Research project

AriSLA 2021 (DSB.AD006.318)

Thematic area

Biomedical sciences

Project area

Biologia Molecolare/Cellulare (DSB.AD006)

Structure responsible for the research project

Institute of molecular genetics (IGM)

Project manager

SOFIA FRANCIA
Phone number: 0382546325
Email: sofia.francia@igm.cnr.it

Abstract

Endogenous DNA dam age have been reported in m otor-neurons (MNs) of ALS patients carrying m utations in the genes encoding for TDP43 or FUS, only recently involved in the DNA dam age response (DDR). We published that DDR activation depends on the RNases DROSHA and DICER, cofactors of FUS and TDP43, for the biogenesis of the DNA dam age response RNA (DDRNA) and that the sm all m olecule Enoxacin, already show to am eliorate ALS sym ptom s, prom otes DNA repair by stim ulating DDRNA production. Our hypothesis is that neurodegeneration of ALS patients with TDP43 or FUS proteinopathies- present in 97% of all ALS cases-is caused by altered DDR functions. Our previous AriSLA-funded project allowed us to confirm that FUS and TDP43 cytoplasm ic inclusions (CI) reduce DROSHA activity and im pair the biogenesis of DDRNAs but also brought us to discover that the form ation of such CI causes aberrant and dysfunctional activation of the m ain DDR kinases ATM and DNAPK leading to widespread nuclear accum ulation of gH2AX and loss of cell viability. In addition, we observed that CI of m utant FUSP525L causes the accum ulation of the autophagic factor P62, which sequesters the nuclear DDR ubiquit

Goals

With the present project, we plan to validate different molecular approaches targeting factors involved in DNA damage signalling and repair, to counteract neurodegeneration caused by TDP43 or FUS aggregation in ALS cellular and animal model systems.
Induced pluripotent stem cells (iPSCs) derived from ALS patients with TDP43 or FUS mutations will be differentiated into MNs and treated with ATM or DNA-PK inhibitors prior to DNA damage induction by ionizing radiation (IR). DDR activation, DNA damage accumulation and cell survival will be monitored in ALS MNs and compared to healthy ones.
In the same cellular systems, we will also test the impact of P62 inhibition - by RNAi or through small-molecule administration - on signaling and repairing the DNA damage and if this is sufficient to prevent neurodegeneration of ALS MNs.
The molecular approaches described above will be also validated in an animal model system represented by D. melanogaster strains expressing high levels of human TDP43 or FUS in ommatids which mimics degeneration of retinal neural cells.

Start date of activity

01/05/2021

Keywords

DNA, Damage, ALS

Last update: 28/03/2024