Glycyrrhetinic acid ameliorates chronic heart failure via the Nrf2 pathway

Area of Science:

• Cardiovascular Research
• Molecular Biology
• Pharmacology

Background:

• Chronic heart failure (CHF) is a complex condition characterized by cardiac dysfunction and increased oxidative stress.
• Glycyrrhetinic acid (GA), a compound derived from licorice root, has shown potential therapeutic benefits.
• The precise molecular mechanisms underlying GA's effects on CHF, particularly its interaction with nuclear receptors and oxidative stress pathways, require further elucidation.

Purpose of the Study:

• To investigate the mechanism by which glycyrrhetinic acid (GA) alleviates chronic heart failure (CHF).
• To explore the role of NR3C1-mediated regulation of Nrf2 and its impact on oxidative stress in the context of CHF.
• To determine if GA enhances NR3C1-mediated stabilization of Nrf2.

Main Methods:

• Establishment of a rat model of CHF using transverse aortic constriction, followed by treatment with GA or NR3C1 knockdown.
• In vitro studies using H9c2 cells subjected to isoproterenol to mimic CHF, with treatments including GA, Nrf2 inhibitor, or NR3C1 modulation.
• Assessment of cardiac function, hypertrophy, fibrosis, oxidative stress markers (ROS, GSH, MDA), mitochondrial membrane potential, and gene/protein expression (Nrf2, HO-1).
• Examination of regulatory interactions between NR3C1 and Nrf2 using luciferase, ChIP-qPCR, and CHX assays.

Main Results:

• GA treatment alleviated myocardial hypertrophy and fibrosis in CHF rat models and suppressed oxidative stress in CHF cell models.
• GA upregulated Nrf2 and its downstream target HO-1 protein levels.
• NR3C1 was identified as a key upstream regulator of Nrf2, enhancing its protein stability.
• NR3C1 knockdown diminished Nrf2 and HO-1 expression, disrupted mitochondrial function, and attenuated the protective effects of GA.

Conclusions:

• Glycyrrhetinic acid (GA) alleviates chronic heart failure (CHF) through a mechanism involving NR3C1-mediated stabilization of Nrf2.
• This pathway effectively reduces oxidative stress, offering a novel therapeutic strategy for CHF.
• Targeting the NR3C1-Nrf2 axis presents a promising avenue for managing heart failure.