Ratiometric and discriminative visualization of autophagic processes with a novel dual-responded lysosome-specific fluorescent probe

Biomaterials Research

Research Article

Hongliang Zeng¹  Shengwang Zhang²  Yeshuo Ma²  Wenbin Zeng³  Fei Chen³  Fan Zheng³  Shuai Huang³  Xueyan Huang³  Jipeng Ding³  Bin Feng³ 

[1] Research Institute of Chinese Medicine, Hunan Academy of Chinese Medicine, 410013, Changsha, People’s Republic of China;The Third Xiangya Hospital, Central South University, Changsha, People’s Republic of China;Xiangya School of Pharmaceutical Sciences, Central South University, 410013, Changsha, People’s Republic of China;Hunan Key Laboratory of Diagnostic and Therapeutic Drug Research for Chronic Diseases, Central South University, 410013, Changsha, People’s Republic of China;

关键词: Autophagy visualization;    Fluorescent probe;    Lysosome-specific;    Ratiometric imaging;    Dual-responsive;    pH;    Viscosity;    Acetaminophen-induced liver injury;   

DOI  :  10.1186/s40824-023-00409-3

 received in 2023-05-08, accepted in 2023-06-22,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundAutophagy is a critical self-eating pathway involved in numerous physiological and pathological processes. Lysosomal degradation of dysfunctional organelles and invading microorganisms is central to the autophagy mechanism and essential for combating disease-related conditions. Therefore, monitoring fluctuations in the lysosomal microenvironment is vital for tracking the dynamic process of autophagy. Although much effort has been put into designing probes for measuring lysosomal viscosity or pH separately, there is a need to validate the concurrent imaging of the two elements to enhance the understanding of the dynamic progression of autophagy.MethodsProbe HFI was synthesized in three steps and was developed to visualize changes in viscosity and pH within lysosomes for real-time autophagy tracking. Then, the spectrometric determination was carried out. Next, the probe was applied to image autophagy in cells under nutrient-deprivation or external stress. Additionally, the performance of HFI to monitor autophagy was employed to evaluate acetaminophen-induced liver injury.ResultsWe constructed a ratiometric dual-responsive probe, HFI, with a large Stokes shift over 200 nm, dual-wavelength emission, and small background interference. The ratiometric fluorescent signal (R = I610/I460) of HFI had an excellent correlation with both viscosity and pH. More importantly, high viscosity and low pH had a synergistic promotion effect on the emission intensity of HFI, which enabled it to specially lit lysosomes without disturbing the inherent microenvironment. We then successfully used HFI to monitor intracellular autophagy induced by starvation or drugs in real-time. Interestingly, HFI also enabled us to visualize the occurrence of autophagy in the liver tissue of a DILI model, as well as the reversible effect of hepatoprotective drugs on this event.ConclusionsIn this study, we developed the first ratiometric dual-responsive fluorescent probe, HFI, for real-time revealing autophagic details. It could image lysosomes with minimal perturbation to their inherent pH, allowing us to track changes in lysosomal viscosity and pH in living cells. Ultimately, HFI has great potential to serve as a useful indicator for autophagic changes in viscosity and pH in complex biological samples and can also be used to assess drug safety.

【 授权许可】

CC BY   
© The Author(s) 2023

【 图 表 】

40507_2023_185_Article_IEq30.gif

Fig. 8

12888_2023_4994_Article_IEq4.gif

41116_2023_38_Article_IEq190.gif

Fig. 1

42004_2023_927_Tabaa_HTML.png

41116_2023_38_Article_IEq329.gif

41116_2023_38_Article_IEq321.gif