[中枢神经系统白血病中白血病细胞对血脑屏障的破坏]

[Disruption of blood brain-barrier by leukemic cells in central nervous system leukemia].

作者信息

Feng Sa-ran, Chen Zi-xing, Cen Jian-nong, Shen Hong-jie, Wang Yuan-yuan, Yao Li

机构信息

Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou 215006, China.

出版信息

Zhonghua Xue Ye Xue Za Zhi. 2011 May;32(5):289-93.

PMID:21729594

Abstract

OBJECTIVE

To observe the effect of leukemic cells on blood-brain barrier (BBB) in mice with central nervous system leukemia (CNSL) by establishing mice CNSL model and an in vitro BBB model and explore the mechanism of leukemic cell infiltrating central nervous system (CNS).

METHODS

After splenectomy, cytoxan intraperitoneal injection, and sublethal irradiation, 10 BALB/c nu/nu mice were transplanted intravenously with 1.2 × 10(7) of SHI-1 human monocytic leukemic cells. Mice were monitored for survival and clinical manifestation of nerve palsy. The leukemic cells engrafted were examined by RT-PCR, histopathology and bone marrow (BM) smears. Immunofluorescence analysis with laser scanning fluorescence confocal microscopy was used to determine the expression of fibrinogen and tight-junction protein ZO-1. An in vitro BBB model composed of human brain microvascular endothelial cells (BMVECs) was developed on a Matrigel-based insert. Different leukemic cell lines were seeded onto the upper compartment of transwell insert. After incubated for 24 h with BMVECs, cells that had migrated into the lower compartment were counted and analyzed.

RESULTS

(1) Paralysis with or without sight loss was developed in half the mice 30-35 d after innoculated with SHI-1 cells. Leukemic cells infiltrates were observed in BM and in different part of brain tissues including brain parenchyma. The transcriptions of human MLL/AF6 fusion gene were also detected in BM and brain tissues in paralysis mice. The fibrinogen expression and ZO-1 disruption were detected in the infiltrated tissue. (2) After 24 h incubation with leukemic cells, the BMVECs sheets were disrupted and grew singly and ZO-1 expression was down-regulated markedly. SHI-1 cells showed more injurious to BMVECs and higher invasive rate [(40.33 ± 1.53)% vs (11.83 ± 1.44)%, P < 0.05] than HL-60 cells did.

CONCLUSION

One of the mechanisms of leukemic cells infiltrates CNS in CNSL is injure to the BBB.

摘要

目的

通过建立小鼠中枢神经系统白血病（CNSL）模型和体外血脑屏障（BBB）模型，观察白血病细胞对CNSL小鼠血脑屏障的影响，探讨白血病细胞浸润中枢神经系统（CNS）的机制。

方法

对10只BALB/c裸鼠进行脾切除、腹腔注射环磷酰胺及亚致死剂量照射后，经静脉移植1.2×10⁷个SHI-1人单核细胞白血病细胞。监测小鼠存活情况及神经麻痹的临床表现。通过RT-PCR、组织病理学和骨髓涂片检查植入的白血病细胞。采用激光扫描荧光共聚焦显微镜免疫荧光分析测定纤维蛋白原和紧密连接蛋白ZO-1的表达。在基于基质胶的小室上建立由人脑微血管内皮细胞（BMVECs）组成的体外血脑屏障模型。将不同的白血病细胞系接种到Transwell小室的上室。与BMVECs共孵育24小时后，对迁移到下室的细胞进行计数和分析。

结果

（1）接种SHI-1细胞后30 - 35天，半数小鼠出现伴有或不伴有视力丧失的麻痹。在骨髓及包括脑实质在内的脑组织不同部位观察到白血病细胞浸润。在麻痹小鼠的骨髓和脑组织中也检测到人类MLL/AF6融合基因的转录。在浸润组织中检测到纤维蛋白原表达及ZO-1破坏。（2）与白血病细胞共孵育24小时后，BMVECs片层被破坏并单独生长，ZO-1表达明显下调。SHI-1细胞对BMVECs的损伤更大，侵袭率更高[（40.33±1.53）%对（11.83±1.44）%，P<0.05]，高于HL-60细胞。