• BMB Reports
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• 제49권5호
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• pp.297-302
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• 2016

Loss of pancreatic β-cells by oxidative stress or cytokines is associated with diabetes mellitus (DM). DJ-1 is known to as a multifunctional protein, which plays an important role in cell survival. We prepared cell permeable wild type (WT) and mutant type (M26I) Tat-DJ-1 proteins to investigate the effects of DJ-1 against combined cytokines (IL-1β, IFN-γ and TNF-α)-induced RINm5F cell death. Both Tat-DJ-1 proteins were transduced into RINm5F cells. WT Tat-DJ-1 proteins significantly protected against cell death from cytokines by reducing intracellular toxicities. Also, WT Tat-DJ-1 proteins markedly regulated cytokines-induced pro- and anti-apoptosis proteins. However, M26I Tat-DJ-1 protein showed relatively low protective effects, as compared to WT Tat-DJ-1 protein. Our experiments demonstrated that WT Tat-DJ-1 protein protects against cytokine-induced RINm5F cell death by suppressing intracellular toxicities and regulating apoptosisrelated protein expression. Thus, WT Tat-DJ-1 protein could potentially serve as a therapeutic agent for DM and cytokine related diseases.

• BMB Reports
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• 제48권3호
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• pp.172-177
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• 2015

Upregulation of pro-inflammatory mediators contributes to ${\beta}$-cell destruction and enhanced infiltration of immune cells into pancreatic islets during development of type 1 diabetes mellitus. In this study, we examined the regulatory effects and the mechanisms of action of celastrol against cytotoxicity and pro-inflammatory immune responses in the RINm5F rat pancreatic ${\beta}$-cell line stimulated with a combination of interleukin-1 beta, tumor necrosis factor-alpha, and interferon-${\gamma}$. Celastrol significantly restored cytokine-induced cell death and significantly inhibited cytokine-induced nitric oxide production. In addition, the protective effect of celastrol was correlated with a reduction in pro-inflammatory mediators, such as inducible nitric oxide synthase, cyclooxygenase-2, and CC chemokine ligand 2. Furthermore, celastrol significantly suppressed cytokine-induced signaling cascades leading to nuclear factor kappa B (NF-${\kappa}B$) activation, including $I{\kappa}B$-kinase (IKK) activation, $I{\kappa}B$ degradation, p65 phosphorylation, and p65 DNA binding activity. These results suggest that celastrol may exert its cytoprotective activity by suppressing cytokine-induced expression of pro-inflammatory mediators by inhibiting activation of NF-${\kappa}B$ in RINm5F cells.

• 약학회지
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• 제42권4호
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• pp.408-413
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• 1998

To establish prediabetes in vitro/ model concerning the etiology of Insulin Dependent Diabetes Mellitus (IDDM) in cellular level we have designed experimental prediabefic model in pancreatic beta cells. RINm5F, HIT-T15 and isolated rat islets were chosen as pancreatic beta cells. Since interleukin-$1{\beta}$-induced beta cell cytotoxicity has been implicated in the autoimmune cytotoxicity of IDDM, we used inteleukin-$1{\beta}$ as diabetogenic agent. For establishment of prediabetic in vitro model, the degree of beta cell deterioration was determined by cell proliferation, insulin release and morphological appearance. Cell proliferation, insulin release and morphology were changed dose-dependently in condition that inteleuldn-$1{\beta}$ was exposured to pancreatic beta cells. The concentration and exposure time of interleukin-$1{\beta}$ to set up prediabetic model in beta cell lines and isolated rat islets were 100${\sim}$1000U/ml, 48hr. And 25${\sim}$100U/ml, 48hr, respectively.

• 생명과학회지
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• 제27권5호
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• pp.509-516
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• 2017

