2. Production of functionally optimized, autologous skin generates through hair fol-licle induction in vitro
Funding code: 0311583AA project funded by the BMBF (Federal Ministry of Education and Research) regarding the development of an in vitro 3D model for the analysis of processes in the skin pertaining to the development of the hair.Projektpartner:
Klinik für Dermatologie, Universitätsklinikum Hamburg
Biotissue AG Freiburg (until
GenExpress GmbH (starting 01.01.2004)
One year before the end of the funding phase of the project GenExpress filled in as industrial partner. The objective was the investigation of the encapsulated and variously stimulated cells produced by Prof. Paus with regard to their gene expression profile. This was supposed to be performed with a cDNA chip specially aimed at keratiocytes.Fig.1 Photographic illustration of the encapsulated co-cultures
(A) and immunohistological staining on the marker of the mesenchymal connective tissue Fibronectin (D). Illustrations provided courtesy of Prof. Paus.
To this end, already isolated and sequenced human gene fragments were used for the generation of tissue-specific DNA chips and supplemented with keratinocyte-specific genes.
The DNA chip designed by GenExpress allowed the execution of extensive genomewide gene expression analyses of the encapsulated co-cultures of keratinocytes and mesenchymal cells of the hair root papilla produced by the team of Prof. Paus.Fig. 2 Evaluation of a DNA chip experiment.
Changing the marking of the cDNA from unstimulated and stimulated cells (colourswap) allows very good control of the experimental conditions. Each dot on the illustration corresponds to the fluorescence intensity of a human gene after stimulation through melatonin. Only such genes were considered during analysis that showed a significant expression and presented a difference in expression behaviour of more than 3.5 times.
The result of the project demonstrated that the encapsulated co-culture acted entirely different than co-cultures under standard conditions in the culture dish. The image is much more similar to the tissue structure in vivo.
The gene expression measurements with the chip by GenExpress performed in the short time available could be confirmed through the application of genome-wide, commercially available chips and through real time PCR. They substantiate the immunohistological results.
In doing so, genes were identified that so far have not been known in the epidermalmesenchymal interactions of the skin. With that the project opens up a number of subsequent studies on a cellular as well as molecular level.