| 研究実績の概要 |
Cytoglobin (CYGB) was originally discovered from rat hepatic stellate cells (HSCs) in 2001 by our group, and is the fourth globin in mammals. Cygb deficient mice, Cygb overexpressing mice, and recombinant human CYGB protein were generated in our laboratory. The role of Cygb in anti-fibrosis and cancer were examined in different models of liver injuries including (1) chemical induced liver fibrosis using thioacetamide (TAA) treatment for 10 weeks; (2) carcinogen induced liver cancer using diethylnitrosamine (DEN) for 12 months; (3) diet induced non-alcoholic fatty liver diseases (NASH) using choline deficient amino acid define (CDAA) diet for 16 weeks. We found that in the absence of Cygb liver injuries were magnified in Cygb-KO mice. In contrast, Cygb overexpression protected mice from liver damage induced by different etiologies. Furthermore, we produced rhCYGB protein and found that rhCYGB possess antioxidant and peroxidase activities. Human hepatic stellate cells (HHSteC) under rhCYGB treatment showed suppression of fibrosis related genes such as Collagene 1A1, αSMA, TIMP-1, TGFβ1. In vivo model, rhCYGB administration in TAA-treated mice inhibited liver injuries, inflammation and fibrosis development. Thus, CYGB with ROS scavenger could play an important role for preventing from liver fibrosis
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
TAA model: Compared to WT mice, 10 week-TAA treated Cygb-TG showed markedly decreased inflammation and fibrosis development as indicated by (1) reduced accumulation of neutrophils in the liver (- 2 fold, p< 0.0001) together with specific down regulation of transcription level of Ccl-2 (- 2,4 folds, p < 0.001); (2) declined oxidative stress condition demonstrated by significant decreased expression of NOX-2 at mRNA level; (3) obviously inhibited fibrosis development as shown by decreased Sirius-red positive area, significantly decreased αSMA at protein and mRNA level, together with blocked mRNA level of Col1a1, TGFβ3. CDAA model: Choline deficient L-amino acid-defined diet (CDAA) and its control diet (choline-supplied L-amino acid-defined diet, CSAA) are administrated to WT, Cygb / , and Cygb-TG mice for 16 weeks. The results showed that after 16 weeks of CDAA treatment and or recovery, KO mice still exhibited most severe liver inflammation and fibrosis development and remaining after recovery. In contrast, TG mice showed less inflammation, fibrosis and well recover. rhCYGB production and application:We have produced human recombinant CYGB protein, and examined its potential anti-fibrotic therapy. Interestingly, we found that the rhCYGB binding to human HSCs cells, HHSteC, and supressed collagen production at protein and mRNA level with time and dose dependent.
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| 今後の研究の推進方策 |
1.In vitro study: using primary mouse hepatic stellate cells (HSC) and human HSC cell line to examine the mechanism action of CYGB in protect cells from oxidative stress and toxicity induced liver injuries.
2.Produce rhCYGB for application in vivo with several models including NASH model using CDAA diet, fibrosis model using TAA treatment, or cholestasis liver injury using 3,5-diethoxycar¬bonyl-1,4-dihydrocollidine (DDC) diet.
3.Molecular biology of liver fibrosis and pathological analysis
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