Zhan Rixing, He Weifeng, Wang Fan, Yao Zhihui, Tan Jianglin, Xu Rui, Zhou Junyi, Wang Yuzhen, Li Haisheng, Wu Jun, Luo Gaoxing
Institute of Burn Research; State Key Laboratory of Trauma, Burn and Combined Injury; Key Laboratory of Proteomics of Chongqing, Southwest Hospital, Third Military Medical University, Chongqing, China.
Sci Rep. 2016 Jul 29;6:30687. doi: 10.1038/srep30687.
The migration and reepithelization of epidermal stem cells (ESCs) are the most critical processes in wound healing. The gaseous messenger nitric oxide (NO) has multiple biological effects, but its actions on ESCs are poorly understood. In this study, an NO donor, S-nitroso-N-acetylpenicillamine (SNAP), was found to facilitate the in vitro migration of human ESCs (huESCs) in both live-imaging and scratch models. In addition, pull-down assays demonstrated that SNAP could activate the small GTPases RhoA and Rac1 of the Rho family, but not Cdc42. Moreover, the effects of SNAP on the migration and F-actin polymerization of ESCs could be blocked by inhibitors of cGMP, PKG, RhoA or Rac1, and by a specific siRNA of RhoA or Rac1, but not by a Cdc42 inhibitor or siRNA. Furthermore, the roles of NO in ESC migration via cGMP-Rho GTPase signalling in vivo were confirmed by tracing 5-bromo-2-deoxyuridine (BrdU)-labelled cells in a superficial, partial-thickness scald mouse model. Thus, the present study demonstrated that the NO donor SNAP could promote huESC migration in vitro. Furthermore, NO was found to induce ESC migration via cGMP-Rho GTPase RhoA and Rac1 signalling, but not Cdc42 signalling, both in vivo and in vitro.
表皮干细胞（ESCs）的迁移和再上皮化是伤口愈合过程中最关键的环节。气体信使一氧化氮（NO）具有多种生物学效应，但其对ESCs的作用尚不清楚。在本研究中，发现一种NO供体S-亚硝基-N-乙酰青霉胺（SNAP）在实时成像和划痕模型中均能促进人ESCs（huESCs）的体外迁移。此外，下拉实验表明SNAP可以激活Rho家族的小GTP酶RhoA和Rac1，但不能激活Cdc42。此外，cGMP、PKG、RhoA或Rac1的抑制剂以及RhoA或Rac1的特异性siRNA可阻断SNAP对ESCs迁移和F-肌动蛋白聚合的影响，但Cdc42抑制剂或siRNA则不能。此外，通过在浅表性、部分厚度烫伤小鼠模型中追踪5-溴-2-脱氧尿苷（BrdU）标记的细胞，证实了NO在体内通过cGMP-Rho GTP酶信号传导在ESC迁移中的作用。因此，本研究表明NO供体SNAP可以促进huESCs的体外迁移。此外，研究发现NO在体内和体外均通过cGMP-Rho GTP酶RhoA和Rac1信号传导诱导ESC迁移，而不是通过Cdc42信号传导。
