Dataset Information

Comprehensive expression analysis with cell-type-specific transcriptome in ALS-linked mutant SOD1 mice

ABSTRACT: Non-cell autonomous mechanisms are involved in the pathogenesis of amyotrophic lateral sclerosis (ALS), an adult neurodegenerative disease characterized by selective motor neuron loss. While the emerging role of glial cells in ALS has been noted, the detailed cell-type-specific role of glial cells has not been clarified. Here, we examined mRNA expression changes using microarrays of the spinal cords of three distinct lines of mutant superoxide dismutase (SOD) 1 transgenic mice, an established ALS model. Our analysis used a transcriptome database of component cell types in the central nervous system (CNS), as well as SOD1G93A cell-type transcriptomes. More than half of the differentially expressed genes (DEGs) were highly expressed in microglia, and enrichment analysis of DEGs revealed that immunological reactions were profoundly involved and some transcription factors were upregulated. Our analysis focused on DEGs that are highly expressed in each cell type, as well as chemokines, caspases, and heat shock proteins. Disease-associated microglial genes were upregulated, while homeostatic microglial genes were not, and galectin-3 (Mac2), a known activated microglial marker, was predicted to be ectopically expressed in astrocytes in mutant SOD1 mice. In mutant SOD1 mice, we developed a prediction model for the pathophysiology of different cell types related to TREM2, apolipoprotein E, and lipoproteins. Our analysis offers a viable resource to understand not only the molecular pathologies of each CNS constituent cell type, but also the cellular crosstalk between different cell types under both physiological and pathological conditions in model mice for various neurodegenerative diseases.

ORGANISM(S): Mus musculus

PROVIDER: GSE220705 | GEO | 2022/12/20

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Amyotrophic Lateral Sclerosis (ALS) is generally a late onset neurodegenerative disease. Mutations in the Cu/Zn superoxide dismutase 1 (SOD1) gene accounts for approximately 20% of familial ALS and 2% of all ALS cases. Although a number of hypothesis have been proposed to explain mutant SOD1 toxicity, the molecular mechanisms of the disease remain unclear. SOD1 linked ALS is thought to function in a non-cell autonomous manner such that the motoneurons are critical for the onset and glia contribute to the progress of the disease. To dissect the roles of motoneurons and glia, we used the Gal4-UAS system to determine gene expression changes following the expression of mutant human SOD1 (G85R) selectively in either motoneurons or glia, and concurrently in motoneurons and glia of flies. We conducted a microarray on young (5 days old) and old (45 days old) flies expressing G85R in these cell types and identified a number of genes involved in a variety of processes. The candidate genes identified by this screen may help elucidate the individual and combined contributions of motoneurons and glial cells in ALS. We used microarrays to evaluate the transcriptional profile of 5 day old and 45 day old flies expressing mutant human SOD1 (G85R) in a tissue specific manner in motoneurons, glia, and together in motoneurons and glia and compared the expression to flies expressing wild-type drosophila SOD1 controls. The Gal4-UAS system was used to drive tissue expression of either mutant human SOD1 (G85R) or wild-type drosophila SOD1 (dSOD1) in flies. Flies containing either the motoneuronal driver, D42-Gal4, the glial driver, M1B-Gal4, or the combined motoneuronal and glial drivers, D42+M1B-Gal4 were crossed to flies containing either mutant human SOD1, UAS-G85R, or wild-type drosophila SOD1, UAS-dSOD1, as a control. Adult male progeny were collected within 24 hours after eclosion and aged to 5 (5d) and 45 (45d) days old. Groups of 10 flies were maintained in vials of cornmeal agar food and transferred to fresh food every 5-7 days. For each Gal4-UAS line and each age, 3 biological replicates consisting of 40 whole flies were flash frozen in liquid nitrogen and used to isolate total RNA, for a total of 36 samples.

Project description:Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which motor neurons throughout the brain and spinal cord progressively degenerate resulting in muscle atrophy, paralysis and death. Recent studies using animal models of ALS implicate multiple cell-types (e.g., astrocytes and microglia) in ALS pathogenesis in the spinal motor systems. To ascertain cellular vulnerability and cell-type specific mechanisms of ALS in the brainstem that orchestrates oral-motor functions, we conducted parallel single cell RNA sequencing (scRNA-seq) analysis using the high-throughput Drop-seq method. We isolated 1894 and 3199 cells from the brainstem of wildtype and mutant SOD1 symptomatic mice respectively, at postnatal day 100. We recovered major known cell types and neuronal subpopulations, such as interneurons and motor neurons, and trigeminal ganglion (TG) peripheral sensory neurons, as well as, previously uncharacterized interneuron subtypes. We found that the majority of the cell types displayed transcriptomic alterations in ALS mice. Differentially expressed genes (DEGs) of individual cell populations revealed cell-type specific alterations in numerous pathways, including previously known ALS pathways such as inflammation (in microglia), stress response (ependymal and an uncharacterized cell population), neurogenesis (astrocytes, oligodendrocytes, neurons), synapse organization and transmission (microglia, oligodendrocyte precursor cells, and neuronal subtypes), and mitochondrial function (uncharacterized cell populations). Other cell-type specific processes altered in SOD1 mutant brainstem include those from motor neurons (axon regeneration, voltage-gated sodium and potassium channels underlying excitability, potassium ion transport), trigeminal sensory neurons (detection of temperature stimulus involved in sensory perception), and cellular response to toxic substances (uncharacterized cell populations). DEGs consistently altered across cell types (e.g., Malat1), as well as cell-type specific DEGs, were identified. Importantly, DEGs from various cell types overlapped with known ALS genes from the literature and with top hits from an existing human ALS genome-wide association study (GWAS), implicating the potential cell types in which the ALS genes function with ALS pathogenesis. Our molecular investigation at single cell resolution provides comprehensive insights into the cell types, genes and pathways altered in the brainstem in a widely used ALS mouse model.

Dataset Information

Comprehensive expression analysis with cell-type-specific transcriptome in ALS-linked mutant SOD1 mice

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets