ABSTRACT
Keratinocyte/leucocyte interactions have become an area of intense investigations in the last decade. However, few convenient in vitro models are available at present. We have therefore designed a novel in vitro system for autologous human keratinocyte/leucocyte co-culture. Non-invasive epidermal cell sampling was achieved by using outer root sheath cells from hair follicles. After one passage, pure keratinocyte cultures (no Langerhans cells or melanocytes) were obtained. Co-culture experiments were performed on a Transwell system: keratinocytes were grown on the porous cupula, and then laid on to wells containing leucocytes. Alternatively, leucocytes can be added to the cupula when contact interactions between the two cell types are to be investigated. Using this system, we demonstrated that Phaesolus vulgaris phytohaemagglutinin-activated T lymphocytes (with 10% monocytes) in the lower compartment induced intercellular adhesion molecule 1 (ICAM-1) and HLA-DR expression, and inhibited methyl-3H-thymidine incorporation in normal human autologous keratinocytes cultured on the cupula. These changes were mediated by soluble factors (no cell contacts between keratinocytes and leucocytes), and required lymphocyte activation. This is the first direct in vitro evidence for leucocyte-induced ICAM-1 and HLA-DR expression on keratinocytes. This system is a potential tool for the study of keratinocyte/leucocyte interactions.(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
Cell Communication/physiology , Keratinocytes/physiology , Leukocytes/physiology , Adult , Antigens, CD/metabolism , Antigens, Surface/metabolism , Cell Adhesion Molecules/metabolism , Cell Division/physiology , Cells, Cultured , HLA-DR Antigens/metabolism , Humans , Intercellular Adhesion Molecule-1 , Keratinocytes/immunology , Lymphocyte Activation/physiology , T-Lymphocytes/immunology , T-Lymphocytes/physiologyABSTRACT
The retinoids provide an important new way of treating dermatologic disorders. They have also proved to have a role in the prevention of new lesion formation. New retinoids, of which adapalene is one, have recently been synthesized in order to obtain similar or better efficacy while reducing skin irritation potential. These new molecules are currently under clinical investigation. Preliminary results are encouraging. In the near future, an expanded range of topical retinoids should be available.
Subject(s)
Retinoids/therapeutic use , Skin Diseases/drug therapy , Adapalene , Administration, Cutaneous , Animals , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Humans , Isotretinoin/therapeutic use , Mice , Models, Biological , Naphthalenes/therapeutic use , Psoriasis/drug therapy , Retinoids/chemistry , Retinoids/pharmacology , Skin Aging/drug effects , Tretinoin/therapeutic useABSTRACT
We have evaluated a subchronic model of contact hypersensitivity in the guinea pig to mimic human chronic/recurrent eczema. Repeated challenges of the ears of previously sensitized guinea pigs with 0.1% dinitrochlorobenzene (once a week for 4 weeks) induced a typical oedema response, which increased during the first 48 h after each challenge. Crusts were detectable (48 h after challenge) and histological observations (72 h after challenge) revealed hyperplasia, papillomatosis, hyperkeratosis and some mononuclear cell infiltrates in the dermis. In agreement with clinical observations in humans, topical treatment of challenged animals with corticosteroid (1% hydrocortisone) reduced the oedema, hyperplasia, papillomatosis, and leucocyte infiltrates, while application of 5% bufexamac (a non-steroidal drug) was associated with a slight enhancement of the inflammatory response. Thus, this model presents clinical and histological similarities with human eczema. Its pharmacological relevance is also suggested, although further investigations are required to better define its selectivity.
Subject(s)
Dermatitis, Contact/etiology , Dinitrochlorobenzene , Drug Hypersensitivity/etiology , Skin/drug effects , Animals , Dermatitis, Contact/pathology , Disease Models, Animal , Drug Hypersensitivity/pathology , Ear, External/drug effects , Female , Guinea Pigs , Skin/pathologyABSTRACT
The histological and ultrastructural effects following 3 weeks' topical treatment with two agents (all-trans retinoic acid and a new synthetic retinoid-like substance, CD271) were evaluated on the epidermis and the epithelial wall of the pseudocomedones in rhino mouse skin. The comedolytic effects of these drugs were similar, and consisted of a reduction of the utricular diameter, with normalization of follicular units. Morphological examinations revealed a hyperplastic response with an increase in the number of cell layers of both epidermis and follicular epithelium, and modifications in keratinocyte differentiation. Ultrastructural changes in the epidermis and epithelial wall were observed mainly in the granular and horny layers, with increased desquamation, and a decrease in the cohesiveness of corneocytes. During the first week of treatment, some cutaneous toxic effects were noticed, but they normalized within two weeks. On the other hand, a fine granular material persisted in the intercellular spaces. It is confirmed that the skin of the rhino mouse is a good model for the evaluation of the comedolytic effects of drugs. Moreover, it reveals the specific effects of retinoids on epidermal differentiation. We have demonstrated that topically applied CD271 induces modifications similar to those obtained with all-trans retinoic acid. It is thus concluded that CD271 is a potentially effective anti-acne agent.