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Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing in prevalence globally. MASLD is associated with an increased rate of comorbidities, including cardiovascular disease, liver cirrhosis, and hepatocellular carcinoma (HCC). While the link between MASLD and HCC is well known, the potential association with biliary tract cancer, including cholangiocarcinoma (CCA) and gallbladder cancer (GBC), is less certain. To evaluate whether individuals with MASLD are at increased risk of developing CCA compared to the general population, we performed a nationwide cohort study investigating the longitudinal association between MASLD and CCA., Methods: A retrospective cohort study was performed including all patients ≥18 years of age, diagnosed with MASLD, from 1 st of January 1987 to 31 st of December 2020, through the Swedish National Patient Register. For each patient with MASLD, ten individuals, matched to the MASLD patient on year of diagnosis, age, sex, and municipality were selected as reference individuals. The international Classification of Diseases (ICD) codes were used to define MASLD and incident CCA. Incidence rates were calculated, and regression analyses were performed., Results: Out of the 11,940 exposed patients with MASLD, 11 developed CCA (0.1%) out of whom three were diagnosed with iCCA (0.03%), during a median follow-up time of  five years. Out of 112,537 reference individuals, 62 were diagnosed with CCA (0.3%), out of whom 15 were diagnosed with iCCA (0.01%). The rate of GBC was not higher compared to the reference population., Conclusion: This large cohort study found a low incidence of CCA in patients with MASLD, comparable to the general population which can reassure clinicians and patients that no specific vigilance for CCA should be considered in MASLD patients at present.

Liver transplantation (LTX) using donors after controlled circulatory death (cDCD) is associated with poorer graft survival and increased incidence of nonanastomotic biliary strictures (NASs) compared to livers procured from brain-dead donors (DBD). The use of normothermic regional perfusion (NRP) during cDCD procurement may improve posttransplant outcomes and reduce the incidence of NAS. In Sweden, cDCD LTX was introduced through a national pilot protocol with mandatory NRP. This study aims to evaluate the outcome of cDCD LTX during the pilot period. Donor and recipient data were collected on all cDCD liver transplants during the pilot period between January 2020 to December 2022. Outcome on NAS, patient and graft survival, early allograft dysfunction, acute kidney injury, and comprehensive complication index was compared to a matched cohort of 28 patients transplanted with a DBD liver between 2018 and 2022. Eighteen patients were transplanted with a liver from a cDCD donor after using NRP. The mean functional warm ischemia time was 29 ± 6 minutes. The mean lactate reduction during NRP was 8.7 ± 2.4 mmol/L, and the end NRP perfusate alanine aminotransferase was 1.4 ± 1 µkat/L. When comparing recipients of cDCD liver transplant to DBD, no significant differences were observed in the incidence of NAS, patient and graft survival, comprehensive complication index, early allograft dysfunction, or acute kidney injury. Study protocol magnetic resonance cholangiopancreatography in cDCD patients showed no signs of subclinical biliary strictures. Evaluation of the Swedish national pilot of cDCD LTX with mandatory NRP shows comparable outcomes to a matched DBD cohort with 94.4% 1-year patient and graft survival and no incidence of NAS within the first year., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

The metastatic cascade includes a blood circulation step for cells detached from the primary tumor. This stage involves significant shear stress as well as large and fast deformation as the cells circulate through the microvasculature. These mechanical stimuli are well reproduced in microfluidic devices. However, the recovery dynamics after deformation is also pivotal to understand how a cell can pass through the multiple capillary constrictions encountered during a single hemodynamic cycle. The microfluidic system developed in this work allows single cell recovery to be studied under flow-free conditions following pressure-actuated cell deformation inside constricted microchannels. We used three breast cancer cell lines - namely MCF-7, SK-BR3 and MDA-MB231 - as cellular models representative of different cancer phenotypes. Changing the size of the constriction allows exploration of moderate to strong deformation regimes, the latter being associated with the formation of plasma membrane blebs. In the regime of moderate deformation, all cell types display a fast elastic recovery behavior followed by a slower viscoelastic regime, well described by a double exponential decay. Among the three cell types, cells of the mesenchymal phenotype, i.e. the MDA-MB231 cells, are softer and the most fluid-like, in agreement with previous studies. Our main finding here is that the fast elastic recovery regime revealed by our novel microfluidic system is under the control of cell contractility ensured by the integrity of the cell cortex. Our results suggest that the cell cortex plays a major role in the transit of circulating tumor cells by allowing their fast morphological recovery after deformation in blood capillaries.

Foreign body ingestion in children is a frequent cause for medical consultation. Although most foreign bodies are spontaneously eliminated from the gastrointestinal tract, life-threatening complications such as gastrointestinal obstruction or perforation can occur. We report the case of a 6-year-old boy who died 2 days after the onset of nausea and abdominal pain, with no foreign body ingestion witnessed or reported in the previous days. Autopsy showed a diffuse peritonitis and a perforation of the transverse colon caused by three high-powered magnets stacked together, and attached to the outer stomach wall via a fourth magnet located in the stomach. The cause of death was peritonitis due to bowel perforation by ingested magnets, which were shown to have come from a toy belonging to the child. Ingestion of multiple high-powered magnets carries a high risk of gastrointestinal complications and can exceptionally have a fatal outcome, especially as it often goes unreported and causes non-specific gastrointestinal symptoms that can delay diagnosis and management. This case highlights the need to raise public awareness of the potential risks of ingesting such magnets and to strengthen safety standards to protect children from this serious health hazard., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Despite more than 50 years of research and parallel improvements in hepatology and oncology, there is still today neither a treatment to prevent disease progression in primary sclerosing cholangitis (PSC), nor reliable early diagnostic tools for the associated hepatobiliary cancers. Importantly, the limited understanding of the underlying biological mechanisms in PSC and its natural history not only affects the identification of new drug targets but implies a lack of surrogate markers that hampers the design of clinical trials and the evaluation of drug efficacy. The lack of easy access to large representative well-characterised prospective resources is an important contributing factor to the current situation., Methods: We here present the SUPRIM cohort, a national multicentre prospective longitudinal study of unselected PSC patients capturing the representative diversity of PSC phenotypes. We describe the 10-year effort of inclusion and follow-up, an intermediate analysis report including original results, and the associated research resource. All included patients gave written informed consent (recruitment: November 2011-April 2016)., Findings: Out of 512 included patients, 452 patients completed the five-year follow-up without endpoint outcomes. Liver transplantation was performed in 54 patients (10%) and hepatobiliary malignancy was diagnosed in 15 patients (3%). We draw a comprehensive landscape of the multidimensional clinical and biological heterogeneity of PSC illustrating the diversity of PSC phenotypes. Performances of available predictive scores are compared and perspectives on the continuation of the SUPRIM cohort are provided., Interpretation: We envision the SUPRIM cohort as an open-access collaborative resource to accelerate the generation of new knowledge and independent validations of promising ones with the aim to uncover reliable diagnostics, prognostic tools, surrogate markers, and new treatment targets by 2040., Funding: This work was supported by the Swedish Cancer Society, Stockholm County Council, and the Cancer Research Funds of Radiumhemmet., Competing Interests: The authors have no conflict of interest to disclose., (© 2024 The Author(s).)

