• Clinical and Experimental Reproductive Medicine
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• v.31 no.4
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• pp.209-215
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• 2004

Objective: Embryonic stem (ES) cells could be differentiated into the specific cell types by alternation of culture condition and modification of gene expression. This study was performed to evaluate the differentiation protocol for mouse and human ES cells to insulin secreting cells. Methods: Undifferentiated mouse (JH-I) and human (Miz-hESI) ES cells were cultured on STO feeder layer, and embryoid bodies (EBs) were formed by suspension culture. For the differentiation, EBs were cultured by sequential system with three stage protocol. The differentiating ES cells were collected and marker gene expressions were analyzed by seIni-quantitative RT-PCR in each stage. Amount of secreted insulin levels in culture media of human ES cells were measured by human insulin specific RIA kit. Results: During the differentiation process of human ES cells, GATA-4, a-fetoprotein, glucose transporter-2 and Ngn-3 expression were increased whereas OctA was decreased progressively. Insulin and albuInin mRNAs were expressed from stage IT in mouse ES cells and from stage III in human ES cells. We detected 3.0~7.9 IlU/rnl secretion of insulin from differentiated human ES cells by in vitro culture for 36 days. Conclusion: The sequential culture system could induce the differentiation of mouse and human ES cells into insulin secreting cells. This is the fIrst report of differentiation of human ES cells into insulin secreting cells by in vitro culture with serum and insulin free medium.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.31-38
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• 2024

As in type 1 diabetes, the loss of pancreatic β-cells leads to insulin deficiency and the subsequent development of hyperglycemia. Exercise has been proposed as a viable remedy for hyperglycemia. Lithium, which has been used as a treatment for bipolar disorder, has also been shown to improve glucose homeostasis under the conditions of obesity and type 2 diabetes by enhancing the effects of exercise on the skeletal muscles. In this study, we demonstrated that unlike in obesity and type 2 diabetic conditions, under the condition of insulin-deficient type 1 diabetes, lithium administration attenuated pancreatic a-cell mass without altering insulin-secreting β-cell mass, implying a selective impact on glucagon production. Additionally, we also documented that lithium downregulated the hepatic gluconeogenic program by decreasing G6Pase protein levels and upregulating AMPK activity. These findings suggest that lithium's effect on glucose metabolism in type 1 diabetes is mediated through a different mechanism than those associated with exercise-induced metabolic changes in the muscle. Therefore, our research presents the novel therapeutic potential of lithium in the treatment of type 1 diabetes, which can be utilized along with insulin and independently of exercise.

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.45-54
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• 1995

Pancreatic endocrine cells containing glucagon, insulin, somatostatin and pancreatic polypeptide were identified in the pancreas of the Korean native goat by using immunohistochemical method. Glucagon immunoreative cells were oval or fusiform in shape and located at the periphery of the pancreatic islets. Insulin immunoreactive cells were round or oval in shape and occupied throughout the pancreatic islets except the small area of the periphery. Somatostatin immunoreative cells were oval and elliptical, and mainly located at the periphery of the pancreatic islets. Some of these cells had a cytoplasmic process. Pancreatic polypeptide immunoreactive cells were elliptical or polyhedral and located at the periphery of the pancratic islets where two or more cells formed a cell cluster. The distribution rates of glucagon, insulin, somatostatin and pancreatic polypeptide immunoreactive cells were 24.4%, 44.3%, 13.2% and 18.1% respectively.

• BMB Reports
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• v.52 no.5
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• pp.295-303
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• 2019

Breakthroughs in stem cell technology have contributed to disease modeling and drug screening via organoid technology. Organoid are defined as three-dimensional cellular aggregations derived from adult tissues or stem cells. They recapitulate the intricate pattern and functionality of the original tissue. Insulin is secreted mainly by the pancreatic ${\beta}$ cells. Large-scale production of insulin-secreting ${\beta}$ cells is crucial for diabetes therapy. Here, we provide a brief overview of organoids and focus on recent advances in protocols for the generation of pancreatic islet organoids from pancreatic tissue or pluripotent stem cells for insulin secretion. The feasibility and limitations of organoid cultures derived from stem cells for insulin production will be described. As the pancreas and gut share the same embryological origin and produce insulin, we will also discuss the possible application of gut organoids for diabetes therapy. Better understanding of the challenges associated with the current protocols for organoid culture facilitates development of scalable organoid cultures for applications in biomedicine.

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.55-65
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• 1995

Ultrastructures of pancreatic endocrine cells containing glucagon, insulin, somatosratin and pancreatic polypeptide were studied in the pancreas of the Korean native goat by immunohistochemical and elecron microscopy. Glucagon immunoreatctive cells were round or fusiform in shape and contained secretory granules of 200-260 nm in diameter. The secretory granules were high in electron density and had a halo between the limiting membrane and the central granule core. Insulin immunoreactive cells were round or oval in shape, and contained various sizes of secretory granules from 135 to 300 nm in diameter. The secretory granules were low or moderate electron density and had a variform halo. Somatostatin immunoreactive cells were elliptical or fusiform shape with cytoplasmic processes. They contained the secretory granules of 140-320 nm with moderate electron densities. Pancreatic polypeptide immunoreactive cells were elliptical or fusiform and contained small secretory granules with high electron densities. The secretory granules were 120-230 nm in diameter and the least in number.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.71-77
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• 2012

