• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.43-50
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• 2013

Palmitic acid (PAM), one of the most common saturated fatty acid (SFA) in animals and plants, has been shown to induce apoptosis in exocrine pancreatic AR42J cells. In this study, we investigated cellular mechanisms underlying protective effects of oleic acid (OLA) against the lipotoxic actions of PAM in AR42J cells. Exposure of cells to long-chain SFA induced apoptotic cell death determined by MTT cell viability assay and Hoechst staining. Co-treatment of OLA with PAM markedly protected cells against PAM-induced apoptosis. OLA significantly attenuated the PAM-induced increase in the levels of pro-apoptotic Bak protein, cleaved forms of apoptotic proteins (caspase-3, PARP). On the contrary, OLA restored the decreased levels of anti-apoptotic Bcl-2 family proteins (Bcl-2, Bcl-xL, and Mcl-1) in PAM-treated cells. OLA also induced up-regulation of the mRNA expression of Dgat2 and Cpt1 genes which are involved in triacylglycerol (TAG) synthesis and mitochondrial ${\beta}$-oxidation, respectively. Intracellular TAG accumulation was increased by OLA supplementation in accordance with enhanced expression of Dgat2 gene. These results indicate that restoration of anti-apoptotic/pro-apop-totic protein balance from apoptosis toward cell survival is involved in the cytoprotective effects of OLA against PAM-induced apoptosis in pancreatic AR42J cells. In addition, OLA-induced increase in TAG accumulation and up-regulation of Dgat2 and Cpt1 gene expressions may be possibly associated in part with the ability of OLA to protect cells from deleterious actions of PAM.

• 한국수의병리학회지
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• 제2권1호
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• pp.17-24
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• 1998

This is the first report of c-Jun protein expression and mRNA in a pancreatic islet in a nonobese diabetic(NOD) state mice. In this experiment NOD mice with insulin-dependent diabetes mellitus type I at age 16 weeks(n=7) just before death(n=4) were used. The control group consist of prediabetic NOD(8 weeks n=7) and ICR(8 weeks n=7 and 16 weeks n=7) mice. c-Jun positive cells in the pancreatic islet of NOD mice were localized in the same positions as a-glucagon producing cells. immunoreactivity was negative in the prediabetic NOD(8 weeks) and ICR(8 weeks and 16 weeks) mice. The number of c-Jun positive cells in mice with severe diabetic state just before death were significantly decreased when compared to NOD(16 weeks) mice. Expression of c-Jun in mRNA level was assessed by RT-PCR method. The levels of mRNA in NOD(16 weeks) mice group were elevated in total pancreatic tissues. The present results suggest that the induction of proto-oncogene protein may be of significance in assessing cell specific injury and may play a functional role between pancretic islet $\alpha$-cells and $\beta$-cells in the diabetic state.

• Biomolecules & Therapeutics
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• 제28권2호
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• pp.163-171
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• 2020

Silibinin exhibits antidiabetic potential by preserving the mass and function of pancreatic β-cells through up-regulation of estrogen receptor-α (ERα) expression. However, the underlying protective mechanism of silibinin in pancreatic β-cells is still unclear. In the current study, we sought to determine whether ERα acts as the target of silibinin for the modulation of antioxidative response in pancreatic β-cells under high glucose and high fat conditions. Our in vivo study revealed that a 4-week oral administration of silibinin (100 mg/kg/day) decreased fasting blood glucose with a concurrent increase in levels of serum insulin in high-fat diet/streptozotocin-induced type 2 diabetic rats. Moreover, expression of ERα, NF-E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in pancreatic β-cells in pancreatic islets was increased by silibinin treatment. Accordingly, silibinin (10 μM) elevated viability, insulin biosynthesis, and insulin secretion of high glucose/palmitate-treated INS-1 cells accompanied by increased expression of ERα, Nrf2, and HO-1 as well as decreased reactive oxygen species production in vitro. Treatment using an ERα antagonist (MPP) in INS-1 cells or silencing ERα expression in INS-1 and NIT-1 cells with siRNA abolished the protective effects of silibinin. Our study suggests that silibinin activates the Nrf2-antioxidative pathways in pancreatic β-cells through regulation of ERα expression.

