Modelling atopic dermatitis in healthy human skin for the characterization of topical compounds.

Suitable human models for the development and characterization of topical compounds for inflammatory skin diseases such as atopic dermatitis are not readily available to date. We describe here the development of a translational model involving healthy human skin mimicking major aspects of AD and its application for the characterization of topical Janus kinase inhibitors. Full thickness human abdominal skin obtained from plastic surgery stimulated in vitro with IL4 and IL13 shows molecular features of AD.

Design of a Supersoft Topical JAK Inhibitor, Which Is Effective in Human Skin but Rapidly Deactivated in Blood.

We describe the discovery and characterization of the supersoft topical JAK inhibitor , which is potent in biochemical and cellular assays as well as in human skin models. In blood, the neutral ester is rapidly hydrolyzed ( ∼ 6 min) to the corresponding charged carboxylic acid exhibiting >30-fold reduced permeability. Consequently, acid does not reach the intracellular JAK kinases and is inactive in cellular assays and in blood.

Discovery and Characterization of the Topical Soft JAK Inhibitor CEE321 for Atopic Dermatitis.

The JAK kinases JAK1, JAK2, JAK3, and TYK2 play key roles in cytokine signaling. Activation of the JAK/STAT pathways is linked to many diseases involving the immune system, including atopic dermatitis. As systemic JAK inhibitor pharmacology is associated with side effects, topical administration to the skin has been considered to locally restrict the site of action.

Epoxide hydrolase 1 (EPHX1) hydrolyzes epoxyeicosanoids and impairs cardiac recovery after ischemia.

Stimuli such as inflammation or hypoxia induce cytochrome P450 epoxygenase-mediated production of arachidonic acid-derived epoxyeicosatrienoic acids (EETs). EETs have cardioprotective, vasodilatory, angiogenic, anti-inflammatory, and analgesic effects, which are diminished by EET hydrolysis yielding biologically less active dihydroxyeicosatrienoic acids (DHETs). Previous assays have suggested that epoxide hydrolase 2 (EPHX2) is responsible for nearly all EET hydrolysis.

Evidence for a complex formation between CYP2J5 and mEH in living cells by FRET analysis of membrane protein interaction in the endoplasmic reticulum (FAMPIR).

The potential complex formation between microsomal epoxide hydrolase (mEH) and cytochrome P450-dependent monooxygenase (CYP) has been a subject of research for many decades. Such an association would enable efficient substrate channeling between CYP and mEH and as such represent an attractive strategy to prevent deleterious accumulation of harmful metabolic by-products such as CYP-generated epoxide intermediates. However, such complex formation is experimentally difficult to prove, because CYP and mEH are membrane-bound proteins that are prone to unspecific aggregation after solubilization.

11,12 -Epoxyeicosatrienoic acid (11,12 EET) reduces excitability and excitatory transmission in the hippocampus.

Recent studies suggest a role for the arachidonic acid-derived epoxyeicosatrienoic acids (EETs) in attenuating epileptic seizures. However, their effect on neurotransmission has never been investigated in detail. Here, we studied how 11,12- and 14,15 EET affect excitability and excitatory neurotransmission in mouse hippocampus.