Shames B D, Selzman C H, Meldrum D R, Pulido E J, Barton H A, Meng X, Harken A H, McIntyre R C
Department of Surgery, University of Colorado Health Sciences Center, Denver 80262, USA.
Shock. 1998 Dec;10(6):389-94.
Interleukin-10 (IL-10) protects animals from lethal endotoxemia. This beneficial effect is mediated, in part, by inhibition of inflammatory cytokine production, including tumor necrosis factor-alpha (TNF-alpha). Evidence suggests that IL-10 may inhibit activation of the transcription factor nuclear factor-kappaB (NF-kappaB) through an unknown mechanism. NF-kappaB activation in response to inflammatory signals is dependent upon degradation of its associated inhibitory peptide, inhibitory kappaB-alpha (IkappaB-alpha). We hypothesized that IL-10 prevents human monocyte NF-kappaB activation and resultant TNF-alpha production by stabilization of IkappaB-alpha. The purpose of this study was to determine the effect of IL-10 on lipopolysaccharide (LPS)-induced human monocyte TNF-alpha production, NF-kappaB activation, and IkappaB-alpha degradation. Monocytes were isolated from human donors. Cells were stimulated with endotoxin (LPS, 100 ng/mL) with and without human IL-10 (10 ng/mL). Following stimulation, TNF-alpha was measured in cell supernatants by ELISA, NF-kappaB activity by electrophoretic mobility shift assay, and IkappaB-alpha levels by Western blot. We observed that after LPS stimulation of human monocytes, TNF-alpha increased to 798+/-67 pg/mL (p < .001 versus control). IL-10 attenuated LPS-stimulated TNF-alpha production (297+/-54; p < .001 versus LPS alone). After LPS stimulation in human monocytes, IkappaB-alpha protein levels decreased, and NF-kappaB DNA binding increased. IL-10 pretreatment prevented LPS-induced decreases in IkappaB-alpha protein levels and attenuated NF-kappaB DNA binding. IL-10 appears to prevent activation of NF-kappaB by preserving IkappaB-alpha protein levels, leading to a reduction in TNF-alpha release.
白细胞介素-10（IL-10）可保护动物免受致死性内毒素血症的侵害。这种有益作用部分是通过抑制炎性细胞因子的产生介导的，包括肿瘤坏死因子-α（TNF-α）。有证据表明，IL-10可能通过未知机制抑制转录因子核因子-κB（NF-κB）的激活。对炎性信号作出反应时，NF-κB的激活依赖于其相关抑制肽抑制性κB-α（IkappaB-α）的降解。我们推测，IL-10通过稳定IkappaB-α来阻止人单核细胞NF-κB的激活及随后的TNF-α产生。本研究的目的是确定IL-10对脂多糖（LPS）诱导的人单核细胞TNF-α产生、NF-κB激活及IkappaB-α降解的影响。从人类供体中分离出单核细胞。细胞分别用内毒素（LPS，100 ng/mL）刺激，同时或不同时添加人IL-10（10 ng/mL）。刺激后，通过酶联免疫吸附测定法（ELISA）检测细胞上清液中的TNF-α，通过电泳迁移率变动分析检测NF-κB活性，通过蛋白质免疫印迹法检测IkappaB-α水平。我们观察到，LPS刺激人单核细胞后，TNF-α增加至798±67 pg/mL（与对照组相比，p <.001）。IL-10减弱了LPS刺激的TNF-α产生（297±54；与单独使用LPS相比，p <.001）。LPS刺激人单核细胞后，IkappaB-α蛋白水平下降，NF-κB与DNA的结合增加。IL-10预处理可防止LPS诱导的IkappaB-α蛋白水平下降，并减弱NF-κB与DNA的结合。IL-10似乎通过维持IkappaB-α蛋白水平来阻止NF-κB的激活，从而导致TNF-α释放减少。
