RESUMO
The role of astroglial and microglial cells in the pathogenesis of epilepsy is currently under active investigation. It has been proposed that the activity of these cells may be regulated by the agonists of peroxisome proliferator-activated nuclear receptors (PPARs). This study investigated the effects of a seven-day treatment with the PPAR ß/δ agonist GW0742 (Fitorine, 5 mg/kg/day) on the behavior and gene expression of the astroglial and microglial proteins involved in the regulation of epileptogenesis in the rat brain within a lithium-pilocarpine model of temporal lobe epilepsy (TLE). TLE resulted in decreased social and increased locomotor activity in the rats, increased expression of astro- and microglial activation marker genes (Gfap, Aif1), pro- and anti-inflammatory cytokine genes (Tnfa, Il1b, Il1rn), and altered expression of other microglial (Nlrp3, Arg1) and astroglial (Lcn2, S100a10) genes in the dorsal hippocampus and cerebral cortex. GW0742 attenuated, but did not completely block, some of these impairments. Specifically, the treatment affected Gfap gene expression in the dorsal hippocampus and Aif1 gene expression in the cortex. The GW0742 injections attenuated the TLE-specific enhancement of Nlrp3 and Il1rn gene expression in the cortex. These results suggest that GW0742 may affect the expression of some genes involved in the regulation of epileptogenesis.
Assuntos
Astrócitos , Modelos Animais de Doenças , Epilepsia do Lobo Temporal , Microglia , PPAR delta , PPAR beta , Tiazóis , Animais , Microglia/efeitos dos fármacos , Microglia/metabolismo , Epilepsia do Lobo Temporal/tratamento farmacológico , Epilepsia do Lobo Temporal/genética , Epilepsia do Lobo Temporal/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Ratos , PPAR delta/agonistas , PPAR delta/genética , PPAR delta/metabolismo , Masculino , Tiazóis/farmacologia , Tiazóis/uso terapêutico , PPAR beta/agonistas , PPAR beta/genética , PPAR beta/metabolismo , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Pilocarpina/farmacologia , Citocinas/metabolismo , Citocinas/genética , Fenóis , Compostos de SulfidrilaRESUMO
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung epithelial phenotypes, fibroblast activation, and increased extracellular matrix deposition. Transforming growth factor-beta (TGF-ß)1-induced Smad signaling and downregulation of peroxisomal genes are involved in the pathogenesis and can be inhibited by peroxisome proliferator-activated receptor (PPAR)-α activation. However, the three PPARs, that is PPAR-α, PPAR-ß/δ, and PPAR-γ, are known to interact in a complex crosstalk. METHODS: To mimic the pathogenesis of lung fibrosis, primary lung fibroblasts from control and IPF patients with comparable levels of all three PPARs were treated with TGF-ß1 for 24 h, followed by the addition of PPAR ligands either alone or in combination for another 24 h. Fibrosis markers (intra- and extracellular collagen levels, expression and activity of matrix metalloproteinases) and peroxisomal biogenesis and metabolism (gene expression of peroxisomal biogenesis and matrix proteins, protein levels of PEX13 and catalase, targeted and untargeted lipidomic profiles) were analyzed after TGF-ß1 treatment and the effects of the PPAR ligands were investigated. RESULTS: TGF-ß1 induced the expected phenotype; e.g. it increased the intra- and extracellular collagen levels and decreased peroxisomal biogenesis and metabolism. Agonists of different PPARs reversed TGF-ß1-induced fibrosis even when given 24 h after TGF-ß1. The effects included the reversals of (1) the increase in collagen production by repressing COL1A2 promoter activity (through PPAR-ß/δ activation); (2) the reduced activity of matrix metalloproteinases (through PPAR-ß/δ activation); (3) the decrease in peroxisomal biogenesis and lipid metabolism (through PPAR-γ activation); and (4) the decrease in catalase protein levels in control (through PPAR-γ activation) and IPF (through a combined activation of PPAR-ß/δ and PPAR-γ) fibroblasts. Further experiments to explore the role of catalase showed that an overexpression of catalase protein reduced collagen production. Additionally, the beneficial effect of PPAR-γ but not of PPAR-ß/δ activation on collagen synthesis depended on catalase activity and was thus redox-sensitive. CONCLUSION: Our data provide evidence that IPF patients may benefit from a combined activation of PPAR-ß/δ and PPAR-γ.
