Oxidative stress drives liver failure during in vivo partial reprogramming

Area of Science:

• * Regenerative Medicine
• * Molecular Biology
• * Toxicology

Background:

• * In vivo reprogramming using Yamanaka factors (OCT4, SOX2, KLF4, c-MYC; OSKM) offers potential for tissue regeneration.
• * Sustained expression of OSKM raises safety concerns, particularly regarding tumor formation and organ damage.

Purpose of the Study:

• * To investigate the safety concerns associated with sustained systemic OSKM induction in vivo.
• * To identify the molecular mechanisms underlying toxicity during prolonged reprogramming.
• * To explore therapeutic strategies to mitigate reprogramming-induced toxicity.

Main Methods:

• * Utilized a doxycycline-inducible OSKM mouse model for controlled gene expression.
• * Employed single-nucleus RNA sequencing to analyze cellular changes in hepatocytes.
• * Assessed oxidative stress markers and reactive oxygen species (ROS) production.
• * Evaluated the efficacy of N-acetylcysteine (NAC) as an antioxidant intervention.

Main Results:

• * Prolonged OSKM induction led to early lethality, characterized by hepatocyte dedifferentiation and oxidative stress, without tumor formation.
• * Single-nucleus RNA sequencing identified activation of ROS, oxidative stress, and NRF2 signaling pathways in hepatocytes.
• * Increased ROS production and sex-dependent differences in antioxidant responses implicated oxidative stress in mortality.
• * NAC treatment significantly alleviated oxidative stress and improved survival rates.

Conclusions:

• * Oxidative stress is a critical driver of liver failure during sustained in vivo reprogramming.
• * Antioxidant interventions like NAC can mitigate toxicity and improve survival during reprogramming.
• * Findings support the development of cyclic induction strategies to balance regenerative potential and safety.