Biology subjects

Park, S.

Publications and source records attributed to Park, S..

At least 109 records · Page 6Linked to original sources

bioRxiv2025

Tissue-Specific Iron Levels Modulate Lipid Peroxidation and the FLASH Radiotherapy Effect

Iron is vital to living cells, playing a key role in cellular respiration, DNA synthesis, and various metabolic functions. Importantly, cancer cells have a higher dependency on iron compared to normal cells to support their rapid growth and survival. Due to this fact, tumors are more vulnerable to ferroptosis, an iron-dependent form of regulated cell death. Radiation therapy (RT), a standard treatment for many cancer patients, is known to induce ferroptosis. Ultra-high dose rate FLASH RT offers an improved therapeutic window by minimizing damage to normal tissues while preserving tumor control. However, the precise biological mechanisms behind the protective effects of FLASH RT on normal tissues remain unclear. In this study, we propose that variations in lipid peroxidation and ferroptosis, driven by intrinsic differences in iron levels between normal and cancerous tissues, contribute to this effect. Our findings show that FLASH RT increases lipid peroxidation and induces ferroptosis in tumor cells but does not significantly elevate lipid peroxidation and ferroptosis in normal tissues compared to conventional RT. To determine whether raising iron levels in normal tissues could abrogate the protective effects of FLASH, mice were fed a high-iron diet before RT. A high-iron diet before and after RT reversed the protective effect of FLASH, resulting in increased intestinal damage and lipid peroxidation. This suggests that baseline iron levels and iron-driven lipid peroxidation are critical factors in mediating the protective outcomes of FLASH RT. Overall, our study sheds light on the role of iron in modulating RT responses and provides new mechanistic insights into how FLASH RT influences normal and cancerous tissues.

cancer biology↗

bioRxiv2025

A computational framework for mapping isoform landscape and regulatory mechanisms from spatial transcriptomics data

Transcript diversity including splicing and alternative 3 end usage is crucial for cellular identity and adaptation, yet its spatial coordination remains poorly understood. Here, we present SPLISOSM (SpatiaL ISOform Statistical Modeling), a computational framework for detecting isoform-resolution patterns from spatial transcriptomics data. SPLISOSM leverages multivariate testing to account for spot- and isoform-level dependencies, demonstrating robust and theoretically grounded performance on sparse data. In the mouse brain, we identify over 1,000 spatially variable transcript diversity events, primarily in synaptic signaling pathways linked to neuropsychiatric disorders, and uncover both known and novel regulatory relationships with region-specific RNA binding proteins. We further show that these patterns are evolutionarily conserved between mouse and human prefrontal cortex. Analysis of human glioblastoma highlights pervasive transcript diversity in antigen presentation and adhesion genes associated with specific microenvironmental conditions. Together, we present a comprehensive spatial splicing analysis in the brain under normal and neoplastic conditions.

bioinformatics↗

bioRxiv2025

Genome-wide association mapping and predictive modeling of wet bean mass in a diverse cacao collection

Improving cacao yield, a key objective in post-domestication crop improvement, remains a primary goal for breeders, but progress is often hindered by the confounding effects of population structure. To overcome this, we analyzed 346 diverse cacao accessions using an ML-based association mapping framework (with and without population structure adjustment) and a phenotype-only ML prediction of yield. By correcting for population structure, our Bootstrap Forest-based GWAS revealed association signals that showed consistent enrichment for ribosome and protein-synthesis functions, and a recurrent subset of SNPs with high importance appeared across multiple yield components, including pod index and seed number. In parallel, a Neural Network model was utilized to identify cotyledon mass and length as the most powerful predictors for total wet bean mass (R{superscript 2} = 0.715 by repeated five-fold cross-validation), suggesting a practical, low-cost screening proxy for breeding). Collectively, this study delivers a robust genetic framework and a novel predictive tool to accelerate the development of high-yielding cacao varieties through the early identification of elite clones.

