Inhibitory Factors and Androgenetic Alopecia

Hair loss researchMale pattern baldness (androgenetic alopecia) is a prevalent problem in which the larger hairs on the scalp are replaced by smaller hairs. The hair loss conforms to specific patterns. Ultimately, only very small vellus hairs are left.

People react differently to losing hair: some are indifferent, but many are concerned about their appearance. Current treatments include medications, cosmetic approaches and hair transplants. Pure research is conducted to discover new treatments for male pattern balding.

Androgens (hormones) are behind these changes in the hair. Alterations within the dermal papilla play a large role in the changing of the size of the hair. Culturing dermal papilla cells is a helpful way to research this.

A study published in the British Journal of Dermatology compared dermal papilla cells from balding follicles to cells from bigger, healthy follicles. Cultured dermal papilla cells from balding follicles were studied to see if they secreted different types and quantities of mitogenic factors. The scientists also introduced human cells to into the skin of mice, to find out if the rodent cells recognized mitogenic signals from human cells; this also helped discover if factors from balding dermal papilla cells could change the start of a new mouse hair cycle.

The research found that healthy, regular cells from the scalp produced soluble factors that stimulated hair growth. This showed that, across species, the cells respond to mitogenic signals. Balding cells stimulated a very small amount of growth, and these balding cells also secreted inhibitory factors.  When injected into mice, balding cell media also inhibited new hair growth.

This study concluded that inhibitory factors are secreted by human balding dermal papilla cells, which affects the growth of dermal papilla cells and factors in both people and mice. These secretions also delay hair growth in living mice. Smaller dermal papillae and smaller hairs in male pattern baldness are probably caused by these inhibitory factors. New treatments for male pattern approaches could be developed based on this research.

Source: “Inhibitory autocrine factors produced by the mesenchyme-derived hair follicle dermal papilla may be a key to male pattern baldness” by K. Hamada and V.A. Randall in British Journal of Dermatology 2006 154, pp609–618.