ATP7B detoxifies silver in ciliated airway epithelial cells

Area of Science:

• Cell Biology
• Toxicology
• Infectious Diseases

Background:

• Silver compounds are known antibiotics effective against drug-resistant bacteria.
• Previous research developed a silver compound (SCC1) for lung infections, but noted ciliated cell toxicity.

Purpose of the Study:

• To investigate the role of copper-transporting ATPases (ATP7A and ATP7B) in silver detoxification in airway epithelial cells.
• To understand the cell-specific mechanisms of silver uptake and detoxification in the lung.

Main Methods:

• Primary culture of mouse tracheal epithelial cells (mTEC) exposed to SCC1.
• Analysis of ATP7A, ATP7B, and CTR1 expression and trafficking in mTEC.
• Assessment of cell death in ATP7B-deficient cells (HepG2 and mTEC from ATP7B(-/-) mice) upon SCC1 exposure.

Main Results:

• SCC1 selectively induced ciliated cell death in mTEC.
• ATP7B expression and trafficking were observed specifically in ciliated cells, unlike ATP7A.
• ATP7B deficiency in HepG2 cells and mTEC from knockout mice significantly increased SCC1-induced cell death.
• CTR1 expression was also restricted to ciliated cells.

Conclusions:

• ATP7A, ATP7B, and CTR1 exhibit cell-type-specific expression in airway epithelial cells.
• ATP7B plays a crucial role in detoxifying silver and copper in lung ciliated cells.
• Understanding these mechanisms can inform the development of safer silver-based therapies for lung infections.