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The migratory and matrix-invading capacities of the cumulus-oocyte complex have been shown to be important for the ovulatory process. In metastatic cancers, these capacities are due to increased expression of proteases, however, there is limited information on protease expression in the cumulus-oocyte complexes. The present study examined cumulus-oocyte complex expression of plasmins, matrix metalloproteases, and A Disintegrin and Metalloproteinase with Thrombospondin Motifs family members in the rat and human. In the rat, human chorionic gonadotropin (hCG) administration increased cumulus-oocyte complex expression of Mmp2, Mmp9, Mmp13, Mmp14, Mmp16, Adamts1, and the protease inhibitors Timp1, Timp3, and Serpine1 by 8-12 h. This ovulatory induction of proteases in vivo could be mimicked by forskolin and ampiregulin treatment of cultured rat cumulus-oocyte complexes with increases observed in Mmp2, Mmp13, Mmp14, Mmp16, Mmp19, Plat, and the protease inhibitors Timp1, Timp3, and Serpine1. Comparison of expression between rat cumulus-oocyte complexes and granulosa cells at the time of ovulation showed decreased Mmp9 and increased Mmp13, Mmp14, Mmp16, Adamts1, Timp1, and Timp3 expression in the cumulus-oocyte complexes. In human, comparison of expression between cumulus and granulosa cells at the time of in vitro fertilization retrieval showed decreased MMP1, MMP2, MMP9, and ADAMTS1, while expression of MMP16, TIMP1, and TIMP3 were increased. Treatment of expanding rat cumulus-oocyte complexes with a broad spectrum matrix metalloproteases inhibitor, GM6001, significantly reduced the migration of cumulus cells in vitro. These data provide evidence that multiple proteases and their inhibitors are expressed in the cumulus-oocyte complex and play an important role in imparting the migratory phenotype of the cumulus-oocyte complex at the time of ovulation. Summary Sentence  Multiple proteases and their inhibitors are induced in the cumulus-oocyte complex (COC) during the periovulatory period and potentially play an important role in imparting the migratory phenotype of the COC at the time of ovulation., (© The Author(s) 2024. Published by Oxford University Press behalf of Society for the Study of Reproduction.)

Neutrophils collectively migrate to sites of injury and infection. How these swarms are coordinated to ensure the proper level of recruitment is unknown. Using an ex vivo model of infection, we show that human neutrophil swarming is organized by multiple pulsatile chemoattractant waves. These waves propagate through active relay in which stimulated neutrophils trigger their neighbors to release additional swarming cues. Unlike canonical active relays, we find these waves to be self-terminating, limiting the spatial range of cell recruitment. We identify an NADPH-oxidase-based negative feedback loop that is needed for this self-terminating behavior. We observe near-constant levels of neutrophil recruitment over a wide range of starting conditions, revealing surprising robustness in the swarming process. This homeostatic control is achieved by larger and more numerous swarming waves at lower cell densities. We link defective wave termination to a broken recruitment homeostat in the context of human chronic granulomatous disease., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Chondroprogenitor cells (CPCs), recently identified as a distinct subpopulation, exhibit promise due to their mesenchymal properties, heightened chondrogenesis, and limited hypertrophic traits. The enrichment of progenitors is achieved through differential fibronectin adhesion and migration-based explant assays, with Fibronectin Adhesion Assay-derived Chondroprogenitors (FAA-CPs) and Migratory Chondroprogenitors (MCPs) demonstrating superior potential compared to chondrocytes. This article delves into the details of isolating resident cartilage-derived cells, namely chondrocytes and chondroprogenitors. While valuable insights from chondrocyte research contribute to our understanding of cartilage repair, ongoing efforts are directed toward the use of chondroprogenitors and exploring their potential as an alternative therapeutic approach. Additionally, this methodology article provides a detailed step-by-step protocol for isolating three specific cell types from cartilage: chondrocytes, FAA-CPs, and MCPs. By following standardized procedures, this protocol facilitates the successful extraction of these cell subtypes. Grounded in extensive research, the article focuses on the intricate techniques utilized in isolating the different subsets and the optimized culture conditions required to expand and maintain their cultures. The methodology encompasses enzymatic isolation of human articular cartilage-derived chondrocytes, differential fibronectin adhesion following sequential enzymatic digestion, and migration-based explant assays to obtain cartilage-resident cells.

The reliability of cellular migration measurement in wound healing assays is frequently undermined by the prevalent methodological instability, i.e., tip-based method. We introduce an innovative instrument designed to address these limitations. Our novel cell scraper surpasses the current approach, generating a more consistent and stable cell-free gap. Repeated biological experiments reveal that the cell-free gap produced by the cell scraper exhibits straighter edges and uniform size and shape compared to the tip-based technique (p < 0.05). In terms of product design, the cell scraper boasts a refined color scheme suited for laboratory environments, enhancing the monitoring of experimental outcomes, and permits sterilization through autoclaving for reuse. Notably, after treatment, the cell scraper demonstrates a negligible effect on cell viability and proliferation (97.31% and 24.41%, respectively). Conversely, the tip-based method yields lower cell viability (91.37%) and proliferation (18.79%). This investigation presents the cell scraper as a novel, reusable device capable of generating reproducible cell-free gaps while preserving cellular viability, thereby augmenting the reliability of wound healing assays in comparison to existing techniques.

Spatiotemporal patterns in multicellular systems are important to understanding tissue dynamics, for instance, during embryonic development and disease. Here, we use a multiphase field model to study numerically the behavior of a near-confluent monolayer of deformable cells with intercellular friction. Varying friction and cell motility drives a solid-liquid transition, and near the transition boundary, we find the emergence of local nematic order of cell deformation driven by shear-aligning cellular flows. Intercellular friction contributes to the monolayer's viscosity, which significantly increases the spatial correlation in the flow and, concomitantly, the extent of nematic order. We also show that local hexatic and nematic order are tightly coupled and propose a mechanical-geometric model for the colocalization of [Formula: see text] nematic defects and 5-7 disclination pairs, which are the structural defects in the hexatic phase. Such topological defects coincide with regions of high cell-cell overlap, suggesting that they may mediate cellular extrusion from the monolayer, as found experimentally. Our results delineate a mechanical basis for the recent observation of nematic and hexatic order in multicellular collectives in experiments and simulations and pinpoint a generic pathway to couple topological and physical effects in these systems., Competing Interests: Competing interests statement:The authors declare no competing interest.

Previous studies have implicated epithelial-mesenchymal transition (EMT) in salamander limb regeneration. In this review, we describe putative roles for EMT during each stage of limb regeneration in axolotls and other salamanders. We hypothesize that EMT and EMT-like gene expression programs may regulate three main cellular processes during limb regeneration: (1) keratinocyte migration during wound closure; (2) transient invasion of the stump by epithelial cells undergoing EMT; and (3) use of EMT-like programs by non-epithelial blastemal progenitor cells to escape the confines of their niches. Finally, we propose nontraditional roles for EMT during limb regeneration that warrant further investigation, including alternative EMT regulators, stem cell activation, and fibrosis induced by aberrant EMT., (© 2024 The New York Academy of Sciences.)

