Polystyrene microplastics arrest skeletal growth in puberty through accelerating osteoblast senescence

Area of Science:

• Environmental Science
• Toxicology
• Bone Biology

Background:

• Polystyrene microplastics (PS-MPs) are pervasive environmental contaminants.
• Microplastic accumulation in organs can cause toxic effects.
• The skeletal impact of PS-MPs exposure is largely unknown.

Purpose of the Study:

• To investigate the effects of PS-MPs on skeletal development and bone micro-architecture.
• To elucidate the underlying mechanisms of PS-MPs-induced skeletal abnormalities.
• To explore potential therapeutic strategies targeting autophagy.

Main Methods:

• Exposure of mice to PS-MPs.
• Assessment of skeletal growth parameters (body length, bone length).
• Histological and micro-architectural analysis of bone tissues.
• Evaluation of osteoblast number, osteogenic ability, and autophagy markers.

Main Results:

• PS-MPs accumulated in long and axial bones, reducing overall body and bone length.
• Skeletal growth was impaired, with reduced trabecular bone micro-architecture.
• PS-MPs suppressed osteogenic ability by decreasing osteoblast numbers and accelerating osteoblast senescence.
• Impaired autophagy, characterized by reduced autophagosomes and autophagy-related proteins, was observed in senescent osteoblasts.
• Reactivating autophagy reversed osteoblast senescence and ameliorated PS-MPs-induced skeletal growth arrest.

Conclusions:

• PS-MPs detrimentally affect skeletal growth during puberty by accelerating osteoblast senescence.
• Impaired autophagy plays a crucial role in PS-MPs-induced skeletal abnormalities.
• Reactivating autophagy presents a potential therapeutic strategy to counteract PS-MPs' skeletal health threats.