Elevated Soluble Fms-Like Tyrosine Kinase-1 and Placental-Like Growth Factor Levels Are Associated With Development and Mortality Risk in Heart Failure

Background—Vascular endothelial dysfunction may play an important role in the progression of heart failure (HF). We hypothesize that elevated levels of vascular markers, placental-like growth factor, and soluble Fms-like tyrosine kinase-1 (sFlt-1) are associated with adverse outcomes in patients with HF. We also assessed possible triggers of sFlt-1 elevation in animal HF models. Methods and Results—We measured plasma placental-like growth factor and sFlt-1 in 791 HF patients undergoing elective coronary angiogram. Median (interquartile range) placental-like growth factor and sFlt-1 levels were 24 (20–29) and 382 (277–953) pg/mL, respectively. After 5 years of follow-up, and after using receiver operator characteristic curves to determine optimal cutoffs, high levels of sFlt-1 (≥280 pg/mL; adjusted hazard ratio, 1.47; 95% confidence interval, 1.03–2.09; P=0.035) but not placental-like growth factor (≥25 pg/mL; adjusted hazard ratio, 1.26; 95% confidence interval, 0.94–1.71, P=0.12) were associated with adverse cardiovascular outcomes. In addition, significant elevation of sFlt-1 levels was observed in left anterior descending artery ligation and transverse aortic constriction HF mouse models after 4 and 8 weeks of follow-up, suggesting vascular stress and ischemia as triggers for sFlt-1 elevation in HF. Conclusions—Circulating sFlt-1 is generated as a result of myocardial injury and subsequent HF development. Elevated levels of sFlt-1 are associated with adverse outcomes in stable patients with HF

Multiple sclerosis management during the COVID-19 pandemic

Altres ajuts: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. The development of standardized data collection as part of routine clinical care through Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) was developed and implemented at CC, JH, and CEMCAT in partnership with Biogen. Biogen did not have involvement in study design, data analysis or interpretation, or manuscript preparation.People with multiple sclerosis (MS) may be at higher risk for complications from the 2019 coronavirus (COVID-19) pandemic due to use of immunomodulatory disease modifying therapies (DMTs) and greater need for medical services. To evaluate risk factors for COVID-19 susceptibility and describe the pandemic's impact on healthcare delivery. Surveys sent to MS patients at Cleveland Clinic, Johns Hopkins, and Vall d'Hebron-Centre d'Esclerosi Múltiple de Catalunya in April and May 2020 collected information about comorbidities, DMTs, exposures, COVID-19 testing/outcomes, health behaviors, and disruptions to MS care. There were 3028/10,816 responders. Suspected or confirmed COVID-19 cases were more likely to have a known COVID-19 contact (odds ratio (OR): 4.38; 95% confidence interval (CI): 1.04, 18.54). In multivariable-adjusted models, people who were younger, had to work on site, had a lower education level, and resided in socioeconomically disadvantaged areas were less likely to follow social distancing guidelines. 4.4% reported changes to therapy plans, primarily delays in infusions, and 15.5% a disruption to rehabilitative services. Younger people with lower socioeconomic status required to work on site may be at higher exposure risk and are potential targets for educational intervention and work restrictions to limit exposure. Providers should be mindful of potential infusion delays and MS care disruption

Integrin β3 Crosstalk with VEGFR Accommodating Tyrosine Phosphorylation as a Regulatory Switch

Integrins mediate cell adhesion, migration, and survival by connecting intracellular machinery with the surrounding extracellular matrix. Previous studies demonstrated the importance of the interaction between β3 integrin and VEGF type 2 receptor (VEGFR2) in VEGF-induced angiogenesis. Here we present in vitro evidence of the direct association between the cytoplasmic tails (CTs) of β3 and VEGFR2. Specifically, the membrane-proximal motif around 801YLSI in VEGFR2 mediates its binding to non-phosphorylated β3CT, accommodating an α-helical turn in integrin bound conformation. We also show that Y747 phosphorylation of β3 enhances the above interaction. To demonstrate the importance of β3 phosphorylation in endothelial cell functions, we synthesized β3CT-mimicking Y747 phosphorylated and unphosphorylated membrane permeable peptides. We show that a peptide containing phospho-Y747 but not F747 significantly inhibits VEGF-induced signaling and angiogenesis. Moreover, phospho-Y747 peptide exhibits inhibitory effect only in WT but not in β3 integrin knock-out or β3 integrin knock-in cells expressing β3 with two tyrosines substituted for phenylalanines, demonstrating its specificity. Importantly, these peptides have no effect on fibroblast growth factor receptor signaling. Collectively these data provide novel mechanistic insights into phosphorylation dependent cross-talk between integrin and VEGFR2

