Contiguous Cells Research Articles

Enhancing Wireless Network Efficiency with the Techniques of Dynamic Distributed Load Balancing: A Distance-Based Approach.

The unique combination of the high data rates, ultra-low latency, and massive machine communication capability of 5G networks has facilitated the development of a diverse range of applications distinguished by varying connectivity needs. This has led to a surge in data traffic, driven by the ever-increasing number of connected devices, which poses challenges to the load distribution among the network cells and minimizes the wireless network performance. In this context, maintaining network balance during congestion periods necessitates effective interaction between various network components. This study emphasizes the crucial role that mobility management plays in mitigating the uneven load distribution across cells. This distribution is a significant factor impacting network performance, and effectively managing it is essential for ensuring optimal network performance in 5G and future networks. The study investigated the complexities associated with congested cells in wireless networks to address this challenge. It proposes a Dynamic Distance-based Load-Balancing (DDLB) algorithm designed to facilitate efficient traffic distribution among contiguous cells and utilize available resources more efficiently. The algorithm reacts with congested cells and redistributes traffic to its neighboring cells based on specific network conditions. As a result, it alleviates congestion and enhances overall network performance. The results demonstrate that the DDLB algorithm significantly improves key metrics, including load distribution and rates of handover and radio link failure, handover ping-pong, and failed attached requests.

Establishing guidelines for sentinel lymph node ultrastaging in endometrial cancer

BackgroundMany sentinel lymph node (SLN) ultrastaging protocols for endometrial cancer exist, but there is no consensus method.ObjectiveThis study aims to develop guidelines for size criteria in SLN evaluation for endometrial...

Spatio-temporal coherence of circadian clocks and temporal control of differentiation in Anabaena filaments.

Circadian clock arrays in multicellular filaments of the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 display remarkable spatio-temporal coherence under nitrogen-replete conditions. To shed light on the interplay between circadian clocks and the formation of developmental patterns, we followed the expression of a clock-controlled gene under nitrogen deprivation, at the level of individual cells. Our experiments showed that differentiation into heterocysts took place preferentially within a limited interval of the circadian clock cycle, that gene expression in different vegetative intervals along a developed filament was discoordinated, and that the circadian clock was active in individual heterocysts. Furthermore, Anabaena mutants lacking the kaiABC genes encoding the circadian clock core components produced heterocysts but failed in diazotrophy. Therefore, genes related to some aspect of nitrogen fixation, rather than early or mid-heterocyst differentiation genes, are likely affected by the absence of the clock. A bioinformatics analysis supports the notion that RpaA may play a role as master regulator of clock outputs in Anabaena, the temporal control of differentiation by the circadian clock and the involvement of the clock in proper diazotrophic growth. Together, these results suggest that under nitrogen-deficient conditions, the clock coherent unit in Anabaena is reduced from a full filament under nitrogen-rich conditions to the vegetative cell interval between heterocysts.IMPORTANCECircadian clocks, from unicellular organisms to animals, temporally align biological processes to day and night cycles. We study the dynamics of a circadian clock-controlled gene at the individual cell level in the multicellular filamentous cyanobacterium Anabaena, under nitrogen-stress conditions. Under these conditions, some cells along filaments differentiate to carry out atmospheric nitrogen fixation and lose their capability for oxygenic photosynthesis. We found that clock synchronization is limited to organismic units of contiguous photosynthetic cells, contrary to nitrogen-replete conditions in which clocks are synchronized over a whole filament. We provided evidence that the circadian clock regulates the process of differentiation, allowing it to occur preferentially within a limited time window during the circadian clock period. Lastly, we present evidence that the signal from the core clock to clock-regulated genes is conveyed in Anabaena as in unicellular cyanobacteria.

