Brain natriuretic peptide: Much more than a biomarker

Area of Science:

• Cardiology
• Pulmonology
• Biochemistry

Background:

• Brain natriuretic peptide (BNP) activates natriuretic peptide receptor A (NPR-A), influencing natriuresis, diuresis, and vasodilation, thereby reducing cardiac workload.
• BNP and NT-proBNP are established biomarkers for heart failure diagnosis and correlate with left ventricular function in COPD patients.
• Previous research on NPR-A activation for obstructive pulmonary disorders yielded conflicting results.

Purpose of the Study:

• To explore the teleological activities and paradoxical effects of BNP in chronic obstructive respiratory disorders.
• To review scientific findings on BNP's role beyond its biomarker function in respiratory conditions.

Main Methods:

• Review of in vitro and in vivo studies in animals and humans.
• Analysis of ex vivo models of asthma and COPD.
• Examination of the mechanism of action of BNP in human airways.

Main Results:

• Recent ex vivo studies confirmed BNP's bronchorelaxant effect and protective role against bronchial hyperresponsiveness in asthma and COPD.
• The mechanism involves an autocrine loop via NPR-A on bronchial epithelium, leading to smooth muscle relaxation.
• BNP's action on airway smooth muscle (ASM) occurs despite ASM not expressing NPR-A.

Conclusions:

• BNP exhibits a dual role, acting as both a cardiac biomarker and a therapeutic agent in respiratory disorders.
• The specific mechanism of BNP's action in the airways clarifies its paradoxical effects.
• BNP warrants consideration for its potential therapeutic applications in chronic obstructive respiratory disorders, extending beyond its diagnostic utility.