Wutou decoction alleviates arthritis inflammation in CIA mice by regulating Treg cell stability and Treg/Th17 balance via the JAK2/STAT3 pathway.

Wutou Decoction (WTD) is a classic traditional Chinese medicine formula, which has shown clinical efficacy in treating rheumatoid arthritis (RA). The Treg stability and Th17/Treg imbalance is an important immunological mechanism in RA progression. Whether WTD regulates CD4+ T cell subsets has not been thoroughly investigated yet. This study aimed to explore the potential role and mechanisms of WTD in regulating the diminished stability of Treg cells and the imbalance of CD4+ T cell subsets via in vivo and in vitro experiments. Firstly, the therapeutic effects of WTD on the collagen-induced arthritis (CIA) mouse and its potential regulatory function on CD4+ T cell subsets were evaluated in vivo. Animal specimens were collected after 31 days of treatment with WTD. The anti-arthritic and anti-inflammatory effects of WTD were assessed through arthritis scoring, body weight, spleen index, serum IL-6 levels, and micro-PET/CT imaging. Gene enrichment analysis was performed to evaluate the activation T cell-related signaling pathway. Flow cytometry was used to determine the proportions of CD4+ T cell subsets in vitro and in vitro. Additionally, ELISA was used to assess the secretion of IL-10 and TGF-β by Treg cells under inflammatory conditions. The suppressive function of Treg cells on cell proliferation under inflammatory conditions was examined using CFSE labeling. Immunofluorescence staining was performed to detect the phosphorylation levels of STAT3 in CD4+ T cells from mouse spleen tissues. Western blotting was used to evaluate the phosphorylation levels of JAK2/STAT3 in Treg cells. WTD significantly alleviated joint inflammation in CIA mice. WTD reduced serum IL-6 levels in CIA mice, improved their body weight and spleen index. WTD treatment inhibited the activation of CD4+ T cell subgroup-related signaling in the joint tissues of CIA mice. In vitro and in vitro experiments showed that WTD increased the proportion of Treg cells and decreased the proportion of Th17 cells in CIA mice spleen. Furthermore, WTD promoted the secretion of IL-10 and TGF-β by Treg cells and enhanced the inhibitory capacity of Treg cells on cell proliferation under inflammatory conditions. Immunofluorescence detected decreased STAT3 phosphorylation levels in CD4+ T cells from CIA mice spleen, while western blotting revealed a decrease in JAK2/STAT3 phosphorylation levels in Treg cells in vitro. Inhibiting JAK2/STAT3 phosphorylation is a potential mechanism through which WTD improves Treg cell stability, balances CD4+ T cell subsets, and attenuates RA joint inflammation.

Han L ，Yan J ，Li T ，Shen P ，Ba X ，Lin W ，Zhang R ，Yang Y ，Li Y ，Li C ，Huang Y ，Qin K ，Liu Y ，Huang H ，Zou L ，Wang Y ，Chen Z ，Huang Y ，Tu S ... -  《-》

Gegen Qinlian decoction relieved DSS-induced ulcerative colitis in mice by modulating Th17/Treg cell homeostasis via suppressing IL-6/JAK2/STAT3 signaling.

Gegen Qinlian decoction (GQ) is a traditional Chinese herbal prescription that has been widely used for the treatment of bacterial dysentery and enteric typhoid fever. Recently, GQ has been clinically reported to be a potential candidate for the treatment of ulcerative colitis (UC). However, the immunoregulatory function of GQ in the treatment of UC has not been fully elucidated. This study focused on the role of immune imbalance in the pathogenesis of UC and the immunomodulatory effect of GQ in the treatment of UC. The UC model was established by treating female mice with 3.0% dextran sulfate sodium (DSS) for 7 days, and GQ was orally administered at dosages of 1.5 and 7.5 g/kg/day. Inflammatory factors were detected by ELISA and qRT-PCR. Treg and Th17 cell dysregulation was analyzed by qRT-PCR, immunohistochemistry and flow cytometry. Proteins related to IL-6/JAK2/STAT3 signaling were detected by western blotting. GQ significantly alleviated the symptoms of UC mice and suppressed the activity of myeloperoxidase (MPO). Furthermore, the production of proinflammatory factors, such as IL-1β, TNF-α and IL-6, was dramatically reduced after GQ administration. Furthermore, GQ improved the infiltration of Treg and Th17 cells into the colons and decreased the expression of inflammatory factors, such as TGF-β1 and IL-17. The frequencies of Treg and Th17 cells in the Peyer's patches and spleen were reduced by GQ administration; however, GQ had no significant regulatory effect on normal mice. The western blotting results showed that GQ markedly suppressed the phosphorylation of JAK2 and STAT3 and decreased the transcription function of phosphorylated STAT3. Taken together, these results indicated that GQ alleviated DSS-induced UC by suppressing IL-6/JAK2/STAT3 signaling to restore Treg and Th17 cell homeostasis in colonic tissue.

