RESUMEN
Inflammation in the reproductive tract has become a serious threat to animal fertility. Recently, the role of peroxisome proliferator-activated receptor gamma (PPARγ) in the context of reproduction and the inflammatory response has been highlighted, but the role of PPARß/δ has not been fully elucidated. The aim of the present study was to investigate the in vitro effect of PPARß/δ ligands (agonist: L-165,041 and antagonist: GSK 3787) on the transcriptome profile of porcine endometrium during LPS-induced inflammation in the mid-luteal and follicular phases of the oestrous cycle (days 10-12 and 18-20, respectively) using the RNA-Seq method. During the mid-luteal phase of the oestrous cycle, the current study identified 145 and 143 differentially expressed genes (DEGs) after treatment with an agonist or antagonist, respectively. During the follicular phase of the oestrous cycle, 55 and 207 DEGs were detected after treatment with an agonist or antagonist, respectively. The detected DEGs are engaged in the regulation of various processes, such as the complement and coagulation cascade, NF-κB signalling pathway, or the pathway of 15-eicosatetraenoic acid derivatives synthesis. The results of the current study indicate that PPARß/δ ligands are involved in the control of the endometrial inflammatory response.
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Endometrio , Inflamación , Lipopolisacáridos , PPAR delta , PPAR-beta , Animales , Femenino , Porcinos , Endometrio/efectos de los fármacos , Endometrio/metabolismo , PPAR delta/genética , PPAR delta/metabolismo , PPAR-beta/metabolismo , PPAR-beta/genética , Inflamación/inducido químicamente , Fenoxiacetatos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , TranscriptomaRESUMEN
Nuclear hormone receptors exist in dynamic equilibrium between transcriptionally active and inactive complexes dependent on interactions with ligands, proteins, and chromatin. The present studies examined the hypothesis that endogenous ligands activate peroxisome proliferator-activated receptor-ß/δ (PPARß/δ) in keratinocytes. The phorbol ester treatment or HRAS infection of primary keratinocytes increased fatty acids that were associated with enhanced PPARß/δ activity. Fatty acids caused PPARß/δ-dependent increases in chromatin occupancy and the expression of angiopoietin-like protein 4 (Angptl4) mRNA. Analyses demonstrated that stearoyl Co-A desaturase 1 (Scd1) mediates an increase in intracellular monounsaturated fatty acids in keratinocytes that act as PPARß/δ ligands. The activation of PPARß/δ with palmitoleic or oleic acid causes arrest at the G2/M phase of the cell cycle of HRAS-expressing keratinocytes that is not found in similarly treated HRAS-expressing Pparb/d-null keratinocytes. HRAS-expressing Scd1-null mouse keratinocytes exhibit enhanced cell proliferation, an effect that is mitigated by treatment with palmitoleic or oleic acid. Consistent with these findings, the ligand activation of PPARß/δ with GW0742 or oleic acid prevented UVB-induced non-melanoma skin carcinogenesis, an effect that required PPARß/δ. The results from these studies demonstrate that PPARß/δ has endogenous roles in keratinocytes and can be activated by lipids found in diet and cellular components.
