Jianping Fu

This study proposes a novel synergistic design strategy to enhance the oxidation resistance of FeNiCuAl-based high-entropy alloys by integrating multi-element alloying (Cr-Co-Mn), trace Y modification, and laser-cladding-induced nanocrystallization. While the Base Alloy exhibited a mass gain of approximately 15 mg/cm2 after oxidation at 900 °C for 120 h, the addition of Cr2.5Co2.5Mn2.5 promoted the formation of a multilayered oxide scale (outer MnCr2O4/inner Al2O3), reducing the parabolic oxidation rate constant to 1.7 × 10−5 mg2·cm−4·s−1. The originality of this work lies in the coupling of compositional and microstructural engineering; further addition of 0.5 at.% Y decreased this constant to 1.7 × 10−6 mg2·cm−4·s−1—a three-order-of-magnitude reduction relative to the Base Alloy, while increasing the apparent oxidation activation energy to ~350 kJ/mol. After 100 thermal cycles at 1000 °C, the designed alloy showed a mass change of only 0.05 ± 0.02 mg/cm2, with its critical load and interfacial fracture energy reaching 78 N and 14.8 J/m2, respectively. Furthermore, the alloy retained a hardness of 310 HV, an elastic modulus of 135 GPa, and a tensile strength of 240 MPa at elevated temperature. These results demonstrate that the synergistic integration of chemical and structural optimization provides a new paradigm for designing low-cost, high-performance FeNiCuAl-based protective coatings.

Titanium (Ti) and its nanoparticles are widely used in 3D printing due to a high corrosion resistance, biocompatibility, and lightweight potential. However, the atomic-scale mechanism of sintering densification and phase transition remains unclear, which limits the performance regulation of additively manufactured Ti components. In this work, molecular dynamics simulations were performed to study the sintering and phase-transition behavior of multi-sized Ti nanoparticles under 3D printing conditions. The melting point of 2 nm Ti nanoparticles decreases to about 1000 K, while that of 12 nm particles approaches the bulk value of 1941 K. Two distinct stages were observed during surface-energy-induced phase transition: initial lattice reconstruction at 800–1100 K, followed by complete melting above 1500 K. Smaller nanoparticles exhibited stronger pre-melting and faster atomic diffusion, which effectively filled interparticle pores and reduced the porosity. Increasing particle contact points shortens atomic diffusion paths, accelerates densification, and alleviates stress concentration. This study reveals the size-dependent sintering mechanism of Ti nanoparticles at the atomic level, providing theoretical guidance for the process optimization, microstructure control, and performance improvement of aerospace and biomedical titanium components fabricated by additive manufacturing.

Introduction As a treasured wild plant resource in the Tian shan Mountains, the genetics and evolutionary relationships of Xinjiang wild walnuts ( Juglans regia L.) are of great interest for both walnut conservation and crop improvement. Methods In this study, a total of 200 walnut accessions, including a core germplasm collection of wild walnuts from Xinjiang and local walnut landraces and cultivars, were selected for whole-genome resequencing, with the final dataset supplemented with 24 other publicly available genomic datasets for other walnut taxa. Results Across all samples, there was evidence of four ancestral genetic populations, with three of these represented in the samples from Xinjiang. The Xinjiang wild walnuts form an independent evolutionary clade with low genetic diversity, which was further differentiated into six subgroups, and showed significant genetic differentiation from the cultivated accession. The walnut cultivars and landraces showed mixed ancestry, being assigned to two ancestral populations not represented in the wild walnuts. The Gongliu Wild Walnut Valley served as one of the refugia during the Last Glacial Maximum (LGM) for Tertiary relict species. The unique topography of the Ili River Valley in Xinjiang, along with the relatively isolated geographical location of the Walnut Valley, may have collectively facilitated the formation of a relatively isolated “genetic island” pattern in the Xinjiang wild walnuts. Selective sweep analysis identified 20 genes under selection, including CYP450 genes closely associated with disease resistance and NF-YB3 genes involved in cold stress and other adaptive responses. Discussion A new framework is needed to reconceptualize the genetic relationships of Xinjiang wild walnuts with other germplasms, clarifying their continuous role throughout the evolutionary continuum from glacial refugium to domestication and modern breeding.

