铁调素及膜铁转运蛋白在铁过载小鼠模型中表达变化的研究

Expression Changes of Hepcidin and Ferroportin 1 in Murine Model of Iron Overload

目的:建立铁过载动物模型,探讨铁调素及膜铁转运蛋白在铁过载中的作用。方法:C57BL/6纯系小鼠经腹腔注射右旋糖酐铁(10 mg/次,2次/周,共4周),分别于铁剂注射前,铁剂注射2周,铁剂注射4周取外周血进行血常规及血清铁检查,并对各脏器(肝脏、脾脏,心脏、股骨)铁沉积进行病理分析。应用ELISA方法检测铁过载动物模型血清铁调素水平,RT-PCR及Western blot方法检测骨髓细胞膜铁转运蛋白水平,流式细胞术检测骨髓细胞内铁水平。结果:铁过载动物外周血白细胞总数、血红蛋白水平及血小板数无明显变化,而网织红细胞绝对值及百分比均随铁剂注射次数增加而呈进行性下降(r=-0.938,r=-0.947)。铁过载动物外周血血清铁水平随铁剂注射次数增加而呈进行性升高(r=0.894)。动物各脏器的病理分析结果发现,铁过载动物各脏器均出现不同程度铁沉积。进一步研究发现,铁过载动物外周血铁调素水平均随铁剂注射次数增加而呈进行性升高(r=0.957)。RT-PCR及Western blot结果显示,铁过载动物骨髓细胞膜铁转运蛋白mRNA及蛋白水平均明显增高(P<0.05)。流式细胞术检测结果亦发现,铁过载动物模型骨髓细胞内铁浓度水平明显升高(P<0.05)。结论:铁调素及膜铁转运蛋白在铁过载动物中表达水平明显升高,可能影响骨髓红系造血功能。

Objective： To investigate the changes of hepcidin and ferropotin 1 expression in murine model of iron overload. Methods ： The murine model of iron overload was established, C57BL/6 mice were injected with iron dextran intraperitoneally （10 rag） every 3 days for 4 weeks. Blood routine, serum ferritin and pathological sections were tested at the appointed time-point respectively （before iron injection, 2 weeks and 4 weeks after treatment of iron injection）. The serum hepcidin was assayed by enzyme-linked immunosorbent method. The expression of ferroportin 1 in bone marrow cells was detected by RT-PCR and Western blot, respectively. The labile iron pool of bone marrow ceils was measured by flow cytometry. Results ： The absolute number and percentage of reticulocytes in the iron-overloaded mice were significantly decreased along with the increase of iron injection times （ r = - 0. 938, r = - 0. 947 ）, while no significant change was found in the number of white blood cells, hemoglobin level and platelet count. The level of serum ferritin was increased along with increase of iron injection time （ r = 0. 894）. Iron overload was found in pathological sections of different organs. Furthermore, serum hepcidin was increased along with increase of iron injection time （ r -- 0. 957 ）. RT-PCR and Western blot analyses showed that the expressions of ferroportin 1 at mRNA and protein level were increased in the murine model of iron overload （ P 〈 0.05 ）. Labile iron pool in bone marrow cells was also found to be increased in the murine model of iron overload（ P 〈 O. 05 ）. are increase in a murine model of iron overload, which may bone marrow. Conclusion： The expressions of hepcidin and ferroportin 1 be contributed to the suppression effect on erythropoiesis in