ABSTRACT
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.
Subject(s)
Lectins/metabolism , Psoriasis/metabolism , Skin/metabolism , Binding Sites , Carbohydrate Metabolism , Cell Membrane/metabolism , Humans , Keratins/metabolism , Skin/cytologyABSTRACT
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.
Subject(s)
Epidermis/metabolism , Lectins , Binding Sites , Carbohydrate Metabolism , Cell Membrane/drug effects , Cell Membrane/metabolism , Epidermis/drug effects , Humans , In Vitro Techniques , Keratins , Kinetics , Neuraminidase/pharmacology , Trypsin/pharmacologyABSTRACT
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: (1) Keratinocytes from psoriatic lesions showed reduced 'resting' levels of cyclic AMP as well as a diminished response to adrenaline. (2) 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.
Subject(s)
Cyclic AMP/metabolism , Fluocinolone Acetonide/pharmacology , Psoriasis/metabolism , Skin/metabolism , Adolescent , Adult , Animals , Cattle , Cell Separation , Epinephrine/pharmacology , Female , Histamine/pharmacology , Humans , Keratins , Middle Aged , Psoriasis/pathology , Skin/drug effects , Stimulation, Chemical , Time FactorsABSTRACT
A method is described for the preparation of isolated keratinocytes suitable for subsequent biochemical studies. Scanning electron microscopy showed that the maturation process is accompanied by an increase in cell size and a shortening and eventual loss of microvilli. Psoriatic keratinocytes are distinguishable by exhibiting longer microvilli at all levels of maturation.
Subject(s)
Psoriasis/pathology , Skin/ultrastructure , Adolescent , Adult , Cell Membrane/ultrastructure , Cell Separation/methods , Humans , Keratins , Microscopy, Electron, Scanning , Microvilli/ultrastructure , Middle Aged , Skin/cytology , Skin/pathologySubject(s)
Mitosis/radiation effects , Skin/radiation effects , Ultraviolet Rays , Adolescent , Adult , Humans , Hydrolases/metabolism , Hydrolases/radiation effects , Male , Skin/metabolismABSTRACT
Laboratory investigation of a patient diagnosed as ichthyosiform erythroderma bullosa revealed the following abnormalities: (1) alpha- and beta-galactosidases were elevated in the lesion. (2) alpha-mannosidase activity was extremely low both in the lesion and in relatively normal epidermis. (3) The mannose:glucose ratio of water-soluble hexose-containing material in the scales was very high. (4) Membrane-limited vacuoles, apparently enlarged secondary lysosomes, were observed. We conclude that this patients is the first documented example of a lysosomal storage disease in which overt clinical lesions are confined to the epidermis.
Subject(s)
Disaccharidases/deficiency , Ichthyosis/diagnosis , Lysosomes/enzymology , Mannosidases/deficiency , Metabolic Diseases/diagnosis , Skin Diseases, Vesiculobullous/diagnosis , Adult , Diagnosis, Differential , Humans , Male , Metabolic Diseases/complications , Skin/ultrastructure , Skin Diseases, Vesiculobullous/complicationsABSTRACT
The activities of 14 acid hydrolases have been measured in normal and diseased human epidermis. Our findings were as follows: (i) Increased hydrolase activity was common in lesions; the clinically uninvolved skin of patients, however, invariably showed normal values. (2) The pattern of change was independent of the nature of the didease, the arylsulphatases and beta-glucosidase usually showing the greatest elevations. (3) The magnitude of the changes differed from disease to disease, being most marked in the lesions of psoriasis. (4) Ichthyosiform erythroderma was exceptional in showing elevated levels of the galactosidases and cathepsins B1 and D. We suggest that (with the exception of ichthyosiform erythroderma) the abnormalities which we have observed may be related to the proliferative rate of the epidermis.