Biology subjects

Zhang, W.

Publications and source records attributed to Zhang, W..

At least 271 records · Page 15Linked to original sources

bioRxiv2025

Specific Pathogen Free Ten Gene-Edited Pig Donor for Xenotransplantation

Xenotransplantation has entered the clinical phase to fulfill the global organ shortage. However, recent clinical studies revealed that the xenograft from current gene-edited (GE) pigs still poses the risk of immune rejection, and biosafety concerns. In this study, we successfully constructed a large batch of 10- (GTKO/CMAHKO/ {beta}4GalNT2KO/hCD46/hCD55/hCD59/hTBM/hEPCR/hCD39/hCD47) GE cloned (GEC) donor pigs by utilizing gene editing and somatic cell cloning technology, and successfully obtained F1 generation. Phenotypic characterization of 10-GEC pigs showed the deletion of three xenoantigens along with expression of seven human transgenes in various tissues. Digital droplet polymerase chain reaction, and whole genome sequencing indicated 2 copies of hCD46/hCD55/hCD59/hTBM/hCD39 and 1 copy of hEPCR/hCD47 in pig genome without significant off-target and damage to the porcine own functional genes. The validation results showed that 10-GEC pigs effectively inhibited the attacks of human antibodies, complement, and macrophages on porcine endothelial cells and alleviated the coagulation abnormalities between pigs and humans. 10-GEC pigs were negative for all zoonotic pathogens (48) including cytomegalovirus, except streptococcal infections. Kidney, heart, and liver xenografts from these 10-GE pigs were transplanted to non-human primates (NHP), which started working normally without hyperacute rejection. Among them, the heart and liver transplant recipient died without resuscitation due to unexpected interruption of oxygen supply, while the 2 kidney transplant recipients survived for 23 and 16 days, respectively. Pathological analysis showed that 10-GE pig kidney xenografts showed mesenchymal congestion, and fibrosis, cellular hyperplasia, with minor antibody and complement deposition, and significantly reduced the infiltration of CD68+ macrophage. In summary, we successfully produced a group of specific pathogen free GEC donor pigs that effectively mitigated immune rejection upon multi-organ transplantation to NHP.

immunology↗

bioRxiv2025

SLFN11 Loss-Induced Chemoresistance is Associated with Overexpression of Glycerophospholipid Biosynthesis in Ewing Sarcoma.

Ewing sarcoma (EWS) is an aggressive cancer in adolescents and young adults with frequent relapse rates and poor outcomes in recurrent or metastatic cases. Schlafen family member 11 (SLFN11) gene is associated with the sensitivity to DNA-damaging agents (DDAs). The knockout of SLFN11 is associated with acquired chemoresistance in both cell lines and preclinical models. Here, we aimed to elucidate the metabolic underpinnings of SLFN11-loss associated chemoresistance in patient derived cell lines of EWS. Our integrated transcriptomic and metabolomic analyses revealed downregulation of mitochondrial glycerol-3-phosphate dehydrogenase 2 (GPD2) gene, which was accompanied by the upregulation of glycerophospholipid (GPL) biosynthesis pathway. Further, therapeutic targeting of lipid synthesis with the glycerol-3-phosphate acyltransferase 1 (GPAT1) inhibitor (FSG67) enhanced the efficacy of the DDA (SN-38) in SLFN11-/- cells. These findings indicate that SLFN11 loss-mediated chemoresistance can be targeted by blocking GPL biosynthesis in addition to DDA administration.

cancer biology↗

bioRxiv2025

MONTAGE: A Computation Framework to Identify Spatially Resolved Functional Enrichment Gradients in the Tissue Microenvironment via Spatial Communities

Single-cell spatial-omics has advanced our understanding of how tumor microenvironment contributes to cancer progression. However, most single-cell spatial-omics studies focus on cell types and neighborhoods, offering limited information about functional and clinical relevance of cellular organization. We introduce MONTAGE, a computational framework to reconstruct, functionally analyze, and identify clinically relevant cellular spatial communities (SCs). MONTAGE generates a gene signature matrix of SCs from integrated atlases that offer single-cell resolution with transcriptomics, and reconstructs tissue maps ("montages"), reflecting sequential SC compositional changes along spatial gradients of biological function enrichments. The MONTAGE signature matrix can also be used to deconvolve bulk and spot-based spatial transcriptomic data, and combining with clinical metadata, allows assessing SC clinical relevance. In a head and neck cancer study, MONTAGE reveals SCs enriched with malignant cells and granulocytes shifting to SCs enriched with macrophages and fibroblasts along gradient of epithelial-mesenchymal transition, and clinical prognostic significance of the SCs.

