Azoreductase and Target Simultaneously Activated Fluorescent Monitoring for Cytochrome c Release under Hypoxia

Area of Science:

• Biomedical Engineering
• Cell Biology
• Nanotechnology

Background:

• Hypoxia-induced apoptosis is linked to various diseases, with cytochrome c (Cyt c) release being a key event in the intrinsic pathway.
• Existing methods for tracking Cyt c release lack specificity, particularly in distinguishing hypoxia-induced release from other stimuli.
• Accurate monitoring of Cyt c dynamics is crucial for understanding disease mechanisms and risk assessment.

Purpose of the Study:

• To develop a highly specific fluorescent aptameric nanosensor for real-time monitoring of Cyt c release under hypoxic conditions.
• To enable quantitative analysis and in situ imaging of Cyt c dynamics during hypoxia-induced apoptosis.
• To provide a tool for better understanding apoptotic mechanisms and facilitating risk assessment in hypoxic environments.

Main Methods:

• A novel fluorescent aptameric nanosensor was designed, integrating gold nanoparticles (AuNPs) and a Cyt c-targeted DNA complex.
• The nanosensor utilizes an azobenzene moiety for conjugation to AuNPs and specific reduction by hypoxia-related azoreductase.
• Hypoxia triggers Cyt c release, leading to competitive displacement and subsequent activation of the nanosensor's fluorescence, proportional to Cyt c levels.

Main Results:

• The proposed nanosensor demonstrates simultaneous activation by azoreductase and target (Cyt c).
• The fluorescence enhancement is directly correlated with the amount of Cyt c released under hypoxia.
• The system allows for quantitative analysis and in situ imaging of Cyt c release dynamics with high spatial resolution.

Conclusions:

• The developed aptameric nanosensor offers enhanced specificity for tracking Cyt c release during hypoxia-induced apoptosis.
• This technology provides a valuable tool for studying apoptotic mechanisms and improving risk assessment in hypoxic conditions.
• The findings open new avenues for understanding and potentially mitigating the effects of hypoxia in various disease contexts.