Epidermal hyaluronan

Pienimaki, J. et al. Epidermal growth factor activates hyaluronan synthase 2 in epidermal keratinocytes and increases pericellular and intracellular hyaluronan, J. Biol.Chem., 276, 20428, 2001. 

Hyaluronan is prominent in the very earliest stage of embryogenesis, in maintenance of the undifferentiated state, with its removal required prior to the onset of differentiation.85 The presence of HA inhibits the process of differentiation, permitting expansion of primordial cell masses. In organotypic cultures of rat keratinocytes, HA suppresses epidermal differentiation,86 must be removed before the program of differentiation can be initiated. 

Hyaluronan hinders the onset of differentiation, as discussed earlier. Retinoic acid retards the differentiation of epidermal keratinocytes, as shown in skin organ cultures, a result of the ability of retinoic acid to stimulate HA deposition.263-265 Retinoic acid leads to the accumulation of HA in the superficial layers of the epidermis by stimulating HA synthesis specifically in keratinocytes. Some of this accumulation occurs as expanded intercellular HA, which may account for the weakened cohesion of keratinocytes observed both in vivo and in vitro. 

Passi, A. et al., Hyaluronan suppresses epidermal differentiation in organotypic cultures of rat keratinocytes, Exp. Cell Res., 296, 123, 2004. 

Tammi, R. et al., Degradation of newly synthesized high molecular mass hyaluronan in the epidermal and dermal compartments of human skin in organ culture, J. Invest. Dermatol., 97, 126, 1991. 

Hollander DA, Soranzo C, Falk S, Windolf J. Extensive traumatic soft tissue loss reconstruction in severely injured patients using cultured hyaluronan-based three-dimensional dermal and epidermal autografts. J Trauma 2001 ... 

Pianigiani, E., Andressi, A., Taddenci, R (1999) A new model for studying differentiation and growth of epidermal cultures of hyaluronan-based carrier. Biomaterials, 20 (18), 1689-1694. 

Maytin, E.W., Chung, H.H., Seetharaman, V.M. (2004) Hyaluronan participates in the epidermal response to disruption of the permeability barrier in vivo. American Journal of Pathology, 165(4), 1331-1341. 

Tirone, E. D Alessandris, C. Hascall, V. C. Siracusa, G. Salustri, A. Hyaluronan synthesis by mouse cumulus cells is regulated by interactions between follicle-stimulating hormone (or epidermal growth factor) and a soluble oocyte factor (or transforming growth factor-pi). J. Biol. Chem. 1997,272, 4787-4794. 

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