Whole-transcriptome analysis of liver transcriptome differences between normal and hyperglycemic pigs

Pig is commonly used as an animal model for studying diseases, such as diabetes mellitus (DM), since it has similar anatomic and metabolic features to humans. Nevertheless, available data to profile the whole-transcriptome using next generation sequencing RNA-seq technology are still limited. The purpose of this study was to systematically investigate the liver transcriptome differences between normal pig and hyperglycemic pig. We detected the total RNA sequence of the liver tissues from pigs in three groups, including normal glycemic (CTL) group, spontaneous hyperglycemic (SH) group and streptozotocin (STZ) induced hyperglycemic group. We acquired 105.1 million of 150 bp read pairs, of which 76% mapped to the reference genome. We identified 19,059 novel transcripts and 2,804 putative proteins. A total of 501, 627 and 579 differentially expressed genes (DEGs) were identified in CTL vs. SH, CTL vs. STZ and SH vs. STZ groups, respectively. The intersection of all DEGs acquired 32 genes. Next, the functions of DEGs in the three groups were analyzed, and the results revealed that glycogen biosynthetic process, Type II DM and insulin signaling pathways were significantly enriched. Finally, the protein-protein interaction network of 32 genes was constructed. In conclusion, our study expanded the understanding of biological alterations in transcriptional levels under hyperglycemic conditions in pig model. The qRT-PCR validation of DEGs showed that the expressions of HKDC1 and ADH4 were significantly elevated in hyperglycemic groups. Our results revealed novel candidate genes for treating DM.