Lingguizhugan Decoction improves chronic heart failure by synergistically modulating ?1-AR/Gs/GRKs/?-arrestin signaling bias

Lingguizhugan Decoction (LGZG) demonstrates significant efficacy in treating various cardiovascular diseases clinically, yet its precise mechanism of action remains elusive. This study aimed to elucidate the potential mechanisms and effects of LGZG on isoproterenol (ISO) continuous stimulation-induced chronic heart failure (CHF) in mice, providing direct experimental evidence for further clinical applications. In vivo, continuous ISO infusion was administered to mice, and ventricular myocytes were utilized to explore LGZG?s potential mechanism of action on the ?1-adrenergic receptor (?1-AR)/Gs/G protein-coupled receptor kinases (GRKs)/?-arrestin signaling deflection system in the heart. The findings reveal that LGZG significantly reduced the messenger ribonucleic acid (mRNA) expression of hypertrophy-related biomarkers [atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP)] and improved cardiac remodeling and left ventricular diastolic function in mice with ISO-induced CHF. Furthermore, LGZG inhibited the overactivation of Gs/cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling and downregulated the downstream transcriptional activity of cAMP-response element binding protein (CREB) and the expression of the coactivator CBP/P300. Notably, LGZG downregulated the expression of ?-arrestin1 and GRK 2/3/5 while upregulating the expression of ?1-AR and ?-arrestin2. These results suggest that LGZG inhibits Gs/cAMP/PKA signaling and ?-arrestin/GRK-mediated desensitization and internalization of ?1-AR, potentially exerting cardioprotective effects through the synergistic regulation of the ?1-AR/Gs/GRKs/?-arrestin signaling deflection system via multiple pathways.