genomics↗

bioRxiv2025

Vesicle-mediated oxytocin release drives melanocortin circuit maturation during a neonatal critical period

The hypothalamus is crucial for regulating essential bodily functions, including energy balance. It is an exceedingly complex and heterogeneous brain region that contains a variety of neuronal systems that are interconnected with each other. Among these, the melanocortin system, which comprises pro-opiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons, displays a remarkable anatomical relationship with oxytocin (OT) neurons in the paraventricular nucleus (PVH). Here, we demonstrate that OT neurons are instrumental in the development of the melanocortin system. Chemogenetic inhibition of OT neurons during the first postnatal week selectively disrupts POMC and AgRP projections to the PVH, without affecting other target nuclei like the dorsomedial nucleus. This developmental role is age-dependent, as silencing OT neurons in juvenile or adult stages has no impact on melanocortin circuits. OT neurons release various neuropeptides and neurotransmitters, and their secretion can be modulated by chemogenetic manipulation. Expressing the botulinum toxin serotype B light chain in OT neurons reveals that their developmental actions rely on SNARE-mediated exocytosis. Moreover, administering an OT receptor antagonist during the first postnatal week leads to similar melanocortin circuit defects and long-term metabolic effects. Furthermore, neonatal chemogenetic activation of OT neurons rescues POMC circuit deficits in a mouse model of Prader-Willi Syndrome. These findings reveal that OT acts as a paracrine neurotrophic factor orchestrating the development of melanocortin circuits during a restricted neonatal critical period.

neuroscience↗

bioRxiv2025

Gas Vesicle-Expressing Human Pluripotent Stem Cells Enable Multimodal Ultrasound and Optical Coherence Tomographic Imaging

Genetically encoded imaging reporters are critical tools for tracking cell fate and function in regenerative medicine. Gas vesicles (GVs), air-filled protein nanostructures derived from bacteria, offer unique advantages for noninvasive imaging due to their acoustic and optical properties. In this study, we engineered human pluripotent stem cells (hPSCs) to express GVs using a doxycycline-inducible system. Upon doxycycline (Dox) treatment, GVs formed intracellularly and enabled enhanced contrast in both ultrasound and optical coherence tomography (OCT) imaging. Dynamic ultrasound imaging revealed pressure-dependent GV buckling and harmonic signal generation, while OCT imaging confirmed high sensitivity and depth-resolved detection in both in vitro and ex vivo retinal models. Our work establishes a multimodal GV-based reporter platform compatible with human stem cells and clinically relevant imaging modalities. This approach offers a powerful and versatile tool for noninvasively visualizing and tracking therapeutic cells in real time, advancing the development and monitoring of cell-based therapies.

synthetic biology↗

bioRxiv2025

Co-release of opposing signaling molecules from cortical neurons controls the escalation and release of aggression

Neuropeptides exert broad effects across the brain to influence behavior. However, the mechanism by which the brain uses neuropeptide signaling to exert top-down control over complex behavioral responses remains poorly understood. Prolonged social isolation induces a distinct internal state that results in sweeping changes to behavior, including increased aggression. Here, we find that isolation-induced aggression activates Tachykinin-2 expressing (Tac2+) neurons in the mouse medial prefrontal cortex (mPFC). Genetic characterization of Tac2+ cells in the mPFC reveals them to be a population of unexplored GABAergic neurons. In-depth behavioral analyses combined with in vivo recordings of neural activity demonstrate that mPFC Tac2+ neurons are tuned to distinct phases of isolation-induced aggression: investigatory behaviors that escalate to attack (aggression escalation) and attack itself (aggression release). Loss-of-function perturbations targeting the release of either Neurokinin B (NkB), the stimulatory peptide encoded by Tac2, or the inhibitory neurotransmitter, GABA, reveal that these signaling molecules exert dissociable control over aggression escalation and release. These findings identify distinct roles for opposing signaling molecules co-released from the same population of cells. This suggests a surprising neurochemical mechanism by which neuropeptidergic populations in the prefrontal cortex exert top-down influence over complex behavior via the co-release of signaling molecules with opposing actions but coordinated impacts on behavior.

