Khanlou, N. | bioRxiv Science

bioRxiv2025

A structure-guided antibody detects SOD1 oligomers in diverse ALS genotypes.

Antibodies offer versatility as diagnostic and therapeutic tools to target specific protein epitopes. However, the transient nature of intermediate protein conformations, such as that of amyloid oligomers, poses a challenge for antibody development. We use a structure-guided approach to generate a monoclonal antibody against oligomers of Superoxide Dismutase 1 (SOD1). Mutations in SOD1 are linked to a subset of familial Amyotrophic Lateral Sclerosis (fALS), a fatal neurodegenerative disease. Based on the corkscrew-like features of non-native SOD1 oligomers previously determined, we generate an antibody specific to SOD1 oligomers. We show that the antibody, CSAb detects SOD1 oligomers, not fibrils or native SOD1, and alleviates the cytotoxic effects of SOD1 oligomers in a cell culture model of primary motor neurons. Immunohistochemical analyses of human ALS subjects show CSAb reactivity in both neuronal and non-neuronal cells. Finally, we provide evidence that CSAb reactive SOD1 oligomers are present in non-SOD1 linked fALS and sporadic ALS subjects. Together, our study provides a new probe against SOD1 oligomers and suggests that cytotoxic SOD1 oligomers are prevalent in diverse ALS genotypes.

neuroscience↗

bioRxiv2024

Cellular Modeling of CLN6 with IPSC-derived Neurons and Glia

Neuronal ceroid lipofuscinosis (NCL), type 6 (CLN6) is a neurodegenerative disorder associated with progressive neurodegeneration leading to dementia, seizures, and retinopathy. CLN6 encodes a resident-ER protein involved in trafficking lysosomal proteins to the Golgi. CLN6p deficiency results in lysosomal dysfunction and deposition of storage material comprised of Nile Red+ lipids/proteolipids that include subunit C of the mitochondrial ATP synthase (SUBC). White matter involvement has been recently noted in several CLN6 animal models and several CLN6 subjects had neuroimaging was consistent with leukodystrophy. CLN6 patient-derived induced pluripotent stem cells (IPSCs) were generated from several of these subjects. IPSCs were differentiated into oligodendroglia or neurons using well-established small-molecule protocols. A doxycycline-inducible transgenic system expressing neurogenin-2 (the I3N-system) was also used to generate clonal IPSC-lines (I3N-IPSCs) that could be rapidly differentiated into neurons (I3N-neurons). All CLN6 IPSC-derived neural cell lines developed significant storage material, CLN6-I3N-neuron lines revealed significant Nile Red+ and SUBC+ storage within three and seven days of neuronal induction, respectively. CLN6-I3N-neurons had decreased tripeptidyl peptidase-1 activity, increased Golgi area, along with increased LAMP1+ in cell bodies and neurites. SUBC+ signal co-localized with LAMP1+ signal. Bulk-transcriptomic evaluation of control- and CLN6-I3N-neurons identified >1300 differentially-expressed genes (DEGs) with Gene Ontogeny (GO) Enrichment and Canonical Pathway Analyses having significant changes in lysosomal, axonal, synaptic, and neuronal-apoptotic gene pathways. These findings indicate that CLN6-IPSCs and CLN6-I3N-IPSCs are appropriate cellular models for this disorder. These I3N-neuron models may be particularly valuable for developing therapeutic interventions with high-throughput drug screening assays and/or gene therapy.

neuroscience↗