• Journal of Life Science
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• v.22 no.8
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• pp.1132-1136
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• 2012

Many kind of cell stresses induce gene expression of unfolded protein response (UPR)-associated factors. This study demonstrated that up- and down-regulation of gene expression of endoplasmic reticulum (ER) stress chaperones and ER stress sensors was induced by immobilization stress in the rat organs (adrenal gland, liver, lung, muscle). However, no statistically significant regulation was detected in the others (heart, spleen, thymus, kidney, testis). The results are the first to show that immobilization stress induces UPR associated gene expression, will help to explain immobilization stress-associated ER stress.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.847-858
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• 2007

The endoplasmic reticulum (ER) is an important intracellular organelle for folding and maturation of newly synthesized transmembrane and secretory proteins. The ER provides stringent quality control systems to ensure that only correctly folded proteins exit the ER and unfolded or misfolded proteins are retained and ultimately degraded. The ER has evolved stress response both signaling pathways the unfolded protein response (UPR) to cope with the accmulation of unfolded or misfolded proteins and ER overload response (EOR). Accumulating evidence suggests that, in addition to responsibility for protein processing, ER is also an important signaling compartment and a sensor of cellular stress. In this respect, production of bio-functional recombinant-proteins requires efficient functioning of the ER secretory pathway in host cells. This review briefly summarizes our understanding of the ER signaling developed in the recent years to help of the secretion capacities of recombinant cells.

• Journal of Life Science
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• v.22 no.2
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• pp.281-284
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• 2012

This study demonstrated that upregulation of gene expression of endoplasmic reticulum (ER) stress chaperones (Bip, ERp29, calnexin, and PDI), ER stress sensors (PERK, ATF6, and Ire1), and cAMP phosphodiesterase 7A1 (cAMP PDE7A1) was induced by ER stresses in FRTL5 cells. While removing A23187 from the culture medium restored upregulation of cAMP PDE7A1 gene expression, removal of thapsigargin did not recover its expression. In addition, cAMP PDE7A1 gene expression was strongly inhibited by treatment with A23187 combined with thyroid stimulating hormone (TSH). The results are the first to show that ER stress induces cAMP PDE7A1 gene expression.

• The Korean Journal of Rheology
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• v.11 no.1
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• pp.1-8
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• 1999

This paper experimentally investigates the steady shear behaviors of electro-rheological(ER) fluids under flow mode at high pressure level. As for the ER fluid to be tested, two types of ER fluids are employed; water-based ER fluids (ERF 1, ERF 2) and water-free ER fluid(ERF 3). The water-based ER fluids are composed inhousingly, and the concentrations of dispersed particles are 20 wt% and 30 wt% for ERF 1 and ERF 2, respectively. To generate the flow mode at high pressure, an experimental apparatus operated by two-way hydraulic cylinder is constructed and utilized. The pressure difference is measured by the pressure sensor, while the flow rate is calculated using the measured data of the displacement sensor(LVDT). Consequently, the shear stress and shear rate are distilled by incorporating the measured data; the pressure difference and the flow rate.

• Biomedical Science Letters
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• v.21 no.2
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• pp.126-130
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• 2015

There are several studies that show hypothermia improves cellular ischemia damages on experimental and clinical bases. However, its exact molecular mechanisms are unclear. In this study, we demonstrate that hypothermia induced insulin-like growth factor 1 (IGF1) gene expression, and its expression was dramatically decreased under ischemic insults. It was also demonstrated that hypothermia activated endoplasmic reticulum (ER) stress sensors especially both the phosphorylation of $eIF2{\alpha}$ (eukaryotic translation initiation factor 2 alpha) and ATF6 (activating transcription factor-6) proteolytic cleavage. However, the factors of apoptosis and autophagy were not associated with hypothermia. We suggest that hypothermia-treated IGF1 gene expression after ischemia may show a good possibility for the development of treatments and diagnostic methods in cerebral ischemic damages.

• Biomedical Science Letters
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• v.20 no.3
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• pp.168-172
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• 2014

It has recently been shown that hypothermia treatment improves brain ischemia injury and is being increasingly considered by many clinicians. However, the precise roles of hypothermia for brain ischemia are not yet clear. In the present study we demonstrated firstly that hypothermia induced beta-catenin-interacting protein 1 (CTNNBIP1) gene expression and its expression was dramatically decreased under ischemic conditions. It was also demonstrated that hypothermia activated endoplasmic reticulum (ER) stress sensors especially both, the phosphorylation of $eIF2{\alpha}$, and ATF6 proteolytic cleavage. However, the factors of apoptosis and autophagy were not associated with hypothermia. These findings suggested that hypothermia controlled CTNNBIP1 gene expression under ischemia, which may provide a clue to the development of treatments and diagnostic methods for brain ischemia.