• 제목/요약/키워드: pancreatic islet

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Zinc in Pancreatic Islet Biology, Insulin Sensitivity, and Diabetes

  • Maret, Wolfgang
    • Preventive Nutrition and Food Science
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    • 제22권1호
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    • pp.1-8
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    • 2017
  • About 20 chemical elements are nutritionally essential for humans with defined molecular functions. Several essential and nonessential biometals are either functional nutrients with antidiabetic actions or can be diabetogenic. A key question remains whether changes in the metabolism of biometals and biominerals are a consequence of diabetes or are involved in its etiology. Exploration of the roles of zinc (Zn) in this regard is most revealing because 80 years of scientific discoveries link zinc and diabetes. In pancreatic ${\beta}$- and ${\alpha}$-cells, zinc has specific functions in the biochemistry of insulin and glucagon. When zinc ions are secreted during vesicular exocytosis, they have autocrine, paracrine, and endocrine roles. The membrane protein ZnT8 transports zinc ions into the insulin and glucagon granules. ZnT8 has a risk allele that predisposes the majority of humans to developing diabetes. In target tissues, increased availability of zinc enhances the insulin response by inhibiting protein tyrosine phosphatase 1B, which controls the phosphorylation state of the insulin receptor and hence downstream signalling. Inherited diseases of zinc metabolism, environmental exposures that interfere with the control of cellular zinc homeostasis, and nutritional or conditioned zinc deficiency influence the pathobiochemistry of diabetes. Accepting the view that zinc is one of the many factors in multiple gene-environment interactions that cause the functional demise of ${\beta}$-cells generates an immense potential for treating and perhaps preventing diabetes. Personalized nutrition, bioactive food, and pharmaceuticals targeting the control of cellular zinc in precision medicine are among the possible interventions.

A red seaweed, Polysiphonia morrowii, extract promotes β-cell regeneration in zebrasfish (Danio rerio)

  • Thilini Ranasinghe;Seon-Heui Cha
    • Fisheries and Aquatic Sciences
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    • 제27권1호
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    • pp.17-22
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    • 2024
  • Diabetes Mellitus (DM) is a major health issue increasing worldwide. Currently, nearby half a billion people have diabetes. Two major types of DM that type 1 and type 2-DM have different etiologies but feature a crucial common pathological transition into dysfunction of pancreatic β-cells and consequently leading hyperglycemia and finally go into DM. Therefore, maintaining of β-cells such as preventing β-cells degeneration, and promoting β-cells regeneration and proliferation will be essential approaches in prevention and/or treatment of DM. There are many reports that various types of seaweed control metabolic diseases such as obesity, high blood pressure, and blood sugar control. However, no new drug candidates have been developed yet. Additionally, although seaweed has excellent blood sugar control effects, there is no evidence that it directly proliferates or regenerates beta cells. Therefore, we studied on the promotion of β-cell regeneration by a seaweed, Polysiponia morrowii extract (PME) which preserves β-cells and maintains its function. As a result, it was confirmed that PME directly promotes the proliferation of pancreatic islet β-cells with insulin secretion function in in vivo. Therefore, PME shows potential as a candidate for β-cell regeneration that may play a fundamental role in the treatment of diabetes.

북극여우의 위장췌 내분비세포에 관한 면역조직화학적 연구 (Immunohistochemical study on the gastro-entero-pancreatic(GEP) endocrine cells of the blue fox, Alopex lagopus)

