New insights into the spleen injury by mitochondrial dysfunction of chicken under polystyrene microplastics stress

Area of Science:

• Environmental Science
• Toxicology
• Cell Biology

Background:

• Microplastic contamination is a growing global concern due to its persistence and potential biological toxicity.
• The specific mechanisms by which microplastics induce spleen injury in chickens remain largely unknown.
• Understanding these mechanisms is crucial for assessing the risks to poultry health and food safety.

Purpose of the Study:

• To investigate the impact of polystyrene microplastics on chicken spleen morphology and cellular pathways.
• To elucidate the roles of mitochondrial dysfunction, apoptosis, and ferroptosis in microplastic-induced spleen damage.
• To provide insights into the regulative role of mitochondria in the programmed death of spleen cells exposed to microplastics.

Main Methods:

• Chickens were randomly assigned to four groups and exposed to varying concentrations of microplastics (0, 1, 10, 100 mg/L) for 42 days.
• Spleen damage was assessed morphologically and at the molecular level, analyzing mitochondrial dynamics, apoptosis, ferroptosis, and redox balance.
• Key proteins and markers related to mitochondrial function (Drp1, Mfn1/2, OPA1), apoptosis (Bcl-2/Bax, cytc, caspases), ferroptosis (FTH1, GPX4, SLC7A11), and oxidative stress (MDA, CAT, GSH, T-AOC) were quantified.

Main Results:

• Microplastic exposure caused morphological changes in the spleen, including blurred red-white pulp boundaries and white pulp expansion.
• Microplastics disrupted mitochondrial homeostasis by upregulating Drp1 and downregulating Mfn1, Mfn2, and OPA1.
• The study observed increased apoptosis (decreased Bcl-2/Bax, increased cytc, caspase3/9) and ferroptosis (decreased FTH1, GPX4, SLC7A11), alongside redox imbalance (increased MDA, decreased CAT, GSH, T-AOC).

Conclusions:

• Polystyrene microplastics induce significant spleen injury in chickens through the disruption of mitochondrial dynamics.
• Microplastic exposure triggers programmed cell death pathways, including apoptosis and ferroptosis, in chicken spleen cells.
• This study highlights the critical role of mitochondria in mediating microplastic-induced spleen toxicity and provides a foundation for further research in this area.