• Applied Microscopy
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• 제37권4호
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• pp.249-258
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• 2007

이자섬은 이자를 구성하는 외분비조직에 둘러싸여 존재하는 내분비세포의 집단으로, 이자섬에서 분비되는 인슐린은 $\beta$세포에서 분비되는 호르몬이며, 세포질의 리보좀에서 합성되고 골지체를 경유하여 세포질로 방출되는 기작을 가지고 있다. 충분한 양의 이자섬 이식은 인슐린 의존형 당뇨병인 제1형 당뇨병에서 정상혈당을 회복시키고, 당뇨 합병증을 방지할 수 있는 치료방법으로 사용되고 있다. 하지만 당뇨병 환자에게 이식을 위한 이자섬의 양에 비해 공여자로부터 증여된 이자섬의 양은 제한적이다. 이러한 문제점은 이자섬의 증식으로 연구되고 있으나, 배양된 이자섬이 정상 조직내의 이자섬과 형태적 기능적으로 동일한 것인지에 관한 연구는 미비하였다. 따라서 본 연구에서는 분리된 이자섬과 배양된 이자섬을 구성하는 세포들의 내부구조의 변화를 주사전자현미경, 투과전자현미경을 이용하여 세포의 미세구조를 확인하고, 인슐린 항체를 이용한 $\beta$세포 내의 인슐린 분포양상을 확인하여 다음과 같은 결과를 얻었다. 분리된 이자섬의 $\beta$세포는 일반적인 핵 미토콘드리아, 세포질세망 그리고 인슐린 과립이 분포하고, 배양된 이자섬 $\beta$세포의 경우 분리된 이자섬에 비하여 일반적인 핵의 모습과 부피가 증가한 세포질과 미토콘드리아, 세포질세망 그리고 골지체의 발달이 이루어지는 것으로 관찰되었다. 인슐린 과립의 경우 분리된 이자섬에 비해 감소하며, 세포막 주위에 분포하는 것으로 관찰되었다. 배양된 이자섬에서 관찰되는 인슐린 과립 분포의 변화, 세포질세망의 증가, 골지체의 발달은 배양된 이자섬 $\beta$세포의 인슐린 생성 분비 기능의 향상과 부피의 증가가 이루어지기 위한 세포 내부의 형태적 변화가 이루어지는 것으로 추측된다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.1060-1065
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• 2003

To determine whether dietary fatty acids affect pancreatic $\beta$-cell function, the INS-1 $\beta$-cells and the pancreatic islets isolated from Zucker obese (fa/fa) rats were cultured with stearic acid and conjugated linoleic acid (CLA). As a result, DNA fragmentation laddering was substantially decreased in the INS-1 $\beta$-cells and the isolated pancreatic islets cultured with 2 mM CLA compared to those cultured with stearic acid. To investigate the mechanism by which CLA alleviates cell apoptosis under DNA fragmentation assay, we examined mRNA expressions of apoptosis-related proteins including Bax and Bcl-2 associated with cell death agonist and antagonist, respectively, in both INS-1 cells and islets cultured with 2 mM fatty acids. Bax mRNA expression was not altered by either stearic acid or CLA, whereas Bcl-2 mRNA expression was enhanced by CLA when compared to the stearic acid cultures. However, there were no changes in cell apoptosis and apoptotic-regulating gene products in either INS-1 cells or isolated islets treated with or without 2 mM CLA. It is concluded that CLA maintains $\beta$-cell viability via increased Bcl-2 expression compared to the stearic acid cultures, which may help to alleviate, at least somewhat, the onset of NIDDM in the physiological status. More detailed study is still needed to elucidate the effect of CLA on the prevention of fatty acid-induced $\beta$-cell apoptosis.

• 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.

