| First Author | Robert K | Year | 2005 |
| Journal | Gastroenterology | Volume | 128 |
| Issue | 5 | Pages | 1405-15 |
| PubMed ID | 15887121 | Mgi Jnum | J:101303 |
| Mgi Id | MGI:3603726 | Doi | 10.1053/j.gastro.2005.02.034 |
| Citation | Robert K, et al. (2005) Cystathionine beta synthase deficiency promotes oxidative stress, fibrosis, and steatosis in mice liver. Gastroenterology 128(5):1405-15 |
| abstractText | BACKGROUND & AIMS: Cystathionine beta-synthase (CBS) deficiency causes severe hyperhomocysteinemia, which confers diverse clinical manifestations, notably liver disease. To investigate this aspect of hyperhomocysteinemia, we performed a thorough investigation of liver pathology in CBS-deficient mice, a murine model of severe hyperhomocysteinemia. METHODS: The degree of liver injury and inflammation was assessed by histologic examination, by measurements of products of lipid peroxidation, and by formation of carbonyl groups on protein as a measure for the occurrence of protein oxidation. Analysis of profibrogenic, proinflammatory factors and cell apoptosis was performed by Western blots, real-time quantitative reverse-transcription polymerase chain reaction, caspase-3 activity, DNA laddering, and TUNEL assay. RESULTS: Histologic evaluation of liver specimens of 8- to 32-week-old CBS-deficient mice showed that CBS-deficient mice develop inflammation, fibrosis, and hepatic steatosis, concomitant with an enhanced expression of tissue inhibitor of metalloproteinase-1, alpha-smooth muscle actin, pro(alpha)1 collagen type I, transforming growth factor-beta1, and proinflammatory cytokines. Moreover, even if the proapoptotic protein Bax was dominantly expressed and Bcl-2 was down-regulated, caspase-3 was not activated, DNA laddering was not detected, and number of positive TUNEL cells was not increased in liver of CBS-deficient mice compared with wild-type mice. CONCLUSIONS: The results show that hyperhomocysteinemia in liver of CBS-deficient mice promotes oxidative stress, which may cause mitochondrial damage in association with activation of hepatic stellate cells, leading to liver injury. The absence of caspase-3 activation, DNA fragmentation, and TUNEL-positive cells shows that protective signals may counteract apoptotic signals in liver of CBS-deficient mice. |