Tumor-derived extracellular vesicles (EVs) are potential biomarkers for tumors, but their reliable molecular targets have not been identified. The previous study confirms that ubiquitin-specific protease 22 (USP22) promotes lung adenocarcinoma (LUAD) metastasis in vivo and in vitro. Moreover, USP22 regulates endocytosis of tumor cells and localizes to late endosomes. However, the role of USP22 in the secretion of tumor cell-derived EVs remains unknown. In this study, it demonstrates that USP22 increases the secretion of tumor cell-derived EVs and accelerates their migration and invasion, invadopodia formation, and angiogenesis via EV transfer. USP22 enhances EV secretion by upregulating myosin IB (MYO1B). This study further discovers that USP22 activated the SRC signaling pathway by upregulating the molecule KDEL endoplasmic reticulum protein retention receptor 1 (KDELR1), thereby contributing to LUAD cell progression. The study provides novel insights into the role of USP22 in EV secretion and cell motility regulation in LUAD., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Cell motility plays an essential role in many biological processes as cells move and interact within their local microenvironments. Current methods for quantifying cell motility typically involve tracking individual cells over time, but the results are often presented as averaged values across cell populations. While informative, these ensemble approaches have limitations in assessing cellular heterogeneity and identifying generalizable patterns of single-cell behaviors, at baseline and in response to perturbations. In this study, CaMI is introduced, a computational framework designed to leverage the single-cell nature of motility data. CaMI identifies and classifies distinct spatio-temporal behaviors of individual cells, enabling robust classification of single-cell motility patterns in a large dataset (n = 74 253 cells). This framework allows quantification of spatial and temporal heterogeneities, determination of single-cell motility behaviors across various biological conditions and provides a visualization scheme for direct interpretation of dynamic cell behaviors. Importantly, CaMI reveals insights that conventional cell motility analyses may overlook, showcasing its utility in uncovering robust biological insights. Together, a multivariate framework is presented to classify emergent patterns of single-cell motility, emphasizing the critical role of cellular heterogeneity in shaping cell behaviors across populations., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Early-onset epilepsy following ischemic stroke is a severe neurological condition, the pathogenesis of which remains incompletely understood. Recent studies suggest that Neural stem/progenitor cells (NSPCs) play a crucial role in the disease process, yet the precise molecular mechanisms regulating NSPCs have not been thoroughly investigated. This study utilized single-cell transcriptome sequencing and bioinformatics analysis to identify disease-related genes, which were subsequently validated in both in vitro and in vivo experiments. The findings revealed that Hsp90aa1 (heat shock protein 90 kDa alpha, class A member 1), Jun proto-oncogene (JUN), and CC Motif Ligation 2 (Ccl2) constitute an important regulatory axis influencing the migration and differentiation of NSPCs, potentially impacting the onset and progression of early-onset epilepsy post-ischemic stroke. Additionally, the expression of Hsp90aa1 was found to influence the likelihood of seizure occurrence and the severity of brain ischemia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

In textbook illustrations of migrating cells, actomyosin contractility is typically depicted as the contraction force necessary for cell body retraction. This dogma has been transformed by the molecular clutch model, which acknowledges that actomyosin traction forces also generate and transmit biomechanical signals at the leading edge, enabling cells to sense and shape their migratory path in mechanically complex environments. To fulfill these complementary functions, the actomyosin system assembles a gradient of contractile energy along the front-rear axis of migratory cells. Here, we highlight the hierarchic assembly and self-regulatory network structure of the actomyosin system and explain how the kinetics of different nonmuscle myosin II (NM II) paralogs synergize during contractile force generation. Our aim is to emphasize how protrusion formation, cell adhesion, contraction, and retraction are spatiotemporally integrated during different modes of migration, including chemotaxis and durotaxis. Finally, we hypothesize how different NM II paralogs might tune aspects of migration in vivo, highlighting future research directions., (© 2024 The Author(s). BioEssays published by Wiley Periodicals LLC.)

Gliomas are malignant tumors of the central nervous system; current treatment methods have low efficacy. Twisted gastrulation BMP signaling modulator 1 (TWSG1) has been shown to play a role in gliomas but it is not known whether TWSG1 participates in glioma pathogenesis and macrophage immune regulation. This study identified a total of 24 differentially expressed genes with survival differences in gliomas using bioinformatics analysis. Among them, TWSG1 exhibited the strongest correlation with gliomas and was positively correlated with macrophage enrichment. The results showed that TWSG1 was highly expressed in various glioma cell lines, with the highest expression observed in the A172 cell line. Silencing TWSG1 significantly decreased the viability, migration, and invasion of A172 cells in vitro and tumor growth in a mouse xenograft model in vivo. It also reduced the expression of the matrix metalloproteinases MMP2 and MMP9 both in vivo and in vitro. Silencing TWSG1 significantly reduced the expression of M2 macrophage makers and upregulated the expression of M1 macrophage markers in A172 cells and tumor tissues. These data suggest that interference with TWSG1 suppressed the progression of A172 glioma cells and regulated immune infiltration., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Association of Neuropathologists, Inc. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

During brain maturation, astrocytes establish complex morphologies unveiling intense structural plasticity. Connexin 30 (Cx30), a gap-junction channel-forming protein expressed postnatally, dynamically regulates during development astrocyte morphological properties by controlling ramification and extension of fine processes. However, the underlying mechanisms remain unexplored. Here, we found in vitro that Cx30 interacts with the actin cytoskeleton in astrocytes and inhibits its structural reorganization and dynamics during cell migration. This translates into an alteration of local physical surface properties, as assessed by correlative imaging using stimulated emission depletion (STED) super resolution imaging and atomic force microscopy (AFM). Specifically, Cx30 impaired astrocyte cell surface topology and cortical stiffness in motile astrocytes. As Cx30 alters actin organization, dynamics, and membrane physical properties, we assessed whether it controls astrocyte migration. We found that Cx30 reduced persistence and directionality of migrating astrocytes. Altogether, these data reveal Cx30 as a brake for astrocyte structural and mechanical plasticity., (© 2024 The Author(s). GLIA published by Wiley Periodicals LLC.)

Glioma, a formidable form of brain cancer, poses significant challenges in terms of treatment and prognosis. Circular RNA nucleoporin 98 (circNUP98) has emerged as a potential regulator in various cancers, yet its role in glioma remains unclear. Here, we elucidate the functional role of circNUP98 in glioma cell proliferation, invasion, and migration, shedding light on its therapeutic implications. Glioma cells were subjected to si-NUP98 transfection, followed by assessments of cell viability, proliferation, invasion, and migration. Subcellular localization of circNUP98 was determined, and its downstream targets were identified. We delineated the binding relationships between circNUP98 and microRNA (miR)-520f-3p, as well as between miR-520f-3p and ETS transcription factor ELK4 (ELK4). The expression levels of circNUP98/miR-520f-3p/ELK4 were quantified. Our findings demonstrated that circNUP98 was upregulated in glioma cells, and its inhibition significantly attenuated glioma cell proliferation, invasion, and migration. Mechanistically, circNUP98 functioned as a sponge for miR-520f-3p, thereby relieving the inhibitory effect of miR-520f-3p on ELK4. Moreover, inhibition of miR-520f-3p or overexpression of ELK4 partially rescued the suppressive effect of circNUP98 knockdown on glioma cell behaviors. In summary, our study unveils that circNUP98 promotes glioma cell progression via the miR-520f-3p/ELK4 axis, offering novel insights into the therapeutic targeting of circNUP98 in glioma treatment., (© 2024 International Society for Developmental Neuroscience.)

