Tewari M, Tuncay O C, Milchman A, Reddy P J, Reddy C D, Cressman D E, Taub R, Newton R C, Tewari D S
Department of Orthodontics, School of Dentistry, Temple University, Philadelphia, PA 19140, USA.
Arch Oral Biol. 1996 May;41(5):461-8. doi: 10.1016/0003-9969(96)00148-3.
During earlier examination of interleukin-1 (IL-1)-induced matrix metalloproteinase gene expression in human gingival fibroblasts a highly induced immediate early gene, I kappa B-alpha, a NF kappa B DNA-binding inhibitor, was identified. The aim now was to investigate whether recombinant (r)IL-1 beta induces the stimulation of NF kappa B and its inhibitor proteins in human gingival fibroblasts and to understand if inhibition of its activity affects collagenase gene expression. Primary gingival fibroblasts (human) were treated with rIL-1 beta to determine the effect on NF kappa B-like DNA-binding activity. IL-1 induced the production of steady-state mRNA levels of I kappa B-alpha in the cultured fibroblasts. Nuclear run-on transcription studies demonstrated that rIL-1 induction of I kappa B-alpha may be transcriptionally regulated. Using electrophoretic mobility gel-shift assays it was shown that rIL-1 activates NF kappa B-like, DNA-binding activity in these fibroblasts. NF kappa B-like DNA-binding activity was rapidly induced and turned over in gingival fibroblasts with peak activity at 30 min after rIL-1 treatment. Further, treatment with chymotrypsin protease inhibitor and antioxidant inhibitor prevented IL-1-induced, NF kappa B-like, DNA-binding activity and collagenase mRNA production. When coupled with the existence of NF kappa B consensus DNA-binding sites on the collagenase gene promoter, these findings suggest that the stimulation of NF kappa B in gingival fibroblasts by rIL-1 could play an important part in the regulation of their collagenase gene expression. The ability of IL-1 to stimulate this expression may define a pivotal role for this cytokine in the pathogenesis of periodontitis.
在早期对人牙龈成纤维细胞中白细胞介素 -1（IL-1）诱导的基质金属蛋白酶基因表达的研究中，发现了一种高度诱导的即刻早期基因——IκB-α，它是一种NFκB DNA结合抑制剂。现在的目的是研究重组（r）IL-1β是否能诱导人牙龈成纤维细胞中NFκB及其抑制蛋白的激活，并了解抑制其活性是否会影响胶原酶基因的表达。用rIL-1β处理原代人牙龈成纤维细胞，以确定对NFκB样DNA结合活性的影响。IL-1诱导培养的成纤维细胞中IκB-α稳态mRNA水平的产生。核转录延伸研究表明，rIL-1对IκB-α的诱导可能受到转录调控。通过电泳迁移率凝胶阻滞分析表明，rIL-1可激活这些成纤维细胞中的NFκB样DNA结合活性。在牙龈成纤维细胞中，NFκB样DNA结合活性被迅速诱导并周转，rIL-1处理后30分钟活性达到峰值。此外，用胰凝乳蛋白酶蛋白酶抑制剂和抗氧化剂抑制剂处理可阻止IL-1诱导的NFκB样DNA结合活性和胶原酶mRNA的产生。鉴于胶原酶基因启动子上存在NFκB共有DNA结合位点，这些发现表明rIL-1对牙龈成纤维细胞中NFκB的激活可能在其胶原酶基因表达的调控中起重要作用。IL-1刺激这种表达的能力可能决定了这种细胞因子在牙周炎发病机制中的关键作用。
