Search bioRxiv⌕ Search

bioRxiv · 10.1101/2024.01.22.576608

Reanalysis of published data can help to characterize neuronal death after Spinal Cord Injury

Abstract

Spinal cord injury (SCI) is a disabling disorder of the spinal cord resulting from trauma or disease. Neuronal death is a central event in the pathophysiology of spinal cord injury. Despite its importance and the large number of research studies carried out, we only have a fragmentary vision of the process focused on the specific targets of each study. It is our opinion that the research community has accumulated enough information which may be reanalyzed with novel tools to get a much more detailed, integrated vision of neuronal death after SCI. This work embeds this vision by creating NeuroCluedo, an open data repository to store and share images as well as the results from their analysis. We have employed this repository to upload the raw and processed images of spinal cord sections from a mouse model of moderate contusive SCI (Reigada et al., 2015) and used this information to: compare manual-, threshold-, and neuronal network-based neuron identifications; and to explore neuronal death at the injury penumbra 21 days after injury and the neuroprotective effects of the anti-apoptotic drug ucf-101. The results from these analyses i) indicate that the three identification methods yield coherent estimates of the total number of neurons per section; ii) identified the neural network as the optimal method, even in spinal sections with major artifacts and marked autofluorescence associated with spinal damage; iii) characterize neuronal distribution among Rexed laminae in the mice T11; iv) reveal that neuronal death distributes through all the gray matter in the penumbrae sections closer to the injury epicenter but concentrate in the intermediate region in sections located farther away; and that v) antiapoptotic effects of UCF-101 are highest in the intermediate region of the gray substance of the caudal segments closest to the injury epicenter. All methods and results, including raw and processed images, software, macros, and scripts, together with all data matrixes and results have been deposited and documented in the Open Science Framework (OSF) repository Neurocluedo (https://osf.io/n32z9/).

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ruiz Amezcua, P., Ibanez Barranco, N., Reigada, D., Novillo, I., Soto, A., Barreda-Manso, M. A., Munoz-Galdeano, T., Maza, R. M., Esteban, F. J., Nieto-Diaz, M.. 2024-01-23. Reanalysis of published data can help to characterize neuronal death after Spinal Cord Injury. https://doi.org/10.1101/2024.01.22.576608

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Trans-branching of polyubiquitin chains orchestrates the DNA replication stress response

Polyubiquitin chain geometry dictates functional consequences of ubiquitylation. Although branched polyubiquitin chains are abundant in cells, little is known about their functions. Here we show that branching on the DNA replication factor PCNA, mediated by the ubiquitin-conjugating enzyme UBE2K and involving lysines 63 and 48 of ubiquitin, orchestrates the sequence of events in response to replication stress. By inducing VCP-dependent extraction of PCNA from chromatin, branching promotes re-priming of stalled forks and necessitates a BRCA1-dependent pathway of daughter-strand gap repair. Our study identifies hyper-accumulation of daughter-strand gaps as the mechanistic basis underlying the toxicity of inhibitors of the PCNA-specific isopeptidase, USP1, in BRCA1-deficient cells. Moreover, an unexpected preference of UBE2K to operate in trans suggests a general timing mechanism to organize hierarchies amongst ubiquitin signals.

molecular biology↗

Impaired proteostasis is an early feature of the diabetic heart in humans and mice

Diabetes and obesity increase cardiac lipid levels leading to cardiomyopathy and heart failure. We hypothesized that intermittent fasting would reduce cardiac lipid levels. Surprisingly, intermittent fasting increased myocardial triglyceride content, but rescued mortality and attenuated cardiomyopathy in mice overexpressing cardiomyocyte acyl-CoA synthetase 1 (MHC-ACSL1). Lipid overload caused cardiomyocyte accumulation of polyubiquitinated protein aggregates containing desmin, a scaffolding intermediate filament protein, which intermittent fasting prevented. Furthermore, intermittent fasting reversed elevated myocardial C16:0 ceramide content, and knockdown of ceramide synthase CerS5 and CerS6 reduced palmitate-induced protein aggregation, highlighting a role for C16:0 ceramides in this pathology. Conversely, impairing aggrephagy with cardiomyocyte-specific p62 ablation induced heart failure in mice fed a high-fat diet, with paradoxically reduced cardiac lipid content. Crucially, non-failing diabetic human hearts also exhibited protein aggregate pathology. Taken together, these results demonstrate that impaired proteostasis characterizes cardiomyopathy from cardiac lipid overload and identify a promising new therapeutic target for this condition.

molecular biology↗

Spatial profiling and neurovascular communication in the developing and adolescent cortex following prenatal alcohol exposure

Fetal alcohol spectrum disorders (FASD) constitute a wide range of developmental, cognitive, and behavioral impairments caused by prenatal alcohol exposure (PAE). Although neuronal and vascular consequences of PAE have been studied, how alcohol affects the cerebrovasculature within the framework of the neurovascular unit (NVU) across development remains poorly understood. At minimum, the NVU comprises neurons, astrocyte endfeet, and endothelial cells (ECs), which coordinate to maintain brain homeostasis. Here, we used the NanoString Digital Spatial Profiling platform to characterize spatial transcriptomic data from neurons, astrocytes, and ECs from PAE and saccharin (SAC) control cortices at embryonic day 18 (E18) and postnatal day 28 (P28). Differentially expressed genes were then used for Ingenuity Pathway Analysis (IPA) to identify altered biological pathways and perform comparison analyses across developmental time points, while CellChat was used to infer cell cell communication networks. We uncovered thousands of differentially expressed genes and numerous altered pathways and biological processes in PAE cortices across development. Both IPA and CellChat analyses implicated dysregulation of vascular and extracellular matrix (ECM) remodeling, cell adhesion, and neuroinflammatory signaling. CellChat further predicted the loss of several key bidirectional relationships and altered ligand-receptor interactions among neurovascular cell types at E18 and P28. Overall, these findings identify PAE associated alterations in neurovascular gene expression and intercellular signaling across development, providing potential mechanisms by which PAE may disrupt neurodevelopment.

molecular biology↗