Unflavored electronic cigarette exposure induces alterations in airway ciliary structure and function.

Area of Science:

• Pulmonary toxicology
• Cell biology
• Biomolecular engineering

Background:

• Electronic cigarettes (e-cigs) are marketed as safer than traditional cigarettes.
• E-liquids contain vegetable glycerin (VG), propylene glycol (PG), nicotine, and flavors.
• The airway effects of inhaled e-cig compounds are not fully understood.

Purpose of the Study:

• Investigate e-cig exposure effects on human airway epithelial cells.
• Focus on mucociliary clearance, a key lung defense mechanism.
• Analyze cellular and molecular changes in air-liquid interface (ALI) cultures.

Main Methods:

• Developed a microcontroller-based system for reproducible e-cig exposure.
• Utilized air-liquid interface (ALI) cultures of primary human airway epithelial cells.
• Employed transmission electron microscopy and phosphoproteomic analysis.

Main Results:

• Observed heterogeneous, donor-dependent effects of e-cig flavors.
• Found reduced ciliary beat frequency in ALI cultures exposed to unflavored PG:VG (30:70) with 5% nicotine.
• Identified ciliary ultrastructure defects and altered protein phosphorylation related to cytoskeletal remodeling.

Conclusions:

• Exposure to unflavored e-cigs reduces mucociliary clearance.
• E-cig use, regardless of flavor, negatively impacts lung defense mechanisms.
• Findings suggest potential risks associated with e-cig inhalation.