• Radiation Oncology Journal
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• 제30권4호
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• pp.226-227
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• 2012

• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.301-307
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• 2009

Inflammatory processes of vascular endothelial cells play a key role in the development ofatherosclerosis. We determined the anti-inflammatory effects and mechanisms of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on LPS-treated human umbilical vein endothelial cells (HUVECs) to evaluate their cardioproteerive potential. Cells were pretreated with DHA, EPA, or troglitazone prior to activation with LPS. Expression of COX-2, prostaglandin $E_2$ ($PGE_2$) and IL-6 production, and $NF-{\kappa}B$ activity were measured by Western blot, ELISA, and luciferase activity, respectively. Results showed that EPA, DHA, or troglitazone significantly reduced COX-2 expression, $NF-{\kappa}B$ luciferase activity, and $PGE_2$ and IL-6 production in a dose-dependent fashion. Interestingly, low doses (10 ${\mu}$M) of DHA and EPA, but not troglitozone, significantly increased the activity of $NF-{\kappa}B$ in resting HUVECs. Our study suggests that while DHA, EPA, and troglitazone may be protective on HUVECs under inflammatory conditions in a dose-dependent manner. However there may be some negative effects when the concentrations are abnormally low, even in normal endothelium.

• Asian-Australasian Journal of Animal Sciences
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• 제23권11호
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• pp.1519-1526
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• 2010

Serum lipid (SL) is a commercially available cholesterol-rich, proteinaceous compound extracted from bovine serum. Here we investigated the adipogenic transdifferentiation potential of SL on bovine myogenic satellite cells. Exposure of satellite cells to SL could generate lipid droplets on day 2, and further exposure to SL increased cytoplasmic lipid accumulation giving adipocyte morphology. The expression analysis of PPAR gamma and GPDH adipocyte markers along with Oil-red-O staining results confirmed the transdifferentiation potential of SL. When cells were treated at different concentrations (5, 10, 20, $40{\mu}l$/ml) of SL, the results indicated that even levels as low as $5{\mu}l$ SL /ml could induce transdifferentiation, and maximum induction was obtained at $20{\mu}l$ SL/ml. After treatment with SL at different concentrations the expression levels of PPAR gamma varied significantly (p<0.05), whereas the expression of other adipogenic transcription factors showed no difference, indicating that SL acts through PPAR gamma. The combined effect of SL and troglitazone proved to be the best combination for induction of transdifferentiation compared to the individual effect of SL or troglitazone. Thus, overall results clearly show that SL induces transdifferentiation of bovine myogenic satellite cells to adipocytes.

• Radiation Oncology Journal
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• 제30권2호
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• pp.78-87
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• 2012

Purpose: Troglitazone (TRO) is a peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases $Cu^{2+}/Zn^{2+}$-superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. Materials and Methods: Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 ${\mu}M$ of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. Results: By 5 ${\mu}M$ TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0-G1 phase cells were increased in HeLa and Me180 by 5 ${\mu}M$ TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 ${\mu}M$ TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 ${\mu}M$ TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. Conclusion: TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalase-mediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPAR ${\gamma}$ expression level.

• Journal of Animal Science and Technology
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• 제57권11호
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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.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.117-117
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• 2003

PPARs (peroxisome proliferator activated receptors) are member of nuclear hormone receptors superfamily. Activations of PPARs upon binding with ligands modulate glucose metabolite, differentiation of adipocyte, inflammation response, and so on. Thiazolidinedione analog is one of potential antidiabetic drug that binds and activates PPARν selectively and enhances insulin sensitivity. In an effort to develop novel and effective antidiabetic thiazolidindione analogs, syntheses of benzoxazole and benzothiazole-linked thiazolidinedione analogs were performed via coupling reaction of benzoxazolylalkylaminoethanol with hydroxybenzylthiazolidinedione to develop novel and effective antidiabetic thiazolidindiones. All compounds were evaluated their biological potency by PPARν transactivation assay and revealed the similar potency with Troglitazone. However, lengthening of N-alkyl substituent did not seem to be beneficial for the activity.