systems biology↗

bioRxiv2025

ArchLips: A comprehensive in silico database for high-throughput identification of archaeal lipids

Archaeal membrane lipids are markedly distinct from those in bacteria and eukaryotes, serving as unique biomarkers for unraveling their ecological and biogeochemical roles. Recent advancements in lipidomics have facilitated detailed cellular-level characterizations of lipid compounds. However, the lack of a comprehensive and dedicated database has severely limited large-scale, high-throughput investigations of archaeal lipids. We present ArchLips, a comprehensive database containing 218,868 in silico molecular structures and tandem mass spectra of 199,248 corresponding archaeal lipids. ArchLips enables the rapid and accurate identification of characterized archaeal lipid compounds from both pure cultures and environmental samples, serving as a transformative tool for enhancing our understanding of archaeal diversity and their ecological and evolutionary significance within global ecosystems.

biochemistry↗

bioRxiv2025

Holistic Motor Control of Zebra Finch Song Syllable Sequences

How brain circuits are organized to skillfully produce learned sequences of behaviors is still poorly understood. Here, we functionally examine how the cortical song premotor region HVC, which is necessary for zebra finch song, controls the sequential production of learned song syllables. We find that HVC can generate the complete sequence of learned song syllables independently of its main synaptic input pathways. Thalamic input to HVC is permissive for song initiation but it is not required for transitions between syllables or completing song. We show that excitation of HVC neurons during song reliably causes vocalizations to skip back to the beginning of song, reminiscent of a skipping record. This restarting of syllable sequences can be induced at any moment in song and depends on local circuits within HVC. We identify and computationally model a synaptic network including intratelencephalic premotor and corticostriatal neurons within HVC that are essential for completing song syllable sequences. Together, our results show that the learned zebra finch song is controlled by a cortical sequence-generating network in HVC that, once started, can sustain production of all song syllables independent of major extrinsic input pathways. Thus, sequential neuronal activity can be organized to fuse well-learned vocal-motor sequences, ultimately achieving holistic control of this naturally learned behavior.

neuroscience↗

bioRxiv2025

Strain-level metagenomic profiling using pangenome graphs with PanTax

Microbes are omnipresent, thriving in a range of habitats, from oceans to soils, and even within our gastrointestinal tracts. They play a vital role in maintaining ecological equilibrium and promoting the health of their hosts. Consequently, understanding the diversity in terms of strains in microbial communities is crucial, as variations between strains can lead to different phenotypic expressions or diverse biological functions. However, current methods for taxonomic classification from metagenomic sequencing data have several limitations, including their reliance solely on species resolution, support for either short or long reads, or their confinement to a given single species. Most notably, most existing strain-level taxonomic classifiers rely on the sequence representation of multiple linear reference genomes, which fails to capture the sequence correlations among these genomes, potentially introducing ambiguity and biases in metagenomic profiling. Here, we present PanTax, a pangenome graph-based taxonomic profiler that overcomes the short-comings of sequence-based approaches, because pangenome graphs possess the capability to depict the full range of genetic variability present across multiple evolutionarily or environmentally related genomes. PanTax provides a comprehensive solution to taxonomic classification for strain resolution, compatibility with both short and long reads, and compatibility with single or multiple species. Extensive benchmarking results demonstrate that PanTax drastically outperforms state-of-the-art approaches, primarily evidenced by its significantly higher precision or recall at strain level, while maintaining comparable or better performance in other aspects across various datasets. PanTax is an open-source user-friendly tool that is publicly available at https://github.com/LuoGroup2023/PanTax.

bioinformatics↗

bioRxiv2025

Robotic performance is comparable to human operators for cell therapy manufacturing tasks

