Air-liquid interface culture changes surface properties of A549 cells

Area of Science:

• Cell Biology
• Toxicology
• Respiratory Medicine

Background:

• A549 cells are widely used for respiratory cytotoxicity assessment.
• Air-liquid interface (ALI) culture enhances the physiological relevance of respiratory cell models.
• Previous studies suggest ALI culture may alter A549 cell phenotype.

Purpose of the Study:

• To investigate the influence of ALI culture on A549 cell phenotype compared to conventional culture.
• To characterize changes in A549 cells cultured in transwell systems under ALI conditions.

Main Methods:

• Morphological and proliferation assessments.
• Transepithelial electrical resistance (TEER) measurements.
• Whole genome transcription analysis, Western blot, and immunocytochemistry.
• Lipid staining, surface morphology, cell elasticity, surface tension, and cytotoxicity assays.

Main Results:

• A549 cells in ALI culture exhibited minor changes in alveolar differentiation markers.
• Significant alterations were observed in lipid staining, surface morphology, and surface tension.
• Cytotoxicity of quartz particles was markedly different in ALI-cultured A549 cells.

Conclusions:

• ALI culture induces substantial changes in A549 cell surface properties.
• These surface property modifications, rather than increased surfactant protein expression, drive altered physiological responses.
• Findings highlight the importance of ALI culture for accurate A549 cell-based respiratory toxicity studies.