들깨(Perilla frutescents (L.) Britton var.) 새싹은 꿀풀과에 속하는 1년생 초본이다. 본 연구의 목적은 들깨 새싹 에탄올 추출물이 사이토카인으로 유도된 췌장 베타 세포 손상에 대한 예방 효과를 평가하기 위함이다. 췌장 소도 주위에 염증 세포 침습으로 의해 분비되는 사이토카인은 1형 당뇨병의 발병원인에 해당된다. 인터루킨-$1{\beta}$ (IL-$1{\beta}$), 인터페론-${\gamma}$ (IFN-${\gamma}$), 종양괴사인자-${\alpha}$ (TNF-${\alpha}$) 등의 사이토카인은 활성산소 형성을 유도한다. 세포 내 활성산소 축적은 췌장 베타 세포 기능장애와 세포사멸을 이끈다. 들깨 새싹 추출물은 항산화 효과를 증가 시켰으며 활성산소 생성을 억제하였다. 사이토카인은 세포생존율을 감소시켰고, iNOS와 COX-2의 발현을 증가시키고 산화질소 생성을 유도하였다. 들깨 새싹 추출물은 사이토카인으로 유도된 세포생존을 농도 의존적으로 예방하였다. 또한, 사이토카인에 의한 산화질소 생성과 iNOS와 COX-2의 단백질 발현 증가를 억제하였다. 더 나아가 들깨 새싹 추출물은 췌장 베타 세포주(RIN-m5F)에서 $I{\kappa}B{\alpha}$ 인산화 억제를 통해서 NF-${\kappa}B$의 활성화를 상당히 감소시켰다. 요약하자면, 본 연구 결과는 들깨 새싹 추출물이 사이토카인으로 유도된 췌장 베타 세포 손상에 대한 보호 효과를 가지고 있다는 것이 확인되었다. 결과적으로 들깨 새싹은 혈당 증가에 의한 산화 스트레스와 염증성 사이토카인에 의한 베타 세포 손상을 완화하여 당뇨에 유익할 것으로 사료된다.

• 디지털융복합연구
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• 제17권7호
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• pp.275-284
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• 2019

난초과의 석곡(石斛; Dendrobii herba) 에탄올 추출물(EED)의 항당뇨 활성 및 항당뇨 기전을 조사하였다. 스트렙토 조 토신에 의해 유도된 당뇨병 마우스에서 EED를 하루 4회 경구 투여하여 공복 혈당, 당화혈색소 수치, 인슐린 수치 및 글루탐산 옥살 아세트산 트랜스 아미나 아제 및 글루탐산 피루브산 트랜스 아미나 아제의 간 기능을 감소시키는 실험연구를 통해 그 약리적 기전을 밝혀내고자 했다. EED는 L6 근육 세포에서 세포 내 포도당 섭취뿐만 아니라 RINm5F 베타 세포에서 포도당에 의한 인슐린 분비를 증가시켰다. 따라서 EED는 인슐린 분비를 증가시킬 뿐만 아니라 세포 당 흡수를 증가시킴으로써 항당뇨병 활성을 나타내는데 커다란 가능성을 보여주었으며, 향후 석곡(石斛; Dendrobii herba) 에탄올 추출물에 대한 약리적 기전에 대한 연구가 더욱 활발하게 이루어져 당뇨병 치료에 큰 공헌을 할 수 있게 되기를 기대해본다.

• Natural Product Sciences
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• 제22권3호
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• pp.175-179
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• 2016

The aim of this study was to evaluate the anti-diabetic effects of the water extract of Lespedeza cuneata (LCW) using rat insulinoma (RIN) m5F cells and streptozotocin (STZ)-induced diabetic rats. The effect of LCW on the protection of pancreatic beta cells was assessed using MTT assay, and nitric oxide production was assessed using Griess reagent. STZ-induced diabetic rats were treated with 100 and 400 mg/kg body weight of LCW for 5 weeks. In results, LCW significantly protected cytokine-induced toxicity and NO production, and increased insulin secretion in RINm5F cells. LCW significantly decreased serum blood glucose, thiobarbituric acid reactive substances (TBARS), blood urea nitrogen (BUN) and advanced glycation end products (AGEs) levels, and renal fibronectin expression in STZ-induced diabetic rats. Also, LCW effectively improved BW loss in STZ-induced diabetic rats. Thus, our results suggest that LCW has a beneficial effect on cytokine-induced pancreatic beta cell damage and biomarkers of diabetic complication in hyperglycemic rats.

• Archives of Pharmacal Research
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• 제26권7호
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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.

