Embryonic AP1 Transcription Factor Deficiency Causes a Collodion Baby-Like Phenotype

Abstract

AP1 transcription factors are important controllers of gene expression in the epidermis, and altered AP1 factor function can perturb keratinocyte proliferation and differentiation. However, our understanding of how AP1 signaling changes may underlie or exacerbate skin disease is limited. We have shown that inhibiting AP1 factor function in suprabasal adult epidermis leads to reduced filaggrin levels and to a phenotype that resembles the genetic disorder, ichthyosis vulgaris. We now show that inhibiting AP1 factor function during development in embryonic epidermis produces marked phenotypic changes including reduced filaggrin mRNA and protein levels, compromised barrier function, marked ultrastructural change and enhanced dehydration susceptibility that resembles the phenotype observed in the flaky tail mouse, a model for ichthyosis vulgaris. In addition, the AP1 factor-deficient newborn mice also display a collodion membrane phenotype which is not observed in flaky tail mice or in newborn individuals with ichthyosis vulgaris, but is present in other forms of ichthyosis. This mixed phenotype suggests that a need for a better understanding of the possible role of filaggrin loss and AP1 transcription factor deficiency in ichthyoses and collodion membrane formation.

Single-cell transcriptomics reveals gene expression dynamics of human fetal kidney development

“…Functional annotation analysis of genes that were differentially expressed between SSBpod and Pods revealed enrichment of a binding site for AP-1. This transcription factor has been found to be important for the development of the skin [61], neural precursor cells [62], and the heart valve [63] in mice. A role of AP-1 in kidney development has not been described yet, and further research is needed to elucidate its potential function.…”