  • 이재현;이형식
    • 대한수의학회지
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    • 제33권4호
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    • pp.579-589
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    • 1993
  • 북극여우의 위장췌 내분비세포의 부위별 분포, 출현빈도 및 세포의 종류를 밝히고자 면역조직화학적으로 관찰하였던 바 위장관에서는 6종, 췌장에서는 4종의 면역반응세포가 동정되었다. 5-HT 및 somatostatin 면역반응세포는 전위방관에 다수 분포하였으나 이중 somatostatin 면역반응세포는 장관에서 소수로 관찰되었다. Gas/CCK 면역반응세포는 주로 유문부와 십이지장에 국한하여 다수 분포하였다. Glucagon 면역반응세포는 분문부와 위저부에서 다수 그리고 장관에서 소수 관찰되었다. BPP 면역반응세포는 분문부와 위저부에 중등도, 대장에 소수분포하였다. 다수의 porcine CG 면역반응세포가 분문부와 위저부에서만 동정되었다. 한편 췌장에서는 somatostatin, glucagon, BPP 및 insulin 등 4종의 면역반응세포가 췌도 및 외분비에서 관찰되었다. 이상의 결과는 위췌장 내분비세포의 부위별 분포와 출현빈도가 동물종에 따라 매우 상이하다는 사실을 시사한다.

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개에 있어서 약물에 의한 당뇨병의 유발과 혈당제어의 감시에 관한 연구 II. 당뇨병 모델 개에 있어서 혈당량과 혈청 Fructosamine농도 변화의 시간적 상관관계 (Drug-Induced Diabetes Mellitus and Monitoring Hyperglycemic Control in Dogs II. Relationship among Blood Glucose and Serum Fructosamine)

  • 이창우;최회인;김본원
    • 한국임상수의학회지
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    • 제15권2호
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    • pp.291-302
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    • 1998
  • Four out of 15 dogs were successfully induced diabetes mellitus with intravenous iqiection of 30 mg of streptozotgin and 50 mg of alloxan monohydrate per kilogram body weight and maintained more than 9 weeks without iqiection of insulin or oral hypoglycemic sgent Histopathologicallyi these four dogs have typical diabetic lesions such as degeneration and vacuolation of pancreatic islet cells, and fatty change of liver at necropsy in the end of study. Serum glucose level increased dramatically at 24 hours post-injection but serum fructosamine level increased gradually and reached plateau at 31-41 days post-injection of streptozotocin and alloxan. Serum fructosamine concert%lion correlated very well with serum glucose concentration of preceding 4-7 weeks in experimentally induced diabetic dogs. Our data suggest that serum fructosamine reflects mean glucose concentration of preceding 4-7 weeks in experimentally induced diabetic dogs.

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한국재래산양 췌장내분비세포의 면역전자현미경적 연구 (Immunoelectron Microscopic Study on the Endocrine Pancreas of the Native Korean Goat)

  • 이재현;교본선춘;견태관;삼촌성;이형식
    • Applied Microscopy
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    • 제26권1호
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    • pp.67-77
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    • 1996
  • 한국재래산양의 췌장내분비세포에 대해 몇종의 항혈청을 이용하여 면역전자현미경적으로 관찰하여 다음과 같은 결론을 얻었다. 췌도에서는 glucagon (A), insulin (B), somatostatin (D) 및 pancreatic polypeptides (PP-I과 PP-II) 등 5종의 세포를 동정하였다. 이 중 A, B 및 D세포의 정태학적 특징은 다른포유동물의 그것과 유사하였고 D세포는 serotonin 면역성이 인정되었다. PP세포는 과립의 형태학적 특징으로 보아 두가지 형태가 인정되었으며, 제I형은 원형인 동질성의 과립 ($220{\sim}440nm$)을 가지며, 과립내용물과 한계막 사이에는 얇은 halo를 보였으나 제II형은 과립이 다형태성을 보이며 ($240{\sim}440nm$ major axis, $150{\sim}200nm$ minor axis) 과립내용물과 한계막 사이는 거의 밀착되어 있었다. 이상의 결과로 한국재래산양의 췌도에는 A, B, D, PP-I 및 PP-II 등 5형의 세포로 구성되어 있으며, 이 중 PP-I세포는 다른 포유류의 PP세포에, PP-II세포는 enterochromaffin cell에 상당할 것으로 생각되었다.

