Objective: To observe the effect of platelets on hematopoietic stem cell (HSCs) implantation in mice with radiation-induced bone marrow injury and bone marrow transplantation models. Methods: ①Male C57BL/6 mice were divided into a single irradiation group and a radiation infusion group after receiving (60)Co semimyeloablative irradiation for 18-10 weeks. The irradiation infusion group received 1×10(8) platelets expressing GFP fluorescent protein. ② The allogeneic bone marrow transplantation model was established. The experimental groups included the simple transplantation group (BMT) and the transplantation infusion group (BMT+PLT). The BMT group was infused through the tail vein only 5 × 10(6) bone marrow cells, the BMT+PLT group needs to be infused with bone marrow cells at the same time 1× 10(8) platelets. ③ Test indicators included peripheral blood cell and bone marrow cell counts, flow cytometry to detect the proportion of hematopoietic stem cell (HSC) and hematopoietic progenitor cells, bone marrow cell proliferation and apoptosis, and pathological observation of vascular niche damage and repair. Results: ①On the 3rd, 7th, 14(th), and 21st days after irradiation, the bone marrow cell count of the infusion group was higher than that in the single irradiation group (P<0.05), and the peripheral blood cell count was also higher. A statistically significant difference was found between the white blood cell count on the 21st day and the platelet count on the 7th day (P<0.05). In the observation cycle, the percentage of bone marrow cell proliferation in the infusion group was higher, while the percentage of apoptosis was lower. ② The results of bone tissue immunofluorescence after irradiation showed that the continuity of hematopoietic niche with red fluorescence was better in the irradiation infusion group. ③The chimerism percentage in the BMT+PLT group was always higher than that in the BMT group after transplantation.④ The BMT+PLT group had higher bone marrow cell count and percentage of bone marrow cell proliferation on the 7th and 28th day after transplantation than that in the BMT group, and the percentage of bone marrow cell apoptosis on the 14th day was lower than that in the BMT group (P<0.05). After the 14th day, the percentage of stem progenitor cells in the bone marrow cells of mice was higher than that in the BMT group (P<0.05). ⑤The immunohistochemical results of bone marrow tissue showed that the continuity of vascular endothelium in the BMT+PLT group was better than that in the BMT group. Conclusion: Platelet transfusion can alleviate the injury of vascular niche, promotes HSC homing, and is beneficial to hematopoietic reconstruction.
目的： 观察血小板输注对(60)Co照射所致小鼠骨髓造血龛损伤修复和骨髓移植后造血重建的影响。 方法： ①以8~10周雄性C57BL/6小鼠为研究对象，接受(60)Co全身照射后分为单独照射组和照射输注组（经尾静脉输注1×10(8)个表达GFP荧光蛋白的血小板）。②建立小鼠异基因造血干细胞移植模型，分为单纯移植组（BMT组）和移植+血小板输注组（BMT+PLT组）。BMT组仅通过尾静脉输注5×10(6)个骨髓细胞，BMT+PLT组在输注骨髓细胞的同时输注1×10(8)个血小板。检测外周血血细胞和骨髓细胞计数，流式细胞术检测骨髓造血干细胞（HSC）和造血祖细胞（HPC）比例、骨髓细胞增殖率和凋亡率，病理观察造血龛的损伤与修复。 结果： ①在照射后第3、7、14和21天，照射输注组骨髓细胞计数和外周血细胞计数均高于单纯照射组（P值均<0.05），第21天输注组白细胞计数高于单纯照射组，第7天血小板计数高于单纯照射组（P值均<0.05）。在观察周期内照射输注组骨髓细胞增殖率较高，而凋亡率较低；②免疫荧光结果显示照射输注组造血龛的连续性更好；③在移植后，BMT+PLT组嵌合率始终高于BMT组；④BMT+PLT组在移植后第7、28天的骨髓细胞计数和骨髓细胞增殖率均高于BMT组，第14天骨髓细胞凋亡率低于BMT组（P值均<0.05），骨髓细胞中HSC、HPC占比在第14天以后均高于BMT组（P值均<0.05）；⑤骨髓组织的免疫组化染色结果显示BMT+PLT组血管内皮连续性更好。 结论： 输注血小板可减轻(60)Co照射所致小鼠骨髓造血龛的损伤，有利于骨髓移植后造血重建。.
Keywords: Bone marrow transplantation; Hematopoietic microenvironment; Mouse; Platelet transfusion.