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Queratinocitos , PPAR delta , PPAR-beta , Estearoil-CoA Desaturasa , Queratinocitos/metabolismo , Queratinocitos/efectos de los fármacos , PPAR-beta/metabolismo , PPAR-beta/genética , Animales , Ratones , Estearoil-CoA Desaturasa/metabolismo , Estearoil-CoA Desaturasa/genética , PPAR delta/metabolismo , PPAR delta/genética , Ácidos Grasos/metabolismo , Proteína 4 Similar a la Angiopoyetina/metabolismo , Proteína 4 Similar a la Angiopoyetina/genética , Humanos , Ácido Oléico/farmacología , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Ácidos Grasos Monoinsaturados/farmacología , Ácidos Grasos Monoinsaturados/metabolismo , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patologíaRESUMEN
To probe the functions of Aster glehni (AG) extract containing various caffeoylquinic acids on dyslipidemia, obesity, and skeletal muscle-related diseases focused on the roles of skeletal muscle, we measured the levels of biomarkers involved in oxidative phosphorylation and type change of skeletal muscle in C2C12 cells and skeletal muscle tissues from apolipoprotein E knockout (ApoE KO) mice. After AG extract treatment in cell and animal experiments, western blotting, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) were used to estimate the levels of proteins that participated in skeletal muscle type change and oxidative phosphorylation. AG extract elevated protein expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), phosphorylated 5'-AMP-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor beta/delta (PPARß/δ), myoblast determination protein 1 (MyoD), and myoglobin in skeletal muscle tissues. Furthermore, it elevated the ATP concentration. However, protein expression of myostatin was decreased by AG treatment. In C2C12 cells, increments of MyoD, myoglobin, myosin, ATP-producing pathway, and differentiation degree by AG were dependent on PPARß/δ and caffeoylquinic acids. AG extract can contribute to the amelioration of skeletal muscle inactivity and sarcopenia through myogenesis in skeletal muscle tissues from ApoE KO mice, and function of AG extract may be dependent on PPARß/δ, and the main functional constituents of AG are trans-5-O-caffeoylquinic acid and 3,5-O-dicaffeoylquinic acid. In addition, in skeletal muscle, AG has potent efficacies against dyslipidemia and obesity through the increase of the type 1 muscle fiber content to produce more ATP by oxidative phosphorylation in skeletal muscle tissues from ApoE KO mice.
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Ratones Noqueados , Desarrollo de Músculos , Músculo Esquelético , PPAR delta , PPAR-beta , Extractos Vegetales , Ácido Quínico , Animales , Ratones , Ácido Quínico/análogos & derivados , Ácido Quínico/farmacología , Extractos Vegetales/farmacología , PPAR-beta/metabolismo , PPAR-beta/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/efectos de los fármacos , Desarrollo de Músculos/efectos de los fármacos , PPAR delta/metabolismo , PPAR delta/genética , Masculino , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Humanos , Proteína MioD/metabolismo , Proteína MioD/genética , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/genética , Ratones Endogámicos C57BL , Proteínas Quinasas Activadas por AMP/metabolismoRESUMEN
BACKGROUND: Osteoporosis is a prevalent metabolic bone disease in older adults. Peroxisome proliferator-activated receptor ß (PPARß), the most abundant PPAR isotype expressed in bone tissues, plays a critical role in regulating the energy metabolism of osteoblasts. However, the botanical compounds targeting PPARß for the treatment of osteoporosis remain largely unexplored. PURPOSE: To discover a potent PPARß agonist from botanical compounds, as well as to investigate the anti-osteoporosis effects and to elucidate the underlying mechanisms of the newly identified PPARß agonist. METHODS: The PPARß agonist effects of botanical compounds were screened by an in vitro luciferase reporter gene assay. The PPARß agonist effects of pectolinarigenin (PEC) in bone marrow mesenchymal stromal cells (BMSCs) were validated by Western blotting. RNA-seq transcriptome analyses were conducted to reveal the underlying osteoporosis mechanisms of PEC in BMSCs. The PPARß antagonist (GSK0660) and Wnt signaling inhibitor (XAV969) were used to explore the role of the PPARß and Wnt signaling cascade in the anti-osteoporosis effects of PEC. PEC or the PEG-PLGA nanoparticles of PEC (PEC-NP) were intraperitoneally administrated in both wild-type mice and ovariectomy-induced osteoporosis mice to examine its anti-osteoporotic effects in vivo. RESULTS: PEC, a newly identified naturally occurring PPARß agonist, significantly promotes osteogenic differentiation and up-regulates the osteogenic differentiation-related genes (Runx2, Osterix, and Bmp2) in BMSCs. RNA sequencing and functional gene enrichment analysis suggested that PEC could activate osteogenic-related signaling pathways, including Wnt and PPAR signaling pathways. Further investigations suggested that PEC could enhance Wnt/ß-catenin signaling in a PPARß-dependent manner in BMSCs. Animal tests showed that PEC-NP promoted bone mass and density, increased the bone cell matrix protein, and accelerated bone formation in wild-type mice, while PEC-NP also played a preventive role in ovariectomy-induced osteoporosis mice via maintaining the expression level of bone cell matrix protein, balancing the rate of bone formation, and slowing down bone loss. Additionally, PEC-NP did not cause any organ injury and body weight loss after long-term use (11 weeks). CONCLUSION: PEC significantly promotes bone formation and reduces bone loss in both BMSCs and ovariectomy-induced osteoporosis mice via enhancing the Wnt signaling cascade in a PPARß-dependent manner, providing a new alternative therapy for preventing estrogen deficiency-induced osteoporotic diseases.
