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A high salt intake exacerbates insulin resistance, evoking hypertension due to systemic perivascular inflammation, oxidative-nitrosative stress and endothelial dysfunction. Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blockers (ARBs) have been shown to abolish inflammation and redox stress but only partially restore endothelial function in mesenteric vessels. We investigated whether sympatho-adrenal overactivation evokes coronary vascular dysfunction when a high salt intake is combined with insulin resistance in male Goto–Kakizaki (GK) and Wistar rats treated with two different classes of β-blocker or vehicle, utilising synchrotron-based microangiography in vivo. Further, we examined if chronic carvedilol (CAR) treatment preserves nitric oxide (NO)-mediated coronary dilation more than metoprolol (MET). A high salt diet (6% NaCl w/w) exacerbated coronary microvessel endothelial dysfunction and NO-resistance in vehicle-treated GK rats while Wistar rats showed modest impairment. Microvascular dysfunction was associated with elevated expression of myocardial endothelin, inducible NO synthase (NOS) protein and 3-nitrotyrosine (3-NT). Both CAR and MET reduced basal coronary perfusion but restored microvessel endothelium-dependent and -independent dilation indicating a role for sympatho-adrenal overactivation in vehicle-treated rats. While MET treatment reduced myocardial nitrates, only MET treatment completely restored microvessel dilation to dobutamine (DOB) stimulation in the absence of NO and prostanoids (combined inhibition), indicating that MET restored the coronary flow reserve attributable to endothelium-derived hyperpolarisation (EDH). In conclusion, sympatho-adrenal overactivation caused by high salt intake and insulin resistance evoked coronary microvessel endothelial dysfunction and diminished NO sensitivity, which were restored by MET and CAR treatment in spite of ongoing inflammation and oxidative-nitrosative stress presumably caused by uninhibited renin–angiotensin–aldosterone system (RAAS) overactivation.

Background Cardiorenal syndrome (CRS) is a major health burden worldwide in need of novel therapies, as current treatments remain suboptimal. The present study assessed the therapeutic potential of apoptosis signal-regulating kinase 1 (ASK1) inhibition in a rat model of CRS. Methods Adult male Sprague-Dawley rats underwent surgery for myocardial infarction (MI) (week 0) followed by 5/6 subtotal nephrectomy (STNx) at week 4 to induce to induce a combined model of heart and kidney dysfunction. At week 6, MI + STNx animals were randomized to receive either 0.5% carboxymethyl cellulose (Vehicle, n = 15, Sham = 10) or G226 (15 mg/kg daily, n = 11). Cardiac and renal function was assessed by echocardiography and glomerular filtration rate (GFR) respectively, prior to treatment at week 6 and endpoint (week 14). Haemodynamic measurements were determined at endpoint prior to tissue analysis. Results G226 treatment attenuated the absolute change in left ventricular (LV) fractional shortening and posterior wall thickness compared to Vehicle. G226 also attenuated the reduction in preload recruitable stroke work. Increased myocyte cross sectional area, cardiac interstitial fibrosis, immunoreactivity of cardiac collagen-I and III and cardiac TIMP-2 activation, were significantly reduced following G226 treatment. Although we did not observe improvement in GFR, G226 significantly reduced renal interstitial fibrosis, diminished renal collagen-I and -IV, kidney injury molecule-1 immunoreactivity as well as macrophage infiltration and SMAD2 phosphorylation. Conclusion Inhibition of ASK1 ameliorated LV dysfunction and diminished cardiac hypertrophy and cardiorenal fibrosis in a rat model of CRS. This suggests that ASK1 is a critical pathway with therapeutic potential in the CRS setting.

Neovascular AMD (nAMD) leads to vision loss and is a leading cause of visual impairment in the industrialised world. Current treatments that target blood vessel growth have not been able to treat subretinal fibrosis and nAMD patients continue to lose vision. The molecular mechanisms involved in the development of fibrotic lesions in nAMD are not well understood. The aim of this study was to further understand subretinal fibrosis in the laser photocoagulation model of choroidal neovascularization (CNV) by studying the whole transcriptome of the RPE/choroid following CNV and the application of an anti-fibrotic following CNV. Seven days after laser induced CNV, RPE and choroid tissue was separated and underwent RNAseq. Differential expression analysis and pathway analysis revealed an over representation of immune signalling and fibrotic associated pathways in CNV compared to control RPE/choroid tissue. Comparisons between the mouse CNV model to human CNV revealed an overlap in upregulated expression for immune genes (Ccl2, Ccl8 and Cxcl9) and extracellular matrix remodeling genes (Comp, Lrcc15, Fndc1 and Thbs2). Comparisons between the CNV model and other fibrosis models showed an overlap of over 60% of genes upregulated in either lung or kidney mouse models of fibrosis. Treatment of CNV using a novel cinnamoyl anthranilate anti-fibrotic (OCX063) in the laser induced CNV model was selected as this class of drugs have previously been shown to target fibrosis. CNV lesion leakage and fibrosis was found to be reduced using OCX063 and gene expression of genes within the TGF-beta signalling pathway. Our findings show the presence of fibrosis gene expression pathways present in the laser induced CNV mouse model and that anti-fibrotic treatments offer the potential to reduce subretinal fibrosis in AMD.

Drug repurposing is promoted as a cost- and time-effective mechanism for providing new medicines. Often, however, there is insufficient consideration by academic researchers of the processes required to ensure that a repurposed drug can be used for a new indication. This may explain the inability of drug repurposing to fulfill its promise. Important aspects, often overlooked, include financial and intellectual property considerations, the clinical and regulatory path, and clinical equipoise, which provides ethical justification for randomized controlled trials. The goal of drug repurposing is to obtain a new regulator-approved label for an existing drug, and so, the trajectory for drug repurposing and traditional drug development is similar. Here, we discuss factors critical for a successful repurposed medicine to help academic investigators better identify drug repurposing opportunities.