• Journal of Acupuncture Research
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• 제26권6호
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• pp.1-9
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• 2009

Objectives : For evaluation of preventive and anti-diabetic activities of Cinnamomi ramulus(CR) herbal acupuncture on pancreatic islet damage in streptozotocin(STZ)-induced diabetic rat. Methods : CR herbal acupuncture was performed at Bisu($BL_{20}$) for 3 weeks subcutaneously starting1 week before STZ i.p. injection. SD rats were divided into four groups(n=10 for each group); 1) NC group, non-treated normal control group, 2) STZ group, STZ administered control group, 3) CR125 group, CR(125mg/kg) + STZ administered group, and 4) CR250 group, CR(250mg/kg) + STZ administered group. Results : Both of CR250 and CR125 groups showed increase in insulin secretion and decrease in the level of serum triglyceride and non-esterified fatty acid in a dose-dependent manner compared to the STZ group. Only CR250 group showed decrease in the levels of glucose and total cholesterol compared to the STZ group. CR herbal acupuncture prevents $\beta$-cell damage of pancreatic islet, showing round figure on the sections of the pancreas. In the pancreatic cells, expressions of iNOS, JNK-2, P-JNK-1/2 and ERK-1/2 were decreased compared to the STZ group. CR herbal acupuncture solution did not show any cytotoxicity by MTS assay and inhibited expressions of iNOS and COX-2 in the STZ-induced diabetic rats. Conclusions : Therefore, we suggest that CR herbal acupuncture may act as a prophylactic as well as a therapeutic modality for diabetes mellitus.

• 대한본초학회지
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• 제30권2호
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• pp.1-9
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• 2015

Objectives : The present study was conducted to examine whether Toosendan Fructus has an ameliorative effect on diabetes-induced alterations such as oxidative stress and inflammation in the pancreas of non-obese diabetic (NOD) mice, a model of human type I diabetes. Methods : Extracts of Toosendan Fructus (ETF) were administered to NOD mice at three doses (50 mg/kg, 100 mg/kg and 200 mg/kg). Mice at 18 weeks of age were measured glucose tolerance using intraperitoneal glucose tolerance test. After 28 weeks of ETF treatment, glucose, total cholesterol (TC), triglyceride (TG), and proinflammatory cytokines in serum, western blot analyses and a histopathological examination in pancreas tissue, and on the onset of diabetes were investigated. Results : The results showed that levels of glucose, glucose tolerance, TC, TG, interferon-${\gamma}$, interleukin (IL)-1 ${\beta}$, IL-6, and IL-12 in serum were down-regulated, while IL-4, IL-10, SOD, and catalase significantly increased. In addition, ETF improved protein expression of proinflammatory mediaters (such as cyclooxygenase-2, and inducible nitric oxide synthase) and a proapoptotic protein (caspase-3) in the pancreatic tissue. Also, in the groups treated with ETF (100 mg/kg or 200 mg/kg), insulitis and infiltration of granulocytes were alleviated. Conclusions : Based on these results, the anti-diabetic effect of ETF may be due to its anti-inflammatory and antioxidant effect. Our findings support the therapeutic evidence for Toosendan Fructus ameliorating the development of diabetic pancreatic damage via regulating inflammation and apoptosis. Our future studies will be focused on the search for active compounds in these extracts.

