Regulation of β2-adrenergic receptor in keratinocytes; Glucocorticoids increase steady-state levels of receptor numbes and mRNA in FRSK cells

J19

520

CELL CYCLE PROGRESSION OF CULTURED HUMAN CYTES AFTER A SINGLE TREATMENT WITH PUVA

EPIDERMAL

SHIGERU KAWARA, HIDEAKI SAKAI and TAKAE HIRONE Deoartment of Dermatoloov. Kanazawa University Mebicine, Kanazawa "-.

KEPATINO-

School

BIOCHEMICALDEMONSTRATIONAND IMMUNOHISTOCHEMICAL LOCALIZATIONOF PROTEASOMES (HIGH MOLECULARWEIGHT PROTEASE) IN HUMAN SKIN YASUSHI SUGA, KENJI TAKAMORI AND HIDEOKI OGAWA Departmentof Dermatolozv.Juntendo Univ. School of Mehicine, Tokyo

of

To investigate the effect of PUVA on cell cycle progression cultured human epidermal keratinocytes exposed to PUVA 0.4 J/cm2 were examined by cell kinetic methods. The cell number in PUVA-treated cultures slightly increased for the first 48 h, thereafter it remained almost constant until 120 h. After the single treatment the G,+M fraction showed a slight decrease for the first 6 h, followed by a marked increase from 24 to 120 h. However, the population of M cells within the G,+M compartment was small from 12 to 120h. Also, the proportion of Ki-67 positive cells within the G,+ M compartment markedly decreased from 72 120 h. The results suggest that PUVA produces an accumulation of G, cells, many of which may be in quiescent st.ate(GxQ phase).

The biochemicalpropertiesand immunohistochemical localizationof proteasomes (High Molecular Weight Pu~tease) of human skin were investigated. Immunohistochemicalstaining of normal human skin showed that proteasomeswere localized in the cytoplasm of the aidermis

to

in the dermis.

To clarify

the role

of

expression of proteasomes in the cytoplasm of the epidermis in PSO. However, the expression in malignant cells, such as SCC and Bowen's disease, greatly increased in the nuclei but not in the cytoplasm. These results indicate that the ezwression of oroceasomes in eoidermis is chaneeable in va;ious kinds bi-skin disease.'And they may be-related to cell division and differentiation.

522

521 MOLECULAR

HUMAN

but not

proteasomesin human skin, we compared their expressionin psoriasis vulgaris (PSO), squamous cell carcinoma (SCC), Bowen's disease and basal cell epitherioma(BCE). Immunohistochemical staining showed considerably increased

CLONING

EPIDERMAL

AND EXPRESSION TRANSGLUTAMINASE

OF

THE

GENE

FOR

THE

EFFECTS

RERATINOCYTE

KIYOFUMI YAMANISHI. FOO MIN LIEW. KEISUKE KONISHI. HIROKAZU YASUNO, lHIROSHI DOI, lJIRO HIRANO AND 'SHOJI FUKUSHIMA Department of Dermatology, Kyoto Prefectural University of Medicine, Kyoto. and 'Advanced Skin Research Institute, Yokohama.

OF

EXFOLIATIVE

TREATED

WITH

TOXIN

A ON THE

CYTOCHALASIN

MOUSE EPIDERMRL

D

SHO7.O F"TAM"P.A, YUKI TAKAGI AND YRSUO ASADA Department of Dermatlogy, Kansai Medical university moriguchi, Osaka We have already reported that cytochalasin (CD) treatment obstructed cell-cell detachment induced by pemphigus antibody (PF-Rb). investigate the effect of CD on exfoliative toxin A (ET-R) induced acantholysis in mouse keratinocyte (MK). Cytoskeletal and desmosomal components were studied by immunofluorescene on MK incubated with ET-A before and after treatment of CD. As a result, obv~o"s differences could not be detected the desmosomal and cvtoskeletal formation on the cell-cell However, celldetachment induced by ET-A and that by PF-Ab. cell detachment was observed on the several keratinocyte incubated with ET-A after treatment of CD. These results indicate that mechanism of cell-cell detachment induced by ET-A and/or PF-Al2 may be different.

me presentstudy 25madea plan to

We have cloned a cDNA encoding human epidermal transglutaminase (HETG), a enzyme of key keratinization. A cDNA library from cultured human keratinocytes was screened by a PCR-amplified partial cDNA fragment of the enzyme with oligonucleotide primers based on the homology of the The cDNA of HETG is transglutaminase (TG) family. 2734 bp coding a protein of 817 amino acids. The active site cystein residues are highly conserved among the TG family, but the N-terminal region is unique to the HETG. Using the cDNA as a probe, we will also present the expression the HETG gene in various conditions of cultured keratinocytes.

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524

REGULATION OF& -ADRENERGIC RECEPTOR IN XERATINOCYTES; GLUCOCORTICOIDS INCREASE STEADY-STATE LEVELS OF RECEPTOR NUMBES AND mP.iiAIN FRSK CELLS

DEMONSTRATION OF ANIONIC SITES IN NORMAL AND PSORIATIC EPIDERMIS WITH POLY-L-LYSINE-GOLD COMPLEX.

HIDETOSHI TAKAHASHI AND HAJIME IIZUKA Department of Dermatology, Asahikawa Medical College, Asahikawa

KENJI SAGA, AND MAKOTO TAKAHASHI Department of Dermatology, Sapporo Medical College, Sapporo

Glucocorticoids increase the beta-adrenergic adenvlate cvclase reap~nse of epidermal keratinocyte;. Using a cultured cell line of fetal rat keratinocvte (FRSK cells), we investisated the regulatory mechanism of the beta-adrenergic augmentation effect. Dexamethasone treatment (lKlO+M) increased 1.5-fold the6-adrenergic adenylate cyclase response. The’ increase in the@ adrenersic receptor (BAR) number and BAR mRNA was observed by receptor binding assay and by nothern blot analysis. Our results indicate that glucocorticoids regulate thea-adrenergic adenylate cyclase response of FRSK cells through the enhanced expression of the receptor.

It is becoming evident that the surface charge of a cell is important for cellular function. The presence and the distribution of anionic sites were studied in normal and psoriaticepidermiswith poly-L-lyslne-goldcomplex (cationic rolloidalgold). Lowicryl K4M embedded sections were incubated on droplets of the cationic colloidal gold and observed with a transmissionelectron microscope. In normal epidermis,anionic sites were distributedon the ceil membraneof keratinocytesin the basal and lower spinous layer. Horny layer, granular layer, and upper spinous layer did not show any reactivity. In psoriaticepidermis,anionic sitrswere distributedin the upper epidermisas well as in the lower

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epidermis.