• Journal of Life Science
• /
• v.25 no.4
• /
• pp.473-480
• /
• 2015

The endoplasmic reticulum (ER) in the eukaryotic cells is the first compartment in the secretory pathway. Almost secretory proteins and membrane proteins are secreted through the ER, in which post-translational modifications occur via diverse signals from the ER lumen to the cytoplasm and nucleus. Only then are correctly-folded proteins secreted to the outside cells. Unfolded proteins that accumulate in the ER cause a kind of intracellular stress, ER stress, and activate an unfolded protein response (UPR) system. The 3 major transducers of the UPR are inositol requiring 1 (IRE1), PKR-like ER kinase (PERK) and activating transcription factor 6 (ATF6), all of which are ER transmembrane proteins. Recently, novel types of a new ATF6 family have been identified. Those commonly have an ER-transmembrane domain, a transcription-activation domain and a basic leucine zipper (bZIP) domain―Luman, OASIS, BBF2H7, CREBH and CREB4. Each factor functions by regulating the UPR in specific organs and tissues. Although the detailed molecular mechanisms of OASIS family members are unknown, in this study we comprehensively introduce these molecular signals.

• Biomedical Science Letters
• /
• v.26 no.1
• /
• pp.37-41
• /
• 2020

The hemolymph of Korean rhinoceros Allomyrina dichotoma consists of blood and lymph in which various kinds of proteins function physiologically. We have previously demonstrated that A. dichotoma hemolymph has the potential to treatment and prevent diabetes through activating transcription factor 3-gene (ATF3) regulation. In this study, we investigate the expression of Kruppel-like factor 4 (KLF4) in A. dichotoma hemolymph-treated INS-1 pancreatic β-cells. The new findings show that A. dichotoma hemolymph, which upregulates KLF4 gene expression in a dose-dependent and time-dependent manner. In addition, hemolymph combine with mild endoplasmic reticulum (ER) stress, which also differentially regulates KLF4 gene expression. These results may provide insights to KLF4 gene-related disease therapies through KLF4 gene regulation.

• The Korean Journal of Physiology and Pharmacology
• /
• v.15 no.6
• /
• pp.345-351
• /
• 2011

High glucose leads to physio/pathological alterations in diabetes patients. We investigated collagen production in human gingival cells that were cultured in high concentrations of glucose. Collagen synthesis and secretion were increased when the cells were exposed to high concentrations of glucose. We examined endoplasmic reticulum (ER) stress response because glucose metabolism is related to ER functional status. An ER stress response including the expression of glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), inositol requiring enzyme alpha (IRE-$1{\alpha}$) and phosphoreukaryotic initiation factor alpha (p-eIF-$2{\alpha}$) was activated in the presence of high glucose. Activating transcription factor 4 (ATF-4), a downstream protein of p-eIF-$2{\alpha}$ as well as a transcription factor for collagen, was also phosphorylated and translocalized into the nucleus. The chemical chaperone 4-PBA inhibited the ER stress response and ATF-4 phosphorylation as well as nuclear translocation. Our results suggest that high concentrations of glucose-induced collagen are linked to ER stress and the associated phosphorylation and nuclear translocation of ATF-4.

• Korean Journal of Pharmacognosy
• /
• v.44 no.2
• /
• pp.104-109
• /
• 2013

Hesperidin (HES), a flavonone glycoside isolated from the citrus fruits such as lemons and oranges, has been reported to have many biological properties including antiinflammatory, antioxidant, and antiallergy activities. In this study, we focused on the action of HES modulating Th2-associated cytokines such as IL-4 and IL-13 expression in PMA/ionomycin (PI)-stimulated rat basophilic leukemia (RBL-2H3) cells. The production of IL-4 and IL-13 was quantified by ELISA and the mRNA expression was detected by using RT-PCR assay. In addition, western blot analysis was performed to determine the transcription factors involved in the cytokine expression. We found that HES significantly decreased PI-induced IL-4 and IL-13 productions and also decreased the level of mRNA in a dose-dependent manner. Furthermore, western blot analysis of the transcription factors implied that HES down-regulated the protein level of c-Jun and c-Fos, which are the activating protein 1 (AP-1) family and nuclear factor-kappaB (NF-${\kappa}B$) characterized as a transcription factors related to the Th2-associated cytokine expression. Taken together, our data showed that the action of HES responsible for antiallergy activities is based on suppression of Th2-associated cytokines through inhibition of AP-1 and NF-${\kappa}B$ transcription factors.

• IMMUNE NETWORK
• /
• v.11 no.4
• /
• pp.196-202
• /
• 2011

Background: B cell-activating factor belonging to the TNF family (BAFF) is primarily expressed by macrophages and dendritic cells, and stimulates B cell proliferation, differentiation, survival, and Ig production. In the present study, we explored the effect of activin A on BAFF expression by APCs. Methods: To investigate the effect of activin A on BAFF expression by mouse APCs, we measured the level of BAFF expression at the transcriptional and protein levels using RT-PCR and ELISA. Results: Activin A markedly enhanced BAFF expression in mouse macrophages and dendritic cells at both the transcriptional and protein levels. SB431542, an activin receptor-like kinase 4 (ALK4) inhibitor, completely abrogated activin A-induced BAFF transcription. Furthermore, overexpression of DN-Smad3 abolished activin-induced BAFF expression at the transcriptional and protein levels. Conclusion: These results demonstrate that activin A can enhance BAFF expression through ALK4-Smad3 pathway.

