Biology subjects

Wood, M. J.

Publications and source records attributed to Wood, M. J..

15 recordsLinked to original sources

bioRxiv2025

Dysregulated MEG3 in Myotonic Dystrophy 1: nuclear retention, pathological role, and therapeutic correction by antisense conjugates.

MEG3, a long non-coding RNA (lncRNA), has been shown to play a critical role in regulating apoptosis. Its downregulation inhibits apoptosis in cancer cells, whereas its upregulation has been associated with cell death in both cardiovascular disease and, more recently, Alzheimers Disease. Here we show that MEG3 is upregulated in Myotonic Dystrophy 1 (DM1). Specifically, we show MEG3 upregulation by several-fold in DM1 human muscle cells and in two DM1 mouse models, HSA-LR and LC15. In human DM1 muscle cells we observe nuclear retention of MEG3 and an increase in its transcript diversity. Furthermore, we observe a general trend of nuclear retention in DM1 affecting lncRNAs and microRNAs (miRNAs), in contrast to mRNAs, when compared to healthy cells. This altered nuclear retention may contribute to the pathological effects of non-coding RNA dysregulation in DM1. Importantly, we demonstrate that treatment with antisense conjugates targeting the repeat expansion causing DM1, an approach currently being tested in Clinical Trials, corrects MEG3 levels in HSA-LR mice, without additional therapeutic interventions targeting MEG3.

molecular biology↗

bioRxiv2024

Exercise and disease state influence the beneficial effects of Fn14-depletion on survival and muscle pathology in the SOD1G93A amyotrophic lateral sclerosis (ALS) mouse model

BackgroundAmyotrophic lateral sclerosis (ALS) is a devastating and incurable neurodegenerative disease. Accumulating evidence strongly suggests that intrinsic muscle defects exist and contribute to disease progression, including imbalances in whole-body metabolic homeostasis. We have previously reported that tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and fibroblast growth factor inducible 14 (Fn14) are significantly upregulated in skeletal muscle of the SOD1G93A ALS mouse model. While antagonising TWEAK did not impact survival, we did observe positive effects in skeletal muscle. Given that Fn14 has been proposed as the main effector of the TWEAK/Fn14 activity and that Fn14 can act independently from TWEAK in muscle, we suggest that manipulating Fn14 instead of TWEAK in the SOD1G93A ALS mice could lead to differential and potentially improved benefits. MethodsWe thus investigated the contribution of Fn14 to disease phenotypes in the SOD1G93A ALS mice. To do so, Fn14 knockout mice (Fn14-/-) were crossed onto the SOD1G93A background to generate SOD1G93A;Fn14-/- mice. Investigations were performed on both unexercised and exercised (rotarod and/or grid test) animals (wild type (WT), Fn14-/-, SOD1G93A and SOD1G93A;Fn14-/-). ResultsHere, we firstly confirm that the TWEAK/Fn14 pathway is dysregulated in skeletal muscle of SOD1G93A mice. We then show that Fn14-depleted SOD1G93A mice display an increased lifespan and decreased muscle pathology, without an impact on motor function, and that this is dependent on exposure to exercise. Indeed, we observe that endurance (rotarod) and resistance (grid test) exercises influence the positive effects of Fn14 deletion on survival and muscle phenotypes in SOD1G93A mice, which may be further influenced by genotype and disease state. ConclusionsOur study provides further insights on the different roles of the TWEAK/Fn14 pathway in pathological skeletal muscle and how they can be influenced by age, disease and metabolic state. This is particularly relevant in the ALS field, where combinatorial therapies that include exercise regimens are currently being explored. As such, a better understanding and consideration of the interactions between treatments, muscle metabolism and exercise will be of importance in future studies.

pathology↗

bioRxiv2024

Thrombospondins 1 and 4 undergo coordinated transport to multicore cytotoxic granules to regulate SMAP biogenesis and function in CTL-mediatedcytotoxicity

