Heme-oxygenase-1 response, a marker of oxidative stress, in a mouse model of AA amyloidosis.
Expression of heme-oxygenase-1 (HO-1), an important marker of oxidative stress, has been studied extensively in the context of Alzheimer's disease. Evidence of HO-1 expression during AA amyloidosis is, at best, sketchy. We present comparative data on HO-1 response in alveolar hydatid cyst (AHC) infected amyloid sensitive (C57BL/6) and amyloid resistant (CE/J) mouse strains. Histochemical and peroxidase-immunoperoxidase methods were used to monitor serum amyloid A (SAA) and AA fibril deposition and HO-1 expression in hepato-splenic reticuloendothelial (RE) cells of the AHC-infected mice prior and during AA fibril deposition. Based on the cumulative data, we conclude that HO-1 expression corresponded closely with tissue deposition of SAA, but was unrelated to AA fibril deposition. To ascertain whether SAA deposition might act as the trigger for HO-1 expression in the RE cells, macrophages were incubated for up to 72 h with SAA-containing mouse serum. The SAA-treated macrophages, although negative for HO-1 protein, demonstrated SAA in the cell extracts and immunocytochemically in the vacuolar compartments, indicating macrophage-mediated endocytosis and trafficking of SAA. In sum, these results exclude SAA and AA fibrils as the primary triggers in the induction of HO-1 expression in RE cells; the potential role of inflammatory cytokines in HO-1 response need to be investigated further.
Kamalvand
Golnar
G
Department of Microbiology and Immunology, McGill University, Lyman Duff Building, 3775 University Street, Montreal, Quebec, H3A 2B4 Canada.
Pinard
Geneviève
G
Ali-Khan
Zafer
Z
D000686:Amyloidosis / Q000209:etiology / Q000378:metabolism*; D000818:Animals; D001053:Apolipoproteins / Q000378:metabolism; D004195:Disease Models, Animal; D004443:Echinococcosis / Q000150:complications / Q000378:metabolism; D004444:Echinococcosis, Hepatic / Q000150:complications / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D017737:Macrophages, Peritoneal / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress / Q000502:physiology*; D000685:Serum Amyloid A Protein / Q000378:metabolism; D013154:Spleen / Q000378:metabolism / Q000473:pathology; D013158:Splenic Diseases / Q000150:complications / Q000378:metabolism
D001053:Apolipoproteins; D008565:Membrane Proteins; D000685:Serum Amyloid A Protein; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse