Reape T J, Wilson V J, Kanczler J M, Ward J P, Burnand K G, Thomas C R
Department of Medicine, U.M.D.S., St Thomas' Hospital, London, UK.
J Mol Cell Cardiol. 1997 Jun;29(6):1639-48. doi: 10.1006/jmcc.1997.0399.
Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the epidermal growth factor family which binds to and activates the epidermal growth factor (EGF) receptor. HB-EGF mRNA is expressed by monocytes and vascular smooth muscle cells (VSMC) in culture, and has been shown to be a potent VSMC mitogen in vitro. The aim of this study was to screen normal and human atherosclerotic arteries and SMC cultured from these arteries for expression of HB-EGF, and to determine its cellular localization in human lesions. Using the highly sensitive technique of reverse transcription polymerase chain reaction (RT-PCR), we screened biopsies taken from normal human vessel walls and atherosclerotic tissue, for expression of HB-EGF mRNA. Northern blotting and RT-PCR were employed to determine levels of HB-EGF gene expression in SMC, cultured from normal and atherosclerotic arteries. Cellular localization of mRNA and protein, within human atherosclerotic plaques, was assessed using in situ hybridization with 35S labelled riboprobes, and immunohistochemistry with polyclonal antibodies specific for human HB-EGF. HB-EGF mRNA was found to be expressed in human atherosclerotic lesions and in VSMC cultured from these lesions. Expression of HB-EGF could not be detected in quiescent aortic VSMC using Northern blotting, but was highly up-regulated in these cells after treatment with basic fibroblast growth factor (bFGF) for 24 h. Although HB-EGF mRNA was detected in all vascular tissue examined using RT-PCR, in situ hybridization and immunohistochemistry revealed expression of HB-EGF in small portions of diseased arteries only. Immunohistochemistry showed strong staining for macrophages in all areas of HB-EGF expression. No association of HB-EGF with SMC was observed in any of the specimens examined. In conclusion, HB-EGF, a potent mitogen for VSMC, is expressed by macrophages in human.
肝素结合表皮生长因子样生长因子（HB-EGF）是表皮生长因子家族的成员，它能结合并激活表皮生长因子（EGF）受体。HB-EGF mRNA在培养的单核细胞和血管平滑肌细胞（VSMC）中表达，并且已被证明在体外是一种有效的VSMC有丝分裂原。本研究的目的是筛查正常人和人类动脉粥样硬化动脉以及从这些动脉培养的平滑肌细胞（SMC）中HB-EGF的表达情况，并确定其在人类病变中的细胞定位。我们使用逆转录聚合酶链反应（RT-PCR）这种高灵敏度技术，筛查取自正常人体血管壁和动脉粥样硬化组织的活检样本中HB-EGF mRNA的表达情况。采用Northern印迹法和RT-PCR来测定从正常动脉和动脉粥样硬化动脉培养的SMC中HB-EGF基因的表达水平。使用35S标记的核糖探针进行原位杂交以及用针对人HB-EGF的多克隆抗体进行免疫组织化学，来评估人类动脉粥样硬化斑块内mRNA和蛋白质的细胞定位。发现HB-EGF mRNA在人类动脉粥样硬化病变以及从这些病变培养而来的VSMC中表达。使用Northern印迹法在静止的主动脉VSMC中检测不到HB-EGF的表达，但在用碱性成纤维细胞生长因子（bFGF）处理24小时后，这些细胞中的HB-EGF表达被高度上调。尽管使用RT-PCR在所有检测的血管组织中都检测到了HB-EGF mRNA，但原位杂交和免疫组织化学显示HB-EGF仅在病变动脉的小部分区域表达。免疫组织化学显示在HB-EGF表达的所有区域巨噬细胞均有强染色。在任何检测的标本中均未观察到HB-EGF与SMC有关联。总之，HB-EGF作为一种有效的VSMC有丝分裂原，在人类中由巨噬细胞表达。
