• 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.

• Korean Journal of Pharmacognosy
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• v.36 no.2 s.141
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• pp.88-92
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• 2005

Apoptosis plays an important role in autoimmune chronic (Hashimoto's) thyroiditis, a disorder that often results in hypothyroidism. The goal of this study was to induce apoptosis by the combination of inflammatory cytokines, interferon $(IFN)-{\gamma}$ and tumor necrosis factor $(TNF)-{\alpha}$, and to investigate a potential role of medicinal plants in the thyroid follicular cells (FRTL) in vitro. The apoptosis was evaluated by cellular viability, DNA fragmentation, and terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labeling (TUNEL) assay. Extract of Gamgung-tang (GGT, Glycyrrhizae Radix, black beans, Angelicae Radix, and Cnidii Rhizoma) $(0.3{\sim}9.0mg/ml)$ was shown to maintain the viability of cells treated with $IFN-{\gamma}(100U/ml)$ and $TNF-{\alpha}$ (0.5 ng/ml). FRTL cells were found to undergo DNA fragmentation with the inflammatory cytokines. The extract of GGT inhibited DNA fragmentation in dose-dependent manner. The cells with TUNEL-positive nuclei were detected with $IFN-{\gamma}$ and $TNF-{\alpha}$ treatment. The number of TUNEL-positive cells decreased with the treatment of extract of GGT. These results indicate that medicinal plants inhibit the occurrence of apoptosis in thyroid follicular cells, therefore, may have therapeutic potential in the treatment of autoimmune chronic thyroiditis.

• Biomedical Science Letters
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• v.13 no.2
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• pp.153-155
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• 2007

Ferritin heavy chain 1 (FTH1) is an ubiquitous and highly conserved protein which plays a major role in iron homeostasis. The expression of FTH1 was specifically enhanced under various condition of endoplasmic reticulum (ER) stresses drugs such as Brefeldin A (BFA), DTT (Dithiothreitol), calcium ionophore A23187 and tunicamycin. We firstly report here that ER-stress induces up-regulated expression of FTH1 in FRTL-5 culture thyrocytes.

• Journal of Life Science
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• v.13 no.3
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• pp.248-251
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• 2003

The kinetics of dimerization of a newly synthesized thyroglobulin (Tg), the precursor protein in the manufacture of thyroid hormone, was investigated in the endoplasmic reticulum of thyrocytes FRTL-5 cell line. The folded monomeric Tg was first detectable in a conformationally unstable form, from the examination of lysates of pulse labeled cultured thyrocytes by denaturing and nondenaturing gel electrophoresis by 15 min after biosynthesis. The first dimeric Tg was formed by 30 min after; the monomer declined and the dimer progressively increased, and 40 min after remarkable dimeric Tg form was found. Finally, dimerization was complete at 60 min after.

• Journal of Life Science
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• v.20 no.8
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• pp.1249-1253
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• 2010

Sericin is a type of high molecular weight water-soluble glycoprotein surrounding fibroin (silk protein) that has been used as a cell culture supplement and accelerates cell proliferation in various serum-free media. The purpose of this study was to investigate the enhancing effect of thyroglobulin (Tg) secretion by sericin in thyrocytes, FRTL-5 cells. While Tg-mRNA expression was not enhanced, a secreted form of Tg was obviously increased by sericin. In this status, expression of both endoplasmic reticulum (ER) molecular chaperones (Bip & calreticulin) and ER membrane proteins (IRE1, PERK & ATF6) was enhanced. The proximal step of IRE1, XBP1 mRNA splicing was slightly detected however, the proximal step of PERK, phosphorylation of $eIF2{\alpha}$, was changeless. In addition, sericin enhanced cell viability by the MTT assay. The above results showing the ability of sericin to promote protein production demonstrated its potential usefulness as a new biomaterial.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.1023-1025
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• 2007

Ajuba is a number of proteins containing cytosolic LIM domain. Its function may provide a new pathway whereby cell-cell adhesive events are transmitted to the nucleus to regulate cell proliferation and differentiation decisions. Here, Ajuba gene expression was investigated its molecular properties associated with endoplasmic reticulum (ER) stresses (tunicamycin, DTT, A23187 and BFA) which induced remarkable ex-pression of Ajuba mRNA. The mRNA half life of Ajuba was also determined, its half life of Ajuba mRNA in FRTL-5 cells was approximately 2 hr after the initial translation. Although the obvious bioligical function of Ajuba is not clear, on the base of the results, Ajuba gene expression is deeply associated with ER stresses.