Hsa_circ_0099630 knockdown induces the proliferation and osteogenic differentiation and attenuates the apoptosis of porphyromonas gingivalis lipopolysaccharide–induced human periodontal ligament fibroblasts

BACKGROUND: Periodontitis is an inflammatory destructive bone disease and is the most critical cause of tooth loss in adults. Recent studies have reported that circular RNAs (circRNAs) are essential in periodontitis. However, the influence and mechanism of hsa_circ_0099630 on periodontitis are not clear. METHODS: Normal periodontal tissues and inflammatory periodontal tissues were obtained from healthy patients and patients with periodontitis, respectively. Hsa_circ_0099630 was 1st identified by polymerase chain reaction (PCR) and sanger sequencing, and hsa_circ_0099630 expression was determined by real-time (RT)-quantitative PCR in periodontitis. Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) was used to construct an inflammation model in vitro. Next, cell proliferation, apoptosis, and osteogenic differentiation were monitored using Cell Counting Kit-8, flow cytometry, and western blot in the Pg-LPS-induced human periodontal ligament fibroblasts (HPLFs). The microRNA (miRNA)/messenger RNA (mRNA) axis of hsa_circ_0099630 was predicted and screened, and the function of the target genes was analyzed by a Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. RESULTS: The identified hsa_circ_0099630 was upregulated in the gingival tissue of patients with periodontitis. Next, an inflammation model was constructed using Pg-LPS in the HPLFs. We discovered that Pg-LPS or hsa_circ_0099630 overexpression suppressed cell proliferation and osteogenic differentiation, and induced apoptosis in HPLFs. Additionally, hsa_circ_0099630 knockdown induced proliferation and osteogenic differentiation and prevented apoptosis in the Pg-LPS-induced HPLFs. We also screened the vast miRNA/mRNA axis associated with hsa_circ_0099630. CONCLUSIONS: The current study uncovered the crucial role of hsa_circ_0099630 in periodontitis.