Biology subjects

Ribe, E.

Publications and source records attributed to Ribe, E..

4 recordsLinked to original sources

bioRxiv2025

Synaptotoxic forms of amyloid-b and a-synuclein act through a common pathway.

It has been suggested that -synuclein (Syn), a major player in Parkinsons disease (PD), plays a role in Alzheimers disease (AD). Several reports have also concluded that Syn and amyloid-{beta} (A{beta}) are mechanistically linked, although how is unclear. Synapse loss is an early feature in both PD and AD and held to be the driver of both diseases. We have previously uncovered a signalling pathway required for A{beta}-driven dendritic spine loss - a non-canonical branch of Wnt signalling known as the Wnt/Planar Cell Polarity (Wnt/PCP) pathway. We asked if a synaptotoxic form of Syn known to impact dendritic spines, the A53T autosomal dominant PD mutant form of Syn (A53T-Syn), might act on synapses through the same pathway. Here, by blocking all Wnt activity with the porcupine inhibitor IWP2, we show that A53T-Syn-driven spine loss is Wnt-dependent. By silencing Daam1, which is unique to Wnt/PCP, we show that A53T-Syn spine loss is Daam1-dependent. Finally, using the pan-ROCK inhibitor fasudil indicates the mechanism also involves ROCK1/2, which Daam1 signals to via RhoA to modulate actin cytoskeletal dynamics within dendritic spines. Together, these observations indicate that A53T-Syn-driven spine loss involves the Wnt/PCP pathway, the same pathway that mediates A{beta} synaptotoxicity. This indicates that A{beta} and Syn are mechanistically connected and that a common pathway is responsible for synapse loss in AD and PD. It also begins to explain why this group of neurodegenerative diseases have many features in common and suggests that drugs which target Wnt/PCP could be of benefit for both AD and PD.

neuroscience↗

bioRxiv2023

Deep learning-based cell profiling based on neuronal morphology

Treatment of neurons with {beta}-amyloid peptide (A{beta}1-42) has been widely used as a model to interrogate the cellular and molecular mechanisms underlying Alzheimers disease, and as an assay system to identify drugs that reverse or block disease phenotype. Prior studies have largely relied on high content imaging (HCI) to extract cellular features such as neurite length or branching, but these have not offered a robust/comprehensive means of relating readout to A{beta}1-42 concentrations. Here, we use a deep learning-based cell profiling technique to directly measure the impact of A{beta}1-42 on primary murine cortical neurons. The deep learning model achieved approximately 80% accuracy, compared to 54% for the cell phenotypic feature-based approach. The deep learning model could distinguish subtle neuronal morphological changes induced by a range of A{beta}1-42 concentration. When tested on a separate dataset, the accuracy remained comparable and dropped by only 2%. Our study demonstrates that deep learning-based cell profiling is superior to HCI-based feature extraction on neuronal morphology and it provides an alternative to a dose/response curve, where the modality of the response does not have to be pre-determined. Moreover, this approach could form the basis of a screening tool that can be applied to any cellular model where appropriate phenotypic markers based on genotypes and/or pathological insults are available.

bioinformatics↗

bioRxiv2022

Neurodegenerative disease associated pathways in brain of the triple transgenic Alzheimer's model are reversed in vivo following two weeks peripheral administration of fasudil

The pan ROCK inhibitor fasudil acts as a vasodilator and has been used as a medication post cerebral stroke for the past 27 years in Japan and China. More recently, on the basis of the involvement of ROCK inhibition on synaptic function, neuronal survival and processes associated with neuroinflammation, it has been suggested that the drug may be repurposed for neurodegenerative diseases. Indeed, fasudil has demonstrated preclinical efficacy in many neurodegenerative disease models. To facilitate an understanding of the wider biological processes at play due to ROCK inhibition in the context of neurodegeneration we performed a global gene expression analysis on the brains of Alzheimers disease model mice treated with fasudil via peripheral i.p injection. Our results show that fasudil tends to drive gene expression in a reverse sense to that seen in postmortem neurodegenerative disease brains. The results are most striking in terms of pathway enrichment analysis where pathways regulated in Alzheimers disease and by fasudil treatment are overwhelmingly regulated in opposite directions. Thus, our results bolster the repurposing potential of fasudil by demonstrating an anti-neurodegenerative phenotype in a disease context and highlight the potential of in vivo transcriptional profiling of drug activity.

neuroscience↗

bioRxiv2017

Genetic and real-world clinical data, combined with empirical validation, nominate JAK-STAT signalling as a target for Alzheimer’s Disease therapeutic development

As Genome Wide Association Studies (GWAS) have grown in size, the number of genetic variants that have been nominated for an increasing number of diseases has correspondingly increased. Despite this increase in the number of associated SNPs per disease, their biological interpretation has in many cases remained elusive. To address this, we have combined GWAS results with an orthogonal source of evidence, namely real-world, routinely collected clinical data from more than 6 million patients in order to drive target nomination. First we show that when examined at a pathway level, analysis of all GWAS studies groups Alzheimers disease (AD) in a cluster with disorders of immunity and inflammation. Using clinical data we show that the degree of comorbidity of these diseases with AD correlates with the strength of their genetic association with molecular participants in the JAK-STAT pathway. Using four independent open-science datasets we then find evidence for altered regulation of JAK-STAT pathway genes in AD. Finally, we use both in vitro and in vivo rodent models to demonstrate that A{beta} induces gene expression of key drivers of this pathway, providing experimental evidence validating these data-driven observations. These results therefore nominate JAK-STAT anomalies as a prominent aetiopathological event in AD and hence potential target for therapeutic development, and moreover demonstrate a de-novo multi-modal approach to derive information from rapidly increasing genomic datasets.\n\nOne Sentence SummaryCombining evidence from genome wide association studies, real-world clinical and cohort molecular data together with experimental studies in rodent model systems nominates JAK-STAT signaling as an aetiopathological event in Alzheimers disease

bioinformatics↗