• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.459-466
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• 2016

Adipogenic differentiation of mesenchymal stem cells (MSCs) is critical for metabolic homeostasis and nutrient signaling during development. However, limited information is available on the pivotal modulators of adipogenic differentiation of MSCs. Adaptor protein Lnk (Src homology 2B3 [SH2B3]), which belongs to a family of SH2-containing proteins, modulates the bioactivities of different stem cells, including hematopoietic stem cells and endothelial progenitor cells. In this study, we investigated whether an interaction between insulin-like growth factor-1 receptor (IGF-1R) and Lnk regulated IGF-1-induced adipogenic differentiation of MSCs. We found that wild-type MSCs showed greater adipogenic differentiation potential than $Lnk^{-/-}$ MSCs. An ex vivo adipogenic differentiation assay showed that $Lnk^{-/-}$ MSCs had decreased adipogenic differentiation potential compared with wild-type MSCs. Interestingly, we found that Lnk formed a complex with IGF-1R and that IGF-1 induced the dissociation of this complex. In addition, we observed that IGF-1-induced increase in the phosphorylation of Akt and mammalian target of rapamycin was triggered by the dissociation of the IGF-1R-Lnk complex. Expression levels of a pivotal transcription factor peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$) and its adipogenic target genes (LPL and FABP4) significantly decreased in $Lnk^{-/-}$ MSCs. These results suggested that Lnk adaptor protein regulated the adipogenesis of MSCs through the $IGF-1/Akt/PPAR-{\gamma}$ pathway.

• Biomolecules & Therapeutics
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• v.23 no.1
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• pp.71-76
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• 2015

Peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) was identified as a cell-intrinsic regulator of Th17 cell differentiation. Th17 cells have been associated with several autoimmune diseases, including experimental autoimmune encephalomyelitis (EAE), inflammatory bowel disease (IBD), and collagen-induced arthritis. In this study, we confirmed $PPAR{\gamma}$-mediated inhibition of Th17 cell differentiation and cytokine production at an early stage. Treatment with ciglitazone, a $PPAR{\gamma}$ ligand, reduced both IL-$1{\beta}$-mediated enhancement of Th17 differentiation and activation of Th17 cells after polarization. For Th17 cell differentiation, we found that ciglitazone-treated cells had a relatively low proliferative activity and produced a lower amount of cytokines, regardless of the presence of IL-$1{\beta}$. The inhibitory activity of ciglitazone might be due to decrease of CCNB1 expression, which regulates the cell cycle in T cells. Hence, we postulate that a pharmaceutical $PPAR{\gamma}$ activator might be a potent candidate for treatment of Th17-mediated autoimmune disease patients.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2219-2223
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• 2012

Human peroxisome proliferator-activated receptor gamma ($hPPAR{\gamma}$) has been implicated in numerous pathologies, including obesity, diabetes, and cancer. Previously, we verified that amentoflavone is an activator of $hPPAR{\gamma}$ and probed the molecular basis of its action. In this study, we investigated the mechanism of action of amentoflavone in cancer cells and demonstrated that amentoflavone showed strong cytotoxicity against MCF-7 and HeLa cancer cell lines. We showed that $hPPAR{\gamma}$ expression in MCF-7 and HeLa cells is specifically stimulated by amentoflavone, and suggested that amentoflavone-induced cytotoxic activities are mediated by activation of $hPPAR{\gamma}$ in these two cancer cell lines. Moreover, amentoflavone increased PTEN levels in these two cancer cell lines, indicating that the cytotoxic activities of amentoflavone are mediated by increasing of PTEN expression levels due to $hPPAR{\gamma}$ activation.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.184-194
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• 2016

The peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) gene plays an important role in the biosynthesis process controlled by a number of fatty acid transcription factors. This study investigates the relationships between 130 single-nucleotide polymorphisms (SNPs) in the $PPAR{\gamma}$ gene and the fatty acid composition of muscle fat in the commercial population of Korean native cattle. We identified 38 SNPs and verified relationships between 3 SNPs (g.1159-71208 A>G, g.42555-29812 G>A, and g.72362 G>T) and the fatty acid composition of commercial Korean native cattle (n = 513). Cattle with the AA genotype of g.1159-71208 A>G and the GG genotype of g.42555-29812 G>A and g.72362 G>T had higher levels of monounsaturated fatty acids and carcass traits (p<0.05). The results revealed that the 3 identified SNPs in the $PPAR{\gamma}$ gene affected fatty acid composition and carcass traits, suggesting that these 3 SNPs may improve the flavor and quality of beef in commercial Korean native cattle.

