Increased angiogenic potential of endothelial progenitor cells isolated from patients with endstage kidney disease using cellular therapy.

Abstract

Aim: To enhance the angiogenic potential of endothelial progenitor cells (EPCs), isolated and expanded from patients with dialysis-dependent chronic kidney disease, using mesenchymal stem cells (MSCs) and serelaxin (Rln). Background(s): EPCs are critical for revascularization and adequate wound healing after injury. However less is known about enhancing EPC function as a means of regeneration in patients with progressive kidney damage. Method(s): Mononuclear cells were isolated from blood of ESKD patients prior to dialysis. Endothelial colony forming units (CFU) were quantified in vitro after 7 days and identified via uptake of Dil-AC-LDL and lectin binding. After 4weeks of culture, phenotypic analysis was performed using immunocytochemistry for endothelial lineage. Angiogenic potential of EPCs was tested using wound healing, proliferation and tube forming assays both with/without MSCs and Rln and compared to primary human endothelial cells. Result(s): Primary human endothelial cells cultured directly or with conditioned media from MSCs in combination with Rln (1 ng/mL) performed significantly better in wound healing (p<0.001), proliferation (p<0.05) and tube forming assays (p<0.05) compared to basal media, MSCs or Rln alone. EPCs isolated from patients with ESKD demonstrated double positive staining of Dil-ac-LDL and lectin and had impaired CFU compared to control patients without ESKD. The majority of EPCs had transitioned into mature endothelial cells by 4weeks of culture, visualized using confocal microscopy by their cobblestone morphology and positive staining for vWF, CD31 and VEGFR2. Conclusion(s): EPCs can be successfully isolated from patients with ESKD and matured into endothelial cells after 4weeks of culture. Their angiogenic potential can bemodulated and enhanced ex vivo with the use of MSCs and Rln, which may have implications in kidney revascularization after injury.