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Epidermis/ultrastructure , Naphthalenes/pharmacology , Tretinoin/pharmacology , Adapalene , Administration, Cutaneous , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Disease Models, Animal , Epidermis/drug effects , Female , Male , Mice , Mice, Hairless , Microscopy, Electron , Naphthalenes/administration & dosage , Tretinoin/administration & dosageABSTRACT
The rhino mouse has been used as an experimental model to screen topically active comedolytic agents. Adult rhino mice were treated on the back once daily for 5 consecutive days per week during 3 weeks. Skin histological preparations were analyzed by image analysis techniques to quantify the number of epidermal comedones, comedo profile and epidermal thickness. Using both a negative (treated with acetone) and a positive (treated with Aberel gel 0.025%) control group of animals in all experiments conducted over a period of about 3 years, we defined the upper and lower limit of acceptability of the results. Topical treatment with an acetone solution of all-trans retinoic acid (0.01, 0.03, 0.1%) and 13-cis-retinoic acid (0.1%) induced comedolysis and a marked increase in epidermal thickness. Commercial preparations of all-trans retinoic acid (Aberel lotion, gel and cream, Retin A cream, Retacnyl cream) presented a similar comedolytic activity. However, the epidermal thickening was higher with Retin A and weaker with Retacnyl. CD271, a new modulator of cell differentiation, applied either in acetone solution (0.01, 0.1%) or in lotion, gel or cream formulations (0.1%) also demonstrated a marked activity (i.e. comedolysis and epidermal thickening). These data confirm that the rhino mouse model can be used to assay drugs applied either in solvent or in topical formulations. Activity in this model compares favorably with published clinical observations in the treatment of acne.
Subject(s)
Epidermis/drug effects , Naphthalenes/pharmacology , Retinoids/pharmacology , Acne Vulgaris/drug therapy , Adapalene , Administration, Topical , Animals , Biopsy , Disease Models, Animal , Epidermis/pathology , Female , Image Processing, Computer-Assisted , Male , Mice , Mice, Hairless , Naphthalenes/administration & dosage , Naphthalenes/therapeutic use , Retinoids/administration & dosage , Retinoids/therapeutic useSubject(s)
Pharmacology/methods , Skin Diseases/drug therapy , Skin/drug effects , Animals , Disease Models, Animal , Humans , Models, BiologicalSubject(s)
Drug Hypersensitivity/prevention & control , Hypersensitivity, Delayed/prevention & control , Oxazoles/toxicity , Oxazolone/toxicity , Animals , Drug Hypersensitivity/physiopathology , Edema/chemically induced , Edema/prevention & control , Female , Hypersensitivity, Delayed/physiopathology , Kinetics , Mice , Mice, Inbred BALB C , Peroxidase/metabolismSubject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cell Differentiation/drug effects , Naphthalenes/pharmacology , Adapalene , Animals , Arachidonic Acid , Arachidonic Acids , Carrageenan , Chemotaxis, Leukocyte/drug effects , Croton Oil , Erythema/drug therapy , Guinea Pigs , Humans , Hydroxyeicosatetraenoic Acids/biosynthesis , In Vitro Techniques , Inflammation/chemically induced , Inflammation/drug therapy , Lipoxygenase/metabolism , Luminescent Measurements , Mice , Neutrophils/drug effects , Passive Cutaneous Anaphylaxis/drug effects , Rabbits , Rats , Ultraviolet RaysSubject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Arachidonic Acids , Edema/chemically induced , Animals , Arachidonic Acid , Cyclooxygenase Inhibitors , Dose-Response Relationship, Drug , Lipoxygenase Inhibitors , Male , Mice , Mice, Inbred C3H , Mice, Inbred Strains , Rats , Rats, Inbred Strains , Species SpecificityABSTRACT
Several biochemical parameters including ornithine decarboxylase activity (ODC) and tissue polyamine levels were measured during the hexadecane-induced epidermal hyperplasia of hairless rat skin. Animals received three applications of 200 microliters pure n-hexadecane on day 1. ODC activity and polyamine levels (putrescine, spermidine and spermine) in the epidermis were significantly increased and reached maximum elevations at 12 h after the start of n-hexadecane treatment with DNA synthesis peaking at 24 h. Histological studies confirmed a significant cellular edema at 24 h after the beginning of the treatment followed at 48 h by an epidermal hyperplasia which was maximum at 72 h. These data support the view that ODC activation, increased biosynthesis of polyamines and DNA are early events in epidermal cell hyperproliferation.
