Cultured keratinocytes

Chen, P. H. et al., Effects of arsenic and UVB on normal human cultured keratinocytes Impact on apoptosis and implication on photocarcinogenesis, Chem. Res. Toxicol., 18, 139, 2005. 

Peus, D., Vasa, R. A., Meves, A., Pott, M., Beyerle, A., SquiUace, K., and Pittelkow, M. R., 1998, H202 is an important mediator of UVB-induced EGF-ieceptor phosphorylation in cultured keratinocytes, J. Invest. Dermatol. 110 966-971. 

IL-23 has recently been shown to be produced by dendritic cells and by human cultured keratinocytes in healthy skin and in psoriasis - its role in atopic dermatitis has to be defined [22]. Interaction of keratinocytes with activated T cells via CD40-CD40L may enhance IL-23 production and subsequently the IFN-y production by memory T cells [23]. 

In Vitro Cell Culture Keratinocytes (KC) comprise some 95% of the cells in the... 

Finally, use of more complex models is in progress. For example, Lee et al. [77] studied the phototoxic impact of chemicals on reconstructed skin models that were prepared from cultured keratinocytes and melanocytes on de-epidermized dermis. 

Keywords Permacol Integra Skin substitute Dermal substitute Cultured keratinocytes Collagen. Animal model... 

The biomaterials tested exhibited successful integration, confirming results of previous studies, and the partial wound epithelialisation was achieved by day 21 where either split-thickness skin graft or cultured keratinocytes were applied over dermal substitute biomaterial (Figs. 25.2 and 25.3). 

Results of our experiments suggest that (1) dermal substitute biomaterials may contribute to the improved wound re-epithehalisation when combined with cultured autologous keratinocytes and (2) porcine collagen paste is able to support splitthickness skin graft survival as well as autologous cultured keratinocyte proliferation. 

Kangesu T, Navsaria HA, Manek S, Shurey CB, Jones CR, Fryer PR, Leigh IM, Green CJ (1993) A porcine model using skin graft chambers for studies on cultured keratinocytes. Br J... 

Hofland, H.E., et al. 1991. Interactions of non-ionic surfactant vesicles with cultured keratinocytes and human skin in vitro A survey of toxicological aspects and ultrastructural changes in stratum corneum. J Control Release 16 155. 

Ruse M, Broome AM, Eckert RL. 2003. S100A7 (psoriasin) interacts with epidermal fatty acid binding protein and localizes in focal adhesion-like structures in cultured keratinocytes. J Invest Dermatol 121(1) 132—141. 

G9. Golan, T. D., Elkon, K. B., Gharavi, A. E., and Krueger, J. G., Enhanced membrane binding of autoantibodies to cultured keratinocytes of systemic lupus erythematosus patients after ultraviolet B/ultraviolet A irradiation. J. Clin. Invest. 90, 1067-1076 (1992). 

Grangsjo, A. et al., X-ray microanalysis of cultured keratinocytes methodological aspects and effects of the irritant sodium lauryl sulphate on elemental composition, J. Microsc., 199, 208, 2000. 

In skin, calcium can provide signals for the cells, either extracellular or intracellular (in the cytosol). The extra- and intracellular signaling may be connected to each other, but may also act separately. In cultured keratinocytes, extracellular calcium levels influence growth and differentiation.9,10 Low extracellular calcium levels (<0.1 mM) induce the growth of keratinocytes as a monolayer with a high proliferation rate, rapidly becoming confluent. In this condition keratinocytes never stratify, but possess many of the characteristics of basal cells the cells synthesize keratin proteins and are connected by occasional gap junctions but not by desmosomes. High extracellular calcium levels (>1 mM) induce differentiation of keratinocytes. Keratinocytes rapidly flatten, form desmosomes, and differentiate with stratification. Moreover, cornified envelopes form in cells of the uppermost layers.9,10... 