neuroscience↗

bioRxiv2025

Precise, Specific, and Sensitive De Novo Antibody Design Across Multiple Cases

The precision design of antibodies, which naturally recognize diverse molecules through six variable loops, remains a critical challenge in therapeutic molecule discovery. In this study, we demonstrate that precise, sensitive, and specific antibody design can be achieved without prior antibody information across eight distinct target proteins. For each target, binders were identified from a yeast display scFv library of approximately 106 sequences, constructed by combining 102 designed light chain sequences with 104 designed heavy chain sequences. Binders with varying binding strengths were identified for all eight targets, including a case where no experimentally resolved target protein structure was available, demonstrating the highest level of precision compared to previous de novo antibody design reports. To further validate the designed antibodies, they were characterized in the IgG format for five distinct targets. The antibodies exhibited favorable developability properties, positioning them as promising hit or lead candidates. Notably, for one target in particular, the IgG-formatted antibodies exhibited affinity, activity, and developability, comparable to a commercial antibody, highlighting the sensitivity of the design method. Furthermore, binders capable of distinguishing closely related protein subtypes or mutants were identified, demonstrating that the method can achieve high molecular specificity. Cryo-EM analysis experimentally validated the designs accuracy by confirming that the key binding interactions were precisely as designed. These findings underscore the effectiveness of precision molecular design based on atomic-accuracy structure prediction. This study establishes computational antibody design as a viable approach for generating therapeutic molecules with tailored properties, with promising potential for achieving the efficacy and safety required for successful therapeutics.

bioengineering↗

bioRxiv2025

The graphene-based affinity cryo-EM grid for the endogenous protein structure determination

Following recent advancements in cryo-electron microscopy (cryo-EM) instrumentation and software algorithms, the next bottleneck in achieving high-resolution cryo-EM structures arises from sample preparation. To overcome this, we developed a graphene-based affinity cryo-EM grid, the Graffendor (GFD) grid, to target low-abundance endogenous protein complexes. To maintain grid quality and consistency within a single batch of 36 grids, we established a one-step crosslinking batch-production method using genetically modified ALFA nanobody as affinity probe (GFD-A grid). Using low concentrations of {beta}-galactosidase-2xALFA, we demonstrated the GFD-A grids efficiency in capturing tagged proteins and resolving its cryo-EM structure at 2.71 [A]. To test its application for endogenous proteins, we engineered yeast cells with a C-terminal tandem affinity tag (3xALFA-Tev-3xFlag: ATF) at Pop6, a shared component of RNase MRP and RNase P. Cryo-EM structures of RNase MRP and RNase P were resolved at 3.3 [A] and 3.0 [A] from cell lysates, and 3.6 [A] and 3.9 [A] from anti-flag elution, respectively. Notably, additional densities were observed in the structures obtained from cell lysates, which were absent in those from the anti-FLAG eluate. These findings establish the GFD-A grid as a robust platform for investigating endogenous proteins, capable of capturing transient interactions and enhancing the resolution of challenging cryo-EM structures with greater efficiency.

biochemistry↗

bioRxiv2025

Context-specific interaction of the lipid regulator DIP-2 with phospholipid synthesis in axon regeneration and maintenance.