Although numerous cell and gene therapies have received regulatory approval, their adoption has been hampered by high cost and challenges in scaling out manufacturing. Many autologous cell therapies are individually manufactured for each patient using traditional manual methods in high-cost environments. Therefore, robotics and automation offer a potential solution to meet the growing demand for such therapies. To ensure identical biological outcomes, automation must replicate validated manual workflows, a requirement that poses significant engineering challenges, especially for aseptic manipulation and compatibility with manual-centric instruments and consumables. Here we describe the design and performance of a modular robotic cluster consisting of specialized modules containing widely adopted equipment. The robotic arm uses custom end-effectors to handle standard consumables and instruments such as syringes, vials, bags, cell counters, bioreactors, incubators, and closed centrifuges. We compared the performance of skilled human operators against the robotic cluster across multiple tasks: transferring cells between sterile bags, cell counting, drawing volume from a vial to a syringe, and resuspension and sampling from both a bag and G-Rex 100M-CS bioreactor. The robotic system also executed high-complexity operations with industry-standard instruments: cell selection using a CytoSinct 1000 and wash/buffer exchange with a CTS Rotea Counterflow centrifugation system. Experimental results for each unit operation show that the robotic clusters performance is equivalent to manual operations on the selected key metrics. These data demonstrate that the robotic system can efficiently and robustly perform specific unit operations, which can be combined in any order for end-to-end cell therapy manufacturing processes. One Sentence summaryA modular robotic system can perform key unit operations in cell therapy manufacturing with accuracy comparable to human operators while ensuring throughput and flexibility.

bioengineering↗

bioRxiv2025

A real-time detection and non-destructive warning method for zebrafish body surface anomalies based on improved YOLOv8 framework

The detection of anomalies on fish surfaces is of critical importance for assessing fish health status, preventing fish disease outbreaks, predicting changes in water quality, enhancing fish welfare. The zebrafish (Danio rerio), a key model organism, has been increasingly utilized in various fields, including medicine, genetics and environmental toxicology. This has led to a corresponding increase in demand for intelligent management and detection systems. However, traditional methods of fish disease detection may have irreversible effects on fish, particularly small species, and often fail to meet the precision, non-destructive warning, and real-time requirements for zebrafish detection. To address this issue, this study proposes a novel method based on the YOLOv8 framework, designated ESC-YOLOv8-seg. This method significantly enhances the precision and speed of detecting surface abnormalities on small fish in complex settings by integrating the EMA the SPPELAN and C2f-Faster modules, and adding a detection head tailored for small targets. Furthermore, the integration of positional information and surface features enables the method to achieve real-time monitoring and non-destructive early warning of fish surface abnormalities. The proposed method enhances precision in small target detection and achieves high accuracy in discerning subtle differences among detection targets. In real aquaculture settings, it can reach an average speed of 106 FPS with a detection accuracy of 98%. Although this study has been designed to meet the specific needs of zebrafish scientific research, it is highly generalisable and can be applied to the real-time detection of underwater surface abnormalities in a range of fish species in aquaculture.

bioinformatics↗

bioRxiv2025

A Versatile Marker-Free Genome Engineering Platform to Overcome Homologous Recombination Bias in Microbes: A Case Study in Synechococcus elongatus UTEX 2973

The single crossover occurring via homologous recombination is a common phenomenon exited among most microbes like Escherichia, Clostridium, Streptococcus, Lactobacillus, and cyanobacteria, threatening the stability of engineered strains. Among them, fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 (Syn2973) is an attractive photosynthetic chassis for CO2 bioconversion. To address the challenge of homologous recombination, we constructed two endogenous plasmid-based shuttle vectors, pSES and pSEL, enabling stable DNA delivery without reliance on homologous recombination. In parallel, two robust counter-selection systems were developed based on sepT2 and rpsL, which, in combination with positive selection markers, significantly improved the screening efficiency of double-crossover mutants. Building upon these tools, we established three marker-free platforms: (i) T4CROSS, which employs two plasmids and four rounds of single crossover; (ii) TRIPLEARM, which uses a single plasmid containing three homologous arms for three rounds of single crossover; and (iii) CRISPRARM, which integrates CRISPR/Cpf1-mediated genome editing with homologous recombination. All three methods successfully repaired mutations in the pilMNOQ pilus gene cluster in Syn2973, restoring natural competence with high efficiency and positive selection rates. As proof of concept, we employed the CRISPRARM platform for a three-step sequential engineering of the sucrose biosynthetic pathway. The final engineered strain produced 7.12 g{middle dot}L-1 of sucrose within four days.

synthetic biology↗

bioRxiv2025

Rapid sexual reproduction in a mixotrophic dinoflagellate revealed through temporal partitioning of cellular processes