• Nutrition Research and Practice
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• 제15권3호
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• pp.294-308
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• 2021

BACKGROUD/OBJECTIVES: Allomyrina dichotoma larva (ADL), one of the many edible insects recognized as future food resources, has a range of pharmacological activities. In a previous study, an ADL extract (ADLE) reduced the hepatic insulin resistance of high-fat diet (HFD)-induced diabetic mice. On the other hand, the associated molecular mechanisms underlying pancreatic beta-cell dysfunction remain unclear. This study examined the effects of ADLE on palmitate-induced lipotoxicity in a beta cell line of a rat origin, INS-1 cells. MATERIALS/METHODS: ADLE was administered to high-fat diet treated mice. The expression of apoptosis-related molecules was measured by Western blotting, and reactive oxidative stress generation and nitric oxide production were measured by DCH-DA fluorescence and a Griess assay, respectively. RESULTS: The administration of ADLE to HFD-induced diabetic mice reduced the hyperplasia, 4-hydroxynonenal levels, and the number of apoptotic cells while improving the insulin levels compared to the HFD group. Treatment of INS-1 cells with palmitate reduced insulin secretion, which was attenuated by the ADLE treatment. Furthermore, the ADLE treatment prevented palmitate-induced cell death in INS-1 cells and isolated islets by reducing the apoptotic signaling molecules, including cleaved caspase-3 and PARP, and the Bax/Bcl2 ratio. ADLE also reduced the levels of reactive oxygen species generation, lipid accumulation, and nitrite production in palmitate-treated INS-1 cells while increasing the ATP levels. This effect corresponded to the decreased expression of inducible nitric oxide synthase (iNOS) mRNA and protein. CONCLUSIONS: ADLE helps prevent lipotoxic beta-cell death in INS-1 cells and HFD-diabetic mice, suggesting that ADLE can be used to prevent or treat beta-cell damage in glucose intolerance during the development of diabetes.

• The Korean Journal of Physiology and Pharmacology
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• 제3권5호
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• pp.521-528
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• 1999

Reactive oxygen species (ROS), generated by infiltrating neutrophils, are considered as an important regulator in the pathogenesis and deveolpment of pancreatitis. The present study aims to investigate whether neutrophils primed by $4{\beta}-phorbol\;12{\beta}-myristate\;13{\alpha}-acetate$ (PMA) affect the productions $H_2O_2$ and lipid peroxide (LPO), $NF-_{\kappa}B$ activation and cytokine production in pancreatic acinar cells, and whether these alterations were inhibited by an antioxidant, N-acetylcysteine (NAC) and superoxide dismutase (SOD). $H_2O_2$ (ferrithiocyanate method), LPO (as thiobarbiturate reactive substances), and cytokines $(IL-l{\bata},\; IL-6,\;TNF-{\alpha};\;enzyme-linked\;immunosorbent\;assay)$ and $NF-_{\kappa}B$ activation (electrophoretic mobility shift assay) were analyzed in acinar cells treated with or without PMA-primed neutrophils in the absence or presence of NAC (10 mM) or SOD (300 U/ml). As a result, the productions of H2O2, LPO and $TNF-{\alpha}$ were increased with the ratio of PMA-primed neutrophils to acinar cells while the productions of LPO, $IL-l{\beta},\;IL-6\;and\;TNF-{\alpha}$ were increased with time. PMA-primed neutrophils resulted in the activation of $NF-_{\kappa}B.$ Both NAC and SOD inhibited neutrophil-induced alterations in acinar cells. In conclusion, ROS, generated by neutrophils, activates $NF-_{\kappa}B,$ resulting in upregulation of inflammatary cytokines in acinar cells. Antioxidants might be clinically useful antiinflammatory agents by inhibiting oxidant-mediated activation of $NF-_{\kappa}B$ and decreasing cytokine production.

