Inactivation of amyloid-enhancing factor (AEF): study on experimental murine AA amyloidosis.
It is known that amyloid-enhancing factor (AEF) shortens the preamyloid phase in experimentally induced AA amyloidosis in mice. Because it is reported that AEF serves as both a nidus and a template for amyloid formation, AA amyloidosis may have transmissibility by a prion-like mechanism. It has been shown that amyloid fibrils also have AEF activity, and amyloid fibrils with AEF activity were named fibril-amyloid enhancing factor (F-AEF). In this study, we investigated methods to inactivate the AEF activity. AEF was extracted from the thyroid gland obtained at autopsy of a patient with AA amyloidosis. Before injection into mice, AEF was treated with several methods for inactivation. Of all the tested treatments, 1 N NaOH, 0.1 N NaOH, and autoclaving consistently demonstrated complete inactivation of AEF. Heat treatment led to incomplete inactivation, but 0.01 N NaOH, 0.001 N NaOH, pepsin, trypsin, pronase, and proteinase K treatment had no effect on AEF activity. By analysis with transmission electron microscopy, the AEF preparation contains amyloid fibrils, and a change of ultrastructure was shown after 1 N NaOH, 0.1 N NaOH, and autoclaving treatment. Furthermore, immunoblotting of AEF with antihuman AA antibody revealed that the protein band was scarcely found after autoclaving, 1 N NaOH, and 0.1 N NaOH treatment. Our results suggest that, similar to Creutzfeldt-Jakob disease (CJD), amyloidosis may require chemical or autoclaving decontamination.
Omoto
Masatoshi
M
Department of Neurology and Clinical Neuroscience, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube City, and Department of Pathology, Kokura Memorial Hospital, Yamaguchi, 755-8505, Japan. omoto-path@umin.ac.jp
Yokota
Tadaaki
T
Cui
Dan
D
Hoshii
Yoshinobu
Y
Kawano
Hiroo
H
Gondo
Toshikazu
T
Ishihara
Tokuhiro
T
Kanda
Takashi
T
D000682:Amyloid / Q000737:chemistry / Q000378:metabolism; D000686:Amyloidosis / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control*; D000818:Animals; D003141:Communicable Diseases / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000635:transmission*; D004195:Disease Models, Animal; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005260:Female; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017053:Infection Control / Q000379:methods; D007274:Injections, Intraperitoneal; D051379:Mice; D008813:Mice, Inbred ICR; D046529:Microscopy, Electron, Transmission; D011328:Prions / Q000737:chemistry / Q000378:metabolism; D000685:Serum Amyloid A Protein / Q000737:chemistry / Q000378:metabolism; D013154:Spleen / Q000737:chemistry / Q000473:pathology; D013242:Sterilization / Q000379:methods*; D013961:Thyroid Gland / Q000737:chemistry / Q000473:pathology
D000682:Amyloid; D006023:Glycoproteins; D011328:Prions; D000685:Serum Amyloid A Protein; C046748:amyloid enhancing factor