In this masters thesis the student analyzed methylation and expression of the reelin gene (RELN). Since the protein reelin is probably associated with susceptibility for mental disorders, we decided to examine RELN gene in association with suicidal behavior. RELN gene contains a CpG island, and therefore the gene expression could be regulated also through methylation. The changes of methylation may result with a reduction or increase of mRNA expression level, which affects the representation of the protein in the tissue. We set up two hypotheses: (1) methylation level of RELN gene in both investigated tissues is significantly different (higher) in the group of suicide victims than in the control group and (2) expression of RELN mRNA in the brain of the suicide victims is significantly lower than in the control group. For each sample we examined two amplicons within the RELN promotor in blood and two brain areas, where we determined the degree of methylation and mRNA expression. A statistically significant difference in average degree of methylation of the CpG island between the two investigated groups was not confirmed. Instead we determined that there is comparable degree of methylation between blood, which represents a source for peripheral markers, and brain, and this could speak in favor of the mirror effect between tissues. A statistically significant difference in RELN mRNA expression in the brain was not confirmed between the two investigated groups. Despite our negative results, reelin remains very important gene in the research of mental disorders.
D.10 Educational activities
The doctoral candidate deals in her doctoral thesis with the genes of the neurothrophic system (BDNF, NGFR, NTRK). The genes have been studied on three levels: single nucleotide polymorphisms, DNA methylation and gene expression. Results and discussion: By analyzing the distribution of haplotype frequencies in the BDNF gene in suicide victims compared with control subjects, we determined a higher frequency of haplotype CATTC (rs7124442 (T / C) -rs10767664 (A / T) -rs962369 (T / C) -rs12273363 (T / C) -rs908867 (C / T)). In suicide victims was the alternative allele of SNP rs7124442 (C) more frequently represented in the specific context of the wild-type alleles of four other SNPs, and therefore we concluded that the alternative allele of the SNP rs7124442 (C), in the haplotype with allele wild-type SNP rs10767664, rs962369, rs12273363 and rs908867, may be associated with suicide. In the methylation study lower rate of methylation in the region of BDNF I2 before the first exon was determined in suicide victims compared to controls. In brain tissue the differences in the level of metiliranosti were not determined, however in the brain region BA9 of the suicide victims, compared to control subjects, we found a higher level of expression of mRNA isoform I of the BDNF gene. The investigated subjects therefore differ in the methilation of BDNF I2 region before the first exon in the blood, but the level of methylation I2 BDNF in the blood does not reflect the state of methylation in BA9 and hippocampus. Conclusion: In our work, we showed that the genes of neurotrophic system between the investigated groups differs in the levels of the SNPs frequency distridutions, methylation and expression at the mRNA. In the suicide victims, compared to controls, higher frequency of the haplotype C-A-T-T-C in the BDNF gene, lower rate of methylation in the region of BDNF gene before the first exon (I2), and higher level of expression of isoform mRNA I of the BDNF gene were determined.
D.09 Tutoring for postgraduate students