• Korean Journal of Microbiology
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• v.47 no.4
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• pp.342-347
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• 2011

T cells play a key role in viral infection. However, in patients with chronic hepatitis C virus (HCV) infection, HCV-specific T cells are dysfunctional and impaired in the liver, which is the primary site for HCV replication. There are multiple potential mechanisms for HCV-specific T cell dysfunction including induction of immune inhibitory pathways (program death-1; PD-1, cytotoxic t lymphocyte associated antigen-4; CTLA-4) and immune tolerance induced specific for the liver. However, the interaction between hepatocytes and HCV-specific CD8 T cells has not clearly established. In this study, we confirmed huh (human hepatoma) 7.5 cells expressing HLA (human leukocyte antigen) A2 presented antigen to activate HCV-specific CD8 T cells in HLA A2-restricted manner and expression of PD-L (program death ligand) 1 on huh7.5 cells reduced HCV-specific CD8 T cell activation, suggesting an immune modulatory activity. Loss of HCV-specific tetramer responses following antigenic stimulation correlated with increased caspase-3 activity. In addition, PD-L1 on huh7.5 cells rescued HCV-specific CD8 T cells from apoptosis. Our results suggest that the interaction between PD-L1 and PD-1 can recover the function of HCV-specific CD8 T cells in the liver, which could be applied in therapy of HCV chronic infection.

• Proceedings of the Korean Nutrition Society Conference
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• 2004.05a
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• pp.189-189
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• 2004

• Journal of Applied Biological Chemistry
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• v.63 no.2
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• pp.169-174
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• 2020

The objective of this study was to investigate the effects of a hypodermic injectable solution comprised of an LPM LB meso solution containing Melissa officinalis L. leaf extract (LPM) on the lipogenesis in the 3T3-L1 cells line. The lipid accumulation measured by oil red o staining in the 3T3-L1 adipocytes treated with LPM, which was reduced in a dose dependent manner and showed 91.7 to 62.9% compared to control group. Its effectiveness with a 50% solution was significantly higher than the hydroxycitric acid (positive control) treatment without showing cell cytotoxicity. In a quantitative real-time PCR, it was demonstrated that the LPM treatment appeared to upregulate the mRNA expression of the adipogenesis-related genes, which included the peroxisome proliferator-activated receptor gamma (50% concentration) while down-regulating the CCAAT-enhancer binding protein alpha (50% concentration) and the sterol regulatory element-binding protein 1c (10, 25, and 50% concentrations). The results from the current study suggest that the LPM could be useful biomaterials that can inhibit obesity in the 3T3-L1 cells, which could possibly be by regulating the specific adipogenic gene transcription factors.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.186-191
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• 2005

Previous studies have demonstrated that expression of galectin-3, a member of family of beta-galactoside-binding animal lectin, is associated with pathological conditions including cancer, atherosclerosis, and viral infection. An increase of this lectin has been observed after infection by Kirsten murine sarcoma, human T lymphotropic virus-l (HTLV-l), and human immunodeficiency virus-l (HIV-l). Viral transactivation protein Tax of HTLV-l mediates the increase in the lectin. In case of HIV-1, there are evidences that Tat would be related with increase in galectin-3. We investigated whether Tat directly induced galectin-3 expression in cells. We found that HIV-l tat gene activated galectin-3 promoter in RAW264.7 cells. To demonstrate direct induction of galectin-3 by HIV-l tat, we transfected the tat into a rabbit smooth muscle cell line (Rb1) and obtained RblTatCl-2, a clone of cell stably transfected with tat gene. The Rb1TatCl-2 cells exhibited activation of LTR promoter and up-regulation of galectin-3 transcript as well as protein. Our results indicate that HIV-l tat alone is sufficient to induce the expression of galectin-3. The Rb1TatCl-2 cells could be valuable for study of the effect of HIV-1 tat on expression of cellular genes.

• Journal of Life Science
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• v.30 no.6
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• pp.532-541
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• 2020

In this study, we describe the inhibition of adipocyte differentiation by the lactic acid bacteria (LAB) fermentation product of Chrysanthemum indicum L. (CI) extract to control obesity. Preparation of LAB-fermented products was performed to overcome the cytotoxicity of CI extract. During fermentation and 3T3-L1 cell line experiment, cytotoxicity was not induced in the CI fermentation products over 1 day in culture. Fermented materials from highly proliferative cultures were selected for treatment of 3T3-L1 cells and for comparison with unfermented control groups. Cell survival and undifferentiated cell populations were decreased differentiation population in all experimental groups compared with controls, as measured using fluorescence-activated cell sorting analysis. Akt pathway activity increased upon treatment with these fermented extracts in 3T3-L1 cells. Gli2 depleted at the protein level in association with adipocyte differentiation. LAB KCTC 3115- and 3109-fermented extract treatment caused controlled Gli2 protein accumulation. Moreover, KCTC 3115 and 3109 were found to reduce C/EBPα and FAS was depleted, whereas pACC was increased at the protein level upon treatment with the fermentation products of each of the four LAB used in this study. With Lactococcus lactis subsp. lactis KCTC 3115 fermentation, the regulation of adipose differentiation and hedgehog signaling were also suppressed, thereby inhibiting the differentiation of progenitor cells. The basis for the activation of hedgehog signaling may provide insights into the treatment of obesity and the inhibition of adipocyte differentiation.