Protein-bound uremic toxins (PBUTs) have adverse effects on vascular function, which is imperative in the progression of cardiovascular and renal diseases. The role of sphingolipids in PBUT-mediated vasculo-endothelial pathophysiology is unclear. This study assessed the therapeutic potential of dihydroceramide desaturase 1 (Des1) inhibition, the last enzyme involved in de novo ceramide synthesis, to mitigate the vascular effects of the PBUT indoxyl sulfate (IS). Rat aortic rings were isolated and vascular reactivity was assessed in organ bath experiments followed by immunohistochemical analyses. Furthermore, cultured human aortic endothelial cells were assessed for phenotypic and mechanistic changes. Inhibition of Des1 by a selective inhibitor CIN038 (0.1 to 0.3 μM) improved IS-induced impairment of vasorelaxation and modulated immunoreactivity of oxidative stress markers. Des1 inhibition also reversed IS-induced reduction in endothelial cell migration (1.0 μM) by promoting the expression of angiogenic cytokines and reducing inflammatory and oxidative stress markers. These effects were associated with a reduction of TIMP1 and the restoration of Akt phosphorylation. In conclusion, Des1 inhibition improved vascular relaxation and endothelial cell migration impaired by IS overload. Therefore, Des1 may be a suitable intracellular target to mitigate PBUT-induced adverse vascular effects. Refereed/Peer-reviewed

Cardiorenal syndrome (CRS) is a multi-organ disease, encompassing heart, kidney and vascular system dysfunction. CRS is a worldwide problem, with high morbidity, mortality, and inflicts a significant burden on the health care system. The pathophysiology is complex, involving interactions between neurohormones, inflammatory processes, oxidative stress and metabolic derangements. Therapies remain inadequate, mainly comprising symptomatic care with minimal prospect of full recovery. Challenges include limiting the contradictory effects of multi-organ targeted drug prescriptions and continuous monitoring of volume overload. Novel strategies such as multi-organ transplantation and innovative dialysis modalities have been considered but lack evidence in the CRS context. The adjunct use of pharmaceuticals targeting alternative pathways showing positive results in preclinical models also warrants further validation in the clinic. In recent years, studies have identified the involvement of gut dysbiosis, uraemic toxin accumulation, sphingolipid imbalance and other unconventional contributors, which has encouraged a shift in the paradigm of CRS therapy.

Hypertension plays an important role in the development and progression of chronic kidney disease. Studies to date, with mineralocorticoid receptor antagonists (MRA), have demonstrated varying degrees of results in modifying the development of renal fibrosis. This study aimed to investigate whether treatment with a MRA commenced following the establishment of hypertension, a situation more accurately representing the clinical setting, modified the progression of renal fibrosis. Using male Cyp1a1Ren2 rats (n = 28), hypertension was established by addition of 0.167% indole‐3‐carbinol (w/w) to the rat chow, for 2 weeks prior to treatment. Rats were then divided into normotensive, hypertensive (H), or hypertensive with daily oral spironolactone treatment (H + SP) (human equivalent dose 50 mg/day). Physiological data and tissue were collected after 4 and 12 weeks for analysis. After 4 weeks, spironolactone had no demonstrable effect on systolic blood pressure (SBP), proteinuria, or macrophage infiltration in the renal cortex. However, glomerulosclerosis and renal cortical fibrosis were significantly decreased. Following 12 weeks of spironolactone treatment, SBP was lowered (not back to normotensive levels), proteinuria was reduced, and the progression of glomerulosclerosis and renal cortical fibrosis was significantly blunted. This was associated with a significant reduction in macrophage and myofibroblast infiltration, as well as CTGF and pSMAD2 expression. In summary, in a model of established hypertension, spironolactone significantly blunted the progression of renal fibrosis and glomerulosclerosis, and downregulated the renal inflammatory response, which was associated with reduced proteinuria, despite only a partial reduction in systolic blood pressure. This suggests a blood pressure independent effect of MRA on renal fibrosis., In the setting of severe hypertension, spironolactone reduces kidney fibrosis independent of a hypotensive effect. Mineralocorticoid receptor antagonism reduces hypertensive‐mediated kidney fibrosis.

The uremic toxin indoxyl sulfate (IS), elevated in chronic kidney disease (CKD), is known to contribute towards progressive cardiovascular disease. IS activates the aryl hydrocarbon receptor (AhR) mediating oxidative stress and endothelial dysfunction via activation of the CYP1A1 pathway. The present study examines AhR inhibition with the antagonist, CH223191, on IS-mediated impairment of vascular endothelial function and disruption of redox balance. The acute effects of IS on endothelium-dependent relaxation were assessed in aortic rings from Sprague Dawley rats exposed to the following conditions: (1) control; (2) IS (300 μM); (3) IS + CH223191 (1 μM); (4) IS + CH223191 (10 μM). Thereafter, tissues were assessed for changes in expression of redox markers. IS reduced the maximum level of endothelium-dependent relaxation (Rmax) by 42% (p < 0.001) compared to control, this was restored in the presence of increasing concentrations of CH223191 (p < 0.05). Rings exposed to IS increased expression of CYP1A1, nitro-tyrosine, NADPH oxidase 4 (NOX4), superoxide, and reduced eNOS expression (p < 0.05). CH223191 (10 μM) restored expression of these markers back to control levels (p < 0.05). These findings demonstrate the adverse impact of IS-mediated AhR activation on the vascular endothelium, where oxidative stress may play a critical role in inducing endothelial dysfunction in the vasculature of the heart and kidneys. AhR inhibition could provide an exciting novel therapy for CVD in the CKD setting.

