Thermostable direct hemolysin from Grimontia hollisae causes in vitro and in vivo hepatotoxicity
| Autor: | Lin, Yan-Ren, 林晏任 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 G. hollisae thermostable direct hemolysin (Gh-TDH) is produced by most strains of G. hollisae. This toxin has been reported to be absorbed in the intestines in humans. In addition to being absorbed by the intestine, TDH may also cause secondary injury to the liver via effects on the venous return of the portal system. However, a relationship between the TDH and the liver has not been reported or analyzed. In this study, we analyzed the hepatotoxicity of TDH in vivo and in vitro to provide insights into the acute injury and recovery stages of THD-induced hepatotoxicity in living animals. Liver cells (primary human non-cancer cell and FL83B mouse cells) were treated and mice (BALB/c) were fed with this toxin to investigate its hepatotoxicity. In this study, G. hollisae recombinant thermostable direct hemolysin (Gh-rTDH) was purified for further analysis. Morphological examination and cytotoxicity assays using liver cells were also performed. The morphological changes included cell detachment and a loss of cell cytoplasm with cell shrinkage. The MTT assay revealed that the cytoviability of liver cells decreased in proportion to the concentration of Gh-rTDH over different treatment durations (dose and time dependent.). Moreover, we noted that Gh-rTDH damaged liver cells in vitro when the concentration of Gh-rTDH exceeded 10-6 μg/ml. Fluorescein isothiocyanate-conjugated toxin was used to analyze the localization of this protein in liver cells. Cellular localization showed that the toxin was initially located around the cellular margins and subsequently entered the nucleus. Mice were subjected to liver function measurements and liver biopsies following toxin treatment and wild-type bacterial infection. Liver function measurements and liver biopsies of the mice following treatment with toxin or infection with wild-type Grimontia hollisae showed elevated levels of transaminases and damage to the periportal area, respectively. PET (positron emission tomography)/CT (computed tomography) images were taken to assess liver metabolism during acute injury and recovery. The PET/CT images revealed that the reconstruction of the liver continued for at least one week after exposure to a single dose of the toxin or bacterial infection. In conclusion, the hepatotoxicity of Gh-TDH was firstly demonstrated. The damage was located in the periportal area of the liver, and the liver became functionally insufficient. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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