• Molecules and Cells
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• v.43 no.4
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• pp.373-383
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• 2020

Our previous study revealed a novel role of Fas-associated death domain-containing protein (FADD) in islet development and insulin secretion. Insulin-degrading enzyme (IDE) is a zinc metalloprotease that selectively degrades biologically important substrates associated with type 2 diabetes (T2DM). The current study was designed to investigate the effect of FADD phosphorylation on IDE. We found that the mRNA and protein levels of IDE were significantly downregulated in FADD-D mouse livers compared with control mice. Quantitative real-time polymerase chain reaction analysis showed that FADD regulates the expression of IDE at the transcriptional level without affecting the stability of the mRNA in HepG2 cells. Following treatment with cycloheximide, the IDE protein degradation rate was found to be increased in both FADD-D primary hepatocytes and FADD-knockdown HepG2 cells. Additionally, IDE expression levels were reduced in insulin-stimulated primary hepatocytes from FADD-D mice compared to those from control mice. Moreover, FADD phosphorylation promotes nuclear translocation of FoxO1, thus inhibiting the transcriptional activity of the IDE promoter. Together, these findings imply a novel role of FADD in the reduction of protein stability and expression levels of IDE.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.249-255
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• 2015

Diabetes mellitus, the most common metabolic disorder, is divided into two types: type 1 and type 2. The essential treatment of type 1 diabetes, caused by immune-mediated destruction of ${\beta}-cells$, is transplantation of the pancreas; however, this treatment is limited by issues such as the lack of donors for islet transplantation and immune rejection. As an alternative approach, stem cell therapy has been used as a new tool. The present study revealed that bone marrowderived mesenchymal stromal cells (BM-MSCs) could be transdifferentiated into pancreatic cells by the insertion of a key gene for embryonic development of the pancreas, the pancreatic and duodenal homeobox factor 1 (PDX1). To avoid immune rejection associated with xenotransplantation and to develop a new cell-based treatment, BM-MSCs from ${\alpha}$-1,3-galactosyltransferase knockout (GalT KO) pigs were used as the source of the cells. Transfection of the EGFP-hPDX1 gene into GalT KO pig-derived BM-MSCs was performed by electroporation. Cells were evaluated for hPDX1 expression by immunofluorescence and RT-PCR. Transdifferentiation into pancreatic cells was confirmed by morphological transformation, immunofluorescence, and endogenous pPDX1 gene expression. At 3~4 weeks after transduction, cell morphology changed from spindle-like shape to round shape, similar to that observed in cuboidal epithelium expressing EGFP. Results of RT-PCR confirmed the expression of both exogenous hPDX1 and endogenous pPDX1. Therefore, GalT KO pig-derived BM-MSCs transdifferentiated into pancreatic cells by transfection of hPDX1. The present results are indicative of the therapeutic potential of PDX1-expressing GalT KO pig-derived BM-MSCs in ${\beta}-cell$ replacement. This potential needs to be explored further by using in vivo studies to confirm these findings.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.1-1
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• 2011

We developed a new generalized synthetic procedure, called as "heat-up process," to produce uniform-sized nanocrystals of many transition metals and oxides without a size selection process. We were able to synthesize uniform magnetite nanocrystals as much as 1 kilogram-scale from the thermolysis of Fe-oleate complex. Clever combination of different nanoscale materials will lead to the development of multifunctional nano-biomedical platforms for simultaneous targeted delivery, fast diagnosis, and efficient therapy. In this presentation, I would like to present some of our group's recent results on the designed fabrication of multifunctional nanostructured materials based on uniform-sized magnetite nanoparticles and their medical applications. Uniform ultrasmall iron oxide nanoparticles of <3 nm were synthesized by thermal decomposition of iron-oleate complex in the presence of oleyl alcohol. These ultrasmall iron oxide nanoparticles exhibited good T1 contrast effect. In in vivo T1 weighted blood pool magnetic resonance imaging (MRI), iron oxide nanoparticles showed longer circulation time than commercial gadolinium complex, enabling high resolution imaging. We used 80 nm-sized ferrimagnetic iron oxide nanocrystals for T2 MRI contrast agent for tracking transplanted pancreatic islet cells and single-cell MR imaging. We reported on the fabrication of monodisperse magnetite nanoparticles immobilized with uniform pore-sized mesoporous silica spheres for simultaneous MRI, fluorescence imaging, and drug delivery. We synthesized hollow magnetite nanocapsules and used them for both the MRI contrast agent and magnetic guided drug delivery vehicle.

