ALTERED DISTRIBUTION OF HEPARAN-SULFATE PROTEOGLYCANS IN PSORIASIS

Heparan sulfate proteoglycans (HSPGs) are components of the basement m embrane (BM) of various tissues. They consist of a core protein and ne gatively charged glycosaminoglycan side chains: the heparan sulfate (H S) moieties. In psoriasis, uninvolved skin of psoriasis patients and i n normal skin, the distribution of HSPGs was studied immunohistochemic ally by means of three different monoclonal antibodies: JM-72, directe d against the HSPG-core protein, JM-13 against the sulfated domains of HS and JM-403 against the unmodified/low sulfated parts of HS. In pso riasis JM-13 staining was consistently absent in the tips of the derma l papillae, whereas JM-13 showed a continuous staining in the BM of un involved and normal skin. JM-403 staining was present in BM of all spe cimens. In addition, a honeycomb-lie staining was found in epidermis o f normal skin and to a lesser extent in uninvolved skin, due to bindin g with plasma membrane-associated HS. In psoriasis this JM-403 stainin g of the epidermis was invariably absent. JM-72 showed a continuous st aining of BM in all biopsies. In conclusion, normal human skin and inv olved psoriatic skin show clear differences in expression of HS. These data may provide insight into the role of HSPGs in psoriasis, which r emains further to be elucidated.