RESUMO
High ethanol consumption triggers neuroinflammation, implicated in sustaining chronic alcohol use. This inflammation boosts glutamate, prompting dopamine release in reward centers, driving prolonged drinking and relapse. Fibrate drugs, activating peroxisome proliferator-activated receptor alpha (PPAR-α), counteract neuroinflammation in other contexts, prompting investigation into their impact on ethanol-induced inflammation. Here, we studied, in UChB drinker rats, whether the administration of fenofibrate in the withdrawal stage after chronic ethanol consumption reduces voluntary intake when alcohol is offered again to the animals (relapse-type drinking). Furthermore, we determined if fenofibrate was able to decrease ethanol-induced neuroinflammation and oxidative stress in the brain. Animals treated with fenofibrate decreased alcohol consumption by 80% during post-abstinence relapse. Furthermore, fenofibrate decreased the expression of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukins IL-1ß and IL-6, and of an oxidative stress-induced gene (heme oxygenase-1), in the hippocampus, nucleus accumbens, and prefrontal cortex. Animals treated with fenofibrate showed an increase M2-type microglia (with anti-inflammatory proprieties) and a decrease in phagocytic microglia in the hippocampus. A PPAR-α antagonist (GW6471) abrogated the effects of fenofibrate, indicating that they are dependent on PPAR-α activation. These findings highlight the potential of fenofibrate, an FDA-approved dyslipidemia medication, as a supplementary approach to alleviating relapse severity in individuals with alcohol use disorder (AUD) during withdrawal.
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Metabolic syndrome (MetS) is a cluster of factors that increase the risk of developing diabetes, stroke, and heart failure. The pathophysiology of injury by ischemia/reperfusion (I/R) is highly complex and the inflammatory condition plays an important role by increasing matrix remodeling and cardiac apoptosis. Natriuretic peptides (NPs) are cardiac hormones with numerous beneficial effects mainly mediated by a cell surface receptor named atrial natriuretic peptide receptor (ANPr). Although NPs are powerful clinical markers of cardiac failure, their role in I/R is still controversial. Peroxisome proliferator-activated receptor α agonists exert cardiovascular therapeutic actions; however, their effect on the NPs' signaling pathway has not been extensively studied. Our study provides important insight into the regulation of both ANP and ANPr in the hearts of MetS rats and their association with the inflammatory conditions caused by damage from I/R. Moreover, we show that pre-treatment with clofibrate was able to decrease the inflammatory response that, in turn, decreases myocardial fibrosis, the expression of metalloprotease 2 and apoptosis. Treatment with clofibrate is also associated with a decrease in ANP and ANPr expression.
Assuntos
Síndrome Metabólica , Traumatismo por Reperfusão , Ratos , Animais , Fator Natriurético Atrial/metabolismo , PPAR alfa/agonistas , Clofibrato/farmacologia , Síndrome Metabólica/complicações , Síndrome Metabólica/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Receptores do Fator Natriurético Atrial/metabolismo , Peptídeos Natriuréticos , Isquemia , Arritmias Cardíacas , Inflamação/tratamento farmacológicoRESUMO
Obesity causes white and brown adipocyte dysfunction, reducing browning and stimulating whitening. Drugs that tackle adipocyte dysfunction through thermogenesis stimulation could be used to treat obesity. This study sought to address whether a combination of the PPAR-alpha agonist (WY14643) and DPP4i (linagliptin) potentiates browning and mitigates adipose tissue dysfunction, emphasizing the pathways related to browning induction and the underlying thermogenesis in high-fat-fed mice. Adult male C57BL/6 mice were randomly assigned to receive a control diet (C, 10% lipids) or a high-fat diet (HF, 50% lipids) for 12 weeks. Experiment 1 aimed to evaluate whether 5 weeks of combined therapy was able to potentiate browning using a five-group design: C, HF, HFW (monotherapy with WY14643, 2.5 mg/kg body mass), HFL (monotherapy with linagliptin, 15 mg/kg body mass), and HFC (a combination of both drugs). Experiment 2 further addressed the pathways involved in browning maximization using a four-group study design: C, CC (C diet plus the drug combination), HF, and HFC (HF diet plus the drug combination). The HF group showed overweight, oral glucose intolerance, sWAT adipocyte hypertrophy, and reduced numerical density of nuclei per area of BAT confirming whitening. Only the combined treatment normalized these parameters in addition to body temperature increase, browning induction, and whitening rescue. The high expression of thermogenic marker genes parallel to reduced expression of inflammatory and endoplasmic reticulum stress genes mediated the beneficial findings. Hence, the PPAR-alpha agonist and DPP-4i combination is a promising target for obesity control by inducing functional brown adipocytes, browning of sWAT, and enhanced adaptive thermogenesis.
