2,3',4,4',5-Pentachlorobiphenyl induced thyroid dysfunction by increasing mitochondrial oxidative stress

Area of Science:

• Environmental Toxicology
• Endocrinology
• Mitochondrial Biology

Background:

• Polychlorinated biphenyls (PCBs) are persistent organic pollutants linked to thyroid diseases.
• Previous studies indicated PCB118 induces thyroid dysfunction and mitochondrial ultrastructure abnormalities.

Purpose of the Study:

• To elucidate the specific effects of PCB118 on mitochondria.
• To investigate the relationship between mitochondrial damage and PCB118-induced thyroid dysfunction.

Main Methods:

• Wistar rats and FRTL-5 rat thyroid cells were exposed to PCB118.
• Thyroid hormone levels, sodium/iodide symporter (NIS) expression, and mitochondrial damage were assessed.
• Gene expression analysis and reactive oxygen species (ROS) production were measured.

Main Results:

• PCB118 exposure impaired thyroid function and caused mitochondrial damage in thyroid tissues.
• PCB118 increased ROS production and activated the JNK pathway.
• Expression of key mitochondrial respiratory chain genes decreased.

Conclusions:

• PCB118 damages mitochondria through increased oxidative stress.
• PCB118-induced thyroid dysfunction is potentially mediated by ROS-dependent JNK pathway activation.