Gouty arthritis is a common inflammatory disease characterized by monosodium urate (MSU) crystal induced nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activation with up-regulated caspase-1 protease and IL-1β in macrophages. Cucurbitacin B (CuB) is a tetracyclic triterpene that possesses a potential anti-inflammatory activity. However, the immunomodulatory and anti-inflammatory effects of CuB on gout have not been well characterized. Therefore, the purpose of the present study was to determine whether CuB exhibits anti-inflammatory effects on gout and to analyze the underlying molecular mechanism. We examined the effects of CuB on various stimuli-activated bone marrow-derived macrophages (BMDMs) and the mice model with MSU-induced acute gouty arthritis. Our results demonstrated that CuB effectively suppressed multiple stimuli-activated IL-1β secretion by interrupting NLRP3 inflammasome complex formation, inhibiting NLRP3 inflammasome activation and suppressing key enzymes of glycolysis in macrophages. Consistent with this, CuB pretreatment also ameliorated MSU-induced arthritis in vivo models of gout arthritis, manifested by reduced foot swelling and inflammatory cell infiltration. Taken together, our data provide the evidence that CuB is a NLRP3 inflammasome inhibitor with therapeutic potential for treating NLRP3 inflammasome-mediated diseases, especially gouty arthritis.
Ying Xue, Ran Li, Ping Fang, Zheng-qin Ye, Yong Zhao, Yun Zhou, Ke-qin Zhang, and Ling Li
Jie Sun, Yan Liu, Jinhui Yu, Jin Wu, Wenting Gao, Liyuan Ran, Rujiao Jiang, Meihua Guo, Dongyu Han, Bo Liu, Ning Wang, Youwei Li, He Huang, Li Zeng, Ying Gao, Xin Li, and Yingjie Wu
Astragalus polysaccharide (APS) is the main component of Astragalus membranaceus, an anti-diabetic herb being used for thousands of years in Traditional Chinese medicine (TCM). In this study, we aimed to evaluate the impact of APS on hepatic insulin signaling, autophagy and ER stress response in high-fat-diet (HFD)-induced insulin resistance (IR) mice. APS was intra-gastrically administrated and metformin was used as a control medicine. Apart from monitoring the changes in the important parameters of IR progression, the gene and protein expression of the key factors marking the state of hepatic ER stress and autophagic flux were examined. We found that, largely comparable to the metformin regime, APS treatment resulted in an overall improvement of IR, as indicated by better control of body weight and blood glucose/lipid levels, recovery of liver functions and regained insulin sensitivity. In particular, the excessive and pro-apoptotic ER stress response and inhibition of autophagy, as a result of prolonged HFD exposure, were significantly corrected by APS administration, indicating a switch of the cellular fate in favor of cell survival. Using the HepG2/IR cell model, we demonstrated that APS modulated the insulin-initiated phosphorylation cascades in a similar manner to metformin. This study provides a rationale for exploiting the insulin-sensitizing potential of APS, which has a therapeutic performance almost equivalent to metformin, to enrich our options in the treatment of IR.