scholarly journals β,β-Carotene Decreases Peroxisome Proliferator Receptor γ Activity and Reduces Lipid Storage Capacity of Adipocytes in a β,β-Carotene Oxygenase 1-dependent Manner

2010 ◽  
Vol 285 (36) ◽  
pp. 27891-27899 ◽  
Author(s):  
Glenn P. Lobo ◽  
Jaume Amengual ◽  
Hua Nan M. Li ◽  
Marcin Golczak ◽  
M. Luisa Bonet ◽  
...  
Author(s):  
Serena Stopponi ◽  
Yannick Fotio ◽  
Carlo Cifani ◽  
Hongwu Li ◽  
Carolina L Haass-Koffler ◽  
...  

Abstract Background and aims Andrographis paniculata is an annual herbaceous plant which belongs to the Acanthaceae family. Extracts from this plant have shown hepatoprotective, anti-inflammatory and antidiabetic properties, at least in part, through activation of the nuclear receptor Peroxisome Proliferator-Activated Receptor-gamma (PPAR γ). Recent evidence has demonstrated that activation of PPARγ reduces alcohol drinking and seeking in Marchigian Sardinian (msP) alcohol-preferring rats. Methods The present study evaluated whether A. paniculata reduces alcohol drinking and relapse in msP rats by activating PPARγ. Results Oral administration of an A. paniculata dried extract (0, 15, 150 mg/kg) lowered voluntary alcohol consumption in a dose-dependent manner and achieved ~65% reduction at the dose of 450 mg/kg. Water and food consumption were not affected by the treatment. Administration of Andrographolide (5 and 10 mg/kg), the main active component of A. paniculata, also reduced alcohol drinking. This effect was suppressed by the selective PPARγ antagonist GW9662. Subsequently, we showed that oral administration of A. paniculata (0, 150, 450 mg/kg) prevented yohimbine- but not cues-induced reinstatement of alcohol seeking. Conclusions Results point to A. paniculata-mediated PPARγactivation as a possible therapeutic strategy to treat alcohol use disorder.


2021 ◽  
Vol 22 (8) ◽  
pp. 3829
Author(s):  
Mohamed F. Dora ◽  
Nabil M. Taha ◽  
Mohamed A. Lebda ◽  
Aml E. Hashem ◽  
Mohamed S. Elfeky ◽  
...  

Iron oxide nanoparticle (IONP) therapy has diverse health benefits but high doses or prolonged therapy might induce oxidative cellular injuries especially in the brain. Therefore, we conducted the current study to investigate the protective role of quercetin supplementation against the oxidative alterations induced in the brains of rats due to IONPs. Forty adult male albino rats were allocated into equal five groups; the control received a normal basal diet, the IONP group was intraperitoneally injected with IONPs of 50 mg/kg body weight (B.W.) and quercetin-treated groups had IONPs + Q25, IONPs + Q50 and IONPs + Q100 that were orally supplanted with quercetin by doses of 25, 50 and 100 mg quercetin/kg B.W. daily, respectively, administrated with the same dose of IONPs for 30 days. IONPs induced significant increases in malondialdehyde (MDA) and significantly decreased reduced glutathione (GSH) and oxidized glutathione (GSSG). Consequently, IONPs significantly induced severe brain tissue injuries due to the iron deposition leading to oxidative alterations with significant increases in brain creatine phosphokinase (CPK) and acetylcholinesterase (AChE). Furthermore, IONPs induced significant reductions in brain epinephrine, serotonin and melatonin with the downregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and mitochondrial transcription factor A (mtTFA) mRNA expressions. IONPs induced apoptosis in the brain monitored by increases in caspase 3 and decreases in B-cell lymphoma 2 (Bcl2) expression levels. Quercetin supplementation notably defeated brain oxidative damages and in a dose-dependent manner. Therefore, quercetin supplementation during IONPs is highly recommended to gain the benefits of IONPs with fewer health hazards.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1025
Author(s):  
Ahmed Alalaiwe ◽  
Jia-You Fang ◽  
Hsien-Ju Lee ◽  
Chun-Hui Chiu ◽  
Ching-Yun Hsu

