A novel BRET-based genetically encoded biosensor for functional imaging of hypoxia

Area of Science:

• Biomedical Imaging
• Molecular Biology
• Cancer Research

Background:

• Optical imaging, particularly fluorescence, is vital for visualizing biological processes like cancer.
• Green fluorescent protein (GFP) is popular but limited by autofluorescence and signal dispersion for in vivo tracing.
• Near-infrared (NIR) fluorescent proteins offer deep tissue penetration and reduced autofluorescence for enhanced imaging.

Purpose of the Study:

• To develop a novel genetically encoded biosensor for detecting hypoxia in tumors.
• To overcome the limitations of traditional fluorescent proteins in in vivo imaging.
• To create a hypoxia-sensing tool activated by the HIF-1alpha transcription factor.

Main Methods:

• Development of a fluorescence-bioluminescence genetically encoded biosensor.
• Activation of the biosensor by the hypoxia-inducible factor 1-alpha (HIF-1alpha).
• Fusion of fluorescent and bioluminescent proteins to induce bioluminescence resonance energy transfer (BRET).

Main Results:

• The developed biosensor enables real-time imaging without autofluorescence interference.
• Deep tissue visualization is achieved using NIR fluorescent proteins.
• The fusion protein functions as a new class of hypoxia-sensing genetically encoded biosensor via BRET.

Conclusions:

• The novel biosensor provides a powerful tool for in vivo tumor monitoring.
• NIR fluorescence and BRET overcome limitations of conventional imaging techniques.
• This genetically encoded biosensor offers improved sensitivity and specificity for hypoxia detection in cancer biology.