- The Effect of Chronic High Glucose Concentration on Endoplasmic Reticulum Stress in INS-1 Cells.
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Mi Kyung Kim, Hye Young Seo, Tae Sung Yun, Nam Kyung Kim, Yu Jin Hah, Yun Jung Kim, Ho Chan Cho, Young Yun Jang, Hye Soon Kim, Seong Yeol Ryu, In Kyu Lee, Keun Gyu Park
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Korean Diabetes J. 2008;32(2):112-120. Published online April 1, 2008
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DOI: https://doi.org/10.4093/kdj.2008.32.2.112
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Abstract
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- BACKGROUND
The highly developed endoplasmic reticulum (ER) structure is one of the characteristic features of pancreatic beta-cells. Recent study showed that ER stress causes beta-cell dysfunction. However, little is known about the effects of high glucose concentration on induction of ER stress in pancreatic beta-cells. Therefore, this study was designed to evaluate whether exposure of high glucose concentration in rat insulinoma cell line, INS-1 cell induces ER stress and whether ER stress decreases insulin gene expression. METHODS: The effect of 30 mM glucose on insulin expression and secretion in INS-1 cells was evaluated by Northern blot analysis and glucose-stimulated insulin secretion (GSIS). Cell viability was evaluated by XTT assay. The effect of 30 mM glucose on phosphorylation of eIF2alpha and CHOP expression, which are markers of ER stress were evaluated by Western blot analysis. RT-PCR analysis was performed to determine whether high glucose concentration induces XBP-1 splicing. To investigate whether ER stress decreases insulin gene expression, the effect of tunicamycin on insulin mRNA expression was evaluated by Northern blot analysis. RESULTS: The prolonged exposure of INS-1 cells with the 30 mM glucose concentration decreased insulin mRNA expression in a time dependent manner and impaired GSIS while did not influence on cell viability. 30 mM glucose increased phosphorylation of eIF2alpha, XBP-1 splicing and CHOP expression in INS-1 cells. Tunicamycin-treated INS-1 increased XBP-1 splicing and decreased insulin mRNA expression in a dose dependent manner. CONCLUSION: This study showed that prolonged exposure of INS-1 with high glucose concentration induces ER stress and ER stress decreases insulin gene expression. Further studies about underlying molecular mechanism by which ER stress induces beta-cell dysfunction are needed.
- A Case of Cured Diabetes Mellitus after Occult Malignant Pheochromocytoma Removal.
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Ho Chan Cho, Hye Soon Kim, Yoon Jung Kim, Yu Jin Hah, Nam Keong Kim, Mi Kyung Kim, Keun Gyu Park, Yong Hoon Kim, Sun Young Kwon
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Korean Diabetes J. 2007;31(6):520-524. Published online November 1, 2007
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DOI: https://doi.org/10.4093/jkda.2007.31.6.520
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Abstract
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- Pheochromocytoma is characterized by a combination of various clinical manifestations that include the classic triad of severe headache, palpitations and diaphoresis. In addition, hyperglycemia can be caused by overproduction of catecholamines, which are secreted by a catecholamine-secreting neoplasm of adrenal or extra-adrenal chromaffin tissue. We encountered a case of diabetes with an occult malignant adrenal pheochromocytoma, who did not have any classic manifestations. A 37-year-old male was admitted because of polydipsia, polyuria, and weight loss. Fasting blood glucose level was 497 mg/dL, hemoglobin A1c level was 15%, and diabetic retinopathy and peripheral polyneuropathy were also accompanied. Incidentally, right adrenal mass was detected by ultrasonography of abdomen. Urinary excretion of total metanephrine and epinephrine were elevated. Adrenal CT showed a 7.1 cm sized right adrenal cystic mass with enhancing solid portion and hemorrhagic content. The scan with 123I-MIBG revealed the cystic mass with increased rim uptake in the region of right adrenal gland. After removal of the tumor, the increased levels of catecholamine were normalized. Moreover, blood glucose level was normalized without administration of insulin or oral hypoglycemic agents. The pathologic examination showed that the neoplasm was a malignant adrenal pheochromocytoma. We report this case that diabetes was cured after removal of malignant tumor with literature review at first in Korea.
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- Pheochromocytoma with Markedly Abnormal Liver Function Tests and Severe Leukocytosis
Chai Ryoung Eun, Jae Hee Ahn, Ji A Seo, Nan Hee Kim Endocrinology and Metabolism.2014; 29(1): 83. CrossRef
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