Hyun-Jun Jang

Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use.

Polyethylene glycols (PEGs) are products of condensed ethylene oxide and water that can have various derivatives and functions. Since many PEG types are hydrophilic, they are favorably used as penetration enhancers, especially in topical dermatological preparations. PEGs, together with their typically nonionic derivatives, are broadly utilized in cosmetic products as surfactants, emulsifiers, cleansing agents, humectants, and skin conditioners. The compounds studied in this review include PEG/PPG-17/6 copolymer, PEG-20 glyceryl triisostearate, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil. Overall, much of the data available in this review are on PEGylated oils (PEG-40 and PEG-60 hydrogenated castor oils), which were recommended as safe for use in cosmetics up to 100% concentration. Currently, PEG-20 glyceryl triisostearate and PEGylated oils are considered safe for cosmetic use according to the results of relevant studies. Additionally, PEG/PPG-17/6 copolymer should be further studied to ensure its safety as a cosmetic ingredient.

High-Throughput Cytotoxicity Testing System of Acetaminophen Using a Microfluidic Device (MFD) in HepG2 Cells

A lab-on-a-chip (LOC) is a microfluidic device (MFD) that integrates several lab functions into a single chip of only millimeters in size. LOC provides several advantages, such as low fluidic volumes consumption, faster analysis, compactness, and massive parallelization. These properties enable a microfluidic-based high-throughput drug screening (HTDS) system to acquire cell-based abundant cytotoxicity results depending on linear gradient concentration of drug with only few hundreds of microliters of the drug. Therefore, a microfluidic device was developed containing an array of eight separate microchambers for cultivating HepG2 cells to be exposed to eight different concentrations of acetaminophen (APAP) through a diffusive-mixing-based concentration gradient generator. Every chamber array with eight different concentrations (0, 5.7, 11.4, 17.1, 22.8, 28.5, 34.2, or 40 mM) APAP had four replicating cell culture chambers. Consequently, 32 experimental results were acquired with a single microfluidic device experiment. The microfluidic high-throughput cytotoxicity device (μHTCD) and 96-well culture system showed comparable cytotoxicity results with increasing APAP concentration of 0 to 40 mM. The HTDS system yields progressive concentration-dependent cytotoxicity results using minimal reagent and time. Data suggest that the HTDS system may be applicable as alternative method for cytotoxicity screening for new drugs in diverse cell types.

Genome-wide Copy Number Variation in a Korean Native Chicken Breed

College of Pharmacy, Dankook University, Cheonan 330-714, KoreaABSTRACT Copy number variation (CNV) is a form of structural variation that shows various numbers of copies in segments of the DNA. It has been shown to account for phenotypic variations in human diseases and agricultural production traits. Currently, most of chicken breeds in the poultry industry are based on European-origin breeds that have been mostly provided from several international breeding companies. Therefore, National Institute of Animal Science, RDA has been trying to restore and improve Korean native chicken breeds (12 lines of 5 breeds) for about 20 years. Thanks to the recent advance of sequencing technologies, genome-wide CNV can be accessed in the higher resolution throughout the genome of species of interest. However, there is no systematic study available to dissect the CNV in the native chicken breed in Korea. Here, we report genome-wide copy number variations identified from a genome of Korean native chicken (Line L) by comparing between the chicken reference sequence assembly (Gallus gallus) and a de novo sequencing assembly of the Korean native chicken (Line L). Throughout all twenty eight chicken autosomes, we identified a total of 501 CNVs; defined as gain and loss of duplication and deletion respectively. Furthermore, we performed gene ontology (GO) analysis for the putative CNVs using DAVID, leading to 68 GO terms clustered independently. Of the clustered GO terms, genes related to transcription and gene regulation were mainly detected. This study provides useful genomic resource to investigate potential biological impli- cations of CNVs with traits of interest in the Korean native chicken.(Key words : copy number variation, Korean native chicken, de novo sequencing)

Negligible Pharmacokinetic Interaction of Red Ginseng and Losartan, an Antihypertensive Agent, in Sprague-Dawley Rats

Red ginseng (RG) is one of the top selling herbal medicines in Korea, but is not recommended in hypertensive patients. In this study, the pharmacokinetic (PK) interaction between RG and losartan, an antihypertensive drug, was examined. RG was orally administered for 2 wk to male Sprague-Dawley (S-D) rats at either control (0), 0.5, 1, or 2 g/kg/d for 2 wk. After the last administration of RG and 30 min later, all animals were treated with 10 mg/kg losartan by oral route. In addition, some S-D rats were administered RG orally for 21 d at 2 g/kg followed by losartan intravenously (iv) at 10 mg/kg/d. Post losartan administration, plasma samples were collected at 5, 15, and 30 min and 1, 1.5, 2, 3, 6, 12, and 24 h. Plasma concentrations of losartan and E-3174, the active metabolite of losartan, were analyzed by a high-pressure liquid chromatography–tandem mass spectrometer system (LC-MS/MS). Oral losartan administration showed dose-dependent pharmacokinetics (PK) increase with time to maximum plasma, but this was not significant between different groups. There was no significant change in tmax with E-3174 PK. With iv losartan, pharmacokinetics showed elevation of area under the plasma concentration–time curve from time zero extrapolated to infinitity. There was not a significant change in AUCinf with E-3174 PK. Therefore, RG appeared to interfere with biotransformation of losartan, as RG exerted no marked effect on E-3174 PK in S-D rats. Data demonstrated that oral or iv treatment with losartan in rats pretreated with RG for 2 wk showed that losartan PK was affected but E-3174 PK remained unchanged among different dose groups. These results suggested that RG induces negligible influence on losartan and E-3174 PK in rats.

