scholarly journals The G0/G1 switch gene 2 is a novel PPAR target gene

2005 ◽  
Vol 392 (2) ◽  
pp. 313-324 ◽  
Author(s):  
Fokko Zandbergen ◽  
Stéphane Mandard ◽  
Pascal Escher ◽  
Nguan Soon Tan ◽  
David Patsouris ◽  
...  

PPARs (peroxisome-proliferator-activated receptors) α, β/δ and γ are a group of transcription factors that are involved in numerous processes, including lipid metabolism and adipogenesis. By comparing liver mRNAs of wild-type and PPARα-null mice using microarrays, a novel putative target gene of PPARα, G0S2 (G0/G1 switch gene 2), was identified. Hepatic expression of G0S2 was up-regulated by fasting and by the PPARα agonist Wy14643 in a PPARα-dependent manner. Surprisingly, the G0S2 mRNA level was highest in brown and white adipose tissue and was greatly up-regulated during mouse 3T3-L1 and human SGBS (Simpson–Golabi–Behmel syndrome) adipogenesis. Transactivation, gel shift and chromatin immunoprecipitation assays indicated that G0S2 is a direct PPARγ and probable PPARα target gene with a functional PPRE (PPAR-responsive element) in its promoter. Up-regulation of G0S2 mRNA seemed to be specific for adipogenesis, and was not observed during osteogenesis or myogenesis. In 3T3-L1 fibroblasts, expression of G0S2 was associated with growth arrest, which is required for 3T3-L1 adipogenesis. Together, these data indicate that G0S2 is a novel target gene of PPARs that may be involved in adipocyte differentiation.

PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Li Fang ◽  
Man Zhang ◽  
Yanhui Li ◽  
Yan Liu ◽  
Qinghua Cui ◽  
...  

The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors of the nuclear receptor superfamily. Upon ligand binding, PPARs activate target gene transcription and regulate a variety of important physiological processes such as lipid metabolism, inflammation, and wound healing. Here, we describe the first database of PPAR target genes, PPARgene. Among the 225 experimentally verified PPAR target genes, 83 are for PPARα, 83 are for PPARβ/δ, and 104 are for PPARγ. Detailed information including tissue types, species, and reference PubMed IDs was also provided. In addition, we developed a machine learning method to predict novel PPAR target genes by integratingin silicoPPAR-responsive element (PPRE) analysis with high throughput gene expression data. Fivefold cross validation showed that the performance of this prediction method was significantly improved compared to thein silicoPPRE analysis method. The prediction tool is also implemented in the PPARgene database.


2007 ◽  
Vol 64 (9) ◽  
pp. 1145-1157 ◽  
Author(s):  
S. Mandard ◽  
R. Stienstra ◽  
P. Escher ◽  
N. S. Tan ◽  
I. Kim ◽  
...  

2018 ◽  
Vol 475 (10) ◽  
pp. 1687-1699 ◽  
Author(s):  
Eunjin Koh ◽  
Young Kyung Kim ◽  
Daye Shin ◽  
Kyung-Sup Kim

Mitochondrial pyruvate carrier (MPC), which is essential for mitochondrial pyruvate usage, mediates the transport of cytosolic pyruvate into mitochondria. Low MPC expression is associated with various cancers, and functionally associated with glycolytic metabolism and stemness. However, the mechanism by which MPC expression is regulated is largely unknown. In this study, we showed that MPC1 is down-regulated in human renal cell carcinoma (RCC) due to strong suppression of peroxisome proliferator-activated receptor-gamma co-activator (PGC)-1 alpha (PGC-1α). We also demonstrated that overexpression of PGC-1α stimulates MPC1 transcription, while depletion of PGC-1α by siRNA suppresses MPC expression. We found that PGC-1α interacts with estrogen-related receptor-alpha (ERR-α) and recruits it to the ERR-α response element motif located in the proximal MPC1 promoter, resulting in efficient activation of MPC1 expression. Furthermore, the MPC inhibitor, UK5099, blocked PGC-1α-induced pyruvate-dependent mitochondrial oxygen consumption. Taken together, our results suggest that MPC1 is a novel target gene of PGC-1α. In addition, low expression of PGC-1α in human RCC might contribute to the reduced expression of MPC, resulting in impaired mitochondrial respiratory capacity in RCC by limiting the transport of pyruvate into the mitochondrial matrix.


Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5525-5531 ◽  
Author(s):  
Gary M. Leong ◽  
Sofia Moverare ◽  
Jesena Brce ◽  
Nathan Doyle ◽  
Klara Sjögren ◽  
...  

