Gene expression profiling of chicken primordial germ cell ESTs

BACKGROUND: Germ cells are the only cell type that can penetrate from one generation to next generation. At the early embryonic developmental stages, germ cells originally stem from primordial germ cells, and finally differentiate into functional gametes, sperm in male or oocyte in female, after sexual maturity. This study was conducted to investigate a large-scale expressed sequence tag (EST) analysis in chicken PGCs and compare the expression of the PGC ESTs with that of embryonic gonad. RESULTS: We constructed 10,851 ESTs from a chicken cDNA library of a collection of highly separated embryonic PGCs. After chimeric and problematic sequences were filtered out using the chicken genomic sequences, there were 5,093 resulting unique sequences consisting of 156 contigs and 4,937 singlets. Pearson chi-square tests of gene ontology terms in the 2nd level between PGC and embryonic gonad set showed no significance. However, digital gene expression profiling using the Audic's test showed that there were 2 genes expressed significantly with higher number of transcripts in PGCs compared with the embryonic gonads set. On the other hand, 17 genes in embryonic gonads were up-regulated higher than those in the PGC set. CONCLUSION: Our results in this study contribute to knowledge of mining novel transcripts and genes involved in germline cell proliferation and differentiation at the early embryonic stages

Change in gene expression of mouse embryonic stem cells derived from parthenogenetic activation

BACKGROUND We previously established parthenogenetic mouse embryonic stem cells (ESCs) and this study was subsequently conducted for elucidating the influence of oocyte parthenogenesis on gene expression profile of ESCs. METHODS Gene expression of parthenogenetic ESC (pESC)-1 or pESC-2 was separately compared with that of two normally fertilized ESC (nfESC) lines (B6D2F1 and R1 strains), and quantification of mRNA expression was conducted for validating microarray data. RESULTS In two sets of comparison, reaction of 11 347 and 15 454 gene probes were altered by parthenogenesis, while strain difference changed the expression of 15 750 and 14 944 probes. Level of correlation coefficient was higher in the comparisons between normal fertilization and parthenogenesis (0.974-0.985) than in the comparisons between strains of nfESCs (0.97-0.971). Overall, the expression of 3276-3329 genes was changed after parthenogenesis, and 88% (96/109) of major functional genes differentially (P < 0.01) expressed in one comparison set showed the same change in the other. When we monitored imprinted genes, expression of nine paternal and eight maternal genes were altered after parthenogenesis and 88% (14/16) of these was confirmed by mRNA quantification. CONCLUSIONS The change in gene expression after parthenogenesis was similar to, or less than, the change induced by a strain difference under a certain genetic background. These results may suggest the clinical feasibility of parthenogenesis-derived, pluripotent cell

A set of stage-specific gene transcripts identified in EK stage X and HH stage 3 chick embryos

<p>Abstract</p> <p>Background</p> <p>The embryonic developmental process in avian species is quite different from that in mammals. The first cleavage begins 4 h after fertilization, but the first differentiation does not occur until laying of the egg (Eyal-Giladi and Kochav (EK) stage X). After 12 to 13 h of incubation (Hamburger and Hamilton (HH) stage 3), the three germ layers form and germ cell segregation in the early chick embryo are completed. Thus, to identify genes associated with early embryonic development, we compared transcript expression patterns between undifferentiated (stage X) and differentiated (HH stage 3) embryos.</p> <p>Results</p> <p>Microarray analysis primarily showed 40 genes indicating the significant changes in expression levels between stage X and HH stage 3, and 80% of the genes (32/40) were differentially expressed with more than a twofold change. Among those, 72% (23/32) were relatively up-regulated at stage X compared to HH stage 3, while 28% (9/32) were relatively up-regulated at HH stage 3 compared to stage X. Verification and gene expression profiling of these GeneChip expression data were performed using quantitative RT-PCR for 32 genes at developmental four points; stage X (0 h), HH stage 3 (12 h), HH stage 6 (24 h), and HH stage 9 (30 h). Additionally, we further analyzed four genes with less than twofold expression increase at HH stage 3. As a result, we identified a set of stage-specific genes during the early chick embryo development; 21 genes were relatively up-regulated in the stage X embryo and 12 genes were relatively up-regulated in the HH stage 3 embryo based on both results of microarray and quantitative RT-PCR.</p> <p>Conclusion</p> <p>We identified a set of genes with stage-specific expression from microarray Genechip and quantitative RT-PCR. Discovering stage-specific genes will aid in uncovering the molecular mechanisms involved the formation of the three germ layers and germ cell segregation in the early chick embryos.</p

Prevalence of sarcopenia and sarcopenic obesity in Korean adults: The Korean Sarcopenic Obesity Study (KSOS)

