Search results for "Peroxisome Proliferator-Activated Receptor"
showing 10 items of 123 documents
The cyclopentenone-type prostaglandin 15-deoxy-delta12,14-prostaglandin J2 inhibits CD95 ligand gene expression in T lymphocytes: interference with p…
2003
Abstract 15-Deoxy-Δ12,14-PGJ2 (15d-PGJ2) is a cyclopentenone-type PG endowed with anti-inflammatory properties and produced by different cells, including those of the immune system. 15d-PGJ2 is a natural ligand of the peroxisome proliferator-activated receptor (PPAR)-γ nuclear receptor, but relevant PPARγ-independent actions mediated by this prostanoid have been described. Fas (APO-1/CD95) and its ligand (Fas-L) are cell surface proteins whose interaction activates apoptosis of Fas-expressing targets. In T cells, the Fas-Fas-L system regulates activation-induced cell death and has been implicated in diseases in which lymphocyte homeostasis is compromised. Moreover, several studies have desc…
The loss of muscle mass and sarcopenia: non hormonal intervention.
2011
Muscle aging is a key component of the increase in frailty in human populations. The generation of critical levels of power is a prerequisite to perform simple tasks of daily living, such as rising from a chair or climbing stairs. There is great scientific and social interest to determine which behaviors can lead to the maintenance of the muscle mass in young immobilized subjects and in the elderly. Several hormonal treatments have been proposed for the treatment of sarcopenia. However, the side effects associated to these treatments emphasize the need of finding non-toxic and non-hormonal treatments that help increase muscle strength, improve muscle function, and decrease the degree of dep…
Peroxisome proliferator-activated receptors as regulators of lipid metabolism; tissue differential expression in adipose tissues during cold acclimat…
2004
Brown (BAT) and white (WAT) adipose tissues play a key role in the body energy balance orchestrated by the central nervous system. Hibernators have developed a seasonal obesity to respond to inhospitable environment. Jerboa is one of the deep hibernator originated from sub-desert highlands. Thus, this animal represents an excellent model to study cold adaptation mechanism. We report that the adipogenic factor PPARgamma exhibits a differential expression between BAT and WAT at mRNA level. A specific induction was only seen in WAT of pre-hibernating jerboa. Interestingly, PPAR beta/delta is specifically induced in BAT and brain of pre-hibernating jerboa, highlighting for the first time the po…
Cigarette smoke increases BLT2 receptor functions in bronchial epithelial cells: in vitro and ex vivo evidence
2013
Summary Leukotriene B4 (LTB4) is a neutrophil chemotactic molecule with important involvement in the inflammatory responses of chronic obstructive pulmonary disease (COPD). Airway epithelium is emerging as a regulator of innate immune responses to a variety of insults including cigarette smoke, the major risk factor for COPD. In this study we have explored whether cigarette smoke extracts (CSE) or soluble mediators present in distal lung fluid samples (mini-bronchoalveolar lavages) from smokers alter the expression of the LTB4 receptor 2 (BLT2) and peroxisome proliferator-activated receptor-α (PPAR-α) in bronchial epithelial cells. We also evaluated the effects of CSE on the expression of i…
Differences in cell proliferation in rodent and human hepatic derived cell lines exposed to ciprofibrate.
2005
International audience; Humans appear to be refractory to some effects of peroxisome proliferators including alterations in cell proliferation, whereas rodents are susceptible. In this study, differences between the human and rat response to peroxisome proliferators were evaluated using rat and human tumour liver cell lines. Rat 7777 cells were more responsive than human HepG2 cells to ciprofibrate as they exhibited a higher decrease in cell number than HepG2, and underwent apoptosis. Results from these studies reveal a surprising response in tumour cell lines as the typical in vivo response of increased cell proliferation and reduced apoptosis was not observed in rat tumour cell lines at c…
The nuclear receptor PPARγ selectively inhibits Th17 differentiation in a T cell–intrinsic fashion and suppresses CNS autoimmunity
2009
T helper cells secreting interleukin (IL)-17 (Th17 cells) play a crucial role in autoimmune diseases like multiple sclerosis (MS). Th17 differentiation, which is induced by a combination of transforming growth factor (TGF)-beta/IL-6 or IL-21, requires expression of the transcription factor retinoic acid receptor-related orphan receptor gamma t (ROR gamma t). We identify the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR gamma) as a key negative regulator of human and mouse Th17 differentiation. PPAR gamma activation in CD4(+) T cells selectively suppressed Th17 differentiation, but not differentiation into Th1, Th2, or regulatory T cells. Control of Th17 differentia…
Garcinoic acid prevents β-amyloid (Aβ) deposition in the mouse brain
2020
Garcinoic acid (GA or δ-T3-13'COOH), is a natural vitamin E metabolite that has preliminarily been identified as a modulator of nuclear receptors involved in β-amyloid (Aβ) metabolism and progression of Alzheimer's disease (AD). In this study, we investigated GA's effects on Aβ oligomer formation and deposition. Specifically, we compared them with those of other vitamin E analogs and the soy isoflavone genistein, a natural agonist of peroxisome proliferator–activated receptor γ (PPARγ) that has therapeutic potential for managing AD. GA significantly reduced Aβ aggregation and accumulation in mouse cortical astrocytes. Similarly to genistein, GA up-regulated PPARγ expression and apolipoprote…
A human relevance investigation of PPARα-mediated key events in the hepatocarcinogenic mode of action of propaquizafop in rats
2018
Propaquizafop is an herbicide with demonstrated hepatocarcinogenic activity in rodents. A rodent-specific mode of action (MOA) in the liver via activation of peroxisome proliferator-activated receptor α (PPARα) has been postulated based on existing data. Experience with PPARα-inducing pharmaceuticals indicates a lack of human relevance of this MOA. The objective of the present investigation was to evaluate the dependency of early key events leading to liver tumors on PPARα activation in wildtype (WT) compared to PPARα-knockout (KO) rats following 2 weeks exposure to 75, 500 and 1000 ppm propaquizafop in the diet. In WT rats, both WY-14643 (50 mg/kg bw/day) and propaquizafop (dose-dependentl…
Induction of the peroxisome proliferator activated receptor by fenofibrate in rat liver
1992
AbstractThe process of peroxisome proliferation in rodent liver by hypolipidemic compounds and related substances has recently been shown to be receptor-madiated. In the present study, we have examined the effect of oral administration of the strong peroxisome proliferator fenofibrate on the hepatic expression level of the peroxisome proliferator activated receptor (PPAR) in rats. Immunoblots of rat liver cytosols and nuclear extracs using antibodies raised against recombinant PPAR/β-galactosidase fusion proteins revealed a pronounced increase in the amount of PPAR protein in response to fenofibrate treatment. This induction could also be confirmed at the level or RNA by Northern blotting. …
Differential expression of PGC-1α and metabolic sensors suggest age-dependent induction of mitochondrial biogenesis in Friedreich ataxia fibroblasts.
2011
11 pages, 6 figures. PMID:21687738[PubMed] PMCID: PMC3110204