Ehrenreich H, Anderson R W, Fox C H, Rieckmann P, Hoffman G S, Travis W D, Coligan J E, Kehrl J H, Fauci A S
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
J Exp Med. 1990 Dec 1;172(6):1741-8. doi: 10.1084/jem.172.6.1741.
Endothelins are peptides, originally isolated from endothelial cells, with potent vasoactive and mitogenic properties. In this study, we demonstrate that human macrophages synthesize and secrete endothelins. Cultured human macrophages were found by immunocytochemistry to stain positively for endothelin 1 and endothelin 3. Their capability to produce and release these peptides was confirmed by a combination of reverse-phase high-performance liquid chromatography and radioimmunoassays, specific for endothelin 1 and 3, respectively. Immunoreactive peptides were identified both in cellular extracts and in macrophage-conditioned medium. The secretion of endothelin 1, but not of endothelin 3, from macrophages could be stimulated 6-10-fold by lipopolysaccharide or phorbol myristate acetate (PMA). Northern blot analysis of total macrophage RNA using an endothelin 1 cDNA probe revealed induction of endothelin mRNA in PMA-treated macrophages. Furthermore, immunoreactive endothelin 1 and 3 were found in U937 cells, a human promonocytic line, and in freshly isolated human monocytes. In contrast, no immunoreactive endothelin was detected in cell extracts from human neutrophils and lymphocytes. The expression of endothelins in tissue macrophages was demonstrated in paraffin sections of human lung using immunohistochemistry. In conclusion, the finding that human macrophages produce endothelins suggests an important role for these peptides in the microenvironment of tissue macrophages. Macrophage-derived endothelins may have an essential function in blood vessel physiology, and aberrant production may contribute to vessel pathology.
内皮素是最初从内皮细胞中分离出来的肽类，具有强大的血管活性和促有丝分裂特性。在本研究中，我们证明人类巨噬细胞能合成并分泌内皮素。通过免疫细胞化学发现，培养的人类巨噬细胞内皮素-1和内皮素-3染色呈阳性。分别采用针对内皮素-1和内皮素-3的反相高效液相色谱法和放射免疫分析法相结合，证实了它们产生和释放这些肽的能力。在细胞提取物和巨噬细胞条件培养基中均鉴定出免疫反应性肽。脂多糖或佛波醇肉豆蔻酸酯乙酸盐（PMA）可使巨噬细胞分泌内皮素-1（而非内皮素-3）的量增加6至10倍。用内皮素-1 cDNA探针进行总巨噬细胞RNA的Northern印迹分析显示，PMA处理的巨噬细胞中有内皮素mRNA的诱导表达。此外，在人原单核细胞系U937细胞和新鲜分离的人单核细胞中发现了免疫反应性内皮素-1和内皮素-3。相反，在人中性粒细胞和淋巴细胞的细胞提取物中未检测到免疫反应性内皮素。利用免疫组织化学在人肺石蜡切片中证实了组织巨噬细胞中内皮素的表达。总之，人类巨噬细胞产生内皮素这一发现表明这些肽在组织巨噬细胞的微环境中具有重要作用。巨噬细胞衍生的内皮素可能在血管生理学中具有重要功能，其异常产生可能导致血管病变。