• BMB Reports
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• v.46 no.12
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• pp.582-587
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• 2013

Adipocyte differentiation is a complex developmental process forming adipocytes from various precursor cells. The murine 3T3-L1 preadipocyte cell line has been most frequently used in the studies of adipocyte differentiation. Differentiation of 3T3-L1 preadipocytes includes a medium containing fetal bovine serum (FBS) with hormonal induction. In this study, we observed that differentiation medium containing adult bovine serum (ABS) instead of FBS did not support differentiation of preadipocytes. Impaired adipocyte differentiation was due to the presence of a serum protein factor in ABS that suppresses differentiation of preadipocytes. Using a proteomic analysis, alpha-2-macroglobulin and paraoxonase/arylesterase 1, which were previously shown to suppress differentiation of preadipocytes, were identified as anti-adipogenic proteins. Although their functional mechanisms have not yet been elucidated, the anti-adipogenic effects of these proteins are discussed.

• Journal of Biomedical Engineering Research
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• v.41 no.6
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• pp.235-246
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• 2020

This study aimed to evaluate the inhibitory effect of micro-current stimulation(MCS) on adipogenesis regarding with Wnt/β-catenin pathway using the ob/ob mouse and 3T3-L1 cell line. 6-week old ob/ob male mice were equally assigned to four groups: obese group(ob), obese with MCS groups(50 μA, 200 μA, and 400 μA). 6-week old C57BL/6J male mice were assigned to the control group(CON). We analyzed abdominal adipose tissue volume by using in vivo micro-CT and measured the body weight, feed intake, liver weight and triglycerides in serum. All the MCS groups showed that significantly reduced body weight and triglycerides in serum. In the case of liver weight and abdominal adipose tissue volume, the inhibitory effect of adipogenesis was shown in the 200 μA and 400 μA groups. To elucidate the anti-obesity effect of MCS, β-catenin, C/EBPα and FAS protein expressions were analyzed by western blotting. β-catenin expression was upregulated, C/EBPα and FAS expression were down-regulated in the relatively high-intensity groups(200 μA and 400 μA). Thus, the 200 μA and 400 μA for the intensity of MCS were chosen for cell experiments. In the 3T3-L1 cell line, Wnt/β-catenin pathway including Wnt10b, Wnt3a, β-catenin and Cyclin D1 was activated in all MCS groups. Accordingly, the expression level of C/EBPα was decreased during the differentiation and lipid droplet was significantly reduced in Oil red O staining results. These results suggest that the Wnt/β-catenin signaling might be activated by MCS with current intensities between 200-400 μA and it may lead to anti-obesity effects.

• Natural Product Sciences
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• v.17 no.3
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• pp.212-215
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• 2011

In the course of screening anti-adipogenic activity of natural products employing the preadipocyte cell line, 3T3-L1 as an in vitro assay system, the EtOAc fraction of the stem barks of Acer tegmentosum Maxim (Aceraceae) showed significant inhibitory activity on adipocyte differentiation as assessed by measuring fat accumulation using Oil Red O staining. Activity-guided fractionation led to the isolation of active constituent, (+)-catechin. (+)-Catechin showed inhibitory activity on adipocyte differentiation in dose-dependent manner. Further studies with interval treatment demonstrated that (+)-catechin exerted inhibitory activity on adipocyte differentiation via acting on early stage of adipogenesis. Our present study also showed that (+)-catechin significantly inhibited the preadipocyte proliferation. Taken together, these results suggest that (+)-catechin, a constituent of A. tegmentosum might contribute the anti-adipogenic activity of A. tegmentosum.

• Natural Product Sciences
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• v.16 no.4
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• pp.291-294
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• 2010

In obesity, adipocytes undergo abnormal growth characterized by increased cell numbers and differentiation. Thus, inhibition of mitogenesis of preadipocytes and their differentiation to adipocytes would be beneficial for the prevention and progression of obesity. In the present study, we attempted to evaluate antiadipogenic activity of adlay (Coix seed, the seed of Coix lacryma-jobi L. var. ma-yuen Stapf) employing preadipocytes cell line, 3T3-L1 as an in vitro assay system. Because several varieties of adlay are in use in Korea, anti-adipogenic activity of three varieties of adlay such as Sang-Gang, Jo-Hyun and Yulmu-Ilho was evaluated. All the three varieties of adlay showed significant inhibitory activity on adipocyte differentiation as assessed by measuring fat accumulation using Oil Red O staining. Adlay, however, showed little effects on adipocyte proliferation. Further studies with interval treatment demonstrated that adlay exerted inhibitory activity on adipocyte differentiation via acting on early stage of adipogenesis. Taken together, adlay might be useful in the prevention of obesity.

• KSBB Journal
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• v.27 no.6
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• pp.381-386
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• 2012

Obesity increases the risk of many adult diseases, such as atherosclerosis, diabetes, hypertension, ischemic heart disease and breast cancer. Inhibition of adipogenesis is an effective way in the anti-obesity management. Because of main components of Saururus chinensis is flavonoid, it has been showed some improvement by its antioxidant effects on the atherosclerosis, heart disease and diabetic hyperlipidemia. But mechanism of anti-obesity effect of S. chinensis is not clear. We investigated the effects of ethanol extracts of S. chinensis on adipogenesis in the 3T3-L1 pre-adipocyte. The 3T3-L1 cell line is commonly used to study adipogenesis in vitro. In this study, ethanol extracts of S. chinensis significantly decrease the lipid accumulation in the 3T3-L1 cells proved by measuring triglyceride contents and Oil red O staining. The proposed mechanism of inhibition of adipogenesis in the 3T3-L1 cells with ethanol extracts of S. chinensis is down-regulation of transcriptional factors and adipocyte-specific genes such CCAAT/enhancer binding protein ${\alpha}$ ($C/EBP{\alpha}$) and Peroxisome proliferator activated receptor ${\gamma}$ ($PPAR{\gamma}$) in concentration dependent pattern. These results suggest that ethanol extracts of S. chinensis inhibits adipognesis in the 3T3-L1 cells and can be used as a safe and efficient natural substance to manage anti-obesity.