• Tuberculosis and Respiratory Diseases
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• 제77권2호
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• pp.60-64
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• 2014

MicroRNAs (miRNAs) are a class of small noncoding RNAs that modulate target gene activity, and are aberrantly expressed in most types of cancer as well in lung cancer. A miRNA can potentially target a diverse set of mRNAs; further, it plays a critical role in lung tumorigenesis as well as affects patient outcome. Previous studies focused mainly on abnormal miRNAs expressions in lung cancer tissues. Interestingly, circulating miRNAs were identified in human plasma and serum in 2008. Since then, considerable effort has been directed to the study of circulating miRNAs as one of the biomarkers of lung cancer. miRNAs expression of tissues and blood in lung cancer patients is being analyzed by more researchers. Recently, to overcome the high false-positivity of low-dose chest computed tomography scan, miRNAs in lung cancer screening are being investigated. This article summarizes the recent researches regarding clinical applications of miRNAs in the diagnosis and management of lung cancer.

• Pediatric Infection and Vaccine
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• 제6권1호
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• pp.123-130
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• 1999

목 적 : 무균성뇌막염은 소아에서 주로 발생하는 질환으로, 흔히 장 바이러스에 의해 초래 된다. 저자들은 그동안 우리나라에서 분리된 무균성뇌막염 원인바이러스의 5'-NCR에 대한 sequencing을 통하여 prototype과의 homology를 비교하고 이 연구를 진단에 이용하기 위한 기초자료로 이용하기 위하여 본 연구를 시도하였다. 방 법 : 과거 4년간 우리나라에서 분리한 장바이러스 Coxsackie B1, Echovirus 3, 7, 9, 30 을 이용하여 RNA를 분리하고 RT-PCR을 이용하여 DNA를 합성한 후, direct sequencing을 이용하여 WHO에서 얻은 prototype과 homology를 비교하였다. 결 과 : 1) PCR product는 155bp와 440bp부위에 특징적인 띠를 관찰할 수 있었다. 2) 155bp에 관한 sequencing homology를 보면 prototype의 Coxsackie virus와 echovirus 는 92.1%의 homology를 보였다. 3) 환자에서 분리한 Coxsackie B1은 prototype과 94.1%의 homology를 보였다. 4) 환자에서 분리한 Echovirus 3은 92.8%, Echovirus 7은 92.8%, Echovirus 9는 94.1%, Echovirus 30은 82.9%의 homology를 보였다. 결 론 : 장바이러스의 5'-NCR은 homology가 높아서 진단에 이용하기에 좋으며 이 부위를 통한 typing을 위해서는 더 긴 부위를 sequencing할 필요가 있다.

• Reproductive and Developmental Biology
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• 제38권2호
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• pp.79-84
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• 2014

MicroRNAs (miRNAs) are approximately 22 nucleotides of small noncoding RNAs that control gene expression at the posttranscriptional level through translational inhibition and destabilization of their target mRNAs. The miRNAs are phylogenetically conserved and have been shown to be instrumental in a wide variety of key biological processes including cell cycle regulation, apoptosis, metabolism, imprinting, and differentiation. Recently, a paper has shown that expression of the miRNA-302/367 cluster expressed abundantly in mouse and human embryonic stem cells (ESCs) can directly reprogram mouse and human somatic cells to induced pluripotent stem cells (iPSCs) efficiently in the absence of any of the four factors, Oct4, Sox2, c-Myc, and Klf4. To apply this efficient method to porcine, we analyzed porcine genomic sequence containing predicted porcine miRNA-302/367 cluster through ENSEMBL database, generated a non-replicative episomal vector system including miRNA-302/367 cluster originated from porcine embryonic fibroblasts (PEF), and tried to make porcine iPSCs by transfection of the miRNA-302/367 cluster. Colonies expressing EGFP and forming compact shape were found, but they were not established as iPSC lines. Our data in this study show that pig miRNA-302/367 cluster could not satisfy requirement of PEF reprogramming conditions for pluripotency. To make pig iPSC lines by miRNA, further studies on the role of miRNAs in pluripotency and new trials of transfection with conventional reprogramming factors are needed.

