Postdoctoral Researcher:

Epidermolysis bullosa simplex is a group of genetic disorder that cause skin fragility with erosions and blisters induced by mild mechanical trauma (minor injury or friction) such as rubbing or scratching.

Four major types of epidermolysis bullosa simplex were identified depending on severity:

1. Weber-Cockayne type (the mildest form)
2. Koebner type
3. Epidermolysis bullosa simplex with mottled pigmentation
4. Dowling-Meara type (the most severe form)

The symptoms include generalized blistering, palmoplantar keratoderma, nail dystrophy, and oral ulcerations. These symptoms are induced by the separation of the keratinocytes of the epidermal stratum basale and is attributed in most of cases to dominant genetic mutations in the keratin 5 and 14 intermediate filament (IF) proteins.

Studying the wild type and mutant IF proteins found in EBS cells will offer insight into this disorder and advance the biomechanical knowledge of the IF cytoskeleton. Recent studies into the IF have demonstrated that it differs complexly from its cytoskeleton neighbours: actin and microtubules. IF proteins have extraordinary extensibility, and elastic properties that allow it to be stretched to 35% its length without damage, and 250% before failing. In this project, we will investigate whether the recently elucidated tensile properties of IFs in vitro are relevant to the pathophysiology of EBS skin fragility in vivo.

Contact informations:

Publications:

• Haddad O., Chotard-Ghodsnia R., Verdier C., Duperray A., Tumor cell/endothelial cell tight contact upregulates endothelial adhesion molecule expression mediated by NFκB: differential role of the shear stress. Experimental Cell Reseach. 2009. doi:10.1016/j.yexcr.2009.11.015.

• O. Haddad, J.R. Hawse, M. Subramaniam, T.C. Spelsberg, S.F. Bensamoun. TIEG1 osteocytes display defects in morphology, density and surrounding hypomineralized bone. 2009. Journal of Musculoskeletak Research,12 (3): 1–10

• Chotard-Ghodsnia R., Haddad O., Leyrat A., Drochon A., Verdier C., Duperray A. Morphological analysis of tumor cell/ endothelial cell interactions under shear flow . 2006. Journal of Biomechanics, 40 (2):335-44.