Jingxia Zhao

Astilbin inhibits Th17 cell differentiation and ameliorates imiquimod-induced psoriasis-like skin lesions in BALB/c mice via Jak3/Stat3 signaling pathway.

The flavonoid astilbin is the major active component extracted from the rhizome of Smilax glabra, which has been widely used in China to treat inflammatory and autoimmune diseases, Psoriasis is a common chronic inflammatory disease in which T helper 17 (Th17) cells play an important role, provoking inflammation. We employed an imiquimod (IMQ)-induced psoriasis-like mouse model to investigate the effect of astilbin in inflammation. Mice were administered 25 to 50mg/kg astilbin. Inflammation of psoriasis-like lesions was assessed by histology, circulating levels of T cells were assessed by flow cytometry and cytokines by bead-based immunoassay. Jak/Stat3 in isolated T cells was assessed by Western blotting and RORγt expression was assessed by RT-PCR. Administration of astilbin ameliorated IMQ-induced keratinocyte proliferation, infiltration of CD3+ cells to psoriatic lesions and ameliorated elevations in circulating CD4+ and CD8+ T cells and inflammatory cytokines (IL-17A, TNF-α, IL-6, IFN-γ and IL-2). In vitro, astilbin inhibited Th17 cell differentiation and IL-17 secretion of isolated T cells, and inhibited Jak/Stat3 signaling in Th17 cells, while up-regulating Stat3 inhibitor SCOSE3 expression in psoriatic lesions. Thus, astilbin likely alleviates psoriasis-like skin lesions by inhibiting Th17 related inflammation. Astilbin represents as an interesting candidate drug for immunoregulation of psoriasis.

Hydroxysafflor Yellow A Inhibits LPS-Induced NLRP3 Inflammasome Activation via Binding to Xanthine Oxidase in Mouse RAW264.7 Macrophages

Hydroxysafflor yellow A (HSYA) is an effective therapeutic agent for inflammatory diseases and autoimmune disorders; however, its regulatory effect on NLRP3 inflammasome activation in macrophages has not been investigated. In this study, we predicted the potential interaction between HSYA and xanthine oxidase (XO) via PharmMapper inverse docking and confirmed the binding inhibition via inhibitory test (IC50 = 40.04 μM). Computation docking illustrated that, in this HSYA-XO complex, HSYA was surrounded by Leu 648, Leu 712, His 875, Leu 873, Ser 876, Glu 879, Phe 649, and Asn 650 with a binding energy of −5.77 kcal/M and formed hydrogen bonds with the hydroxyl groups of HSYA at Glu 879, Asn 650, and His 875. We then found that HSYA significantly decreased the activity of XO in RAW264.7 macrophages and suppressed LPS-induced ROS generation. Moreover, we proved that HSYA markedly inhibited LPS-induced cleaved caspase-1 activation via suppressing the sensitization of NLRP3 inflammasome and prevented the mature IL-1β formation from pro-IL-1β form. These findings suggest that XO may be a potential target of HSYA via direct binding inhibition and the combination of HSYA-XO suppresses LPS-induced ROS generation, contributing to the depression of NLRP3 inflammasome and inhibition of IL-1β secretion in macrophages.

Paeoniflorin inhibits imiquimod-induced psoriasis in mice by regulating Th17 cell response and cytokine secretion.

Paeoniflorin (PF) is the main active ingredients of radix paeoniae rubra and radix paeoniae alba, which are used widely in Traditional Chinese Medicine. This study aimed to assess the capacity of PF to inhibit imiquimod (IMQ)-induced psoriasis. Mice treated with IMQ were divided into four groups and administered 240mg/kg/day or 120mg/kg/day of PF, 1mg/kg/day of methotrexate (MTX), or normal saline intragastrically. Weight-matched mice treated with vaseline were used as controls. Morphology, structural features, keratinocyte proliferation and differentiation, inflammatory cell infiltration, levels of Th1/Th2/Th17/Treg cytokine mRNA, and phosphorylation of Th17 differentiation-related proteins were assessed. Mouse spleen cells were incubated under Th17 polarizing conditions, then with PF (2, 20, and 200μg/ml) and cell viability, Th17 differentiation, and Th17 cytokines and the orphan nuclear receptor (RORγt) mRNA levels were assessed. PF alleviated IMQ-induced keratinocyte proliferation and inflammatory cell infiltration, and reduced mRNA levels of Th17 cytokines at day 4 and phosphorylation of Th17 differentiation-related proteins. However, 2, 20, or 200μg/ml PF did not affect spleen cell viability, and 2 and 20μg/ml PF reduced IL-17 secretion under Th17 polarizing conditions. Finally, 2 and 20μg/ml PF inhibited mRNA expression of Th17 cytokines and phosphorylation of Stat3 in spleen cells under Th17 polarizing conditions. These results suggest that PF inhibits IMQ-induced psoriasis by regulating Th17 cell response and cytokine secretion via phosphorylation of Stat3.

