PROTEOGLYCAN ALTERATIONS IN SKIN FIBROBLAST-CULTURES FROM PATIENTS AFFECTED WITH PSEUDOXANTHOMA-ELASTICUM

Proteoglycans (PGs) were investigated in fibroblast cultures from both apparently normal and involved areas of skin from two patients affect ed with Pseudoxanthoma elasticum (PXE) and compared to control normal cells. Biochemical analysis showed that cells from the PXE-affected pa tients produced a PC population with stronger polyanion properties, as well as a markedly increased amount of high hydrodynamic-size PGs. Mo reover, PGs from PXE-affected cells showed abnormal hydrophobic intera ction properties when examined under associative conditions and includ ed heparan sulphate (HS)-containing populations with anomalous electro phoretic mobility. These phenomena were particularly evident in the ca se of PGs secreted into the growth medium. In agreement with these fin dings immunohistochemical study showed alterations affecting decorin a nd biglycan, as well as a different content and distribution of HS-PGs in PXE-affected cells. The same biochemical and morphological alterat ions were confirmed for both patients on different cell cultures and w ere present in cells from both apparently normal and affected skin are as, being more pronounced in the latter. Our results indicate that PXE -affected fibroblasts in culture exhibit an abnormal PC metabolism, wh ich could affect the normal assembly of extracellular matrix.