[H3K27 acetylation promotes lncRNA OIP5-AS1 transcription and induces apoptosis of nasal epithelial cells in allergic rhinitis through up-regulation of TLR4].

Objective To investigate the effect of lysine 27 residue of histone H3 (H3K27) acetylation modification on the transcriptional promotion of long noncoding RNA OPA interacting protein 5-antisense RNA 1 (lncRNA OIP5-AS1) and apoptosis of nasal epithelial cells (NECs) in allergic rhinitis (AR) via regulating Toll-like receptor 4 (TLR4). Methods Interleukin-13 (IL-13) was used to treat NECs to establish an AR cell model. Real-time quantitative PCR was utilized to detect the expressions of OIP5-AS1 and TLR4 in nasal mucosal tissues of AR patients and in the in vitro cell model. The concentrations of macrophage colony-stimulating factor (GM-CSF), eotaxin-1, and mucin 5AC (MUC5AC) were detected by ELISA. The apoptosis of NECs was determined by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL). A dual-luciferase report experiment was carried out to verify the relationship between OIP5-AS1 and TLR4. Chromatin immunoprecipitation (ChIP) assay was performed to verify H3K27 acetylation of histones in the OIP5-AS1 promoter region. Results Compared with healthy controls and untreated NECs, OIP5-AS1 and TLR4 were both up-regulated in nasal mucosal tissues from AR patients and IL-13-stimulated NECs. Knockdown of OIP5-AS1 decreased the level of TLR4 in IL-13-treated NECs, while overexpression of OIP5-AS1 increased the level of TLR4. Inhibition of OIP5-AS1 reduced the apoptosis rate, and inhibited the secretion of GM-CSF, eotaxin-1, and MUC5AC from IL-13-treated NECs, while overexpression of TLR4 partially reversed the effects of OIP5-AS1 knockdown on NEC apoptosis and the secretion of GM-CSF, eotaxin-1, and MUC5AC. In addition, H3K27 acetylation was markedly enriched in the promoter region of OIP5-AS1, and H3K27 acetylation promoted the expression of OIP5-AS1 in IL-13-treated NECs. Conclusion H3K27 acetylation promotes OIP5-AS1 transcription and induces NEC apoptosis in AR via upregulation of TLR4.

POSTN Regulates Fibroblast Proliferation and Migration in Laryngotracheal Stenosis Through the TGF-ß/RHOA Pathway.

OBJECTIVES: To investigate the role of periostin (POSTN) and the transforming growth factor ß (TGF-ß) pathway in the formation of laryngotracheal stenosis (LTS) scar fibrosis and to explore the specific signaling mechanism of POSTN-regulated TGF-ß pathway in tracheal fibroblasts. METHODS: Bioinformatics analysis was performed on scar data sets from the GEO database to preliminarily analyze the involvement of POSTN and TGF-ß pathways in fibrosis diseases. Expression of POSTN and TGF-ß pathway-related molecules was analyzed in LTS scar tissue at the mRNA and protein levels. The effect of POSTN on the biological behavior of tracheal fibroblasts was studied using plasmid DNA overexpression and siRNA silencing techniques to regulate POSTN expression and observe the activation of TGF-ß1 and the regulation of cell proliferation and migration via the TGF-ß/RHOA pathway. RESULTS: The bioinformatics analysis revealed that POSTN and the TGF-ß pathway are significantly involved in fibrosis diseases. High expression of POSTN and TGF-ß/RHOA pathway-related molecules (TGFß1, RHOA, CTGF, and COL1) was observed in LTS tissue at both mRNA and protein levels. In tracheal fibroblasts, overexpression or silencing of POSTN led to the activation of TGF-ß1 and regulation of cell proliferation and migration through the TGF-ß/RHOA pathway. CONCLUSION: POSTN is a key molecule in scar formation in LTS, and it regulates the TGF-ß/RHOA pathway to mediate the formation of cicatricial LTS by acting on TGF-ß1. This study provides insights into the molecular mechanisms underlying LTS and suggests potential therapeutic targets for the treatment of this condition. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.