Steady-state regulation of COPII-dependent secretory cargo sorting by inositol trisphosphate receptors, calcium, and penta EF hand proteins

Recently, we demonstrated that agonist-stimulated Ca2+ signaling involving IP3 receptors modulates ER export rates through activation of the penta-EF Hand proteins apoptosis-linked gene-2 (ALG-2) and peflin. It is unknown, however, whether IP3Rs and penta-EF proteins regulate ER export rates at steady state. Here we tested this idea in normal rat kidney epithelial cells by manipulation of IP3R isoform expression. Under standard growth conditions, spontaneous cytosolic Ca2+ oscillations occurred simultaneously in successive groups of contiguous cells, generating intercellular Ca2+ waves that moved across the monolayer periodically. Depletion of IP3R-3, typically the least promiscuous IP3R isoform, caused increased cell participation in intercellular Ca2+ waves in unstimulated cells. The increased spontaneous signaling was sufficient to cause increased ALG-2 and COPII coat subunit Sec31A and decreased peflin localization at ER exit sites, resulting in increased ER-to-Golgi transport of the COPII client cargo VSV-G. The elevated ER-to-Golgi transport caused greater concentration of VSV-G at ER exit sites and had reciprocal effects on transport of VSV-G and a bulk-flow cargo, though both cargos equally required Sec31A. Inactivation of client cargo sorting using 4-phenylbutyrate had opposing reciprocal effects on client and bulk-flow cargo and neutralized any effect of ALG-2 activation on transport. This work extends our knowledge of ALG-2 mechanisms and indicates that in normal rat kidney cells, IP3R isoforms regulate homeostatic Ca2+ signaling that helps determine the basal secretion rate and stringency of COPII-dependent cargo sorting.

Corneal endothelial validation in the eye bank: differences in automated methods and repeatability

To evaluate reproducibility of endothelial cell density (ECD) measurements using the Konan Cell Check D in donor corneas by two different ophthalmologists and to compare the two automated cell count methods (center and flex-center) available in the software of this specular microscope. ECD values were quantified in 54 donor corneas by two independent investigators using the Cell Check D (Konan Medical USA Inc) with both automated cell count methods. In the center method, at least 30 contiguous cells are marked. For the flex-center method, an area is delineated and only the cells within the designated area are counted. The mean ECD was 2473.81±378.22 cells/mm2. Good ECD intergrader reproducibility for the center (ICC=0.821) and the flex-center method (ICC=0.784) were noted. Poor reliability was observed for coefficient of variation and hexagonality (ICC≤0.265). When both methods for ECD analysis were compared, a moderate correlation for the two independent graders using the two manual (center and flex-center) methods was detected (correlation coefficient of 0.678 and 0.745 for each of the investigators). Comparison between methods yielded significantly higher ECD with the flex-center method (P=0.013). When corneas were divided by ECD, those under 2200 cells/mm2 and those between 2200 and 2700 cells/mm2 also had significantly higher ECD with the flex-center method (P<0.022). ECD values are reproducible with both methods, although the flex-center method ECDs tend to be higher, particularly in cases of low ECD. Eye banks and surgeons should exercise caution in making decisions based only on small differences in ECD.

SepT, a novel protein specific to multicellular cyanobacteria, influences peptidoglycan growth and septal nanopore formation in Anabaena sp. PCC 7120.

Multicellular organization is a requirement for the development of complex organisms, and filamentous cyanobacteria such as Anabaena represent a paradigmatic case of bacterial multicellularity. The Anabaena filament can include hundreds of communicated cells that exchange nutrients and regulators and, depending on environmental conditions, can include different cell types specialized in distinct biological functions. Hence, the specific features of the Anabaena filament and how they are propagated during cell division represent outstanding biological issues. Here, we studied SepT, a novel coiled-coil-rich protein of Anabaena that is located in the intercellular septa and influences the formation of the septal specialized structures that allow communication between neighboring cells along the filament, a fundamental trait for the performance of Anabaena as a multicellular organism.