• Genomics & Informatics
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• 제3권1호
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• pp.15-23
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• 2005

Background MicroRNAs (miRNAs) are a class of noncoding RNAs found in various organisms such as plants and mammals. However, most of the mRNAs regulated by miRNAs are unknown. Furthermore, miRNA targets in genomes cannot be identified by standard sequence comparison since their complementarity to the target sequence is imperfect in general. In this paper, we propose a kernel-based method for the efficient prediction of miRNA targets. To help in distinguishing the false positives from potentially valid targets, we elucidate the features common in experimentally confirmed targets. Results The performance of our prediction method was evaluated by five-fold cross-validation. Our method showed 0.64 and 0.98 in sensitivity and in specificity, respectively. Also, the proposed method reduced the number of false positives by half compared with TargetScan. We investigated the effect of feature sets on the classification of miRNA targets. Finally, we predicted miRNA targets for several miRNAs in the Caenorhabditis elegans (C. elegans) 3' untranslated region (3' UTR) database. Condusions The targets predicted by the suggested method will help in validating more miRNA targets and ultimately in revealing the role of small RNAs in the regulation of genomes. Our algorithm for miRNA target site detection will be able to be improved by additional experimental­knowledge. Also, the increase of the number of confirmed targets is expected to reveal general structural features that can be used to improve their detection.

• IMMUNE NETWORK
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• 제11권5호
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• pp.227-244
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• 2011

MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression via degradation or translational repression of their target messenger RNAs (mRNAs). Recent studies have clearly demonstrated that miRNAs play critical roles in several biologic processes, including cell cycle, differentiation, cell development, cell growth, and apoptosis and that miRNAs are highly expressed in regulatory T (Treg) cells and a wide range of miRNAs are involved in the regulation of immunity and in the prevention of autoimmunity. It has been increasingly reported that miRNAs are associated with various human diseases like autoimmune disease, skin disease, neurological disease and psychiatric disease. Recently, the identification of miRNAs in skin has added a new dimension in the regulatory network and attracted significant interest in this novel layer of gene regulation. Although miRNA research in the field of dermatology is still relatively new, miRNAs have been the subject of much dermatological interest in skin morphogenesis and in regulating angiogenesis. In addition, miRNAs are moving rapidly center stage as key regulators of neuronal development and function in addition to important contributions to neurodegenerative disorder. Moreover, there is now compelling evidence that dysregulation of miRNA networks is implicated in the development and onset of human neruodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Tourette's syndrome, Down syndrome, depression and schizophrenia. In this review, I briefly summarize the current studies about the roles of miRNAs in various autoimmune diseases, skin diseases, psychoneurological disorders and mental stress.

• BMB Reports
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• 제45권8호
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• pp.464-469
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• 2012

Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. MiRNA let-7 family is known to be involved in the regulation of cell apoptosis. However, the function of let-7 in ox-LDL induced ECs apoptosis and atherosclerosis is still unknown. Here, we show that let-7c expression was markedly up-regulated in ox-LDL induced apoptotic human umbilical cord vein endothelial cells (HUVECs). Let-7c over-expression enhanced apoptosis in ECs whereas inhibition of let-7c could partly alleviate apoptotic cell death mediated by ox-LDL. Searching for how let-7c affected apoptosis, we discovered that antiapoptotic protein Bcl-xl was a direct target of let-7c in ECs. Our data suggest that let-7c contributes to endothelial apoptosis through suppression of Bcl-xl.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.593-602
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• 2021

