Polystyrene microplastics induces the injury of human corneal epithelial cells through ROS-mediated p53 pathway

Area of Science:

• Ocular toxicology
• Environmental health
• Cell biology

Background:

• Microplastic pollution is a growing environmental concern.
• The impact of microplastics on ocular tissues is not well understood.
• Human corneal epithelial cells (HCEP) are the first line of defense against external factors in the eye.

Purpose of the Study:

• To investigate the toxicological effects of polystyrene microplastics (PS-MPs) on human corneal epithelial cells (HCEP).
• To elucidate the underlying mechanisms of PS-MP-induced cellular damage in HCEP.

Main Methods:

• Cytotoxicity was assessed using CCK-8 assays.
• Cell cycle, apoptosis, and necrosis were analyzed by flow cytometry.
• Reactive oxygen species (ROS) and DNA damage (γ-H2AX) were detected via immunofluorescence.
• Protein expression related to cell death pathways was evaluated using western blotting.

Main Results:

• PS-MP cytotoxicity was dependent on particle size and concentration, with smaller particles and higher concentrations causing more harm.
• Exposure to PS-MPs induced cell cycle arrest, necrosis, and apoptosis in HCEP cells.
• PS-MPs led to excessive ROS production and DNA damage, which were mitigated by ROS scavengers.
• ROS scavengers reversed PS-MP-induced alterations in key proteins involved in cell cycle regulation, necrosis, and apoptosis.

Conclusions:

• PS-MP exposure induces significant cellular damage in HCEP, including cell cycle arrest, necrosis, and apoptosis.
• This damage is mediated by ROS overproduction and subsequent activation of the P53 signaling pathway.
• The findings highlight the potential ocular toxicity of microplastics and suggest ROS-related pathways as therapeutic targets.