Dataset Information

Altered Ca+2 homeostasis induces Calpain-Cathepsin axis activation in sCJD.

ABSTRACT: Sporadic Creutzfeldt-Jakob disease (sCJD) is the most prevalent form of human prion disease and it is characterized by the presence of neuronal loss, spongiform degeneration, chronic inflammation and the accumulation of misfolded and pathogenic prion protein (PrPSc). The molecular mechanisms underlying these alterations are largely unknown, but the presence of intracellular neuronal calcium (Ca+2) overload, a general feature in models of prion diseases, is suggested to play a key role in prion pathogenesis. Here we describe the presence of massive regulation of Ca+2 responsive genes in sCJD brain tissue, accompanied by two Ca+2-dependent processes: endoplasmic reticulum stress and the activation of the cysteine proteases Calpains 1/2. Pathogenic Calpain activation in sCJD is linked to the cleavage of their cellular substrates, impaired autophagy and lysosomal damage, which is partially reversed by Calpain inhibition in a cellular prion model. Calpain 1 treatment enhances seeding activity of PrPSc in a prion conversion assay. Neuronal lysosomal impairment caused by Calpain over activation leads to the release of the lysosomal protease Cathepsin S that in sCJD mainly localises in axons. Additionally, massive Cathepsin S overexpression is detected in microglial cells. Alterations in Ca+2 homeostasis and activation of Calpain-Cathepsin axis already occur at pre-clinical stages of the disease as detected in a humanized sCJD mouse model. Altogether our work indicates that unbalanced Calpain-Cathepsin activation is a relevant contributor to the pathogenesis of sCJD at multiple molecular levels and a potential target for therapeutic intervention.

ORGANISM(S): Mus musculus

PROVIDER: GSE90977 | GEO | 2017/05/15

SECONDARY ACCESSION(S): PRJNA356545

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Sheep scrapie (Sc) is the classical transmissible spongiform encephalopathy (prion disease). The conversion of normal cellular prion protein (PrPC) to disease-associated prion protein (PrPSc) is a fundamental component of prion disease pathogenesis. The molecular mechanisms contributing to prion diseases and the impact of PrPSc accumulation on cellular biology are not fully understood. To define the molecular changes associated with PrPSc accumulation, primary sheep microglia were inoculated with PrPSc and then the transcriptional profile of these PrPSc-accumulating microglial cells was compared to the profile of PrPSc-lacking microglial cells using the Affymetrix Bovine Genome Array. The experimental design included three biological replicates, each with three technical replicates, and samples that were collected at the point of maximal PrPSc accumulation levels as measured by ELISA. The array analysis revealed 19 upregulated genes and 30 downregulated genes in PrPSc-accumulating microglia. Three transcripts (CCL2, SGK1, and AASDHPPT) were differentially regulated in a direction similar to previous reports from mouse or human models, whereas the response of three other transcripts (MT1E, NR4A1, PKP2) conflicted with previous reports. Overall, the results demonstrated a limited transcriptional response to PrPSc accumulation, when compared to microglia and macrophage cultures infected with other agents such as viruses and bacteria. This is the first microarray-based analysis of prion accumulation in primary cells derived from a natural TSE-host. Experiment Overall Design: Primary sheep microglial cells were either inoculated with PrPSc (Inoc) or sham-inoculated (Mock) Experiment Overall Design: Three biological replicates per treatment. Experiment Overall Design: Three technical replicates per biological replicate. Experiment Overall Design: biological replicate: Inoc12A, Inoc12B.2, Inoc12C Experiment Overall Design: biological replicate: Mock12A, Mock12B.2, Mock12C Experiment Overall Design: technical replicate - extract: Inoc12A.1, Inoc12A.2, Inoc12A.3 Experiment Overall Design: technical replicate - extract: Inoc12B.2.1, Inoc12B.2.2, Inoc12B.2.3 Experiment Overall Design: technical replicate - extract: Inoc12C.1, Inoc12C.2, Inoc12C.3 Experiment Overall Design: technical replicate - extract: Mock12A.1, Mock12A.2, Mock12A.3 Experiment Overall Design: technical replicate - extract: Mock12B.2.1, Mock12B.2.2, Mock12B.2.3 Experiment Overall Design: technical replicate - extract: Mock12C.1, Mock12C.2, Mock12C.3

Dataset Information

Altered Ca+2 homeostasis induces Calpain-Cathepsin axis activation in sCJD.

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets