Biology subjects

Wagner, D. E.

Publications and source records attributed to Wagner, D. E..

At least 19 recordsLinked to original sources

bioRxiv2026

Spatially restricted bmp16 in an extra-embryonic syncytium promotes dorsoventral patterning

How nuclei within a shared cytoplasm organize gene expression programs to direct developmental signaling remains incompletely understood. Here, we combine single-nucleus RNA sequencing, spatial transcriptomic mapping, and functional perturbations to characterize the zebrafish yolk syncytial layer (YSL), an extra-embryonic syncytium that supports embryonic development and patterning. We identify extensive transcriptional covariation among YSL nuclei, revealing coordinated multigene programs organized along dorsoventral and animal-vegetal axes. Within the YSL, we identify an animal-ventral subdomain expressing several BMP ligand transcripts including bmp16, a member of the BMP2/4 subfamily. We found bmp16 expression to be exclusively extra-embryonic during gastrulation, and functional perturbations reveal that bmp16 is sufficient to ventralize embryos upon overexpression and acts synergistically with bmp2b to promote ventral fates. Ventral YSL expression of Bmp transcripts depends on a transcriptional program downstream of mxtx2 and is maintained independently of BMP pathway autoregulation, while negative regulation by hhex restricts bmp16 expression to the ventral YSL. Together, these findings establish the YSL as a spatially organized syncytium in which coordinated nuclear gene expression programs support localized sources of embryonic patterning signals.

developmental biology↗

bioRxiv2026

Dynamic polyadenylation safeguards developmental trajectories during paused embryogenesis

Embryonic pausing, including forms of diapause, enables development to be reversibly suspended during adverse conditions, but how paused embryos preserve cell fate patterning remains unclear. Using zebrafish, we show that developmental pausing results in the temporary collapse of Wnt, BMP, FGF, and Nodal signaling gradients, despite broad preservation of cell identity at the transcriptional level. In parallel, pausing induces a dormancy-enriched gene expression program (DEEP), which includes the non-canonical poly(A) polymerase tent5ba. Tent5ba promotes survival through pausing, sustains DEEP expression, and is required for robust reestablishment of axial patterning upon developmental re-entry. Poly(A)-tail and transcriptional profiling further link tent5ba to the stabilization of mRNA targets associated with robust developmental outcomes, supporting a model in which transcript polyadenylation safeguards patterning fidelity through suspended embryogenesis.

developmental biology↗

bioRxiv2026

BMP signaling during gastrulation pre-patterns the dorsal spinal cord

The classic model of dorsal spinal cord patterning proposes that roofplate-derived BMP patterns dorsal interneuron subtypes in a concentration-dependent manner. However, genetic perturbations of BMP pathway components produce variable effects, challenging this model. Here we implemented single-cell profiling, fate mapping, and mosaic perturbations to determine when BMP signaling patterns dorsal neural fates in vivo. Contrary to the classic model, we demonstrate that dorsal fates are patterned by BMP signaling during gastrulation. Following neural tube formation, BMP signaling continues but plays limited roles in domain specification and maturation. Fate mapping revealed that dorsal progenitors originate from the ventral gastrula, adopting BMP-dependent transcriptional states that prime dorsal neural fate. We propose that dorsal neural fates are initially patterned by gastrulation-stage sources of BMP, prior to roofplate induction.

developmental biology↗

bioRxiv2026

Intracellular pH dynamics promotes zebrafish larval tail regeneration

Intracellular pH (pHi) dynamics regulates numerous cell behaviors, including migration and proliferation. While these functions are well-established in cell lines, the role of pHi changes in vivo is less well understood. We generated a transgenic zebrafish line expressing a fluorescent ratiometric pHi biosensor and identified functional changes in pHi during zebrafish larval tail regeneration. We found that tail amputation led to a transient decrease in pHi, followed by a prolonged increase in pHi above pre-amputation values. Moreover, we showed that pharmacologically inhibiting Na+/H+ exchanger (NHE) activity or decreasing extracellular pH attenuated the post-amputation increase in pHi, reduced subsequent cell proliferation, and impaired tail regeneration. We further found that inhibiting NHE activity post-amputation led to elevated inflammation, disrupted myeloid cell behavior, decreased reactive oxygen species, and increased glycogen synthase kinase-3 (GSK3) activity. Finally, we showed that the regeneration defects in larvae with disrupted pHi were partially rescued by the GSK3 inhibitor BIO. Our data reveal a previously unrecognized role for pHi dynamics in coordinating tissue behaviors in vivo and enabling zebrafish larval tail regeneration.

developmental biology↗

bioRxiv2026

ZMAP: A single-cell meta-atlas of zebrafish embryonic development reveals a consensus hierarchy of cell identities

Single-cell RNA sequencing (scRNA-seq) efforts have generated large collections of high-resolution cellular atlases of embryonic development, providing unprecedented views of the dynamic gene expression programs that accompany cell fate specification. Alongside parallel efforts in other models, zebrafish has emerged as one of the most extensively profiled vertebrate embryonic systems, with numerous scRNA-seq atlases spanning both embryonic and early larval stages. Despite this progress, cross-study comparisons between datasets remain challenging due to differences in sample processing, mapping, and annotation conventions. Here we present ZMAP (Zebrafish Meta Atlas Project), a harmonized reference integrating 8 published whole-embryo zebrafish scRNA-seq datasets comprising 798,790 cells across 15 developmental time windows. ZMAP unifies component studies through a shared embedding, a standardized marker-gene discovery pipeline, and a hierarchical annotation ontology. Using ZMAP, we inferred "consensus identity programs" - marker gene signatures for each ontology group that were reproducibly detected across studies. To promote broad usage, we provide a Python-based API for automated annotation and retrieval of marker gene sets and reference objects, as well as a web portal that supports interactive 2D and 3D exploration of the UMAP embedding, gene and annotation-level queries, and access to consensus marker resources.

developmental biology↗

bioRxiv2025

Two parallel lineage-committed progenitors contribute to the developing brain

The hindbrain is a life-sustaining brain region. In one model, a common neural progenitor generates all brain regions. Here our studies of mouse embryos and human pluripotent stem cells (hPSCs) support a different model: two parallel brain progenitors emerge simultaneously during gastrulation, anterior neural ectoderm (forebrain/midbrain progenitor) and posterior neural ectoderm (hindbrain progenitor). Not only are they lineage-committed to respectively form forebrain/midbrain vs. hindbrain in vitro, but they also have diverging chromatin landscapes foreshadowing future forebrain/midbrain vs. hindbrain identities. Leveraging these differences, we differentiated hPSCs into hindbrain rhombomere 5/6-specific motor neurons, hitherto difficult to generate in vitro. We postulate the brain is a composite organ emanating from two lineage-restricted progenitors; these dual progenitors may be evolutionarily conserved across 550 million years from hemichordates to mammals.

developmental biology↗

bioRxiv2025

Transcriptional Roadmap of the Human Airway Epithelium Identifying HLF as a Novel Regulator of Basal Stem Cell Function

RationaleThe human airway epithelium depends on a coordinated hierarchy of stem-and differentiated cells to maintain tissue integrity and respond to injury. Defining the transcriptional and translational programs that govern these processes is critical for understanding airway disease and advancing regenerative therapies. ObjectivesTo map the transcriptional landscape of the human airway epithelium and identify regulatory factors controlling basal stem cell function and epithelial differentiation. MethodsWe performed single-cell RNA sequencing on bronchial biopsies from nine healthy never-smokers, categorized into young (<40 years) and aged (>60 years) cohorts. Unbiased cell type annotation and pseudotime trajectory analysis were used to define cell states and transcription factor dynamics. Measurements and Main ResultsAll major airway epithelial cell types were identified, with conserved composition and transcriptional programs across age groups. Basal stem cells (BSCs) exhibited elevated ribosomal gene expression, indicating increased translational readiness. Pseudotime analysis revealed transitions from basal to differentiated states, with MYC, JUN, and FOS upregulated in proliferative suprabasal cells. HLF emerged as a BSC-enriched transcription factor downregulated upon differentiation. Functional assays showed that HLF overexpression suppresses proliferation in airway BSC and in lung squamous carcinoma cells, while Hlf-deficient mice display basal cell hyperplasia and deficient differentiation. In lung cancer datasets, low HLF expression correlated with worse patient survival. ConclusionsThis study defines conserved gene programs in the human airway epithelium and identifies HLF as a novel regulator of BSC proliferation and potential tumor suppressor. These findings may inform the development of regenerative therapies and contribute to improved understanding and treatment of lung disease.