Neurons maintain their morphology over prolonged periods of adult life with limited regeneration after injury. C. elegans DIP-2 is a conserved regulator of lipid metabolism that affects axon maintenance and regeneration after injury. Here, we investigated genetic interactions of dip-2 with mutants in genes involved in lipid biosynthesis and identified roles of phospholipids in axon regrowth and maintenance. CEPT-2 and EPT-1 are enzymes catalyzing the final steps in the de novo phospholipid synthesis (Kennedy) pathway. Loss of function mutants of cept-2 or ept-1 show reduced axon regrowth and failure to maintain axon morphology. We demonstrate that CEPT-2 is cell-autonomously required to prevent age-related axonal defects. Interestingly, loss of function in dip-2 led to suppression of the axon regrowth phenotype observed in either cept-2 or ept-2 mutants, suggesting that DIP-2 acts to counterbalance phospholipid synthesis. Our findings reveal the genetic regulation of lipid metabolism to be critical for axon maintenance under injury and during aging. Article SummaryLittle is known about how adult neurons live long with limited regenerative capacity. This study investigates the role of lipid metabolism in sustaining neuronal health in C. elegans. Mutating phospholipid synthetic genes impairs axon regrowth after injury. Lack of DIP-2, a lipid regulator, restores regrowth, suggesting DIP-2 counterbalances phospholipid synthesis. Moreover, neuronal phospholipid synthesis is essential for preventing age-dependent axonal defects. These findings reveal phospholipid biosynthesis is key to axon integrity during aging and injury. As lipid metabolism is implicated in neurological disorders, this study serves as an entry point into investigating neuronal lipid biology under various conditions.

neuroscience↗

bioRxiv2025

Developmental Variations in Recurrent Spatiotemporal Brain Propagations from Childhood to Adulthood

The brain undergoes profound structural and functional transformations from childhood to adolescence. Convergent evidence suggests that neurodevelopment proceeds in a hierarchical manner, characterized by heterogeneous maturation patterns across brain regions and networks. However, the maturation of the intrinsic spatiotemporal propagations of brain activity remains largely unexplored. This study aims to bridge this gap by delineating spatiotemporal propagations from childhood to early adulthood. By leveraging a recently developed approach that captures time-lag dynamic propagations, we characterized intrinsic dynamic propagations along three axes: sensory-association (S-A), task-positive to default networks (TP-D), and somatomotor-visual (SM-V) networks, which progress towards adult-like brain dynamics from childhood to early adulthood. Importantly, we demonstrated that as participants mature, there is a prolonged occurrence of the S-A and TP-D propagation states, indicating that they spend more time in these states. Conversely, the prevalence of SM-V propagation states declines during development. Notably, top-down propagations along the S-A axis exhibited an age-dependent increase in occurrence, serving as a superior predictor of cognitive scores compared to bottom-up S-A propagation. These findings were replicated across two independent cohorts (N = 677 in total), emphasizing the robustness and generalizability of these findings. Our results provide new insights into the emergence of adult-like functional dynamics during youth and their role in supporting cognition.

neuroscience↗

bioRxiv2025

Temporal and spatial composition of the tumor microenvironment predicts response to immune checkpoint inhibition

Immune checkpoint inhibition (ICI) has fundamentally changed cancer treatment. However, only a minority of patients with metastatic triple negative breast cancer (TNBC) benefit from ICI, and the determinants of response remain largely unknown. To better understand the factors influencing patient outcome, we assembled a longitudinal cohort with tissue from multiple timepoints, including primary tumor, pre-treatment metastatic tumor, and on-treatment metastatic tumor from 117 patients treated with ICI (nivolumab) in the phase II TONIC trial. We used highly multiplexed imaging to quantify the subcellular localization of 37 proteins in each tumor. To extract meaningful information from the imaging data, we developed SpaceCat, a computational pipeline that quantifies features from imaging data such as cell density, cell diversity, spatial structure, and functional marker expression. We applied SpaceCat to 678 images from 294 tumors, generating more than 800 distinct features per tumor. Spatial features were more predictive of patient outcome, including features like the degree of mixing between cancer and immune cells, the diversity of the neighboring immune cells surrounding cancer cells, and the degree of T cell infiltration at the tumor border. Non-spatial features, including the ratio between T cell subsets and cancer cells and PD-L1 levels on myeloid cells, were also associated with patient outcome. Surprisingly, we did not identify robust predictors of response in the primary tumors. In contrast, the metastatic tumors had numerous features which predicted response. Some of these features, such as the cellular diversity at the tumor border, were shared across timepoints, but many of the features, such as T cell infiltration at the tumor border, were predictive of response at only a single timepoint. We trained multivariate models on all of the features in the dataset, finding that we could accurately predict patient outcome from the pre-treatment metastatic tumors, with improved performance using the on-treatment tumors. We validated our findings in matched bulk RNA-seq data, finding the most informative features from the on-treatment samples. Our study highlights the importance of profiling sequential tumor biopsies to understand the evolution of the tumor microenvironment, elucidating the temporal and spatial dynamics underlying patient responses and underscoring the need for further research on the prognostic role of metastatic tissue and its utility in stratifying patients for ICI.

