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Quantum dots (QDOTs) have been widely recognized by the scientific community and the biotechnology industry, as witnessed by the exponential growth of this field in the past several years. We describe the synthesis and characterization of visible and near infrared QDots-a critical step for engineering organic molecules like proteins and peptides for building nanocomposite materials with multifunctional properties suitable for biological applications.

A new method for in vitro and possibly in vivo ultrahigh-resolution colocalization and distance measurement between biomolecules is described, based on semiconductor nanocrystal probes. This ruler bridges the gap between FRET and far-field (or near-field scanning optical microscope) imaging and has a dynamic range from few nanometers to tens of micrometers. The ruler is based on a stage-scanning confocal microscope that allows the simultaneous excitation and localization of the excitation point-spread-function (PSF) of various colors nanocrystals while maintaining perfect registry between the channels. Fit of the observed diffraction and photophysics-limited images of the PSFs with a two-dimensional Gaussian allows one to determine their position with nanometer accuracy. This new high-resolution tool opens new windows in various molecular, cell biology and biotechnology applications.

The role of complement activation on the cerebral vasculature after cardiopulmonary bypass (CPB) is unclear. The goal of the study was to assess whether heparin-coated CPB reduces complement activation, and influences cerebral blood flow velocities (CBFV). Twenty-four patients undergoing coronary surgery were randomly allocated to non-coated (NC-group) or heparin-coated (HC-group) CPB. Complement activation was assessed by measuring sC5b-9. Transcranial Doppler (TCD) was performed on middle cerebral arteries before and after CPB. Systolic (SV), diastolic (DV) and mean (MV) CBFV were measured. Significant increase of sC5b-9 (p=0.003) was observed in the NC-group and CBFV increased after CPB (SV by 27%, p=0.05; DV by 40%, p=0.06; MV by 33%, p=0.04) whereas no changes were detected in the HC-group. TCD values were higher in the NC-group than in the HC-group (SV, p=0.04; DV, p=0.03; MV, p=0.03) although cardiac index, systemic vascular resistance, haematocrit and pCO2 were similar. Postoperative SV, DV and MV were significantly correlated with sC5b-9 (r=0.583, p=0.009; r=0.581, p=0.009; r=0.598, p=0.007, respectively). Increased CBFV after CPB are correlated to the level of complement activation and may be controlled by heparin-coated circuits. [ABSTRACT FROM PUBLISHER]

