P-02   THE USE OF LASER CAPTURE MICRODISSECTION TECHNOLOGY FOR THE EXAMINATION OF GENE EXPRESSION IN HUMAN HAIR FOLLICLES

S. Blümel, D. Ewald, S. Fritz, N. Max, M. Otte, A. Goppelt SWITCH Biotech AG, Floriansbogen 2-4, 82061 Neuried, Germany.

Currently there is only limited information available concerning genes responsible for hair growth control under physiological and/or pathological conditions. A better understanding of molecular targets in hair biology should lead to the development of more specific and more effective drug candidates. The analysis of gene expression for indications with a polygenic basis e.g. androgenetic alopecia is a novel approach to understand the regulation of the hair cycle and the miniaturisation process of the hair follicle. We established a technology to study the differential gene expression with very limited biopsy material (300-1000 cells) derived from the human scalp. Laser capture microdissection allowed the isolation of dermal papilla cells of anagen and telogen hair follicles in selected human biopsies. The mRNA was amplified and used for hybridisations on filters representing approximately 9000 human genes. Generally, we observed a shut-down of most genes in telogen phase resulting in a lower transcriptional level compared to anagen hair follicles. A minor fraction of the analysed genes appeared to be induced in telogen. In parallel, we analysed differential gene expression in the anagen and telogen phase with mRNA derived from human trichogram material of individual hair follicles. A wide overlap was detected between the screening results of the trichogram and LCM material. Differences might be due to preparation, especially because trichogram material is usually devoid of dermal papilla cells. Selected targets from the primary screens have been verified by real time RT-PCR and immunohistochemistry demonstrating the validity of the screening approach. The laser capture microdissection technology represents a significant improvement of the sensitivity and selectivity of screens. It is especially useful in in vivo studies of hair disorders or the analysis of current treatments (e.g. minoxidil, finasteride), because the genuine transcriptome might be altered when hair follicles are cultured in vitro.