Expression and Distribution of Laminin, Fibronectin and Tenascin is Stage Dependently Modulated in the Skin of Chronic Venous Insufficiency

Abstract

Objective:The regulation of tissue remodelling is a function of extracellular matrix (ECM) deposition. Our aim was to determine the expression and distribution pattern of the ECM proteins laminin, fibronectin and tenascin in all stages of chronic venous insufficiency (CVI) from telangiectases to ulceration.Methods:In punch biopsies of 25 patients with various stages of CVI and five healthy volunteers, ECM proteins were stained using indirect immunofluroescence. The staining pattern in the affected skin was evaluated by two independent, double-blinded investigators by microscopic examination.Results:In specimens of healthy skin or skin with telangiectases or pigmentation, a faint and partly inhomogeneous ECM staining pattern was detected in the upper dermis. In venous eczema, lipodermatosclerosis and venous leg ulcers, an increased expression and a wide-meshed distribution pattern throughout the dermis was observed for laminin, fibronectin and tenascin. Fragmentation of ECM components was first observed in venous eczema, persisting in the more severe stages of CVI. Laminin staining revealed unusual streak-like distributions in the papillary dermis, pronounced in Pigmentation and lipodermatosclerosis and diminished in leg ulcers.Conclusions:Our results indicate an important role of laminin, fibronectin and tenascin, and in particular of their proteolytic fragments, in the early phases of CVI, such as venous eczema, by creating permissive environments for cell migration and differentiation, essential for wound healing.