Cryostat Sections Of Human Skin Research Articles

Autoradiographic mapping of beta-adrenoceptors in human skin.

A high density of beta 2-adrenoceptors has been found in human skin. Using autoradiographic mapping we investigated the distribution of beta 1- and beta 2-receptors in normal and diseased human skin. Cryostat sections of human skin obtained at biopsy were incubated with [125I]-iodocyanopindolol and nonspecific binding was identified by incubation of adjacent sections with 200 microM (-)-isoproterenol; beta 2-receptors were visualized using CGP 20712A and beta 1-receptors using ICI 118,551 as competing agents. The epidermis was densely labelled with an even distribution throughout all layers. Most of the beta-receptors were of the beta 2-subtype, with practically no beta 1-receptors. beta-Receptors were also localized to eccrine sweat glands, dermal blood vessels, and perivascular inflammatory cells, but there was no labelling of sebaceous glands. Topical glucocorticoids caused an increase in the density of epidermal beta-receptors. We conclude that keratinocytes and eccrine sweat glands express high densities of beta 2-receptors, suggesting that they may have a physiological role in the regulation of these cells.

Immunocytochemical Localization of Androgen Receptors in Human Skin Using Monoclonal Antibodies Against the Androgen Receptors

Androgen receptors were localized in cryostat sections of human skin using monoclonal antibodies to the human androgen receptor. Bound antibodies were detected using biotinylated rabbit anti-rat IgG, peroxidase-conjugated streptavidin, and diaminobenzidine as chromogen. In the neonatal foreskin, antibody to androgen receptor bound to keratinocytes in the epidermis and to fibroblasts and vascular endothelial cells in the dermis. Immunohistochemical staining was stronger in nuclei than in cytoplasm. This staining was specific, because there was no significant staining when antibody to the androgen receptor was replaced with IgG from nonimmunized rats or with buffer, or when antibody to androgen receptor was incubated, prior to immunostaining, with a trp E-human androgen-receptor fusion protein used as immunogen. Incubation of androgen receptor antibody with trp E alone did not affect staining. Androgen-receptor antibody also bound to keratinocytes, fibroblasts, and endothelial cells in skin from adult men and women. Skin from the scalp, nose, lip, back, and chest gave positive staining for androgen receptor. Antibody to androgen receptor also bound to the coil and ductal cells of eccrine glands, external root sheath of hair follicles, epithelium in the hair bulb, dermal papilla cells, and sebocytes. There was no significant binding to adipocytes, collagen, or stratum corneum. These results show that androgen receptor is present in cells that are known to be targets for androgens and also in cells in which the biologic effects of androgens are yet to be characterized.

The Elastolytic Activity of Cathepsin G: An Ex Vivo Study with Dermal Elastin

To determine whether human neutrophil cathepsin G can act by itself or in concert with human neutrophil elastase to destroy elastic fibers in vivo, we used cryostat sections of human skin as an ex vivo substrate for these leukoproteinases. Specifically stained dermal elastic fibers were quantitated using an accurate and almost entirely automatic morphometric procedure that included computerized threshold selection and elimination of non-elastic dark elements. AA, the area fraction occupied by the dermal elastic fibers, was found to be 0.100 +/- 0.014 (mean +/- SD) for 21 control skin sections originating from a single donor. Measurement of the fiber diameters in these control sections (2.4 +/- 0.8 microns [mean +/- SD]) allowed calculation of the Weibel factor used to convert AA into Vv, the volume fraction occupied by the elastic fibers: Vv was 0.028 +/- 0.004 (mean +/- SD). Incubation of skin sections with elastase, cathepsin G, or mixtures of the two enzymes resulted in an important decrease in AA accompanied by a slight increase in the average fiber diameter. The largest increase (14%) was noticed for cathepsin G and was due to a preferential attack of thin fibers and to fiber fragmentation. The AA of fibers remaining after elastolytic activity of cathepsin G was 20 to 30% that of elastase in this ex vivo assay. On the other hand, cathepsin G stimulated the elastolytic activity of elastase. For instance, the activity of a mixture of 1.1 microM elastase and 1.5 microM cathepsin G was 1.9-fold higher than the sum of the activities of the individual proteinases. The stimulation increased with the cathepsin G concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical markers of human sebaceous gland differentiation.

