Chemokine-like factor 1 (CLFK1) is over-expressed in patients with atopic dermatitis.

BACKGROUND: Human chemokine-like factor 1 (CKLF1), a recently discovered chemokine, has a broad spectrum of biological functions in immune-mediated diseases. It is highly expressed on Th2 lymphocytes and is a functional ligand for human CCR4. CKLF1 has a major role in the recruitment and activation of leucocytes, which plays an important role in the pathogenesis of allergic diseases. The present study was designed to determine the expression of CKLF1 in skin and serum in patients with atopic dermatitis (AD). METHODS: The CKLF1 protein expression in skin lesion was analyzed by immunohistochemistry and ELISA. The mRNA expression of CKLF1 in skin lesion was detected by Real-time PCR. The serum levels of CKLF1, IgE, eotaxin, IL-4, IL-5, and IL-13 were measured by ELISA. RESULTS: Histopathological changes in the skin of AD patients showed local inflammation with epidermal thickening and significant inflammatory cellular infiltration. Immunohistochemistry results demonstrated that CKLF1-staining positive cells were located in the epidermal and dermis, and that the CKLF1 expression in AD patients was significantly higher than that in normal control. The CKLF1 mRNA expression in AD patients was significantly higher than that in healthy controls. Serum CKLF1 and IgE levels were significantly increased in AD patients, as were the serum levels of IL-4, IL-5, IL-13 and eotaxin. CONCLUSIONS: Both CKLF1 protien and mRNA levels are overexpressed in the skin lesion of AD patients, along with an increase in serum CKLF1 level, indicating that CKLF1 may play an important role in the development of atopic dermatitis.

Effects of cigarette smoke extracts on the growth and senescence of skin fibroblasts in vitro.

Epidemiological studies have shown that cigarette smoke (CS), a very common environmental factor, plays an important role in skin aging. Although some in vivo studies have suggested that CS affects skin aging, the detailed effects of CS on skin cells in vitro remain largely unknown. In this study, we investigated the effects of cigarette smoke extract (CSE) on the growth, proliferation, and senescene of skin fibroblasts and the possible mechanism underlying these effects. Primary cultured human fibroblasts were exposed to a range of concentrations of CSE. Cell viability and cell proliferation after CSE exposure were analyzed with the methyl thiazolyl tetrazolium (MTT) assay and bromodeoxyuridine incorporation assay, respectively. Growth curves of fibroblasts exposed to different concentrations of CSE were developed and prolonged CSE-exposed cells were observed. Morphological and ultrastructural changes in fibroblasts were assessed by inverted light microscopy and transmission electron microscopy (TEM). Dying cells were stained with senescence-associated ß-galactosidase (SA ß-gal). Intracellular reactive oxygen species (ROS) levels, superoxide dismutase (SOD) activity, and glutathione peroxidase (GSH-Px) activity were determined by a colorimetric method. We found that proliferative capacity and growth were inhibited by CSE exposure in a dose- and time-dependent manner. Fibroblasts exposed to even low concentrations of CSE for a long period of time (5 passages) showed significantly increased SA ß-gal activity and typical features of aging cells. Meanwhile, CSE inhibited superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and augmented ROS levels. Our observations suggest that CSE exposure impairs fibroblast growth and proliferation and leads to features similar to those seen in senescent cells. Oxidative stress injury and inhibition of antioxidant defense activity may be involved in CSE-induced fibroblast senescence.

Characterization of a small molecule inhibitor of tumor necrosis factor-alpha production.