Assuntos
Inibidores da Dipeptidil Peptidase IV , Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Inibidores da Dipeptidil Peptidase IV/farmacologia , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Linagliptina/metabolismo , Linagliptina/uso terapêutico , Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/tratamento farmacológico , Obesidade/etiologia , Obesidade/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , TermogêneseRESUMO
Cisplatin is a chemotherapy drug widely used in the treatment of solid tumors. However, nephrotoxicity has been reported in about one-third of patients undergoing cisplatin therapy. Proximal tubules are the main target of cisplatin toxicity and cellular uptake; elimination of this drug can modulate renal damage. Organic transporters play an important role in the transport of cisplatin into the kidney and organic cations transporter 2 (OCT-2) has been shown to be one of the most important transporters to play this role. On the other hand, multidrug and toxin extrusion 1 (MATE-1) transporter is the main protein that mediates the extrusion of cisplatin into the urine. Cisplatin nephrotoxicity has been shown to be enhanced by increased OCT-2 and/or reduced MATE-1 activity. Peroxisome proliferator-activated receptor alpha (PPAR-α) is the transcription factor which controls lipid metabolism and glucose homeostasis; it is highly expressed in the kidneys and interacts with both MATE-1 and OCT-2. Considering the above, we treated wild-type and PPAR-α knockout mice with cisplatin in order to evaluate the severity of nephrotoxicity. Cisplatin induced renal dysfunction, renal inflammation, apoptosis and tubular injury in wild-type mice, whereas PPAR-α deletion protected against these alterations. Moreover, we observed that cisplatin induced down-regulation of organic transporters MATE-1 and OCT-2 and that PPAR-α deletion restored the expression of these transporters. In addition, PPAR-α knockout mice at basal state showed increased MATE-1 expression and reduced OCT-2 levels. Here, we show for the first time that PPAR-α deletion protects against cisplatin nephrotoxicity and that this protection is via modulation of the organic transporters MATE-1 and OCT-2.
Assuntos
Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Transportador 2 de Cátion Orgânico/metabolismo , PPAR alfa/genética , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Regulação para Baixo/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Transporte de Cátions Orgânicos/genética , Transportador 2 de Cátion Orgânico/genética , PPAR alfa/metabolismo , Índice de Gravidade de Doença , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Fructose dietary intake affects the composition of the intestinal microbiota and influences the development of hepatic steatosis. Endotoxins produced by gram-negative bacteria alter intestinal permeability and cause bacterial translocation. This study evaluated the effects of gut microbiota modulation by a purified PPAR-alpha agonist (WY14643), a DPP-4 inhibitor (linagliptin), or their association on intestinal barrier integrity, endotoxemia, and hepatic energy metabolism in high-fructose-fed C57BL/6 mice. Fifty mice were divided to receive the control diet (C group) or the high-fructose diet (HFRU) for 12 weeks. Subsequently, the HFRU group was divided to initiate the treatment with PPAR-alpha agonist (3.5 mg/kg/BM) and DPP-4 inhibitor (15 mg/kg/BM). The HFRU group had glucose intolerance, endotoxemia, and dysbiosis (with increased Proteobacteria) without changes in body mass in comparison with the C group. HFRU group showed damaged intestinal ultrastructure, which led to liver inflammation and marked hepatic steatosis in the HFRU group when compared to the C group. PPAR-alpha activation and DPP-4 inhibition countered glucose intolerance, endotoxemia, and dysbiosis, ameliorating the ultrastructure of the intestinal barrier and reducing Tlr4 expression in the liver of treated animals. These beneficial effects suppressed lipogenesis and mitigated hepatic steatosis. In conclusion, the results herein propose a role for PPAR-alpha activation, DPP-4 inhibition, and their association in attenuating hepatic steatosis by gut-liver axis modulation in high-fructose mice model. These observations suggest these treatments as potential targets to treat hepatic steatosis and avoid its progression.
