ABSTRACT

Aim: The transcription factor Foxn1 is a regulator of scar-ended cutaneous wound healing in mice. However, the link between Foxn1 and Wnt signaling has not been explored in the context of cutaneous repair. Here, we investigate the effects of β-catenin-dependent and -independent Wnt signaling represented by Wnt10a and Wnt11, respectively, in healing of full-thickness cutaneous wounds in C57BL/6 mice.

Material and Methods: Quantitative polymerase chain reaction, western blot, and immunostaining were performed to assess the spatial and temporal distribution of Wnt10a, Wnt11, and β-catenin in skin during wound healing. A co-culture system consisting of keratinocytes transfected with an adenoviral vector carrying Foxn1-GFP and dermal fibroblasts (DFs) was employed to determine the influence of epidermal signals on the capacity of DFs to produce extracellular matrix (ECM) proteins in vitro. The levels of types I and III collagen in conditioned media from DFs cultures were examined via enzyme-linked immunosorbent assay.

Results: The expression of Wnt10a, Wnt11, and β-catenin increased at post-wounding days 14 and 21 when tissue remodeling occurred. Foxn1::Egfp transgenic mice experiments demonstrated that Wnts were abundant in the epidermis adjacent to the wound margin and to a lesser extent in the dermis. The Wnt10a signal colocalized with Foxn1-eGFP in the epithelial tongue and neo-epidermis during the initial stage of wound healing. Foxn1 overexpression in keratinocytes affected DFs function related to collagen synthesis.

Conclusions: Wnt ligands contribute to cutaneous wound repair, predominantly by engagement in ECM maturation. The data indicates a possible relationship between Foxn1 and Wnts in post-traumatic skin tissue.

摘要

目的：转录因子 Foxn1 是小鼠瘢痕末端皮肤伤口愈合的调节因子。然而，Foxn1 和 Wnt 信号之间的联系尚未在皮肤修复的背景下进行探索。在这里，我们研究了分别由 Wnt10a 和 Wnt11 代表的 β-连环蛋白依赖性和非依赖性 Wnt 信号在 C57BL/6 小鼠全层皮肤伤口愈合中的作用。

材料和方法：进行定量聚合酶链反应、蛋白质印迹和免疫染色以评估伤口愈合过程中皮肤中 Wnt10a、Wnt11 和 β-连环蛋白的空间和时间分布。采用由携带 Foxn1-GFP 和真皮成纤维细胞 (DF) 的腺病毒载体转染的角质形成细胞组成的共培养系统来确定表皮信号对 DF在体外产生细胞外基质 (ECM) 蛋白的能力的影响。通过酶联免疫吸附测定法检测来自 DFs 培养物的条件培养基中 I 型和 III 型胶原蛋白的水平。

结果：Wnt10a、Wnt11和β-catenin的表达在伤后第14天和第21天发生组织重塑时增加。Foxn1::Egfp 转基因小鼠实验表明，Wnts 在靠近伤口边缘的表皮中含量丰富，在真皮中含量较少。在伤口愈合的初始阶段，Wnt10a 信号与 Foxn1-eGFP 在上皮舌和新表皮共定位。角质形成细胞中的 Foxn1 过表达影响与胶原合成相关的 DF 功能。

结论：Wnt 配体有助于皮肤伤口修复，主要是通过参与 ECM 成熟。数据表明 Foxn1 和 Wnts 在创伤后皮肤组织中可能存在关系。