• What is hair cloning by cell culture
• What is hair cloning by cell culture references

What is hair cloning by cell culture

At the top is an isolated human dermal papilla. Below, the dermal papilla has been placed in culture medium and dermal papilla cells are beginning to grow out

Dermal papilla cells are the driving force behind each hair follicle. These cells sit as a little ball at the root of a follicle and send out chemical signals that control cell growth in the rest of the follicle. It has been known since the late 1960s that these cells could be isolated and transplanted into skin with no hair follicles and the dermal papilla cells would promote the formation of a brand new hair follicle.

In the mid 1980s it was shown that dermal papilla cells could be isolated and grown in culture, to make more of them, and then implanted into the skin to make new hair follicles. By culturing the cells, dermal papilla from just a few donor hair follicles could be grown into enough cells for implantation to induce many new follicles - hair cloning.

More recently in 1999, researchers, led by Colin Jahoda at Durham University in Britain, took cells at the bottom of hair follicles from Jahoda's own scalp and from a colleague's. These cells from the dermal papilla were then transplanted into the forearm of Jahoda's wife, Amanda Reynolds. Within five weeks, the transplanted tissue - no bigger than the head of a pin - made a total of five fully grown hairs in Amanda's arm. This simple experiment shows the potential of being able to induce new hair follicles in human skin.

Even more interesting from the scientific point of view is that the hair follicles were made in a woman using cells derived from a man. Normally the foreign cells would be rejected by the recipient. But the scientists suspect the cells taken from the base of follicle may have some type of immune privilege which allows them to mix with foreign cells. So instead of being rejected by the woman's immune system, the male cells interacted with her cells to create new follicles. So it may be possible to use dermal papilla cells from one human source to induce hair follicles in another individual without the cells being rejected as foreign.

The new work suggests the possibility of a quick hair cloning procedure with the creation of new hair in just about anyone. The cells could be removed from a person's own scalp or, if that person cannot produce good quality cells, they could be collected from someone else. They could then be multiplied through laboratory culture before being transplanted.

It is not yet clear whether such newly grown hair will last, grow at the correct angle, or satisfy other requirements for a cosmetically acceptable treatment. The microsurgery used in the experiment is complex, time consuming, and expensive right now. However, it could potentially be developed into a relatively simple procedure. The greatest problem facing developers will be to work out how to get the new hairs to all grow at an appropriate angle to line up with the natural hair follicles on our scalps. To do this will require that we understand much more about the gene expression involved in the induction of new hair follicles and what genes tell the hair to grow in a certain direction.

There is also the possibility that injecting cells that can induce new hair follicles might also induce tumor development and skin cancer in a few people. Such concerns will have to be addressed before the treatment method becomes available to the general public.

What is hair cloning by cell culture

• Reynolds AJ, Lawrence C, Cserhalmi-Friedman PB, Christiano AM, Jahoda CA. Trans-gender induction of hair follicles. Nature. 1999 Nov 4;402(6757):33-4.
• Jahoda CA, Horne KA, Oliver RF. Induction of hair growth by implantation of cultured dermal papilla cells. Nature. 1984 Oct 11-17;311(5986):560-2.
• Jahoda CA, Reynolds AJ, Oliver RF. Induction of hair growth in ear wounds by cultured dermal papilla cells. J Invest Dermatol. 1993 Oct;101(4):584-90.
• Horne KA, Jahoda CA, Oliver RF. Whisker growth induced by implantation of cultured vibrissa dermal papilla cells in the adult rat. J Embryol Exp Morphol. 1986 Sep;97:111-24.
• Reynolds AJ, Jahoda CA.Hair follicle stem cells? A distinct germinative epidermal cell population is activated in vitro by the presence of hair dermal papilla cells. J Cell Sci. 1991 Jun;99 ( Pt 2):373-85.