*Context:* Sarcopenic obesity (SO), a combination of excess weight and reduced muscle mass and/or strength, is suggested to be associated with an increased risk of adverse health outcomes. &#xd;&#xa;*Objectives:* To examine the prevalence and characteristics of Sarcopenic and SO defined by using different indices such as Appendicular Skeletal muscle Mass (ASM)/height^2^ and Skeletal Muscle Index (SMI (%): skeletal muscle mass (kg)/weight (kg) &#xd7; 100) for Korean adults. &#xd;&#xa;*Methods:* 591 participants were recruited from the Korean Sarcopenic Obesity Study (KSOS) which is an ongoing prospective observational cohort study. Analysis was conducted in 526 participants (328 women, 198 men) who had complete data on body composition using Dual X-ray absorptiometry and computed tomography. &#xd;&#xa;*Results:* The prevalence of sarcopenia and SO increases with aging. Using two or more standard deviations (SD) of ASM/height^2^ below reference values from young, healthy adults as a definition of sarcopenia, the prevalence of sarcopenia and SO was 6.3% and 1.3% in men and 4.1% and 1.7% in women over 60 years of age. However, using two or more SD of SMI, the prevalence of sarcopenia and SO was 5.1% and 5.1% respectively in men and 14.2% and 12.5% respectively in women. As defined by SMI, subjects with SO had 3 times the risk of metabolic syndrome (OR = 3.03, 95% confidence interval (CI) = 1.26-7.26) and subjects with non-sarcopenic obesity had approximately 2 times the risk of metabolic syndrome (OR = 1.89, 95% CI = 1.18-3.02) compared with normal subjects. &#xd;&#xa;*Conclusion:* Obese subjects with relative sarcopenia were associated with a greater likelihood for metabolic syndrome. As Koreans were more obese and aging, the prevalence of SO and its impact on health outcomes are estimated to be rapidly grow. Further research is requested to establish the definition, cause and consequences of SO.&#xd;&#xa

Effective gamma-ray sterilization and characterization of conductive polypyrrole biomaterials

Conductive polymers, including polypyrrole (PPy), have been extensively explored to fabricate electrically conductive biomaterials for bioelectrodes and tissue engineering scaffolds. For their in vivo uses, a sterilization method without severe impairment of original material properties and performance is necessary. Gamma-ray radiation has been commonly applied for sterilization of medical products because of its simple and uniform sterilization without heat generation. Herein we describe the first study on gamma-ray sterilization of PPy bioelectrodes and its effects on their characteristics. We irradiated PPy bioelectrodes with different doses (0–75 kGy) of gamma-rays. Gamma-ray irradiation of the PPy (γ-PPy) increased the oxygenation and hydrophilicity of the surfaces. Interestingly, gamma-ray irradiation did not alter the electrical impedances and conductivities of the PPy substrates. Additionally, γ-PPy prepared with various dopants (e.g., para-toluene sulfonate, polystyrene sulfonate, and chlorine) showed the electrochemical properties similar to the non-irradiated control. Gamma-ray irradiation at doses of ≥15 kGy was required for effective sterilization as evidenced by complete eradication of gram positive and negative bacteria. γ-PPy substrates also showed cytocompatibility similar to untreated control PPy, indicating no substantial alteration of cytocompatibility. In conclusion, gamma ray sterilization is a viable method of sterilization of conducting polymer-based biomaterials for biomedical applications

Establishment of a piglet model for peritoneal metastasis of ovarian cancer

Background : A piglet model for peritoneal metastasis (PM) of ovarian cancer was developed. It will contribute to establishing innovative chemotherapeutical and surgical strategies without any limitation on rodent models. Methods : A total of 12 four- to five-week-old piglets of 7 to 8 kg were used. Two phases of ovarian cancer cell injections were performed with laparoscopic surgery. In phase I trial, 5.0 × 106 SK-OV-3 cells in 0.1 ml suspension were inoculated into the omentum, peritoneum, and uterine horns of two piglets twice with a one-week interval. In the phase II trial, 5.0 × 106 SNU-008 cells in 0.1 ml suspension were injected only into uterine horns within the same time frame because tumor implantation after inoculation of SK-OV-3 cells was not observed at the omentum or peritoneum in the phase I trial. Modified peritoneal cancer index (PCI) score was used to monitor tumorigenesis up to 4 weeks after inoculation. Tumor tissues disseminated in the peritoneum 4 weeks after injection were used for histological examination with hematoxylin and eosin (H&E) and paired-box gene 8 (PAX-8) staining. Results : In the phase I trial, two piglets showed PM with modified PCI scores of 5 and 4 at 3 weeks after the first inoculation, which increased to 14 and 15 after 4 weeks, respectively. In the phase II trial, PM was detected in eight of ten piglets, which showed modified PCI scores of 6 to 12 at 4 weeks after the first inoculation. The overall incidence of PM from the total of 12 piglets after inoculation was 75%. Immunohistochemical H&E and PAX-8 staining confirmed metastatic tumors. Conclusions : This study provides strong evidence that piglets can be employed as a model for PM by inoculating ovarian cancer cell lines from humans. Using two cell lines, the PM rate is 75%.This research was supported by a grant from Seoul National University (No,800–20190437). Moreover, Commercializations Promotion Agency for R&D Outcomes supported this research with a grant funded by the Korea government (the Ministry of Science and ICT; No. 1711151316)