Polysubstituted cyclopropanes are valuable in complex molecule synthesis but challenging to access due to low atom economy and harsh conditions. Herein, we report a copper-mediated, peroxide-initiated cyclopropanation of activated alkenes with active methylene compounds via a radical pathway. This diazo-free, prefunctionalization-free method, integrated with continuous flow, enhances safety, scalability, and efficiency. Operable under mild conditions with broad substrate scope, it offers a practical and atom-economical route to diverse polysubstituted cyclopropanes.

Flow-based Generative Models (FGMs) effectively transform noise into complex data distributions. Incorporating Optimal Transport (OT) to couple noise and data during FGM training has been shown to improve the straightness of flow trajectories, enabling more effective inference. However, existing OT-based methods estimate the OT plan using (mini-)batches of sampled noise and data points, which limits their scalability to large and high-dimensional datasets in FGMs. This paper introduces AlignFlow, a novel approach that leverages Semi-Discrete Optimal Transport (SDOT) to enhance the training of FGMs by establishing an explicit, optimal alignment between noise distribution and data points with guaranteed convergence. SDOT computes a transport map by partitioning the noise space into Laguerre cells, each mapped to a corresponding data point. During FGM training, i.i.d. noise samples are paired with data points via the SDOT map. AlignFlow scales well to large datasets and model architectures with negligible computational overhead. Experimental results show that AlignFlow improves the performance of a wide range of state-of-the-art FGM algorithms and can be integrated as a plug-and-play component. Code is available at: https://github.com/konglk1203/AlignFlow.

Focal adhesions (FAs) are dynamic structures central to cell migration, serving as mechanotransduction sites linking the extracellular matrix (ECM) to intracellular signaling pathways such as FA kinase (FAK). How FAK becomes activated in response to cell-ECM adhesive forces at single FAs to facilitate directional motion is poorly understood. Using micropillar-based force microscopy and FA-targeted FRET biosensors, we monitored real-time traction forces and FAK activity at individual FAs during assembly and disassembly. Our results demonstrate oscillatory temporal coupling of traction force and FAK activity in high-tension FAs before FA disassembly. Cross-correlation analyses revealed that force precedes FAK activation, guiding FA turnover. Atomistic molecular simulations unveiled a force-induced mechanism where traction forces disrupt autoinhibitory FERM-kinase interactions in FAK, enabling catalytic activity without structural unfolding. Our findings provide mechanistic insights into the spatiotemporal integration of mechanical forces and biochemical signaling in cell migration.

In this study, postimplantation human epiblast and amnion development are modeled using a stem cell-based embryoid system. A dataset of 3697 fluorescent images, along with tissue, cavity, and cell masks, is generated from experimental data. A computational pipeline analyzes morphological and marker expression features, revealing key developmental processes such as tissue growth, cavity expansion, and cell differentiation. To uncover hidden developmental dynamics, a deep manifold learning framework is introduced. This framework uses an autoencoder to project embryoid images into a twenty-dimensional (20D) latent space and models the dynamics using a mean-reverting stochastic process of mixed Gaussians. The approach accurately captures phenotypic changes observed at discrete experimental time points. Moreover, it enables the generation of artificial yet realistic embryoid images at finer temporal resolutions, providing deeper insights into the progression of early human development.

