A protein known as caspase-14 has been identified as the enzyme involved in the protection of the skin against UVB damage and water loss, according to a study published online in Nature Cell Biology.
The involvement of caspase-family members in programmed cell death and inflammation is well understood but, a function for caspase-14 had previously not been identified. Using caspase-14 knockout mice, Wim Declercq and colleagues show that caspase-14 is responsible for the correct degradation of profilaggrin and filaggrin. Filagrin is responsible for aggregating keratin and other proteins in the upper layers of the epidermis to form the stratum corneum -- a layer of flattened dead-cell remnants that creates a protective barrier for the skin. The controlled processing of profillagrin to produce filagrin ultimately maintains the integrity of the epidermis. In mice lacking caspase-14, their skin exhibits a defective stratum corneum and is more sensitive to water loss and UVB photodamage.
The identification of caspase-14 and its role in skin-barrier formation opens avenues for the pharmaceutical manipulation of this process to prevent the damage induced by UVB, the primary agent responsible for sunburn and skin ageing.
Wim Declercq (Ghent University, Belgium)
Abstract available online.
(C) Nature Cell Biology press release.
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