Background: Transcatheter aortic valve implantation now has a major role in the treatment of patients with severe aortic stenosis. However, evidence is scarce on its feasibility and safety to treat patients with pure aortic regurgitation., Aims: We sought to evaluate the results of transcatheter aortic valve implantation using the balloon-expandable SAPIEN 3 transcatheter heart valve (Edwards Lifesciences, Irvine, CA, USA) in patients with pure aortic regurgitation on native non-calcified valves., Methods: We conducted a retrospective and prospective French multicentre observational study. We included all patients with symptomatic severe pure aortic regurgitation on native non-calcified valves, contraindicated to or at high risk for surgical valve replacement, who underwent transcatheter aortic valve implantation using the SAPIEN 3 transcatheter heart valve., Results: A total of 37 patients (male sex, 73%) with a median age of 81years (interquartile range 69-85years) were screened using transthoracic echocardiography and computed tomography and were included at eight French centres. At baseline, 83.8% of patients (n=31) had dyspnoea New York Heart Association class≥III. The device success rate was 94.6% (n=35). At 30days, the all-cause mortality rate was 8.1% (n=3) and valve migration occurred in 10.8% of cases (n=4). Dyspnoea New York Heart Association class≤II was seen in 86.5% of patients (n=32), and all survivors had aortic regurgitation grade≤1. At 1-year follow-up, all-cause mortality was 16.2% (n=6), 89.7% (n=26/29) of survivors were in New York Heart Association class≤II and all had aortic regurgitation grade≤2., Conclusion: Transcatheter aortic valve implantation using the SAPIEN 3 transcatheter heart valve seems promising to treat selected high-risk patients with pure aortic regurgitation on non-calcified native valves, contraindicated to surgical aortic valve replacement., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Background: The present study is a sub-analysis of the multicenter, randomized PERSIST-AVR trial (PERceval Sutureless Implant versus Standard Aortic Valve Replacement) comparing the in-hospital and 1-year results of sutureless versus conventional stented bioprostheses in isolated surgical aortic valve replacement (SAVR) within two different surgical approaches: mini-sternotomy (MS) and full-sternotomy (FS)., Methods: A total of 819 patients (per-protocol population) underwent preoperative randomization to sutureless or stented biological valve at 47 centers worldwide. Sub-analysis on isolated SAVR was performed. Results were compared between sutureless and stented within the two different surgical approaches., Results: 285 patients were implanted with Perceval (67% in MS) and 293 with stented valves (65% in MS). Sutureless group showed significantly reduced surgical times both in FS and MS. In-hospital results show no differences between Perceval and stented valves in FS, while a lower incidence of new-onset of atrial fibrillation (3.7% vs 10.8%) with Perceval in MS. After 1-year, use of sutureless valve showed a significant reduction of MACCE (5.2% vs 10.8%), stroke rate (1.0% vs 5.4%), new-onset of atrial fibrillation (4.2% vs 11.4%) and re-hospitalizations (21.8 days vs 47.6 days), compared to stented valves but presented higher rate of pacemaker implantation (11% vs 1.6%)., Conclusions: Sutureless bioprosthesis showed significantly reduced procedural times during isolated SAVR in both surgical approaches. Patients with sutureless valves and MS access showed also better 1-year outcome regarding MACCEs, stroke, re-hospitalization and new-onset atrial fibrillation, but presented a higher rate of permanent pacemaker implantation compared to patients with stented bioprosthesis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objectives: Sutureless aortic valves demonstrated non-inferiority to standard stented valves for major cardiovascular and cerebral events at 1 year after aortic valve replacement. We aim to assess the factors correlating with permanent pacemaker implantation (PPI) in both cohorts., Methods: PERSIST-AVR is a prospective, randomized, open-label trial. Patients undergoing aortic valve replacement were randomized to receive a sutureless aortic valve replacement (Su-AVR) or stented sutured bioprosthesis (SAVR). Multivariable analysis was performed to identify possible independent risk factors associated with PPI. A logistic regression analysis was performed to estimate the risk of PPI associated to different valve size., Results: The 2 groups (Su-AVR; n = 450, SAVR n = 446) were well balanced in terms of preoperative risk factors. Early PPI rates were 10.4% in the Su-AVR group and 3.1% in the SAVR. PPI prevalence correlated with valve size XL (P = 0.0119) and preoperative conduction disturbances (P = 0.0079) in the Su-AVR group. No predictors were found in the SAVR cohort. Logistic regression analysis showed a significantly higher risk for PPI with size XL compared to each individual sutureless valve sizes [odds ratio (OR) 0.272 vs size S (95%confidence interval 0.07-0.95), 0.334 vs size M (95% CI 0,16-0; 68), 0.408 vs size L (95% CI 0,21-0.81)] but equivalent risk of PPI rates for all other combination of valve sizes., Conclusions: Su-AVR is associated with higher PPI rate as compared to SAVR. However, the increased PPI rate appears to be size-dependent with significant higher rate only for size XL. The combination of preoperative conduction disorder and a size XL can lead to a higher probability of early PPI in Su-AVR., Clinical Trial Registration Number: NCT02673697., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Homologs of the mutagenic Escherichia coli DNA polymerase V (pol V) are encoded by numerous pathogens and mobile elements. We have used Rum pol (RumA'2B), from the integrative conjugative element (ICE), R391, as a model mobile element-encoded polymerase (MEPol). The highly mutagenic Rum pol is transferred horizontally into a variety of recipient cells, including many pathogens. Moving between species, it is unclear if Rum pol can function on its own or requires activation by host factors. Here, we show that Rum pol biochemical activity requires the formation of a physical mutasomal complex, Rum Mut, containing RumA'2B-RecA-ATP, with RecA being donated by each recipient bacteria. For R391, Rum Mut specific activities in vitro and mutagenesis rates in vivo depend on the phylogenetic distance of host-cell RecA from E. coli RecA. Rum pol is a highly conserved and effective mobile catalyst of rapid evolution, with the potential to generate a broad mutational landscape that could serve to ensure bacterial adaptation in antibiotic-rich environments leading to the establishment of antibiotic resistance., (© The Author(s) 2022. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Using a series of multiheme cytochromes, the metal-reducing bacterium Shewanella oneidensis MR-1 can perform extracellular electron transfer (EET) to respire redox-active surfaces, including minerals and electrodes outside the cell. While the role of multiheme cytochromes in transporting electrons across the cell wall is well established, these cytochromes were also recently found to facilitate long-distance (micrometer-scale) redox conduction along outer membranes and across multiple cells bridging electrodes. Recent studies proposed that long-distance conduction arises from the interplay of electron hopping and cytochrome diffusion, which allows collisions and electron exchange between cytochromes along membranes. However, the diffusive dynamics of the multiheme cytochromes have never been observed or quantified in vivo, making it difficult to assess their hypothesized contribution to the collision-exchange mechanism. Here, we use quantum dot labeling, total internal reflection fluorescence microscopy, and single-particle tracking to quantify the lateral diffusive dynamics of the outer membrane-associated decaheme cytochromes MtrC and OmcA, two key components of EET in S. oneidensis. We observe confined diffusion behavior for both quantum dot-labeled MtrC and OmcA along cell surfaces (diffusion coefficients DMtrC = 0.0192 ± 0.0018 µm2/s, DOmcA = 0.0125 ± 0.0024 µm2/s) and the membrane extensions thought to function as bacterial nanowires. We find that these dynamics can trace a path for electron transport via overlap of cytochrome trajectories, consistent with the long-distance conduction mechanism. The measured dynamics inform kinetic Monte Carlo simulations that combine direct electron hopping and redox molecule diffusion, revealing significant electron transport rates along cells and membrane nanowires.

