LAUSR

Neuronal ceroid lipofuscionosis type 6 (CLN6) is a neurodegenerative disease associated with dementia, seizures, and retinopathy. The disorder is due to mutations in the CLN6 gene encoding a resident ER transmembrane protein of unknown function. Similar to other NCLs, the cellular pathology associated with CLN6 includes the abnormal accumulation of autofluorescent storage material, with subunit C of the mitochondrial ATP synthase (SUBC) being the predominant component. Four CLN6 patient-derived IPSC lines were generated and differentiated into neuroprogenitor cells (NPCs), cortical neurons and oligodendroglia in order to model human CLN6. CLN6-IPSCs and CLN6-NPCs did not possess any overt storage material and were similar to control cells with regards to subcellular organelle morphology and organization. IPSC-derived CLN6-neurons were generated with two neuronal differentiation protocols, a more conventional dual-SMAD protocol and an inducible neurogenin-2 (I3N) protocol. CLN6-neuronal cultures differentiated with the dual-SMAD protocol consisted of a mixed population of neural cells (mitotic NPCs ad post-mitotic neurons) and had significantly increased SUBC+ puncta after ~30-40 days in culture compared to control lines. Alternatively, the I3N-CLN6 cultures generated post-mitotic neurons in only 3-5 days (consisting of >95% TUJ1+ cells) that had accumulated SUBC+ puncta during the same period. Preliminary studies with IPSC-derived oligodendroglia from CLN6 lines also had increased SUBC+ puncta. These findings indicate that molecular markers for this disorder can be monitored in IPSC-derived neural cells. Differentiated neurons and oligodendroglia are undergoing further phenotypic characterization and RNA evaluation to identify other cellular markers of CLN6 disease. These molecular markers can then be used to measure efficacy of therapeutic interventions including small molecule compounds, anti-sense oligonucleotides, and gene therapy.