Sharpe, G.R., Gillespie, J.I., and Greenwell, J.R., An increase in intracellular free calcium is an early event during differentiation of cultured keratinocytes, Fed. Eur. Biochem. Soc. Lett. 254, 25-28, 1989. 

Previous reports demonstrated that exposure to a dry environment made skin more sensitive pathologically.34,37-39 The signaling system of the epidermis against environmental changes has not been clarified yet. The cultured keratinocyte, however, an oscillation of intercellular calcium is induced by the air exposure (see Figure 10.3). 

FIGURE 10.3 Oscillation of intercellular calcium in the cultured keratinocyte immediately after air exposure. Vertical axis shows the ratio of emission 340 to 380 nm. 

Although glucosylceramides are the predominant epidermal glycosphingolipids,8 various classes of glycosphingolipids such as acylglucosylceramides and gangliosides have been identified in epidermis and cultured keratinocytes. 

Isolated keratinocytes subjected to cyclic strain exhibit a significant increase in cell proliferation, DNA synthesis, and protein synthesis compared to stationary or constantly loaded cells, which appear to involve changes in cyclic AMP. Takei et al. (1997) reported a strain-induced reduction in the levels of cyclic adenosine monophosphate, protein kinase A (PKA), and prostaglandin E2 (PGE2) as compared to stationary controls. Takei et al. (1997) also studied the effects of cyclic strain on protein kinase C (PKC) activation and translocation in cultured keratinocytes. 

Takei T, Han O, Ikeda M, Male P, Mills I, Sumpio BE. Cyclic strain stimulates isoform-specific PKC activation and translocation in cultured keratinocytes. J Cell Biochem. 1997a 67 327-337. 

Kangesu T, Manek S, Terenghi G, Gu X-H, Navsaria HA, Polak JM, et al. Nerve and blood vessel growth in response to grafted dermis and cultured keratinocytes. Plastic Reconstr Surg 1998 101 1029-1038. 

R. Martin, S. Bevan, J. Boorman, I. Grant, S. E. James, I. Jones, N. Parkhouse, R. Ng, P. Rubin, and B. Woodward, Cultured keratinocytes experimental and clinical directions in the quest for tissue engineered new skin, in Cultured Human Keratinocytes and Tissue Engineering Skin Substitutes (Pubs. Thieme Verlag, Stuttgart, 2001), pp. 107-116. 

Another study in this direction was performed by Qiatelet et al. [72]. They investigated the effect of DD on the biological properties of chitosan films by culturing keratinocytes and fibroblasts on chitosan films having different DDs. They found that DD has no significant effect on the in vitro cytocompatibility of chitosan films towards keratinocytes and fibroblasts. They demonstrated that the lower the DD of chitosan, the lower was the cell adhesion on the films, and found that keratinocyte proliferation increases when the DD of chitosan films increases. They concluded from their study that the DD plays a key role in cell adhesion and proliferation, but does not change the cytocompatibility of chitosan. 

Myers SR, Grady J, Soranzo C, Sanders R, Green C, Leigh IM, Navsaria HA. A hyaluronic acid membrane delivery system for cultured keratinocytes clinical take rates in the porcine kerato-dermal model. J Burn Care Rehabil 1997 18 214-222. 

Liu et al. (39) reported that the accumulation of VA in cultured keratinocytes caused perturbations in the contents of other fatty acids. Treatment with 20 Xg/mL VA for 24 h and 4 d resulted in reductions of 35 and 29% for LA, respectively. AA was reduced by 32% after 24 h, but no effect was observed after 4 d following treatment with 20 pg/mL VA. In the present study, however, increasing levels of TFA and CLA, did not lead to perturbations of LA and/or AA contents, respectively, in any PL class studied. 

Torma, H., Lontz, W., Liu, W, Rollman, O, and Vahlquist, A (1994) Expression of cytosolic retinoid-binding protein genes in human skin biopsies and cultured keratinocytes and fibroblasts Br. J Derm. 131,243-249. 

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