USE OF CELLULAR MODELS TO INVESTIGATE THE ROLE OF THE UNFOLDED PROTEIN RESPONSE IN TDP-43 ASSOCIATED NEURODEGENERATIVE DISEASES

MONTENEGRO, MAURICIO; SANCHEZ, GONZALO; RODRÍGUEZ ELGASSI, JUAN; CHARIF, SANTIAGO E.; COTARELO MARIA; BLAUSTEIN M; IGAZ, LIONEL M.

Simposio; Simposio LATBRAIN 2022; 2022

Iniciativa Cerebro Latinoamericano (LATBrain)

TDP-43 is aubiquitously expressed, predominantly nuclear protein with multiple roles inRNA processing. In neurodegenerative diseases, such as amyotrophic lateralsclerosis (ALS) and frontotemporal lobar degeneration (FTLD), a key finding isthat pathological TDP-43 accumulates in the cytoplasm, forming aggregates. Activationof the Unfolded Protein Response (UPR) in patients suffering from thesediseases has been proposed to be linked to TDP-43 toxicity. The UPR is acellular stress signaling cascade essentially triggered by the accumulation ofmisfolded proteins in the Endoplasmic Reticulum (ER). Upon detection of ERstress, the ER launches three mechanistically distinct pathways (IRE1, PERK andATF6) guiding proadaptive and/or proapoptotic cell fate decisions. To study therole of the UPR in TDP-43-mediated pathogenesis we use cellular models overexpressingwild-type, nuclear TDP-43 (TDP-43 WT) or a cytoplasmic form of TDP-43 (TDP-43-ΔNLS) which recapitulateALS/FTD features. Hela cells transfected with a set of fluorescent reporters willallow us to monitor the activation of the three UPR branches in single cells andin real time. Cells will be co-transfected with either TDP-43 WT, TDP-43-ΔNLS or a TDP-43 shRNAand treated with UPR inducers or vehicle. Biochemical analysis of endogenousUPR components will also be performed to study the effects of TDP-43dysregulation on UPR activity. These experiments will shed light on the role ofthe UPR in TDP-43 proteinopathies.