bioRxiv Science⌕ Search

Biology subjects

Nabawi, Y.

Publications and source records attributed to Nabawi, Y..

2 recordsLinked to original sources

C9orf72 ALS-causing mutations lead to nucleoporin Nup107 aggregation and subsequent pathological changes

Amyotrophic lateral sclerosis (ALS) is a fatal disorder caused by motor neuron degeneration. Hexanucleotide repeat expansions in the C9orf72 gene, the most common genetic cause of ALS (C9-ALS), drive toxicity through different mechanisms. These pathological changes include alterations in stress granules (SGs), ribonucleoprotein complexes formed under stress conditions. Here, we show that G3BP1, a core component of SGs, aberrantly interacts with the nucleoporin Nup107 in motor neurons derived from patient iPSCs carrying C9orf72 mutations. Moreover, Nup107 colocalizes with SGs and aggregates in C9-ALS motor neurons. Notably, knockdown of the C. elegans ortholog of Nup107 alleviates ALS-associated phenotypes in worm models, including reduced lifespan and motility. Our findings provide insights into C9-ALS pathogenesis and identify Nup107 as a potential therapeutic target.

cell biology↗

A critical period for prefrontal cortex PV interneuron myelination and maturation

AbstractRecent studies have highlighted axonal myelination as a common feature of parvalbumin-positive (PV) interneurons throughout the cerebral cortex. However, the precise function of PV interneuron myelination remains incompletely understood. In this study, we used the cuprizone model of demyelination to investigate how PV interneuron myelination might influence their neuronal physiology. Specifically, we examined whether impairing myelination from postnatal day 21 onwards, during a critical neurodevelopmental period of the prefrontal cortex (PFC), can affect PV interneuron maturation and function. Using whole-cell patch-clamp recordings to examine intrinsic properties of PV interneurons in the PFC, we found that juvenile demyelination induced robust alterations of PV interneuron firing patterns. Specifically, we observed that demyelination caused an impairment in the ability of PV interneurons to sustain high frequency firing associated with a substantial decrease in Kv3-specific currents. We also found a significant impairment in PV interneuron autaptic self-inhibitory transmission, a feature implicated in temporal control of PV interneuron firing during cortical network activity. Following a remyelination period of 5 weeks, PV interneuron properties were only partially recovered and mice showed clear social deficits, suggesting that transient juvenile demyelination leads to long-lasting behavioral impairments. In contrast, adult demyelination had no significant effects on PV interneuron firing properties. Together, our data uncovers a critical period for juvenile myelination as an important factor in PFC PV interneuron development and brain maturation.

neuroscience↗