Assuntos
Inibidores da Dipeptidil Peptidase IV/farmacologia , Frutose/administração & dosagem , Microbioma Gastrointestinal/efeitos dos fármacos , Linagliptina/farmacologia , Fígado/efeitos dos fármacos , PPAR alfa/fisiologia , Animais , Glicemia/análise , Dieta , Endotoxemia/prevenção & controle , Fígado Gorduroso/prevenção & controle , Microbioma Gastrointestinal/fisiologia , Intestinos/efeitos dos fármacos , Intestinos/ultraestrutura , Lipogênese/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/efeitos dos fármacos , Proliferadores de Peroxissomos , Pirimidinas/farmacologiaRESUMO
Hypercholesterolemia, also called high cholesterol, is a form of hyperlipidemia, which may be a consequence of diet, obesity or diabetes. In addition, increased levels of low-density lipoprotein (LDL) and reduced levels of high-density lipoprotein (HDL) cholesterol are associated with a higher risk of atherosclerosis and coronary heart disease. Thus, controlling cholesterol levels is commonly necessary, and fibrates have been used as lipid-lowering drugs. Gemfibrozil is a fibrate that acts via peroxisome proliferator-activated receptor alpha to promote changes in lipid metabolism and decrease serum triglyceride levels. However, anemia and leukopenia are known side effects of gemfibrozil. Considering that gemfibrozil may lead to anemia and that gemfibrozil acts via peroxisome proliferator-activated receptor alpha, we treated wild-type and peroxisome proliferator-activated receptor alpha-knockout mice with gemfibrozil for four consecutive days. Gemfibrozil treatment led to anemia seven days after the first administration of the drug; we found reduced levels of hemoglobin, as well as red blood cells, white blood cells and a reduced percentage of hematocrits. PPAR-alpha-knockout mice were capable of reversing all of those reduced parameters induced by gemfibrozil treatment. Erythropoietin levels were increased in the serum of gemfibrozil-treated animals, and we also observed an increased expression of hypoxia-inducible factor-2 alpha (HIF-2α) and erythropoietin in renal tissue, while PPAR-alpha knockout mice treated with gemfibrozil did not present increased levels of serum erythropoietin or tissue HIF-2α and erythropoietin mRNA levels in the kidneys. We analyzed bone marrow and found that gemfibrozil reduced erythrocytes and hematopoietic stem cells in wild-type mice but not in PPAR-alpha-knockout mice, while increased colony-forming units were observed only in wild-type mice treated with gemfibrozil. Here, we show for the first time that gemfibrozil treatment leads to anemia and leukopenia via peroxisome proliferator-activated receptor alpha in mice.
