Study on the interleukin-1 signaling

本实验以人黑色素瘤细胞A375为材料，研究了IL-1对人黑色素瘤细胞增殖的影响及其获得性抵抗的机制。由于I型IL-1受体（IL-1 R）介导IL-1信号，本研究还对IL-1 R在体内外的表达调控机制进行了研究. IL-1抗增殖作用的机制IL-1 R cDNA转染对IL-1产生抗性的A375-5细胞，获得了对IL-1敏感的转染细胞。利用该克隆，我们研究了IL-1信号转导。IL-1下调ODC活性。虽然ODC mRNA水平没有变化，但ODC的蛋白质含量减少。抗酶（AZ）是一种通过与ODC结合而使ODC失活并导致ODC降解的蛋白质因子，其mRNA被IL-1上调。反义AZ抑制IL-1的作用。因此，IL-1诱导的AZ在IL-1信号转导中起重要作用.对IL-1获得性耐药机制的研究利用长期培养获得的对IL-1抗增殖作用产生耐药的细胞，探讨其耐药机制。将IL-1 α正义和反义表达载体分别转染IL-1敏感细胞和抗性细胞。然而，转染子对IL-1的敏感性没有改变。因此，IL-1 α的表达似乎不足以抵抗. IL-1 R表达的调控以人成纤维细胞系TIG-1为材料，研究了I型IL-1 R表达的调控机制。酪氨酸激酶在IL-1 R的组成性表达中起重要作用，LPS诱导小鼠肝脏IL-1 R mRNA表达显著增加。上调似乎是由内源性产生的IL-1和IL-6诱导的。

The mechanisms of IL-latiproliferative effect and the acquired resistance to IL-1 effect were studied using human melanoma cells A375. As type I IL-1 receptor (IL-1R) transduces IL-1 signal, the regulatory mechanisms of IL-1R expression in vitro and in vivo were also studied.1. The mechanism of IL-1 antiproliferative effectIL-1R cDNA was transfected into A375-5 which is resistant to IL-1 because it expresses very low number of IL-1R.We obtained the transfectant which became sensitive to IL-1. Using this clone we studied the IL-1 signaling. IL-1 downregulated ODC activity. Although ODC mRNA level was not changed, the amount of protein of ODC decreased. The mRNA of antizyme (AZ), a proteinous factor which inactivates ODC by binding to ODC and causes degradation of ODC,was upregulated by IL-1. Furthermore, antisense of AZ inhibited IL-1 effects. Terefore, AZ induced by IL-1 appeared to be important in the IL-1 signaling.2. The mechanism of acquired resistance to IL-1Using the cells which acquired resistance to IL-1 antiproliferative effect after long period of culture, we studied the mechanism. Expression vectors of IL-1alpha sense and IL-1alpha antisense were transfected into IL-1 sensitive and resistant cells, respectively. However, the sensitivity of the transfectants to IL-1 was not changed. Therefore, expression of IL-1alpha appeared not to be sufficient to the resistance.3. Regulation of IL-1R expressionUsing human fibroblast cell line TIG-1, we studied the regulatory mechanism of type I IL-1R wxpression. Tyrosine kinase appeared to play an important role in constitutive expression of IL-1R.Whtn mice were injected with LPS,a marked increase of IL-1R mRNA was induced in the liver. The upregulation apperaed to be induced by the endogenously produced IL-1 and IL-6.