• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.902-910
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• 2007

Objective : Peroxisome proliferator-activated receptor (PPAR)-gamma, a transcription factor in adipocyte differentiation, has important effects on insulin sensitivity, atherosclerosis, endothelial cell function and inflammation. Through these effects, PPAR-gamma2 might be involved with type 2 diabetes and vascular disease, including diabetic complications. Recently, it has been reported that the C161T polymorphism in the exon 6 of PPAR-gamma is associated with type 2 diabetes interacting with uncoupling protein 2 (UCP2) gene, and is associated with acute myocardial infarction. We studied the association of this polymorphism with type 2 diabetes and its complications, such as retinopathy, ischemic stroke, nephropathy and neuropathy in Korean non-diabetic and type 2 diabetic populations. Methods : Three hundred and thirty eight type 2 diabetic patients (retinopathy: 64, ischemic stroke: 67, nephropathy: 39 and neuropathy: 76) and 152 healthy matched control subjects were evaluated. The PPAR-gamma C161T polymorphism was analyzed by PCR-RFLP. Results : PPAR-gamma C161T genotype and allele frequency did not show significant differences between type 2 diabetic patients and healthy controls (T allele: 17.0 vs. 14.5, OR= 1.21, P=0.3188). In the analysis for diabetic complications, T allele in diabetic nephropathy was significantly higher than controls (P=0.0358). T allele in the ischemic stroke patients was also higher than healthy controls, although it had no significance (P=0.1375). Conclusions : These results suggest that the C161T polymorphism of the PPAR-gamma gene might be associated with diabetic nephropathy in type 2 diabetes.

• Biomedical Science Letters
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• v.14 no.3
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• pp.139-146
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• 2008

The peroxisome proliferator-activated receptor ${\gamma}$ $(PPAR{\gamma})$ plays a central role in adipogenesis and lipid storage. The $(PPAR{\gamma})$ ligands, thiazolidinediones (TZDs), enhance in vitro adipogenesis in several cell types, but the role of the TZDs on in vivo adipogenesis is still poorly understood. To investigate how $PPAR{\gamma}$ ligand troglitazone regulates adipogenesis in female mice, we examined the effects of the troglitazone on adipose tissue mass, morphological changes of adipocytes, and the expression of $PPAR{\gamma}$ target and adipocyte-specific genes in low fat diet-fed female C57BL/6 mice. Administration of troglitazone for 13 weeks did not change body and total white adipose tissue weights compared with control mice. Troglitazone treatment also did not cause a significant decrease in the average size of adipocytes in parametrial adipose tissue although it is reported to increase the number of small adipocytes in male animals. Troglitazone did not affect the mRNA expression of $PPAR{\gamma}$ and its target genes as well as adipocyte-specific genes in parametrial adipose tissue. These results suggest that $PPAR{\gamma}$ does not seem to be associated with adipogenesis in females with functioning ovaries and that its inability to induce adipogenesis may be due to sex-related factors.

• BMB Reports
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• v.36 no.2
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• pp.207-213
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• 2003

Peroxisome proliferator-activated receptors (PPARs) are orphan nuclear hormone receptors that are known to control the expression of genes that are involved in lipid homeostasis and energy balance. PPARs activate gene transcription in response to a variety of compounds, including hypolipidemic drugs. Most of these compounds have high affinity to the ligand-binding domain (LBD) of PPARs and cause a conformational change within PPARs. As a result, the receptor is converted to an activated mode that promotes the recruitment fo co-activators such as the steroid receptor co-activator-1 (SRC-1). Based on the activation mechanism of PPARs (the ligand binding to $PPAR{\gamma}$ induces interactions of the receptor with transcriptional co-activators), we performed Western blot and ELISA. These showed that the indomethacin, a $PPAR{\gamma}$ ligand, increased the binding between $PPAR{\gamma}$ and SRC-1 in a ligand dose-dependent manner. These results suggested that the in vitro conformational change of $PPAR{\gamma}$ by ligands was also induced, and increased the levels of the ligand-dependent interaction with SRC-1. Collectively, we developed a novel and useful ELISA system for the mass screening of $PPAR{\gamma}$ ligands. This screening system (based on the interaction between $PPAR{\gamma}$ and SRC-1) may be a promising system in the development of drugs for metabolic disorders.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.11-11
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• 2003