Supramolecular Attack Particles (SMAPs) are particulate entities, characterized by a cytotoxic core enriched in granzymes and perforin surrounded by a glycoproteic shell, released by CTLs and NK cells. Prior proteomic analysis identified thrombospondin-1 (TSP-1) and thrombospondin-4 (TSP-4) as putative components of SMAPs. While TSP-1 has been validated as a component of the SMAP shell and shown to contribute significantly to CTL-mediated killing, the expression and function of TSP-4 in CTLs, and its interplay with TSP-1 in SMAP biogenesis and function, has not been investigated as yet. Here we demonstrate that TSP-4 and TSP-1 have a complementary expression profile during in vitro human CD8+ T cell differentiation to CTLs and sequentially localize to lytic granules (LG), with TSP-4 being required for TSP-1 association with LGs. Correlative light microscopy identified the TSP-enriched LGs as the SMAP-containing multicore granules. We show by STED microscopy a heterogeneity among TSP-enriched LGs, the most abundant population being positive for both TSP-4 and TSP-1. We also show that TSP-1 and TSP-4 are co-released in association with SMAPs at immune synapses formed on planar supported lipid bilayers, as assessed by dSTORM imaging. Finally, we provide evidence that TSP-4 is required for CTL- and SMAP-mediated cell killing. Of note, we found that chronic lymphocytic leukemia (CLL) cell supernatants, which suppress CTL mediated killing, also suppress expression of TSP-4 as well as of cytolytic effectors and impair SMAP biogenesis. These results identify TSP-4 as a key player in SMAP structure and activity and suggest that SMAPs may be a new target for immune suppression by CLL.

immunology↗

bioRxiv2024

Reduced Capsaicin-Induced Mechanical Allodynia and Neuronal Responses in the DRG in the Presence of Shp1 Overexpression

Transient Receptor Potential Vanilloid 1 (TRPV1) is a nonselective cation channel expressed by pain-sensing neurons and has been an attractive target for the development of drugs to treat pain. Recently, Src homology region 2 domain-containing phosphatase-1 (SHP-1) was shown to dephosphorylate TRPV1 in dorsal root ganglia (DRG) neurons, which was linked with alleviating different pain phenotypes. These previous studies were performed in male rodents only and did not directly investigate the role of SHP-1 in TRPV-1 mediated sensitization. Therefore, our goal was to determine the impact of Shp1 overexpression on TRPV1-mediated neuronal responses and capsaicin-induced pain behavior in mice of both sexes. Twelve-week-old male and female mice overexpressing Shp1 (Shp1-Tg) and their wild type (WT) littermates were used. Shp1 overexpression was confirmed in the DRG of Shp1-Tg mice by RNA in situ hybridization and RT-qPCR. Trpv1 and Shp1 were found to be co-expressed in DRG sensory neurons in both genotypes. Functionally, this overexpression resulted in lower magnitude intracellular calcium responses to 200 nM capsaicin stimulation in DRG cultures from Shp1-Tg mice compared to WTs. In vivo, we tested the effects of Shp1 overexpression on capsaicin-induced pain through a model of capsaicin footpad injection. While capsaicin injection evoked nocifensive behavior (paw licking) and paw swelling in both genotypes and sexes, only WT mice developed mechanical allodynia after capsaicin injection. We observed similar level of TRPV1 protein expression in the DRG of both genotypes, however, a higher amount of tyrosine phosphorylated TRPV1 was detected in WT DRG. These experiments suggest that, while SHP-1 does not mediate the acute swelling and nocifensive behavior induced by capsaicin, it does mediate a protective effect against capsaicin-induced mechanical allodynia in both sexes. The protective effect of SHP-1 might be mediated by TRPV1 dephosphorylation in capsaicin-sensitive sensory neurons of the DRG.

neuroscience↗

bioRxiv2023

A transcriptomics-based drug repositioning approach to identify drugs with similar activities for the treatment of muscle pathologies in spinal muscular atrophy (SMA) models

Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder caused by the reduction of survival of motor neuron (SMN) protein levels. Although three SMN-augmentation therapies are clinically approved that significantly slow down disease progression, they are unfortunately not cures. Thus, complementary SMN-independent therapies that can target key SMA pathologies and that can support the clinically approved SMN-dependent drugs are the forefront of therapeutic development. We have previously demonstrated that prednisolone, a synthetic glucocorticoid (GC) improved muscle health and survival in severe Smn-/-;SMN2 and intermediate Smn2B/- SMA mice. However, long-term administration of prednisolone can promote myopathy. We thus wanted to identify genes and pathways targeted by prednisolone in skeletal muscle to discover clinically approved drugs that are predicted to emulate prednisolones activities. Using an RNA-sequencing, bioinformatics and drug repositioning pipeline on skeletal muscle from symptomatic prednisolone- treated and untreated Smn-/-;SMN2 SMA and Smn+/-;SMN2 healthy mice, we identified molecular targets linked to prednisolones ameliorative effects and a list of 580 drug candidates with similar predicted activities. Two of these candidates, metformin and oxandrolone, were further investigated in SMA cellular and animal models, which highlighted that these compounds do not have the same ameliorative effects on SMA phenotypes as prednisolone; however, a number of other important drug targets remain. Overall, our work further supports the usefulness of prednisolones potential as a second-generation therapy for SMA, identifies a list of potential SMA drug treatments and highlights improvements for future transcriptomic-based drug repositioning studies in SMA.

pathology↗

bioRxiv2023

HOIL1 regulates group 3 innate lymphoid cell numbers in the colon and protects against systemic dissemination, colonic ulceration, and lethality from Citrobacter rodentium infection

HOIL1-deficient patients experience chronic intestinal inflammation and diarrhea as well as increased susceptibility to certain bacterial infections. HOIL1 is a component of the linear ubiquitin chain assembly complex (LUBAC) that regulates immune signaling pathways including NF-{kappa}B-activating pathways. We have shown previously that HOIL1 is essential for survival following Citrobacter rodentium gastrointestinal infection of mice, but the mechanism of protection by HOIL1 was not examined. C. rodentium is a murine model for human attaching and effacing (A/E) pathogens, enteropathogenic and enterohemorrhagic Escherichia coli, that cause diarrhea and food-borne illnesses, and lead to severe disease in children and immunocompromised individuals. In this study, we found that C. rodentium infection caused severe colitis and dissemination of C. rodentium to systemic organs in Hoil1-/-mice. HOIL1 was important in radiation-resistant cells and in the innate immune response to limit early replication of C. rodentium in the intestine, and to modulate induction of inflammatory cytokines. Using cell type-specific knock-out mice, we found that HOIL1 was dispensable in intestinal epithelial cells (IEC), but was required in CD11c- and lysozyme 2-expressing myeloid cells to prevent weight loss and systemic dissemination of C. rodentium. While HOIL1-deficiency did not affect populations of neutrophils or macrophages, dendritic cells and group 3 innate lymphoid cell (ILC3) numbers were reduced, resulting in a defect in IL-22 induction during C. rodentium infection. Understanding the role HOIL1 plays in limiting the pathogenesis of A/E lesion-forming bacteria will provide further insights into the innate immune response to gastrointestinal pathogens and inflammatory disorders.

immunology↗

bioRxiv2022

The matrisome of the murine and human dorsal root ganglion: a transcriptomal approach

The extracellular matrix (ECM) is a dynamic structure composed of a large number of molecules that can be divided into six different categories and are collectively called the matrisome. The ECM plays pivotal roles in physiological and pathological processes in many tissues, including the nervous system. Intriguingly, alterations in ECM molecules/pathways are often associated with painful human conditions and murine experimental pain models. Nevertheless, mechanistic insight into the interplay of normal or defective ECM and pain is largely lacking. To expand the knowledge on ECM composition and synthesis in the peripheral nervous system, we used a transcriptomal approach to investigate the expression and cellular origin of matrisome genes in murine and human dorsal root ganglia (DRG), containing the cell bodies of sensory neurons. Bulk RNA sequencing data showed that over 60% of all matrisome genes were expressed in both murine and human DRG, with proportionally more core matrisome genes (glycoproteins, collagens, and proteoglycans) expressed compared to matrisome-associated genes (ECM-affiliated genes, ECM regulators and secreted factors). Examination of the cellular origin of matrisome expression by single cell RNA sequencing on murine DRG revealed that core matrisome genes, especially collagens, were expressed by vascular leptomeningeal-like (fibroblast) cell types whereas matrisome-associated genes were mainly expressed by neuronal cell types. We analyzed cell-cell communication networks with the CellChat R package and predicted an important role for the Collagen signaling pathway in connecting vascular cell types and nociceptors in murine tissue, which we confirmed by analysis of spatial transcriptomic data from human DRG. RNAscope in situ hybridization and immunohistochemistry confirmed expression of collagens in fibroblasts surrounding nociceptors in human DRG. This study supports the idea that the DRG matrisome may contribute to neuronal signaling in both mouse and human. The identification of the cellular distribution of murine and human matrisome genes provides a framework to study the role of the ECM in peripheral nervous tissue and its effects on pain signaling. HighlightsO_LITranscriptomal analyses of mouse and human dorsal root ganglia (DRG) revealed that over 60% of matrisome genes are expressed by murine and human dorsal root ganglia (DRG), with over 85% of the genes with orthologues overlapping between both species. C_LIO_LIMatrisome-associated genes had the highest expression in both species and included conserved expression of annexins, S100 calcium binding proteins and cathepsins. C_LIO_LICollagens and collagen receptors are expressed by distinct cell types in murine and human DRG, suggesting that the collagen signaling pathway could be involved in cell-cell signaling. C_LI

