Effect of endothelin-1 on proliferation,cell cycle and NO secreting function of endothelial progenitor cells from rat bone marrow

AIM To study the effects of endothelin-1 on proliferation, cell cycle and NO secreting function of endothelial progenitor cells from rat bone marrow. METHODS Mononuclear cells were collected from rat bone marrow by density gradient centrifugation, cultured with medium 199 and were identified to be EPC on day 6 by DiⅠ-ac-LDL and FITC-UEA-Ⅰ double staining. Different concentrations of ET-1 (group A, 0 mol /L; group B, 10-9 mol /L; group C, 10-8 mol/L; group D, 10-7 mol /L; group E, 10-6 mol /L) were added into culture medium to detect the effect on EPC. MTT assay was performed to detect the effect of ET-1 on the multiplication ability of EPC and Flow cytometry was employed to detect the cell cycle. NO content was measured in the cell culture medium by nitrate reductase method to find the promotion of ET-1 on cell functions. RESULTS Compared with that in the control group (group A, 0.405±0.017), the proliferation of EPC greatly enhanced in ET-1 group (group C, 0.434±0.016; group D, 0.463±0.015; group E, 0.473±0.015)(n=8, P0.01). The amount of EPC in ET-1 group in G0/G1 phase (group C, 57.28%±3.65%; group D, 44.99%±3.19%; group E, 40.29%±3.74%) was significantly lower than those in control group (group A, 70.55%±1.37%)(n=5, P0.01). Compare with that in the control group (20.04%±1.64%)(9.41%±0.81%), the amount of EPC in ET-1 group in S phase (group C, 26.75%±2.87%; group D, 32.79%±2.41%; group E, 35.74%±2.94%) and in G2/M phase (group C, 15.96%±1.71%; group D, 22.22%±2.22%; group E, 23.64%±2.86%) increased (n=5, P0.01). Compare with that in the control group(group A, 7.45±2.41), NO secreting function of EPC increased in ET-1 group (group C, 11.70±1.80; group D, 15.69±1.86; group E, 16.89±1.55)(n=8, P0.01). Group B showed no or only minor difference as compared with control group. CONCLUSION ET-1 stimulates EPC proliferation, promotes the division and multiplication of EPC and enhances the NO secretion capacity.