• 생명과학회지
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• 제21권2호
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• pp.202-210
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• 2011

지방세포 분화 과정 중에 key regulator로서 기능을 하는 여러 전사조절인자(PPAR$\gamma$, C/EBP$\alpha$, SREBP, LXR)가 동정되었고, 주로 DNA 복제나 DNA 수선 단계에서 중요한 역할을 한다고 밝혀진 복제 조절인자인 RFC140이 지방세포 분화에도 중요한 인자임이 밝혀졌다. 이 연구에서 우리는 RFC140과 RFC38에 대한 발현조절을 확인하였으며, RFC140이 PPAR$\gamma$와의 단백질-단백질 결합을 통하여 PPAR$\gamma$에 의해 조절되는 유전자의 발현을 증가시킴을 확인하였다. 이러한 결과들은 특이적인 지방세포 전사인자에 의해 발현이 조절되는 RFC140과 RFC38이 지방세포의 분화과정에 필수적임을 제시한다.

• Clinical and Experimental Pediatrics
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• 제56권4호
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• pp.151-158
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• 2013

Purpose: We investigated the mRNA levels of peroxisome proliferator-activated receptor (PPAR)-${\alpha}$, PPAR-${\gamma}$, adipokines, and cytokines in the lung tissue of lean and obese mice with and without ovalbumin (OVA) challenge, and the effect of rosiglitazone, a PPAR-${\gamma}$ agonist. Methods: We developed 6 mice models: OVA-challenged lean mice with and without rosiglitazone; obese mice with and without rosiglitazone; and OVA-challenged obese mice with and without rosiglitazone. We performed real-time polymerase chain reaction for leptin, leptin receptor, adiponectin, vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-${\alpha}$, transforming growth factor (TGF)-${\beta}$, PPAR-${\alpha}$ and PPAR-${\gamma}$ from the lung tissue and determined the cell counts and cytokine levels in the bronchoalveolar lavage fluid. Results: Mice with OVA challenge showed airway hyperresponsiveness. The lung mRNA levels of PPAR${\alpha}$ and PPAR-${\gamma}$ increased significantly in obese mice with OVA challenge compared to that in other types of mice and decreased after rosiglitazone administeration. Leptin and leptin receptor expression increased in obese mice with and without OVA challenge and decreased following rosiglitazone treatment. Adiponectin mRNA level increased in lean mice with OVA challenge. Lung VEGF, TNF-${\alpha}$, and TGF-${\beta}$ mRNA levels increased in obese mice with and without OVA challenge compared to that in the control mice. However, rosiglitazone reduced only TGF-${\beta}$ expression in obese mice, and even augmented VEGF expression in all types of mice. Rosiglitazone treatment did not reduce airway responsiveness, but increased neutrophils and macrophages in the bronchoalveolar lavage fluid. Conclusion: PPAR-${\alpha}$ and PPAR-${\gamma}$ expressions were upregulated in the lung tissue of OVA-challenged obese mice however, rosiglitazone treatment did not downregulate airway inflammation in these mice.

• Biomolecules & Therapeutics
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• 제23권3호
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• pp.218-224
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• 2015

Endocannabinoids can affect multiple cellular targets, such as cannabinoid (CB) receptors, transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and peroxisome proliferator-activated receptor ${\gamma}$($PPAR{\gamma}$). The stimuli to induce adipocyte differentiation in hBM-MSCs increase the gene transcription of the $CB_1$ receptor, TRPV1 and $PPAR{\gamma}$. In this study, the effects of three endocannabinoids, N-arachidonoyl ethanolamine (AEA), N-arachidonoyl dopamine (NADA) and 2-arachidonoyl glycerol (2-AG), on adipogenesis in hBM-MSCs were evaluated. The adipocyte differentiation was promoted by AEA whereas inhibited by NADA. No change was observed by the treatment of non-cytotoxic concentrations of 2-AG. The difference between AEA and NADA in the regulation of adipogenesis is associated with their effects on $PPAR{\gamma}$ transactivation. AEA can directly activate $PPAR{\gamma}$. The effect of AEA on $PPAR{\gamma}$ in hBM-MSCs may prevail over that on the $CB_1$ receptor mediated signal transduction, giving rise to the AEA-induced promotion of adipogenesis. In contrast, NADA had no effect on the $PPAR{\gamma}$ activity in the $PPAR{\gamma}$ transactivation assay. The inhibitory effect of NADA on adipogenesis in hBM-MSCs was reversed not by capsazepine, a TRPV1 antagonist, but by rimonabant, a $CB_1$ antagonist/inverse agonist. Rimonabant by itself promoted adipogenesis in hBM-MSCs, which may be interpreted as the result of the inverse agonism of the $CB_1$ receptor. This result suggests that the constantly active $CB_1$ receptor may contribute to suppress the adipocyte differentiation of hBM-MSCs. Therefore, the selective $CB_1$ agonists that are unable to affect cellular $PPAR{\gamma}$ activity inhibit adipogenesis in hBM-MSCs.