The medial ganglionic eminence (MGE) gives rise to parvalbumin (PV)- and somatostatin (SST)-expressing cortical interneurons essential for regulating cortical excitability. Although PV interneurons are linked to various neurodevelopmental and neurodegenerative disorders, reliably generating them from human pluripotent stem cells (hPSCs) has been extremely challenging. We present a robust, reproducible protocol for generating single-rosette MGE organoids (MGEOs) from hPSCs. Transcriptomic analyses reveal that MGEOs exhibit MGE regional identity and faithfully model the developing human fetal MGE. As MGEOs mature, they generate abundant PV-expressing cortical interneurons, including putative basket and axoaxonic cells, at a scale not previously achieved in vitro. When fused with human cortical organoids (hCOs), these interneurons rapidly migrate into the hCOs, integrate into excitatory networks, and contribute to complex electrophysiological patterns and the emergence of large numbers of fast-spiking neurons. Using this model, we uncover a previously unreported migration deficit of MGE interneurons in a disease model of SLC6A1 developmental and epileptic encephalopathy, offering potential insights into the developmental contributions to epileptogenesis. MGEOs thus offer a powerful in vitro approach for probing human MGE-lineage cortical and subcortical GABAergic neuron development, modeling various neuropsychiatric disorders, and advancing cell-based therapies for neurodevelopmental and neurodegenerative disorders.

Studies of fate patterning during development typically emphasize cell-cell communication via diffusible chemical signals. Recent experiments on stem cell colonies, however, suggest that in some cases mechanical stresses, rather than secreted chemicals, enable long-ranged cell-cell interactions that specify positional information and pattern cell fates. These findings inspire a model of mechanical patterning: fate affects cell contractility, and pressure in the cell layer biases fate. Cells at the colony edge, more contractile than cells at the center, seed a pattern that propagates via force transmission. Strikingly, our model implies that the width of the outer fate domain varies nonmonotonically with substrate stiffness, a prediction that we confirm experimentally; we argue that a similar dependence on substrate stiffness can be achieved by a chemical morphogen only if strong constraints on the signaling pathway's mechanobiology are met. Our findings thus support the idea that mechanical stress can mediate patterning in the complete absence of chemical morphogens, even in nonmotile cell layers, thus expanding the repertoire of possible roles for mechanical signals in development and morphogenesis. Future tests of additional model predictions, like the effect of anisotropic substrate rigidity, will further broaden the range of achievable fate patterns.

Symmetry breaking and tissue patterning are fundamental processes in mammalian development. Understanding these events is essential not only for advancing mammalian developmental biology but also for the ongoing efforts to create in vitro models of mammalian embryogenesis and organogenesis using stem cells. This review highlights recent bioengineering innovations designed to control exogenous and endogenous gradients of soluble biochemical signals and insoluble biophysical cues, effectively guiding cell differentiation and spatial organization in embryo and organ modeling. Specifically, we discuss microfluidics- and micropatterning-based multicellular culture systems, as well as approaches that use porous beads loaded with soluble factors and engineered cells as synthetic signaling centers to replicate dynamic in vivo signaling. We evaluate the effectiveness and limitations of each technique in influencing cell fate decisions, morphogenesis, and patterning, and explore their applications in modeling mammalian development. Finally, we outline emerging approaches that leverage bioengineered tools to construct mammalian embryo and organ models for both basic research and translational applications.

Neural organoids have been utilized to recapitulate different aspects of the developing nervous system. While hailed as promising experimental tools for studying human neural development and neuropathology, current neural organoids do not fully recapitulate the anatomy nor microcircuitry level functionality of the developing brain, spinal cord or the peripheral nervous system. In this article, we discuss emerging bioengineering approaches that control morphogen signals and biophysical microenvironments, which have improved the efficiency, fidelity and utility of neural organoids. Furthermore, advancements in bioengineered tools have facilitated more sophisticated analyses of neural organoid functions and applications, including improved neural-bioelectronic interfaces and organoid-based information processing. Emerging bioethical issues associated with advanced neural organoids are also discussed. Future opportunities of neural organoid research lie in enhancing their fidelity, maturity and complexity and expanding their applications in a scalable manner.