Emerin is an integral nuclear envelope protein that participates in the maintenance of nuclear shape. When mutated or absent, emerin causes X-linked Emery-Dreifuss muscular dystrophy (EDMD). To understand how emerin takes part in molecular --scaffolding at the nuclear envelope and helps protect the nucleus against mechanical stress, we established its nanoscale organization using single-molecule tracking and super-resolution microscopy. We show that emerin monomers form localized oligomeric nanoclusters stabilized by both lamin A/C and the SUN1-containing linker of nucleoskeleton and cytoskeleton (LINC) complex. Interactions of emerin with nuclear actin and BAF (also known as BANF1) additionally modulate its membrane mobility and its ability to oligomerize. In nuclei subjected to mechanical challenges, the mechanotransduction functions of emerin are coupled to changes in its oligomeric state, and the incremental self-assembly of emerin determines nuclear shape adaptation against mechanical forces. We also show that the abnormal nuclear envelope deformations induced by EDMD emerin mutants stem from improper formation of lamin A/C and LINC complex-stabilized emerin oligomers. These findings place emerin at the center of the molecular processes that regulate nuclear shape remodeling in response to mechanical challenges., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)

Objective: Sutureless aortic valves are an effective option for aortic valve replacement (AVR) showing non-inferiority to standard stented aortic valves for major cardiovascular and cerebral events at 1-year. We report the 1-year hemodynamic performance of the sutureless prostheses compared with standard aortic valves, assessed by a dedicated echocardiographic core lab., Methods: Perceval Sutureless Implant vs. Standard Aortic Valve Replacement (PERSIST-AVR) is a prospective, randomized, adaptive, open-label trial. Patients undergoing AVR, as an isolated or combined procedure, were randomized to receive a sutureless [sutureless aortic valve replacement (Su-AVR)] ( n = 407) or a stented sutured [surgical AVR (SAVR)] ( n = 412) bioprostheses. Site-reported echocardiographic examinations were collected at 1 year. In addition, a subgroup of the trial population (Su-AVR n = 71, SAVR = 82) had a complete echocardiographic examination independently assessed by a Core Lab (MedStar Health Research Institute, Washington D.C., USA) for the evaluation of the hemodynamic performance., Results: The site-reported hemodynamic data of stented valves and sutureless valves are stable and comparable during follow-up, showing stable reduction of mean and peak pressure gradients through one-year follow-up (mean: 12.1 ± 6.2 vs. 11.5 ± 4.6 mmHg; peak: 21.3 ± 11.4 vs. 22.0 ± 8.9 mmHg). These results at 1-year are confirmed in the subgroup by the core-lab assessed echocardiogram with an average mean and peak gradient of 12.8 ± 5.7 and 21.5 ± 9.1 mmHg for Su-AVR, and 13.4 ± 7.7 and 23.0 ± 13.0 mmHg for SAVR. The valve effective orifice area was 1.3 ± 0.4 and 1.4 ± 0.4 cm 2 at 1-year for Su-AVR and SAVR. These improvements are observed across all valve sizes. At 1-year evaluation, 91.3% ( n = 42) of patients in Su-AVR and 82.3% in SAVR ( n = 51) groups were free from paravalvular leak (PVL). The rate of mild PVL was 4.3% ( n = 2) in Su-AVR and 12.9% ( n = 8) in the SAVR group. A similar trend is observed for central leak occurrence in both core-lab assessed echo groups., Conclusion: At 1-year of follow-up of a PERSIST-AVR patient sub-group, the study showed comparable hemodynamic performance in the sutureless and the stented-valve groups, confirmed by independent echo core lab. Perceval sutureless prosthesis provides optimal sealing at the annulus with equivalent PVL and central regurgitation extent rates compared to sutured valves. Sutureless valves are therefore a reliable and essential technology within the modern therapeutic possibilities to treat aortic valve disease., Competing Interests: UK was employed by Herzzentrum Dresden GmbH Universitätsklinik. This study received funding from Corcym S.r.l. The funder had the following involvement with the study: all trial-related activities and participated in site selection, data monitoring, trial management, and statistical analysis. TFi: consultant CORCYM and BioStable. TFo: consultant CORCYM (Steering Committee). BM and MS: consultant CORCYM Steering Committee and Proctor. ER: consultant CORCYM (Steering Committee and Proctor), speaker for Abbott, consultant, speaker and investigator for Edwards and Medtronic. NB: educational grants: Edwards Lifesciences and CORCYM, Speaker Honoraria: Edwards Lifesciences, CORCYM and Medtronic. OF, GT, SP, SK, JG-P: consultant CORCYM (Proctor). MA: consultant Abbott and Edwards (Proctor), advisor Medtronic. FR: consultant CORCYM and AtriCure (Proctor), Research Support Recipient Medtronic. RL: Consultant Medtronic, LivaNova, CORCYM and Getinge (honoraria paid to the Maastricht University) and Member of the Medical Advisory Board for Eurosets (honoraria paid to the Maastricht University). FA has no personal conflict of interest but directs an academic Core laboratory carrying institutional contracts (MedStar Health) for his work with Corcym/Livanova, Edwards, Medtronic, Boston Scientific, Abbott, Foldax, Biotronik. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Fischlein, Caporali, Asch, Vogt, Pollari, Folliguet, Kappert, Meuris, Shrestha, Roselli, Bonaros, Fabre, Corbi, Troise, Andreas, Pinaud, Pfeiffer, Kueri, Tan, Voisine, Girdauskas, Rega, García-Puente, De Kerchove, Lorusso and on behalf of the PERSIST-AVR Investigators.)