Preeclampsia is a common pregnancy complication affecting 5% to 7% of all pregnancies worldwide annually. While the pathogenesis is not fully understood, maternal endothelium dysfunction is thought to be a central component to preeclampsia development. Studies to dissect maternal endothelial dysfunction, particularly on a patient-specific basis, are hampered by limited access to systemic primary endothelial cells (ECs). The objective of this study was to establish a replenishable, patient-specific in vitro EC model to allow robust mechanistic studies to dissect endothelial dysfunction in preeclampsia. Induced pluripotent stem cells (iPSCs) from three women with a history of normotensive pregnancies were differentiated into ECs. The established ECs were exposed to pooled sera from normotensive pregnancies, preeclamptic pregnancies, normotensive postpartum for non-pregnant comparison and controls. Endothelial functions including nitric oxide (NO) release, cell migration, tube formation and viability were evaluated. Levels of NO release were significantly lower after incubation with preeclamptic sera compared to the fetal bovine serum (FBS) control, and normotensive and non-pregnant (postpartum) sera treatments were also lower than FBS but higher than preeclamptic sera treatments. Tube formation and cell migration were also impaired with preeclamptic sera compared to FBS controls. Cell viabilities remained unaffected by any sera treatment. Consistent outcomes were obtained across all three patient-specific lines treated with the same pooled sera. Establishment of patient-derived iPSC-ECs treated with pregnancy sera serves as a novel model to explore the interplay between individual maternal endothelial health and circulating factors that lead to endothelial dysfunction in preeclampsia., (© 2024. The Author(s).)

The purpose of this study was to investigate the effects of BOC on glioblastoma cells and its underlying mechanisms. In vitro, BOC-knockdown was performed in glioma cell lines. CCK-8 and Transwell were used to assess the impact of BOC on the viability, invasion, and migration of gliobma cells. RNA-seq technology was employed to analyze the differential gene expression between BOC-knockdown glioma cells and the control group, and qRT-PCR was used to validate the expression of downstream differential genes. SMO-overexpression was performed to investigate the effects of SMO on glioma cells. A BOC-knockdown mouse subcutaneous tumor model was to verify the effects of BOC on mouse tumors. Tissue microarray technology was used to detect the expression of BOC and SMO in samples of normal human brain tissue and glioma tissue. In vitro, BOC-knockdown inhibited the viability, invasion, and migration of glioma cells, as well as downregulated the expression of downstream differential genes SMO, EGFR, HRAS, and MRAS. Conversely, SMO-overexpression upregulated the viability, invasion, and migration abilities of BOC-knockdown cells. In vivo, BOC-knockdown suppressed tumor growth in mice and downregulated the expression of downstream differential genes SMO, EGFR, HRAS, and MRAS. Tissue microarray results showed that both BOC and SMO were highly expressed in glioma tissues. BOC is aberrantly overexpressed in glioma patients and promotes glioma development. Mechanistically, BOC activates the Hedgehog (Hh) and RAS signaling pathways by upregulating the expression of SMO, EGFR, HRAS, and MRAS, thereby facilitating the Proliferation, invasion and migration of glioma cells., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Introduction: Preeclampsia is a pregnancy-specific disorder characterized by de novo development of hypertension and proteinuria over 20 weeks gestation that has been associated with the dysfunction of trophoblasts. Current evidence suggests that syncytin-1 plays an important role in the non-fusogenic biological activity of trophoblasts, except for specific fusogenic function. However, the underlying mechanism remains unclear., Methods: The expression and location of syncytin-1 in normal and the late-onset preeclampsia placentas were detected by quantitative real-time PCR, western blotting and immunofluorescence. Morphological and apoptosis analysis were processed in placentas. The ex vivo extravillous explant culture model was used to explore the effect of syncytin-1 on EVT outgrowths. Real-time quantitative PCR and immunoblotting were used to calculate syncytin-1 levels in the trophoblast cells before and after syncytin-1 knockdown or overexpression. CCK-8 assay was used to detect the cell viability. TUNEL staining and immunoblotting were processed in trophoblast cells. Transwell assays and wound healing assays were utilize to assess the invasion and migration of trophoblastic cells. Conditional knockout of syncytin-a mouse model was conducted to present the change of placentas in vivo. The ex vivo extravillous explant culture model was used to explore the effect of syncytin-1 on EVT outgrowths. Western blotting was used to identify the key proteins of PI3K/Akt pathways and invasion-related proteins in trophoblast cells., Results and Discussion: Here, reduced syncytin-1 was identified in the late-onset preeclampsia placentas. Reduced syncytin-1 may attenuates the EMT process by promoting apoptosis, inhibiting proliferation and invasion by suppressed PI3K/Akt pathway in trophoblast cells. Our findings provide novel insights into the non-fusogenic biological function of reduced syncytin-1 that may be involves in the pathogenesis of preeclampsia., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Dysfunction of retinal vascularization plays pathogenic roles in retinopathy of prematurity (ROP). Hypoxia-inducible factor 1 alpha (HIF1A) is activated by hypoxia and contributes to ROP progression. Herein, we clarified the mechanism underlying HIF1A activation in human retinal vascular endothelial cells (HRECs) under hypoxia., Methods: Protein expression was assayed by immunoblot analysis. Cell migration, microtubule formation, invasion, proliferation, and viability were detected by wound-healing, tube formation, transwell, EdU, and CCK-8 assays, respectively. Bioinformatics was used to predict the deubiquitinase-HIF1A interactions and RNA binding proteins (RBPs) bound to USP33. The impact of USP33 on HIF1A deubiquitination was validated by immunoprecipitation (IP) assay. RNA stability analysis was performed with actinomycin D (Act D) treatment. The ELAVL1/USP33 interaction was assessed by RNA immunoprecipitation experiment., Results: In hypoxia-exposed HRECs, HIF1A and USP33 protein levels were upregulated. Deficiency of HIF1A or USP33 suppressed cell migration, proliferation and microtubule formation of hypoxia-exposed HRECs. Mechanistically, USP33 deficiency led to an elevation in HIF1A ubiquitination and degradation. USP33 deficiency reduced HIF1A protein levels to suppress the proliferation and microtubule formation of hypoxia-induced HRECs. Moreover, the RBP ELAVL1 stabilized USP33 mRNA to increase USP33 protein levels. ELAVL1 decrease repressed the proliferation and microtubule formation of hypoxia-induced HRECs by reducing USP33., Conclusion: Our study identifies a novel ELAVL1/USP33/HIF1A regulatory cascade with the ability to affect hypoxia-induced pathological proliferation, angiogenesis, and migration in HRECs., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Collective migration is an important component of many biological processes, including wound healing, tumorigenesis, and embryo development. Spatial agent-based models (ABMs) are often used to model collective migration, but it is challenging to thoroughly predict these models' behavior throughout parameter space due to their random and computationally intensive nature. Modelers often coarse-grain ABM rules into mean-field differential equation (DE) models. While these DE models are fast to simulate, they suffer from poor (or even ill-posed) ABM predictions in some regions of parameter space. In this work, we describe how biologically-informed neural networks (BINNs) can be trained to learn interpretable BINN-guided DE models capable of accurately predicting ABM behavior. In particular, we show that BINN-guided partial DE (PDE) simulations can (1) forecast future spatial ABM data not seen during model training, and (2) predict ABM data at previously-unexplored parameter values. This latter task is achieved by combining BINN-guided PDE simulations with multivariate interpolation. We demonstrate our approach using three case study ABMs of collective migration that imitate cell biology experiments and find that BINN-guided PDEs accurately forecast and predict ABM data with a one-compartment PDE when the mean-field PDE is ill-posed or requires two compartments. This work suggests that BINN-guided PDEs allow modelers to efficiently explore parameter space, which may enable data-driven tasks for ABMs, such as estimating parameters from experimental data. All code and data from our study is available at https://github.com/johnnardini/Forecasting&#95;predicting&#95;ABMs ., (© 2024. The Author(s), under exclusive licence to the Society for Mathematical Biology.)

