Cardiac hypertrophy are the major health challenges in the whole world. Ginsenoside Rd is an important component of cell growth and tumorigenesis, but the role and mechanism of ginsenoside Rd in pressure overload induced cardiac dysfunction and remodeling are still not fully illuminated. Here, cardiac hypertrophic remodeling and dysfunction were induced by pressure overload in mice. Myocardial histology was detected by Masson's trichrome staining and hematoxylin-eosin staining (H&E). Western blot was used to detect protein levels of signal mediators. Cardiac function was evaluated by echocardiography, and qPCR analysis was used to detect mRNA expression of hypertrophy and fibrosis markers. Cardiomyocyte size was detected by Wheat germ agglutinin (WGA) staining. Dihydroethidine (DHE) staining was used to detect oxidative stress. We also detected the influence of Ginsenoside Rd on rat neonatal cardiac myocytes (NRCMs) treated by Phenylephrine (PE). Our results showed that Ginsenoside Rd significantly improved pressure overload induced contractile dysfunction, fibrosis, cardiac hypertrophy, inflammation and oxidative stress in mice. Moreover, protein levels of AKT, calcineurin A, ERK1/2 and TGF-β1 were significantly decreased in the Ginsenoside Rd-treated hearts as compared to control. Ginsenoside Rd treated in cardiomyocytes inhibited PE-induced cardiomyocyte hypertrophy. These results revealed that ginsenoside Rd improved cardiac dysfunction and remodeling induced by pressure overload, which is related to the inhibition of a variety of signaling pathways.
6 November 2018 in Journal of the American Heart Association
Background: Platelets play a role in promoting inflammatory responses under several disease conditions. Platelets are activated in hypertensive patients. However, the mechanisms responsible for platelet‐mediating vascular inflammation are unknown. The present study investigated the role of platelets in promoting vascular inflammation following angiotensin II (Ang II ) stimulation, and the efficacy of antiplatelet intervention. Methods and Results: Within a mouse model of Ang II infusion (490 ng/kg per min), we measured the portion of P‐selectin–positive platelets and platelet‐monocyte (P‐M) binding in blood samples, and platelet accumulation and P‐M binding in vessels under Ang II stimulation at days 1, 3, and 7. We tested the efficacy of clopidogrel (15 mg/kg per day, followed by 5 mg/kg per day) on Ang II ‐induced platelet activation, P‐M binding, vascular platelet accumulation, as well as vascular inflammation and remodeling at day 7 or 14. Clopidogrel reduced platelet vascular deposition (28.7±2.4% versus 18.3±2.9%), suppressed inflammatory cell infiltration (3.6±0.8×10 4 /vessel versus 2.3±1.2×10 4 /vessel) and oxidative stress, and attenuated vascular remodeling and dysfunction (55.0±5.5% versus 84.0±6.0%) following Ang II stimulation at day 7 or 14. Clopidogrel suppressed Ang II ‐induced P‐M binding both at circulating (13.4±3.3% versus 5.9±2.7%) and regional (33.4±4.3% versus 11.9±2.7%) levels. Conclusions: Platelets play a critical role in vascular inflammation under Ang II stimulation, with a marked promotion of P‐M binding as an important mechanism. Clopidogrel prevented vascular inflammation in Ang II ‐infused mice.
Ventricular remodeling refers to the structural and functional changes of the heart under various stimuli or disease influences and may also be accompanied by myocardial fibrosis, where an excessive amount of fibrous tissue appears in the myocardial tissue, affecting the heart's normal contraction and relaxation. Hypertension is posing the potential risk of causing myocardial injury and remodeling. The significance of the renin-angiotensin-aldosterone system (RAAS) in myocardial remodeling cannot be overlooked. Drug targeting of RAAS can effectively lower blood pressure and reduce left ventricular mass. Studies have shown that ginsenoside Rh4 can inhibit oxidative stress and inflammatory responses. In this study, a myocardial remodeling model was established using angiotensin (Ang) II, and the inhibitory effect of RH4 on myocardial hypertrophy and remodeling induced by Ang II was investigated using pathological staining and quantitative polymerase chain reaction (qPCR). Immunofluorescence and qPCR demonstrated that Rh4 causes myocardial hypertrophy and the generation of reactive oxygen species (ROS) in vitro. The Rh4 target was identified using transcriptomics. The findings indicated that RH4 could inhibit myocardial hypertrophy, inflammatory fibrosis, and oxidative stress induced by Ang II, suggesting potential cardiovascular protection effects. In vitro experiments have shown that Rh4 inhibits myocardial hypertrophy. Transcriptomics revealed that nuclear factor interleukin-3 (NFIL3) is a downstream regulator of Rh4. By constructing AAV9-NFIL3 and injecting it into mice, it was found that NFIL3 overexpression interfered with anti-Ang II-induced myocardial remodeling of Rh4. These results indicate that Rh4 demonstrates potential therapeutic effects on myocardial hypertrophy and fibrosis.