• 동의생리병리학회지
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• 제22권2호
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• pp.422-426
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• 2008

In this study, the preventive effects of Radix Trichosanthis extracts (RTE) against cytokine-induced ${\beta}-cell$ death were assessed. Cytokines generated by immune cells infiltrating pancreatic islets are crucial mediators of ${\beta}-cell$ destruction in insulin-dependent diabetes mellitus. The treatment of RIN cells with $interleukin-1{\beta}$ ($IL-1{\beta}$) and $interferon-{\gamma}$ ($IFN-{\gamma}$) resulted in a reduction of cell viability. RTE protected $IL-1{\beta}$ and $IFN-{\gamma}$-mediated viability reduction in a concentration-dependent manner. Incubation with RTE also induced a significant suppression of $IL-1{\beta}$ and $IFN-{\gamma}$-induced inducible nitric oxide synthase (iNOS) protein expression. The molecular mechanism by which RTE inhibited iNOS protein expression appeared to involve the inhibition of $NF{-\kappa}B$ activation. The $IL-1{\beta}$ and $IFN-{\gamma}$-stimulated RIN cells showed increases in $NF{-\kappa}B$ binding activityand $I{\kappa}B{\alpha}$ degradation in cytosol compared to unstimulated cells. However, pretreatment with RTE inhibited cytokines-induced $I{\kappa}B{\alpha}$ degradation and $NF{-\kappa}B$ activation in RINm5F cells. Furthermore, the protective effects of RTE were verified via protection of impairment in glucose-stimulated insulin secretions in $IL-1{\beta}$ and $IFN-{\gamma}$-treated islets.

• BMB Reports
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• 제51권7호
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• pp.362-367
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• 2018

A major feature of type 1 diabetes mellitus (T1DM) is hyperglycemia and dysfunction of pancreatic ${\beta}$-cells. In a previous study, we have shown that Tat-DJ-1 protein inhibits pancreatic RINm5F ${\beta}$-cell death caused by oxidative stress. In this study, we examined effects of Tat-DJ-1 protein on streptozotocin (STZ)-induced diabetic mice. Wild type (WT) Tat-DJ-1 protein transduced into pancreas where it markedly inhibited pancreatic ${\beta}$-cell destruction and regulated levels of serum parameters including insulin, alkaline phosphatase (ALP), and free fatty acid (FFA) secretion. In addition, transduced WT Tat-DJ-1 protein significantly inhibited the activation of $NF-{\kappa}B$ and MAPK (ERK and p38) expression as well as expression of COX-2 and iNOS in STZ exposed pancreas. In contrast, treatment with C106A mutant Tat-DJ-1 protein showed no protective effects. Collectively, our results indicate that WT Tat-DJ-1 protein can significantly ameliorate pancreatic tissues in STZ-induced diabetes in mice.

• 대한한의학방제학회지
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• 제27권3호
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• pp.223-236
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• 2019

Dengropanax morfiferus (D), Broussonitia kazinoki (B), and Cudriania tricuspidata (E), a widely cultivated species in South Korea, has been used as traditional medicine to treat numerous diseases. In this study, we evaluated the antidiabetic effects in a various signaling mechanisms using mixed extract and major component contents were analyzed by HPLC in the combined extracts from Dengropanax morfiferus, Broussonitia kazinoki, and Cudriania tricuspidata (DBCE). DBCE inhibited ${\alpha}$-glucosidase and ${\alpha}$-amylase activation and showed potent antioxidant effects, which are evaluated using DPPH, ABTS, and SOD assay. Cytokines, which are released by inflammatory cells in pancreatic islets, are involved in the pathogenesis of type 1 diabetes mellitus. DBCE showed the protective effects in RINm5F cells against cytokines-induced damage by suppressing inducible nitric oxide (NO) synthase and COX-2 expression and NO production. Insulin resistance is the primary characteristic of type 2 diabetes. Therefore, the regulatory effect of DBCE on glucose uptake and production are investigated in insulin-responsive human HepG2 cells. DBCE stimulated glucose uptake, prevented Glut2 and phosphor-IRS1 downregulation induced by high glucose (HG, 30 mM). Moreover, DBCE pretreatment diminished glucose levels, PEPCK and G6Pase overexpression provoked by HG. These findings suggest that DBCE might be used for diabetes treatment through alpha-glucosidase or alpha-amylase activity regulation, pancreatic beta cell protection, hepatic glucose sensitivity improvement. Cytokines, which are released by inflammatory cells' infiltrations around the pancreatic islets, are involved in the pathogenesis of type 1 diabetes mellitus.