MIP-1α和血小板第4因子对造血干细胞化疗药物损伤的保护作用

Protection of hematopoietic stem cells by MIP-1α and PF4 against the cytotoxicity of chemotherapeutic agents

目的 研究巨噬细胞炎性蛋白 (MIP 1α)、血小板第 4因子 (PF4)及二者联合对造血干细胞化疗药物损伤的保护效应及其分子机制。方法 将骨髓、脐血单个核细胞及白血病细胞株HL 6 0分别予MIP 1α、PF4、MIP 1α +PF4、PBS预处理 48h ,再经柔红霉素 (DNR)孵育 2 4h后 ,用锥虫蓝 (台盼蓝 )拒染法测细胞活性 ,用流式细胞仪测细胞周期及CD34 + CD38- 细胞含量 ,细胞集落培养、免疫化学法测细胞P16、P2 7蛋白。结果 经MIP 1α及PF4预处理的骨髓和脐血单个核细胞 ,细胞活性、CD34+ CD38-细胞、集落形成能力均比对照组显著增加 (P <0 .0 5 )。MIP 1α、PF4组正常脐血及骨髓细胞S +G2 期百分率低于对照组 (P <0 .0 5 )。MIP 1α可上调细胞周期调控蛋白P16表达。PF4对P16、P2 7表达无影响。MIP 1α的保护作用强于PF4,但两者无协同效应。HL 6 0细胞P16、P2 7蛋白表达、细胞周期、细胞活性均不受MIP 1α、PF4的影响。结论 造血负调控因子MIP 1α、PF4能可逆性、选择性地保护正常造血细胞免受化疗药损伤 ,MIP 1α通过上调造血祖细胞G1 S期调控基因p16表达 ,使细胞阻滞于G0 期 ,提高细胞对周期特异性化疗药的耐受性。

Objective To study the protective effects of macrophage inflammatory protein 1α(MIP 1α) and platelet factor 4(PF4), alone and in combination, on hematopoietic stem/progenitor cells against the cytotoxicity of chemotherapeutic drugs. Methods Bone marrow and cord blood mononuclear cells(BMMNC and CBMNC) and HL 60 cells were pretreated with MIP 1α, PF4, MIP 1α+ PF4,and PBS respectively for 48 hours, and then incubated with DNR for an additional 24 hours. Cell viability, cell cycle, CD 34 + CD 38 - cells, colony forming units(CFU) and protein expression of p16, p27 gene were measured. Results ①Cell viability, the number of CD 34 + CD 38 - cells and CFU yields of BMMNC and CBMNC in MIP 1α and PF4 groups were significantly higher than that in control groups(P<0.05). ②Cells in S+G 2 phase in MIP 1α and PF4 groups were significantly fewer than that in control groups(P<0.05). ③MIP 1α upregulated the expression of p16 gene of stem/progenitor cells. PF4 showed no effects on expression of both p16 and p27 genes. ④Hematopoietic protection of MIP 1α was stronger than that of PF4. No cooperative effect could be seen in combination of the two agents.⑤Cell viability, cell cycle and expression of p16 and p27 gene of HL 60 cells were not affected by either MIP 1α or PF4. Conclusion MIP 1α and PF4 can reversibly and selectively protect hematopoietic stem/progenitor cells against cytotoxicity of chemotherapeutic agents. MIP 1α can suppress cell proliferation by upregulating the expression of p16 gene and block the cell cycle at G 0 phase, resulting in the elevation of cell resistance to chemotherapeutic drugs.