CCN1 upregulates IL-36 via AKT/NF-κB and ERK/CEBP ß-mediated signaling pathways in psoriasis-like models.

Psoriasis is a chronic skin disorder characterized by epidermal keratinocyte hyperproliferation and inflammatory infiltration. CCN1 (also termed CYR61 or cysteine-rich angiogenic inducer 61) is an extracellular matrix-associated protein that is involved in multiple physiological functions. In psoriasis, we recently demonstrated that the overexpression of CCN1 promoted keratinocyte proliferation and activation. Furthermore, CCN1 was highly expressed in psoriatic skin lesions from psoriasis vulgaris patients. Here, we dissect the underlying molecular mechanism in imiquimod (IMQ) and interleukin (IL)-23-induced psoriasis-like models. Our results demonstrate that CCN1 can significantly upregulate IL-36 production in the murine skin of IMQ and IL-23-induced psoriasis-like models. Injection of CCN1-neutralizing antibody improved epidermal acanthosis and significantly reduced IL-36 production in vivo. These results suggest that CCN1 can be a critical upstream pro-inflammatory factor in psoriasis. In primary normal human epidermal keratinocytes, we demonstrated that CCN1 can selectively induced the production of IL-36α and IL-36γ through the activation of the protein kinase B (AKT)/nuclear factor kappa light chain enhancer of activated B cells (NF-κB) and extracellular-regulated kinase (ERK)/CCAAT/enhancer binding protein ß (CEBPß) signaling pathways via integrin receptor α6ß1 in vitro. Our results suggest that targeting CCN1 can be a potential therapeutic strategy for psoriasis.

Circulating Cysteine Rich Protein 61 (Cyr61, CCN1) in Chinese Adults: Distribution and Reference Intervals.

BACKGROUND: The circulating levels of Cyr61 (also known as CCN1) may prove to have great clinical value in the diagnosis, monitoring and prognosis of many disorders in humans. However, the reference intervals (RIs) for this analyte in human subjects have not previously been well established. Therefore, establishing RIs and determining the distribution of circulating Cyr61 levels are very important for future clinical studies and could provide an orientation value for exploring its clinical usefulness. METHODS: The Cyr61 levels in 2,514 healthy Chinese Han subjects (1,250 males and 1,264 females, aged 18 - 88 years, recruited from 4 hospitals in Shanghai and Fujian) were measured with a sandwich ELISA (R&D Systems, USA). The RIs were determined in a manner consistent with the Clinical and Laboratory Standards Institute guidelines. RESULTS: The levels of serum Cyr61 showed a non-Gaussian distribution. A statistically significant difference was observed between the males and females such that the median level of Cyr61 in the males was significantly higher than that in the females. Furthermore, the Cyr61 levels significantly increased with age in the female group whereas no difference was observed among the different age groups among the males. The RIs for serum Cyr61 were 3.3 - 184 pg/mL and 5.0 - 182 pg/mL in females aged 18 - 45 and 46 - 88 years, respectively. The RI for serum Cyr61 was 4.0 - 198 pg/mL in the males. CONCLUSIONS: The RIs for serum Cyr61 were established among Chinese Han individuals. The effects of age and gender on the distribution characteristics of serum Cyr61 were studied, revealing that the RIs were gender and, in females, age-specific, which may suggest that a female hormone, estrogen plays a role in the regulation of Cyr61 expression in vivo.

Hypoxia-Induced Cyr61/CCN1 Production in Infantile Hemangioma.