cancer biology↗

bioRxiv2025

Mapping brain function underlying naturalistic motor observation and imitation using high-density diffuse optical tomography

BackgroundAutism spectrum disorder (ASD), a condition defined by deficits in social communication, restricted interests, and repetitive behaviors, is associated with early impairments in motor imitation that persist through childhood and into adulthood. Alterations in the mirror neuron system (MNS), crucial for interpreting and imitating actions, may underlie these ASD-associated differences in motor imitation. High-density diffuse optical tomography (HD-DOT) overcomes logistical challenges of functional magnetic resonance imaging to enable identification of neural substrates of naturalistic motor imitation. ObjectiveWe aim to investigate brain function underlying motor observation and imitation in autistic and non-autistic adults. We hypothesize that HD-DOT will reveal greater activation in regions associated with the MNS during motor imitation than motor observation, and that MNS activity will negatively correlate with autistic traits and motor fidelity. MethodsWe imaged brain function using HD-DOT in N = 100 participants as they engaged in observing or imitating a sequence of arm movements. Additionally, during imitation, participant movements were simultaneously recorded with 3D cameras for computer-vision-based assessment of motor imitation (CAMI). Cortical responses were estimated using general linear models, and multiple regression was used to test for associations with autistic traits, assessed via the Social Responsiveness Scale-2 (SRS), and imitation fidelity, assessed via CAMI. ResultsBoth observing and imitating motor movements elicited significant activations in higher-order visual and MNS regions, including the inferior parietal lobule, superior temporal gyrus, and inferior frontal gyrus. Imitation additionally exhibited greater activation in the superior parietal lobule, primary motor cortex, and supplementary motor area. Notably, the right temporal-parietal junction exhibited activation during observation but not during imitation. Higher autistic traits were associated with increased activation during motor observation in the right superior parietal lobule. No significant correlation between brain activation and CAMI scores was observed. ConclusionsOur findings provide robust evidence of shared and task-specific cortical responses underlying motor observation and imitation, emphasizing the differential engagement of MNS regions during motor observation and imitation.

neuroscience↗

bioRxiv2025

Population-level encoding of somatosensation in mouse sensorimotor cortex

Somatosensation constructs the bodys dynamic sense of state and allows for dexterous and precise movements. The heterogeneous responses of single neurons in sensorimotor cortex to so-matosensation have led to disparate views of the computational role of this brain area in sensori-motor processing. Here, we use population-level analyses of neural activity recorded during passive limb movements to assess the structure and to summarize the properties of neural encoding in sensorimotor cortex. We used 2-photon imaging to record the activity of thousands of neurons in eight anesthetized mice during passive deflections of each limb. We additionally analyzed neu-ral responses to passive limb movements in eight awake mice, sourced from an open dataset [1]. We employed principal component analysis on the neural activity in each dataset and found that a small fraction of principal components explained a large fraction of variance in the neural re-sponses. Low-dimensional representations of limb movements were well conserved across animals, including the orthogonal representations of ipsilateral and contralateral limbs. This organization of somatosensory information mirrors the well-known structure of neural encoding of motor com-mands in sensorimotor cortex. Furthermore, neural populations dually encoded both changes in joint angles during movements and more abstract information, i.e., the direction of limb movement. Increasing the size of the neural population improved encoding of both types of movement infor-mation and better differentiated representations from movements in opposing directions. Together, these results demonstrate that population-level encoding of somatosensory information in mouse sensorimotor cortex is structured to facilitate sensorimotor integration across the brain.