Curcumin is a known anti-adipogenic agent for alleviating obesity and related disorders. Comprehensive comparisons of the anti-adipogenic activity of curcumin with other curcuminoids is minimal. This study compared adipogenesis inhibition with curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC), and their underlying mechanisms. We differentiated 3T3-L1 cells in the presence of curcuminoids, to determine lipid accumulation and triglyceride (TG) production. The expression of adipogenic transcription factors and lipogenic proteins was analyzed by Western blot. A significant reduction in Oil red O (ORO) staining was observed in the cells treated with curcuminoids at 20 μM. Inhibition was increased in the order of curcumin < DMC < BDMC. A similar trend was observed in the detection of intracellular TG. Curcuminoids suppressed differentiation by downregulating the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), leading to the downregulation of the lipogenic enzymes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). AMP-activated protein kinase α (AMPKα) phosphorylation was also activated by BDMC. Curcuminoids reduced the release of proinflammatory cytokines and leptin in 3T3-L1 cells in a dose-dependent manner, with BDMC showing the greatest potency. BDMC at 20 μM significantly decreased leptin by 72% compared with differentiated controls. Molecular docking computation indicated that curcuminoids, despite having structural similarity, had different interaction positions to PPARγ, C/EBPα, and ACC. The docking profiles suggested a possible interaction of curcuminoids with C/EBPα and ACC, to directly inhibit their expression.


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 679-679
Author(s):  
Quy N Diep ◽  
Rhian M Touyz ◽  
Ernesto L Schiffrin

9 Omega-3 fatty acids (n-3 FAs) exert a blood pressure-lowering effect in hypertension, possibly by influencing vascular structure. We previously demonstrated that n-3 FAs might induce vascular smooth muscle cell (VSMC) apoptosis, which could exert an effect on structure of blood vessels. This study investigated signaling pathways through which n-3 FAs mediate apoptosis in VSMCs. Cultured Mesenteric VSMCs from Sprague Dawley rats were stimulated with docosahexaenoic acid (DHA), a representative n-3 FA. Morphological changes of apoptosis and DNA fragmentation were examined by phase-contrast microscopy and fluorescence microscopy with Hoechst 33342 staining. To clarify possible pathways of apoptosis, expression of phosphorylated p38 mitogen-activated protein kinases (p38 MAPKs), bax, bcl-2, cytochrome C and peroxisome proliferator-activated receptors-α (PPARs-α) was evaluated by Western blot analysis. DHA treatment induced cell shrinkage, cell membrane blebbing and apoptotic bodies in VSMCs. DHA increased apoptosis (%) in a time-dependent manner to 1.5±0.1, 3.6±0.5, 7.1±0.4, 22.5±0.6, 50.8±1.8 and 61.4±0.9 after 0, 1, 3, 6, 17, and 24 h, respectively. DHA time-dependently activated p38 MAPKs, bax, PPARs-α and cytochrome C with maximal effects obtained after 5, 30 min, 1 h and 3 h, respectively to 551±42, 245±55, 310±12 and 407±14.7 % of controls, respectively. SB-203580 (10 -5 M) and SB-202190 (10 -5 M), selective p38 inhibitors, reduced DHA-elicited apoptosis and expression of PPARs-α, but had no effect on expression of bax or cytochrome C. The present results indicate that DHA induces apoptosis in VSMCs through at least two distinct mechanisms: (i) a p38-dependent pathway that regulates PPAR-α and (ii) a p38-independent pathway via dissipation of mitochondrial transmembrane potential. The death-signaling pathway mediated by DHA may involve an integration of these multiple pathways. By triggering VSMC apoptosis, DHA could play a pathophysiological role in vascular remodeling in cardiovascular disease.


Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3266-3276 ◽  
Author(s):  
Kim Ravnskjaer ◽  
Michael Boergesen ◽  
Blanca Rubi ◽  
Jan K. Larsen ◽  
Tina Nielsen ◽  
...  

