340 research outputs found

    Erythropoietin Receptor Signaling Mitigates Renal Dysfunction-Associated Heart Failure by Mechanisms Unrelated to Relief of Anemia

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    ObjectivesWe examined the effect of asialoerythropoietin (asialoEPO), a nonerythrogenic derivative of erythropoietin (EPO), on renal dysfunction-associated heart failure.BackgroundAlthough EPO is known to exert beneficial effects on cardiac function, the clinical benefits in patients with chronic kidney disease are controversial. It remains to be addressed whether previously reported outcomes were the result of relief of the anemia, adverse effects of EPO, or direct cardiovascular effects.MethodsMice underwent 5/6 nephrectomy to cause renal dysfunction. Eight weeks later, when renal dysfunction was established, anemia and cardiac dysfunction and remodeling were apparent. Mice were then assigned to receive saline (control), recombinant human erythropoietin (rhEPO) at 5,000 IU (714 pmol)/kg, or asialoEPO at 714 pmol/kg, twice/week for 4 weeks.ResultsAlthough only rhEPO relieved the nephrectomy-induced anemia, both rhEPO and asialoEPO significantly and similarly mitigated left ventricular dilation and dysfunction. The hearts of rhEPO- or asialoEPO-treated mice showed less hypertrophy, reflecting decreases in cardiomyocyte hypertrophy and degenerative subcellular changes, as well as significant attenuation of fibrosis, leukocyte infiltration, and oxidative deoxyribonucleic acid damage. These phenotypes were accompanied by restored expression of GATA-4, sarcomeric proteins, and vascular endothelial growth factor and decreased inflammatory cytokines and lipid peroxidation. Finally, myocardial activation was observed of extracellular signal-regulated protein kinase and signal transducer and activator of transcription pathways in the treated mice.ConclusionsEPO receptor signaling exerts direct cardioprotection in an animal model of renal dysfunction-associated heart failure, probably by mitigating degenerative, pro-fibrosis, inflammatory, and oxidative processes but not through relief of anemia

    Three minute, but not one minute, ischemia and nicorandil have a preconditioning effect in patients with coronary artery disease

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    AbstractOBJECTIVESThis study focused on 1) the determination of the optimal preconditioning (PC) duration, and 2) the protective effect of nicorandil (NC), a hybrid nitrate with a Katpchannel opening effect, during a percutaneous transluminal coronary angioplasty (PTCA) model in humans.BACKGROUNDThe ischemic PC effect is induced in 180 s ischemia, but not in 120 s ischemia in rabbit hearts. However, the duration of ischemia that induces PC effect and the role of the Katpchannel in the PC effect in humans are still unclear.METHODSForty-six patients with stable angina were randomly allocated to four groups: the duration of the first inflation as PC ischemia was 60 s in the PC60 group (n = 12), and 180 s in the PC180 group (n = 12). In the other groups, NC (80 μg/kg) was intravenously given for 1 min in the NC group (n = 12), and isosorbide dinitrate (ISDN) (40 μg/kg) was given in the ISDN group (n = 10). Five minutes after first inflation or drug administration, a second inflation was conducted for 120 s in each group. In the ECG, the lead with the largest shift in ST segment (deltaST max), and the sum of elevated ST levels in all leads (sigmaST) were determined.RESULTSIn the PC60 group, no significant difference was observed in either deltaST max or sigmaST between the first and second inflation. However, the second inflation in the PC180 group showed significantly lower levels of deltaST max and sigmaST compared with those of the first inflation. In the NC group, both deltaST max and sigmaST measured at 30 s and 60 s after balloon inflation were significantly lower than those of the first inflation in the PC60 and PC180 control groups. In the ISDN group, no significant difference was observed in deltaST max or sigmaST.CONCLUSIONIn human PTCA models, a PC effect is observed in 180 s ischemia, but not in 60 s ischemia. A pharmacological PC effect is induced by NC, a Katpchannel opener with a nitrate-like effect but not ISDN. This suggests that the opening of Katpchannels plays an important role in the protecting effect of NC

    Adenovirus-mediated stromal cell-derived factor-1 alpha gene transfer improves cardiac structure and function after experimental myocardial infarction through angiogenic and antifibrotic actions

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    Stromal cell-derived factor 1α (SDF-1) is not only a major chemotactic factor, but also an inducer of angiogenesis. The effects of SDF-1α on the left ventricular remodeling in a rat myocardial infarction (MI) model were analyzed. Myocardial infarction was induced by ligation of the left coronary artery in rats. 0.5 × 1010 pfu/ml AdV-SDF-1 or 0.5 × 1010 pfu/ml Adv-LacZ were immediately injected into the infarcted myocardium, 120 μl cell-free PBS were injected into the infarcted region or the myocardial wall in control, and sham group, respectively. We found that AdV-SDF-1 group had higher LVSP and ±dP/dtmax, lower LVEDP compared to control or Adv-LacZ group. The number of c-Kit+ stem cells, and gene expression of SDF-1, VEGF and bFGF were obviously increased, which was associated with reduced infarct size, thicker left ventricle wall, greater vascular density and cardiocytes density in infarcted hearts of AdV-SDF-1 group. Furthermore, the expression of collagen type I and type III mRNA, and collagen accumulation in the infarcted area was lower, which was associated with decreased TGF-β1, TIMP-1 and TIMP-2 expression in AdV-SDF-1 group. Conclusion: SDF-1α could improve cardiac structure and function after Myocardial infarction through angiogenic and anti-fibrotic actions

    Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

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    Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council
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