Biology subjects

Mclean, S. L.

Publications and source records attributed to Mclean, S. L..

3 recordsLinked to original sources

bioRxiv2026

ESCRT-I Inhibition Protects against NMDAR Hypofunction and Restores Synaptic Homeostasis in a Cellular Model of Schizophrenia

N-methyl-D-aspartate receptor (NMDAR) hypofunction is a central pathophysiological mechanism in schizophrenia, yet direct NMDAR potentiation has shown limited clinical benefit, potentially because it fails to address deficits in receptor trafficking and surface stability. The endosomal sorting complexes required for transport (ESCRT) machinery governs the lysosomal fate of internalised membrane proteins, but its role in synaptic receptor homeostasis during glutamatergic dysfunction remains unclear. Phencyclidine (PCP), a non-competitive NMDAR antagonist, is widely used to model NMDAR hypofunction and schizophrenia-like phenotypes. Here, we show that sub-chronic PCP exposure induced persistent NMDAR hypofunction, impaired GABAergic transmission, and collapsed of excitation/inhibition (E/I) balance in primary hippocampal neurons. Genetic inhibition of the ESCRT-I component TSG101 prevented these deficits, enabled functional recovery following PCP washout, and increased surface expression of functional NMDARs and GABAA receptors without altering receptor pharmacology or biophysical properties. At the network level, TSG101 knockdown restored inhibitory tone, normalised excitatory activity, and stabilised E/I balance. Moreover, TSG101 knockdown rescued PCP-induced reductions in PSD-95 and BDNF, restored ERK1/2 signalling, and re-established activity-dependent nuclear translocation of Fos-like (Fos-L), consistent with reactivation of transcriptional plasticity. These findings identify ESCRT-I as a regulator of synaptic stability, positioning endosomal sorting pathways as a potential therapeutic target for schizophrenia.

neuroscience↗

bioRxiv2026

ESCRT Machinery Dysfunction in Motor Neurone Disease: TSG101, CHMP2B, and VPS4a Differentially Regulate TDP-43 Pathology, Autophagy, and Exosome Biogenesis

Motor Neurone Disease (MND) is characterised by progressive degeneration of upper and lower motor neurons, accompanied by cytoplasmic mislocalisation and hyperphosphorylation of TDP-43 -- hallmarks that implicate failure of endolysosomal proteostasis. The Endosomal Sorting Complexes Required for Transport (ESCRT) pathway governs multivesicular body (MVB) formation, lysosomal cargo delivery, and autophagosome closure, yet its expression profile in human MND tissue and mechanistic contribution to disease pathology have not been established. Here, we report subunit-specific dysregulation of ESCRT proteins in postmortem motor cortex and spinal cord from MND patients: CHMP2B (ESCRT-III) is significantly upregulated in both regions, whilst TSG101 (ESCRT-I) and VPS37A (ESCRT-I) are significantly downregulated in motor cortex, indicating a region-specific remodelling of the ESCRT network. In a tunicamycin-induced ER stress model using NSC-34 motor neuron-like cells and primary cortical neurons, TSG101 overexpression reduced total and phosphorylated TDP-43, suppressed mTOR signalling, and restored autophagic flux, whereas TSG101 knockdown exacerbated TDP-43 accumulation and cytoplasmic mislocalisation. CHMP2B modulation selectively regulated TDP-43 phosphorylation without altering total TDP-43 levels, consistent with a casein kinase 1-dependent mechanism operating independently of bulk autophagy. Both TSG101 and VPS4a were required to maintain neuronal CD9 tetraspanin localisation to early endosomes; their depletion redirected CD9 to late endosomal and lysosomal compartments under ER stress. Extracellular vesicle characterisation revealed a functional divergence: TSG101 is required for general exosome biogenesis, whereas VPS4a ATPase activity specifically mediates loading of pathological TDP-43 cargo into EVs. Dynamic light scattering confirmed that ER stress and ESCRT modulation produce distinct, condition-specific alterations in EV size and polydispersity. These findings establish ESCRT dysfunction as a multifaceted contributor to MND pathogenesis and identify TSG101, CHMP2B, and VPS4a as mechanistically distinct therapeutic targets warranting preclinical validation.

neuroscience↗

bioRxiv2026

Distinct Endosomal Sorting Complexes Required for Transport Components Differentially Regulate Glutamate and Gamma-Aminobutyric Acid Receptor Surface Expression

Endosomal sorting complexes required for transport (ESCRT) regulate membrane protein trafficking through coordinated cargo selection and endosomal processing, yet their contribution to neurotransmitter receptor sorting remains to be defined. Here, we examined how modulation of distinct complex components influences the surface expression of excitatory and inhibitory neurotransmitter receptors. Using surface biotinylation and imaging approaches in heterologous cells and primary neurons, we altered tumour susceptibility gene 101 (TSG101), a core complex I component, and vacuolar protein sorting-associated protein 4A (VPS4a), an ATPase required for complex III disassembly. Reduction of tumour susceptibility gene 101 increased receptor association with early endosomes and enhanced receptor surface localisation, whereas disruption of VPS4A promoted receptor accumulation within late endosomal compartments and impaired degradative progression. Inhibitory receptor subtypes displayed variable sensitivity. Together, these findings demonstrate that endosomal sorting complex components regulate receptor surface expression through stage-specific trafficking mechanisms associated with altered receptor recycling and degradative processing. Graphical abstractDistinct ESCRT components regulate neurotransmitter receptor trafficking through stage-specific control of the endosomal pathway. ESCRT-I disruption promotes early endosomal retention and recycling, whereas ESCRT-III impairment causes late endosomal accumulation and reduced degradation, together increasing receptor surface expression (created using Biorender). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/732891v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@1fe66b9org.highwire.dtl.DTLVardef@10a29d7org.highwire.dtl.DTLVardef@4109c4org.highwire.dtl.DTLVardef@1e84f19_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