Glycocalyx shedding is markedly increased during the acute phase of Takotsubo cardiomyopathy

Background: Acute myocardial infarction (AMI) and other forms of myocardial acute oxidative stress are associated with variable “shedding” of the endothelial glycocalyx (GCS) which can be quantitated ex vivo by release into plasma of glycocalyx components such as Syndecan-1 (SD-1). Previous studies have implicated release of both catecholamines and BNP as potential accentuating factors in GCS: since these are prominent aspects of the pathogenesis of Takotsubo cardiomyopathy (TTC), we hypothesised that TTC is associated with increased GCS and the extent of GCS is predictable on the basis of NT-proBNP and catecholamine releases. Methods: SD-1 concentrations were measured in 48 TTC patients acutely and after 3 months, and compared with those in 12 healthy controls, and 17 patients with AMI. Correlations were sought between SD-1 levels markers of severity of TTC episodes in individual patients. Results: Acute SD-1 concentrations in TTC patients were elevated significantly (p < 0.0001, 1-way ANOVA) compared to control values. There were no significant correlations between SD-1 concentrations and any markers of severity of acute TTC episodes, such as NT-proBNP or catecholamine release. Over 3 months, SD-1 concentrations fell significantly (p = 0.0002) to approximately the same values as in control subjects. Conclusions: TTC is associated acutely with a marked increase in GCS. Potentially, GCS might contribute to increased coronary vascular permeability in TTC, thus dissociating development of myocardial oedema from severity of associated inflammation. Prevention of GCS represents a potential therapeutic option in TTC

Benzenehexol-based 2D MOF as high-performance electrocatalyst for oxygen reduction reaction

© 2022 Elsevier B.V.Two-dimensional (2D) conductive metal–organic frameworks (MOFs) were an emerging class of potential oxygen reduction reaction (ORR) electrocatalysts to replace platinum-containing electrode materials. Herein, by first-principles calculations, we systematically studied the structural stability, electronic properties and ORR catalytic activity of metal-hexahydroxybenzene nanosheets, M3(C6O6), M = 3d and 4d transition metals. Based on formation energy, phonon spectrum and ab-initio molecular dynamics analyses, eight monolayer M3(C6O6) (M = Cr, Mn, Fe, Co, Cu, Zn, Ru and Rh) show superior thermodynamic, kinetic and thermal stabilities. Further ORR catalytic activity evaluation shown Cu3(C6O6) and Rh3(C6O6) had promising applications in catalyzing ORR 4e- pathway, with limiting potentials 0.76 and 0.80 V, respectively. The linear relationship between integrated crystal orbital Hamilton population (ICOHP) and ΔGOH∗ explains the suitable adsorption energy of OH* on the catalyst, resulting in the excellent ORR activity of Cu3(C6O6) and Rh3(C6O6). Our study on M3(C6O6) provides references for the research of other 2D MOFs as ORR catalysts.11Nsciescopu