BACKGROUND: Numerous studies have shown that reducing the level of tumor necrosis factor-alpha (TNFα) through the use of anti-TNF antibodies or soluble TNF receptor is a safe and efficacious treatment to inflammatory diseases such as rheumatoid arthritis. Therefore, novel approaches to achieve this outcome are desired. The aim of this study was to investigate the characterization of a small molecule inhibitor, Y316, which blocks TNF mRNA upregulation and TNF production by lipopolysaccharides (LPS) stimulated monocytes. METHODS: Peripheral blood mononuclear cells (PBMC) from healthy volunteers were plated in 24-well plates and stimulated with LPS (1 µg/ml), phorbol-12-myristate-13-acetate (PMA) (100 ng/ml), zymosan (10 µg/ml) and Tsst (100 ng/ml). Supernatants were collected after 4-hour culture at 37°C, and quantitative determination of TNFα, interleukin-1ß (IL-1ß), IL-6, IL-8, IL-10 and IL-2 production in the supernatants was performed by colorimetric enzyme-linked immunosorbent assay (ELISA). Total RNA of PBMC was isolated and cytokine mRNA quantitation was performed by using a RNA level measuring kit (R & D Systems). PBMC were pretreated with Y316 (10 µmol/L, 1 µmol/L, 0.1 µmol/L, 0.01 µol/L and 0.001 µmol/L) or dimethyl sulfoxide at 37°C for 10 minutes, and then stimulated with LPS or PMA, protein concentrations of p44.42, IKBα, P38 and Jun NH2-terminal kinase were determined by Western blotting. Cyclic adenosine-3',5'-monophosphate (cAMP) of PBMC was measured by enzyme immunoassay kit (Amersham Pharmacia Biotech). RESULTS: Y316 blocked TNF production and inhibited the upregulation of TNF mRNA levels in response to LPS, and also prevented the production of IL-1 and IL-6. In contrast, Y316 augmented the production of IL-10 in LPS-stimulated monocytes. Y316 failed to prevent the production of IL-2 and TNF in antigen-stimulated T cells, suggesting that its effects may be cell-type specific. Y316 prevented the phosphorylation and activation of the MAPK, ERK, and therefore appeared to mediate its effects on TNF by acting at an early point in the signaling cascade induced in response to LPS. There was no effect of Y316 on cAMP levels either alone or in the presence of LPS. CONCLUSIONS: Y316 appears to be a small molecule inhibiting TNF production, which may act via a novel mechanism. Identification of the target of Y316 may lead to the development of alternative strategies for achieving selective cytokine inhibition.

[Antipruritic mechanisms of pimecrolimus cream for facial dermatitis in adult women patients].

OBJECTIVE: To investigate the antipruritic mechanisms of pimecrolimus cream for women facial dermatitis. METHODS: Topical pimecrolimus cream 1% was applied in 52 women patients with facial dermatitis. The Investigators Global Assessment (IGA) score, severity of pruritus (SP) scores, and a basic syntax and molecular substrate (molecular psychophysics) of nociception and pruriception established by temperature-sensitive transient receptor potential (TRP) channels were used to evaluate the clinical signs, severity of pruritus, and skin sensory phenomenon. RESULTS: The IGA scores at day 1 and 4 of treatment and the SP score at day 1, 4, and 11 of treatment were significantly lower than the baseline scores before treatment (P < 0.05). Among these 52 patients, 28 (53.8%) showed positive capsaicin-like response (i.e., burning with consequent rapid amelioration of pruritus) at the application sites, 12 (23.1%) showed camphor-like response (i.e., warming with consequent rapid amelioration of pruritus), and 12 (23.1%) showed negative capsaicin-like response or negative camphor-like response. CONCLUSIONS: Treatment with pimecrolimus cream 1% can rapidly and effectively improve the signs and symptoms of facial dermatitis in adult women patients. Pimecrolimus cream 1% may act on the transient potential vanilloid 1 (TRPV1) receptor in the skin sensory afferents to induce capsaicin-like response or camphor-like response and then desensitizes TRPV1 and rapidly inhibits or alleviate itching.

[Effect of topical tacrolimus ointment on expression of Toll-like receptors 2 and 4 in lesional atopic dermatitis skin].

OBJECTIVE: To investigate the role of Toll-like receptor(TLR) 2 and TLR4 in pathogenesis of atopic dermatitis(AD) and the effect of topical tacrolimus ointment on expression of TLR2 and TLR4 in lesional AD skin. METHODS: Immunohistochemistry was employed to study the expression of TLR2 and TLR4 in normal skin and lesional AD skin before and after using topical tacrolimus ointment. RESULTS: The basal keratinocytes in normal skin constitutively expressed TLR2 and TLR4. In contrast, lesional epidermis from 9 patients with acute AD overexpressed TLR2 and TLR4 on the whole epidermis keratinocytes with membranous and cytoplasmic staining pattern. After using topical tacrolimus ointment for three weeks, TLR2 and TLR4 were expressed on basal and suprabasal keratinocytes with membranous and cytoplasmic staining pattern. CONCLUSION: These data suggest that TLR2 and TLR4 expressed by epidermal keratinocytes constitute part of the innate immune system of the skin, and increased TLR2 and TLR4 expression may be related to the skin innate immuno-inflammatory response in atopic dermatitis. Topical tacrolimus may directly or indirectly inhibit or down-regulate TLR2 and TLR4 expression in KC and inhibit skin innate immuno-inflammatory response related to TLR-NFkappaB signal transduction and regulation in atopic dermatitis.