Abstract Fatty acids (FAs) are known to be important regulators of insulin secretion from pancreatic β-cells. FA-coenzyme A esters have been shown to directly stimulate the secretion process, whereas long-term exposure of β-cells to FAs compromises glucose-stimulated insulin secretion (GSIS) by mechanisms unknown to date. It has been speculated that some of these long-term effects are mediated by members of the peroxisome proliferator-activated receptor (PPAR) family via an induction of uncoupling protein-2 (UCP2). In this study we show that adenoviral coexpression of PPARα and retinoid X receptor α (RXRα) in INS-1E β-cells synergistically and in a dose- and ligand-dependent manner increases the expression of known PPARα target genes and enhances FA uptake and β-oxidation. In contrast, ectopic expression of PPARγ/RXRα increases FA uptake and deposition as triacylglycerides. Although the expression of PPARα/RXRα leads to the induction of UCP2 mRNA and protein, this is not accompanied by reduced hyperpolarization of the mitochondrial membrane, indicating that under these conditions, increased UCP2 expression is insufficient for dissipation of the mitochondrial proton gradient. Importantly, whereas expression of PPARγ/RXRα attenuates GSIS, the expression of PPARα/RXRα potentiates GSIS in rat islets and INS-1E cells without affecting the mitochondrial membrane potential. These results show a strong subtype specificity of the two PPAR subtypes α and γ on lipid partitioning and insulin secretion when systematically compared in a β-cell context.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S27-S27
Author(s):  
Yuning Hou ◽  
Xiaonan Sun ◽  
Pooneh Gheinani ◽  
Xiaoqing Guan ◽  
Shaligram Sharma ◽  
...  

Abstract Background and Aims The expression and role of methyltransferase SET and MYND domain-containing protein 5 (SMYD5) in inflammatory bowel diseases (IBD) is completely unknown. Here, we investigated the role and the underlying mechanism of epithelial SMYD5 in IBD pathogenesis and progression. Methods The expression and subcellular localization of SMYD5 and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) were examined by Western blot analysis, immunofluorescence staining, and immunohistochemistry in intestinal epithelial cells (IECs) and in colon tissues from human IBD patients and mice with experimental colitis. Mice with Smyd5 conditional knockout in IECs and littermate controls were subjected to DSS-induced experimental colitis and the disease severity and inflammation were assessed. SMYD5-regulated mitochondrial biogenesis was examined by RT-qPCR and transmission electron microscopy and mitochondrial oxygen consumption rate was measured in a Seahorse Analyzer system. The interaction between SMYD5 and PGC-1α was determined by co-immunoprecipitation assay. PGC-1α degradation and turnover (half-life) were analyzed by cycloheximide chase assay. SMYD5-mediated PGC-1α methylation was measured via in vitro methylation followed by mass spectrometry to identify the specific lysine residues that were methylated. Results Up-regulated SMYD5 and down-regulated PGC-1α were observed in IECs from IBD patients and mice with experimental colitis. However, Smyd5 depletion in IECs protected mice from DSS-induced colitis. SMYD5 was critically involved in regulating mitochondrial biology such as mitochondrial biogenesis, respiration, and apoptosis. Mechanistically, SMYD5 regulated mitochondrial functions in a PGC-1α dependent manner. Further, SMYD5 mediated lysine methylation of PGC-1α and facilitated its ubiquitination and proteasomal degradation. Conclusion SMYD5 attenuates mitochondrial functions in IECs and promotes IBD progression by enhancing the proteasome-mediated degradation of PGC-1α protein in a methylation-dependent manner. Strategies to decrease SMYD5 expression and/or increase PGC-1α expression in IECs might be a promising therapeutic approach to treat patients with IBD.


Author(s):  
Boussoualim Naouel ◽  
Trabsa Hayat ◽  
Krache Imane ◽  
Ouhida Soraya ◽  
Arrar Lekhmissi ◽  
...  