BACKGROUND: Hypoxia may play a role in the pathogenesis of infantile hemangioma. Cysteine-rich angiogenic inducer 61 (Cyr61), or CCN1, can be induced under hypoxic conditions in several types of cells. However, whether CCN1 has any impact on infantile hemangioma remains unknown. This study aims to explore the expression of CCN1 in infantile hemangioma and to investigate the effect of hypoxia on CCN1 and vascular endothelial growth factor-A (VEGF-A) production. METHODS: Hemangioma-derived endothelial cells and hemangioma-derived stem cells were isolated from surgical specimens of proliferative infantile hemangioma. RNA extracted from infantile hemangioma tissue, hemangioma-derived endothelial cells, and hemangioma-derived stem cells was used to analyze gene expression by real-time polymerase chain reaction. The effects of CCN1 blockade were examined in hemangioma-derived stem cells. Immunostaining, immunoblotting, and enzyme-linked immunosorbent assays were used to assess protein expression. RESULTS: By double-label immunofluorescence staining, the authors first identified that CCN1 was abundant in proliferative infantile hemangioma lesions and colocalized well with immature microvessels. The authors found that the mRNA level of CCN1 in proliferative infantile hemangioma was significantly higher than in healthy controls, as was involuting infantile hemangioma. Treatment with the hypoxia inducer cobalt chloride dramatically increased CCN1 production in hemangioma-derived endothelial cells in a time-dependent manner. Furthermore, blocking or knockdown of CCN1 expression reduced the expression of VEGF-A in hemangioma-derived stem cells. Lastly, the signaling pathway study showed that CCN1 up-regulation of VEGF-A synthesis in hemangioma-derived stem cells depends on nuclear factor-κB and JNK activation. CONCLUSIONS: These findings provide new evidence that CCN1 participates in the crosstalk between hemangioma-derived endothelial cells and hemangioma-derived stem cells through promoting VEGF-A expression in the hypoxic environment of infantile hemangioma angiogenesis and vasculogenesis. Targeting of CCN1 might be a novel therapeutic strategy for infantile hemangioma.

CYR61, a potential biomarker of tumor inflammatory response in epithelial ovarian cancer microenvironment of tumor progress.

BACKGROUND: Recent studies have found that inflammatory response is involved in the pathogenesis of ovarian cancer. Advanced ovarian cancer is often presented with ascites that is rich in cytokines, inflammatory factors or cancer cells. Therefore, it is important to study the microenvironment of ascites in order to further clarify the occurrence and progression of ovarian cancer. As a pro-inflammatory factor, the Cyr61 expression patterns are inconsistent in human tumors. Although it has been reported that Cyr61 is related to the progression of ovarian cancer, its specific mechanism is not yet clear. This study sought to evaluate the Cyr61 levels of ascites, serum and different tissues of ovarian cancer to explore the potential association of Cyr61with the tumor-associated inflammatory microenvironment of EOC. METHODS: Tumor specimens were procured from patients with ovarian serous cystadenocarcinoma and ovarian serous cystadenoma. Cyr61 and IL-6 levels of serum or ascites were determined by ELISA (Enzyme-Linked ImmunoSorbent Assay), while Cyr61 expressions of different ovarian tumor tissues were evaluated by IHC (Immunohistochemistry). Then the correlation of Cyr61 level in ascites with clinicopathologic features was analyzed. And other laboratory data were obtained from medical records. RESULTS: Both in ascites and serum, significantly higher Cyr61 levels were found in ovarian serous cystadenocarcinoma. In malignant ascites, higher Cyr61 level of ovarian serous cystadenocarcinoma was more closely associated with FIGO stage, initial tumor size > 10 cm and the residual tumor size. And the increased IL-6 level was linearly related to Cyr61 level. Moreover, the serum levels of Cyr61, IL-6 and CRP in advanced stage of ovarian cancer were much higher than those in early stage. Lastly, the IHC data demonstrate that Cyr61 expression of ovarian serous adenocarcinoma was higher than that of ovarian serous cystadenoma, but it was lower than the paired metastatic lesions. CONCLUSIONS: As a pro-inflammatory factor, increased ascites Cyr61 level is associated with FIGO stage, initial tumor size > 10 cm and the residual tumor size. Moreover, serum Cyr61 may be used as a potential marker for EOC inflammatory response. Finally, Cyr61 may be involved in the process of tumor metastasis and progression by producing IL-6 and CRP in the EOC inflammatory microenvironment.

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.

Molecular basis for the recognition of CCN1 by monoclonal antibody 093G9.

CCN1, also named Cyr61 (cysteine-rich protein 61), is the first identified member of the CCN family that is composed of 6 secreted extracellular matrix-associated glycoproteins. CCN1 has been demonstrated to participate in pathogenesis of rheumatoid arthritis through various pathways. A monoclonal antibody, namely, 093G9, is effective to antagonize the effects of CCN1 and hence has potential therapeutic benefits against rheumatoid arthritis. Here, we show that the epitope recognized by 093G9 is mapped to residues 77 to 80 of CCN1, and a cyclic peptide encompassing residues 75 to 81 of CCN1 displays high binding affinity for 093G9. The crystal structure of the 093G9 Fab in complex with the cyclic peptide was determined at 2.7 Å resolution, which reveals the intensive interactions between CCN1 and 093G9. Particularly, residues Asn79 and Phe80 of CCN1 are inserted into cavities mainly formed by residues of complementarity-determining region loop L3 and framework region L2 and by residues of complementarity-determining region loops H2 and H3, respectively, which contribute most of the interactions and therefore are critical for the recognition by 093G9. Together, these findings not only identify the epitope of CCN1 for 093G9 but also reveal the molecular mechanism of recognition and binding of CCN1 by 093G9.