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hPDX1 유전자의 삽입에 의한 직접 췌도세포 분화 (Transdifferentiation of α-1,3-Galactosyltransferase Knock Out (GalT KO) Pig Derived Bone Marrow Mesenchymal Stromal Cells (BM-MSCs) into Pancreatic Cells by Transfection of hPDX1)

  • 옥선아;오건봉;황성수;김영임;권대진;임기순
    • 한국수정란이식학회지
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    • 제30권3호
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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.

전사체 프로파일을 이용한 고려 홍삼의 항당뇨 기전 연구 (Anti-diabetic Mechannism Study of Korean Red Ginseng by Transcriptomics)

  • 원해단;신은정;정성현
    • 약학회지
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    • 제52권5호
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    • pp.345-354
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    • 2008
  • This study was designed to investigate the anti-diabetic effect and mechanism of Korean red ginseng extract through transcriptomics in C57BL/KsJ db/db mice. The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. At the end of treatment, we measured blood glucose, insulin, hemoglobin A1c (HbA1c), triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). RGL-treated group lowered the blood glucose and HbA1c levels by 19.6% and 11.4% compared to those in diabetic control group. In addition, plasma adiponectin and leptin levels in RGL-treated groups were increased by 20% and 12%, respectively, compared to those in diabetic control. Morphological analyses of liver, pancreas and epidydimal adipose tissue were done by hematoxylin-eosin staining, and pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. RGL-treated group revealed higher insulin contents and lower glucagon contents compared to diabetic control. To elucidate an action mechanism of Korean red ginseng, DNA microarray analyses were performed in liver and fat tissues, and western blot and RT-PCR were conducted in liver for validation. According to hierarchical clustering and principal component analysis of gene expression Korean red ginseng treated groups were close to metformin treated group. In summary, Korean red ginseng lowered the blood glucose level through protecting destruction of islet cells and shifting glucose metabolism from hepatic glucose production to glucose utilization and improving insulin sensitivity through enhancing plasma adiponectin and leptin levels.

Anti-diabetic effect and mechanism of Korean red ginseng extract in C57BL/KsJ db/db mice

  • ;;정성현
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2007년도 추계 학술대회
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    • pp.57-58
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    • 2007
  • Purpose: Ginseng is a well-known medical plant used in traditional Oriental medicine. Korean red ginseng (KRG) has been known to have potent biological activities such as radical scavenging, vasodilating, anti-tumor and anti-diabetic activities. However, the mechanism of the beneficial effects of KRG on diabetes is yet to be elucidated. The present study was designed to investigate the anti-diabetic effect and mechanism of KRG extract in C57BL/KsJ db/db mice. Methods: The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. During the experiment, body weight and blood glucose levels were measured once every week. At the end of treatment, we measured Hemoglobin A1c (HbA1c), blood glucose, insulin, triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). Morphological analyses of liver, pancreas and white adipose tissue were done by histological observation through hematoxylin-eosin staining. Pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. To elucidate an action of mechanism of KRG, DNA microarray analyses were performed, and western blot and RT-PCR were conducted for validation. Results: Compared to the DC group mice, body weight gain of PIO treated group mice showed 15.2% increase, but the other group mice did not showed significant differences. Compared to the DC group, fasting blood glucose levels were decreased by 19.8% in RGL, 18.3% in RGH, 67.7% in MET, 52.3% in GPZ, 56.9% in PIO-treated group. With decreased plasma glucose levels, the insulin resistance index of the RGL-treated group was reduced by 27.7% compared to the DC group. Insulin resistance values for positive drugs were all markedly decreased by 80.8%, 41.1% and 68.9%, compared to that of DC group. HbA1c levels in RGL, RGH, MET, GPZ and PIO-treated groups were also decreased by 11.0%, 6.4%, 18.9%, 16.1% and 27.9% compared to that of DC group, and these figure revealed a similar trend shown in plasma glucose levels. Plasma TG and NEFA levels were decreased by 18.8% and 16.8%, respectively, and plasma adiponectin and leptin levels were increased by 20.6% and 12.1%, respectively, in the RGL-treated group compared to those in DC group. Histological analysis of the liver of mice treated with KRG revealed a significantly decreased number of lipid droplets compared to the DC group. The control mice exhibited definitive loss and degeneration of islet, whereas mice treated with KRG preserved islet architecture. Compared to the DC group mice, KRG resulted in significant reduction of adipocytes. From the pancreatic islet double-immunofluorescence staining, we observed KRG has increased insulin production, but decreased glucagon production. KRG treatment resulted in stimulation of AMP-activated protein kinase (AMPK) phosphorylation in the db/db mice liver. To elucidate mechanism of action of KRG extract, microarray analysis was conducted in the liver tissue of mice treated with KRG extract, and results suggest that red ginseng affects on hepatic expression of genes responsible for glycolysis, gluconeogenesis and fatty acid oxidation. In summary, multiple administration of KRG showed the hypoglycemic activity and improved glucose tolerance. In addition, KRG increased glucose utilization and improved insulin sensitivity through inhibition of lipogenesis and activation of fatty acid $\beta$-oxidation in the liver tissue. In view of our present data, we may suggest that KRG could provide a solid basis for the development of new anti-diabetic drug.

