Mechanism of cardiomyocyte PGC-1α gene regulation by ERRα

2013 ◽  
Vol 91 (3) ◽  
pp. 148-154 ◽  
Author(s):  
Angela Ramjiawan ◽  
Rushita A. Bagchi ◽  
Laura Albak ◽  
Michael P. Czubryt
Keyword(s):  
Cardiac Metabolism ◽  
Luciferase Reporter ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Impaired Metabolism ◽  
Repressive Effect ◽  
Evolutionarily Conserved ◽  
Reporter Assays

Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) regulates critical genes involved in cardiac mitochondrial biogenesis and fatty acid oxidation, and its loss is associated with impaired metabolism and various cardiac pathologies. Estrogen-related receptor α (ERRα) targets many of the same genes as PGC-1α, and extensive cross talk exists between these 2 regulators. Here we report the identification of an evolutionarily conserved ERRα binding site within the PGC-1α promoter. Using luciferase reporter assays and overexpression, inhibition, or knockdown of ERRα, we show that PGC-1α expression is critically dependent upon ERRα in primary cardiomyocytes. We demonstrate that short-term hypoxia results in reduced ERRα mRNA expression, which precedes a similar loss of PGC-1α mRNA. However, chromatin immunoprecipitation reveals that despite a key role for ERRα in regulating PGC-1α in normoxic cardiomyocytes, ERRα loss is not responsible for PGC-1α loss in hypoxia. Histone deacetylase 5 (HDAC5) has previously been demonstrated to strongly inhibit expression of PGC-1α, and we show that overexpression of ERRα is sufficient to overcome this repressive effect. Our data elucidates the mechanism by which ERRα regulates cardiac PGC-1α gene expression, and suggests that ERRα may provide a means to normalize PGC-1α expression that could be useful in the development of strategies aimed at improving cardiac metabolism in disease.

scholarly journals Activated AMPK inhibits PPAR-α and PPAR-γ transcriptional activity in hepatoma cells

2011 ◽  
Vol 301 (4) ◽  
pp. G739-G747 ◽  
Author(s):  
Margaret S. Sozio ◽  
Changyue Lu ◽  
Yan Zeng ◽  
Suthat Liangpunsakul ◽  
David W. Crabb
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Luciferase Reporter ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Short Term ◽  
Reporter Activity ◽  
Ppar Γ ◽  
Compound C ◽  
Α Activity

AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-α (PPAR-α) are critical regulators of short-term and long-term fatty acid oxidation, respectively. We examined whether the activities of these molecules were coordinately regulated. H4IIEC3 cells were transfected with PPAR-α and PPAR-γ expression plasmids and a peroxisome-proliferator-response element (PPRE) luciferase reporter plasmid. The cells were treated with PPAR agonists (WY-14,643 and rosiglitazone), AMPK activators 5-aminoimidazole-4-carboxamide riboside (AICAR) and metformin, and the AMPK inhibitor compound C. Both AICAR and metformin decreased basal and WY-14,643-stimulated PPAR-α activity; compound C increased agonist-stimulated reporter activity and partially reversed the effect of the AMPK activators. Similar effects on PPAR-γ were seen, with both AICAR and metformin inhibiting PPRE reporter activity. Compound C increased basal PPAR-γ activity and rosiglitazone-stimulated activity. In contrast, retinoic acid receptor-α (RAR-α), another nuclear receptor that dimerizes with retinoid X receptor (RXR), was largely unaffected by the AMPK activators. Compound C modestly increased AM580 (an RAR agonist)-stimulated activity. The AMPK activators did not affect PPAR-α binding to DNA, and there was no consistent correlation between effects of the AMPK activators and inhibitor on PPAR and the nuclear localization of AMPK-α subunits. Expression of either a constitutively active or dominant negative AMPK-α inhibited basal and WY-14,643-stimulated PPAR-α activity and basal and rosiglitazone-stimulated PPAR-γ activity. We concluded that the AMPK activators AICAR and metformin inhibited transcriptional activities of PPAR-α and PPAR-γ, whereas inhibition of AMPK with compound C activated both PPARs. The effects of AMPK do not appear to be mediated through effects on RXR or on PPAR/RXR binding to DNA. These effects are independent of kinase activity and instead appear to rely on the activated conformation of AMPK. AMPK inhibition of PPAR-α and -γ may allow for short-term processes to increase energy generation before the cells devote resources to increasing their capacity for fatty acid oxidation.

scholarly journals Components from the Steamed Leaves of Acanthopanax koreanum and their Effects on PPAR Activity in HepG2 Cells

2011 ◽  
Vol 6 (9) ◽  
pp. 1934578X1100600
Author(s):  
Jeong Ah Kim ◽  
Seok Bean Song ◽  
Seo Young Yang ◽  
Young Ho Kim
Keyword(s):  
Mass Spectrometry ◽  
Biological Effects ◽  
Positive Control ◽  
Luciferase Reporter ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Acanthopanax Koreanum ◽  
Specificity And Sensitivity ◽  
Reporter Assays ◽  
C Nmr

