According to study, researchers from at Indiana University School of Medicine, they showed a new method to grow hairy skin from mouse pluripotent stem cells. The discovery that could lead to new approaches to model disease and new therapies for the treatment of skin disorders and cancers. This study published in the journal Cell Reports

Dr. Koehler and his team's findings build on their past work creating a technique for growing inner ear cells from stem cells, in which mouse stem cells are cultured in a three-dimensional ball and treated with specific signaling molecules to coax the cells into producing inner ear tissue. The researchers noticed that skin was a byproduct of the inner ear growth process.

"In the developing embryo, the inner ear comes from the same layer of cells as the top layer of the skin, [the epidermis], so it was no surprise that skin and inner ear tissue formed in tandem," Dr. Koehler said. "We were surprised to find that the bottom layer of the skin [the dermis] also develops." In the current study, Dr. Koehler and his team show how the epidermis and dermis cells form a sphere-like cluster of cells, called a skin "organoid."

The cells in skin organoids are organized much like cells in normal skin, but inside-out, meaning the top layer of the skin faces the interior of the organoid. The team identified culture conditions that allowed skin organoids to precede through the stages of development much like skin in the embryo. The researchers confirmed that the timing of development and expression of key proteins closely match skin and hair development in the mouse embryo.

Dr. Koehler said he cautions that there are several technical hurdles that they have yet to overcome for the skin organoid model to reach its full potential as a drug discovery tool. For instance, the skin organoids are missing immune cells, blood vessels and nerve endings found in normal skin. "The shape of skin organoids is another problem that needs to be addressed in the future," he said.

"Because the organoids are inside-out compared to normal skin, the layers of dead cells and hairs cannot be shed as they are normally, so we need to find a way to flip the structure of skin organoids." Without these changes, the skin organoids have a shelf life of about a month, which is just long enough to study the complete development of mouse skin and hair.

Koehler and his team are currently using the mouse organoids as a template to derive hairy skin from human pluripotent stem cells. This work has the potential to lead to new skin grafting techniques incorporating hair follicles and therapies for human diseases, including alopecia, acne and skin cancers.