Chronic, Environmentally Relevant PM_2.5 Exposure Exacerbates Metabolic Dysfunction-Associated Steatotic Liver Disease...

Area of Science:

• Environmental Health
• Toxicology
• Metabolic Diseases

Background:

• Epidemiological studies link fine particulate matter (PM2.5) to metabolic dysfunction-associated steatotic liver disease (MASLD) and kidney dysfunction.
• Existing animal models often use acute, high-dose PM2.5 exposures, not reflecting chronic, moderate human exposure levels.

Purpose of the Study:

• To establish and utilize a long-term mouse model of chronic, moderate PM2.5 exposure combined with a Western diet.
• To investigate the effects of this combined exposure on liver and kidney pathology and function.

Main Methods:

• A seven-month mouse model exposed to a Western diet and chronic PM2.5 (~50 μg/m³).
• Assessment of MASLD biomarkers, organ histopathology, and hepatic gene expression.
• Measurement of serum creatinine and proteinuria for renal function evaluation.

Main Results:

• Western diet drove MASLD and insulin resistance; PM2.5 co-exposure significantly exacerbated hepatic pathology and fibrosis.
• PM2.5 exposure independently increased serum creatinine and proteinuria, indicating early-stage kidney dysfunction without major structural damage.
• Upregulation of pro-inflammatory and pro-fibrotic genes in the liver of co-exposed mice.

Conclusions:

• Chronic, moderate PM2.5 exposure aggravates diet-induced liver disease and contributes to renal dysfunction.
• This study provides experimental evidence for the multi-organ health risks of air pollution in metabolically vulnerable populations.