红细胞生成素诱导小鼠骨髓纤维化模型的实验研究

A Mouse Model of Myelofibrosis Induced by High Dose of Recombinant Human Erythropoietin

本研究旨在利用大剂量人重组红细胞生长素(rhEPO)诱导骨髓纤维化(M F)小鼠模型。60只昆明小鼠分为正常对照和EPO诱导组,分别用生理盐水和rhEPO进行腹腔注射,在实验第6、30、60、90、120和150天每组分别处死5只鼠。用细胞分析仪测定外周血白细胞数、血红蛋白(Hb)水平、红细胞平均体积(MCV)、红细胞分布宽度(RDW)和血小板量;用流式细胞术检测骨髓CD34阳性细胞率,称重肝、脾,计算肝、脾系数,利用HE和网状纤维染色分析肝、脾、股骨病理变化;应用高清CT测定股骨皮质厚度、髓腔直径和腰椎密度。结果表明,与正常对照组相比,EPO组各阶段白细胞轻度增高,但无统计学差异(p>0.05);Hb和RDW在第6和30天增高显著(p<0.05);MCV在第6天增高显著(p<0.05);各阶段血小板数降低,在第120和150天差异显著(p<0.05)。EPO组第60天肝肿大明显,肝系数差异显著(p<0.05);各阶段脾肿大,脾系数差异显著(p<0.05)。EPO组各阶段骨髓CD43阳性细胞率显著增高(p<0.05),第150天CT显示股骨皮质增厚,髓腔变窄,密度不均,腰椎密度增高。病理检查显示,EPO组小鼠肝脂肪化和空泡化,脾脏巨核细胞增多,股骨硬化和骨髓纤维组织增多。结论:大剂量rhEPO可诱导小鼠出现M F特有临床和病理特点。本研究对建立新的M F模型和病理研究有重要意义。

Tn order to set up a mouse model of myelofibrosis （MF） induced with high dose recombinant human erythropoietin （rhEPO）. 60 mice were collected and divided into EPO and control groups, the former was injected with rhEPO and the latter with normal saline intraperitoneally. 5 mice from each group were executed on day 6,30, 60, 90, 120 and 150 respectively. Their WBC count, Hb level, MCV, RDW and platelet amount were measured by automatic blood cell analyzer; CD34＋ cell ratio in bone marrow were analyzed by flow cytometry; liver and spleen coefficients were measured; pathological changes of liver, spleen, femur were observed by HE staining and reticular fibers staining; cortex thickness, femoral canal diameter and lumbar spine density were determined by computerized tomography （CT）. The results indicated that as compared with normal control group in EPO induced group, WBC count was increased slightly in whole period, but without statistic significance （p 〉 0.05 ）, Hb level and RDW increased at day 6 and 30 significantly （p 〈 0.05 ）, MCV increased at day 6 significantly （p 〈 0.05 ）, but platelet amount decreased significantly at all time points （p 〈 0.05 ）. Most mice in EPO-induced group had hepatomegalia and their liver and spleen coefficient increased significantly at day 60 （p 〈 0.05 ）, while most mice had splenomegaly and its coefficient was increased significantly at all time-points （p 〈 0.05 ）. CD43＋ cell ratio of EPO group increased significantly in whole period （p 〈 0.05）. CT scanning displayed femoral cortical thickening, medulla canal narrowing and lumbar spine density increasing at day 150, meanwhile, HE staining and reticular fiber staining showed the fatty degeneration or vacuolization in liver, splenegnly with megakaryocytic proliferation, femur bone marrow fibrosis and osteosclerosis. It is concluded that the mouse induced by high dose of rhEPO displays the myelofibrosis associated with splenic extramedullary hemopoiesis,and this study is useful to establish a practical MF model, and to explore its pathological mechanism.