Dinophysis are specialist mixotrophs that must balance prey capture, cell division, and sexual recombination during blooms, yet relatively little is known about the occurrence and role of sex in their ecology. Here, mating was investigated in D. acuminata through continuous automated microscopy of cells in culture and during natural blooms. Both in culture and in situ, vegetative division and mating were phased on a diel timescale, occurring primarily at night and near dawn, regardless of prey availability. When prey were available, feeding occurred primarily during daylight hours. The sequencing of division and mating phases, the correlation of their daily amplitudes, and the timing of their establishment after a two-day light block suggests linkage of these processes. Mating, though frequent (up to 14% day-1 in culture), was also not associated with zygote accumulation or resting stage formation but rapid cell reproduction via meiosis. Confinement of division and mating to nighttime and early morning may minimize conflict with photosynthesis-related metabolism and/or predator exposure. Sexual reproduction was the dominant mode of proliferation during the observed blooms, accounting for 71% and 64% of new cell production in 2015 and 2021, respectively. Because it is dependent on encounter of a compatible gamete, sexual reproduction is increasingly accessible as blooms intensify. This sexual mode of proliferation may also alleviate populations susceptibility to pathogens, parasites, and other threats via genetic recombination, an example of Red Queen dynamics.

ecology↗

bioRxiv2025

Cell cycle-coupled transcriptional network orchestrates human B cell fate bifurcation

Bifurcation of activated human B cells into plasmablast (PB) and germinal center precursor (preGC) fates underlies protective and autoimmune antibody responses, yet gene regulatory networks (GRNs) governing the alternative trajectories remain poorly defined. Using temporal single-cell multiomics, we assembled state-specific human B cell GRNs spanning four scales: transcription factor (TF)-to-fate, TF-to-gene, cis-regulatory element (CRE)-to-gene and nucleotide-to-CRE. Applying the framework to in vitro differentiated and tonsil B cells revealed concordant regulatory architectures and impacts of in silico TF perturbations. CRISPR perturbations validated many TF-to-fate and TF-to-gene predictions and revealed a mutually repressive BATF-IRF4/PRDM1 network module. The GRNs were used to predict and interpret effects of autoimmune disease variants, uncovering partitioning of disease risk at distinct TF motifs and B cell states. Predicted functional variants were independently supported by chromatin and expression QTLs and reporter assays. A web application enables exploration of B cell regulatory determinants of vaccine responses and autoimmune diseases.

immunology↗

bioRxiv2025

N1 cassette-lacking NMDA receptors mediate the antidepressant activity of ketamine

Ketamine has emerged as a rapid-acting and robust antidepressant1,2. However, the mechanism of its antidepressant action remains enigmatic. The core issue that has yet to be resolved is whether NMDA receptors (NMDARs), which are subject to open channel blockade by ketamine3,4, mediate the antidepressant effect. NMDARs naturally undergo alternative splicing of the obligatory GluN1 subunit5, producing receptor diversity in the brain that has not been considered in the actions of ketamine. Here we discover that alternative splicing of Grin1 exon 5, which leads to exclusion (GluN1a) or inclusion (GluN1b) of the N1 cassette, located in the N-terminal domain of GluN1 distant from the pore, unexpectedly dictates the level and dynamics of NMDAR blockade by ketamine and gates its antidepressant activity. We find that ketamine prevents NMDAR-dependent long-term potentiation (LTP) in the CA1 region of the hippocampus in mice engineered to exclude Grin1 exon 5 (GluN1a mice), but ketamine has no effect on LTP in mice engineered to include this exon (GluN1b mice). Ketamine inhibits synaptic NMDARs in CA1 pyramidal neurons in both GluN1a and GluN1b mice, with the level of steady-state blockade marginally greater in GluN1a- than in GluN1b-containing NMDARs. However, the rate of relief of ketamine blockade upon membrane depolarization is markedly slower in GluN1a than in GluN1b neurons such that GluN1a-containing receptors remain blocked during bursting activity, whereas those containing GluN1b escape the ketamine blockade. Furthermore, ketamine treatment, either via systemic administration or local infusion into the hippocampus, induces an antidepressant effect in GluN1a mice but has no effect in GluN1b mice. Collectively, we identify GluN1a-containing NMDARs, which are persistently blocked by ketamine during neuronal firing activity, to be selectively responsible for the antidepressant effect.

neuroscience↗

bioRxiv2025

Deciphering of single-cell chromatin accessibility and transcriptome reveals the discrepancy for ex vivo human erythropoiesis

