Hydrogen peroxide probes directed to different cellular compartments

Area of Science:

• Cellular biology
• Redox homeostasis
• Biochemistry

Background:

• Controlled generation and removal of hydrogen peroxide (H2O2) are crucial for cellular redox homeostasis and signaling.
• The hydrogen peroxide biosensor HyPer allows for the examination of these processes in mammalian cells.

Purpose of the Study:

• To utilize the HyPer biosensor to investigate the compartmentalization and dynamics of hydrogen peroxide in mammalian cells.
• To characterize the control mechanisms of hydrogen peroxide generation and removal in various cellular compartments.

Main Methods:

• Expression of the HyPer biosensor in HEK 293 cells, targeted to different cellular compartments (nucleus, cytosol, peroxisomes, mitochondria, endoplasmic reticulum).
• Monitoring of hydrogen peroxide levels and redox states in real-time using HyPer.
• Analysis of HyPer responses to various redox perturbations and signaling events, including studies on cells deficient in thioredoxin reductase, sulfhydryl oxidases, or subjected to selenium deficiency.

Main Results:

• HyPer detected low micromolar levels of hydrogen peroxide in mammalian cells.
• The biosensor revealed a low peroxide tone across various compartments, with HyPer predominantly in a reduced state, except for the endoplasmic reticulum where it was mostly oxidized.
• Hydrogen peroxide generation was monitored in different compartments following signaling events, and its potential translocation between compartments was observed.

Conclusions:

• HyPer is a valuable tool for monitoring hydrogen peroxide in distinct cellular compartments.
• Hydrogen peroxide can translocate between cellular compartments, influencing cellular redox dynamics.
• The study provides insights into the compartmentalization, dynamics, and homeostatic control of hydrogen peroxide in mammalian cells.