Dai C H, Krantz S
Department of Medicine, Department of Veterans Affairs Medical Center, Nashville, Tennessee.
Exp Hematol. 1992 Oct;20(9):1055-60.
When orthovanadate, an inhibitor of protein tyrosine phosphatase activity, was added to highly purified human blood erythroid burst-forming units (BFU-E) a marked increase in the number and size of erythroid bursts was evident at an optimum concentration of 4 microM. Because BFU-E are stimulated by stem cell factor (SCF), interleukin 3 (IL-3), and erythropoietin (EP), this effect could occur through an enhancement of any one of these pathways. However, no effect was observed on human erythroid colony-forming units (CFU-E), indicating that vanadate was not potentiating the effect of EP. The time course of decline in BFU-E, when vanadate was added in vitro on successive days, followed the time course produced by delayed addition of SCF but not IL-3. In addition, vanadate markedly enhanced the effect of an optimal concentration of IL-3, but it could only enhance the effect of SCF when SCF concentrations were less than optimum. These experiments demonstrate that vanadate markedly stimulates the number and size of human BFU-E in vitro and that it mimics the effect of SCF. Vanadate may be acting as a phosphatase inhibitor that potentiates the kinase activity induced by SCF, but elucidation of its specific biochemical effects on these cells awaits further investigation.
当向高度纯化的人血红细胞爆式集落形成单位（BFU-E）中添加蛋白酪氨酸磷酸酶活性抑制剂原钒酸盐时，在4 microM的最佳浓度下，红细胞爆式集落的数量和大小明显增加。由于BFU-E受到干细胞因子（SCF）、白细胞介素3（IL-3）和促红细胞生成素（EP）的刺激，这种效应可能通过增强这些途径中的任何一种来发生。然而，在人红细胞集落形成单位（CFU-E）上未观察到任何效应，这表明钒酸盐并没有增强EP的作用。当连续数天在体外添加钒酸盐时，BFU-E数量下降的时间进程与延迟添加SCF所产生的时间进程一致，但与IL-3不同。此外，钒酸盐显著增强了最佳浓度IL-3的作用，但只有当SCF浓度低于最佳浓度时，它才能增强SCF的作用。这些实验表明，钒酸盐在体外显著刺激人BFU-E的数量和大小，并且它模拟了SCF的作用。钒酸盐可能作为一种磷酸酶抑制剂，增强了由SCF诱导的激酶活性，但其对这些细胞的具体生化作用还有待进一步研究。
