血小板第4因子对急性辐射损伤小鼠骨髓细胞周期的调控作用

Protective effects of platelet factor 4 on bone marrow of mice with radiation injury and its mechanism

目的:研究血小板第4因子(plateletfactor4,PF4)对急性辐射损伤小鼠骨髓细胞的保护作用,初步探讨其机制。方法:雄性BALB/c小鼠随机分为3组:照射组、PF4+照射组、正常对照组。PF4+照射组在照射前26及20h腹腔注射PF440μg·kg-1,前两组全身一次性4Gy60Co-γ射线照射,照射后d1、2、4、8流式细胞仪测定小鼠骨髓细胞的细胞周期,免疫组化法动态观察骨髓基质细胞p21蛋白表达水平变化。结果:流式细胞仪测定细胞周期,照射后d1、2的照射组及照射后d1的PF4+照射组G0+G1期细胞百分数均明显高于正常对照组,而照射组与PF4+照射组各时间点之间亦存在明显差异(P<0.05)。照射后d2、8PF4+照射组的G0+G1期细胞百分数与正常对照组无明显差异(P>0.05)。免疫组化结果显示照射后d2、4PF4+照射组骨髓基质细胞p21蛋白呈强阳性表达,照射组呈弱阳性。而照射后d8照射组骨髓基质细胞p21蛋白呈强阳性表达,PF4+照射组则呈弱阳性表达。正常对照组p21蛋白表达水平较低。结论:PF4通过调节细胞周期对小鼠骨髓细胞有明显的辐射保护作用,可尽快恢复其造血功能,p21蛋白的高表达可能在此保护机制中起到了一定的作用。

AIM： To study the protective effects of platelet factor 4（PF4） on the bone marrow cells of the radiation injury mice and to do some preliminary studies for its mechanism. METHODS： BALB/c male mice were randomly divided into three groups： exposure group, protection group with PF4 and control group. The mice of protection group were injected PF4 （40 μg·kg^-1 ） into abdominal cavity twice at 26 h and 20 h before irradiation of 4 Gy^60 Co-γ ray. The cell cycle of bone marrow cells was determined with flow cytometry on d 1,2,4,8 after irradiation. The expression level of p21 in BMSCs were detected with immunohistochemistry. RESULTS：The cells on G0 ＋ G1 phase of exposure group on d 1,2 and of protection group on d 1 were significantly higher than that ofcontrol group, the difference between exposure group and protection group is notable at every time point （P 〈0. 05）, while the difference between protection group on d 2,8 and exposure group on the same day was not significant（ P 〉 0.05）. On d 2,4 after irradiation, the expression of p21 in BMSCs of protection group was up-regulated compared with that of exposure group. On d8 the result was opposite. CONCLUSION： PF4 has obvious protective effects on the bone marrow of the radiation injury mice by controlling cell cycle and recovering its hematopoietic function as early as possible. The high expression of p21 maybe has a certain effect on the protective mechanism.