Assuntos
Fibrose Pulmonar Idiopática , PPAR delta , PPAR gama , PPAR beta , Humanos , Fibrose Pulmonar Idiopática/metabolismo , Fibrose Pulmonar Idiopática/patologia , Fibrose Pulmonar Idiopática/genética , PPAR gama/metabolismo , PPAR gama/genética , PPAR beta/metabolismo , PPAR beta/genética , PPAR beta/agonistas , Células Cultivadas , PPAR delta/metabolismo , PPAR delta/genética , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibroblastos/efeitos dos fármacos , Peroxissomos/metabolismo , Peroxissomos/efeitos dos fármacos , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Masculino , Fator de Crescimento Transformador beta1/metabolismo , FemininoRESUMO
Leptin, acting centrally or peripherally, has complex effects on cardiac remodeling and heart function. We previously reported that central leptin exerts an anti-hypertrophic effect in the heart via cardiac PPARß/δ activation. Here, we assessed the impact of central leptin administration and PPARß/δ inhibition on cardiac function. Various cardiac properties, including QRS duration, R wave amplitude, heart rate (HR), ejection fraction (EF), end-diastolic left ventricular mass (EDLVM), end-diastolic volume (EDV), and cardiac output (CO) were analyzed. Central leptin infusion increased cardiac PPARß/δ protein content and decreased HR, QRS duration, and R wave amplitude. These changes induced by central leptin suggested a decrease in the ventricular wall growth, which was confirmed by MRI. In fact, the EDLVM was reduced by central leptin while increased in rats co-treated with leptin and GSK0660, a selective antagonist of PPARß/δ activity. In summary, central leptin plays a dual role in cardiac health, potentially leading to ventricular atrophy and improving heart function when PPARß/δ signaling is intact. The protective effects of leptin are lost by PPARß/δ inhibition, underscoring the importance of this pathway. These findings highlight the therapeutic potential of targeting leptin and PPARß/δ pathways to combat cardiac alterations and heart failure, particularly in the context of obesity.
Assuntos
Leptina , PPAR delta , PPAR beta , Animais , Leptina/farmacologia , Leptina/metabolismo , PPAR beta/metabolismo , PPAR beta/agonistas , PPAR delta/metabolismo , PPAR delta/agonistas , Ratos , Masculino , Coração/efeitos dos fármacos , Ratos Wistar , Atrofia , Frequência Cardíaca/efeitos dos fármacos , Miocárdio/metabolismo , Miocárdio/patologia , Sulfonas , TiofenosRESUMO
The formation of memory T cells is a fundamental feature of adaptative immunity, allowing the establishment of long-term protection against pathogens. Although emerging evidence suggests that metabolic reprogramming is crucial for memory T cell differentiation and survival, the underlying mechanisms that drive metabolic rewiring in memory T cells remain unclear. Here, we found that up-regulation of the nuclear receptor peroxisome proliferator-activated receptor ß/δ (PPARß/δ) instructs the metabolic reprogramming that occurs during the establishment of central memory CD8+ T cells. PPARß/δ-regulated changes included suppression of aerobic glycolysis and enhancement of oxidative metabolism and fatty acid oxidation. Mechanistically, exposure to interleukin-15 and expression of T cell factor 1 facilitated activation of the PPARß/δ pathway, counteracting apoptosis induced by antigen clearance and metabolic stress. Together, our findings indicate that PPARß/δ is a master metabolic regulator orchestrating a metabolic switch that may be favorable for T cell longevity.