• 약학회지
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• 제41권2호
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• pp.260-267
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• 1997

To establish prediabetes in vitro model concerning the etiology of IDDM(Insulin Dependent Diabetes Mellitus) in cellular level we have designed prediabetes in vitro models in pa ncreatic beta cells. HIT-T15, RINm5F and isolated rat islets were chosen as pancreatic beta cells, and streptozotocin (STZ) used as diabetogenic agent. Degree of beta cell destruction to establish prediabetic in vitro model was determined by cell proliferation and insulin release using thymidine uptake and radio immuno assay. When HIT-T15 and RINm5F cells were treated with STZ, the degree of cell deterioration was dependent upon the origin and passage number of beta cells, and in the case of isolated islets STZ showed the more sensitivity than above two beta cell lines. The concentration and exposure time of STZ treatment to establish prediabetes in vitro model in beta cell lines and isolated rat islets were 2 ~ 10mM, 30 min. and 1 ~ 5mM, 30 min., respectively.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1615-1621
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• 2022

Tissue regeneration is the ultimate treatment for many degenerative diseases, however, repair and regeneration of damaged organs or tissues remains a challenge. Previously, we showed that B1 Ab and H3 Ab induce stem cells to differentiate into microglia and brown adipocyte-like cells, while trafficking to the brain and heart, respectively. Here, we present data showing that another selected agonist antibody, P1 antibody, induces the migration of cells to the pancreatic islets and differentiates human stem cells into beta-like cells. Interestingly, our results suggest the purified P1 Ab induces beta-like cells from fresh, human CD34⁺ hematopoietic stem cells and mouse bone marrow. In addition, stem cells with P1 Ab bound to expressed periostin (POSTN), an extracellular matrix protein that regulates tissue remodeling, selectively migrate to mouse pancreatic islets. Thus, these results confirm that our in vivo selection system can be used to identify antibodies from our library which are capable of inducing stem cell differentiation and cell migration to select tissues for the purpose of regenerating and remodeling damaged organ systems.

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.261-266
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• 2003

Type 1 diabetes is an organ-specific autoimmune disease caused by the cytotoxic T cells-mediated destruction of the insulin-producing beta cells in the Langerhans pancreatic islets. Hepatocyte growth factor (HGF) is a potent mitogen and a promoter of proliferation of insulin producing beta cells of pancreatic islets. To study the role of HGF via viral vector in the development of streptozotocin (STZ)-induced diabetes in mice, we have developed an adenoviral vector genetically engineered to carry the gene for human HGF (hHGF) and evaluate the change of blood glucose, insulin level, and insulin-secreting beta cells of pancreatic islets. We demonstrate that the treatment with hHGF gene prevented the development of STZ-induced diabetes and increased serum insulin level to above normal range. Furthermore, it preserved pancreatic beta cells from destruction. These in vivo results may support previous findings that HGF is insulinotropic agent for beta cells and HGF treatment renders the cells to be resistant to the development of diabetes from STZ administration. We suggest that an adenoviral mediated hHGF gene therapy is a good candidate for the prevention and treatment of type 1 diabetes.

• Applied Microscopy
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• 제31권3호
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• pp.267-274
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• 2001

Streptozotocin(STZ)을 투여하여 고혈당을 유발시킨 생쥐의 이자섬에 생진양혈탕가미방이 미치는 영향을 규명하고자, 전방액 (0.4ml/day)을 21일간 투여하여 혈당 및 BUN의 변화와 인슐린 면역조직화학적 검색 및 전자 현미경을 이용한 $\beta$세포의 미세구조 변화를 관찰하였다. STZ을 투여한 대조군 이자섬의 면역조직화학적 검사 결과 insulin에 양성반응을 보이는 세포가 거의 관찰되지 않았으나, 생진양혈탕가미방을 투여한 실험군의 $\beta$세포들은 대조군에 비하여 강한 양성반응을 보였다. 전자현미경 관찰에서, 대조군 생쥐의 $\beta$세포는 핵의 핵막이 정상군에 비하여 뚜렷하지 않았으며 세포질소기관의 발달도 미약하였다. 세포질내에 함유되어 있는 분비과립의 수가 현저히 감소하였으며 전자밀도가 높은 중심부분의 크기도 정상군에 비하여 현저히 작았다. 실험군의 $\beta$세포에서는 insulin분비소포의 수는 정상군에 비하여 다소 적게 관찰되었으나 대조준에 비해서는 증가하였으며, 전자밀도가 높은 중심부분의 크기도 대조군에 비하여 다소 증가하였다. 혈당은 대조군($365.33{\pm}91.01$, mg/dl)에비하여 실험군($179.56{\pm}73.36$, mg/dl)에서 유의성있게 감소하였다. 위와 같은 결과로 보아 생진양혈탕가미방이 STZ로 유발된 당뇨 생쥐의 치료에 효능이 있음을 확인할 수 있었다.

