scholarly journals Transcriptional Regulation by Nuclear Corepressors and PGC-1α: Implications for Mitochondrial Quality Control and Insulin Sensitivity

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Zhengtang Qi ◽  
Shuzhe Ding

The peroxisome proliferator-activated receptors (PPARs) and estrogen-related receptor (ERRα) are ligand-activated nuclear receptors that coordinately regulate gene expression. Recent evidence suggests that nuclear corepressors, NCoR, RIP140, and SMRT, repress nuclear receptors-mediated transcriptional activity on specific promoters, and thus regulate insulin sensitivity, adipogenesis, mitochondrial number, and activity in vivo. Moreover, the coactivator PGC-1αthat increases mitochondrial biogenesis during exercise and calorie restriction directly regulates autophagy in skeletal muscle and mitophagy in the pathogenesis of Parkinson's disease. In this paper, we discuss the PGC-1α’s novel role in mitochondrial quality control and the role of nuclear corepressors in regulating insulin sensitivity and interacting with PGC-1α.

PPAR Research ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Angela Tesse ◽  
Ramaroson Andriantsitohaina ◽  
Thierry Ragot

Activation of peroxisome proliferator-activated receptors (PPARs), and particularly of PPARαand PPARγ, using selective agonists, is currently used in the treatment of metabolic diseases such as hypertriglyceridemia and type 2 diabetes mellitus. PPARαand PPARγanti-inflammatory, antiproliferative and antiangiogenic properties in cardiovascular cells were extensively clarified in a variety of in vitro and in vivo models. In contrast, the role of PPARδin cardiovascular system is poorly understood. Prostacyclin, the predominant prostanoid released by vascular cells, is a putative endogenous agonist for PPARδ, but only recently PPARδselective synthetic agonists were found, improving studies about the physiological and pathophysiological roles of PPARδactivation. Recent reports suggest that the PPARδactivation may play a pivotal role to regulate inflammation, apoptosis, and cell proliferation, suggesting that this transcriptional factor could become an interesting pharmacological target to regulate cardiovascular cell apoptosis, proliferation, inflammation, and metabolism.


2010 ◽  
Vol 299 (3) ◽  
pp. E335-E340 ◽  
Author(s):  
Asmaà Fritah ◽  
Mark Christian ◽  
Malcolm G. Parker

RIP140 is a transcriptional coregulator highly expressed in metabolic tissues where it has important and diverse actions. RIP140-null mice show that it plays a crucial role in the control of lipid metabolism in adipose tissue, skeletal muscle, and the liver and is essential for female fertility. RIP140 has been shown to act as a ligand-dependent transcriptional corepressor for metabolic nuclear receptors such as estrogen-related receptors and peroxisome proliferator-activated receptors. The role of RIP140 as a corepressor has been strengthened by the characterization of RIP140-overexpressing mice, although it emerges through several studies that RIP140 can also behave as a coactivator. Nuclear localization of RIP140 is important for controlling transcription of target genes and is subject to regulation by posttranslational modifications. However, cytoplasmic RIP140 has been shown to play a role in the control of metabolism through direct regulation of glucose transport in adipocytes. In this review, we focus on recent advances highlighting the growing importance of RIP140 as a regulator of energy homeostasis.


Author(s):  
Carla Quiroga ◽  
Juan José Barberena ◽  
Jocelyne Alcaraz-Silva ◽  
Sérgio Machado ◽  
Claudio Imperatori ◽  
...  

: The peroxisome proliferator activated receptors (PPARs) are a superfamily of well-recognized ligand-binding nuclear receptors comprising three isoforms: PPARα, PPARγ, and PPARβ/δ. In response to endogenous lipid messengers, PPARs trigger the transcription of genes related to a wider spectrum of physiological phenomena, including fatty acid oxidation, inflammation, and adipogenesis among many others. Thus, the importance of PPARs as putative protective therapy in health issues has increased the interest in studying these nuclear receptors, including the management of neurodegenerative disorders, multiple sclerosis, and likely addiction. In recent years, several pieces of evidence from animal models have demonstrated the promising role of PPARs as a critical element for interventions in addictive behaviors by reducing the reinforcing properties of addictive substances such as alcohol. However, there is a lack of data in scope and has so far been unexplored the function of PPARs in additional drugs such as cannabis, opioids, methamphetamine, or cocaine. Similar scenario has been found for the management of binge-type eating disorders. Thus, here we review recent advances in understanding the relevance of the PPAR controlling addiction.


