Cell-trappable fluorescent probes for endogenous hydrogen sulfide signaling and imaging H ₂ O ₂ -dependent H ₂ S production

Abstract

Hydrogen sulfide (H 2 S) is a reactive small molecule generated in the body that can be beneficial or toxic owing to its potent redox activity. In living systems, disentangling the pathways responsible for H 2 S production and their physiological and pathological consequences remains a challenge in part due to a lack of methods for monitoring changes in endogenous H 2 S fluxes. The development of fluorescent probes with appropriate selectivity and sensitivity for monitoring production of H 2 S at biologically relevant signaling levels offers opportunities to explore its roles in a variety of systems. Here we report the design, synthesis, and application of a family of azide-based fluorescent H 2 S indicators, Sulfidefluor-4, Sulfidefluor-5 acetoxymethyl ester, and Sulfidefluor-7 acetoxymethyl ester, which offer the unique capability to image H 2 S generated at physiological signaling levels. These probes are optimized for cellular imaging and feature enhanced sensitivity and cellular retention compared with our previously reported molecules. In particular, Sulfidefluor-7 acetoxymethyl ester allows for direct, real-time visualization of endogenous H 2 S produced in live human umbilical vein endothelial cells upon stimulation with vascular endothelial growth factor (VEGF). Moreover, we show that H 2 S production is dependent on NADPH oxidase-derived hydrogen peroxide (H 2 O 2 ), which attenuates VEGF receptor 2 phosphorylation and establishes a link for H 2 S/H 2 O 2 crosstalk. molecular imaging | redox biology | thiol | VEGFR

Fluorescent probes for hydrogen sulfide detection and bioimaging

“…8,9 The fluorophores of these probes were based on Rhodamine 110. The detection mechanism was illustrated in Fig.…”

Bio-inspired porous antenna-like nanocube/nanowire heterostructure as ultra-sensitive cellular interfaces

“…Numerous cellular functions are closely correlated with small molecules, such as O 2 , 4 glucose, 5 glutathione, 6 NO, 7 CO 8 and H 2 O 2 , 9 for enzymatic co-factors, signaling and expression. Among them, H 2 O 2 is an important reactive oxygen species that can diffuse across cell membranes and lead to oxidative protein modification.…”

FRET ratiometric probes reveal the chiral-sensitive cysteine-dependent H2S production and regulation in living cells

“…Recently, they further reported a novel possible pathway for the production of H 2 S from D-cysteine in mammalian cells 12 . As new biogenesis and biological functions of H 2 S continue to emerge [12][13][14][15] , new biocompatible tools to selectively visualize cellular H 2 S in real-time at its site of release are urgently needed 11 .Fluorescent probes could be used for H 2 S detection in a non-invasive manner in living systems [13][14][15][16][17] . The probebased tools have been successfully used to image endogenous H 2 S production from thiol substrates including LCys and glutathione (GSH) 13 or by vascular endothelial growth factor stimulation 17 .…”

“…The probebased tools have been successfully used to image endogenous H 2 S production from thiol substrates including LCys and glutathione (GSH) 13 or by vascular endothelial growth factor stimulation 17 . Inspired by these work 13,17 , we are interested to image endogenous H 2 S production of all possible pathways in living cells semi-quantitatively or quantitatively, based on ratiometric probes rather than intensity-based probes, in view of that ratiometric measurements can cancel out variability caused by uneven loading and distribution of fluorescence probes in cells 18 .…”

“…Fluorescent probes could be used for H 2 S detection in a non-invasive manner in living systems [13][14][15][16][17] . The probebased tools have been successfully used to image endogenous H 2 S production from thiol substrates including LCys and glutathione (GSH) 13 or by vascular endothelial growth factor stimulation 17 .…”