Evolutionary distinct roles of γ-secretase subunit nicastrin in zebrafish and humans. Issue 2 (February 2022)

• Record Type: Journal Article
• Authors: Hermasch, Matthias Andreas; Janning, Helena; Perera, Roshan Priyarangana; Schnabel, Viktor; Rostam, Nadia; Ramos-Gomes, Fernanda; Muschalek, Wiebke; Bennemann, Anette; Alves, Frauke; Ralser, Damian Johannes; Betz, Regina Christine; Schön, Michael Peter; Dosch, Roland; Frank, Jorge
• Is Part Of: Journal of dermatological science. Volume 105:Issue 2(2022)
• Page Start: 80
• Page End: 87
• Publication Date: 2022-02
• Subjects: DDD Dowling-Degos disease -- hpf hours post fertilization -- HS Hidradenitis suppurativa -- MO Morpholino -- NCSTN Nicastrin; Dowling-Degos disease -- Gamma-secretase -- Nicastrin -- Pigmentation -- Zebrafish; Dermatology -- Periodicals; Skin Diseases -- Periodicals; Dermatologie -- Périodiques; 616.5005
• DOI: 10.1016/j.jdermsci.2022.01.001
• Languages: English
• ISSNs: 0923-1811

Abstract

Highlights: Injection of human NCSTN mutations encoding null alleles leads to zebrafish hypopigmentation. Alterations in melanophore number, size, migration, and distribution are observed. Phenotype can be rescued by co-injection of zebrafish ncstn and human NCSTN mRNA. Hypopigmentation is also reversed by co-injection of human NCSTN missense mutation p.P211R. The zebrafish ncstn gene and the human NCSTN gene may have acquired evolutionarily distinct roles. Abstract: Background: Mutations in the genes that encode the human γ-secretase subunits Presenilin-1, Presenilin Enhancer Protein 2, and Nicastrin (NCSTN) are associated with familial hidradenitis suppurativa (HS); and, regarding Presenilin Enhancer Protein 2, also with comorbidity for the hereditary pigmentation disorder Dowling-Degos disease. Objective: Here, the consequences of targeted inactivation of ncstn, the zebrafish homologue of human NCSTN, were studied. Methods: After morpholino (MO)-mediated ncstn -knockdown, the possibilities of phenotype rescue through co-injection of ncstn -MO with wildtype zebrafish ncstn or human NCSTN mRNA were investigated. Further, the effects of the co-injection of a human missense, nonsense, splice-site, and frameshift mutation were studied. Results: MO-mediated ncstn -knockdown resulted in a significant reduction in melanophore morphology, size and number; and alterations in their patterns of migration and distribution. This phenotype was rescued by co-injection of zebrafish ncstn RNA, human NCSTN RNA, or a construct encoding the human NCSTN missense mutation p.P211R. Conclusion: Human NCSTN mutations encoding null alleles confer loss-of-function regarding pigmentation homeostasis in zebrafisch. In contrast, the human missense mutation p.P211R was less harmful, asserting sufficient residual ncstn activity to maintain pigmentation in zebrafish. Since fish lack the anatomical structures affected by HS, our data suggest that the zebrafish ncstn gene and the human NCSTN gene have probably acquired different functions during evolution. In fish, one major role of ncstn is the maintenance of pigmentation homeostasis. In contrast, one of the roles of NCSTN in humans is the prevention of inflammatory processes in the adnexal structures of the skin, as seen in familial HS.