Qiuye Chen, Tianjiao Wang, Lele Liu, Tao Zhou, Li Zhang
This study intended to illustrate the therapeutic effects of puerarin in the treatment of periodontitis, and the involvements of autophagy and Notch signaling pathway. Lipopolysaccharide from Porphyromonas gingivalis (Pg-LPS) stimulated human periodontal ligament stem cells (hPDLSCs) and ligature-induced periodontitis rats were utilized for in vitro and in vivo investigations, respectively. Cells viability was determined by CCK-8 assay. Alkaline phosphatase (ALP) and alizarin red staining were employed to monitor osteogenic differentiation. Autophagosome was observed under transmission electron microscopy. Autolysosome was detected by the colocalization of LC3 and LAMP1. Pathological injury in periodontal tissues was assessed by Hematoxylin and eosin staining and Masson staining. Notch signaling pathway inhibitor, DAPT, was used to explore the involvements of Notch pathway. Compared to control, level of inflammatory factors (IL-6 and TNF-α) was increased, cell viability was impaired, autophagy (less autophagosomes and autolysosomes, reduced expression of LC3 II/I and Beclin1, and increased p62) was inhibited in Pg-LPS-stimulated hPDLSCs. Puerarin treatments (5, 10, and 20 µM) could reverse such changes caused by Pg-LPS stimulation. In addition, puerarin treatments significantly reversed the reduced ALP activity, calcium deposits and expression of osteogenic markers (OPN, RUNX2 and COL2) in Pg-LPS-stimulated hPDLSCs. Puerarin treatment activated the inhibited Notch pathway in hPDLSCs caused by Pg-LPS. DAPT treatment could offset the roles of puerarin on autophagy and osteogenic differentiation. Similarly, puerarin could improve the pathological injury, promote autophagy and Notch pathway in periodontal tissues of ligature-induced periodontitis rats. Puerarin promoted osteogenic differentiation and autophagy activation in periodontitis, and Notch signal pathway involved in such effects of puerarin in periodontitis.