The association of stromal antigen 3 (STAG3) sequence variations with spermatogenic impairment in the male Korean population / 亚洲男科学杂志(英文版)

The stromal antigen 3 (STAG3) gene, encoding a meiosis-specific cohesin component, is a strong candidate for causing male infertility, but little is known about this gene so far. We identified STAG3 in patients with nonobstructive azoospermia (NOA) and normozoospermia in the Korean population. The coding regions and their intron boundaries of STAG3 were identified in 120 Korean men with spermatogenic impairments and 245 normal controls by using direct sequencing and haplotype analysis. A total of 30 sequence variations were identified in this study. Of the total, seven were exonic variants, 18 were intronic variants, one was in the 5'-UTR, and four were in the 3'-UTR. Pathogenic variations that directly caused NOA were not identified. However, two variants, c.3669+35C>G (rs1727130) and +198A>T (rs1052482), showed significant differences in the frequency between the patient and control groups (P = 0.021, odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.098-2.918) and were tightly linked in the linkage disequilibrium (LD) block. When pmir-rs1052482A was cotransfected with miR-3162-5p, there was a substantial decrease in luciferase activity, compared with pmir-rs1052482T. This result suggests that rs1052482 was located within a binding site of miR-3162-5p in the STAG3 3'-UTR, and the minor allele, the rs1052482T polymorphism, might offset inhibition by miR-3162-5p. We are the first to identify a total of 30 single-nucleotide variations (SNVs) of STAG3 gene in the Korean population. We found that two SNVs (rs1727130 and rs1052482) located in the 3'-UTR region may be associated with the NOA phenotype. Our findings contribute to understanding male infertility with spermatogenic impairment.

Carrier screening for (CGG)n repeat expansion of FMR1 gene in Korean women

PURPOSE: We examined the prevalence and CGG/AGG repeat structure of expanded alleles of the FMR1 gene in preconceptional and pregnant Korean women. MATERIALS AND METHODS: The CGG repeats in the FMR1 genes of 1,408 women were analyzed by polymerase chain reaction and Southern blot analysis. To estimate the prevalence of expansion alleles, the individuals were divided into low risk and high risk group. RESULTS: Within this population, 98.4% had normal alleles and 1.6% had abnormal alleles including intermediate (0.6%), premutation (0.5%), full mutation (0.1%), and hemizygous (0.4%) alleles. There were 2 premutation alleles (1:666, 95% confidence interval [CI] 1:250-1,776) in the low risk group and 5 premutation alleles (1:15, 95% 1:6-36) in the high risk group. There were 8 intermediate alleles (1:167, 95% CI 1:130-213) in the low risk group and 1 intermediate alleles (1:76, 95% CI 1:11-533) in the high group. Six of the 7 premutation alleles did not contain AGG interruptions within the repeats and 1 had a single AGG interruption. Four of the 9 intermediate alleles contained 2-3 AGG, 4 had a single AGG, and 1 had no AGG interruptions. CONCLUSION: Our study demonstrates the prevalence and CGG/AGG structure of expansion alleles in Korean women. The identified premutation prevalence is higher than that of other Asian populations and lower than that of Caucasian populations. Although our study is limited by size and population bias, our findings could prove useful for genetic counseling of preconceptional or pregnant women.

Bupivacaine-induced Apoptosis in the Primary Cultured Cardiomyocytes via p38 MAPKs / 대한마취과학회지

BACKGROUND: It is known that bupivacaine induce cell death in several immortalized cells. However, there is no report concerning bupivacaine-induced cell death in the primary cultured cardiomyocytes. We compared the direct cytotoxicity of local anesthetics in cardiomyocytes. Furthermore, the mechanisms of cell death were evaluated. METHODS: The myocardial cells of rat pups were cultured 3 days after seeding. The methyltetrazolium (MTT) assay was employed to quantify differences in cellular viability. To confirm apoptosis, Hoechst-propidium iodide staining, DNA fragmentation by electrophoresis and western blot analysis were performed. And to examine the mechanisms of cell death, intracellular calcium and expression levels of mitogen-activated protein kinases (MAPKs) family members were evaluated. RESULTS: Among the local anesthetics under 1 mM concentration for 18 h, only bupivacaine significantly decreased the MTT activity (P < 0.001). Bupivacaine induced cell death in a dose-responsive and time dependent manner. Cell death showed apoptotic characteristics, such as DNA fragmentation, chromatin condensation, decrease of precursor caspase-3 protein level, increased cleaved PARP, and cytochrome C release into the cytoplasm. Bupivacaine phosphorylated three major MAPKs, i.e. extracellular signal-regulated kinases (ERKs), p38 kinase and c-Jun N-terminal kinases (JNKs) stress-activated protein kinases. Administration of ERK inhibitor increase cell death, whereas inhibitors of p38 kinase and JNK decreased cell death (P < 0.05). In addition, the intracellular calcium level was approximately 4 times higher after the bupivacaine treatment (P < 0.001), which was inhibited by calcium chelators (P < 0.001). Calcium chelators inhibited expression of MAPKs. CONCLUSIONS: In bupivacaine-induced apoptosis in cardiomyocytes, intracellular calcium increase and MAPKs family plays important roles.

Dedifferentiation of conditionally immortalized hepatocytes with long-term in vitro passage

The rat hepatocytes were immortalized using a temperature-sensitive mutant of SV40 large T antigen (tsT) to develop as a possible substitute for primary hepatocytes. Four rat hepatocyte lines that have been developed and maintained more than passage 50, were characterized for their cellular morphology, T antigen and p53 expression, chromosomes, liver-specific differentiation, telomerase activity and anchorage independent growth. All of four cell lines showed a typical epithelial cell morphology, but the population-doubling time became short with passage: 18 to 60%. T antigen expression was increased with passage about 3 to 65 times at permissive temperature but decreased significantly at non-permissive temperature. The expression level of p53 unchanged during passages was also decreased at non-permissive temperature. The distribution of chromosome number changed somewhat with passage. The production levels of albumin and urea in four cell lines were 2.4 to 13.0% and 7.5 to 19.9% of those produced in primary hepatocytes, respectively and were decreased to an undetectable level with passage. Telomerase activity was increased 10 fold following immortalization of cells, but anchorage independent growth of cells did not develop. These results indicate that conditionally immortalized hepatocytes become dedifferentiated with in vitro passage, which may be caused by marked chromosomal damages that occur with compulsive and continuous replications by the increment of T antigen content with passage and its sequential inhibition of p53 function.