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Lee H.,Chung - Ang University | Lee H.,Forensic Center | Bae S.,Chung - Ang University | Yoon Y.,Chung - Ang University
Journal of Nutritional Biochemistry | Year: 2013

(-)Epigallocatechin gallate (EGCG) is the most abundant catechin in green tea and reportedly has anti-obesity and anti-adipogenic effects. In this study, we determined that the up-regulation of the WNT/β-catenin pathway is the anti-adipogenic mechanisms of EGCG in 3T3-L1 cells. EGCG treatment down-regulates the expression of major genes involved in the adipogenesis pathway including peroxisome proliferator-activated receptor (PPAR)γ, CCAAT/enhancer binding protein (C/EBP)α, fatty acid binding protein (FABP)4 and fatty acid synthase (FASN), while up-regulating the nuclear level of β-catenin. Knockdown of β-catenin using small interfering (si) RNA attenuated the inhibitory effects of EGCG on intracellular lipid accumulation. β-catenin siRNA transfection also recovered terminal adipocyte markers such as FABP4, FASN, lipoprotein lipase and adiponectin, which were down-regulated by EGCG. The DNA binding activities as well as the expression levels of PPARγ and C/EBPα, which were down-regulated by EGCG, were significantly restored by β-catenin siRNA transfection. In addition, we found that EGCG efficiently up-regulates the WNT/β-catenin pathway. Among the members of the WNT/β-catenin pathway, the expressions of low density lipoprotein receptor-related protein (LRP)5, LRP6, disheveled (DVL)2 and DVL3 were significantly up-regulated, while AXIN expression was down-regulated by EGCG, and the phosphorylation of glycogen synthase kinase 3β was increased. These results suggest that EGCG activates the WNT/β-catenin pathway, resulting in the up-regulation of β-catenin, which down-regulates the major genes of the adipogenesis pathway. Taken together, our findings clearly show that the anti-adipogenic effects of EGCG are, at least partially, dependent on the WNT/β-catenin pathway. © 2013 Elsevier Inc.

Ma Y.,Forensic Center | Ma Y.,China Pharmaceutical University | Liu J.,China Pharmaceutical University | Hou J.,China Pharmaceutical University | And 6 more authors.
PLoS ONE | Year: 2014

Diabetes mellitus type 1 (DM1) is an autoimmune disease that gradually destroys insulin-producing beta-cells. We have previously reported that mucosal administration of fusion protein of HSP65 with tandem repeats of P277 (HSP65-6P277) can reduce the onset of DM1 in non-obese diabetic (NOD) mice. To deliver large amounts of the fusion protein and to enhance long-term immune tolerance effects, in the present study, we investigated the efficacy of using orally administrated L. lactis expressing HSP65-6P277 to reduce the incidence of DM1 in NOD mice. L. lactis strain NZ9000 was engineered to express HSP65-6P277 either constitutively or by nisin induction. After immunization via gavage with the recombinant L. lactis strains to groups of 4-week old female NOD mice for 36 weeks, we observed that oral administration of recombinant L. Lactis resulted in the prevention of hyperglycemia, improved glucose tolerance and reduced insulitis. Immunologic analysis showed that treatment with recombinant L. lactis induced HSP65- and P277- specific T cell immuno-tolerance, as well as antigen-specific proliferation of splenocytes. The results revealed that the DM1-preventing function was in part caused by a reduction in the pro-inflammatory cytokine IFN-γ and an increase in the anti-inflammatory cytokine IL-10. Orally administered recombinant L. lactis delivering HSP65-6P277 may be an effective therapeutic approach in preventing DM1. © 2014 Ma et al.

