PHOSPHOLIPIDS AND GLYCOSPHINGOLIPIDS IN CULTURED SKIN FIBROBLASTS FROM PATIENTS WITH PROGRESSIVE SYSTEMIC-SCLEROSIS (SCLERODERMA)

Objective. A comparative investigation of glycosphingolipids and phosp holipids of cultured skin fibroblasts from healthy donors and patients with progressive systemic sclerosis (SSc) was performed. Methods. Cul ture techniques, qualitative and quantitative lipid analyses, determin ation of neuraminidase activity, and immunofluorescence microscopy wer e used. Results. The quantitative content of individual phospholipids in the fibroblasts of SSc patients (PF) was equally elevated, on the a verage 2.8 times in comparison with the fibroblasts of healthy donors (DF). The total content of neutral glycosphingolipids was slightly ele vated only because of a 1.5-fold increase of monoglucosylceramide in P F. A decrease in the amount of the gangliosides GM3 and GM1 and the ab sence of the disialogangliosides in PF in comparison with DF, were dem onstrated. Immunofluorescent assay also showed a decrease of gangliosi de epitopes on the cellular surface of PF in comparison with DF. The G M3-neuraminidase activity of PF homogenates was increased two-fold in comparison to normal values. Conclusions. These results are discussed in connection with abnormalities in membrane receptor functions, alter ations in the cell phenotype and AMP-cyclase system activity, as well as hyperproduction of extracellular matrix proteins by PF.