A Two-Photon Probe Based on Naphthalimide-Styrene Fluorophore for the In Vivo Tracking of Cellular Senescence

[EN] Cellular senescence is a state of stable cell cycle arrest that can negatively affect the regenerative capacities of tissues and can contribute to inflammation and the progression of various aging-related diseases. Advances in the in vivo detection of cellular senescence are still crucial to monitor the action of senolytic drugs and to assess the early onset or accumulation of senescent cells. Here, we describe a naphthalimide-styrene-based probe (HeckGal) for the detection of cellular senescence both in vitro and in vivo. HeckGal is hydrolyzed by the increased lysosomal beta-galactosidase activity of senescent cells, resulting in fluorescence emission. The probe was validated in vitro using normal human fibroblasts and various cancer cell lines undergoing senescence induced by different stress stimuli. Remarkably, HeckGal was also validated in vivo in an orthotopic breast cancer mouse model treated with senescence-inducing chemotherapy and in a renal fibrosis mouse model. In all cases, HeckGal allowed the unambiguous detection of senescence in vitro as well as in tissues and tumors in vivo. This work is expected to provide a potential technology for senescence detection in aged or damaged tissues.
R.M. laboratory members thank the financial support from the Spanish Government (project RTI2018-100910-B-C41) and the Generalitat Valenciana (project PROMETEO 2018/024). B.L.-T. is grateful to the Spanish Ministry of Economy for their PhD grants (FPU15/02707). I.G. thanks her contract from IDM. J.F.-B. thanks to his postdoctoral fellowship (CD19/00038). J.A.L.-D. thanks the financial support from the Ministry of Science/MICINN (IJCI-2017-33047). Work in the laboratory of M.S. was funded by the IRB and by grants from the Spanish Ministry of Economy cofunded by the European Regional Development Fund (ERDF) (SAF201348256-R), the European Research Council (ERC-2014-AdG/669622), and the "laCaixa" Foundation. The D.M.-E. laboratory is supported by the Cancer Research U.K. (CRUK), Cambridge Centre Early Detection Programme, by a CRUK Early Detection OHSU project award (C62187/A26989), by a Medical Research Council (MRC) New Investigators Research Grant (NIRG, MR/R000530/1).