scholarly journals Therapeutic Potential of Peroxisome Proliferator-Activated Receptor (PPAR) Agonists in Substance Use Disorders: A Synthesis of Preclinical and Human Evidence

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1196 ◽  
Author(s):  
Justin Matheson ◽  
Bernard Le Foll

Targeting peroxisome proliferator-activated receptors (PPARs) has received increasing interest as a potential strategy to treat substance use disorders due to the localization of PPARs in addiction-related brain regions and the ability of PPAR ligands to modulate dopamine neurotransmission. Robust evidence from animal models suggests that agonists at both the PPAR-α and PPAR-γ isoforms can reduce both positive and negative reinforcing properties of ethanol, nicotine, opioids, and possibly psychostimulants. A reduction in the voluntary consumption of ethanol following treatment with PPAR agonists seems to be the most consistent finding. However, the human evidence is limited in scope and has so far been less promising. There have been no published human trials of PPAR agonists for treatment of alcohol use disorder, despite the compelling preclinical evidence. Two trials of PPAR-α agonists as potential smoking cessation drugs found no effect on nicotine-related outcomes. The PPAR-γ agonist pioglitazone showed some promise in reducing heroin, nicotine, and cocaine craving in two human laboratory studies and one pilot trial, yet other outcomes were unaffected. Potential explanations for the discordance between the animal and human evidence, such as the potency and selectivity of PPAR ligands and sex-related variability in PPAR physiology, are discussed.

2014 ◽  
Vol 28 (11) ◽  
pp. 1756-1768 ◽  
Author(s):  
Matthew B. Wright ◽  
Michele Bortolini ◽  
Moh Tadayyon ◽  
Martin Bopst

The clinical impact of the fibrate and thiazolidinedione drugs on dyslipidemia and diabetes is driven mainly through activation of two transcription factors, peroxisome proliferator-activated receptors (PPAR)-α and PPAR-γ. However, substantial differences exist in the therapeutic and side-effect profiles of specific drugs. This has been attributed primarily to the complexity of drug-target complexes that involve many coregulatory proteins in the context of specific target gene promoters. Recent data have revealed that some PPAR ligands interact with other non-PPAR targets. Here we review concepts used to develop new agents that preferentially modulate transcriptional complex assembly, target more than one PPAR receptor simultaneously, or act as partial agonists. We highlight newly described on-target mechanisms of PPAR regulation including phosphorylation and nongenomic regulation. We briefly describe the recently discovered non-PPAR protein targets of thiazolidinediones, mitoNEET, and mTOT. Finally, we summarize the contributions of on- and off-target actions to select therapeutic and side effects of PPAR ligands including insulin sensitivity, cardiovascular actions, inflammation, and carcinogenicity.


2019 ◽  
Vol 106 ◽  
pp. 23-48 ◽  
Author(s):  
Patricia Sampedro-Piquero ◽  
David Ladrón de Guevara-Miranda ◽  
Francisco J. Pavón ◽  
Antonia Serrano ◽  
Juan Suárez ◽  
...  

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.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Antonietta Bernardo ◽  
Luisa Minghetti

In the recent years, the peroxisome proliferator-activated receptor- (PPAR-), a well known target for type II diabetes treatment, has received an increasing attention for its therapeutic potential in inflammatory and degenerative brain disorders. PPAR- agonists, which include naturally occurring compounds (such as long chain fatty acids and the cyclopentenone prostaglandin 15-deoxy prostaglandin ), and synthetic agonists (among which the thiazolidinediones and few nonsteroidal anti-inflammatory drugs) have shown anti-inflammatory and protective effects in several experimental models of Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, multiple sclerosis and stroke, as well as in few clinical studies. The pleiotropic effects of PPAR- agonists are likely to be mediated by several mechanisms involving anti-inflammatory activities on peripheral immune cells (macrophages and lymphocytes), as well as direct effects on neural cells including cerebral vascular endothelial cells, neurons, and glia. In the present article, we will review the recent findings supporting a major role for PPAR- agonists in controlling neuroinflammation and neurodegeneration through their activities on glial cells, with a particular emphasis on microglial cells as major macrophage population of the brain parenchyma and main actors in brain inflammation.