• 생명과학회지
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• 제22권10호
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• pp.1316-1323
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• 2012

본 연구는 한우유래 myoblast에서 지방세포분화 유도 전사인자들을 과발현시켜 지방세포로의 교차분화를 유도하기 위하여 실시하였다. 한우 유래 satellite cell을 배양한 후 adipogenic transcription factor인 $PPAR{\gamma}$, C/$EBP{\alpha}$, SREBP1c, KLF5등을 단독 또는 co-transfection을 실시하여 세포에 과발현을 유도하였다. 이들 세포들은 adipogenic differentiation medium에서 2일간 배양한 후growth medium에서 8일간 추가로 배양하였다. 지방세포로의 교차분화 유무는 Oil-red O염색과 지방세포 마커 유전자들의 발현으로 확인하였다. $PPAR{\gamma}$과 C/$EBP{\alpha}$를 각각 단독으로 과발현을 유도한 경우myoblast에서 지방세포로의 교차분화를 유도하기에는 충분하지 못하였다. 그러나 $PPAR{\gamma}$와 C/$EBP{\alpha}$을 co-transfection을 실시한 경우 지방세포로의 교차분화가 유도되었고, 세포내지방구형성, 지방세포 마커유전자의 발현, 근세포 마커유전자의 발현 감소 등이 확인되었다. KLF5 와 $PPAR{\gamma}$를 동시에 과발현할 경우 지방세포로의 교차분화를 볼 수 있었지만 KLF단독의 경우는 교차분화를 유도하지 못하였다. 할성형SREBP1c (tSREBP1c)의 경우, 단독으로 myoblast에 과발현을 처리한 경우만으로 지방세포로의 교차분화를 유도할 수 있었다. 이들 결과는 한우유래 satellite cell을 이용하여 지방세포분화 전사인자를 단독 혹은 조합하여 이들 세포에 과발현 시킬 경우 지방세포로의 교차분화를 유도할 수 있음을 보여 주었다.

• Biomolecules & Therapeutics
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• 제25권6호
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• pp.641-647
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• 2017

Galangin (3,5,7-trihydroxyflavone) is a polyphenolic compound abundant in honey and medicinal herbs, such as Alpinia officinarum. In this study, we investigated the anti-inflammatory effects of galangin under in vitro and in vivo neuroinflammatory conditions caused by polyinosinic-polycytidylic acid (poly(I:C)), a viral mimic dsRNA analog. Galangin suppressed the production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in poly(I:C)-stimulated BV2 microglia. On the other hand, galangin enhanced anti-inflammatory interleukin (IL)-10 production. Galangin also suppressed the expression of pro-inflammatory markers in poly(I:C)-injected mouse brains. Further mechanistic studies showed that galangin inhibited poly(I:C)-induced nuclear factor (NF)-${\kappa}B$ activity and phosphorylation of Akt without affecting MAP kinases. Interestingly, galangin increased the expression and transcriptional activity of peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, known to play an anti-inflammatory role. To investigate whether PPAR-${\gamma}$ is involved in the anti-inflammatory function of galangin, BV2 cells were pre-treated with PPAR-${\gamma}$ antagonist before treatment of galangin. We found that PPAR-${\gamma}$ antagonist significantly blocked galangin-mediated upregulation of IL-10 and attenuated the inhibition of tumor necrosis factor (TNF)-${\alpha}$ and IL-6 in poly(I:C)-stimulated microglia. In conclusion, our data suggest that PI3K/Akt, NF-${\kappa}B$, and PPAR-${\gamma}$ play a pivotal role in mediating the anti-inflammatory effects of galangin in poly(I:C)-stimulated microglia.