Elevated Soluble Fms-Like Tyrosine Kinase-1 and Placental-Like Growth Factor Levels Are Associated With Development and Mortality Risk in Heart Failure

Background—Vascular endothelial dysfunction may play an important role in the progression of heart failure (HF). We hypothesize that elevated levels of vascular markers, placental-like growth factor, and soluble Fms-like tyrosine kinase-1 (sFlt-1) are associated with adverse outcomes in patients with HF. We also assessed possible triggers of sFlt-1 elevation in animal HF models. Methods and Results—We measured plasma placental-like growth factor and sFlt-1 in 791 HF patients undergoing elective coronary angiogram. Median (interquartile range) placental-like growth factor and sFlt-1 levels were 24 (20–29) and 382 (277–953) pg/mL, respectively. After 5 years of follow-up, and after using receiver operator characteristic curves to determine optimal cutoffs, high levels of sFlt-1 (≥280 pg/mL; adjusted hazard ratio, 1.47; 95% confidence interval, 1.03–2.09; P=0.035) but not placental-like growth factor (≥25 pg/mL; adjusted hazard ratio, 1.26; 95% confidence interval, 0.94–1.71, P=0.12) were associated with adverse cardiovascular outcomes. In addition, significant elevation of sFlt-1 levels was observed in left anterior descending artery ligation and transverse aortic constriction HF mouse models after 4 and 8 weeks of follow-up, suggesting vascular stress and ischemia as triggers for sFlt-1 elevation in HF. Conclusions—Circulating sFlt-1 is generated as a result of myocardial injury and subsequent HF development. Elevated levels of sFlt-1 are associated with adverse outcomes in stable patients with HF

Paraoxonase 2 prevents the development of heart failure

BACKGROUND:Mitochondrial oxidation is a major source of reactive oxygen species (ROS) and mitochondrial dysfunction plays a central role in development of heart failure (HF). Paraoxonase 2 deficient (PON2-def) mitochondria are impaired in function. In this study, we tested whether PON2-def aggravates HF progression. METHODS AND RESULTS:Using qPCR, immunoblotting and lactonase activity assay, we demonstrate that PON2 activity was significantly decreased in failing hearts despite increased PON2 expression. To determine the cardiac-specific function of PON2, we performed heart transplantations in which PON2-def and wild type (WT) donor hearts were implanted into WT recipient mice. Beating scores of the donor hearts, assessed at 4 weeks post-transplantation, were significantly decreased in PON2-def hearts when compared to WT donor hearts. By using a transverse aortic constriction (TAC) model, we found PON2 deficiency significantly exacerbated left ventricular remodeling and cardiac fibrosis post-TAC. We further demonstrated PON2 deficiency significantly enhanced ROS generation in heart tissues post-TAC. ROS generation was measured through dihydroethidium (DHE) using high-pressure liquid chromatography (HPLC) with a fluorescent detector. By using neonatal cardiomyocytes treated with CoCl2 to mimic hypoxia, we found PON2 deficiency dramatically increased ROS generation in the cardiomyocytes upon CoCl2 treatment. In response to a short CoCl2 exposure, cell viability and succinate dehydrogenase (SDH) activity assessed by MTT assay were significantly diminished in PON2-def cardiomyocytes compared to those in WT cardiomyocytes. PON2-def cardiomyocytes also had lower baseline SDH activity. By using adult mouse cardiomyocytes and mitochondrial ToxGlo assay, we found impaired cellular ATP generation in PON2-def cells compared to that in WT cells, suggesting that PON2 is necessary for proper mitochondrial function. CONCLUSION:Our study suggests a cardioprotective role for PON2 in both experimental and human heart failure, which may be associated with the ability of PON2 to improve mitochondrial function and diminish ROS generation

Telocinobufagin, a Novel Cardiotonic Steroid, Promotes Renal Fibrosis via Na+/K+-ATPase Profibrotic Signaling Pathways