Analysis of metabolomic patterns in thoroughbreds before and after exercise

Objective Evaluation of exercise effects in racehorses is important in horseracing industry and animal health care. In this study, we compared metabolic patterns between before and after exercise to screen metabolic biomarkers for exercise effects in thoroughbreds. Methods The concentration of metabolites in muscle, plasma, and urine was measured by 1H nuclear magnetic resonance (NMR) spectroscopy analysis and the relative metabolite levels in the three samples were compared between before and after exercise. Subsequently, multivariate data analysis based on the metabolic profiles was performed using orthogonal partial least square discriminant analysis (OPLS-DA) and variable important plots and t-test was used for basic statistical analysis. Results From 1H NMR spectroscopy analysis, 35, 25, and 34 metabolites were detected in the muscle, plasma, and urine. Aspartate, betaine, choline, cysteine, ethanol, and threonine were increased over 2-fold in the muscle; propionate and trimethylamine were increased over 2-fold in the plasma; and alanine, glycerol, inosine, lactate, and pyruvate were increased over 2-fold whereas acetoacetate, arginine, citrulline, creatine, glutamine, glutarate, hippurate, lysine, methionine, phenylacetylglycine, taurine, trigonelline, trimethylamine, and trimethylamine N-oxide were decreased below 0.5-fold in the urine. The OPLS-DA showed clear separation of the metabolic patterns before and after exercise in the muscle, plasma, and urine. Statistical analysis showed that after exercise, acetoacetate, arginine, glutamine, hippurate, phenylacetylglycine trimethylamine, trimethylamine N-oxide, and trigonelline were significantly decreased and alanine, glycerol, inosine, lactate, and pyruvate were significantly increased in the urine (p<0.05). Conclusion In conclusion, we analyzed integrated metabolic patterns in the muscle, plasma, and urine before and after exercise in racehorses. We found changed patterns of metabolites in the muscle, plasma, and urine of racehorses before and after exercise.

Molecular Analysis of Alternative Transcripts of the Equine Cordon-Bleu WH2 Repeat Protein-Like 1 ( COBLL1 ) Gene

The purpose of this study was to investigate the alternative splicing in equine cordon-bleu WH2 repeat protein-like 1 (COBLL1) gene that was identified in horse muscle and blood leukocytes, and to predict functional consequences of alternative splicing by bioinformatics analysis. In a previous study, RNA-seq analysis predicted the presence of alternative spliced isoforms of equine COBLL1, namely COBLL1a as a long form and COBLL1b as a short form. In this study, we validated two isoforms of COBLL1 transcripts in horse tissues by the real-time polymerase chain reaction, and cloned them for Sanger sequencing. The sequencing results showed that the alternative splicing occurs at exon 9. Prediction of protein structure of these isoforms revealed three putative phosphorylation sites at the amino acid sequences encoded in exon 9, which is deleted in COBLL1b. In expression analysis, it was found that COBLL1b was expressed ubiquitously and equivalently in all the analyzed tissues, whereas COBLL1a showed strong expression in kidney, spinal cord and lung, moderate expression in heart and skeletal muscle, and low expression in thyroid and colon. In muscle, both COBLL1a and COBLL1b expression decreased after exercise. It is assumed that the regulation of COBLL1 expression may be important for regulating glucose level or switching of energy source, possibly through an insulin signaling pathway, in muscle after exercise. Further study is warranted to reveal the functional importance of COBLL1 on athletic performance in race horses.

Genetic Variations of Chicken TYR Gene and Associations with Feather Color of Korean Native Chicken (KNC)

Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764, KoreaABSTRACT Tyrosinase (TYR) gene is located on chromosome 1 in chicken and it is composed of five exons and four introns. TYR gene is described as a key enzyme in melanin biosynthesis. Most examples of complete albinism in chicken have been due to defects in the tyrosinase gene. The association of feather color and sequence polymorphism in the Tyrosinase (TYR) gene was investigated using Korean Native chicken H breed (H_PL), Korean Native chicken L/W breed(L/W_PL) and ‘Woorimatdag’ commercial chickens (Woorimatdag_CC). From L_PL and W_PL breed analyses, 4 synonymous SNPs (locus G33A, G116A, C217T and C247T) and 2 SNPs (G838A and G958A) were detected in 4th exon and 4th intron of TYR gene respectively. The genotype frequencies for 6 SNPs were compared between L_PL and W_PL and W_PL represented homozygous SNP types in all the analyzed SNP positions while L_PL displayed various SNP types.(Key words : Korean native chickens, feather color, TYR, SNP)

Primary Culture of Chicken Tracheal Epithelial Cells and Study on Those Characters for Recombinant Virus Infection

Tracheal epithelial cells (TECs) are an important tool for studies of viral respiratory diseases. Primary TECs have been cultured from human, mouse and hamster. It is also necessary to diagnose viral respiratory disease and reveal infection mechanisms in chicken. In this study, we isolated tracheal epithelial layers from tracheal of 20-day-old chicks and cultured primary TECs from the isolated layers. Ciliated cells which were a typical morphology of TECs were observed in cultured primary TECs and maintained until cell passage 5 (15 to 20 days). When we analyzed expression patterns of epithelial marker genes (retinoic acid responder, FGF-binding protein, virus activating protease (VAP) in TECs compared to immor- talized chicken embryonic fibroblast cell line (DF-1), all the marker genes are highly expressed in TECs than in DF-1. When TECs were cultured with 0.1 and 1 MOI of ND virus (rNDV-GFP strain) to test the susceptibility of TECs for ND virus, 12.6% and 48.2% of the incubated TECs were infected respectively. In addition, when DF-1 was incubated with 1 MOI of ND virus, the virus infection rate of DF-1 was three times lower than the virus infection rate of TECs. These data could