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.
Animals ; Heart Failure/genetics* ; Signal Transduction/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Mice ; Male ; G-Protein-Coupled Receptor Kinases/genetics* ; Mice, Inbred C57BL ; Humans ; Isoproterenol ; Arrestins/genetics* ; Chronic Disease

G protein-coupled receptor kinase 5 (GRK5) plays an important role in the regulation of GPCR-transduced signals. Our previous study showed that acute administration of morphine could significantly increase GRK5 mRNA level in the cerebral cortex and hippocampus of the rat brain. The current study investigated the potential effects of acute administration of addictive drugs including morphine, heroine and cocaine on GRK5 mRNA level in the rat brain using in situ hybridization and analyzed the effects of acute and chronic morphine treatments on GRK5 protein level in the rat brain using Western blotting assay. Our results showed that 2 h after the initial morphine (10 mg/kg), cocaine (15 mg/kg) and heroine (1 mg/kg) treatment, the mRNA level of GRK5 in the parietal cortex increased about 110% (P<0.01), 70% (P<0.05) and 100% (P<0.01), respectively. In the temporal cortex, GRK5 mRNA level increased about 90% (P<0.01), 40% (P<0.05) and 80.0% (P<0.01), respectively . In the hippocampus, the mRNA level of GRK5 increased about 60% (P<0.01), 30% (P<0.05) and 80% (P<0.01). However, the mRNA level of GRK5 remained unchanged after acute morphine, cocaine or heroine treatment. In the cerebral cortex of the rat brain, the acute administration of morphine (NS-Mor) increased GRK5 protein level by about 60% while the chronic morphine treatment (Mor-Mor) increased GRK5 protein level even higher [about 130% compared with the control group (chronic saline treatment, NS-NS) group, P<0.01]. In the hippocampus, GRK5 protein level remained unchanged after acute administration of morphine (P>0.1),while the level of GRK5 protein tended to decrease after chronic morphine treatment (P=0.098). In the thalamus, acute morphine treatment caused no change in GRK5 protein level (P>0.1) while after chronic morphine treatment, GRK5 protein level decreased significantly (more than 90%, P<0.01), Taken together, our results indicate that addictive drugs can regulate GRK5 in the rat brain on protein level as well as on mRNA level and suggest that GRK5 may play a role in addiction of psychoactive substances.
Animals ; Brain ; metabolism ; Cocaine ; adverse effects ; G-Protein-Coupled Receptor Kinase 5 ; Heroin ; adverse effects ; Male ; Morphine ; adverse effects ; Protein-Serine-Threonine Kinases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Substance-Related Disorders ; metabolism