Department of Pathology, The Ohio State University, Columbus, Ohio 43210, USA.
J Invest Dermatol. 2012 Feb;132(2):458-65. doi: 10.1038/jid.2011.324. Epub 2011 Oct 13.
Scar formation is a potentially detrimental process of tissue restoration in adults, affecting organ form and function. During fetal development, cutaneous wounds heal without inflammation or scarring at early stages of development; however, they begin to heal with significant inflammation and scarring as the skin becomes more mature. One possible cell type that could regulate the change from scarless to fibrotic healing is the mast cell. We show here that dermal mast cells in scarless wounds generated at embryonic day 15 (E15) are fewer in number, less mature, and do not degranulate in response to wounding as effectively as mast cells of fibrotic wounds made at embryonic day 18 (E18). Differences were also observed between cultured mast cells from E15 and E18 skin, with regard to degranulation and preformed cytokine levels. Injection of mast cell lysates into E15 wounds disrupted scarless healing, suggesting that mast cells interfere with scarless repair. Finally, wounds produced at E18, which normally heal with a scar, healed with significantly smaller scars in mast cell-deficient Kit(W/W-v) mice compared with Kit(+/+) littermates. Together, these data suggest that mast cells enhance scar formation, and that these cells may mediate the transition from scarless to fibrotic healing during fetal development.
瘢痕形成是成体组织修复中一种潜在的有害过程，影响器官形态和功能。在胎儿发育过程中，皮肤伤口在发育早期没有炎症或瘢痕形成而愈合；然而，随着皮肤的成熟，它们开始以明显的炎症和瘢痕形成而愈合。一种可能调节从无瘢痕到纤维性愈合的细胞类型是肥大细胞。我们在这里表明，在胚胎第 15 天（E15）形成的无瘢痕伤口中的真皮肥大细胞数量较少，成熟度较低，并且对创伤的脱颗粒反应不如在胚胎第 18 天（E18）形成的纤维性伤口中的肥大细胞有效。从 E15 和 E18 皮肤培养的肥大细胞之间也观察到了差异，涉及脱颗粒和预先形成的细胞因子水平。肥大细胞裂解物注入 E15 伤口会破坏无瘢痕愈合，这表明肥大细胞干扰了无瘢痕修复。最后，在肥大细胞缺失的 Kit(W/W-v)小鼠中，通常会形成瘢痕的 E18 伤口与 Kit(+/+)同窝仔鼠相比，形成的瘢痕明显较小。综上所述，这些数据表明肥大细胞增强了瘢痕形成，并且这些细胞可能在胎儿发育过程中介导从无瘢痕到纤维性愈合的转变。
