Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425-2211, USA.
Exp Cell Res. 2010 Feb 1;316(3):376-89. doi: 10.1016/j.yexcr.2009.10.022. Epub 2009 Oct 30.
Biological functions of tissue kallikrein (TK, KLK1) are mainly mediated by kinin generation and subsequent kinin B2 receptor activation. In this study, we investigated the potential role of TK and its signaling pathways in cultured human keratinocyte migration and in a rat skin wound healing model. Herein, we show that TK promoted cell migration and proliferation in a concentration- and time-dependent manner. Inactive TK or kinin had no significant effect on cell migration. Interestingly, cell migration induced by active TK was not blocked by icatibant or L-NAME, indicating an event independent of kinin B2 receptor and nitric oxide formation. TK's stimulatory effect on cell migration was inhibited by small interfering RNA for proteinase-activated receptor 1 (PAR(1)), and by PAR(1) inhibitor. TK-induced migration was associated with increased phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK), which was blocked by inhibition of protein kinase C (PKC), Src, EGFR and ERK. TK-induced cell migration and EGFR phosphorylation were blocked by metalloproteinase (MMP) inhibitor, heparin, and antibodies against EGFR external domain, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AR). Local application of TK promoted skin wound healing in rats, whereas icatibant and EGFR inhibitor blocked TK's effect. Skin wound healing was further delayed by aprotinin and neutralizing TK antibody. This study demonstrates a novel role of TK in skin wound healing and uncovers new signaling pathways mediated by TK in promoting keratinocyte migration through activation of the PAR(1)-PKC-Src-MMP pathway and HB-EGF/AR shedding-dependent EGFR transactivation.
组织激肽释放酶（TK，KLK1）的生物学功能主要通过缓激肽的产生和随后的缓激肽 B2 受体激活来介导。在这项研究中，我们研究了 TK 及其信号通路在培养的人角质形成细胞迁移和大鼠皮肤伤口愈合模型中的潜在作用。在此，我们表明 TK 以浓度和时间依赖的方式促进细胞迁移和增殖。无活性 TK 或缓激肽对细胞迁移没有显著影响。有趣的是，活性 TK 诱导的细胞迁移不受icatibant 或 L-NAME 阻断，表明这一事件与缓激肽 B2 受体和一氧化氮形成无关。PKC、Src、EGFR 和 ERK 的抑制可抑制 TK 对细胞迁移的刺激作用。TK 诱导的迁移与表皮生长因子受体（EGFR）和细胞外信号调节激酶（ERK）的磷酸化增加有关，PKC、Src、EGFR 和 ERK 的抑制可阻断这一作用。TK 诱导的细胞迁移和 EGFR 磷酸化被金属蛋白酶（MMP）抑制剂肝素、EGFR 外域抗体、肝素结合表皮生长因子样生长因子（HB-EGF）和双调蛋白（AR）阻断。TK 的局部应用促进了大鼠皮肤伤口愈合，而 icatibant 和 EGFR 抑制剂阻断了 TK 的作用。抑肽酶和中和 TK 抗体进一步延迟了皮肤伤口愈合。本研究证明了 TK 在皮肤伤口愈合中的新作用，并揭示了 TK 通过激活 PAR(1)-PKC-Src-MMP 途径和 HB-EGF/AR 脱落依赖性 EGFR 转激活促进角质形成细胞迁移的新信号通路。
