Ratiometric fluorescence imaging of Golgi H₂O₂ reveals a correlation between Golgi oxidative stress and hypertension

Abstract

Based on a novel Golgi-targeting phenylsulfonamide group, a two-photon (TP) fluorescent probe, Np-Golgi, was developed for in situ H2O2 ratiometric imaging in living systems.

Boronate-Based Probes for Biological Oxidants: A Novel Class of Molecular Tools for Redox Biology

“…Typically, an organelle-targeting moiety is covalently attached to a probe for that purpose (Xu W. et al, 2016 ; Zhu et al, 2016 ; Gao et al, 2019 ). Examples of the cellular organelles that have been targeted to accumulate boronate-based redox probes include mitochondria (see below), nucleus (Dickinson et al, 2011b ; Wen et al, 2014 ), endoplasmic reticulum, Golgi apparatus (Wu et al, 2018b ; Wang H. et al, 2019 ), and lysosomes (Kim et al, 2015 ; Liu et al, 2017 ; Ren et al, 2017 ). Also, simultaneous monitoring of H 2 O 2 in mitochondria and endoplasmic reticulum has been reported using a combination of targeted probes, yielding products of different fluorescence parameters (Xiao et al, 2016 ).…”

Protect to Detect: A Golgi Apparatus Targeted Probe to Image Mobile Zinc Through the Use of a Lipophilic Cell-Labile Protecting Group Strategy

“…However, initial fluorescence microscopy tests of the probes in HeLa cells (Fig. S23, ESI) showed that the cells incubated with 2 do not display any intracellular fluorescence, indicating that 2, as expected due to its hydrophilic nature, 27 is not membrane permeable. In contrast, cells incubated with 1 clearly showed evidence of probe internalisation.…”

“…Recently cysteine has been reported as a Golgi apparatus targeting unit, 23,24 since galactosyltransferase and protein kinase D were found to anchor to the Golgi region via their cysteine residues or cysteine rich domains. 25,26 However, cysteine as a targeting vector has its limitations in small molecule probes since it is rather hydrophilic, 27 and consequently not membrane permeable in some cases. Such poor membrane permeability has been classically addressed through the use of an ethyl ester protected carboxylic acid in the commercial zinc probe Zinquin, which was assumed to undergo esterase catalysed cleavage in cellulo, 28 and this strategy has also been utilized to load cells with some other small molecule zinc probes.…”

“…8 In this work, we present our recent efforts to develop a Golgi apparatus targeting Zn 2+ probe, which can be used to study changes to mobile Zn 2+ levels during oxidative stress. To overcome the poor membrane permeability of cysteine previously noted, 27 a trityl protecting group was used to increase the hydrophobicity of the probe. Following passive diffusion into cells, the labile trityl group was removed intracellularly releasing the free cysteine, which then anchors the probe to the Golgi apparatus ( Fig.…”

Subcellular localised small molecule fluorescent probes to image mobile Zn2+

“…Furthermore, cysteine has been reported as a Golgi apparatus targeting unit in other systems, 77,78 since galactosyltransferase and protein kinase D were found to anchor to the Golgi region via their cysteine residues or cysteine rich domains 79,80 and this may also nd utility. However, it has been noted that cysteine is too hydrophilic, 81 and consequently not membrane permeable in some cases. We therefore incorporated an S-trityl protected cysteine moiety into a new Zn 2+ probe through 'click' chemistry, and conrmed the probe to be membrane permeable.…”