BackgroundErythroid cells can be generated from hematopoietic stem and progenitor cells (HSPC) derived from various sources; however, few studies decode ex vivo human erythropoiesis for the discrepancies at single-cell multi-omics resolution and uncover the underlying restraints for erythrocyte regeneration. ResultsWe deciphered ex vivo human erythropoiesis at two differentiation states from three sources at single-cell chromatin accessibility and transcriptomes level. We identified detrimental myeloid differentiation tendencies during early differentiation. These tendencies were linked to low glutamine activity in cord blood- and iPSC-derived erythropoiesis. The erythroid progenitor differentiation is restricted by cell cycle and hypoxia signaling deficiencies, which are pronounced in the iPSC-derived erythropoiesis. We delineated the erythroid differentiation trajectory of various ex vivo erythropoiesis systems, and revealed a distinct roadmap from HSC to orthochromatic erythroblast with unprecedented resolution. The integrative analysis of single-cell chromatin accessibility and transcriptome across developmental stages uncovered a dynamic coordination, and highlighted the pivotal role of chromatin accessibility and associated enhancers in regulating ex vivo erythropoiesis. Cell-cell communications in the ex vivo erythropoiesis system were not as well established as those in the BM, suggesting that modulating cell-cell communication signals in distinct ex vivo erythropoiesis system may facilitate erythrocyte regeneration. ConclusionsThis study comprehensively characterized the discrepancies and constraints in ex vivo human erythropoiesis at single-cell multi-omics resolution, offering novel strategies to overcome these constraints. These insights are critical for advancing functional erythrocyte generation and have significant implications for clinical applications.

developmental biology↗

bioRxiv2025

MLO-mediated Ca2+ influx regulates root hair tip growth in Arabidopsis

O_LIRoot hair tip-growth involves coordinated Ca2+ and ROS signaling to promote growth while maintaining tip integrity. MILDEW RESISTANCE LOCUS-O (MLO) proteins act downstream of FERONIA (FER) receptor-like kinases in pollen tubes and synergids to regulate calcium dynamics. This study uses a constitutively active MLO (faNTA) to identify a new role for the FER/MLO signaling module in regulating [Ca2+]cyt oscillations in growing root hairs. C_LIO_LIfaNTA bypasses FER signaling in root hairs, complementing not only the previously reported fer-4 root hair bursting phenotype, but also the complete loss of polarity in spherical root hairs. This complementation correlates with the restoration of tip-focused [Ca2+]cyt oscillations that are disrupted in fer mutants, suggesting that MLOs are involved in regulating [Ca2+]cyt dynamics in growing root hairs. C_LIO_LIMLO15 was identified as a regulator of root hair tip-growth based on disrupted root hair growth and [Ca2+]cyt signatures in mlo15-4. We also link the FER/MLO module to ROS accumulation by showing that faNTA is sufficient to restore ROS levels in fer-4 root hairs and that ROS levels are decreased in mlo15-4 root hairs. C_LIO_LIWe propose that MLOs act downstream of FER to mediate Ca2+ influx and promote ROS production in order to regulate root hair tip-growth. C_LI Plain Language SummaryRoot hairs are important for expanding the surface area of the root for optimal absorption of water and minerals. A FERONIA/MLO signal module promotes tip growth in these specialized cells by regulating calcium and reactive oxygen species accumulation. Understanding tip growth mechanisms may help optimize root responses to environmental challenges.

plant biology↗

bioRxiv2025

Histone 3 lysine 36 trimethylation by SETD2 shapes an epigenetic landscape in intestinal stem cells to orchestrate lipid metabolism and prevent cell senescence.

The self-renewal capacity of intestinal stem cells (ISCs) declines with aging, leading to a loss of homeostasis and an increased susceptibility to intestinal diseases. Despite the established significance of lipid metabolism and epigenetic regulation in ISC function, the molecular mechanisms that connect these processes to aging-related ISC dysfunction remain elusive. Here, we demonstrate that Histone 3 lysine 36 trimethylation (H3K36me3) caused by SETD2 is critical for ISC stemness. We found that H3K36me3 deficiency results in reduced ISC proliferation and differentiation, disrupts fatty acid oxidation (FAO) metabolism, and induces ISC senescence. Mechanistically, the loss of H3K36me3 triggers the activity of the SWI/SNF chromatin remodeling complex and leads to increased chromatin accessibility and enhancer activation, which alters FAO- and senescence-related gene expression. Importantly, we discover that metabolic intervention can prevent the senescence of ISC due to H3K36me3 deficiency. Our findings reveal a crucial role for H3K36me3 in maintaining the epigenetic landscape that orchestrates FAO metabolism and determines intestinal stem cell functions, emphasizing the role of FAO as a key modulator between H3K36me3 and ISC aging, suggesting that metabolic intervention may help mitigate age-related ISC dysfunction.

