• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.54-54
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• 2003

Prostate gland contains neuroendocrine cells (PNECs) are playing important roles in physiological and pathophysiological processes of the prostate gland. Here, we investigated the role of purinoceptors in PNECs freshly isolated from rat ventral prostate (RPNECs) that show immunoreactivity to chromogranin A. Fura-2 ratiometry revealed that ATP evokes both fast Ca$\^$2+/ influx and store Ca$\^$2+/ release in RPNECs. A whole-cell patch clamp study demonstrated fast inactivating cationic current activated by ATP or by ${\alpha}$,${\beta}$-MeATP, which was blocked by ATP-TNP. The activation of P2X inward current was tightly associated with a sharp increase in [Ca$\^$2+/]$\sub$c/. The presence of P2X1/3 subtypes were proved by RT-PCR analysis. For the stored Ca$\^$2+/ release, ATP and UTP showed similar effects, suggesting the dominant role or P2Y2 subtypes, also confirmed by RT-PCR. Both P2X (${\alpha}$,${\beta}$-MeATP) and P2Y (UTP) stimulation induced changes in the cell morphology (initial shrinkage and blob formation on the surface) reversibly. Exocytotic membrane trafficking events were monitored with the membrane-bound fluorescent dye, FM1-43 using confocal microscopy. In spite of the similar Ca$\^$2+/ responses, UTP was far less effective in triggering exocytosis than ${\alpha}$,${\beta}$ -MeATP. Since serotonin is reportedly stored in the secretory granule of PNECs, we directly examined whether the aforementioned agonists elicit release of serotonin using carbon fiber electrode-amperometry. In accordance with the results of FM1 -43 experiments, ${\alpha}$,${\beta}$-MeATP efficiently evoke serotonin secretion while not with UTP. In summary, the P2X-mediated Ca$\^$2+/ influx plays crucial roles in the exocytosis of RPNECs. Although a global increase in [Ca$\^$2+]$\sub$c/ might be related with the morphological changes, a sharp rise of [Ca$\^$2+/]$\sub$c/ in the putative sub-plasmalemmal ‘microdomains’ might be a decisive factor for the exocytosis.

• The Korean Journal of Nuclear Medicine
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• v.37 no.3
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• pp.190-198
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• 2003

Purpose: To evaluate radiation sensitivity of dendritic cells in comparison with lymphocytes. Materials and methods: T lymphocytes captured from peripheral blood were irradiated by 0 Gy, 10 Gy, 30 Gy. Apoptosis was measured by flowcytometry for staining of Annexin V 4 hours after irradiation. Immature and mature dendritic cells processed from blood hematopoietic stem cell were irradiated by 0 Gy, 10 Gy, 30 Gy, 100 Gy respectively and apoptosis was measured by flowcytometry with time difference as 4h, 24h and 48h after irradiation. Morphometric analysis by percent nucleus was measured in three cell groups, also. Results: Lymphocytes showed radiation sensitivity by increasing apoptotic fraction according to radiation dose. However, both mature and immature dendritic cells showed consistent fraction of apoptosis in spite of increasing radiation dose. Percent nucleus ratio is significantly higher in lymphocytes than that of mature or immature dendritic cells. Stimulation of T-cell by dendritic cells was not changed after irradiation. Conclusion: Dendritic cells showed radioresistance which was associated with small size of nucleus in comparison with lymphocytes and this result would be used as a basal data of radio-labelling for the cellular trafficking studios in nuclear medicine fields.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.246-253
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• 2015

