Active superelasticity in three-dimensional epithelia of controlled shape

Fundamental biological processes are carried out by curved epithelial sheets that enclose a pressurized lumen. How these sheets develop and withstand three-dimensional deformations has remained unclear. Here we combine measurements of epithelial tension and shape with theoretical modelling to show that epithelial sheets are active superelastic materials. We produce arrays of epithelial domes with controlled geometry. Quantification of luminal pressure and epithelial tension reveals a tensional plateau over several-fold areal strains. These extreme strains in the tissue are accommodated by highly heterogeneous strains at a cellular level, in seeming contradiction to the measured tensional uniformity. This phenomenon is reminiscent of superelasticity, a behaviour that is generally attributed to microscopic material instabilities in metal alloys. We show that in epithelial cells this instability is triggered by a stretch-induced dilution of the actin cortex, and is rescued by the intermediate filament network. Our study reveals a type of mechanical behaviour—which we term active superelasticity—that enables epithelial sheets to sustain extreme stretching under constant tension.Peer ReviewedPostprint (author's final draft

Mapping mechanical stress in curved epithelia of designed size and shape

We thank C. Pérez-González, N. Castro, and all of the members of the Roca-Cusachs, Arroyo, and Trepat laboratories for their discussions and support. This work was supported by: Generalitat de Catalunya (Agaur, SGR-2021-01425 to X.T., SGR-2021-00523 to R.S., the CERCA Programme, and “ICREA Academia” award to M.A. and P.R-C.); Spanish Ministry for Science and Innovation MICCINN/FEDER (PID2021- 128635NB-I00, MCIN/AEI/ 10.13039/501100011033 and “ERDF-EU A way of making Europe” to X.T., PID2019-110949GB-I00 to M.A., PID2019- 110298GB-I00 to P.R.-C., PID2021-128674OB-I00, RTI2018-101256-J-I00, and RYC2019-026721-I to R.S.); European Research Council (Adv883739 to X.T., CoG-681434 to M.A.); Fundació la Marató de TV3 (project 201903-30-31-32 to X.T.); Deutsche Forschungsgemeinschaft (DFG GO3403/1-1 to T.G.); IBEC, IRB, and CIMNE are recipients of a Severo Ochoa Award of Excellence from the MINECO; European Commission (H2020-FETPROACT-01-2016-731957 to P.R-C.); La Caixa Foundation (LCF/PR/HR20/52400004 and ID 100010434 under the agreement LCF/ PR/HR20/52400004 to P.R-C. and X.T.). R.S. is a Serra Húnter fellow.The function of organs such as lungs, kidneys and mammary glands relies on the three-dimensional geometry of their epithelium. To adopt shapes such as spheres, tubes and ellipsoids, epithelia generate mechanical stresses that are generally unknown. Here we engineer curved epithelial monolayers of controlled size and shape and map their state of stress. We design pressurized epithelia with circular, rectangular and ellipsoidal footprints. We develop a computational method, called curved monolayer stress microscopy, to map the stress tensor in these epithelia. This method establishes a correspondence between epithelial shape and mechanical stress without assumptions of material properties. In epithelia with spherical geometry we show that stress weakly increases with areal strain in a size-independent manner. In epithelia with rectangular and ellipsoidal cross-section we find pronounced stress anisotropies that impact cell alignment. Our approach enables a systematic study of how geometry and stress influence epithelial fate and function in three-dimensions.Peer ReviewedPostprint (published version

Multicentre, randomised, single-blind, parallel group trial to compare the effectiveness of a Holter for Parkinson's symptoms against other clinical monitoring methods: study protocol

