Biggs Leah C, Naridze Rachelle L, DeMali Kris A, Lusche Daniel F, Kuhl Spencer, Soll David R, Schutte Brian C, Dunnwald Martine
Department of Pediatrics, The University of Iowa, Iowa City, IA 52242, USA Interdisciplinary Graduate Program in Genetics, The University of Iowa, Iowa City, IA 52242, USA.
Department of Pediatrics, The University of Iowa, Iowa City, IA 52242, USA.
J Cell Sci. 2014 Jul 1;127(Pt 13):2840-8. doi: 10.1242/jcs.139246. Epub 2014 Apr 28.
Interferon regulatory factor 6 (Irf6) regulates keratinocyte proliferation and differentiation. In this study, we tested the hypothesis that Irf6 regulates cellular migration and adhesion. Irf6-deficient embryos at 10.5 days post-conception failed to close their wound compared with wild-type embryos. In vitro, Irf6-deficient murine embryonic keratinocytes were delayed in closing a scratch wound. Live imaging of the scratch showed deficient directional migration and reduced speed in cells lacking Irf6. To understand the underlying molecular mechanisms, cell-cell and cell-matrix adhesions were investigated. We show that wild-type and Irf6-deficient keratinocytes adhere similarly to all matrices after 60 min. However, Irf6-deficient keratinocytes were consistently larger and more spread, a phenotype that persisted during the scratch-healing process. Interestingly, Irf6-deficient keratinocytes exhibited an increased network of stress fibers and active RhoA compared with that observed in wild-type keratinocytes. Blocking ROCK, a downstream effector of RhoA, rescued the delay in closing scratch wounds. The expression of Arhgap29, a Rho GTPase-activating protein, was reduced in Irf6-deficient keratinocytes. Taken together, these data suggest that Irf6 functions through the RhoA pathway to regulate cellular migration.
干扰素调节因子6（Irf6）调控角质形成细胞的增殖和分化。在本研究中，我们验证了Irf6调控细胞迁移和黏附的假说。与野生型胚胎相比，受孕后10.5天的Irf6基因缺陷型胚胎无法闭合伤口。在体外，Irf6基因缺陷型小鼠胚胎角质形成细胞在闭合划痕伤口时出现延迟。对划痕的实时成像显示，缺乏Irf6的细胞定向迁移不足且速度降低。为了解潜在的分子机制，我们研究了细胞间和细胞与基质的黏附。我们发现，野生型和Irf6基因缺陷型角质形成细胞在60分钟后与所有基质的黏附情况相似。然而，Irf6基因缺陷型角质形成细胞始终更大且铺展得更开，这种表型在划痕愈合过程中持续存在。有趣的是，与野生型角质形成细胞相比，Irf6基因缺陷型角质形成细胞的应力纤维网络和活性RhoA增加。阻断RhoA的下游效应器ROCK可挽救划痕伤口闭合延迟的现象。Rho GTP酶激活蛋白Arhgap29在Irf6基因缺陷型角质形成细胞中的表达降低。综上所述，这些数据表明Irf6通过RhoA途径发挥作用来调控细胞迁移。