• KSBB Journal
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• v.31 no.3
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• pp.145-150
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• 2016

Boehmeria nivea (L.) Gaud., a flowering plant, has been widely cultivated in Asian countries including Korea. It has been reported that B. nivea exhibits health beneficial effects for the prevention of inflammation, oxidative stress, and virus-related diseases. In this study, we evaluated the inhibitory effect of B. nivea on adipocyte differentiation and angiogenesis. DPPH radical scavenging activities of 70% ethanol extract of B. nivea (EBN) and water extract of B. nivea (WBN) were $90.8{\pm}1.1%$ and $20{\pm}6.9%$, respectively. EBN was also effective in the reduction of adipocyte differentiation in 3T3-L1 cells. We next examined the transcriptional activity of peroxisome proliferator-activated receptor gamma ($PPAR-{\gamma}$), a pivotal target for anti-obesity. We found that treatment with rosiglitazone induced the transactivation of $PPAR-{\gamma}$. Under the same condition, $800{\mu}g/mL$ EBN reduced the transactivation of $PPAR-{\gamma}$ in rosiglitazone-induced cells. These results demonstrate that EBN-inhibited adipocyte differentiation was accompanied by $PPAR-{\gamma}$ inhibition. The study also tested whether EBN exhibits an anti-angiogenic effect by inhibiting tube formation in HUVECs. We found that EBN effectively inhibits tube formation, suggesting that EBN exhibited an anti-angiogenic effect. Taken together, B. nivea can be used as a functional food for the prevention of obesity and angiogenesis-related diseases including cancer.

• YAKHAK HOEJI
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• v.53 no.4
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• pp.184-188
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• 2009

Fluorouracil (5-FU) is one of the most widely used chemotherapeutic drugs in the treatment of advanced colorectal cancer patients. Capsaicin (N-vanillyl-8-methyl-alpha-nonenamide), a spicy component of hot pepper, is a homovanillic acid derivative that preferentially induces cancer cells to undergo apoptosis. The purpose of the present study is to examine whether capsaicin enhances the anticancer effect of 5-fluorouracil in HT-29 human colon cancer cells by inducing apoptosis, and whether PPARgamma is involved in the capsaicin action in combination treatment with 5-FU. Treatment of the cells with either 5-FU or capsaicin alone for 48 h had little effect on the cell viability up to $50{\mu}M$ concentration, whereas co-treatment of the cells with capsaicin in the presence of 5-FU for 48 h significantly decreased the cell viability in a concentration-dependent manner. In addition, caspase-3 activity, a marker enzyme for apoptosis, was significantly increased by the combined treatment with 5-FU and capsaicin compared to the 5-FU or capsaicin alone treatment. Also, treatment with troglitazone, a peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) agonist, further enhanced the effect of the combination treatment on the cell viability and caspase-3 activity, and bisphenol A diglycidyl ether (BADGE), a $PPAR{\gamma}$ antagonist, blocked the effect of the combination treatment. These results suggest that the combination treatment of HT-29 cells with 5-FU and capsaicin induces apoptotic cell death at relatively low concentration than each drug alone, and the combination treatment may be associated with the $PPAR{\gamma}$ pathway activation.

• Journal of Life Science
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• v.24 no.3
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• pp.323-328
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• 2014

MicroRNAs comprise a family of small noncoding RNAs that modulate physiological processes, including adipogenesis. MicroRNA-17 (miR-17) promotes adipocyte differentiation and enhances lipid accumulation. The transcriptional regulation of miR-17 during adipogenesis remains unknown. In this study, we investigated whether miR-17 is a target of peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), which is a key regulator of adipogenesis. The levels of miR-17 and the expression of $PPAR{\gamma}$ increased after the induction of adipocyte differentiation. Three putative peroxisome proliferator response elements (PPREs) were identified in the miR-17 promoter region. Using chromatin immunoprecipitation and luciferase reporter assays, we observed the interaction of $PPAR{\gamma}$ with the miR-17 promoter. Mutagenesis experiments showed that the -677/-655 region of the miR-17 promoter could function as a PPRE site. These results suggest that $PPAR{\gamma}$ is essential for transcriptional activation of the miR-17 gene, thereby contributing to understanding the molecular mechanism of adipogenesis in adipocytes.