G-protein coupled receptor 64 (GPR64) acts as a tumor suppressor in endometrial cancer

Background Endometrial cancer is the most common gynecological cancer. G-protein coupled receptor 64 (GPR64) belongs to a family of adhesion GPCRs and plays an important role in male fertility. However, the function of GPR64 has not been studied in endometrial cancer. Our objective is to investigate the role of GPR64 in endometrial cancer. Methods We examined the levels of GPR64 in human endometrioid endometrial carcinoma by immunohistochemistry analysis. To determine a tumor suppressor role of GPR64 in endometrial cancer, we used a siRNA loss of function approach in human endometrial adenocarcinoma cell lines. Results GPR64 levels were remarkably lower in 10 of 21 (47.62%) of endometrial carcinoma samples compared to control. Depletion of GPR64 by siRNA transfection revealed an increase of colony formation ability, cell proliferation, cell migration, and invasion activity in Ishikawa and HEC1A cells. The expression of Connexin 43 (Cx43), a member of the large family of gap junction proteins, was reduced through activation of AMP-activated protein kinase (AMPK) in Ishikawa cells with GPR64-deficicy. Conclusions These results suggest that GPR64 plays an important tumor suppressor role in endometrial cancer.Grant numbers and sources of support: The design, data collection, data analysis, and data interpretation of this study were supported by Bio-industry Technology Development Program (IPET312060–5), Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea (to J.M.L.), and NIH R01 HD084478 (to J.W.J.). The analysis and interpretation of data and writing support of this manuscript were supported by Basic Science Research Program through the National Research Foundation of Korea (NRF-2016R1D1A1B03934346), Ministry of Education, Science and Technology, Republic of Korea (to J.Y.Y.) and Grant Number P50CA098258 from the National Cancer Institute (to R.R.B. and T.H.K.)

Change in gene expression of mouse embryonic stem cells derived from parthenogenetic activation

We previously established parthenogenetic mouse embryonic stem cells (ESCs) and this study was subsequently conducted for elucidating the influence of oocyte parthenogenesis on gene expression profile of ESCs

Prevalence and risk factors of Helicobacter pylori infection in Korea: Nationwide multicenter study over 13 years

Background : The aim of this study was to evaluate the time trend of seropositivity of Helicobacter pylori (H. pylori) over the period of 13 years in an asymptomatic Korean population, and investigate associated risk factors. Methods : This cross-sectional nationwide multicentre study surveyed anti-H. pylori IgG antibodies in 19,272 health check-up subjects (aged [greater than and equal to]16 years) in 2011. Risk factors for H. pylori infection were investigated using logistic regression. Seropositivity in asymptomatic subjects without H. pylori eradication was compared between the years 1998 and 2005. Birth cohort effects were also evaluated. Results : After exclusion of subjects with a history of H. pylori eradication therapy (n = 3,712, 19.3%) and gastric symptoms (n = 4,764, 24.7%), the seroprevalence of H. pylori infection was 54.4% in 10,796 subjects. This was significantly lower than the seroprevalence of 59.6% in 2005 and that of 66.9% in 1998, and this decrease of seropositivity of H. pylori became widespread across all ages and in most areas of the country. This decreasing trend could be explained by cohort analysis. All younger birth cohorts had a lower seroprevalence of H. pylori than older birth cohorts at the same age. Decreased seroprevalence within the same birth cohorts also accounted for this phenomenon. Clinical risk factors of H. pylori infection were higher cholesterol level ([greater than and equal to] 240 mg/dl) (OR = 1.33; 95% CI = 1.14-1.54), male gender, older age, low income, and residence in a rural area. Conclusions : A decreasing trend of H. pylori seroprevalence due to a birth cohort effect requires further studies on its related human host factors as well as socio-economic and hygienic factors. In addition, the relationship between H. pylori infection and high cholesterol level needs more investigation regarding underlying pathogenesis.This work was supported by the National Research Foundation of Korea (NRF) grant for the Global Core Research Center (GCRC) funded by the Korea government (MSIP) (No. 2011-0030001)Peer Reviewe