Assuntos
Anemia/induzido quimicamente , Genfibrozila/efeitos adversos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Hipolipemiantes/efeitos adversos , Leucopenia/induzido quimicamente , PPAR alfa/metabolismo , Anemia/metabolismo , Animais , Contagem de Células , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/metabolismo , Leucopenia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: The anti-cancer effect of peroxisome proliferator-activated receptor (PPAR) α ligands on growth and metastatic potential of melanoma cells has been shown previously. However, the mechanism underlying these effects remains to be elucidated. Here, we investigated the effects of fenofibrate (PPAR ligand) on Toll-like receptor-4 (TLR-4) signaling in mice melanoma. METHODS: Mice melanoma cells (B16F10) were treated with fenofibrate or LPS or LPS + fenofibrate or pre-treated with CLI-095 (a TLR4 inhibitor), followed by fenofibrate. In in vivo model, C57BL/6 mice were subcutaneously injected with B16F10 cells (with/without LPS pre-treatment), and fenofibrate was administrated after development of palpable tumors. Cell proliferation, the expression level of Tlr4, Myd88, Nf-κb1 genes, TLR-4 protein expression, TNF-α levels, and tumor volume were measured. RESULT: Our results indicated that fenofibrate significantly inhibited the Tlr-4, Myd-88, and Nf-kb1 mRNA expression and TNF-α concentration in B16F10 LPS-stimulated cells. In addition, blocking TLR-4 signaling increased the anti-inflammatory potential of fenofibrate. Also fenofibrate can reduce LPS-induced tumor volume, Tlr-4, Myd-88, Nf-kb1 mRNA, and TLR-4 protein expression in tumor tissue and also TNF-α level in tumor tissue lysate. CONCLUSION: Our data indicate that fenofibrate may exert its anti-melanoma effects via interaction with TLR4-dependent signaling pathway (TLR-4/MyD-88/ NF-kB).
Assuntos
Fenofibrato/farmacologia , Melanoma/tratamento farmacológico , PPAR alfa/agonistas , Receptor 4 Toll-Like/fisiologia , Animais , Linhagem Celular Tumoral , Camundongos , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/genética , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Receptor 4 Toll-Like/análise , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
AIMS: High fat diet consumes and thyroid hormones (THs) disorders may affect nutrients metabolism, but their impact on the absorptive epithelium, the first place of nutrients access, remains unknown. Our aim was to evaluate the intestinal morphology and nutrients transporters content in mice fed standard (LFD) or high fat (HFD) diets in hypo or hyperthyroidism-induced condition. MATERIAL AND METHODS: C57BL/6 male mice fed LFD or HFD diets for 12â¯weeks, followed by saline, PTU (antithyroid drug) or T3 treatment up to 30â¯days. The mice were euthanized and proximal intestine was removed to study GLUT2, GLUT5, PEPT1, FAT-CD36, FATP4, NPC1L1 and NHE3 distribution by Western blotting. Since PPAR-a is activated by fatty acids, which is abundant in the HFD, we also evaluated whether PPAR-a affects nutrients transporters. Thus, mice were treated with fenofibrate, a PPAR-a agonist. KEY FINDINGS: HFD decreased GLUT2, PEPT1, FAT-CD6 and NPC1L1, but increased NHE3, while GLUT5 and FATP4 remained unaltered. THs did not alter distribution of nutrients transporters neither in LFD nor in HFD groups, but they increased villi length and depth crypt in LFD and HFD, respectively. Fenofibrate did not affect content of nutrients transporters, excluding PPAR-a involvement on the HFD-induced changes. SIGNIFICANCE: We assume that chronic HFD consumption reduced most of the nutrients transporters content in the small intestine of mice, which might limit the entrance of nutrients and gain weight. Since NHE3 promotes sodium absorption, and it was increased in HFD group, this finding could contribute to explain the hypertension observed in obesity.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Hipertireoidismo/metabolismo , Hipotireoidismo/metabolismo , Mucosa Intestinal/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , PPAR alfa/metabolismo , Animais , Antitireóideos/farmacologia , Fenofibrato/farmacologia , Teste de Tolerância a Glucose , Hipertireoidismo/induzido quimicamente , Hipolipemiantes/farmacologia , Hipotireoidismo/induzido quimicamente , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Intestinos/efeitos dos fármacos , Intestinos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , PPAR alfa/antagonistas & inibidores , Propiltiouracila/farmacologia , Trocador 3 de Sódio-Hidrogênio/metabolismo , Hormônios Tireóideos/metabolismo , Tri-Iodotironina/farmacologiaRESUMO
