Buchanan Edward P, Longaker Michael T, Lorenz H Peter
Division Plastic Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Adv Clin Chem. 2009;48:137-61. doi: 10.1016/s0065-2423(09)48006-5.
The developing fetus has the ability to heal wounds by regenerating normal epidermis and dermis with restoration of the extracellular matrix (ECM) architecture, strength, and function. In contrast, adult wounds heal with fibrosis and scar. Scar tissue remains weaker than normal skin with an altered ECM composition. Despite extensive investigation, the mechanism of fetal wound healing remains largely unknown. We do know that early in gestation, fetal skin is developing at a rapid pace and the ECM is a loose network facilitating cellular migration. Wounding in this unique environment triggers a complex cascade of tightly controlled events culminating in a scarless wound phenotype of fine reticular collagen and abundant hyaluronic acid. Comparison between postnatal and fetal wound healing has revealed differences in inflammatory response, cellular mediators, cytokines, growth factors, and ECM modulators. Investigation into cell signaling pathways and transcription factors has demonstrated differences in secondary messenger phosphorylation patterns and homeobox gene expression. Further research may reveal novel genes essential to scarless repair that can be manipulated in the adult wound and thus ameliorate scar.
发育中的胎儿具有通过再生正常表皮和真皮并恢复细胞外基质（ECM）结构、强度和功能来愈合伤口的能力。相比之下，成人伤口通过纤维化和瘢痕愈合。瘢痕组织比正常皮肤更脆弱，其ECM组成也有所改变。尽管进行了广泛研究，但胎儿伤口愈合的机制在很大程度上仍然未知。我们确实知道，在妊娠早期，胎儿皮肤快速发育，ECM是一个松散的网络，便于细胞迁移。在这种独特环境中受伤会引发一系列复杂且严格控制的事件，最终形成具有精细网状胶原蛋白和丰富透明质酸的无瘢痕伤口表型。产后伤口愈合与胎儿伤口愈合的比较揭示了炎症反应、细胞介质、细胞因子、生长因子和ECM调节剂方面的差异。对细胞信号通路和转录因子的研究表明，第二信使磷酸化模式和同源框基因表达存在差异。进一步的研究可能会揭示无瘢痕修复所必需的新基因，这些基因可在成人伤口中进行调控，从而改善瘢痕。
