Biology subjects

Morrison, H.

Publications and source records attributed to Morrison, H..

10 recordsLinked to original sources

bioRxiv2026

Multi-Lab Testing of Early Preclinical Discoveries Identifies Promising Treatments

A fundamental challenge in drug development is the frequent failure of early laboratory research to translate into clinical benefit. One promising solution is to confirm findings from exploratory single-laboratory studies across multiple laboratories before clinical testing. We investigated this approach following the conduct of preclinical multi-laboratory studies across different fields of medicine. For this, we evaluated effect sizes, experimental rigor, and a set of criteria to identify determinants of confirmation success. When tested under increased rigor, only a fraction of multi-laboratory studies confirmed the initial results. The underlying effect size reduction was associated with outcome-relevant experimental differences between exploratory and confirmatory stages. In summary, multi-laboratory studies proved highly informative and served as an effective filter for promising treatments.

scientific communication and education↗

bioRxiv2026

Sex-Dependent Proteomic Remodelling During ex vivo Degeneration of Young and Aged Murine Peripheral Nerves

IntroductionPeripheral nerve ageing leads to profound proteomic remodelling, with shifts in metabolic and inflammatory signalling pathways resembling changes that occur during nerve degeneration and regeneration following injury. Moreover, aged nerves exhibit impaired degeneration and regeneration, contributing to age-related peripheral neuropathies that show sex-specific differences in prevalence. However, it remains unclear whether these alterations arise from intrinsic nerve changes or an altered systemic environment. Therefore, we investigated the impact of sex on age-related proteome changes and nerve-intrinsic proteomic responses in young and aged male and female nerves using an ex vivo degeneration model. MethodsMass spectrometry-based proteomics were performed on young and old nerves from male and female animals, as well as on contralateral nerves after seven days of ex vivo nerve degeneration. A comparative bioinformatic analysis was then used to identify changes during ageing and ex vivo nerve degeneration that were independent of sex, as well as changes that were sex-specific. ResultsEx vivo nerve degeneration induced extensive proteome remodelling in mouse sciatic nerves that was largely independent of age and sex. Principal component and clustering analyses clearly separated intact from degenerated nerves, while revealing only subtle age- and sex-related effects, with more pronounced ageing-associated changes in males. Approximately 20% of age-regulated proteins and 7-10% of degeneration-regulated proteins exhibited sex-specific expression patterns. Degeneration was characterised by increased abundance of lysosomal and repair-associated proteins alongside reduced myelin and axonal proteins, consistent with active tissue remodelling. In aged nerves, impaired protein clearance and partial pre-activation of degeneration-associated pathways suggested altered injury responses. Comparative analyses demonstrated positive correlations of protein abundance changes between ex vivo and in vivo degeneration datasets, although the temporal dynamics were altered in aged nerves. Pathway enrichment analyses identified coordinated regulation of metabolic, RNA-processing and vesicular transport pathways, while ageing was associated with enhanced immune signalling and reduced lipid metabolism. Sex-specific analyses revealed stronger inflammatory signatures in males, whereas females exhibited enrichment of metabolic pathways, including folate biosynthesis. ConclusionThese findings reveal distinct sex-specific molecular features of peripheral nerve ageing, characterised by enhanced inflammatory signalling in males and metabolic adaptations that may confer resilience in females. Our datasets provide a comprehensive molecular resource of sex-dependent changes in peripheral nerve ageing and nerve-intrinsic injury responses, offering a foundation for identifying therapeutic strategies to promote healthy peripheral nerve ageing. Plain English summaryAge-related peripheral neuropathies are common disorders that can cause pain, numbness, weakness and reduced mobility, affecting millions of people worldwide. They become more common from around the age of 50 and affect men and women differently. These conditions are thought to result from age-related changes in the structure and function of peripheral nerves, which reduce their ability to repair themselves after injury. In this study, we used advanced protein analysis (proteomics) to investigate how ageing affects peripheral nerves in male and female mice. We also used an ex vivo model, in which nerves are studied outside the body, to examine how age and sex influence the molecular changes that occur during nerve degeneration. We found that degeneration caused widespread changes in the proteins present in the sciatic nerve in both young and old mice. Most of these changes were similar in males and females, but some important differences emerged. Male nerves showed stronger signs of inflammation, whereas female nerves showed increased activity of metabolic pathways, including those involved in folate metabolism. Ageing nerves also appeared less able to remove damaged material and showed signs of activating degeneration-related processes even before injury. Overall, the ex vivo model reproduced many of the molecular changes seen after nerve injury in living animals, although it did not fully capture the inflammatory response, suggesting that signals from the rest of the body, including factors carried in the blood, also contribute to nerve degeneration. HighlightsO_LIEx vivo nerve degeneration caused major protein changes in young and old mouse sciatic nerves. C_LIO_LIMost degeneration-related protein changes were shared between males and females. C_LIO_LIAgeing altered the nerve proteome, with stronger ageing-related shifts in males. C_LIO_LIMale nerves showed stronger inflammatory and immune-related signatures. C_LIO_LIFemale nerves showed enrichment of metabolic pathways, including folate biosynthesis, and ex vivo degeneration did not fully reproduce the inflammatory response seen after injury in vivo. C_LI

