Project description:Heart failure with preserved ejection fraction (HFpEF) is a highly prevalent and intractable form of cardiac decompensation commonly associated with diastolic dysfunction. Here, we show that diastolic dysfunction in patients with HFpEF is associated with a cardiac deficit in nicotinamide adenine dinucleotide (NAD+). Elevating NAD+ by oral supplementation of its precursor, nicotinamide, improved diastolic dysfunction induced by aging (in 2-year-old C57BL/6J mice), hypertension (in Dahl salt-sensitive rats) or cardiometabolic syndrome (in ZSF1 obese rats). Mechanistically, this effect was mediated partly through alleviated systemic comorbidities and enhanced myocardial bioenergetics, as evidenced by cardiac trasncriptome and metabolome analyses. Simultaneously, nicotinamide directly improved cardiomyocyte passive stiffness and calcium-dependent active relaxation through increased deacetylation of titin and the sarcoplasmic reticulum calcium ATPase 2a, respectively. In a long-term human cohort study, high dietary intake of naturally occurring NAD+ precursors was associated with lower blood pressure and reduced risk of cardiac mortality. Collectively, these results suggest NAD+ precursors, and especially nicotinamide, as potential therapeutic agents to treat diastolic dysfunction and HFpEF in humans.
Project description:Obesity is a complex metabolic disease considered a global pandemic and associated with high incidence of cardiovascular disease. The excess of adipose tissue may promotes maladaptation that result in alterations in structure and function of the heart; however, the mechanisms are not fully elucidated. Proteomics may provide a deeper understanding into the pathophysiological process and contribute to the identification of new potential therapeutic targets. Thus, the aim of this was evaluate the myocardial protein expression in healthy and obese rats induced by Western diet to better comprehend the network of mechanisms inherent to cardiac dysfunction in obesity. For this purpose, we performed proteomic approaches based on nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) followed by label-free quantification.
Project description:Aims: Despite the high prevalence of heart failure with preserved ejection fraction (HFpEF), the pathomechanisms remain elusive and specific therapy is lacking. Disease-causing factors include metabolic risk, notably obesity. However, proteomic changes in HFpEF are poorly understood, hampering therapeutic strategies. We sought to elucidate how metabolic syndrome affects cardiac protein expression, phosphorylation and acetylation in the Zucker diabetic fatty/Spontaneously hypertensive heart failure F1 (ZSF1) rat HFpEF model, and to evaluate some changes regarding their potential for treatment. Main methods: ZSF1 obese and lean rats were fed a Purina diet up to the onset of HFpEF in the obese animals. We quantified the proteome, phosphoproteome and acetylome of ZSF1 obese versus lean heart tissues by mass spectrometry and singled out targets for site-specific evaluation. Key findings: We found the acetylome of ZSF1 obese versus lean hearts more severely altered (21% of proteins changed) than the phosphoproteome (9%) or proteome (3%). Proteomic alterations, confirmed by immunoblotting, indicated low-grade systemic inflammation and endothelial remodeling in obese hearts, but low nitric oxide-dependent oxidative/nitrosative stress. Altered acetylation in ZSF1 obese hearts mainly affected pathways important for metabolism, energy production and mechanical function, including hypo-acetylation of mechanical proteins but hyper-acetylation of proteins regulating fatty acid metabolism. Hypo-acetylation and hypo-phosphorylation of elastic titin in ZSF1 obese hearts explained myocardial stiffening. Significance: Cardiometabolic syndrome alters posttranslational modifications, notably acetylation, in experimental HFpEF. Pathway changes implicate a HFpEF signature of low-grade inflammation, endothelial dysfunction, metabolic and mechanical impairment, and suggest titin stiffness and mitochondrial metabolism as promising therapeutic targets.
Project description:Diet induced obesity in rat was associated with myocardial dysfunction, hypertension and fibrosis. This study aimed to explore microRNA expression profiles in diet obesity-induced rat myocardium. Wistar rats were feed normal chow or high-fat diet for 20 weeks. After that, cardiac function was evaluated by echocardiography. Left ventricular myocardium was harvest to assess the extent of hypertension and fibrosis, meanwile, the left ventricular microRNA expression was analyzed using Agilent Rat miRNA microarray. Significant cardiac dysfunction, hypertension and fibrosis were found in diet-induced obesity rats as compared with normal diet rats. rno-miR-141-3p and rno-miR-144-3p were also significantly increased in myocardium of diet-induced obesity rat. These findings suggest that specific miRNA differences may contribute to the alteration in cardiac function, hypertension and fibrosis which responses to diet-induced obesity.
Project description:Adult Cardiac hypoxia as a crucial pathogenesis factor can induce detrimental effects on cardiac injury and dysfunction. The global transcriptome and translatome reflecting the cellular response to hypoxia have not yet been extensively studied in myocardium. In this study, adult rats were subjected to acute normobaric hypoxia at 10% oxygen with 10 min (mild hypoxia) and 30 min (severe hypoxia). Rat H9C2 cardiomyocytes were treated with the culture condition (1% O2, 94% N2, and 5% CO2) for mild hypoxia (8 hr) and severe hypoxia(24 hr). We then conducted RNA-seq and Ribo-seq in non-infarcted left ventricular myocardial tissues and H9C2 cells exposed to different periods of hypoxia stress in vivo and in vitro.