Paeonol ameliorates imiquimod-induced psoriasis-like skin lesions in BALB/c mice by inhibiting the maturation and activation of dendritic cells

Paeonol, an active component derived from the traditional Chinese medicine Cortex Moutan, possesses anti-inflammatory, analgesic, antioxidant and anti-allergic properties. Psoriasis is a chronic, recurrent, inflammatory dermatosis accompanied by excessive activation of Toll-like receptors (TLRs) in dendritic cells (DCs), which are primarily responsible for initiating an immune response. We investigated the effect of paeonol on inflammation in an imiquimod (IMQ)-induced psoriasis-like mouse model and murine bone marrow-derived dendritic cells (BMDCs) stimulated by R848. Mice were intragastrically administered 100 mg/kg (high), 50 mg/kg (medium) and 25 mg/kg (low) paeonol, respectively. We evaluated inflammation of psoriasis-like lesions based on histological changes, protein levels of myeloid differentiation factor 88 (MyD88) and TLR8 in skin lesions by western blotting, and levels of CD11c+ DCs in skin by immunoassay and in spleens by flow cytometry. Inflammatory cytokines [interleukin (IL)-23, IL-12 and IL-1β] in skin lesions and BMDCs were also assessed by RT-PCR and ELISA. Application of paeonol decreased IMQ-induced keratinocyte proliferation, and infiltration of CD3+ cells, while the treatment ameliorated CD11c+ cells in the spleen and skin, and reduced MyD88 and TLR8 proteins in skin lesions. Paeonol inhibited IMQ-induced mRNA expression of IL-23, but not IL-12 and IL-1β in BMDCs, along with significantly lower levels of DCs expressing MHCII, CD80 and CD86 in vitro. These results indicate that paeonol suppresses the maturation and activation of DCs by decreasing MyD88 and TLR8 proteins in the TLR7/8 signaling pathway which finally alleviates psoriasis-like skin lesions. The TLR7/8 signaling pathway in DCs provides an important insight into the mechanism of psoriasis, and paeonol may be a potent therapeutic drug for psoriasis.

Ferulic acid protects against heat stress-induced intestinal epithelial barrier dysfunction in IEC-6 cells via the PI3K/Akt-mediated Nrf2/HO-1 signaling pathway

Abstract Purpose: Intestinal epithelial barrier dysfunction is crucial in the pathogenesis of intestinal and systemic diseases. Ferulic acid (FA) possesses promising antioxidant activities. In a previous study, we demonstrated potentially protective effects of FA against heat stress-induced intestinal epithelial barrier dysfunction in IEC-6 cells. However, the underlying mechanisms are unclear. The present study aimed to elucidate whether FA protects IEC-6 cells from heat stress-induced intestinal epithelial barrier dysfunction via antioxidative mechanisms. Materials and methods: IEC-6 cells were pretreated with FA prior to hyperthermia exposure at 42 °C for 6 h, and the levels of intracellular reactive oxygen species (ROS), malondialdehyde (MDA), nitrogen oxide (NO), and superoxide dismutase (SOD) activity were analyzed. The intestinal epithelial barrier function was determined by transepithelial electrical resistance (TER) values and 4-kDa fluorescein isothiocyanate-dextran (FD4) flux in IEC-6 cell monolayers. Expression of related proteins was detected by Western blotting. Results: FA suppressed heat stress-induced intestinal oxidative stress damage by reducing ROS, MDA and NO production, while enhancing SOD activity. Furthermore, FA treatment strengthened intestinal barrier function via increasing the phosphorylation levels of Akt, nuclear factor-erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1) protein expression, which was reversed by zinc protoporphyrin (an HO-1 inhibitor). Additionally, LY294002, a specific PI3K/Akt inhibitor, significantly suppressed FA-induced Nrf2 nuclear translocation and HO-1 protein expression and inhibited FA-induced occludin and ZO-1 protein expression. Conclusions: FA protected against heat stress-induced intestinal epithelial barrier dysfunction via activating the PI3K/Akt-mediated Nrf2/HO-1 signaling pathway in IEC-6 cells.

