scholarly journals The Role of Lipid Sensing Nuclear Receptors (PPARs and LXR) and Metabolic Lipases in Obesity, Diabetes and NAFLD

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 645
Author(s):  
Emmanuel D. Dixon ◽  
Alexander D. Nardo ◽  
Thierry Claudel ◽  
Michael Trauner
Keyword(s):  
Fatty Acids ◽  
Nuclear Receptors ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Alcoholic Fatty Liver ◽  
Organ Manifestations ◽  
Lipid Sensing ◽  
Metabolic Inflexibility ◽  
Metabolic Activities

Obesity and type 2 diabetes mellitus (T2DM) are metabolic disorders characterized by metabolic inflexibility with multiple pathological organ manifestations, including non-alcoholic fatty liver disease (NAFLD). Nuclear receptors are ligand-dependent transcription factors with a multifaceted role in controlling many metabolic activities, such as regulation of genes involved in lipid and glucose metabolism and modulation of inflammatory genes. The activity of nuclear receptors is key in maintaining metabolic flexibility. Their activity depends on the availability of endogenous ligands, like fatty acids or oxysterols, and their derivatives produced by the catabolic action of metabolic lipases, most of which are under the control of nuclear receptors. For example, adipose triglyceride lipase (ATGL) is activated by peroxisome proliferator-activated receptor γ (PPARγ) and conversely releases fatty acids as ligands for PPARα, therefore, demonstrating the interdependency of nuclear receptors and lipases. The diverse biological functions and importance of nuclear receptors in metabolic syndrome and NAFLD has led to substantial effort to target them therapeutically. This review summarizes recent findings on the roles of lipases and selected nuclear receptors, PPARs, and liver X receptor (LXR) in obesity, diabetes, and NAFLD.

The role of nitrated fatty acids and peroxisome proliferator-activated receptor gamma in modulating inflammation

2014 ◽  
Vol 23 (1) ◽  
pp. 283-287 ◽  
Author(s):  
Venkata Ramireddy Narala ◽  
Parasuraman Aiya Subramani ◽  
Vydyanath R. Narasimha ◽  
Firdose Begum Shaik ◽  
Kalpana Panati
Keyword(s):  
Fatty Acids ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

scholarly journals LRRK2 Regulates CPT1A to Promote β-Oxidation in HepG2 Cells

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4122 ◽  
Author(s):  
Chiao-Wei Lin ◽  
Yu-Ju Peng ◽  
Yuan-Yu Lin ◽  
Harry John Mersmann ◽  
Shih-Torng Ding
Keyword(s):  
Lipid Metabolism ◽  
Hepg2 Cells ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Alcoholic Fatty Liver ◽  
Cytokine Tumor Necrosis Factor ◽  
Factor Α ◽  
Amp Activated Protein Kinase ◽  
Necrosis Factor

Leucine-rich repeat kinase 2 (LRRK2) is involved in lipid metabolism; however, the role of LRRK2 in lipid metabolism to affect non-alcoholic fatty liver disease (NAFLD) is still unclear. In the mouse model of NAFLD induced by a high-fat diet, we observed that LRRK2 was decreased in livers. In HepG2 cells, exposure to palmitic acid (PA) down-regulated LRRK2. Overexpression and knockdown of LRRK2 in HepG2 cells were performed to further investigate the roles of LRRK2 in lipid metabolism. Our results showed that β-oxidation in HepG2 cells was promoted by LRRK2 overexpression, whereas LRRK2 knockdown inhibited β-oxidation. The critical enzyme of β-oxidation, carnitine palmitoyltransferase 1A (CPT1A), was positively regulated by LRRK2. Our data suggested that the regulation of CPT1A by LRRK2 may be via the activation of AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor α (PPARα). The overexpression of LRRK2 reduced the concentration of a pro-inflammatory cytokine, tumor necrosis factor α (TNFα), induced by PA. The increase in β-oxidation may promote lipid catabolism to suppress inflammation induced by PA. These results indicated that LRRK2 participated in the regulation of β-oxidation and suggested that the decreased LRRK2 may promote inflammation by suppressing β-oxidation in the liver.

scholarly journals Adipogenesis and lipotoxicity: role of peroxisome proliferator-activated receptor γ (PPARγ) and PPARγcoactivator-1 (PGC1)

2007 ◽  
Vol 10 (10A) ◽  
pp. 1132-1137 ◽  
Author(s):  
Gema Medina-Gomez ◽  
Sarah Gray ◽  
Antonio Vidal-Puig
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Peroxisome Proliferator ◽  
Metabolic Complications ◽  
Peroxisome Proliferator Activated Receptor ◽  
Toxic Response ◽  
Increased Risk ◽  
And Function