Non-alcoholic fatty liver disease (NAFLD) presents with growing prevalence worldwide, though its pharmacological treatment remains to be established. This study aimed to evaluate the effects of a PPAR-alpha agonist on liver tissue structure, ultrastructure, and metabolism, focusing on gene and protein expression of de novo lipogenesis and gluconeogenesis pathways, in diet-induced obese mice. Male C57BL/6 mice (three months old) received a control diet (C, 10% of lipids, n = 10) or a high-fat diet (HFD, 50% of lipids, n = 10) for ten weeks. These groups were subdivided to receive the treatment (n = 5 per group): C, C-alpha (PPAR-alpha agonist, 2.5 mg/kg/day mixed in the control diet), HFD and HFD-alpha group (PPAR-alpha agonist, 2.5 mg/kg/day mixed in the HFD). The effects were compared with biometrical, biochemical, molecular biology and transmission electron microscopy (TEM) analyses. HFD showed greater body mass (BM) and insulinemia than C, both of which were tackled by the treatment in the HFD-alpha group. Increased hepatic protein expression of glucose-6-phosphatase, CHREBP and gene expression of PEPCK in HFD points to increased gluconeogenesis. Treatment rescued these parameters in the HFD-alpha group, eliciting a reduced hepatic glucose output, confirmed by the smaller GLUT2 expression in HFD-alpha than in HFD. Conversely, favored de novo lipogenesis was found in the HFD group by the increased expression of PPAR-gamma, and its target gene SREBP-1, FAS and GK when compared to C. The treatment yielded a marked reduction in the expression of all lipogenic factors. TEM analyses showed a greater numerical density of mitochondria per area of tissue in treated than in untreated groups, suggesting an increase in beta-oxidation and the consequent NAFLD control. PPAR-alpha activation reduced BM and treated insulin resistance (IR) and NAFLD by increasing the number of mitochondria and reducing hepatic gluconeogenesis and de novo lipogenesis protein and gene expressions in a murine obesity model.
Assuntos
Gorduras na Dieta/efeitos adversos , Fígado/metabolismo , Mitocôndrias Hepáticas/metabolismo , Obesidade/tratamento farmacológico , PPAR alfa/agonistas , Pirimidinas/farmacologia , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Gorduras na Dieta/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose-6-Fosfatase/biossíntese , Resistência à Insulina , Lipogênese/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Mitocôndrias Hepáticas/patologia , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Proteínas Nucleares/biossíntese , Obesidade/induzido quimicamente , Obesidade/metabolismo , Obesidade/patologia , PPAR alfa/metabolismo , PPAR gama/biossíntese , Fosfoenolpiruvato Carboxiquinase (ATP)/biossíntese , Proteína de Ligação a Elemento Regulador de Esterol 1/biossíntese , Fatores de Transcrição/biossíntese , Receptor fas/biossínteseRESUMO
The antineoplastic drug cisplatin promotes renal injury, which limits its use. Protocols that reduce renal cisplatin toxicity will allow higher doses to be used in cisplatin treatment. Here, we compare physical exercise and caloric restriction (CR) as protocols to reduce cisplatin renal injury in mice. Male C57BL/6 were divided into four groups: Control, cisplatin, exercise + cisplatin, and 30% CR + cisplatin. Animals were injected with a single dose of cisplatin (20 mg/kg i.p.) and sacrificed 96 h after injection. Quantitative real time PCR, histological analyses, immunohistochemistry, and biochemical measurements were performed to investigate renal injury, necrosis, apoptosis, and inflammatory mechanisms. Both protocols protected against cisplatin renal injury, but CR was more effective in reducing uraemia and renal necrosis. The CR + Cisplatin group exhibited reduced serum IL-1ß and TNF-α levels. No differences were noted in the renal mRNA expression of cytokines. Both interventions reduced apoptosis, but only the CR + Cisplatin group decreased TNFR2 protein expression. PPAR-α was activated in mice after CR. An antagonist of PPAR-α blocked the protective effect of CR. Both interventions attenuated the nephrotoxicity caused by cisplatin injection, but CR + Cisplatin showed a better response by modulating TNFR2. Moreover, part of the CR benefit depends on PPAR-α activation.