Mitochondrial dynamics and distribution is critical for their role in bioenergetics and cell survival. We investigated the consequence of altered fission/fusion on mitochondrial function and motility in INS-1E rat clonal ${\beta}$-cells. Adenoviruses were used to induce doxycycline-dependent expression of wild type (WT-Mfn1) or a dominant negative mitofusin 1 mutant (DN-Mfn1). Mitochondrial morphology and motility were analyzed by monitoring mitochondrially-targeted red fluorescent protein. Adenovirus-driven overexpression of WT-Mfn1 elicited severe aggregation of mitochondria, preventing them from reaching peripheral near plasma membrane areas of the cell. Overexpression of DN-Mfn1 resulted in fragmented mitochondria with widespread cytosolic distribution. WT-Mfn1 overexpression impaired mitochondrial function as glucose- and oligomycin-induced mitochondrial hyperpolarization were markedly reduced. Viability of the INS-1E cells, however, was not affected. Mitochondrial motility was significantly reduced in WT-Mfn1 overexpressing cells. Conversely, fragmented mitochondria in DN-Mfn1 overexpressing cells showed more vigorous movement than mitochondria in control cells. Movement of these mitochondria was also less microtubule-dependent. These results suggest that Mfn1-induced hyperfusion leads to mitochondrial dysfunction and hypomotility, which may explain impaired metabolism-secretion coupling in insulin-releasing cells overexpressing Mfn1.

• 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.

• Diabetes and Metabolism Journal
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• v.42 no.6
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• pp.451-464
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• 2018

Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by a less intensive autoimmune process and a broad clinical phenotype compared to classical type 1 diabetes mellitus (T1DM), sharing features with both type 2 diabetes mellitus (T2DM) and T1DM. Since patients affected by LADA are initially insulin independent and recognizable only by testing for islet-cell autoantibodies, it could be difficult to identify LADA in clinical setting and a high misdiagnosis rate still remains among patients with T2DM. Ideally, islet-cell autoantibodies screening should be performed in subjects with newly diagnosed T2DM, ensuring a closer monitoring of those resulted positive and avoiding treatment of hyperglycaemia which might increase the rate of ${\beta}-cells$ loss. Thus, since the autoimmune process in LADA seems to be slower than in classical T1DM, there is a wider window for new therapeutic interventions that may slow down ${\beta}-cell$ failure. This review summarizes the current understanding of LADA, by evaluating data from most recent studies, the actual gaps in diagnosis and management. Finally, we critically highlight and discuss novel findings and future perspectives on the therapeutic approach in LADA.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.3
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• pp.219-225
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• 2022

Glucagon like peptide-1 (GLP-1) released from enteroendocine L-cells in the intestine has incretin effects due to its ability to amplify glucose-dependent insulin secretion. Promotion of an endogenous release of GLP-1 is one of therapeutic targets for type 2 diabetes mellitus. Although the secretion of GLP-1 in response to nutrient or neural stimuli can be triggered by cytosolic Ca²⁺ elevation, the stimulus-secretion pathway is not completely understood yet. Therefore, the aim of this study was to investigate the role of reverse Na⁺/Ca²⁺ exchanger (rNCX) in Ca²⁺ entry induced by muscarinic stimulation in NCI-H716 cells, a human enteroendocrine GLP-1 secreting cell line. Intracellular Ca²⁺ was repetitively oscillated by the perfusion of carbamylcholine (CCh), a muscarinic agonist. The oscillation of cytosolic Ca²⁺ was ceased by substituting extracellular Na⁺ with Li⁺ or NMG⁺. KB-R7943, a specific rNCX blocker, completely diminished CCh-induced cytosolic Ca²⁺ oscillation. Type 1 Na⁺/Ca²⁺ exchanger (NCX₁) proteins were expressed in NCI-H716 cells. These results suggest that rNCX might play a crucial role in Ca²⁺ entry induced by cholinergic stimulation in NCI-H716 cells, a GLP-1 secreting cell line.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.121-121
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• 2019

In Islamic dietary guidelines, Halal foods are allowed as edible blessed food. Most foods were categorized within halal for Muslims. The main point of Halal food is that foods are clean in every process and based on Halal standard which might be different in each country. Most pancreatic ${\beta}$ cells synthetize, store, and release insulin. Specific molecular, functional as well as ultrastructural traits of pancreatic ${\beta}$ cells could control their insulin secretion properties and survival phentoype. Insulin-secreting pancreatic ${\beta}$-cells are essential regulators of mammalian metabolism. In addition, the pancreatic ${\beta}$ cell plays an important role in the pathogenesis of type 1 and type 2 diabetes as improving glucose homeostasis by preserving, expanding and improving the function of this key cell type. However, the pharmacological effect of halal food has not been unclear yet, especially food habit-dependent diabetes. The aim of the this study was to determine the preventive effect of Iran plants extract (Almond, Garlic, Cumin, Ginkgo biloba, Holy basil, Psyllium, Satureja khuzistanica, Fenugreek, Green tea, Ipomoea betatas, Blueberry) on RINm5F cells and MIN6 cells as pancreatic ${\beta}$ cell line. The cytotoxicity of the extracts of Iran plants on RINm5F cells and MIN6 cells were measured by using MTT assays. The preventive effects of Iran plant extracts were measured by WST-8 cell proliferation assay on streptozotocin (STZ)-induced cell death in MIN6 cells. In presented result showed that all extract of Iran plants (0.01-10mg/ml) did not show cytotoxicity in RINm5F cells and MIN6 cells. Among non-cytotoxic extract, the protective effects could be detect in high dose concentration. These results suggest that the extract of Iran plants may serve as a potential therapy for diabetes.