189 | Effects of the Val66Met polymorphism in the BDNF gene on intracellular trafficking: implications in neuropsychiatric disorders

Disorders of the Nervous System

Author: Dalila Noelia Jazmín Mancino | Email: dmancino@immf.uncor.edu

Dalila Noelia Jazmín Mancino , Agustín Anastasía

1° Instituto de Investigación Médica Mercedes y Martín Ferreyra – INIMEC-CONICET-UNC, Córdoba, Argentina
2° Instituto de Ciencias Biomédicas de Córdoba (IUCBC), Córdoba, Argentina

A polymorphism in Brain Derived Neurotrophic Factor (BDNF) gene at ≈25% frequency leads to the substitution of Valine with Metionine at position 66 (Val66Met) in the sequence of the prodomain of BDNF (pBDNF) and is associated with cognitive deficits. Although little is known about the mechanisms through which this variant affects human behaviour, it has been demonstrated that pBDNF Met induces growth cone retraction and morphological changes in dendrites and dendritic spines, both in vitro and in vivo in neurons of the CNS. We propose that pBDNF Met induces structural alterations in CNS circuits by perturbing intracellular protein trafficking. To test this, pBDNF Val and pBDNF Met expression vectors were cloned into neurons. Initial optimization of plasmid transfections was conducted in both Hek293 cell cultures and 7 DIV neurons. Preliminary analysis has demonstrated that pBDNF induces cell death. Characterization involved quantifications of pyknotic nuclei, along with biochemical and immunofluorescence analysis of active caspase 3 and c-Jun N-terminal kinases (JNK). Ongoing experiments seek optimal timing for studying the impact of pBDNF on intracellular trafficking prior to the cell death. Once determined, a synchronization system of the secretory pathway in cultured neurons will be employed to study protein trafficking within the endomembrane system. These experiments will enhance understanding the mechanisms behind vulnerability to CNS disorders in pBDNF Met carriers.