Myocardial injury is a major contributor to left ventricular (LV) remodelling activating neurohormonal and inflammatory processes that create an environment of enhanced oxidative stress. This results in geometric and structural alterations leading to reduced LV systolic function. In this study we evaluated the efficacy of NP202, a synthetic flavonol, on cardiac remodelling in a chronic model of myocardial infarction (MI).A rat model of chronic MI was induced by permanent surgical ligation of the coronary artery. NP202 treatment was commenced 2 days post-MI for 6 weeks at different doses (1, 10 and 20 mg/kg/day) to determine efficacy. Cardiac function was assessed by echocardiography prior to treatment and at week 6, and pressure-volume measurements were performed prior to tissue collection. Tissues were analysed for changes in fibrotic and inflammatory markers using immunohistochemistry and gene expression analysis.Rats treated with NP202 demonstrated improved LV systolic function and LV geometry compared to vehicle treated animals. Furthermore, measures of hypertrophy and interstitial fibrosis were attenuated in the non-infarct region of the myocardium with NP202 at the higher dose of 20 mg/kg (P 0.05). At the tissue level, NP202 reduced monocyte chemoattractant protein-1 expression (P 0.05) and tended to attenuate active caspase-3 expression to similar levels observed in sham animals (P = 0.075).Improved LV function and structural changes observed with NP202 may be mediated through inhibition of inflammatory and apoptotic processes in the MI setting. NP202 could therefore prove a useful addition to standard therapy in patients with post-MI LV dysfunction.

This study investigated the prevalence of physical activity prescriptions in the management of high blood pressure (BP), the characteristics of people given these, and whether prescriptions were associated with the physical activity beliefs and practices of patients. A retrospective cohort study was undertaken, involving 365 general practitioners (GPs) from across Australia. The records of up to 20 patients per GP with high BP (N = 6512) were audited to identify physical activity and pharmacological prescriptions over four consecutive consultations. A sub-sample (n = 535) of patients completed a physical activity questionnaire. Physical activity prescriptions were recorded for 42.6% of patients with controlled BP, 39.5% for those with mild hypertension and 35.7% of those with moderate to severe hypertension. These were more likely in patients with cardiovascular disease (OR 1.41, 95% CI 1.23-1.62) and diabetes (OR 1.21, 95% CI 1.04-1.42), and less likely in those with moderate to severe hypertension (OR 0.80, 95% CI 0.69-0.94), aged 75 years and over (OR 0.62, 95% CI 0.51-0.74) and with high cholesterol (OR 0.73, 95% CI 0.57-0.94). Patients receiving a physical activity prescription were more likely to report this behaviour as important for their health and that they had increased their levels of participation. Most patients with high BP are not receiving physical activity prescriptions, and GPs show greater readiness to address this behaviour in patients with existing chronic disease. There is a need for efficacious and practical strategies for promoting physical activity that can be adopted in the routine management of high BP in general practice.

Visual Abstract, Highlights • Treatment of female rats with a single dose of isoproterenol results in apical hypokinesis mimicking Takotsubo syndrome • Myocardial inflammation includes increased content of 3-nitrotyrosine and poly(ADP-ribose), indicating nitrosative stress and PARP-1 activation, respectively • Pretreatment with 3-aminobenzamide (a PARP-1 inhibitor) attenuates negative inotropic changes • We conclude that the peroxynitrite/PARP-1 cascade contributed to negative inotropy in this model of Takotsubo syndrome, consistent with the limited data available in patients, Summary Previous studies have shown that patients with Takotsubo syndrome (TS) have supranormal nitric oxide signaling, and post-mortem studies of TS heart samples revealed nitrosative stress. Therefore, we first showed in a female rat model that isoproterenol induces TS-like echocardiographic changes, evidence of nitrosative stress, and consequent activation of the energy-depleting enzyme poly(ADP-ribose) polymerase-1. We subsequently showed that pre-treatment with an inhibitor of poly(ADP-ribose) polymerase-1 ameliorated contractile abnormalities. These findings thus add to previous reports of aberrant β-adrenoceptor signaling (coupled with nitric oxide synthase activation) to elucidate mechanisms of impaired cardiac function in TS and point to potential methods of treatment.

Cardiac fibrosis refers to an excessive deposition of extracellular matrix (ECM) in cardiac tissue. Fibrotic tissue is stiffer and less compliant, resulting in subsequent cardiac dysfunction and heart failure. Cardiac fibrosis in the ageing heart may involve activation of fibrogenic signalling and inhibition of anti-fibrotic signalling, leading to an imbalance of ECM turnover. Excessive accumulation of ECM such as collagen in older patients contributes to progressive ventricular dysfunction. Overexpression of collagen is derived from various sources, including higher levels of fibrogenic growth factors, proliferation of fibroblasts and cellular transdifferentiation. These may be triggered by factors, such as oxidative stress, inflammation, hypertension, cellular senescence and cell death, contributing to age-related fibrotic cardiac remodelling. In this review, we will discuss the fibrogenic contributors in age-related cardiac fibrosis, and the potential mechanisms by which fibrogenic processes can be interrupted for therapeutic intent.

Introduction Cardiovascular disease (CVD) mortality is significantly higher in chronic kidney disease (CKD) patients, with vascular calcification and atherosclerosis proving to be major contributors. Endothelial dysfunction is an early marker of atherosclerosis, triggered by oxidative stress and reduced nitric oxide production. The uremic toxin indoxyl sulphate (IS), a protein-bound non-dialyzable molecule derived from dietary tryptophan that accumulates in the blood of CKD patients, activates the aryl hydrocarbon receptor (AhR) promoting downstream cytochrome P450 1A1 (CYP1A1) expression mediating oxidative stress and potentially endothelial dysfunction. Targeting IS-induced AhR activation in the endothelium has not previously been examined and may represent a novel approach in targeting endothelial dysfunction. Purpose To assess the ability of the AhR antagonist, CH223191, to inhibit IS-mediated impairment of endothelial function and disruption of redox balance. Methods To assess endothelium-dependent relaxation, the thoracic aorta from adult male Sprague Dawley rats (N=10) were used in ex vivo experiments. Rings (5mm) from the aorta were exposed to IS (300μM) in the presence and absence of the AhR antagonist CH223191 (1 and 10μM), prior to pre-constriction of the vessel with phenylephrine (30μM) followed by relaxation with acetylcholine (ACh; 1nM-30μM). Control rings were not exposed to IS or CH223191 to determine normal endothelial responses to ACh. Responses were recorded with isometric force transducers connected to a PowerLab using Chart Software. Tissue sections from these rings were stained for superoxide using dihydroethidium. To examine key AhR-mediated oxidative stress pathways, separate aortic rings were exposed to IS and CH223191, under the above conditions, for 4 hours prior to RNA extraction and real-time PCR analysis. Results IS reduced the maximum level of endothelium-dependent relaxation (Rmax) to 50.17±2.71% (P CH223191 restores endothelial function Conclusion Our findings demonstrate the adverse impact of IS-mediated AhR activation on the vascular endothelium, where oxidative stress may play a critical role inducing endothelial dysfunction in the vasculature of the heart and kidneys. AhR inhibition may provide a novel therapy for CVD in the CKD setting. Acknowledgement/Funding National Health and Medical Research Council of Australia Program Grant

