Hyaluronan fragments stimulate endothelial recognition of injury through TLR4
Hyaluronan fragments stimulate endothelial recognition of injury through TLR4
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DOI：
10.1074/jbc.m310859200
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发表时间：
2004-04-23
影响因子：
4.8
通讯作者：
Gallo, RL
中科院分区：
文献类型：
--
作者：
Taylor, KR;Trowbridge, JM;Gallo, RL
组织必须迅速识别损伤，以应对微生物的快速生长。在皮肤中，真皮微血管内皮细胞也必须对来自周围组织的危险信号作出反应，并立即参与启动伤口修复过程。细胞外基质的成分，如透明质酸，在伤口中被迅速分解成分子量较小的低聚糖，这些低聚糖可以激活多种生物过程。本研究旨在确定损伤后释放的透明质酸片段是否能刺激内皮细胞，以及这种反应的机制是什么。通过基因芯片芯片分析，内皮细胞对透明质酸片段有反应，其中趋化因子IL-8的增加最为显著。在人内皮细胞培养和小鼠模型中，通过观察透明质酸片段给药后血清MIP-2和KC的水平，用定性逆转录pcr和ELISA验证了这一观察结果。通过使用TLR4阻断抗体和TLR4缺陷小鼠可以看出，激活是TLR4依赖的，但不是由于存在未检测到的污染物，而是通过透明质酸降解酶软骨素酶ABC消化或透明质酸特异性阻断肽Pep-1孵育后失活。LPS活性的失活并不能降低透明质酸片段的作用。这些观察结果表明，细胞外基质的内源性成分可以刺激内皮细胞在伤口防御和修复反应的初始阶段触发对损伤的识别。
Tissues must quickly recognize injury to respond to the rapid pace of microbial growth. In skin, dermal microvascular endothelial cells must also react to danger signals from the surrounding tissue and immediately participate by initiating the wound repair process. Components of the extracellular matrix such as hyaluronan are rapidly broken down into smaller molecular weight oligosaccharides in a wound, and these can activate a variety of biological processes. This study set out to determine if hyaluronan fragments released following injury can stimulate endothelial cells and what mechanism is responsible for this response. Using genechip microarray analysis, a response to hyaluronan fragments was detected in endothelial cells with the most significant increase observed for the chemokine IL-8. This observation was verified with qualitative reverse transcriptase-PCR and ELISA in human endothelial cell culture, and in a mouse model by observing serum levels of MIP-2 and KC following hyaluronan fragment administration in vivo. Activation was TLR4-dependent, as shown by use of TLR4 blocking antibody and TLR4-deficient mice, but not due to the presence of undetected contaminants as shown by inactivation following digestion with the hyaluronan-degrading enzyme chondroitinase ABC or incubation with the hyaluronan-specific blocking peptide Pep-1. Inactivation of LPS activity failed to diminish the action of hyaluronan fragments. These observations suggest that endogenous components of the extracellular matrix can stimulate endothelia to trigger recognition of injury in the initial stages of the wound defense and repair response.