Formation of organs and specialized tissues in embryonic development requires migration of cells to specific targets. In some instances, such cells migrate as a robust cluster. We here explore a recent local approximation of non-local continuum models by Falcó et al. (SIAM J Appl Math 84:17-42, 2023). We apply their theoretical results by specifying biologically-based cell-cell interactions, showing how such cell communication results in an effective attraction-repulsion Morse potential. We then explore the clustering instability, the existence and size of the cluster, and its stability. For attractant-repellent chemotaxis, we derive an explicit condition on cell and chemical properties that guarantee the existence of robust clusters. We also extend their work by investigating the accuracy of the local approximation relative to the full non-local model., (© 2024. The Author(s), under exclusive licence to the Society for Mathematical Biology.)

Drosophila border cell clusters model collective cell migration. Airyscan super-resolution microscopy enables fine-scale description of cluster shape and texture. Here we describe how to convert Airyscan images of border cell clusters into 3D models of the surface and detect regions of convex and concave curvature. We use spectral decomposition analysis to compare surface textures across genotypes to determine how genes of interest impact cluster surface geometry. This protocol applies to border cells and could generalize to additional cell types. For complete details on the use and execution of this protocol, please refer to Gabbert et al. 1 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Many active systems display nematic order, while interacting with their environment. In this Letter, we show theoretically how environment-stored memory acts an effective external field that aligns active nematics. The coupling to the environment leads to substantial modifications of the known phase diagram and dynamics of active nematics, including nematic order at arbitrarily low densities and arrested domain coarsening. We are motivated mainly by cells that remodel fibers in their extra-cellular matrix (ECM), while being directed by the fibers during migration. Our predictions indicate that remodeling promotes cellular and ECM alignment, and possibly limits the range of ordered ECM domains, in accordance with recent experiments.

During embryonic development of the retina of the eye, astrocytes, a type of glial cell, migrate over the retinal surface and form a dynamic mesh. This mesh then serves as scaffolding for blood vessels to form the retinal vasculature network that supplies oxygen and nutrients to the inner portion of the retina. Astrocyte spreading proceeds in a radially symmetric manner over the retinal surface. Additionally, astrocytes mature from astrocyte precursor cells (APCs) to immature perinatal astrocytes (IPAs) during this embryonic stage. We extend a previously-developed continuum model that describes tension-driven migration and oxygen and growth factor influenced proliferation and differentiation. Comparing numerical simulations to experimental data, we identify model equation components that can be removed via model reduction using approximate Bayesian computation (ABC). Our results verify experimental studies indicating that the choroid oxygen supply plays a negligible role in promoting differentiation of APCs into IPAs and in promoting IPA proliferation, and the hyaloid artery oxygen supply and APC apoptosis play negligible roles in astrocyte spreading and differentiation., (© 2024. The Author(s), under exclusive licence to the Society for Mathematical Biology.)

Collective cell migration is crucial in various physiological processes, including wound healing, morphogenesis, and cancer metastasis. Adherens Junctions (AJs) play a pivotal role in regulating cell cohesion and migration dynamics during tissue remodeling. While the role and origin of the junctional mechanical tension at AJs have been extensively studied, the influence of the actin cortex structure and dynamics on junction plasticity remains incompletely understood. Moreover, the mechanisms underlying stress dissipation at junctions are not well elucidated. Here, we found that the ligand-independent phosphorylation of epithelial growth factor receptor (EGFR) downstream of de novo E-cadherin adhesion orchestrates a feedback loop, governing intercellular viscosity via the Rac pathway regulating actin dynamics. Our findings highlight how the E-cadherin-dependent EGFR activity controls the migration mode of collective cell movements independently of intercellular tension. This modulation of effective viscosity coordinates cellular movements within the expanding monolayer, inducing a transition from swirling to laminar flow patterns while maintaining a constant migration front speed. Additionally, we propose a vertex model with adjustable junctional viscosity, capable of replicating all observed cellular flow phenotypes experimentally., Competing Interests: Competing interests statement:The authors declare no competing interest.

Background: Facilitating the healing process of injured anterior cruciate ligament (ACL) tissue is crucial for patients to safely return to sports. Stem cell derived exosomes have shown positive effects on enhancing the regeneration of injured tendons/ligaments. However, clinical application of exosomes in terms of storage and pre-assembly is challenging. We hypothesized that lyophilized exosomes derived from human umbilical cord stem cells (hUSC-EX) could enhance the cell activity of chronically injured ACL cells., Materials and Methods: We harvested the 8 weeks injured ACL cells from rabbit under IACUC (No. 110232) approval. The studied exosomes were purified from the culture medium of human umbilical cord stem cells (IRB approval No. A202205014), lyophilized to store, and hydrated for use. We compared exosome treated cells with non-exosome treated cells (control group) from the same rabbits. We examined the cell viability, proliferation, migration capability and gene expression of type I and III collagen, TGFβ, VEGF, and tenogenesis in the 8 weeks injured ACL cells after hUSC-EX treatment., Results: After hydration, the average size of hUSC-EX was 84.5 ± 70.6 nm, and the cells tested positive for the Alix, TSG101, CD9, CD63, and CD81 proteins but negative for the α-Tubulin protein. After 24 h of treatment, hUSC-EX significantly improved the cell viability, proliferation and migration capability of 8 weeks injured ACL cells compared to that of no exosome treatment group. In addition, the expression of collagen synthesis, TGFβ, VEGF, and tenogenesis gene were all significantly increased in the 8 weeks injured ACL cells after 24 h hUSC-EX delivery., Discussion: Lyophilized exosomes are easily stored and readily usable after hydration, thereby preserving their characteristic properties. Treatment with lyophilized hUSC-EX improved the activity and gene expression of 8 weeks injured ACL cells., Conclusion: Lyophilized hUSC-EX preserve the characteristics of exosomes and can improve chronically injured (8 weeks) ACL cells. Lyophilized hUSC-EX could serve as effective and safe biomaterials that are ready to use at room temperature to enhance cell activity in patients with partial ACL tears and after remnant preservation ACL reconstruction., (© 2024. The Author(s).)

