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 differen- tially expressed proteins following treatments with Helicobacter pylori and diethylnitrosamine (DENA) in the liver of Gulo-/- mice using a proteomic approach. Expression of p53, 14-3-3ε and 14-3-3δ 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, 14-3-3ε and 14-3-3δ were observed by immunohistochemistry. Proteome analyses us- ing 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 ef- fect, and vitamin C also protected the liver against oxidative stress.
In order to investigate genetic stability and gene expression profile after cloning procedure, two groups of cloned pigs were used for swine leukocyte antigen (SLA) gene nucleotide alteration and microarray analyses. Each group was consist of cloned pigs derived from same cell line (n=3 and 4, respectively). Six SLA loci were analyzed for cDNA sequences and protein translations. In total, 16 SLA alleles were identified and there were no evidence of SLA nucleotide alteration. All SLA sequences and protein translations were identical among the each pig in the same group. On the other hand, microarray assay was performed for profiling gene expression of the cloned pigs. In total, 43,603 genes were analyzed and 2,150~4,300 reliably hybridized spots on the each chip were selected for further analysis. Even though the cloned pigs in the same group had identical genetic background, 18.6~47.3% of analyzed genes were differentially expressed in between each cloned pigs. Furthermore, on gene clustering analysis, some cloned pigs showed abnormal physiological phenotypes such as inflammation, cancer or cardiomyopathy. We assumed that individual environmental adaption, sociality and rank in the pen might have induced these different phenotypes. In conclusion, the results of the present study indicate that SLA locus genes appear to be stable following SCNT. However, gene expressions and phenotypes between cloned pigs derived from the same cell line were not identical even under the same rearing conditions.