Archaeal type IV pili stabilize Haloferax volcanii biofilms in flow

Multicellular communities of contiguous cells attached to solid surfaces called biofilms represent a common microbial strategy to improve resilience in adverse environments.1,2,3 While bacterial biofilms have been under intense investigation, whether archaeal biofilms follow similar assembly rules remains unknown.4,5Haloferax volcanii is an extremely halophilic euryarchaeon that commonly colonizes salt crust surfaces. H.volcanii produces long and thin appendages called type IV pili (T4Ps). These play a role in surface attachment and biofilm formation in both archaea and bacteria. In this study, we employed biophysical experiments to identify the function of T4Ps in H.volcanii biofilm morphogenesis. H.volcanii expresses not one but six types of major pilin subunits that are predicted to compose T4Ps. Non-invasive imaging of T4Ps in live cells using interferometric scattering (iSCAT) microscopy reveals that piliation varies across mutants expressing single major pilin isoforms. T4Ps are necessary to secure attachment of single cells to surfaces, and the adhesive strength of pilin mutants correlates with their level of piliation. In flow, H.volcanii forms clonal biofilms that extend in three dimensions. Notably, the expression of PilA2, a single pilin isoform, is sufficient to maintain levels of piliation, surface attachment, and biofilm formation that are indistinguishable from the wild type. Furthermore, we discovered that fluid flow stabilizes biofilm integrity; as in the absence of flow, biofilms tend to lose cohesion and disperse in a density-dependent manner. Overall, our results demonstrate that T4P-surface and possibly T4P-T4P interactions promote biofilm formation and integrity and that flow is a key factor regulating archaeal biofilm formation.

HER2 Status Assessment in Endometrial Serous Carcinoma: Comparative Analysis of Two Proposed Testing and Interpretation Algorithms.

HER2 status is now routinely assessed in endometrial serous carcinoma (ESC) due to the reported predictive value of HER2 protein overexpression and/or gene amplification. Herein the authors compare 2 proposed testing and interpretation guidelines for HER2 in ESC. Forty-three consecutive cases of ESC that had been dually tested by both HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were interpreted using 2 sets of guidelines. Guideline set 1 (GS1) is the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines for breast cancer. Guideline set 2 (GS2) is a recent proposal that is a slight modification of the enrollment criteria for the clinical trial (NCT01367002) that demonstrated a survival benefit for anti-HER2 therapy in ESC. By IHC, GS1 and GS2, respectively classified 39.5% (17/43) and 28% (12/43) of ESC as HER2-negative, 37.2% (16/43) and 53.4% (23/43) as HER2 equivocal, and 23.2% (10/43) and 18.6% (8/43) as HER2-positive (P > 0.05 for all). IHC and FISH were highly concordant at the extremes using either set of guidelines, as no cases were found to be IHC3+/FISH-negative or IHC 0-1+/FISH-positive. GS1 and GS2 were comparable regarding the proportion of IHC equivocal cases that were HER2 amplified by FISH (19% vs 23% respectively; [P = 0.71]). GS1 and GS2 displayed 98% (42/43) concordance regarding the final (IHC and/or FISH-based) classification of tumors as being HER2-positive or negative, and the same 13 cases were ultimately classified as HER2 amplified using either GS1 or GS2. One "discordant" case was classified as HER2-positive using GS2 but HER2-negative using GS1 (HER2 IHC score 2+ using both guidelines, HER2:CEP17 signal ratio of 3, HER2 signal number of 3.4). Six (14%) of the 43 cases (FISH Groups: 2, 3, and 4) would require IHC results to interpret the FISH findings using GS1. Because GS1 requires that the HER2 IHC staining be observed within a homogeneous and contiguous invasive cell population, and this is not a requirement in GS2, GS2 may be better suited for ESC given its frequently heterogeneous staining pattern. Additional studies may be required on the optimal interpretation of problematic dual-probe FISH scenarios in GS2 and the necessity for IHC correlation in such scenarios. Using either set of guidelines, our findings support a reflex testing strategy of restricting FISH testing to cases that are IHC equivocal.

The Defenders of the Alveolus Succumb in COVID-19 Pneumonia to SARS-CoV-2 and Necroptosis, Pyroptosis, and PANoptosis.

