Hori, N.; Kawamoto, S.; Uemura, K.; Okumura, Y.; Tanaka, K.; Park, J. H.; Ohtani, N.; Motooka, D.; Hara, E.

The p16-3MR mouse model has previously been reported to effectively visualize and eliminate senescent cells in vivo. However, we now report significant issues with this model. Noninvasive bioluminescence imaging without shaving the black fur detected almost no luminescence signals, but they became visible after shaving. However, these signals were very faint and attributed to the auto-luminescence of coelenterazine-h, rather than reporter gene expression. Further experiments showed no significant bioluminescent changes with aging, doxorubicin treatment, or during wound healing, contradicting earlier reports. Comparative analysis between p16-3MR mice from different sources revealed no differences, suggesting functional issues with Renilla luciferase (Rluc) and herpes simplex virus 1 thymidine kinase (HSV-TK) expression in this mouse model. Our findings underscore the necessity of using white-furred mice or ensuring proper fur shaving for accurate in vivo bioluminescence imaging. We recommend the reevaluation of previously published studies that used p16-3MR mice without proper controls to ensure data accuracy. These results provide critical insights for researchers using p16-3MR mice in senescence studies.