• IMMUNE NETWORK
• /
• v.12 no.3
• /
• pp.84-88
• /
• 2012

B cell-activating factor belonging to the TNF family (BAFF) is primarily expressed by macrophages and stimulates B cell proliferation, differentiation, survival, and Ig production. In this study, we explored the effect of lactoferrin (LF) on BAFF expression by murine macrophages. We determined the level of BAFF expression at the transcriptional and protein levels using RT-PCR and ELISA, respectively. LF markedly enhanced BAFF expression in mouse macrophages at both the transcriptional and protein levels. Overexpression of Smad3/4 further increased LF-induced BAFF transcription while DN-Smad3 abolished the LF-induced BAFF expression. These results demonstrate that LF can enhance BAFF expression through Smad3/4 pathway.

• Experimental and Molecular Medicine
• /
• v.50 no.11
• /
• pp.11.1-11.12
• /
• 2018

USP15 has been shown to stabilize transcription factors, to be amplified in many cancers and to mediate cancer cell survival. However, the underlying mechanism by which USP15 regulates multiple myeloma (MM) cell proliferation and apoptosis has not been established. Here, our results showed that USP15 mRNA expression was upregulated in MM patients. USP15 silencing induced MM cell proliferation inhibition, apoptosis, and the expression of nuclear and cytoplasmic NF-${\kappa}Bp65$, while USP15 overexpression exhibited an inverse effect. Moreover, in vivo experiments indicated that USP15 silencing inhibited MM tumor growth and NF-${\kappa}Bp65$ expression. PDTC treatment significantly inhibited USP15 overexpression-induced cell proliferation, apoptosis inhibition, and NF-${\kappa}Bp65$ expression. USP15 overexpression promoted NF-${\kappa}Bp65$ expression through inhibition of its ubiquitination, whereas NF-${\kappa}Bp65$ promoted USP15 expression as a positive regulator. Taken together, the USP15-NF-${\kappa}Bp65$ loop is involved in MM tumorigenesis and may be a potential therapeutic target for MM.

• Herbal Formula Science
• /
• v.25 no.4
• /
• pp.527-536
• /
• 2017

Objectives : The present study, to confirm the osteoblast differentiation effects of Acer tegmentosum Maxim. (AT) extract. Methods : In this experiment, cell viability, Alizarin red S assay, and Alkaline phosphatase (ALP) activity with AT extract (50, $100{\mu}g/m{\ell}$). Also, we studied the expression of differentiation regulator with AT extract in primary calvarial osteoblasts cells (pOB). Results : As a result of AT treatment, we determined that AT extract stimulates ALP activity and alizarin red activities in the pOB cells for mineralization for 18 days. Moreover, these factors increasing osteogenic markers such as Runt-related transcription factor2 ($Run{\times}2$), osteocalcin (OC), osteopontin, osterix, smad1, smad5, activating transcription factor4 (ATF4) and collagen type I alpha 1. Conclusions : These results indicate that AT extract have effect on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of bone diseases.

• Korean Journal of Veterinary Research
• /
• v.52 no.2
• /
• pp.99-104
• /
• 2012

The present study was performed to evaluate the relationship between the neurotoxicity of acrylamide and the differential gene expression pattern in mice. Both locomotor test and rota-rod test showed that the group treated with higher than 30 mg/kg/day of acrylamide caused impaired motor activity in mice. Based on cDNA microarray analysis of mouse brain, myelin basic protein gene, kinesin family member 5B gene, and fibroblast growth factor (FGF) 1 and its receptor genes were down-regulated by acrylamide. The genes are known to be essential for neurofilament synthesis, axonal transport, and neuroprotection, respectively. Interestingly, both FGF 1 and its receptor genes were down-regulated. Genes involved in nucleic acid binding such as AU RNA binding protein/enoyl-coA hydratase, translation initiation factor (TIF) 2 alpha kinase 4, activating transcription factor 2, and U2AF 1 related sequence 1 genes were down-regulated. More interesting finding was that genes of both catalytic and regulatory subunit of protein phosphatases which are important for signal transduction pathways were down-regulated. Here, we propose that acrylamide induces neurotoxicity by regulation of genes associated with neurofilament synthesis, axonal transport, neuro-protection, and signal transduction pathways.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.4
• /
• pp.493-503
• /
• 2022

Forkhead transcription factor 3a (Foxo3a) is believed to be a tumor suppressor as its inactivation leads to cell transformation and tumor development. However, further investigation is required regarding the involvement of the activating transcription factor 3 (ATF3)-mediated Tat-interactive protein 60 (Tip60)/Foxo3a pathway in cancer cell apoptosis. This study demonstrated that Chelidonium majus upregulated the expression of ATF3 and Tip60 and promoted Foxo3a nuclear translocation, ultimately increasing the level of Bcl-2-associated X protein (Bax) protein. ATF3 overexpression stimulated Tip60 expression, while ATF3 inhibition by siRNA repressed Tip60 expression. Furthermore, siRNA-mediated Tip60 inhibition significantly promoted Foxo3a phosphorylation, leading to blockade of Foxo3a translocation into the nucleus. Thus, we were able to deduce that ATF3 mediates the regulation of Foxo3a by Tip60. Moreover, siRNA-mediated Foxo3a inhibition suppressed the expression of Bax and subsequent apoptosis. Taken together, our data demonstrate that Chelidonium majus induces SKOV-3 cell death by increasing ATF3 levels and its downstream proteins Tip60 and Foxo3a. This suggests a potential therapeutic role of Chelidonium majus against ovarian cancer.