Huidan Li

Paeoniflorin inhibits skin lesions in imiquimod-induced psoriasis-like mice by downregulating inflammation

Psoriasis is a common chronic immune-mediated inflammatory disease. It is well known that macrophages, neutrophils and T-helper 1 (Th1)/T-helper 17 (Th17) cells play important roles in skin lesions by provoking inflammation. Paeoniflorin (PF) is the major effective component extracted from the root of Paeonia lactiflora, which has been widely used in China to treat inflammatory and autoimmune diseases, including psoriasis. Although PF shows a clinical therapeutic effect on psoriasis patients, how PF affects infiltrated immune cells in psoriasis skin lesions is still unknown. In this study, using a generated imiquimod (IMQ)-induced psoriasis-like mouse model, we found that PF ameliorates inflammation and skin lesions. Subsequent analyses showed that PF decreases the number of F4/80(+)CD68(+) macrophages and their related cytokine production (TNF-α, IL-1β, IL-6, IL-12 and inducible nitric oxide synthase (iNOS)) in the skin of IMQ-challenged mice. Moreover, PF suppresses the number of CD11b(+)Gr-1(+) neutrophils and the expression of macrophage inflammatory protein-2 (MIP-2; a counterpart of human IL-8, which is responsible for the recruitment of neutrophils in mice). Finally, PF also down-regulates Th1- and Th17-related cytokine expression. Therefore, our new findings reveal that PF alleviates psoriatic skin lesions by inhibiting inflammation, which provides new insights into the immunomodulatory effect of PF in psoriasis treatment.

Cyr61 participates in the pathogenesis of rheumatoid arthritis by promoting proIL-1β production by fibroblast-like synoviocytes through an AKT-dependent NF-κB signaling pathway.

IL-1β plays a major role in the development of rheumatoid arthritis (RA). We previously showed that Cyr61 participates in RA pathogenesis as a proinflammatory factor. Here, we found that the levels of IL-1β and Cyr61 were higher in RA SF than in osteoarthritis (OA) SF. IL-1β mRNA and proIL-1β protein levels were remarkably increased in Cyr61-stimulated FLS; however, IL-1β was hardly detectable in the supernatant. We also found that the level of adenosine triphosphate (ATP) in SF and ST was significantly increased in RA patients and that the level of IL-1β in supernatants from Cyr61-activated FLS increased significantly when we added exogenous ATP to the culture. Mechanistically, Cyr61 induced proIL-1β production in FLS via the AKT-dependent NF-κB signaling pathway, and ATP caused Cyr61-induced proIL-1β to generate IL-1β in a caspase-1-dependent manner. Our results reveal a novel role of Cyr61 in RA that involves the promotion of proIL-1β production in FLS.

CCN1, a Pro-Inflammatory Factor, Aggravates Psoriasis Skin Lesions by Promoting Keratinocyte Activation

Psoriasis is a common chronic skin disease characterized by epidermal hyperplasia and inflammation. The pathogenesis of psoriasis is multifactorial and is not fully understood. Here we demonstrate that CCN1 (also called Cyr61, which is short for cysteine-rich 61), an extracellular matrix protein that is also considered a pro-inflammatory factor, is highly expressed in the lesional skin of psoriasis patients, as well as in that of imiquimod (IMQ)- and IL-23-treated psoriasis-like mice. Then we show that blocking CCN1 function in vivo attenuates epidermal hyperplasia and inflammation in psoriasis-like mice. Further, in primary cultured normal human keratinocytes and HaCaT (human keratinocyte cell line) cells, CCN1 promotes keratinocyte activation, including the proliferation and expression of immune-related molecules. Finally, we observe that integrin α6β1 is the receptor of CCN1 in keratinocytes, and CCN1 stimulation activates the downstream phosphoinositide-3 kinase/Akt/NF-κB signaling pathway. Taken together, our findings reveal that CCN1 has a critical role in psoriasis pathogenesis. Moreover, as CCN1 is a secreted extracellular matrix (ECM) protein, our study also provides evidence that ECM, which is involved in psoriatic pathogenesis, could be a potent target for psoriasis treatment.

