Amyloid-?(1a42) Protofibrils Formed in Modified Artificial Cerebrospinal Fluid Bind and Activate Microglia

• Published in: Journal of neuroimmune pharmacology 2013-03, Vol.8 (1), p.312-322
• Main Authors: Paranjape, Geeta S, Terrill, Shana E, Gouwens, Lisa K, Ruck, Benjamin M, Nichols, Michael R
• Format: Article
• Language: English
• ISSN: 1557-1890; 1557-1904
• DOI: 10.1007/s11481-012-9424-6

Soluble aggregated forms of amyloid-? protein (A?) have garnered significant attention recently for their role in Alzheimeras disease (AD). Protofibrils are a subset of these soluble species and are considered intermediates in the aggregation pathway to mature A? fibrils. Biological studies have demonstrated that protofibrils exhibit both toxic and inflammatory activities. It is important in these in vitro studies to prepare protofibrils using solution conditions that are appropriate for cellular studies as well as conducive to biophysical characterization of protofibrils. Here we describe the preparation and characterization of A?(1a42) protofibrils in modified artificial cerebrospinal fluid (aCSF) and demonstrate their prominent binding and activation of microglial cells. A simple phosphate/bicarbonate buffer system was prepared that maintained the ionic strength and cell compatibility of F-12 medium but did not contain numerous supplements that interfere with spectroscopic analyses of A? protofibrils. Reconstitution of A?(1a42) in aCSF and isolation with size exclusion chromatography (SEC) revealed curvilinear ?-sheet protofibrils