Subject(s)
Alkanes/toxicity , Biogenic Polyamines/biosynthesis , DNA/biosynthesis , Skin/pathology , Animals , Hyperplasia , Male , Ornithine Decarboxylase/metabolism , Rats , Skin/metabolism , Thymidine/metabolism , Time FactorsSubject(s)
Anthralin/pharmacology , Anti-Inflammatory Agents, Non-Steroidal , Sulfonamides , Animals , Anthralin/analogs & derivatives , Anthralin/toxicity , Chemotaxis, Leukocyte/drug effects , Dermatitis, Contact/etiology , Edema/prevention & control , Erythema/prevention & control , In Vitro Techniques , RabbitsABSTRACT
Inflammation and hyperplasia are frequently associated in skin diseases. In order to verify this relationship, we studied the antagonistic effect of different classes of antiinflammatory agents on the inflammatory and hyperplasiogenic responses elicited by one topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA) to the ear of the guinea-pig. Edema and DNA synthesis were chosen as relevant parameters. All antiinflammatory agents tested significantly inhibited DNA synthesis induced by TPA. Moreover, all compounds except quinacrine and phenylbutazone also inhibited edema formation. In conclusion, our results demonstrate that while edema and hyperplasia are frequently associated, this is not always the case.
Subject(s)
Anti-Inflammatory Agents/pharmacology , DNA/biosynthesis , Edema/drug therapy , Animals , Dermatitis, Contact/drug therapy , Dermatitis, Contact/metabolism , Dermatitis, Contact/pathology , Edema/chemically induced , Guinea Pigs , Hyperplasia , Male , Tetradecanoylphorbol AcetateABSTRACT
We use a mutant hairless Sprague Dawley rat to evaluate the capacity of retinoids to inhibit the epidermal ornithine decarboxylase activity induced by sellotape stripping. In order to minimize the variability introduced by the animals in our model we decided to validate the hairless rats used. A number of animal parameters were examined using a single lot of 50 males and 50 females aged from 4 to 11 weeks and acclimatized to laboratory conditions. The body weight growth curves were established. Nude animals present two periods of hair growth, the first at 6-7 weeks and the second at about 10-11 weeks. Hair development is more pronounced in males. No histological change was observed in the stratum corneum but an increase in epidermal thickness was noted in males aged 9 weeks. Removal of the stratum corneum by sellotape stripping was more effective and reproducible in the females, as determined histologically. Sellotape-stripping induction of ornithine decarboxylase in the epidermis was higher in rats aged 5-6 weeks and reached a plateau in animals aged 6-12 weeks. Individual variations obtained were lower in females (about 5%-10% in females and 10%-20% in males). The present research suggests that female rats aged about 8 weeks provide maximum reproducibility of response and ease of use.
Subject(s)
Epidermis/enzymology , Models, Biological , Ornithine Decarboxylase/biosynthesis , Rats, Inbred Strains/metabolism , Animals , Enzyme Induction , Epidermis/anatomy & histology , Female , Male , RatsABSTRACT
This is the first report of human gastrointestinal arachidonate and prostanoids measured quantitatively by gas chromatography-mass spectrometry (GC-MS) in extracts of human cancers and macroscopically normal tissues from the stomach and colon. There were microgram/g amounts of arachidonate, and the particularly high yield from the tumours may explain why they usually produce more prostaglandins than the normal tissues in which they arise. There was only a small conversion of the arachidonate into prostanoids. 6-Keto-PGF1 alpha was the most abundant metabolite measured, particularly in the tumour extracts, with smaller amounts of prostaglandins E2, F2 alpha and D2.
Subject(s)
Arachidonic Acids/metabolism , Gastrointestinal Neoplasms/analysis , Prostaglandins/analysis , Arachidonic Acid , Arachidonic Acids/analysis , Colon/analysis , Gas Chromatography-Mass Spectrometry , Humans , Stomach/analysisABSTRACT
Skin was studied by transmission electron microscopy after cryoultramicrotomy. Global and ultrastructural preservation of the tissue was obtained with satisfactory cohesion between dermis and epidermis. The main constitutive elements could be observed with good definition allowing easy recognition of all the organelles and therefore absolute identification of each cellular type encountered. The methodology provided a comparable quality to the conventional technique. Ice crystal artefacts were minimized but slight enlargement of intercellular spaces persisted. One of the main advantages of this procedure is that neither lipidic solvents nor embedding resins, are used, so that one can envisage cytochemical studies.
Subject(s)
Skin/ultrastructure , Animals , Epidermis/ultrastructure , Frozen Sections , Humans , Keratins/analysis , Microscopy, Electron/methods , Rats , Skin/cytology , Swine , Swine, MiniatureABSTRACT
In mouse skin, antiproliferative agents including retinoids inhibit induction of ornithine decarboxylase activity by a variety of hyperproliferative stimuli. In the hairless rat skin, ornithine decarboxylase activity was induced by ten successive strippings with cellotape and by topical application of 12-O-tetradecanoyl-phorbol-13-acetate. Topical application of all trans-retinoic acid (25 nmol/cm2) immediately after the tape stripping of the skin significantly inhibited the induction of ornithine decarboxylase activity at all time points measured. The inhibition by all trans-retinoic acid of ornithine decarboxylase induced by cellotape stripping was dose dependent as was found to be the case for arotinoid, retinol, Ro-10-1670, motretinid, 13-cis-retinoic acid, etretinate, and vitamin A. Oral administration of all trans-retinoic acid also inhibited the ornithine decarboxylase activity induced by cellotape stripping. We propose the assay of ornithine decarboxylase activity in the hairless rat epidermis after tape stripping for a rapid evaluation of new retinoids.