This study takes the intangible cultural heritage tourism of the Macao Special Administrative Region as the research object. Through literature integration and analysis combined with comparative research methods, it investigates the cultural and tourism development paths of intangible cultural heritage resources of performance, skills, and festivals in the Macao region. The research suggests that there are still some contradictions in the cultural and tourism development model of the Macao region. The technological empowerment is insufficient, the in-depth exploration of culture is inadequate, and there is a mutual dissolution between the improvement of participation and commercialization. Therefore, in the future, the Macao region should enhance the integrated development of cultural and tourism products, strengthen the independent design of intangible cultural heritage tourism products, and increase the extension of cultural value and the nesting of economic benefits. It is necessary to innovatively incorporate intangible cultural heritage inheritors into the product design chain, create city IPs, develop the night economy, and reflect the urban characteristics of cultural and tourism products. This research is helpful in providing certain references for cultural tourism in high-density cities.

In the version of this article initially published, the surname of Ras Trokovic was misspelled (as Torokovic). In Extended Data Fig. 10c, the “+” entry in the DE row under “Karvas et al.” appeared as a minus sign. The corrections have been made in the HTML and PDF versions of the article.

The establishment of modern biliary surgery system, alongside pivotal scientific paradigm shifts, has heralded a new era featured by precision, personalization, life-cycle care, and multidisciplinary management in the treatment of both benign and malignant biliary diseases. However, two formidable challenges persist in haunting the treatment of biliary diseases: (1) The refinement of surgical techniques has reached a plateau in reducing the disability associated with benign biliary conditions and in improving survival outcomes in biliary tract cancers; (2) Traditional evidence-based clinical studies have shown limited power in addressing complex dilemmas, such as determining whether to excise or preserve pathological gallbladders or selecting the optimal biliary drainage strategy. Consequently, the authors propose the conceptual framework of "biliary ecosystem". In this model, diverse and abundant cholangiocytes represent forest, while blood vessels, nerves, and lymphatic vessels serve as nurturing soil, biliary stem cells function as seeds, bile flows like river network, and hepatocytes mark the river's origins. Both benign and malignant biliary diseases exhibit significant spatiotemporal dynamics. The bile ducts form the "macro" environment, bile constitutes the "sub-macro" environment, and diverse cellular niches create the microenvironment. Specific pathological biliary conditions are shaped by intricate regulatory mechanisms that operate across these three tiers. Within the biliary ecosystem, cellular subpopulations exist remarkable diversity with states of homeostasis, oscillation, perturbation, or imbalance, underpinned by complex signaling networks. This holistic approach allows us to reframe and critically examine the pressing scientific issues confronting biliary tract diseases. Based on this framework, the authors distill key scientific questions and offer preliminary recommendations for embracing the paradigm shift. The authors anticipate that this conceptual model will promote interdisciplinary integration and accelerate clinical and translational researches.

Stem cell-based embryo models offer unprecedented experimental tools for studying early human development. The usefulness of embryo models hinges on their molecular, cellular and structural fidelities to their in vivo counterparts. To authenticate human embryo models, single-cell RNA sequencing has been utilized for unbiased transcriptional profiling. However, an organized and integrated human single-cell RNA-sequencing dataset, serving as a universal reference for benchmarking human embryo models, remains unavailable. Here we developed such a reference through the integration of six published human datasets covering development from the zygote to the gastrula. Lineage annotations are contrasted and validated with available human and nonhuman primate datasets. Using stabilized Uniform Manifold Approximation and Projection, we constructed an early embryogenesis prediction tool, where query datasets can be projected on the reference and annotated with predicted cell identities. Using this reference tool, we examined published human embryo models, highlighting the risk of misannotation when relevant references are not utilized for benchmarking and authentication.

Valproic acid (VPA), a clinically approved small molecule, has been reported to activate Wnt signalling that is critical for dorsal-ventral (DV) patterning of neural tube. However, little is known about the impact of VPA on DV patterning process. Here, we show that even though VPA has a negative impact on the early formation of human neural tube organoids (hNTOs), it significantly enhances the efficiency of ventrally patterned hNTOs, when VPA is added during the entire differentiation process. RNA sequencing and RT-qPCR analysis demonstrates VPA activates endogenous Wnt signalling in hNTOs. Surprisingly, transcriptome analysis also identifies upregulation of genes for degradation of GLI2 and GLI3 proteins, whose truncated fragment are transcriptional repressors of Shh signalling. The Western-blot analysis confirms the increase of GLI3R proteins after VPA treatment. Thus, VPA might enhance ventral patterning of hNTOs through both activating Wnt, which can antagonise Shh signalling by inducing GLI3 expression, and/or inhibiting Shh signalling by inducing GLI protein degradation. We further obtain results to show that VPA still increases patterning efficiency of hNTOs with a weak influence on their early formation when the initiation time of VPA is delayed and its duration is reduced. Taken together, this study demonstrates that VPA enhances the generation of more reproducible hNTOs with ventral patterning, opening the avenues for the applications of hNTOs in developmental biology and regenerative medicine.

