Rapamycin can alleviate the submandibular gland pathology of Sjögren's syndrome by limiting the activation of cGAS-STING signaling pathway.

BACKGROUND: Sjögren's Syndrome (SS) is also known as autoimmune exocrine gland disease. Previous studies have confirmed that adaptive immunity plays an important role in the development of this disease. But less is known about the role of the innate immune system. METHODS: To identify the core pathways, and local infiltrated immune cells in the local immune microenvironment of SS. We verified the activation of these core genes and core signaling pathways in SS model mice by in vivo experiment and transcriptome sequencing. RESULTS: Finally, we identified 6 core genes EPSTI1, IFI44L, MX1, CXCL10, IFIT3, and IFI44. All the 6 genes had good diagnostic value. Based on multi-omics sequencing results and experimental studies, we found that cGAS-STING signaling pathway is most relevant to the pathogenesis of SS. By in vivo experiments, we verified that autophagy is the key brake to limit the activation of cGAS-STING signaling pathway. CONCLUSIONS: Maladaptive activation of autophagy and cGAS-STING signaling pathway are central contributors to the SG pathogenesis of pSS patient. Regulating autophagy by rapamycin may be a possible treatment for Sjögren's syndrome in the future.

Bitongqing Attenuates CIA Rats by Suppressing Macrophage Pyroptosis and Modulating the NLRP3/Caspase-1/GSDMD Pathway.

Background: Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovitis and inflammatory cell infiltration. The traditional Chinese medicine prescription, Bitongqing (BTQ) exhibited significant efficacy in the clinical treatment of RA. However, the potential therapeutic mechanisms of BTQ in treating RA have not been fully investigated. This study aims to elucidate the effect of BTQ on collagen-induced arthritis (CIA) rat macrophage pyroptosis, providing a theoretical basis for treating RA. Methods: This research employed liquid chromatography-mass spectrometry (LC-MS) to identify the primary components of BTQ. The therapeutic effects of BTQ were evaluated in a rat model of CIA. In vivo experiments were conducted using pathohistological staining, immunofluorescence, micro-CT, and Western blotting. Next, Mouse leukemia cells of monocyte macrophage cells (RAW264.7) were induced to undergo pyroptosis using lipopolysaccharide (LPS) and adenosine triphosphate (ATP), and the impact of BTQ on RAW264.7 macrophages was assessed through cell viability, immunofluorescence analysis, lactate dehydrogenase (LDH) secretion measurement, and Western blotting. Results: BTQ had a therapeutic effect on CIA rats, which was mainly manifested as a reduction in joint inflammation, foot swelling, bone erosion, and amelioration of pathological changes in these rats. Further studies revealed that BTQ inhibited the levels of cytokine production interleukin-18 (IL-18) and interleukin-1ß (IL-1ß), and likewise, it inhibited the expression of key proteins in the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) mediated pyroptosis in the synovial tissues of CIA rats. The results of in vitro experiments demonstrated that BTQ attenuated LDH secretion, decreased IL-18 and IL-1ß cytokine production, and downregulated expression of key proteins involved in the NLRP3-mediated pyroptosis on RAW264.7 macrophages. Conclusion: The therapeutic potential of BTQ in CIA lies in its ability to inhibit NLRP3-mediated macrophage pyroptosis, thereby suggesting a promising strategy for the treatment of RA.