HIF1, HSF1, and NRF2: Oxidant-Responsive Trio Raising Cellular Defenses and Engaging Immune System

Area of Science:

• Cellular Biology
• Molecular Toxicology
• Biochemistry

Background:

• Cellular homeostasis is constantly threatened by reactive oxygen species (ROS) and electrophilic damage.
• Human cells possess sophisticated protective mechanisms activated by oxidative and electrophilic stress.
• Key transcription factors like NRF2, HSF1, and HIF1 orchestrate cellular defense responses.

Purpose of the Study:

• To review the mechanisms by which ROS and reactive electrophiles activate NRF2, HSF1, and HIF1.
• To elucidate the roles of the gene expression programs controlled by these transcription factors in cellular protection.
• To discuss the interplay between these transcription factors in establishing multilayered cellular defenses and their links to innate immunity.

Main Methods:

• Literature review of chemical and biological activation pathways.
• Analysis of gene expression programs regulated by NRF2, HSF1, and HIF1.
• Examination of the crosstalk and synergistic effects of these transcription factor pathways.

Main Results:

• ROS and reactive electrophiles activate NRF2 (antioxidant response), HSF1 (heat shock response), and HIF1 (hypoxia response).
• These transcription factors initiate largely non-overlapping gene expression programs, forming robust, multilayered cellular defenses.
• Stress responses are linked to innate immunity, impacting damaged cell clearance, inflammation, and cancer immunosurveillance.

Conclusions:

• Coordinated activation of NRF2, HSF1, and HIF1 provides comprehensive cellular protection against diverse toxic insults.
• Multilayered defense strategies mitigate the limitations of individual stress response pathways.
• Innate immunity interactions within these stress responses have complex implications for tissue homeostasis and cancer biology.