Three ent-kaurane diterpenes (1-3), four lupane-triterpene glycosides (4-7), and an oleanane-triterpene glycoside (8) were isolated from the ethyl acetate and water extracts of the steamed leaves of Acanthopanax koreanum using a combination of various column chromatographies. The structures of the isolates were determined by 1H-, 13C-NMR spectroscopy and mass spectrometry. To investigate the biological effects of the eight compounds (1-8) on peroxisome proliferator-activated receptor gamma (PPARγ), luciferase reporter assays were used. Among the tested compounds, ent-kaur-16-en-19-oic acid (1), 16α-hydroxy- ent-kauran-19-oic acid (2), and 17-hydroxy- ent-kaur-15-en-19-oic acid (3) showed considerable effects on PPARγ activity, compared with the positive control, troglitazone. To evaluate specificity and sensitivity of the active compounds (1-3) in the regulation of transactivation of PPARs, Gal4-PPARs-LBD luciferase reporter assays were examined. In this study, the three ent-kaurane diterpenes (1-3) were found to up-regulate PPARβ/δ and PPARγ activities, whereas they did not activate PPARα activity.

Cardiac function and metabolism in Type 2 diabetic mice after treatment with BM 17.0744, a novel PPAR-α activator

2002 ◽  
Vol 283 (3) ◽  
pp. H949-H957 ◽  
Author(s):  
Ellen Aasum ◽  
Darrell D. Belke ◽  
David L. Severson ◽  
Rudolph A. Riemersma ◽  
Marie Cooper ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Contractile Function ◽  
Ex Vivo ◽  
Plasma Concentrations ◽  
Cardiac Metabolism ◽  
Left Ventricular ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Hearts from diabetic db/ db mice, a model of Type 2 diabetes, exhibit left ventricular failure and altered metabolism of exogenous substrates. Peroxisome proliferator-activated receptor-α (PPAR-α) ligands reduce plasma lipid and glucose concentrations and improve insulin sensitivity in db/ db mice. Consequently, the effect of 4- to 5-wk treatment of db/ db mice with a novel PPAR-α ligand (BM 17.0744; 25–38 mg · kg−1 · day−1), commencing at 8 wk of age, on ex vivo cardiac function and metabolism was determined. Elevated plasma concentrations of glucose, fatty acids, and triacylglycerol (34.0 ± 3.6, 2.0 ± 0.4, and 0.9 ± 0.1 mM, respectively) were reduced to normal after treatment with BM 17.0744 (10.8 ± 0.6, 1.1 ± 0.1, and 0.6 ± 0.1 mM). Plasma insulin was also reduced significantly in treated compared with untreated db/ db mice. Chronic treatment of db/ db mice with the PPAR-α agonist resulted in a 50% reduction in rates of fatty acid oxidation, with a concomitant increase in glycolysis (1.7-fold) and glucose oxidation (2.3- fold). Correction of the diabetes-induced abnormalities in systemic and cardiac metabolism after BM 17.0744 treatment did not, however, improve left ventricular contractile function.

scholarly journals Peroxisome Proliferator-Activated Receptor-γ Increases Adiponectin Secretion via Transcriptional Repression of Endoplasmic Reticulum Chaperone Protein ERp44

Endocrinology ◽  
2010 ◽  
Vol 151 (7) ◽  
pp. 3195-3203 ◽  
Author(s):  
Qinqiang Long ◽  
Ting Lei ◽  
Bin Feng ◽  
Changjun Yin ◽  
Dan Jin ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcriptional Repression ◽  
Energy Homeostasis ◽  
Luciferase Reporter ◽  
Peroxisome Proliferator ◽  
Response Element ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Pparγ Agonist ◽  
Peroxisome Proliferator Response Element

Adiponectin, an adipocyte-derived hormone, is a versatile player involved in the regulation of energy homeostasis, cardiovascular disease, and diabetes. Within adipocytes, adiponectin is retained in the lumen of the endoplasmic reticulum (ER) by binding to the thiol protein ER resident protein 44 kDa (ERp44), which is apparently regulated by the activation of nuclear receptor peroxisome proliferator-activated receptor (PPAR)-γ. However, the precise role of ERp44 in adiponectin secretion remains elusive. In the present study, we investigated the functional correlation between ERp44 and adiponectin in a pig model. The transcription of porcine ERp44 was regulated by PPARγ, which was consistent with the finding of putative peroxisome proliferator response element sites within ERp44 promoter. Using chromatin immunoprecipitation and luciferase reporter assays, we demonstrated that the transcription of porcine ERp44 is repressed through binding of PPARγ to a peroxisome proliferator response element site located between positions −981 and −1004 in its 5′-flanking region. In human embryonic kidney 293 cells stably transfected with cDNA encoding porcine adiponectin, the secretion of adiponectin was significantly up-regulated and the ERp44 mRNA was down-regulated observably, by either the treatment of PPARγ agonist rosiglitazone or the overexpression of PPARγ in these cells. Taken together, our results indicated that PPARγ is an essential regulatory factor for the transcriptional activity of ERp44, which in turn controls the secretion of adiponectin.

