Total glucosides of paeony alleviates experimental Sjögren's syndrome through inhibiting NLRP3 inflammasome activation of submandibular gland cells

Abstract

Objectives: The mechanisms by which total glucosides of paeony (TGP) mitigates Sjögren's syndrome (SS) remains elusive. In the present study, we aim to explore the relationship between the therapeutic effects of TGP in the treatment of SS and NLRP3 inflammasome activation in submandibular gland (SG) cells.

Methods: Female non-obese diabetic (NOD) mice were selected as the model of SS. The mice were divided into PBS and TGP treatment group. For treatment, TGP (400mg·kg-1) was administered intragastrically every day for 4 weeks. The SS-like symptoms and pathological changes of the SG of mice were compared between the PBS and TGP group. The activation of NLRP3 inflammasome in SG was detected by RT-qPCR, immunohistochemistry and western blot. The SG cells stimulated by lipopolysaccharide (LPS) and adenosine triphosphate (ATP) for activation of NLRP3 inflammasome were treated with or without TGP. Then, NLRP3 inflammasome activation was assessed. The IL-1β and IL-18 in homogenate of SG, serum and supernatant were detected by ELISA.

Results: Compared with balb/c mice, NOD mice showed SS-like symptoms and lymphocyte infiltration in SG, and the expression of NLRP3 inflammasome in SG was significantly increased. The SS-like symptoms were alleviated, and lymphocyte infiltration in SG was reduced, and the level of NLRP3 inflammasome in SG mice was decreased after TGP treatment. TGP also significantly inhibit the activation of NLRP3 inflammasome of SG cells in vitro.

Conclusions: Collectively, our results indicated that TGP alleviates SS through inhibition of the activation of NLRP3 inflammasome of SG. These findings clarified the mechanism underlying the therapeutic effects of TGP on SS, and provided new evidence for the further application of TGP in the treatment of SS.