Keloids are transcriptionally distinct from normal and hypertrophic scars

• Published in: EJD. European journal of dermatology Vol. 33; no. 6; pp. 604 - 611
• Main Authors: Walter, Annika S., Stocks, Marcus, Akova, Elif, Gauglitz, Gerd, Hartmann, Daniela, Aszodi, Attila, Böcker, Wolfgang, Saller, Maximilian M., Volkmer, Elias
• Format: Journal Article
• Language: English
• Published: Paris John Libbey Eurotext 01.12.2023
• Subjects: Cicatrix, Hypertrophic - genetics; Cicatrix, Hypertrophic - metabolism; Cicatrix, Hypertrophic - pathology; Dermatology; Humans; Hypertrophy - pathology; Investigative Report; Keloid - genetics; Keloid - pathology; Medicine; Medicine & Public Health; Skin - pathology; Wound Healing - genetics; RNA sequencing; hand surgery; keloids; wound healing; skin scar; hypertrophic scar
• ISSN: 1167-1122; 1952-4013
• DOI: 10.1684/ejd.2023.4582

Background Wound healing and skin regeneration after injury are complex biological processes, and deep injuries with a high degree of tissue destruction may result in severe scar formation. Clinically scars can be classified into normal, hypertrophic and keloid scars. However, the molecular signature of each scar type is currently not known. Objectives The aim of this study was to reveal the transcriptional landscape of normal, hypertrophic and keloid skin scars following hand and plastic surgery based on total RNA sequencing. Materials & Methods Eighteen skin scar samples from hand and plastic surgeries of human donors were minced directly after removal and stored in TRIzol (Thermo Fisher, USA). Samples were then subjected to RNA isolation, cDNA library preparation, bulk RNA sequencing and bioinformatics analysis. Results We show that keloid scars transcriptionally differed from normal and hypertrophic scars. Normal and hypertrophic scars presented overlapping clustering, and eight genes were shown to be commonly expressed between hypertrophic and normal scars. No genes were specifically expressed at a higher level in keloid and normal scars. Based on gene ontology pathway analysis, genes with a higher level of expression in keloid scars lead to increased (extra-) cellular matrix proliferation and cell interaction. Moreover, tumour-like genes were more highly expressed in keloid scars, supporting the clinical impression of strong and diffuse growth. Conclusion This study furthers our understanding of the classification of differential scar types based on molecular signature, which may shed light on new diagnostic and therapeutic strategies for keloid scars in the future.