Determination of Hydrogen Sulfide in Endoplasmic Reticulum by Two-Photon Fluorescence

Abstract

An endoplasmic reticulum (ER) targetable two-photon fluorescent probe termed ER-N3 is presented for the determination of hydrogen sulfide (H₂S) in living cells and mice. The results demonstrate that ER-N3 was highly selective and sensitive to H₂S. Confocal fluorescence imaging in living cells indicated that ER-N3 was accumulated in the endoplasmic reticulum and visualized exogenous and endogenous H₂S production. Moreover, a burst of H₂S upregulated by the nitric oxide donor sodium nitroprusside was monitored. Meanwhile, the increase of H₂S ended following the addition of DL-propargylglycine, an inhibitor for cystathionine β-synthase and cystathionine γ-lyase that are the main sources of H₂S. Importantly, the exogenous H₂S was visualized in abdominal tissue of mice by utilizing two-photon fluorescence microscopy. The ER-N3 fluorescent probe may be an excellent tool to image H₂S fluctuations in the endoplasmic reticulum and characterize the relationship between H₂S and disease in vivo.

Keywords:

• Endoplasmic reticulum
• fluorescence imaging
• fluorescent probe
• hydrogen sulfide
• two-photon luminescence

Compliance with ethical standards

All animal experiments were conducted at the Laboratory of Shandong Normal University in compliance with university guidelines for the care and use of laboratory animals.

Conflict of interest

The authors declare that they have no conflicts of interest.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (21907058), Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals (2019FCCEKL04), and Key Laboratory of Molecular and Nano Probes, Ministry of Education (2018KLMNP02).