Impaired angiogenesis in diabetic critical limb ischemia is mediated by a miR-130b/INHBA signaling axis

Patients with peripheral artery disease (PAD) and diabetes compose a high-risk population for development of critical limb ischemia (CLI) and amputation, although the underlying mechanisms remain poorly understood. Comparison of dysregulated microRNAs from diabetic patients with PAD and diabetic mice with limb ischemia revealed the conserved microRNA, miR-130b-3p. In vitro angiogenic assays demonstrated that miR-130b rapidly promoted proliferation, migration, and sprouting in endothelial cells (ECs), whereas miR-130b inhibition exerted antiangiogenic effects. Local delivery of miR-130b mimics into ischemic muscles of diabetic mice (db/db) following femoral artery ligation (FAL) promoted revascularization by increasing angiogenesis and markedly improved limb necrosis and amputation. RNA-Seq and gene set enrichment analysis from miR-130b-overexpressing ECs revealed the BMP/TGF-beta signaling pathway as one of the top dysregulated pathways. Accordingly, overlapping downregulated transcripts from RNA-Seq and miRNA prediction algorithms identified that miR-130b directly targeted and repressed the TGF-beta superfamily member inhibin-beta-A (INHBA). miR-130b overexpression or siRNA-mediated knockdown of INHBA induced IL-8 expression, a potent angiogenic chemokine. Lastly, ectopic delivery of silencer RNAs (siRNA) targeting Inhba in db/db ischemic muscles following FAL improved revascularization and limb necrosis, recapitulating the phenotype of miR-130b delivery. Taken together, a miR-130b/INHBA signaling axis may provide therapeutic targets for patients with PAD and diabetes at risk of developing CLI.

Automated summary

Patients with peripheral artery disease (PAD) and diabetes are at high risk for critical limb ischemia (CLI) and amputation, but the underlying mechanisms are poorly understood. A conserved microRNA, miR-130b-3p, was found in dysregulated microRNAs from diabetic patients with PAD and diabetic mice with limb ischemia. In vitro studies showed that miR-130b promoted angiogenesis in endothelial cells (ECs), while inhibition of miR-130b had antiangiogenic effects. Local delivery of miR-130b mimics into ischemic muscles of diabetic mice improved revascularization and reduced limb necrosis and amputation. The miR-130b/INHBA signaling axis may provide potential therapeutic targets for patients with PAD and diabetes at risk of developing CLI.