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Células Madre Mesenquimatosas , Ratones Endogámicos C57BL , Osteoporosis , PPAR-beta , Vía de Señalización Wnt , Animales , Vía de Señalización Wnt/efectos de los fármacos , Osteoporosis/tratamiento farmacológico , PPAR-beta/metabolismo , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Femenino , Ratones , Osteogénesis/efectos de los fármacos , Ovariectomía , Saponinas/farmacología , Proteína Morfogenética Ósea 2/metabolismo , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Cromonas , Sulfonas , TiofenosRESUMEN
Various liver diseases pose great threats to humans. Although the etiologies of these liver diseases are quite diverse, they share similar pathologic phenotypes and molecular mechanisms such as oxidative stress, lipid and glucose metabolism disturbance, hepatic Kupffer cell (KC) proinflammatory polarization and inflammation, insulin resistance, and hepatic stellate cell (HSC) activation and proliferation. Peroxisome proliferator-activated receptor ß/δ (PPARß/δ) is expressed in various types of liver cells with relatively higher expression in KCs and HSCs. Accumulating evidence has revealed the versatile functions of PPARß/δ such as controlling lipid homeostasis, inhibiting inflammation, regulating glucose metabolism, and restoring insulin sensitivity, suggesting that PPARß/δ may serve as a potential molecular drug target for various liver diseases. This article aims to provide a concise review of the structure, expression pattern and biological functions of PPARß/δ in the liver and its roles in various liver diseases, and to discuss potential future research perspectives.
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Hepatopatías , PPAR delta , PPAR-beta , Humanos , PPAR-beta/fisiología , PPAR-beta/metabolismo , PPAR delta/fisiología , PPAR delta/metabolismo , Hepatopatías/metabolismo , Hepatopatías/tratamiento farmacológico , Terapia Molecular Dirigida , Resistencia a la InsulinaRESUMEN
BACKGROUND/AIM: Myelodysplastic syndromes (MDS) are clinically heterogeneous hematological malignancies with an increased risk of transformation to acute myeloid leukemia, emphasizing the importance of identifying new diagnostic and prognostic markers. This study sought to investigate the predictive ability of all-trans retinoic acid (ATRA)-dependent nuclear transcription factors RARα and PPARß/δ gene expression in MDS patients. MATERIALS AND METHODS: Peripheral blood specimens were collected from 49 MDS patients and 15 healthy volunteers. The specimens were further separated in Ficoll density gradient to obtain the mononuclear cells fractions. Gene expression analysis was carried out using quantitative real-time polymerase chain reaction (qRT-PCR) technique. RESULTS: In the mononuclear cell fractions of MDS patients, RARα expression was increased (p<0.05) and PPARß/δ expression was decreased (p<0.01) compared to healthy volunteers. When RARα and PPARß/δ expression was compared in groups of MDS patients with different risks of disease progression, no statistically significant difference was found for RARα expression, while PPARß/δ expression was significantly lower in the high-risk group of patients compared to the low-risk group (p<0.05). The expression of RARα was significantly associated with overall survival (p<0.05). ROC analysis showed that the expression of PPARß/δ, rather than RARα expression, could have potential diagnostic value for MDS patients (AUC=0.75, p=0.003 and AUC=0.65, p=0.081, respectively). CONCLUSION: RARα and PPARß/δ genes are putative biomarkers that may be associated with the diagnosis and prognosis of MDS.
