Eukaryotic Initiation Factor 4E (eIF4E) as a Target of Anti-Psoriatic Treatment

Abstract

Eukaryotic translation initiation factor 4E (eIF4E) has been known to play a critical role in the regulation of gene expression and essential cellular processes such as proliferation, apoptosis and differentiation. We explored herein its role in the pathophysiology of psoriasis. The inhibition of eIF4E by siRNA or briciclib, an eIF4E small molecule inhibitor, downregulated the expression of eIF4E itself and its two complex partners eIF4A and G, as well as other eIFs (e.g. eIF1A, eIF2α, eIF3A, eIF3B, eIF5 and eIF6). This inhibition also abolished psoriatic inflammation in both the imiquimod and TGFß mouse model, as well as in a human 3D-psoriasis tissue model. Downregulation of eIF4E and the other eIFs by application of briciclib (particularly when given topically) was linked to the normalization of cellular proliferation, restoration of the inflammatory milieu and epidermal hyperplasia of psoriasis, and normalization of levels of pro-inflammatory cytokines (e.g. TNFα, IL-1b, IL-17 and IL-22), and as well as keratinocyte differentiation markers (e.g. KRT16 and FLG). These results demonstrate translational imbalance and underline the crucial role played by eIF4E and other eIFs in the pathophysiology of psoriasis. This work opens up avenues for the development of novel topical anti-psoriatic treatment strategies by targeting eIF4E.