Peroxisome proliferator-activated receptor (PPAR) is nuclear hormone receptors that can be activated by a variety of compounds. Two PPAR gamma isoforms are expressed at the protein level in mouse, gamma 1 and gamma 2. And PPAR gamma is intimately associated with cell differentiation and proliferation[1]. So aim of this study, investigated where express PPAR gamma in mouse gastric cancer tissues, including human gastric cancer cell lines and expression pattern of PPAR gamma. (omitted)

• Journal of Animal Science and Technology
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• v.57 no.11
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• pp.40.1-40.7
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• 2015

Background: Activation of peroxisome proliferator activated receptor gamma ($PPAR{\gamma}$) in the alveolar macrophages (AM) by selective synthetic $PPAR{\gamma}$ ligands, improves the ability of the cells to resolve inflammation. In birds, respiratory macrophages are known as free avian respiratory macrophages (FARM) and show distinct functional differences from AM. The effects of treating FARM with $PPAR{\gamma}$ ligands are unclear. Methods: FARM were harvested by lavage of chicken respiratory tract and their morphology assessed at microscopic level. The effects of $PPAR{\gamma}$ agonists on the FARM in vitro viability, phagocytic capacity and proinflammatory cytokine (TNF-${\alpha}$) production were assessed. Results: FARM had eccentric nucleus and plasma membrane ruffled with filopodial extensions. Ultrastructurally, numerous vesicular bodies presumed to be lysosomes were present. FARM treated with troglitazone, a selective $PPAR{\gamma}$ agonist, had similar in vitro viability with untreated FARM. However, treated FARM co-cultured with polystyrene particles, internalized more particles with a mean volume density of 41 % compared to that of untreated FARM of 21 %. Further, treated FARM significantly decreased LPS-induced TNF-${\alpha}$ production in a dose dependent manner. Conclusion: Results from this study show that $PPAR{\gamma}$ synthetic ligands enhance phagocytic ability of FARM. Further the ligands attenuate production of proinflammatory cytokines in the FARM, suggesting potential therapeutic application of $PPAR{\gamma}$ ligands in the management of respiratory inflammatory disorders in the poultry industry.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.928-931
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• 2009

Effects of perilla leaf extracts (PLE) on adipocytes differentiation of 3T3-L1 cells were examined. Ethanol extract of PLE treatment significantly decreased lipid accumulation, a marker of adipogenesis, in a dose-dependent manner. Moreover, gene expression levels of peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), the key adipogenic transcription factor, were markedly decreased by PLE. PLE also suppressed adipocyte fatty acid binding protein (aP2) and glycerol-3-phosphate dehydrogenase (GPDH), which are adipogenic marker proteins. These results suggest that PLE treatment suppressed differentiation of 3T3-L1 adipocytes, in part by down-regulating expression of adipogenic transcription factor and other specific target genes.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2717-2721
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• 2011

Peroxisome proliferator-activated receptors (PPARs) are a subfamily of nuclear receptors (NRs). Human peroxisome proliferator-activated receptor gamma (hPPAR${\gamma}$) has been implicated in the pathology of numerous diseases, including obesity, diabetes, and cancer. ELISA-based hPPAR${\gamma}$ activation assay showed that biapigenin increased the binding between hPPAR${\gamma}$ and steroid receptor coactivator-1 (SRC-1) by approximately 3-fold. In order to confirm that biapigenin binds to hPPAR${\gamma}$, fluorescence quenching experiment was performed. The results showed that biapigenin has higher binding affinity to hPPAR${\gamma}$ at nanomolar concentrations compared to indomethacin. Biapigenin showed anticancer activity against HeLa cells. Biapigenin was noncytotoxic against HaCa T cell. All these data implied that biapigenin may be a potent agonist of hPPAR${\gamma}$ with anticancer activity. We will further investigate its anticancer effects against human cervical cancer.

