Modeling of Ionizing Radiation Induced Hair Follicle Regenerative Dynamics

This study developed a new ordinary differential equation (ODE) model to investigate the mechanisms behind hair follicle (HF) regeneration induced by ionizing radiation (IR) and compared it to the irreversible degeneration during the catagen phase. The model, calibrated using experimental data from mice, includes four cell states: quiescent outer root sheath (ORS), active ORS, matrix (Mx), and apoptosis cells. The findings suggest that the homeostatic state of anagen HFs is stable and does not depend on apoptosis feedback strength, explaining why HFs can regenerate after IR-induced damage but not during catagen. The research provides insights into the control mechanisms of HF regenerative dynamics.