• BMB Reports
• /
• v.47 no.6
• /
• pp.311-317
• /
• 2014

microRNAs (miRNAs) are a class of small, non-coding RNAs that play critical posttranscriptional regulatory roles typically through targeting of the 3'-untranslated region of messenger RNA (mRNA). Mature miRNAs are known to be involved in global cellular processes, such as differentiation, proliferation, apoptosis, and organogenesis, due to their capacity to target multiple mRNAs. Thus, imbalances in the expression and/or activity of miRNAs are involved in the pathogenesis of numerous diseases, including pulmonary arterial hypertension (PAH). PAH is a progressive disease characterized by vascular remodeling due to excessive proliferation of pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs). Recently, studies have evaluated the roles of miRNAs involved in the pathogenesis of PAH in these pulmonary vascular cells. This review provides an overview of recent discoveries on the role of miRNAs in the pathogenesis of PAH and discusses the potential for miRNAs as therapeutic targets and biomarkers of PAH.

• BMB Reports
• /
• v.51 no.9
• /
• pp.429-436
• /
• 2018

Fructose in the form of sucrose and high fructose corn syrup is absorbed by the intestinal transporter and mainly metabolized in the small intestine. However, excess intake of fructose overwhelms the absorptive capacity of the small intestine, leading to fructose malabsorption. Carbohydrate response element-binding protein (ChREBP) is a basic helix-loop-helix leucine zipper transcription factor that plays a key role in glycolytic and lipogenic gene expression in response to carbohydrate consumption. While ChREBP was initially identified as a glucose-responsive factor in the liver, recent evidence suggests that ChREBP is essential for fructose-induced lipogenesis and gluconeogenesis in the small intestine as well as in the liver. We recently identified that the loss of ChREBP leads to fructose intolerance via insufficient induction of genes involved in fructose transport and metabolism in the intestine. As fructose consumption is increasing and closely associated with metabolic and gastrointestinal diseases, a comprehensive understanding of cellular fructose sensing and metabolism via ChREBP may uncover new therapeutic opportunities. In this mini review, we briefly summarize recent progress in intestinal fructose metabolism, regulation and function of ChREBP by fructose, and delineate the potential mechanisms by which excessive fructose consumption may lead to irritable bowel syndrome.

• Korean Journal of Microbiology
• /
• v.6 no.1
• /
• pp.12-21
• /
• 1968

The accelerate effects on the growth rate and the capacity of fermentation of L. delbrukii and B. subtilis was investigated in the Henneberg's medium added by various amounts of cellular components of Chlorella and Scenedesmus and also was investigated in the media added micronutritional elements such as Mn, Fe and Mo, etc. The results in the comparative experiments are as follow; 1. Various amounts of Chlorella cell components in the media accelerated remarkably the lactic acid formation and growth of L. delbrukii. For example, lactic acid formation in the medium of contained 1 percent Chlorella cell components was promoted more than twice effects compare with control. 2. The formation of .alpha.-amylase by B. subtilis in the medium of 2 percent Chlorella cell contents was also promoted more than nine twice effects compare with control. 3. The formation of lactic acid of L. delbruckii in the medium of Scenedesmus cell contents was a little more than in the medium of Chlorella cell contents. 4. The lactic acid fermented level attained with the addition of 0.2-0.25 percent Chlorella cells was the effect of promoting fermentation attained of saturating level at 100$\mu$g. /ml. of Mn and 0. 1 $\mu$g./ml. of Fe.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.5
• /
• pp.520-526
• /
• 2017

Carnosine was recently reported to protect against the DNA damage induced by oxidative stress. In this study, we investigated the protective effect of eel Anguilla japonica carnosine extracts prepared using different methods (heat treatment extracts, HTEs; ion exchange chromatography, IEC; ultrafiltration permeation, UFP) on leukocyte DNA damage using the comet assay. Human leukocytes were incubated with extracts of eel carnosine at concentrations (of 10, 50, $100{\mu}g/mL$), and then subjected to an oxidative stimulus [$200{\mu}M$ hydrogen peroxide ($H_2O_2$)]. Pretreatment of the cells for 30 min with carnosine significantly reduced the genotoxicity of $H_2O_2$ measured as DNA strand breaks. The protective effects of the three types of extract (HTE, IEC, and UFP) increased with concentration. At the highest concentration (100 g/mL). there were no statistical differences in oxidative damage between each extract treatment and PBS-treated negative controls. When leukocytes were incubated with carnosine for 30 min after exposure to $H_2O_2$. the protective ability of each extract changed. Therefore, eel carnosine inhibits the $H_2O_2$ induced damage to cellular DNA in human leukocytes, supporting the protective effect of this compound against oxidative damage.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.6
• /
• pp.2775-2780
• /
• 2012