Assuntos
Linfócitos T CD8-Positivos , Camundongos Endogâmicos C57BL , PPAR delta , PPAR beta , Animais , PPAR beta/metabolismo , PPAR beta/imunologia , Linfócitos T CD8-Positivos/imunologia , PPAR delta/imunologia , PPAR delta/metabolismo , Camundongos , Memória Imunológica/imunologia , Células T de Memória/imunologia , Camundongos Knockout , Interleucina-15/imunologia , Interleucina-15/metabolismo , Camundongos Transgênicos , Reprogramação Metabólica , Receptores Citoplasmáticos e NuclearesRESUMO
The role of peroxisome proliferator-activated receptor (PPAR)ß/δ in hepatic fibrosis remains a subject of debate. Here, we examined the effects of a PPARß/δ agonist on the pathogenesis of liver fibrosis and the activation of hepatic stellate cells (HSCs), the main effector cells in liver fibrosis, in response to the pro-fibrotic stimulus transforming growth factor-ß (TGF-ß). The PPARß/δ agonist GW501516 completely prevented glucose intolerance and peripheral insulin resistance, blocked the accumulation of collagen in the liver, and attenuated the expression of inflammatory and fibrogenic genes in mice fed a choline-deficient high-fat diet (CD-HFD). The antifibrogenic effect of GW501516 observed in the livers CD-HFD-fed mice could occur through an action on HSCs since primary HSCs isolated from Ppard-/- mice showed increased mRNA levels of the profibrotic gene Col1a1. Moreover, PPARß/δ activation abrogated TGF-ß1-mediated cell migration (an indicator of cell activation) in LX-2 cells (immortalized activated human HSCs). Likewise, GW501516 attenuated the phosphorylation of the main downstream intracellular protein target of TGF-ß1, suppressor of mothers against decapentaplegic (SMAD)3, as well as the levels of the SMAD3 co-activator p300 via the activation of AMP-activated protein kinase (AMPK) and the subsequent inhibition of extracellular signal-regulated kinase-1/2 (ERK1/2) in LX-2 cells. Overall, these findings uncover a new mechanism by which the activation of AMPK by a PPARß/δ agonist reduces TGF-ß1-mediated activation of HSCs and fibrosis via the reduction of both SMAD3 phosphorylation and p300 levels.
Assuntos
Proteínas Quinases Ativadas por AMP , Proteína p300 Associada a E1A , Células Estreladas do Fígado , Cirrose Hepática , Camundongos Endogâmicos C57BL , PPAR delta , PPAR beta , Proteína Smad3 , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/patologia , Animais , Fosforilação/efeitos dos fármacos , PPAR beta/agonistas , PPAR beta/metabolismo , PPAR beta/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , PPAR delta/metabolismo , PPAR delta/agonistas , PPAR delta/genética , Proteína Smad3/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Proteína p300 Associada a E1A/metabolismo , Masculino , Camundongos , Humanos , Tiazóis/farmacologia , Dieta Hiperlipídica/efeitos adversos , Camundongos Knockout , Resistência à Insulina , Linhagem Celular , Fator de Crescimento Transformador beta1/metabolismoRESUMO
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.
Assuntos
Endométrio , Inflamação , Lipopolissacarídeos , PPAR delta , PPAR beta , Animais , Feminino , Suínos , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , PPAR delta/genética , PPAR delta/metabolismo , PPAR beta/metabolismo , PPAR beta/genética , Inflamação/induzido quimicamente , Fenoxiacetatos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , TranscriptomaRESUMO
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.
Assuntos
Queratinócitos , PPAR delta , PPAR beta , Estearoil-CoA Dessaturase , Queratinócitos/metabolismo , Queratinócitos/efeitos dos fármacos , PPAR beta/metabolismo , PPAR beta/genética , Animais , Camundongos , Estearoil-CoA Dessaturase/metabolismo , Estearoil-CoA Dessaturase/genética , PPAR delta/metabolismo , PPAR delta/genética , Ácidos Graxos/metabolismo , Proteína 4 Semelhante a Angiopoietina/metabolismo , Proteína 4 Semelhante a Angiopoietina/genética , Humanos , Ácido Oleico/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ácidos Graxos Monoinsaturados/farmacologia , Ácidos Graxos Monoinsaturados/metabolismo , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologiaRESUMO
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.
