Understanding the Role of Glycogen Metabolism in Human Hair Follicle Biology

The document from 2018 explored the significance of glycogen metabolism in human hair follicle (HF) biology, suggesting the presence of a Cori cycle within the HF. It was observed that human HFs, especially in the anagen phase, have high glycogen levels that decrease in catagen and are absent in telogen. The study highlighted distinct expression patterns of key enzymes like Glut1, PYGL, PGM1, and GYS1 in different HF parts. Inhibition experiments with a PYGL inhibitor on primary ORS keratinocytes caused glycogen accumulation and reduced glycogen breakdown during glucose deprivation. The detection of PCK1 in the ORS indicates that HFs might synthesize glucose from lactate. Lactic acidosis induced in ORS keratinocytes led to increased glycogen synthesis and upregulation of GYS1 and PCK1. These results imply that HFs may use glycogen for energy and cellular processes, and further research is needed to confirm these potential functions.