In this study, we evaluated the lipoprotein lipase (LPL) inhibitory activity of 11 water extracts derived from Cinnamomum cassia Blume, Sarcodon aspratus, Cordyceps militaris, Crataegus pinnatifida Bunge, Corni fructus, Allium cepa, Coix lacryma-jobi, Plantago asiatica L., Lentinus edodes, Rosa rugosa, and Foeniculum fructus. The results of the LPL secretion and activity assay showed Sarcodon aspratus (NE) extract have an LPL secretion inhibitory acitivity. The cause of reduction in LPL secretion after NE treatment was investigated using molecular biology methods. NE treatment affected the LPL content in cells, but did not affect LPL mRNA expression. It also increased the mRNA expression level of sortilin-related receptor LDLR class A (SorLA), a receptor that induces endocytosis and intracellular trafficking of LPL. Finally, cell fractionation revealed that NE treatment induced the expression of CCAAT-enhancer-binding protein beta ($C/EBP{\beta}$), a SorLA transcription factor, in the nuclei of 3T3-L1 adipocytes. These results show that NE's anti-obesity effect involves inhibition of LPL secretion through $C/EBP{\beta}$-mediated induction of SorLA expression.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.310-322
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• 2000

Background : Phospholipase C(PLC) plays an important role in cellular signal transduction and is thought to be critical in cellular growth, differentiation and transformation of certain malignancies. Two second messengers produced from the enzymatic action of PLC are diacylglycerol (DAG) and inositol 1, 4, 5-trisphosphate (IP3). These two second messengers are important in down stream signal activation of protein kinase C and intracellular calcium elevation. In addition, functional domains of the PLC isozymes, such as Src homology 2 (SH2) domain, Src homology 3 (SH3) domain, and pleckstrin homology (PH) domain play crucial roles in protein translocation, lipid membrane modificailon and intracellular memrane trafficking which occur during various mitogenic processes. We have previously reported the presence of PLC-${\gamma}1$, ${\gamma}2$, ${\beta}1$, ${\beta}3$, and ${\delta}1$ isozymes in normal human lung tissue and tyrosine-kinase-independent activation of phospholipase C-${\gamma}$ isozymes by tau protein and AHNAK. We had also found that the expression of AHNAK protein was markedly increased in various mstologic types of lung can∞r tissues as compared to the normallungs. However, the report concerning expression of various PLC isozymes in lung canærs and other lung diseases is lacking. Therefore, in this study we examined the expression of PLC isozymes in the paired surgical specimens taken from lung cancer patients. Methods : Surgically resected lung cancer tissue samples taken from thirty seven patients and their paired normal control lungs from the same patients, The expression of various PLC isozymes were studied. Western blot analysis of the tissue extracts for the PLC isozymes and immunohistochemistry was performed on typical samples for localization of the isozyme. Results : In 16 of 18 squamous cell carcinomas, the expression of PLC-${\gamma}1$ was increased. PLC-${\gamma}1$ was also found to be increased in all of 15 adenocarcinoma patients. In most of the non-small cell lung cancer tissues we had examined, expression of PLC-${\delta}1$ was decreased. However, the expression of PLC-${\delta}1$ was markedly increased in 3 adenocarcinomas and 3 squamous carcinomas. Although the numbers were small, in all 4 cases of small cell lung cancer tissues, the expression of PLC-${\delta}1$ was nearly absent. Conclusion : We found increased expression of PLC-${\gamma}1$ isozyme in lung cancer tissues. Results of this study, taken together with our earlier findings of AHNAK protein-a putative PLD-${\gamma}$, activator-over-expression, and the changes observed in PLC-${\delta}1$ in primary human lung cancers may provide a possible insight into the derranged calcium-inositol signaling pathways leading to the lung malignancies.

• Journal of Nutrition and Health
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• v.48 no.1
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• pp.9-18
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• 2015