CCN1 promotes IL-1ß 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-1ß production in keratinocytes. Furthermore, endogenous ATP and caspase-1 were required for mature IL-1ß production stimulated by CCN1 in keratinocytes. After binding to the receptor of integrin α6ß1, CCN1 activated the downstream p38 MAPK signaling pathway, thus inducing the expression of IL-1ß. In addition, we inhibited CCN1 function in mouse models of psoriasis, and decreased IL-1ß production was observed in vivo. Overall, we showed that CCN1 increased IL-1ß production via p38 MAPK signaling, indicating a role for CCN1 protein in regulating inflammation in psoriasis.

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

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-1ß 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.

Cyr61/CCN1 is involved in the pathogenesis of psoriasis vulgaris via promoting IL-8 production by keratinocytes in a JNK/NF-κB pathway.

PURPOSE: Interleukin-8 (IL-8) is an important factor in the pathogenesis of psoriasis vulgaris, which is characterized by proliferation of keratinocytes, neutrophil infiltration and angiogenesis. Cysteine-rich 61 (Cyr61/CCN1), a secreted extracellular matrix protein, is a novel proinflammatory factor. Whether Cyr61 is involved in the development of psoriasis vulgaris via IL-8 production remains unknown. In this study we explore the role of Cyr61 in IL-8 expression regulation in vivo and in vitro. METHODS: Skin samples from normal donors and psoriasis vulgaris patients were examined the profile of Cyr61 and IL-8 using immunohistochemistry, real-time PCR and Western blotting. HaCaT cells were treated with Cyr61 and IL-8 expression was analyzed by real-time PCR and ELISA. Signal transduction pathways in Cyr61-induced IL-8 production were investigated by real-time PCR, western blotting, luciferase reporter assay or chromatin immunoprecipitation (ChIP) assay. IMQ-induced psoriasis-like mice were treated with anti-Cyr61monoclonal antibodies (mAb), or IgG1 as a control. RESULTS: We found that Cyr61 was abundant in the epidermis of patients with psoriasis vulgaris and positively correlated with the pathogenesis of skin lesions. Cyr61 induced IL-8 production by keratinocytes in a dose dependent manner. This IL-8 synthesis occurred in an IL-1ß- and TNF-α- independent mode via PI3K, AKT and JNK activation, with binding of enhanced AP-1, C/EBPß and NF-κB to sites located in the IL-8 promoter region. Treatment with anti-Cyr61 mAb led to reduction of MIP-2 level, decreased neutrophil infiltration, and attenuated inflammation in vivo. CONCLUSIONS: Our results not only reveal a novel mechanism illustrating the role of Cyr61 in epidermis pathogenesis but also suggest that therapies targeting Cyr61 may represent a novel strategy in the treatment of psoriasis vulgaris.

Cyr61 participates in the pathogenesis of acute lymphoblastic leukemia by enhancing cellular survival via the AKT/NF-κB signaling pathway.

Cyr61 (CCN1) is the product of a growth factor-inducible immediate early gene and is involved in cell adhesion, survival, proliferation, and differentiation. Cyr61 is overexpressed in human tumors and is involved in the development of tumors. However, the role that Cyr61 plays in acute lymphoblastic leukemia (ALL) cells remains undetermined. The aim of this study was to identify the role of Cyr61 in regulating ALL cell survival. Here, we found that the level of Cyr61 was increased in the plasma and bone marrow (BM) from ALL patients compared with samples from normal control patients. Furthermore, we observed that Cyr61 could effectively stimulate Jurkat (T ALL cell lines), Nalm-6 (B ALL cell lines), and primary ALL cell survival. Mechanistically, we showed that Cyr61 stimulated ALL cell survival via the AKT/NF-κB signaling pathways and the consequent up-regulation of Bcl-2. Taken together, our study is the first to reveal that Cyr61 is elevated in ALL and promotes cell survival through the AKT/NF-κB pathway by up-regulating Bcl-2. Our findings suggest that Cyr61 plays an important role in the pathogenesis of ALL.