• Journal of Ginseng Research
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• 제39권2호
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• pp.141-147
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• 2015

Background: Adipocytes, which are the main cellular component of adipose tissue, are the building blocks of obesity. The nuclear hormone receptor $PPAR{\gamma}$ is a major regulator of adipocyte differentiation and development. Obesity, which is one of the most dangerous yet silent diseases of all time, is fast becoming a critical area of research focus. Methods: In this study, we initially aimed to investigate whether the ginsenoside Rf, a compound that is only present in Panax ginseng Meyer, interacts with $PPAR{\gamma}$ by molecular docking simulations. After we performed the docking simulation the result has been analyzed with several different software programs, including Discovery Studio, Pymol, Chimera, Ligplus, and Pose View. All of the programs identified the same mechanism of interaction between $PPAR{\gamma}$ and Rf, at the same active site. To determine the drug-like and biological activities of Rf, we calculate its absorption, distribution, metabolism, excretion, and toxic (ADMET) and prediction of activity spectra for substances (PASS) properties. Considering the results obtained from the computational investigations, the focus was on the in vitro experiments. Results: Because the docking simulations predicted the formation of structural bonds between Rf and $PPAR{\gamma}$, we also investigated whether any evidence for these bonds could be observed at the cellular level. These experiments revealed that Rf treatment of 3T3-L1 adipocytes downregulated the expression levels of $PPAR{\gamma}$ and perilipin, and also decreased the amount of lipid accumulated at different doses. Conclusion: The ginsenoside Rf appears to be promising compound that could prove useful in antiobesity treatments.

• 동의생리병리학회지
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• 제20권2호
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• pp.383-387
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• 2006

To investigate the effect of GyeongshinhaeGihwan 1(GGT1) frequently used as an anti-obesity herbal medicine in oriental medicine on the expression of obesity-related genes, we measured the changes in mRNA levels of these genes by GGT1 in human growth hormone transgenic (hGHTg) obese female rats, and these effects by GGT1 were compared with those of reductil (RD), an anti-obesity drug approved by FDA. Rats received once daily oral administrations of autoclaved water, RD, or GGT1 for 8 weeks. At the end of study, rats were sacrificed and tissues were harvested. Total RNA from adipose tissue, liver and kidney was prepared and the mRNA levels for LPL (lipoprotein lipase), $PPAR{\gamma}$ (peroxisome proliferator activated receptor-gamma), $PPAR{\delta}$ (peroxisome proliferator activated receptor-delta), leptin, $TNF{\alpha}$ (tumor necrosis factor-alpha), and internal standard G3PDH (glyceraldehyde-3-phosphate dehydrogenase) were analyzed by RT-PCR. Compared with control group, $PPAR{\gamma}$ mRNA levels of liver and kidney were decreased in both RD and GGT1 groups, and the effects were more prominent in GGT1 group than in RD group, suggesting that GGT1 is effective in the inhibition of lipid storage by decreasing the $PPAR{\gamma}$ expression. $PPAR{\delta}$ mRNA levels of adipose tissue were increased by RD and GGT1 compared with DW, and the magnitude of increase were higher in GGT1 group than in RD group, indicating that GGT1 stimulates fatty acid oxidation and energy metabolism by activating $PPAR{\delta}$ expression. GGT1 group had higher concentrations of serum leptin, a well-known inhibitor of appetite, than control and RD groups. However, The mRNA levels of leptin, LPL, and $TNF{\alpha}$ were not changed by GGT1. These results indicate that GGT1 can prevent obesity in hGHTg obese female rats by down-regulating and up-regulating the mRNA expression of $PPAR{\gamma}$ and $PPAR{\delta}$, respectively, and that this anti-obesity effects were more pronounced in GGT1 group compared with RD group. In addition, GGT1 seems to inhibit obesity by increasing the circulating leptin levels.