Assuntos
Células-Tronco Mesenquimais , Camundongos Endogâmicos C57BL , Osteoporose , PPAR beta , Via de Sinalização Wnt , Animais , Via de Sinalização Wnt/efeitos dos fármacos , Osteoporose/tratamento farmacológico , PPAR beta/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Feminino , Camundongos , Osteogênese/efeitos dos fármacos , Ovariectomia , Saponinas/farmacologia , Proteína Morfogenética Óssea 2/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Cromonas , Sulfonas , TiofenosRESUMO
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.
Assuntos
Hepatopatias , PPAR delta , PPAR beta , Humanos , PPAR beta/fisiologia , PPAR beta/metabolismo , PPAR delta/fisiologia , PPAR delta/metabolismo , Hepatopatias/metabolismo , Hepatopatias/tratamento farmacológico , Terapia de Alvo Molecular , Resistência à InsulinaRESUMO
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.
Assuntos
Camundongos Knockout , Desenvolvimento Muscular , Músculo Esquelético , PPAR delta , PPAR beta , Extratos Vegetais , Ácido Quínico , Animais , Camundongos , Ácido Quínico/análogos & derivados , Ácido Quínico/farmacologia , Extratos Vegetais/farmacologia , PPAR beta/metabolismo , PPAR beta/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/efeitos dos fármacos , Desenvolvimento Muscular/efeitos dos fármacos , PPAR delta/metabolismo , PPAR delta/genética , Masculino , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Humanos , Proteína MyoD/metabolismo , Proteína MyoD/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Camundongos Endogâmicos C57BL , Proteínas Quinases Ativadas por AMP/metabolismoRESUMO
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.
Assuntos
Neoplasias , Oxirredução , PPAR beta , Compostos Fitoquímicos , Espécies Reativas de Oxigênio , Transdução de Sinais , Humanos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Oxirredução/efeitos dos fármacos , PPAR beta/metabolismo , Transdução de Sinais/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Compostos Fitoquímicos/química , PPAR delta/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Estresse Oxidativo/efeitos dos fármacosRESUMO
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.
Assuntos
Diferenciação Celular , Oligodendroglia , Valeratos , Animais , Valeratos/farmacologia , Camundongos , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Precursoras de Oligodendrócitos/efeitos dos fármacos , Células Precursoras de Oligodendrócitos/metabolismo , Células Cultivadas , Camundongos Endogâmicos C57BL , Camundongos Knockout , PPAR beta/metabolismo , PPAR beta/agonistasRESUMO
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.
Assuntos
Síndromes Mielodisplásicas , PPAR delta , PPAR beta , Humanos , Relevância Clínica , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , PPAR delta/genética , PPAR delta/metabolismo , PPAR beta/genética , PPAR beta/metabolismo , TretinoínaRESUMO
BACKGROUND: Activation of mast cells plays an important role in brain inflammation. CD300a, an inhibitory receptor located on mast cell surfaces, has been reported to reduce the production of pro-inflammatory cytokines and exert protective effects in inflammation-related diseases. Peroxisome proliferator-activated receptor ß/δ (PPARß/δ), a ligand-activated nuclear receptor, activation upregulates the transcription of CD300a. In this study, we aim to investigate the role of PPARß/δ in the attenuation of germinal matrix hemorrhage (GMH)-induced mast cell activation via CD300a/SHP1 pathway. METHODS: GMH model was induced by intraparenchymal injection of bacterial collagenase into the right hemispheric ganglionic eminence in P7 Sprague Dawley rats. GW0742, a PPARß/δ agonist, was administered intranasally at 1 h post-ictus. CD300a small interfering RNA (siRNA) and PPARß/δ siRNA were injected intracerebroventricularly 5 days and 2 days before GMH induction. Behavioral tests, Western blot, immunofluorescence, Toluidine Blue staining, and Nissl staining were applied to assess post-GMH evaluation. RESULTS: Results demonstrated that endogenous protein levels of PPARß/δ and CD300a were decreased, whereas chymase, tryptase, IL-17A and transforming growth factor ß1 (TGF-ß1) were elevated after GMH. GMH induced significant short- and long-term neurobehavioral deficits in rat pups. GW0742 decreased mast cell degranulation, improved neurological outcomes, and attenuated ventriculomegaly after GMH. Additionally, GW0742 increased expression of PPARß/δ, CD300a and phosphorylation of SHP1, decreased phosphorylation of Syk, chymase, tryptase, IL-17A and TGF-ß1 levels. PPARß/δ siRNA and CD300a siRNA abolished the beneficial effects of GW0742. CONCLUSIONS: GW0742 inhibited mast cell-induced inflammation and improved neurobehavior after GMH, which is mediated by PPARß/δ/CD300a/SHP1 pathway. GW0742 may serve as a potential treatment to reduce brain injury for GMH patients.
