Altered Expression of Extra-Cellular Matrix Proteins and Integrin Receptors in Discoid Lupus Erythematosus

Discoid lupus erythematosus (DLE) is a skin disorder characterised by an active inflammatory phase that leads to the formation of atrophic scars. The molecular basis underlying the development of atrophic scars is not yet known. In this study we investigated the expression of the extra-cellular matrix (ECM) components of the BM, Laminin-1 (Ln-1), Laminin-5 (Ln-5), Collagen IV (Coll IV) and the expression of their integrin receptors α2β1, α3β1 and α6β4. In active DLE lesions expression of the ECM BM components is discontinuous and uneven and the integrins are largely absent or present with an altered polarity. In established lesions both ECM BM components and their integrin receptors are absent. In conclusion, altered expression of ECM BM components together with altered expression of their integrin receptors is responsible for the lack of cross-talk between keratinocytes and the surrounding microenvironment and this could lead to the development of atrophic scars.