E-cigarette Aerosol Containing Nicotine Increases Aortic Stiffness in Young Mice

Area of Science:

• Cardiovascular Science
• Toxicology
• Vascular Biology

Background:

• E-cigarette (E-cig) use is prevalent, particularly among youth.
• The impact of E-cig exposure on vascular stiffening and remodeling remains poorly understood.

Purpose of the Study:

• To evaluate the effects of short-term E-cig aerosol exposure on vascular properties in young and adult mice.
• To investigate the impact of E-cig-derived chemicals on cultured endothelial cells (ECs) and vascular smooth muscle cells (SMCs).

Main Methods:

• Mice (6- and 14-weeks old) were exposed to E-cig aerosol with/without nicotine for 3 weeks.
• Aortic stiffness was assessed using pulse wave velocity and ex-vivo myography.
• Histological evaluation and analysis of elastin content were performed.
• Cultured human ECs and SMCs were treated with E-cig chemical constituents (e.g., acrolein, formaldehyde, nicotine).

Main Results:

• E-cig aerosol exposure significantly increased aortic stiffness (e.g., 114% in young mice with nicotine).
• Aortic elastin content decreased following E-cig exposure.
• In vitro, E-cig chemicals induced endothelial activation markers and extracellular remodeling proteins.
• Nicotine exposure in vitro reduced aortic relaxation independently of the endothelium.

Conclusions:

• Short-term E-cig aerosol exposure induces significant vascular stiffening and remodeling in mice.
• These vascular alterations may increase susceptibility to cardiovascular disease.
• Younger animals, despite greater remodeling capacity, are also adversely affected.