Elafibranor interrupts adipose dysfunction-mediated gut and liver injury in mice with alcoholic steatohepatitis

2019 ◽  
Vol 133 (3) ◽  
pp. 531-544 ◽  
Author(s):  
Tzu-Hao Li ◽  
Ying-Ying Yang ◽  
Chia-Chang Huang ◽  
Chih-Wei Liu ◽  
Hung-Cheng Tsai ◽  
...  

Abstract Background: Reversal of alcohol-induced peroxisome proliferator-activated receptor (PPAR) α (PPARα) and PPARδ dysfunction has been reported to decrease the severity of alcoholic steatohepatitis (ASH). Autophagy is essential for cell survival and tissue energy homeostasis. Emerging evidence indicates that alcohol-induced adipose tissue (AT) autophagy dysfunction contributes to injury in the intestine, liver, and AT of ASH. Methods: The effects and mechanisms of dual PPARα/δ agonist elafibranor on autophagy stimulation were investigated using mice with ASH. Results: C57BL/6 mice on ethanol diet showed AT dysfunction, disrupted intestinal barrier, and ASH, which was accompanied by alcohol-mediated decrease in PPARα, PPARδ, and autophagy levels in intestine, liver, and AT. Chronic treatment with elafibranor attenuated AT apoptosis and inflammation by restoration of tissue PPARα, PPARδ, and autophagy levels. In ASH mice, alcohol-induced AT dysfunction along with increased fatty acid (FA) uptake and decreased free FA (FFA) release from AT was inhibited by elafibranor. The improvement of AT autophagy dysfunction by elafibranor alleviated inflammation and apoptosis-mediated intestinal epithelial disruption in ASH mice. Acute elafibranor incubation inhibited ethanol-induced ASH-mice-sera-enhanced autophagy dysfunction, apoptosis, barrier disruption, and intracellular steatosis in Caco-2 cells and primary hepatocytes (PHs). Conclusion: Altogether, these findings demonstrated that the PPARα/δ agonist, elafibranor, decreased the severity of liver injury by restoration of alcohol-suppressed AT autophagy function and by decreasing the release of apoptotic markers, inflammatory cytokines, and FFA, thereby reducing intestinal epithelium disruption and liver inflammation/apoptosis/steatosis in ASH mice. These data suggest that dual PPAR agonists can serve as potential therapeutic agents for the management of ASH.

2019 ◽  
Vol 13 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Alessandra Ammazzalorso ◽  
Rosa Amoroso

A wide group of natural compounds (flavonoids, stilbenes, neolignans and others) has been identified as Peroxisome Proliferator-Activated Receptor (PPAR) agonists, with a large variety of chemical structure and different activity versus the three PPAR subtypes. These receptors are transcription factors controlling metabolic pathways in the organism, involved in lipid and glucose metabolism, cell differentiation and energy homeostasis. Otherwise, very little is known about natural compounds able to inhibit PPARs. A number of studies demonstrate that PPARγ repression has a beneficial effect in reducing body weight and improving insulin sensitivity, suggesting a potential clinical role in obesity and type 2 diabetes. This review analyzes natural compounds able to repress PPAR activity and their potential use in metabolic disorders.


2019 ◽  
Vol 20 (22) ◽  
pp. 5589
Author(s):  
Jaeim Lee ◽  
Ok-Hee Kim ◽  
Sang Chul Lee ◽  
Kee-Hwan Kim ◽  
Jin Sun Shin ◽  
...  

