Borghaei R C, Rawlings P L, Mochan E
Philadelphia College of Osteopathic Medicine, Pennsylvania 19131, USA.
Arthritis Rheum. 1998 Aug;41(8):1398-406. doi: 10.1002/1529-0131(199808)41:8<1398::AID-ART8>3.0.CO;2-B.
To determine the effects of interleukin-4 (IL-4) on IL-1 induction of collagenase (matrix metalloproteinase 1 [MMP-1]) and stromelysin-1 (MMP-3) in human synovial fibroblasts.
Northern blot analysis was performed to determine the effects of IL-4 on IL-1 induction of MMP messenger RNA (mRNA). MMP protein levels were determined by enzyme-linked immunosorbent assay, and prostaglandin E2 (PGE2) levels were measured by enzyme immunoassay. Run-on transcription assays and transient transfection experiments were performed to determine whether the effects of IL-4 occur at the level of transcription. Activator protein 1 (AP-1) binding was assessed by electrophoretic mobility shift assay.
Northern blot analysis revealed that coincubation of synovial fibroblasts with IL-1 and IL-4 resulted in a significant decrease in both collagenase and stromelysin mRNA levels compared with IL-1 alone, with a concomitant decrease in MMP protein levels. This inhibition is dose dependent, with an IC50 (50% inhibition concentration) for both MMPs of approximately 0.3 ng of IL-4 per ml, and is at least somewhat selective, since IL-1 induction of c-fos mRNA is not affected. Nuclear run-on experiments and transient transfection studies demonstrated that the suppression of IL-1-induced collagenase and stromelysin expression by IL-4 occurs at least in part at the transcriptional level, and that binding of transcription factor AP-1 is not affected. Although IL-1-induced levels of PGE2 are reduced by IL-4, exogenous addition of PGE2 does not abrogate the inhibitory effects of IL-4 on MMP expression.
IL-4 inhibits IL-1 induction of both collagenase and stromelysin, as well as PGE2 production, in human synovial fibroblasts. The inhibition occurs at least in part at the level of transcription, does not affect binding of transcription factor AP-1, and appears to involve a mechanism that is independent of the ability of IL-4 to inhibit production of PGE2.
确定白细胞介素-4（IL-4）对白细胞介素-1（IL-1）诱导人滑膜成纤维细胞产生胶原酶（基质金属蛋白酶1 [MMP-1]）和基质溶解素-1（MMP-3）的影响。
进行Northern印迹分析以确定IL-4对IL-1诱导MMP信使核糖核酸（mRNA）的影响。通过酶联免疫吸附测定法测定MMP蛋白水平，通过酶免疫测定法测量前列腺素E2（PGE2）水平。进行连续转录分析和瞬时转染实验以确定IL-4的作用是否发生在转录水平。通过电泳迁移率变动分析评估激活蛋白1（AP-1）结合情况。
Northern印迹分析显示，与单独使用IL-1相比，滑膜成纤维细胞与IL-1和IL-4共同孵育导致胶原酶和基质溶解素mRNA水平均显著降低，同时MMP蛋白水平也降低。这种抑制作用具有剂量依赖性，两种MMP的半数抑制浓度（IC50）约为每毫升0.3纳克IL-4，并且至少具有一定的选择性，因为IL-1诱导的c-fos mRNA不受影响。细胞核连续转录实验和瞬时转染研究表明，IL-4对IL-1诱导的胶原酶和基质溶解素表达的抑制至少部分发生在转录水平，并且转录因子AP-1的结合不受影响。虽然IL-4降低了IL-1诱导的PGE2水平，但外源性添加PGE2并不能消除IL-4对MMP表达的抑制作用。
IL-4抑制IL-1诱导人滑膜成纤维细胞产生胶原酶和基质溶解素以及PGE2。这种抑制至少部分发生在转录水平，不影响转录因子AP-1的结合，并且似乎涉及一种独立于IL-4抑制PGE2产生能力的机制。
