posted on 2024-02-05, 20:03authored byChengmei Liu, Yu Mei, Haifeng Yang, Qian Zhang, Ke Zheng, Peng Zhang, Caifeng Ding
Senescence is an important biological process, which
leads to the
gradual degradation of its physiological function and increases morbidity
and mortality. Herein, a novel ratiometric fluorescent probe (P1) was constructed by using benzothiazolyl acetonitrile dye
as fluorophore, exhibiting significantly enhanced blue-shifted emission
to indicate the activity of β-galactosidase (β-gal), a
commonly used biomarker for the detection of senescent cells. After
incubation with β-gal, the excimer emission of P1 at 620 nm was weakened, while the emission at 533 nm was significantly
enhanced, forming an obvious ratiometric probe with high sensitivity
and low detection limit (2.7 mU·mL–1). More
importantly, probe P1 can locate lysosomes accurately,
allowing us to monitor the emergence of living cell senescence in
real time. P1 was successfully used to detect β-gal
activity in PC-12 cells, Hep G2 cells, and RAW 264.7 cells. It showed
strong green fluorescence signal in senescent cells and red fluorescence
signal in normal cells, indicating that it can detect endogenous senescence-related
β-gal content in living cells. For invivo drug-induced senescence imaging, after 5 weeks of injection
of D-galactose or hydroxyurea, the mice showed significant fluorescence
enhancement in specific channels to indicate the activity of β-gal invivo. At the same time, the senescence
of cell-specific organs and skin tissues at the organ level were also
detected, which proved that the drug-induced senescence of brain,
skin, and muscle tissues was the most serious. These results supported
the important application value of P1 in senescence biomedical
research.