Keratinocytes

The CaR regulates numerous biological processes, including the expression of various genes (e.g., PTH) the secretion of hormones (PTH and calcitonin), cytokines (MCP-1), and calcium (e.g., into breast milk) the activities of channels (potassium channels) and transporters (aquaporin-2) cellular shape, motility (of macrophages), and migration cellular adhesion (of hematopoietic stem cells) and cellular proliferation (of colonocytes), differentiation (of keratinocytes), and apoptosis (of H-500 ley dig cancer cells) [3]. 

In the skin, ENaC is expressed in keratinocytes of the epidermis and in hair follicles. It could play a role in terminal differentiation by modulating keratinocyte calcium signaling. The skin expresses MR, GR, and 11 3HSD2, but the role of aldosterone and glucocorticoids on ENaC activity and keratinocyte differentiation is not yet understood. 

MMP-28 Epilysin Secreted Discovered in 2001, given its name due to have been discovered in human keratinocytes. Highly expressed in lung, placenta, salivary glands, heart, uterus, skin... 

Non-neuronal cells (including astrocytes, mechan-osensory hair cells, macrophages, keratinocytes, endothelial cells of the vascular system, muscle cells, lymphocytes, intestinal epithelial cells and various cell-types of the lungs)... 

Fig. 14 Effect of the molecular weight of tamarind seed xyloglucan depolymerized by ( ) 7-irradiation, ( ) ultrasonication, and ( ) endo-glucanase treatment on the production of various cytokines (Tumor necrosis factor a, TNE-a Interleukin 8, IL-8 Interleukin 10, IL-10 and Interleukin 12, IL-12) in HaCaT cells (Immortalized keratinocytes line) [301]...

Type I IFNs form a superfamily of innate cytokines that comprise IFN-a (alpha), with 13 human subtypes, IFN-p (beta), IFN-co (omega), IFN-x (tau), IFN-k (kappa), IFN-e (epsilon), IFN-A, (lambda), and IFN- (zeta) (Pestka et al. 2004). Only IFN-a, IFN-p, IFN-cd, IFN-k, and IFN-e are expressed in humans. All IFN-a subtypes are secreted by leukocytes, whereas IFN-p is also produced by fibroblasts. IFN-x is exclusively expressed in ruminants at a specific stage of pregnancy (Martal et al. 1998), whereas IFN-k is expressed by human keratinocytes (LaFleur et al. 2001). 

Kozlowski A, Charles SA, Harris JM (2001) Development of pegylated interferons for the treatment of chronic hepatitis C. BioDrugs 15 419 29 Krown SE, AeppU D, Balfour HH Jr (1999) Phase II, randomized, open-label, community-based trial to compare the safety and activity of combination therapy with recombinant interferon-alpha2b and zidovudine versus zidovudine alone in patients with asymptomatic to mildly symptomatic HIV infection. J Acquir Immune Defic Syndr Hum Retrovirol 20 245-254 LaFleur DW, NardeUi B, Tsareva T, Mather D, Feng P, Semenuk M, Taylor K, Buergin M, Chinchilla D, Roshke V, Chen G, Ruben SM, Pitha PM, Coleman TA, Moore PA (2001) Interferon-kappa, a novel type I interferon expressed in human keratinocytes. J Biol Chem 276 39765-39771... 

Salicylic acid has a keratolytic effect, thus eliminating superficial pigmented keratinocytes and stimulating cells turnover. This superficial peeling allows TCA to act a low concentration to remove pigmented keratinocytes through papillary dermis (see Fig. 14.12). 

Inhibition of the passage of melanosomes from melanocytes to keratinocytes... 

Basket weave or compact stratum corneum, acanthosis and/or atrophy, keratinocyte atypia, flattened rete ridges... 

Lawrence et al. [66] in a split face study, compared the efficacy and safety of Jessner s solution and 35% TCA with 5% fluorouracil in the treatment of widespread facial actinic keratoses. Fifteen patients were treated. Both treatments reduced the number of visible actinic keratoses by 75%. Similarly, both caused equivalent reductions in keratinocyte atypia, hyperkeratosis, and parakeratosis. Compared to fluorouracil, only one application of the peel was necessary. 

Bovine aorta smooth muscle cells Bovine aorta endothelial cells Porcine aorta endothelial cells Rat keratinocytes... 

Of all the epidermal cells studied in vitro with respect to antioxidant status, perhaps keratinocytes are the most important. These cells differentiate as they move upwards through the epidermis and there is evidence that, in... 

De Leo, V.A., Scheide, S., Meshulam, J., Hanson, D. and Cardulla, A. (1988). Ultraviolet radiation alters choline phospholipid metabolism in human keratinocytes. J. Invest. Dermatol. 91, 303-308. 

Epidermal growth factor suppresses nitric oxide and hydrogen peroxide production by keratinocytes. Potential role for nitric oxide in the regulation of wound healing. J. Biol. Chem. 267, 21277-21280. 

Punnonen, K., Puntala, A., Jansen, C.T. and Ahotupa, M. (1991a). UVB irradiation induces lipid peroxidation and reduces antioxidant enzyme activities in human keratinocytes in vitro. Acta Dermato-Venereol. 71,... 

Reiners, J.J. and Rupp, T. (1989). Conversion of xanthine dehydrogenase to xanthine oxidase occurs during keratinocyte differentiation modulation by 12-O-tetradecanoylphorbol-13-acetate. J. Invest. Dermatol. 93, 132—135. 

Reiners, J.J., Hale, M.A. and Cantu, A.R. (1988). Distribution of catalase and its modulation by 12-O-tetradecanoylphorbol-13-acetate in murine dermis and subpopulations of keratinocytes differing in their stages of differentiation. Carcinogenesis 9, 1259-1263. 

Worwood, M. (1990). Ferritin. Blood Rev. 4, 259-269. Yohn, J.J., Duncan, K.O., Loudon, E., Dormish, J., Repine, J.E. and Norris, D.A. (1992). Human keratinocyte catalase synthesis is decreased by simulated sunlight exposure (abstr). J. Invest. Dermatol. 98, 655A. 

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