Peroxisome proliferator activated receptor λ coactivator 1α (PGC-1α) is a potent regulator of mitochondrial biogenesis and energy metabolism. In this study, we investigated the therapeutic potential of the secretome released from the adipose-derived stem cells (ASCs) transfected with PGC-1α (PGC-secretome). We first generated PGC-1α-overexpressing ASCs by transfecting ASCs with the plasmids harboring the gene encoding PGC-1α. Secretory materials released from PGC-1α-overexpressing ASCs were collected and their therapeutic potential was determined using in vitro (thioacetamide (TAA)-treated AML12 cells) and in vivo (70% partial hepatectomized mice) models of liver injury. In the TAA-treated AML12 cells, the PGC-secretome significantly increased cell viability, promoted expression of proliferation-related markers, such as PCNA and p-STAT, and significantly reduced the levels of reactive oxygen species (ROS). In the mice, PGC-secretome injections significantly increased liver tissue expression of proliferation-related markers more than normal secretome injections did (p < 0.05). We demonstrated that the PGC-secretome does not only have higher antioxidant and anti-inflammatory properties, but also has the potential of significantly enhancing liver regeneration in both in vivo and in vitro models of liver injury. Thus, reinforcing the mitochondrial antioxidant potential by transfecting ASCs with PGC-1α could be one of the effective strategies to enhance the therapeutic potential of ASCs.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Jennifer G. Robinson

Trials of peroxisome proliferator-activated receptor (PPAR) agonists have shown mixed results for cardiovascular prevention. Fibrates are PPAR- agonists that act primarily to improve dyslipidemia. Based on low- and high-density lipoprotein cholesterol (LDL and HDL) effects, gemfibrozil may be of greater cardiovascular benefit than expected, fenofibrate performed about as expected, and bezafibrate performed worse than expected. Increases in both cardiovascular and noncardiovascular serious adverse events have been observed with some fibrates. Thiazolidinediones (TZDs) are PPAR- agonists used to improve impaired glucose metabolism but also influence lipids. Pioglitazone reduces atherosclerotic events in diabetic subjects, but has no net cardiovascular benefit due to increased congestive heart failure risk. Rosiglitazone may increase the risk of atherosclerotic events, and has a net harmful effect on the cardiovascular system when congestive heart failure is included. The primary benefit of TZDs appears to be the prevention of diabetic microvascular complications. Dual PPAR- agonists have had unacceptable adverse effects but more selective agents are in development. PPAR- and pan-agonists are also in development. It will be imperative to prove that future PPAR agonists not only prevent atherosclerotic events but also result in a net reduction on total cardiovascular events without significant noncardiovascular adverse effects with long-term use.


PPAR Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Seong-Hoon Yun ◽  
Sang-Heum Han ◽  
Joo-In Park

Peroxisome proliferator-activated receptor γ (PPARγ) is part of a nuclear receptor superfamily that regulates gene expression involved in cell differentiation, proliferation, immune/inflammation response, and lipid metabolism. PPARγ coactivator-1α (PGC-1α), initially identified as a PPARγ-interacting protein, is an important regulator of diverse metabolic pathways, such as oxidative metabolism and energy homeostasis. The role of PGC-1α in diabetes, neurodegeneration, and cardiovascular disease is particularly well known. PGC-1α is also now known to play important roles in cancer, independent of the role of PPARγ in cancer. Though many researchers have studied the expression and clinical implications of PPARγ and PGC-1α in cancer, there are still many controversies about the role of PPARγ and PGC-1α in cancer. This review examines and summarizes some recent data on the role and action mechanisms of PPARγ and PGC-1α in cancer, respectively, particularly the recent progress in understanding the role of PPARγ in several cancers since our review was published in 2012.


2017 ◽  
Vol 58 (2) ◽  
pp. 57-66 ◽  
Author(s):  
Rose Kohlie ◽  
Nina Perwitz ◽  
Julia Resch ◽  
Sebastian M Schmid ◽  
Hendrik Lehnert ◽  
...  

