Tokumaru S, Higashiyama S, Endo T, Nakagawa T, Miyagawa J I, Yamamori K, Hanakawa Y, Ohmoto H, Yoshino K, Shirakata Y, Matsuzawa Y, Hashimoto K, Taniguchi N
Department of Biochemistry, Osaka University Medical School, Suita, Osaka 565-0871, Japan.
J Cell Biol. 2000 Oct 16;151(2):209-20. doi: 10.1083/jcb.151.2.209.
Keratinocyte proliferation and migration are essential to cutaneous wound healing and are, in part, mediated in an autocrine fashion by epidermal growth factor receptor (EGFR)-ligand interactions. EGFR ligands are initially synthesized as membrane-anchored forms, but can be processed and shed as soluble forms. We provide evidence here that wound stimuli induce keratinocyte shedding of EGFR ligands in vitro, particularly the ligand heparin-binding EGF-like growth factor (HB-EGF). The resulting soluble ligands stimulated transient activation of EGFR. OSU8-1, an inhibitor of EGFR ligand shedding, abrogated the wound-induced activation of EGFR and caused suppression of keratinocyte migration in vitro. Soluble EGFR-immunoglobulin G-Fcgamma fusion protein, which is able to neutralize all EGFR ligands, also suppressed keratinocyte migration in vitro. The application of OSU8-1 to wound sites in mice greatly retarded reepithelialization as the result of a failure in keratinocyte migration, but this effect could be overcome if recombinant soluble HB-EGF was added along with OSU8-1. These findings indicate that the shedding of EGFR ligands represents a critical event in keratinocyte migration, and suggest their possible use as an effective clinical treatment in the early phases of wound healing.
角质形成细胞的增殖和迁移对于皮肤伤口愈合至关重要，并且部分是通过表皮生长因子受体（EGFR）-配体相互作用以自分泌方式介导的。EGFR配体最初以膜锚定形式合成，但可被加工并以可溶性形式脱落。我们在此提供证据表明，伤口刺激在体外诱导角质形成细胞脱落EGFR配体，尤其是配体肝素结合表皮生长因子样生长因子（HB-EGF）。产生的可溶性配体刺激EGFR的瞬时激活。EGFR配体脱落抑制剂OSU8-1消除了伤口诱导的EGFR激活，并在体外导致角质形成细胞迁移受到抑制。能够中和所有EGFR配体的可溶性EGFR-免疫球蛋白G-Fcγ融合蛋白在体外也抑制了角质形成细胞迁移。将OSU8-1应用于小鼠伤口部位，由于角质形成细胞迁移失败，大大延迟了再上皮化，但如果将重组可溶性HB-EGF与OSU8-1一起添加，则可以克服这种效应。这些发现表明，EGFR配体的脱落代表角质形成细胞迁移中的关键事件，并提示它们可能作为伤口愈合早期阶段的有效临床治疗方法。