In recent years there has been a substantial increase in the use of functional foods for disease control. Fruits and vegetables produce phytochemicals such as flavonoids and antioxidants which can lower oxidative stress and reduce the risk of chronic ailments like cancer. The aim of the present study was to investigate the antioxidant capacity and the possible protective effects of Amaranthus paniculatus leaves on the antioxidant defense system in Ehrlich's ascites carcinoma (EAC)-treated mice. Oral administration of the leaf extract at different doses caused a significant decrease in tumor volume, viable cell count and tumor weight and elevated the life span of EAC bearing mice. It also showed an improved antioxidant potential as evidenced by a significant increase in the cellular antioxidant defense system such as catalase, superoxide dismutase and reduced glutathione and also significantly reduced the levels of TBARS. The levels of RBC, hemoglobin and lymphocyte count were altered in EAC bearing mice and were reverted back to near normal levels after the treatment with the leaf extracts. Their adequate content of total phenolics and flavonoids, DPPH scavenging activity which further suggests that the extracts exert a significant protection against oxidative stress conditions.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.10
• /
• pp.61-67
• /
• 2004

The next generation cellular wireless communication systems require high data rate transmissions and large system capacities. In order to meet these requirements, multiple antennas can be used at the base and mobile stations, forming MIMO(Multiple Input Multiple Output) channels. This paper proposes a MIMO SDMA(Space Division Multiple Access) technique with dynamic slot allocation which allows the transmitter to efficiently transmit parallel data streams to each of multiple receivers. The proposed technique can increase system capacities significantly by transmitting a larger number of data streams than conventional MIMO techniques while minimizing the performance degradation due to the beamforming dimension reduction.

• ALGAE
• /
• v.30 no.2
• /
• pp.103-119
• /
• 2015

Photosynthetic rates of the large centric diatom Coscinodiscus granii were measured by means of multicolor variable chlorophyll fluorescence imaging, single cell $^{14}C$ assimilation, and optical $O_2$ sensor measurements during light acclimatization of cultures grown at five different irradiances: 50, 150, 235, 332, and $450{\mu}mol$ photons $m^{-2}\;s^{-1}$. Photo-acclimatization was evident from changes of cellular chlorophyll a content, growth rates, and light response curves. Each of the applied methods evaluates different parts and reactions in the photosynthetic apparatus, which makes a direct quantitative comparison of rates difficult, although a different degree of correlation were found between all three methods. However, when used in combination, they provide information about the internal relationship of photosynthetic pathways as well as the variation in photosynthetic capacity between individual cells within a single algal culture.

• Journal of Korea Foundry Society
• /
• v.30 no.1
• /
• pp.22-28
• /
• 2010

Metal foam is a porous or cellular structure material and representative property is a very high porosity. Foamed materials have very special properties such as sound, vibration, energy and impact absorption capacity. Especially this properties are widely used for safety demands of architecture, auto and aircraft industry. But metal foam need to increased its compression strength and hardness. This study were researched about Al-Si alloy foams with variation amount of Si contents for their fabrication and properties such as porosity, cell structure, microstructure and mechanical properties. The result are that the range of pore size is 2~4 $mm{\phi}$, the high porosity are 88%, high yield strength is 1.8MPa, the strain ratio is 60~70% and vickers hardness is 33.1~50.6.

• BMB Reports
• /
• v.45 no.5
• /
• pp.299-304
• /
• 2012

The ubiquitin-proteasome system is a major proteolytic system for nonlysosomal degradation of cellular proteins. Here, we investigated the response of mouse embryonic stem (ES) cells under proteotoxic stress. Proteasome inhibitors induced expression of heat shock protein 70 (HSP70) in a concentration- and time-dependent manner, and also induced apoptosis of ES cells. Importantly, more apoptotic cells were observed in ES cells compared with other somatic cells. To understand this phenomenon, we further investigated the expression of HSP70 and pluripotent cell markers. HSP70 expression was more significantly increased in somatic cells than in ES cells, and expression levels of pluripotent cell markers such as Oct4 and Nanog were decreased in ES cells. These results suggest that higher sensitivity of ES cells to proteotoxic stress may be related with lower capacity of HSP70 expression and decreased pluripotent cell marker expression, which is essential for the survival of ES cells.

• Molecular & Cellular Toxicology
• /
• v.1 no.2
• /
• pp.92-98
• /
• 2005

DNA microarray analysis of gene expression in toxicogenomics typically requires relatively large amounts of total RNA. This limits the use of DNA microarray when the sample available is small. To confront this limitation, different methods of linear RNA amplification that generate antisense RNA (aRNA) have been optimized for microarray use. The target preparation strategy using amplified RNA in DNA microarray protocol can be divided into direct-incorporation labeling which resulted in cDNA targets (Cy-dye labeled cDNA from aRNA) and indirect-labeling which resulted in cRNA targets (i.e. Cy-dye labeled aRNA), respectively. However, despite the common use of amplified targets (cDNA or cRNA) from aRNAs, no systemic assessment for the use of amplified targets and bias in terms of hybridization performance has been reported. In this investigation, we have compared the hybridization performance of cRNA targets with cDNA targets from aRNA on a 10 K cDNA microarrays. Under optimized hybridization conditions, we found that 43% of outliers from cDNA technique and 86% from the outlier genes were reproducibly detected by both targets hybridization onto cDNA microarray. This suggests that the cRNA labeling method may have a reduced capacity for detecting the differential gene expression when compared to the cDNA target preparation. However, further validation of this discordant result should be pursued to determine which techniques possesses better accuracy in identifying truly differential genes.