Punicalagin, a PTP1B inhibitor, induces M2c phenotype polarization via up-regulation of HO-1 in murine macrophages

Abstract Current data have shown that punicalagin (PUN), an ellagitannin isolated from pomegranate, possesses anti‐inflammatory and anti‐oxidant properties; however, its direct targets have not yet been reported. This is the first report that PTP1B serves as a direct target of PUN, with IC50 value of 1.04 &mgr;M. Results from NPOI further showed that the Kon and Koff of PUN‐PTP1B complex were 3.38e2 M−1 s−1 and 4.13e‐3 s−1, respectively. The active site Arg24 of PTP1B was identified as a key binding site of PUN by computation simulation and point mutation. Moreover, inhibition of PTP1B by PUN promoted an M2c‐like macrophage polarization and enhanced anti‐inflammatory cytokines expression, including IL‐10 and M‐CSF. Based on gene expression profile, we elucidated that PUN treatment significantly up‐regulated 275 genes and down‐regulated 1059 genes. M1‐like macrophage marker genes, such as Tlr4, Irf1/2, Hmgb1, and Stat1 were down‐regulated, while M2 marker genes, including Tmem171, Gpr35, Csf1, Il1rn, Cebpb, Fos, Vegf&agr;, Slc11a1, and Bhlhe40 were up‐regulated in PUN‐treated macrophages. Hmox‐1, a gene encoding HO‐1 protein, was preferentially expressed with 16‐fold change. Inhibition of HO‐1 obviously restored PUN‐induced M2 polarization and IL‐10 secretion. In addition, phosphorylation of both Akt and STAT3 contributed to PUN‐induced HO‐1 expression. This study provided new insights into the mechanisms of PUN‐mediated anti‐inflammatory and anti‐oxidant activities and provided new therapeutic strategies for inflammatory diseases. Graphical abstract Figure. No caption available. HighlightsPunicalagin is a promising PTP1B inhibitor.Arg24 acts as a key binding site in PUN‐PTP1B combination.Punicalagin promotes an M2c like macrophage polarization.Punicalagin‐induced HO‐1 expression is essential to M2 macrophages polarization.Punicalagin has great potential as a preventive strategy in inflammatory diseases.

Multi-glycoside of Tripterygium wilfordii Hook. f. ameliorates imiquimod-induced skin lesions through a STAT3-dependent mechanism involving the inhibition of Th17-mediated inflammatory responses

Multi-glycoside of Tripterygium wilfordii Hook. f. (GTW) possesses anti-inflammatory and immunosuppressive properties, and has been used as a traditional treatment for psoriasis for many years, although the underlying immunological mechanisms remain poorly understood. The T helper (Th)17 cell response is considered to play a major role in the pathogenesis of psoriasis. Th17 cells are implicated in the mechanism of pathogenesis of imiquimod (IMQ)-induced skin inflammation. Using a mouse model, we demonstrated that GTW protected mice from developing psoriasis-like lesions induced by topical IMQ administration. This protection was associated with significantly decreased mRNA levels of Th17 cytokines such as interleukin (IL)-17A, IL-17F and IL-22 in mouse skin samples as well as fewer IL-17-secreting splenic CD4+ lymphocytes in IMQ-exposed mice. There were no significant effects on the proportion of CD4+ interferon (IFN)-γ+ T cells, CD4+IL-4+ T cells and CD4+CD25+Foxp3+ Treg cells in the spleen cells. Taken together with the unchanged mRNA levels of Th1 cytokine IFN-γ, Th2 cytokine IL-4 and Treg cytokine IL-10 in IMQ-exposed mouse skin following GTW administration, our findings suggest that the immunosuppressive effect of GTW in psoriasis is exerted mainly on Th17 cells, rather than on Th1, Th2 or Treg cells. Furthermore, we showed that GTW suppressed Th17 function through the inhibition of STAT3 phosphorylation. These results have the potential to pave the way for the use of GTW as an agent for the treatment of psoriasis.

Suppressive effect of β,β-dimethylacryloyl alkannin on activated dendritic cells in psoriasis by the TLR7/8 pathway

β,β-dimethylacryloyl alkannin (DMA) is a key component of Lithospermum and possesses good efficacy for treating psoriasis. DMA inhibits activated dendritic cells (DCs), but the mechanism is unknown. Therefore, this study aimed to explore the modulation of the TLR7/8 pathway by DMA in psoriasis-activated DCs. Models of psoriasis-like skin lesions were established using BALB/c mice; 8 mice were treated with DMA (2.5mg/kg). Bone marrow cells were isolated and induced into DCs using R848, a TLR7/8 agonist. Splenic CD11c+ cells were detected by flow cytometry. Skin CD11c+ cells were detected by immunofluorescence. TLR7, TLR8, MYD88, and IRAKM proteins were detected by Western blot. The effects of DMA on surface molecules of DCs were observed by flow cytometry. mRNA expression of inflammatory factors was detected by qRT-PCR. Secreted cytokines were detected by cytometric bead array. Compared with the model group, psoriasis-like skin lesions were alleviated by DMA, the splenic CD11c+ cells were significantly decreased (P<0.01), and CD11c+ cell numbers in skin lesions were decreased (P<0.01). Expression levels of TLR7, MYD88, and IRAKM were significantly decreased (P<0.05). R848-stimulated DCs showed increased expression of I-A/I-E, CD80, and CD86 (P<0.01), increased IL-23 and IL-1β mRNA and secretion (P<0.05), and increased TLR7, TLR8, MYD88, and IRAKM expression (P<0.01); DMA inhibited all of these effects of the TLR7/8 pathway activation by R848 (P<0.05). In conclusion, DMA could inhibit psoriasis-activated DCs via the TLR7/8 pathway.