Alveolar type II (ATII) pneumocytes as defenders of the alveolus are critical to repairing lung injury. We investigated the ATII reparative response in coronavirus disease 2019 (COVID-19) pneumonia, because the initial proliferation of ATII cells in this reparative process should provide large numbers of target cells to amplify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus production and cytopathological effects to compromise lung repair. We show that both infected and uninfected ATII cells succumb to tumor necrosis factor-α (TNF)-induced necroptosis, Bruton tyrosine kinase (BTK)-induced pyroptosis, and a new PANoptotic hybrid form of inflammatory cell death mediated by a PANoptosomal latticework that generates distinctive COVID-19 pathologies in contiguous ATII cells. Identifying TNF and BTK as the initiators of programmed cell death and SARS-CoV-2 cytopathic effects provides a rationale for early antiviral treatment combined with inhibitors of TNF and BTK to preserve ATII cell populations, reduce programmed cell death and associated hyperinflammation, and restore functioning alveoli in COVID-19 pneumonia.

Toker Cell Hyperplasia in the Nipple-Areolar Complex of Transmasculine Individuals

We previously reported breast histopathologic features associated with testosterone therapy in transmasculine chest-contouring surgical specimens. During that study, we observed a high frequency of intraepidermal glands in the nipple-areolar complex (NAC) formed by Toker cells. This study reports Toker cell hyperplasia (TCH)—the presence of clusters of Toker cells consisting of at least 3 contiguous cells and/or glands with lumen formation—in the transmasculine population. Increased numbers of singly dispersed Toker cells were not considered TCH. Among the 444 transmasculine individuals, 82 (18.5%) had a portion of their NAC excised and available for evaluation. We also reviewed the NACs from 55 cisgender women who were aged <50 years old and had full mastectomies. The proportion of transmasculine cases with TCH (20/82; 24.4%) was 1.7-fold higher than cisgender women (8/55; 14.5%) but did not achieve significance (P = .20). However, in cases with TCH, the rate of gland formation is 2.4-fold higher in transmasculine cases, achieving borderline significance (18/82 vs 5/55; P = .06). Among transmasculine individuals, TCH was significantly more likely to be present in those with higher body mass index (P = .03). A subset of 5 transmasculine and 5 cisgender cases were stained for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), androgen receptor (AR), cytokeratin 7, and Ki67. All 10 cases were cytokeratin 7+ and Ki67−; 9 out of 10 cases were AR+. Toker cells in transmasculine cases demonstrated variable expression of ER, PR, and HER2. For cisgender cases, Toker cells were consistently ER+, PR−, and HER2−. In conclusion, there is a higher rate of TCH in the transmasculine than cisgender population, particularly among transmasculine individuals with high body mass index and taking testosterone. To our knowledge, this is the first study to demonstrate that Toker cells are AR+. Toker cell features display variable ER, PR, and HER2 immunoreactivity. The clinical significance of TCH in the transmasculine population remains to be elucidated.

Aquaporin-1 and Aquaporin-4 Expression in Ependyma, Choroid Plexus and Surrounding Transition Zones in the Human Brain.

The choroid plexus (CP) is a structure in the brain ventricles that produces the main part of the cerebrospinal fluid (CSF). It is covered with specialized cells which show epithelial characteristics and are the site of the blood-CSF barrier. These cells form a contiguous cell sheet with ventricle-lining ependymal cells which are known to express aquaporin-4 (AQP4). In contrast, CP epithelial cells express aquaporin-1 (AQP1) apically. We investigated the expression patterns of aquaporins in the CP-ependyma transition from human body donors using immunofluorescence and electron microscopy. Ependymal cells and subependymal astrocytes at the base of the CP showed a particularly high AQP4 immunoreactivity. Astrocytic processes formed a dense meshwork or glial plate around the blood vessels entering the CP. Interestingly, some of these astrocytic processes were in direct contact with the CP stroma, which contains fenestrated blood vessels, separated only by a basal lamina. Electron microscopy confirmed the continuity of the subastrocytic basal lamina with the CP epithelium. We also probed for components of the AQP4 anchoring dystrophin-dystroglycan complex. Immunolabeling for dystrophin and AQP4 showed an overlapping staining pattern in the glial plate but not in previously reported AQP4-positive CP epithelial cells. In contrast, dystroglycan expression was associated with laminin staining in the glial plate and the CP epithelium. This suggests different mechanisms for AQP4 anchoring in the cell membrane. The high AQP4 density in the connecting glial plate might facilitate the transport of water in and out of the CP stroma and could possibly serve as a drainage and clearing pathway for metabolites.