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Psoriasis is a polygenic, inflammatory and progressive disease, characterized by an abnormal differentiation and hyperproliferation of keratinocytes, associated with impaired immunologic activation and systemic disorders, while psoriatic arthritis is a chronic inflammatory articular disease. Pathophysiology of psoriasis comprises a dysfunction of the immune system cells with an interactive network between cells and cytokines supporting the initiation and perpetuation of disease and leading to inflammation of skin, enthesis and joints. Recent studies have shown an important role of systemic inflammation in the development of atherosclerosis. Corroborating these findings, patients with severe Psoriasis have marked incidence of psoriatic arthritis, cardiovascular diseases, hypertension, dyslipidemia, obesity and diabetes mellitus, showing an increased risk for acute myocardial infarction, which suggests that the condition is not restricted to the skin. Nuclear receptors are ligand-dependent transcription factors, whose activation affects genes that control vital processes. Among them the peroxisome proliferator-activated receptor is responsible for establishing the relationship between lipids, metabolic diseases and innate immunity. In the skin, peroxisome proliferator-activated receptors have an important effect in keratinocyte homeostasis, suggesting a role in diseases such as psoriasis. The peroxisome proliferator-activated receptors agonists represent a relevant source of research in the treatment of skin conditions, however more clinical studies are needed to define the potential response of these drugs in patients with psoriasis and psoriatic arthritis.
A psoríase é uma doença poligênica, inflamatória, progressiva e recorrente, caracterizada por um ciclo evolutivo acelerado dos queratinócitos, associado à ativação imune desordenada e a alterações sistêmicas correlacionadas, sendo a artrite psoriásica o comprometimento articular inflamatório crônico que pode ocorrer em pacientes com a doença cutânea. Na inflamação autoimune, uma rede interativa entre células e citocinas suporta o início e a perpetuação da doença. A fisiopatologia da psoríase e da artrite psoriásica compreende uma disfunção das células do sistema imune e da rede de citocinas, levando à inflamação de pele, enteses e articulações. Estudos recentes têm demonstrado um papel importante da inflamação sistêmica no desenvolvimento da aterosclerose. Corroborando esses achados, pacientes portadores de psoríase grave apresentam marcada incidência de artrite psoriásica, doença cardiovascular, hipertensão arterial sistêmica, dislipidemia, obesidade e diabetes mellitus, evidenciando um risco aumentado para infarto agudo do miocárdio e sugerindo que a doença não se restringe à pele. Os receptores nucleares são fatores de transcrição ligante-dependente cuja ativação afeta genes controladores de processos vitais. Entre eles, destacam-se os receptores ativados pelo proliferador de peroxissoma, responsáveis por estabelecer a relação entre os lipídios, doenças metabólicas e imunidade inata. Na pele, os receptores ativados pelo proliferador de peroxissoma têm ação importante na homeostase dos ceratinócitos, exibindo uma função pró-diferenciação, antiproliferativa e imunomoduladora, sugerindo um papel relevante ...
