Development of a new treatment strategy for wound healing using recombinant type VII collagen

VII型胶原蛋白是一种非纤维状胶原蛋白，是表皮基底膜下锚定纤维结构的主要组分，并且对于皮肤基底膜区的完整性至关重要。VII型胶原基因内的突变与营养不良形式的大疱性表皮病（DEB）相关，DEB是一组机械性大疱性疾病，其特征在于皮肤脆性和倾向于形成基底层下致密水疱。DEB患者伤口愈合延迟。本研究的目的是阐明重组VII型胶原对创伤愈合的治疗作用。首先，我们纯化了大量的重组VII型胶原。我们将VII型胶原基因导入HaCaT细胞、NIH3T3细胞和293细胞中，并通过G418进行稳定转化子的筛选。在这些细胞系中，293细胞主要表达VII型胶原。我们可以显示来自VII型胶原基因敲除小鼠和DEB患者的角质形成细胞和成纤维细胞的低移动性，但是添加重组VII型胶原挽救了受损的移动性。此外，重组VII型胶原蛋白应用于皮肤溃疡改善伤口愈合，我们提出VII型胶原蛋白作为抗溃疡药物。因此，我们认为，我们可以实现建立一个新的战略，用于治疗伤口使用重组VII型胶原蛋白。

Type VII collagen, a non-fibrillar collagen, is a major component of anchoring fibril structures beneath the epidermal basement membrane, and is of critical importance for integrity of the cutaneous basement membrane zone. Mutations within the type VII collagen gene are associated with the dystrophic forms of epidermolysis bullosa (DEB), a group of mechanobullous diseases characterized by cutaneous fragility and tendency to form sub-basal lamina densa blisters. The patients with DEB showed delayd wound healing. The aim of this study was to clarify therapeutic effect of recombinant type VII collagen on wound healing. First, we purified a large amount of recombinant type VII collagen. We introduced the type VII collagen gene into HaCaT cells, NIH3T3 cells and 293 cells and performed selection of stable transformants by G418.293 cells expressed type VII collagen mostly among those cell lines. We could show low mobility of keratinocytes and fibroblasts from type VII collagen-gene knockout mouse and DEB patients, but addtion of recombinant type VII collagen rescued impaired mobility. Furthermore, application of recombinant type VII collagen to skin ulcer improved wound healing and we proposed type VII collagen as an anti-ulcer drug. Thus, we think that we can achieve establishment of a new strategy for treatment of wound using recombinant type VII collagen.