Formation of keto-type ceramides in palmoplantar keratoderma based on biallelic KDSR mutations in patients.
Fiche publication
Date publication
octobre 2021
Journal
Human molecular genetics
Auteurs
Membres identifiés du Cancéropôle Est :
Pr AUBIN François
Tous les auteurs :
Pilz R, Opálka L, Majcher A, Grimm E, Van Maldergem L, Mihalceanu S, Schäkel K, Enk A, Aubin F, Bursztejn AC, Brischoux-Boucher E, Fischer J, Sandhoff R
Lien Pubmed
Résumé
Functional skin barrier requires sphingolipid homeostasis. 3-ketodihydrosphingosine reductase or KDSR is a key enzyme of sphingolipid anabolism catalyzing the reduction of 3-ketodihydrosphingosine to sphinganine. Biallelic mutations in the KDSR gene may cause erythrokeratoderma variabilis et progressive-4, later specified as PERIOPTER syndrome, emphasizing a characteristic periorifical and ptychotropic erythrokeratoderma. We report another patient with compound heterozygous mutations in KDSR, born with generalized harlequin ichthyosis, which progressed into palmoplantar keratoderma. To determine whether patient-associated KDSR mutations lead to KDSR substrate accumulation and/or unrecognized sphingolipid downstream products in stratum corneum we analyzed lipids of this and previously published patients with non-identical biallelic mutations in KDSR. In stratum corneum of both patients we identified hitherto unobserved skin ceramides with an unusual keto-type sphingoid base in lesional and non-lesional areas, which accounted for up to 10% of the measured ceramide species. Furthermore, an overall shorter mean chain length of free and bound sphingoid bases was observed-shorter mean chain length of free sphingoid bases was also observed in lesional psoriasis vulgaris SC, but not generally in lesional atopic dermatitis SC. Formation of keto-type ceramides is probably due to a bottle neck in metabolic flux through KDSR and a bypass by ceramide synthases, which highlights the importance of tight intermediate regulation during sphingolipid anabolism and reveals substrate deprivation as potential therapy.
Référence
Hum Mol Genet. 2021 Oct 23;: