scholarly journals Cyclin D1 represses peroxisome proliferator-activated receptor alpha and inhibits fatty acid oxidation

Oncotarget ◽  
2016 ◽  
Vol 7 (30) ◽  
pp. 47674-47686 ◽  
Author(s):  
Sushama Kamarajugadda ◽  
Jennifer R. Becker ◽  
Eric A. Hanse ◽  
Douglas G. Mashek ◽  
Mara T. Mashek ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Cyclin D1 ◽  
Fatty Acid Oxidation ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Receptor Alpha

scholarly journals Pancreatic Islet Adaptation to Fasting Is Dependent on Peroxisome Proliferator-Activated Receptor α Transcriptional Up-Regulation of Fatty Acid Oxidation

Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 375-382 ◽  
Author(s):  
Sandrine Gremlich ◽  
Christopher Nolan ◽  
Raphaël Roduit ◽  
Rémy Burcelin ◽  
Marie-Line Peyot ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Pancreatic Islet ◽  
Cellular Response ◽  
Uncoupling Protein ◽  
Acid Oxidation ◽  
Hyperinsulinemic Hypoglycemia ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

The cellular response to fasting and starvation in tissues such as heart, skeletal muscle, and liver requires peroxisome proliferator-activated receptor-α (PPARα)-dependent up-regulation of energy metabolism toward fatty acid oxidation (FAO). PPARα null (PPARαKO) mice develop hyperinsulinemic hypoglycemia in the fasting state, and we previously showed that PPARα expression is increased in islets at low glucose. On this basis, we hypothesized that enhanced PPARα expression and FAO, via depletion of lipid-signaling molecule(s) for insulin exocytosis, are also involved in the normal adaptive response of the islet to fasting. Fasted PPARαKO mice compared with wild-type mice had supranormal ip glucose tolerance due to increased plasma insulin levels. Isolated islets from the PPARα null mice had a 44% reduction in FAO, normal glucose use and oxidation, and enhanced glucose-induced insulin secretion. In normal rats, fasting for 24 h increased islet PPARα, carnitine palmitoyltransferase 1, and uncoupling protein-2 mRNA expression by 60%, 62%, and 82%, respectively. The data are consistent with the view that PPARα, via transcriptionally up-regulating islet FAO, can reduce insulin secretion, and that this mechanism is involved in the normal physiological response of the pancreatic islet to fasting such that hypoglycemia is avoided.

scholarly journals PPARα augments heart function and cardiac fatty acid oxidation in early experimental polymicrobial sepsis

2017 ◽  
Vol 312 (2) ◽  
pp. H239-H249 ◽  
Author(s):  
Stephen W. Standage ◽  
Brock G. Bennion ◽  
Taft O. Knowles ◽  
Dolena R. Ledee ◽  
Michael A. Portman ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Mouse Models ◽  
Heart Function ◽  
Left Ventricular ◽  
Cardiac Response ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Regulatory State ◽  
Peroxisome Proliferator Activated Receptor

Children with sepsis and multisystem organ failure have downregulated leukocyte gene expression of peroxisome proliferator-activated receptor-α (PPARα), a nuclear hormone receptor transcription factor that regulates inflammation and lipid metabolism. Mouse models of sepsis have likewise demonstrated that the absence of PPARα is associated with decreased survival and organ injury, specifically of the heart. Using a clinically relevant mouse model of early sepsis, we found that heart function increases in wild-type (WT) mice over the first 24 h of sepsis, but that mice lacking PPARα ( Ppara−/−) cannot sustain the elevated heart function necessary to compensate for sepsis pathophysiology. Left ventricular shortening fraction, measured 24 h after initiation of sepsis by echocardiography, was higher in WT mice than in Ppara−/− mice. Ex vivo working heart studies demonstrated greater developed pressure, contractility, and aortic outflow in WT compared with Ppara−/− mice. Furthermore, cardiac fatty acid oxidation was increased in WT but not in Ppara−/− mice. Regulatory pathways controlling pyruvate incorporation into the citric acid cycle were inhibited by sepsis in both genotypes, but the regulatory state of enzymes controlling fatty acid oxidation appeared to be permissive in WT mice only. Mitochondrial ultrastructure was not altered in either genotype indicating that severe mitochondrial dysfunction is unlikely at this stage of sepsis. These data suggest that PPARα expression supports the hyperdynamic cardiac response early in the course of sepsis and that increased fatty acid oxidation may prevent morbidity and mortality. NEW & NOTEWORTHY In contrast to previous studies in septic shock using experimental mouse models, we are the first to demonstrate that heart function increases early in sepsis with an associated augmentation of cardiac fatty acid oxidation. Absence of peroxisome proliferator-activated receptor-α (PPARα) results in reduced cardiac performance and fatty acid oxidation in sepsis.

scholarly journals PPARα: Energy Combustion, Hypolipidemia, Inflammation and Cancer

2010 ◽  
Vol 8 (1) ◽  
pp. nrs.08002 ◽  
Author(s):  
Sean R. Pyper ◽  
Navin Viswakarma ◽  
Songtao Yu ◽  
Janardan K. Reddy
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Gene Knockout ◽  
Nuclear Hormone Receptor ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Synthetic Chemicals ◽  
Gene Knockout Mouse ◽  
Lipid Sensor

The peroxisome proliferator-activated receptor α (PPARα, or NR1C1) is a nuclear hormone receptor activated by a structurally diverse array of synthetic chemicals known as peroxisome proliferators. Endogenous activation of PPARα in liver has also been observed in certain gene knockout mouse models of lipid metabolism, implying the existence of enzymes that either generate (synthesize) or degrade endogenous PPARα agonists. For example, substrates involved in fatty acid oxidation can function as PPARα ligands. PPARα serves as a xenobiotic and lipid sensor to regulate energy combustion, hepatic steatosis, lipoprotein synthesis, inflammation and liver cancer. Mainly, PPARα modulates the activities of all three fatty acid oxidation systems, namely mitochondrial and peroxisomal β-oxidation and microsomal co-oxidation, and thus plays a key role in energy expenditure. Sustained activation of PPARα by either exogenous or endogenous agonists leads to the development of hepatocellular carcinoma resulting from sustained oxidative and possibly endoplasmic reticulum stress and liver cell proliferation. PPARα requires transcription coactivator PPAR-binding protein (PBP)/mediator subunit 1(MED1) for its transcriptional activity.

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