Introduction: Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver disease that is characterized by an inflammatory and fibrotic process affecting bile ducts which eventually develops into liver cirrhosis and liver failure. The aim of this study was to investigate serum IgG subclass distribution in patients with PSC and its possible association with PSC outcomes., Patients and Methods: We performed a retrospective analysis of 181 patients who had been diagnosed with PSC between January 1970 and December 2015 and followed at our outpatient clinic. Their demographic, immunological, and clinical characteristics were recorded and analyzed., Results: This study included 181 patients with PSC (120 males, 61 females). There was no association between IgGs and the development of autoimmune hepatitis, cirrhosis, cholangiocarcinoma, liver transplantation, inflammatory bowel disease, and colectomy. Patients with elevated IgG4 had statistically significant higher rates of cholangitis ( p = 0.02) and endoscopic retrograde cholangiopancreatography (ERCP) ( p = 0.009). High IgG4 values were observed in nine patients who underwent ERCP. In these nine patients, on average, IgG4 was evaluated 5 years after ERCP (min 3 days, max 11 years). Subanalysis considering only IgG4 values evaluated before ERCP showed no significant difference but remains significant if we consider IgG4 values after ERCP., Conclusion: Elevated IgG4 in our study showed a possible association with higher rates of cholangitis and ERCP among patients with primary sclerosing cholangitis. It seems that IgGs may be a useful tool for the prediction of outcomes in patients with PSC. A prospective study is necessary, especially to study the trends of IgGs values during disease as well as the role of possible seroconversion.

Background: For some patients undergoing resection under the suspicion of a perihilar cholangiocarcinoma (pCCA), postoperative diagnosis may differ from the preoperative diagnosis. While a postoperative finding of benign bile duct stricture is known to affect 3-15% of patients, less has been described about the consequences of finding other biliary tract cancers postoperatively. This study compared pre- and postoperative diagnoses, risk characteristics, and outcomes after surgery for suspected pCCA., Methods: Retrospective single-center study, Karolinska University Hospital, Stockholm, Sweden (January 2009-May 2017). The primary postoperative outcome was overall survival. Secondary outcomes were disease-free survival and postoperative complications. Survival analysis was performed by the Kaplan-Meier method., Results: Seventy-one patients underwent resection for suspected pCCA. pCCA was confirmed in 48 patients (68%). Ten patients had benign lesions (14%), 2 (3%) were diagnosed with other types of cholangiocarcinoma (CCA, distal n = 1, intrahepatic n = 1), while 11 (15%) were diagnosed with gallbladder cancer (GBC). GBC patients were older than patients with pCCA (median age 71 versus 58 years, p = 0.015), with a large proportion of patients with a high tumor extension stage (≥ T3, 91%). Median overall survival was 20 months (95% CI 15-25 months) for patients with pCCA and 17 months (95% CI 11-23 months) for patients with GBC (p = 0.135). Patients with GBC had significantly shorter median disease-free survival (DFS), 10 months (95% CI 3-17 months) compared 17 months (95% CI 15-19 months) for patients with pCCA (p = 0.010)., Conclusions: At a large tertiary referral center, 15% of patients resected for suspected pCCA were postoperatively diagnosed with GBC. Compared to patients with pCCA, GBC patients were older, with advanced tumors and shorter DFS. The considerable rate of re-classification stresses the need for improved preoperative staging, as these prognostic differences could have implications for treatment strategies., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Alpha-synuclein (aSyn) aggregation spreads between cells and underlies the progression of neuronal lesions in the brain of patients with synucleinopathies such as Parkinson's diseases. The mechanisms of cell-to-cell propagation of aggregates, which dictate how aggregation progresses at the network level, remain poorly understood. Notably, while prion and prion-like spreading is often simplistically envisioned as a "domino-like" spreading scenario where connected neurons sequentially propagate protein aggregation to each other, the reality is likely to be more nuanced. Here, we demonstrate that the spreading of preformed aSyn aggregates is a limited process that occurs through molecular sieving of large aSyn seeds. We further show that this process is not facilitated by synaptic connections. This was achieved through the development and characterization of a new microfluidic platform that allows reconstruction of binary fully oriented neuronal networks in vitro with no unwanted backward connections, and through the careful quantification of fluorescent aSyn aggregates spreading between neurons. While this allowed us for the first time to extract quantitative data of protein seeds dissemination along neural pathways, our data suggest that prion-like dissemination of proteinopathic seeding aggregates occurs very progressively and leads to highly compartmentalized pattern of protein seeding in neural networks., (© 2023. The Author(s).)

Metabolism and mechanics are two key facets of structural and functional processes in cells, such as growth, proliferation, homeostasis and regeneration. Their reciprocal regulation has been increasingly acknowledged in recent years: external physical and mechanical cues entail metabolic changes, which in return regulate cell mechanosensing and mechanotransduction. Since mitochondria are pivotal regulators of metabolism, we review here the reciprocal links between mitochondrial morphodynamics, mechanics and metabolism. Mitochondria are highly dynamic organelles which sense and integrate mechanical, physical and metabolic cues to adapt their morphology, the organization of their network and their metabolic functions. While some of the links between mitochondrial morphodynamics, mechanics and metabolism are already well established, others are still poorly documented and open new fields of research. First, cell metabolism is known to correlate with mitochondrial morphodynamics. For instance, mitochondrial fission, fusion and cristae remodeling allow the cell to fine-tune its energy production through the contribution of mitochondrial oxidative phosphorylation and cytosolic glycolysis. Second, mechanical cues and alterations in mitochondrial mechanical properties reshape and reorganize the mitochondrial network. Mitochondrial membrane tension emerges as a decisive physical property which regulates mitochondrial morphodynamics. However, the converse link hypothesizing a contribution of morphodynamics to mitochondria mechanics and/or mechanosensitivity has not yet been demonstrated. Third, we highlight that mitochondrial mechanics and metabolism are reciprocally regulated, although little is known about the mechanical adaptation of mitochondria in response to metabolic cues. Deciphering the links between mitochondrial morphodynamics, mechanics and metabolism still presents significant technical and conceptual challenges but is crucial both for a better understanding of mechanobiology and for potential novel therapeutic approaches in diseases such as cancer., (© 2023 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.)