Assuntos
Humanos , Artrite Psoriásica/tratamento farmacológico , Receptores Ativados por Proliferador de Peroxissomo/agonistas , Psoríase/tratamento farmacológico , Anti-Inflamatórios/uso terapêutico , Artrite Psoriásica/metabolismo , Citocinas/metabolismo , Fatores Imunológicos/uso terapêutico , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Psoríase/metabolismoRESUMO
O objetivo deste trabalho foi estudar a ação do fenofibrato, um agonista do receptor ativador da proliferação peroxissomal alfa, no remodelamento cardíaco e na expressão de componentes do sistema renina-angiotensina (SRA) em um modelo de obesidade induzida por dieta. Camundongos machos C57B1/6 com três meses de idade foram alimentados durante 11 semanas com dieta controle (grupo C, 3,57 kcal/g de dieta) ou dieta hiperlipídica (grupo HL, 5,40 kcal/g de dieta), em seguida foram separados em quatro grupos e estudados durante cinco semanas: C; HO; C-L (C mais fenofibrato) e HL-F (HL mais fenofibrato). Os animais HL foram mais pesados e apresentaram maior pressão arterial (PA) comparados aos animais C, mas HL-F foram mais leves e tiveram PA menor que HL. A resistência insulínica vista nos camundongos HL foi melhorada com fenofibrato nos camundongos HL-F. Fenofibrato reduziu colesterol total, triglicerídeos e aumentou HDL-c. Os animais HL apresentou um ventrículo esquerdo (VE) mais pesado e com espessura da parede maior, como também cardiomiócitos maiores e uma menor razão cardiomiócito/capilares que os animais C. Fenofibrato foi eficiente em melhorar estas alterações. As expressões cardíacas de Angiotensina II (ANG II) e de seu receptor tipo 1 (AT1R) foram maiores, enquanto que a expressão de seu receptor tipo 2 (AT2R) foi menor nos animais HL que nos animais C, e fenofibrato foi eficiente em atenuar estas diferenças. Como conclusão, a dieta HL lidera para a obesidade, elevação da PA, hipertrofia cardíaca, alterações metabólicas e expressão proteica alterada do SRA em camundongos, sugerindo a participação do SRA nestas alterações. Fenofibrato é eficiente em diminuir a PA e controlar a expressão proteica do SRA, assim como no tratamento da resistência insulínica e do remodelamento cardíaco adverso, diminuindo a hipertrofia dos cardiomiócitos e melhorando a vascularização do miocárdio, desta maneira, diminuindo importantes fatores de risco para doenças ...
The aim was to study the action of fenofibrate, a peroxisome proliferator-activated receptor alpha agonist, in cardiac remodeling and protein expressions of RAS components in a model of obesity induced by diet. 3-mo-old C57B1/6 male were fed for 11 weeks with standard chow (SC group, 3.57 kcal/g of chow) or high-fat chow (HF group, 5.40 kcal/g of chow), then they were separated into four groups and studied for five weeks: SC; HF; SC-F (SC plus fenofibrate) and HF-F (HF plus fenofibrate). HF was heavier and had higher blood pressure (BP) than SC, but HF-F was lighter and had lower BP than HF. The insulin resistance seen in HF mice was corrected by fenofibrate in HF-F mice. Fenofibrate reduced total cholesterol, triglycerides and raised the HDL-c. HF had thicker and heavier left ventricle (LV) with bigger LV cardiomyocyte and smaller cardiomyocyte-to-capillaries ratio than SC, and fenofibrate was efficient in treating these alterations. Cardiac expressions of angiotensin II (ANG II) and ANG II receptor 1 were higher, and ANG II receptor 2 was lower in HF than in SC, and fenofibrate was efficient in attenuating these differences. In conclusion , HF diet leads to obesity, BP elevation, cardiac hypertrophy, metabolic changes and altered RAS protein expression in mice, suggesting that RAS is involved. Fenofibrate is efficient in decreasing BP and in controlling RAS protein expressions, and treats the insulin resistance and the adverse cardiac remodeling decreasing the cardiomyocyte hypertrophy and improving the myocardial vascularization, therefore, decreasing important cardiovascular risk factors
Assuntos