Temperature responsive poly(N-isopropylacrylamide-co-styrene) nanofilms for non-enzymatic cell sheet harvesting

In this study, temperature-responsive cell culture substrates with non-enzymatic cell sheet detachment attributes in response to temperature reduction were prepared. Poly(N-isopropylacrylamide) (PNIPAAm) with a physiologically proximal lower critical solution temperature (LCST) induces a temperature responsivity to the substrate, and polystyrene was used to regulate the hydrophobicity of the substrate. Different compositions of poly(NIPAAm-co-styrene) were synthesized by free radical polymerization. The resulting copolymers were characterized using Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. The copolymer composition was calculated from 1HNMR results. The molecular weight and molecular weight distribution were measured by gel permeation chromatography (GPC). The nanofilms of the prepared copolymers were physically coated by spin-coating technique on tetramethyl orthosilicate (TMOS) pre-coated glass slides. Attenuated total reflection-FTIR (ATR-FTIR) and field emission scanning electron microscopy (FESEM) analyses showed that the spin coating procedure was performed successfully, and the change in the water contact angle (WCA) in response to temperature alteration indicated the temperature-responsive behavior of the polymer layers. L929 mouse fibroblast cell line was cultured on nanofilm-coated glass slides until a confluent cell sheet covered the entire surface. An almost integrated cell sheet was harvested by temperature reduction from 37 °C to 20 °C. The results revealed that copolymer composition is vital in harvesting contiguous cell sheets. This fabrication method, compared to others such as plasma polymerization and surface-initiated atom transfer radical polymerization (SI-ATRP), is very cost-effective and applicable for large-scale cell culture investigations.

Computational Assessment of Different Structural Models for Claudin-5 Complexes in Blood-Brain Barrier Tight Junctions.

The blood-brain barrier (BBB) strictly regulates the exchange of ions and molecules between the blood and the central nervous system. Tight junctions (TJs) are multimeric structures that control the transport through the paracellular spaces between the adjacent brain endothelial cells of the BBB. Claudin-5 (Cldn5) proteins are essential for TJ formation and assemble into multiprotein complexes via cis-interactions within the same cell membrane and trans-interactions across two contiguous cells. Despite the relevant biological function of Cldn5 proteins and their role as targets of brain drug delivery strategies, the molecular details of their assembly within TJs are still unclear. Two different structural models have been recently introduced, in which Cldn5 dimers belonging to opposite cells join to generate paracellular pores. However, a comparison of these models in terms of ionic transport features is still lacking. In this work, we used molecular dynamics simulations and free energy (FE) calculations to assess the two Cldn5 pore models and investigate the thermodynamic properties of water and physiological ions permeating through them. Despite different FE profiles, both structures present single/multiple FE barriers to ionic permeation, while being permissive to water flux. These results reveal that both models are compatible with the physiological role of Cldn5 TJ strands. By identifying the protein-protein surface at the core of TJ Cldn5 assemblies, our computational investigation provides a basis for the rational design of synthetic peptides and other molecules capable of opening paracellular pores in the BBB.