Paeoniflorin ameliorates symptoms of experimental Sjogren's syndrome associated with down-regulating Cyr61 expression

Paeoniflorin (PF), an active compound extracted from Paeony root, has been used in therapy of autoimmune diseases with effective clinical efficiency and higher safety. Sjogrens syndrome (SS) is a chronic, systemic, immune-mediated inflammatory disease. In this study, we demonstrated that novel pro-inflammatory factor Cyr61/CCN1 was up-regulated in epithelial cells of salivary glands of primary SS patients and submandibular gland autoantigen-induced experimental SS mice. Blocking Cyr61 expression with special monoclonal antibody improved saliva secretion by ameliorating inflammatory infiltration and cytokines production in vivo. Furthermore, we showed that PF could alleviate inflammation by down-regulating Cyr61 expression in experimental SS mice. In conclusion, our new findings revealed for the first time that Cyr61 involves the pathogenesis of primary SS and PF alleviates SS-like symptoms associated with inhibiting Cyr61 expression, providing new insights into the potential molecular mechanism of PF in primary SS treatment.

Evaluation of the efficacy and safety of different Tripterygium preparations on collagen-induced arthritis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE Tripterygium preparations (TPs), a traditional Chinese Medicines extracted from Tripterygium wilfordii Hook f., are widely used for treatment of rheumatoid arthritis (RA). However, TPs from different Pharmaceutical factory have different efficacy and side effects for RA treatment. AIM OF THE STUDY The purpose of the current study is to evaluate the efficacy and safety of four TPs from different Pharmaceutical factory in china on the treatment of collagen-induced arthritis (CIA) rats and provide a theoretical and experimental basis for the individualized use of TPs. MATERIALS AND METHODS The model of wistar rats of CIA was made, and the rats were perfused a stomach with four TPs for 3 weeks continuously. Then arthritis severity was determined by visual examination of the paws and histopathologic changes of joint, liver, kidney and testis were determined by hematoxylin-eosin (H&E) staining. The expression of inflammatory cytokines (IL-1β, TNF-α, IL-17 and IL-6) in the joint was analyzed by real-time PCR, and the count and motion parameters (sperm motility and progressive sperm) of sperm in cauda epididymis were assessed with computer-assisted sperm analysis (CASA) system. Routine blood tests were conducted using automated hematology analyzer, and the aspartate aminotransferase (AST), alanine aminotransferase (ALT) activities, creatinine (Cr), and blood urea nitrogen (BUN) in serum of CIA rats were measured using a UniCel DxC 880i autoanalyzer. RESULTS All of tested TPs could reduce inflammatory score, histopathological arthritis severity and joint׳s inflammatory cytokines (IL-1β, TNF-α, IL-17 and IL-6) expression in CIA rats, however, TP-D showed stronger inhibitory effect for inflammatory score compared with other three TPs in vivo. All of tested TPs did not show hepatotoxicity and nephrotoxicity and also had little effect for the concentration of hemoglobin (Hb) and the count of white blood cell (WBC). Analysis of red blood cell (RBC) number showed that TP-C and TP-D could reverse lower RBC number in untreated CIA rats to normal level. Interestingly, the results showed TPs named TP-C and TP-D could decrease platelet (PLT) number which significantly increases in untreated CIA rats. Reproductive toxicity, the main side effect of TPs, assay showed that the sperm quality (density, viability, and motility) in four of TPs-treated CIA rats were decreased significantly, consistently with spermatogenic cell density reduced. However parallel analysis showed that in four TPs-treated rats, the number of sperm, motile sperm and progressive sperm were highest in TP-D group, in contrast, were lowest in TP-C group. CONCLUSIONS These findings suggested that four TPs showed significantly therapeutic effect on ameliorating inflammation of CIA rats, with no obvious hepatotoxicity and nephrotoxicity in vivo. TP-D showed advantages with its higher efficacy and less reproductive toxicity as well as increasing RBC number, decreasing PLT number in CIA treatment. Thus, in the development of individualized treatment plan for RA patients, TP-D might be considered preferentially.

