Single-cell analysis reveals cellular heterogeneity, gene expression profiles, and pathway dynamics in acne vulgaris.

Acne vulgaris is a common dermatological condition, particularly in adolescents, and is associated with significant physical and psychological impacts. Its pathogenesis involves genetic factors, sebaceous gland dysfunction, inflammatory responses, and alterations in skin microbiota. Despite advancements in treatment, a comprehensive understanding of its cellular and molecular mechanisms remains limited, making therapeutic strategies challenging. Single-cell RNA sequencing (scRNA-seq) data from six acne vulgaris patients were obtained from the GEO database (GSE175817), filtered, and integrated. Differentially expressed genes (DEGs) were identified and subjected to functional enrichment analysis to explore the underlying pathogenesis. Gene set variation analysis (GSVA) was used to investigate metabolic pathway alterations, and ligand-receptor interactions were analyzed to examine cell-to-cell communication between lesional and non-lesional skin tissues. The integration of scRNA-seq data yielded the identification of eight distinct cell clusters, including endothelial cells, myeloid cells, lymphocytes, melanocytes, sebaceous gland cells, smooth muscle cells, keratinocytes and fibroblasts. The proportions of lymphoid and myeloid cells were found to be significantly different between the lesional and non-lesional sites. The differential expression of genes (DEGs) was found to be significantly specific to the different cell clusters. Abnormal intercellular communication was found to result in a substantial increase in the number and intensity of communications in the area of acne vulgaris lesions. Moreover, specific ligand-receptor pairs for SPP1 and IL6 associated with acne vulgaris were identified. Furthermore, the presence of specific alterations in metabolic pathways, including riboflavin metabolism, niacin metabolism, and lipoic acid metabolism, was observed. Our findings demonstrate the cellular heterogeneity and dysfunction of intercellular communication and metabolic signaling in the lesional skin tissues of patients with acne vulgaris. These findings have important implications for understanding the complex biological processes of acne vulgaris.