Ratiometric Visualization of NO/H₂S Cross-Talk in Living Cells and Tissues Using a Nitroxyl-Responsive Two-Photon Fluorescence Probe

Abstract

It is of scientific significance to explore the intricate relationship between two crucial gasotransmitters nitric oxide (NO) and hydrogen sulfide (HS) because they exert similar and interdependent biological actions within the living organisms. Nevertheless, visualization of the NO/HS crosstalk using effective molecular imaging tools remains challenging. To address this issue, and given that nitroxyl (HNO) has been implicated as the interdependent production of NO and HS via a network of cascading chemical reactions, we herein design a ratiometric two-photon fluorescent probe for HNO, termed TP-Rho-HNO, which consists of benzo[h]chromene-rhodol scaffold as two-photon energy transfer cassette with phosphine moiety as specific HNO recognition unit. The newly proposed probe has been successfully applied in ratiometric two-photon bioimaging of endogenous HNO derived from NO and HS interaction in the human umbilical vein cells (HUVECs) and as well as in rat brain tissues. Intriguingly, the imaging results consistently demonstrate that the mutually dependent upgeneration of HS and NO are present in living biosystems, indicating that this molecular probe would provide a powerful approach to elucidate the chemical foundation for the anfractuous cross-talk between the NO and HS signaling pathways in biology.

Donor and Ring‐Fusing Engineering for Far‐Red to Near‐Infrared Triphenylpyrylium Fluorophores with Enhanced Fluorescence Performance for Sensing and Imaging

“…In addition, most of the above fluorophores only show changes in fluorescence intensity after decoration, which is not suitable for the development of ratiometric fluorescent probes with long‐wavelength emissions. However, ratiometric imaging is more attractive as it avoids various interference factors, such as environmental conditions and the inhomogeneous distribution of probes in cells …”

“…However,r atiometric imaging is more attractive as it avoidsv arious interference factors, such as environmental conditions and the inhomogeneous distribution of probes in cells. [23,[28][29][30] Rational molecular engineering of fluorophores, based on a deep understanding of their structure-photophysical property relationship (SPPR), is crucial and imperative to yield novel fluorophores with desired opticala nd biological characteristics. [31,32] Despitem ajor efforts,o nly af ew fluorochromes have been subjected to systematic SPPR research.…”

A Ratiometric Fluorescent Probe for Selective Detection of Hypochlorite Anion

“…By contrast, the ratiometric fluorescent probes can provide the observation changes in the ratio of the intensities of the absorption or the emission at two wavelengths, with the perceived color changes for rapid visual sensing. [8][9][10][11] In this study, we report a new ratiometric fluorescent probe, which was based on rhodamine and naphthalimide structure and could be synthesized easily within a few steps. This probe produced strong red fluorescence after the addition of NaClO while the probe itself presented a green fluorescence.…”

A Chemiluminescent Probe for HNO Quantification and Real‐Time Monitoring in Living Cells

“…In order to interrogate the ability of HNOCL-1 to measure NO reduction chemistry in living cells,w et reated A549 cells with HNOCL-1 and then added DEA NONOate and Na 2 S( Figure 3C). [16,53] Control experiments in the absence of H 2 Sand DEA NONOate or using N-acetyl cysteine (NAC) as at hiol scavenger returned signal to baseline levels. [16,53] Control experiments in the absence of H 2 Sand DEA NONOate or using N-acetyl cysteine (NAC) as at hiol scavenger returned signal to baseline levels.…”

“…Ac lear, statistically significant increase was observed ( Figure 3D), in agreement with previous studies. [16,53] Control experiments in the absence of H 2 Sand DEA NONOate or using N-acetyl cysteine (NAC) as at hiol scavenger returned signal to baseline levels. Fluorescence microscopy images of the fluorescent product of the HNOCL-1 and HNO confirm cellular uptake (Figure S14).…”