Cardiotonic steroids (CTS) are Na+/K+-ATPase (NKA) ligands that are elevated in volume-expanded states and associated with cardiac and renal dysfunction in both clinical and experimental settings. We test the hypothesis that the CTS telocinobufagin (TCB) promotes renal dysfunction in a process involving signaling through the NKA α-1 in the following studies. First, we infuse TCB (4 weeks at 0.1 µg/g/day) or a vehicle into mice expressing wild-type (WT) NKA α-1, as well as mice with a genetic reduction (~40%) of NKA α-1 (NKA α-1+/−). Continuous TCB infusion results in increased proteinuria and cystatin C in WT mice which are significantly attenuated in NKA α-1+/− mice (all p < 0.05), despite similar increases in blood pressure. In a series of in vitro experiments, 24-h treatment of HK2 renal proximal tubular cells with TCB results in significant dose-dependent increases in both Collagens 1 and 3 mRNA (2-fold increases at 10 nM, 5-fold increases at 100 nM, p < 0.05). Similar effects are seen in primary human renal mesangial cells. TCB treatment (100 nM) of SYF fibroblasts reconstituted with cSrc results in a 1.5-fold increase in Collagens 1 and 3 mRNA (p < 0.05), as well as increases in both Transforming Growth factor beta (TGFb, 1.5 fold, p < 0.05) and Connective Tissue Growth Factor (CTGF, 2 fold, p < 0.05), while these effects are absent in SYF cells without Src kinase. In a patient study of subjects with chronic kidney disease, TCB is elevated compared to healthy volunteers. These studies suggest that the pro-fibrotic effects of TCB in the kidney are mediated though the NKA-Src kinase signaling pathway and may have relevance to volume-overloaded conditions, such as chronic kidney disease where TCB is elevated

Structural statistics for the 15 final NMR structures of VpepB.

a)<p>Ordered residues (residues with sum of phi and psi order parameters <1.8) are considered for r.m.s.d. calculations and Ramachandran statistics.</p

Summary of the <i>in vitro</i> evidence for a direct interaction between VEGFR2 and β₃CTs and structure of the VEGFR2 ⁸⁰¹YLSI motif in bound conformation.

<p>Chemical shift titrations were performed in water at 25°C at pH 6.1 with β₃ concentrations of in a range of 30–100 µM. Expanded region of ¹⁵N HSQC spectra show chemical shift perturbations for <b>a</b>) β₃NP. <b>b</b>) β₃MP in presence of VpepA at the ratio 1∶1. <b>c</b>) Chemical shift changes in ¹⁵N labeled β₃NP upon addition of VpepA at the ratios of 1∶1 (red) and 1∶2 (green). <b>d</b>) Chemical shift changes in ¹⁵N labeled β₃MP upon addition of VpepA at the ratios of 1∶1 (red) and 1∶2 (green). Delta [ppm] refers to the combined HN and N chemical shift changes according to the equation: Δδ(HN,N) = ((Δδ_HN²+0.2(Δδ_N)²)^1/2, where Δδ = δ_bound-δ_free. Transferred NOEs: all the NOESY experiments were performed in 50 mM NaCl and 25 mM Na-phosphate buffer at pH 6.1 and 25°C with peptide to protein ratio of 50 to 1 and peptide concentrations of 1 mM; <b>e</b>) VpepB alone is shown in black and VpepB in combination with GST-β₃ is shown in green; <b>f</b>) VpepC alone (black) and VpepC in combination with GST-β₃ (green). <b>g</b>) Ribbon representation of VpepB structure. Hydrophobic residues of ⁸⁰¹YLSI region are shown in dark gray. <b>h</b>) Backbone superimposition of the 15 lowest energy conformers of VpepB. Residues used for superimposition are ⁸⁰¹YLSI. Molecular graphics images were produced using the UCSF Chimera package (Pettersen et al., 2004).</p

The pY747 peptide has no effect on β3^−/− or DiYF mice.

<p><b>a</b>) pY747 peptide does not inhibit VEGF-induced aortic ring growth from β3^−/− mice. Mouse aortic rings were embedded in matrigel in the presence of 40 ng/mL of VEGF and 40 µM of peptides as indicated. <b>b</b>) Quantification of aortic ring assay as indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031071#pone-0031071-g004" target="_blank">Fig. 4a</a>. <b>c</b>) pY747 could not inhibit bFGF-induced aortic ring growth, Mouse aortic rings were isolated from wild type (WT), β3^−/−, and DiYF mice and embedded in matrigel in the presence of 40 ng/mL of VEGF, 20 ng/mL of bFGF or pY747 peptides as indicated. Aortic rings were incubated for 3 days for wild type and β3^−/− aortic rings and 4 days for DiYF aortic rings (longer incubation was used to obtain visible aortic sprouting which is diminished in these mice). <b>d</b>) pY747 peptide does not inhibit angiogenesis in DiYF mice. Peptides' effect on <i>in vivo</i> angiogenesis in wild type mice and DiYF mice was tested as described. <b>e</b>) Quantification of blood vessels in matrigel plus assay as indicated.</p