Study reports pathway of tributyl phosphate-induced liver aging via mitochondrial DNA escape

Researchers reported that exposure to the environmental pollutant tributyl phosphate accelerates liver senescence in animal and cell models through a pathway involving fumarate accumulation, mitochondrial DNA leakage, and FPR2 activation.

Researchers investigated the mechanisms of hepatic senescence induced by tributyl phosphate (TBP) in rats and BRL-3A cells.

The study found that TBP exposure elevated cellular senescence markers, including cell cycle arrest, increased ROS, elevated beta-galactosidase activity, and MMP-1 upregulation.

TBP exposure led to an accumulation of fumarate, which was shown to directly drive mitochondrial DNA (mtDNA) escape into the cytoplasm.

Cytoplasmic mtDNA subsequently activated formyl peptide receptor 2 (FPR2), triggering downstream senescence and chromatin-remodeling alterations, including downregulation of HP1 and upregulation of p53, lys9, and gamma-H2A.X.

The pathological changes in BRL-3A cells were reversed through FPR2 inhibition (via WRW4), cytoplasmic mtDNA depletion (via ethidium bromide), or fumarate clearance (via Lv-FH).

The study provides a molecular link between an environmental toxicant and accelerated organ-specific senescence, emphasizing that liver aging is heavily driven by external factors rather than chronological aging alone.

It establishes a direct mechanism connecting metabolic disruption (fumarate accumulation), mitochondrial structural failure (mtDNA leakage), and innate immune receptor activation (FPR2) in cellular aging.

By demonstrating that FPR2 inhibition or fumarate clearance can reverse TBP-induced senescence markers, the research identifies novel potential targets for therapies aimed at preventing or reversing environmentally accelerated tissue degeneration.

The identification of FPR2 and fumarate-mediated mtDNA leakage as drivers of environmental senescence expands the target landscape for therapies focused on mitochondrial integrity and organ rejuvenation.

The findings may drive interest in mitochondrial protection platforms as a means to shield metabolic organs from pollutant-induced senescence, though active clinical programs specifically addressing this environmental mechanism are currently limited.

Further preclinical validation of FPR2 inhibitors and fumarate clearance strategies in wider in vivo models of toxicant-induced liver damage.

Investigation into whether similar environmental pollutants leverage this fumarate-mediated mtDNA escape pathway to accelerate aging in other high-metabolic tissues.