1990 Fiscal Year Final Research Report Summary
Mechanism of Amyloid Fibril Formation and Resorption - A Protein A-Gold Immunoelectron Microscopic Study -
| Project/Area Number |
01570195
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Experimental pathology
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| Research Institution | Yamaguchi University |
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Principal Investigator |
TAKAHASHI Mutsuo Yamaguchi University Clinical Laboratories Associate Professor, 医学部, 助教授 (50112230)
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| Co-Investigator(Kenkyū-buntansha) |
UCHINO Fumiya Yamaguchi University Pathology Professor, 医学部, 教授 (20034902)
ISHIHARA Tokuhiro Yamaguchi University Pathology Associate Professor, 医学部, 助教授 (70089910)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Amyloidosis / Kupffer cell / Immunoelectron microscopy / Intracellular formation |
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| Research Abstract |
Amyloid formation and resorption in the murine liver were examined by the technique of protein A-gold immunoelectron microscopy using anti-mouse amyloid antiserum. The liver biopsy was done 4 days after the injections of amyloid enhancing factor and casein solution, and the mice were sacrificed 1 an 2 weeks after the biopsy.
In the biopsied liver, amyloid fibrils were seen mainly in the Disse's space along the cytoplasmic invaginations of Kupffer cells. By immunoelectron microscopy, gold particles labeled several inclusions within the cytoplasm of the Kupffer cells. These inclusions, being regularly round to fusiform in shape and measuring 0.5-1.0 mum in width and 1.0-3.0 mum in length, were constantly membrane-bounded. Some of them contained fibrillar structures, corresponding to amyloid fibrils, while most were composed of a homogeneous, granular matrix. These inclusions were thought to be derived from lysosomes or phagolysosomes based on their ultrastructural configurations. In the stage of amyloid resorption, gold particles labeled irregularly-shaped heterophagosomes in the Kupffer cells. These heterophagosomes contained flocculent and phagocytized membranous structures and amyloid fibrils as well, showing various stages of digestion.
The present results provide an additional support for the concept that some amyloid fibrils are formed within lysosome-derived organelles of the Kupffer cells following proteolytic cleavage of pinocytized serum amyloid A protein (a precursor protein of secondary amyloidosis).
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