• Molecules and Cells
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• v.24 no.2
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• pp.167-176
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• 2007

Peroxisome proliferator-activated receptor-gamma ($PPAR{\gamma}$) is expressed at very high levels in the gastrointestinal epithelium. Many of the functions of $PPAR{\gamma}$ in gastrointestinal epithelial cells have been elucidated in recent years, and a pattern is emerging which suggests that this receptor plays an important role in gastrointestinal physiology. There is also strong evidence that $PPAR{\gamma}$ is a colon cancer suppressor in pre-clinical rodent models of sporadic colon cancer, and there is considerable interest in exploitation of $PPAR{\gamma}$ agonists as prophylactic or chemopreventive agents in colon cancer. Studies in mice and in human colon cancer cell lines suggest several mechanisms that might account for the tumor suppressive effects of $PPAR{\gamma}$ agonists, although it is not in all cases clear whether these effects are altogether mediated by $PPAR{\gamma}$. Conversely, several reports suggest that $PPAR{\gamma}$ agonists may promote colon cancer under certain circumstances. This possibility warrants considerable attention since several million individuals with type II diabetes are currently taking $PPAR{\gamma}$ agonists. This review will focus on recent data related to four critical questions: what is the physiological function of $PPAR{\gamma}$ in gastrointestinal epithelial cells; how does $PPAR{\gamma}$ suppress colon carcinogenesis; is $PPAR{\gamma}$ a tumor promoter; and what is the future of $PPAR{\gamma}$ in colon cancer prevention?

• Journal of Korean Medicine for Obesity Research
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• v.4 no.1
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• pp.1-11
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• 2004

Objectives: The effects of peroxisome proliferator-activated receptor ${\gamma}2\;(PPAR{\gamma}2)$ Pro12Ala (P12A) polymorphism on body mass index (BMI) and type 2 diabetes are well documented; however, until now, only a few studies have evaluated the effects of this polymorphism on body fat distribution. This study was conducted to elucidate the effects of this polymorphism on computed tomography (CT)-measured body fat distribution and other obesity-related parameters in Korean female subjects. Methods & Results: The frequencies of $PPAR{\gamma}2$ genotypes were: PP type, 93.0%; PA type, 6.8%; and AA type, 0.2%. The frequency of the A allele was 0.035. Body weight (P .012), BMI (P .012), and waist-to-hip ratio (WHR) (P .001) were significantly higher in subjects with PA/AA compared with subjects with PP. When body composition was analyzed by bioimpedance analysis, lean body mass and body water content were similar between the 2 groups. However, body fat mass (P .003) and body fat percent (P .025) were significantly higher in subjects with PA/AA compared with subjects with PP. Among overweight subjects with BMI of greater than 25, PA/AA was associated with significantly higher abdominal subcutaneous fat (P .000), abdominal visceral fat (P .031), and subcutaneous upper and lower thigh adipose tissue (P .010 and .013). However, among lean subjects with BMI of less than 25, no significant differences associated with $PPAR{\gamma}2$ genotype were found, suggesting that the fat-accumulating effects of the PA/AA genotype were evident only among overweight subjects, but not among lean subjects. When serum lipid profiles, glucose, and liver function indicators were compared among overweight subjects, no significant difference associated with $PPAR{\gamma}2$ genotype was found. Changes in body weight, BMI, WHR, and body fat mass were measured among overweight subjects who finished a 1-month weight lose program of a hypocaloric diet and exercise; no significant differences associated with $PPAR{\gamma}2$ genotype were found. Conclusions: The results of this study suggest that the $PPAR{\gamma}2$ PA/AA genotype is associated with increased subcutaneous and visceral fat areas in overweight Korean female subjects, but does not significantly affect serum biochemical parameters and outcomes of weight loss programs.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.2
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• pp.67-75
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• 2013

Objective: To investigate the effect of peroxisome proliferator activated receptor ${\gamma}$(PPAR${\gamma}$) agonist on the cell proliferation properties and expression of human telomerase reverse transcriptase (hTERT) and aromatase in cultured endometrial stromal cell (ESC) from patients with endometriosis. Methods: Human endometrial tissues were obtained from women with endometriosis and healthy women (controls) using endometrial biopsy. Isolated ESCs were cultured and the cell proliferation was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay and expression of hTERT, aromatase, and cyclooxygenase (COX)-2 by western blotting according to the addition of rosiglitazone (PPAR${\gamma}$ agonist). Results: We demonstrate that the cultured ESCs of endometriosis showed hTERT protein overexpression and increased cellular proliferation, which was inhibited by rosiglitazone, in a dose-dependent manner. At the same time, PPAR${\gamma}$ agonist also inhibited aromatase and COX-2 expression, resulting in decreased prostaglandin $E_2$ production in the ESCs of endometriosis. Conclusion: This study suggests that PPAR${\gamma}$ agonist plays an inhibitory role in the proliferative properties of eutopic endometrium with endometriosis by down-regulation of hTERT and COX-2 expression; this could be a new treatment target for endometriosis.