Cytosine β-D-arabinofuranoside used as a Paradigm Modifier to Increase Production of Tau Aggregates in a Cellular Model of Tauopathy

Abstract

Intraneuronal deposition of filamentous tau is a hallmark of Alzheimer’s disease (AD) and related tauopathies. We developed previously a cellular model recapitulating such tau anomaly and demonstrated therein consistent production of 70-kD tau. Importantly, the 70-kD species appears to derive from tau fragments with carboxy-terminal truncation and is larger than intact tau in size, suggesting the oligomeric nature in its assembly from tau. To generate the 70-kD tau in sufficient quantity for its characterization at the molecular level, we explored and demonstrated herein that cytosine β-D-arabinofuranoside is a useful paradigm modifier to increase production of the 70-kD tau. Such oligomeric tau was enriched thereafter by immunoprecipitation to remove tau species with intact carboxy-terminus. Two-dimensional gel electrophoresis revealed that the 70-kD tau has an isoelectric point of 5.8–6.0. Future elucidation of key aggregates will provide valuable insights into the natural history of neurofibrillary degeneration and identify novel targets to develop therapeutic interventions.