Drained triaxial tests have been performed to explore the effect of particle loss on shearing behaviour and critical states in granular mixtures. The mixtures comprise Leighton Buzzard sand (d50 = 0.8 mm), to which was added 15% by mass of salt particles of different nominal sizes: 0.063 mm, 0.25 mm and 0.5 mm. Shearing behaviours before and after particle loss (by dissolution) were compared. A good fit is observed between the test data and a stress-dilatancy relationship for the post-dissolution tests, highlighting the ability of the stress-dilatancy analysis as a means to interpret the effects of particle loss on shearing. It was noted that critical state strength parameter M is determined by the post-dissolution grading regardless of size of removed particle. However, the duration of contractant volumetric strain increased with the larger removed particles (0.25 mm & 0.5 mm) even when initial specific volumes were virtually identical. It is suggested that a loose volumetric state is reached if the sand particle network is initially disrupted by the amount and/or size of salt particles, which following dissolution results in structural or fabric phenomena that are not reflected in scalar volumetric measures such as specific volume.

Coronary microvessel endothelial dysfunction and nitric oxide (NO) depletion contribute to elevated passive tension of cardiomyocytes, diastolic dysfunction and predispose the heart to heart failure with preserved ejection fraction. We examined if diastolic dysfunction at the level of the cardiomyocytes precedes coronary endothelial dysfunction in prediabetes. Further, we determined if myofilaments other than titin contribute to impairment. Utilizing synchrotron microangiography we found young prediabetic male rats showed preserved dilator responses to acetylcholine in microvessels. Utilizing synchrotron X-ray diffraction we show that cardiac relaxation and cross-bridge dynamics are impaired by myosin head displacement from actin filaments particularly in the inner myocardium. We reveal that increased PKC activity and mitochondrial oxidative stress in cardiomyocytes contributes to rho-kinase mediated impairment of myosin head extension to actin filaments, depression of soluble guanylyl cyclase/PKG activity and consequently stiffening of titin in prediabetes ahead of coronary endothelial dysfunction.

Aims Indoxyl sulfate (IS), a protein-bound uremic toxin, is implicated in endothelial dysfunction, which contributes to adverse cardiovascular events in chronic kidney disease. Apoptosis signal regulating kinase 1 (ASK1) is a reactive oxygen species-driven kinase involved in IS-mediated adverse effects. This study assessed the therapeutic potential of ASK1 inhibition in alleviating endothelial effects induced by IS. Main methods IS, in the presence and absence of a selective ASK1 inhibitor (GSK2261818A), was assessed for its effect on vascular reactivity in rat aortic rings, and cultured human aortic endothelial cells where we evaluated phenotypic and mechanistic changes. Key findings IS directly impairs endothelium-dependent vasorelaxation and endothelial cell migration. Mechanistic studies revealed increased production of reactive oxygen species-related markers, reduction of endothelial nitric oxide synthase and increased protein expression of tissue inhibitor of matrix metalloproteinase 1 (TIMP1). IS also increases angiopoietin-2 and tumour necrosis factor α gene expression and promotes transforming growth factor β receptor abundance. Inhibition of ASK1 ameliorated the increase in oxidative stress markers, promoted autocrine interleukin 8 pro-angiogenic signalling and decreased anti-angiogenic responses at least in part via reducing TIMP1 protein expression. Significance ASK1 inhibition attenuated vasorelaxation and endothelial cell migration impaired by IS. Therefore, ASK1 is a viable intracellular target to alleviate uremic toxin-induced impairment in the vasculature.

Dihydrosphingolipids refer to sphingolipids early in the biosynthetic pathway that do not contain a C4-trans-double bond in the sphingoid backbone: 3-ketosphinganine (3-ketoSph), dihydrosphingosine (dhSph), dihydrosphingosine-1-phosphate (dhS1P) and dihydroceramide (dhCer). Recent advances in research related to sphingolipid biochemistry have shed light on the importance of sphingolipids in terms of cellular signalling in health and disease. However, dihydrosphingolipids have received less attention and research is lacking especially in terms of their molecular mechanisms of action. This is despite studies implicating them in the pathophysiology of disease, for example dhCer in predicting type 2 diabetes in obese individuals, dhS1P in cardiovascular diseases and dhSph in hepato-renal toxicity. This review gives a comprehensive summary of research in the last 10-15 years on the dihydrosphingolipids, 3-ketoSph, dhSph, dhS1P and dhCer, and their relevant roles in different diseases. It also highlights gaps in research that could be of future interest.

Landfill reclaimed soil here refers to largely degraded materials excavated from old landfill sites, which after processing can be reinstated as more competent fill, thereby restoring the former landfill space. The success of the process depends on the presence of remaining degradable particles and their influence on settlement. Tests on salt-sand mixtures, from which the salt is removed, have been used to quantify the impact of particle loss on settlement. Where the amount of particle loss is small, say 10% by mass or less, settlements are small and apparently independent of lost particle size. A conceptual model is presented to explain this behaviour in terms of nestling particles and strong force chains. At higher percentages of lost particles, greater rates of settlement together with some sensitivity to particle size were observed. The conceptual model was then applied to two landfill reclaimed soils, the long-term settlements of which were found to be consistent with the conceptual model suggesting that knowledge of particle content and relative size are sufficient to estimate the influence of degradable particles in landfill reclaimed soils.

