PS-B02-4: GLYCINE BETAINE ALLEVIATES MYOCARDIAL HYPERTROPHY IN SPONTANEOUS HYPERTENSION RATS BY REGULATING AMPK/NF-KAPPAB/STIM1/ORAI1 SIGNALING PATHWAY

Abstract

Background: Spontaneous hypertension is one of the common cardiovascular diseases. Glycine betaine (GB) is a natural vitamin that has the potential to lower blood pressure. This work attempted to investigate the precise mechanism of action of GB in spontaneous hypertension. Methods: Spontaneous hypertension rats (SHRs) were administrated with 100, 200 or 400 mg/kg of GB by gavage, or followed by injection of lentivirus-mediated STIM1 overexpression vector. The heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart weight/body weight (HW/BW) of rats were monitored. The pathological changes of myocardium were examined by hematoxylin and eosin staining and Masson staining. The expression of gene and protein was detected by quantitative real-time PCR and western blotting. Results: GB at 200 and 400 mg/kg reduced the levels of HR, SBP, DBP and HW/BW in SHRs. GB decreased the cross-sectional area and fibrotic area in the myocardium, and down-regulated the expression of ANP and beta-MHC in the myocardium of SHRs. It indicated that GB treatment effectively alleviated myocardial hypertrophy in SHRs. Additionally, GB treatment enhanced p-AMPK expression and repressed the expression of p-NF-kappaB, STIM1 and Orai1 in the myocardium of SHRs. STIM1 overexpression reversed GB treatment-mediated inhibition of myocardial hypertrophy in SHRs. Conclusion: This study demonstrated that GB activated AMPK and repressed NF-kappaB/STIM1/Orai1 signaling pathway, which contributed to alleviate myocardial hypertrophy in SHRs. Thus, this work provides a theoretical basis for GB as an antihypertensive drug.