Genome-wide transcriptional alterations during vascular growth in skeletal muscles of type 2 diabetic mice in response to femoral artery ligation

Diabetes is a major risk factor of cardiovascular disease including coronary and peripheral arterial disease, attributed to impaired arteriogenesis and angiogenesis. Mechanisms behind them are poorly understood due to the complexity of these processes in presence of diabetes. To understand the cellular and molecular mechanisms underlying impaired adaptive vascular responses in type 2 diabetic (T2DM) mouse models of hindlimb ischemia using Genome-wide mRNA sequencing.In response to FAL, collateral density and lumen area were significantly reduced in adductor muscles of T2DM mice at day 7 and 14 days post-FAL. mRNA sequencing suggested an altered gene expression typical for monocyte and macrophage (Mϕ) subsets. Similarly, gene expressions typical of dendritic cell and lymphocyte were altered in adductor muscles of T2DM mice. Ischemic muscles of T2DM mice displayed impaired angiogenesis as revealed by endothelial staining. mRNA sequencing suggested downregulation of crucial genes implicated in angiogenesis and differential expression of genes typical for Mϕ subsets. Immunohistochemistry analysis corroborated with the mRNA sequencing analysis, suggesting an altered Mϕ polarization behind the impaired arteriogenesis and angiogenesis seen in T2DM mouse models of hindlimb ischemia. Hindlimb ischemia was induced by femoral artery ligation (FAL). Arteriole and capillary parameters together with blood flow were analyzed from normoxic adductor and ischemic gastrocnemius muscles respectively, at day 7 and 14 post-FAL. Total RNA was isolated from both adductor and gastrocnemius muscles at day 7 post-FAL and sequencing was performed with libraries prepared from Poly (A) RNA fraction, using Illumina Genome Analyzer II.