L-精氨酸抑制非对称性二甲基精氨酸对内皮祖细胞的增殖作用

Depressant Effects of Asymmetric Dimethylarginine on the Proliferation of Endothelial Progenitor Cell and the Antagonism of L-Arginine

目的研究非对称性二甲基精氨酸对人脐带血内皮祖细胞增殖的影响及观测L-精氨酸对非对称性二甲基精氨酸的抑制作用。方法从脐带血中分离出单个核细胞,体外培养7天,在贴壁细胞中加入不同浓度的非对称性二甲基精氨酸(1、5和10μmol/L)作用不同时间(24、48和72h),用MTT比色法和细胞克隆计数法评价非对称性二甲基精氨酸对内皮祖细胞增殖的影响;加入L-精氨酸后采用MTT比色法和高倍荧光显微镜下DiI标记的乙酰化低密度脂蛋白染色细胞计数法分析L-精氨酸对非对称性二甲基精氨酸作用内皮祖细胞的影响;硝酸还原酶法测定培养基上清液一氧化氮含量,采用化学比色法测定培养基上清液总一氧化氮合酶活力。结果非对称性二甲基精氨酸呈量效和时效性地减少内皮祖细胞数目和增殖能力;随着L-精氨酸浓度的增加,L-精氨酸能有效抑制非对称性二甲基精氨酸对内皮祖细胞的作用。结论非对称性二甲基精氨酸可能通过抑制内皮祖细胞的增殖促进内皮功能不全的发展,而外源性L-精氨酸能抑制非对称性二甲基精氨酸的作用。

Aim To investigate the effects of asymmetric dimethylarginine （ADMA） on the proliferation of endothelial progenitor cell （EPC） of human umbilical cord blood and observe whether L-arginine can antagonize the effects of ADMA. Methods Mononuclear cells were isolated from fresh cord blood and cultured for 7days, attached cells were incubated with different concentration of ADMA （ 1, 5 and 10 μmol/L） among different times （24, 48 and 72 h）. MTT assay was used and colony forming units （CFU） were quantified to evaluate the proliferation of EPC after treated with ADMA. Meanwhile, MTr assay was used and DiⅠ-acLDL uptake cells under high-power field of fluorescence microscopy were quantified to assay effects of L-arginine on ADMA-induced EPC proliferation. Nitric oxide （NO） and nitric oxide synthase （NOS） in the supematant were measured by nitrate reductase assay and chemical colorimetry assay. Results Incubation of EPC with ADMA dose and time-dependently decreased the number and the proliferation of EPC. In addition, the depressant effect of ADMA on EPC were dismissed with the inceasing dosage of L-arginine. Conclusions It is suggested that ADMA can promote endothelial dysfunction by means of depressant EPC proliferation and exogeno L-arginine maybe antagonize the effects of ADMA.