neuroscience↗

bioRxiv2025

Mapping cancer gene dynamics through state-specific interactions

Metastatic cancer, a major cause of mortality, has been understudied compared to primary tumors, leaving gaps in our understanding of how cancer genes adapt between these states. We analyzed the association between mutations and copy-number alterations in 25,000 tumor samples from both primary and metastatic cancers. Our findings show that cancer genes display distinct interaction strengths across these states, with 27.45% of genes, including ARID1A, FBXW7, and SMARCA4, shifting between one-hit and two-hit drivers. Interaction strengths varied by cancer state and treatment conditions, revealing seven state-specific interactions. We also identified 38 primary-specific and 21 metastatic-specific high-order interactions, enriched in cancer hallmarks, indicating unique tumor progression mechanisms. These findings highlight dynamic tumor progression mechanisms and underscore the importance of considering cancer state in research and treatment strategies for precise therapeutic interventions.

genomics↗

bioRxiv2025

Mitoxantrone inhibits and downregulates ERα through binding at the DBD-LBD interface

Targeting the estrogen receptor (ER or ER) through competitive antagonists, receptor downregulators, or estrogen synthesis inhibition remains the primary therapeutic strategy for luminal breast cancer. We have identified a novel mechanism of ER inhibition by targeting the critical interface between its DNA-binding domain (DBD) and ligand-binding domain (LBD). We demonstrate that mitoxantrone (MTO), a topoisomerase II inhibitor, binds at this previously unexplored DBD-LBD interface. Using comprehensive computational, biophysical, biochemical, and cellular analyses, we show that independent of its DNA damage response activity, MTO binding induces distinct conformational changes in ER, leading to its cytoplasmic redistribution and subsequent proteasomal degradation. Notably, MTO effectively inhibits clinically relevant ER mutations (Y537S and D538G) that confer resistance to current endocrine therapies, outperforming fulvestrant in both in vitro and in vivo assays. Our findings establish domain-domain interaction targeting as a viable therapeutic strategy for ER, with translational implications for other nuclear receptors.

cancer biology↗

bioRxiv2024

Unicore enables scalable and accurate phylogenetic reconstruction with structural core genes

The analysis of single-copy core genes, common to most members of a clade, is important for key tasks in biology including phylogenetic reconstruction and assessing genome quality. Core genes are traditionally identified by the analysis of amino acid similarities among proteomes, but can also be defined using structures, which bear potential in deep clades beyond the twilight zone of amino acids. Despite breakthroughs in accurate AI-driven protein structure prediction, obtaining full 3D structural models on a proteomic scale is still prohibitively slow. Here, we present Unicore, a novel method for identifying structural core genes at a scale suitable for downstream phylogenetic analysis. By applying the ProstT5 protein language model to the input proteomes to obtain their 3Di structural strings, Unicore saves over three orders of magnitude in runtime compared to a full 3D prediction. Using Foldseek clustering, Unicore identifies single-copy structures universally present in the species and aligns them using Foldmason. These structural core gene alignments are projected back to amino acid information for downstream phylogenetic analysis. We demonstrate that this approach defines core genes with linear run-time scaling over the number of species, up to 56 times faster than OrthoFinder, while reconstructing phylogenetic relationships congruent with conventional approaches. Unicore is universally applicable to any given set of taxa, even spanning superkingdoms and overcoming limitations of previous methods requiring orthologs of fixed taxonomic scope, and is available as a free and open source software at https://github.com/steineggerlab/unicore.

