骨髓移植小鼠骨髓基质细胞内皮抑制素(endostatin)及血管细胞黏附分子-1(VCAM-1)表达相关性研究

本研究探讨内皮抑制素（endostatin）及血管细胞黏附分子-1（VCAM-1）在骨髓移植（BMT）小鼠骨髓基质细胞中表达的相关性及川芎嗪对其表达的影响。取健康BALB／c小鼠，随机分为3组：正常组（不做处理），骨髓移植对照组（简称生理盐水组）和骨髓移植＋川芎嗪治疗组（简称川芎嗪组）。生理盐水组和川芎嗪组分别胃饲生理盐水0．2毫升／只和川芎嗪注射液每次2毫影只，2次／天。在BMT后第7、14、21、28天处死小鼠，用间接免疫荧光法和RT—PCR法检测骨髓基质细胞endostatin mRNA及其蛋白、VCAM-1 mRNA及其蛋白的表达情况，并探讨二者表达的相关性。结果表明：endostatin蛋白主要表达于骨髓基质细胞核内，VCAM-1蛋白主要表达于细胞浆内。BMT后第7、14、21天川芎嗪组和生理盐水组endostatin mRNA和蛋白的表达水平显著低于正常组（P〈0．01或P〈0．05），且川芎嗪组低于生理盐水组（P〈0．01或P〈0．05）；到第28天生理盐水组已基本恢复正常，而川芎嗪组仍未恢复正常水平。BMT后第7、14、21天川芎嗪组和生理盐水组VCAM-1 mRNA和蛋白的表达均明显低于正常组（P〈0．01或P〈0．05），且川芎嗪组明显高于生理盐水组（P〈0．01或P〈0．05），到第28天，川芎嗪组VCAM-1的表达已基本恢复正常，而生理盐水组仍未恢复正常，两组之间有显著性差异（P〈0．01）。相关分析显示，生理盐水组骨髓基质细胞endostatin和VCAM-1 mRNA及其蛋白表达呈负相关（P〈0.01或P〈0．05），而川芎嗪组endostatin和VCAM-1 mRNA及其蛋白表达呈正相关（P〈0．01或P〈O．05）。结论：内皮抑制素可通过影响骨髓基质细胞表面VCAM-1的表达水平，阻碍基质细胞与造血细胞之间和细胞外基质与造血细胞之间的联系而影响骨髓造血；川芎嗪能提高BMT小鼠骨髓基质细胞表面黏附分子的表达，加快BMT后HSPC的归巢及在骨髓中的增殖，并通过反馈调节BMT小鼠骨髓基质细胞新血管生成抑制因子内皮抑制素的表达，促进骨髓微环境的修复，加速移植后骨髓的造血重建。

Relationship between Endostatin and Vascular Cell Adhesion Molecule-1 Expressions on Bone Marrow Stromal Cells in BMT-mice

This study was aimed to investigate the relationship between endostatin and vascular cell adhesion molecule-1 (VCAM-1) expressions on bone marrow stromal cells (BMSC) in mice after bone marrow transplantation (BMT) and effect of ligustrazine on their expressions. The mice were randomly divided into 3 groups: normal group (without treatment), saline group (control of BMT) and ligustrazine group (BMT+ligustrazine). BMT mouse models were established. The normal group was not treated, the saline group was given normal saline (0.2 ml/mouse, twice a day ) through gastric tube, while the ligustrazine group was given ligustrazine (0.2 ml/mouse, twice a day) also through gastric tube. On day 7,14,21 and 28 after BMT, mice were killed by euthanasia. The expression levels of endostatin and VCAM-1 in bone marrow stromal cells were detected by immunohistochemistry and RT-PCR analysis respectively. The results showed that the endostatin protein mainly expressed in nuclei of BMSCs, the VCAM-1 protein mainly expressed in plasma of BMSCs. On day 7, 14, 21 affter BMT the expression levels of endostatin mRNA and protein in ligustrazin and saline groups were significantly lower than that in normal group (P<0.01 or P<0.05), while their expression levels in ligustrazine group were lower than that in saline group. On day 28 the expression levels in saline group returned to nomal, while the expression levels in ligustrazine group not were normalized. On day 7, 14, 21 after BMT the expression levels of VCAM-1 mRNA and protein in ligustrazine and saline groups were significantly lower than that in normal group (P<0.01 or P<0.05), but their expression levels in ligustrazine group were significantly ligher than that in saline group (P<0.01 or P<0.05). On day 28 the VCAM-1 expression level in ligustrazine group returned to normal, while its expression level in saline group not were normalized. The difference between these two groups was significant (P<0.01). Correlation analysis revealed that there was a negative correlation between endostation and VCAM-1 expression in saline group, there was a positive correlation between endostatin and VCAM-1 expression in ligustrazine group. It is concluded that the endostatin can influence hemotopoiesis in bone marrow by effacting VCAM-1 expression on BMSC and hindering connection between stromal cells and hematopoietic cells as well as extracellnlar stroma and hematopoietic cells, while ligustrazine can enhance the adhesion malecule expression on stromal cell surface of bone marrow in BMT-mice, accelerate the homing and proliferation of HSPC in bone marrow after BMT, meanwhile can promote the repair of bone marrow microenvinment, accelerate hematopoietic reconstitution of bone marrow after BMT through feeback regulation of endostatin expression of BMSC in BMT-mice.