neuroscience↗

bioRxiv2026

A Multicenter Confirmatory Randomized-Controlled Study of rhNRGβ1 Protein Replacement Therapy in a Murine Model of NF2-related Schwannomatosis

BackgroundPrevious exploratory studies identified recombinant human Neuregulin-1 {beta} (rhNRG{beta}1) as a promising therapeutic strategy for inhibiting the growth of Nf2-deficient schwannomas by promoting cellular differentiation. Because robust confirmation across independent laboratories is essential for advancing promising preclinical findings toward clinical translation, we conducted a multicenter, randomized, controlled confirmatory study under stringent preclinical standards. MethodsIn a pre-registered trial (DOI: 10.17590/asr.0000304), 216 mice (Nf2-flox;P0-Cre;Nefh- Cre) were randomized at three independent research sites. Following a standardized sciatic nerve crush, mice received systemic rhNRG{beta}1 (10 {micro}g/kg) or vehicle for 13 weeks. Rigorous quality measures included double-blinding, standardized surgery, centralized data management, and an automated Fiji macro for objective nerve thickness quantification (Primary Outcome). Secondary molecular outcomes included Western blot and in-depth, quantitative proteomics and phosphoproteomics. All methods were SOP-based for reproducible and comparable results across the three study centers ResultsThe primary confirmatory analysis revealed no reduction in nerve thickness in the rhNRG{beta}1 group (pbest case imputation = 0.076 and pworst case imputation = 0.533). Secondary analyses via quantitative Western blotting and DIA proteomics demonstrated that core biochemical markers of Schwann cell differentiation (MBP, ERBB2) remained unchanged across all centers. Based on the absence of macroscopic or primary biochemical effects, further histological analysis was omitted to avoid scientific redundancy. High-depth profiling of a predefined 60-protein functional marker panel confirmed a remarkably stable tumor proteome across all replication sites and both sexes, with no evidence of coordinated changes in key downstream oncogenic signaling pathways (Hippo/YAP, mTORC1, and RTK-Ras-MAPK) or metabolic signaling cascades. These findings indicate an absence of measurable target engagement under our tested dosing regimen, potentially reflecting pharmacokinetic or tissue-delivery limitations rather than an invalidation of the underlying biological pathway. ConclusionDespite high statistical power and rigorous methodology, this study could not confirm rhNRG{beta}1 as a robust therapeutic candidate for schwannoma growth arrest or shrinkage. These findings suggest that previously reported therapeutic effects were either highly context- dependent or could not be reproduced under adequately powered, rigorously controlled experimental conditions. As underpowered preclinical studies are more susceptible to random biological variation, our results highlight the importance of sufficient sample sizes alongside robust experimental design. Our study underscores the value of trial-like methodological standards in preclinical therapeutic evaluation to identify ineffective interventions (dead ends) early and strengthen translational decision-making. Although we could not confirm the previously reported efficacy of rhNRG{beta}1, the multicenter framework established here provides a methodological benchmark for robust preclinical testing in translational oncology, with the potential to improve reproducibility and the success of therapies progressing to early-phase clinical trials. From a translational perspective, these findings provide a robust foundation for optimizing future rhNRG{beta}1-based therapeutic approaches through improved dosing, delivery routes, and treatment schedules.

cancer biology↗

bioRxiv2026

Convergent molecular signatures of ageing and injury in the peripheral nervous system

Peripheral nervous system (PNS) ageing is marked by structural and functional decline, yet it remains unclear whether ageing constitutes a distinct biological programme or reflects a chronic injury-like state. To address this, we performed an unbiased, comparative molecular analysis of PNS ageing, neuroprotective dietary restriction (DR), and nerve injury. We conducted transcriptomic and proteomic profiling of peripheral nerves from young, old and geriatric mice fed ad libitum or subjected to long-term DR, and proteomics of nerves collected at multiple time points following injury. Age-associated molecular changes followed both linear and non-linear trajectories, and DR partially attenuated these ageing-related alterations. Notably, ageing-and injury-induced proteomic signatures showed considerable similarities, supporting the concept that an aged nerve resembles an injured nerve. Together, our study provides the most comprehensive molecular resource of PNS changes during ageing, DR, and injury, enabling the definition of key molecular signatures underlying PNS physiology. All datasets are integrated into the "PNS-omics Viewer", a Shiny web application designed to facilitate data mining of the herein presented datasets (tba).

