Role of TTF-1 in leptin action for hypothalamic neuronal development

摘要

We investigated the expression of miRNAs within the retino- tectal system of late-stage pigeon embryos. Especially during development, miRNAs fine-tune gene expression on the post- transcriptional level and thereby, regulate entire pathways. While retinal processes do not seem to rely on the asymmetrical expres- sion of miRNAs, the right tectum opticum showed a higher expression of the miR-183 cluster than the left side. Target prediction analyses revealed potentially regulated mRNA and the pathways involved, such as axon guidance, calcium signal- ing, neurotrophin, Rap1, NF-KB, and PI3K-Akt signaling pathway. Importantly, most of these pathways are triggered by upstream neurotrophin signaling. Therefore, we analyzed the expression of the neurotrophin receptors TrkB and TrkC, that both harbor several potential binding sites for the miR-183 cluster. On mRNA level, the expressions of both receptors were rather symmetrical which could point to a regulatory control via inhibition of the post-translational machinery instead of mRNA degradation. To test if TrkB and TrkC are truly regulated by the miR-183 cluster, we are currently ana- lyzing the protein expression via Western Blot. Preliminary results indicate an asymmetrical expression of both receptors. All together this project sheds light onto the potential mechanisms by which light shapes the brain into its lateralized system.