cell biology↗

bioRxiv2025

A heart releasing neuropeptide that synchronizes brain-heart regulation during courtship behavior

Distinct internal states drive varied animal behaviors, yet the mechanisms by which non-neuronal factors encode these states remain largely unknown. Here, we show that cardiac activity regulates internal mating states through a conserved brain-heart axis in male flies and mice. In Drosophila, a ppk23-P1 pathway triggers heart rate acceleration upon female perception via crustacean cardioactive peptide, while the heart secretes ion transport peptide that feeds back onto P1 neurons to enhance courtship. Ejaculation rapidly decreases heart rate via Corazonin, mitigating prolonged tachycardia. In mice, a conserved Substance P-TacR1 pathway modulates courtship. Finally, we developed a computational framework to decode internal mating states from cardiac physiology, revealing distinct cardiac signatures. Our findings unveil a novel role for heart-derived neuropeptides in internal state regulation, elucidate a positive feedback loop between the heart and brain, and demonstrate the evolutionary conservation of the brain-heart axis in orchestrating dynamic behavioral and physiological states.

neuroscience↗

bioRxiv2025

AT1R and Integrin β3 Synergize to Drive Aortic Dissection via Non-Canonical Wnt/β-Catenin Signaling

Aortic dissection (AD), a life-threatening cardiovascular emergency, continues to impose high mortality due to insufficient therapeutic options, as monotherapy targeting angiotensin II type 1 receptor (AT1R) demonstrates limited clinical efficacy. Utilizing single-cell RNA sequencing, we identified integrin {beta}3 as a critical driver of AD progression, with expression levels positively correlated with disease severity. Histopathological validation in human AD specimens and a murine angiotensin II (AngII)-infusion model confirmed marked upregulation of integrin {beta}3 activation. Pharmacological blockade of integrin {beta}3 with Cyclo(-RGDfK) significantly attenuated aortic pathogenesis in vivo, reducing dissection incidence and aortic degeneration. Mechanistically, AngII-mediated AT1R activation induced formation of a receptor complex with integrin {beta}3, triggering its conformational activation. Transcriptomic profiling revealed that activated integrin {beta}3 potentiates vascular endothelial dysfunction by binding glycogen synthase kinase 3{beta} (GSK3{beta}), which stabilizes {beta}-catenin via a non-canonical Wnt signaling axis. This pathway drives endothelial barrier disruption, hallmarks of aortic wall destabilization in AD. Our findings unveil a previously unrecognized synergy between AT1R and integrin {beta}3, implicating aberrant Wnt/{beta}-catenin signaling as a nexus of endothelial injury in AD pathogenesis. These results advocate for a paradigm-shifting dual-therapeutic strategy concurrently targeting AT1R and integrin {beta}3 to restore vascular homeostasis, offering a mechanistically grounded approach to mitigate this lethal disease. This work bridges critical gaps in understanding AD pathophysiology and provides a transformative framework for precision therapeutics.

pharmacology and toxicology↗

bioRxiv2025

Reactive Oxygen Species Counteract Wound Contraction and Promote Wound Healing

Reactive oxygen species (ROS) are second messengers that drive wound closure. However, the mechanism by which ROS regulate wound contraction to facilitate wound healing remains unclear. Here, we report that ROS counteract wound contraction by inhibiting the phosphorylation of myosin regulatory light chain. Acute ROS inhibition, through pharmacological perturbations, disturbs wound relaxation, delays wound closure, and impairs regrowth following amputation. Moreover, actomyosin inhibition relaxes tailfin contraction without impairing wound closure or regrowth. Over-contraction, on the other hand, impedes wound closure. Meanwhile, chronic depletion of epithelial ROS during embryonic development, achieved through morpholino-mediated knockdown of the duox gene, alters tissue stiffness, as measured using atomic force microscopy-based nanoindentation. Despite a reduced contraction force, the wound also appears to be over-contracted, with delayed healing and regrowth. An in silico linear elasticity simulation to calculate the second principal stress based on node-wise prescribed displacement recapitulated the contraction dynamics during acute and chronic ROS inhibition. Together, our results provide a novel understanding of how reactive oxygen species (ROS) facilitate wound closure, a process instrumental in restoring tissue integrity and maintaining homeostasis.

cell biology↗