Zhao Y ，Luan H ，Jiang H ，Xu Y ，Wu X ，Zhang Y ，Li R ... -  《-》

Arsenic trioxide improves Treg and Th17 balance by modulating STAT3 in treatment-naïve rheumatoid arthritis patients.

We aimed to investigate the immunologic mechanisms by which arsenic trioxide (As2O3) may inhibit T helper 17 (Th17) cell differentiation while promoting regulatory T (Treg) cell generation by modulating signal transducer and activator of transcription 3 (STAT3) in treatment-naïve rheumatoid arthritis (RA) patients. Naïve CD4+T cells isolated by fluorescence-activated cell sorting from treatment-naïve RA patients and healthy controls were used to investigate the effect of As2O3 on the process of polarization and the related cytokines. STAT3 transfection experiments were conducted with small interfering RNA (siRNA) and lentivirus STAT3 to verify the mechanism of As2O3 on Th17-Treg balance in vitro. A collagen-induced arthritis (CIA) model was used to detect the clinical scores, histopathological change, bone destruction, Th17-Treg proportion and joint tissue immunohistochemistry. We found that As2O3 prevented activated naïve CD4+T-cells from differentiating into Th17 cells and reduced cytokine production by activated Th17 cells by downregulating their signature transcription factors, STAT3 and orphan nuclear receptors. Notably, As2O3 reduced Th17 cells frequency while increasing Treg cells frequency under specific polarizing conditions in treatment-naïve RA patients by transfecting siRNA STAT3 and lentivirus STAT3. Furthermore, we noticed that applying As2O3 in the CIA model attenuated the infiltration of joint inflammation and bone destruction, and significantly improved the imbalanced Treg-Th17 ratio. These data indicate that As2O3 may be a potential immune modulator for treatment-naïve RA patients that helps to balance of Treg and Th17 cells through modulating STAT3.

Li C ，Zhang J ，Wang W ，Wang H ，Zhang Y ，Zhang Z ... -  《-》

Tibetan medicine Ershiwuwei Lvxue Pill attenuates collagen-induced arthritis via inhibition of JAK2/STAT3 signaling pathway.