Natural Aldose Reductase Inhibitor: A Potential Therapeutic Agent for Non-alcoholic Fatty Liver Disease

2020 ◽  
Vol 21 (6) ◽  
pp. 599-609 ◽  
Author(s):  
Longxin Qiu ◽  
Chang Guo
Keyword(s):  
Oxidative Stress ◽  
Liver Disease ◽  
Fatty Liver ◽  
Aldose Reductase ◽  
Fatty Liver Disease ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Alcoholic Fatty Liver ◽  
Nonalcoholic Fatty Liver

Aldose reductase (AR) has been reported to be involved in the development of nonalcoholic fatty liver disease (NAFLD). Hepatic AR is induced under hyperglycemia condition and converts excess glucose to lipogenic fructose, which contributes in part to the accumulation of fat in the liver cells of diabetes rodents. In addition, the hyperglycemia-induced AR or nutrition-induced AR causes suppression of the transcriptional activity of peroxisome proliferator-activated receptor (PPAR) α and reduced lipolysis in the liver, which also contribute to the development of NAFLD. Moreover, AR induction in non-alcoholic steatohepatitis (NASH) may aggravate oxidative stress and the expression of inflammatory cytokines in the liver. Here, we summarize the knowledge on AR inhibitors of plant origin and review the effect of some plant-derived AR inhibitors on NAFLD/NASH in rodents. Natural AR inhibitors may improve NAFLD at least in part through attenuating oxidative stress and inflammatory cytokine expression. Some of the natural AR inhibitors have been reported to attenuate hepatic steatosis through the regulation of PPARα-mediated fatty acid oxidation. In this review, we propose that the natural AR inhibitors are potential therapeutic agents for NAFLD.

scholarly journals Adipocyte PHLPP2 inhibition prevents obesity-induced fatty liver

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
KyeongJin Kim ◽  
Jin Ku Kang ◽  
Young Hoon Jung ◽  
Sang Bae Lee ◽  
Raffaela Rametta ◽  
...  
Keyword(s):  
Fatty Liver ◽  
Whole Body ◽  
Acid Oxidation ◽  
Chow Diet ◽  
Peroxisome Proliferator ◽  
Obese Mice ◽  
Ph Domain ◽  
Peroxisome Proliferator Activated Receptor

AbstractIncreased adiposity confers risk for systemic insulin resistance and type 2 diabetes (T2D), but mechanisms underlying this pathogenic inter-organ crosstalk are incompletely understood. We find PHLPP2 (PH domain and leucine rich repeat protein phosphatase 2), recently identified as the Akt Ser473 phosphatase, to be increased in adipocytes from obese mice. To identify the functional consequence of increased adipocyte PHLPP2 in obese mice, we generated adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice. A-PHLPP2 mice show normal adiposity and glucose metabolism when fed a normal chow diet, but reduced adiposity and improved whole-body glucose tolerance as compared to Cre- controls with high-fat diet (HFD) feeding. Notably, HFD-fed A-PHLPP2 mice show increased HSL phosphorylation, leading to increased lipolysis in vitro and in vivo. Mobilized adipocyte fatty acids are oxidized, leading to increased peroxisome proliferator-activated receptor alpha (PPARα)-dependent adiponectin secretion, which in turn increases hepatic fatty acid oxidation to ameliorate obesity-induced fatty liver. Consistently, adipose PHLPP2 expression is negatively correlated with serum adiponectin levels in obese humans. Overall, these data implicate an adipocyte PHLPP2-HSL-PPARα signaling axis to regulate systemic glucose and lipid homeostasis, and suggest that excess adipocyte PHLPP2 explains decreased adiponectin secretion and downstream metabolic consequence in obesity.

scholarly journals Andrographis paniculata and Its Main Bioactive Ingredient Andrographolide Decrease Alcohol Drinking and Seeking in Rats Through Activation of Nuclear PPARγ Pathway

2021 ◽  
Author(s):  
Serena Stopponi ◽  
Yannick Fotio ◽  
Carlo Cifani ◽  
Hongwu Li ◽  
Carolina L Haass-Koffler ◽  
...  
Keyword(s):  
Oral Administration ◽  
Alcohol Drinking ◽  
Andrographis Paniculata ◽  
Peroxisome Proliferator ◽  
Herbaceous Plant ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Treatment Administration ◽  
Dried Extract

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.

Sign in / Sign up

Export Citation Format

Share Document