Nicotine alters mucin rheological properties.
Tobacco smoke exposure, the major cause of chronic obstructive pulmonary disease (COPD), instigates a dysfunctional clearance of thick obstructive mucus. However, the mechanism underlying the formation of abnormally viscous mucus remains elusive. We investigated whether nicotine can directly alter the rheological properties of mucin by examining its physicochemical interactions with human airway mucin gels secreted from A549 lung epithelial cells. Swelling kinetics and multiple particle tracking were utilized to assess mucin gel viscosity change when exposed to nicotine. Herein we show that nicotine (≤50 nM) significantly hindered postexocytotic swelling and hydration of released mucins, leading to higher viscosity, possibly by electrostatic and hydrophobic interactions. Moreover, the close association of nicotine and mucins allows airway mucus to function as a reservoir for prolonged nicotine release, leading to correlated pathogenic effects. Our results provide a novel explanation for the maltransport of poorly hydrated mucus in smokers. More importantly, this study further indicates that even low-concentration nicotine can profoundly increase mucus viscosity and thus highlights the health risks of secondhand smoke exposure.
Bioengineering, University of California at Merced, Merced, California; Center for Biomedical Engineering, Chang Gung University, Taoyuan, Taiwan; and MicroBase Technology Corporation, Taoyuan, Taiwan.
Eric Y
EY
Chen
Bioengineering, University of California at Merced, Merced, California;
Albert
A
Sun
Bioengineering, University of California at Merced, Merced, California;
Chi-Shuo
CS
Chen
Bioengineering, University of California at Merced, Merced, California;
Alexander J
AJ
Mintz
Bioengineering, University of California at Merced, Merced, California; wchin2@ucmerced.edu.
Wei-Chun
WC
Chin
D000818:Animals; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects; D005782:Gels / Q000737:chemistry; D006801:Humans; D009077:Mucins / Q000187:drug effects*; D009093:Mucus / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology*; D010316:Particle Size; D012212:Rheology; D012907:Smoking; D013552:Swine; D014783:Viscosity
D005782:Gels; D009077:Mucins; D009538:Nicotine
chronic obstructive pulmonary disease; environmental tobacco smoke; mucin swelling kinetics; mucociliary clearance; tobacco smoke; viscosity