CHARACTERIZATION OF THE UNFOLDED PROTEIN RESPONSE THROUGH THE USE OF FLUORESCENT REPORTERS IN CULTURED SINGLE CELLS AND IN DISEASE MODELS

VEGGETTI M; BLAUSTEIN M; COTARELO M; IGAZ LM; COLMAN-LERNER A

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

Sociedades de BioCiencias de la República Argentina

The Unfolded Protein Response (UPR) is a cellular stresssignaling cascade essentially triggered by the accumulation of misfoldedproteins in the Endoplasmic Reticulum (ER). Three mechanistically distinctpathways (IRE1, PERK and ATF6) make up this collective response aimed atrestoring homeostasis. However, if this objective is not met within a logicaltime span, the UPR triggers apoptosis. This dichotomy of outcomes makesdetermining the cell?s fate a real enigma which could be solved through a clearcharacterization of the UPR dynamics.In order to do this, we employed a set of fluorescent reportersthat allows us to monitor the activation of the UPR in human single cells andin real time. We have previously characterized novel reporters for the ATF6 andIRE1 pathways, and we describe here the design of new reporters for the PERKpathway. We have also developed a protocol for automated imaging andsegmentation of cells as well as for quantitative analysis of UPR activation.We aim to study the activation dynamics of the three UPR pathways in singlecells in order to shed light onto the decision-making mechanisms involved incell death and survival. Interestingly, some evidences show that the UPR might beassociated with neurodegenerative diseases: activation of UPR in patientssuffering from frontotemporal lobar degeneration (FTLD) and amyotrophic lateralsclerosis (ALS) has been linked to the toxicity of Tar DNA bindingProtein-43 (TDP-43), the main component of intracellular inclusions related tothese diseases. Confirmation of this integrated network would open thepossibility of designing new therapies targeted to patients suffering fromneurodegeneration.