García-Mendívil Laura, Mediano Diego R, Hernaiz Adelaida, Sanz-Rubio David, Vázquez Francisco J, Marín Belén, López-Pérez Óscar, Otero Alicia, Badiola Juan J, Zaragoza Pilar, Ordovás Laura, Bolea Rosa, Martín-Burriel Inmaculada
Laboratorio de Genética Bioquímica (LAGENBIO), Instituto Agroalimentario de Aragón (IA2), Instituto de Investigación Sanitaria de Aragón (IISAragón), Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
Biomedical Signal Interpretation and Computational Simulation (BSICoS), Institute of Engineering Research (I3A), University of Zaragoza & Instituto de Investigación Sanitaria (IIS), 50018 Zaragoza, Spain.
Animals (Basel). 2021 Apr 15;11(4):1137. doi: 10.3390/ani11041137.
Scrapie is a prion disease affecting sheep and goats and it is considered a prototype of transmissible spongiform encephalopathies (TSEs). Mesenchymal stem cells (MSCs) have been proposed as candidates for developing in vitro models of prion diseases. Murine MSCs are able to propagate prions after previous mouse-adaptation of prion strains and, although ovine MSCs express the cellular prion protein (PrP), their susceptibility to prion infection has never been investigated. Here, we analyze the potential of ovine bone marrow-derived MSCs (oBM-MSCs), in growth and neurogenic conditions, to be infected by natural scrapie and propagate prion particles (PrP) in vitro, as well as the effect of this infection on cell viability and proliferation. Cultures were kept for 48-72 h in contact with homogenates of central nervous system (CNS) samples from scrapie or control sheep. In growth conditions, oBM-MSCs initially maintained detectable levels of PrP post-inoculation, as determined by Western blotting and ELISA. However, the PrP signal weakened and was lost over time. oBM-MSCs infected with scrapie displayed lower cell doubling and higher doubling times than those infected with control inocula. On the other hand, in neurogenic conditions, oBM-MSCs not only maintained detectable levels of PrP post-inoculation, as determined by ELISA, but this PrP signal also increased progressively over time. Finally, inoculation with CNS extracts seems to induce the proliferation of oBM-MSCs in both growth and neurogenic conditions. Our results suggest that oBM-MSCs respond to prion infection by decreasing their proliferation capacity and thus might not be permissive to prion replication, whereas ovine MSC-derived neuron-like cells seem to maintain and replicate PrP.
羊瘙痒病是一种影响绵羊和山羊的朊病毒病，被认为是传染性海绵状脑病（TSEs）的原型。间充质干细胞（MSCs）已被提议作为开发朊病毒病体外模型的候选细胞。小鼠间充质干细胞在对朊病毒株进行小鼠适应性传代后能够传播朊病毒，尽管绵羊间充质干细胞表达细胞朊蛋白（PrP），但其对朊病毒感染的易感性从未被研究过。在此，我们分析了绵羊骨髓来源的间充质干细胞（oBM-MSCs）在生长和神经发生条件下被自然羊瘙痒病感染并在体外传播朊病毒颗粒（PrP）的潜力，以及这种感染对细胞活力和增殖的影响。将培养物与来自患羊瘙痒病或对照绵羊的中枢神经系统（CNS）样本匀浆接触48 - 72小时。在生长条件下，通过蛋白质印迹法和酶联免疫吸附测定法测定，接种后oBM-MSCs最初能维持可检测水平的PrP。然而，PrP信号随时间减弱并消失。感染羊瘙痒病的oBM-MSCs比感染对照接种物的细胞倍增率更低且倍增时间更长。另一方面，在神经发生条件下，通过酶联免疫吸附测定法测定，接种后oBM-MSCs不仅能维持可检测水平的PrP，而且该PrP信号还随时间逐渐增加。最后，接种中枢神经系统提取物似乎在生长和神经发生条件下均能诱导oBM-MSCs的增殖。我们的结果表明，oBM-MSCs通过降低其增殖能力对朊病毒感染做出反应，因此可能不允许朊病毒复制，而绵羊间充质干细胞来源的神经元样细胞似乎能维持并复制PrP。
