Abstract: The present invention relates to a cell culture medium comprising (a) an inhibitor of bone morphogenetic protein-4 (BMP-4) and (b) an inhibitor of pigment epithelium-derived factor (PEDF, also known as SerpinF1). In one embodiment, the inhibitors are antibodies against BMP-4 and PEDF, respectively. The medium allows to culture keratinocytes under non-differentiating conditions. The invention also relates to corresponding methods and kits. As the media and methods disclosed allow for an improved manufacture of keratinocytes, the invention also relates to the treatment of skin wounds and to the manufacture of corresponding medicaments. This will be of advantage for treatment e.g. of burns, ulcers, etc., in which transplantation of keratinocytes or skin is required.

Abstract: The present invention relates to a cell culture medium comprising (a) an inhibitor of bone morphogenetic protein-4 (BMP-4) and (b) an inhibitor of pigment epithelium-derived factor (PEDF, also known as SerpinF1). In one embodiment, the inhibitors are antibodies against BMP-4 and PEDF, respectively. The medium allows to culture keratinocytes under non-differentiating conditions. The invention also relates to corresponding methods and kits. As the media and methods disclosed allow for an improved manufacture of keratinocytes, the invention also relates to the treatment of skin wounds and to the manufacture of corresponding medicaments. This will be of advantage for treatment e.g. of burns, ulcers, etc., in which transplantation of keratinocytes or skin is required.

Abstract: Disclosed is a method for cultivating keratinocytes and increasing the yield of proliferating keratinocytes by using fibroblasts the JNK activity of which is eliminated or decreased, the use of said fibroblasts and keratinocytes in wound healing and a method for the identification of a JNK-regulated secretable factor.

Abstract: The invention relates to genetically modified fibroblast cells which comprise the following properties: (a) a gene, encoding a subunit of the transcription factor AP-1, of its genome is inactivated and/or a component, acting on the AP-1 transcription factor of the signal transduction pathway is modified resulting in a modified AP-1 activity; (b) functionally linked with a promoter, it contains in an expression vector the gene from (a) in a form such that the active subunit is only expressed after induction of the promoter or the subunit encoded by the gene is present in inactive form and a form that can be activated.

Abstract: The invention relates to genetically modified fibroblast cells which comprise the following properties: (a) a gene, encoding a subunit of the transcription factor AP-1, of its genome is inactivated and/or a component, acting on the AP-1 transcription factor of the signal transduction pathway is modified resulting in a modified AP-1 activity; (b) functionally linked with a promoter, it contains in an expression vector the gene from (a) in a form such that the active subunit is only expressed after induction of the promoter or the subunit encoded by the gene is present in inactive form and a form that can be activated.