SPINK5 knockdown in organotypic human skin culture as a model system for Netherton syndrome: effect of genetic inhibition of serine proteases kallikrein 5 and kallikrein 7.

Netherton syndrome (NS; OMIM 256500) is a genetic skin disease resulting from defects in the serine protease inhibitor Kazal-type 5 (SPINK5) gene, which encodes the protease inhibitor lympho-epithelial Kazal type inhibitor (LEKTI). We established a SPINK5 knockdown skin model by transfecting SPINK5 small interfering RNA (siRNA) into normal human epidermal keratinocytes, which were used together with fibroblast-populated collagen gels to generate organotypic skin cultures. This model recapitulates some of the NS skin morphology: thicker, parakeratotic stratum corneum frequently detached from the underlying epidermis and loss of corneodesmosomes.

Structure-activity relationship studies on a novel class of antiproliferative agents derived from Lavendustin A. Part I: Ring A modifications.

The potent antiproliferative agent SDZ LAP 977, which has shown efficacy in a clinical proof of concept study in actinic keratosis patients, has been previously demonstrated to block the cell cycle in mitosis. In the present study, we further explored the mode of action: SDZ LAP 977 binds to the "colchicine binding site" on tubulin and, thus, inhibits tubulin polymerization in vitro. Moreover, we established structure-activity relationships for the effect of modifications in the 2,5-dimethoxyphenyl moiety ("ring A") of the molecule on in vitro antiproliferative activity.

Inhibition of T-cell activation in vitro in human peripheral blood mononuclear cells by pimecrolimus and glucocorticosteroids and combinations thereof.

Pimecrolimus is an ascomycin macrolactam derivative that has been recently approved for the topical treatment of atopic dermatitis. In this study we report for the first time on a direct comparison of the inhibitory activity of pimecrolimus and the glucocorticosteroids betamethasone 17-valerate, dexamethasone and hydrocortisone at the level of T-cell proliferation and cytokine production. Stimulated human peripheral blood mononuclear cell (PBMC) systems were used that are either sensitive or resistant to calcineurin inhibitors or glucocorticosteroids.

Differential inhibition of primary versus preactivated T cells by pimecrolimus but not by tacrolimus in vitro.

Background: Recent studies in murine models of allergic contact dermatitis have shown that systemic treatment with pimecrolimus in contrast to tacrolimus did not inhibit the sensitization phase, whereas both compounds equivalently suppressed the inflammatory response in sensitized animals. This finding indicated a differential sensitivity of antigen-naïve and primed T cells towards pimecrolimus and tacrolimus.

Methods: T cells obtained from healthy and allergic donors were subjected to primary and secondary stimulation by allogeneic or staphylococcal superantigen-presenting dendritic cells (DC).

Effects of ceramide-1-phosphate on cultured cells: dependence on dodecane in the vehicle.

Ceramide-1-phosphate (C1P), the product of ceramide kinase, is a sphingophospholipid with recently recognized signaling properties. In particular, it was reported to be mitogenic and capable of direct stimulation of cytosolic phospholipase A(2alpha). Much of the present knowledge has relied on the use of C1P of various acyl chain lengths, together with diverse protocols to deliver it to cultured cells.

6-[2-(adamantylidene)-hydroxybenzoxazole]-O-sulfamate, a steroid sulfatase inhibitor for the treatment of androgen- and estrogen-dependent diseases.

Steroid sulfatase (STS) offers a new target for the treatment of steroid hormone-dependent diseases, such as breast and prostate cancer and androgen-dependent skin diseases. We here characterize a novel non-estrogenic inhibitor of the enzyme, namely 6-[2-(adamantylidene)-hydroxybenzoxazole]-O-sulfamate (AHBS), with special attention to its potential use in the treatment of acne. The compound blocks STS activity in homogenates of human skin with IC(50)=16 nM.

6-(2-adamantan-2-ylidene-hydroxybenzoxazole)-O-sulfamate: a potent non-steroidal irreversible inhibitor of human steroid sulfatase.

We report the synthesis and results from the in vitro evaluation of 6-(adamantan-2-ylidene-hydroxybenzoxazole)-O-sulfamate 1 as an irreversible inhibitor of human steroid sulfatase (STS). Highly straightforward, condensation of 2-methyl-6-hydroxybenzoxazole with 2-adamantanone, subsequent elimination of water and sulfamoylation provide the title compound in 45% overall yield from the inexpensive 2,4-dihydroxyacetophenone. 1 was found to be a potent irreversible inhibitor of purified human steroid sulfatase (STS) and specific for this enzyme relative to human arylsulfatases A and B.

LAV694, a new antiproliferative agent showing improved skin tolerability vs. clinical standards for the treatment of actinic keratosis.

The skin tolerability of the tubulin polymerisation inhibitor LAV694 was compared to that of 5% 5-fluorouracil (5-FU) and 0.5% podophyllotoxin in vitro using a human reconstructed epidermis (HRE), and in vivo using minipigs. Topical treatment of HRE for 1 or 3 days with a 0.

Estrogenic potential of 2-alkyl-4-(thio)chromenone 6-O-sulfamates: potent inhibitors of human steroid sulfatase.

2-Alkylchromen-4-one 6-O-sulfamates, a new class of potent steroid sulfatase (STS) inhibitors, were evaluated for their estrogenic potential. Structure-activity relationships for estrogenic activity were identified; however, no correlation with STS inhibition was found. Estrogenicity is favored by bulky side chains and can be effectively abrogated by an (additional) linear substituent.