Regulation of cell proliferation is a crucial aspect of tissue development and homeostasis and plays a major role in morphogenesis, wound healing, and tumor invasion. A phenomenon of such regulation is contact inhibition, which describes the dramatic slowing of proliferation, cell migration and individual cell growth when multiple cells are in contact with each other. While many physiological, molecular and genetic factors are known, the mechanism of contact inhibition is still not fully understood. In particular, the relevance of cellular signaling due to interfacial contact for contact inhibition is still debated. Cellular automata (CA) have been employed in the past as numerically efficient mathematical models to study the dynamics of cell ensembles, but they are not suitable to explore the origins of contact inhibition as such agent-based models assume fixed cell sizes. We develop a minimal, data-driven model to simulate the dynamics of planar cell cultures by extending a probabilistic CA to incorporate size changes of individual cells during growth and cell division. We successfully apply this model to previous in-vitro experiments on contact inhibition in epithelial tissue: After a systematic calibration of the model parameters to measurements of single-cell dynamics, our CA model quantitatively reproduces independent measurements of emergent, culture-wide features, like colony size, cell density and collective cell migration. In particular, the dynamics of the CA model also exhibit the transition from a low-density confluent regime to a stationary postconfluent regime with a rapid decrease in cell size and motion. This implies that the volume exclusion principle, a mechanical constraint which is the only inter-cellular interaction incorporated in the model, paired with a size-dependent proliferation rate is sufficient to generate the observed contact inhibition. We discuss how our approach enables the introduction of effective bio-mechanical interactions in a CA framework for future studies., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Published by Elsevier Ltd.)

Purpose: Corneal wounding healing is critical for maintaining clear vision, however, a complete understanding of its dynamic regulatory mechanisms remains elusive. Here, we used single-cell RNA sequencing (scRNA-seq) to analyze the cellular activities and transcriptional changes of corneal limbal epithelial cells at different stages after wound healing in cynomolgus monkeys, which exhibit a closer transcriptomic similarity to humans., Methods: Corneal limbal tissues were collected during uninjured, 1-day and 3-day healing stages, dissociated into single cells, and subjected to scRNA-seq using the 10× Genomics platform. Cell types were clustered by graph-based visualization methods and unbiased computational analysis. Additionally, cell migration assays and immunofluorescent staining were performed on cultured human corneal epithelial cells., Results: We characterized nine cell clusters by scRNA-seq analysis of the cynomolgus monkey corneal epithelium. By comparing heterogeneous transcriptional changes in major cell types during corneal healing, we highlighted the importance of limbal epithelial cells (LEPCs) and basal epithelial cells (BEPCs) in extracellular matrix (ECM) formation and wound healing, as well as suprabasal epithelial cells (SEPCs) in epithelial differentiation during the healing processes. We further identified five different sub-clusters in LEPC, including the transit amplifying cell (TAC) sub-cluster that promotes early healing through the activation of thrombospondin-1 (THBS1) expression., Conclusions: Our study represents the first comprehensive exploration of the detailed transcriptome profile of individual corneal cells during the wound healing process in nonhuman primates. We demonstrate the intricate mechanisms involved in corneal healing and provide a promising avenue for potential therapies in corneal wound healing.

Purpose: Insight into the immune status of the living eye is essential as we seek to understand ocular disease and develop new treatments. The nonhuman primate (NHP) is the gold standard preclinical model for therapeutic development in ophthalmology, owing to the similar visual system and immune landscape in the NHP relative to the human. Here, we demonstrate the utility of phase-contrast adaptive optics scanning light ophthalmoscope (AOSLO) to visualize immune cell dynamics on the cellular scale, label-free in the NHP., Methods: Phase-contrast AOSLO was used to image preselected areas of retinal vasculature in five NHP eyes. Images were registered to correct for eye motion, temporally averaged, and analyzed for immune cell activity. Cell counts, dimensions, velocities, and frequency per vessel were determined manually and compared between retinal arterioles and venules. Based on cell appearance and circularity index, cells were divided into three morphologies: ovoid, semicircular, and flattened., Results: Immune cells were observed migrating along vascular endothelium with and against blood flow. Cell velocity did not significantly differ between morphology or vessel type and was independent of blow flood. Venules had a significantly higher cell frequency than arterioles. A higher proportion of cells resembled "flattened" morphology in arterioles. Based on cell speeds, morphologies, and behaviors, we identified these cells as nonclassical patrolling monocytes (NCPMs)., Conclusions: Phase-contrast AOSLO has the potential to reveal the once hidden behaviors of single immune cells in retinal circulation and can do so without the requirement of added contrast agents that may disrupt immune cell behavior.

Heat-shock protein 90 (Hsp90) plays a crucial role in tumorigenesis and tumor progression; however, its mechanism of action in gastric cancer (GC) remains unclear. Here, the role of Hsp90 in GC metabolism is the focus of this research. High expression of Hsp90 in GC tissues can interact with glycolysis, collectively affecting prognosis in clinical samples. Both in vitro and in vivo experiments demonstrate that Hsp90 is able to regulate the migration and stemness properties of GC cells. Metabolic phenotype analyses indicate that Hsp90 influences glycolytic metabolism. Mechanistically, Hsp90 interacts with glycolysis-related enzymes, forming multienzyme complexes to enhance glycolysis efficiency and yield. Additionally, Hsp90 binds to cytoskeleton-related proteins, regulating the regional distribution of glycolytic enzymes at the cell margin and lamellar pseudopods. This effect could lead to a local increase in efficient energy supply from glycolysis, further promoting epithelial-mesenchymal transition (EMT) and metastasis. In summary, Hsp90, through its interaction with metabolic enzymes related to glycolysis, forms multi-enzyme complexes and regulates regional distribution of glycolysis by dynamic cytoskeletal adjustments, thereby promoting the migration and stemness of GC cells. These conclusions also support the potential for a combined targeted approach involving Hsp90, glycolysis, and the cytoskeleton in clinical therapy., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

