Dollee Porter and Will Hendren

Chromosome and the Affected Gene

The AR gene provides instructions for making a protein called an androgen receptor. Androgen receptors allow the body to respond appropriately to dihydrotestosterone and other androgens. Studies suggest that variations in the AR gene lead to increased activity of androgen receptors in hair follicles.

Disease bascis

-Causes: Hair loss in alopecia areata occurs when cells from the immune system surround and attack the base of the hair follicle, causing the hair to fall out and enter a dormant state.

-Symptoms: The main symptom is hair loss, but anxiety, itching, and small dents in nails are also common symptoms.

-Cell Signaling Pathway Involved: That study suggested that a “danger signal” in the hair follicles of the patients attracts the immune cells to the follicle and sparks the attack. A specific set of T cells responsible for attacking the hair follicles.T cells are instructed to attack and identified several key immune pathways.

-Correct Mechanism Involved: The hair follicles function normally allowing the T cells to not interact unless it is needed.

-Incorrect Mechanism: The hair follicles send danger signals when there is really no threat to the follicles and then that engages the T cells to attack.

How the Disease Affects You

Current Direction of Research

Two FDA-approved JAK inhibitors tested separately by the researchers—ruxolitinib and tofacitinib—were able to block these immune pathways and stop the attack on the hair follicles. In mice with extensive hair loss from the disease, both drugs completely restored the animals’ hair within 12 weeks. Each drug’s effect was also long-lasting, as the new hair persisted for several months after stopping treatment.

Picture on right: Hair follicle (blue) being attacked by T cells (green)