Mammalian milk including microRNAs (miRNAs) as a novel class of noncoding RNAs, that can be transferred to infants and it plays on a critical role in biological functions such as immune regulation and development. However, the origin and functional importance of milk-derived miRNAs are still undetermined. This study applied RNA sequencing to explore the featured profiles of miRNA expression in colostrum and mature milk-originated exosomes from human, bovine, and caprine milk. These dietary exosome-derived miRNAs are highly conserved in human, bovine and caprine milk. Interestingly, abundant miRNAs expressed in human milk are similarly conserved across species. In addition, we confirmed that immune-related miRNAs (miR-30a-5p, miR-22-3p, and miR-26a) are commonly observed in the colostrum and mature milk of cows and caprines as well as humans. Our results provide new insights and resources for investigating the functionality of immune-associated miRNAs and evaluating physiological and biological condition in human, bovine and caprine milk as biomarkers.

• BMB Reports
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• 제51권12호
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• pp.613-622
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• 2018

RNA helicases DDX5 and DDX17 are multitasking proteins that regulate gene expression in different biological contexts through diverse activities. Special attention has long been paid to their function as coregulators of transcription factors, providing insight about their functional association with a number of chromatin modifiers and remodelers. However, to date, the variety of described mechanisms has made it difficult to understand precisely how these proteins work at the molecular level, and the contribution of their ATPase domain to these mechanisms remains unclear as well. In light of their association with long noncoding RNAs that are key epigenetic regulators, an emerging view is that DDX5 and DDX17 may act through modulating the activity of various ribonucleoprotein complexes that could ensure their targeting to specific chromatin loci. This review will comprehensively describe the current knowledge on these different mechanisms. We will also discuss the potential roles of DDX5 and DDX17 on the 3D chromatin organization and how these could impact gene expression at the transcriptional and post-transcriptional levels.

• 식물분류학회지
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• 제51권1호
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• pp.109-114
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• 2021

Veronica nakaiana Ohwi (Plantaginaceae) is an endemic taxon on Ulleungdo Island, Korea. We report the second complete chloroplast genome sequence of V. nakaiana. Its genome size is 152,319 bp in length, comprising a large single-copy of 83,195 bp, a small single-copy of 17,702 bp, and a pair of inverted repeat regions of 25,711 bp. The complete genome contains 115 genes, including 51 protein-coding genes, four rRNA genes, and 31 tRNA genes. When comparing the two chloroplast genomes of V. nakaiana, 11 variable sites are recognized: seven SNPs and four indels. Two substitutions in the coding regions are recognized: rpoC2 (synonymous substitution) and rpl22 (nonsynonymous substitution). In nine noncoding regions, one is in the tRNA gene (trnK-UUU), one is in the intron of atpF, and seven are in the intergenic spacers (trnH-GUG~psbA, trnK-UUU, rps16~trnQ-UUG, trnC-GCA~petN, psbZ~trnG-GCC, ycf3~trnS-GGA, ycf4~cemA, and psbB~psbT). The data provide the level of genetic variation in V. nakaiana. This result will be a useful resource to formulate conservation strategies for V. nakaiana, which is a rare endemic species in Korea.

• Molecules and Cells
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• 제45권9호
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• pp.603-609
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• 2022

Cells can communicate in a variety of ways, such as by contacting each other or by secreting certain factors. Recently, extracellular vesicles (EVs) have been proposed to be mediators of cell communication. EVs are small vesicles with a lipid bilayer membrane that are secreted by cells and contain DNA, RNAs, lipids, and proteins. These EVs are secreted from various cell types and can migrate and be internalized by recipient cells that are the same or different than those that secrete them. EVs harboring various components are involved in regulating gene expression in recipient cells. These EVs may also play important roles in the senescence of cells and the accumulation of senescent cells in the body. Studies on the function of EVs in senescent cells and the mechanisms through which nonsenescent and senescent cells communicate through EVs are being actively conducted. Here, we summarize studies suggesting that EVs secreted from senescent cells can promote the senescence of other cells and that EVs secreted from nonsenescent cells can rejuvenate senescent cells. In addition, we discuss the functional components (proteins, RNAs, and other molecules) enclosed in EVs that enter recipient cells.