BACKGROUND Renal denervation (RDN) is effective at reducing blood pressure (BP) among patients with treatment-resistant hypertension (TRH). However, recent findings regarding the effectiveness of RDN for BP reduction compared with standard treatment of care (SoC) has initiated a rigorous debate about its role in TRH management. In this study, we sought to determine the thresholds for cardiovascular risk and costs of RDN which would make RDN cost-effective. METHODS A Markov model was constructed to simulate cardiovascular events over a lifetime among TRH subjects aged 60 years at baseline, and without prior cardiovascular disease. The effect on lowering BP was based on results observed in clinical trials of RDN undertaken to date, and the expected subsequent change to cardiovascular risk was drawn from a published meta-regression. Cost and utility data were drawn from published sources. Incremental cost-effectiveness ratios (ICER) in terms of Australian dollars (AUD) per life year and per quality-adjusted life year (QALY) gained were estimated to assess RDN cost-effectiveness relative to SoC from the Australian health care perspective, assuming a willingness-to-pay threshold of AUD 50,000. RESULTS Over a lifetime horizon, the model predicted that at the current estimated costs of RDN (AUD 9531/€6573, 1€ = 1.45 AUD), it would be cost-effective only if it was targeted to patients whose 10-year predicted cardiovascular risk was at least 13.2% initially. The ICERs (discounted) were AUD 49,519 per life year gained and AUD 47,130 per QALY gained. CONCLUSIONS At current costs and based on currently observed effects on BP reduction, RDN would be cost-effective among patients with TRH.

ClC-5 is a chloride/proton exchanger that plays an obligate role in albumin uptake by the renal proximal tubule. ClC-5 forms an endocytic complex with the albumin receptor megalin/cubilin. We have identified a novel ClC-5 binding partner, cytosolic aspartyl aminopeptidase (DNPEP; EC 3.4.11.21), that catalyzes the release of N-terminal aspartate/glutamate residues. The physiological role of DNPEP remains largely unresolved. Mass spectrometric analysis of proteins binding to the glutathione- S-transferase (GST)-ClC-5 C terminus identified DNPEP as an interacting partner. Coimmunoprecipitation confirmed that DNPEP and ClC-5 also associated in cells. Further experiments using purified GST-ClC-5 and His-DNPEP proteins demonstrated that the two proteins bound directly to each other. In opossum kidney (OK) cells, confocal immunofluorescence studies revealed that DNPEP colocalized with albumin-containing endocytic vesicles. Overexpression of wild-type DNPEP increased cell-surface levels of ClC-5 and albumin uptake. Analysis of DNPEP-immunoprecipitated products from rat kidney lysate identified β-actin and tubulin, suggesting a role for DNPEP in cytoskeletal maintenance. A DNase I inhibition assay showed a significant decrease in the amount of G actin when DNPEP was overexpressed in OK cells, suggesting a role for DNPEP in stabilizing the cytoskeleton. DNPEP was not present in the urine of healthy rats; however, it was readily detected in the urine in rat models of mild and heavy proteinuria (diabetic nephropathy and anti-glomerular basement membrane disease, respectively). Urinary levels of DNPEP were found to correlate with the severity of proteinuria. Therefore, we have identified another key molecular component of the albumin endocytic machinery in the renal proximal tubule and describe a new role for DNPEP in stabilizing the actin cytoskeleton.

Summary Hyperglycaemia increases the risk of developing diabetic nephropathy, with primary targets in the glomerulus and proximal tubule. Importantly, glomerular damage in the kidney leads to elevated albumin levels in the filtrate, which contributes to tubular structural modifications that lead to dysfunction. Diabetes alters the endocannabinoid system in a number of target organs, with previous research characterizing tissue-specific changes in the expression of the cannabinoid receptor 1 (CB1) and G protein-coupled receptor 55 (GPR55), a putative cannabinoid receptor, in diabetes. Although these receptors have a functional role in the cannabinoid system in the kidney, there has been little investigation into changes in the expression of CB1 and GPR55 in the proximal tubule under diabetic conditions. In this study, CB1 and GPR55 messenger RNA and protein levels were quantified in cultured human kidney cells and then treated with either elevated glucose, elevated albumin, or a combination of glucose and albumin for 4, 6, 18, or 24 h. In addition, CB1 and GPR55 protein expression was characterized in whole-kidney lysate from streptozotocin-induced diabetic Sprague-Dawley rats. In vitro exposure to elevated glucose and albumin increased CB1 and GPR55 messenger RNA and protein expression in proximal tubule cells in a time-dependant manner. In whole kidney of streptozotocin-induced diabetic rats, CB1 protein was upregulated, whereas GPR55 protein concentration was not altered. Thus, expression of CB1 and GPR55 in proximal tubules is altered in response to elevated levels of glucose and albumin. Further investigations should determine if these receptors are effective physiological targets for the treatment and prevention of diabetic nephropathy.

This study investigated the prevalence of physical activity prescriptions in the management of high blood pressure (BP), the characteristics of people given these, and whether prescriptions were associated with the physical activity beliefs and practices of patients. A retrospective cohort study was undertaken, involving 365 general practitioners (GPs) from across Australia. The records of up to 20 patients per GP with high BP (N = 6512) were audited to identify physical activity and pharmacological prescriptions over four consecutive consultations. A sub-sample (n = 535) of patients completed a physical activity questionnaire. Physical activity prescriptions were recorded for 42.6% of patients with controlled BP, 39.5% for those with mild hypertension and 35.7% of those with moderate to severe hypertension. These were more likely in patients with cardiovascular disease (OR 1.41, 95% CI 1.23-1.62) and diabetes (OR 1.21, 95% CI 1.04-1.42), and less likely in those with moderate to severe hypertension (OR 0.80, 95% CI 0.69-0.94), aged 75 years and over (OR 0.62, 95% CI 0.51-0.74) and with high cholesterol (OR 0.73, 95% CI 0.57-0.94). Patients receiving a physical activity prescription were more likely to report this behaviour as important for their health and that they had increased their levels of participation. Most patients with high BP are not receiving physical activity prescriptions, and GPs show greater readiness to address this behaviour in patients with existing chronic disease. There is a need for efficacious and practical strategies for promoting physical activity that can be adopted in the routine management of high BP in general practice.