Abstract Suppressors of cytokine signaling (SOCS) are important negative regulators of cytokine action. We recently reported that estrogen stimulates SOCS-2 expression and inhibits GH signaling in kidney cells. The effects of estrogen on SOCS expression in other tissues are unclear. The aim of this study was to investigate in vivo and in vitro whether estrogen affected SOCS expression in the liver, a major target organ of GH. The in vivo hepatic effects of estrogen on ovariectomized mice lacking estrogen receptor (ER)-α, ERβ, or both and their wild-type littermates were examined by DNA microarray analysis. In vitro, the effects of estrogen on SOCS expression in human hepatoma cells were examined by reverse transcription quantitative PCR. Long-term (3 wk) estrogen treatment induced a 2- to 3-fold increase in hepatic expression of SOCS-2 and -3 in wild-type and ERβ knockout mice but not in those lacking ERα or both ER subtypes. Short-term treatment (at 24 h) increased the mRNA level of SOCS-3 but not SOCS-2. In cultured hepatoma cells, estrogen increased SOCS-2 and -3 mRNA levels by 2-fold in a time- and dose-dependent manner (P < 0.05). Estrogen induced murine SOCS-3 promoter activity by 2-fold (P < 0.05) in constructs containing a region between nucleotides −1862 and −855. Moreover, estrogen and GH had additive effects on the SOCS-3 promoter activity. In summary, estrogen, via ERα, up-regulated hepatic expression of SOCS-2 and -3, probably through transcriptional activation. This indicates a novel mechanism of estrogen regulation of cytokine action.


Endocrinology ◽  
2019 ◽  
Vol 160 (9) ◽  
pp. 2101-2114 ◽  
Author(s):  
Qing Lu ◽  
Ana P Davel ◽  
Adam P McGraw ◽  
Sitara P Rao ◽  
Brenna G Newfell ◽  
...  

Abstract Angiotensin II (AngII) and the mineralocorticoid receptor (MR) ligand aldosterone both contribute to cardiovascular disorders, including hypertension and adverse vascular remodeling. We previously demonstrated that AngII activates MR-mediated gene transcription in human vascular smooth muscle cells (SMCs), yet the mechanism and the impact on SMC function are unknown. Using an MR-responsive element-driven transcriptional reporter assay, we confirm that AngII induces MR transcriptional activity in vascular SMCs and endothelial cells, but not in Cos1 or human embryonic kidney-293 cells. AngII activation of MR was blocked by the MR antagonist spironolactone or eplerenone and the protein kinase C-δ (PKCδ) inhibitor rottlerin, implicating both in the mechanism. Similarly, small interfering RNA knockdown of PKCδ in SMCs prevented AngII-mediated MR activation, whereas knocking down of MR blocked both aldosterone- and AngII-induced MR function. Coimmunoprecipitation studies reveal that endogenous MR and PKCδ form a complex in SMCs that is enhanced by AngII treatment in association with increased serine phosphorylation of the MR N terminus. AngII increased mRNA expression of the SMC-MR target gene, FKBP51, via an MR-responsive element in intron 5 of the FKBP51 gene. The impact of AngII on FKBP51 reporter activity and gene expression in SMCs was inhibited by spironolactone and rottlerin. Finally, the AngII-induced increase in SMC number was also blocked by the MR antagonist spironolactone and the PKCδ inhibitor rottlerin. These data demonstrate that AngII activates MR transcriptional regulatory activity, target gene regulation, and SMC proliferation in a PKCδ-dependent manner. This new mechanism may contribute to synergy between MR and AngII in driving SMC dysfunction and to the cardiovascular benefits of MR and AngII receptor blockade in humans.


2003 ◽  
Vol 69 (5) ◽  
pp. 2521-2532 ◽  
Author(s):  
C. Lange ◽  
D. Rittmann ◽  
V. F. Wendisch ◽  
M. Bott ◽  
H. Sahm

ABSTRACT Addition of l-valine (50 to 200 mM) to glucose minimal medium had no effect on the growth of wild-type Corynebacterium glutamicum ATCC 13032 but inhibited the growth of the derived valine production strain VAL1 [13032 ΔilvA ΔpanBC(pJC1ilvBNCD)] in a concentration-dependent manner. In order to explore this strain-specific valine effect, genomewide expression profiling was performed using DNA microarrays, which showed that valine caused an increased ilvBN mRNA level in VAL1 but not in the wild type. This unexpected result was confirmed by an increased cellular level of the ilvB protein product, i.e., the large subunit of acetohydroxyacid synthase (AHAS), and by an increased AHAS activity of valine-treated VAL1 cells. The conclusion that valine caused the limitation of another branched-chain amino acid was confirmed by showing that high concentrations of l-isoleucine could relieve the valine effect on VAL1 whereas l-leucine had the same effect as valine. The valine-caused isoleucine limitation was supported by the finding that the inhibitory valine effect was linked to the ilvA deletion that results in isoleucine auxotrophy. Taken together, these results implied that the valine effect is caused by competition for uptake of isoleucine by the carrier BrnQ, which transports all branched-chained amino acids. Indeed, valine inhibition could also be relieved by supplementing VAL1 with the dipeptide isoleucyl-isoleucine, which is taken up by a dipeptide transport system rather than by BrnQ. Interestingly, addition of external valine stimulated valine production by VAL1. This effect is most probably due to a reduced carbon usage for biomass production and to the increased expression of ilvBN, indicating that AHAS activity may still be a limiting factor for valine production in the VAL1 strain.


