• Title/Summary/Keyword: pancreatic islets

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A Method for the Separation of Mouse Pancreatic Islets Using Discontinuous Percoll Gradient Centrifugation

  • Cho, Yu-Ree;Kim, Sang-Duk;Chang, Hyo-Ihl;Sung, Ha-Chin;Lee, Cherl-Ho;Kim, Chan-Wha
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.522-524
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    • 1999
  • A discontinuous Percoll gradient was used to separate islets from the collagenase-treated mouse pancreas easily and rapidly. Since the osmolality of Percoll is very low, adjustment of its osmolality to 340 mOs/kg $H_2$O was essential for securing the optimal separation. A discontinuous gradient layering with Percoll solution of 1.09 g, 1.07g, and1.05g/m, respectively, when centrifuged at 800$\times$g for 10 min, resulted in an optimal condition for separation and yielded a banding pattern with an even distribution of islet cells. No significant difference was observed in the morphological features between the Percoll-isolated and the manually-isolated islets. In conclusion, the discontinuous Percoll gradient can be effectively used to isolate the pancreatic islets from mice with four-fold higher efficiency compared to the handpicking method.

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Prediabetic In vitro Model in Pancreatic Beta Cells Induced by Interleukin-$1{\beta}$ (췌장 베타세포에서 인터루킨-$1{\beta}$로 유도한 인슐린 의존형 당뇨병 실험 모델)

  • Lee, Ihn-Soon;Lee, In-Ja;Kim, Kyong-Tai
    • YAKHAK HOEJI
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    • v.42 no.4
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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.

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Immune Tolerance in Murine Islet Transplantation Across HY Disparity (HY 항원 불일치 췌도 이식에 의한 면역 관용의 유도)

  • Choi, Seung-Eun;Park, Chung-Gyu
    • IMMUNE NETWORK
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    • v.4 no.1
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    • pp.53-59
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    • 2004
  • Background: Minor histocompatibility HY antigen, as a transplantation antigen, has been known to cause graft rejection in MHC (major histocompatibility complex) matched donor-recipient. The aim of our study is to investigate the role of male antigen (HY) disparity on MHC matched pancreatic islet transplantation and to examine the mechanism of the immune reaction. Methods: Pancreatic islets were isolated and purified by collagen digestion followed by Ficoll gradient. The isolated islets of male C57BL6/J were transplanted underneath the kidney capsule of syngeneic female mice rendered diabetic with streptozotocine. Blood glucose was monitored for the rejection of engrafted islets. After certain period of time, tail to flank skin transplantation was performed either on mouse transplanted with HY mismatched islets or on sham treated mouse. The rejection was monitored by scoring gross pathology of the engrafted skin. Results: HY mismatched islets survived more than 300 days in 14 out of 15 mice. The acceptance of second party graft (male B6 islets) and the rejection of third party graft (male BALB/c islets) in these mice suggested the tolerance to islets with HY disparity. B6 Skin with HY disparity was rejected on day $25{\pm}7$. However, HY mismatched skin transplanted on the mice tolerated to HY mismatched islets survived more than 240 days. Tetramer staining in these mice indicated the CTL recognizing MHC Db/Uty was not deleted or anergized. Conclusion: The islet transplantation across HY disparity induced tolerance to HY antigen in C57BL6 mouse, which in turn induced tolerance to HY mismatched skin, which otherwise would be rejected within 25 days. The MHC tetramer staining suggested the underlying mechanisms would not be clonal deletion or anergy.

MULTIPLE PEGYLATION OF PANCREATIC ISLETS FOR IMMUNOPROTECTION IN ISLET TRANSPLANTATION

  • Yang, Kyung-Wook;Lee, Moon-Kyu;Byun, Young-Ro
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.695-698
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    • 2000
  • We studied the viability and function of islet with monomethoxy polyethylene glycol (mPEG) grafted onto its membrane. Islets were isolated from rat and were repeatedly reacted with activated mPEG (mw 5000) in order to increase grafting density. The density of grafted PEG on the islet membrane was confirmed by Fluorescein-PEG-NHS. An assessment of islet viability using AO / PI staining method showed that multiple PEGylation did not reduce islet viability. The function of PEG grafted islets was evaluated by measuring released insulin from islets. Insulin secreted from the PEGylated islets for 1 h did not show any significant difference compared to control (non-PEGylated) islets. In addition, PEGylated islets responded in the same pattern as control islets in the perifusion test.

