Intracellular oxygen mapping using a myoglobin-mCherry probe with fluorescence lifetime imaging

Area of Science:

• Biochemistry
• Cell Biology
• Biomedical Optics

Background:

• Oxygen (O2) is a critical biometabolite regulating cellular respiration and physiological processes.
• Current methods for measuring intracellular oxygen concentration often involve invasive techniques or lack single-cell resolution.
• Existing optical methods struggle to detect metabolic heterogeneity within individual cells or different regions of a single cell.

Purpose of the Study:

• To develop and validate a noninvasive, sensitive fluorescence lifetime microscopy probe for intracellular oxygen monitoring.
• To investigate the heterogeneity of intracellular oxygen concentration ([O2]) in cancer cells.
• To map mitochondrial oxygen consumption at a single-cell level.

Main Methods:

• Development of a myoglobin-mCherry fluorescence lifetime microscopy probe for intracellular targeting.
• Application of the probe to monitor mitochondrial oxygen contributions in A549 nonsmall cell lung cancer cells.
• Utilizing a peptide-based targeting strategy to specifically localize the probe within mitochondria.

Main Results:

• Demonstrated the noninvasive and sensitive detection of intracellular oxygen levels using the myoglobin-mCherry probe.
• Revealed significant heterogeneity in intracellular oxygen concentration ([O2]) within A549 cells.
• Successfully mapped mitochondrial oxygen concentration at a single-cell level, highlighting metabolic variations.

Conclusions:

• The myoglobin-mCherry probe provides a powerful tool for noninvasive, high-resolution imaging of intracellular oxygen dynamics.
• The findings underscore the metabolic heterogeneity of oxygen consumption within cancer cells.
• This approach offers new possibilities for understanding cellular respiration and developing targeted therapies.