Cyr61 participates in the pathogenesis of rheumatoid arthritis via promoting MMP-3 expression by fibroblast-like synoviocytes

Abstract Objectives: The aim of this study was to investigate the effect and potential mechanism of Cysteine-rich 61 (Cyr61) on stimulating MMP-3 expression by fibroblast-like synoviocytes (FLS) from rheumatoid arthritis (RA) patients. Methods: Primarily cultured RA FLS were treated with exogenous Cyr61 protein or Cyr61-siRNA, then, MMP-3 expression was analyzed by real-time PCR, western blotting and ELISA. Signal transduction pathways in Cyr61-induced MMP-3 production were examined by real-time PCR, western blotting, confocal microscopy, luciferase reporter assay. Mice with collagen-induced arthritis (CIA) were treated with anti-Cyr61 monoclonal antibodies (mAb), or IgG1 as control and MMP-3 in the joint was detected by IHC, real-time PCR and western blotting. Results: High expressed MMP-3 and Cyr61 were positively correlated in RA ST; Cyr61 stimulated MMP-3 production in FLS of RA patients in an IL-1β and TNF-α independent manner. Cyr61 induced MMP-3 could further enhance the invasive ability of RA FLS. Mechanistically, we found that Cyr61 promoted MMP-3 production via the P38, JNK-dependent AP-1 signaling pathway. Blockage of Cyr61 function with monoclonal antibody could decrease MMP-3 expression in the joints of CIA mice. Conclusion: This study provides new evidence that Cyr61 participates in RA pathogenesis not only as a pro-inflammatory factor but also plays a key role in bone erosion via promoting MMP-3 expression. We suggest that targeting of Cyr61 may represent a potential strategy in RA treatment.

CCN1 promotes IL-1β production in keratinocytes by activating p38 MAPK signaling in psoriasis.

CCN1, an extracellular protein also known as cysteine-rich protein 61 (Cyr61), is a novel pro-inflammatory factor involved in the pathogenesis of rheumatoid arthritis. As an inflammatory disease, psoriasis is characterized by keratinocyte activation-induced epidermal hyperplasia and cytokine-mediated inflammation. We demonstrated in our previous study that CCN1 promoted keratinocyte activation in psoriasis. However, the role of CCN1 in regulating inflammation in psoriasis is still unknown. Here, we showed that CCN1 increased inflammatory cytokine IL-1β production in keratinocytes. Furthermore, endogenous ATP and caspase-1 were required for mature IL-1β production stimulated by CCN1 in keratinocytes. After binding to the receptor of integrin α6β1, CCN1 activated the downstream p38 MAPK signaling pathway, thus inducing the expression of IL-1β. In addition, we inhibited CCN1 function in mouse models of psoriasis, and decreased IL-1β production was observed in vivo. Overall, we showed that CCN1 increased IL-1β production via p38 MAPK signaling, indicating a role for CCN1 protein in regulating inflammation in psoriasis.

Cyr61/CCN1 induces CCL20 production by keratinocyte via activating p38 and JNK/AP-1 pathway in psoriasis

BACKGROUND Psoriasis is a common chronic skin disease characterized by epidermal hyperplasia and inflammation. Cysteine-rich angiogenic inducer 61 (Cyr61/CCN1) has recently been implicated in psoriasis pathogenesis by promoting keratinocyte activation. However, the mechanisms by which CCN1 enhances cutaneous inflammation are not fully understood. OBJECTIVE In this study, we investigated the role of CCN1 on the expression of CCL20 in human keratinocyte. METHODS AND RESULTS By double-label immunofluorescence staining, we first identified that the expression of CCN1 colocalized well with CCL20 production in the epidermis of psoriasis skin lesion. Furthermore, in vivo, blocking or knockdown CCN1 expression ameliorated skin inflammation and reduced the expression of CCL20 in both imiquimod and IL-23-induced psoriasis-like mouse models, which indicated that CCN1 might be involved in the regulation of CCL20 production in psoriasis. Next, in vitro, we stimulated primary normal human epidermal keratinocyte (NHEK) with exogenous protein CCN1 and found that CCN1 directly upregulated CCL20 production independent of TNF-α, IL-22 and IL-17 pathway. Lastly, the signaling pathway study showed that CCN1 enhanced the binding of AP-1 to the CCL20 promoter via crosstalk with p38 and JNK. CONCLUSIONS Our study demonstrates that CCN1 stimulates CCL20 production in vitro and in vivo, and thus supports the notion that overexpressed CCN1 in hyperproliferating keratinocyte is functionally involved in the recruitment of inflammatory cells to skin lesions affected by psoriasis.