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Síndromes Mielodisplásicos , PPAR delta , PPAR-beta , Humanos , Relevancia Clínica , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/genética , PPAR delta/genética , PPAR delta/metabolismo , PPAR-beta/genética , PPAR-beta/metabolismo , TretinoinaRESUMEN
Oligodendrocytes are the myelinating cells in the CNS and multiple sclerosis (MS) is a demyelinating disorder that is characterized by progressive loss of myelin. Although oligodendroglial progenitor cells (OPCs) should be differentiated into oligodendrocytes, for multiple reasons, OPCs fail to differentiate into oligodendrocytes in MS. Therefore, increasing the maturation of OPCs to oligodendrocytes may be of therapeutic benefit for MS. The ß-hydroxy ß-methylbutyrate (HMB) is a muscle-building supplement in humans and this study underlines the importance of HMB in stimulating the maturation of OPCs to oligodendrocytes. HMB treatment upregulated the expression of different maturation markers including PLP, MBP, and MOG in cultured OPCs. Double-label immunofluorescence followed by immunoblot analyses confirmed the upregulation of OPC maturation by HMB. While investigating mechanisms, we found that HMB increased the maturation of OPCs isolated from peroxisome proliferator-activated receptor ß-/- (PPARß-/-) mice, but not PPARα-/- mice. Similarly, GW6471 (an antagonist of PPARα), but not GSK0660 (an antagonist of PPARß), inhibited HMB-induced maturation of OPCs. GW9662, a specific inhibitor of PPARγ, also could not inhibit HMB-mediated stimulation of OPC maturation. Furthermore, PPARα agonist GW7647, but neither PPARß agonist GW0742 nor PPARγ agonist GW1929, alone increased the maturation of OPCs. Finally, HMB treatment of OPCs led to the recruitment of PPARα, but neither PPARß nor PPARγ, to the PLP gene promoter. These results suggest that HMB stimulates the maturation of OPCs via PPARα and that HMB may have therapeutic prospects in remyelination.
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Diferenciación Celular , Oligodendroglía , Valeratos , Animales , Valeratos/farmacología , Ratones , Oligodendroglía/efectos de los fármacos , Oligodendroglía/metabolismo , Diferenciación Celular/efectos de los fármacos , Células Precursoras de Oligodendrocitos/efectos de los fármacos , Células Precursoras de Oligodendrocitos/metabolismo , Células Cultivadas , Ratones Endogámicos C57BL , Ratones Noqueados , PPAR-beta/metabolismo , PPAR-beta/agonistasRESUMEN
Significance: Peroxisome proliferator-activated receptors (PPARs) have a moderately preserved amino-terminal domain, an extremely preserved DNA-binding domain, an integral hinge region, and a distinct ligand-binding domain that are frequently encountered with the other nuclear receptors. PPAR-ß/δ is among the three nuclear receptor superfamily members in the PPAR group. Recent Advances: Emerging studies provide an insight on natural compounds that have gained increasing attention as potential anticancer agents due to their ability to target multiple pathways involved in cancer development and progression. Critical Issues: Modulation of PPAR-ß/δ activity has been suggested as a potential therapeutic strategy for cancer management. This review focuses on the ability of bioactive phytocompounds to impact reactive oxygen species (ROS) and redox signaling by targeting PPAR-ß/δ for cancer therapy. The rise of ROS in cancer cells may play an important part in the initiation and progression of cancer. However, excessive levels of ROS stress can also be toxic to the cells and cancer cells with increased oxidative stress are likely to be more vulnerable to damage by further ROS insults induced by exogenous agents, such as phytocompounds and therapeutic agents. Therefore, redox modulation is a way to selectively kill cancer cells without causing significant toxicity to normal cells. However, use of antioxidants together with cancer drugs may risk the effect of treatment as both act through opposite mechanisms. Future Directions: It is advisable to employ more thorough and detailed methodologies to undertake mechanistic explorations of numerous phytocompounds. Moreover, conducting additional clinical studies is recommended to establish optimal dosages, efficacy, and the impact of different phytochemicals on PPAR-ß/δ.
