Keloids are disfiguring, hypertrophic scars with yet poorly understood pathomechanisms, which could lead to severe functional impairments. Here we analyzed the characteristics of keloidal cells by single cell sequencing and discovered the presence of an abundant population of Schwann cells that persisted in the hypertrophic scar tissue after wound healing. In contrast to normal skin, keloidal Schwann cells show a unique, pro-fibrotic phenotype. Our data support the hypothesis that keloidal Schwann cells contribute to the formation of the extracellular matrix and are able to affect M2 polarization of macrophages. Indeed, we show that macrophages in keloids predominantly display a M2 polarization and produce factors that inhibit Schwann cell differentiation. This study suggests the contribution of a Schwann cell - macrophage cross-talk to the continuous expansion of keloids, and that targeting Schwann cells might represent an interesting novel treatment option for keloids.

瘢痕疙瘩是一种毁容性、肥厚性疤痕，其病理机制尚不清楚，可能导致严重的功能障碍。在这里，我们通过单细胞测序分析了瘢痕疙瘩细胞的特征，发现存在大量的雪旺细胞群，这些细胞群在伤口愈合后持续存在于肥厚性瘢痕组织中。与正常皮肤相比，瘢痕疙瘩雪旺细胞表现出独特的促纤维化表型。我们的数据支持这样的假设，即瘢痕疙瘩雪旺氏细胞有助于细胞外基质的形成并能够影响巨噬细胞的 M2 极化。事实上，我们发现瘢痕疙瘩中的巨噬细胞主要表现出 M2 极化并产生抑制雪旺氏细胞分化的因子。