Berman B, Wietzerbin J
Dermatology Department, University of California, Davis School of Medicine.
J Dermatol Sci. 1992 Mar;3(2):82-90. doi: 10.1016/0923-1811(92)90040-i.
Interferons alpha and gamma (IFN-alpha, IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) exert different regulatory effects on the proliferation and biosynthetic activities of human dermal fibroblasts. Inasmuch as these cytokines bind to specific receptors in order to exert their activities, the expression of IFN-alpha, IFN-gamma and TNF-alpha receptors on fibroblasts from human adult normal and scleroderma skin cultured in vitro were quantitated. Adsorption was detected by incubating confluent normal and scleroderma fibroblasts with various concentrations of [125I]cytokine. Replicate experiments revealed 19,742 +/- 2057 (Kd = 1.15 x 10(-9) M) TNF-alpha receptors per normal dermal fibroblast and 15,006 +/- 75 (Kd = 6.75 x 10(-10) M) TNF-alpha receptors per scleroderma fibroblast. Cross-linking 125I-TNF-alpha to its receptor on normal and scleroderma fibroblasts revealed 130- and 100-kDa TNF-receptor complexes. Although no quantitative or qualitative differences were detected between these two cell types with regard to receptor numbers, TNF-alpha affinity or receptor protein as detected by radiolabelled TNF-alpha, differences were detected in levels of mRNA specific for TNF-alpha receptors. Northern blot analysis revealed normal fibroblasts to constitutively contain mainly mRNA specific for the 55-kDa TNF receptor and indicate that they are capable of responding to TNF-alpha-induced up-regulation of mRNA specific for the 75 kDa TNF receptor. Scleroderma fibroblasts, however, constitutively contain mRNA for both TNF receptors and fail to respond to TNF-alpha up-regulation of the message for the 75-kDa receptor for TNF.(ABSTRACT TRUNCATED AT 250 WORDS)
α干扰素和γ干扰素（IFN-α、IFN-γ）以及肿瘤坏死因子α（TNF-α）对人皮肤成纤维细胞的增殖和生物合成活性发挥着不同的调节作用。由于这些细胞因子需结合特定受体才能发挥其活性，因此对体外培养的来自成人正常皮肤和硬皮病皮肤的成纤维细胞上IFN-α、IFN-γ和TNF-α受体的表达进行了定量分析。通过将汇合的正常和硬皮病成纤维细胞与不同浓度的[125I]细胞因子孵育来检测吸附情况。重复实验显示，每个正常皮肤成纤维细胞有19,742±2057个（Kd = 1.15×10^(-9) M）TNF-α受体，每个硬皮病成纤维细胞有15,006±75个（Kd = 6.75×10^(-10) M）TNF-α受体。将125I-TNF-α与正常和硬皮病成纤维细胞上的受体进行交联，发现了130 kDa和100 kDa的TNF受体复合物。尽管就受体数量、TNF-α亲和力或通过放射性标记的TNF-α检测到的受体蛋白而言，这两种细胞类型之间未检测到定量或定性差异，但在TNF-α受体特异性mRNA水平上检测到了差异。Northern印迹分析显示，正常成纤维细胞组成性地主要含有针对55 kDa TNF受体的特异性mRNA，并表明它们能够对TNF-α诱导的75 kDa TNF受体特异性mRNA的上调做出反应。然而，硬皮病成纤维细胞组成性地含有两种TNF受体的mRNA，并且对TNF-α诱导的75 kDa TNF受体信息上调无反应。（摘要截断于250字）
