Transcriptome analysis of zebrafish models of familial Alzheimer's disease and Sanfilippo syndrome childhood dementia display effects-in-common on the lysosome, oxidative phosphorylation and the ribosome
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ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE242370 | GEO | 2025/01/31
REPOSITORIES: GEO
Similar Datasets
Project description:Neural cells are under immense pressure to maintain proper degradation of molecules using their endo-lysosomal pathway (ELP). In Alzheimer’s disease (AD), the gradual cognitive worsening of this age-related disorder is partially due to dysfunction of the ELP. However, AD is a complex disorder and how the genetic landscape eventually leads to AD is unclear. Sanfilippo syndrome childhood dementia (mucopolysaccharidosis type III, MPSIII) is an extreme consequence of ELP dysfunction, where inherited recessive mutations result in the inability to properly catabolise a particular polysaccharide, which ultimately accumulates and interferes with the function of the ELP. Unlike AD, Sanfilippo is genetically simple (all causative genes are identified). The primary biochemical consequences are understood and animal models of Sanfilippo are considered excellent models of the human disease. Since Sanfilippo and AD show similar pathological changes, they likely share disease-associated mechanisms. Here, we dissect the similarity between AD and Sanfilippo using RNA-seq. We have generated zebrafish knock-in models of both diseases: the early-onset familial AD-like (EOfAD-like) mutation psen1 Q96_K97del and the MPSIII-like mutation naglu A603fs. We generated a family of zebrafish containing wild type, heterozygous EOfAD-like and homozygous MPSIII-like genotypes. We raised the family until 7 days post fertilisation and performed mRNA-seq on n = 8 induvial larvae per genotype. A power calculation revealed that this experiment was only contained ~50% power to detect differentially expressed genes. Nevertheless, changes to the expression of genes encoding proteins involved in lysosomal function could be detected in the MPS-III mutant larvae, suggesting a homeostatic response as the cells which make up the larval RNA-seq samples respond to dysfunctional lysosomes.
2022-11-08 | GSE217196 | GEO
Project description:Gene expression analysis of brain samples of wt MPS IIIB mice and MPS IIIB mice treated with AAV-NAGLU
2022-12-01 | E-MTAB-2984 | biostudies-arrayexpress
Project description:Mucopolysaccharidosis IIIB (MPS IIIB) is an inherited metabolic disease due to deficiency of α-N-Acetylglucosaminidase (NAGLU) enzyme with subsequent storage of undegradedheparan sulfate (HS). The main clinical manifestations of the disease are profound intellectual disability and neurodegeneration. To identify potential biomarkers and novel neuropathological mechanisms of MPS IIIB, a label-free quantitative proteomic approach was applied to compare the proteome profile of brains from MPS IIIB and control mice. Proteins were identified through a bottom up analysis and 130 were significantly under-represented and 74 over-represented in MPS IIIB mouse brains compared to wild type (WT). Multiple bioinformatic analyses of the differentially abundant proteins allowed to define three major clusters: proteins involved in cytoskeletal regulation, synaptic vesicle trafficking, and energy metabolism. The results highlight the involvement of these clustered proteins in the neuropathology of MPS IIIB disease. The proteins identified in this study would provide potential targets for diagnostic and therapeutic studies of MPS IIIB.
2020-02-26 | PXD017363 | Pride
Project description:Background: Mutations in PRESENILIN 1 (PSEN1) which still produce a transcript encoding a full-length, but mutant protein are the most common cause of early-onset familial Alzheimer’s disease (EOfAD). The only frameshift mutations found in PSEN1 causes familial acne inversa (fAI) without EOfAD. The molecular consequences of heterozygosity for these mutations, and how they lead to completely different diseases, remains largely unexplored. Objective: To identify the similarities and differences of the effects of heterozygosity for mutations in psen1 causing EOfAD (T428del) or fAI (W233fs) on the brain transcriptome of young adult zebrafish. Methods: RNA sequencing was performed with high read depth on mRNA isolated from the brains of young adult (6 month old) zebrafish arising from a single family which contained either a single, heterozygous EOfAD-like or fAI-like mutation in the endogenous psen1 gene, and their wild type siblings. Results: Both mutations appeared to downregulate genes encoding the ribosomal subunits, and upregulated genes involved in inflammation. Genes involved in energy metabolism appeared to only be affected in EOfAD-like mutants, while genes involved in Notch, Wnt and neutrophin signalling pathways were only significantly altered by the fAI-like mutation. Further investigation of direct transcriptional targets of Notch revealed an apparent increase in Notch signalling. Conclusion: We observed both common, and distinct effects on transcriptomes of the heterozygous mutants compared to their wild type siblings. The distinct effects observed may shed light to how these mutations give rise to completely different diseases.
