Conformationally-Locked C-Glycosides: Tuning Aglycone Interactions for Optimal Cheperone Behaviour in Gaucher Fibroblasts

A series of conformationally locked C-glycosides based on the 3-aminopyrano[3,2-b]pyrrol-2(1H)-one (APP) scaffold has been synthesized. The key step involved a totally stereocontrolled C-Michael addition of a serine-equivalent C-nucleophile to tri-O-benzyl-2-nitro-D-galactal, previously published by the authors. Stereoselective transformations of the Michael adduct allowed us the synthesis of compounds with mono- or diantennated aglycone moieties and different topologies. In vitro screening showed highly selective inhibition of bovine liver β-glucosidase/β-galactosidase and specific inhibition of human β-glucocerebrosidase among lysosomal glycosidases for compounds bearing palmitoyl chains in the aglycone, with a marked dependence of the inhibition potency upon their number and location. Molecular dynamics simulations highlighted the paramount importance of an optimal orientation of the hydrophobic substituent to warrant efficient non-glycone interactions, which are critical for the binding affinity. The results provide a rationale for the strong decrease of the inhibition potency of APP compounds on going from neutral to acidic pH. The best candidate was found to behave as pharmacological chaperone in Gaucher fibroblasts with homozygous N370S and F213I mutations, with enzyme activity enhancements similar to those encountered for the reference compound AmbroxolMinisterio de Economía y Competitividad CTQ2012-36365, SAF2013-44021-RJunta de Andalucía FQM-1467European Union Seventh Framework Programme FP7-People-2012-CI

Aortic Sinus Contrast Retention During TAVR : A Warning Sign Preceding a Potential Thrombotic Complication

Sinus contrast material retention after transcatheter aortic valve replacement (TAVR) is a rare phenomenon that may reflect an increased risk for thrombotic complications. We present 3 cases of persistent contrast agent retention in the sinus of Valsalva during the TAVR procedure that portend the occurrence of embolic stroke or bioprosthetic valve thrombosis. (Level of Difficulty: Advanced.

Glycosylated apolipoprotein J in cardiac ischaemia: molecular processing and circulating levels in patients with acute ischaemic events.

AIM: Using proteomics, we previously found that serum levels of glycosylated (Glyc) forms of apolipoprotein J (ApoJ), a cytoprotective and anti-oxidant protein, decrease in the early phase of acute myocardial infarction (AMI). We aimed to investigate: (i) ApoJ-Glyc intracellular distribution and secretion during ischaemia; (ii) the early changes in circulating ApoJ-Glyc during AMI; and (iii) associations between ApoJ-Glyc and residual ischaemic risk post-AMI. METHODS AND RESULTS: Glycosylated apolipoprotein J was investigated in: (i) cells from different organ/tissue origin; (ii) a pig model of AMI; (iii) de novo AMI patients (n = 38) at admission within the first 6 h of chest pain onset and without troponin T elevation at presentation (early AMI); (iv) ST-elevation myocardial infarction patients (n = 212) who were followed up for 6 months; and (v) a control group without any overt cardiovascular disease (n = 144). Inducing simulated ischaemia in isolated cardiac cells resulted in an increased intracellular accumulation of non-glycosylated ApoJ forms. A significant decrease in ApoJ-Glyc circulating levels was seen 15 min after ischaemia onset in pigs. Glycosylated apolipoprotein J levels showed a 45% decrease in early AMI patients compared with non-ischaemic patients (P < 0.0001), discriminating the presence of the ischaemic event (area under the curve: 0.934; P < 0.0001). ST-elevation myocardial infarction patients with lower ApoJ-Glyc levels at admission showed a higher rate of recurrent ischaemic events and mortality after 6-month follow-up (P = 0.008). CONCLUSIONS: These results indicate that ischaemia induces an intracellular accumulation of non-glycosylated ApoJ and a reduction in ApoJ-Glyc secretion. Glycosylated apolipoprotein J circulating levels are reduced very early after ischaemia onset. Its continuous decrease indicates a worsening in the evolution of the cardiac event, likely identifying patients with sustained ischaemia after AMI

Prognostic Impact of Nutritional Status After Transcatheter Edge-to-Edge Mitral Valve Repair: The MIVNUT Registry

