Intermediate filaments are part of a dynamic protein network, called the cytoskeleton, that provides shape, structural organization and mechanical resilience to human cells and tissues. Indeed, intermediate filaments have been proven to be very strong, while at the same time remaining flexible and elastic (Kreplak et al, 2005). Remarkably, they seem to stiffen when subjected to high mechanical force (Janmey et al, 1991), making them important contributors to integrity of cells, especially in tissues subjected to pronounced mechanical stress, such as our skin.

In agreement, mutations in genes encoding keratins, a group of intermediate filament-associated proteins that are prominent in epithelial tissues, are associated with severe skin diseases (Omary et al, 2009). Here we show the staining of the keratin 14 protein in the keratinocyte cell line HaCaT. Mutations in KRT14 are the major cause of Epidermolysis Bullosa Simplex (EBS). This is a heritable disease in which the basal layer of the skin becomes so fragile that it will peel and form blisters even under mild rubbing, with scarification and excessive thickening of the skin as a result. There is currently no cure for EBS, but gene-, cell- and protein-based therapy options are being studied at pre-clinical and clinical levels (Chamcheu et al., 2012).

Ulrika Axelsson