CircRNA Profiling Identifies hsa_circRNA_003201 Associated with a Predicted NLRX1-Related Regulatory Network in an Acne-Associated Inflammatory Sebocyte Model

Abstract

Background Circular RNAs (circRNAs) are a class of non-coding RNAs that regulate gene expression and have been implicated in inflammatory skin diseases. Sebocytes play a central role in acne pathogenesis by regulating sebum production and inflammatory responses. However, the roles of circRNAs in sebocytes during acne remain poorly understood. This study aimed to characterize circRNA expression profiles and explore their potential functions in acne-associated inflammation. Methods Human SZ95 sebocytes were stimulated with formalin-killed Cutibacterium acnes (f-C. acnes) to establish an acne-like inflammatory model. CircRNA expression was profiled using microarray analysis with three biological replicates per group. Differentially expressed circRNAs were identified, and a circRNA-miRNA-mRNA regulatory network was constructed. Predicted target genes were analyzed by GO and KEGG enrichment analyses. Selected circRNAs, miRNAs, and mRNAs were further validated by RT-qPCR using four independent biological replicates. NLRX1 protein expression in acne and control tissues was examined by immunohistochemistry. Results Sixteen differentially expressed circRNAs were identified in f-C. acnes-treated sebocytes, including 12 upregulated and 4 downregulated circRNAs (fold change ≥1.5, P<0.05). RT-qPCR confirmed five circRNAs, including hsa_circRNA_003201, hsa_circRNA_100840, hsa_circRNA_102619, hsa_circRNA_051123, and hsa_circRNA_005161. Functional enrichment analyses suggested that predicted target genes were associated with lipid metabolism, epidermal differentiation, inflammatory responses, and NOD-like receptor signaling. The predicted hsa_circRNA_003201/miR-519c-5p/NLRX1 axis was selected for further investigation. NLRX1 protein expression was increased in acne lesions compared with control tissues and showed a consistent pattern with hsa_circRNA_003201 in the acne-like inflammatory model. Conclusion This study provides a circRNA expression profile in an acne-like inflammatory sebocyte model and identifies hsa_circRNA_003201 as a candidate circRNA associated with acne-associated inflammation. The findings suggest a potential circRNA-miRNA-mRNA regulatory network involving NLRX1 and provide new insights into acne inflammatory mechanisms. Further functional studies are required to validate the proposed regulatory relationships.