PHire: A Novel Genetically Encoded Red Intracellular pH Sensor Expressed in Cells and Flies

Intracellular pH regulation is vital for normal cellular function and is controlled by membrane H+ and HCO3‑ transporters. Most pH reporters have green fluorescence (i.e., BCECF, pHlorin) making simultaneous Ca2+, Cl‐, or other sensing (i.e., green fluorescent sensors) or GFP‐tags impossible. We previously reported a red‐fluorescent pH sensor (pHire) with an alkaline‐shifted pKa that increases fluorescence with increasing intracellular pH. pHire was transiently transfect into TM5 cells, but these fibroblast‐like cells did not address continuous expression in epithelial or excitable cells. Our objective was to evaluate pHire responses in multiple cell‐types and show that it can be used for fluorescent multiplexing.We selected pHire‐expressing rat pancreatic β‐cells (INS1pHire) and porcine kidney epithelial cells (LLCPK1pHire), and then FACS sorted to keep the top 10‐20% fluorescent cells. To test pHire’s usefulness for intact animals, we made transgenic, UAS‐pHire Drosophila, allowing pHire expression in specific tissues via genetic crossing with promoter‐GAL4 lines. By using perfusion chambers, we monitored cellular pHire‐responses to acid‐loading (NH4Cl pulse) and CO2/HCO3‑ addition.Stable selection of pHire cell lines ensures single cells as well as contiguous cell layers for acid‐base transporter evaluation. Addition of NH4Cl quickly alkalinizes all pHire cells. Different acid‐recovery rates were found in individual cells with LLCPK1pHire cells recovering faster than INS1pHire cells. CO2/HCO3‑ addition acidified both mammalian cell‐types. LLCPK1pHire cells typically show a Na+ dependent recovery (consistent with electrogenic Na+ bicarbonate cotransporter, NBCe1, activity) that is absent from INS1pHire cells. Infection of INS1pHire cells with a NBCe1A‐GFP AAV allowed clear demonstration of NBCe1 activity.To test pHire’s stability in living animals, we next generated a UAS‐pHire transgenic Drosophila line, allowing pHire expression in specific tissues via genetic crossing with various promoter‐GAL4 lines. We tested renal epithelial (principal cells: Uro‐GAL4, CapaR‐GAL4; stellate cells: c724‐GAL4) and CNS (elav‐GAL4) expression. As observed in mammalian cells, NH4Cl acid‐loading showed robust and more uniform non‐HCO3‑ recovery. The pH‐calibration curves for pHire in Drosophila cells were similar those obtained in mammalian cells (pKa&gt;7.4). Thus, pHire characteristics are not changed by continuous expression in whole organisms.This study shows that the pHire sensor can be constitutively expressed into multiple cell lines or whole animals (flies) with an ideal pH range of pH 6 to 9. pHire may also be multiplexed with GFP labels and biosensors to allow real‐time, pH measurements with other ions of interest at a cellular scale. Finally, our data demonstrate that genetically encoded pHire is a reliable and useful tool for studying acid‐base transporters in a variety of cell‐types.

Improved solution of the Budget constrained Fuel Treatment Scheduling problem and extensions

This paper considers the budget constrained fuel treatment scheduling (BFTS) problem where, in the context of wildfire mitigation, the goal is to inhibit the potential of fire spread in a landscape by proper fuel treatment activities. Given a time horizon represented by consecutive unit periods, the landscape is divided into cells and represented as a grid graph where each cell has a fuel age that increases over time and becomes old if no treatment is applied in the meantime: this induces a potential high fire risk whenever two contiguous cells are old. Cells fuel ages can be reset to zero under appropriate fuel treatments but there is a limited budget for treatment in each period. The problem calls for finding a suitable selection of cells to be treated so as to minimize the presence of old contiguous cells over the whole time horizon. We prove that problem BFTS is strongly NP-complete on paths and thus on grid graphs and show that no polynomial time approximation algorithm exists unless P=NP. We provide an enhanced integer linear programming formulation of the problem with respect to the relevant literature that shows up to be efficiently solved by an ILP solver on reasonably large size instances. Finally, we consider a harder periodic variant of the problem with the aim of finding a cyclic treatment plan with cycles of length T and propose a matheuristic approach capable of efficiently tackling those instances where an ILP solver applied to the ILP formulation runs into difficulties.