Background Malnutrition is associated with poor prognosis in several cardiovascular diseases. However, its prognostic impact in patients undergoing transcatheter edge-to-edge mitral valve repair (TEER) is not well known. This study sought to assess the prevalence, clinical associations, and prognostic consequences of malnutrition in patients undergoing TEER. Methods and Results A total of 892 patients undergoing TEER from the international MIVNUT (Mitral Valve Repair and Nutritional Status) registry were studied. Malnutrition status was assessed with the Controlling Nutritional Status score. The association of nutritional status with mortality was analyzed with multivariable Cox regression models, whereas the association with heart failure admission was assessed by Fine-Gray models, with death as a competing risk. According to the Controlling Nutritional Status score, 74.4% of patients with TEER had any degree of malnutrition at the time of TEER (75.1% in patients with body mass index <25?kg/m2, 72.1% in those with body mass index ?25?kg/m2). However, only 20% had moderate-severe malnutrition. TEER was successful in most of patients (94.2%). During a median follow-up of 1.6?years (interquartile range, 0.6-3.0), 267 (29.9%) patients died and 256 patients (28.7%) were admitted for heart failure after TEER. Compared with normal nutritional status moderate-severe malnutrition resulted a strong predictor of mortality (adjusted hazard ratio [HR], 2.1 [95% CI, 1.1-2.4]; P<0.001) and heart failure admission (adjusted subdistribution HR, 1.6 [95% CI, 1.1-2.4]; P=0.015). Conclusions Malnutrition is common among patients submitted to TEER, and moderate-severe malnutrition is strongly associated with increased mortality and heart failure readmission. Assessment of nutritional status in these patients may help to improve risk stratification

Acute Mitral Regurgitation Secondary to Spontaneous Left Atrial Appendage Occluder Migration

A patient underwent left atrial appendage occlusion due to recurrent stroke despite new oral anticoagulant therapy. The patient later presented with severe acute mitral regurgitation secondary to occluder device migration, which was retrieved percutaneously from the descending aorta via the femoral artery. Mitral surgical repair was required and successfully performed. (Level of Difficulty: Intermediate.

Coronary microvascular dysfunction in takotsubo syndrome assessed by angiography-derived index of microcirculatory resistance : A pressure-wire-free tool

Background: Coronary microvascular dysfunction (CMD) has been proposed as a key mechanism in Takotsubo syndrome (TTS). The non-hyperaemic angiography-derived index of microcirculatory resistance (NH-IMRangio) has been validated as a pressure-wire-free tool for the assessment of coronary microvasculature. We aimed to study the presence of CMD in TTS patients and its association with levels of cardiac biomarkers and systolic dysfunction patterns. Methods: We recruited 181 consecutive patients admitted for TTS who underwent cardiac angiography at a tertiary center from January 2014 to January 2021. CMD was defined as an NH-IMRangio ≥ 25. Plasma levels of NT-proBNP, high-sensitive cardiac troponin T (hs-cTnT) and the left ventricular ejection fraction (LVEF) by echocardiography were measured at admission. Results: Mean age was 75.3 years, 83% were women and median LVEF was 45%. All patients presented CMD (NH-IMRangio ≥ 25) in at least one epicardial coronary artery. The left anterior descending artery (LAD) showed higher median NH-IMRangio values than left circumflex (LCx) and right coronary arteries (RCA) (44.6 vs. 31.3 vs. 36.1, respectively; p < 0.001). NH-IMRangio values differed among ventricular contractility patterns in the LAD and RCA (p = 0.0152 and 0.0189, respectively) with the highest values in the midventricular + apical and mid-ventricular + basal patterns. NT-proBNP levels, but not high-sensitive cardiac troponin T (hs-cTnT), were correlated with both the degree and the extent of CMD in patients with TTS. Lower LVEF was also associated with higher NH-IMRangio values. Conclusions: CMD is highly prevalent in patients admitted for TTS and is associated with both a higher degree of systolic dysfunction and higher BNP levels, but not troponin

Synthesis, conformational analysis and: In vivo assays of an anti-cancer vaccine that features an unnatural antigen based on an sp²-iminosugar fragment