Background: Anchusa azurea Mill. (AA) is a medicinal plant largely used traditionally in folk medicine in Algeria, it is locally named: hamham. It is effective in the treatment of various diseases. Objectives: The aim of the present study is to determine the antioxidant, anti-inflammatory and anti-hemolytic effects of phenolic fractions from Anchusa azurea Mill. Methods: In this study, various extracts from Anchusa azurea Mill. (AA) using solvents with increasing polarity were prepared. The quantification of polyphenols and flavonoids was determined. The anti-radical activity of the different extracts was evaluated using DPPH and by measuring the inhibition of the oxidative degradation of β-carotene. The In vitro antihemolytic effect of the plant extracts is determined (CrE, ChE, AcE and AqE). For each extract, four concentrations were tested: 10.59, 21.18, 42.37, 84.74 µg/ml. Vitamin C is used as a standard. Free-radical attack was measured by measuring the HT50 (Half-Hemolysis Time). The anti-inflammatory effect using PMA on mice of the methanolic extract (CrE) was evaluated. Results: The quantification of polyphenols and flavonoids showed that ethyl acetate extract (AcE) contains a higher amount of polyphenols. However, chloroform extract (ChE) presents a higher amount of flavonoids. AcE showed an important scavenging activity using the DPPH radical (IC50= 68.35 µg/ml). The results showed that AcE also exhibited very great inhibition on the oxidation of β-carotene/linoleic acid (84.33%). All extracts increased the HT50 values (Half-Hemolysis Time) in a dose-dependent manner. The three highest concentrations (21.18, 42.37 and 84.74 µg / ml) of ChE caused a very significant delay (p ≤ 0.001) of hemolysis compared to the negative control and the positive control "VIT C". The anti-inflammatory effect using PMA on mice showed that the methanolic extract (CrE) of AA reduced the weight of the ear edema. Conclusions: This plant has a strong pharmacological power, which supports its traditional medicinal use.


2021 ◽  
Vol 21 (7) ◽  
pp. 3943-3949
Author(s):  
Jaegoo Yeon ◽  
Sung-Suk Suh ◽  
Ui-Joung Youn ◽  
Badamtsetseg Bazarragchaa ◽  
Ganbold Enebish ◽  
...  

Iris bungei Maxim. (IB), which is native to China and Mongolia, is used as a traditional medicine for conditions such as inflammation, cancer, and bacterial infections. However, the effects of Iris bungei Maxim. on adipocyte differentiation have not been studied. In the present study, we first demonstrated the molecular mechanisms underlying the adipogenic activity of the methanol extract of Mongolian I. bungei Maxim. (IB). IB significantly enhanced intracellular lipid accumulation and adipocyte differentiation in 3T3-L1 preadipocytes in a concentration-dependent manner. Moreover, IB markedly stimulated the expression of genes related to adipogenesis such as peroxisome proliferator-activated receptor γ, adiponectin, and aP2. In addition, we also observed that IB induces lipogenic genes such as fatty acid synthase, sterol regulatory element binding protein 1c, stearoyl-CoA desaturase, and acetyl-CoA carboxylase. Interestingly IB regulated adipocyte differentiation in both the early and middle stages. Taken together, these adipogenic and lipogenic effects of IB suggest its efficacy for the prevention and/or treatment of type 2 diabetes.


2019 ◽  
Vol 149 (9) ◽  
pp. 1553-1564 ◽  
Author(s):  
Ji Ye Lim ◽  
Chun Liu ◽  
Kang-Quan Hu ◽  
Donald E Smith ◽  
Dayong Wu ◽  
...  

