Biology subjects

Spencer, K.

Publications and source records attributed to Spencer, K..

3 recordsLinked to original sources

bioRxiv2022

RaMP-DB 2.0: a renovated knowledgebase for deriving biological and chemical insight from genes, proteins, and metabolites

RaMP-DB 2.0 is a web interface, API, relational database and R package designed for straightforward and comprehensive functional interpretation of metabolomic and multi-omic data. Since its first release in 2018, RaMP-DB 2.0 has been upgraded with an expanded breadth and depth of functional and chemical annotation. Content from the source databases (Reactome, HMDB, and Wikipathways) has been updated, and new data types related to metabolite annotations have been incorporated. Structural information incorporated in RaMP-DB 2.0 includes SMILES strings, InChIs, InChIKeys. Chemical classes have been sourced from ClassyFire and LIPID MAPS. Accordingly, the RaMP-DB 2.0 R package has been updated and supports queries on pathways, common reactions, ontologies, chemical classes, and chemical structures. Additionally, RaMP-DB 2.0 now supports enrichment analyses on pathways and chemical classes. Our process for integrating annotations across resources has also been upgraded to lessen the burden of harmonization, thereby supporting more frequent updates. The code used to build all components of RaMP-DB 2.0 is freely available on GitHub at https://github.com/ncats/ramp-db and https://github.com/ncats/RaMP-Backend.

bioinformatics↗

bioRxiv2021

Leukocyte proliferation mediates disease pathogenesis in the Ndufs4(KO) mouse model of Leigh syndrome

Symmetric, progressive, necrotizing lesions in the brainstem are a defining feature of Leigh syndrome (LS). A mechanistic understanding of the pathogenesis of these lesions has been elusive. Here, we report that leukocyte proliferation is causally involved in the pathogenesis of Leigh syndrome. Directly depleting leukocytes with a colony-stimulating factor 1 receptor (CSF1R) inhibitor dramatically attenuates disease, including complete prevention of CNS lesion formation and substantial extension of survival. Leukocyte depletion rescues a range of symptoms including hyperlactemia, seizures, respiratory function, and neurologic symptoms. These data provide a mechanistic explanation for the beneficial effects of mTOR inhibition. More importantly, these findings dramatically alter our understanding of the pathogenesis of LS, demonstrating that immune involvement directly drives disease. These findings have significant implication for the mechanisms of disease resulting from mitochondrial dysfunction, and may lead to novel therapeutic strategies. One-Sentence SummaryPharmacologic targeting of leukocytes prevents CNS lesions, neurological disease, and metabolic dysfunction in the Ndufs4(KO) mouse model of Leigh syndrome.

pathology↗

bioRxiv2021

Light-induced asymmetries in the embryonic retina are mediated by the vascular system and extracellular matrix

Left-right asymmetries in the nervous system (lateralisation) influence a broad range of behaviours, from social responses to navigation and language. The role and pathways of endogenous and environmental mechanisms in the ontogeny of lateralisation remains to be established. The domestic chick is a model of both endogenous and experience-induced lateralisation driven by light exposure. Following the endogenous rightward rotation of the embryo, the asymmetrical position in the egg results in a greater exposure of the right eye to environmental light. To identify the genetic pathways activated by asymmetric light stimulation, and their time course, we exposed embryos to different light regimes: darkness, 6 hours of light and 24 hours of light. We used RNA-seq to compare gene expression in the right and left retinas and telencephalon. As expected, no differential expression between left and right was present in darkness. We detected differential gene expression in right vs left retina after 6 hours of light exposure. This difference disappeared before 24 hours of light exposure, suggesting that light-induced activation is a self-terminating phenomenon. This transient effect of light exposure was associated with a downregulation of the sensitive-period mediator gene DIO2 (iodothyronine deiodinase 2) in the right retina. No differences between genes expressed in the right vs. left telencephalon were detected. Gene networks associated with lateralisation were connected to vascularisation, cell motility, and the extracellular matrix. Interestingly, we know that the extracellular matrix- including the differentially expressed PDGFRB (platelet-derived growth factor receptor {beta}) gene - is involved in both sensitive periods and in the endogenous chiral mechanism of primary cilia, that drives lateralisation. Our data show a similarity between endogenous and experience-driven lateralisation, identifying functional gene networks that affect lateralisation in a specific time window.

neuroscience↗