In Vitro Reconstitution of Skin: Fibroblasts Facilitate Keratinocyte Growth and Differentiation on Acellular Reticular Dermis

Extensive full-thickness burns require replacement of both epidemis and dermis. We have described a method in which allogeneic dermis from engrafted cryopreserved cadaver skin was combined with cultured autologous keratinocytes. In the present study we combined human keratinocytes and fibroblasts, and acellular human dermis in vitro and transplanted this “reconstituted skin” into athymic mice. Both human papillary dermis in which the basement membrane zone has been retained and human reticular dermis that has been repopulated with human dermal fibroblasts are good substrates for keratinocyte attachment, stratification, growth, and differentiation. Both of these dermal preparations can be lyophilized and stored at room temperature without losing their ability to support keratinocyte growth. In contrast, human papillary dermis that has been treated with trypsin lacks laminin and collagen type IV in the BMZ and supports keratinocyte attachment and differentiation less well

Basic fibroblast growth factor from human keratinocytes is a natural mitogen for melanocytes.

To survive and proliferate in pure culture, human melanocytes require basic fibroblast growth factor (bFGF) and cAMP. Without these factors, even in the presence of serum, the cells die. Melanocytes cultured in the presence of keratinocytes, however, survive for weeks without added bFGF and cAMP. We show here that the growth factor for melanocytes produced by human keratinocytes is bFGF because its activity can be abolished by neutralizing antibodies to bFGF and by a bFGF synthetic peptide that inhibits the binding of the growth factor to its receptor. The melanocyte mitogen in keratinocytes is cell associated and increases after irradiation with ultraviolet B. Northern blots reveal bFGF gene transcripts in keratinocytes but not melanocytes. These studies demonstrate that bFGF elaborated by keratinocytes in vitro sustains melanocyte growth and survival, and they suggest that keratinocyte-derived bFGF is the natural growth factor for normal human melanocytes in vivo

Basic fibroblast growth factor from human keratinocytes is a natural mitogen for melanocytes

Abstract. To survive and proliferate in pure culture, human melanocytes require basic fibroblast growth factor (bFGF) and cAMP. Without these factors, even in the presence of serum, the cells die. Melanocytes cultured in the presence of keratinocytes, however, survive for weeks without added bFGF and cAMP. We show here that the growth factor for melanocytes produced by human keratinocytes is bFGF because its activity can be abolished by neutralizing antibodies to bFGF and by a bFGF synthetic peptide that inhibits PIDERMAL melanocytes survive and may even proliferate for several weeks when cultured in the presence of keratinocytes (Prunieras et al., 1964). In contrast, melanocytes die within a week when cultured alone in routine media (Halaban, 1988) or medium optimal for keratinocyt