Engineered 3D brain-like models have advanced the understanding of neurological mechanisms and disease, yet their mechanical signature, while fundamental for brain function, remains understudied. The surface tension for instance controls brain development and is a marker of cell-cell interactions. Here, 3D magnetic brain-like tissue spheroids composed of intermixed primary glial and neuronal cells at different ratios are engineered. Remarkably, the two cell types self-assemble into a functional tissue, with the sorting of the neuronal cells toward the periphery of the spheroids, whereas the glial cells constitute the core. The magnetic fingerprint of the spheroids then allows their deformation when placed under a magnetic field gradient, at a force equivalent to a 70 g increased gravity at the spheroid level. The tissue surface tension and elasticity can be directly inferred from the resulting deformation, revealing a transitional dependence on the glia/neuron ratio, with the surface tension of neuronal tissue being much lower. The results suggest an underlying mechanical contribution to the exclusion of the neurons toward the outer spheroid region, and depict the glia/neuron organization as a sophisticated mechanism that should in turn influence tissue development and homeostasis relevant in the neuroengineering field., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Background and Objective: Gallbladder cancer (GBC) is a rare malignancy in the Nordic countries and no common Nordic treatment guidelines exist. This study aimed to characterize the current diagnostic and treatment strategies in the Nordic countries and disclose differences in these strategies., Methods: This was a survey study with a cross-sectional questionnaire of all 19 university hospitals providing curative-intent surgery for GBC in Sweden, Norway, Denmark, and Finland., Results: In all Nordic countries except Sweden, neoadjuvant/downstaging chemotherapy was used in GBC patients. In T1b and T2, majority of the centers (15-18/19) performed extended cholecystectomy. In T3, majority of the centers (13/19) performed cholecystectomy with resection of segments 4b and 5. In T4, majority of the centers (12-14/19) chose palliative/oncological care. The centers in Sweden extended lymphadenectomy beyond the hepatoduodenal ligament, whereas all other Nordic centers usually limited lymphadenectomy to the hepatoduodenal ligament. All Nordic centers except those in Norway used adjuvant chemotherapy routinely for GBC. There were no major differences between the Nordic centers in diagnostics and follow-up., Conclusions: The surgical and oncological treatment strategies of GBC vary considerably between the Nordic centers and countries.

A perimetastatic capsule is a strong positive prognostic factor in liver metastases, but its origin remains unclear. Here, we systematically quantify the capsule's extent and cellular composition in 263 patients with colorectal cancer liver metastases to investigate its clinical significance and origin. We show that survival improves proportionally with increasing encapsulation and decreasing tumor-hepatocyte contact. Immunostaining reveals the gradual zonation of the capsule, transitioning from benign-like NGFR high stroma at the liver edge to FAP high stroma towards the tumor. Encapsulation correlates with decreased tumor viability and preoperative chemotherapy. In mice, chemotherapy and tumor cell ablation induce capsule formation. Our results suggest that encapsulation develops where tumor invasion into the liver plates stalls, representing a reparative process rather than tumor-induced desmoplasia. We propose a model of metastases growth, where the efficient tumor colonization of the liver parenchyma and a reparative liver injury reaction are opposing determinants of metastasis aggressiveness., (© 2023. Springer Nature Limited.)

Research into the neuroanatomical basis of emotions has resulted in a plethora of studies over the last twenty years. However, studies about positive emotions and pleasant sensations remain rare and their anatomical-functional bases are less understood than that of negative emotions. Pleasant sensations can be evoked by electrical brain stimulations (EBS) during stereotactic electroencephalography (SEEG) performed for pre-surgical exploration in patients with drug-resistant epilepsy. We conducted a retrospective analysis of 10 106 EBS performed in 329 patients implanted with SEEG in our epileptology department. We found that 13 EBS in 9 different patients evoked pleasant sensations (.60% of all responses). By contrast we collected 111 emotional responses of negative valence (i.e., 5.13% of all responses). EBS evoking pleasant sensations were applied at 50 Hz with an average intensity of 1.4 ± .55 mA (range .5-2 mA). Pleasant sensations were reported by nine patients of which three patients presented responses to several EBS. We found a male predominance among the patients reporting pleasant sensations and a prominent role of the right cerebral hemisphere. Results show the preponderant role of the dorsal anterior insula and amygdala in the occurrence of pleasant sensations., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

BACKGROUND Solid pseudopapillary neoplasm (SPN) of the pancreas, which predominantly affects young women, is an uncommon condition with low malignant potential. It is often asymptomatic. This tumor has a low metastatic rate and a good prognosis in contrast to other pancreatic tumors. Approximately 14% of SPNs develop liver metastasis, but for SPNs with malignant features liver metastasis has been reported to occur in over 55% of cases. Complete surgical resection is the treatment of choice for increasing the survival rate in metastatic recurrent disease. When surgical resection is impossible, liver transplantation has shown promising results in a few cases. The purpose of this article is to present the first case of a male patient who underwent liver transplantation for this indication. CASE REPORT We present the case of a 60-year-old male patient who previously had pancreas surgery, numerous liver resections, and chemotherapy for SPN, but nevertheless developed recurrence of multiple liver metastases. His metastatic liver disease was regarded as unresectable. The lymphatic structure was also affected. The patient underwent orthotopic liver transplantation with a deceased donor graft after multidisciplinary evaluation. Resection of involved lymphatic structures was also performed. At 2-year follow-up, the patient was alive and recurrence free. CONCLUSIONS This is the first published report of a male patient who underwent liver transplantation due to SPN metastasis. Our case demonstrates that liver transplantation should be further investigated for selected cases of SPN of the pancreas with liver metastatic disease when surgical resection is deemed unattainable.