Reduced clearance of lipoproteins by HDL scavenger receptor class B1 (SR-B1) plays an important role in occlusive coronary artery disease. However, it is not clear how much microvascular dysfunction contributes to ischemic cardiomyopathy. Our aim was to determine the distribution of vascular dysfunction in vivo in the coronary circulation of male mice after brief exposure to Paigen high fat diet, and whether this vasomotor dysfunction involved nitric oxide (NO) and or endothelium derived hyperpolarization factors (EDHF). We utilised mice with hypomorphic ApoE lipoprotein that lacked SR-B1 (SR-B1−/−/ApoER61h/h, n = 8) or were heterozygous for SR-B1 (SR-B1+/−/ApoER61h/h, n = 8) to investigate coronary dilator function with synchrotron microangiography. Partially occlusive stenoses were observed in vivo in SR-B1 deficient mice only. Increases in artery-arteriole calibre to acetylcholine and sodium nitroprusside stimulation were absent in SR-B1 deficient mice. Residual dilation to acetylcholine following L-NAME (50 mg/kg) and sodium meclofenamate (3 mg/kg) blockade was present in both mouse groups, except at occlusions, indicating that EDHF was not impaired. We show that SR-B1 deficiency caused impairment of NO-mediated dilation of conductance and microvessels. Our findings also suggest EDHF and prostanoids are important for global perfusion, but ultimately the loss of NO-mediated vasodilation contributes to atherothrombotic progression in ischemic cardiomyopathy.

Angiotensin receptor neprilysin inhibitor (ARNi) enhances beneficial natriuretic peptides by inhibiting their breakdown through neprilysin. Although the first-in-class ARNi sacubitril/valsartan (LCZ696) reduced mortality and morbidity in heart failure (HF) with reduced ejection fraction (EF) compared to angiotensin converting enzyme inhibitor (ACEi), mechanistic data on ARNi are scarce. ARNi may be superior to ACEi in attenuating adverse cardiac remodeling and dysfunction post-myocardial infarction (MI).Rats randomized at 1 week post-MI were administered LCZ696 (60 mg/kg, N = 12), the ACEi perindopril (2 mg/kg, N = 11) or vehicle (corn oil, N = 13), orally for 4 weeks. Sham rats received vehicle (corn oil, N = 9). Echocardiography was assessed before and after treatment, prior to invasive hemodynamics using pressure-volume analysis. Hypertrophy and fibrosis was evaluated by histochemical staining, and analysis of myocardial gene and protein expression using real-time quantitative PCR and Western blot.Compared to Sham, MI groups had large infarcts (40%) and reduced left ventricular (LV) EF. LCZ696 improved LVEF and end systolic pressure-volume relationship compared to perindopril (P 0.05). LCZ696 but not perindopril reduced lung weight and LV filling pressures post-MI. Reductions in cardiac hypertrophy and fibrosis were similar, however gene expression of hypertrophic markers, ANP and βMHC were reduced with LCZ696 versus perindopril. LCZ696 versus perindopril reduced myocardial TIMP2 gene expression with a trend (P = 0.067) to lowering collagen I.LCZ696 attenuated adverse cardiac remodeling and dysfunction and reduced pulmonary congestion and hypertrophic markers after MI compared to perindopril. This study supports clinical evaluation of ARNi versus ACEi in targeting post-MI cardiac dysfunction and remodeling.

Background Cardiac remodelling is a dynamic process whereby structural and functional changes occur within the heart in response to injury or inflammation. Recent studies have demonstrated reactive oxygen species sensitive MAPK, apoptosis signal-regulating kinase 1 (ASK1) plays a critical role in cardiac remodelling. This study aims to determine the effectiveness of small molecule ASK1 inhibitors on these processes and their therapeutic potential. Methods Neonatal rat cardiac fibroblasts (NCF) were pre-treated with ASK1 inhibitors, G2261818A (G226) and G2358939A (G235), for 2 hours before stimulated with 100 nM angiotensin II (AngII), 10 μM indoxyl sulphate (IS) or 10 ng/ml transforming growth factor β1 (TGFβ1) for 48 hours. Neonatal rat cardiac myocytes (NCM) were pre-treated with G226 and G235 for 2 hours before being stimulated with 100 nM AngII for 60 hours, 10 μM IS, 10 ng/ml interleukin 1β (IL-1β) or tumour necrosis factor α (TNFα) for 48 hours. 3H-proline and 3H-leucine incorporation was used to assess collagen turnover and hypertrophy, respectively. Pro-fibrotic, pro-hypertrophic and THP-1 inflammatory cytokine gene expressions were determined by RT-PCR. Results Both G226 and G235 dose-dependently attenuated AngII-, IS-, IL-1β- and TNFα-stimulated NCM hypertrophy and hypertrophic gene expression, IS-, AngII- and TGFβ1-stimulated NCF collagen synthesis and AngII- and TGFβ1-stimulated pro-fibrotic gene expression. Inhibition of ASK1 by G226 and G235 inhibited lipopolysaccharides-stimulated inflammatory cytokine gene expression in THP-1 cells. Conclusions Selective ASK1 inhibition confers anti-hypertrophic and anti-fibrotic effects in cardiac cells, and anti-inflammation in monocytic cells. ASK1 inhibitors may represent novel therapeutic agents to alleviate cardiac remodelling post cardiac injury where hypertrophy, fibrosis and inflammation play critical roles.

To address the pathophysiological mechanisms underlying chronic kidney disease with comorbid cardiac dysfunction, we investigated renal and cardiac, functional and structural damage when myocardial infarction (MI) was applied in the setting of kidney injury (induced by 5/6 nephrectomy—STNx). STNx or Sham surgery was induced in male Sprague–Dawley rats with MI or Sham surgery performed 4 weeks later. Rats were maintained for a further 8 weeks. Rats (n = 36) were randomized into four groups: Sham+Sham, Sham+MI, STNx+Sham and STNx+MI. Increased renal tubulointerstitial fibrosis (P < 0.01) and kidney injury molecule‐1 expression (P < 0.01) was observed in STNx+MI compared to STNx+Sham animals, while there were no further reductions in renal function. Heart weight was increased in STNx+MI compared to STNx+Sham or Sham+MI animals (P < 0.05), despite no difference in blood pressure. STNx+MI rats demonstrated greater cardiomyocyte cross‐sectional area and increased cardiac interstitial fibrosis compared to either STNx+Sham (P < 0.01) or Sham+MI (P < 0.01) animals which was accompanied by an increase in diastolic dysfunction. These changes were associated with increases in ANP, cTGF and collagen I gene expression and phospho‐p38 MAPK and phospho‐p44/42 MAPK protein expression in the left ventricle. Addition of MI accelerated STNx‐induced structural damage but failed to significantly exacerbate renal dysfunction. These findings highlight the bidirectional response in this model known to occur in cardiorenal syndrome (CRS) and provide a useful model for examining potential therapies for CRS.