molecular biology↗

bioRxiv2025

Neural plate pre-patterning enables specification of intermediate neural progenitors in the spinal cord

Spinal cord organization begins with the specification of a series of neural progenitor domains along the dorsal-ventral axis of the neural tube. Patterning at the dorsal and ventral ends is established by canonical morphogen gradients. Intermediate progenitor domains are located distally to morphogen sources yet display similar organization. How this is achieved is unclear and the relevant positional cues have not been identified. Here we show that intermediate progenitor domains are established through a distinct mechanism that operates in the preceding neural plate stage and leverages its multiple signaling inputs and morphogenesis. An integrated spatial atlas of transcription factor expression, signaling activity, and cell movement reveals that the neural plate comprises an array of cell states, defined by combinatorial signaling and morphogenesis-driven transitions between local signaling environments. Specifically, we find that p0 and p1 intermediate progenitors, located immediately outside the morphogen-patterned region, arise from specific precursor states that are established in the posterior neural plate by tailbud-derived Wnt signaling. Convergent-extension movements subsequently drive progenitor specification by displacing precursors out of Wnt/FGF signaling fields while shaping them into stripe-like domains. Thus, by controlling signaling exposure, tissue dynamics convert positional information encoded by signaling history into downstream fate specification. This mode of patterning may operate broadly across developmental contexts, with implications for tissue engineering and patterning-related disorders.

developmental biology↗

bioRxiv2024

Comprehensive profiling of migratory primordial germ cells reveals niche-specific differences in non-canonical Wnt and Nodal-Lefty signaling in anterior vs posterior migrants

Mammalian primordial germ cells (PGCs) migrate asynchronously through the embryonic hindgut and dorsal mesentery to reach the gonads. We previously found that interaction with different somatic niches regulates PGC proliferation along the migration route. To characterize transcriptional heterogeneity of migrating PGCs and their niches, we performed single-cell RNA sequencing of 13,262 mouse PGCs and 7,868 surrounding somatic cells during migration (E9.5, E10.5, E11.5) and in anterior versus posterior locations to enrich for leading and lagging migrants. Analysis of PGCs by position revealed dynamic gene expression changes between faster or earlier migrants in the anterior and slower or later migrants in the posterior at E9.5; these differences include migration-associated actin polymerization machinery and epigenetic reprogramming-associated genes. We furthermore identified changes in signaling with various somatic niches, notably strengthened interactions with hindgut epithelium via non-canonical WNT (ncWNT) in posterior PGCs compared to anterior. Reanalysis of a previously published dataset suggests that ncWNT signaling from the hindgut epithelium to early migratory PGCs is conserved in humans. Trajectory inference methods identified putative differentiation trajectories linking cell states across timepoints and from posterior to anterior in our mouse dataset. At E9.5, we mainly observed differences in cell adhesion and actin cytoskeletal dynamics between E9.5 posterior and anterior migrants. At E10.5, we observed divergent gene expression patterns between putative differentiation trajectories from posterior to anterior including Nodal signaling response genes Lefty1, Lefty2, and Pycr2 and reprogramming factors Dnmt1, Prc1, and Tet1. At E10.5, we experimentally validated anterior migrant-specific Lefty1/2 upregulation via whole-mount immunofluorescence staining for LEFTY1/2 and phosphorylated SMAD2/3, suggesting that elevated autocrine Nodal signaling in migrating PGCs occurs as they near the gonadal ridges. Together, this positional and temporal atlas of mouse PGCs supports the idea that niche interactions along the migratory route elicit changes in proliferation, actin dynamics, pluripotency, and epigenetic reprogramming.

developmental biology↗

bioRxiv2023

Deep learning for rapid and reproducible histology scoring of lung injury in a porcine model