2021-02-01 | GSE164466 | GEO
Project description:To prevent or ameliorate Alzheimer’s disease (AD) requires that we understand its molecular basis. AD develops over decades but detailed molecular analysis of AD brains is limited to postmortem tissue where the stresses initiating the disease may be obscured by compensatory responses and neurodegenerative processes. Rare, dominant mutations in a small number of genes drive early onset of familial AD (EOfAD). Numerous transgenic models of AD have been constructed in mouse and other organisms based on these mutant genes, but transcriptomic analysis of these models has raised serious doubts regarding their representation of the disease state. Objective: In the absence of an understanding of the molecular mechanism(s) underlying AD, we posit that the most valid approach is to model the human genetic state as closely as possible – i.e. to analyse single, heterozygous EOfAD-like mutations of endogenous genes in intact brains. We used genome editing to introduce an EOfAD-like mutation (Q96_K97del) into the endogenous presenilin 1 (psen1) gene of zebrafish. We analysed transcriptomes of young adult (6-month-old) entire brains from a family of heterozygous mutant and wild type sibling fish. Gene ontology (GO) analysis revealed effects on mitochondria, particularly ATP synthesis, and on ATP-dependent processes including vacuolar acidification.
2019-02-06 | GSE126096 | GEO
Project description:To prevent or delay the onset of Alzheimer’s disease (AD), we must understand its molecular basis. The great majority of AD cases arise sporadically with a late onset after 65 years of age (LOAD). However, rare familial cases of AD can occur due to dominant mutations in a small number of genes that cause an early onset prior to 65 years of age (EOfAD). As EOfAD and LOAD share similar pathologies and disease progression, analysis of EOfAD genetic models may give insight into both subtypes of AD. Sortilin-related receptor 1 (SORL1) is genetically associated with both EOfAD and LOAD and provides a unique opportunity to investigate the relationships between both forms of AD. Currently, the role of SORL1 mutations in AD pathogenesis is unclear. To understand the molecular consequences of SORL1 mutation, we performed targeted mutagenesis of the orthologous gene in zebrafish. We generated an EOfAD-like mutation, V1482Afs, and a putatively null mutation, to investigate whether EOfAD-like mutations in sorl1 display haploinsufficiency by acting through loss-of-function mechanisms. We performed mRNA-sequencing on whole brains, comparing wild type fish with their siblings heterozygous for EOfAD-like or putatively loss-of-function mutations in sorl1, or transheterozygous for these mutations. Differential gene expression analysis identified a small number of differentially expressed genes due to the sorl1 genotypes. We also performed enrichment analysis on all detectable genes to obtain a more complete view on changes to gene expression by performing three methods of gene set enrichment analysis, then calculated an overall significance value using the harmonic mean p-value. This identified subtle effects on expression of genes involved in energy production, mRNA translation and mTORC1 signalling in both the EOfAD-like and null mutant brains, implying that these effects are due to sorl1 haploinsufficiency. Surprisingly, we also observed changes to expression of genes occurring only in the EOfAD-mutation carrier brains, suggesting gain-of-function effects. Transheterozygosity for the EOfAD-like and null mutations (i.e. lacking wild type sorl1), caused apparent effects on iron homeostasis and other transcriptome changes distinct from the single-mutation heterozygous fish. Our results provide insight into the possible early brain molecular effects of an EOfAD mutation in human SORL1. Differential effects of heterozygosity and complete loss of normal SORL1 expression are revealed.
