Polystyrene Nanoplastics Induce Early Mitochondrial Dysfunction in H9c2 Cardiomyoblasts Without Substantial Cell...

Area of Science:

• Environmental toxicology
• Cell biology
• Cardiovascular research

Background:

• Micro- and nanoplastics, particularly polystyrene nanoplastics (PSNPs), are environmental contaminants found in human tissues.
• Mitochondria are vital for cardiac energy metabolism, making them a potential target for nanoplastic toxicity.

Purpose of the Study:

• To investigate the effects of 100 nm PSNPs on mitochondrial structure and function in H9c2 cardiomyoblasts.
• To assess cellular uptake, intracellular distribution, and impact on mitochondrial health and cardiac cell metabolism.

Main Methods:

• H9c2 cardiomyoblasts were exposed to PSNPs.
• Evaluated cellular uptake, mitochondrial ultrastructure, reactive oxygen species (ROS) production, mitochondrial membrane potential, mitochondrial dynamics, mitophagy gene expression, mitochondrial DNA copy number, and metabolic function.

Main Results:

• PSNPs were internalized but did not localize to mitochondria within 24 hours.
• Observed mitochondrial ultrastructural changes (crista loosening, vacuolization), reduced membrane potential, altered mitochondrial dynamics gene expression (Opa1, Drp1 upregulation), suppressed mitophagy genes (PINK1/Parkin), and decreased maximal respiratory capacity.
• No significant cytotoxicity, ROS increase, or altered basal metabolic activity/glycolysis was noted.

Conclusions:

• PSNP exposure induces early mitochondrial structural and functional alterations in cardiac cells.
• These changes occur without substantial immediate cell damage, suggesting a potential impairment of cardiac adaptive capacity.
• Further research is needed to understand long-term cardiac health implications of PSNP exposure.