The concept of spatial confinement is the basis of cell positioning and guidance in in vitro studies. In vivo, it reflects many situations faced during embryonic development. In vitro, spatial confinement of neurons is achieved using different technological approaches: adhesive patterning, topographical structuring, microfluidics and the use of hydrogels. The notion of chemical or physical frontiers is particularly central to the behaviors of growth cones and neuronal processes under confinement. They encompass phenomena of cell spreading, boundary crossing, and path finding on surfaces with different adhesive properties. However, the most universal phenomenon related to confinement, regardless of how it is implemented, is the acceleration of neuronal growth. Overall, a bi-directional causal link emerges between the shape of the growth cone and neuronal elongation dynamics, both in vivo and in vitro. The sensing of adhesion discontinuities by filopodia and the subsequent spatial redistribution and size adaptation of these actin-rich filaments seem critical for the growth rate in conditions in which adhesive contacts and actin-associated clutching forces dominate. On the other hand, the involvement of microtubules, specifically demonstrated in 3D hydrogel environments and leading to ameboid-like locomotion, could be relevant in a wider range of growth situations. This review brings together a literature collected in distinct scientific fields such as development, mechanobiology and bioengineering that highlight the consequences of confinement and raise new questions at different cellular scales. Its ambition is to stimulate new research that could lead to a better understanding of what gives neurons their ability to establish and regulate their exceptional size., Competing Interests: Conflict of interest The author declare no conflict of interest and competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Presence of multiple hepatic lesions in intrahepatic cholangiocarcinoma (iCCA) is included in staging as a negative prognostic factor, but both prognostic value and therapeutic implications remain debated. The aim of this study was to systematically review the prognostic influence of multiple lesions on survival after resection for iCCA, with stratification for distribution and number of lesions., Methods: Medline and Embase were systematically searched to identify records (2010-2021) reporting survival for patients undergoing primary resection for iCCA. Included were original articles reporting overall survival, with data on multiple lesions including tumour distribution (satellites/other multiple lesions) and/or number. For meta-analysis, the random effects model and inverse variance method were used. PRISMA 2020 guidelines were followed., Results: Thirty-one studies were included for review. For meta-analysis, nine studies reporting data on the prognostic influence of satellite lesions (2737 patients) and six studies reporting data on multiple lesions other than satellites (1589 patients) were included. Satellite lesions (hazard ratio 1.89, 95% confidence interval 1.67-2.13) and multiple lesions other than satellites (hazard ratio 2.41, 95% confidence interval 1.72-3.37) were significant negative prognostic factors. Data stratified for tumour number, while limited, indicated increased risk per additional lesion., Conclusion: Satellite lesions, as well as multiple lesions other than satellites, was a negative prognostic factor in resectable iCCA. Considering the prognostic impact, both tumour distribution and number of lesions should be evaluated together with other risk factors to allow risk stratification for iCCA patients with multiple lesions, rather than precluding resection for the entire patient group., Competing Interests: Conflict of interest disclosure Hannes Jansson, Christina Villard, Lynn E. Nooijen, Poya Ghorbani, Joris I. Erdmann and Ernesto Sparrelid have no conflicts of interest do disclose., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background & Aims: The evidence for hepatobiliary tumour surveillance in patients with primary sclerosing cholangitis (PSC) is scarce. In this study, we aimed to prospectively evaluate cholangiocarcinoma (CCA) surveillance with yearly MRI with cholangiopancreatography (MRI/MRCP) in a nationwide cohort., Methods: In total, 512 patients with PSC from 11 Swedish hospitals were recruited. The study protocol included yearly clinical follow-ups, liver function tests and contrast-enhanced MRI/MRCP and carbohydrate antigen (CA) 19-9. Patients with severe/progressive bile duct changes on MRI/MRCP were further investigated with endoscopic retrograde cholangiopancreatography. Patients were followed for 5 years or until a diagnosis of CCA, liver transplantation (LT) and/or death. Risk factors associated with CCA were analysed with Cox regression., Results: Eleven patients (2%) were diagnosed with CCA, and two (0.5%) with high-grade bile duct dysplasia. Severe/progressive bile duct changes on MRI/MRCP were detected in 122 patients (24%), of whom 10% had an underlying malignancy. The primary indication for LT (n = 54) was biliary dysplasia in nine patients (17%) and end-stage liver disease in 45 patients (83%), of whom three patients (7%) had unexpected malignancy in the explants. The median survival for patients with CCA was 13 months (3-22 months). Time to diagnosis of high-grade dysplasia and/or hepatobiliary malignancy was significantly associated with severe/progressive bile duct changes on MRI/MRCP (hazard ratio 10.50; 95% CI 2.49-44.31) and increased levels of CA19-9 (hazard ratio 1.00; 95% CI 1.00-1.01)., Conclusion: In an unselected cohort of patients with PSC, yearly CA19-9 and MRI/MRCP surveillance followed by ERCP was ineffective in detecting cancer early enough to support long-term survival. Given the low occurrence of CCA, studies on individualised strategies for follow-up and improved diagnostic methods for PSC-related CCA are warranted., Impact and Implications: A prospective nationwide 5-year study was conducted to evaluate yearly cholangiocarcinoma surveillance using MRI and CA19-9 in patients with primary sclerosing cholangitis. Only 2% of the patients were diagnosed with cholangiocarcinoma during follow-up and their prognosis remained poor despite surveillance. This surveillance strategy failed to detect cancer early enough to support long-term survival. Therefore, individualised strategies and improved diagnostic methods will be required to improve the early detection of cholangiocarcinoma in patients with primary sclerosing cholangitis., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Noxo1, the organizing element of the Nox1-dependent NADPH oxidase complex responsible for producing reactive oxygen species, has been described to be degraded by the proteasome. We mutated a D-box in Noxo1 to express a protein with limited degradation and capable of maintaining Nox1 activation. Wild-type (wt) and mutated Noxo1 (mut1) proteins were expressed in different cell lines to characterize their phenotype, functionality, and regulation. Mut1 increases ROS production through Nox1 activity affects mitochondrial organization and increases cytotoxicity in colorectal cancer cell lines. Unexpectedly the increased activity of Noxo1 is not related to a blockade of its proteasomal degradation since we were unable in our conditions to see any proteasomal degradation either for wt or mut1 Noxo1. Instead, D-box mutation mut1 leads to an increased translocation from the membrane soluble fraction to a cytoskeletal insoluble fraction compared to wt Noxo1. This mut1 localization is associated in cells with a filamentous phenotype of Noxo1, which is not observed with wt Noxo1. We found that mut1 Noxo1 associates with intermediate filaments such as keratin 18 and vimentin. In addition, Noxo1 D-Box mutation increases Nox1-dependent NADPH oxidase activity. Altogether, Nox1 D-box does not seem to be involved in Noxo1 degradation but rather related to the maintenance of the Noxo1 membrane/cytoskeleton balance.