neuroscience↗

bioRxiv2023

Proteomic analysis of peripheral nerve myelin during murine aging

Aging of the peripheral nervous system (PNS) is associated with structural and functional changes that lead to a reduction in regenerative capacity and the development of age-related peripheral neuropathy. Myelin is central to maintaining physiological peripheral nerve function and differences in myelin maintenance, degradation, formation and clearance have been suggested to contribute to age-related PNS changes. Recent proteomic studies have elucidated the complex composition of the total myelin proteome in health and its changes in neuropathy models. However, changes in the myelin proteome of peripheral nerves during aging have not been investigated. Here we show that the proteomes of myelin fractions isolated from young and old nerves show only subtle changes. In particular, we found that the three most abundant peripheral myelin proteins (MPZ, MBP and PRX) do not change in old myelin fractions. We also show a tendency for high-abundance myelin proteins other than these three to be downregulated, with only a small number of ribosome-related proteins significantly downregulated and extracellular matrix proteins such as collagens upregulated. In addition, we illustrate that the peripheral nerve myelin proteome reported in this study is suitable for assessing myelin degradation and renewal during peripheral nerve degeneration and regeneration. Our results suggest that the peripheral nerve myelin proteome is relatively stable and undergoes only subtle changes in composition during mouse aging. We proffer the resultant dataset as a resource and starting point for future studies aimed at investigating peripheral nerve myelin during aging. Said datasets are available in the PRIDE archive under the identifier PXD040719 (aging myelin proteome) and PXD041026 (sciatic nerve injury proteome).

neuroscience↗

bioRxiv2023

Impact of inflammatory preconditioning on murine microglial proteome response induced by focal ischemic brain injury

Preconditioning with LPS induces neuroprotection against subsequent cerebral ischemic injury, mainly involving innate immune pathways. Microglia are CNS-resident immune cells that respond early to danger signals through memory-like differential reprogramming. However, the cell-specific molecular mechanisms underlying preconditioning are not fully understood. To elucidate the distinct molecular mechanisms of preconditioning on microglia, we compared these cell-specific proteomic profiles in response to LPS preconditioning and without preconditioning and subsequent transient focal brain ischemia and reperfusion, - using an established mouse model of transient focal brain ischemia and reperfusion. A proteomic workflow, based on isolated microglia obtained from mouse brains by cell sorting and coupled to mass spectrometry for identification and quantification, was applied. Our data confirm that LPS preconditioning induces marked neuroprotection, as indicated by a significant reduction in brain infarct volume. The established brain cell separation method was suitable for obtaining an enriched microglial cell fraction for valid proteomic analysis. The results show a significant impact of LPS preconditioning on microglial proteome patterns by type I interferons, presumably driven by the interferon cluster regulator proteins Stat1/2.

neuroscience↗

bioRxiv2021

High molecular weight DNA extraction strategies for long-read sequencing of complex metagenomes

By offering extremely long contiguous characterization of individual DNA molecules, rapidly emerging long-read sequencing strategies offer comprehensive insights into the organization of genetic information in genomes and metagenomes. However, successful long-read sequencing experiments demand high concentrations of highly purified DNA of high molecular weight (HMW), which limits the utility of established DNA extraction kits designed for short-read sequencing. Challenges associated with input DNA quality intensify further when working with complex environmental samples of low microbial biomass, which requires new protocols that are tailored to study metagenomes with long-read sequencing. Here, we use human tongue scrapings to benchmark six HMW DNA extraction strategies that are based on commercially available kits, phenol-chloroform (PC) extraction, and agarose encasement followed by agarase digestion. A typical end goal of HMW DNA extractions is to obtain the longest possible reads during sequencing, which is often achieved by PC extractions as demonstrated in sequencing of cultured cells. Yet our analyses that consider overall read-size distribution, assembly performance, and the number of circularized elements found in sequencing results suggest that non-PC methods may be more appropriate for long-read sequencing of metagenomes.

