Abstract 11795: CXCL5 Inhibition Recovers Neovascularization in Diabetes Mellitus

Introduction: Diabetes mellitus (DM) is a chronic inflammatory disease accompanied by dysfunction of vascular endothelial cells. Vascular complications are the main causes of death in patients with DM. CXCL5 is an inflammatory chemokine that upregulated in patients with type 2 DM. However, its role in diabetic vasculopathy was not clarified. This study aimed to explore the impacts and mechanistic insights of CXCL5 in neovasculogenesis in DM.

Methods: Endothelial progenitor cells (EPCs) and human aortic endothelial cells (HAECs) were used in vitro. Streptozotocin-induced diabetic mice and dbdb mice were used as type 1 and type 2 DM models. CXCL5 knockout mice were also used to generate the diabetic animal model. The hindlimb ischemia surgery, matrigel plug assay, and aortic ring assay were conducted. Flow cytometry were used to evaluate the circulating number of EPCs.

Results: CXCL5 concentrations were increased in plasma and EPCs culture medium from type 2 DM patients. CXCL5 inhibition by neutralizing antibody upregulated VEGF/SDF-1 expression and improved migration and tube formation abilities in EPCs from type 2 DM patients and high glucose-treated EPCs from non-diabetic subjects as well as HAECs. Intraperitoneal injection of CXCL5 neutralizing antibody increased circulating EPC number, enhanced capillary density, and recovered the blood flow after hindlimb ischemia surgery in both type 1 and type 2 diabetic animals. Protein levels of VEGF and SDF-1 in ischemic muscle were upregulated in the CXCL5 inhibition group. Additionally, diabetic mice injected with CXCL5 neutralizing antibody showed higher hemoglobin contents and neovascular branches in the matrigel plug assay and aortic ring assay, respectively. Importantly, CXCL5 knockout diabetic mice showed improved ischemia-induced angiogenesis and higher expression of angiogenic proteins in ischemic muscle compared with wild-type diabetic mice.

Conclusion: CXCL5 inhibition can improve neovasculogenesis via protecting vascular endothelial function and upregulating angiogenic protein expressions in both type 1 and type 2 DM. Further clinical studies are needed to verify that CXCL5 may be a potential therapeutic target for DM vascular complications.