Department of Biomedicine, Aarhus University, Aarhus, Denmark.
PLoS One. 2012;7(5):e36658. doi: 10.1371/journal.pone.0036658. Epub 2012 May 10.
Integrins constitute a superfamily of transmembrane signaling receptors that play pivotal roles in cutaneous homeostasis by modulating cell growth and differentiation as well as inflammatory responses in the skin. Subrabasal expression of integrins α2 and/or β1 entails hyperproliferation and aberrant differentiation of keratinocytes and leads to dermal and epidermal influx of activated T-cells. The anatomical and physiological similarities between porcine and human skin make the pig a suitable model for human skin diseases. In efforts to generate a porcine model of cutaneous inflammation, we employed the Sleeping Beauty DNA transposon system for production of transgenic cloned Göttingen minipigs expressing human β1 or α2 integrin under the control of a promoter specific for subrabasal keratinocytes. Using pools of transgenic donor fibroblasts, cloning by somatic cell nuclear transfer was utilized to produce reconstructed embryos that were subsequently transferred to surrogate sows. The resulting pigs were all transgenic and harbored from one to six transgene integrants. Molecular analyses on skin biopsies and cultured keratinocytes showed ectopic expression of the human integrins and localization within the keratinocyte plasma membrane. Markers of perturbed skin homeostasis, including activation of the MAPK pathway, increased expression of the pro-inflammatory cytokine IL-1α, and enhanced expression of the transcription factor c-Fos, were identified in keratinocytes from β1 and α2 integrin-transgenic minipigs, suggesting the induction of a chronic inflammatory phenotype in the skin. Notably, cellular dysregulation obtained by overexpression of either β1 or α2 integrin occurred through different cellular signaling pathways. Our findings mark the creation of the first cloned pig models with molecular markers of skin inflammation. Despite the absence of an overt psoriatic phenotype, these animals may possess increased susceptibility to severe skin damage-induced inflammation and should be of great potential in studies aiming at the development and refinement of topical therapies for cutaneous inflammation including psoriasis.
整合素是一种跨膜信号受体超家族，通过调节皮肤细胞的生长和分化以及炎症反应，在皮肤稳态中发挥关键作用。整合素 α2 和/或 β1 的基底下表达导致角质形成细胞的过度增殖和异常分化，并导致激活的 T 细胞向真皮和表皮内浸润。猪皮肤与人类皮肤在解剖学和生理学上的相似性使得猪成为人类皮肤病的合适模型。为了建立猪的皮肤炎症模型，我们利用 Sleeping Beauty DNA 转座子系统生产转基因克隆哥廷根迷你猪，在基底下角质形成细胞特异性启动子的控制下表达人 β1 或 α2 整合素。使用转基因供体成纤维细胞池，通过体细胞核移植进行克隆，产生重构胚胎，随后将其转移到代孕母猪体内。产生的猪都是转基因的，携带 1 到 6 个转基因整合子。对皮肤活检和培养的角质形成细胞进行的分子分析显示，人整合素的异位表达并定位于角质形成细胞膜内。在β1 和 α2 整合素转基因迷你猪的角质形成细胞中发现了皮肤稳态失调的标志物，包括 MAPK 通路的激活、促炎细胞因子 IL-1α 的表达增加以及转录因子 c-Fos 的表达增强，表明皮肤中诱导了慢性炎症表型。值得注意的是，通过过度表达 β1 或 α2 整合素获得的细胞失调是通过不同的细胞信号通路发生的。我们的研究结果标志着具有皮肤炎症分子标志物的第一个克隆猪模型的创建。尽管没有明显的银屑病表型，但这些动物可能对严重皮肤损伤诱导的炎症具有更高的易感性，并且在旨在开发和改进皮肤炎症包括银屑病的局部治疗的研究中具有巨大的潜力。
