOX4, PPARA, CCL2, PDGFB, IL8, VWF, CD36) and verified their expression levels by real-time polymerase chain reaction. The protein interactions between the seven genes were then analysed using the STRING database. The results predicted that CCL2 interacts with NOX4, PPARα, PDGFß and VWF individually. Thus, we examined the protein expression levels of CCL2, NOX4, PPARα, PDGFß and VWF, and found that the expression levels of all proteins were significantly upregulated after the lipid peroxidative injury, with CCL2 and PPARα exhibiting the highest expression levels. Therefore, we investigated the interregulatory relationship between CCL2 and PPARα and their roles in the repair of endothelial cell injury. With the help of gene overexpression and knockdown techniques, we discovered that PPARα promotes the repair of endothelial cell injury by upregulating CCL2 expression in human umbilical vein endothelial cells but that CCL2 cannot regulate PPARα expression. Therefore, we believe that PPARα participates in the repair of endothelial cell lipid peroxidative injury through regulating the expression of CCL2.


Assuntos
Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/metabolismo , Peroxidação de Lipídeos , PPAR alfa/metabolismo , Transdução de Sinais , Transcriptoma , Sequência de Bases , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , PPAR alfa/genética
19.
Int J Mol Sci ; 20(23)2019 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-31771283

RESUMO

Excess energy intake can trigger an uncontrolled inflammatory response, leading to systemic low-grade inflammation and metabolic disturbances that are hypothesised to contribute to cardiovascular disease and type 2 diabetes. The long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are suggested to mitigate this inflammatory response, but the mechanisms are unclear, especially at the tissue level. Adipose tissues, the first tissues to give an inflammatory response, may be an important target site of action for EPA and DHA. To evaluate the effects of EPA and DHA in white and brown adipose tissues, we fed male C57Bl/6J mice either a high fat diet (HFD) with 5% corn oil, an HFD with 40% of the corn oil substituted for purified EPA and DHA triglycerides (HFD-ED), or normal chow, for 8 weeks. Fatty acid profiling and transcriptomics were used to study how EPA and DHA affect retroperitoneal white and brown adipose tissues. HFD-ED fed mice showed reduced lipid accumulation and levels of the pro-inflammatory fatty acid arachidonic acid in both white and brown adipose tissues, compared with HFD-corn oil fed animals. The transcriptomic analysis showed changes in ß-oxidation pathways, supporting the decreased lipid accumulation in the HFD-ED fed mice. Therefore, our data suggests that EPA and DHA supplementation of a high fat diet may be anti-inflammatory, as well as reduce lipid accumulation in adipose tissues.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Dieta Hiperlipídica , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Ácido Araquidônico/metabolismo , Óleo de Milho/farmacologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Ácidos Graxos Ômega-3/farmacologia , Regulação da Expressão Gênica , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/genética , PPAR alfa/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
20.
Lipids Health Dis ; 18(1): 207, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775868

RESUMO

OBJECTIVE: Endoplasmic reticulum (ER) stress and mitochondrial function affected intramuscular fat accumulation. However, there is no clear evident on the effect of the regulation of ER stress and mitochondrial function by Angiotensin-converting enzyme 2 (ACE2) on the prevention of intramuscular fat metabolism. We investigated the effects of ACE2 on ER stress and mitochondrial function in skeletal muscle lipid metabolism. METHODS: The triglyceride (TG) content in skeletal muscle of ACE2 knockout mice and Ad-ACE2-treated db/db mice were detected by assay kits. Meanwhile, the expression of lipogenic genes (ACCα, SREBP-1c, LXRα, CPT-1α, PGC-1α and PPARα), ER stress and mitochondrial function related genes (GRP78, eIF2α, ATF4, BCL-2, and SDH6) were analyzed by RT-PCR. Lipid metabolism, ER stress and mitochondrial function related genes were analyzed by RT-PCR in ACE2-overexpression C2C12 cell. Moreover, the IKKß/NFκB/IRS-1 pathway was determined using lysate sample from skeletal muscle of ACE2 knockout mice. RESULTS: ACE2 deficiency in vivo is associated with increased lipid accumulation in skeletal muscle. The ACE2 knockout mice displayed an elevated level of ER stress and mitochondrial dysfunctions in skeletal muscle. In contrast, activation of ACE2 can ameliorate ER stress and mitochondrial function, which slightly accompanied by reduced TG content and down-regulated the expression of skeletal muscle lipogenic proteins in the db/db mice. Additionally, ACE2 improved skeletal muscle lipid metabolism and ER stress genes in the C2C12 cells. Mechanistically, endogenous ACE2 improved lipid metabolism through the IKKß/NFκB/IRS-1 pathway in skeletal muscle. CONCLUSIONS: ACE2 was first reported to play a notable role on intramuscular fat regulation by improving endoplasmic reticulum and mitochondrial function. This study may provide a strategy for treating insulin resistance in skeletal muscle.


Assuntos
Estresse do Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Metabolismo dos Lipídeos/genética , Mitocôndrias/metabolismo , Músculo Esquelético/metabolismo , Peptidil Dipeptidase A/genética , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Animais , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Fator de Iniciação 2 em Eucariotos/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Resistência à Insulina , Receptores X do Fígado/genética , Receptores X do Fígado/metabolismo , Masculino , Camundongos , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , PPAR alfa/genética , PPAR alfa/metabolismo , Peptidil Dipeptidase A/deficiência , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Succinato Desidrogenase/genética , Succinato Desidrogenase/metabolismo , Triglicerídeos/metabolismo
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