2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Erja-Leena Paukkeri ◽  
Antti Pekurinen ◽  
Eeva Moilanen

AbstractPeroxisome proliferator-activated receptor (PPAR) agonists, fibrates and thiazolidinediones, are commonly used drugs in the treatment of dyslipidemia and diabetes. Their targets, PPARα and PPARγ, have also been shown to have a role in the regulation of inflammatory responses linking metabolism and inflammation. In the present study we investigated the effects of PPAR agonists on macrophage activation. In addition to the proinflammatory classical activation, we also focused on interleukin (IL) 4 and 13 -induced alternative activation which is a significant macrophage phenotype in tissue repairing processes and in fibrosing diseases. PPARα agonists GW7647 and fenofibrate as well as PPARγ agonist GW1929 inhibited lipopolysaccharide-induced classical macrophage activation and production of the characteristic biomarkers of this phenotype, i.e. IL-6 and nitric oxide, in murine J774 macrophages. Remarkably, the PPARα agonists also inhibited IL-4 and IL-13 –induced expression of alternative activation markers arginase-1, fizz1 and mannose receptor 1 whereas the PPARγ agonist GW1929 enhanced their expression in J774 macrophages. The PPARα agonists GW7647 and fenofibrate also attenuated the production of alternative activation markers chemokine (C-C motif) ligand 13 and plateletderived growth factor in human THP-1 macrophages. The present findings show that PPARα and PPARγ agonists differently regulate classical and alternative macrophage phenotypes. Furthermore, PPARα activation was introduced as a novel concept to down-regulate alternative macrophage activation indicating that PPARα agonists have therapeutic potential in conditions associated with aberrant alternative macrophage activation such as fibrosing diseases.


2020 ◽  
Author(s):  
Victor Pando-Naude ◽  
Sebastian Toxto ◽  
Sofia Fernandez-Lozano ◽  
E. Christine Parsons ◽  
Sarael Alcauter ◽  
...  

AbstractSubstance use disorders (SUDs) are characterized by a compulsion to seek and consume one or more substances of abuse, with a perceived loss of control and negative emotional state. Repeated use of a substance results in synaptic and morphological changes, secondary to toxicity and SUD pathology in the dopamine striato-thalamo-cortical and limbic pathways. These neuroadaptations seem to vary between studies, which could be related to divergent effects of substances, consumption severity or other unknown factors. We therefore identified studies investigating the effects of SUDs using volumetric whole-brain voxel-based morphometry (VBM) in gray (GM) and white matter (WM). We performed a systematic review and meta-analysis of VBM studies using the anatomic likelihood estimation (ALE) method implemented in GingerALE (PROSPERO pre-registration CRD42017071222). Fifty studies met inclusion criteria and were included in the final quantitative meta-analysis, with a total of 538 foci, 88 experiments and 4370 participants. We found convergence and divergence in brain regions and volume effects (higher vs lower volume) in GM and WM depending on the severity of consumption pattern and type of substance. Convergent pathology was evident across substances in GM of the insula, anterior cingulate cortex, putamen, and thalamus, and in WM of the thalamic radiation and internal capsule bundle. Divergent pathology between occasional use (cortical pathology) and addiction (cortical-subcortical pathology) provides evidence of a possible top-down neuroadaptation. Our findings indicate distinctive brain morphometry alterations in SUDs, which may inform our understanding of disease progression and ultimately therapeutic approaches.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Roberto Scatena ◽  
Patrizia Bottoni ◽  
Bruno Giardina

Before the discovery of peroxisome proliferator activated receptors (PPARs), it was well known that certain drugs considered as classical PPAR-alpha agonists induced hepatocarcinoma or peroxisome proliferation in rodents. These drugs were derivatives of fibric acid, and they included clofibrate, bezafibrate, and fenofibrate. However, such toxicity has never been observed in human patients treated with these hypolipidemic drugs. Thiazolidinediones are a new class of PPAR activators showing greater specificity for the isoform of PPARs. These drugs are used as insulin sensitizers in the treatment of type II diabetes. In addition, they have been shown to induce cell differentiation or apoptosis in various experimental models of cancer. PPAR- ligands have also been shown to induce cancer cell differentiation and, paradoxically, PPAR- drug activators have been reported to act as carcinogens. The confusing picture that emerges from these data is further complicated by the series of intriguing side effects observed following administration of pharmacological PPAR ligands (rhabdomyolysis, liver and heart toxicity, anemia, leucopenia). These side effects cannot be easily explained by simple interactions between the drug and nuclear receptors. Rather, these side effects seem to indicate that the ligands have biological activity independent of the nuclear receptors. Considering the emerging role of mitochondria in cancer and the potential metabolic connections between this organelle and PPAR physiology, characterization of the reciprocal influences is fundamental not only for a better understanding of cancer biology, but also for more defined pharmacotoxicological profiles of drugs that modulate PPARs.


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