Endocrinology ◽  
2006 ◽  
Vol 147 (3) ◽  
pp. 1508-1516 ◽  
Author(s):  
David Patsouris ◽  
Janardan K. Reddy ◽  
Michael Müller ◽  
Sander Kersten

Peroxisome proliferator-activated receptors (PPARs) are transcription factors involved in the regulation of numerous metabolic processes. The PPARα isotype is abundant in liver and activated by fasting. However, it is not very clear what other nutritional conditions activate PPARα. To examine whether PPARα mediates the effects of chronic high-fat feeding, wild-type and PPARα null mice were fed a low-fat diet (LFD) or high-fat diet (HFD) for 26 wk. HFD and PPARα deletion independently increased liver triglycerides. Furthermore, in wild-type mice HFD was associated with a significant increase in hepatic PPARα mRNA and plasma free fatty acids, leading to a PPARα-dependent increase in expression of PPARα marker genes CYP4A10 and CYP4A14. Microarray analysis revealed that HFD increased hepatic expression of characteristic PPARα target genes involved in fatty acid oxidation in a PPARα-dependent manner, although to a lesser extent than fasting or Wy14643. Microarray analysis also indicated functional compensation for PPARα in PPARα null mice. Remarkably, in PPARα null mice on HFD, PPARγ mRNA was 20-fold elevated compared with wild-type mice fed a LFD, reaching expression levels of PPARα in normal mice. Adenoviral overexpression of PPARγ in liver indicated that PPARγ can up-regulate genes involved in lipo/adipogenesis but also characteristic PPARα targets involved in fatty acid oxidation. It is concluded that 1) PPARα and PPARα-signaling are activated in liver by chronic high-fat feeding; and 2) PPARγ may compensate for PPARα in PPARα null mice on HFD.


2003 ◽  
Vol 369 (3) ◽  
pp. 721-729 ◽  
Author(s):  
María J. BARRERO ◽  
Nuria CAMARERO ◽  
Pedro F. MARRERO ◽  
Diego HARO

The expression of several genes involved in fatty acid metabolism is regulated by peroxisome proliferator-activated receptors (PPARs). To gain more insight into the control of carnitine palmitoyltransferase (CPT) gene expression, we examined the transcriptional regulation of the human CPT II gene. We show that the 5′-flanking region of this gene is transcriptionally active and binds PPARα in vivo in a chromatin immunoprecipitation assay. In addition, we characterized the peroxisome proliferator-responsive element (PPRE) in the proximal promoter of the CPT II gene, which appears to be a novel PPRE. The sequence of this PPRE contains one half-site which is a perfect consensus sequence (TGACCT) but no clearly recognizable second half-site (CAGCAC); this part of the sequence contains only one match to the consensus, which seems to be irrelevant for the binding of PPARα. As expected, other members of the nuclear receptor superfamily also bind to this element and repress the activation mediated by PPARα, thus showing that the interplay between several nuclear receptors may regulate the entry of fatty acids into the mitochondria, a crucial step in their metabolism.


PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Anne Bugge ◽  
Susanne Mandrup

The peroxisome proliferator-activated receptors (PPARs) are central regulators of fat metabolism, energy homeostasis, proliferation, and inflammation. The three PPAR subtypes, PPAR, /, and activate overlapping but also very different target gene programs. This review summarizes the insights into PPAR subtype-specific transactivation provided by genome-wide studies and discusses the recent advances in the understanding of the molecular mechanisms underlying PPAR subtype specificity with special focus on the regulatory role of AF-1.


2000 ◽  
Vol 20 (14) ◽  
pp. 5343-5349 ◽  
Author(s):  
J. Cliff Yoon ◽  
Troy W. Chickering ◽  
Evan D. Rosen ◽  
Barry Dussault ◽  
Yubin Qin ◽  
...  

ABSTRACT The nuclear receptor peroxisome proliferator-activated receptor γ regulates adipose differentiation and systemic insulin signaling via ligand-dependent transcriptional activation of target genes. However, the identities of the biologically relevant target genes are largely unknown. Here we describe the isolation and characterization of a novel target gene induced by PPARγ ligands, termed PGAR (for PPARγ angiopoietin related), which encodes a novel member of the angiopoietin family of secreted proteins. The transcriptional induction of PGAR follows a rapid time course typical of immediate-early genes and occurs in the absence of protein synthesis. The expression of PGAR is predominantly localized to adipose tissues and placenta and is consistently elevated in genetic models of obesity. Hormone-dependent adipocyte differentiation coincides with a dramatic early induction of the PGAR transcript. Alterations in nutrition and leptin administration are found to modulate the PGAR expression in vivo. Taken together, these data suggest a possible role for PGAR in the regulation of systemic lipid metabolism or glucose homeostasis.


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