Animais , Masculino , Ratos , Fenofibrato/farmacologia , PPAR alfa/agonistas , Remodelação Ventricular , Remodelação Ventricular/fisiologia , Sistema Renina-Angiotensina , Sistema Renina-Angiotensina/fisiologia , Doenças Cardiovasculares/prevenção & controle , Gorduras na Dieta/administração & dosagem , Resistência à Insulina , Pressão Arterial , Sobrepeso/induzido quimicamenteRESUMO
O receptor CD40 e seu ligante CD40L possuem um papel importante na interface entre a resposta imune inata e a adaptativa. Disfunções desta via de sinalização são descritas em doenças de origem inflamatória e autoimunes. Em Lúpus eritematoso sistêmico (LES) foi descrito um aumento nos níveis séricos de CD40L solúvel, que participa na produção de autoanticorpos. Receptores ativados por proliferadores de peroxisomos (PPARs) são fatores de transcrição que inicialmente foram descritos como envolvidos apenas no metabolismo lipídico, mas que atualmente são também descritos como atuantes no controle da resposta imune. Com isso, nosso objetivo é determinar se a ativação dos PPARs modula o processo inflamatório através da interação com CD40/CD40L in vitro ou in vivo. Células de linhagem monocítica humana THP-1 foram tratadas por 24 horas com forbol-éster (PMA, 40 nM) e posteriormente estimuladas com CD40L recombinante (rhCD40L, 1 g/ml) por diferentes períodos. Transcritos de mRNA foram analisados por real time PCR e os resultados expressos como razão da expressão do gene housekeeping GAPDH. As células THP-1 apresentam um aumento na expressão de PPAR e após 16 e 2 horas de estímulo com rhCD40L, respectivamente. Estas células também foram estimuladas com LPS (10 g/ml) e LPS+rhCD40L para sabermos se a resposta obtida anteriormente era específica ao estímulo com rhCD40L. O resultado mostra que há uma diminuição na expressão de PPAR e após o estimulo com LPS ou LPS+rhCD40L, indicando que nessas condições a modulação da expressão de PPARs é especifica para a via de sinalização CD40/CD40L. Foi medida também a expressão de CD36, que é descrito na literatura como um indicador da atividade de PPARs. O resultado mostra que o estímulo com CD40L promove um aumento de CD36, o que indica indiretamente que o PPAR estava ativo neste modelo experimental. Para mostrar a interação direta destas duas vias de sinalização, silenciamos o gene de PPAR por siRNA e posteriormente anlisamos...
The membrane receptor CD40 and its ligand CD40L play an important role in the interface between innate and acquired immunity. Dysfunction of this signaling pathway was described in inflammatory and autoimmune diseases. In systemic lupus erythematosus (SLE), increased serum levels of soluble CD40L have been detected, where it plays a significant role in the generation of auto-antibodies. Peroxisome proliferator activator receptors (PPARs) are transcription factors originally described in lipid metabolism. More recently, they were also characterized as inflammatory modulators. Therefore, our objective was to determine whether the activation of PPARs may modulate the inflammatory process through interaction with the CD40/CD40L signaling pathway in vitro and in vivo. Macrophages derived from the human monocytic cell line THP-1 by 24h-treatment with PMA (40 nM) were stimulated with human recombinant CD40L (rhCD40L, 1 g/ml) for different periods. Messenger RNA (mRNA) transcripts for PPAR , and were determined by real time PCR and expressed as a ratio of the housekeeping gene GAPDH transcripts. THP-1 cells express a basal level of PPAR and gene transcription, which is increased 16 and 2 hours after exposure to rhCD40L, respectively. We also stimulated the THP-1 cells with LPS (10 g/ml) and LPS+rhCD40L to see if the increase of PPAR was a response specific to the rhCD40L stimuli. The data show that there is a decrease in PPAR and genes expression upon LPS or LPS+rhCD40L stimulation, indicating that in these times (2 and 16 hours) the response is specific for the CD40/CD40L signaling pathway. Increased expression of CD36 is known as an indicator of PPARs activity. We measured CD36 and saw an increase of this receptor after rhCD40L stimulus, indicating indirectly that PPARs were active in this experimental model. To prove the direct interaction between CD40/CD40L and PPAR , we silenced the PPAR gene by siRNA and analyzed the expression of CD80, which is known...