Introduction In recent years, multiple studies have aimed to develop and validate portable technological devices capable of monitoring the motor complications of Parkinson's disease patients (Parkinson's Holter). The effectiveness of these monitoring devices for improving clinical control is not known. Methods and analysis This is a single-blind, cluster-randomised controlled clinical trial. Neurologists from Spanish health centres will be randomly assigned to one of three study arms (1:1:1): (a) therapeutic adjustment using information from a Parkinson?s Holter that will be worn by their patients for 7 days, (b) therapeutic adjustment using information from a diary of motor fluctuations that will be completed by their patients for 7 days and (c) therapeutic adjustment using clinical information collected during consultation. It is expected that 162 consecutive patients will be included over a period of 6 months. The primary outcome is the efficiency of the Parkinson?s Holter compared with traditional clinical practice in terms of Off time reduction with respect to the baseline (recorded through a diary of motor fluctuations, which will be completed by all patients). As secondary outcomes, changes in variables related to other motor complications (dyskinesia and freezing of gait), quality of life, autonomy in activities of daily living, adherence to the monitoring system and number of doctor?patient contacts will be analysed. The noninferiority of the Parkinson's Holter against the diary of motor fluctuations in terms of Off time reduction will be studied as the exploratory objective. Ethics and dissemination approval for this study has been obtained from the Hospital Universitari de Bellvitge Ethics Committee. The results of this study will inform the practical utility of the objective information provided by a Parkinson's Holter and, therefore, the convenience of adopting this technology in clinical practice and in future clinical trials. We expect public dissemination of the results in 2022.Funding This work is supported by AbbVie S.L.U, the Instituto de Salud Carlos III [DTS17/00195] and the European Fund for Regional Development, 'A way to make Europe'

Language statistical learning responds to reinforcement learning principles rooted in the striatum

Statistical learning (SL) is the ability to extract regularities from the environment. In the domain of language, this ability is fundamental in the learning of words and structural rules. In lack of reliable online measures, statistical word and rule learning have been primarily investigated using offline (post-familiarization) tests, which gives limited insights into the dynamics of SL and its neural basis. Here, we capitalize on a novel task that tracks the online SL of simple syntactic structures combined with computational modeling to show that online SL responds to reinforcement learning principles rooted in striatal function. Specifically, we demonstrate-on 2 different cohorts-that a temporal difference model, which relies on prediction errors, accounts for participants' online learning behavior. We then show that the trial-by-trial development of predictions through learning strongly correlates with activity in both ventral and dorsal striatum. Our results thus provide a detailed mechanistic account of language-related SL and an explanation for the oft-cited implication of the striatum in SL tasks. This work, therefore, bridges the long-standing gap between language learning and reinforcement learning phenomena

Active superelasticity in three-dimensional epithelia of controlled shape

Fundamental biological processes are carried out by curved epithelial sheets that enclose a pressurized lumen. How these sheets develop and withstand three-dimensional deformations has remained unclear. Here we combine measurements of epithelial tension and shape with theoretical modelling to show that epithelial sheets are active superelastic materials. We produce arrays of epithelial domes with controlled geometry. Quantification of luminal pressure and epithelial tension reveals a tensional plateau over several-fold areal strains. These extreme strains in the tissue are accommodated by highly heterogeneous strains at a cellular level, in seeming contradiction to the measured tensional uniformity. This phenomenon is reminiscent of superelasticity, a behaviour that is generally attributed to microscopic material instabilities in metal alloys. We show that in epithelial cells this instability is triggered by a stretch-induced dilution of the actin cortex, and is rescued by the intermediate filament network. Our study reveals a type of mechanical behaviour—which we term active superelasticity—that enables epithelial sheets to sustain extreme stretching under constant tension.Peer Reviewe

Effects of simvastatin in chronic obstructive pulmonary disease: Results of a pilot, randomized, placebo-controlled clinical trial

Introduction: Statins may have pleiotropic effects in COPD, but mechanisms remain unclear. Objectives: To assess the pleiotropic effect of statins in patients with stable COPD on (1): lung function (2); pulmonary and systemic inflammation (3); endothelial function (vascular stiffness) and circulating vascular growth factors; and (4), serum uric acid levels. Method: Pilot, double-blind, randomized, placebo-controlled clinical trial in 24 patients with stable COPD, all statin-naïve, who were randomized (1:1) to receive simvastatin 40 mg/24 h during 12 weeks (n = 12; 69.0 ± 7.3 years; post-bd FEV1 53.4 ± 10.0% pred.) or placebo (n = 12; 66.4 ± 4.6 years; post-bd FEV1 48.2 ± 12.6% pred.). Nine patients per group (total n = 18) completed the study. Results: Lung function, pulmonary and systemic inflammatory markers and the degree of vascular stiffness did not change significantly in any group. However, treatment with simvastatin increased the plasma levels of erythropoietin (Epo) (4.2 ± 2.2 mIU/mL to 6.8 ± 3.2 mlU/mL, p < 0.05) and reduced those of serum uric acid (7.1 ± 1.3 mg/dL to 6.5 ± 1.4 mg/dL, p < 0.01). Conclusions: Short-term treatment with simvastatin in stable COPD patients did not modify lung function, pulmonary and systemic inflammation, or vascular stiffness, but it changed Epo and uric acid levels