Background: Metastatic spread of colorectal cancer to the liver impacts prognosis. Advances in chemotherapy have resulted in increased resectability rates and thereby improved survival in patients with colorectal liver metastases (CRLM). However, criteria are needed to ensure that patients selected for hepatic resection benefit from the invasive therapy. The study aimed to construct a predictive model for overall survival (OS) in patients with CRLM, based on preoperatively available information., Methods: The retrospective cohort study reviewed all patients with CRLM discussed at multidisciplinary team conference at Karolinska University Hospital, Stockholm, Sweden, 2013-2018. Independent prognostic factors for OS were identified, based on which a score model was generated. The model was validated on patients treated for CRLM at Hôpital Universitaire Paul Brousse, Villejuif, France, 2007-2018. Calibration and discrimination methods were used for internal and external validation., Results: The Swedish development cohort included 1013 patients, the French validation cohort 391 patients. Poor OS was significantly associated with age>60years (hazard ratio (HR) 3.57 (95%CI 2.18-9.94)), number of CRLM (HR 4.59 (2.83-12.20)), diameter of largest CRLM>5 cm (HR 2.59 (1.74-5.03)), right-sided primary tumour (HR 2.98 (2.00-5.80)), extrahepatic disease (HR 4.14 (2.38-15.87)) and non-resectability (HR 0.77 (0.66-0.90)). The C-statistic for prediction of OS was .74, in the development cohort and 0.69 in the validation cohort., Conclusion: The presented predictive score model can adequately predict OS for patients at the initial diagnosis of CRLM. The prognostic model could be of clinical value in the management of all patients with CRLM, by predicting individualized survival and thereby facilitating treatment recommendations., Competing Interests: Declaration of competing interest None., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Microtubule targeting agents (MTA) are anti-cancer molecules that bind tubulin and interfere with the microtubule functions, eventually leading to cell death. In the present study, we used an in vitro microtubule polymerization assay to screen several venom families for the presence of anti-microtubule activity. We isolated myotoxin-3, a peptide of the crotamine family, and three isoforms from the venom of the Northern Pacific rattlesnake Crotalus oreganus oreganus , which was able to increase tubulin polymerization. Myotoxin-3 turned out to be a cell-penetrating peptide that slightly diminished the viability of U87 glioblastoma and MCF7 breast carcinoma cells. Myotoxin 3 also induced remodeling of the U87 microtubule network and decreased MCF-7 microtubule dynamic instability. These effects are likely due to direct interaction with tubulin. Indeed, we showed that myotoxin-3 binds to tubulin heterodimer with a Kd of 5.3 µM and stoichiometry of two molecules of peptide per tubulin dimer. Our results demonstrate that exogenous peptides are good candidates for developing new MTA and highlight the richness of venoms as a source of pharmacologically active molecules.

Autoantibodies against leucine-rich glioma-inactivated 1 (LGI1) occur in patients with encephalitis who present with frequent focal seizures and a pattern of amnesia consistent with focal hippocampal damage. To investigate whether the cellular and subcellular distribution of LGI1 may explain the localization of these features, and hence gain broader insights into LGI1's neurobiology, we analysed the detailed localization of LGI1 and the diversity of its protein interactome, in mouse brains using patient-derived recombinant monoclonal LGI1 antibodies. Combined immunofluorescence and mass spectrometry analyses showed that LGI1 is enriched in excitatory and inhibitory synaptic contact sites, most densely within CA3 regions of the hippocampus. LGI1 is secreted in both neuronal somatodendritic and axonal compartments, and occurs in oligodendrocytic, neuro-oligodendrocytic and astro-microglial protein complexes. Proteomic data support the presence of LGI1-Kv1-MAGUK complexes, but did not reveal LGI1 complexes with postsynaptic glutamate receptors. Our results extend our understanding of regional, cellular and subcellular LGI1 expression profiles and reveal novel LGI1-associated complexes, thus providing insights into the complex biology of LGI1 and its relationship to seizures and memory loss., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The cell wall is a key component of fungi. It constitutes a highly regulated viscoelastic shell which counteracts internal cell turgor pressure. Its mechanical properties thus contribute to define cell morphology. Measurements of the elastic moduli of the fungal cell wall have been carried out in many species including Candida albicans , a major human opportunistic pathogen. They mainly relied on atomic force microscopy, and mostly considered the yeast form. We developed a parallelized pressure-actuated microfluidic device to measure the bending stiffness of hyphae. We found that the cell wall stiffness lies in the MPa range. We then used three different ways to disrupt cell wall physiology: inhibition of beta-glucan synthesis, a key component of the inner cell wall; application of a hyperosmotic shock triggering a sudden decrease of the hyphal diameter; deletion of two genes encoding GPI-modified cell wall proteins resulting in reduced cell wall thickness. The bending stiffness values were affected to different extents by these environmental stresses or genetic modifications. Overall, our results support the elastic nature of the cell wall and its ability to remodel at the scale of the entire hypha over minutes.

DNA supercoiling is an essential mechanism of bacterial chromosome compaction, whose level is mainly regulated by topoisomerase I and DNA gyrase. Inhibiting either of these enzymes with antibiotics leads to global supercoiling modifications and subsequent changes in global gene expression. In previous studies, genes responding to DNA relaxation induced by DNA gyrase inhibition were categorised as 'supercoiling-sensitive'. Here, we studied the opposite variation of DNA supercoiling in the phytopathogen Dickeya dadantii using the non-marketed antibiotic seconeolitsine. We showed that the drug is active against topoisomerase I from this species, and analysed the first transcriptomic response of a Gram-negative bacterium to topoisomerase I inhibition. We find that the responding genes essentially differ from those observed after DNA relaxation, and further depend on the growth phase. We characterised these genes at the functional level, and also detected distinct patterns in terms of expression level, spatial and orientational organisation along the chromosome. Altogether, these results highlight that the supercoiling-sensitivity is a complex feature, which depends on the action of specific topoisomerases, on the physiological conditions, and on their genomic context. Based on previous in vitro expression data of several promoters, we propose a qualitative model of SC-dependent regulation that accounts for many of the contrasting transcriptomic features observed after DNA gyrase or topoisomerase I inhibition., (© The Author(s) 2022. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Brain tissues demonstrate heterogeneous mechanical properties, which evolve with aging and pathologies. The observation in these tissues of smooth to sharp rigidity gradients raises the question of brain cell responses to both different values of rigidity and their spatial variations, in dependence on the surface chemistry they are exposed to. Here, we used recent techniques of hydrogel photopolymerization to achieve stiffness texturing down to micrometer resolution in polyacrylamide hydrogels. We investigated primary neuron adhesion and orientation as well as glial cell proliferative properties on these rigidity-textured hydrogels for two adhesive coatings: fibronectin or poly-l-lysine/laminin. Our main observation is that glial cell adhesion and proliferation is favored on the stiffer regions when the adhesive coating is fibronectin and on the softer ones when it consists of poly-l-lysine/laminin. This behavior was unchanged by the presence or the absence of neuronal cells. In addition, glial cells were not confined by sharp, micron-scaled gradients of rigidity. Our observations suggest that rigidity sensing could involve adhesion-related pathways that profoundly depend on surface chemistry.

