Biosensors reveal subcellular redox status in live cells

Area of Science:

• Cellular Biology
• Biochemistry
• Physiology

Background:

• Redox homeostasis is essential for cellular function and signaling.
• Disruption of redox balance is implicated in various diseases.
• Subcellular compartments exhibit distinct redox environments.

Purpose of the Study:

• To investigate real-time, in situ redox dynamics of hydrogen peroxide (H2O2), nicotinamide adenine dinucleotide phosphate (NADPH), and glutathione (GSH) in cytoplasm and mitochondria.
• To understand how metabolic pathways like glycolysis and oxidative phosphorylation regulate redox equilibrium across subcellular domains.
• To compare the stress-responsive regulation of mitochondrial versus cytoplasmic redox systems during pathological conditions.

Main Methods:

• Utilized genetically encoded fluorescent sensors (Hyper7, iNap, roGFP2) for real-time monitoring.
• Tracked redox dynamics of H2O2, NADPH, and GSH in cytoplasm and mitochondria.
• Employed pathological models including cardiac hypertrophy, ischemia-reperfusion, and cuproptosis.

Main Results:

• Glycolysis and oxidative phosphorylation differentially regulate redox metabolites in a compartment-specific manner.
• Mitochondrial redox systems show superior stress-responsive regulation compared to cytoplasmic systems.
• Enhanced dynamic redox responses were observed in mitochondria during injury progression in pathological models.

Conclusions:

• Precise subcellular redox mapping provides critical insights into dynamic signal transduction.
• Compartment-specific redox regulation plays a key role in cellular stress responses.
• Targeting compartment-specific redox interventions offers potential therapeutic strategies for redox-associated diseases.