Rajput, Ashish

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","35"],["dc.bibliographiccitation.journal","Acta Neuropathologica Communication"],["dc.bibliographiccitation.lastpage","20"],["dc.bibliographiccitation.volume","5"],["dc.contributor.author","Llorens, Franc"],["dc.contributor.author","Fischer, Andre"],["dc.contributor.author","Thüne, Katrin"],["dc.contributor.author","Sikorska, Beata"],["dc.contributor.author","Schmitz, Matthias"],["dc.contributor.author","Tahir, Waqas"],["dc.contributor.author","Fernández-Borges, Natalia"],["dc.contributor.author","Cramm, Maria"],["dc.contributor.author","Gotzmann, Nadine"],["dc.contributor.author","Carmona, Margarita"],["dc.contributor.author","Streichenberger, Nathalie"],["dc.contributor.author","Michel, Uwe"],["dc.contributor.author","Zafar, Saima"],["dc.contributor.author","Schuetz, Anna-Lena"],["dc.contributor.author","Rajput, Ashish"],["dc.contributor.author","Andréoletti, Olivier"],["dc.contributor.author","Bonn, Stefan"],["dc.contributor.author","Liberski, Pawel P."],["dc.contributor.author","Torres, Juan Maria"],["dc.contributor.author","Ferrer, Isidre"],["dc.contributor.author","Zerr, Inga"],["dc.date.accessioned","2018-01-09T14:57:08Z"],["dc.date.available","2018-01-09T14:57:08Z"],["dc.date.issued","2017-04-27"],["dc.description.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 (Ca2+) 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 Ca2+ responsive genes in sCJD brain tissue, accompanied by two Ca2+-dependent processes: endoplasmic reticulum stress and the activation of the cysteine proteases Calpains 1/2. Pathogenic Calpain proteins 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. Additionally, 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, although massive Cathepsin S overexpression is detected in microglial cells. Alterations in Ca2+ 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."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2017"],["dc.identifier.doi","10.1186/s40478-017-0431-y"],["dc.identifier.pmid","28449707"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14726"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/11612"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.relation.eissn","2051-5960"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Altered Ca2+ homeostasis induces Calpain-Cathepsin axis activation in sporadic Creutzfeldt-Jakob disease"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","149"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Journal of general physiology"],["dc.bibliographiccitation.lastpage","170"],["dc.bibliographiccitation.volume","149"],["dc.contributor.author","Wolfes, Anne C."],["dc.contributor.author","Ahmed, Saheeb"],["dc.contributor.author","Awasthi, Ankit"],["dc.contributor.author","Stahlberg, Markus A."],["dc.contributor.author","Rajput, Ashish"],["dc.contributor.author","Magruder, Daniel S."],["dc.contributor.author","Bonn, Stefan"],["dc.contributor.author","Dean, Camin"],["dc.date.accessioned","2019-07-09T11:43:25Z"],["dc.date.available","2019-07-09T11:43:25Z"],["dc.date.issued","2017"],["dc.description.abstract","Interactions between astrocytes and neurons rely on the release and uptake of glial and neuronal molecules. But whether astrocytic vesicles exist and exocytose in a regulated or constitutive fashion is under debate. The majority of studies have relied on indirect methods or on astrocyte cultures that do not resemble stellate astrocytes found in vivo. Here, to investigate vesicle-associated proteins and exocytosis in stellate astrocytes specifically, we developed a simple, fast, and economical method for growing stellate astrocyte monocultures. This method is superior to other monocultures in terms of astrocyte morphology, mRNA expression profile, protein expression of cell maturity markers, and Ca(2+) fluctuations: In astrocytes transduced with GFAP promoter-driven Lck-GCaMP3, spontaneous Ca(2+) events in distinct domains (somata, branchlets, and microdomains) are similar to those in astrocytes co-cultured with other glia and neurons but unlike Ca(2+) events in astrocytes prepared using the McCarthy and de Vellis (MD) method and immunopanned (IP) astrocytes. We identify two distinct populations of constitutively recycling vesicles (harboring either VAMP2 or SYT7) specifically in branchlets of cultured stellate astrocytes. SYT7 is developmentally regulated in these astrocytes, and we observe significantly fewer synapses in wild-type mouse neurons grown on Syt7(-/-) astrocytes. SYT7 may thus be involved in trafficking or releasing synaptogenic factors. In summary, our novel method yields stellate astrocyte monocultures that can be used to study Ca(2+) signaling and vesicle recycling and dynamics in astrocytic processes."],["dc.description.abstract","whether astrocytic vesicles exist and exocytose in a regulated or constitutive fashion is under debate. The majority of studies have relied on indirect methods or on astrocyte cultures that do not resemble stellate astrocytes found in vivo. Here, to investigate vesicle-associated proteins and exocytosis in stellate astrocytes specifically, we developed a simple, fast, and economical method for growing stellate astrocyte monocultures. This method is superior to other monocultures in terms of astrocyte morphology, mRNA expression profile, protein expression of cell maturity markers, and Ca2+ fluctuations: In astrocytes transduced with GFAP promoter–driven Lck-GCaMP3, spontaneous Ca2+ events in distinct domains (somata, branchlets, and microdomains) are similar to those in astrocytes co-cultured with other glia and neurons but unlike Ca2+ events in astrocytes prepared using the McCarthy and de Vellis (MD) method and immunopanned (IP) astrocytes. We identify two distinct populations of constitutively recycling vesicles (harboring either VAMP2 or SYT7) specifically in branchlets of cultured stellate astrocytes. SYT7 is developmentally regulated in these astrocytes, and we observe significantly fewer synapses in wild-type mouse neurons grown on Syt7−/− astrocytes. SYT7 may thus be involved in trafficking or releasing synaptogenic factors. In summary, our novel method yields stellate astrocyte monocultures that can be used to study Ca2+ signaling and vesicle recycling and dynamics in astrocytic processes."],["dc.identifier.doi","10.1085/jgp.201611607"],["dc.identifier.pmid","27908976"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14524"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/58885"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/260916/EU//SYT ACTIVITY"],["dc.relation.issn","1540-7748"],["dc.rights","CC BY-NC-SA 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-sa/3.0"],["dc.subject.ddc","612"],["dc.title","A novel method for culturing stellate astrocytes reveals spatially distinct Ca2+ signaling and vesicle recycling in astrocytic processes."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]