Cigarette Smoke Mediates Nasal Epithelial Barrier Dysfunction via TNF-α

Area of Science:

• Respiratory Medicine
• Toxicology
• Cell Biology

Background:

• Cigarette smoke is known to impair lung epithelial barriers.
• The impact of cigarette smoke on nasal epithelial barriers remains largely unknown.

Purpose of the Study:

• To investigate the effects of cigarette smoke on nasal epithelial barrier function.
• To elucidate the underlying mechanisms of cigarette smoke-induced nasal epithelial damage.

Main Methods:

• Rats were exposed to cigarette smoke for 3 or 6 months to assess inflammatory markers and barrier function.
• Human bronchial epithelial cells were cultured in vitro with or without tumor necrosis factor-alpha (TNF-α) to examine protein continuity and tight junction expression.

Main Results:

• Cigarette smoke exposure in rats led to decreased tight junction proteins and increased inflammatory factors (IL-8, IL-6, TNF-α).
• In vitro, TNF-α disrupted the continuity and downregulated tight junction proteins in bronchial epithelial cells.

Conclusions:

• Cigarette smoke exposure disrupts the nasal mucosal barrier, with damage severity correlating to exposure duration.
• TNF-α plays a role in cigarette smoke-induced nasal epithelial barrier dysfunction by affecting tight junction proteins.