Despite decades of research, the driving forces behind keloids, an itching, painful and movement-restricting skin disorder, are still not fully understood. Here we performed single cell RNA sequencing to gain novel insights on the cellular composition and transcriptional pattern of keloids. Bioinformatics analysis revealed a so far undescribed accumulation of Schwann cells in keloids, which was not detectable in normal skin and normal scars. Compared to Schwann cells from normal skin, keloidal Schwann cells showed a completely distinct phenotype. These Schwann cells displayed an increased expression level of genes involved in extracellular matrix formation and wound healing and showed features of repair Schwann cells present in regenerating nerves. Further in depth analyses defined a set of twenty-one genes, which transcriptionally characterized this pro-fibrotic Schwann cell-type. Immunofluorescence confirmed our transcriptomics data and showed that Schwann cells pervaded the whole keloid without any contact to axons. As repair Schwann cells interact with macrophages, we further examined the macrophage populations and their interaction with keloidal Schwann cells in more detail. We identified several factors affecting macrophage polarization and Schwann cell-differentiation, both contributing to exacerbated matrix formation and growth of keloids. Together, our results indicate a so far undescribed contribution of Schwann cells to keloid formation, suggesting them as a novel target for the treatment of keloids.

ESDR590 - Schwann cells – an unexpected key player in keloid formation

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.