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The glycocalyx of epidermal keratinocytes from psoriatic patients has been investigated by means of lectins. Striking changes were found in the levels of glucose and/or mannose (concanavalin A) and of N-acetylglucosamine and/or sialic acid (wheat germ agglutinin) on the surface of cells from the psoriatic lesion. Smaller but significant changes were seen in the clinically uninvolved epidermis of the patient. A marked increase in the affinity of the cell surface for Ulex europus agglutinin (fucose-specific) confirms our previous reports of structural alterations in fucose-containing oligosaccharides in psoriasis. [ABSTRACT FROM AUTHOR]

We report the uptake of four labelled sugars by keratinocytes isolated from normal epidermis, psoriatic ‘uninvolved’ skin and psoriatic lesions. Our findings include the following: (1) The rate of uptake of all sugars by the psoriatic lesion is increased. (2) This abnormally high uptake diminishes dramatically during 22 h incubation in vitro. (3) There is a striking abnormality in the metabolism of fucose by psoriatic keratinocytes; our data suggest an increased rate of incorporation of fucose into glycoconjugates. We have already described morphological changes (Gommans et al., 1979a) and functional disturbances (Gommans et al., 1979b) of the plasma membrane in psoriatic keratinocytes. The remaining papers in this series will deal with the glycoconjugates (glycoprotein, glycolipid and proteoglycans) which are essential components of the membrane and its receptors. In this communication we report the uptake of labelled sugars by isolated keratinocytes and their incorporation into glycoconjugates. In particular, we have asked two questions. First, to what extent can the known membrane abnormalities in psoriasis (Mahrle & Orfanos, 1977) be characterized in terms of a specific biochemical defect? Second, if such a defect exists, is this also manifest in the clinically uninvolved skin of the psoriatic patient? [ABSTRACT FROM AUTHOR]

The sugar composition of the surface of isolated human keratinocytes has been investigated using lectins. A method is described in which the FITC-labelled lectin is displaced with competing sugar prior to measurement. This avoids errors due to aspecific binding and utilizes the minimum biological sample. Evidence is presented which indicates that little cell surface glycoconjugate is lost during the preparation of the keratinocyte suspension from human epidermal slices using the technique described here. Values for keratinocytes are similar to those reported for fibroblast lines, being much higher than those found using erythrocytes or lymphocytes. [ABSTRACT FROM AUTHOR]

Comments on the theories about the cause of psoriasis. Views on the involvement of langerhan cells in increasing the intracellular cyclic adenylic acid that promote differentiation and reduce proliferation in organized epithelium; Ideas on the characteristics of langerhan cells; Insights on the effects of alteration of monocyte-macrophage function in psoriatic patient.

Cyclic AMP Levels have been determined for the first time in isolated keratinocytes. Values were more reproducible than those reported using epidermal slices. Evidence is presented to show that damage to hormone receptors is minimal. Other observations include the following: (i) Keratinocytes from psoriatic lesions showed reduced `resting' levels of cyclic AMP as well as a diminished response to adrenaline. (z) Cyclic AMP levels were maximal in the basal cells, falling dramatically in fully differentiated keratinocytes. (3) The topical application of a corticosteroid (fluocinolone acetonide) did not modulate the response of adenyl cyclase to hormonal stimulation. [ABSTRACT FROM AUTHOR]

Phospholipase A2 has been measured in the lesions and the ‘uninvolved’ skin of patients with psoriasis. We confirm a previous report that there is a generalized increase in the activity of this enzyme in psoriatic skin. [ABSTRACT FROM AUTHOR]

This article studies that cyclic AMP is decreased in mononuclear leukocytes from psoriasis patients. Certain abnormalities of monocyte function have recently been described which seem to be characteristic of the psoriatic individual, occurring even in the absence of cutaneous lesions. These include increased chemotaxis, increased phagocytic capacity and increased bacteriocidal capacity. The cyclic AMP measurements are presented in the table. The reduction in 'resting' levels in the psoriatic MNL is statistically significant and that following adrenaline stimulation is probably significant.