Chronic kidney disease (CKD) results from the development of fibrosis, ultimately leading to end-stage renal disease (ESRD). Although human bone marrow-derived mesenchymal stem cells (MSCs) can accelerate renal repair following acute injury, the establishment of fibrosis during CKD may affect their potential to influence regeneration capacity. Here we tested the novel combination of MSCs with the antifibrotic serelaxin to repair and protect the kidney 7 d post-unilateral ureteral obstruction (UUO), when fibrosis is established. Male C57BL6 mice were sham-operated or UUO-inured (n = 4-6) and received vehicle, MSCs (1 × 10(6)), serelaxin (0.5 mg/kg per d), or the combination of both. In vivo tracing studies with luciferin/enhanced green fluorescent protein (eGFP)-tagged MSCs showed specific localization in the obstructed kidney where they remained for 36 h. Combination therapy conferred significant protection from UUO-induced fibrosis, as indicated by hydroxyproline analysis (P < 0.001 vs. vehicle, P < 0.05 vs. MSC or serelaxin alone). This was accompanied by preserved structural architecture, decreased tubular epithelial injury (P < 0.01 vs. MSCs alone), macrophage infiltration, and myofibroblast localization in the kidney (both P < 0.01 vs. vehicle). Combination therapy also stimulated matrix metalloproteinase (MMP)-2 activity over either treatment alone (P < 0.05 vs. either treatment alone). These results suggest that the presence of an antifibrotic in conjunction with MSCs ameliorates established kidney fibrosis and augments tissue repair to a greater extent than either treatment alone.

Background Myocardial microvascular dysfunction has been implicated in the pathogenesis of myocardial infarction (MI). We tested the hypothesis that patients with MI have lower microvasculature density in myocardium remote from the site of infarction than patients with similar extent of coronary artery disease (CAD) without MI and examined the relationship between myocardial capillary length density and plasma levels of angiogenesis-related biomarkers. Methods We analyzed biopsies from non-ischemic left ventricular (LV) myocardium and measured plasma levels of angiogenesis-related biomarkers in patients undergoing coronary artery bypass graft surgery, 57 without previous MI (no-MI) and 27 with recent non-ST-segment-elevation MI (NSTEMI). Comparison was made with biopsies from 31 aortic stenosis (AS) patients and 6 patients with "normal" LV without CAD. Results Myocardial microvascular density of NSTEMI patients was approximately half the density of no-MI patients, and similar to AS patients. Whereas the reduced microvascular density of AS patients was accounted for by their cardiomyocyte hypertrophy, this was not the case for NSTEMI patients, who had higher diffusion radius/cardiomyocyte width ratio than no-MI, "normal" LV, and AS patients. NSTEMI patients had lower plasma levels of carboxymethyl lysine and low molecular weight fluorophores, higher vascular endothelial growth factor (VEGF) receptor-1/VEGF-A ratio, and higher endostatin and hepatocyte growth factor levels than no-MI patients. Conclusions Recent MI was associated with reduced microvasculature density in myocardium remote from the site of infarction and alteration in plasma levels of angiogenesis-related biomarkers.

article Background: A contributory role for soluble epoxide hydrolase (sEH) in cardiac remodeling post-myocardial infarction (MI) has been suggested; however effects of sEH inhibition following MI have not been evaluated. In this study, we examined in vivo post-MI anti-remodeling effects of a novel sEH inhibitor (GSK2188931B) in the rat, and evaluated its direct in vitro effects on hypertrophy, fibrosis and inflammation. Methods and results: Post-MI administered GSK2188931B (80 mg/kg/d in chow) for 5 weeks improved left ventricular (LV) ejection fraction compared to vehicle-treated (Veh) rats (Pb0.01; Sham 65±2%, MI+Veh 30±2%, MI+GSK 43±2%) without affecting systolic blood pressure. Percentage area of LV tissue sections stained positive for picrosirius red (PS) and collagen I (CI) were elevated in LV non-infarct zone (Pb0.05; NIZ; PS: Sham 1.46±0.13%, MI+Veh 2.14±0.22%, MI+GSK 1.28±0.14%; CI: Sham 2.57±0.17%, MI+Veh 5.06±0.58%, MI+GSK 2.97±0.34%) and peri-infarct zone (Pb0.001; PIZ; PS: Sham 1.46±0.13%, MI+Veh 9.06±0.48%, MI+GSK 6.31±0.63%; CI: Sham 2.57±0.17%, MI+Veh 10.51±0.64%, MI+GSK 7.77±0.57%); GSK2188931B attenuated this increase (Pb0.05). GSK2188931B reduced macrophage infiltration into the PIZ (Pb0.05). GSK2188931B reduced AngII- and TNFα-stimulated myocyte hypertrophy, AngII- and TGFβ-stimulated cardiac fibroblast collagen synthesis, including markers of gene expression ANP, β-MHC, CTGF and CI (Pb0.05). GSK2188931B reduced TNFα gene expression in lipopolysaccharide (LPS)- stimulated monocytes (Pb0.05). Conclusion: sEH inhibition exerts beneficial effects on cardiac function and ventricular remodeling post-MI, and direct effects on fibrosis and hypertrophy in cardiac cells. These findings suggest that sEH is an important contributor to the pathological remodeling following MI, and may be a useful target for therapeutic blockade in this setting.

