Comparative RNA-Seq transcriptome analyses of diabetic nerve and kidney disease II

Diabetic kidney disease (DKD) and diabetic peripheral neuropathy (DPN) are common complications of type 1 (T1D) and type 2 (T2D) diabetes. However, the mechanisms underlying the development and progression of these complications are unclear. Thus, the goal of the current study was to use system biology approaches to examine DKD and DPN pathogenesis in T1D and T2D mouse models on the same genetic background. We optimized a streptozotocin-induced db/+ murine model of T1D and compared it to our established db/db T2D mouse model of the same C57BLKS/J background and confirmed both develop DKD and DPN. Transcriptomic data from glomeruli and sciatic nerve tissue from T1D and T2D mice were analyzed by self-organizing map and differential gene expression analysis followed by functional enrichment. Consistent with prior literature, pathways related to immune function and inflammation were dysregulated in both DKD and DPN in T1D and T2D mice. The gene-level analysis identified a high degree of concordance in DEGs in both DKD and DPN and across diabetes type, suggesting genetic background influences diabetic complications. These findings offer new insight as the influence of genetic background on DPN in mouse models has not been well defined. Collectively, these findings support the role of inflammation and genetic background in complications of both T1D and T2D. mRNA profiles of four diabetic complication-prone tissues (sciatic nerve, dorsal root ganglia, kidney glomeruli and kidney cortex) from 16-week old BKS.Cg-m +/+ Leprdb/J mice with/without pioglitazone treatment of 15 mg/kg for 11 weeks. For type 1 diabetes model, a single high-dose 150 mg/kg (i.p.) streptozotocin (STZ) injection at 5 weeks of age, while db/db genetic model was used for type 2 diabetes model. Deep sequencing of six biological replicates in each tissues using Illumina HiSeq 2000.