• Molecules and Cells
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• v.39 no.3
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• pp.179-185
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• 2016

Posttranscriptional regulation of RNA metabolism, including RNA processing, intron splicing, editing, RNA export, and decay, is increasingly regarded as an essential step for fine-tuning the regulation of gene expression in eukaryotes. RNA-binding proteins (RBPs) are central regulatory factors controlling posttranscriptional RNA metabolism during plant growth, development, and stress responses. Although functional roles of diverse RBPs in living organisms have been determined during the last decades, our understanding of the functional roles of RBPs in plants is lagging far behind our understanding of those in other organisms, including animals, bacteria, and viruses. However, recent functional analysis of multiple RBP family members involved in plant RNA metabolism and elucidation of the mechanistic roles of RBPs shed light on the cellular roles of diverse RBPs in growth, development, and stress responses of plants. In this review, we will discuss recent studies demonstrating the emerging roles of multiple RBP family members that play essential roles in RNA metabolism during plant growth, development, and stress responses.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.220-228
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• 2017

Many crops including cereals, tuber crops, feeds, and turf grasses are often damaged by various environmental stresses such as drought, salt, cold, and high temperature, causing the reduction of their productivity. Plants are sessile and cannot escape from environmental stresses. Thus, plants evolve in the direction of overcoming the environmental stresses. Some plant genes such as ARF, ABI3, NAC, HSF, and WRKY are known to respond to environmental stresses as they transcriptionally regulate the stress response pathways. For example, the OsWRKY76 gene contributes to the enhanced resistance to low temperatures and pathogenic infections. The AtWRKY28 also plays a role in environmental stresses. Zoysiagrass (Zoysia japonica Steud.) is popularly grown for gardens and golf courses. However, the function of the WRKY gene, another environmental stress-related gene, is not known in zoysiagrass. In this study, the ZjWRKY3 and ZjWRKY7 genes with one shared WRKY domain have been isolated in zoysiagrass. The expression of these genes increased in response to low temperature, drought, and salt stresses. Furthermore, the infection of the brown patch-causing Rhozoctonia solani induced the expression of ZjWRKY3 and ZjWRKY7. The corresponding proteins bind to the W-box of the Zjchi promoter, possibly regulating their transcriptions. The researchers suggest that the ZjWRKY3 and ZjWRKY7 genes transcriptionally regulate abiotic and biotic stress related downstream genes.

• Journal of Life Science
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• v.27 no.12
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• pp.1415-1420
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• 2017

The metallothionein (MT) gene (IbMT3) was selected from an EST library of suspension-cultured sweet potato cells. The MT gene, which is one of abundant ESTs in the library, is involved in stress regulation of cells and tissues. A full-length IbMT3 cDNA was obtained and analysis of its nucleotide sequence revealed that IbMT3 encoded a type 3 MT protein, based on its structural characteristics. The function of type 3 MT in plants is not yet known. Northern blot analysis showed stronger expression of IbMT3 in suspension-cultured cells than in sweet potato plant leaves. Since cell culture is known to impose a state of oxidative stress on cells, sweet potato plants were subjected to oxidative stress to investigate the transcriptional regulation of IbMT3. When the herbicide methyl viologen (MV) was administered for 6, 12, and 24 hr, IbMT3 transcription rapidly increased at 6 hr and then decreased. A cold treatment at $15^{\circ}C$ for 24 and 48 hr resulted in a gradual increase in IbMT3 expression. These findings indicate that IbMT3 expression is regulated in response to environmental and oxidative stress. IbMT3 isoform is expected to have antioxidant effects in sweet potato plants and may play an important role in cellular adaptation to oxidative stress.

