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Marsala, M.

Publications and source records attributed to Marsala, M..

2 recordsLinked to original sources
bioRxiv2025

Reversable Acute Sedation Response of Phosphorothioate Antisense Oligonucleotides Following Local Delivery to the Central Nervous System

Antisense oligonucleotides (ASOs) locally delivered to the central nervous system (CNS) are being approved as therapies for neurological diseases. After intrathecal injection of some ASOs, transient toxicities have been reported, but considerable inconsistencies remain in classifying them and their underlying mechanisms. Here, we characterize an acute sedation response that can include loss of lower spinal reflexes, hypoactivity, paresis, sedation and ataxia, peaking [~]3 hours post-intrathecal injection of some phosphorothioate ASOs and reversing by 24 hours with no sequelae. Acute sedation is distinct from acute activation, which is hyperactivity and muscle cramping that occurs immediately after administering oligonucleotides. Acute sedation translates across species from rodents to non-human primates and is sequence-, dose-, and chemistry-dependent. Acute sedation can be mitigated by strategic placement of phosphorothioate backbone linkages in ASOs and by avoiding G-rich sequences. The acute sedation response can be modeled in primary neural cultures, with good predictability of in vivo response. Mechanistically, we demonstrate that acute sedation is caused by high extracellular ASO concentrations inhibiting synaptic transmission, which reverses as ASO is cleared from the extracellular space and taken up into cells. Our results provide a comprehensive framework for quantifying and mitigating acute sedation caused by some phosphorothioate ASOs. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/638136v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@c3c957org.highwire.dtl.DTLVardef@1d7a062org.highwire.dtl.DTLVardef@162adf5org.highwire.dtl.DTLVardef@18ad055_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗
bioRxiv2022

Stathmin-2 loss leads to neurofilament-dependent axonal collapse driving motor and sensory denervation

The human mRNA most affected by TDP-43 loss-of-function is transcribed from the STMN2 gene and encodes stathmin-2 (also known as SCG10), whose loss is a neurodegenerative disease hallmark. Here using multiple in vivo approaches, including transient antisense oligonucleotide (ASO)-mediated suppression, chronic shRNA-mediated depletion in aging mice, and germline deletion, we establish stathmin-2 to be essential for acquisition and maintenance of neurofilament-dependent structuring of axoplasm critical for maintaining diameter and conduction velocity of large-myelinated axons. Sustained stathmin-2 loss from an otherwise mature adult nervous system is demonstrated over a time course of eight months to initiate and drive motor neuron disease that includes 1) shrinkage in inter-neurofilament spacing that is required to produce a three-dimensional space filling array that defines axonal caliber, 2) collapse of mature axonal caliber with tearing of outer myelin layers, 3) reduced conduction velocity, 4) progressive motor and sensory deficits (including reduction of the pain transducing neuropeptide CGRP), and 5) muscle denervation. Demonstration that chronic stathmin-2 reduction is itself sufficient to trigger motor neuron disease reinforces restoration of stathmin-2 as an attractive therapeutic approach for TDP-43-dependent neurodegeneration, including the fatal adult motor neuron disease ALS.

cell biology↗