Unique immunomodulatory effect of paeoniflorin on type I and II macrophages activities.

It has been widely accepted that macrophages are divided into M1 "pro-inflammatory" macrophages and M2 "anti-inflammatory" macrophages and an uncontrolled macrophage polarization plays an important role in the pathogenesis of different diseases. As the main substance of total glucosides of peony, paeoniflorin (PF), has been widely used to treat autoimmune and autoinflammatory diseases for years. Mechanistically, PF has been found to alter activities of many immune cells, which could further reduce inflammation and tissue damage. However, whether and how PF affects macrophages activities in vitro remains unknown. In current study, using M1 and M2 cells generated from mouse bone marrow precursors, we explored the role of PF in regulating M1/M2 cells activity in vitro. The results showed that PF inhibited LPS-induced M1 activity by reducing iNOS expression and NO production via decreasing LPS/NF-κB signaling pathway; whereas, PF enhanced IL-4-provoked M2 function by up-regulating Arg-1 production and activity via increasing IL-4/STAT6 signaling pathway. Our new finding indicates that PF can suppress M1 cells activity and enhance M2 cells function simultaneously, which could help to ameliorate autoimmune and autoinflammatory diseases in clinical 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. Sjogren's 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.

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 α6ß1 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 selectively inhibits LPS-provoked B-cell function.

B cells are important in the development of autoimmune disorders through mechanisms involving dysregulated polyclonal B-cell activation, production of pathogenic antibodies, and targeting which reduces inflammation and tissue damage effectively but often leads to patients suffering from secondary infection. Paeoniflorin (PF) is the main substance of the Total glucosides of peony and has been widely used to treat autoimmune diseases for years. However, whether PF affects B cell activity remains unknown. In this study, using purified murine spleen B cells, we analyzed the effects of PF on B-cell function in vitro. We found that PF inhibited the expression of CD69/CD86 and the proliferation of B cells stimulated by LPS. In addition, PF reduced the B-cell differentiation and immunoglobulin production that was stimulated by LPS. Interestingly, PF did not alter B-cell activation and proliferation provoked by anti-CD40 or IL-4. These results indicated for the first time that PF inhibits B-cell activation, proliferation and differentiation by selectively blocking the LPS/TLR4 signaling pathway. Furthermore, our data suggest that PF selectively inhibits inflammation and tissue damage mediated by LPS-activated B cells but does not alter CD40/CD40L- or IL-4-provoked B-cell function in autoimmune diseases treatment, which might aid in protecting patients from secondary infection.

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

IL-1ß 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-1ß and Cyr61 were higher in RA SF than in osteoarthritis (OA) SF. IL-1ß mRNA and proIL-1ß protein levels were remarkably increased in Cyr61-stimulated FLS; however, IL-1ß 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-1ß in supernatants from Cyr61-activated FLS increased significantly when we added exogenous ATP to the culture. Mechanistically, Cyr61 induced proIL-1ß production in FLS via the AKT-dependent NF-κB signaling pathway, and ATP caused Cyr61-induced proIL-1ß to generate IL-1ß in a caspase-1-dependent manner. Our results reveal a novel role of Cyr61 in RA that involves the promotion of proIL-1ß production in FLS.

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-1ß, 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.

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-1ß, 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-1ß, 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.

A novel p53/microRNA-22/Cyr61 axis in synovial cells regulates inflammation in rheumatoid arthritis.

OBJECTIVE: We previously showed that Cyr61 acts to promote fibroblast-like synoviocyte (FLS) proliferation and Th17 cell differentiation, suggesting that Cyr61 plays an important role in mediating the joint inflammation and damage in rheumatoid arthritis (RA). The aim of this study was to investigate whether Cyr61 expression is regulated at the posttranscription level, and if so, how this regulation connects to other etiologic factors in RA. METHODS: Expression of microRNA-22 (miR-22) in synovial tissue was detected by real-time polymerase chain reaction (PCR) using miRNA-specific TaqMan MGB probes. MicroRNA-22 promoter activity was analyzed using a Dual-Luciferase Reporter Assay. Cytokine expression was measured by enzyme-linked immunosorbent assay, and the expression of other factors was measured by real-time PCR or Western blotting. RESULTS: MicroRNA-22 directly targeted the 3'-untranslated region of Cyr61 messenger RNA and inhibited Cyr61 expression. Expression of miR-22 was down-regulated and was negatively correlated with Cyr61 expression in RA synovial tissue. Furthermore, wild-type p53 activated miR-22 transcription by binding to the promoter region of the miR-22 gene, while the mutant forms of p53 frequently found in RA synovial tissue were shown to have lost the ability to activate miR-22 expression. As a result, miR-22 was down-regulated, contributing to the overexpression of Cyr61 in RA FLS. CONCLUSION: Our results not only reveal a novel mechanism whereby p53 is involved in the posttranscriptional regulation of Cyr61 expression via miRNA-22, but also provide a molecular explanation for the role of somatic mutations of p53, which are frequently observed in RA synovial tissue, in the etiology of this autoimmune disease.