The ultimate outcome of the gastrulation in mammalian development is a recognizable trilaminar disc structure containing organized cell lineages with spatially defined identities in an emerging coordinate system 1–4 . Despite its importance in human development, gastrulation remains difficult to study. Stem cell-based embryo models, including those that recapitulate different aspects of pre- and peri-gastrulation human development 5–15 , are emerging as promising tools for studying human embryogenesis 16–18 . However, it remains unclear whether existing human embryo models are capable of modeling the development of the trilaminar embryonic disc structure, a hallmark of human gastrulation. Here we report a transgene-free human embryo model derived solely from primed human pluripotent stem cells (hPSCs), which recapitulates various aspects of peri-gastrulation human development, including formation of trilaminar embryonic layers situated between dorsal amnion and ventral definitive yolk sac and primary hematopoiesis. We term this model the peri-gastrulation trilaminar embryonic disc (PTED) embryoid. The development of PTED embryoid does not follow natural developmental sequences of cell lineage diversification or spatial organization. Instead, it exploits both extrinsic control of tissue boundaries and intrinsic self-organizing properties and embryonic plasticity of the diverse peri-gastrulation-stage cell lineages, leading to the emergence of in vivo -like tissue organization and function at a global scale. Our lineage tracing study reveals that in PTED embryoids, embryonic and extraembryonic mesoderm cells, as well as embryonic and extraembryonic endoderm cells, share common progenitors emerging during peri-gastrulation development. Active hematopoiesis and blood cell generation are evident in the yolk sac-like structure of PTED embryoids. Together, PTED embryoids provide a promising and ethically less challenging model for studying self-organizing properties of peri-gastrulation human development.

SUMMARY Emerging human pluripotent stem cell (hPSC)-based embryo models are useful for studying human embryogenesis. Particularly, there are hPSC-based somitogenesis models using free-floating culture that recapitulate somite formation. Somitogenesis in vivo involves intricately orchestrated bio-chemical and -mechanical events. However, none of the current somitogenesis models controls biochemical gradients or biomechanical signals in the culture, limiting their applicability to untangle complex biochemical-biomechanical interactions that drive somitogenesis. Here we report a new human somitogenesis model by confining hPSC-derived presomitic mesoderm (PSM) tissues in microfabricated trenches. Exogenous microfluidic morphogen gradients imposed on PSM cause axial patterning and trigger spontaneous rostral-to-caudal somite formation. A mechanical theory is developed to explain the size dependency between somites and PSM. The microfluidic somitogenesis model is further exploited to reveal regulatory roles of cellular and tissue biomechanics in somite formation. This study presents a useful microengineered, hPSC-based model for understanding the bio-chemical and -mechanical events that guide somite formation.

