A Crispr-cas9 PGRN neuronal cell model for functional analysis of FTD disease mutations.

Progranulin (PGRN) is genetically associated with frontotemporal dementia (FTD) but the neurobiology remains unclear. We performed genetic studies on 256 FTD patients and identified a rare exon six GRN deletion g10325_10331delCTGCTGT in three autosomal dominant Southern Italian pedigrees. Transcriptional and translational analysis demonstrated that FTD patients carrying this GRN mutation have a deficiency of the protein. To provide an efficient system to investigate the effects of PGRN depletion on neuronal cells, we generated a stable clone with PGRN deficiency by CRISPRCas9. To begin testing the hypothesis that patients with PGRN deficiency have an impaired autophagic-lysosomal pathway, we performed mRNA expression analysis of autophagy related genes. Preliminary results demonstrated decreased expression of autophagy-related genes Beclin2 and LC3 in GRN knock-out cells compared to wild-type cells. Our preliminary observations support the role of the GRN gene in the etiology of FTD and the hypothesis that PGRN insufficiency can predispose to neuron degeneration.