Purpose: Poncirus trifoliata has been reported to have anti-inflammatory, antioxidant, and immune activities. However, its anti-obesity activity and the mechanism by which the water extract of dried, immature fruit of Poncirus trifoliata (PF-W) acts are not clear. This study suggests a potential mechanism associated with the anti-obesity activity of PF-W. Methods: We measured the effect of PF-W on lipoprotein lipase (LPL) regulation using enzyme-linked immunosorbent assay (ELISA) and an activity assay. The LPL regulation mechanism was examined by reverse transcription polymerase chain reaction (RT-PCR) to measure the mRNA expression of biomarkers related to protein transport and by western blot for analysis of the protein expression of the transcription factor CCAAT-enhancer-binding protein ($C/EBP{\beta}$). Results: The total polyphenol and flavonoid content of PF-W was $52.15{\pm}4.02$ and $6.56{\pm}0.47mg/g$, respectively. PF-W treatment decreased LPL content in media to $58{\pm}5%$ of that in control adipocyte media, and increased LPL content to $117{\pm}3.5%$ of that in control adipocytes, but did not affect the mRNA expression of LPL. PF-W also increased the mRNA expression of sortilin-related receptor (SorLA), a receptor that induces endocytosis and intracellular trafficking of LPL, in a concentration- and time-dependent manner. Finally, cell fractionation revealed that PF-W treatment induced the expression of $C/EBP{\beta}$, a SorLA transcription factor, in the nuclei of 3T3-L1 adipocytes. Conclusion: The LPL secretion and activity assay showed PF-W to be an LPL secretion inhibitor, and these results suggest the potential mechanism of PF-W involving inhibition of LPL secretion through $C/EBP{\beta}$-mediated induction of SorLA expression.

• Tuberculosis and Respiratory Diseases
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• v.64 no.5
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• pp.347-355
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• 2008

Background: IPF is characterized by chronic, fibrosing inflammatory lung disease of unknown etiology. Typical symptoms of IPF are exertional dyspnea with nonproductive cough. Why patients with typical IPF have dry cough rather than productive cough, is unknown. IP-10 plays an important regulatory role in leukocyte trafficking into the lung. The present study investigated the effect of IP-10 in the pathogenesis of dry cough rather than productive cough in IPF patients. Methods: IP-10 concentration was measured by ELISA from BALF of IPF patients. To evaluate the role of IP-10 in mucin expression, the expression of the MUC5AC mucin gene was measured in NCI-H292 cells, a human pulmonary mucoepidermoid carcinoma cell line, after stimulation by TNF-${\alpha}$ with or without IP-10 pretreatment. EGFR-MAPK expression was also examined as a possible mechanism. Results: IP-10 levels were significantly higher in the BALF of IPF patients compared to healthy controls. IP-10 pretreatment reduced TNF-${\alpha}$ induced MUC5AC mucin expression by inhibiting the EGFR-MAPK signal transduction pathway in NCI-H292 cells. Conclusion: These findings suggest that little mucus production in IPF patients might be attributable to IP-10 overproduction, which inhibits the EGFR-MAPK signal transduction pathway required for MUC5AC mucin gene expression.

• Journal of Life Science
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• v.34 no.5
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• pp.333-338
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• 2024

Kinesin-1 is a heterotetrameric protein composed of two heavy chains (KHCs, also known as KIF5s) with a motor domain and two light chains (KLCs) without a motor domain. KIF5 has three subtypes, namely, KIF5A, KIF5B, and KIF5C, which share high amino acid homology except in their carboxy (C)-terminal region. KIF5A is responsible for transporting cargo within the cell. The adaptor proteins that bind to the C-terminal region of KIF5A mediate between kinesin-1 and cargo. However, the proteins regulating the intracellular cargo transport of kinesin-1 have not yet been fully identified. In this study, we identified ADP-ribosylation factor GTPase-activating protein 1 (ArfGAP1), which is involved in the intracellular trafficking of lysosomes, as a binding partner of KIF5A. KIF5A binds to the C-terminal region of ArfGAP1, and ArfGAP1 binds to the C-terminal region of KIF5A but does not interact with KIF5B, KIF5C, kinesin light chain 1 (KLC1), or KIF3A. When co-expressed in mammalian cells, ArfGAP1 co-localized with KIF5A and co-immunoprecipitated with KIF5A, KIF5B, and KLC1, but not with KIF3B. These results suggest that kinesin-1 may be regulated by ArfGAP1 in the intracellular transport of cargo.