Cryostat sections of human skin were stained with monoclonal antibodies to involucrin, a range of cytokeratins, epithelial membrane antigen (EMA), and an ovarian cystadenocarcinoma antibody (OM1) to identify combinations of antibodies that could be used to discriminate between basal and differentiated sebocytes and other cell types present in the pilosebaceous unit. Both the EMA and OM1 monoclonal antibodies specifically recognized differentiated sebocytes. No staining of basal sebocytes or other epidermal cell types was seen. Differentiated (but not basal) sebocytes were also stained by a cytokeratin 10 antibody (LH2). Conversely, the basal sebocytes were recognized by an antibody specific to basal keratinocytes (LH6). Cells of the sebaceous duct stained with both LH2 and LH6 and also with the anti-involucrin monoclonal antibody. Cytokeratin 4 has been detected in sebaceous glands by protein analysis but has not previously been detectable immunohistochemically. We show by immunofluorescence after limited proteolysis that cytokeratin 4 epitopes are distributed in all sebaceous gland cells, including the duct cells.

Altered binding of Ulex europaeus I lectin to psoriatic epidermis.

We have used Ulex europaeus I (UEA I) lectin, specific for alpha-L-fucose-containing glycoconjugates, in fluorescence microscopy to stain cryostat sections of human skin from normal persons and patients with psoriasis and lichen simplex. In normal skin the upper layers of the stratum spinosum and the stratum granulosum were strongly reactive with UEA I, whereas the lower layers of the epidermis did not react. The staining intensity of the upper epidermis was similar to that of the endothelium of dermal blood vessels. Biopsies of the lesional skin of lichen simplex showed an intense UEA I-specific staining throughout the whole epidermis, similar in intensity to that seen in the upper epidermis of normal skin. In psoriatic lesions positive UEA I-specific fluorescence was seen throughout the whole epidermis, but the fluorescence was more faint and often granular. In uninvolved skin of psoriatic patients the whole epidermis showed a diffuse UEA I-specific fluorescence, differing in this respect from normal skin. In normal skin UEA I binds to epidermal cells which are at a certain state of differentiation. The results with psoriatic epidermis confirm that both uninvolved and lesional epidermis have a defect in epidermal maturation, as shown by the altered binding of UEA I lectin.

Binding of Wheat Gliadin in Vitro to Reticulin in Normal and Dermatitis Herpetiformis Skin

We have demonstrated by indirect immunofluorescence that wheat gliadin binds in vitro to reticulin-like fibrils present in cryostat sections of human skin, and rat liver, kidney and stomach. Gliadin was seen to bind to fibrils throughout the dermis of both normal and dermatitis herpetiformis skin, and this was particularly striking in the dermal papillae. Serum from 2 dermatitis herpetiformis patients who did not have antireticulin antibody gave reticulin staining when retested by immunofluorescence on cryostat sections of rat tissue pretreated with gliadin. Gliadin treated sections may prove useful in screening patients with gluten sensitive enteropathy for anti-gliadin antibody. Binding of gliadin to skin sites in dermatitis herpetiformis patients and subsequent deposition of antigliadin antibody at these sites may be involved in the development of skin lesions.

The activation of antigens of the basement membrane zone by proteolytic enzymes in vitro

Following brief exposure of cryostat sections of human skin to the action of proteolytic enzymes (papain or trypsin), there was a pronounced increase in the antibody binding sites of the basement membrane zone, shown in indirect immunofluorescence by an increased intensity in fluorescence of the basement membrane zone as compared with preparations which had not previously undergone incubation, and by an increase of 5-6 (papain) or 4-5 (trypsin) titre dilution steps. This effect was practically absent when guinea-pig tongue was used as the antigenic substrate. In conjunction with findings published in the literature, our results can be interpreted as indicating that the activation of the basement membrane zone antigens by proteolytic enzymes is associated with an increase in antigenicity which results in the formation of "auto-antibodies" of the basement membrane zone antibody type.