Assessment of Markers Expressed in Human Hair Follicles According to Different Skin Regions

The study aimed to investigate the expression patterns of markers cytokeratin 15 (K15), cytokeratin 6 (K6), and Ki-67, as well as apoptosis in human hair follicles (HFs) from different body regions. Biopsies were taken from the scalp, leg, abdomen, back, and waist of healthy individuals. Histological examination showed that scalp HFs had clearer hair layers compared to other regions. K15 expression was highest in the scalp and significantly lower in the waist and abdomen. K6 expression was significantly higher in the scalp than in the abdomen. However, the number of Ki-67-positive and TUNEL-positive cells, indicating proliferation and apoptosis respectively, did not show significant differences across regions. These findings suggest regional differences in HF marker expression and may be relevant for understanding the molecular aspects of human hair follicle stem cells in health and disease.