Ershiwuwei Lvxue Pill (ELP, མགྲིན་མཚལ་ཉེར་ལྔ།), a traditional Tibetan medicine preparation, has been used hundreds of years for the clinical treatment of rheumatoid arthritis (RA) in the highland region of Tibet, China. However, the underlying mechanism of its therapeutic effect remains unclear. The present study aimed to investigate the potential pharmacological mechanisms of anti-arthritic effect of ELP. The main chemical constituents of ELP were analyzed by ultra-performance liquid chromatography quadrupole-time-flight mass spectrometry (UPLC-Q-TOF-MS). Forty-eight male Wistar rats (220 ± 20 g) were randomly divided into six groups: normal group, collagen-induced arthritis (CIA) group, methotrexate group (1.05 mg/kg), ELP groups (115, 230 and 460 mg/kg). CIA rat models were assigned to evaluate the anti-RA activity of ELP by determining the paws swelling, arthritis score, organ coefficients of spleen and thymus, and histopathological analysis of knee joints of synovial tissues. The levels of TNF-α, IL-10, IL-6 and IL-17 in serum were measured by ELISA. In addition, mRNA and protein expression levels associated with JAK2/STAT3 signaling pathway in synovial tissues of CIA rats were detected by qRT-PCR, immunohistochemistry and Western blot analyses. Fourteen main chemical constituents of ELP were quantitatively determined by UPLC-Q-TOF-MS analysis. Treatment with ELP reduced the paw swelling, arthritis score and organ coefficients of spleen and thymus. Histopathological examination revealed the protective effects of ELP on CIA rats with knee joint injury. The levels of serum pro-inflammatory cytokines (TNF-α, IL-6 and IL-17) were markedly reduced while the anti-inflammatory cytokine IL-10 was significantly increased with the treatment of ELP. Further investigations showed ELP down-regulated the mRNA and protein expression levels of Bcl-2, whereas up-regulated Bax, SOCS1 and SOCS3. Meanwhile, the ratios of p-JAK2/JAK2 and p-STAT3/STAT3 proteins from synovial tissues were dramatically decreased with the treatment of ELP, whereas no changes of the mRNA and protein expression levels of JAK2 and STAT3 were observed. These results indicated that ELP reduced the severity of arthritis and joint swelling, suggesting an antirheumatic effect on CIA rats. The possible mechanism is related to inhibiting inflammatory response and inducing apoptosis in synovial tissues by regulating JAK2/STAT3 signaling pathway. However, further in vivo and in vitro investigations are still needed to clarify the underlying mechanism of ELP in treating RA.

Liu C ，Zhao Q ，Zhong L ，Li Q ，Li R ，Li S ，Li Y ，Li N ，Su J ，Dhondrup W ，Meng X ，Zhang Y ，Tu Y ，Wang X ... -  《-》

Wutou decoction attenuates the synovial inflammation of collagen-induced arthritis rats via regulating macrophage M1/M2 type polarization.

Thousands of years of clinical practice in the treatment of joint-related diseases support the efficacy and safety of Wutou decoction (WTD). Nevertheless, the lack of pharmacological evidence and unclear mechanisms make it difficult for WTD to become a recognized complementary therapy for the treatment of rheumatoid arthritis (RA). This study aimed to investigate the effect of WTD against synovial inflammation in RA and whether this effect depends on the regulation of macrophage polarization. Sprague-Dawley rats were used to establish the collagen-induced arthritis (CIA) model. WTD with low and high doses was administered for 45 days. RAW264.7 cells were stimulated by lipopolysaccharide (LPS) or interleukin (IL)-4 to polarize M1 and M2 macrophages, which were pre-treated with WTD extract for 4 h. The anti-arthritic and anti-inflammatory effects of WTD were studied using arthritis score, histopathological staining, immunostaining, and enzyme-linked immunosorbent assay (ELISA). The polarization state of RAW264.7 cells and related pro/anti-inflammatory cytokines was detected by ELISA, reverse transcription quantitative polymerase chain reaction and western blotting. Western blotting and immunofluorescence were used to investigate the effect of WTD on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptors γ (PPARγ) activation both in vivo and in vitro. WTD significantly reduced the arthritis score and the pathological damage of the knee joint and decreased the expression of tumor necrosis factor alpha (TNF-α), IL-6 in serum, TNF-α, IL-1β, monocyte chemoattractant protein-1 (MCP-1), and matrix metalloproteinase-3 (MMP3) in the knee synovium. WTD inhibited M1 type polarization and promoted M2 type polarization, both in vitro and in vivo, and reduced the expression of pro-inflammatory cytokines while increasing the expression of anti-inflammatory cytokines. Experiments showed that WTD inhibited the phosphorylation of NF-κB and downstream p38 in the synovium of CIA rats and LPS-induced M1 type polarized RAW264.7 cells. In addition, PPARγ expression in the synovium of CIA rats was mainly located in the cytoplasm, and WTD treatment increased the nuclear translocation of PPARγ, which was further verified in RAW264.7 cells. NF-κB and PPARγ regulating M1 and M2 macrophage polarization and subsequent secretion of pro-inflammatory and anti-inflammatory cytokines are the underlying mechanisms of WTD that ameliorate RA synovial inflammation.

Lin W ，Shen P ，Huang Y ，Han L ，Ba X ，Huang Y ，Yan J ，Li T ，Xu L ，Qin K ，Chen Z ，Tu S ... -  《-》