PPAR Research ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Lihong Chen ◽  
Guangrui Yang

Peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptors that function as transcription factors regulating the expression of numerous target genes. PPARs play an essential role in various physiological and pathological processes, especially in energy metabolism. It has long been known that metabolism and circadian clocks are tightly intertwined. However, the mechanism of how they influence each other is not fully understood. Recently, all three PPAR isoforms were found to be rhythmically expressed in given mouse tissues. Among them, PPARαand PPARγare direct regulators of core clock components, Bmal1 and Rev-erbα, and, conversely, PPARαis also a direct Bmal1 target gene. More importantly, recent studies using knockout mice revealed that all PPARs exert given functions in a circadian manner. These findings demonstrated a novel role of PPARs as regulators in correlating circadian rhythm and metabolism. In this review, we summarize advances in our understanding of PPARs in circadian regulation.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Chaoqun Wang ◽  
Zihao Li ◽  
Baolei Zhao ◽  
Yaohua Wu ◽  
Yao Fu ◽  
...  

Peroxisome proliferator-activated receptors (PPARs) α and γ have been shown to be protective in hepatic ischemia/reperfusion (I/R) injury. However, the precise role of PPARγ coactivator-1α (PGC-1α), which can coactivate both of these receptors, in hepatic I/R injury, remains largely unknown. This study was designed to test our hypothesis that PGC-1α is protective during hepatic I/R injury in vitro and in vivo. Our results show that endogenous PGC-1α is basally expressed in normal livers and is moderately increased by I/R. Ectopic PGC-1α protects against hepatic I/R and hepatocyte anoxia/reoxygenation (A/R) injuries, whereas knockdown of endogenous PGC-1α aggravates such injuries, as evidenced by assessment of the levels of serum aminotransferases and inflammatory cytokines, necrosis, apoptosis, cell viability, and histological examination. The EMSA assay shows that the activation of PPARα and PPARγ is increased or decreased by the overexpression or knockdown of PGC-1α, respectively, during hepatic I/R and hepatocyte A/R injuries. In addition, the administration of specific antagonists of either PPARα (MK886) or PPARγ (GW9662) can effectively decrease the protective effect of PGC-1α against hepatic I/R and hepatocyte A/R injuries. We also demonstrate an important regulatory role of PGC-1α in reactive oxygen species (ROS) metabolism during hepatic I/R, which is correlated with the induction of ROS-detoxifying enzymes and is also dependent on the activations of PPARα and PPARγ. These data demonstrate that PGC-1α protects against hepatic I/R injury, mainly by regulating the activation of PPARα and PPARγ. Thus, PGC-1α may be a promising therapeutic target for the protection of the liver against I/R injury.


2006 ◽  
Vol 4 (1) ◽  
pp. nrs.04010 ◽  
Author(s):  
Laurent Gelman ◽  
Jerome N. Feige ◽  
Cicerone Tudor ◽  
Yves Engelborghs ◽  
Walter Wahli ◽  
...  

The mode of action of nuclear receptors in living cells is an actively investigated field but much remains hypothetical due to the lack, until recently, of methods allowing the assessment of molecular mechanisms in vivo. However, these last years, the development of fluorescence microscopy methods has allowed initiating the dissection of the molecular mechanisms underlying gene regulation by nuclear receptors directly in living cells or organisms. Following our analyses on peroxisome proliferator activated receptors (PPARs) in living cells, we discuss here the different models arising from the use of these tools, that attempt to link mobility, DNA binding or chromatin interaction, and transcriptional activity.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Joëlle Dupont ◽  
Christine Chabrolle ◽  
Christelle Ramé ◽  
Lucie Tosca ◽  
Stéphanie Coyral-Castel

The mechanisms controlling the interaction between energy balance and reproduction are the subject of intensive investigations. The integrated control of these systems is probably a multifaceted phenomenon involving an array of signals governing energy homeostasis, metabolism, and fertility. Two fuel sensors, PPARs, a superfamily of nuclear receptors and the kinase AMPK, integrate energy control and lipid and glucose homeostasis. Adiponectin, one of the adipocyte-derived factors mediate its actions through the AMPK or PPARs pathway. These three molecules are expressed in the ovary, raising questions about the biological actions of fuel sensors in fertility and the use of these molecules to treat fertility problems. This review will highlight the expression and putative role of PPARs, AMPK, and adiponectin in the ovary, particularly during folliculogenesis, steroidogenesis, and oocyte maturation.


Sign in / Sign up

Export Citation Format

Share Document