Abstract The segmentation clock, a genetic oscillator in the presomitic mesoderm (PSM), is known to be influenced by biochemical signals, yet its potential regulation by mechanical cues remains unclear. The complex PSM microenvironment has made it challenging to isolate the effects of mechanical signals on clock behavior. Here we investigated how mechanical stimuli affect clock oscillations by culturing zebrafish PSM cells on bioengineered elastic substrates (PDMS micropost arrays) with tunable rigidities ranging from 0.6 to 1,200 kPa. We observed an inverse sigmoidal relationship between substrate rigidity and the percentage of oscillating PSM cells, with a switching rigidity threshold between 3-6 kPa. The oscillation periods of oscillating PSM cells showed a consistently broad distribution across the substrate rigidity conditions tested. Moreover, these oscillatory PSM cells exhibited distinct biophysical properties, including reduced motility, contractility, and sustained circularity, compared to non-oscillating ones. These findings highlight a role of cell-substrate interactions in regulating segmentation clock behavior, providing insights into the mechanobiology of somitogenesis. Highlights Oscillatory behaviors of single PSM cells respond to substrate rigidity in a switch-like manner, transitioning from an oscillatory state to a quiescent state at a critical rigidity threshold between 2.9 kPa and 6 kPa. Increased substrate rigidity significantly suppresses the percentage of oscillating PSM cells, while oscillation period and cycle number show no consistent rigidity-dependent trend. Non-oscillating PSM cells exhibit distinct biophysical properties compared to oscillating ones, including reduced circularity, a polarized and elongated morphology, greater motility, and increased contractility. Aggregates of PSM cells exhibit similar trends in response to substrate rigidity changes, except for increased oscillation percentages across different rigidity conditions, suggesting a potential interplay between cell-cell and cell-matrix communications in influencing clock oscillation behavior.

Developing functional organs from stem cells remains a challenging goal in regenerative medicine. Existing methodologies, such as tissue engineering, bioprinting and organoids, only offer partial solutions. This Perspective focuses on two emerging approaches promising for engineering human organs from stem cells: stem cell-based embryo models and interspecies organogenesis. Both approaches exploit the premise of guiding stem cells to mimic natural development. We begin by summarizing what is known about early human development, as a blueprint for recapitulating organogenesis in both embryo models and interspecies chimeras. The latest advances in both fields are discussed, before highlighting the technological and knowledge gaps to be addressed before the goal of developing human organs could be achieved using the two approaches. We conclude by discussing challenges facing embryo modeling and interspecies organogenesis and outline future prospects for advancing both fields towards the generation of human tissues and organs for basic research and translational applications.

In this study, WC-12Co cemented carbides were prepared by laser powder bed fusion (LPBF) on a WC-20Co substrate. The effects of the scanning speed and the substrate on the microstructure, mechanical properties and wear characteristics of the WC-12Co cemented carbide were investigated. The results showed that an alternating distribution of coarse and fine WC grains is observed in the LPBF-prepared WC-12Co cemented carbides. As the laser scanning speed decreases or the laser energy density increases, the WC phase gradually decomposes, accompanied by the loss of C and the formation of ƞ phases. WC-12Co cemented carbides produced at a lower scanning speed exhibit a higher density of thermal cracks, while those produced at a higher scanning speed have a larger number of pores. As the laser scanning speed increases, the transverse rupture strength (TRS) first increases to a maximum value of 823.13 MPa and then decreases. The variation of TRS is mainly attributed to the evolution of the brittle ƞ-phase and metallurgical defects. For WC-12Co cemented carbides formed at low scanning speeds, the brittle η-phase may fracture and cut through the matrix during the friction process, leading to an increase in coefficient of friction (COF) and wear mass loss. For samples formed at high scanning speeds, the formation and detachment of the shear layer could accelerate the friction process and undermine the wear resistance of the WC-12Co cemented carbide. Therefore, the sample prepared at the scanning speed of 400 mm/s shows the best wear performance.

Focal adhesions (FAs) are nanoscale complexes containing clustered integrin receptors and intracellular structural and signaling proteins that function as principal sites of mechanotransduction in part via promoting the nuclear translocation and activation of the transcriptional coactivator yes-associated protein (YAP). Knockdown of FA proteins such as focal adhesion kinase (FAK), talin, and vinculin can prevent YAP nuclear localization. However, the mechanism(s) of action remain poorly understood. Herein, we investigated the role of different functional domains in vinculin, talin, and FAK in regulating YAP nuclear localization. Using genetic or pharmacological inhibition of fibroblasts and human mesenchymal stem cells (hMSCs) adhering to deformable substrates, we find that disruption of vinculin-talin binding versus talin-FAK binding reduces YAP nuclear localization and transcriptional activity via different mechanisms. Disruption of vinculin-talin binding or knockdown of talin-1 reduces nuclear size, traction forces, and YAP nuclear localization. In contrast, disruption of the talin binding site on FAK or elimination of FAK catalytic activity did not alter nuclear size yet still prevented YAP nuclear localization and activity. These data support both nuclear tension-dependent and independent models for matrix stiffness-regulated YAP nuclear localization. Our results highlight the importance of vinculin-talin-FAK interactions at FAs of adherent cells, controlling YAP nuclear localization and activity.