Acute respiratory distress syndrome (ARDS) is a life-threatening condition with mortality rates between 30-50%. Although in vitro models replicate some aspects of ARDS, small and large animal models remain the primary research tools due to the multifactorial nature of the disease. When using these animal models, histology serves as the gold standard method to confirm lung injury and exclude other diagnoses as high-resolution chest images are often not feasible. Semi-quantitative scoring performed by independent observers is the most common form of histologic analysis in pre-clinical animal models of ARDS. Despite progress in standardizing analysis procedures, objectively comparing histological injuries remains challenging, even for highly-trained pathologists. Standardized scoring simplifies the task and allows better comparisons between research groups and across different injury models, but it is time-consuming, and interobserver variability remains a significant concern. Convolutional neural networks (CNNs), which have emerged as a key tool in image analysis, could automate this process, potentially enabling faster and more reproducible analysis. Here we explored the reproducibility of human standardized scoring for an animal model of ARDS and its suitability for training CNNs for automated scoring at the whole slide level. We found large variations between human scorers, even for pre-clinical experts and board-certified pathologies in evaluating ARDS animal models. We demonstrate that CNNs (VGG16, EfficientNetB4) are suitable for automated scoring and achieve up to 83% F1-score and 78% accuracy. Thus, CNNs for histopathological classification of acute lung injury could help reduce human variability and eliminate a time-consuming manual research task with acceptable performance.

bioinformatics↗

bioRxiv2023

Label-free high-resolution infrared spectroscopy for spatiotemporal analysis of complex living systems

Label-free chemical and structural imaging of complex living tissue and biological systems is the holy grail of biomedical research and clinical diagnostics. The current analysis techniques are time-consuming and/or require extensive sample preparation, often due to the presence of interfering molecules such as water, making them unsuitable for the analysis of such systems. Here, we demonstrate a proof-of-principle study using label-free optical photothermal mid-infrared microspectroscopy (O-PTIR) for fast, direct spatiotemporal chemical analysis of complex living biological systems at submicron resolution. While other analytical methods can provide only static snapshots of molecular structures, our O-PTIR approach enables time-resolved and in situ investigation of chemical and structural changes of diverse biomolecules in their native conditions. This comprises a technological breakthrough in infrared spectroscopy to analyze biomolecules under native conditions over time: in fresh unprocessed biopsies, living brain tissue, and vertebrates without compromising their viability. One-Sentence SummaryProof-of-principle application of non-destructive O-PTIR for high-resolution spatiotemporal chemical and structural analysis of unprocessed biopsies, living brain tissue, and vertebrates.

molecular biology↗

bioRxiv2022

Modeling of Aberrant Epithelial Reprogramming in Idiopathic Pulmonary Fibrosis using Human Induced Pluripotent Stem Cell-derived Alveolar Organoids

Repeated injury of the lung epithelium is proposed to be a main driver of idiopathic pulmonary fibrosis (IPF). However, none of the available therapies target the epithelium and there is a limited amount of human models of fibrotic epithelial damage with suitability for drug screening and discovery. We developed a model of the epithelial reprogramming seen in IPF using alveolar organoids derived from human induced pluripotent stem cells stimulated with a cocktail of pro-fibrotic and inflammatory cytokines. This fibrosis cocktail induced persistent epithelial reprogramming and expression of extracellular matrix. Deconvolution of RNA-seq data indicated that the fibrosis cocktail increased the proportion of cells with the KRT5-/KRT17+ aberrant basaloid phenotype, recently identified in the lungs of IPF patients. Treatment with nintedanib and pirfenidone had effects on markers of extracellular matrix, pro-fibrotic mediators and epithelial reprogramming. Thus, our system recapitulates key aspects of IPF and is a promising system for drug discovery.

cell biology↗

bioRxiv2022

Simultaneous isolation of proximal and distal lung progenitor cells from individual mice using a 3D printed guide reduces proximal cell contamination of distal lung epithelial cell isolations

