[Trace elements storage peculiarities and metallothionein content in human thyroid gland under iodine deficiency...

Area of Science:

• Biochemistry
• Endocrinology
• Toxicology

Context:

• Thyroid gland function is influenced by trace elements like iodine and copper.
• Goiter development involves complex molecular changes, including metal dysregulation and oxidative stress.
• Metallothioneins are key proteins involved in metal detoxification and cellular defense.

Purpose:

• To investigate the relationship between iodine and copper accumulation in thyroid nodular and paranodular tissues.
• To assess the role of metal-binding proteins, antioxidants, and oxidative damage markers in goitrous thyroid tissue.
• To evaluate the compensatory mechanisms of metallothioneins in response to altered metal levels and oxidative stress.

Summary:

• Thyroid nodular and paranodular tissues exhibited significantly lower total iodine and higher copper content compared to contralateral tissues.
• Increased copper was partially sequestered by metallothioneins, which were upregulated along with their metal-binding forms and free thiols.
• Elevated cytotoxicity markers, including cathepsin D activity and DNA strand breaks, were observed in affected tissues, indicating oxidative damage.

Impact:

• Findings highlight the critical role of copper dysregulation and metallothionein activity in thyroid goiter pathogenesis.
• This research provides insights into the molecular mechanisms underlying thyroid nodule formation and progression.
• Understanding these processes may inform future therapeutic strategies for thyroid disorders involving metal imbalance and oxidative stress.