In this study, we developed a novel type of dibenzocyclooctyne (DBCO)-functionalized microbubbles (MBs) and validated their attachment to azide-labelled sialoglycans on human pluripotent stem cells (hPSCs) generated by metabolic glycoengineering (MGE). This enabled the application of mechanical forces to sialoglycans on hPSCs through molecularly specific acoustic tweezing cytometry (mATC), that is, displacing sialoglycan-anchored MBs using ultrasound (US). It was shown that subjected to the acoustic radiation forces of US pulses, sialoglycan-anchored MBs exhibited significantly larger displacements and faster, more complete recovery after each pulse than integrin-anchored MBs, indicating that sialoglycans are more stretchable and elastic than integrins on hPSCs in response to mechanical force. Furthermore, stimulating sialoglycans on hPSCs using mATC reduced stage-specific embryonic antigen-3 (SSEA-3) and GD3 expression but not OCT4 and SOX2 nuclear localization. Conversely, stimulating integrins decreased OCT4 nuclear localization but not SSEA-3 and GD3 expression, suggesting that mechanically stimulating sialoglycans and integrins initiated distinctive mechanoresponses during the early stages of hPSC differentiation. Taken together, these results demonstrated that MGE-enabled mATC uncovered not only different mechanical properties of sialoglycans on hPSCs and integrins but also their different mechanoregulatory impacts on hPSC differentiation, validating MGE-based mATC as a new, powerful tool for investigating the roles of glycans and other cell surface biomolecules in mechanotransduction.

Abstract In this study, we developed a novel type of dibenzocyclooctyne (DBCO)‐functionalized microbubbles (MBs) and validated their attachment to azide‐labelled sialoglycans on human pluripotent stem cells (hPSCs) generated by metabolic glycoengineering (MGE). This enabled the application of mechanical forces to sialoglycans on hPSCs through molecularly specific acoustic tweezing cytometry (mATC), that is, displacing sialoglycan‐anchored MBs using ultrasound (US). It was shown that subjected to the acoustic radiation forces of US pulses, sialoglycan‐anchored MBs exhibited significantly larger displacements and faster, more complete recovery after each pulse than integrin‐anchored MBs, indicating that sialoglycans are more stretchable and elastic than integrins on hPSCs in response to mechanical force. Furthermore, stimulating sialoglycans on hPSCs using mATC reduced stage‐specific embryonic antigen‐3 (SSEA‐3) and GD3 expression but not OCT4 and SOX2 nuclear localization. Conversely, stimulating integrins decreased OCT4 nuclear localization but not SSEA‐3 and GD3 expression, suggesting that mechanically stimulating sialoglycans and integrins initiated distinctive mechanoresponses during the early stages of hPSC differentiation. Taken together, these results demonstrated that MGE‐enabled mATC uncovered not only different mechanical properties of sialoglycans on hPSCs and integrins but also their different mechanoregulatory impacts on hPSC differentiation, validating MGE‐based mATC as a new, powerful tool for investigating the roles of glycans and other cell surface biomolecules in mechanotransduction.

