Cellular and Molecular Neurobiology
Author: Mauricio Norman Montenegro | email: mauricio.montenegro909@gmail.com
Mauricio Montenegro 1°, Gonzalo Sánchez 2°, Juan Rodríguez Elgassi 2°, Santiago Charif 2°, María Cotarelo 2°, Matías Blaustein 2°, Lionel Muller Igaz 1°
1° IFIBIO Houssay, Grupo de Neurociencia de Sistemas, Facultad de Medicina, Universidad de Buenos Aires – CONICET, Buenos Aires, Argentina.
2° Instituto de Biociencias, Biotecnología y Biología traslacional (iB3), Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires.
TDP-43 is a ubiquitously expressed, predominantly nuclear protein with multiple roles in RNA processing. In neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), a key finding is that pathological TDP-43 accumulates in the cytoplasm, forming aggregates. Activation of the Unfolded Protein Response (UPR) in patients suffering from these diseases has been proposed to be linked to TDP-43 toxicity. The UPR is a cellular stress signaling cascade essentially triggered by the accumulation of misfolded proteins in the Endoplasmic Reticulum (ER). Upon detection of ER stress, the ER launches three mechanistically distinct pathways (IRE1, PERK and ATF6) guiding proadaptive and/or proapoptotic cell fate decisions. To study the role of the UPR in TDP-43-mediated pathogenesis we use cellular models overexpressing wild-type, nuclear TDP-43 (TDP-43 WT) or a cytoplasmic form of TDP-43 (TDP-43-ΔNLS) which recapitulate ALS/FTD features. Hela cells transfected with a set of fluorescent reporters will allow us to monitor the activation of the three UPR branches in single cells and in real time. Cells will be co-transfected with either TDP-43 WT, TDP-43-ΔNLS or a TDP-43 shRNA and treated with UPR inducers or vehicle. Biochemical analysis of endogenous UPR components will also be performed to study the effects of TDP-43 dysregulation on UPR activity. These experiments will shed light on the role of the UPR in TDP-43 proteinopathies.