Assuntos
PPAR delta , PPAR beta , Humanos , Ratos , Animais , PPAR delta/genética , PPAR delta/metabolismo , PPAR beta/genética , PPAR beta/metabolismo , Animais Recém-Nascidos , Mastócitos/metabolismo , Quimases , Interleucina-17 , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta1 , Triptases , Hemorragia Cerebral , Tiazóis/farmacologia , Inflamação , RNA Interferente PequenoRESUMO
Di-2-ethylhexyl phthalic acid (DEHP) is one of the most widely used plasticizers in the industry, which can improve the flexibility and durability of plastics. It is prone to migrate from various daily plastic products through wear and leaching into the surrounding environment and decompose into the more toxic metabolite mono-2-ethylhexyl phthalic acid (MEHP) after entering the human body. However, the impacts and mechanisms of MEHP on neuroblastoma are unclear. We exposed MYCN-amplified neuroblastoma SK-N-BE(2)C cells to an environmentally related concentration of MEHP and found that MEHP increased the proliferation and migration ability of tumor cells. The peroxisome proliferator-activated receptor (PPAR) ß/δ pathway was identified as a pivotal signaling pathway in neuroblastoma, mediating the effects of MEHP through transcriptional sequencing analysis. Because MEHP can bind to the PPARß/δ protein and initiate the expression of the downstream gene angiopoietin-like 4 (ANGPTL4), the PPARß/δ-specific agonist GW501516 and antagonist GSK3787, the recombinant human ANGPTL4 protein, and the knockdown of gene expression confirmed the regulation of the PPARß/δ-ANGPTL4 axis on the malignant phenotype of neuroblastoma. Based on the critical role of PPARß/δ and ANGPTL4 in the metabolic process, a non-targeted metabolomics analysis revealed that MEHP altered multiple metabolic pathways, particularly lipid metabolites involving fatty acyls, glycerophospholipids, and sterol lipids, which may also be potential factors promoting tumor progression. We have demonstrated for the first time that MEHP can target binding to PPARß/δ and affect the progression of neuroblastoma by activating the PPARß/δ-ANGPTL4 axis. This mechanism confirms the health risks of plasticizers as tumor promoters and provides new data support for targeted prevention and treatment of neuroblastoma.
Assuntos
Dietilexilftalato/análogos & derivados , Neuroblastoma , PPAR delta , PPAR beta , Ácidos Ftálicos , Humanos , PPAR beta/agonistas , PPAR beta/genética , PPAR beta/metabolismo , Proteína Proto-Oncogênica N-Myc , Plastificantes/toxicidade , Angiopoietinas/genética , Angiopoietinas/metabolismo , Ácidos Ftálicos/toxicidade , Ácidos Ftálicos/metabolismo , PPAR delta/agonistas , PPAR delta/genética , PPAR delta/metabolismo , Proteína 4 Semelhante a AngiopoietinaRESUMO
Elafibranor is a dual peroxisome proliferator-activated receptor (PPAR)α and ß/δ agonist that has reached a phase III clinical trial for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we examined the effects of elafibranor in mice fed a choline-deficient high-fat diet (CD-HFD), a model of metabolic dysfunction-associated steatohepatitis (MASH) that presents obesity and insulin resistance. Our findings revealed that elafibranor treatment ameliorated steatosis, inflammation, and fibrogenesis in the livers of CD-HFD-fed mice. Unexpectedly, elafibranor also increased the levels of the epithelial-mesenchymal transition (EMT)-promoting protein S100A4 via PPARß/δ activation. The increase in S100A4 protein levels caused by elafibranor was accompanied by changes in the levels of markers associated with the EMT program. The S100A4 induction caused by elafibranor was confirmed in the BRL-3A rat liver cells and a mouse primary hepatocyte culture. Furthermore, elafibranor reduced the levels of ASB2, a protein that promotes S100A4 degradation, while ASB2 overexpression prevented the stimulating effect of elafibranor on S100A4. Collectively, these findings reveal an unexpected hepatic effect of elafibranor on increasing S100A4 and promoting the EMT program.