The human nervous system is a highly complex but organized organ. The foundation of its complexity and organization is laid down during regional patterning of the neural tube, the embryonic precursor to the human nervous system. Historically, studies of neural tube patterning have relied on animal models to uncover underlying principles. Recently, models of neurodevelopment based on human pluripotent stem cells, including neural organoids1, 2, 3, 4–5 and bioengineered neural tube development models6, 7, 8, 9–10, have emerged. However, such models fail to recapitulate neural patterning along both rostral–caudal and dorsal–ventral axes in a three-dimensional tubular geometry, a hallmark of neural tube development. Here we report a human pluripotent stem cell-based, microfluidic neural tube-like structure, the development of which recapitulates several crucial aspects of neural patterning in brain and spinal cord regions and along rostral–caudal and dorsal–ventral axes. This structure was utilized for studying neuronal lineage development, which revealed pre-patterning of axial identities of neural crest progenitors and functional roles of neuromesodermal progenitors and the caudal gene CDX2 in spinal cord and trunk neural crest development. We further developed dorsal–ventral patterned microfluidic forebrain-like structures with spatially segregated dorsal and ventral regions and layered apicobasal cellular organizations that mimic development of the human forebrain pallium and subpallium, respectively. Together, these microfluidics-based neurodevelopment models provide three-dimensional lumenal tissue architectures with in vivo-like spatiotemporal cell differentiation and organization, which will facilitate the study of human neurodevelopment and disease. Newly developed microfluidic neural tube-like and forebrain-like structures based on human pluripotent stem cells can model pivotal aspects of neural patterning along both the rostral–caudal and dorsal–ventral axes.

Many amniote vertebrate species including humans can form identical twins from a single embryo, but this only occurs rarely. It has been suggested that the primitive-streak-forming embryonic region emits signals that inhibit streak formation elsewhere but the signals involved, how they are transmitted and how they act has not been elucidated. Here we show that short tracks of calcium firing activity propagate through extraembryonic tissue via gap junctions and prevent ectopic primitive streak formation in chick embryos. Cross-regulation of calcium activity and an inhibitor of primitive streak formation (Bone Morphogenetic Protein, BMP) via NF-κB and NFAT establishes a long-range BMP gradient spanning the embryo. This mechanism explains how embryos of widely different sizes can maintain positional information that determines embryo polarity. We provide evidence for similar mechanisms in two different human embryo models and in Drosophila, suggesting an ancient evolutionary origin.

Primordial germ cells (PGCs) are the embryonic precursors of sperm and eggs. They transmit genetic and epigenetic information across generations. Given the prominent role of germline defects in diseases such as infertility, detailed understanding of human PGC (hPGC) development has important implications in reproductive medicine and studying human evolution. Yet, hPGC specification remains an elusive process. Here, we report the induction of hPGC-like cells (hPGCLCs) in a bioengineered human pluripotent stem cell (hPSC) culture that mimics peri-implantation human development. In this culture, amniotic ectoderm-like cells (AMLCs), derived from hPSCs, induce hPGCLC specification from hPSCs through paracrine signaling downstream of ISL1. Our data further show functional roles of NODAL, WNT, and BMP signaling in hPGCLC induction. hPGCLCs are successfully derived from eight non-obstructive azoospermia (NOA) participant-derived hPSC lines using this biomimetic platform, demonstrating its promise for screening applications.

INTRODUCTION: The present study explored the effects and possible mechanisms of ZDHHC16 in a model of cerebral apoplexy (CA). MATERIAL AND METHODS: Patients with CA were collected from our hospital. Mice were used to establish an middle cerebral artery occlusion (MCAO) model. RESULTS: ZDHHC16 levels in patients with CA were up-regulated. ZDHHC16 up-regulation promoted inflammation and accelerated mitochondrial damage in the in vitro model. ZDHHC16 gene up-regulation promoted ferroptosis of neurocytes. The inhibition of ZDHHC16 prevented cerebral apoplexy in the mouse model. ZDHHC16 up-regulation suppressed CREB through interlinkage of CREB by promoting CREB ubiquitination. CREB agonists inhibited the effects of ZDHHC16 up-regulation in the in vitro model. CREB inhibitor inhibited the effects of ZDHHC16 down-regulation in the in vitro model. CONCLUSIONS: We conclude that ZDHHC16 promoted ferroptosis and inflammation in a model of CA through the suppression of CREB. The findings might be of benefit in the treatment of CA or other nervous system diseases.