Structure of High-Resolution SAR Winds Over the Venice Lagoon Area

The spatial characteristics at mesoscale <inline-formula> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> of the strongest sea surface winds blowing on the Adriatic Sea and Venice Lagoon, Italy, have been investigated through 500 m <inline-formula> <tex-math notation="LaTeX">$\times500$ </tex-math></inline-formula> m wind fields extracted, without external information, from the C-band Sentinel-1 synthetic aperture radar (SAR) images interferometric wide (IW) swath ground range detected high resolution (GRDH) level 1 (L1) by a deep learning method based on a residual neural network (ResNet). The derived SAR wind directions have been used to retrieve the wind speed using the <monospace>C&#x005F;SARMOD2</monospace> geophysical model function (GMF). The resulting wind fields have been compared with European Centre for Medium-range Weather Forecasts (ECMWF) and <i>in situ</i> data: the wind direction bias <inline-formula> <tex-math notation="LaTeX">$|\beta _\theta |\le 1 {\textstyle ^\circ }$ </tex-math></inline-formula> indicates a very good agreement and the value of RMS difference against <i>in situ</i> winds of <inline-formula> <tex-math notation="LaTeX">$16 {\textstyle ^\circ }$ </tex-math></inline-formula> results smaller than those reported in the literature; the wind speed bias <inline-formula> <tex-math notation="LaTeX">$\beta _{w}=-1.5\,\, {\textstyle \text {ms}^{-1}}$ </tex-math></inline-formula> with respect to <i>in situ</i> data indicates an underestimation of SAR speed. However, the innovation brought by ResNet results is evident in the study of the spatial structure of the wind fields, showing unprecedented details. The spatial gradients of wind direction and speed obtained (<inline-formula> <tex-math notation="LaTeX">$\approx 6 {\textstyle ^\circ }/\text {km}$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$0.5\,\, {\textstyle \text {ms}^{-1}}/\text {km}$ </tex-math></inline-formula>, respectively) are well consistent with those derived from previous experimental campaigns. The maps of the atmospheric wind stress curl derived from the ResNet wind fields exhibit the presence of contiguous cells with positive and negative values roughly elongated in the wind direction, not reproducible with such profusion of details by any other existing datasets. ResNet wind fields provide exhaustive coverage of the Venice lagoon, allowing to study their spatial structure: under northeasterly winds, the wind speed increases on average from northern to southern lagoon by 30&#x0025; in agreement with a case study reported in the literature. Local differences of ResNet wind direction with respect to ECMWF (<inline-formula> <tex-math notation="LaTeX">$\pm 30 {\textstyle ^\circ }$ </tex-math></inline-formula> maximum) generate local differences of wind speed as large as <inline-formula> <tex-math notation="LaTeX">$\pm 2\,\, {\textstyle \text {ms}^{-1}}$ </tex-math></inline-formula>.

Cell-cell adhesion impacts epithelia response to substrate stiffness: Morphology and gene expression

Monolayer epithelial cells interact constantly with the substrate they reside on and their surrounding neighbors. As such, the properties of epithelial cells are profoundly governed by the mechanical and molecular cues that arise from both the substrate and contiguous cell neighbors. Although both cell-substrate and cell-cell interactions have been studied individually, these results are difficult to apply to native confluent epithelia, in which both jointly regulate the cell phenotype. Specifically, it remains poorly understood about the intertwined contributions from intercellular adhesion and substrate stiffness on cell morphology and gene expression, two essential microenvironment properties. Here, by adjusting the substrate modulus and altering the intercellular adhesion within confluent kidney epithelia, we found that cell-substrate and cell-cell interactions can mask each other's influence. For example, we found that epithelial cells exhibit an elongated morphological phenotype only when the substrate modulus and intercellular adhesions are both reduced, whereas their motility can be upregulated by either reduction. These results illustrate that combinatorial changes of the physical microenvironment are required to alter cell morphology and gene expression.

