Actin cytoskeleton redox proteome oxidation by cadmium

Area of Science:

• Environmental Health
• Cell Biology
• Toxicology

Background:

• Epidemiological studies link environmental cadmium (Cd) exposure to increased lung disease risk.
• Cd's impact on actin and associated proteins is known, but mechanisms at environmental exposure levels are unclear.
• Previous work showed redox-dependent inflammatory signaling (NF-κB) is sensitive to actin disruption.

Purpose of the Study:

• To investigate Cd's effects on the actin cytoskeleton proteome and related pathways in lung cells using mass spectrometry-based redox proteomics.
• To assess Cd's impact at environmentally relevant low concentrations.
• To understand the redox mechanisms underlying Cd-induced lung cell alterations.

Main Methods:

• Mass spectrometry-based redox proteomics to identify oxidized proteins.
• Exposure of lung fibroblasts and pulmonary artery endothelial cells to low-dose Cd.
• Immunofluorescence microscopy to visualize actin and destrin.
• Assessment of total protein thiols and glutathione redox state.

Main Results:

• Cd exposure at low environmental concentrations caused selective oxidation of peptidyl Cys in actin cytoskeleton regulatory proteins.
• These effects occurred without altering total protein thiols or glutathione redox state.
• Immunofluorescence revealed Cd stimulated filamentous actin formation and nuclear localization of destrin.

Conclusions:

• Redox states of peptidyl Cys in actin cytoskeleton proteins are selectively targeted by Cd in lung cells at environmentally relevant exposure levels.
• Cd's effects on the actin cytoskeleton may contribute to lung pathogenesis.
• This study highlights the role of specific protein cysteine oxidation in mediating environmental toxicant effects on cellular structure and function.