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Neoplasias , Oxidación-Reducción , PPAR-beta , Fitoquímicos , Especies Reactivas de Oxígeno , Transducción de Señal , Humanos , Especies Reactivas de Oxígeno/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Oxidación-Reducción/efectos de los fármacos , PPAR-beta/metabolismo , Transducción de Señal/efectos de los fármacos , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Fitoquímicos/química , PPAR delta/metabolismo , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Estrés Oxidativo/efectos de los fármacosRESUMEN
ABSTRACT Background: Sleep disorders induce anxiety and forgetfulness and change habits. The chemical hypnotic drugs currently used have serious side effects and, therefore, people are drawn towards using natural compounds such as plant-based healing agents. Abscisic acid (ABA) is produced in a variety of mammalian tissues and it is involved in many neurophysiological functions. Objective: To investigate the possible effect of ABA on pentobarbital-induced sleep and its possible signaling through GABA-A and PPAR (γ and β) receptors, in male Wistar rats. Methods: The possible effect of ABA (5 and 10 µg/rat, intracerebroventricularly) on sleep onset latency time and duration was evaluated in a V-maze model of sleep. Pentobarbital sodium (40 mg/kg, intraperitoneally) was injected to induce sleep 30 min after administration of ABA. PPARβ (GSK0660, 80 nM/rat), PPARγ (GW9662, 3 nM/rat) or GABA-A receptor (bicuculline, 6 µg/rat) antagonists were given 15 min before ABA injection. Diazepam (2 mg/kg, intraperitoneally) was used as a positive control group. Results: ABA at 5 µg significantly boosted the pentobarbital-induced subhypnotic effects and promoted induction of sleep onset in a manner comparable to diazepam treatment. Furthermore, pretreatment with bicuculline significantly abolished the ABA effects on sleep parameters, while the amplifying effects of ABA on the induction of sleep onset was not significantly affected by PPARβ or PPARγ antagonists. The sleep prolonging effect of ABA was significantly prevented by both PPAR antagonists. Conclusions: The data showed that ABA boosts pentobarbital-induced sleep and that GABA-A, PPARβ and PPARγ receptors are, at least in part, involved in ABA signaling.
RESUMO Introdução: Os distúrbios do sono induzem a ansiedade e esquecimento e mudam hábitos. Os medicamentos hipnóticos químicos utilizados atualmente têm efeitos colaterais graves e, portanto, as pessoas são atraídas para o uso de compostos naturais, como agentes de cura à base de plantas. O ácido abscísico (ABA) é produzido em uma variedade de tecidos de mamíferos e está envolvido em muitas funções neurofisiológicas. Objetivo: Investigar o possível efeito do ABA no sono induzido por pentobarbital e sua possível sinalização por meio dos receptores GABA-A e PPAR (γ e β), em ratos Wistar machos. Métodos: O possível efeito do ABA (5 e 10 µg/rato, intracerebroventricularmente) no tempo de latência e duração do início do sono foi avaliado em um modelo de labirinto em V de sono. Pentobarbital sódico (40 mg/kg, intraperitonealmente) foi injetado para induzir o sono 30 minutos após a administração de ABA. PPARβ (GSK0660, 80 nM/rato), PPARγ (GW9662, 3 nM/rato) ou antagonistas do receptor GABA-A (bicuculina, 6 µg/rato) foram administrados 15 minutos antes da injeção de ABA. Diazepam (2 mg/kg, intraperitonealmente) foi utilizado como grupo de controle positivo. Resultados: ABA a 5 µg aumentou significativamente os efeitos sub-hipnóticos induzidos por pentobarbital e promoveu a indução do início do sono de forma comparável ao tratamento com diazepam. Além disso, o pré-tratamento com bicuculina aboliu significativamente os efeitos do ABA nos parâmetros do sono, ao passo que os efeitos amplificadores do ABA na indução do início do sono não foram significativamente afetados pelos antagonistas do PPARβ ou PPARγ. O efeito de prolongamento do sono do ABA foi significativamente prevenido por ambos os antagonistas do PPAR. Conclusões: Os dados mostraram que o ABA estimula o sono induzido por pentobarbital e que os receptores GABA-A, PPARβ e PPARγ estão, pelo menos em parte, envolvidos na sinalização ABA.
