Abstract 15275: Dysregulated Micro-RNA Expression in Fat Tissue Linked to Angiogenesis Response in Patients in Peripheral Artery Disease

Abstract

Microvascular dysfunction contributes to adverse clinical outcomes in patients with peripheral artery disease (PAD). Compromised angiogenesis may be a treatment target for limb ischemia but is challenging to assess in patients. Selected circulating miRNAs have been implicated in the pathogenesis of PAD, thus, we seek to identify and find correlation between altered miRNA signatures and angiogenesis potential in patients with PAD. We collected adipose tissue from ischemic limbs of patients with PAD (n=15, age=64±11, 33% women, 66% T2DM, 61% current smoking) at the time of revascularization surgery. Control adipose tissue was procured from patients without PAD undergoing joint replacement surgery (n=6, age=58±6, 50% women, 17% T2DM, 33% current smoking). Endothelial cell sprouting assay demonstrated lower angiogenesis response over 8 days in adipose tissue samples from PAD patients compared to controls (p=0.008). We performed miRNA profiling using NextSeq (Illumina Inc.) sequencer. miRNA NGS libraries were prepared using QIAseq miRNA Library Kit. Quality controlled NGS libraries were sequenced according to the manufacturer protocol. Our results demonstrated 40 upregulated and 11 downregulated miRNAs (FDR q<0.01, log2 fold change>2) in PAD fat tissue compared to controls. Using bioinformatics approaches to prioritize differentially expressed miRNA predicted to impact pathways relevant to cardiovascular disease, we identified miR205-5p and miR182-5p as top candidate. There were higher levels of miR205-5p (4.8-fold, FDRq=1.5e-10) and miR182-5p (4.1-fold, FDRq=5.4e-16) in adipose tissue from PAD patients compared to controls. We confirmed the differentially expressed levels using qPCR in selected samples. Ingenuity pathway analysis indicates that miR205-5p inhibits VEGF-A, a key regulator of angiogenesis. We observed a trend toward an association of miR205-5p (r=-0.58, p=0.1) and miR182-5p (r=-0.67, p=0.06) and lower angiogenesis response. Taken together our findings demonstrate impaired microvascular angiogenesis response in patients with PAD along with upregulation of selected miRNA predicted to impair angiogenesis pathways.