Keratinocyte-specific long non-coding RNA NR037661 controls alternative splicing of ANGPTL4 to induce keratinocyte differentiation.

Background: Aberrant differentiation of keratinocytes has been implicated in various skin diseases. However, the impact of lncRNA on keratinocyte differentiation and RNA alternative splicing remains poorly understood. The primary aim of this study was to delineate the landscape of differentially expressed lncRNAs in keratinocytes undergoing differentiation and to elucidate the underlying molecular mechanisms. Methods: Primary human keratinocytes (HKEn) were subjected to comprehensive microarray analysis to identify the differentially expressed lncRNAs upon calcium stimulation. Loss-of-function experiments were carried out to explore the role of NR037661 in keratinocyte differentiation. RNA sequencing analysis was performed to study the potential target genes of NR037761. RNA pull-down assay, SDS-PAGE, silver staining and mass spectrometry analysis were utilized to explore the potential proteins that interacted with NR037761 and participated in NR037761-mediated keratinocyte differentiation. The effects of NR037761 on the alternative splicing and expression of Angiopoietin-like 4 (ANGPTL4) were analyzed by RT-PCR and Western blot. Results: NR037661 specifically interacts with the splicing factor Serine/arginine repetitive matrix protein 2 (SRRM2), facilitating its nuclear localization. This interaction modulates the alternative splicing (AS) of ANGPTL4 mRNA, ultimately influencing keratinocyte differentiation. Conclusions: Our findings illuminate a novel regulatory mechanism underlying keratinocyte differentiation, potentially revealing new therapeutic targets for skin diseases.