S100A1 is a member of the S100 family of small ubiquitous Ca 2+ -binding proteins, which participates in the regulation of cell differentiation, motility, and survival. It exists as homo- or heterodimers. S100A1 has also been shown to bind Zn 2+ , but the molecular mechanisms of this binding are not yet known. In this work, using ESI-MS and ITC, we demonstrate that S100A1 can coordinate 4 zinc ions per monomer, with two high affinity (K D ~4 and 770 nm) and two low affinity sites. Using competitive binding experiments between Ca 2+ and Zn 2+ and QM/MM molecular modeling we conclude that Zn 2+ high affinity sites are located in the EF-hand motifs of S100A1. In addition, two lower affinity sites can bind Zn 2+ even when the EF-hands are saturated by Ca 2+ , resulting in a 2Ca 2+ :S100A1:2Zn 2+ conformer. Finally, we show that, in contrast to calcium, an excess of Zn 2+ produces a destabilizing effect on S100A1 structure and leads to its aggregation. We also determined a higher affinity to Ca 2+ (K D ~0.16 and 24 μm) than was previously reported for S100A1, which would allow this protein to function as a Ca 2+ /Zn 2+ -sensor both inside and outside cells, participating in diverse signaling pathways under normal and pathological conditions.

Background: Abdominal aortic aneurysms (AAAs) primarily affect elderly men. The effect of sex on aneurysm development has been associated with the effects of sex hormones through mechanisms that are not fully understood. The present study examined the association between the levels of sex hormones and the occurrence of AAAs in elderly men., Methods: A prospective case-control study was conducted of 452 men aged 65 years participating in screening for AAAs from 2013 to 2019. Of the 452 men, 230 had an AAA and 222 an aortic diameter of <30 mm (control group). Questionnaires and blood samples were collected and stored consecutively. The serum levels of total testosterone, estradiol, progesterone, luteinizing hormone, and sex hormone-binding globulin were analyzed using electrochemiluminescent immunoassays. Multivariable logistic regression analysis was used to assess the association between sex hormones and AAA., Results: The median aneurysm diameter was 33 mm. Men with AAA had greater estradiol (93 pmol/L vs 84 pmol/L; P =.003) and progesterone (0.41 nmol/L vs 0.17 nmol/L; P < .001) levels compared with the controls. The testosterone levels were lower in the AAA group than in the control group (13 nmol/L vs 14 nmol/L; P = .026). AAA was associated with detectable levels of progesterone (odds ratio [OR], 6.69; 95% confidence interval [CI], 3.86-11.47), smoking (OR, 5.26; 95% CI, 3.12-8.85), coronary heart disease (OR, 4.06; 95% CI, 1.92-8.58), and a body mass index >25 kg/m 2 (OR, 2.26; 95% CI, 1.34-3.82)., Conclusions: The observed higher estradiol and progesterone levels in men with an AAA suggest an effect of sex hormones on aneurysm development. The association between progesterone levels and the aortic diameter stresses the importance of focusing on the potential effect of this unconsidered female sex hormone on aneurysm formation., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Although mutations leading to a compromised nuclear envelope cause diseases such as muscular dystrophies or accelerated aging, the consequences of mechanically induced nuclear envelope ruptures are less known. Here, we show that nuclear envelope ruptures induce DNA damage that promotes senescence in non-transformed cells and induces an invasive phenotype in human breast cancer cells. We find that the endoplasmic reticulum (ER)-associated exonuclease TREX1 translocates into the nucleus after nuclear envelope rupture and is required to induce DNA damage. Inside the mammary duct, cellular crowding leads to nuclear envelope ruptures that generate TREX1-dependent DNA damage, thereby driving the progression of in situ carcinoma to the invasive stage. DNA damage and nuclear envelope rupture markers were also enriched at the invasive edge of human tumors. We propose that DNA damage in mechanically challenged nuclei could affect the pathophysiology of crowded tissues by modulating proliferation and extracellular matrix degradation of normal and transformed cells., Competing Interests: Declaration of interests M. Gentili, N.M., and M.P. are authors of a patent entitled “Method to monitor and quantify interphase nuclear envelope rupture events” (WO2017140875A1)., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Furanocoumarins are phytoalexins often cited as an example to illustrate the arms race between plants and herbivorous insects. They are distributed in a limited number of phylogenetically distant plant lineages, but synthesized through a similar pathway, which raised the question of a unique or multiple emergence in higher plants. The furanocoumarin pathway was investigated in the fig tree (Ficus carica, Moraceae). Transcriptomic and metabolomic approaches led to the identification of CYP76F112, a cytochrome P450 catalyzing an original reaction. CYP76F112 emergence was inquired using phylogenetics combined with in silico modeling and site-directed mutagenesis. CYP76F112 was found to convert demethylsuberosin into marmesin with a very high affinity. This atypical cyclization reaction represents a key step within the polyphenol biosynthesis pathway. CYP76F112 evolutionary patterns suggests that the marmesin synthase activity appeared recently in the Moraceae family, through a lineage-specific expansion and diversification. The characterization of CYP76F112 as the first known marmesin synthase opens new prospects for the use of the furanocoumarin pathway. It also supports the multiple acquisition of furanocoumarin in angiosperms by convergent evolution, and opens new perspectives regarding the ability of cytochromes P450 to evolve new functions related to plant adaptation to their environment., (© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation.)