• Tuberculosis and Respiratory Diseases
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• 제70권3호
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• pp.206-217
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• 2011

Background: Transcription factor FOXP3 characterizes the thymically derived regulatory T cells. FOXP3 is expressed by cancer cell itself and FOXP3 expression was induced by TGF-${\beta}$ treatment in pancreatic cancer cell line. However, the expression of FOXP3 expression is not well known in patients with lung cancer. This study was conducted to investigate the expression of FOXP3 in patients with lung cancer and to investigate the regulation of FOXP3 expression by the treatment of TGF-${\beta}$ and DNA methyltransferase inhibitor in lung cancer cell lines. Methods: FOXP3 expression in the tissue of patients with resected non-small cell lung cancer (NSCLC) was evaluated by immunohistochemistry. The regulation of FOXP3 expression was investigated by Western blot and RT-PCR after lung cancer cell lines were stimulated with TGF-${\beta}1$ and TGF-${\beta}2$. The regulation of FOXP3 expression was also investigated by RT-PCR and flow cytometry after lung cancer cell lines were treated with DNA methyltransferase inhibitor (5-AZA-dC). Results: FOXP3 expression was confirmed in 27% of patients with NSCLC. In NCI-H460 cell line, TGF-${\beta}2$ decreased FOXP3 mRNA and protein expressions. In A549 cell line, both TGF-${\beta}1$ and TGF-${\beta}2$ decreased FOXP3 mRNA and protein expressions. 5-AZA-dC increased FOXP3 mRNA expression in NCI-H460 and A549 cell lines. Moreover, 5-AZA-dC increased intracellular FOXP3 protein expression in A549 cell lines. Conclusion: It was shown that FOXP3 is expressed by cancer cell itself in patients with NSCLC. Treatment of TGF-${\beta}2$ and DNA methyltransferase inhibitor seems to be associated with the regulation of FOXP3 expression in lung cancer cell lines.

• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.163-168
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• 2003

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic ${\beta}$ cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu,Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ)-induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic ${\beta}$ cell destruction in ROS-mediated diabetes.

• 한국식품영양과학회지
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• 제39권8호
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• pp.1102-1106
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• 2010

본 연구는 진피 에탄올 추출물의 alloxan에 의해 유도된 HIT-T15 세포의 산화적 손상으로부터 세포 생존율 및 인슐린분비 조절능에 대해 조사하였다. 진피 에탄올 추출물의 총 폴리페놀 함량과 총 플라보노이드 함량을 측정한 결과, 각각 $57.00{\pm}2.91\;mg/g$, $8.11{\pm}2.83\;mg/g$으로 나타났으며 alloxan 처리 농도가 증가됨에 따라 HIT-T15 세포의 생존율은 감소하였으며, alloxan 11.58 mM에서 약 50%의 세포 독성이 일어남을 확인하였다. 동결건조 된 진피 에탄올 추출물(CP-Et) 0.125~0.75 mg/mL 농도에서 무처리구의 세포 생존율은 $100.90{\pm}1.51{\sim}97.56{\pm}0.73%$로 나타나 HIT-T15 세포에 대한 CP-Et의 처리 농도는 0.125~0.75 mg/mL로 결정하였다. 0.125, 0.25, 0.5 mg/mL 농도의 CP-Et를 처리한 결과, alloxan에 의해 유도된 산화적 세포손상으로부터 세포 생존율이 각각 $80.52{\pm}3.29$, $74.17{\pm}6.75$, $67.53{\pm}5.8%$로 나타나 유의성 있게 보호되어짐을 확인하였다. CP-Et를 처리한 HIT-T15 세포에서는 산화적 손상에 대한 세포 생존율과는 다르게 0.125 mg/mL 농도에서 $116.93{\pm}2.11{\mu}g/mg$로 인슐린 분비가 대조구와 비교 시 유의적으로 증가되었음을 확인 할 수 있었다. 따라서 진피 에탄올 추출물에 의한 항산화적 방어로 2형 당뇨의 $\beta$-cell 양의 감소와 인슐린 저항성에 대한 개선이 가능함을 제시하며, 그 작용 기작에 대해서는 차후 더 많은 연구가 필요하다 하겠다.