The respiratory epithelium consists of multiple, functionally distinct cell-types and is maintained by regionally-specific progenitor populations which repair the epithelium following injury. Several in vitro methods exist for studying lung epithelial repair using primary murine lung epithelial cells, but isolation methods are hampered by a lack of surface markers distinguishing epithelial progenitors along the respiratory epithelium. Here, we developed a 3D-printed lobe divider (3DLD) to aid in simultaneous isolation of proximal versus distal lung epithelial progenitors from individual mice which give rise to differentiated epithelia in multiple in vitro assays. In contrast to 3DLD-isolated distal progenitor cells, classic manual tracheal ligation methods followed by lobe removal resulted in co-isolation of rare proximal progenitors with distal cells which altered the transcriptional landscape of distal organoid cultures. Thus, cell isolation with the 3DLD generates reproducible distal versus proximal progenitor populations and minimizes the potential for contaminating populations to confound in vitro assays. HighlightsO_LI3DLD reproducibly separates lung lobes and extrapulmonary airways (bronchi/trachea) C_LIO_LI3DLD cell isolation yields consistent isolation of distal epithelial cells (DECs) C_LIO_LIContamination of proximal cells in classic DEC isolations may alter in vitro results C_LIO_LI3DLD allows for simultaneous isolation of proximal and DECs from single animals C_LI eTOC blurbAlsafadi et al. describes a new method for simultaneous isolation of lung epithelial proximal and distal progenitors using the aid of a 3D printed device (3DLD). Both isolated cell types differentiate in multiple in vitro assays. The 3DLD guide minimized contamination of proximal cells in distal cell isolations whose presence can alter the transcriptional landscape of distal epithelial organoids.

cell biology↗

bioRxiv2021

3D printed lung on a chip device with a stretchable nanofibrous membrane for modeling ventilator induced lung injury

Mechanical ventilation is often required in patients with pulmonary disease to maintain adequate gas exchange. Despite improved knowledge regarding the risks of over ventilating the lung, ventilator induced lung injury (VILI) remains a major clinical problem due to inhomogeneities within the diseased lung itself as well as the need to increase pressure or volume of oxygen to the lung as a life-saving measure. VILI is characterized by increased physical forces exerted within the lung, which results in cell death, inflammation and long-term fibrotic remodeling. Animal models can be used to study VILI, but it is challenging to distinguish the contributions of individual cell types in such a setup. In vitro models, which allow for controlled stretching of specific lung cell types have emerged as a potential option, but these models and the membranes used in them are unable to recapitulate some key features of the lung such as the 3D nanofibrous structure of the alveolar basement membrane while also allowing for cells to be cultured at an air liquid interface (ALI) and undergo increased mechanical stretch that mimics VILI. Here we develop a lung on a chip device with a nanofibrous synthetic membrane to provide ALI conditions and controllable stretching, including injurious stretching mimicking VILI. The lung on a chip device consists of a thin (i.e. [~]20 {micro}m) stretchable poly(caprolactone) (PCL) nanofibrous membrane placed between two channels fabricated in polydimethylsiloxane (PDMS) using 3D printed molds. We demonstrate that this lung on a chip device can be used to induce mechanotrauma in lung epithelial cells due to cyclic pathophysiologic stretch ([~]25%) that mimics clinical VILI. Pathophysiologic stretch induces cell injury and subsequently cell death, which results in loss of the epithelial monolayer, a feature mimicking the early stages of VILI. We also validate the potential of our lung on a chip device to be used to explore cellular pathways known to be altered with mechanical stretch and show that pathophysiologic stretch of lung epithelial cells causes nuclear translocation of the mechanotransducers YAP/TAZ. In conclusion, we show that a breathable lung on a chip device with a nanofibrous membrane can be easily fabricated using 3D printing of the lung on a chip molds and that this model can be used to explore pathomechanisms in mechanically induced lung injury.

bioengineering↗

bioRxiv2020

KRAS signalling in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) arises from mesothelial cells lining the pleural cavity of asbestos-exposed individuals and rapidly leads to the development of pleural effusion and death. MPM harbours loss-of-function mutations in genes like BAP1, NF2, CDKN2A, and TP53, but isolated deletion of these genes alone in mice does not cause MPM and mouse models of the disease are sparse. Here we show that a significant proportion of human MPM harbour point mutations and copy number alterations in the KRAS proto-oncogene. These mutations are likely pathogenic, since ectopic expression of mutant KRASG12D in the pleural mesothelium of conditional mice causes MPM. Murine MPM cell lines derived from these tumours carry the initiating KRASG12D lesions, secondary Bap1 alterations, and human MPM-like gene expression profiles. Moreover, they are transplantable and actionable by KRAS inhibition. Our results indicate that KRAS mutations likely play an important and underestimated role in MPM, which warrants further exploration.

