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/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 suppresses growth of human malignant melanoma.

Cysteine-rich protein 61 (CCN1/CYR61) is an important marker of proliferation and metastasis in malignant melanoma, making it a potential target for melanoma treatment. In this study, we compared the expression of CRY61 in Chinese patients with malignant melanoma with its expression in patients with other skin tumors or with no skin pathological conditions. We examined the effects of anti-human CYR61 monoclonal antibody on proliferation and evaluated the changes in CYR61 expression and cell proliferation in response to treatment with either epirubicin or interferon (IFN)-α. CYR61 was expressed at lower levels in patients with malignant melanoma than in patients with other skin tumors or with no pathology. Following the treatment of B16 cells with epirubicin and IFN-α, CYR61 levels increased, cell growth was inhibited, and proliferating cell nuclear antigen expression decreased. Thus, CYR61 could become a therapeutic target for malignant melanoma patients with high CYR61 expression.

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.

A population-based study of acquired bilateral nevus-of-Ota-like macules in Shanghai, China.

Acquired bilateral nevus-of-Ota-like macule (ABNOM) is a common skin dyspigmentation in Asian females. Although its clinical characteristics are well defined, its epidemiology and pathogenesis remain unclear. A large population-based cross-sectional study was conducted to determine the prevalence and risk factors of ABNOM. A total of 8,680 subjects (ages ranging from newborn to 99 years old; 54% female) were selected from urban areas in Shanghai, China, using a multistage sampling method. All participants (response rate=97%) were interviewed and examined for the presence of various pigmentary disorders by board-certified dermatologists. ABNOM was found in 2.5% of the study population (0.5% of males and 4.2% of females), and 90% of cases observed were female. In females, prevalence rose after the age of 15 years and sharply declined after the age of 50 years, with nearly half of the cases observed within ages 45-55 years (prevalence=8.5%). Age, contraceptive use, and sun exposure were independently associated with ABNOM. Women with ABNOM were less likely to have facial nevomelanocytic nevi and seborrheic keratoses. These findings indicate that sex hormone alteration and UV exposure may independently have an important role on the pathogenesis of ABNOM.