scholarly journals Peroxisome proliferator-activated receptor gamma is induced during differentiation of colon epithelium cells

1999 ◽  
Vol 162 (3) ◽  
pp. 331-340 ◽  
Author(s):  
M Lefebvre ◽  
B Paulweber ◽  
L Fajas ◽  
J Woods ◽  
C McCrary ◽  
...  

Peroxisome proliferator-activated receptor gamma (PPARgamma), a fatty acid-activated nuclear receptor, is implicated in adipocyte differentiation and insulin sensitisation. In view of the association of dietary fat intake and bowel disease, the expression of PPARgamma in rodent and human intestine was studied. Expression of PPARgamma mRNA was examined by Northern blot hybridisation, RNase protection, and/or competitive RT-PCR assays, whereas PPARgamma protein levels were evaluated by immunoblotting and immunohistochemistry. PPARgamma mRNA and protein were abundantly expressed in colon relative to the small intestine both in rodents and in man. Interestingly, expression of PPARgamma was primarily localised in the more differentiated epithelial cells in the colon. The level of expression of PPARgamma in colon was similar to the levels seen in adipose tissue. Expression of PPARgamma increased from proximal to distal segments of the colon in man. In Caco-2 and HT-29 human adenocarcinoma cells, PPARgamma expression increased upon differentiation, consistent with PPARgamma being associated with a differentiated epithelial phenotype. High-level expression of PPARgamma was observed in the colon, but not in the small intestine, suggesting a potential role of this nuclear receptor in the colon.

2006 ◽  
Vol 291 (5) ◽  
pp. G851-G856 ◽  
Author(s):  
Jin Shimakura ◽  
Tomohiro Terada ◽  
Hirofumi Saito ◽  
Toshiya Katsura ◽  
Ken-ichi Inui

We previously demonstrated that starvation markedly increased the amount of mRNA and protein levels of the intestinal H+/peptide cotransporter (PEPT1) in rats, leading to altered pharmacokinetics of the PEPT1 substrates. In the present study, the mechanism underlying this augmentation was investigated. We focused on peroxisome proliferator-activated receptor α (PPARα), which plays a pivotal role in the adaptive response to fasting in the liver and other tissues. In 48-h fasted rats, the expression level of PPARα mRNA in the small intestine markedly increased, accompanied by the elevation of serum free fatty acids, which are endogenous PPARα ligands. Oral administration of the synthetic PPARα ligand WY-14643 to fed rats increased the mRNA level of intestinal PEPT1. Furthermore, treatment of the human intestinal model, Caco-2 cells, with WY-14643 resulted in enhanced PEPT1 mRNA expression and uptake activity of glycylsarcosine. In the small intestine of PPARα-null mice, augmentation of PEPT1 mRNA during fasting was completely abolished. In the kidney, fasting did not induce PEPT1 expression in either PPARα-null or wild-type mice. Together, these results indicate that PPARα plays critical roles in fasting-induced intestinal PEPT1 expression. In addition to the well-established roles of PPARα, we propose a novel function of PPARα in the small intestine, that is, the regulation of nitrogen absorption through PEPT1 during fasting.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Sae-Rom Yoo ◽  
Chang-Seob Seo ◽  
Hyeun-Kyoo Shin ◽  
Soo-Jin Jeong

Background. Oyaksungi-san (OYSGS) is a herbal formula that has been used for treating cardiovascular diseases in traditional Asian medicine. Here, we investigated the antiadipogenic effect of OYSGS extract in 3T3-L1 adipose cells.Methods. 3T3-L1 preadipocytes were differentiated into adipocytes with or without OYSGS. After differentiation, we measured Oil Red O staining, glycerol-3-phosphate dehydrogenase (GPDH) activity, leptin production, mRNA, and protein levels of adipogenesis-related factors.Results. OYSGS extract dramatically inhibited intracellular lipid accumulation in the differentiated adipocytes. It also significantly suppressed the (GPDH) activity, triglyceride (TG) content, and leptin production by reducing the expression of adipogenesis-related genes including lipoprotein lipase, fatty acid binding protein 4, CCAAT/enhancer-binding protein-alpha (C/EBP-α), and peroxisome proliferator-activated receptor gamma (PPAR-γ). Furthermore, OYSGS clearly enhanced phosphorylation of AMP-activated protein kinase (AMPK) as well as its substrate acetyl CoA (ACC) carboxylase.Conclusions. Our results demonstrate that OYSGS negatively controls TG accumulation in 3T3-L1 adipocytes. We suggest antiadipogenic activity of OYSGS and its potential benefit in preventing obesity.