• Korean Journal of Plant Taxonomy
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• v.45 no.3
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• pp.262-265
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• 2015

Two species of Syrrhopodon [S. japonicus (Besch.) Broth. and S. armatus Mitt.] were newly recorded from Jeju Island. S. japonicus was found on a rock covered with fine soil on the Che-oreum Volcano. This species is clearly distinguished from other species of the genus by its plants to 40 mm long, leaves bordered with several rows of short cells, and the margins at the leaf shoulders being regularly serrate. Syrrhopodon armatus was found on tree bark on Seopseom islet. It differs morphologically from other species of the genus in terms of its plant at 10 mm long, leaves bordered with one to several rows of linear and hyaline cells, leaves with spinous teeth at the shoulders. We propose new Korean names for these two species: 'Seon-o-reum-i-kki' and 'Jag-eun-seon-o-reum-i-kki,' respectively, which are based on their plant size and their first locations in Korea.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.1
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• pp.39-44
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• 2006

Type I diabetes (T1D) is an organ-specific autoimmune disease caused by the T cell-mediated destruction of the insulin-producing ${\beta}$ cells in the pancreatic islets. The onset of T1D is the consequence of a progressive destruction of islet ${\beta}$ cells mediated by an imbalance between effector $CD4^+$ T helper (Th)1 and regulatory $CD4^+$ Th2 cell function. Since interferon-alpha (IFN-${\alpha}$) has been known to modulate immune function and autoimmunity, we investigated whether administration of adenoviralmediated IFN-${\alpha}$ gene would inhibit the diabetic process in NOD mice. The development of diabetes was significantly inhibited by a single injection of adenoviral-mediated IFN-${\alpha}$ gene before 8 weeks of age. Next, we examined the hypothesis that Th2-type cytokines are associated with host protection against autoimmune diabetes, whereas Th1-type cytokines are associated with pathogenesis of T1D. The expression of IFN-${\alpha}$ induced increase of serum IL-4 and IL-6 (Th2 cytokines) levels and decrease of serum IL-12 and IFN-${\gamma}$ (Th1 cytokines) levels. Therefore, overexpression of IFN-${\alpha}$ by adenoviralmediated delivery provides modulation of pathogenic progression and protection of NOD mice from T1D.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.2
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• pp.340-345
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• 2008

Extract of Acanthopanax senticosus has recently been demonstrated to possess significant antidiabetic potential, in accordance with the traditional use of this plant as an antidiabetic natural health product. The present study evaluated the effects of fermented extract (FE) of this plant on glucose-stimulated insulin secretion, glucose uptake, and streptozotocin-induced type 1 diabetes model. A 3 h pretreatment with FE prevented $IL-1{\beta}$ and $IFN-{\gamma}$ toxicity in isolated rat islets. However, it did not affect insulin-stimulated glucose uptake in C2C12 myotubes. In addition, pretreatment of mice with FE blocked the destruction of streptozotocin-induced islets and the development of type 1 diabetes. FE reduced blood glucose level, increased insulin secretion, and improved glucose tolerance in streptozotocin-treated mice, whereas nonfermented extract (NFE) had moderate effects. Immunohistochemical staining for insulin clearly showed that pretreatment with FE blocked the STZ-induced islets destruction and restored the number of islet cells that secreted insulin to the level of the control. Although the active principles and their mechanisms of action remain to be identified, FE may nevertheless represent a novel complementary therapy and a source of novel therapeutic agents against type 1 diabetes mellitus.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1462-1469
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• 2007

This study has been carried out to understand the effect of Gangsim-tang on the hyperglycemic mice induced with Streptozotocin(STZ). The 60 mg/kg of streptozotocin(STZ) was treated into mice twice by 24 hrs interval and then 120 mg/kg STZ was treated again 3 days after the earlier treated. Control group was administered mice with 0.9％ saline(2ml/kg), and experimental groups were administered Gangsim-tang extract(GA group, 10 ㎎/㎏/day; GB group, 30 mg/kg/day) after hyperglycemic induction daily for 6 weeks. The body weight of experimental groups was lower than control. The blood glucose concentration increased continuously, reaching to 298.9 mg/dl after 6 weeks, however, experimental groups of the GA and GB groups significantly(p<0.01) decreased in the 4, 5, and 6 weeks groups. Blood glucose tolerance test was not significant between control and experimental groups. We examined the blood transaminase activities to know the effect of herbal medicine on liver function. The glutamic-oxaloacetic transaminase(GOT) activity was lower in group GB than in control. The glutamic-pyruvic transaminse(GPT) activity was lower in group GA and GB than in control. The superoxide dismutase(SOD) and catalase activities were higher in the group GA compared to control. The results of immunohistochemical study, Langerhan's islet of pancreas was destructed by treatment of STZ in the control, and a few of insulin positive cells observed in the control and experimental group. These results suggest that administration of Gangsim-tang extract to the hyperglycemic mice induced with STZ not regeneration of ${\beta}-cells$ but control of the blood glucose level.

