scholarly journals Effect of LXR/RXR agonism on brain and CSF Aβ40 levels in rats

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 138 ◽  
Author(s):  
Songli Wang ◽  
Paul Wen ◽  
Stephen Wood
Keyword(s):  
Principal Component ◽  
Amyloid Plaques ◽  
Peroxisome Proliferator ◽  
Liver X Receptors ◽  
Peroxisome Proliferator Activated Receptor ◽  
Abnormal Accumulation ◽  
Csf Levels ◽  
X Receptors ◽  
The Brain ◽  
Receptor Family

Alzheimer's disease (AD) is characterized pathologically by the presence of amyloid plaques and neurofibrillary tangles.  The amyloid hypothesis contends that the abnormal accumulation of Aβ, the principal component of amyloid plaques, plays an essential role in initiating the disease.  Impaired clearance of soluble Aβ from the brain, a process facilitated by apolipoprotein E (APOE), is believed to be a contributing factor in plaque formation.  APOE expression is transcriptionally regulated through the action of a family of nuclear receptors including the peroxisome proliferator-activated receptor gamma and liver X receptors (LXRs) in coordination with retinoid X receptors (RXRs).  It has been previously reported that various agonists of this receptor family can influence brain Aβ levels in rodents.  In this study we investigated the effects of LXR/RXR agonism on brain and cerebrospinal fluid (CSF) levels of Aβ40 in naïve rats.  Treatment of rats for 3 days or 7 days with the LXR agonist, TO901317 or the RXR agonist, Bexarotene did not result in significant changes in brain or CSF Aβ40 levels.

scholarly journals Effect of LXR/RXR agonism on brain and CSF Aβ40 levels in rats

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 138 ◽  
Author(s):  
Songli Wang ◽  
Paul Wen ◽  
Stephen Wood
Keyword(s):  
Principal Component ◽  
Amyloid Plaques ◽  
Peroxisome Proliferator ◽  
Liver X Receptors ◽  
Peroxisome Proliferator Activated Receptor ◽  
Abnormal Accumulation ◽  
Csf Levels ◽  
X Receptors ◽  
The Brain ◽  
Receptor Family

Alzheimer's disease (AD) is characterized pathologically by the presence of amyloid plaques and neurofibrillary tangles. The amyloid hypothesis contends that the abnormal accumulation of Aβ, the principal component of amyloid plaques, plays an essential role in initiating the disease. Impaired clearance of soluble Aβ from the brain, a process facilitated by apolipoprotein E (APOE), is believed to be a contributing factor in plaque formation. APOE expression is transcriptionally regulated through the action of a family of nuclear receptors including the peroxisome proliferator-activated receptor gamma and liver X receptors (LXRs) in coordination with retinoid X receptors (RXRs). It has been previously reported that various agonists of this receptor family can influence brain Aβ levels in rodents. In this study we investigated the effects of LXR/RXR agonism on brain and cerebrospinal fluid (CSF) levels of Aβ40 in naïve rats. Treatment of rats for 3 days or 7 days with the LXR agonist, T0901317 or the RXR agonist, bexarotene did not result in significant changes in brain or CSF Aβ40 levels.

scholarly journals Activated Liver X Receptors Stimulate Adipocyte Differentiation through Induction of Peroxisome Proliferator-Activated Receptor γ Expression

2004 ◽  
Vol 24 (8) ◽  
pp. 3430-3444 ◽  
Author(s):  
Jong Bae Seo ◽  
Hyang Mi Moon ◽  
Woo Sik Kim ◽  
Yun Sok Lee ◽  
Hyun Woo Jeong ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Adipocyte Differentiation ◽  
Specific Gene ◽  
Peroxisome Proliferator ◽  
Liver X Receptors ◽  
Gene Promoters ◽  
Peroxisome Proliferator Activated Receptor ◽  
Specific Gene Expression ◽  
X Receptors

ABSTRACT Liver X receptors (LXRs) are nuclear hormone receptors that regulate cholesterol and fatty acid metabolism in liver tissue and in macrophages. Although LXR activation enhances lipogenesis, it is not well understood whether LXRs are involved in adipocyte differentiation. Here, we show that LXR activation stimulated the execution of adipogenesis, as determined by lipid droplet accumulation and adipocyte-specific gene expression in vivo and in vitro. In adipocytes, LXR activation with T0901317 primarily enhanced the expression of lipogenic genes such as the ADD1/SREBP1c and FAS genes and substantially increased the expression of the adipocyte-specific genes encoding PPARγ (peroxisome proliferator-activated receptor γ) and aP2. Administration of the LXR agonist T0901317 to lean mice promoted the expression of most lipogenic and adipogenic genes in fat and liver tissues. It is of interest that the PPARγ gene is a novel target gene of LXR, since the PPARγ promoter contains the conserved binding site of LXR and was transactivated by the expression of LXRα. Moreover, activated LXRα exhibited an increase of DNA binding to its target gene promoters, such as ADD1/SREBP1c and PPARγ, which appeared to be closely associated with hyperacetylation of histone H3 in the promoter regions of those genes. Furthermore, the suppression of LXRα by small interfering RNA attenuated adipocyte differentiation. Taken together, these results suggest that LXR plays a role in the execution of adipocyte differentiation by regulation of lipogenesis and adipocyte-specific gene expression.