Kim M.H.,Yonsei University | Kim M.H.,Forensic Center | Kim Y.,Yonsei University | Kim J.W.,Yonsei University | And 5 more authors.
Plant and Cell Physiology | Year: 2013

Brassinosteroids (BRs) activate the BRI1 and BAK1/SERK3 membrane receptor complex, which leads to a wide range of changes in gene expression, plant growth and development. As an initial step to elucidate additional roles of BAK1, we cloned a BAK1-binding protein, BAK1-Associating Receptor-Like Kinase 1 (BARK1), and characterized its gene expression and root phenotypes. BARK1 is a putative membrane LRR-RLK (leucine-rich repeat receptor-like kinase) protein that specifically binds to BAK1 and its homologs. Careful examination of BARK1 expression using transgenic plants expressing a green fluorescent protein (GFP) reporter under the control of the native BARK1 promoter (BARK1p::GFP) revealed that this gene is ubiquitously expressed in most plant tissues, and shows especially strong expression in the xylem vasculature of primary and lateral roots as well as in mature pollen. Interestingly, the expression of the BARK1 gene was increased in the BR biosynthetic loss-of-function mutant, det2, and a loss-of-function mutant of BR signaling, bak1-3. In contrast, this gene was down-regulated in the bzr1-1D plant, which is a BR signal gain-of-function mutant. BARK1-overexpressing transgenic plants clearly enhanced primary root growth in a dose-dependent manner, and their roots were hypersensitive to BR-induced root growth inhibition. In addition, both the number and density of lateral roots were dramatically increased in the BARK1 transgenic plants in a dose-dependent manner. Together with observations that ARF (AUXIN RESPONSE FACTOR) genes are up-regulated in the BARK1 overexpressor, we suggest that the BARK1 overexpressor phenotype with more lateral roots is partly due to the increased expression of ARF genes in this genetic background. In conclusion, BAK1-interacting BARK1 protein may be involved in BR-mediated plant growth and development such as in lateral roots via auxin regulation. © 2013 The Author.

Lee H.,Chung - Ang University | Lee H.,Forensic Center | Bae S.,Chung - Ang University | Yoon Y.,Chung - Ang University
International Journal of Molecular Medicine | Year: 2012

1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the active metabolite of vitamin D, was found to have anti-adipogenic activity, however, its mechanism of action has not been fully elucidated. In this study, 3T3-L1 preadipocytes were differentiated in the presence and absence of 1,25(OH)2D3, and the expression of the genes and proteins of the wingless-type MMTV integration site (WNT)/β-catenin pathway were analyzed. While the expression of the members of the WNT/β-catenin pathway were significantly downregulated during the adipogenesis of untreated 3T3-L1 cells, 1,25(OH)2D3 treatment was found to maintain the WNT/β-catenin pathway. Among the members of the WNT/β-catenin pathway, the levels of WNT10B and disheveled (DVL)2 as well as the phosphorylation of glycogen synthase kinase (GSK)3β were maintained by 1,25(OH)2D3 treatment. The levels of nuclear β-catenin, which were downregulated during adipogenesis, were also maintained by 1,25(OH)2D3 treatment. The results of this study suggested that the anti-adipogenic effect of 1,25(OH)2D3 was mediated by the maintenance of the WNT/β-catenin pathway, which was normally downregulated during adipogenesis.

Choi S.-Y.,Hannam University | Park G.-S.,Forensic Center | Lee S.Y.,Korea Research Institute of Bioscience and Biotechnology | Kim J.Y.,Korea Research Institute of Bioscience and Biotechnology | Kim Y.K.,Korea Research Institute of Bioscience and Biotechnology
Archives of Pharmacal Research | Year: 2011

In the course of searching for cholesteryl ester transfer protein (CETP) inhibitors from natural sources, a new type of CETP inhibitor, [10]-dehydrogingerdione (1), was isolated from the extract of rhizomes of Zingiber officinale Roscoe. By NMR spectroscopic analysis of its 1HNMR, 13C-NMR, and 1H-1H COSY, HMBC, HMQC and NOESY, more precise structure, compared with its originally proposed structures, of [10]-dehydrogingerdione has been elucidated. This active compound inhibited human plasma CETP with IC50 values of 35 μM. © 2011 The Pharmaceutical Society of Korea and Springer Netherlands.

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