E-Cigarette Smoke Exposure Elevates Renal MR Expression and Induces BP Elevation

Area of Science:

• Nephrology
• Cardiovascular Research
• Toxicology

Background:

• E-cigarette use is linked to elevated blood pressure (BP), but mechanisms are unclear.
• The mineralocorticoid receptor (MR) regulates BP and electrolyte balance.
• The role of renal MR in e-cigarette-induced BP elevation requires investigation.

Purpose of the Study:

• To investigate the role of the renal mineralocorticoid receptor (MR) in e-cigarette-induced blood pressure elevation.
• To elucidate the underlying molecular mechanisms linking e-cigarette use to hypertension.

Main Methods:

• Mice exposed to e-cigarette aerosols (with/without nicotine) and MR antagonist eplerenone.
• Analysis of renal MR abundance, BP, urinary metabolic profiles, and key signaling pathways.
• In vitro studies using mouse renal Cortical Collecting Duct (CCD) M1 cells.

Main Results:

• Nicotine e-cigarettes increased renal MR, mean arterial BP, and pSer⁹GSK3β, while decreasing 11β-HSD2.
• Urinary metabolic changes (elevated corticosterone/11-dehydrocorticosterone ratio, reduced sodium) and increased renal epithelial sodium channel expression were observed.
• Eplerenone treatment normalized BP and reversed these metabolic and molecular changes.

Conclusions:

• Aerosol nicotine from e-cigarettes induces renal MR activation, contributing to BP elevation.
• This pathway involves reduced 11β-HSD2 and activated pSer⁹GSK3β in the kidneys.
• Findings suggest potential renal health risks associated with e-cigarette use.