2021 ◽  
Vol 49 (11) ◽  
pp. 030006052110550
Author(s):  
Xing Wang ◽  
Shuchun Chen ◽  
Dan Lv ◽  
Zelin Li ◽  
Luping Ren ◽  
...  

Objective To investigate the effect of liraglutide on the browning of white fat and the suppression of obesity via regulating microRNA (miR)-27b in vivo and in vitro. Methods Sprague-Dawley rats were fed a high-fat (HF) diet and 3T3-L1 pre-adipocytes were differentiated into mature white adipocytes. Rats and mature adipocytes were then treated with different doses of liraglutide. The mRNA and protein levels of browning-associated proteins, including uncoupling protein 1 (UCP1), PR domain containing 16 (PRDM16), CCAAT enhancer binding protein β (CEBPβ), cell death-inducing DFFA-like effector A (CIDEA) and peroxisome proliferator-activated receptor-γ-coactivator 1α (PGC-1α), were detected using quantitative real-time polymerase chain reaction and Western blotting. Results Liraglutide decreased body weight and reduced the levels of blood glucose, triglyceride and low-density lipoprotein cholesterol in HF diet-fed rats. Liraglutide increased the levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α in vivo and vitro. The levels of miR-27b were upregulated in HF diet-fed rats, whereas liraglutide reduced the levels of miR-27b. In vitro, overexpression of miR-27b decreased the mRNA and protein levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α. Transfection with the miR-27b mimics attenuated the effect of liraglutide on the browning of white adipocytes. Conclusion Liraglutide induced browning of white adipose through regulation of miR-27b.


2019 ◽  
Vol 20 (22) ◽  
pp. 5589
Author(s):  
Jaeim Lee ◽  
Ok-Hee Kim ◽  
Sang Chul Lee ◽  
Kee-Hwan Kim ◽  
Jin Sun Shin ◽  
...  

Peroxisome proliferator activated receptor λ coactivator 1α (PGC-1α) is a potent regulator of mitochondrial biogenesis and energy metabolism. In this study, we investigated the therapeutic potential of the secretome released from the adipose-derived stem cells (ASCs) transfected with PGC-1α (PGC-secretome). We first generated PGC-1α-overexpressing ASCs by transfecting ASCs with the plasmids harboring the gene encoding PGC-1α. Secretory materials released from PGC-1α-overexpressing ASCs were collected and their therapeutic potential was determined using in vitro (thioacetamide (TAA)-treated AML12 cells) and in vivo (70% partial hepatectomized mice) models of liver injury. In the TAA-treated AML12 cells, the PGC-secretome significantly increased cell viability, promoted expression of proliferation-related markers, such as PCNA and p-STAT, and significantly reduced the levels of reactive oxygen species (ROS). In the mice, PGC-secretome injections significantly increased liver tissue expression of proliferation-related markers more than normal secretome injections did (p < 0.05). We demonstrated that the PGC-secretome does not only have higher antioxidant and anti-inflammatory properties, but also has the potential of significantly enhancing liver regeneration in both in vivo and in vitro models of liver injury. Thus, reinforcing the mitochondrial antioxidant potential by transfecting ASCs with PGC-1α could be one of the effective strategies to enhance the therapeutic potential of ASCs.


Endocrinology ◽  
2014 ◽  
Vol 155 (1) ◽  
pp. 143-155 ◽  
Author(s):  
LeBris S. Quinn ◽  
Barbara G. Anderson ◽  
Jennifer D. Conner ◽  
Tami Wolden-Hanson ◽  
Taylor J. Marcell

Physical exercise induces transient upregulation of the pro-oxidative mediators peroxisome proliferator-activated receptor-δ (PPARδ), silent information regulator of transcription (sirtuin)-1 (SIRT1), PPARγ coactivator 1α (PGC-1α), and PGC-1β in skeletal muscle. To determine the role of the cytokine IL-15 in acute postexercise induction of these molecules, expression of these factors after a bout of exhaustive treadmill running was examined in the gastrocnemius muscle of untrained control and IL-15–knockout (KO) mice. Circulating IL-15 levels increased transiently in control mice after exercise. Control mice, but not IL-15–KO mice, upregulated muscle PPARδ and SIRT1 protein after exercise, accompanied by a complex pattern of mRNA expression for these factors. However, in exhaustive exercise, control mice ran significantly longer than IL-15–KO mice. Therefore, in a second experiment, mice were limited to a 20-minute run, after which a similar pattern of induction of muscle PPARδ and SIRT1 protein by control mice only was observed. In a separate experiment, IL-15–KO mice injected systemically with recombinant IL-15 upregulated muscle PPARδ and SIRT1 mRNA within 30 minutes and also exhibited increased muscle PPARδ protein levels by 3 hours. After exercise, both control and IL-15–KO mice downregulated IL-15 receptor-α (IL-15Rα) mRNA, whereas IL-15Rα–deficient mice exhibited constitutively elevated circulating IL-15 levels. These observations indicate IL-15 release after exercise is necessary for induction of PPARδ and SIRT1 at the protein level in muscle tissue and suggest that exercise releases IL-15 normally sequestered by the IL-15Rα in the resting state. These findings could be used to develop an IL-15–based strategy to induce many of the metabolic benefits of physical exercise.