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Comparative Analysis of Phospholipase D2 Localization in the Pancreatic Islet of Rat and Guinea Pig

  • Ryu, Gyeong-Ryul;Kim, Myung-Jun;Song, Chan-Hee;Min, Do-Sik;Rhie, Duck-Joo;Yoon, Shin-Hee;Hahn, Sang-June;Kim, Myung-Suk;Jo, Yang-Hyeok
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.4
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    • pp.211-215
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    • 2003
  • To examine the localization pattern of phospholipase D2 (PLD2) in the pancreatic islet (the islet of Langerhans) depending on species, we conducted a morphological experiment in the rat and guinea pig. Since individual islets display a typical topography with a central core of B cell mass and a peripheral boundary of A, D, and PP cells, double immunofluorescent staining with a panel of antibodies was performed to identify PLD2-immunoreactive cells in the islets PLD2 immunoreactivity was mainly present in A and PP cells of the rat pancreatic islets. And yet, in the guinea pig, PLD2 immunoreactivity was exclusively localized in A cells, and not in PP cells. These findings suggest a possibility that PLD2 is mainly located in A cells of rodent pancreatic islets, and that the existence of PLD2 in PP cells is not universal in all species. Based on these results, it is suggested that PLD2 may play a significant role in the function of A and/or PP cells via a PLD-mediated signaling pathway.

Agonist (P1) Antibody Converts Stem Cells into Migrating Beta-Like Cells in Pancreatic Islets

  • Eun Ji Lee;Seung-Ho Baek;Chi Hun Song;Yong Hwan Choi;Kyung Ho Han
    • Journal of Microbiology and Biotechnology
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    • v.32 no.12
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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.

Prevention of Diabetes Using Adenoviral Mediated Hepatocyte Growth Factor Gene Transfer in Mice

  • Lee, Hye-Jeong;Kim, Hyun-Jeong;Roh, Mee-Sook;Lee, Jae-Ik;Lee, Sung-Won;Jung, Dong-Sik;Kim, Duk-Kyu;Park, Mi-Kyoung
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.5
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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.

Immunohistochemical study of the pancreatic endocrine cells in the ICR mice (ICR 마우스 췌장 내분비세포에 대한 면역조직화학적 연구)

  • Ku, Sae-kwang;Lee, Hyeung-sik;Lee, Jae-hyun
    • Korean Journal of Veterinary Research
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    • v.42 no.1
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    • pp.21-28
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    • 2002
  • The regional distribution and relative frequency of the pancreatic endocrine cells in the ICR mouse were studied by immunohistochemical (PAP) method using four types of specific antisera against insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). The pancreas of mice could be divided into three portions; pancreatic islets, exocrine and pancreatic ducts. Pancreatic islets, furthermore, were subdivided into three regions (central, mantle and peripheral region) according to their located types of immunoreactive cells. In the pancreatic islet portions, insulin-immunoreactive cells were located in the central and mantle regions but most of somatostatin-, glucagon- and PP-immunoreactive cells were detected in the mantle and peripheral regions with various frequencies. In addition, PP-immunoreactive cells were also found in the central regions of pancreatic islets of ICR mouse. In the exocrine portions, all four types of immunoreactive cells were demonstrated in the ICR mouse. In the pancreatic duct portions, insulin- and glucagon-immunoreactive cells were situated in the epithelial lining of ICR mouse with a few and rare frequencies, respectively. In addition, rare PP-immunoreactive cells were also demonstrated in the subepithelial regions of the pancreatic duct. However, no somatostatin-immunoreactive cells were demonstrated.

Immunohistochemical study of pancreatic poly-peptide-immunoreactive cells in the pancreas of the Korean native goat (Capra hircus) during developmental stages (발생단계에 따른 한국재래산양 췌장에서 pancreatic polypeptide 면역반응세포에 대한 면역조직화학적 연구)

  • Ham, Tae-su
    • Korean Journal of Veterinary Research
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    • v.40 no.3
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    • pp.421-430
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    • 2000
  • The regional distribution and relative frequency of the pancreatic polypeptide (PP)-immunoreactive cells in the pancreas of the Korean native goat (Capra hircus) were studied by immunohistochemical methods (PAP methods) using specific antisera against to PP during developmental stage, fetus, neonate, 1-month-old, 6-month-old and adult. The different regional distribution and relative frequency of PP-immunoreactive cells in the pancreas of Korean native goat were observed during development. In the exocrine portions, they were detected in the all ages and distributed in the interacinar regions. PP-immunoreactive cells were increased from neonate to 1-month-old but thereafter decreased with developmental stage. In the pancreatic duct, PP-immunoreactive cells were demonstrated from 1-month-old but they were decreased with developmental stages in these regions. These cells were observed in the subepithelial connective tissue of the pancreatic duct with a few frequencies in 1-and 6-month-old. However, they were located in the interepithelial cells of the pancreatic duct in the adult with rare frequency. In the endocrine portion (pancreatic islets), PP-immunoreactive cells were observed from neonate, and the regional distribution of PP-immunoreactive cells from 1-month-old was divided into two patterns : dispersed 1) in the marginal regions of the pancreatic islets with moderate or a few frequencies, and 2) in the whole pancreatic islets (in a case of 1-month-old) or in the central cores (in a case of 6-month-old and adult) with numerous frequency. In conclusion, the different regional distribution and relative frequency of PP-immunoreactive cells in the pancreas of the Korean native goat were observed during development. It is suggested that the changing of feeding habits and physiological conditions during different developmental stages may cause these differences.

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