• Genes and Genomics
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• v.40 no.11
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• pp.1181-1197
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• 2018

Tropical plant rubber tree (Hevea brasiliensis) is the sole source of commercial natural rubber and low-temperature stress is the most important limiting factor for its cultivation. To characterize the gene expression profiles of H. brasiliensis under the cold stress and discover the key cold stress-induced genes. Three cDNA libraries, CT (control), LT2 (cold treatment at $4^{\circ}C$ for 2 h) and LT24 (cold treatment at $4^{\circ}C$ for 24 h) were constructed for RNA sequencing (RNA-Seq) and gene expression profiling. Quantitative real time PCR (qRT-PCR) was conducted to validate the RNA-Seq and gene differentially expression results. A total of 1457 and 2328 differentially expressed genes (DEGs) in LT2 and LT24 compared with CT were respectively detected. Most significantly enriched KEGG pathways included flavonoid biosynthesis, phenylpropanoid biosynthesis, plant hormone signal transduction, cutin, suberine and wax biosynthesis, Pentose and glucuronate interconversions, phenylalanine metabolism and starch and sucrose metabolism. A total of 239 transcription factors (TFs) were differentially expressed following 2 h or/and 24 h of cold treatment. Cold-response transcription factor families included ARR-B, B3, BES1, bHLH, C2H, CO-like, Dof, ERF, FAR1, G2-like, GRAS, GRF, HD-ZIP, HSF, LBD, MIKC-MADS, M-type MADS, MYB, MYB-related, NAC, RAV, SRS, TALE, TCP, Trihelix, WOX, WRKY, YABBY and ZF-HD. The genome-wide transcriptional response of rubber tree to the cold treatments were determined and a large number of DEGs were characterized including 239 transcription factors, providing important clues for further elucidation of the mechanisms of cold stress responses in rubber tree.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.403-409
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• 2014

The Bis protein is known to be involved in a variety of cellular processes including apoptosis, migration, autophagy as well as protein quality control. Bis expression is induced in response to a number of types of stress, such as heat shock or a proteasome inhibitor via the activation of heat shock factor (HSF)1. We report herein that Bis expression is increased at the transcriptional level in HK-2 kidney tubular cells and A172 glioma cells by exposure to oxidative stress such as $H_2O_2$ treatment and oxygen-glucose deprivation, respectively. The pretreatment of HK-2 cells with N-acetyl cysteine, suppressed Bis induction. Furthermore, HSF1 silencing attenuated Bis expression that was induced by $H_2O_2$, accompanied by increase in reactive oxygen species (ROS) accumulation. Using a series of deletion constructs of the bis gene promoter, two putative heat shock elements located in the proximal region of the bis gene promoter were found to be essential for the constitutive expression is as well as the inducible expression of Bis. Taken together, our results indicate that oxidative stress induces Bis expression at the transcriptional levels via activation of HSF1, which might confer an expansion of antioxidant capacity against pro-oxidant milieu. However, the possible role of the other cis-element in the induction of Bis remains to be determined.

• BMB Reports
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• v.36 no.1
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• pp.95-109
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• 2003

Inflammatory lung diseases are characterized by chronic inflammation and oxidant/antioxidant imbalance. The sources of the increased oxidative stress in patients with chronic inflammatory lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) derive from the increased burden of inhaled oxidants, and from the increased amounts of reactive oxygen species (ROS) generated by several inflammatory, immune and various structural cells of the airways. Increased levels of ROS produced in the airways is reflected by increased markers of oxidative stress in the airspaces, sputum, breath, lungs and blood in patients with lung diseases. ROS, either directly or via the formation of lipid peroxidation products such as 4-hydroxy-2-nonenal may play a role in enhancing the inflammation through the activation of stress kinases (JNK, MAPK, p38) and redox sensitive transcription factors such as NF-${\kappa}B$ and AP-1. Recent evidences have indicated that oxidative stress and pro-inflammatory mediators can alter nuclear histone acetylation/deacetylation allowing access for transcription factor DNA binding leading to enhanced pro-inflammatory gene expression in various lung cells. Understanding of the mechanisms of redox signaling, NF-${\kappa}B$/AP-1 regulation, the balance between histone acetylation and deacetylation and the release and expression of pro- and anti-inflammatory mediators may lead to the development of novel therapies based on the pharmacological manipulation of antioxidants in lung inflammation and injury. Antioxidants that have effective wide spectrum activity and good bioavailability, thiols or molecules which have dual antioxidant and anti-inflammatory activity, may be potential therapeutic agents which not only protect against the direct injurious effects of oxidants, but may fundamentally alter the underlying inflammatory processes which play an important role in the pathogenesis of chronic inflammatory lung diseases.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.124-129
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• 2011