Cyr61 is involved in neutrophil infiltration in joints by inducing IL-8 production by fibroblast-like synoviocytes in rheumatoid arthritis.

INTRODUCTION: It is well known that neutrophils play very important roles in the development of rheumatoid arthritis (RA) and interleukin (IL)-8 is a critical chemokine in promoting neutrophil migration. We previously showed that increased production of Cyr61 by fibroblast-like synoviocytes (FLS) in RA promotes FLS proliferation and Th17 cell differentiation, thus Cyr61 is a pro-inflammatory factor in RA pathogenesis. In this study, we explored the role of Cyr61 in neutrophil migration to the joints of RA patients. METHODS: RA FLS were treated with Cyr61 and IL-8 expression was analyzed by real-time PCR and ELISA. The migration of neutrophils recruited by the culture supernatants was determined by the use of a chemotaxis assay. Mice with collagen-induced arthritis (CIA) were treated with anti-Cyr61 monoclonal antibodies (mAb), or IgG1 as a control. Arthritis severity was determined by visual examination of the paws and joint destruction was determined by hematoxylin-eosin (H&E) staining. Signal transduction pathways in Cyr61-induced IL-8 production were investigated by real-time PCR, western blotting, confocal microscopy, luciferase reporter assay or chromatin immunoprecipitation (ChIP) assay. RESULTS: We found that Cyr61 induced IL-8 production by RA FLS in an IL-1ß and TNF-α independent pathway. Moreover, we identified that Cyr61-induced IL-8-mediated neutrophil migration in vitro. Using a CIA animal model, we found that treatment with anti-Cyr61 mAb led to a reduction in MIP-2 (a counterpart of human IL-8) expression and decrease in neutrophil infiltration, which is consistent with an attenuation of inflammation in vivo. Mechanistically, we showed that Cyr61 induced IL-8 production in FLS via AKT, JNK and ERK1/2-dependent AP-1, C/EBPß and NF-κB signaling pathways. CONCLUSIONS: Our results here reveal a novel role of Cyr61 in the pathogenesis of RA. It promotes neutrophil infiltration via up-regulation of IL-8 production in FLS. Taken together with our previous work, this study provides further evidence that Cyr61 plays a key role in the vicious cycle formed by the interaction between infiltrating neutrophils, proliferated FLS and activated Th17 cells in the development of RA.

Total glucosides of paeony attenuated functional maturation of dendritic cells via blocking TLR4/5 signaling in vivo.

It is well known that dendritic cells (DCs) play a critical role in the initiation and development of an immune response. Inhibitory effect on DC maturation alters immune-mediated inflammatory reaction in vivo. Total glucosides of paeony (TGP) are active compounds extracted from the roots of Paeonia lactiflora and have been widely used to ameliorate inflammation in therapy for autoimmune diseases. However, whether TGP act on DC maturation remains unknown. In this study, we investigated the effect of TGP on DC maturation in ovalbumin (OVA) immunized mice. Ear inflammation was inhibited by TGP (150 mgkg(-1), i.p.×11 days) obviously. The antigen presenting capacity of DC derived from TGP-treated mice was arrested. Meanwhile, OVA specific T cell proliferation was inhibited. In addition, we found that maturation of DCs was decreased by TGP treatment. Furthermore, OVA specific T cell proliferation was rescued by the adoptive transfer of mature DCs (mDCs) into TGP treated OVA-challenged mice. The research on the mechanism showed that TGP significantly inhibited activation of TLR4/5 singling. All these results demonstrated that TGP inhibited DC maturation and function by selectively blocking TLR4/5 activation in vivo, which in turn leads to reduce immune-mediated inflammation in vivo, adding a novel mechanism and therapeutic target of TGP for inflammatory and autoimmune disease treatment.