• Journal of Ginseng Research
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• v.41 no.1
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• pp.103-112
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• 2017

Background: 20(S)-Protopanaxadiol 20-O-D-glucopyranoside, also called compound K (CK), exerts antidiabetic effects that are mediated by insulin secretion through adenosine triphosphate (ATP)-sensitive potassium ($K_{ATP}$) channels in pancreatic ${\beta}$-cells. However, the antidiabetic effects of CK may be limited because of its low bioavailability. Methods: In this study, we aimed to enhance the antidiabetic activity and lower the toxicity of CK by including it with ${\beta}$-cyclodextrin (CD) (CD-CK), and to determine whether the CD-CK compound enhanced pancreatic islet recovery, compared to CK alone, in an alloxan-induced diabetic zebrafish model. Furthermore, we confirmed the toxicity of CD-CK relative to CK alone by morphological changes, mitochondrial damage, and TdT-UTP nick end labeling (TUNEL) assays, and determined the ratio between the toxic and therapeutic dose for both compounds to verify the relative safety of CK and CD-CK. Results: The CD-CK conjugate ($EC_{50}=2.158{\mu}M$) enhanced the recovery of pancreatic islets, compared to CK alone ($EC_{50}=7.221{\mu}M$), as assessed in alloxan-induced diabetic zebrafish larvae. In addition, CD-CK ($LC_{50} =20.68{\mu}M$) was less toxic than CK alone ($LC_{50}=14.24{\mu}M$). The therapeutic index of CK and CD-CK was 1.98 and 9.58, respectively. Conclusion: The CD-CK inclusion complex enhanced the recovery of damaged pancreatic islets in diabetic zebrafish. The CD-CK inclusion complex has potential as an effective antidiabetic efficacy with lower toxicity.

• YAKHAK HOEJI
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• v.12 no.1_2
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• pp.1-15
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• 1968

The levels of activities of amylase, lipase and trypsin in both the pancreatic tissue and serum of 18 species of vertebrate animals were measured and enzymologically compared with each other. 1) The value of amylase in the pancreas of experimental mammalia has been found decreasing in the order pig, rat, dog, cat, rabbit and cow; that of pancreatic lipase has been found decreasing in the order of pig, dog, cat, rat, rabbit and cow; and that of trypsin has been found decreasing in the order of pig, cow, dog, rat, rabbit. Thus the value of all the above three kinds of enzymes were observed highest in pig, but in cow amylase and lipase were observed lowest while trypsin were observed considerably high. 2) In view of diets, the comparatively high values of pancreatic enzyme were observed in the ommivorous animals such as pig, rat, dog, while the values observed low in the herbivorous animals, such as cow and rabbit. 3) In the bovine, the values were observed moderately high except lipase which were found comparatively low. 4) In the Reptilia and Amphibia such a mud turttle and frog, the values were shown in similar measure with each other, that is, the pancreatic amylase and trypsin were observed considerably high while the lipase was found low. 5) In the species of Reptilia such as a viper and snake, the activities of pancreatic enzymes were not detected. But in the tissue of liver, stomach, activities of the enzymes were found considerably high. Lacertilia animals such as lizard the values of pancreatic enzymes were little observed. 6) In the fish in which the pancreatic tissue is scattered in the liver, the pancreatic enzymes were found in the liver tissue considerably higher than in the other tissues but lower than in the warm-blooded animals, especially the lipase was lower. 7) In generally the values of serum amylase and lipase were observed higher than those of man; and even in the cold-blooded animals in which the values of pancreatic enzymes were shown low or none, the values were also observed high. 8) The above three kinds of pancreatic enzyme values of those experimental animals have shown a tendency of higher degree in higher taxa than in lower taxa according to taxonomical order. 9) In view of tissue, the pancreatic cell was observed large in the mammalian animals such as rat and pig and cytoplasm was also abundantly contained in the acinous cell; and the bovine and the snake haave the pancreatic cells of the similar rosette form the comparatively large acinous cells of long rhombic form in the comparatively large acinous cells of long rhombic form in which the spindle shaped neucleus and the abundant cytoplasm were contained. In the fish the pancreatic cell were found scattered in the liver in which the very large pancreatic islet were found.

• Archives of Pharmacal Research
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• v.26 no.7
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• pp.559-563
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• 2003

Cytokines produced by immune cells infiltrating pancreatic islets have been incriminated as important mediators of $\beta$-cell destruction in insulin-dependent diabetes mellitus. In non insulin-dependent diabetes, cytokines are also associated with impaired $\beta$-cell function in high glucose condition. By the screening of various natural products blocking $\beta$-cell destruction, we have recently found that epigallocatechin gallate (EGCG) can prevent the in vitro destruction of RINm5F cell, an insulinoma cell line, that is induced by cytokines. In that study we suggested that EGCG could prevent cytokine-induced $\beta$-cell destruction by down-regulation of nitric oxide synthase (NOS) through inhibition of NF-kB activation. Here, to verify the in vivo antidiabetogenic effect of EGCG, we examined the possibility that EGCG could also prevent the experimental autoimmune diabetes induced by the treatment of multiple low doses of streptozotocin (MLD-STZ), which is recognized as an inducer of type I autoimmune diabetes. Administration of EGCG (100 mg/day/kg for 10 days) during the MLD-STZ induction of diabetes reduced the increase of blood glucose levels caused by MLD-STZ. Ex vivo analysis of $\beta$-islets showed that EGCG downregulates the MLD-STZ-induced expression of inducible NOS (iNOS). In addition, morphological examination showed that EGCG treatment ameliorated the decrease of islet mass induced by MLD-STZ. In combination these results suggest that EGCG could prevent the onset of MLD-STZ-induced diabetes by protecting pancreatic islets. Our results therefore revealed the possible therapeutic value of EGCG for the prevention of diabetes mellitus progression.