Brown adipose tissue (BAT) is key to energy homeostasis. By virtue of its thermogenic potential, it may dissipate excessive energy, regulate body weight and increase insulin sensitivity. Catecholamines are critically involved in the regulation of BAT thermogenesis, yet research has focussed on the effects of noradrenaline and adrenaline. Some evidence suggests a role of dopamine (DA) in BAT thermogenesis, but the cellular mechanisms involved have not been addressed. We employed our extensively characterised murine brown adipocyte cells. D1-like and D2-like receptors were detectable at the protein level. Stimulation with DA caused an increase in cAMP concentrations. Oxygen consumption rates (OCR), mitochondrial membrane potential (Δψm) and uncoupling protein 1 (UCP1) levels increased after 24 h of treatment with either DA or a D1-like specific receptor agonist. A D1-like receptor antagonist abolished the DA-mediated effect on OCR, Δψm and UCP1. DA induced the release of fatty acids, which did not additionally alter DA-mediated increases of OCR. Mitochondrial mass (as determined by (i) CCCP- and oligomycin-mediated effects on OCR and (ii) immunoblot analysis of mitochondrial proteins) also increased within 24 h. This was accompanied by an increase in peroxisome proliferator-activated receptor gamma co-activator 1 alpha protein levels. Also, DA caused an increase in p38 MAPK phosphorylation and pharmacological inhibition of p38 MAPK abolished the DA-mediated effect on Δψm. In summary, our study is the first to reveal direct D1-like receptor and p38 MAPK-mediated increases of thermogenesis and mitochondrial mass in brown adipocytes. These results expand our understanding of catecholaminergic effects on BAT thermogenesis.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Heidi N. Bagley ◽  
Yan Wang ◽  
Michael S. Campbell ◽  
Xing Yu ◽  
Robert H. Lane ◽  
...  

Intrauterine growth restriction (IUGR) predisposes to obesity and adipose dysfunction. We previously demonstrated IUGR-induced increased visceral adipose deposition and dysregulated expression of peroxisome proliferator activated receptor-γ2 (PPARγ2) in male adolescent rats, prior to the onset of obesity. In other studies, activation of PPARγincreases subcutaneous adiponectin expression and normalizes visceral adipose deposition. We hypothesized that maternal supplementation with docosahexaenoic acid (DHA), a PPARγagonist, would normalize IUGR adipose deposition in association with increased PPARγ, adiponectin, and adiponectin receptor expression in subcutaneous adipose. To test these hypotheses, we used a well-characterized model of uteroplacental-insufficiency-(UPI-) induced IUGR in the rat with maternal DHA supplementation. Our primary findings were that maternal DHA supplementation during rat pregnancy and lactation (1) normalizes IUGR-induced changes in adipose deposition and visceral PPARγexpression in male rats and (2) increases serum adiponectin, as well as adipose expression of adiponectin and adiponectin receptors in former IUGR rats. Our novel findings suggest that maternal DHA supplementation may normalize adipose dysfunction and promote adiponectin-induced improvements in metabolic function in IUGR.


2014 ◽  
Vol 34 (4) ◽  
pp. 646-653 ◽  
Author(s):  
Wen Huang ◽  
Lei Chen ◽  
Bei Zhang ◽  
Minseon Park ◽  
Michal Toborek

The strategies to protect against the disrupted blood–brain barrier (BBB) in HIV-1 infection are not well developed. Therefore, we investigated the potential of peroxisome proliferator-activated receptor (PPAR) agonists to prevent enhanced BBB permeability induced by HIV-1-specific protein Tat. Exposure to Tat via the internal carotid artery (ICA) disrupted permeability across the BBB; however, this effect was attenuated in mice treated with fenofibrate (PPAR α agonist) or rosiglitazone (PPAR γ agonist). In contrast, exposure to GW9662 (PPAR γ antagonist) exacerbated Tat-induced disruption of the BBB integrity. Increased BBB permeability was associated with decreased tight junction (TJ) protein expression and activation of ERK1/2 and Akt in brain microvessels; these effects were attenuated by cotreatment with fenofibrate but not with rosiglitazone. Importantly, both PPAR agonists also protected against Tat-induced astrogliosis and neuronal loss. Because disruption of TJ integrity has been linked to matrix metalloproteinase (MMP) activity, we also evaluated Tat-induced effects in MMP-9-deficient mice. Tat-induced cerebrovascular toxicity, astrogliosis, and neuronal loss were less pronounced in MMP-9-deficient mice as compared with wild-type controls and were further attenuated by PPAR agonists. These results indicate that enhancing PPAR activity combined with targeting MMPs may provide effective therapeutic strategies in brain infection by HIV-1.


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