Caveolae are cell membrane invaginations of defined lipid and protein composition that flatten with increasing membrane tension. Super-resolution light microscopy and electron microscopy have revealed that caveolae can take a variety of cuplike shapes. We show here that, for the range in membrane tension relevant for cell membranes, the competition between membrane tension and membrane bending yields caveolae with cuplike shapes similar to those observed experimentally. We find that the caveola shape and its sensitivity to changes in membrane tension can depend strongly on the caveola spontaneous curvature and on the size of caveola domains. Our results suggest that heterogeneity in caveola shape produces a staggered response of caveolae to mechanical perturbations of the cell membrane, which may facilitate regulation of membrane tension over the wide range of scales thought to be relevant for cell membranes.

Background:  Management of the aortic root during acute Type A aortic dissection (TAAD) repair remains controversial in term of long-term evolution and reoperation. The aim of this study was to assess the long-term outcomes of the aortic root after conservative management during primary surgery., Methods:  One hundred sixty-four consecutive patients were included in this monocentric retrospective study. The primary endpoint was reoperation on the aortic root during long-term follow-up. Forty-six patients had aortic root replacement (ARR) and 118 had supracoronary aortic replacement (SCR). The 10-year survival, occurrence of significant aortic regurgitation, and radiologic aortic root dilatation in each group were assessed during follow-up., Results:  Patients from ARR group were younger than those from SCR group ( p  < 0.0001). Median follow-ups of ARR group and SCR group are 4.4 (interquartile range [IR]: 2.6-8.3) and 6.15 (IR: 2.8-10.53) years, respectively. Reoperation of the aortic root during long-term follow-up was similar in both groups (ARR group: 5.1%, SCR group: 3.3%, p  = 0.636). The 10-year survivals of ARR and SCR groups were 64.8 ± 12.3% and 46.3 ± 5.8% ( p  = 0.012), respectively. Long-term significant aortic regurgitation occurred in one patient (1.7%) and seven patients (7.6%) of the ARR and SCR groups ( p  = 0.176), respectively. Radiologic aortic root diameters in the SCR group were similar between postoperative period and follow-up studies ( p  = 0.58). Reoperation on the distal aorta ( p  = 0.012) and patent radiologic false lumen of the descending aorta ( p  = 0.043) were independent risk factors of late death., Conclusion:  SCR is an effective technique for primary TAAD surgery and does not increase the rate of late reoperation on the aortic root., Competing Interests: The authors declare no conflict of interest related to this article., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).)

Introduction: Despite suffering a severe aortic stenosis, some patients are denied either surgical or transcatheter aortic valve implantation (TAVI) therapy because of a frail condition. We aimed to identify whether a comprehensive geriatric assessment (CGA) might be useful to predict the prognosis of presumably frail patients with severe aortic stenosis., Material and Methods: Between March 2011 and July 2016, 818 patients were consecutively and prospectively enrolled. 161 had a CGA and were considered for analysis. Considering combined CGA and heart team recommendations, 102 TAVI procedures were performed (TAVI group) and 59 patients constituted the no-TAVI group. The primary endpoint was all-cause mortality at 1 year., Results: There was no difference between the TAVI and the no-TAVI groups considering morphometric data, cardiovascular risk factors or symptoms. The no-TAVI group had higher surgical risk (logistic EuroSCORE1 33.4 ±17.8 vs. 22.7 ±14.9; p < 0.001) and more moderate renal insufficiency (82% vs. 57%; p = 0.001). One-year mortality was 16% in the TAVI group and 46% in the no-TAVI group ( p < 0.001). Multivariate analysis revealed that history of pulmonary edema, moderate renal failure, and not having a TAVI were associated with 1-year mortality. There was an interaction between the Five-Times-Sit-to-Stand-Test (FTSST) and the effect of TAVI on mortality ( p = 0.049), as FTSST was the only predictor for 1-year mortality in the no-TAVI group (HR = 0.18, 95% CI: 0.04-0.76; p = 0.019)., Conclusions: One-year mortality was higher in geriatric-assessed frail patients who did not undergo TAVI. FTSST, which assesses patients' mobility, was the only prognostic marker for 1-year mortality, on top of the usual medical parameters., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2021 Termedia & Banach.)

Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory response (SIRS) and affects the organ vascular bed. Experimentally, the lack of pulsatility alters myogenic tone of resistance arteries and increases the parietal inflammatory response. The purpose of this study was to compare the vascular reactivity of the internal thoracic arteries (ITAs) due to the inflammatory response between patients undergoing coronary artery bypass grafting (CABG) under CPB with a roller pump or with a centrifugal pump., Methods: Eighty elective male patients undergoing CABG were selected using one or two internal thoracic arteries under CPB with a roller pump (RP group) or centrifugal pump (CFP group). ITA samples were collected before starting CPB (Time 1) and before the last coronary anastomosis during aortic cross clamping (Time 2). The primary endpoint was the endothelium-dependent relaxation of ITAs investigated using wire-myography. The secondary endpoint was the parietal inflammatory response of arteries defined by the measurements of superoxide levels, leukocytes and lymphocytes rate and gene expression of inflammatory proteins using. Terminal complement complex activation (SC5b-9) and neutrophil activation (elastase) analysis were performed on arterial blood at the same times., Results: Exposure time of ITAs to the pump flow was respectively 43.3 minutes in the RP group and 45.7 minutes in the CFP group. Acetylcholine-dependent relaxation was conserved in the two groups whatever the time. Gene expression of C3 and C4a in the artery wall decreased from Time 1 to Time 2. No oxidative stress was observed in the graft. There was no difference between the groups concerning the leukocytes and lymphocytes rate. SC5b-9 and elastase increased between Time 1 and Time 2., Conclusion: Endothelium-dependent relaxation of the internal thoracic arteries was preserved during CPB whatever the type of pump used. The inflammatory response observed in the blood was not found in the graft wall within this time frame., Trial Registration: Name of trial study protocol: IPITA Registration number (ClinicalTrials.gov): NCT04168853., Competing Interests: The authors have declared that no competing interests exist.

Focused ultrasound (FUS) is a rapidly developing stimulus technology with the potential to uncover novel mechanosensory dependent cellular processes. Since it is non-invasive, it holds great promise for future therapeutic applications in patients used either alone or as a complement to boost existing treatments. For example, FUS stimulation causes invasive but not non-invasive cancer cell lines to exhibit marked activation of calcium signaling pathways. Here, we identify the membrane channel PANNEXIN1 (PANX1) as a mediator for activation of calcium signaling in invasive cancer cells. Knockdown of PANX1 decreases calcium signaling in invasive cells, while PANX1 overexpression enhances calcium elevations in non-invasive cancer cells. We demonstrate that FUS may directly stimulate mechanosensory PANX1 localized in endoplasmic reticulum to evoke calcium release from internal stores. This process does not depend on mechanosensory stimulus transduction through an intact cytoskeleton and does not depend on plasma membrane localized PANX1. Plasma membrane localized PANX1, however, plays a different role in mediating the spread of intercellular calcium waves via ATP release. Additionally, we show that FUS stimulation evokes cytokine/chemokine release from invasive cancer cells, suggesting that FUS could be an important new adjuvant treatment to improve cancer immunotherapy., (Copyright © 2020 Lee, Yoon, Wang, Moon, Koo, Jung, Chen, Jiang, Lu, Fernandez, Chow, Weitz, Salvaterra, Pinaud and Shung.)

Background: This study aims to compare the effects of storage solutions commonly used in coronary artery bypass grafting on the vascular reactivity in vein graft interposed in arterial position in syngeneic rats., Methods: Twenty-seven male Lewis rats were sacrified to sample a vein graft implanted 6 weeks ago into abdominal aorta position. The vein grafts were inferior venae cavae initially pretreated with heparinized saline solution (HS) or autologous heparinized blood (AHB) or our referent solution, GALA. The endothelial functionality, the in situ Reactive Oxygen Species (ROS) levels and the histological characteristics were conducted from segments of arterialized vein graft., Results: At 6 weeks, graft thrombosis occurred respectively in 22% of AHB group, 62.5% in the HS group and 82.5% in the GALA group. In each group, significative intimal hyperplasia was observed. After 6 weeks, an endothelium-remodeling layer associated with an increase of wall thickness was observed in each group. Endothelium-dependent tone was reduced in the vein graft regardless of the group. No difference was observed concerning the ROS in vein graft between the different groups. In distal aortic sections, ROS levels were increased in HS and GALA groups., Conclusions: Storage solutions used in this experimental model of vein graft implanted in arterial position cause graft injury and a complete disappearance of vascular reactivity. GALA solution did not reduce intimal risk hyperplasia when the vein graft was exposed to arterial flow in a rat model.

