@article{ArgyrousideNijsLagattaetal.2019, author = {Argyrousi, Elentina K. and de Nijs, Laurence and Lagatta, Davi C. and Schl{\"u}tter, Anna and Weidner, Magdalena T. and Z{\"o}ller, Johanna and van Goethem, Nick P. and Joca, S{\^a}mia R. L. and van den Hove, Daniel L. A. and Prickaerts, Jos}, title = {Effects of DNA methyltransferase inhibition on pattern separation performance in mice}, series = {Neurobiology of Learning and Memory}, volume = {159}, journal = {Neurobiology of Learning and Memory}, doi = {https://doi.org/10.1016/j.nlm.2019.02.003}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221226}, pages = {6-15}, year = {2019}, abstract = {Enhancement of synaptic plasticity through changes in neuronal gene expression is a prerequisite for improved cognitive performance. Moreover, several studies have shown that DNA methylation is able to affect the expression of (e.g. plasticity) genes that are important for several cognitive functions. In this study, the effect of the DNA methyltransferase (DNMT) inhibitor RG108 was assessed on object pattern separation (OPS) task in mice. In addition, its effect on the expression of target genes was monitored. Administration of RG108 before the test led to a short-lasting, dose-dependent increase in pattern separation memory that was not present anymore after 48 h. Furthermore, treatment with RG108 did not enhance long-term memory of the animals when tested after a 24 h inter-trial interval in the same task. At the transcriptomic level, acute treatment with RG108 was accompanied by increased expression of Bdnf1, while expression of Bdnf4, Bdnf9, Gria1 and Hdac2 was not altered within 1 h after treatment. Methylation analysis of 14 loci in the promoter region of Bdnf1 revealed a counterintuitive increase in the levels of DNA methylation at three CpG sites. Taken together, these results indicate that acute administration of RG108 has a short-lasting pro-cognitive effect on object pattern separation that could be explained by increased Bdnf1 expression. The observed increase in Bdnf1 methylation suggests a complex interplay between Bdnf methylation-demethylation that promotes Bdnf1 expression and associated cognitive performance. Considering that impaired pattern separation could constitute the underlying problem of a wide range of mental and cognitive disorders, pharmacological agents including DNA methylation inhibitors that improve pattern separation could be compelling targets for the treatment of these disorders. In that respect, future studies are needed in order to determine the effect of chronic administration of such agents.}, language = {en} } @article{deNijsChoeSteinbuschetal.2019, author = {de Nijs, Laurence and Choe, Kyonghwan and Steinbusch, Hellen and Schijns, Olaf E. M. G. and Dings, Jim and van den Hove, Daniel L. A. and Rutten, Bart P. F. and Hoogland, Govert}, title = {DNA methyltransferase isoforms expression in the temporal lobe of epilepsy patients with a history of febrile seizures}, series = {Clinical Epigenetics}, volume = {11}, journal = {Clinical Epigenetics}, doi = {10.1186/s13148-019-0721-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223636}, year = {2019}, abstract = {Background Temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) is a common pharmaco-resistant epilepsy referred for adult epilepsy surgery. Though associated with prolonged febrile seizures (FS) in childhood, the neurobiological basis for this relationship is not fully understood and currently no preventive or curative therapies are available. DNA methylation, an epigenetic mechanism catalyzed by DNA methyltransferases (DNMTs), potentially plays a pivotal role in epileptogenesis associated with FS. In an attempt to start exploring this notion, the present cross-sectional pilot study investigated whether global DNA methylation levels (5-mC and 5-hmC markers) and DNMT isoforms (DNMT1, DNMT3a1, and DNMT3a2) expression would be different in hippocampal and neocortical tissues between controls and TLE patients with or without a history of FS. Results We found that global DNA methylation levels and DNMT3a2 isoform expression were lower in the hippocampus for all TLE groups when compared to control patients, with a more significant decrease amongst the TLE groups with a history of FS. Interestingly, we showed that DNMT3a1 expression was severely diminished in the hippocampus of TLE patients with a history of FS in comparison with control and other TLE groups. In the neocortex, we found a higher expression of DNMT1 and DNMT3a1 as well as increased levels of global DNA methylation for all TLE patients compared to controls. Conclusion Together, the findings of this descriptive cross-sectional pilot study demonstrated brain region-specific changes in DNMT1 and DNMT3a isoform expression as well as global DNA methylation levels in human TLE with or without a history of FS. They highlighted a specific implication of DNMT3a isoforms in TLE after FS. Therefore, longitudinal studies that aim at targeting DNMT3a isoforms to evaluate the potential causal relationship between FS and TLE or treatment of FS-induced epileptogenesis seem warranted.}, language = {en} }