• Animal Bioscience
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• v.34 no.4
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• pp.662-669
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• 2021

Objective: Effects of linseed oil (LO) supplementation on the fat content and fatty acid profile of breast meat, and the expression of three genes in the liver, breast muscle and fat tissues of commercial 154-day-old hybrid male turkeys were investigated. Methods: The animals in the control group were fed a commercially available feed and received no LO supplementation (n = 70), whereas animals in the LO group (n = 70) were fed the same basic diet supplemented with LO (day 15 to 21, 0.5%; day 22 to 112, 1%). The effect of dietary LO supplementation on fatty acid composition of breast muscle was examined by gas chromatography, and the expression of fatty acid desaturase 2 (FADS2), peroxisome proliferator activated receptor gamma (PPARγ), and insulin-like growth factor 1 (IGF1) genes was analysed by means of quantitative reverse transcription polymerase chain reaction. Results: The LO supplementation affected the fatty acid composition of breast muscle. Hepatic FADS2 levels were considerably lower (p<0.001), while adipose tissue expression was higher (p<0.05) in the control compared to the LO group. The PPARγ expression was lower (p<0.05), whereas IGF1 was higher (p<0.05) in the fat of control animals. There were no significant (p>0.05) differences in FADS2, PPARγ, and IGF1 gene expressions of breast muscle; however, omega-6/omega-3 ratio of breast muscle substantially decreased (p<0.001) in the LO group compared to control. Conclusion: Fatty acid composition of breast meat was positively influenced by LO supplementation without deterioration of fattening parameters. Remarkably, increased FADS2 expression in the liver of LO supplemented animals was associated with a significantly decreased omega-6/omega-3 ratio, providing a potentially healthier meat product for human consumption. Increased PPARγ expression in fat tissue of the LO group was not associated with fat content of muscle, whereas a decreased IGF1 expression in fat tissue was associated with a trend of decreasing fat content in muscle of the experimental LO group.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5219-5223
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• 2015

Helicobacter pylori (H. pylori) infection as a serious problem in both adults and children can induce chronic gastritis, peptic ulcer disease (PUD), and possibly gastric cancer. The aim of the current study was to survey antibiotic resistance and also to determine influence of PPAR$\gamma$ polymorphism in patients with H. pylori infection. During an 11-month-period, 98 H. pylori isolates were collected from 104 biopsy specimens. In vitro susceptibility of H. pylori isolates to 4 antimicrobial agents metronidazole, clarithromycin, amoxicillin and tetracycline were assessed by quantitative method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guideline. PPAR$\gamma$ polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of H. pylori infection in our study was 94.2%. In vitro susceptibility data showed that highest level of resistance was related to metronidazole (66.3%), and the majority of H. pylori isolates were highly susceptible to amoxicillin and tetracycline (94.9% and 96.9%, respectively). Genotypic frequencies were 25.5% for CC (Pro12Pro), 40.8% for GC (Pro12Ala) and 33.7% for GG (Ala12Ala). In our study, CG genotype had highest distributions among infected patients with H. pylori. The study suggests that the PPAR-$\gamma$ Pro12Ala polymorphism could be evaluated as a potential genetic marker for susceptibility to gastric cancer in the presence of H. pylori infection.

• Preventive Nutrition and Food Science
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• v.18 no.2
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• pp.85-91
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• 2013

Recent studies have shown that Rosa canina L. and tiliroside, the principal constituent of its seeds, exhibit anti-obesity and anti-diabetic activities via enhancement of fatty acid oxidation in the liver and skeletal muscle. However, the effects of rosehip, the fruit of this plant, extract (RHE), or tiliroside on lipid accumulation in adipocytes have not been analyzed. We investigated the effects of RHE and tiliroside on lipid accumulation and protein expression of key transcription factors in both in vitro and in vivo models. RHE and tiliroside inhibited lipid accumulation in a dose-dependent manner in 3T3-L1 cells. We also analyzed the inhibitory effect of RHE on white adipose tissue (WAT) in high-fat diet (HFD)-induced obesity mice model. Male C57BL/6J mice were fed HFD or HFD supplemented with 1% RHE (HFDRH) for 8 weeks. The HFDRH-fed group gained less body weight and had less visceral fat than the HFD-fed group. Liver weight was significantly lower in the HFDRH-fed group and total hepatic lipid and triglyceride (TG) content was also reduced. A significant reduction in the expression of peroxisome proliferator-activated receptor gamma (PPAR${\gamma}$) was observed in epididymal fat in the HFDRH-fed group, in comparison with controls, through Western blotting. These results suggest that downregulation of PPAR${\gamma}$ expression is involved, at least in part, in the suppressive effect of RHE on lipid accumulation in WAT.