This work presents an advanced agent-based model developed within the FLAMEGPU2 framework, aimed at simulating the intricate dynamics of cell microenvironments. Our primary objective is to showcase FLAMEGPU2's potential in modelling critical features such as cell-cell and cell-ECM interactions, species diffusion, vascularisation, cell migration, and/or cell cycling. By doing so, we provide a versatile template that serves as a foundational platform for researchers to model specific biological mechanisms or processes. We highlight the utility of our approach as a microscale component within multiscale frameworks. Through four example applications, we demonstrate the model's versatility in capturing phenomena such as strain-stiffening behaviour of hydrogels, cell migration patterns within hydrogels, spheroid formation and fibre reorientation, and the simulation of diffusion processes within a vascularised and deformable domain. This work aims to bridge the gap between computational efficiency and biological fidelity, offering a scalable and flexible platform to advance our understanding of tissue biology and engineering., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Oxidative stress (OS) is mainly associated with the pathogenesis of intervertebral disc (IVD) degeneration; it causes nucleus pulposus cells (NPCs) to undergo senescence and triggers autophagy and apoptosis. This study aims to evaluate the regeneration potential of extracellular vesicles (EVs) derived from human umbilical cord-mesenchymal stem cells (hUC-MSCs) in an in vitro rat NPC-induced OS model., Design: NPCs were isolated from rat coccygeal discs, propagated, and characterized. OS was induced by hydrogen peroxide (H 2 O 2 ), which is confirmed by 2,7-dichlorofluorescein diacetate (H 2 DCFDA) assay. EVs were isolated from hUC-MSCs and characterized by analyzing the vesicles using fluorescence microscope, scanning electron microscope (SEM), atomic force microscope (AFM), dynamic light scattering (DLS), and Western blot (WB). The in vitro effects of EVs on migration, uptake, and survival of NPCs were determined., Results: SEM and AFM topographic images revealed the size distribution of EVs. The phenotypes of isolated EVs showed that the size of EVs was 403.3 ± 85.94 nm, and the zeta potential was -0.270 ± 4.02 mV. Protein expression analysis showed that EVs were positive for CD81 and annexin V. Treatment of NPCs with EVs reduced H 2 O 2 -induced OS as evidenced by a decrease in reactive oxygen species (ROS) levels. Co-culture of NPCs with DiI-labeled EVs showed the cellular internalization of EVs. In the scratch assay, EVs significantly increased NPC proliferation and migration toward the scratched area. Quantitative polymerase chain reaction analysis showed that EVs significantly reduced the expression of OS genes., Conclusion: EVs protected NPCs from H 2 O 2 -induced OS by reducing intracellular ROS generation and improved NPC proliferation and migration., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Platelet-derived growth factor receptor β positive (PDGFRβ + ) pericytes detach from the microvascular wall and migrate into the injury center following spinal cord injury (SCI), which has been widely regarded as the main source of fibrotic scar, but the mechanism of migration and fibroblast transition remains elusive. Here we show the associated spatiotemporal distribution between microglia and pericytes at three and seven days post-injury (dpi). The increased expression of Sphingosine kinase-1 (SPHK1) in microglia significantly raised the concentration of Sphingosine-1-phosphate (S1P) in the spinal cord, which promotes migration and fibroblast transition of pericyte. In vitro experiments, we found the elevated Sphingosine 1-phosphate receptor 3 (S1P3), the S1P/S1PR3 axis inhibited the phosphorylation of YAP and promoted its nuclear translocation, which contributed to the formation of alpha-smooth muscle actin (α-SMA) and collagen type I (COL1) protein, This process can be blocked by an S1P3 specific inhibitor TY52156 in vitro. The S1P/S1P3/YAP pathway might be a potential target for treatment in SCI., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled., (Copyright © 2024. Published by Elsevier Inc.)

Ovarian cancer is the most lethal gynecologic cancer in developed countries. In the tumor microenvironment, the extracellular matrix (ECM) and flow shear stress are key players in directing ovarian cancer cells invasion. Artificial ECM models based only on ECM proteins are used to build an ovarian tumor-on-chip to decipher the crosstalk between ECM and shear stress on the migratory behavior and cellular heterogeneity of ovarian tumor cells. This work shows that in the shear stress regime of the peritoneal cavity, the ECM plays a major role in driving individual or collective ovarian tumor cells migration. In the presence of basement membrane proteins, migration is more collective than on type I collagen regardless of shear stress. With increasing shear stress, individual cell migration is enhanced; while, no significant impact on collective migration is measured. This highlights the central position that ECM and flow shear stress should hold in in vitro ovarian cancer models to deepen understanding of cellular responses and improve development of ovarian cancer therapeutic platforms. In this frame, adding flow provides significant improvement in biological relevance over the authors' previous work. Further steps for enhanced clinical relevance require not only multiple cell lines but also patient-derived cells and sera., (© 2024 Wiley‐VCH GmbH.)

Background: Glioma is the most common malignant brain tumor. GPR133 is a key factor in the progression of glioma. However, the role of GPR133 in glioma invasion and EMT and the microRNAs (miRNAs) associated with this pathway are still poorly understood. Objective: This study aims to elucidate the biological function of miR-106a-5p and GPR133 in glioma as well as the molecular mechanism of their interaction. Methods: The mRNA expression of miR-106a-5p and GPR133 in glioma specimens and cells was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The protein level of GPR133 and the levels of invasion- and EMT-related proteins were measured by western blotting. miR-106a-5p and GPR133 function in glioma cells was determined through cell counting kit-8 (CCK-8), transwell, wound healing, colony formation assays in vitro and xenograft assays in vivo . To determine the targeting relationship between miR-106a-5p and GPR133, a dual-luciferase reporter assay was conducted. Results: A marked reduction in miR-106a-5p expression was observed in glioma cells and specimens. Patients with high expression of miR-106a-5p had a good prognosis, while patients with high expression of GPR133 had a shorter OS. Additionally, overexpression of miR-106a-5p or downregulation of GPR133 inhibited the progression of glioma cells. Furthermore, miR-106a-5p negatively regulated GPR133 expression by binding to its 3'-UTR, and restrained the invasion, migration, proliferation and EMT of glioma cells by targeting GPR133. Conclusions: miR-106a-5p is a tumor suppressor that negatively regulates GPR133. The miR-106a-5p/GPR133 axis could potentially serve as a therapeutic target for glioma.

The development of innovative strategies for cell membranes engineering is of prime interest to explore and manipulate cell-cell interactions. Herein, an enzyme-sensitive recognition marker that can be introduced on cell surface via bioorthogonal chemistry is designed. Once functionalized in this fashion, the cells gain the ability to assemble with cell partners coated with the complementary marker through non-covalent click chemistry. The artificial cell adhesion induces natural biological processes associated with cell proximity such as inhibiting cancer cell proliferation and migration. On the other hand, the enzymatic activation of the stimuli-responsive marker triggers the disassembly of cells, thereby restoring the tumor cell proliferation and migration rates. Thus, the study shows that the ready-to-use complementary markers are valuable tools for controlling the formation and the breaking of bonds between cells, offering an easy way to investigate biological processes associated to cell proximity., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

The endothelial-mesenchymal transition (EndMT) of endothelial progenitor cells (EPCs) plays a notable role in pathological vascular remodeling. Emerging evidence indicated that long non-coding RNA-regulator of reprogramming (linc-ROR) can promote epithelial-mesenchymal transition (EMT) in a variety of cancer cells. Nevertheless, the function of linc-ROR in EPC EndMT has not been well elucidated. The present study investigated the effect and possible mechanisms of function of linc-ROR on the EndMT of EPCs. A linc-ROR overexpression lentiviral vector (LV linc-ROR) or a linc-ROR short hairpin RNA lentiviral vector (LV-shlinc-ROR) was used to up or downregulate linc-ROR expression in EPCs isolated from human umbilical cord blood. Functional experiments demonstrated that LV-linc-ROR promoted the proliferation and migration of EPCs, but inhibited EPC angiogenesis in vitro. In the meantime, reverse transcription-quantitative PCR and western blotting results showed that the expression of the endothelial cell markers vascular endothelial-cadherin and CD31 was decreased, while the expression of the mesenchymal cell markers ?-smooth muscle actin and SM22? was increased at both mRNA and protein levels in LV-linc-ROR-treated EPCs, indicating that linc-ROR induced EPC EndMT. Mechanistically, the dual-luciferase reporter assay demonstrated that microRNA (miR/miRNA)-145 was a direct target of linc-ROR, and miR-145 binds to the 3'-untranslated region of Smad3. Moreover, LV-shlinc-ROR increased the expression of miR-145, but decreased the expression of Smad3. In conclusion, linc-ROR promotes EPC EndMT, which may be associated with the miR-145/Smad3 signaling pathway. Keywords: Endothelial progenitor cells, Endothelial to mesenchymal transition, Linc-ROR, MiR-145, Atherosclerosis.