[EXPRESS] Quantitative Evaluation to Efficacy and Safety of Therapies for Psoriasis: A Network Meta-Analysis.

Therapies treating psoriasis can be categorized into five classes according to their mechanism: anti-metabolites (AM), anti-interleukin-12/23 agents (anti-IL12/23), anti-interleukin-17 agents (anti-IL17), anti-T-cell agent (ANT), and anti-tumor necrosis factor-α agent (anti-TNF-α). This network meta-analysis (NMA) aimed to give a quantitative and systemic evaluation of safety and efficacy for the five kinds of therapies mentioned above. Odds ratios and mean differences were calculated to evaluate binary and continuous outcomes, respectively. Forest plots were conducted to show the performance of pair-wise comparison of above therapies in each outcome, and surface under the cumulative ranking curves was given to evaluate the relative ranking of above therapies in each outcome. Node splitting was conducted to evaluate the consistency between direct and indirect evidence. Direct comparisons from 65 studies (32,352 patients) were included in this NMA. Our results showed an excellent efficacy of anti-IL12/23 and anti-IL17. However, these two therapies and anti-TNF-α were revealed to have a high possibility to cause adverse effects (AEs) such as infections. Additionally, node splitting showed that no inconsistency appeared between the direct and indirect comparisons. Anti-IL12/23 was the most recommended therapy according to this NMA. Anti-IL17 had similar efficacy to anti-IL12/23 but should be applied with caution since it has poor performance in safety outcomes.

Indirubin ameliorates imiquimod-induced psoriasis-like skin lesions in mice by inhibiting inflammatory responses mediated by IL-17A-producing γδ T cells

HighlightsIndirubin alleviates IMQ‐induced psoriasis‐like inflammation.The production of &ggr;&dgr; T cell and CCR6 &ggr;&dgr; T in the spleen and lymph nodes changed in indirubin treated mice.Indirubin suppressed IL‐17 A expression and secretion, and Jak3/Stat3 activation in in vitro cultured &ggr;&dgr; T cells. Objectives: Indirubin (IR) is a bisindole compound extracted from the leaves of Chinese herb Indigo Naturalis. Indigo Naturalis has been widely used in traditional Chinese medicine to treat inflammatory and autoimmune diseases. Psoriasis is a chronic immune‐mediated inflammatory skin disease in which &ggr;&dgr; T cells play an important role. This study aims to determine the immunoregulatory effects and the underlying mechanisms of Indirubin in psoriasis‐related inflammatory responses. Methods: BALB/c mice with imiquimod (IMQ)‐induced psoriasis‐like dermatitis were treated with saline (Model), 1 mg/kg methotrexate (MTX) that serves as a positive control, or 12.5, 25 and 50 mg/kg Indirubin(IR) intragastrically. Keratinocytes proliferation, inflammatory cells infiltration, the expression of inflammatory cytokines and Jak/Stat pathway‐related proteins in the skin lesion were examined. The abundance of &ggr;&dgr; T cells in lymph nodes and spleen was determined by flow cytometry. The IL‐17 expression and secretion, and the activation of Jak3/Stat3 pathways in in vitro cultured &ggr;&dgr; T cell were tested. Results: Indirubin ameliorated keratinocyte proliferation, reduced the infiltration of CD3+ T cells, IL‐17 A‐producing &ggr;&dgr; T cells, and CD11b+ neutrophils, inhibited the mRNA expression of Il1, Il6, Il23, Il17a and Il22, and the protein expression of Jak/Stat pathway‐related molecules in the skin lesion. Indirubin also reduced the abundance of &ggr;&dgr; T cell and CCR6+ &ggr;&dgr; T cells (the major IL‐17 A producer) in spleen and lymph nodes. In cultured &ggr;&dgr; T cells, Indirubin inhibited the mRNA expression of Il17a and Ifng, and the secretion of IL‐17 A, while suppressed the activation of Jak3/Stat3 pathways. Conclusion: Indirubin alleviates IMQ‐induced psoriasis‐like dermatitis mainly through reducing the inflammatory responses mediated by IL‐17 A‐producing &ggr;&dgr; T cells involving Jak3/Stat3 activation. Our results highlighted the novel mechanisms by which Indirubin ameliorates psoriasis‐related inflammatory responses, supporting its therapeutic potential.