A growing genetic tree in the soil of prostate.

In this issue of Cell Stem Cell, Grossmann etal. (2021) reconstructed the developmental history of the prostate gland in a 59-year-old male by 3D tracking of somatic mutations across 319 micro-dissected specimens. It provides a genetic picture of how the human prostate gland is shaped during embryogenesis, puberty, and adult life.

Human tendon-derived cell sheets created by magnetic force-based tissue engineering hold tenogenic and immunomodulatory potential

Cell sheet technology and magnetic based tissue engineering hold the potential to become instrumental in developing magnetically responsive living tissues analogues that can be potentially used both for modeling and therapeutical purposes. Cell sheet constructions more closely recreate physiological niches, through the preservation of contiguous cells and cell-ECM interactions, which assist the cellular guidance in regenerative processes.We herein propose to use magnetically assisted cell sheets (magCSs) constructed with human tendon-derived cells (hTDCs) and magnetic nanoparticles to study inflammation activity upon magCSs exposure to IL-1β, anticipating its added value for tendon disease modeling.Our results show that IL-1β induces an inflammatory profile in magCSs, supporting its in vitro use to enlighten inflammation mediated events in tendon cells. Moreover, the response of magCSs to IL-1β is modulated by pulsed electromagnetic field (PEMF) stimulation, favoring the expression of anti-inflammatory genes, which seems to be associated to MAPK(ERK1/2) pathway. The anti-inflammatory response to PEMF together with the immunomodulatory potential of magCSs opens new perspectives for their applicability on tendon regeneration that goes beyond advanced cell based modeling. Statement of significanceThe combination of cell sheets and magnetic-based technologies holds promise as instrumental bio-instructive tools both for tendon disease modelling and for the development of magnetically responsive living tendon substitutes. We have previously shown that remote actuation of a pulsed electromagnetic field (PEMF) modulated the inflammatory response of IL-1β-treated human tendon-derived cell (hTDCs) monolayers. As magnetic cell sheets (magCSs) technologies enable improved cellular organization and matrix deposition, these constructions could better recapitulate tendon niches. In this work, we aimed to apply magCSs technologies to study hTDCs responses in inflammatory environments. Overall results show that PEMF-stimulated-magCSs hold evidence for immunomodulatory properties and to become a living tendon model envisioning tendon regenerative therapies.

Multiphoton Imaging of Ca2+ Instability in Acute Myocardial Slices from a RyR2R2474S Murine Model of Catecholaminergic Polymorphic Ventricular Tachycardia.

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a familial stress-induced arrhythmia syndrome, mostly caused by mutations in Ryanodine receptor 2 (RyR2), the sarcoplasmic reticulum (SR) Ca2+ release channel in cardiomyocytes. Pathogenetic mutations lead to gain of function in the channel, causing arrhythmias by promoting diastolic spontaneous Ca2+ release (SCR) from the SR and delayed afterdepolarizations. While the study of Ca2+ dynamics in single cells from murine CPVT models has increased our understanding of the disease pathogenesis, questions remain on the mechanisms triggering the lethal arrhythmias at tissue level. Here, we combined subcellular analysis of Ca2+ signals in isolated cardiomyocytes and in acute thick ventricular slices of RyR2R2474S knock-in mice, electrically paced at different rates (1–5 Hz), to identify arrhythmogenic Ca2+ dynamics, from the sub- to the multicellular perspective. In both models, RyR2R2474S cardiomyocytes had increased propensity to develop SCR upon adrenergic stimulation, which manifested, in the slices, with Ca2+ alternans and synchronous Ca2+ release events in neighboring cardiomyocytes. Analysis of Ca2+ dynamics in multiple cells in the tissue suggests that SCRs beget SCRs in contiguous cells, overcoming the protective electrotonic myocardial coupling, and potentially generating arrhythmia triggering foci. We suggest that intercellular interactions may underscore arrhythmic propensity in CPVT hearts with ‘leaky’ RyR2.