Background: Unresectable colorectal liver metastases (CRLM) is a condition with poor prognosis. A recent treatment alternative improving survival in patients with unresectable CRLM, has emerged with the introduction of liver transplantation (LT), yet not uncontroversial with the current organ shortage. This study aimed to retrospectively investigate the potential of declined donors with acceptable risk as liver graft donors and patients with unresectable CRLM as potential recipients., Methods: All declined donors in central Sweden and all patients with CRLM discussed at multidisciplinary team conference at Karolinska University Hospital, January 2013-October 2018, were identified. Donors were classified according to the European Committee Guide to the quality and safety of organs for transplantation and potential recipients were evaluated by selection criteria, based on studies on the Norwegian Secondary Cancer study database., Results: Out of 1,462 evaluated potential donors, 62 (2.7 pmp) donors were identified, corresponding to 6-18% of the utilized donor pool. Out of 1,008 included patients with CRLM, 25 (2.1 pmp) potential recipients were recognized. Eligibility for LT and left-sided colon cancer were favorable prognostic factors., Conclusions: Today's donor pool could increase with the use of extended criteria donors, which is sufficient and display an acceptable risk-benefit ratio for patients with unresectable CRLM. With current selection criteria a small subset of patients with unresectable CRLM are eligible recipients. This subset of patients has a better survival compared to patients ineligible for LT., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/hbsn.2020.03.10). The authors have no conflicts of interest to declare., (2021 Hepatobiliary Surgery and Nutrition. All rights reserved.)

Dickeya dadantii is an important pathogenic bacterium that infects a number of crops including potato and chicory. While extensive works have been carried out on the control of the transcription of its genes encoding the main virulence functions, little information is available on the post-transcriptional regulation of these functions. We investigated the involvement of the RNA chaperones Hfq and ProQ in the production of the main D. dadantii virulence functions. Phenotypic assays on the hfq and proQ mutants showed that inactivation of hfq resulted in a growth defect, a modified capacity for biofilm formation and strongly reduced motility, and in the production of degradative extracellular enzymes (proteases, cellulase, and pectate lyases). Accordingly, the hfq mutant failed to cause soft rot on chicory leaves. The proQ mutant had reduced resistance to osmotic stress, reduced extracellular pectate lyase activity compared to the wild-type strain, and reduced virulence on chicory leaves. Most of the phenotypes of the hfq and proQ mutants were related to the low amounts of mRNA of the corresponding virulence factors. Complementation of the double mutant hfq-proQ by each individual protein and cross-complementation of each chaperone suggested that they might exert their effects via partially overlapping but different sets of targets. Overall, it clearly appeared that the two Hfq and ProQ RNA chaperones are important regulators of pathogenicity in D. dadantii. This underscores that virulence genes are regulated post-transcriptionally by non-coding RNAs., Competing Interests: The 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 © 2021 Leonard, Villard, Nasser, Reverchon and Hommais.)

Plants produce ∼300 aromatic compounds enzymatically linked to prenyl side chains via C-O bonds. These O -prenylated aromatic compounds have been found in taxonomically distant plant taxa, with some of them being beneficial or detrimental to human health. Although their O -prenyl moieties often play crucial roles in the biological activities of these compounds, no plant gene encoding an aromatic O -prenyltransferase ( O -PT) has been isolated to date. This study describes the isolation of an aromatic O -PT gene, CpPT1 , belonging to the UbiA superfamily, from grapefruit ( Citrus × paradisi, Rutaceae). This gene was shown responsible for the biosynthesis of O -prenylated coumarin derivatives that alter drug pharmacokinetics in the human body. Another coumarin O -PT gene encoding a protein of the same family was identified in Angelica keiskei , an apiaceous medicinal plant containing pharmaceutically active O -prenylated coumarins. Phylogenetic analysis of these O -PTs suggested that aromatic O -prenylation activity evolved independently from the same ancestral gene in these distant plant taxa. These findings shed light on understanding the evolution of plant secondary (specialized) metabolites via the UbiA superfamily., Competing Interests: The authors declare no competing interest.

Aim: Surgical treatment of colorectal cancer with synchronous colorectal liver metastases (SCRLM) can follow three different strategies with regard to the timing of liver resection. The aim of this study was to describe the selection of surgical strategy, focusing on differences between colon and rectal cancer with SCRLM, postoperative morbidity/mortality and survival., Method: This was a retrospective population-based study of patients with SCRLM registered in the Swedish Colorectal Cancer Registry in the Stockholm/Gotland region during 2010-2017 and treated with surgical resection of the primary tumour and liver metastases (LM). Patients were followed for 5 years or censored at 22 November 2018., Results: A total of 238 patients met the inclusion criteria during the study period. Patients with rectal cancer were treated with the 'liver first' strategy in 70% of cases, whereas the main treatment strategies for colonic tumours were 'simultaneous resection' (44%) and 'primary first' (37%). Rectal cancer had a superior 5-year survival rate compared with colon tumours with SCRLM (62 vs. 47%; p = 0.033). There was no difference in survival between treatment strategies irrespective of primary tumour location. Postoperative complications occurred most commonly among rectal tumours treated with simultaneous resection (p = 0.024)., Conclusion: Patients with rectal cancer and SCRLM were more often treated with the 'liver first' strategy than patients with colon cancer. Patients with rectal cancer and SCRLM where both primary tumour and LM were operated on had significantly better survival than corresponding patients with colon cancer., (© 2020 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.)

Microfluidic-based fluorescent exclusion method allows to tackle the issue of neuronal growth from a volume perspective. Based on this technology, we studied the two main actin-rich structures accompanying the early stages of neuron development, i.e. growth cones, located at the tip of growing neuronal processes, and propagative actin waves. Our work reveals that growth cones tend to loose volume during their forward motion, as do actin waves during their journey from the cell body to the tip of neuronal processes, before the total transfer of their remaining volume to the growth cone. Actin waves seem thus to supply material to increasingly distant growth cones as neurons develop. In addition, our work may suggest the existence of a membrane recycling phenomena associated to actin waves as a pulsatile anterograde source of material and by a continuous retrograde transport.

