骨髓增生异常综合征富集造血祖细胞半胱天冬酶活性检测及意义

目的　了解骨髓增生异常综合征 (MDS)患者不同阶段骨髓造血祖细胞凋亡的变化及半胱天冬酶caspase3、caspase9的作用。方法　应用负筛选法纯化MDS患者骨髓造血祖细胞 (包括CD3 4 +和CD3 4 -细胞 ) ,通过AnnexinⅤ方法检测其凋亡 ,同时应用分光光度法测定细胞内caspase3、caspase9的活性。结果　①MDS RA组 12例 ,凋亡率为 39.5 % ;RAEB组 10例 ,凋亡率为 31.0 % ,两组凋亡率均明显高于对照组 (P <0 .0 1)。RAEB t/AML组 12例 ,凋亡率为 18.8% ,与对照组相比 ,差异无显著性。②MDS RA组caspase3活性较正常对照升高约 4 5倍 (P <0 .0 1) ,caspase9的活性较正常对照升高约 2 0倍(P <0 .0 1)。RAEB组 ,caspase3活性较正常对照升高约 14倍 (P <0 .0 1) ,caspase9的活性较正常对照升高 2倍余 (P <0 .0 1)。RAEB t/AML组 ,caspase3活性稍高于正常对照 (无统计学意义 ) ,caspase9的活性与正常对照相比 ,差异无显著性。③RAEB组中有 3例最终转为急性髓系白血病 (AML) ,其凋亡率、caspase3和caspase9的平均吸光度值均相应下降。结论　MDS患者骨髓造血祖细胞在疾病不同阶段凋亡率是不同的 ,caspase3、caspase9活性升高 ,可能是造成MDS骨髓造血祖细胞过度凋亡的重要原因 ,caspase9活性下降可能是MDS发展过程中骨髓造

Analysis of caspases activity of hematopoietic progenitor cells and its significance in myelodysplastic syndromes

OBJECTIVE: To investigate the changes of apoptosis and the activity of caspases 3 and 9 in bone marrow hematopoietic progenitor cells in myelodysplastic syndromes (MDS). METHODS: Bone marrow hematopoietic progenitor cells (including both CD(34)(+) and CD(34)(-) cells) were collected by negative selection in 34 patients with MDS. Apoptosis was measured with Annexin V assay and activities of caspases 3 and 9 by spectrophotometer. RESULTS: 1. Apoptosis was significantly increased in MDS-RA (39.5%, P < 0.01) and MDS-RAEB (31.0%, P < 0.05), but was not different statistically in MDS-RAEBt/AML (18.8%) compared with that of control. 2. Activities of caspases 3 and 9 increased 45 and 20 fold in MDS-RA, increased 14 and 2 fold in MDS-RAEB, respectively and was not increased in MDS-RAEBt/AML compared with that of control. 3. Apoptosis and activities of caspases 3 and 9 reduced in 3 cases of MDS-RAEB group who progressed into AML. CONCLUSION: Increased activities of caspases 3 and 9 may be one of causes of excessive apoptosis in MDS. With progress to AML, activities of caspases 3 and 9 and apoptosis reduced. Reduced activity of caspase 9 may result in apoptosis "escape" and progression into AML.