tretinoin and Epidermolysis-Bullosa

Basal layers of stratified epithelia express keratins K5, K14, and K15, which assemble into intermediate filament networks. Mutations in K5 or K14 genes cause epidermolysis bullosa simplex (EBS), a disorder with blistering in the basal layer due to cell fragility. Nonkeratinizing stratified epithelia, e.g., in the esophagus, produce more keratin K15 than epidermis, which alleviates the esophageal symptoms in patients with K14 mutations. Hypothesizing that increasing the cellular content of K15 could compensate for the mutant K14 and thus ease skin blistering in K14 EBS patients, we cloned the promoter of the K15 gene and examined its transcriptional regulation. Using cotransfection, gel mobility shifts, and DNase I footprinting, we have identified the regulators of K15 promoter activity and their binding sites. We focused on those that can be manipulated with extracellular agents, transcription factors C/EBP, AP-1, and NF-kappaB, nuclear receptors for thyroid hormone, retinoic acid, and glucocorticoids, and the cytokine gamma interferon (IFN-gamma). We found that C/EBP-beta and AP-1 induced, while retinoic acid, glucocorticoid receptors, and NF-kappaB suppressed, the K15 promoter, along with other keratin gene promoters. However, the thyroid hormone and IFN-gamma uniquely and potently activated the K15 promoter. Using these agents, we could boost the amounts of K15 in human epidermis. Our findings suggest that treatments based on thyroid hormone and IFN-gamma could become effective agents in therapy for patients with EBS.

Topics: Animals; Base Sequence; Cells, Cultured; Epidermal Cells; Epidermis; Epidermolysis Bullosa; Gene Expression Regulation; Glucocorticoids; Humans; Interferon-gamma; Keratin-14; Keratin-15; Keratins; Molecular Sequence Data; Promoter Regions, Genetic; Receptors, Glucocorticoid; Receptors, Retinoic Acid; Receptors, Thyroid Hormone; Thyroid Hormones; Transcription Factors; Transcription, Genetic; Tretinoin

Topics: Epidermolysis Bullosa; Female; Humans; Isotretinoin; Middle Aged; Tretinoin

Human skin fibroblast cultures have been employed to study the effects of a variety of vitamin A analogues (retinoids) on the expression of two enzymes involved in collagen degradation in the skin, collagenase and a gelatinolytic protease. In normal and recessive dystrophic epidermolysis bullosa fibroblast cultures, retinoic acid compounds were effective inhibitors of the accumulation of both enzymes in the culture medium with half-maximal inhibitions occurring at 0.25-1 microM for collagenase and at 3-6 microM for the gelatinolytic protease. Various retinoids exhibited differing degrees of inhibitory actions, so that at a 1 microM concentration, relative inhibitions were: 13-cis-retinoic acid greater than all-trans-retinoic acid greater than aromatic retinoid (Ro 10-9359) much greater than retinol. The retinoic acid-mediated decrease in collagenase activity was accompanied by a parallel decrease in immunoreactive collagenase protein, suggesting that the retinoic acids were acting to inhibit synthesis of the enzyme. However, an additional effect of these agents was encountered. Although the retinoids themselves had no direct collagenase inhibitory action, medium derived from cultures maintained in these retinoids showed direct inhibitory capacity which was dependent both on the concentration of retinoic acid and on the length of time in culture. The results suggest that the retinoic acids modulate collagenase in vitro by two mechanisms: by decreasing the synthesis of enzyme protein and by modulating the expression of an inhibitory molecule.

Topics: Cells, Cultured; Epidermolysis Bullosa; Etretinate; Fibroblasts; Gelatinases; Humans; Microbial Collagenase; Pepsin A; Skin; Tretinoin

The effects of a variety of retinoids on collagenase and gelatinase expression have been examined in skin fibroblast cultures derived from normal volunteers and from patients with the hereditary blistering disorder, recessive dystrophic epidermolysis bullosa. Both 13-cis- and all-trans-retinoic acid were effective inhibitors of collagenase production in both cell types. In the case of collagenase, the inhibition of collagenase activity was paralleled by a reduction in immunoreactive enzyme protein, suggesting that these retinoids act by inhibiting synthesis and/or secretion of the enzyme. Retinoic acid also inhibited production of the second enzyme in the collagen degradative pathway, gelatinase. In this case, the decrease in gelatinase activity was equal to or slightly greater than the achieved in collagenase expression. The observation that certain retinoids modulate the two crucial enzymes in the degradation of collagen in the skin suggests that they might be useful therapeutic agents in recessive dystrophic epidermolysis bullosa, a disease in which the pathogenesis of blistering is in part related to connective tissue destruction.

Topics: Cells, Cultured; Epidermolysis Bullosa; Fibroblasts; Gelatinases; Humans; Isomerism; Isotretinoin; Microbial Collagenase; Pepsin A; Skin; Tretinoin; Vitamin A

Topics: Cells, Cultured; Dose-Response Relationship, Drug; Epidermolysis Bullosa; Genes, Recessive; Glucocorticoids; Humans; Microbial Collagenase; Phenytoin; Tretinoin

Topics: Adolescent; Aged; Anti-Bacterial Agents; Child; Cryosurgery; Darier Disease; Elastic Tissue; Epidermolysis Bullosa; Female; Humans; Impetigo; Larva Migrans; Lichen Planus; Male; Middle Aged; Papilloma; Pemphigus; Skin Diseases; Tongue Neoplasms; Tretinoin