Assuntos
Hepatopatia Gordurosa não Alcoólica , PPAR delta , PPAR beta , Animais , Camundongos , Ratos , Dieta Hiperlipídica , Transição Epitelial-Mesenquimal , Fígado , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR delta/metabolismo , PPAR beta/agonistas , PPAR beta/metabolismo , PPAR beta/uso terapêuticoRESUMO
BACKGROUND AND AIMS: Hepatic ischaemia/reperfusion injury (HIRI) is a pathophysiological process that occurs during the liver resection and transplantation. Reportedly, peroxisome proliferator-activated receptor ß/δ (PPARß/δ) can ameliorate kidney and myocardial ischaemia/reperfusion injury. However, the effect of PPARß/δ in HIRI remains unclear. METHODS: Mouse hepatic ischaemia/reperfusion (I/R) models were constructed for in vivo study. Primary hepatocytes and Kupffer cells (KCs) isolated from mice and cell anoxia/reoxygenation (A/R) injury model were constructed for in vitro study. Liver injury and inflammation were investigated. Small molecular compounds (GW0742 and GSK0660) and adenoviruses were used to interfere with PPARß/δ. RESULTS: We found that PPARß/δ expression was increased in the I/R and A/R models. Overexpression of PPARß/δ in hepatocytes alleviated A/R-induced cell apoptosis, while knockdown of PPARß/δ in hepatocytes aggravated A/R injury. Activation of PPARß/δ by GW0742 protected against I/R-induced liver damage, inflammation and cell death, whereas inhibition of PPARß/δ by GSK0660 had the opposite effects. Consistent results were obtained in mouse I/R models through the tail vein injection of adenovirus-mediated PPARß/δ overexpression or knockdown vectors. Furthermore, knockdown and overexpression of PPARß/δ in KCs aggravated and ameliorated A/R-induced hepatocyte injury, respectively. Gene ontology and gene set enrichment analysis showed that PPARß/δ deletion was significantly enriched in the NF-κB pathway. PPARß/δ inhibited the expression of p-IKBα and p-P65 and decreased NF-κB activity. CONCLUSIONS: PPARß/δ exerts anti-inflammatory and anti-apoptotic effects on HIRI by inhibiting the NF-κB pathway, and hepatocytes and KCs may play a synergistic role in this phenomenon. Thus, PPARß/δ is a potential therapeutic target for HIRI.
Assuntos
PPAR delta , PPAR beta , Traumatismo por Reperfusão , Camundongos , Animais , PPAR beta/genética , PPAR beta/metabolismo , NF-kappa B/metabolismo , PPAR delta/genética , PPAR delta/metabolismo , Fígado/metabolismo , Tiazóis/farmacologia , Inflamação , Modelos Animais de Doenças , Traumatismo por Reperfusão/prevenção & controle , IsquemiaRESUMO
There is great interest on medium chain fatty acids (MCFA) for cardiovascular health. We explored the effects of MCFA on the expression of lipid metabolism and inflammatory genes in macrophages, and the extent to which they were mediated by the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPAR ß/δ). J774A.1 murine macrophages were exposed to octanoate or decanoate as MCFA, a long-chain fatty acid control (palmitate), or the PPAR ß/δ agonist GW501516, with or without lipopolysaccharide (LPS) stimulation, and with or without an siRNA-induced knockdown of PPAR ß/δ. MCFA increased the expression of Plin2, encoding a lipid-droplet associated protein with anti-inflammatory effects in macrophages, in a partially PPAR ß/δ-dependent manner. Both MCFA stimulated expression of the cholesterol efflux pump ABCA1, more pronouncedly under LPS stimulation and in the absence of PPAR ß/δ. Octanoate stimulated the expression of Pltp, encoding a phospholipid transfer protein that aids ABCA1 in cellular lipid efflux. Only palmitate increased expression of the proinflammatory genes Il6, Tnf, Nos2 and Mmp9. Non-stimulated macrophages exposed to MCFA showed less internalization of fluorescently labeled lipoproteins. MCFA influenced the transcriptional responses of macrophages favoring cholesterol efflux and a less inflammatory response compared to palmitate. These effects were partially mediated by PPAR ß/δ.
