Characterization of a small molecule inhibitor of tumor necrosis factor-alpha production / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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-1β (IL-1β), 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).</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Antipruritic mechanisms of pimecrolimus cream for facial dermatitis in adult women patients / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the antipruritic mechanisms of pimecrolimus cream for women facial dermatitis.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>