Of all the cytokines or growth factors that have been postulated to play a role in hair follicle, insulin-like growth factor- 1 (IGF-1) is known to be regulated by androgens. Dermal Papila cells from balding scalp follicles were found to secrete significantly less IGF-1, IGFBP-2 and IGFBP-4 (P < 0.05) than their non-balding counterparts. Our data confirmed that the downregulation of IGF-1 may be one of the important mechanisms contributing to male pattern baldness. Produced by mesenchymal Dermal Papila cells, inhibits apoptosis and promotes epithelial cell growth.
The expression of insulin-like growth factor (IGF)-1 in the dermal papilla is discussed to play an important role in the development of pattern balding. Older men with vertex balding showed higher plasma levels of IGF-1 and lower circulating levels of IGF binding protein 3. A decreased expression of IGF-1 was found in the balding scalp tissue. The gene locus for IGF-1 can be found on chromosome 12 (12q22-q23)
Theoretically, treatments that can stimulate the secretion of IGF-1 may slow hair loss. IGF-1 has also been shown to be upregulated in DP cells of patients with AGA who respond to finasteride.