Thr/Ser) is a well-known tumor-associated carbohydrate determinant. The use of glycopeptides that incorporate this structure has become a significant and promising niche of research owing to their potential use as anticancer vaccines. Herein, the conformational preferences of a glycopeptide with an unnatural Tn antigen, characterized by a threonine decorated with an sp2-iminosugar-type α-GalNAc mimic, have been studied both in solution, by combining NMR spectroscopy and molecular dynamics simulations, and in the solid state bound to an anti-mucin-1 (MUC1) antibody, by X-ray crystallography. The Tn surrogate can mimic the main conformer sampled by the natural antigen in solution and exhibits high affinity towards anti-MUC1 antibodies. Encouraged by these data, a cancer vaccine candidate based on this unnatural glycopeptide and conjugated to the carrier protein Keyhole Limpet Hemocyanin (KLH) has been prepared and tested in mice. Significantly, the experiments in vivo have proved that this vaccine elicits higher levels of specific anti-MUC1 IgG antibodies than the analog that bears the natural Tn antigen and that the elicited antibodies recognize human breast cancer cells with high selectivity. Altogether, we compile evidence to confirm that the presentation of the antigen, both in solution and in the bound state, plays a critical role in the efficacy of the designed cancer vaccines. Moreover, the outcomes derived from this vaccine prove that there is room for exploring further adjustments at the carbohydrate level that could contribute to designing more efficient cancer vaccines

"Impact of age on management and prognosis of resuscitated sudden cardiac death patients"

Background: Sudden cardiac death (SCD) has a great impact on healthcare due to cardiologic and neurological complications. Admissions of elderly people in Cardiology Intensive Care Units have increased. We assessed the impact of age in presentation, therapeutic management and in vital and neurological prognosis of SCD patients. Methods: We carried out a retrospective, observational, multicenter registry of patients who were admitted with a SCD in 5 tertiary hospitals from January 2013 to December 2020. We divided our cohort into two groups (patients 1 at admission, time to CPR initiation > 5 min, time to ROSC > 20 min and lactate > 2 mmol/L were independent predictors for in-hospital mortality. Non-shockable rhythm, Killip class > 1 at admission, time to CPR initiation > 5 min and time to ROSC > 20 min but not age were independent predictors for poor neurological outcomes. Conclusions: Age determined a less aggressive management and it was associated with a worse vital prognosis in patients admitted with a SCD. Nevertheless, age was not associated with worse neurological outcomes

Water Sculpts the Distinctive Shapes and Dynamics of the Tumor-Associated Carbohydrate Tn Antigens: Implications for Their Molecular Recognition

The tumor-associated carbohydrate Tn antigens include two variants, αGalNAc-O-Thr and αGalNAc-O-Ser. In solution, they exhibit dissimilar shapes and dynamics and bind differently to the same protein receptor. Here, we demonstrate experimentally and theoretically that their conformational preferences in the gas phase are highly similar, revealing the essential role of water. We propose that water molecules prompt the rotation around the glycosidic linkage in the threonine derivative, shielding its hydrophobic methyl group and allowing an optimal solvation of the polar region of the antigen. The unusual arrangement of αGalNAc-O-Thr features a water molecule bound into a >pocket> between the sugar and the threonine. This mechanism is supported by trapping, for the first time, such localized water in the crystal structures of an antibody bound to two glycopeptides that comprise fluorinated Tn antigens in their structure. According to several reported X-ray structures, installing oxygenated amino acids in specific regions of the receptor capable of displacing the bridging water molecule to the bulk-solvent may facilitate the molecular recognition of the Tn antigen with threonine. Overall, our data also explain how water fine-tunes the 3D structure features of similar molecules, which in turn are behind their distinct biological activities.We thank MINECO (projects CTQ2015-67727-R and UNLR13-4E-1931 to F.C. and J.M.P; CTQ2013-44367-C2-2-P and BFU2016-75633-P to R.H.-G.; CTQ2015-64597-C2-1P to J.J.-B.; CTQ2015-70524-R and RYC-2013-14706 to G.J.O; SEV-2016-0644 to CIC bioGUNE; CTQ2017-89150-R to E.J.C.; and CTQ2015-68148-C2-1-P to J.A.F.). F.C. thanks the EU (Marie-Sklodowska Curie ITN, ProteinConjugates). J.A.F. and E.J.C. thank UPV/EHU (UFI11/23 and PPG17/10) for financial support. I.A.B. thanks the Asociación Española Contra el Cancer en La Rioja for a grant. I.C. thanks Universidad de La Rioja for the FPI grant. R.H-G. thanks Agencia Aragonesa para la Investigación y Desarrollo (ARAID) and the Diputación General de Aragón (DGA, group number E34_R17) for financial support. The research leading to these results has also received funding from the FP7 (2007-2013) under BioStruct-X (grant agreement no. 283570 and BIOSTRUCTX_ 5186). We thank synchrotron radiation source ALBA (Barcelona) and beamline XALOC. Computational resources of CESGA, Universidad de La Rioja (BERONIA) and UPV/EHU (SGIker and I2Basque) were used in this work. We thank Prof. J. P. Simons (Oxford University) for valuable comments and scientific discussions.Peer Reviewe