Résumé
Objective To investigate the role of voltage-gated potassium channel in the human skin squamous cell carcinoma A431 cells and human keratinocyte HaCaT cells. Methods MTT assay was performed to detect the effect of different concentrations of tetraethylammonium (TEA) on the proliferation of cultured A431 cells and HaCaT cells. Besides, enzyme-linked immunosorbent assay (ELISA) was conducted to detect the expression of HERG channel protein in A431 cells, HaCaT cells and normal human skin tissue.Results TEA inhibited the proliferation of A431 cells and HaCaT cells in a dose- and time-dependent manner.After treated with TEA (≥ 10 mmol/L) for 24 or more hours, the proliferation of A431 cells and HaCaT cells was obviously suppressed. A significant difference was observed in the average concentration of HERG channel protein between A431 cells, HaCaT cells and normal human skin tissue (49.7114 ± 3.55696 pg/ml, 35.7471 ±4.14696 pg/ml, 36.8857 ± 3.47810 pg/ml, all P < 0.05). Conclusions The block of voltage-gated potassium channel could inhibit the proliferation of A431 cells and HaCaT cells, and the expression of voltage-gated potassium channel seems to be higher in human skin squamous cell carcinoma cells.
Résumé
Objective To analyze the changes in number and biological ability of endothelial progenitor cells (EPCs) from peripheral blood of SLE patients. Methods Mononuclear cells (MNCs) were isolated by Ficoll density gradient centrifugation from peripheral blood of 20 female SLE patients and 20 healthy female controls. EPCs were identified by double staining using antibodies to CD34 and CD133, or antibodies to CD133 and vascular endothelial growth factor receptor 2 (VEGFR2). Phycoerythrin (PE) conjugated antiCD34, fluorescein isothiocyanate (FITC) conjugated anti-CD133 and APC conjugated anti-VEGFR2 antibodies were used in a three color flow cytometric analysis to determine the percentage of EPCs in peripheral MNCs.The proliferation and migration ability of EPCs were measured by MTT assay and modified millicell chamber assay, respectively. The adhesion activity of EPCs was evaluated by counting the number of adherent cells.Results The percentage and proliferation rate of EPCs in peripheral MNCs from female SLE patients were significantly lower than those from the healthy controls(4.49% ± 1.66% vs 20.81% ± 4.14%, 23.11% ± 3.16%vs 35.65% ± 1.74%, both P ＜ 0.01 ). The migration and adhesion ability of EPCs from SLE patients was impaired compared with those from the healthy controls (12.00 ± 2.12 vs 23.60 ± 3.0 cells/field, 22.43 ± 4.43vs 36.43 ± 3.69 cells/filed, both P ＜ 0.01 ). Conclusion There is a decrease in the number and an impairment in biological ability of EPCs in SLE patients.