Diabetes is independently associated with a specific cardiomyopathy, characterized by impaired cardiac muscle relaxation and force development. Using synchrotron radiation small-angle x-ray scattering, this study investigated in the in situ heart and in real-time whether changes in cross-bridge disposition and myosin interfilament spacing underlie the early development of diabetic cardiomyopathy. Experiments were conducted using anesthetized Sprague-Dawley rats 3 weeks after treatment with either vehicle (control) or streptozotocin (diabetic). Diffraction patterns were recorded during baseline and dobutamine infusions simultaneous with ventricular pressure-volumetry. From these diffraction patterns myosin mass transfer to actin filaments was assessed as the change in intensity ratio (I1,0/I1,1). In diabetic hearts cross-bridge disposition was most notably abnormal in the diastolic phase (p < 0.05) and to a lesser extent the systolic phase (p < 0.05). In diabetic rats only, there was a transmural gradient of contractile depression. Elevated diabetic end-diastolic intensity ratios were correlated with the suppression of diastolic function (p < 0.05). Furthermore, the expected increase in myosin head transfer by dobutamine was significantly blunted in diabetic animals (p < 0.05). Interfilament spacing did not differ between groups. We reveal that impaired cross-bridge disposition and radial transfer may thus underlie the early decline in ventricular function observed in diabetic cardiomyopathy.

Soil particles may be lost through dissolution, degradation or erosion. Regardless of the process of loss, there follows a change in soil structure both in terms of phase composition and grading. In this paper, the influence of size and amount of particle loss on phase composition at two stresses is investigated. The tests are performed on sand–salt mixtures, loaded in a modified permeation oedometer and subsequently dissolved. Changes in overall volume and void ratio are presented. Two significant observations about the volumetric consequences of particle loss can be made. First, overall volume changes are directly related to the amount of dissolved particles and to a lesser extent, the size of particle lost. Second, particle loss leads to an increase in void ratio; the magnitude of the increase is related to the amount of dissolved particles but appears not to be sensitive to either the size of particle lost or the pre-dissolution void ratio. Based on the observed response and a dissolution-induced void change parameter, the influence of different mechanisms of volume change is discussed. Tests were performed at two different vertical stresses with no discernible influence on void ratio change.

Background Tranilast has been shown to inhibit TGFβ1-related fibrosis and organ failure in various disease models. We sought to examine the effects of tranilast on left ventricular (LV) remodelling post-MI. Methods Following coronary artery ligation, Sprague Dawley rats were randomised to receive tranilast (300mg/kg/d, p.o.) or vehicle control over one of two treatment periods: (1) from 24h until seven days post-MI, (2) from seven days to 28 days post-MI. Cardiac tissue was harvested for molecular, immunohistochemical and cell culture analyses. Results Tranilast treatment of MI rats from 24h until seven days post-MI reduced myocardial collagen content, α1 (I) procollagen, TGFβ1 and CTGF mRNA transcripts, monocyte/macrophage infiltration and exacerbated infarct expansion compared with vehicle-treatment. Delaying the commencement of tranilast treatment to seven days post-MI attenuated myocardial fibrosis, gene expression of α1(I) procollagen, α1(III) procollagen, fibronectin, TGFβ1 and CTGF mRNA transcripts, and monocyte/macrophage infiltration at 28d compared to vehicle-treatment, without detriment to infarct healing. Extended post-MI also preserved LV infarct size. In cultures of rat cardiac fibroblasts, tranilast attenuated TGFβ1-stimulated fibrogenesis. Conclusion Tranilast inhibits myocardial TGFβ1 expression, fibrosis in rat post-MI and collagen production in cardiac fibroblasts. While tranilast intervention from 24h post-MI exacerbated infarct expansion, delaying the commencement of treatment to seven days post-MI impeded LV remodelling.

Obesity is associated with atrial fibrillation (AF); however, the mechanisms by which it induces AF are unknown.To examine the effect of progressive weight gain on the substrate for AF.Thirty sheep were studied at baseline, 4 months, and 8 months, following a high-calorie diet. Ten sheep were sampled at each time point for cardiac magnetic resonance imaging and hemodynamic studies. High-density multisite biatrial epicardial mapping was used to quantify effective refractory period, conduction velocity, and conduction heterogeneity index at 4 pacing cycle lengths and AF inducibility. Histology was performed for atrial fibrosis, inflammation, and intramyocardial lipidosis, and molecular analysis was performed for endothelin-A and -B receptors, endothelin-1 peptide, platelet-derived growth factor, transforming growth factor β1, and connective tissue growth factor.Increasing weight was associated with increasing left atrial volume (P = .01), fibrosis (P = .02), inflammatory infiltrates (P = .01), and lipidosis (P = .02). While there was no change in the effective refractory period (P = .2), there was a decrease in conduction velocity (P.001), increase in conduction heterogeneity index (P.001), and increase in inducible (P = .001) and spontaneous (P = .001) AF. There was an increase in atrial cardiomyocyte endothelin-A and -B receptors (P = .001) and endothelin-1 (P = .03) with an increase in adiposity. In association, there was a significant increase in atrial interstitial and cytoplasmic transforming growth factor β1 (P = .02) and platelet-derived growth factor (P = .02) levels.Obesity is associated with atrial electrostructural remodeling. With progressive obesity, there were changes in atrial size, conduction, histology, and expression of profibrotic mediators. These changes were associated with spontaneous and more persistent AF.

Heart failure still has a significant disease burden with poor outcomes worldwide despite advances in therapy. The standard therapies have been focused on blockade of renin–angiotensin–aldosterone system with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and mineralocorticoid antagonists and the sympathetic nervous system with β-blockers. The natriuretic peptide system is a potential counter-regulatory system that promotes vasodilatation and natriuresis. Angiotensin receptor neprilysin inhibitors are a new class drug capable of blocking the renin–angiotensin–aldosterone system and enhancing the natriuretic peptide system to improve neurohormonal balance. The success of the PARADIGM-HF trial with LCZ696 and its approval for heart failure treatment is likely to generate a paradigm shift. This review summarises the current knowledge of LCZ696 with a focus on pharmacology, pharmacokinetics and pharmacodynamics, mechanisms of action, clinical efficacy and safety.