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

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 G_0+G_1 phase of exposure group on d 1、2 and of protection group on d 1 were significantly higher than that of control 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.