The role of the ferric uptake regulator (Fur) of Helicobacter pylori in the oxidative stress was investigated in this study. A fur knockout mutant of H. pylori was constructed by replacing the fur gene with an aphA (kanamycin resistant marker) gene. Photodynamic therapy using methylene blue (MB) and 660 nm light was chosen to induce oxidative stress. The bactericidal effect of photodynamic therapy (PDT) was compared between wild type H. pylori and fur knockout mutant H. pylori. The degree of oxidative damage of DNA was confirmed using alkaline gel electrophoresis and an assay of 8-hydroxy-2-deoxyguanosine (8-OHdG). In control groups, the number of viable cells was maintained constantly during experiment. After PDT, the mutant H. pylori showed 10,000 times decreased viable cell number compared with wild type H. pylori. Depending on the exposure time of 660 nm light, the 3-fold increase in the concentration of 8-OHdG was observed in mutant H. pylori. The results of this study showed that H. pylori's Fur protein may play a role in oxidative stress induced by PDT.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.92-97
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• 2012

The trial was conducted to evaluate the effects of sea buckthorn leaves (SBL) on meat flavor in broilers during heat stress. A total 360 one-day-old Arbor Acre (AA) broilers (male) were randomly allotted to 4 treatments with 6 replicates pens pretreatment and 15 birds per pen. The control group was fed a basal diet, the experimental group I, II and III were fed the basal diet supplemented with 0.25%, 0.5%, 1% SBL, respectively. During the 4th week, broilers were exposed to heat stress conditions ($36{\pm}2^{\circ}C$), after which, muscle and liver samples were collected. High performance liquid chromatography (HPLC) was performed to measure the content of inosine monophosphate (IMP); Real-Time PCR was performed to determine the expression of the ADSL gene. The results showed that the content of breast muscle IMP of group I, II and III was significantly increased 68%, 102% and 103% (p<0.01) compared with the control, respectively; the content of thigh muscle IMP of group II and III was significantly increased 56% and 58% (p<0.01), respectively. Additionally, ADSL mRNA expression in group I, II and III was increased significantly 80%, 65% and 49% (p<0.01) compared with the control, respectively. The content of IMP and expression of ADSL mRNA were increased by basal diet supplemented with SBL, therefore, the decrease of meat flavor caused by heat stress was relieved.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10339-10343
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• 2015

Breast cancer is the most common cancer among females worldwide and a most prevalent malignancy in Iranian women. Chronic stress may make an important contribution to cancer, especially in the breast. Numerous studies showed roles of neurotransmitters in the occurrence and progression of cancers which are mediated by their various types of receptors. This study was conducted to evaluate alterations in the expression profile of dopamine receptor genes in peripheral blood mononuclear cells (PBMC) as stress factors in breast cancer patients and the human breast cancer cell line (MCF-7). Peripheral blood samples were obtained from 30 patients and 30 healthy individuals. Total mRNA was extracted from PBMC and MCF-7 cells and RT-PCR was performed to confirm the presence of five dopamine receptors (DRD1-DRD5). Expression changes of dopamine receptor genes were evaluated by real time PCR. We observed that DRD2-DRD4 in PBMCs of breast cancer patients were increased compared to healthy individuals. In addition, all dopamine receptor subtypes but DRD1 were expressed in MCF-7 cells. Therefore, alterations of these receptors as stress factors should be assessed for selecting appropriate drugs such as D2-like agonists for treatment of breast cancer after performing complimentary tests. Determining the expression profile of dopamine receptor genes thus seems promising.