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O'Shea, R.

Publications and source records attributed to O'Shea, R..

4 recordsLinked to original sources

Intranasal oxytocin mRNA-LNP can promote social behaviour and reduce pain

The COVID-19 epidemic and success of mRNA-LNP vaccines demonstrated the transformative potential of mRNA therapeutics. Beyond vaccination, mRNA delivery offers a platform for transient on-demand expression of therapeutic proteins for both rare and common diseases. While delivery of therapeutics to the liver is relatively straightforward, targeted delivery of mRNA-LNPs to the central nervous system (CNS) remains a significant challenge. Here we show that intranasal mRNA-LNP delivery results in localized mRNA cargo uptake and functional expression in the respiratory and olfactory epithelium, where the encoded cargo protein is secreted and can enter the CNS. Guided by genomic data of pain-associated gene expression, we identified secreted proteins as candidate mRNA-encoded analgesics. Intranasal mRNA-LNP encoding a synthetic oxytocin transcript (OXT) resulted in bioactive oxytocin peptide delivery to the CNS. Functionally, intranasal OXT mRNA-LNP enhanced social behaviour and attenuated pain responses across multiple behavioural paradigms, without impairing motor coordination. Importantly, repeated dosing was well tolerated and intranasal mRNA-LNP did not elicit an inflammatory response or alter overall health. Together, these findings establish intranasal mRNA-LNP delivery of secreted ligands as a safe, non-invasive route to target the CNS, unlocking a new class of mRNA therapeutics for pain or other disorders of the brain. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=189 SRC="FIGDIR/small/711938v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@131252aorg.highwire.dtl.DTLVardef@17efb79org.highwire.dtl.DTLVardef@1afe479org.highwire.dtl.DTLVardef@c0f2f5_HPS_FORMAT_FIGEXP M_FIG C_FIG One sentence summaryIntranasal administration of mRNA-LNP enables local transfection in nasal epithelium and subsequent secretion of therapeutic oxytocin peptides into the brain, promoting social interactions and reducing pain.

neuroscience↗

Spared nerve injury induces long-term and brain region-specific changes in oligodendrocyte density in mice

BackgroundEmerging evidence suggests a role for non-neuronal cells in the pathophysiology of chronic pain. Chronic pain causes profound alterations of the transcriptomic program of oligodendroglia, but the effect of pain on the oligodendroglial cells themselves remains unknown. MethodsMale and female C57BL6/J mice underwent spared nerve injury (SNI). Mechanical hypersensitivity was assessed five weeks later using the von Frey test. Six weeks post-surgery, mice were perfused, brains dissected, and immunostained for oligodendrocyte precursors cells (OPC) and mature oligodendrocytes (OL) in four brain regions involved in pain chronification: anterior cingulate cortex (ACC), central amygdala (CeA), basolateral amygdala (BLA), and periaqueductal gray (PAG). ResultsWe found OL were reduced in the ACC and CeA of both sexes six weeks after SNI. Conversely, BLA OL were increased in both sexes following SNI. There was a sex-dependent effect of SNI on PAG-OL, where OL were only reduced in females. SNI did not affect OPC in any of the studied brain regions, but female PAG and BLA appeared to have fewer OPC than males independent of SNI. ConclusionLong-term nerve injury differentially affects OL in a brain region- and sex-dependent manner. This effect is observable six weeks after injury, suggesting a long-lasting impact of chronic pain on oligodendroglial cells. OPC, on the other hand, are remarkably stable. This finding aligns with previous literature showing OPC maintain homeostasis, even in pathological conditions. SignificanceOligodendrocytes ensheathe axons to increase conduction speed, stabilize neuronal connections, and fine-tune neuron-to-neuron communication. Furthermore, pharmacological stimulation of myelination improves pain-induced cognitive deficits in mice, suggesting therapeutic potential in targeting oligodendrocytes in pain. A better understanding of how pain impacts oligodendroglia is thus crucial to better understand the pathophysiology of pain and identify new therapeutic targets.

neuroscience↗

A General Fluorescence-Based Method for Quantifying and Mapping Biomolecular Polarity In Vitro and In Cells

Spatial discretization of biomolecules in the complex cellular environment is crucial for biomolecular form and function. The ability to better understand the driving force of spatial discretization of biomolecules in the complex cellular matrix remains a challenging task. We report on the robust polarity sensitive solvatochromic probe, FLAM, in conjunction with spectral phasor analysis as a general method for studying environmental polarity in biological systems. We find that phase separated proteins of SFPQ have distinct polarity depending on the type of phase separation occurring, suggesting that polarity plays a role in the formation of phase separated condensates. When using FLAM in cells, distinct subcellular environmental polarity distribution but similar trend of changes is observed for cells under similar type of stressors. Taken together, our method puts forth an exciting development in the tool set for the study of phase separation.

biochemistry↗

Decoding Complex Sounds Using Broadband Population Recordings from Secondary Auditory Cortex of Macaques

Direct electronic communication with sensory areas of the neocortex is a challenging ambition for brain-computer interfaces. Here, we report the first successful neural decoding of English words with high intelligibility from intracortical spike-based neural population activity recorded from the secondary auditory cortex of macaques. We acquired 96-channel full-broadband population recordings using intracortical microelectrode arrays in the rostral and caudal parabelt regions of the superior temporal gyrus (STG). We leveraged a new neural processing toolkit to investigate the choice of decoding algorithm, neural preprocessing, audio representation, channel count, and array location on neural decoding performance. The results illuminated a view of the auditory cortex as a spatially distributed network and a general purpose processor of complex sounds. The presented spike-based machine learning neural decoding approach may further be useful in informing future encoding strategies to deliver direct auditory percepts to the brain as specific patterns of microstimulation.

neuroscience↗