2003 Fiscal Year Final Research Report Summary
Liver cell rearrangement and apoptosis duirng retardation of fetal hematopoiesis
| Project/Area Number |
14570031
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | KAWASAKI MEDICAL SCHOOL |
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Principal Investigator |
SASAKI Kazunobu Kawasaki Med School, Dept of Anatomy, Professor, 医学部, 教授 (90002261)
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| Co-Investigator(Kenkyū-buntansha) |
KUMANO Ichiro Kawasaki Med School, Dept of Anatomy, Instructor, 医学部, 助手 (10289176)
SONODA Yuji Kawasaki Med School, Dept of Anatomy, Instructor, 医学部, 助手 (80268599)
IWATSUKI Hirohiko Kawasaki Med School, Dept of Anatomy, Associate Professor, 医学部, 助教授 (70069061)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Liver Hematopoiesis / Hepatocyte / Programmed cell death / Macrophages / Apoptosis / F4 / 80 / Iron staining / Neonatal mouse |
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| Research Abstract |
Neonatal livers examined by the TUNEL method have been found to contain dying hematopoietic cells, and a few hepatocytes have been also found to be positive. Regarding the ultrastructural features of dying hepatocytes, two different types of cell death; types I and II were observed. The early features of type I cell death appeared in the cytoplasm, which was characterized by dilated rough endoplasmic reticulum. Type II cell death was characterized by compaction and margination of heterochromatin resulting in the formation of sharply circumscribed masses. Type I corresponds to cytoplasmic type degeneration and non-apoptotic death, whereas type II corresponds to nuclear type cell death or classical apoptotic death. The incidence of type I cell death was much higher than that of type II.
Immunochistochemical staining with rat anti-mouse macrophage monoclonal antibody F4/80 permits a more objective identification of macrophages under light micorscopy. There was a rapid increase in the number of F4/80-positive cells per unit area from 11 days of gestation, but there was a significant decrease between 4 and 13 days after birth(p<0.01). In fetal livers, F4/80-positive cells were identified among hepatic cell cords as central macrophages of erythroblastic islands in the hematopoietic foci. The macrophages contained phagosomes from extruded nuclei of erythroblasts and Fe-positive inclusions. At 19 days of gestation, a few F4/80-positive cells without hematopoietic cells also appeared among hepatocytes. In neonatal livers, a few small F4/80-positive but Fe-negative mononuclear cells also appeared. Some of large macrophages underwent cell death not only through classical apoptosis but also through a process called "dark cell formation." The small F4/80-positive but Fe-negative mononuclear cells in early postnatal livers could be considered as a candidate for a precursor of hepatic resident macrophages.
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Research Products
(12 results)
