miR-15a/-16 Inhibit Angiogenesis by Targeting the Tie2 Coding Sequence: Therapeutic Potential of a miR-15a/16 Decoy System in Limb Ischemia

Abstract

MicroRNA-15a (miR-15a) and miR-16, which are transcribed from the miR-15a/miR-16-1 cluster, inhibit post-ischemic angiogenesis. MicroRNA (miRNA) binding to mRNA coding sequences (CDSs) is a newly emerging mechanism of gene expression regulation. We aimed to (1) identify new mediators of the anti-angiogenic action of miR-15a and -16, (2) develop an adenovirus (Ad)-based miR-15a/16 decoy system carrying a luciferase reporter (Luc) to both sense and inhibit miR-15a/16 activity, and (3) investigate Ad.Luc-Decoy-15a/16 therapeutic potential in a mouse limb ischemia (LI) model. LI increased miR-15a and -16 expression in mouse muscular endothelial cells (ECs). The miRNAs also increased in cultured human umbilical vein ECs (HUVECs) exposed to serum starvation, but not hypoxia. Using bioinformatic tools and luciferase activity assays, we characterized miR-15a and -16 binding to Tie2 CDS. In HUVECs, miR-15a or -16 overexpression reduced Tie2 at the protein, but not the mRNA, level. Conversely, miR-15a or -16 inhibition improved angiogenesis in a Tie2-dependent manner. Local Ad.Luc-Decoy-15a/16 delivery increased Tie2 levels in ischemic skeletal muscle and improved post-LI angiogenesis and perfusion recovery, with reduced toe necrosis. Bioluminescent imaging ( in vivo imaging system [IVIS]) provided evidence that the Ad.Luc-Decoy-15a/16 system responds to miR-15a/16 increases. In conclusion, we have provided novel mechanistic evidence of the therapeutic potential of local miR-15a/16 inhibition in LI.

Angiopoietin-Tie Signaling Pathway in Endothelial Cells: A Computational Model

“…VEGF also affects Tie2 signaling by inducing the release of Ang2 stored in Weibel-Palade bodies (Matsushita et al., 2005) and stimulating the extracellular domain cleavage of Tie2 (Findley et al., 2007). A recent study demonstrated that targeting microRNA-15a and microRNA-16 enhanced Tie2 signaling and improved angiogenesis and perfusion (Besnier et al., 2019), suggesting that the present model can further integrate with computational models of microRNAs to elucidate the intricate interplay between microRNAs, VEGF pathway, and angiopoietin-Tie pathway (Zhao and Popel, 2015, Zhao et al., 2019). The current model provides a platform for further analysis of Tie2 localization and crosstalk with integrin and other signaling pathways to be explored in subsequent studies.…”

Hyperbaric oxygen‐induced long non‐coding RNA MALAT1 exosomes suppress MicroRNA‐92a expression in a rat model of acute myocardial infarction

“…MiR15a has been shown to inhibit angiogenesis. 29,30 We searched and found that rat MALAT1 has a matching site for miR-15a-5p and it is located from 4160 to 4178 bp of rat MALAT1 gene loci. Our study found that HBOinduced exosomes could significantly attenuate the miR15a expression induced by hypoxia in cardiac myocytes ( Figure S6).…”

Circulating MicroRNAs: Biogenesis and Clinical Significance in Acute Myocardial Infarction

“…Many studies on the diagnostic role of circulating miRNAs in AMI were initially based on big data analysis, but follow-up studies have also confirmed their relationship with cardiovascular disease which we will not discuss it here ( Liu W. L. et al, 2015 ; Wei L. X. et al, 2015 ; Xue et al, 2015 ; He and Huang, 2017 ; Besnier et al, 2019 ; Che et al, 2019 ; Li X. D. et al, 2019 ; Shen et al, 2019 ; Zhang et al, 2019 ). Meder et al (2011) identified two downregulated miRNAs, miR-1291 and miR-663b, among 121 miRNAs related to AMI through whole genome miRNA expression profiling.…”