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Animales , Masculino , Ratas , Sueño , Ácido Abscísico/farmacología , Receptores de GABA-A/metabolismo , PPAR-beta/metabolismo , PPAR gamma/metabolismo , Pentobarbital/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Transducción de Señal , Ratas WistarRESUMEN
Abstract Background: Oxidative stress and inflammation are present in coronary artery disease (CAD) and are linked to the activation of the transcription nuclear factor kappa B (NF-κB). To attenuate these complications, transcription factors like nuclear factor erythroid 2-related factor 2 (Nrf2) and peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) can be activated to inhibit NF-κB. However, the available data on expression of NF-κB, Nrf2 and PPARβ/δ in CAD patients are limited. Objective: To evaluate the expression of the transcription factors NF-κB and Nrf2 and PPAR/ in CAD patients. Methods: Thirty-five patients (17 men, mean age 62.4 ? 7.55 years) with CAD and twelve patients (5 men, mean age 63.50 ? 11.46 years) without CAD were enrolled. Peripheral blood mononuclear cells (PBMCs) were isolated and processed for mRNA expression of Nrf2, NF-κB, NADPH: quinone oxidoreductase 1 (NQO1) and PPARβ/δ mRNAs using quantitative real-time polymerase chain reaction (qPCR). p < 0.05 was considered statistically significant. Results: There was no difference in the mRNA expressions of Nrf2 (1.35 ? 0.57), NF-κB (1.08 ? 0.50) or in the antioxidant enzyme NQO1 (1.05 ? 0.88) in the CAD group compared to the group without CAD (1.16 ? 0.76, 0.95 ? 0.33, 0.81 ? 0.55, respectively). However, PPARβ/δ was highest expressed in the CAD group (1.17 ? 0.86 vs. 0.56 ? 0.34, p = 0.008). Conclusion: The main finding of this study was the PPARβ/δ being more expressed in the PBMC of patients with CAD compared to the control group, whereas no differences were observed in Nrf2 or NF-κB mRNA expressions.
Resumo Fundamentos: O estresse oxidativo e a inflamação estão presentes na doença arterial coronariana (DAC) e estão ligados à ativação do fator de transcrição nuclear kappa B (NF-κB). Para atenuar essas complicações, fatores de transcrição como o fator nuclear eritroide 2-relacionado ao fator 2 (Nrf2) e o receptor ativado por proliferador de peroxissoma β/δ (PPARβ/δ) podem ser ativados para inibir o NF-κB. No entanto, os dados disponíveis sobre a expressão de NF-κB, Nrf2 e PPARβ/δ em pacientes com DAC são limitados. Objetivo: Avaliar a expressão dos fatores transcricionais NF-κB e Nrf2 e o PPARβ/δ em pacientes com DAC. Métodos: Trinta e cinco pacientes (17 homens, idade média de 62,4 ± 7,55 anos) com DAC e doze pacientes (5 homens, com idade média de 63,50 ± 11,46 anos) sem DAC foram incluídos. Células mononucleares do sangue periférico (PBMCs) foram isoladas e processadas para a expressão de mRNA do Nrf2, NF-κB, NADPH: quinona oxidoredutase 1 (NQO1) e mRNAs do PPARβ/δ por meio de reação em cadeia da polimerase quantitativa em tempo real (qPCR). Valores de p < 0,05 foram considerados como estatisticamente significativos. Resultados: Não houve diferença nas expressões de mRNA do Nrf2 (1,35 ± 0,57), NF-κB (1,08 ± 0,50) ou na enzima antioxidante NQO1 (1,05 ± 0,88) no grupo DAC em comparação com o grupo sem DAC (1,16 ± 0,76, 0,95 ± 0,33, 0,81 ± 0,55, respectivamente). Entretanto, o PPARβ/δ apresentou maior expressão no grupo com DAC (1,17 ± 0,86 vs. 0,56 ± 0,34, p = 0,008). Conclusão: O principal achado do presente estudo foi o PPARβ/δ apresentar maior expressão nas PBMCs de pacientes com DAC comparados ao grupo controle, ao passo que não foram observadas diferenças nas expressões de mRNA do Nrf2 ou NF-κB.
Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Enfermedad de la Arteria Coronaria/metabolismo , ARN Mensajero/metabolismo , FN-kappa B/metabolismo , PPAR-beta/metabolismo , PPAR delta/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Biomarcadores/metabolismo , Índice de Masa Corporal , Regulación de la Expresión Génica , Reacción en Cadena de la Polimerasa , Estrés Oxidativo , Inflamación/metabolismoRESUMEN
The very low-density lipoprotein receptor (VLDLR) plays an important function in the control of serum triglycerides and in the development of non-alcoholic fatty liver disease (NAFLD). In this study, we investigated the role of peroxisome proliferator-activated receptor (PPAR)ß/δ activation in hepatic VLDLR regulation. Treatment of mice fed a high-fat diet with the PPARß/δ agonist GW501516 increased the hepatic expression of Vldlr. Similarly, exposure of human Huh-7 hepatocytes to GW501516 increased the expression of VLDLR and triglyceride accumulation, the latter being prevented by VLDLR knockdown. Finally, treatment with another PPARß/δ agonist increased VLDLR levels in the liver of wild-type mice, but not PPARß/δ-deficient mice, confirming the regulation of hepatic VLDLR by this nuclear receptor. Our results suggest that upregulation of hepatic VLDLR by PPARß/δ agonists might contribute to the hypolipidemic effect of these drugs by increasing lipoprotein delivery to the liver. Overall, these findings provide new effects by which PPARß/δ regulate VLDLR levels and may influence serum triglyceride levels and NAFLD development
El receptor de las lipoproteínas de muy baja densidad (VLDLR) desempeña una función muy importante en el control de los niveles de triglicéridos séricos y en el desarrollo de la enfermedad del hígado graso no alcohólico (EHGNA). En este estudio hemos investigado el papel de la activación del receptor activado por los proliferadores peroxisómicos (PPAR)ß/δ en la regulación hepática del VLDLR. El tratamiento de ratones alimentados con una dieta rica en grasas con el agonista PPARß/δ GW501516 aumentó la expresión hepática de Vldlr. Asimismo, la exposición de hepatocitos humanos Huh-7 a GW501516 aumentó la expresión de VLDLR y la acumulación de triglicéridos, siendo este ultimo aumento evitado por el knockdown de VLDLR. Finalmente, el tratamiento con otro agonista PPARß/δ incrementó los niveles de VLDLR en el hígado de ratones wild-type, pero no en el de ratones deficientes en PPARß/δ, confirmando la regulación del VLDLR hepático por este receptor. En conjunto, nuestros resultados proporcionan un nuevo efecto por el que PPARß/δ regula los niveles de VLDLR y puede influenciar los niveles de triglicéridos séricos así como el desarrollo de la EHGNA
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Animales , Ratones , PPAR-beta/efectos de los fármacos , PPAR-beta/metabolismo , Hepatocitos/metabolismo , Lipoproteínas VLDL/agonistas , Lipoproteínas VLDL/metabolismo , Grasas de la Dieta , Triglicéridos/metabolismo , Western Blotting , Análisis de Varianza , PPAR-beta/farmacologíaRESUMEN
