Expression of extracellular matrix proteins in reticular variant of mid-dermal elastolysis

Mid-dermal elastolysis (MDE) is a rare disorder of the elastic tissue that is characterized histopathologically by selective loss of elastic fibres in the mid dermis.

We aimed to investigate the protein and mRNA expression of extracellular matrix-related proteins and growth factors in the skin (lesional and non-lesional) of a female patient with the reticular variant of MDE.

Real-time RT-PCR and immunohistochemistry was performed for matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase-1, decorin, biglycan, versican, fibronectin, elastin, extracellular matrix protein 1, cathepsin G, transforming growth factor ß1 and connective tissue growth factor.

Although protein expression of decorin, biglycan and versican was reduced in the mid dermis of lesional skin, mRNA expression did not differ between lesional and non-lesional skin. As expected, elastin expression was significantly diminished in the mid dermis of lesional skin, whereas mRNA expression levels of elastin were equal to non-lesional skin. Immunoreactivity of MMP-1 was increased in lesional upper and mid dermis. Accordingly, MMP-1 mRNA was also significantly higher expressed in MDE when compared with non-lesional skin.

The results of this study confirm data of the previous investigations indicating that increased MMP-1 activity followed by elastin degradation seems to constitute the pathogenetic background of MDE.