AbstractObesity is characterised by an increase in the adipose deposits, resulting from an imbalance between food intake and energy expenditure. When expansion of the adipose tissue reaches its maximum limit, as in obesity, fat accumulates in non-adipose tissues such as liver, heart, muscle and pancreas, developing a toxic response known as lipotoxicity, a condition that promotes the development of insulin resistance and other metabolic complications. Thus, the lipotoxic state may contribute to the increased risk of insulin resistance, diabetes, fatty liver and cardiovascular complications associated with obesity.We are interested in studying adipose tissue, specifically how mechanisms of adipogenesis and remodelling of adipose tissue, in terms of size and function of the adipocytes, could be considered a strategy to increase the capacity for lipid storage and prevent lipotoxicity. The peroxisome proliferator-activated receptors (PPARs) are a family of transcription factors that regulate energy balance by promoting either energy deposition or energy dissipation. Under normal physiological conditions, PPARγ is mainly expressed in adipose tissue and regulates diverse functions such as the development of fat cells and their capacity to store lipids. The generation of PPARγ knockout mice, either tissue specific or isoform specific, has provided new models to study PPARγ’s role in adipose tissue differentiation and function and have highlighted the essential role of PPARγ in adipogenesis and lipogenesis.A second strategy to prevent lipotoxicity is to increase the capacity of tissues to oxidise fatty acids. PPARγcoactivator-1α is a coactivator of PPARγ that induces the expression of genes that promote the differentiation of preadipocytes to brown adipocytes. Recently, it has been implicated in increasing the oxidation of fatty acids via increasing mitochondrial capacity and function, making this co-factor a key candidate for the treatment of lipotoxicity.

The Role of Peroxisome Proliferator-Activated Receptor in Addiction: A Novel Drug Target

2021 ◽  
Vol 21 ◽  
Author(s):  
Carla Quiroga ◽  
Juan José Barberena ◽  
Jocelyne Alcaraz-Silva ◽  
Sérgio Machado ◽  
Claudio Imperatori ◽  
...  
Keyword(s):  
Nuclear Receptors ◽  
Acid Oxidation ◽  
Critical Element ◽  
Peroxisome Proliferator ◽  
Addictive Behaviors ◽  
Health Issues ◽  
Peroxisome Proliferator Activated Receptor ◽  
Peroxisome Proliferator Activated Receptors ◽  
Novel Drug

: 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.

scholarly journals Aberrant miR199a-5p/caveolin1/PPARα axis in hepatic steatosis

2014 ◽  
Vol 53 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Bo Li ◽  
Zhiguo Zhang ◽  
Huizhi Zhang ◽  
Kai Quan ◽  
Yan Lu ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Fatty Liver ◽  
Vital Role ◽  
Mitochondrial Activity ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Alcoholic Fatty Liver ◽  
Atp Levels ◽  
Excessive Accumulation

The prevalence of non-alcoholic fatty liver disease (NAFLD), a condition characterized by an excessive accumulation of triglycerides (TGs) in hepatocytes, has dramatically increased globally during recent decades. MicroRNAs (miRs) have been suggested to play crucial roles in many complex diseases and lipid metabolism. Our results indicated that miR199a-5p was remarkably upregulated in free fatty acid (FA)-treated hepatocytes. To investigate the role of miR199a-5p in the pathogenesis of fatty liver and the potential mechanism by which miR199a-5p regulates NAFLD, we first transfected two hepatocyte cell lines, HepG2 and AML12 cells, with agomiR199a-5p or antagomiR199a-5p. Our results indicated that miR199a-5p overexpression exacerbated deposition of FA and inhibited ATP levels and mitochondrial DNA (mtDNA) contents. Consistently, suppression of miR199a-5p partially alleviated deposition of FA and increased ATP levels and mtDNA contents. Moreover, miR199a-5p suppressed the expression of mitochondrial FA β-oxidation-related genes through inhibition of caveolin1 (CAV1) and the related peroxisome proliferator-activated receptor alpha (PPARα) pathway. Furthermore, suppression of CAV1 gene expression by CAV1 siRNA inhibited the PPARα signalling pathway. Finally, we examined the expression of miR199a-5p in liver samples derived from mice fed a high-fat diet, db/db mice, ob/ob mice and NAFLD patients, and found that miR199a-5p was upregulated while CAV1 and PPARA were downregulated in these systems, which was strongly indicative of the essential role of miR199a-5p in NAFLD. In summary, miR199a-5p plays a vital role in lipid metabolism, mitochondrial activity and mitochondrial β-oxidation in liver. Upregulated miR199a-5p in hepatocytes may contribute to impaired FA β-oxidation in mitochondria and aberrant lipid deposits, probably via CAV1 and the PPARα pathway.

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