• 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.

• 동아시아식생활학회지
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• 제22권3호
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• pp.334-340
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• 2012

손바닥선인장의 한 종류인 노팔(Opuntia ficus-indica (L.) Mill)을 주재료로 하여 제조한 복합물(OF)의 항당뇨 효과를 알아보기 위해 8주령 수컷 SD-rat에게 streptozotoxin을 주사하여 당뇨를 유발하고, 사료에 OF를 첨가하여 3주간 급여하였으며, 1주일 간격으로 공복 시 혈당을, 3주 후에는 당내성과 혈장 인슐린 농도를 측정하고 췌장 조직에 면역조직화학 염색을 실시하였다. 실험동물은 정상 대조군(NC), 당뇨 대조군(DC), 2% OF 급여군(OF-2), 5% OF 급여군(OF-5)으로 구분되었으며, NC와 DC는 기초식이를, OF-2와 OF-5는 기초식이에 각각 2%와 5%의 OF를 섞어서 급여하였다. 실험 개시 후 1주마다 12시간 절식시켜 꼬리정맥에서 혈액을 채취하여 공복 혈당을 측정하였다. 실험 3주 후 12시간을 절식시켜 glucose(50 mg/kg BW)를 복강주사한 다음, 30, 60, 90, 120분 경과 후에 혈당을 측정하여 당내성을 측정하였고, 심장에서 혈액을 채취하여 혈중 인슐린 함량을 분석하였다. 또한 췌장 조직에 대해 면역조직화학 염색을 실시하여 조직학적인 변화를 알아보았다. 3주간의 공복 시 혈당은 OF-5와 OF-2 모두 유의적으로 감소하였다(p<0.05). 당내성 측정 결과, OF 급여군은 DC와는 달리 혈당 농도의 변화 추이가 NC와 유사하였으며, 특히 OF-5는 OF-2에 비해서도 혈당 강하 효과가 높았던 것으로 드러났다. 췌장 조직의 면역염색에 의하면, OF의 혈당강하 기작은 췌장 Langerhans' Islet의 ${\beta}$-세포를 생성시키고, ${\beta}$-세포의 사멸을 억제시켜 인슐린의 분비를 정상화시키는 것이었으며, 이러한 결과는 혈장 인슐린 함량의 증가로 재확인할 수 있었다. 결론적으로 OF는 I형 당뇨에서 현저한 혈당 강하 효과 및 Langerhans' Islet의 ${\beta}$-세포수를 회복시켜줌으로써 I형 당뇨의 치료에 효과가 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.150-156
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• 1999

The induction of proliferation of adult rat islets was investigated under various culture conditions. The islets were isolated from male Sprague-Dawley rats and subsequently embedded in collagen gels, which mimic the in vivo three-dimensional surroundings. During the culture period, the effects of heterologous serum (fetal bovine serum, FBS), epidermal growth factor (EGF), and retinoic acid (RA) on islet growth were examined with respect to the morphological and total DNA content changes. To investigate these changes at the cellular level, whole mount immunocytochemistry using specific antibodies for insulin and glucagon was performed. The results showed that (i) collagen gels as an extracellular matrix can maintain islets in a similar way to that in vivo, (ii) heterologous serum (FBS) had stimulatory effects on islet proliferation in a dose-dependent manner, (iii) RA had inhibitory effects on islet proliferation induced by the serum in a dose-dependent manner, (iv) EGF had weak inhibitory effects on islet proliferation induced by the serum except at the concentration of 10 nM where its effect was not significant, and (v) whole mount immunocytochemistry revealed that newly proliferated islet cells were mainly $\beta$-and $\alpha$-cells.