Hou L, Kapas S, Cruchley A T, Macey M G, Harriott P, Chinni C, Stone S R, Howells G L
Clinical Sciences Research Centre, St. Bartholomew's, London, UK.
Immunology. 1998 Jul;94(3):356-62. doi: 10.1046/j.1365-2567.1998.00528.x.
The protease-activated receptor-2 (PAR-2) is a seven transmembrane domain receptor related to the thrombin receptor, which is activated in vitro by cleavage by trypsin. Affinity-purified rabbit IgG raised against a peptide corresponding to the trypsin cleavage site of PAR-2 was used for an immunohistochemical study of skin. The expression of PAR-2 in epidermis was striking, with keratinocytes showing abundant intercellular and cytoplasmic staining. Basal cells showed the strongest staining intensity and the stratum corneum was negative. Staining with control IgG used at the same concentration was consistently negative. The functional expression of PAR-2 by the simian virus transformed human skin keratinocyte cell line SVK14 was demonstrated by Northern blot analysis, flow cytometric analysis and the measurement of intracellular calcium. Treatment of SVK14 with trypsin or a receptor agonist peptide (SLIGKV-NH2) caused a dose-dependent increase in the secretion of the chemokine interleukin-8 (IL-8) in vitro. The effect of the peptide was specific, since control acetylated peptide was without activity. We conclude that PAR-2 is highly expressed by epidermal keratinocytes and receptor activation in vitro leads to increased IL-8 secretion by keratinocytes. These data raise the possibility that PAR-2 may play a role in epidermal homeostasis and inflammatory conditions.
蛋白酶激活受体-2（PAR-2）是一种与凝血酶受体相关的七跨膜结构域受体，在体外可被胰蛋白酶切割激活。用针对PAR-2胰蛋白酶切割位点对应肽段的亲和纯化兔IgG对皮肤进行免疫组织化学研究。PAR-2在表皮中的表达显著，角质形成细胞呈现丰富的细胞间和细胞质染色。基底细胞染色强度最强，角质层呈阴性。用相同浓度的对照IgG染色始终为阴性。通过Northern印迹分析、流式细胞术分析和细胞内钙测量证实了猿猴病毒转化的人皮肤角质形成细胞系SVK14中PAR-2的功能性表达。用胰蛋白酶或受体激动剂肽（SLIGKV-NH2）处理SVK14在体外导致趋化因子白细胞介素-8（IL-8）分泌呈剂量依赖性增加。该肽的作用具有特异性，因为对照乙酰化肽无活性。我们得出结论，PAR-2在表皮角质形成细胞中高度表达，体外受体激活导致角质形成细胞IL-8分泌增加。这些数据提示PAR-2可能在表皮稳态和炎症状态中起作用。
