Curcumin-carbon dots suppress periodontitis via regulating METTL3/IRE1α signaling

This study aimed to investigate the effects of curcumin-carbon dot conjugates (CUR-CD) on periodontitis. Porphyromonas gingivalis lipopolysaccharide (LPS) was used to establish periodontitis mode in vivo and in vitro. Histological analysis was conducted using hematoxylin and eosin (HE) staining. Bone morphogenetic protein 2 (BMP2) and secreted phosphoprotein 1 (OPN) expression was determined using immunohistochemistry. mRNA levels were detected using reverse transcription quantitative real-time PCR (RT-qPCR). Protein expression was determined using Western blot. N6-methyladenosine (m6A) enrichment was determined using methylated RNA immunoprecipitation (MeRIP) assay. Cytokine release was determined using enzyme-linked immunosorbent assay (ELISA) assay. Osteogenic differentiation was detected using alkaline phosphatase (ALP) staining. The results showed that CUR-CD inhibited the inflammatory response, as well as promoted bone healing in vivo and osteogenic differentiation in vitro. Moreover, CUR-CD downregulated methyltransferase 3 (METTL3), which inhibited m6A modification of endoplasmic reticulum to nucleus signaling 1 (IRElα) and downregulated IRElα expression. However, overexpression of IRElα reversed the effects of CUR-CD, stimulating inflammatory response and inhibiting bone healing and osteogenic differentiation. Collectively, CUR-CD inhibits the progression of periodontitis via downregulating IRElα. Therefore, CUR-CD may be an alternative strategy for periodontitis.