• Asian-Australasian Journal of Animal Sciences
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• 제22권5호
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• pp.721-726
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• 2009

The molecular mechanism of adipocyte differentiation has been well documented. However, the effect of specific nutrients such as lysine on adipocyte differentiation is poorly understood especially in ruminant animals. Therefore, the aim of the present study was to elucidate the influence of lysine on adipocyte differentiation and adipogenic genes in cultured bovine preadipocytes. The preadipocytes were treated with different concentrations of lysine (40, 160, 320 mg/L) or troglitazone (10 ${\mu}M$) for 2 days and then subsequently cultured in differentiation medium until day 6. Expression levels of $C/EBP{\alpha}$ were significantly higher (p<0.001) in 40 and 160 mg/L lysine-treated cells compared to 320 mg/L treatment. Though there was an increasing trend in $PPAR{\gamma}$ expression levels with the decreasing lysine concentration, the results were not significant. The preadipocyte factor (pref-1), expression significantly (p<0.001) reduced with decreasing lysine concentration. The Oil red O staining results were better in 40 mg/L treated cells compared to 160 and 320 mg/L lysine treated cells. Our overall results indicate that insufficient supply of lysine increases the adipogenic potential in bovine intramuscular preadipocytes.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 춘계학술대회
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• pp.1-4
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• 1998

Impaired insulin action in Type 2 diabetes is thought to lead to hyperglycemia, with both environmental and complex genetic factors playing key roles. Although the primary lesion in Type 2 diabetes is unknown, a number of studies suggest that metabolic defects in the liver, skeletal muscle and fat, and pancreatic ${\beta}$-cells contribute to the disease. These metabolic abnormalities are characterized by the overproduction of hepatic glucose, impaired insulin secretion, and peripheral insulin resistance. In current pharmacological treatment of Type 2 diabetes, sulfonylurea (SU) drugs have mainly been used as oral hypoglycemic drugs to stimulate endogenous insulin secretion from ${\beta}$ cells. SU drugs, however, sometimes aggravate the disease by causing fatigue of the pancreatic ${\beta}$ cells, which leads to reduced drug efficacy after long-term treatment. This class of drugs also leads to enhanced obesity arising from the stimulation of endogenous insulin secretion in obese Type 2 diabetic patients, plus an increased incidence of SU-induced hypoglycemia. Since 1980, a major challenge has been made by us to develop a potential pharmacological therapy for the treatment of insulin resistance in peripheral tissues and/or suppression of abnormal hepatic glucose production in Type 2 diabetic patients. Such a drug would be expected to have fewer side effects and retain long-term efficacy.

• 약학회지
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• 제59권5호
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• pp.201-206
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• 2015

The aim of the present study was to optimize in vitro method for the prediction of drug-induced liver injury using human liver microsomes (HLM). Cytotoxicity test of cyclophosphamide and acetaminophen in HepG2 cells cultured with HLM showed that the newly established condition using 0.375 mg/ml HLM for 24 hr incubation was comparable or more sensitive than the previously established condition using 0.75 mg/ml HLM for 12 hr incubation. Although the cytotoxic effect of troglitazone was completely attenuated by 0.75 mg/ml HLM, it was augmented by 0.375 mg/ml HLM in the presence of the NADPH-generating system. The cytotoxic effect of chlormezanone, a withdrawn drug due to hepatotoxicity in human, was increased by HLM in the presence of the NADPH-generating system. In contrast, the cytotoxic effect of methapyrilene, a withdrawn drug due to hepatotoxicity in rats, was decreased by HLM in the presence of the NADPH-generating system. The present study suggests that the optimized in vitro method using HLM can be useful for the prediction of drug-induced hepatotoxicity.

• Asian-Australasian Journal of Animal Sciences
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• 제22권11호
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• pp.1566-1573
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• 2009

Trans-10, cis-12 conjugated linoleic acid (CLA) has been reported to inhibit the adipocyte differentiation of preadipocytes in non-ruminant animals (mice, rat, and human). However, the effects of trans-10, cis-12 CLA have not been clear in ruminants. The objective of this study was to investigate the effects of trans-10, cis-12 CLA on adipocyte differentiation of ovine preadipocytes. Differentiation of these preadipocytes was facilitated by treatment with trans-10, cis-12 CLA. Trans-10, cis-12 CLA increased the number and size of oil red O-stainable lipid drops as well as the levels of GPDH activity. PPAR-$\gamma{2}$ and adipophilin mRNA, adipogenic marker genes, were increased by treatment with trans-10, cis-12 CLA. This result was different from that observed with 3T3-L1 preadipocytes, a clonal cell line derived from rodents. Furthermore, trans-10, cis-12 CLA alone induced the adipocyte differentiation of ovine preadipocytes in differentiation-induction medium without troglitazone. These results suggest that CLA is an inducer and regulator in adipocyte differentiation of ovine preadipocytes, with species differences between ovine and rodent preadipocytes.