scholarly journals From Exercise to Cognitive Performance: Role of Irisin

2021 ◽  
Vol 11 (15) ◽  
pp. 7120
Author(s):  
Mirko Pesce ◽  
Irene La Fratta ◽  
Teresa Paolucci ◽  
Alfredo Grilli ◽  
Antonia Patruno ◽  
...  
Keyword(s):  
The Elderly ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Beneficial Effects ◽  
General Exercise ◽  
Fibronectin Type Iii ◽  
Exercise Induced ◽  
Fibronectin Type Iii Domain ◽  
The Brain

The beneficial effects of exercise on the brain are well known. In general, exercise offers an effective way to improve cognitive function in all ages, particularly in the elderly, who are considered the most vulnerable to neurodegenerative disorders. In this regard, myokines, hormones secreted by muscle in response to exercise, have recently gained attention as beneficial mediators. Irisin is a novel exercise-induced myokine, that modulates several bodily processes, such as glucose homeostasis, and reduces systemic inflammation. Irisin is cleaved from fibronectin type III domain containing 5 (FNDC5), a transmembrane precursor protein expressed in muscle under the control of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). The FNDC5/irisin system is also expressed in the hippocampus, where it stimulates the expression of the neurotrophin brain-derived neurotrophic factor in this area that is associated with learning and memory. In this review, we aimed to discuss the role of irisin as a key mediator of the beneficial effects of exercise on synaptic plasticity and memory in the elderly, suggesting its roles within the main promoters of the beneficial effects of exercise on the brain.

scholarly journals Quercetin Attenuates Brain Oxidative Alterations Induced by Iron Oxide Nanoparticles in Rats

2021 ◽  
Vol 22 (8) ◽  
pp. 3829
Author(s):  
Mohamed F. Dora ◽  
Nabil M. Taha ◽  
Mohamed A. Lebda ◽  
Aml E. Hashem ◽  
Mohamed S. Elfeky ◽  
...  
Keyword(s):  
Iron Oxide ◽  
B Cell Lymphoma ◽  
Basal Diet ◽  
Protective Role ◽  
Iron Oxide Nanoparticle ◽  
Albino Rats ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
The Brain

Iron oxide nanoparticle (IONP) therapy has diverse health benefits but high doses or prolonged therapy might induce oxidative cellular injuries especially in the brain. Therefore, we conducted the current study to investigate the protective role of quercetin supplementation against the oxidative alterations induced in the brains of rats due to IONPs. Forty adult male albino rats were allocated into equal five groups; the control received a normal basal diet, the IONP group was intraperitoneally injected with IONPs of 50 mg/kg body weight (B.W.) and quercetin-treated groups had IONPs + Q25, IONPs + Q50 and IONPs + Q100 that were orally supplanted with quercetin by doses of 25, 50 and 100 mg quercetin/kg B.W. daily, respectively, administrated with the same dose of IONPs for 30 days. IONPs induced significant increases in malondialdehyde (MDA) and significantly decreased reduced glutathione (GSH) and oxidized glutathione (GSSG). Consequently, IONPs significantly induced severe brain tissue injuries due to the iron deposition leading to oxidative alterations with significant increases in brain creatine phosphokinase (CPK) and acetylcholinesterase (AChE). Furthermore, IONPs induced significant reductions in brain epinephrine, serotonin and melatonin with the downregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and mitochondrial transcription factor A (mtTFA) mRNA expressions. IONPs induced apoptosis in the brain monitored by increases in caspase 3 and decreases in B-cell lymphoma 2 (Bcl2) expression levels. Quercetin supplementation notably defeated brain oxidative damages and in a dose-dependent manner. Therefore, quercetin supplementation during IONPs is highly recommended to gain the benefits of IONPs with fewer health hazards.

scholarly journals Signaling Mechanisms of Selective PPARγ Modulators in Alzheimer’s Disease

PPAR Research ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Manoj Govindarajulu ◽  
Priyanka D. Pinky ◽  
Jenna Bloemer ◽  
Nila Ghanei ◽  
Vishnu Suppiramaniam ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Adverse Effects ◽  
Therapeutic Potential ◽  
Protein Accumulation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Continuous Increase ◽  
Therapeutic Benefits ◽  
The Brain

Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by abnormal protein accumulation, synaptic dysfunction, and cognitive impairment. The continuous increase in the incidence of AD with the aged population and mortality rate indicates the urgent need for establishing novel molecular targets for therapeutic potential. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists such as rosiglitazone and pioglitazone reduce amyloid and tau pathologies, inhibit neuroinflammation, and improve memory impairments in several rodent models and in humans with mild-to-moderate AD. However, these agonists display poor blood brain barrier permeability resulting in inadequate bioavailability in the brain and thus requiring high dosing with chronic time frames. Furthermore, these dosing levels are associated with several adverse effects including increased incidence of weight gain, liver abnormalities, and heart failure. Therefore, there is a need for identifying novel compounds which target PPARγ more selectively in the brain and could provide therapeutic benefits without a high incidence of adverse effects. This review focuses on how PPARγ agonists influence various pathologies in AD with emphasis on development of novel selective PPARγ modulators.

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