Fan Zheng, Yeshuo Ma, Jipeng Ding, Shuai Huang, Shengwang Zhang, Xueyan Huang, Bin Feng, Hongliang Zeng, Fei Chen, Wenbin Zeng
{"title":"Ratiometric and discriminative visualization of autophagic processes with a novel dual-responded lysosome-specific fluorescent probe.","authors":"Fan Zheng, Yeshuo Ma, Jipeng Ding, Shuai Huang, Shengwang Zhang, Xueyan Huang, Bin Feng, Hongliang Zeng, Fei Chen, Wenbin Zeng","doi":"10.1186/s40824-023-00409-3","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Autophagy 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.</p><p><strong>Methods: </strong>Probe 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.</p><p><strong>Results: </strong>We 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 = I <sub>610</sub>/I <sub>460</sub>) 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.</p><p><strong>Conclusions: </strong>In 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.</p>","PeriodicalId":9079,"journal":{"name":"Biomaterials Research","volume":null,"pages":null},"PeriodicalIF":11.3000,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10327318/pdf/","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biomaterials Research","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1186/s40824-023-00409-3","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Medicine","Score":null,"Total":0}
引用次数: 1
Abstract
Background: Autophagy 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.
Methods: Probe 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.
Results: We 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 = I 610/I 460) 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.
Conclusions: In 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.
期刊介绍:
Biomaterials Research, the official journal of the Korean Society for Biomaterials, is an open-access interdisciplinary publication that focuses on all aspects of biomaterials research. The journal covers a wide range of topics including novel biomaterials, advanced techniques for biomaterial synthesis and fabrication, and their application in biomedical fields. Specific areas of interest include functional biomaterials, drug and gene delivery systems, tissue engineering, nanomedicine, nano/micro-biotechnology, bio-imaging, regenerative medicine, medical devices, 3D printing, and stem cell research. By exploring these research areas, Biomaterials Research aims to provide valuable insights and promote advancements in the biomaterials field.