microbiology↗

bioRxiv2020

A Pathoconnectome of Early Neurodegeneration

Connectomics has demonstrated that synaptic networks and their topologies are precise and directly correlate with physiology and behavior. The next extension of connectomics is pathoconnectomics: to map neural network synaptology and circuit topologies corrupted by neurological disease in order to identify robust targets for therapeutics. In this report, we characterize the first pathoconnectome, in this case, generated from a retina with photoreceptor degeneration. We observe aberrant connectivity in the rod-network pathway and novel synaptic connections deriving from neurite sprouting. These observations reveal principles of neuron responses to the loss of network components and can be extended to other neurodegenerative diseases.

neuroscience↗

bioRxiv2019

A Ponceau Staining based Dot-Blot Assay for reliable and cost-effective Protein Quantification

Reliable quantification of protein extracts from tissues can be a challenge e.g. due to interference of the high fat content in tissues of the nervous system. Further problems like under- or overerstimation of protein concentrations in protein quantification kits like the bicinchoninic acid (BCA) assay can occur. In addition, common lysis buffers such as RIPA buffer are known to be unable to solubilize a large amount of proteins (~10-30%) leading to unsatisfactory and unreliable experimental results with techniques such as immunoblotting. In this work, we have developed a Ponceau S staining based protein quantification assay. This assay is compatible with tissues or cells directly lysed in 2x SDS gel loading buffer, containing bromophenolblue, leading to more complete protein extraction. Protein concentrations of several samples can be determined in a fast and cost-effective manner and subsequent experiments (e.g. Western blot) can be performed without loss of proteins. The presented protein quantification method is highly reliable, fast and economical. Using this method, it is possible to save between 2300 to 3200{euro} per 1000 lysates as compared to the costs of a commercial BCA kit.

biochemistry↗

bioRxiv2018

ITPase Deficiency Causes Martsolf Syndrome With a Lethal Infantile Dilated Cardiomyopathy

Martsolf syndrome is characterized by congenital cataracts, postnatal microcephaly, developmental delay, hypotonia, short stature and biallelic hypomorphic mutations in either RAB3GAP1 or RAB3GAP2. Through genetic analysis of 85 unrelated \"mutation negative\" probands referred with Martsolf syndrome we identified two individuals with different homozygous null mutations in ITPA, the gene encoding inosine triphosphate pyrophosphatase (ITPase). The probands reported here each presented with a lethal and highly distinctive disorder; Martsolf syndrome with infantile-onset dilated cardiomyopathy. Severe ITPase-deficiency has been previously reported with infantile epileptic encephalopathy (MIM 616647). ITPase acts to prevent incorporation of inosine bases (rl/dl) into RNA and DNA. In Itpa-null cells, dI was undetectable in genomic DNA. dI could be identified at a low level in mtDNA but this was not associated with detectable mitochondrial genome instability, mtDNA depletion or biochemical dysfunction of the mitochondria. rI accumulation was detectable in lymphoblastoid RNA from an affected individual. In Itpa-null mouse embryos rI was detectable in the brain and kidney with the highest level seen in the embryonic heart (rI at 1 in 385 bases). Transcriptome and proteome analysis in mutant cells revealed no major differences with controls. The rate of transcription and the total amount of cellular RNA also appeared normal. rI accumulation in RNA - and by implication rI production - correlates with the severity of organ dysfunction in ITPase deficiency but the basis of the cellulopathy remains cryptic. While we cannot exclude cumulative minor effects, there are no major anomalies in the production, processing, stability and/or translation of mRNA.\n\nAuthor SummaryNucleotide triphosphate bases containing inosine, ITP and dITP, are continually produced within the cell as a consequence of various essential biosynthetic reactions. The enzyme inosine triphosphate pyrophosphatase (ITPase) scavenges ITP and dITP to prevent their incorporation into RNA and DNA. Here we describe two unrelated families with complete loss of ITPase function as a consequence of disruptive mutations affecting both alleles of ITPA, the gene that encodes this protein. Both of the families have a very distinctive and severe combination of clinical problems, most notably a failure of heart muscle that was lethal in infancy or early childhood. They also have features of another rare genetic disorder affecting the brain and the eyes called Martsolf syndrome. We could not detect any evidence of dITP accumulation in genomic DNA from the affected individuals. A low but detectable level of inosine was present in the mitochondrial DNA but this did not have any obvious detrimental effect. The inosine accumulation in RNA was detectable in the patient cells. We made both cellular and animal models that were completely deficient in ITPase. Using these reagents we could show that the highest level of inosine accumulation into RNA was seen in the embryonic mouse heart. In this tissue more than 1 in 400 bases in all RNA in the cell was inosine. In normal tissues inosine is almost undetectable using very sensitive assays. The inosine accumulation did not seem to be having a global effect on the balance of RNA molecules or proteins.

genetics↗