Gene Expression Profiles in Skeletal Muscle and Liver of Type 2 Diabetes Rats

Analyzing changes in gene expression in liver and skeletal muscle from streptozotocin-diabetic rats. From the 9,929 expressed genes across the genome, 1,305 and 997 differentially expressed genes (DEGs, P < 0.01) were identified in comparisons of skeletal muscle and liver, respectively. Interestingly, large numbers of DEGs (200) were common to both comparisons, which was clearly more than the predicted number (131 genes, P < 10-4). Further interpretation of gene ontology used three over-representation analysis software (WebGestalt, Expander and GATHER). All the tools detected one KEGG pathway (MAPK signaling) and two GO biological processes (response to stress and cell death), with enrichment of DEGs in both tissues. In addition, PPI (protein-protein interaction) networks constructed using human homologs not only revealed the tendency of DEGs to form a highly connected module, but also suggested a “hub” role of MAPK related genes (such as MAPK14) in the pathogenesis of T2D.本研究分析链脲佐菌素（streptozotocin）诱导糖尿病大鼠的肝脏与骨骼肌组织的基因表达变化。从全基因组共检测到的9929个表达基因中，分别在骨骼肌与肝脏的组间比较中鉴定出1305个和997个差异表达基因（differentially expressed genes, DEGs，P < 0.01）。值得注意的是，两类比较中共存在200个共享DEGs，该数量显著高于预测值（131个基因，P < 10^-4）。后续针对基因本体（gene ontology, GO）的注释分析采用了三款过表达分析工具：WebGestalt、Expander及GATHER。三款工具均检测到1条KEGG通路（MAPK信号通路，MAPK signaling）与2个GO生物过程条目：应激应答与细胞死亡，且两类组织中的DEGs均呈现显著富集。此外，基于人类同源基因构建的蛋白质相互作用（protein-protein interaction, PPI）网络不仅揭示了DEGs倾向于形成高度连接的模块，还表明MAPK相关基因（如MAPK14）在2型糖尿病（type 2 diabetes, T2D）的发病机制中发挥“枢纽”作用。