Assuntos
PPAR delta , PPAR beta , Camundongos , Animais , PPAR delta/metabolismo , PPAR beta/genética , PPAR beta/metabolismo , Caprilatos/farmacologia , Linhagem Celular , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Ácidos Graxos/farmacologia , Colesterol/metabolismo , Palmitatos/farmacologiaRESUMO
Evidence is mounting that sinomenine and peroxisome proliferator-activated receptor ß/δ (PPARß/δ) are effective against lipopolysaccharide (LPS)-induced acute lung injury (ALI) via anti-inflammatory properties. However, it is unknown whether PPARß/δ plays a role in the protective effect of sinomenine on ALI. Here, we initially observed that preemptive administration of sinomenine markedly alleviated lung pathological changes, pulmonary edema and neutrophil infiltration, accompanied by inhibition of the expression of the pro-inflammatory cytokines Tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6), which were largely reversed following the addition of a PPARß/δ antagonist. Subsequently, we also noticed that sinomenine upregulated adenosine A2A receptor expression in a PPARß/δ-dependent manner in LPS-stimulated bone marrow-derived macrophages (BMDMs). Further investigation indicated that PPARß/δ directly bound to the functional peroxisome proliferator responsive element (PPRE) in the adenosine A2A receptor gene promoter region to enhance the expression of the adenosine A2A receptor. Sinomenine was identified as a PPARß/δ agonist. It could bind with PPARß/δ, and promote the nuclear translocation and transcriptional activity of PPARß/δ. In addition, combined treatment with sinomenine and an adenosine A2A receptor agonist exhibited synergistic effects and better protective roles than their single use against ALI. Taken together, our results reveal that sinomenine exerts advantageous effects on ALI by activating of PPARß/δ, with the subsequent upregulation of adenosine A2A receptor expression, and provide a novel and potential therapeutic application for ALI.
Assuntos
Lesão Pulmonar Aguda , PPAR delta , PPAR beta , Humanos , PPAR beta/metabolismo , Lipopolissacarídeos/farmacologia , Receptor A2A de Adenosina , PPAR delta/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/genéticaRESUMO
Growing evidence suggests a role for peroxisome proliferator-activated receptor ß/δ (PPAR ß/δ) in the angiogenesis, growth, and metastasis of solid tumors, but little is known about its role in multiple myeloma (MM). Angiogenesis in the bone marrow (BM) is characteristic of disease transition from monoclonal gammopathy of undetermined significance (MGUS) to MM. We examined the expression and function of PPAR ß/δ in endothelial cells (EC) from the BM of MGUS (MGEC) and MM (MMEC) patients and showed that PPAR ß/δ was expressed at higher levels in MMEC than in MGEC and that the overexpression depended on myeloma plasma cells. The interaction between myeloma plasma cells and MMEC promoted the release of the PPAR ß/δ ligand prostaglandin I2 (PGI2) by MMEC, leading to the activation of PPAR ß/δ. We also demonstrated that PPAR ß/δ was a strong stimulator of angiogenesis in vitro and that PPAR ß/δ inhibition by a specific antagonist greatly impaired the angiogenic functions of MMEC. These findings define PGI2-PPAR ß/δ signaling in EC as a potential target of anti-angiogenic therapy. They also sustain the use of PPAR ß/δ inhibitors in association with conventional drugs as a new therapeutic approach in MM.