Hsa_circ_0007349 upregulates glutamate-ammonia ligase to modulate gingival fibroblast wound healing

Human gingival fibroblasts (HGFs) are important cells that maintain the structure and integrity of periodontal tissues. Circular RNAs (circRNAs) play critical roles in cellular processes of periodontitis; however, their roles in HGFs remain unclear. This study aimed to elucidate the function and mechanism of a novel circRNA, hsa_circ_0007349, in periodontitis progression by validating its existence, establishing its role in a ceRNA network (targeting miR-127-5p/GLUL), assessing its regulatory effects on HGF functions in vitro, and confirming its pathological impact in a murine periodontitis model.

We performed circRNA sequencing to identify differentially expressed circRNAs between periodontitis and healthy gingival tissues. We selected hsa_circ_0007349, and confirmed its circular structure by Sanger sequencing, RNase R and actinomycin D assays. hsa_circ_0007349/miR-127-5p/glutamate-ammonia ligase (GLUL) interactions were explored using bioinformatics analysis, dual-luciferase reporter assays, RT-qPCR, and western blotting, and their effects on HGF functions were assessed via transcriptome sequencing, Cell Counting Kit-8, cell scratch, and Transwell assays. To further investigate the pathogenic mechanisms, we established a standardized murine periodontitis model using female C57BL/6 mice, followed by histopathological evaluation of periodontal tissue destruction.

Hsa_circ_0007349 expression significantly increased in gingival tissues of patients with periodontitis and in HGFs treated with Porphyromonas gingivalis lipopolysaccharide. hsa_circ_0007349 regulates miR-127-5p to affect cell proliferation, migration, and wound healing, and affects extracellular matrix metabolism and periodontal tissue damage via GLUL.

Hsa_circ_0007349 acts as a competing endogenous RNA to promote HGF proliferation, migration, wound healing and extracellular matrix turnover by targeting miR-127-5p and GLUL.