287 MicroRNA based classifiers in diagnosis and prognosis of cutaneous T cell lymphoma

Abstract

Fragrances are common contact sensitizers, many of which are prohaptens that undergo metabolic activation to a reactive hapten needed to produce a complete antigen. The cutaneous metabolom of the fragrance C was analyzed by HR-MAS NMR (High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance) following its topical application to a 3D human skin equivalent. Identified metabolites of C were 1,2 benzoquinone-hapten-proteinadduct, another up to now unidentified hapten-protein-adduct and formaldehyde by demethylation of C. To clarify the role of cutaneous CYPs we used a modified KeratinoSensÒassay. The addition of single CYP cocktails or CYP-containing microsomes for prohapten bioactivation is highly cytotoxic. This has led to the use of rat liver cytosol whose CYPs differ from those present in human skin .We spiked rat liver cytosol with human cutaneous CYPs and measured the activation of NRF2 in KeratinoSensÒ by the Luciferase assay and cytotoxicity by the MTT-assay. Cinnamic aldehyde served as a positive control since it does not require metabolic activation and SDS was used as an irritant control. Addition of C to the mixture of cytosol-human cutaneous CYPs strongly activated NRF2. Heat inactivated mixtures and preparations containing cytosol alone showed no reactivity. Thus C is a prohapten that undergoes metabolic activation to hapten-protein adducts catalyzed by CYP-isoenzymes present in human skin.