neuroscience↗

bioRxiv2022

Type I PRMT inhibitor MS023 promotes SMN2 exon 7 inclusion and synergizes with nusinersen to rescue the phenotype of SMA mice

Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. The advent of approved treatments for this devastating condition has significantly changed SMA patients life expectancy and quality of life. Nevertheless, these are not without limitations, and research efforts are underway to develop new approaches to be used alone and in combination, to ensure improved and long-lasting benefits for SMA patients. Protein arginine methyltransferases (PRMT) are emerging as druggable epigenetic targets, with several small molecule PRMT inhibitors already in clinical trial stage. From a screen of highly potent and selective next generation epigenetic small molecules, we have identified MS023, a potent and selective type I PRMT inhibitor, able to promote SMN2 exon 7 inclusion and increase SMN protein levels in preclinical SMA model, by inhibiting the binding of splicing factor hnRNPA1 to SMN2 pre-mRNA. Treatment of SMA mice with MS023 results in amelioration of the disease phenotype, with strong synergistic amplification of the positive effect when delivered in combination with the SMN2-targeting antisense oligonucleotide nusinersen. Moreover, transcriptomic analysis revealed that MS023 treatment has very minimal off-target effects and that the added benefit of the combination therapy is mainly attributable to targeting neuroinflammation. Our study warrants further clinical investigation of PRMT inhibition both as a stand-alone and add-on therapy for SMA patients.

neuroscience↗

bioRxiv2022

Age-associated changes in knee osteoarthritis, pain-related behaviors, and dorsal root ganglia immunophenotyping of male and female mice

ObjectiveOsteoarthritis (OA) is a leading cause of chronic pain, yet OA pain management remains poor. Age is the strongest predictor of OA development, and mechanisms driving OA pain are unclear. While injury-induced OA models are useful, only a subset of OA is linked to traumatic injury. Here, we aimed to characterize age-associated joint damage, mechanical sensitization, and dorsal root ganglia (DRG) immune phenotypes in mice of both sexes. MethodsMale or female mice aged 6- or 20-months old were evaluated for histopathologic knee OA, pain-related behaviors, and L3-L5 dorsal root ganglia (DRG) immune characterization via flow cytometry. DRG gene expression in aged mice and humans was also examined. ResultsTwenty-month old male mice had worse cartilage degeneration than 6-month old mice. Older female knees showed increased cartilage degeneration, but to a lesser degree than males. Older mice of both sexes had worse mechanical allodynia, knee hyperalgesia, and grip strength compared to younger mice. For both sexes, DRGs from older mice showed decreased CD45+ cells, and a significant increase in F4/80+ macrophages and CD11c+ dendritic cells. Older male DRGs showed increased expression of Ccl2 and Ccl5 and older female DRGs showed increased Cxcr4 and Ccl3 compared to 6-month DRGs, among other differentially expresssed genes. Human DRG analysis from six individuals >80 years old revealed elevated CCL2 in male DRGs compared to females, whereas CCL3 was higher in female DRGs. ConclusionsHere we show that aging in male and female mice is accompanied by mild knee OA, mechanical sensitization, and changes to immune cell populations in the DRG, suggesting novel avenues for development of analgesic therapies.