We study the stochastic hydrodynamics of colonies of flagellated swimming cells, typified by multicellular choanoflagellates, which can form both rosette and chainlike shapes. The objective is to link cell-scale dynamics to colony-scale dynamics for various colonial morphologies. Via autoregressive stochastic models for the cycle-averaged flagellar force dynamics and statistical models for demographic cell-to-cell variability in flagellar properties and placement, we derive effective transport properties of the colonies, including cell-to-cell variability. We provide the most quantitative detail on disclike geometries to model rosettes, but also present formulas for the dynamics of general planar colony morphologies, which includes planar chain-like configurations., (© 2024. The Author(s), under exclusive licence to the Society for Mathematical Biology.)

Epithelial-Mesenchymal Transition (EMT) is a key process in physiological and pathological settings. EMT is often presented as a linear sequence with (i) disassembly of cell-cell junctions, (ii) loss of epithelial polarity and (iii) reorganization of the cytoskeleton leading to basal extrusion from the epithelium. Once out, cells can adopt a migratory phenotype with a front-rear polarity. While this sequence can occur, in vivo observations have challenged it. It is now accepted that multiple EMT scenarios coexist in heterogeneous cell populations. However, the relative importance of each step as well as that of variability and heterogeneity on the efficiency of cell extrusion has not been assessed. Here we used computational modelling to simulate multiple EMT-like scenarios and confronted these data to the EMT of neural crest cells. Overall, our data point to a key role of nuclear positioning and protrusive activity to generate timely basal extrusion., (© 2024. The Author(s).)

The meninges, choroid plexus (CP) and blood-brain barrier (BBB) are recognized as important gateways for peripheral immune cell trafficking into the central nervous system (CNS). Accumulation of peripheral immune cells in brain parenchyma can be observed during aging and Alzheimer's disease (AD). However, the mechanisms by which peripheral immune cells enter the CNS through these three pathways and how they interact with resident cells within the CNS to cause brain injury are not fully understood. In this paper, we review recent research on T cells recruitment in the brain during aging and AD. This review focuses on the possible pathways through which T cells infiltrate the brain, the evidence that T cells are recruited to the brain, and how infiltrating T cells interact with the resident cells in the CNS during aging and AD. Unraveling these issues will contribute to a better understanding of the mechanisms of aging and AD from the perspective of immunity, and hopefully develop new therapeutic strategies for brain aging and AD., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Osteosarcoma is a soft tissue neoplasm with elevated recurrence risk and highly metastatic potential. Metal response element binding transcriptional factor 2 (MTF2) has been revealed to exert multiple activities in human tissues. The present research was conducted to explore the functions and related response mechanism of MTF2 in osteosarcoma which have not been introduced yet., Methods: Bioinformatics tools identified the differential MTF2 expression in osteosarcoma tissues. MTF2 expression in osteosarcoma cells was examined with Western blot. Cell Counting Kit-8 (CCK-8) assay, 5-Ethynyl-2'-deoxyuridine (EDU) staining, wound healing as well as transwell assays measured cell proliferation, migration and invasion, respectively. Flow cytometry assay detected the cellular apoptotic level. Western blot also measured the expressions of proteins associated with epithelial mesenchymal transition (EMT), apoptosis and enhancer of zeste homolog 2 (EZH2)/secreted frizzled-related protein 1 (SFRP1)/Wnt signaling. Co-immunoprecipitation (Co-IP) assay confirmed MTF2-EZH2 interaction., Results: MTF2 expression was increased in osteosarcoma tissues and cells. MTF2 interference effectively inhibited the proliferation, migration and invasion of osteosarcoma cells and promoted the cellular apoptotic rate. MTF2 directly bound to EZH2 and MTF2 silence reduced EZH2 expression, activated SFRP1 expression and blocked Wnt signaling in osteosarcoma cells. EZH2 upregulation or SFRP1 antagonist WAY-316606 partly counteracted the impacts of MTF2 down-regulation on the SFRP1/Wnt signaling and the biological phenotypes of osteosarcoma cells., Conclusions: MTF2 might down-regulate SFRP1 to activate Wnt signaling and drive the progression of osteosarcoma via interaction with EZH2 protein., (© 2024. The Author(s).)

Hippocampus is a critical component of the central nervous system. SRSF10 is expressed in central nervous system and plays important roles in maintaining normal brain functions. However, its role in hippocampus development is unknown. In this study, using SRSF10 conditional knock-out mice in neural progenitor cells (NPCs), we found that dysfunction of SRSF10 leads to developmental defects in the dentate gyrus of hippocampus, which manifests as the reduced length and wider suprapyramidal blade and infrapyramidal blade.Furthermore, we proved that loss of SRSF10 in NPCs caused inhibition of the differentiation activity and the abnormal migration of NPCs and granule cells, resulting in reduced granule cells and more ectopic granule cells dispersed in the molecular layer and hilus. Finally, we found that the abnormal migration may be caused by the radial glia scaffold and the reduced DISC1 expression in NPCs. Together, our results indicate that SRSF10 is required for the cell migration and formation of dentate gyrus during the development of hippocampus., (Copyright © 2024 IBRO. Published by Elsevier Inc. All rights reserved.)

Cell migration through complex 3D environments relies on the interplay between actin and microtubules. A new study shows that, when cells pass through narrow constrictions, CLASP-dependent microtubule stabilisation at the cell rear controls actomyosin contractility to enable nuclear translocation and preserve cell integrity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Organoids have emerged as valuable tools for the study of development and disease. Assembloids are formed by integrating multiple organoid types to create more complex models. However, the process by which organoids integrate to form assembloids remains unclear and may play an important role in the resulting organoid structure. Here, a microfluidic platform is developed that allows separate culture of distinct organoid types and provides the capacity to partially control the geometry of the resulting organoid surfaces. Removal of a microfabricated barrier then allows the shaped and positioned organoids to interact and form an assembloid. When midbrain and unguided brain organoids were allowed to assemble with a defined spacing between them, axonal projections from midbrain organoids and cell migration out of unguided organoids were observed and quantitatively measured as the two types of organoids fused together. Axonal projection directions were statistically biased toward other midbrain organoids, and unguided organoid surface geometry was found to affect cell invasion. This platform provides a tool to observe cellular interactions between organoid surfaces that are spaced apart in a controlled manner, and may ultimately have value in exploring neuronal migration, axon targeting, and assembloid formation mechanisms., (© 2024 The Author(s). Biotechnology Journal published by Wiley‐VCH GmbH.)

