Erythrophagocytosis by Liver Macrophages (Kupffer Cells) Promotes Oxidative Stress, Inflammation, and Fibrosis in a Rabbit Model of Steatohepatitis
| Autor: | Fumihiko Hato, Kazuo Ikeda, Hideki Fujii, Yuji Nakajima, Kohji Otogawa, Yoshihiro Ikura, Kazuki Nakatani, Kohji Kinoshita, Makiko Ueda, Tetsuo Arakawa, Masahide Sakabe, Ryoko Shiga, Norifumi Kawada |
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| Rok vydání: | 2007 |
| Předmět: |
Hepatitis
medicine.medical_specialty Pathology Growth factor medicine.medical_treatment Kupffer cell Inflammation Biology medicine.disease Pathology and Forensic Medicine Pathogenesis medicine.anatomical_structure Endocrinology Fibrosis Internal medicine medicine Macrophage medicine.symptom Steatohepatitis |
| Zdroj: | The American Journal of Pathology. 170:967-980 |
| ISSN: | 0002-9440 |
| Popis: | Nonalcoholic steatohepatitis (NASH) is a progressive fibrotic disease, the pathogenesis of which has not been fully elucidated. Here, we report a molecular aspect of this disease elucidated using rabbits fed a cholesterol-rich high-fat diet and exhibiting insulin resistance. The liver in this model showed steatohepatitis with fibrosis and high mRNA expression for some cytokines, heme oxygenase-1, transforming growth factor-β1, and collagen α1(I). Erythrocytes isolated from the model showed marked fragility and the externalization of phosphatidylserine (PS) on the outer leaflet of the membrane and were frequently engulfed by Kupffer cells/macrophages in the hepatic sinusoids. Expression of milk fat globule-epidermal growth factor (EGF)-factor 8, a PS-binding protein, was augmented in the liver. In culture, RAW 264.7 cells engulfed erythrocytes oxidized by tert-butyl hydroperoxide, a process that was inhibited by anti-milk fat globule-EGF-factor 8 antibody. In addition, PS-positive erythrocytes appeared entrapped in the model liver in ex vivo perfusion experiments. Finally, in specimens from NASH patients, the aggregation of erythrocytes in inflammatory hepatic sinusoids was notable. These results indicate that the engulfment of PS-externalized, apoptotic signal-positive, erythrocytes by hepatic macrophages may lead to the deposition of iron derived from hemoglobin in the liver and be involved in the pathogenesis of steatohepatitis. |
| Databáze: | OpenAIRE |
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