The Alberta Heart Failure Etiology and Analysis Research Team (HEART) study

BACKGROUND: Nationally, symptomatic heart failure affects 1.5-2% of Canadians, incurs $3 billion in hospital costs annually and the global burden is expected to double in the next 1–2 decades. The current one-year mortality rate after diagnosis of heart failure remains high at >25%. Consequently, new therapeutic strategies need to be developed for this debilitating condition. METHODS/DESIGN: The objective of the Alberta HEART program (http://albertaheartresearch.ca) is to develop novel diagnostic, therapeutic and prognostic approaches to patients with heart failure with preserved ejection fraction. We hypothesize that novel imaging techniques and biomarkers will aid in describing heart failure with preserved ejection fraction. Furthermore, the development of new diagnostic criteria will allow us to: 1) better define risk factors associated with heart failure with preserved ejection fraction; 2) elucidate clinical, cellular and molecular mechanisms involved with the development and progression of heart failure with preserved ejection fraction; 3) design and test new therapeutic strategies for patients with heart failure with preserved ejection fraction. Additionally, Alberta HEART provides training and education for enhancing translational medicine, knowledge translation and clinical practice in heart failure. This is a prospective observational cohort study of patients with, or at risk for, heart failure. Patients will have sequential testing including quality of life and clinical outcomes over 12 months. After that time, study participants will be passively followed via linkage to external administrative databases. Clinical outcomes of interest include death, hospitalization, emergency department visits, physician resource use and/or heart transplant. Patients will be followed for a total of 5 years. DISCUSSION: Alberta HEART has the primary objective to define new diagnostic criteria for patients with heart failure with preserved ejection fraction. New criteria will allow for targeted therapies, diagnostic tests and further understanding of the patients, both at-risk for and with heart failure. TRIAL REGISTRATION: ClinicalTrials.gov NCT02052804

The role of AMP-activate protein kinase (AMPK) in the regulation of cardiac hypertrophy

Backgrond: The polyphenol resveratrol has been attributed to some of the cardioprotective effects of red wine consumption, including the ability to inhibit hypertrophy via its antioxidant properties. A recent discovery in hepatocytes showed that resveratrol can activate AMP-activated protein kinase (AMPK), a key regulator of cellular energy homeostasis. However, it is currently unknown whether resveratrol can also activate cardiac AMPK and the functional consequence of this. As we have shown that activation of AMPK inhibits protein synthesis associated with cardiac hypertrophy, we hypothesized that an additional mechanism by which resveratrol inhibits hypertrophy is via AMPK activation. Methods: To investigate this, neonatal rat cardiac myocytes were treated with vehicle (Veh) or 50 &#181;M resveratrol (Resv) for 24 hours and 10 &#181;M phenylephrine (PE) to induce hypertrophy. Contributors of the hypertrophic response, such as protein synthesis and specific intracellular signalling pathways, were measured using [3H]-phenylalanine incorporation and immunoblot analysis, respectively. Results: Activation of AMPK was achieved with resveratrol even in the presence of phenylephrine, as shown by increased AMPK phosphorylation (Veh+PE = 0.69&#177;0.06 vs Resv+PE = 1.57&#177;0.29 arbitrary units, p < 0.01). Resveratrol also significantly decreased protein synthesis induced by phenylephrine (Veh+PE = 45702.5&#177;5252.9 vs Resv+PE = 32929.0&#177;4512.9 disintegrations per minute, p < 0.05). This was associated with reduced activities of regulators of protein synthesis, namely p70S6 kinase and eukaryotic elongation factor-2 (eEF2). Specifically, resveratrol countered the effects of phenylephrine by blunting the increase in p70S6 kinase phosphorylation while partially restoring eEF2 phosphorylation. Furthermore, resveratrol dramatically decreased nuclear factor of activated T-cells (NFAT) promoter activity, as shown by reduced luciferase activity driven by a NFAT-responsive promoter (Veh+PE = 171100&#177;7881 vs Resv+PE = 27530&#177;5975 luciferase activity, p < 0.001). Conclusions: As the calcineurin-NFAT pathway is thought to be involved in pathological hypertrophy, this provides further evidence that AMPK activation has therapeutic potential, and shows another mechanism by which resveratrol can prevent hypertrophic growth