ABSTRACT Background β-Cryptoxanthin (BCX), a provitamin A carotenoid shown to protect against nonalcoholic fatty liver disease (NAFLD), can be cleaved by β-carotene-15,15′-oxygenase (BCO1) to generate vitamin A, and by β-carotene-9′,10′-oxygenase (BCO2) to produce bioactive apo-carotenoids. BCO1/BCO2 polymorphisms have been associated with variations in plasma carotenoid amounts in both humans and animals. Objectives We investigated whether BCX feeding inhibits high refined-carbohydrate diet (HRCD)-induced NAFLD, dependent or independent of BCO1/BCO2. Methods Six-week-old male wild-type (WT) and BCO1−/−/BCO2−/− double knockout (DKO) mice were randomly fed HRCD (66.5% of energy from carbohydrate) with or without BCX (10 mg/kg diet) for 24 wk. Pathological and biochemical variables were analyzed in the liver and mesenteric adipose tissues (MATs). Data were analyzed by 2-factor ANOVA. Results Compared to their respective HRCD controls, BCX reduced hepatic steatosis severity by 33‒43% and hepatic total cholesterol by 43‒70% in both WT and DKO mice (P &lt; 0.01). Hepatic concentrations of BCX, but not retinol and retinyl palmitate, were 33-fold higher in DKO mice than in WT mice (P &lt; 0.001). BCX feeding increased the hepatic fatty acid oxidation protein peroxisome proliferator-activated receptor-α, and the cholesterol efflux gene ATP-binding cassette transporter5, and suppressed the lipogenesis gene acetyl-CoA carboxylase 1 (Acc1) in the MAT of WT mice but not DKO mice (P &lt; 0.05). BCX feeding decreased the hepatic lipogenesis proteins ACC and stearoyl-CoA desaturase-1 (3-fold and 5-fold) and the cholesterol synthesis genes 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and HMG-CoA synthase 1 (2.7-fold and 1.8-fold) and increased the cholesterol catabolism gene cholesterol 7α-hydroxylase (1.9-fold) in the DKO but not WT mice (P &lt; 0.05). BCX feeding increased hepatic protein sirtuin1 (2.5-fold) and AMP-activated protein kinase (9-fold) and decreased hepatic farnesoid X receptor protein (80%) and the inflammatory cytokine gene Il6 (6-fold) in the MAT of DKO mice but not WT mice (P &lt; 0.05). Conclusion BCX feeding mitigates HRCD-induced NAFLD in both WT and DKO mice through different mechanisms in the liver-MAT axis, depending on the presence or absence of BCO1/BCO2.


2020 ◽  
Vol 4 (18) ◽  
pp. 4522-4537
Author(s):  
Jennifer Yeung ◽  
Reheman Adili ◽  
Adriana Yamaguchi ◽  
Cody J. Freedman ◽  
Angela Chen ◽  
...  

Abstract Arterial thrombosis is the underlying cause for a number of cardiovascular-related events. Although dietary supplementation that includes polyunsaturated fatty acids (PUFAs) has been proposed to elicit cardiovascular protection, a mechanism for antithrombotic protection has not been well established. The current study sought to investigate whether an omega-6 essential fatty acid, docosapentaenoic acid (DPAn-6), and its oxidized lipid metabolites (oxylipins) provide direct cardiovascular protection through inhibition of platelet reactivity. Human and mouse blood and isolated platelets were treated with DPAn-6 and its 12-lipoxygenase (12-LOX)–derived oxylipins, 11-hydroxy-docosapentaenoic acid and 14-hydroxy-docosapentaenoic acid, to assess their ability to inhibit platelet activation. Pharmacological and genetic approaches were used to elucidate a role for DPA and its oxylipins in preventing platelet activation. DPAn-6 was found to be significantly increased in platelets following fatty acid supplementation, and it potently inhibited platelet activation through its 12-LOX–derived oxylipins. The inhibitory effects were selectively reversed through inhibition of the nuclear receptor peroxisome proliferator activator receptor-α (PPARα). PPARα binding was confirmed using a PPARα transcription reporter assay, as well as PPARα−/− mice. These approaches confirmed that selectivity of platelet inhibition was due to effects of DPA oxylipins acting through PPARα. Mice administered DPAn-6 or its oxylipins exhibited reduced thrombus formation following vessel injury, which was prevented in PPARα−/− mice. Hence, the current study demonstrates that DPAn-6 and its oxylipins potently and effectively inhibit platelet activation and thrombosis following a vascular injury. Platelet function is regulated, in part, through an oxylipin-induced PPARα-dependent manner, suggesting that targeting PPARα may represent an alternative strategy to treat thrombotic-related diseases.


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