Background: No randomized study powered to compare balloon expandable (BE) with self expanding (SE) transcatheter heart valves (THVs) on individual end points after transcatheter aortic valve replacement has been conducted to date., Methods: From January 2013 to December 2015, the FRANCE-TAVI nationwide registry (Registry of Aortic Valve Bioprostheses Established by Catheter) included 12 141 patients undergoing BE-THV (Edwards, n=8038) or SE-THV (Medtronic, n=4103) for treatment of native aortic stenosis. Long term mortality status was available in all patients (median 20 months; interquartile range, 14 to 30). Patients treated with BE-THV (n=3910) were successfully matched 1:1 with 3910 patients treated with SE-THV by using propensity score (25 clinical, anatomical, and procedural variables) and by date of the procedure (within 3 months). The first coprimary outcome was ≥ moderate occurrence of paravalvular regurgitation or in-hospital mortality, or both. The second coprimary outcome was 2-year all-cause mortality., Results: In propensity-matched analyses, the incidence of the first coprimary outcome was higher with SE-THV (19.8%) compared with BE-THV (11.9%; relative risk, 1.68 [95% CI, 1.46-1.91]; P <0.0001). Each component of the outcome was also higher in patients receiving SE-THV: ≥ moderate paravalvular regurgitation (15.5% versus 8.3%; relative risk, 1.90 [95% CI, 1.63-2.22]; P <0.0001) and in hospital mortality (5.6% versus 4.2%; relative risk, 1.34 [95% CI, 1.07-1.66]; P =0.01). During follow up, all cause mortality occurred in 899 patients treated with SE-THV (2-year mortality, 29.8%) and in 801 patients treated with BE-THV (2-year mortality, 26.6%; hazard ratio, 1.17 [95% CI, 1.06-1.29]; P =0.003). Similar results were found using inverse probability of treatment weighting using propensity score analysis., Conclusion: The present study suggests that use of SE-THV was associated with a higher risk of paravalvular regurgitation and higher in-hospital and 2-year mortality compared with use of BE-THV. These data strongly support the need for a randomized trial sufficiently powered to compare the latest generation of SE-THV and BE-THV., Clinical Trial Registration: https://www.clinicaltrials.gov. Unique identifier: NCT01777828.

Aims: To investigate the impact of transcatheter aortic valve replacement (TAVR) without preliminary balloon aortic valvuloplasty (pre-BAV) on periprocedural outcomes in a large, real-world registry., Methods and Results: The SOURCE 3 registry was an observational, multi-center, single-arm study of patients with severe, symptomatic aortic stenosis at high surgical risk treated with the SAPIEN 3 transcatheter heart valve (THV). Procedural and 30-day outcomes were compared between two groups of 772 patients each (retrospectively matched) with or without pre-BAV. All baseline clinical, echocardiographic, and anatomical valve characteristics were comparable between groups except for Society of Thoracic Surgeons (STS) score, which was lower in the direct TAVR group (6.0 ± 5.9 vs 7.8 ± 8.3; p = 0.003). In the direct TAVR group, there were less post-dilatations (8.1% vs. 13.1%, p = 0.002), shorter procedural time (70.9 ± 39.8 min vs 73.0 ± 32.2 min, p = 0.033) and fluoroscopy time (13.4 ± 7.0 min vs 14.9 ± 7.4 min, p < 0.001). Other procedural outcomes and echocardiographic variables at 30 days did not differ significantly between the two groups: safety endpoint (10.4% with pre-BAV vs 13.5% with direct TAVR, p = 0.059), mortality (2.1% vs 2.3%, p = 0.730), disabling strokes (0.4% vs 0.5%, p = 0.704), and moderate to severe paravalvular leak (PVL) (3.2% vs 2.2%, p = 0.40). Unexpectedly, new permanent pacemaker implantation and life-threatening bleeds were less frequently observed with pre-BAV group than with direct TAVR (10.4% vs 13.9%, p = 0.032 and 3.5% vs 6.5%, p = 0.007, respectively)., Conclusion: In this large TAVR dataset, direct implantation of the SAPIEN 3 THV without pre-BAV was feasible and safe and resulted in shorter procedures, without impact on 30-day prosthesis function and PVL., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Micropatterning techniques have been widely used in biology, particularly in studies involving cell adhesion and proliferation on different substrates. Cell micropatterning approaches are also increasingly employed as in vitro tools to investigate intracellular mechanotransduction processes. In this report, we examined how modulating cellular shapes on two-dimensional rectangular fibronectin micropatterns of different widths influences nuclear mechanotransduction mediated by emerin, a nuclear envelope protein implicated in Emery-Dreifuss muscular dystrophy (EDMD). Fibronectin microcontact printing was tested onto glass coverslips functionalized with three different silane reagents (hexamethyldisilazane (HMDS), (3-Aminopropyl)triethoxysilane (APTES) and (3-Glycidyloxypropyl)trimethoxysilane (GPTMS)) using a vapor-phase deposition method. We observed that HMDS provides the most reliable printing surface for cell micropatterning, notably because it forms a hydrophobic organosilane monolayer that favors the retainment of surface antifouling agents on the coverslips. We showed that, under specific mechanical cues, emerin-null human skin fibroblasts display a significantly more deformed nucleus than skin fibroblasts expressing wild type emerin, indicating that emerin plays a crucial role in nuclear adaptability to mechanical stresses. We further showed that proper nuclear responses to forces involve a significant relocation of emerin from the inner nuclear envelope towards the outer nuclear envelope and the endoplasmic reticulum membrane network. Cell micropatterning by fibronectin microcontact printing directly on HMDS-treated glass represents a simple approach to apply steady-state biophysical cues to cells and study their specific mechanobiology responses in vitro.