Project description:Abstract Background: Long-term hypertension can lead to hypertensive heart disease, which ultimately progresses to heart failure. As an angiotensin receptor blocker (ARB) antihypertensive drug, allisartan can control blood pressure and improve cardiac remodeling and cardiac dysfunction caused by hypertension. The objective of this study is to investigate the protective effects of Allisartan on the heart of spontaneously hypertensive rats (SHRs) and the underlying mechanisms. Methods: We used spontaneously hypertensive rats (SHRs) as an animal model of hypertensive heart disease and treated them with allisartan orally at a dose of 25 mg/(Kg·day). We continuously monitored the rats' blood pressure levels, measured their body and heart weights, and evaluated their cardiac structure and function using echocardiography. WGA staining and Masson trichrome staining were employed to assess the morphology of the myocardial tissue. We performed transcriptome and proteome analysis using the Solexa/Illumina sequencing platform and tandem mass tag (TMT) technology, respectively. We used immunofluorescence co-localization to analyze Nrf2 nuclear translocation, and TUNEL to detect the level of cell apoptosis. The protein and mRNA levels were determined by Western blotting and qRT-PCR, respectively. Results: Allisartan lowered blood pressure, attenuated cardiac remodeling, and improved cardiac function. Allisartan alleviated cardiomyocyte hypertrophy and cardiac fibrosis. Allisartan significantly affected the pentose phosphate pathway, fatty acid elongation, valine, leucine and isoleucine degradation, glutathione metabolism, and amino sugar and nucleotide sugar metabolism pathways in the hearts of SHRs, and upregulated the expression level of GSTM2. Allisartan activated the PI3K-AKT-Nrf2 signaling pathway and inhibited cardiomyocyte apoptosis. Conclusions: Our study determined that allisartan effectively controls blood pressure in SHRs and improves cardiac remodeling and cardiac dysfunction. Allisartan upregulates the expression level of GSTM2 in the hearts of SHRs and significantly affects glutathione metabolism shown by transcriptomics and proteomics analysis. The cardioprotective effect of allisartan may be mediated through activation of the PI3K-AKT-Nrf2 signaling pathway, upregulation of GSTM2 expression, and reduction of SHRs cardiomyocyte apoptosis.
Project description:The effects of exercise training (ET) on the heart of aortic stenosis (AS) rats are controversial and the mechanisms involved in alterations induced by ET have been poorly clarified. In this study we analyzed the myocardial proteome to identify proteins modulated by moderate intensity aerobic ET in rats with chronic supravalvar AS. Wistar rats were divided into four groups: sedentary control (C-Sed), exercised control (C-Ex), sedentary aortic stenosis (AS-Sed), and exercised AS (AS-Ex). ET consisted of five treadmill running sessions per week for 16 weeks. Statistical analysis was performed by ANOVA or Kruskal-Wallis and Goodman tests. Results were discussed at a significance level of 5%. At the end of the experiment, AS-Ex rats had higher functional capacity, lower blood lactate concentration, and better cardiac structural and left ventricular functional parameters than the AS-Sed. Myocardial proteome analysis showed that AS-Sed had higher protein expressions related to the glycolytic pathway, oxidative stress, and inflammation, and lower protein expressions related to beta-oxidation than C-Sed. AS-Ex had higher expression of one protein related to mitochondrial biogenesis and lower protein expressions associated with oxidative stress and inflammation than AS-Sed. Proteomic data were validated for proteins related to lipid and glycolytic metabolism. In conclusion, chronic pressure overload changes the expression of myocardial proteins that are mainly involved in lipid and glycolytic energy metabolism in rats. Moderate intensity aerobic training attenuates protein expressions related to oxidative stress and inflammation and increases protein expressions related to mitochondrial biogenesis. Protein changes are associated with improved functional capacity, cardiac remodeling and left ventricular function in aortic stenosis rats.
Project description:Background: Sepsis can lead to multiple organ damage, and the heart is one of the most vulnerable organs. Vagal nerve stimulation can reduce myocardial injury in sepsis and improve survival rate. However, the relative effect of disparate cell populations on sepsis induced myocardial dysfunction and the low-level tragus stimulation on it, remain unclear. Methods: We used the cardiac single-cell transcriptomic strategy to characterize the cardiac cell population and the network of cells that forms the heart. And we selected all cardiac macrophage from CD45+ cells using single-cell mRNA sequencing data. Then we used echocardiography performing, western blot and immunofluorescence and immunohistochemical technology to verify the data of the single-cell mRNA sequencing results. Results: In single-cell mRNA sequencing data, our analysis provides a comprehensive map of the cardiac cellular landscape uncovering multiple cell populations that contribute to sepsis induced myocardial dysfunction under low-level tragus stimulation. Pseudo timing analysis in single-cell sequencing showed that low level vagal nerve stimulation could induce the transformation of cardiac monocytes into M2 macrophages and play an anti-inflammatory role. After low-level tragus stimulation, the expression of α7nAChR in the heart tissue increased significantly. Echocardiography showed that low-level tragus stimulation could improve the cardiac function of septic myocardial injury of the mice. Comparing with the sepsis group, the expression of interleukin-1β in heart tissue of the mice in sepsis with low-level tragus stimulation group is significantly lower. Conclusion: Low-level tragus stimulation can improve sepsis-induced myocardial dysfunction by promoting cardiac monocytes to M2 macrophages. Goal of the study: In the present study, we aimed to screen macrophages, their crosstalk with other cells, and macrophages associated with cardiac injury and further verify their origins and roles in the septic myocardial injury process and low-level tragus stimulation (LL-TS) to treat septic myocardial dysfunction.