[Improved angiogenesis by P-selectin glycoprotein ligand-1 overexpression in endothelial progenitor cells]

To explore whether overexpression of P-selectin glycoprotein ligand-1 (PSGL-1) promotes the adhesive ability of endothelial progenitor cells and functionally facilitates neovascularization in mouse model of hindlimb ischemia.

Rat endothelial progenitor cells were transfected with recombinant adenovirus vector encoding human PSGL-1. The mRNA and protein expression levels of PSGL-1 were measured by RT-PCR and Western blot, respectively. The effect of overexpression of PSGL-1 in endothelial progenitor cells was analyzed by adherence assay. Histological examination of skeletal muscle sections retrieved from the mouse ischemic hindlimbs was performed, and the hindlimb blood flow was measured by laser Doppler flow meter.

Adenovirus vector expressing of PSGL-1 gene was successfully constructed with high titer of 3.1 × 10¹¹ pfu/ml. After transfection, PSGL-1 gene was highly expressed in the transfected endothelial progenitor cells. In vitro assay showed that overexpression of PSGL-1 enhanced the adhesive properties of endothelial progenitor cells. When the transfected endothelial progenitor cells were transplanted into the ischemic hindlimb of nude mice, the number of new capillary vessels was (41.0 ± 2.2)/HPF compared to that of (21.0 ± 2.5)/HPF in the negative control group and (10.0 ± 1.6)/HPF in the blank control group (P < 0.01). Furthermore, the blood flow was increased in the experimental group (119.1% ± 7.0%), whereas in the negative control group, it was (93.3% ± 3.0%) and in the blank control group it was (76.3% ± 12.0%), P < 0.01.

Overexpression of PSGL-1 enhances the adhesive and angiogenic properties of endothelial progenitor cells. The approach may provide an effective therapeutic strategy to improve the efficiency of cell-based proangiogenic therapy.