GRP78 conducts protein folding and quality control in the ER and shows elevated expression and cell surface translocation in advanced tumors. However, the underlying mechanisms enabling GRP78 to exert novel signaling functions at cell surface are just emerging. CD44 is a transmembrane protein and an important regulator of cancer metastasis, and isoform switch of CD44 through incorporating additional variable exons to the extracellular juxtamembrane region is frequently observed during cancer progression. Using super-resolution dual-color single-particle tracking, we report that GRP78 interacts with CD44v in plasma membrane nanodomains of breast cancer cells. We further show that targeting cell surface GRP78 by the antibodies can effectively reduce cell surface expression of CD44v and cell spreading of tamoxifen-resistant breast cancer cells. Our results uncover new functions of GRP78 as an interacting partner of CD44v and as a regulator of CD44v membrane homeostasis and cell spreading. This study also provides new insights into anti-CD44 therapy in tamoxifen-resistant breast cancer., (© 2019 Tseng et al.)

Objectives: This study sought to describe the procedural and clinical outcomes of patients undergoing transcarotid (TC) transcatheter aortic valve replacement (TAVR) with the Edwards Sapien 3 device., Background: The TC approach for TAVR holds the potential to become the optimal alternative to the transfemoral gold standard. Limited data exist regarding safety and efficacy of TC-TAVR using the Edwards Sapien 3 device., Methods: The French Transcarotid TAVR prospective multicenter registry included patients between 2014 and 2018. Consecutive patients treated in 1 of the 13 participating centers ineligible for transfemoral TAVR were screened for TC-TAVR. Clinical and echocardiographic data were prospectively collected. Perioperative and 30-day outcomes were reported according to the updated Valve Academic Research Consortium (VARC-2)., Results: A total of 314 patients were included with a median (interquartile range) age of 83 (78 to 88) years, 63% were males, Society of Thoracic Surgeons mortality risk score 5.8% (4% to 8.3%). Most patients presented with peripheral artery disease (64%). TC-TAVR was performed under general anesthesia in 91% of cases, mostly using the left carotid artery (73.6%) with a procedural success of 97%. Three annulus ruptures were reported, all resulting in patient death. At 30 days, rates of major bleeding, new permanent pacemaker, and stroke or transient ischemic attack were 4.1%, 16%, and 1.6%, respectively. The 30-day mortality was 3.2%., Conclusions: TC-TAVR using the Edwards Sapien 3 device was safe and effective in this prospective multicenter registry. The TC approach might be considered, in selected patients, as the first-line alternative approach for TAVR whenever the transfemoral access is prohibited. Sapien 3 device was safe and effective in our multicenter cohort., (Copyright © 2019. Published by Elsevier Inc.)

Mutagenic translesion DNA polymerase V (UmuD'2C) is induced as part of the DNA damage-induced SOS response in Escherichia coli, and is subjected to multiple levels of regulation. The UmuC subunit is sequestered on the cell membrane (spatial regulation) and enters the cytosol after forming a UmuD'2C complex, ~ 45 min post-SOS induction (temporal regulation). However, DNA binding and synthesis cannot occur until pol V interacts with a RecA nucleoprotein filament (RecA*) and ATP to form a mutasome complex, pol V Mut = UmuD'2C-RecA-ATP. The location of RecA relative to UmuC determines whether pol V Mut is catalytically on or off (conformational regulation). Here, we present three interrelated experiments to address the biochemical basis of conformational regulation. We first investigate dynamic deactivation during DNA synthesis and static deactivation in the absence of DNA synthesis. Single-molecule (sm) TIRF-FRET microscopy is then used to explore multiple aspects of pol V Mut dynamics. Binding of ATP/ATPγS triggers a conformational switch that reorients RecA relative to UmuC to activate pol V Mut. This process is required for polymerase-DNA binding and synthesis. Both dynamic and static deactivation processes are governed by temperature and time, in which on → off switching is "rapid" at 37°C (~ 1 to 1.5 h), "slow" at 30°C (~ 3 to 4 h) and does not require ATP hydrolysis. Pol V Mut retains RecA in activated and deactivated states, but binding to primer-template (p/t) DNA occurs only when activated. Studies are performed with two forms of the polymerase, pol V Mut-RecA wt, and the constitutively induced and hypermutagenic pol V Mut-RecA E38K/ΔC17. We discuss conformational regulation of pol V Mut, determined from biochemical analysis in vitro, in relation to the properties of pol V Mut in RecA wild-type and SOS constitutive genetic backgrounds in vivo., Competing Interests: The authors have declared that no competing interests exist.

Background: Transcatheter aortic valve implantation is increasingly being used in patients at lower risk for surgery. We aimed to assess the distribution of surgical risk score categories in current clinical practice and their relationship with clinical outcomes and the calibration and discrimination power of both the logistic EuroSCORE (logES) and EuroSCORE II. The SOURCE 3 study is a European prospective registry of patients with severe aortic stenosis treated with the commercially available SAPIEN 3 transcatheter heart valve., Methods and Results: Out of 1785 patients, 518 patients (low-surgical risk) had a baseline logES <10%, 691 (intermediate-surgical risk) had a logES 10% to 20%, and only 576 patients (high-surgical risk) had a logES ≥20%. Even if low-risk patients were younger compared with the other groups, the mean age was about 80 years old in each risk category. At 1 year, all-cause mortality was 10.3%, 11.4%, and 17.1% in low-, intermediate-, or high-surgical risk patients, respectively, while cardiac mortality was 5.3%, 7.7%, and 11.4%, respectively. Observed mortality rates were substantially lower than that predicted with logES. The observed/predicted mortality ratio was 0.26 in low-surgical risk patients, 0.08 in intermediate-surgical risk patients, and 0.12 in high-surgical risk patients. Similar observations were obtained with EuroSCORE II., Conclusions: In this real-world setting, two-thirds of SAPIEN 3 transcatheter heart valve treated transcatheter aortic valve implantation patients had a logES <20 but were still considered appropriate transcatheter aortic valve implantation candidates by the heart team, mainly because of older age and less frequently because of conditions not captured by risk scores. logES and EuroSCORE II had poor discrimination and calibration power in this transcatheter aortic valve implantation cohort., Clinical Trial Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT02698956.

Many biotechniques use complementary split-fluorescent protein (sFPs) fragments to visualize protein-protein interactions, image cells by ensemble or single molecule fluorescence microscopy, or assemble nanomaterials and protein superstructures. Yet, the reassembly mechanisms of sFPs, including fragment binding rates, folding, chromophore maturation and overall photophysics remain poorly characterized. Here, we evolved asymmetric and self-complementing green, yellow and cyan sFPs together with their full-length equivalents (flFPs) and described their biochemical and photophysical properties in vitro and in cells. While re-assembled sFPs have spectral properties similar to flFPs, they display slightly reduced quantum yields and fluorescence lifetimes due to a less sturdy β-barrel structure. The complementation of recombinant sFPs expressed in vitro follows a conformational selection mechanism whereby the larger sFP fragments exist in a monomer-dimer equilibrium and only monomers are competent for fluorescence complementation. This bimolecular fragment interaction involves a slow and irreversible binding step, followed by chromophore maturation at a rate similar to that of flFPs. When expressed as fusion tags in cells, sFPs behave as monomers directly activated with synthetic complementary fragments. This study resulted in the development of sFP color variants having improved maturation kinetics, brightness, and photophysics for fluorescence microscopy imaging of cellular processes, including single molecule detection.

The in cellulo assembly of plasmonic nanomaterials into photo-responsive probes is of great interest for many bioimaging and nanophotonic applications but remains challenging with traditional nucleic acid scaffolds-based bottom-up methods. Here, we address this quandary using split-fluorescent protein (FP) fragments as molecular glue and switchable Raman reporters to assemble gold or silver plasmonic nanoparticles (NPs) into photonic clusters directly in live cells. When targeted to diffusing surface biomarkers in cancer cells, the NPs self-assemble into surface-enhanced Raman-scattering (SERS) nanoclusters having hot spots homogenously seeded by the reconstruction of full-length FPs. Within plasmonic hot spots, autocatalytic activation of the FP chromophore and near-field amplification of its Raman fingerprints enable selective and sensitive SERS imaging of targeted cells. This FP-driven assembly of metal colloids also yields enhanced photoacoustic signals, allowing the hybrid FP/NP nanoclusters to serve as contrast agents for multimodal SERS and photoacoustic microscopy with single-cell sensitivity.

Patterning cells on microcontact-printed substrates is a powerful approach to control cell morphology and introduce specific mechanical cues on a cell's molecular organization. Although global changes in cellular architectures caused by micropatterns can easily be probed with diffraction-limited optical microscopy, studying molecular reorganizations at the nanoscale demands micropatterned substrates that accommodate the optical requirements of single molecule microscopy techniques. Here, we developed a simple micropatterning strategy that provides control of cellular architectures and is optimized for nanometer accuracy single molecule tracking and three-dimensional super-resolution imaging of plasma and nuclear membrane proteins in cells. This approach, based on fibronectin microcontact printing on hydrophobic organosilane monolayers, allows evanescent wave and light-sheet microscopy of cells whilst fulfilling the stringent optical demands of point reconstruction optical microscopy. By imposing steady-state mechanical cues on cells grown in these micropatterns, we reveal nanoscale remodeling in the dynamics and the structural organizations of the nuclear envelope mechanotransducing protein emerin and of the plasma membrane mechanosensing protein caveolin-1 using single particle tracking photoactivated localization microscopy and direct stochastic optical reconstruction microscopy imaging. In addition to allowing quantitative biophysical studies of mechanoresponsive membrane proteins, this approach provides an easy means to probe mechanical regulations in cellular membranes with high optical resolution and nanometer precision.