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Epigallocatechin Gallate Prevents Autoimmune Diabetes Induced by Multiple Low Doses of Streptozotocin in Mice

  • Song, Eun-Kyung;Hur, Hyeon;Han, Myung-Kwan
    • 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.

NF-${\kappa}B$ Inhibitor Suppresses Hypoxia-induced Apoptosis of Mouse Pancreatic ${\beta}$-cell Line MIN6

  • Koh, Hyun Sook;Kim, Jae Young
    • 대한의생명과학회지
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    • 제20권1호
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    • pp.14-24
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    • 2014
  • Hypoxia is one of the main reasons for islet apoptosis after transplantation as well as during isolation. In this study, we attempted to determine the potential usefulness of NF-${\kappa}B$ inhibitor for suppression of hypoxia-induced ${\beta}$-cell apoptosis as well as the relationship between IP-10 induction and ${\beta}$-cell apoptosis in hypoxia. To accomplish this, we cultured the mouse pancreatic ${\beta}$-cell line MIN6 in hypoxia (1% $O_2$). Among several examined chemokines, only IP-10 mRNA expression was induced under hypoxia, and this induced IP-10 expression was due to NF-${\kappa}B$ activity. Since a previous study suggested that IP-10 mediates ${\beta}$-cell apoptosis, we measured hypoxia-induced IP-10 protein and examined the effect of anti-IP-10 neutralizing Ab on hypoxia-induced ${\beta}$-cell apoptosis. However, IP-10 protein was not detected, and anti-IP-10 neutralizing Ab did not rescue hypoxia-induced MIN6 apoptosis, indicating that there is no relationship between hypoxia-induced IP-10 mRNA expression and hypoxia-induced ${\beta}$-cell apoptosis. Since it was still not clear if NF-${\kappa}B$ functions as an apoptotic or anti-apoptotic mediator in hypoxia-induced ${\beta}$-cell apoptosis, we examined possible involvement of NF-${\kappa}B$ in hypoxia-induced ${\beta}$-cell apoptosis. Treatment with 1 ${\mu}M$ NF-${\kappa}B$ inhibitor suppressed hypoxiainduced apoptosis by more than 50%, while 10 ${\mu}M$ AP-1 or 4 ${\mu}M$ NF-AT inhibitor did not, indicating involvement of NF-${\kappa}B$ in hypoxia-induced ${\beta}$-cell apoptosis. Overall, these results suggest that IP-10 is not involved in hypoxia-induced ${\beta}$-cell apoptosis, and that NF-${\kappa}B$ inhibitor can be useful for ameliorating hypoxia-induced ${\beta}$-cell apoptosis.