cell biology↗

bioRxiv2022

Piezo2 expressing nociceptors mediate mechanical sensitization in experimental osteoarthritis

Osteoarthritis is a very common painful joint disease, for which few treatment options exist. New non-opioid targets are needed for addressing osteoarthritis pain, which is mechanical in nature and associated with daily activities such as walking and climbing stairs. Piezo2 has been implicated in development of mechanical pain, but the mechanisms by which this occurs remain poorly understood. We observed that in two different murine models of osteoarthritis (destabilization of the medial meniscus and natural aging), nociceptor-specific Piezo2 conditional knock-out mice developed osteoarthritic joint damage, but were protected from associated mechanical sensitization. Since nerve growth factor (NGF) is known to mediate nociceptor sensitization, and antibodies that neutralize NGF are effective as a treatment for osteoarthritis pain, we explored the effects of intra-articularly injected NGF on the development of mechanical joint pain. Wild-type mice developed knee swelling and mechanical pain in response to intra-articular NGF, while nociceptor-specific Piezo2 conditional knock-out mice were protected from these effects. Single cell RNA sequencing and in situ hybridization of mouse and human lumbar dorsal root ganglia (DRG) revealed that a subset of nociceptors co-express Piezo2 and Ntrk1 (the gene that encodes the NGF receptor TrkA). These results indicate that Piezo2 plays a key role in nociceptor sensitization processes in the osteoarthritic joint, and targeting Piezo2 may represent a novel therapy for osteoarthritis pain control. One Sentence SummaryNociceptor sensitization to mechanical stimuli is dependent on Piezo2 in mouse models of osteoarthritis.

physiology↗

bioRxiv2022

HOIL1 regulates group 2 innate lymphoid cell numbers and type 2 inflammation in the small intestine

Patients with mutations in HOIL1 experience a complex immune disorder including intestinal inflammation. To investigate the role of HOIL1 in regulating intestinal inflammation, we employed a mouse model of HOIL1 deficiency. The ileum of Hoil1-/- mice displayed features of type 2 inflammation including tuft cell and goblet cell hyperplasia, and elevated expression of Il13, Il5 and Il25 mRNA. Inflammation persisted in the absence of T and B cells, and bone marrow chimeric mice revealed a requirement for HOIL1 expression in radiation-resistant cells to regulate inflammation. Although disruption of IL-4 receptor alpha (IL4R) signaling on intestinal epithelial cells ameliorated tuft and goblet cell hyperplasia, expression of Il5 and Il13 mRNA remained elevated. KLRG1hi CD90lo group 2 innate lymphoid cell (ILC2) were increased independent of IL4R signaling, tuft cell hyperplasia and IL-25 induction. Antibiotic treatment dampened intestinal inflammation indicating commensal microbes as a contributing factor. We have identified a key role for HOIL1, a component of the Linear Ubiquitin Chain Assembly Complex, in regulating type 2 inflammation in the small intestine. Understanding the mechanism by which HOIL1 regulates type 2 inflammation will advance our understanding of intestinal homeostasis and inflammatory disorders and may lead to the identification of new targets for treatment.

immunology↗

bioRxiv2021

Using stationary vital rates in impact assessments may underestimate potential threat

Population viability analysis (PVA) is commonly used to assess future potential risks to threatened species. These models are typically based on mean vital rates, such as survival and fecundity, with some level of environmental stochasticity. However, the vital rates of wild populations, especially those already exhibiting declining trajectories, may be nonstationary, such that the mean or variance changes over time. In this study, we examined whether including observed temporal trends in vital rates affects the predictive accuracy of PVA, as well as the projected impact associated with a hypothetical threat. To achieve this, we ran a series of simulations using Leslie matrix PVA models that included different combinations of environmental stochasticity, temporal trends in vital rates, and threat. We apply our analysis to a long-lived colonial species of seabird, the black-legged kittiwake Rissa tridactyla, that is classified as globally Vulnerable and is potentially highly sensitive to offshore renewable energy development. We found that including observed temporal trends in vital rates was (i) crucial for the accurate reconstruction of observed population dynamics and (ii) had a dramatic effect on the projected impact from the hypothetical threat. In an era when many animal and plant populations are declining due to long-term trends in their vital rates, we identify that including this demographic structure is essential for robustly evaluating potential threats using PVA models. Omitting observed temporal trends in vital rates from impact assessments is highly likely to yield unreliable results that could misinform conservation and management decision making. This result has immediate application for conducting impact assessments on protected species and populations.

