scholarly journals Expression Patterns of Retinoid X Receptors, Retinaldehyde Dehydrogenase, and Peroxisome Proliferator Activated Receptor Gamma in Bovine Preattachment Embryos1

2002 ◽  
Vol 66 (3) ◽  
pp. 692-700 ◽  
Author(s):  
M. Mohan ◽  
J.R. Malayer ◽  
R.D. Geisert ◽  
G.L. Morgan
1999 ◽  
Vol 277 (6) ◽  
pp. F966-F973 ◽  
Author(s):  
Tianxin Yang ◽  
Daniel E. Michele ◽  
John Park ◽  
Ann M. Smart ◽  
Zhiwu Lin ◽  
...  

The discovery that 15-deoxy-Δ12,14-prostaglandin J2(15d-PGJ2) is a ligand for the γ-isoform of peroxisome proliferator-activated receptor (PPAR) suggests nuclear signaling by prostaglandins. Studies were undertaken to determine the nephron localization of PPAR isoforms and their heterodimer partners, retinoid X receptors (RXR), and to evaluate the function of this system in the kidney. PPARα mRNA, determined by RT-PCR, was found predominately in cortex and further localized to proximal convoluted tubule (PCT); PPARγ was abundant in renal inner medulla, localized to inner medullary collecting duct (IMCD) and renal medullary interstitial cells (RMIC); PPARβ, the ubiquitous form of PPAR, was abundant in all nephron segments examined. RXRα was localized to PCT and IMCD, whereas RXRβ was expressed in almost all nephron segments examined. mRNA expression of acyl-CoA synthase (ACS), a known PPAR target gene, was stimulated in renal cortex of rats fed with fenofibrate, but the expression was not significantly altered in either cortex or inner medulla of rats fed with troglitazone. In cultured RMIC cells, both troglitazone and 15d-PGJ2 significantly inhibited cell proliferation and dramatically altered cell shape by induction of cell process formation. We conclude that PPAR and RXR isoforms are expressed in a nephron segment-specific manner, suggesting distinct functions, with PPARα being involved in energy metabolism through regulating ACS in PCT and with PPARγ being involved in modulating RMIC growth and differentiation.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Michael A Burke ◽  
Stephen Chang ◽  
Danos C Christodoulou ◽  
Joshua M Gorham ◽  
Hiroko Wakimoto ◽  
...  

The complex molecular networks underpinning DCM remain poorly understood. To study distinct pathways and networks in the longitudinal development of DCM we performed RNAseq on LV tissue from mice carrying a human DCM mutation in phospholamban (PLN R9C/+ ) before phenotype onset (pre-DCM), with DCM, and during overt heart failure (HF), and also on isolated myocytes and non-myocytes from DCM hearts. PLN R9C/+ mice show progressive fibrosis (20% vs. 1% control, p=6x10 −33 ; n=3) associated with proliferation of cardiac non-myocytes (33% increase over control, p=6x10 −4 ; n=3). Consistent with this, cardiac non-myocytes have upregulated gene expression and pathways, while these are generally downregulated in myocytes. Non-myocytes were enriched in fibrosis, inflammation, and cell remodeling pathways, from pre-DCM to HF. In contrast, myocytes were enriched for metabolic pathways only with overt DCM and HF. Myocytes showed profound derangement of oxidative phosphorylation with DCM (p=2.5x10 −41 ; 44% (53/120) of pathway genes downregulated), suggesting mitochondrial dysfunction. Additionally, we detected probable inhibition of peroxisome proliferator-activated receptor (PPAR) signaling by diminished expression of pathway genes (Figure). DCM and hypertrophic remodeling was compared using RNAseq of a mouse model of HCM; similar patterns of fibrosis with myocyte metabolic dysregulation were evident despite unique differential gene expression patterns between models. DCM caused by PLN R9C/+ is associated with early non-myocyte proliferation and later myocyte metabolic derangement possibly governed by altered PPAR signaling, and is common to DCM and HCM.


2013 ◽  
Vol 95 (2-3) ◽  
pp. 78-88 ◽  
Author(s):  
KAN HE ◽  
ZHEN WANG ◽  
QISHAN WANG ◽  
YUCHUN PAN

SummaryGene expression profiling of peroxisome-proliferator-activated receptor α (PPARα) has been used in several studies, but there were no consistent results on gene expression patterns involved in PPARα activation in genome-wide due to different sample sizes or platforms. Here, we employed two published microarray datasets both PPARα dependent in mouse liver and applied meta-analysis on them to increase the power of the identification of differentially expressed genes and significantly enriched pathways. As a result, we have improved the concordance in identifying many biological mechanisms involved in PPARα activation. We suggest that our analysis not only leads to more identified genes by combining datasets from different resources together, but also provides some novel hepatic tissue-specific marker genes related to PPARα according to our re-analysis.


F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 138 ◽  
Author(s):  
Songli Wang ◽  
Paul Wen ◽  
Stephen Wood

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.


2004 ◽  
Vol 24 (8) ◽  
pp. 3430-3444 ◽  
Author(s):  
Jong Bae Seo ◽  
Hyang Mi Moon ◽  
Woo Sik Kim ◽  
Yun Sok Lee ◽  
Hyun Woo Jeong ◽  
...  

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.


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