Some studies suggest that MSA derived S has substantially greater potency in seeding activity of S inclusion formation compared to in vitro preformed S fibrils, perhaps characteristic of a unique conformer strain [28], but these differences in MSA derived S was not observed by others [43]

Some studies suggest that MSA derived S has substantially greater potency in seeding activity of S inclusion formation compared to in vitro preformed S fibrils, perhaps characteristic of a unique conformer strain [28], but these differences in MSA derived S was not observed by others [43]. notion that S mediated progressive neurodegeneration can occur by a prion-like mechanism. We have previously shown that neonatal brain inoculation with preformed S fibrils in hemizygous M20+/? transgenic mice expressing wild type human S and to a lesser extent in non-transgenic mice can result in a concentration-dependent progressive induction of CNS S pathology. Recent studies using brain lysates from patients with multiple system atrophy (MSA), characterized by S inclusion pathology in oligodendrocytes, show that these may be uniquely potent at inducing S pathology with prion-like strain specificity. We demonstrate here that brain lysates from MSA patients, but not control individuals, can induce S pathology following neonatal brain inoculation in transgenic mice expressing A53T human S (M83 collection), but not in transgenic expressing wild type human S (M20 collection) or non-transgenic mice within the timeframe of the study design. Further, we show that neuroanatomical and immunohistochemical properties of the pathology induced by MSA brain lysates is very similar to what is produced by the neonatal brain injection of preformed human S fibrils in hemizygous M83+/? transgenic mice. Collectively, these findings reinforce the idea that this intrinsic traits of the M83 mouse model dominates over any putative prion-like strain properties of MSA S seeds that can induce pathology. Electronic supplementary material The online version of this article (10.1186/s40478-019-0733-3) contains supplementary material, which is available to authorized users. (by size exclusion chromatography and subsequent anion exchange as previously explained ELN484228 [16]. Protein concentrations were determined by bicinchoninic ELN484228 acid assay using bovine serum albumin as the protein standard. Recombinant S proteins (5?mg/ml in sterile phosphate buffered saline; PBS) were incubated at 37?C with constant shaking at 1050?rpm (Thermomixer R, Eppendorf) for? ?48?h. Fibril formation was monitored by K114 [(multiple system atrophy-cerebellar, olivo-ponto-cerebellar atrophy, multiple system atrophy-parkinsonism, striatonigral degeneration Mouse lines All procedures were performed according to the National Institute of Health Guideline for the ELN484228 Care and Use of Experimental Animals and were approved by the University or college of Florida Institutional Animal Care and Use Committee. M20 and M83 transgenic mice around the C57BL/C3H background were previously explained [15]. The M20?collection is transgenic for WT human S and the M83?collection is transgenic for human S with the pathogenic A53T mutation. Both S transgenic mouse lines were generated with comparable constructs ELN484228 with expression driven by the mouse prion protein promoter resulting in widespread Tmem140 CNS expression and similar expression, although expressing in the M20 collection is slightly higher (Additional?file?1: Determine S1) [4, 15, 38]. nTg mice on the same C57BL/C3H background were also used. Mouse experimental procedures M83 mice were managed as homozygous mice and were mated with nTg C3H/BL6 mice to generate neonatal M83+/? for injections. M20 mice were managed as hemizygous mice and were mated with nTg C3H/BL6 mice to generate both neonatal M20+/? and littermate nTg control mice that were utilized for neonatal injections and genotyped thereafter. Neonatal M83+/?, M20+/?, and nTg mice were injected with 2?l of brain homogenate or PBS control into both hemispheres using a 10?ml Hamilton syringe with a 30?g needle on day P0 as previously explained [8, 37]. Mice were aged 5?month or until they developed hindlimb paralysis, whichever came first. Harvesting, fixation, and processing were conducted as previously explained [36]. Similarly, some neonatal M83+/? mice were bilaterally injected with either 2?l of WT or A53T human S fibrils (5?mg/ml) and aged for 4?months for comparison. Briefly, mice were euthanized by CO2, followed by cardiac perfusion of PBS/heparin..