Tianle Zhan1, Baoli Wang1, Jiayao Fu1, Yanxiong Shao1, Lei Ye1, Huan Shi2, Lingyan Zheng3. 1. Department of Oral Surgery, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center of Oral Disease, Shanghai, China; Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. 2. Department of Oral Surgery, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center of Oral Disease, Shanghai, China; Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. Electronic address: shihuan1312@163.com. 3. Department of Oral Surgery, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center of Oral Disease, Shanghai, China; Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. Electronic address: zhenglingyan73@163.com.
Abstract
BACKGROUND: Hyperactivation of B cells by activators has been demonstrated to play a central role in the pathogenesis of Sjögren's syndrome (SS). In this study, we found that artesunate (ART) can attenuate BAFF-induced B cell hyperactivation and SS-like symptoms in NOD/Ltj mice. PURPOSE: To determine the efficacy of ART in attenuating SS-like symptoms in vivo and explore the underlying mechanism in vitro. STUDY DESIGN: ART was intragastrically injected into SS-like NOD/Ltj mice. The cytokine hsBAFF was used to activate Raji and Daudi B cells to mimic B cell hyperactivation in vitro. METHODS: The efficacy of ART in inhibiting SS progression was studied in NOD/Ltj mice. Salivary flow rate, the number of lymphocytic infiltration foci, the level of autoantibodies and the extent of B cell infiltration were measured in the indicated groups. CCK-8 assays, flow cytometry-based EdU staining and Annexin V/PI staining were also used to detect the effect of ART on the survival and proliferation mechanism in BAFF-induced Raji and Daudi cells. Further studies determined that TRAF6 degradation is a potential mechanism by which ART determines B cell fate. RESULTS: Treatment with ART inhibited lymphocytic foci formation, B cell infiltration and autoantibody secretion in SS-like NOD/Ltj mice. In vitro assay results indicated that ART effectively inhibited BAFF-induced viability, survival and proliferation of neoplastic B cells. Mechanistically, ART targeted BAFF-activated NFκB by regulating the proteasome-mediated degradation of TRAF6 in Raji and Daudi cells. CONCLUSION: ART ameliorated murine SS-like symptoms and regulated TRAF6-NFκB signaling, thus determining survival and proliferation of B cells.
BACKGROUND: Hyperactivation of B cells by activators has been demonstrated to play a central role in the pathogenesis of Sjögren's syndrome (SS). In this study, we found that artesunate (ART) can attenuate BAFF-induced B cell hyperactivation and SS-like symptoms in NOD/Ltj mice. PURPOSE: To determine the efficacy of ART in attenuating SS-like symptoms in vivo and explore the underlying mechanism in vitro. STUDY DESIGN:ART was intragastrically injected into SS-like NOD/Ltj mice. The cytokine hsBAFF was used to activate Raji and Daudi B cells to mimic B cell hyperactivation in vitro. METHODS: The efficacy of ART in inhibiting SS progression was studied in NOD/Ltj mice. Salivary flow rate, the number of lymphocytic infiltration foci, the level of autoantibodies and the extent of B cell infiltration were measured in the indicated groups. CCK-8 assays, flow cytometry-based EdU staining and Annexin V/PI staining were also used to detect the effect of ART on the survival and proliferation mechanism in BAFF-induced Raji and Daudi cells. Further studies determined that TRAF6 degradation is a potential mechanism by which ART determines B cell fate. RESULTS: Treatment with ART inhibited lymphocytic foci formation, B cell infiltration and autoantibody secretion in SS-like NOD/Ltj mice. In vitro assay results indicated that ART effectively inhibited BAFF-induced viability, survival and proliferation of neoplastic B cells. Mechanistically, ART targeted BAFF-activated NFκB by regulating the proteasome-mediated degradation of TRAF6 in Raji and Daudi cells. CONCLUSION:ART ameliorated murine SS-like symptoms and regulated TRAF6-NFκB signaling, thus determining survival and proliferation of B cells.