DISSECTING THE SIGNALLING PATHWAYS INVOLVED IN THEANTI-HYPERTROPHIC EFFECTS OF RESVERATROL

Background: Pathological left ventricular hypertrophy is associated with all-cause mortality; however, effective treatment for this condition is currently lacking. We have shown that activation of AMP-activated protein kinase (AMPK) by resveratrol can inhibit myocardial hypertrophy by decreasing protein synthesis and suppressing nuclear factor ofactivated T-cells (NFAT) activation. However, the mechanism by which resveratrol affects AMPK isunknown. Since LKB1 is the upstream kinase of AMPK, we hypothesize that resveratrol signals via LKB1 toactivate AMPK and it is this signalling pathway that contributes to the anti-hypertrophic effects of resveratrol. Methods: Wildtype (WT), LKB1 null, and AMPK null mouseembryonic fibroblasts (MEFs) were treated with vehicle or 100?M resveratrol for 1 h. Cell lysates were subjected to immunoblot analysis to examine the phosphorylation status of the proteins of interest. NFAT-dependent transcription was also measured in these MEFs using a NFAT-luciferase reporter transgene. Results: While resveratrol treatment increased AMPK phosphorylation in WT MEFs, resveratrol was unable to activate AMPK in LKB1 null MEFs. In addition, resveratrol suppressed NFAT-dependent transcription in WT MEFs, yet failed to inhibit NFAT activity in AMPK null MEFs. Conclusion: These data combined with our previous data suggest that resveratrol signals through LKB1 to activate AMPK and that this activation results in suppressed protein synthesis and reduced NFAT activation. As the development of pathologicalcardiac hypertrophy is dependent on protein synthesis and NFAT activation, inhibition of these two pathways by resveratrol may be an exciting new approach for the treatment of pathological cardiac hypertrophy

Energy recovery method of damping oscillations of the vehicle suspension

Abstract. The paper analyses the existing methods of energy recovery of vehicle suspension oscillation damping. It reveals the most preferred method in which an electromagnetic device of rotational type with a ball screw gear is used. The influence of the road parameters on the dynamic loads in the drive of an electromechanical generator is etermined by mathematical modellin

Increased hepatic CD36 expression with age is associated with enhanced susceptibility to nonalcoholic fatty liver disease

CD36 has been associated with obesity and diabetes in human liver diseases, however, its role in age-associated nonalcoholic fatty liver disease (NAFLD) is unknown. Therefore, liver biopsies were collected from individuals with histologically normal livers (n=30), and from patients diagnosed with simple steatosis (NAS; n=26). Patients were divided into two groups according to age and liver biopsy samples were immunostained for CD36. NAFLD parameters were examined in young (12-week) and middle-aged (52-week) C57BL/6J mice, some fed with chow-diet and some fed with low-fat (LFD; 10% kcal fat) or high-fat diet (HFD; 60% kcal fat) for 12-weeks. CD36 expression was positively associated with age in individuals with normal livers but not in NAS patients. However, CD36 was predominantly located at the plasma membrane of hepatocytes in aged NAS patients as compared to young. In chow-fed mice, aging, despite an increase in hepatic CD36 expression, was not associated with the development of NAFLD. However, middle-aged mice did exhibit the development of HFD-induced NAFLD, mediated by an increase of CD36 on the membrane. Enhanced CD36-mediated hepatic fat uptake may contribute to an accelerated progression of NAFLD in mice and humans. Therapies to prevent the increase in CD36 expression and/or CD36 from anchoring at the membrane may prevent the development of NAFLD