Agrobacterium fabrum C58 is a plant-associated bacterium that is able to denitrify under anoxic conditions. The cluster of denitrification genes harbored by this strain has been well characterized. It includes nir and nor operons encoding nitrite and nitric oxide reductases, respectively. However, the reductase involved in nitrate reduction has not yet been studied and little information is available on denitrification regulators in A. fabrum C58. In this study, we aimed to (i) characterize the nitrate reductase, (ii) determine its role in A. fabrum C58 fitness and root colonization and (ii) reveal the contribution of small RNA on denitrification regulation. By constructing a mutant strain defective for napA, we demonstrated that the reduction of nitrate to nitrite was catalyzed by the periplasmic nitrate reductase, NapA. We evidenced a positive role of NapA in A. fabrum C58 fitness and suggested that A. fabrum C58 is able to use components exuded by plant roots to respire anaerobically. Here, we showed that NorR small RNA increased the level of norCBQ mRNA and a decrease of NorR is correlated with a decrease in N2O emission. Together, our results underscore the importance of understanding the denitrification pathway at the strain level in order to develop strategies to mitigate N2O production at the microbial community level., (© The Author(s) 2020. Published by Oxford University Press on behalf of FEMS.)

Objective: There is no medical treatment to prevent abdominal aortic aneurysm (AAA) growth and rupture, both of which are linked to smoking. Our objective was to map the tunica-specific pathophysiology of AAA with consideration of the intraluminal thrombus, age, and sex, and to subsequently identify which mechanisms were linked to smoking and diameter growth rate. Approach and Results: Microarray analyses were performed on 246 samples from 76 AAA patients and 13 controls. In media and adventitia, there were 5889 and 2701 differentially expressed genes, respectively. Gene sets related to adaptive and innate immunity were upregulated in both tunicas. Media-specific gene sets included increased matrix disassembly and angiogenesis, as well as decreased muscle cell development, contraction, and differentiation. Genes implicated in previous genome-wide association studies were dysregulated in media. The intraluminal thrombus had a pro-proteolytic and proinflammatory effect on the underlying media. Active smoking resulted in increased inflammation, oxidative stress, and angiogenesis in all tissues and enriched lipid metabolism in adventitia. Processes enriched with active smoking in control aortas overlapped to a high extent with those differentially expressed between AAAs and controls. The AAA diameter growth rate (n=24) correlated with T- and B-cell expression in media, as well as lipid-related processes in the adventitia., Conclusions: This tunica-specific analysis of gene expression in a large study enabled the detection of features not previously described in AAA disease. Smoking was associated with increased expression of aneurysm-related processes, of which adaptive immunity and lipid metabolism correlated with growth rate.

Topography of the extracellular environment is now recognized as a major biophysical regulator of cell behavior and function. The study of the influence of patterned substrates on cells, named contact guidance, has greatly benefited from the development of micro and nano-fabrication techniques, allowing the emergence of increasingly diverse and elaborate engineered platforms. The purpose of this review is to provide a comprehensive view of the process of contact guidance from cellular to subcellular scales. We first classify and illustrate the large diversity of topographies reported in the literature by focusing on generic cellular responses to diverse topographical cues. Subsequently, and in a complementary fashion, we adopt the opposite approach and highlight cell type-specific responses to classically used topographies (arrays of pillars or grooves). Finally, we discuss recent advances on the key subcellular and molecular players involved in topographical sensing. Throughout the review, we focus particularly on neuronal cells, whose unique morphology and behavior have inspired a large body of studies in the field of topographical sensing and revealed fascinating cellular mechanisms. We conclude by using the current understanding of the cell-topography interactions at different scales as a springboard for identifying future challenges in the field of contact guidance., (Copyright © 2020 Leclech and Villard.)

The remote actuation of cellular processes such as migration or neuronal outgrowth is a challenge for future therapeutic applications in regenerative medicine. Among the different methods that have been proposed, the use of magnetic nanoparticles appears to be promising, since magnetic fields can act at a distance without interactions with the surrounding biological system. To control biological processes at a subcellular spatial resolution, magnetic nanoparticles can be used either to induce biochemical reactions locally or to apply forces on different elements of the cell. Here, we show that cell migration and neurite outgrowth can be directed by the forces produced by a switchable parallelized array of micro-magnetic pillars, following the passive uptake of nanoparticles. Using live cell imaging, we first demonstrate that adherent cell migration can be biased toward magnetic pillars and that cells can be reversibly trapped onto these pillars. Second, using differentiated neuronal cells we were able to induce events of neurite outgrowth in the direction of the pillars without impending cell viability. Our results show that the range of forces applied needs to be adapted precisely to the cellular process under consideration. We propose that cellular actuation is the result of the force on the plasma membrane caused by magnetically filled endo-compartments, which exert a pulling force on the cell periphery.

Cancer mortality mainly arises from metastases, due to cells that escape from a primary tumor, circulate in the blood as circulating tumor cells (CTCs), permeate across blood vessels and nest in distant organs. It is still unclear how CTCs overcome the harsh conditions of fluid shear stress and mechanical constraints within the microcirculation. Here, a minimal model of the blood microcirculation was established through the fabrication of microfluidic channels comprising constrictions. Metastatic breast cancer cells of epithelial-like and mesenchymal-like phenotypes were flowed into the microfluidic device. These cells were visualized during circulation and analyzed for their dynamical behavior, revealing long-lived plastic deformations and significant differences in biomechanics between cell types. γ-H2AX staining of cells retrieved post-circulation showed significant increase of DNA damage response in epithelial-like SK-BR-3 cells, while gene expression analysis of key regulators of epithelial-to-mesenchymal transition revealed significant changes upon circulation. This work thus documents first results of the changes at the cellular, subcellular and molecular scales induced by the two main mechanical stimuli arising from circulatory conditions, and suggest a significant role of this still elusive step of the metastatic cascade in cancer cells heterogeneity and aggressiveness.

Alpha-synuclein (aSyn)-rich aggregates propagate in neuronal networks and compromise cellular homeostasis leading to synucleinopathies such as Parkinson's disease. Aggregated aSyn spread follows a conserved spatio-temporal pattern that is not solely dependent on connectivity. Hence, the differential tropism of aSyn-rich aggregates to distinct brain regions, or their ability to amplify within those regions, must contribute to this process. To better understand what underlies aSyn-rich aggregates distribution within the brain, we generated primary neuronal cultures from various brain regions of wild-type mice and mice expressing a reduced level of aSyn, and exposed them to fibrillar aSyn. We then assessed exogenous fibrillar aSyn uptake, endogenous aSyn seeding, and endogenous aSyn physiological expression levels. Despite a similar uptake of exogenous fibrils by neuronal cells from distinct brain regions, the seeded aggregation of endogenous aSyn differed greatly from one neuronal population to another. The different susceptibility of neuronal populations was linked to their aSyn expression level. Our data establish that endogenous aSyn expression level plays a key role in fibrillar aSyn prion-like seeding, supporting that endogenous aSyn expression level participates in selective regional brain vulnerability.