PDF(Pubmed)
Abstract：
Thymic stromal lymphopoietin (TSLP), mainly expressed by epithelial cells, plays a central role in asthma. In humans, TSLP exists in two variants: the long form TSLP (lfTSLP) and a shorter TSLP isoform (sfTSLP). Macrophages (HLMs) and mast cells (HLMCs) are in close proximity in the human lung and play key roles in asthma. We evaluated the early proteolytic effects of tryptase and chymase released by HLMCs on TSLP by mass spectrometry. We also investigated whether TSLP and its fragments generated by these enzymes induce angiogenic factor release from HLMs. Mass spectrometry (MS) allowed the identification of TSLP cleavage sites caused by tryptase and chymase. Recombinant human TSLP treated with recombinant tryptase showed the production of 1-97 and 98-132 fragments. Recombinant chymase treatment of TSLP generated two peptides, 1-36 and 37-132. lfTSLP induced the release of VEGF-A, the most potent angiogenic factor, from HLMs. By contrast, the four TSLP fragments generated by tryptase and chymase failed to activate HLMs. Long-term TSLP incubation with furin generated two peptides devoid of activating property on HLMs. These results unveil an intricate interplay between mast cell-derived proteases and TSLP. These findings have potential relevance in understanding novel aspects of asthma pathobiology.
摘要：
胸腺基质淋巴细胞生成素(TSLP),主要由上皮细胞表达，在哮喘中起着核心作用。在人类中,TSLP以两种变体存在:长型TSLP(lfTSLP)和较短TSLP同工型(sfTSLP)。巨噬细胞（HLM）和肥大细胞（HLMC）在人肺中非常接近，并在哮喘中起关键作用。我们通过质谱评估了HLMC释放的类胰蛋白酶和糜蛋白酶对TSLP的早期蛋白水解作用。我们还研究了TSLP及其由这些酶产生的片段是否诱导从HLMs释放血管生成因子。质谱（MS）允许鉴定由类胰蛋白酶和糜蛋白酶引起的TSLP切割位点。用重组类胰蛋白酶处理的重组人TSLP显示产生1-97和98-132片段。重组糜酶处理TSLP产生两种肽，1-36和37-132。lfTSLP诱导VEGF-A的释放，最有效的血管生成因子，来自HLMs。相比之下，由类胰蛋白酶和糜蛋白酶产生的四个TSLP片段未能激活HLMs。与弗林蛋白酶的长期TSLP孵育产生了两种对HLMs缺乏激活特性的肽。这些结果揭示了肥大细胞衍生的蛋白酶和TSLP之间的复杂相互作用。这些发现在理解哮喘病理生物学的新方面具有潜在的相关性。
