• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.267-276
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• 2005

Background : The transforming growth $factor-{\beta}1$ ($TGF-{\beta}1$) plays a key role in lung fibrosis. However, the molecular mechanisms involved in $TGF-{\beta}1$-induced lung fibrosis are unclear. $TGF-{\beta}1$ is the key inducer of myofibroblast transdifferentiation via de novo synthesis of ${\alpha}-smooth$ muscle actin (${\alpha}-SMA$). Since $TGF-{\beta}1$ signals through reactive oxygen species (ROS) and ROS have been shown to induce accumulation of extracellular matrix (ECM) in various tissues, this study examined if ROS play a role in $TGF-{\beta}1$-induced fibronectin secretion and ${\alpha}-SMA$ expression in human lung fibroblasts, MRC-5 cells. Methods : Growth arrested and synchronized MRC-5 cells were stimulated with $TGF-{\beta}1$ (0.2-10 ng/ml) in the presence or absence of N-acetylcysteine (NAC) or diphenyleneiodonium (DPI) for up to 96 hours. Dichlorofluorescein (DCF)-sensitive cellular ROS were measured by FACScan and secreted fibronectin and cellular ${\alpha}-SMA$ by Western blot analysis. Results : $TGF-{\beta}1$ increased the level of fibronectin secretion and ${\alpha}-SMA$ expression in MRC-5 cells in a dosedependent manner. Both NAC (20 and 30 mM) and DPI (1 and $5{\mu}M$) significantly inhibited $TGF-{\beta}1$-induced fibronectin and ${\alpha}-SMA$ upregulation. The $TGF-{\beta}1$-induced cellular ROS level was also significantly reduced by NAC and DPI. Conclusions : The results suggest that NADPH oxidase-dependent ROS play an important role in $TGF-{\beta}1$-induced fibronectin secretion and ${\alpha}-SMA$ expression in MRC-5 cells, which leads to myofibroblast transdifferentiation and progressive lung fibrosis.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.296-304
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• 2018

The objective of this study was to analyze the impact of climate change on rice yield and quality. Experiments were conducted using SPAR(Soil-Plant-Atmosphere-Research) chambers, which was designed to create virtual future climate conditions, in the National Institute of Crop Science, Jeonju, Korea, in 2016. In the future climate conditions($+2.8^{\circ}C$ temp, 580 ppm $CO_2$) of year 2051~2060 according to RCP 8.5 scenario, elevated temperature and $CO_2$ accelerated the heading date by about five days than the present climate conditions, resulted in a high temperature environment during grain filling stage. Rice yield decreased sharply in the future climate conditions due to the high temperature induced poor ripening. And the spikelet numbers, ripening ratio, and 1000-grain weight of brown rice were significantly decreased compared to control. The rice grain quality was also decreased sharply, especially due to the increased immature grains. In the future climate conditions, expression of starch biosynthesis-related genes such as granule-bound starch synthase(GBSSI, GBSSII, SSIIa, SSIIb, SSIIIa), starch branching enzyme(BEIIb) and ADP-glucose pyrophosphorylase(AGPS1, AGPS2, AGPL2) were repressed in developing seeds, whereas starch degradation related genes such as ${\alpha}-amylase$(Amy1C, Amy3D, Amy3E) were induced. These results suggest that the reduction in yield and quality of rice in the future climate conditions is likely caused mainly by the poor grain filling by high temperature. Therefore, it is suggested to develop tolerant cultivars to high temperature during grain filling period and a new cropping system in order to ensure a high quality of rice in the future climate conditions.