Nitroreductase-Triggered Fluorophore Labeling of Cells and Tissues under Hypoxia

Yun Jae Yang ¹, Yun Lim Jung ¹, Anushree Shil ¹

⁰Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, South Korea.

Analytical Chemistry +

|

June 28, 2024

View abstract on PubMed

Summary

Researchers developed a novel nitroreductase-activated probe for hypoxia imaging. This bioconjugative agent selectively stains hypoxic tissues, showing promise for image-guided tumor surgery and diagnosing conditions like acute kidney injury.

Area Of Science

Bioconjugation Chemistry
Molecular Imaging
Hypoxia Research

Background

Hypoxia, an oxygen-deficient state, is common in solid tumors and other pathologies.
Nitroreductases are enzymes upregulated under hypoxic conditions.
Targeting hypoxia is crucial for diagnostics and therapeutics.

Purpose Of The Study

To develop a bioconjugative probe activated by nitroreductase for selective staining of hypoxic tissues.
To utilize ortho-quinone methide chemistry for a trigger-release-bioconjugation system.
To assess the probe's efficacy in cell cultures and in vivo models.

Main Methods

Development of a novel bioconjugative probe based on ortho-quinone methide chemistry.
Testing probe activation and fluorescence in cells, focusing on mitochondria and endoplasmic reticulum.
Application of the probe to stain mouse kidney tissue in an acute kidney injury model.
Analysis of fluorescence using two-photon microscopic imaging.

Main Results

The probe demonstrated selective activation by nitroreductase.
Sustained fluorescence was observed in cells and tissues, even after washing.
Kidney tissue in the acute kidney injury model showed significantly higher fluorescence compared to controls.
The probe successfully stained hypoxic tissue in vivo.

Conclusions

The developed probe is effective for selective staining of hypoxic tissues.
The probe exhibits sustained fluorescence, enabling robust imaging.
This technology holds potential for image-guided tumor surgery and diagnosing hypoxic conditions.
Further development could lead to practical clinical staining agents.