Transmissibility of mouse AApoAII amyloid fibrils: inactivation by physical and chemical methods

AApoAII amyloid fibrils have exhibited prion-like transmissibility in mouse senile amyloidosis. We have demonstrated that AApoAII is extremely active and can induce amyloidosis following doses less than 1 pg. We tested physical and chemical methods to disrupt AApoAII fibrils in vitro as determined by thioflavin T binding and electron microscopy (EM) as well as inactivating the transmissibility of AApoAII fibrils in vivo. Complete disruption of AApoAII fibrils was achieved by treatment with formic acid, 6 M guanidine hydrochloride, and autoclaving in an alkaline solution. Injection of these disrupted AApoAII fibrils did not induce amyloidosis in mice. Disaggregation with 6 M urea, autoclaving, and alkaline solution was incomplete, and injection of these AApoAII fibrils induced mild amyloidosis. Treatment with formalin, delipidation, freeze-thaw, and RNase did not have any major effect. A distinct correlation was obtained between the amounts of amyloid fibrils and the transmissibility of amyloid fibrils, th...