Expression profiling by high throughput sequencing
Summary
Purpose: To clarify cellular and molecular mechanisms underlying impaired post-ischemic adaptive vascular responses and to evaluate reconstituted HDL (rHDL)-ApoA-I nanotherapy to rescue the defect in type 2 diabetic (T2DM) mouse model of hindlimb ischemia (HLI). Methods: Mice with beta-cell specific over-expression of insulin-like growth factor-2 in atherosclerotic background (IGF-II/ LDLR-/-ApoB100/100) with T2DM features were used in the study with C57BL/6J mice fed with a regular chow-diet (R36, Lactamin) serving as controls. Mice aged between 16 to 20 weeks were used in the study . Mice were anaesthetized with 1.5-2% isoflurane/air mixture during the surgical procedure. Hair was removed from the operation site and cleaned with sterile water. Single incision was made just above medial thigh and superficial femoral artery was separated from femoral vein and nerve. HLI was induced by unilateral ligation of femoral artery distal to the origin of the profunda femoral artery. The skin was closed with interrupted silk sutures. Mice were were administered with reconstituted ApoA-I nanoparticles with phosphatidyl serine core (rHDL) intravenously starting 2 days post-HLI with doses every 2 days until scarification with Saline injections serving as controls. Adductors muscle aortic endothelial cells (AECs) and Ischemic muscle Macrophages and Endothelial Cells (ECs) were isolated using a combination of magnetic assisted cell sorting and flow Cytometry using Macrophage (F4/80) and EC (CD-31) specific markers. Total RNA isolated from FACS sorted cells were used for RNA seq library preparation. Results: Cell-specific gene expression, flow cytometry and immunohistochemistry revealed a persistent Macrophage and Endothelial cell inflammation and a reduced anti-inflammatory M2-macrophage activation associated with impaired collateral remodelling and sprouting angiogenesis in T2DM mice. Furthermore, reconstituted HDL (rHDL)- ApoA-I was found to rescue impaired collateral remodelling and angiogenesis in T2DM mice through modulating EC and macrophage phenotypes. Conclusions: Our results suggest that an impaired collateral remodelling and sprouting angiogenesis in T2DM mice after HLI is associated with a persistent EC and macrophage inflammation and a reduced activation of anti-inflammatory M2-macrophage. Skewing the macrophage phenotype towards the pro-arteriogenic and pro-angiogenic anti-inflammatory M2-macrophages using reconstituted HDL (rHDL)-ApoA-I nanotherapy may serve as a potential therapeutic modality for T2DM PAD.
Overall design
Macrophage and endothelial cell specific RNA sequencing was performed on 3-4 samples (Each sample was pooled from 3-4 mice) by 3’mRNA-Seq approach using single-end sequencing with 75 bp reads on an Illumina NextSeq500 instrument .
Less...
More...