Differential Expression and Functionality of ATP-Binding Cassette Transporters in the Human Hair Follicle

The study investigated the expression and functionality of ATP-binding cassette (ABC) transporters in human hair follicles, finding that transporters like ABCB1, ABCG2, ABCC1, and ABCC4 are differentially expressed in the follicle, particularly in the stem cell-rich bulge area. ABCG2 was primarily found in the bulge, suggesting a protective role for epithelial stem cells, while other transporters were more widespread. Functional activity was confirmed by the exclusion of Hoechst 33342 dye, which was reversed by transporter inhibition. The findings suggest that ABC transporters could be key in regulating hair follicle biology and may offer therapeutic targets for hair loss and hypertrichosis, although the study did not report the number of human subjects involved.