Chen C, Li J, Micko C J, Pierce G F, Cunningham M R, Lumsden A B
Department of Surgery, Veterans Affairs Medical Center, Decatur, Georgia 30033, USA.
J Surg Res. 1998 Feb 15;75(1):35-41. doi: 10.1006/jsre.1997.5211.
Vascular smooth muscle cell (SMC) proliferation is an integral component of intimal lesion formation. In this study we compared the mitogenic effects of basic fibroblast growth factor (bFGF) and heparin binding epidermal growth factor (HBEGF) and the cytotoxic effects of bFGF and HBEGF conjugated with plant cytotoxin saporin (SAP) on vascular cell cultures. Human vascular SMCs and endothelial cells were cultured and FGF receptor-1 (FGFR-1) and EGF receptor (EGFR) expression were detected by immunohistochemical staining. Cells were grown in 24-well plates. Variable amounts of testing drugs (bFGF, HBEGF, SAP, bFGF-SAP, or HBEGF-SAP) were added to quadruplicate wells after 24 h. Cells without drugs were used as control. The total number of cells was counted at 72 h using a hemocytometer. The cultured human vascular SMCs and endothelial cells expressed both FGFR-1 and EGFR with predominant perinuclear localization. bFGF and HBEGF demonstrated equally potent mitogenic effects on SMC proliferation. SAP alone showed a limited cytotoxic effect on both SMCs and endothelial cells. bFGF had a more potent effect on endothelial cell proliferation than HBEGF. bFGF-SAP was equally cytotoxic for both SMCs and endothelial cells, while HBEGF-SAP had a more selectively cytotoxic effect on SMCs than on endothelial cells. These data suggest that the mitogenic effects of bFGF and HBEGF and the cytotoxic effects of bFGF-SAP and HBEGF-SAP may both be mediated by their corresponding growth factor receptors. Because of its selective cytotoxic effect on SMCs, HBEGF-SAP may become a more attractive agent for controlling intimal lesion formation.
血管平滑肌细胞（SMC）增殖是内膜病变形成的一个重要组成部分。在本研究中，我们比较了碱性成纤维细胞生长因子（bFGF）和肝素结合表皮生长因子（HBEGF）的促有丝分裂作用，以及与植物细胞毒素皂草素（SAP）偶联的bFGF和HBEGF对血管细胞培养物的细胞毒性作用。培养人血管平滑肌细胞和内皮细胞，并通过免疫组织化学染色检测成纤维细胞生长因子受体-1（FGFR-1）和表皮生长因子受体（EGFR）的表达。细胞在24孔板中生长。24小时后，将不同量的测试药物（bFGF、HBEGF、SAP、bFGF-SAP或HBEGF-SAP）加入一式四份的孔中。未加药物的细胞用作对照。72小时时使用血细胞计数器计数细胞总数。培养的人血管平滑肌细胞和内皮细胞均表达FGFR-1和EGFR，主要定位于核周。bFGF和HBEGF对SMC增殖显示出同样有效的促有丝分裂作用。单独的SAP对SMC和内皮细胞均显示出有限的细胞毒性作用。bFGF对内皮细胞增殖的作用比HBEGF更强。bFGF-SAP对SMC和内皮细胞具有同等的细胞毒性，而HBEGF-SAP对SMC的细胞毒性作用比对内皮细胞更具选择性。这些数据表明，bFGF和HBEGF的促有丝分裂作用以及bFGF-SAP和HBEGF-SAP的细胞毒性作用可能均由其相应的生长因子受体介导。由于其对SMC的选择性细胞毒性作用，HBEGF-SAP可能成为控制内膜病变形成更具吸引力的药物。
