Whole-exome sequencing study reveals common copy number variants in protocadherin genes associated with childhood obesity in Koreans.

Recently, the prevalence of childhood obesity has significantly increased in industrialized countries, including Korea, and now controlling obesity is becoming an economic burden. However, knowledge of the risk factors associated with obesity is still limited. In this study, we aimed to discover additional obesity-associated loci in children. To achieve this, we conducted an exome-wide association analysis of copy number variation (CNV) using whole-exome sequencing (WES) data from a total of 102 cases and 86 controls. We newly identified a CNV locus that overlapped two protocadherin genes, PCDHB7 and PCDHB8, which are brain function-related genes (P-value=6.40 × 10-4, odds ratio=2.2189). A subsequent replication analysis using WES data from 203 obese and 291 normal weight children showed that this CNV region satisfied the genome-wide significance standard (Fisher's combined P-value=3.76 × 10-5). Moreover, correlation test using 199 additional samples supported significant association between CNV and increased body mass index. This region also showed a meaningful association with 273 cases and 2596 controls in adult samples. Our findings suggest that differences in the common CNV region at 5q31.3 may have an impact on the pathophysiology of obesity.

Combined untargeted and targeted metabolomic profiling reveals urinary biomarkers for discriminating obese from normal-weight adolescents.

BACKGROUND: Childhood and adolescent obesity may lead to obesity and related complications in adulthood. Biomarkers of obesity can be useful for screening for obesity complications and promoting early intervention during school age. Thus, the metabolomic differences in obese children and adolescents should be investigated for identification of potential biomarkers. OBJECTIVES: We investigated urinary biomarkers to distinguish metabolomic characteristics between obesity and normal weight in adolescents. METHODS: Adolescent subjects were divided into non-obese (n = 91) and obese (n = 93) groups according to body mass index. Untargeted and targeted metabolomic profiling of urine was performed using high-performance liquid chromatography (LC)-quadrupole time-of-flight mass spectrometry (MS), LC-MS/MS and flow injection analysis-MS/MS systems, respectively. RESULTS: Multivariate statistical analysis showed clear discrimination between the untargeted metabolomes of non-obese and obese groups. Seven endogenous metabolites were distinguished in the obese group, and inflammation-related metabolite markers showed strong predictive power for group classification. From targeted metabolomics, 45 metabolites mostly related to inflammation were significantly different in the obese group. CONCLUSIONS: Significantly different metabolome signatures were identified between normal-weight and obese adolescents. Combined untargeted and targeted metabolomics demonstrated that inflammation-driven insulin resistance, ammonia toxicity and oxidative stress may represent crucial metabolomic signatures in obese adolescents.

Interactions between ADIPOQ gene variants and dietary monounsaturated: saturated fatty acid ratio on serum lipid levels in Korean children.

BACKGROUND AND AIMS: Adiponectin plays important roles in the regulation of insulin action and metabolism of glucose and lipids. We investigated whether ADIPOQ genetic variants are associated with serum lipid levels in Korean children and whether those influences might be modulated by dietary factors such as dietary monounsaturated fatty acid to saturated fatty acid ratio (MUFA:SFA). METHOD AND RESULTS: The study included a population-based sample of 687 children aged 7-11 years in Gwacheon city, Kyunggi Province, Korea. Anthropometric and biochemical measurements and ADIPOQ genotype (-11377 C/G, +45 T/G, and +276 G/T) were determined. Dietary intake was estimated with a self reported 3-day food diary. The -11377 G allele carriers had significantly higher serum total cholesterol and LDL cholesterol compared to non-carriers. When dietary MUFA:SFA ratio was dichotomized (MUFA:SFA ≥ 1 or <1), the aggravating effects of the minor allele on serum total and LDL cholesterol were only present when the MUFA:SFA ratio was <1. Additionally, we observed that the ADIPOQ haplotype influenced serum total and LDL cholesterol levels. G-T-G haplotype carriers had higher total and LDL cholesterol levels than non-G-T-G carriers. The deleterious effect of ADIPOQ G-T-G haplotype to increase serum total and LDL cholesterol could be seen only when the MUFA:SFA ratio was <1. CONCLUSION: In this present study, we found interaction effects between ADIPOQ genetic variants and dietary MUFA:SFA ratio on serum lipid levels in Korean children. These results suggest that individual genetic information and dietary fatty acid intake information should be assessed together to achieve an effective outcome for reducing the atherogenic lipid profile.

Detection of antigenic proteins expressed by lymphocystis virus as vaccine candidates in olive flounder, Paralichthys olivaceus (Temminck & Schlegel).

Although the major capsid proteins (MCPs) of lymphocystis disease virus (LCDV) have been characterized, little is known about the host-derived immune response to MCPs and other LCDV antigenic proteins. To identify antigenic proteins of LCDV that could be used as vaccine candidates in olive flounder, Paralichthys olivaceus, we analysed the viral proteins responsible for its virulence by applying immuno-proteomics. LCDV proteins were separated by one-dimensional gel electrophoresis, transferred to polyvinylidene difluoride membrane, and probed with homogeneous P. olivaceus antisera elicited by LCDV natural infection and vaccination with formalin-killed LCDV. Four immune-reactive proteins were obtained at 68-, 51-, 41- and 21 kDa using antisera collected from natural infection while two proteins at 51- and 21 kDa exhibited response to antisera from vaccinated fish, indicating that the latter two proteins have vaccine potential. Using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoelectrospray MS/MS, the 51 and 21 kDa proteins were identified as MCP and an unknown protein, respectively.

Technology of the divalent engineered diarrhea vaccine (K88, K99) production by high cell density fermentation and the antigen overexpression.

This paper describes the production of divalent K88, K99 antigens by high cell density fermentation and gene overexpression. The cell density reached above 40 at A600nm and the antigens were at 2(12) level. The thousands dosage of the vaccine can be made by using 10 I broth of the fermentation. The stability of the plasmid showed that about 30 percent of the bacteria lost its plasmid after 20 h fermentation. It was found that the antigens were overexpressed and located in both the pili of E. coli and in the medium in equal quantities. It means that the expression and regulation of the genes of K88, K99 may be different from the wild type of enterotoxingenic E. coli. A large number of the vaccinated pregnant sow showed that the piglets were effectively protected from the infection of enterotoxingenic E. coli. The results indicated that the large quantities requirement of the vaccine could be provided by using a small fermenter. This vaccine consists of two forms of the antigen K88, K99 which, when present in the pili as well as the medium, is more favorable to stimulate the production of antibody in the colostrum of pregnant sow.