Collective cell migration is a model for nonequilibrium biological dynamics, which is important for morphogenesis, pattern formation, and cancer metastasis. The current understanding of cellular collective dynamics is based primarily on cells moving within a 2D epithelial monolayer. However, solid tumors often invade surrounding tissues in the form of a stream-like 3D structure, and how biophysical cues are integrated at the cellular level to give rise to this collective streaming remains unclear. Here, it is shown that cell cycle-mediated bioenergetics drive a forward advective flow of cells and energy to the front to support 3D collective invasion. The cell division cycle mediates a corresponding energy cycle such that cellular adenosine triphosphate (ATP) energy peaks just before division. A reaction-advection-diffusion (RAD) type model coupled with experimental measurements further indicates that most cells enter an active division cycle at rear positions during 3D streaming. Once the cells progress to a later stage toward division, the high intracellular energy allows them to preferentially stream toward the tip and become leader cells. This energy-driven cellular flow may be a fundamental characteristic of 3D collective dynamics based on thermodynamic principles important for not only cancer invasion but also tissue morphogenesis., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

3D hydrogel-based cell cultures provide models for studying cell behavior and can efficiently replicate the physiologic environment. Hydrogels can be tailored to mimic mechanical and biochemical properties of specific tissues and allow to produce gel-in-gel models. In this system, microspheres encapsulating cells are embedded in an outer hydrogel matrix, where cells are able to migrate. To enhance the efficiency of such studies, a lab-on-a-chip named 3D cell migration-chip (3DCM-chip) is designed, which offers substantial advantages over traditional methods. 3DCM-chip facilitates the analysis of biochemical and physical stimuli effects on cell migration/invasion in different cell types, including stem, normal, and tumor cells. 3DCM-chip provides a smart platform for developing more complex cell co-cultures systems. Herein the impact of human fibroblasts on MDA-MB 231 breast cancer cells' invasiveness is investigated. Moreover, how the presence of different cellular lines, including mesenchymal stem cells, normal human dermal fibroblasts, and human umbilical vein endothelial cells, affects the invasive behavior of cancer cells is investigated using 3DCM-chip. Therefore, predictive tumoroid models with a more complex network of interactions between cells and microenvironment are here produced. 3DCM-chip moves closer to the creation of in vitro systems that can potentially replicate key aspects of the physiological tumor microenvironment., (© 2024 Wiley‐VCH GmbH.)

Mutations of PAK3, a p21-activated kinase, are associated in humans with cognitive deficits suggestive of defective cortical circuits and with frequent brain structural abnormalities. Most human variants no longer exhibit kinase activity. Since GABAergic interneurons express PAK3 as they migrate within the cortex, we here examined the role of PAK3 kinase activity in the regulation of cortical interneuron migration. During the embryonic development, cortical interneurons migrate a long distance tangentially and then re-orient radially to settle in the cortical plate, where they contribute to cortical circuits. We showed that interneurons expressing a constitutively kinase active PAK3 variant (PAK3-ca) extended shorter leading processes and exhibited unstable polarity. In the upper cortical layers, they entered the cortical plate and extended radially oriented processes. In the deep cortical layers, they exhibited erratic non-processive migration movements and accumulated in the deep pathway. Pharmacological inhibition of PAK3 kinase inhibited the radial migration switch of interneurons to the cortical plate and reduced their accumulation in the deep cortical layers. Interneurons expressing a kinase dead PAK3 variant (PAK3-kd) developed branched leading processes, maintained the same polarity during migration and exhibited processive and tangentially oriented movements in the cortex. These results reveal that PAK3 kinase activity, by promoting leading process shortening and cell polarity changes, inhibits the tangential processive migration of interneurons and favors their radial re- orientation and targeting to the cortical plate. They suggest that patients expressing PAK3 variants with impaired kinase activity likely present alterations in the cortical targeting of their GABAergic interneurons., (© 2024. The Author(s).)

Tendon injuries typically display limited reparative capacity, often resulting in suboptimal outcomes and an elevated risk of recurrence or rupture. While cytokines of the IL-6 family are primarily recognised for their inflammatory properties, they also have multifaceted roles in tissue regeneration and repair. Despite this, studies examining the association between IL-6 family cytokines and tendon repair remained scarce. gp130, a type of glycoprotein, functions as a co-receptor for all cytokines in the IL-6 family. Its role is to assist in the transmission of signals following the binding of ligands to receptors. RCGD423 is a gp130 modulator. Phosphorylation of residue Y759 of gp130 recruits SHP2 and SOCS3 and inhibits activation of the STAT3 pathway. In our study, RCGD423 stimulated the formation of homologous dimers of gp130 and the phosphorylation of Y759 residues without the involvement of IL-6 and IL-6R. Subsequently, the phosphorylated residues recruited SHP2, activating the downstream ERK and AKT pathways. These mechanisms ultimately promoted the migration ability of tenocytes and matrix synthesis, especially collagen I. Moreover, RCGD423 also demonstrated significant improvements in collagen content, alignment of collagen fibres, and biological and biomechanical function in a rat Achilles tendon injury model. In summary, we demonstrated a promising gp130 modulator (RCGD423) that could potentially enhance tendon injury repair by redirecting downstream signalling of IL-6, suggesting its potential therapeutic application for tendon injuries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Migratory cells are polarized with protrusive fronts and contractile rears. This spatial organization necessitates long-range coordination of the signals that organize protrusions and contractions. Cells leverage reciprocal interactions of short-range biochemical signals and long-range mechanical forces for this integration. The interface between the plasma membrane and actin cortex is where this communication occurs. Here, we review how the membrane and cortex form an integrated system for long-range coordination of cell polarity. We highlight the role of membrane-to-cortex-attachment proteins as regulators of tension transmission across the cell and discuss the interplay between actin-membrane and polarity signaling complexes. Rather than presenting an exhaustive list of recent findings, we focus on important gaps in our current understanding., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Brain microphysiological systems (bMPS) recapitulate human brain cellular architecture and functionality more closely than traditional monolayer cultures and have become increasingly relevant for the study of neurological function in health and disease. Existing 3D brain models vary in reflecting the relative populations of different cell types present in the human brain. Most models consist mainly of neurons, while glial cells represent a smaller portion of the cell populations. Here, by means of a chemically defined glial-enriched medium (GEM), an improved method to expand the population of astrocytes and oligodendrocytes without compromising neuronal differentiation in bMPS, is presented. An important finding is that astrocytes also change in morphology when cultured in GEM, more closely recapitulating primary culture astrocytes. GEM bMPS are electro-chemically active and show different patterns of calcium staining and flux. Synaptic vesicles and terminals observed by electron microscopy are also present. No significant changes in neuronal differentiation are observed by gene expression, however, GEM enhanced neurite outgrowth and cell migration, and differentially modulated neuronal maturation in two different cell lines. These results have the potential to significantly improve functionality of bMPS for the study of neurological diseases and drug discovery, contributing to the unmet need for safe human models., (© 2023 The Authors. Advanced Biology published by Wiley‐VCH GmbH.)