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目的:使用抗氧化剂调控胞内活性氧物质(ROS)水平,考察其对脐血CD34+细胞体外扩增特性的影响。方法:在体外培养过程中,分别采用超氧化物歧化酶(SOD)、过氧化氢酶(CAT)或N-乙酰半胱氨酸(NAC)3种抗氧化剂降低脐血CD34+细胞内的ROS水平,研究了CD34+细胞在抗氧化剂清除ROS后的体外扩增特性。结果:体外培养时细胞因子的应用会使细胞内的ROS水平显著上升。3种抗氧化剂均能有效地清除细胞内ROS,且清除程度随使用剂量的改变而变化。在培养体系中添加2000U/mL SOD、200U/mL CAT或2mmol/L NAC,扩增后培养物中CD34+细胞及CD34+CD38-细胞的比例、集落生成细胞的密度均有明显提高,但对CD34+细胞扩增倍数影响不大;而加入8000U/mL SOD、1000U/mL CAT或5mmol/L NAC,抑制CD34+细胞的扩增能力。结论:采用细胞因子体外扩增脐血CD34+细胞时,使用低剂量的抗氧化剂适度清除细胞内的ROS,明显提高培养物中造血干/祖细胞的含量,同时并不影响扩增后CD34+细胞的再扩增能力。
OBJECTIVE: To study the effects of antioxidants on intracellular reactive oxygen species (ROS) levels and their effects on the in vitro expansion of cord blood CD34 + cells. Methods: In vitro culture, three antioxidants such as superoxide dismutase (SOD), catalase (CAT) or N-acetylcysteine (NAC) were used to reduce ROS levels in cord blood CD34 + cells , The in vitro expansion of CD34 + cells after anti-oxidant scavenging ROS was investigated. RESULTS: The use of cytokines during in vitro culture significantly increased intracellular ROS levels. All three kinds of antioxidants could effectively eliminate intracellular ROS, and the degree of clearance varied with the dosage. After adding 2000 U / mL SOD, 200 U / mL CAT or 2 mmol / L NAC, the ratio of CD34 + cells and CD34 + CD38- cells in the culture increased the density of colony forming cells, but the CD34 + However, adding 8000 U / mL SOD, 1000 U / mL CAT or 5 mmol / L NAC inhibited the proliferation of CD34 + cells. CONCLUSION: When using cytokines to expand cord blood CD34 + cells in vitro, low doses of antioxidants are used to moderately remove intracellular ROS and significantly increase the content of hematopoietic stem / progenitor cells in culture without affecting the expression of CD34 + cells Re-amplification of capacity.