The glutamine synthetase (GS) from Klebsiella aerogenes is similar to that Escherichia coli in several respects: (i) it repressed by high levels of ammonia the growth medium; (ii) its biosynthetic activity greatly reduced adenylylation; and (iii) adenylylation lowers pH optimum alters response enzymes various inhibitors gamma-glutamyl transferase (gammaGT) assay. There are, however, important differences: isoactivity point for adenylylated non-adenylylated forms gammaGT assay occurs at 7.55...

Identification of tumor necrosis factor-α (TNFα) as the key agent in inflammatory disorders, e.g. rheumatoid arthritis, Crohn's disease, and psoriasis, led to TNFα-targeting therapies, which, although avoiding many side-effects previous drugs, nonetheless causes other side-effects, including secondary infections cancer. By controlling gene expression, TNFα orchestrates cutaneous responses environmental damage inflammation. To define action epidermis, we compared transcriptional profiles...

Epidermal injury results in activation of keratinocytes which produce and respond to growth factors cytokines become migratory. Activated express a specific pair keratin proteins, K6 K16, distinct from the keratins healthy epidermis. Keratinocytes can be activated, for example, by binding appropriate ligands epidermal factor receptor (EGFR). We have analyzed effects EGFR on gene transcription transfecting DNAs containing promoters linked reporter into primary cultures human presence or...

Glucocorticoids (GCs) have a long history of use as therapeutic agents for numerous skin diseases. Surprisingly, their specific molecular effects are largely unknown. To characterize GC action in epidermis, we compared the transcriptional profiles primary human keratinocytes untreated and treated with dexamethasone (DEX) 1, 4, 24, 48, 72 h using large scale microarray analyses. The majority genes were found to be regulated only after 24 remained throughout treatment. In addition regulation...

Transforming growth factor β (TGFβ) is important in inflammation, angiogenesis, reepithelialization and connective tissue regeneration during wound healing. We analyzed components of TGFβ signaling pathway biopsies from 10 patients with nonhealing venous ulcers (VUs). Using comparative genomics transcriptional profiles VUs TGFβ-treated keratinocytes, we found deregulation target genes VUs. quantitative polymerase chain reaction (qPCR) immunohistochemical analysis, suppression TGFβRI, TGFβRII...

Chronic nonhealing venous leg ulcers (VLUs) are widespread and debilitating, with high morbidity associated costs; about $15 billion is spent annually on the care of VLUs in United States. Despite this, there a paucity treatments for because lack pathophysiologic insight into ulcer development as well knowledge regarding biologic actions existing VLU-targeted therapies. The bioengineered bilayered living cellular construct (BLCC) skin substitute U.S. Food Drug Administration-approved...

The epidermis, our first line of defense from ultraviolet (UV) light, bears the majority photodamage, which results in skin thinning, wrinkling, keratosis, and malignancy. Hypothesizing that has specific mechanisms to protect itself organism UV damage, we used DNA arrays follow UV-caused gene expression changes epidermal keratinocytes. Of 6,800 genes examined, regulates at least 198. Three waves can be distinguished, 0.5-2, 4-8, 16-24 h after illumination. contains transcription factors,...

Abstract Interleukin‐1 is a proinflammatory and immunomodulatory cytokine that plays crucial role in inflammatory diseases of the skin, including bacterial infections, bullous diseases, UV damage, especially psoriasis. To characterize molecular effects IL‐1 epidermis, we defined transcriptional changes human epidermal keratinocytes 1, 4, 24, 48 h after treatment with IL‐1α. significantly regulated 388 genes, genes associated proteolysis, adhesion, signal transduction, proliferation,...

Abstract Retinoids (RA) have been used as therapeutic agents for numerous skin diseases, from psoriasis to acne and wrinkles. While RA is known inhibit keratinocyte differentiation, the molecular effects of in epidermis not comprehensively defined. To identify transcriptional targets primary human epidermal keratinocytes, we compared profiles cells grown presence or absence all‐trans retinoic acid 1, 4, 24, 48, 72 h, using large DNA microarrays. As expected, suppresses protein markers...

In the epidermis, retinoids regulate expression of keratins, intermediate filament proteins epithelial cells. We have cloned 5' regulatory regions four human epidermal keratin genes, K#5, K#6, K#10, and K#14, engineered constructs in which these drive CAT reporter gene. By co-transfecting into cells along with vectors expressing nuclear receptors for retinoic acid (RA) thyroid hormone, we demonstrated that can suppress promoters genes. The suppression is ligand dependent; it evident both...

Glucocorticoids (GCs), important regulators of epidermal growth, differentiation, and homeostasis, are used extensively in the treatment skin diseases.Using keratin gene expression as a paradigm physiology pathology, we have developed model system to study molecular mechanism GCs action skin.Here describe novel suppression transcription by glucocorticoid receptor (GR) that represents an example customizing device for transcriptional regulation target specific group genes within tissue, our...

Epidermal keratinocytes respond to injury by becoming activated, <i>i.e.</i> hyperproliferative, migratory, and proinflammatory. These processes are regulated growth factors cytokines. One of the markers activated is keratin K6. We used a novel organ culture system show that tumor necrosis factor α (TNFα) induces expression K6 protein mRNA in human skin. Multiple isoforms encoded distinct genes have patterns expression. By having shown previously proliferative signals, such as epidermal...

In inflamed tissue, normal signal transduction pathways are altered by extracellular signals. For example, the JNK pathway is activated in psoriatic skin, which makes it an attractive target for treatment. To define comprehensively JNK-regulated genes human epidermal keratinocytes, we compared transcriptional profiles of control and inhibitor-treated using DNA microarrays. We identified differentially expressed 1, 4, 24, 48 h after treatment with SP600125. Surprisingly, inhibition...

Expression of keratin proteins, markers epidermal differentiation and pathology, is uniquely regulated by the nuclear receptors for retinoic acid (RAR) thyroid hormone (T3R) their ligands: it constitutively activated unliganded T3R, but suppressed ligand-occupied T3R or RAR. This regulation was studied using gel mobility shift assays with purified transient transfection vectors expressing various receptor mutants. Regulation gene expression RAR occurs through direct binding these to response...