physiology↗

bioRxiv2020

Isolation of high yield and quality RNA from human precision-cut lung slices for RNA-sequencing and computational integration with larger patient cohorts

Precision-cut lung slices (PCLS) have gained increasing interest as a model to study lung biology and disease, as well as for screening novel therapeutics. In particular, PCLS derived from human tissue can better recapitulate some aspects of lung biology and disease as compared to PCLS derived from animals (e.g. clinical heterogeneity), but access to human tissue is limited. A number of different experimental readouts have been established for use with PCLS, but obtaining high yield and quality RNA for downstream gene expression analysis has remained challenging. This is particularly problematic for utilizing the power of next-generation sequencing techniques, such as RNA-sequencing (RNA-seq), for non-biased and high through-put analysis of PCLS human cohorts. In the current study, we present a novel approach for isolating high quality RNA from a small amount of tissue, including diseased human tissue, such as idiopathic pulmonary fibrosis (IPF). We show that the RNA isolated using this method is of sufficient quality for both RT-qPCR and RNA-seq analysis. Furthermore, the RNA-seq data from human PCLS was comparable to data generated from native tissue and could be used in several established computational pipelines, including deconvolution of bulk RNA-seq data using publicly available single-cell RNA-seq data sets. Deconvolution using Bisque revealed a diversity of cell populations in human PCLS derived from distal lung tissue, including several immune cell populations, which correlated with cell populations known to be present and aberrant in human disease, such as IPF.

molecular biology↗

bioRxiv2020

Organ-restricted vascular delivery of nanoparticles for lung cancer therapy

Nanomedicines hold immense promise for a number of devastating diseases due to the ability to custom-design both the carrier and cargo. However, their clinical implementation has been hampered by physicochemical and biological barriers and off-target deposition which impair cell specific targeting, especially in internal organs. This study reports a new delivery approach using organ-restricted vascular delivery to allow for direct administration and recirculation of stimuli-responsive nanoparticles to promote cellular uptake into an organ of interest. Using this technique, nanoparticles reach the interior of dense tumors and are selectively taken up by lung cancer cells. Importantly, this surgical approach is essential as the same nanoparticles do not reach lung tumor cells upon systemic or intratracheal administration. Organ-restricted vascular delivery thus opens up new avenues for optimized nanotherapies for cancer and other diseases.

pharmacology and toxicology↗

bioRxiv2019

Dual airway and alveolar contributions to adult lung homeostasis and carcinogenesis

Lung adenocarcinoma (LUAD) and chronic lung diseases caused by smoking and environmental noxious agents are the deadliest diseases worldwide, sharing a partially charted pathobiology of dysfunctional alveolar repair. Here we sought to identify the respiratory epithelial dynamics and molecular signatures participating in adult lung maintenance and chemical carcinogenesis. We employed novel mouse models of respiratory epithelial marking and ablation, a battery of pulmonary toxins and carcinogens, experimental protocols of carcinogen-induced LUAD, tobacco carcinogen-induced LUAD cell lines, and human transcriptomic data and identified a prominent involvement of airway molecular programs in alveolar maintenance and carcinogen-induced LUAD. The airway-specific transcriptomic signature was redistributed to the alveoli after toxic and carcinogenic insults and resulted in marked contributions of airway-labeled cells to injury-recovered alveoli and LUAD. Airway cells maintained Kras mutations and therefore possibly contributed to lung cancer initiation, while LUAD were spatially linked to neighboring airways. Transcriptomic profiling of carcinogen-induced murine and human LUAD revealed enrichment in airway signatures, while ablation of airway cells distorted alveolar structure and function and protected mice from LUAD development. Collectively, these results indicate that airway cells and/or transcriptomic signatures are essential for alveolar maintenance and LUAD development.

cancer biology↗