2020-10-22 | GSE151999 | GEO
Project description:Early-onset familial Alzheimer’s disease (EOfAD) is promoted by dominant mutations, enabling the study of Alzheimer’s disease (AD) pathogenic mechanisms through generation of EOfAD-like mutations in animal models. In a previous study, we generated an EOfAD-like mutation, psen1Q96_K97del, in zebrafish and performed a transcriptome analysis comparing entire brains from 6-month-old wild type and heterozygous mutant fish. We identified predicted effects on mitochondrial function and endolysosomal acidification. Here we aimed to determine whether similar effects occur in 7 day post fertilization (dpf) zebrafish larvae that might be exploited in screening of chemical libraries to find ameliorative drugs. We generated clutches of wild type and heterozygous psen1Q96_K97del 7 dpf larvae using a paired-mating strategy to reduce extraneous genetic variation before performing a comparative transcriptome analysis. We identified 228 differentially expressed genes and performed Goseq analysis and gene set enrichment analysis (GSEA). This predicted a significant effect on oxidative phosphorylation, consistent with our earlier observations of predicted effects on ATP synthesis in adult heterozygous psen1Q96_K97del brains. The dysregulation of minichromosome maintenance protein complex (MCM) genes strongly contributed to predicted effects on DNA replication and the cell cycle and may explain earlier observations of genome instability due to PSEN1 mutation. The upregulation of crystallin gene expression may be a response to defective activity of mutant Psen1 protein in endolysosomal acidification. Extracellular matrix (ECM) related genes were downregulated, consistent with previous studies of EOfAD mutant iPSC neurons and postmortem late onset AD brains. Also, changes in expression of genes controlling iron ion transport were observed without identifiable changes in the prevalence of transcripts containing iron responsive elements (IREs) in their 3’ untranslated regions. These changes may, therefore, predispose to the apparent iron dyshomeostasis previously observed in 6-month-old heterozygous psen1Q96_K97del EOfAD-like mutant brains.
2020-04-15 | GSE148631 | GEO
Project description:The early cellular stresses which eventually lead to Alzheimer’s disease (AD) remain poorly understood. This is because we cannot access living, asymptomatic human AD brains for detailed molecular analyses. Sortilin-related receptor 1 (SORL1) encodes a multi-domain receptor protein genetically associated with both rare, early-onset familial AD (EOfAD) and common, sporadic late-onset AD (LOAD). SORL1 has been shown to play a role in the trafficking of the amyloid β A4 precursor protein (APP) which is cleaved proteolytically to form one of the pathological hallmarks of AD, amyloid β (Aβ) peptide. However, the other functions of SORL1 are less well understood. Here, we employed a reverse genetics approach to characterise the effect of an EOfAD mutation in SORL1 using zebrafish as a model organism. We performed targeted mutagenesis to generate an EOfAD-like mutation in the zebrafish orthologue of SORL1, and performed RNA-sequencing on mRNA isolated from a family of fish either heterozygous for the EOfAD-like mutation or their wild type siblings and identified subtle effects on the expression of genes likely indicating changes in mitochondrial and ribosomal function.
2021-01-11 | GSE156167 | GEO
Project description:Sanfilippo syndrome childhood dementia, also known as mucopolysaccharidosis type III (MPS III), is a rare inherited lysosomal storage disorder. Subtypes of MPS III are caused by deficiencies in one of four enzymes required for degradation of the glycosaminoglycan heparan sulfate (HS). An inability to degrade HS leads to progressive neurodegeneration and death in the second or third decades of life. Knowledge of MPS III pathogenesis is incomplete, and no effective therapies exist. We generated the hypomorphic mutations sgshS387Lfs, nagluA603Efs and hgsnatG577Sfsin the endogenous zebrafish genes orthologous to human SGSH, NAGLU, and HGSNAT that are loci for mutations causing MPS III subtypes MPS IIIA, B and C respectively. Our models display the primary MPS III disease signature of significant brain accumulation of HS, while behavioural analyses support hyperactivity phenotypes. Brain transcriptome analysis revealed changes related to lysosomal, glycosaminoglycan, immune system and iron homeostasis biology in all three models but also distinct differences in brain transcriptome state between models. The transcriptome analysis also indicated marked disturbance of the oligodendrocyte cell state in the brains of MPS IIIA, B and C zebrafish, supporting that effects on this cell type are an early and consistent characteristic of MPS III. Overall, our zebrafish models recapture key characteristics of the human disease and phenotypes seen in mouse models. Our models will allow exploitation of the zebrafish’s extreme fecundity and accessible anatomy to dissect the pathological mechanisms both common and divergent between the MPS IIIA, B, and C subtypes.
2023-09-29 | GSE244310 | GEO
Project description:We used microarray to detect pathway differences in the various brain regions in a monogenic in mucopolysaccharidosis type VII ( MPS VII ), a mouse model of a lysosomal storage disease A number of changes revealed unexpected system and process alterations, such as upregulation of the immune system with few inflammatory changes (a significant difference from the closely related MPS IIIb model), down-regulation of major oligodendrocyte genes even though white matter changes are not a feature histopathologically, and a plethora of developmental gene changes. 94 samples, no replicates, made up of half normals and half MPS mutant mice for the MPS VII mutation backcrossed on a C3h-heouj background
2012-12-01 | E-GEOD-34071 | biostudies-arrayexpress