Efficacy and safety of the dual-layer flow-diverting stent (FRED) for the treatment of intracranial aneurysms

Purpose: To describe the efficacy and complications of treating cerebral aneurysms with the Flow Re-direction Endoluminal Device (FRED) and to identify predictors for aneurysm occlusion. Methods: A prospective observational registry including all consecutive aneurysms treated with FRED between December 2015 and July 2018 was designed in one therapeutic neuroangiography department. The primary endpoint for treatment efficacy was complete or near-complete occlusion (O'Kelly-Marotta (OKM) C-D), assessed by three-dimensional digital subtraction angiography. Major (all symptomatics) and minor complications were described and those with modified Rankin Scale scores 3-6 were considered clinically relevant. Univariate and multivariate analyses were performed to identify predictors of efficacy. Results: A total of 185 aneurysms were analyzed in 150 patients (mean age 54.3±11.5 years). Mean follow-up was 18.99±11.32 months (range 0-43). Efficacy was evaluated in 156 (84.32%) cases: 132 (84.6%) had OKM C-D occlusion, 31/47 (66%) within the first year and 101/109 (92.7%) later on. Major complications were observed in 12 (6.5%) cases: three strokes (one transient ischemic accident, two minor strokes), six intra-stent thrombosis, and three with bleeding, but only one (0.5%) was clinically relevant. Minor complications (all asymptomatic) were observed in 10 (5.4%) cases: three shortening/repositioning of stent; two arterial dissection, two arterial occlusion, and three intra-stent stenosis. Independent predictors of occlusion were immediate OKM grade B-C-D (OR 4.01, 95% CI 1.51 to 10.62), single aneurysm (OR 3.29, 95% CI 1.05 to 10.32), and small size aneurysm (OR 4.74, 95% CI 1.57 to 14.30). Conclusion: The FRED stent fully complied with efficacy and safety requirements for treatment of intracranial aneurysms. Three predictors of aneurysm occlusion were identified

Transdermal Rotigotine Improves Sleep Fragmentation in Parkinson's Disease: Results of the Multicenter, Prospective SLEEP-FRAM Study.

Sleep disturbances occur frequently in patients with Parkinson's disease (PD). The aim of this study was to investigate the effects of rotigotine on sleep fluctuations in a sample of PD patients with self-reported complaints of nocturnal awakenings. This prospective, open-label, observational, and multicenter study enrolled consecutive outpatients with PD and administered rotigotine (mean dose 8.9 mg/day) for 3 months. The primary endpoint was the change from baseline in sleep fragmentation, assessed using the sleep maintenance subscale score of the Parkinson's Disease Sleep Scale (PDSS). The newly designed Parkinson's Disease Sleep Fragmentation Questionnaire (PD-SFQ) was used to measure other sleep parameters. A total of 62 patients were enrolled (mean age 70.2 years; 66% male). At 3 months, rotigotine significantly improved sleep fragmentation from baseline on the PDSS-2 sleep maintenance subscale (from 3.4 ± 0.9 to 1.9 ± 1.4; P < 0.0001). Rotigotine also significantly improved nocturnal motor symptoms (P < 0.0001), restless legs-like symptoms (P < 0.005), and nocturia (P = 0.004). Rotigotine significantly improved self-reported complaints of sleep fragmentation in PD patients and could be a useful treatment to improve this specific sleep problem in PD. However, these results are based on a small and clinically heterogeneous sample so they must be taken cautiously.The study was funded by an unrestricted grant from UCB