bioinformatics↗

bioRxiv2024

Ipflufenoquin, Novel Dihydroorotate Dehydrogenase Inhibitor: Efficacy Against Strawberry Diseases and Docking Simulations via AlphaFold2 and Autodock Vina

In 2023, fungal diseases, including Botrytis cinerea (gray mold), were isolated from various strawberry fields in Korea. Ipflufenoquin, a novel class 2 dihydroorotate dehydrogenase (DHODH) inhibitor, was applied to plant pathogenic fungal species. EC50 values indicated that ipflufenoquin achieved high sensitivity in B. cinerea while maintaining broad-spectrum activity against other fungi. Fruit and greenhouse trials confirmed its robust efficacy in gray mold diseases, including those resistant to conventional fungicides like pyraclostrobin, fluxapyroxad, and benomyl. However, the ipflufenoquin application was less effective against fungal pathogens like blossom blight and Rhizopus rot, causing shifts in the fungal community and allowing less sensitive species to emerge. Structural prediction using Alphafold2 and molecular docking simulation showed ipflufenoquin was bound to the quinone binding tunnel in DHODH and highlighted the correlation between protein-ligand binding affinity and fungicide susceptibility, with species showing higher affinities being more sensitive. This study is the first to report sensitivity of strawberry fungal species to ipflufenoquin, and this fungicide is recommended in strawberry farms against gray mold disease. Additionally, we conducted in silico predictions of fungicide sensitivity across various plant pathogenic fungi using Alphafod2 and Autodock Vina. This establishes a foundation for future computational analyses to predict the effectiveness of fungicides, offering important baseline data to enhance fungicide management strategies.

microbiology↗

bioRxiv2024

Self-organizing human heart assembloids with autologous and developmentally relevant cardiac neural crest-derived tissues

Neural crest cells (NCCs) are a multipotent embryonic cell population of ectodermal origin that extensively migrate during early development and contribute to the formation of multiple tissues. Cardiac NCCs play a critical role in heart development by orchestrating outflow tract septation, valve formation, aortic arch artery patterning, parasympathetic innervation, and maturation of the cardiac conduction system. Abnormal migration, proliferation, or differentiation of cardiac NCCs can lead to severe congenital cardiovascular malformations. However, the complexity and timing of early embryonic heart development pose significant challenges to studying the molecular mechanisms underlying NCC-related cardiac pathologies. Here, we present a sophisticated functional model of human heart assembloids derived from induced pluripotent stem cells, which, for the first time, recapitulates cardiac NCC integration into the human embryonic heart in vitro. NCCs successfully integrated at developmentally relevant stages into heart organoids, and followed developmental trajectories known to occur in the human heart. They demonstrated extensive migration, differentiated into cholinergic neurons capable of generating nerve impulses, and formed mature glial cells. Additionally, they contributed to the mesenchymal populations of the developing outflow tract. Through transcriptomic analysis, we revealed that NCCs acquire molecular features of their cardiac derivatives as heart assembloids develop. NCC-derived parasympathetic neurons formed functional connections with cardiomyocytes, promoting the maturation of the cardiac conduction system. Leveraging this models cellular complexity and functional maturity, we uncovered that early exposure of NCCs to antidepressants harms the development of NCC derivatives in the context of the developing heart. The commonly prescribed antidepressant Paroxetine disrupted the expression of a critical early neuronal transcription factor, resulting in impaired parasympathetic innervation and functional deficits in cardiac tissue. This advanced heart assembloid model holds great promise for high-throughput drug screening and unraveling the molecular mechanisms underlying NCC-related cardiac formation and congenital heart defects. IN BRIEFHuman neural crest heart assembloids resembling the major directions of neural crest differentiation in the human embryonic heart, including parasympathetic innervation and the mesenchymal component of the outflow tract, provide a human-relevant embryonic platform for studying congenital heart defects and drug safety.

bioengineering↗