Differentially expressed proteins in the liver of Gulo-/- mice following treatments with Helicobacter pylori and diethylnitrosamine / 동물의과학연구지

Vitamin C (ascorbic acid) is an essential nutrient of most living tissues. We established a strain of Gulo-/- mice with known deficiency, in which vitamin C intake can be controlled by diet, like humans, and investigated the differentially expressed proteins following treatments with Helicobacter pylori and diethylnitrosamine (DENA) in the liver of Gulo-/- mice using a proteomic approach. Expression of p53, 14-3-3epsilon and 14-3-3delta in Gulo-/- mice liver tissue was analyzed by immunohistochemistry. 2-DE maps constructed from Gulo-/- mice liver and differentially expressed proteins in liver tissue were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF/MS). In Gulo-/- mice after H. Pylori infection, followed by treatment with DENA, no differences in p53, 14-3-3epsilon and 14-3-3delta were observed by immunohistochemistry. Proteome analyses using MALDI-TOF/MS resulted in successful identification of 12 proteins (nine proteins were up-regulated and three were down-regulated). Specifically, peroxiredoxin-6 and Alpha-1-antitrypsin 1-4 were up-regulated in liver after H. Pylori infection followed by treatment with DENA. These results indicated that oral supplementation with vitamin C led to rescue of Gulo-/- mice from vitamin deficiency, and protected the liver from H.pylori infection and/or DENA effect, and vitamin C also protected the liver against oxidative stress.

The Analysis of Vitamin C Concentration in Organs of Gulo-/- Mice Upon Vitamin C Withdrawal

BACKGROUND: Vitamin C is an essential nutrient for maintaining human life. Vitamin C insufficiency in the plasma is closely related with the development of scurvy. However, in vivo kinetics of vitamin C regarding its storage and consumption is still largely unknown. METHODS: We used Gulo-/- mice, which cannot synthesize vitamin C like human. Vitamin C level in plasma and organs from Gulo-/- mice was examined, and it compared with the level of wild-type mice during 5 weeks. RESULTS: The significant weight loss of Gulo-/- mice was shown at 3 weeks after vitamin C withdrawal. However, there was no differences between wild-type and vitamin C-supplemented Gulo-/- mice (3.3 g/L in drinking water). The concentration of vitamin C in plasma and organs was significantly decreased at 1 week after vitamin C withdrawal. Vitamin C is preferentially deposited in adrenal gland, lymph node, lung, and brain. There were no significant changes in the numbers and CD4/CD8 ratio of splenocytes in Gulo-/- mice with vitamin C withdrawal for 4 weeks. And the architecture of spleen in Gulo-/- mice was disrupted at 5 weeks after vitamin C withdrawal. CONCLUSION: The vitamin C level of Gulo-/- mice was considerably decreased from 1 week after vitamin C withdrawal. Vitamin C is preferentially stored in some organs such as brain, adrenal gland and lung.