Method Preps Neurotoxic Oligomers For Study In Vitro …

To enable the study of tau protein oligomers, researchers led by Rakez Kayed of the Mitchell Center for Neurodegenerative Diseases at the University of Texas Medical Branch have developed a protocol for reproducibly generating samples of the aggregated complexes in solution (Biochemistry, DOI: 10.1021/bi1016233). Tangled fibers of tau protein in the nerve cells of the brain are an established signature of neurodegenerative disorders such as Alzheimer’s disease, and scientists want to understand their formation in order to design targeted therapies. Evidence has emerged that tau oligomers formed as intermediate aggregated species in the tangled-fiber formation process are more neurotoxic than the end products. Because tau, a biomolecule normally responsible for stabilizing microtubules in neurons, is very soluble and disordered in solution, researchers previously had a hard time generating its oligomeric form in vitro. But Kayed’s team succeeded in preparing oligomer samples by seeding a solution of monomeric tau with premade oligomers of amyloid-β peptide, which is also linked to neurodegeneration but aggregates easily in vitro. “Our data suggest that amyloid oligomers specifically are capable of inducing tau aggregation in vitro and perhaps in vivo,” the researchers write.