2001 ◽  
Vol 21 (9) ◽  
pp. 3057-3070 ◽  
Author(s):  
Chenguang Wang ◽  
Maofu Fu ◽  
Mark D'Amico ◽  
Chris Albanese ◽  
Jian-Nian Zhou ◽  
...  

ABSTRACT The nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-regulated nuclear receptor superfamily member. Liganded PPARγ exerts diverse biological effects, promoting adipocyte differentiation, inhibiting tumor cellular proliferation, and regulating monocyte/macrophage and anti-inflammatory activities in vitro. In vivo studies with PPARγ ligands showed enhancement of tumor growth, raising the possibility that reduced immune function and tumor surveillance may outweigh the direct inhibitory effects of PPARγ ligands on cellular proliferation. Recent findings that PPARγ ligands convey PPARγ-independent activities through IκB kinase (IKK) raises important questions about the specific mechanisms through which PPARγ ligands inhibit cellular proliferation. We investigated the mechanisms regulating the antiproliferative effect of PPARγ. Herein PPARγ, liganded by either natural (15d-PGJ2 and PGD2) or synthetic ligands (BRL49653 and troglitazone), selectively inhibited expression of the cyclin D1 gene. The inhibition of S-phase entry and activity of the cyclin D1-dependent serine-threonine kinase (Cdk) by 15d-PGJ2 was not observed in PPARγ-deficient cells. Cyclin D1 overexpression reversed the S-phase inhibition by 15d-PGJ2. Cyclin D1 repression was independent of IKK, as prostaglandins (PGs) which bound PPARγ but lacked the IKK interactive cyclopentone ring carbonyl group repressed cyclin D1. Cyclin D1 repression by PPARγ involved competition for limiting abundance of p300, directed through a c-Fos binding site of the cyclin D1 promoter. 15d-PGJ2 enhanced recruitment of p300 to PPARγ but reduced binding to c-Fos. The identification of distinct pathways through which eicosanoids regulate anti-inflammatory and antiproliferative effects may improve the utility of COX2 inhibitors.


2013 ◽  
Vol 304 (12) ◽  
pp. E1348-E1358 ◽  
Author(s):  
Pawel Dobrzyn ◽  
Aleksandra Pyrkowska ◽  
Monika K. Duda ◽  
Tomasz Bednarski ◽  
Michal Maczewski ◽  
...  

Cardiac hypertrophy is accompanied by molecular remodeling that affects different cellular pathways, including fatty acid (FA) utilization. In the present study, we show that cardiac lipid metabolism is differentially regulated in response to physiological (endurance training) and pathological [abdominal aortic banding (AAB)] hypertrophic stimuli. Physiological hypertrophy was accompanied by an increased expression of lipogenic genes and the activation of sterol regulatory element-binding protein-1c and Akt signaling. Additionally, FA oxidation pathways regulated by AMP-activated protein kinase (AMPK) and peroxisome proliferator activated receptor-α (PPARα) were induced in trained hearts. Cardiac lipid content was not changed by physiological stimulation, underlining balanced lipid utilization in the trained heart. Moreover, pathological hypertrophy induced the AMPK-regulated oxidative pathway, whereas PPARα and expression of its downstream targets, i.e., acyl-CoA oxidase and carnitine palmitoyltransferase I, were not affected by AAB. In contrast, pathological hypertrophy leads to cardiac triglyceride (TG) and diacylglycerol (DAG) accumulation, although the expression of lipogenic genes and the levels of FA transport proteins (CD36 and FATP) were not changed or reduced compared with the sham group. A possible explanation for this phenomenon is a decrease in lipolysis, as evidenced by the increased content of adipose triglyceride lipase inhibitor G0S2, the increased phosphorylation of hormone-sensitive lipase at Ser565, and the decreased protein levels of DAG lipase that attenuate TG and DAG contents. The increased TG and DAG accumulation observed in AAB-induced hypertrophy might have lipotoxic effects, thereby predisposing to cardiomyopathy and heart failure in the future.


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