The Effect of Leptin on the Proliferation of the Endothelial Progenitor Cells from Peripheral Blood

Kim, Hyung Hoi; Kim, Sin Young; Lee, Eun Yup; Moon, Hwa Sook; Son, Han Chul; Joo, Bo Sun

Abstract

BACKGROUND: Leptin has been found to be involved in the regulation of hematopoiesis processes and angiogenesis. Therefore, we investigated the effect of leptin in the proliferation and angiogenesis of peripheral blood (PB)-derived endothelial progenitor cells (EPCs).
METHODS
Mononuclear cells were isolated from PB of healthy male volunteers and were cultured in endothelial cell growth medium-2 (EGM-2). After 6 days of culture, cells were treated with 50 ng/mL vascular endothelial growth factor (VEGF) and/or with various concentrations of leptin (10 ng/mL, 100 ng/mL, 1microgram/mL, and 10 microgram/mL) and were further cultured for one week. Proliferation of EPCs was examined by an assay measuring the uptake of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbo cyanine-labeled acetylated LDL (Dil-ac-LDL) and tubule formation on a matrigel. The control group of cells was not treated with VEGF and/or leptin.
RESULTS
The number of Dil-ac-LDL labeled-EPCs, tubule formation on matrigel and the number of cells present along tubules were significantly increased in the leptin-treated groups of cells as compared to the control group or VEGF treated group of cells (P<.05). The effect was synergistically increased in the group of cells co-treated with leptin and VEGF. The number of EPCs was increased in a leptin dose-dependent manner that was maximal at a concentration of 1microgram/mL leptin.
CONCLUSION
This study shows that leptin increased in vitro proliferation and angiogenesis of EPCs derived from peripheral blood.