• 생명과학회지
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• 제21권5호
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• pp.647-655
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• 2011

Amyloid ${\beta}$ ($A{\beta}$)의 신경독성은 알츠하이머병의 주된 원인이 되고 이러한 신경독성은 일련의 신경세포 사멸반응에 의해 일어난다고 알려져 있다. 본 연구에서는 알츠하이머병의 실험모델로 mouse primary neuronal cell에 $A{\beta}_{25-35}$를 처리하여 세포독성을 유도하는 세포실험모델과 C57BL/6J mouse 뇌실에 $A{\beta}_{25-35}$를 주입하여 인지장애를 일으키는 동물실험모델을 이용하여 phosphodiesterase III 억제제인 cilostazol의 신경보호 효과에 대해 조사하였다. $A{\beta}_{25-35}$를 신경세포에 처리하면 세포생존율이 감소되었고, 세포사멸이 일어난 세포의 수도 증가되었다. 이러한 $A{\beta}_{25-35}$에 의한 세포독성이 cilostazol처리에 의해 회복되었으며, peroxisome proliferator-activated receptor(PPAR)-${\gamma}$ 항진제인 rosiglitazone 또한 동일한 회복효과를 나타내었다. Cilostazol과 rosiglitazone에 의한 이러한 회복효과가 PPAR-${\gamma}$ 길항제인 GW9662에 의해 다시 억제되는 결과를 통해 cilostazol의 효과는 PPAR-${\gamma}$가 매개하는 신호전달이 관여함을 알 수 있었다. 직접 PPAR-${\gamma}$ 활성화 정도를 측정한 결과, $A{\beta}_{25-35}$ 처리에 의해 감소된 PPAR-${\gamma}$ 활성화 정도가 cilostazol과 rosiglitazone에 의해 증가함을 관찰할 수 있었고, 이는 GW9662에 의해 다시 억제됨을 확인하였다. 게다가, cilostazol은 세포사멸이 일어난 세포의 수와 세포사멸 조절단백질인 Bax/Bcl-2의 비율도 감소시켰다. Cilostazol (20 mg/kg, 구강투여)을 C57BL/6J mice 뇌실에 $A{\beta}_{25-35}$를 주입하기 2주 동안 전처리하고, $A{\beta}_{25-35}$ 주입 후 4주 동안 처리하면, 기억력과 학습능력을 증진시킨다는 결과를 water maze 실험을 통해 알 수 있었으며, rosiglitazone (10 mg/kg)을 먹인 동물에서도 동일한 결과를 얻을 수 있었다. 본 연구를 통해서 cilostazol이 PPAR-${\gamma}$ 활성화를 통해 $A{\beta}_{25-35}$로 인한 신경세포 손상과 세포사멸을 약화시켜, 신경세포의 생존을 증진시키고, 알츠하이머에서 인지장애를 개선할 것으로 생각된다. 따라서, phosphodiesterase III 억제제인 cilostazol은 알츠하이머 질병 치료에 새로운 전략이 될 수 있을 것이다.

• 생약학회지
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• 제44권4호
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• pp.397-401
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• 2013

The Galkun-Whanglyeon-Whanggum-Tang, an officially standardized mixture of traditional herbal medicines used in Korea and China, consists of Pueraria lobata, Scullellaria baicalensis, Coptis chinensis and Glycyrrhiza uralensis at a ratio of 6:9:3:2.4. In this study, we evaluated the effect of lowering lipid accumulation in blood by treatment of Galkun-Whanglyeon-Whanggum-Tang in Apo E(-/-) atherosclerotic animal model. ApoE/mice fed with 1.25% cholesterol, 7.5% cocoa butter and 0.5% sodium cholate diet were orally given vehicle or Galkun-Whanglyeon-Whanggum-Tang(10, 100 and 300 mg/kg/day) for 12 weeks. Serum levels of triglyceride(TG), total cholestrerol(TC), low-density lipoprotein(LDL) and high-density lipoprotein(HDL) were analyzed, and PPAR-${\alpha}$ and PPAR-${\gamma}$ were examined by Western blotting analysis. Galkun-Whanglyeon- Whanggum-Tang decreased serum levels of TG, TC and LDL, but not HDL in ApoE/mice. In parallel, Galkun-Whanglyeon-Whanggum-Tang treatment showed the increased activity of PPAR-${\alpha}$ and PPAR-${\gamma}$ in hepatocytes. In summary, Galkun-Whanglyeon-Whanggum-Tang can reduce lipid accumulation in blood, and this effect might be accompanied by the upregulation of PPAR-${\alpha}$ and PPAR-${\gamma}$ in Apo E(-/-) atherosclerotic mouse model.

• Biomolecules & Therapeutics
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• 제23권1호
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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.