Biology subjects

Molloy, C.

Publications and source records attributed to Molloy, C..

4 recordsLinked to original sources

bioRxiv2021

Activation of M1 muscarinic receptors reduce pathology and slow progression of neurodegenerative disease.

The most prevalent types of dementias, including Alzheimers disease, are those that are propagated via the spread of "prion-like" misfolded proteins. Despite considerable effort no treatments are available to slow or stop the progression of these dementias. Here we investigate the possibility that activation of the M1-muscarinic receptor (M1-receptor), which is highly expressed in the brain and that shows pro-cognitive properties, might present a novel disease modifying target. We demonstrate that the progression of murine prion disease, which we show here displays many of the pathological, behavioural and biochemical hallmarks of human neurodegenerative disease, is slowed and normal behaviour maintained by the activation of the M1-receptor with a highly tolerated positive allosteric modulator (VU846). This correlates with a reduction in both neuroinflammation and indicators of mitochondrial dysregulation, as well as a normalisation in the expression of markers associated with neurodegeneration and Alzheimers disease. Furthermore, VU846 preserves expression of synaptic proteins and post-synaptic signalling components that are altered in disease. We conclude that allosteric regulation of M1-receptors has the potential to reduce the severity of neurodegenerative diseases caused by the prion-like propagation of misfolded protein in a manner that extends life span and maintains normal behaviour.

neuroscience↗

bioRxiv2021

Subtly altered topological asymmetry of brain structural covariance networks in autism spectrum disorder across 43 datasets from the ENIGMA consortium

Small average differences in the left-right asymmetry of cerebral cortical thickness have been reported in individuals with autism spectrum disorder (ASD) compared to typically developing controls. Although these alterations affect multiple and widespread cortical regional asymmetries, the extent to which specific structural networks might be affected remains unknown. Inter-regional morphological covariance analysis can capture network connectivity relations between different cortical areas at the macroscale level. Here, we used cortical thickness data from 1,455 individuals with ASD and 1,560 controls, across 43 independent datasets of the ENIGMA consortiums ASD Working Group, to assess hemispheric asymmetries of intra-individual structural covariance networks, using graph theory-based topological metrics. Compared with typical features of small-world architecture in controls, the ASD sample showed significantly altered asymmetry of hemispheric networks involving the fusiform, rostral middle frontal, and medial orbitofrontal cortex, driven by shifts toward higher randomization of the corresponding right-hemispheric networks in ASD. A network involving the superior frontal cortex showed decreased right-hemisphere randomization. Based on comparisons with meta-analyzed functional neuroimaging data, the altered connectivity asymmetry particularly affected networks that subserve working memory, executive functions, language, reading, and sensorimotor processes. Taken together, these findings provide new insights into how altered brain left-right asymmetry in ASD affects specific structural and functional brain networks. Altered asymmetrical brain development in ASD may be partly propagated among spatially distant regions through structural connectivity.

neuroscience↗

bioRxiv2021

Phosphorylation of the M1 muscarinic acetylcholine receptor mediates protection in neurodegenerative disease

There are currently no treatments that can slow the progression of neurodegenerative diseases such as Alzheimers disease (AD). There is, however, a growing body of evidence that activation of the M1 muscarinic acetylcholine receptor (M1-receptor) can not only restore memory loss in AD patients, but in preclinical animal models can also slow neurodegenerative disease progression. The generation of an effective medicine targeting the M1-receptor has however been severely hampered by associated cholinergic adverse responses. By using genetically engineered mouse models that express a G protein-biased M1-receptor, we recently established that M1-receptor mediated adverse responses can be minimised by ensuring activating ligands maintain receptor phosphorylation/arrestin-dependent signalling. Here, we use these same genetic models in concert with murine prion disease, a terminal neurodegenerative disease showing key hallmarks of AD, to establish that phosphorylation/arrestin-dependent signalling delivers neuroprotection that both extends normal animal behaviour and prolongs the life span of prion diseased mice. Our data point to an important neuroprotective property inherent to the M1-receptor and indicate that next generation M1-receptor ligands designed to drive receptor phosphorylation/arrestin-dependent signalling would potentially show low adverse responses whilst delivering neuroprotection that will slow disease progression.

pharmacology and toxicology↗

bioRxiv2021

High-content screening of coronavirus genes for innate immune suppression revealsenhanced potency of SARS-CoV-2 proteins

Suppression of the host intracellular innate immune system is an essential aspect of viral replication. Here, we developed a suite of medium-throughput high-content cell-based assays to reveal the effect of individual coronavirus proteins on antiviral innate immune pathways. Using these assays, we screened the 196 protein products of seven coronaviruses (SARS-CoV-2, SARS-CoV-1, 229E, NL63, OC43, HKU1 and MERS). This includes a previously unidentified gene in SARS-CoV-2 encoded within the Spike gene. We observe immune-suppressing activity in both known host-suppressing genes (e.g., NSP1, Orf6, NSP3, and NSP5) as well as other coronavirus genes, including the newly identified SARS-CoV-2 protein. Moreover, the genes encoded by SARS-CoV-2 are generally more potent immune suppressors than their homologues from the other coronaviruses. This suite of pathway-based and mechanism-agnostic assays could serve as the basis for rapid in vitro prediction of the pathogenicity of novel viruses based on provision of sequence information alone.

systems biology↗