A miRNA/CXCR4 signaling axis impairs monopoiesis and angiogenesis in diabetic critical limb ischemia

Abstract

Patients with peripheral artery disease (PAD) and diabetes have the highest risk of critical limb ischemia (CLI) and amputation, yet the underlying mechanisms remain incompletely understood. MicroRNA (miRNA)-sequencing of plasma from diabetic patients with or without CLI was compared to diabetic mice with acute or subacute limb ischemia to identify conserved miRNAs. miRNA knockout mice on high fat diet were generated to explore impact on CLI. Comparison of dysregulated miRNAs from diabetic human subjects with PAD and diabetic mice with limb ischemia revealed conserved miR-181 family members. High fat-fed, diabetic Mir181a2b2 knockout (KO) mice had impaired revascularization in limbs due to abrogation of circulating Ly6C hi monocytes with reduced accumulation in ischemic skeletal muscles. M2-like KO macrophages under diabetic conditions failed to produce pro-angiogenic cytokines. Single cell transcriptomics of the bone marrow niche revealed that the reduced monocytosis in diabetic KO mice is a result of impaired hematopoiesis with increased CXCR4 signaling in bone marrow Lineage -Sca1 + Kit + (LSK) cells. Exogenous Ly6C hi monocytes from nondiabetic KO mice rescued the impaired revascularization in ischemic limbs of diabetic KO mice. Increased Cxcr4 expression is mediated by the novel miR-181 target, Plac8.Taken together, MiR-181a/b is a putative mediator of diabetic CLI and contributes to alterations in hematopoiesis, monocytosis, and macrophage polarization.

Recent developments in targets for ischemic foot disease

“…37 C57BL/6 mice with global deficiency in alleles miR-181a2b2 had significantly worse recovery of blood supply following HLI induction compared to wild type controls. 37 Bone marrow transplant and cell specific transgenic studies suggested that miR-181 deficiency impaired Ly6Chi monocyte mobilisation from the bone marrow without local effects in endothelial cells. The impairment in blood flow recovery and the density of new capillaries in these mice could be rescued by infusion of Ly6Chi monocytes, illustrating the importance of these cells in angiogenesis.…”

“…35 A number of studies have also implicated microRNAs (miRs) in controlling bone marrow cell contribution to angiogenesis and arteriogenesis. 36,37 Cheng and colleagues studied miRs in patients with PAD and mice models of acute HLI secondary to Femoral artery ligation (FAL) and more gradual HLI secondary to placement of ameroid constrictors around the femoral artery (Supplement Figure 2). 36,37 They identified 22 miRs including three of the four members of the miR-181 family (miR-181a-5p, miR-181b-5p and miR-181c-5p) that were downregulated in the plasma of both patients with diabetes and PAD, and mice with HLI.…”

“…36,37 Cheng and colleagues studied miRs in patients with PAD and mice models of acute HLI secondary to Femoral artery ligation (FAL) and more gradual HLI secondary to placement of ameroid constrictors around the femoral artery (Supplement Figure 2). 36,37 They identified 22 miRs including three of the four members of the miR-181 family (miR-181a-5p, miR-181b-5p and miR-181c-5p) that were downregulated in the plasma of both patients with diabetes and PAD, and mice with HLI. 37 These miR-181 members were also downregulated within the ischaemic limbs of mice with impaired glucose tolerance compared to those with normal glucose handling.…”

“…36,37 They identified 22 miRs including three of the four members of the miR-181 family (miR-181a-5p, miR-181b-5p and miR-181c-5p) that were downregulated in the plasma of both patients with diabetes and PAD, and mice with HLI. 37 These miR-181 members were also downregulated within the ischaemic limbs of mice with impaired glucose tolerance compared to those with normal glucose handling. 37 C57BL/6 mice with global deficiency in alleles miR-181a2b2 had significantly worse recovery of blood supply following HLI induction compared to wild type controls.…”

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

“…Characteristics of human subjects are found in Supplemental Table 1. All human patient samples (25,50) conform to the principles outlined in the Declaration of Helsinki.…”