Organotypic Cocultures as Models to Study Cell-Cell and Cell-Matrix Interactions of Human Hair Follicle Cells

The study explored the interactions between different cell types in human hair follicles using organotypic cocultures to mimic in vivo conditions. It was found that human dermal fibroblasts (HDF) and hair papilla cells (HPC) significantly enhanced the proliferation of outer root sheath (ORS) cells, especially when cocultured in a two-chamber system. In these cocultures, ORS cells developed into stratified epithelia similar to the epidermis, with proper morphology and expression of differentiation markers. The presence of HDF or HPC was crucial for both proliferation and differentiation. However, hair-type differentiation was not achieved, indicating the potential involvement of other unknown components or matrix elements.