ecology↗

bioRxiv2020

Profiling of extracellular small RNAs highlights a strong bias towards non-vesicular secretion

Extracellular environment consists of a plethora of different molecules, including extracellular miRNA that can be secreted in association with extracellular vesicles (EVs) or soluble protein complexes (non-EVs). Yet, it is generally accepted that most of the biological activity is attributed to EV-associated miRNAs. The capability of EVs to transport cargoes has attracted much interest towards developing EVs as therapeutic short RNA carriers by using endogenous loading strategies for miRNA enrichment. Here, by overexpressing miRNA and shRNA sequences of interest in source cells and using size exclusion liquid chromatography (SEC) to separate the cellular secretome into EV and non-EV fractions, we saw that strikingly, <2% of all secreted overexpressed miRNA were found in association with EVs. To see whether the prominent non-EV miRNA secretion also holds true at the basal expression level of native miRNA transcripts, both fractions were further analysed by small RNA sequencing. This revealed a global correlation of EV and non-EV miRNA abundance to that of their parent cells and showed an enrichment only for miRNAs with a relatively low cellular expression level. Further quantification showed that similarly to the transient overexpression context, an outstanding 96.2-99.9% of total secreted miRNA at its basal level was secreted to the non-EV fraction. Yet, even though EVs contain only a fraction of secreted miRNAs, these molecules were found stable at 37{degrees}C in serum-containing environment, indicating that if sufficient miRNA loading to EVs is achieved, EVs can remain miRNA delivery-competent for a prolonged period of time. This study suggests that the passive endogenous EV loading strategy can be a relatively wasteful way of loading miRNA to EVs and active miRNA loading approaches are needed for developing advanced EV miRNA therapies in the future.

molecular biology↗

bioRxiv2019

Combining multi-omics and drug perturbation profiles to identify novel treatments that improve disease phenotypes in spinal muscular atrophy

Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by loss of survival motor neuron (SMN) protein. While SMN restoration therapies are beneficial, they are not a cure. We aimed to identify novel treatments to alleviate muscle pathology combining transcriptomics, proteomics and perturbational datasets. This revealed potential drug candidates for repurposing in SMA. One of the lead candidates, harmine, was further investigated in cell and animal models, improving multiple disease phenotypes, including SMN expression and lifespan. Our work highlights the potential of multiple, parallel data driven approaches for development of novel treatments for use in combination with SMN restoration therapies.

neuroscience↗

bioRxiv2018

Transcriptional and electrophysiological aberrations in an induced pluripotent stem cell-derived model of spinocerebellar ataxia type 7

Spinocerebellar ataxia type 7 (SCA7) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the ATXN7 gene. Patients with this disease suffer from a degeneration of their cerebellar Purkinje neurons and retinal photoreceptors that result in a progressive ataxia and loss of vision. As with many neurodegenerative diseases, studies of pathogenesis have been hindered by a lack of disease-relevant models. To this end, we have generated induced pluripotent stem cells (iPSCs) from a cohort of SCA7 patients in South Africa. First, we differentiated the SCA7 affected iPSCs into neurons which showed evidence of a transcriptional phenotype affecting components of STAGA (ATXN7 and KAT2A) and the heat shock protein pathway (DNAJA1 and HSP70). We then performed electrophysiology on the SCA7 iPSC-derived neurons and found that these cells show features of functional aberrations. Lastly, we were able to differentiate the SCA7 iPSCs into retinal photoreceptors that also showed similar transcriptional aberrations to the SCA7 neurons. Our findings demonstrate that iPSC-derived neurons and photoreceptors from SCA7 patients express molecular and electrophysiological differences that are indicative of impaired neuronal health. We hope that these findings will contribute towards the ongoing efforts to establish the cell-derived models of neurodegenerative diseases that are needed to develop patient-specific treatments.

neuroscience↗