Este trabalho teve o objetivo de estudar o efeito de medicamentos com diferentes ações agonista PPAR (rosiglitazona, fenofibrato e bezafibrato) sobre o perfil lipídico, glicídico e alterações na massa corporal e morfologia do tecido adiposo e pancreático em modelo de diabetes e sobrepeso induzido por dieta. Camundongos C57BL/6 (2 meses de idade) foram alimentados com dieta padrão (SC, n=10) ou dieta hiperlipídica rica em sacarose (HFHS, n=40) por 6 semanas. Logo após, os animais HFHS foram subdividos em: HFHS não tratado e HFHS tratado com rosiglitazona (HFHS-Ro), fenofibrato (HFHS-Fe) ou bezafibrato (HFHS-BZ) (5 semanas). Os camundongos alimentados com dieta HFHS apresentaram maior glicemia e insulina de jejum (+33% e +138%, respectivamente), intolerância à glicose, resistência à insulina, aumento da massa corporal (MC) (+20%) e adiposidade, hipertrofia de adipócitos e redução da imunocoloração para adiponectina no tecido adiposo. No pâncreas houve aumento da massa (+28%), acúmulo de gordura (+700%), hipertrofia da ilhota (+38%) e redução da imunocoloração para GLUT-2 (-60%). A rosiglitazona diminuiu a glicemia e insulina de jejum, porém induziu o ganho de MC e hipertrofia cardíaca. O fenofibrato estabilizou a MC, enquanto o bezafibrato levou a perda de MC. Apenas o bezafibrato impediu a hipertrofia da ilhota. A imunocoloração para GLUT-2 foi aumentada por todos os medicamentos, e não houve alterações na imunocoloração para o PPARalfa. Sinais morfológicos de pancreatite foram vistos no grupo HFHS-Fe, apesar dos níveis normais de amilase e lipase séricos. A rosiglitazona exacerbou a infiltração intrapancreática de gordura (+75% vs. HFHS), e o bezafibrato aumentou a imunocoloração para o PPARbeta/delta nas ilhotas pancreáticas. Em conclusão, o bezafibrato apresentou um efeito mais amplo sobre as alterações metabólicas, morfológicas e biométricas decorrentes da dieta HFHS, sugerindo que a inibição das três isoformas do PPAR seria melhor do que a inibição...
This work aimed to evaluate the effect of peroxisome proliferator-activated receptor (PPAR) agonists (rosiglitazone, fenofibrate and bezafibrate) on lipid and glucose metabolism, body mass, and adipose and pancreatic tissue morphology in a model of diet-induced type 2 diabetes and overweight in mice. Two-month-old male C57BL/6 mice were fed a standard chow (SC, n=10) or a high-fat high-sucrose chow (HFHS, n=40) for 6 weeks, and then HFHS-fed mice were subdivided by treatment: untreated HFHS and HFHS treated with rosiglitazone (HFHS-Ro), fenofibrate (HFHS-Fe), or bezafibrate (HFHS-Bz) (5 weeks on medication). HFHS-fed mice have altered fasting glucose (+33%) and insulin (+138%), GI, IR, increased body mass (+20%) and fat pad weight, adipocyte hypertrophy, and decreased adiponectin immunostain. They also presented increased pancreatic (+28%) mass, intrapancreatic fat (+700%), islet hypertrophy (+38%), and decreased GLUT-2 immunostain (-60%). Rosiglitazone reduced fasting glucose and insulin but induced weight gain and heart hypertrophy. Fenofibrate impaired body mass gain, while bezafibrate induced weight loss. Only bezafibrate impaired islet hypertrophy. GLUT-2 immunostain was improved by all treatments, and there were no alterations in PPAR-alfa stain. There were morphological signs of pancreatitis in fenofibrate-treated mice, although there was no alteration in serum amylase and lipase. Rosiglitazone exacerbated pancreatic fat infiltration (+75% vs. HFHS group), and bezafibrate increased PPAR-beta expression in pancreatic islets. In conclusion, bezafibrate showed a wider range of action on metabolic, morphologic, and biometric alterations due to HFHS intake, suggesting that inhibiting the three PPAR isoforms is better than inhititing each isoform alone. Rosiglitazone exacerbated body mass gain, pancreatic fat infiltration and induced heart hyperthophy as well, thus, precaution has to be taken in prescribing rosiglitazone to obese patients.