Prion protein function in redox homeostasis and associated failure in prion disease

National Institute Of Allergy And Infectious Diseases

Investigators

Linked publications & trials

Abstract

Scope: Prion diseases are infectious diseases affecting humans and animals. They are caused by mis-folding of a normal cellular protein (the prion protein, PrP) into infectious forms (prions), which then propagate themselves by templating more mis-folding events. Reactive oxygen/nitrogen species (ROS/RNS) are formed as byproducts of many cellular processes and can be used as signalling intermediates within the cell. Oxidative stress occurs when the balance between production and detoxification is tipped in favour of increased reactive species, resulting in damage to the cellular components. Our research aims to investigate the relationships between PrP, prions and prion disease with ROS and ROS-producing systems, such as cell metabolism and signal transduction, to generate a significant understanding of both PrP function and prion disease pathogenesis. Research materials, equipment and methods: Our research predominantly uses cell-based techniques to investigate changes in single cells or in cell networks. We have generated a number of cell models, including mouse and human stem cell models. To investigate specific redox-related pathways we use a combination of protein, RNA, live cell function and microscopy analyses. The equipment we hold for these analyses include a chip/multiwell/in vivo MEA system, a Seahorse analyser, two plate readers of differing functional capacity, an automated fluorescence microscope and chemiluminescence/fluorescence imaging system. Research accomplishments: Using induced pluripotent stem cells we developed the first human three-dimensional brain tissue model of prion disease. This was achieved by infecting cerebral organoids with prions. We further demonstrated that cerebral organoid prion infections can reproduce certain features of prion disease that are found in human brains post-mortem. We have since shown that the cerebral organoid model of prion infection can be used to screen putative therapeutics and adapted to various different drug screening paradigms. The scalability of the organoids and their capacity to demonstrate drug toxicity are added advantages to their use as a drug screening tool. In a different avenue of research, we previously developed a mouse model of neurons, astrocytes and oligodendrocytes co-cultured with microglia. We have developed this model further to be cultured in 3D and found that microglia respond differently to aggravating stimuli when cultured within the 3D system with other cells types than they do when cultured alone.