Biology subjects

Ai, X.

Publications and source records attributed to Ai, X..

10 recordsLinked to original sources

bioRxiv2026

A colorectal cancer organoid-CAF co-culture chip for drug screening and personalized therapy

The tumor microenvironment (TME) plays a critical role in cancer progression and therapeutic response, with cancer-associated fibroblasts (CAFs) being a key stromal component. Conventional tumor organoid models lack TME elements, and existing co-culture systems have limitations in recapitulating dynamic, multidimensional interactions. Here, we developed a novel dynamic co-culture chip (BAC) to better model the TME and investigate CAF-tumor cell crosstalk. Using this platform, we established a non-contact co-culture model of patient-derived colorectal cancer cells and CAFs. The resulting model closely recapitulated the morphological and molecular characteristics of the original patient tumors. Compared with tumor organoids cultured alone, the co-culture system exhibited significantly higher resistance to the clinically common chemotherapeutics 5-fluorouracil and oxaliplatin. Moreover, the presence of CAFs promoted tumor recurrence. Notably, drug responses in the co-culture model showed superior concordance with clinical outcomes relative to both organoid-only and animal models. Transcriptomic profiling under different culture conditions provided further insights into the mechanisms driving CAF-mediated interactions. These findings demonstrate that the BAC-based tumor organoid-CAF co-culture model serves as a more accurate platform for predicting drug responses, investigating TME-dependent mechanisms, and guiding personalized cancer therapy.

Cell Biology↗

bioRxiv2026

A hybrid framework integrating structural machine learning and 3D liver-on-chip assay for drug-induced liver injury prediction

Drug-induced liver injury (DILI) remains a major cause of clinical attrition and postmarketing withdrawal, but structure only DILI predictors are difficult to compare because public benchmarks are vulnerable to compound overlap, scaffold similarity and shared label provenance. We present OakuloidTM, an open DILI prediction framework that pairs a leakage audited structure based model with an optional iBAC 3D primary human hepatocyte IC50/Cmax confirmation signal. The structural model integrates gradient boosted descriptor backbones, fingerprint random forests and LivTox proxy-DILI features through a logistic meta learner. Its evaluation is designed as part of the contribution: internal DILIrank, strict external TDC, scaffold disjoint TDC and independent Geci provenance checks are reported with released per compound predictions. Oakuloid reaches AUROC 0.811 on the strict external TDC benchmark and remains competitive under scaffold and fully clean TDC filtering. A channel attribution ablation shows that the external benchmark lead is driven by descriptor based gradient boosted trees rather than by DILIPredictor derived proxy features, reducing a potential circularity concern. The wet lab IC50/Cmax signal is largely orthogonal to structure and supports a confirmation mode that shifts the internal operating point toward higher specificity without claiming a universal AUROC gain. Oakuloid is released with code, model artifacts, calibration analysis, a 122 compound wet lab benchmark and a model card under the Apache License 2.0, supporting reproducible DILI screening and benchmark auditing.

biochemistry↗

bioRxiv2026

Application of a High-Biomimetic Tumor Organoid-CAF Co-Culture Model for the Efficacy Evaluation of CAR-T Drugs

The tumor microenvironment (TME) is a complex ecosystem composed of tumor cells, cancer-associated fibroblasts (CAFs), immune suppressive cells, and the extracellular matrix (ECM), playing a crucial role in tumor development and CAR-T cell therapy efficacy. CAR-T therapy has shown promise in hematological malignancies but faces challenges in solid tumors due to the TMEs ability to suppress CAR-T cell infiltration, proliferation, and cytotoxicity. Traditional drug evaluation models, such as 2D cell cultures and animal models, have significant limitations due to oversimplification of the in vivo environment or physiological differences between species. Organoid models offer a more biomimetic approach but often fail to fully recapitulate the TMEs complexity and heterogeneity. Our research developed a tumor organoid and CAF co-culture model using the IBAC co-culture chip, demonstrating that CAFs significantly impact CAR-T cell therapy efficacy by forming physical (e.g., fibronectin) and chemical (e.g., IL-10) barriers that prevent CAR-T cell infiltration and cytotoxicity. This model provides a high-biomimetic platform for investigating the TMEs effects on CAR-T therapy and highlights the importance of incorporating a comprehensive stromal component into in vitro models to enhance their predictive power for cancer treatment.

cell biology↗

bioRxiv2026

An immune-poised state of human bronchial epithelial cells mediates RSV resistance in adults

Respiratory syncytial virus (RSV) impairs STAT3 activation in infected ciliated cells in infants, but not adults, causing apoptosis to facilitate virus spread. How age regulates the STAT3 response to RSV in human bronchial epithelial cells (BEpiCs) is unknown. Here, we identify an age-associated immune-poised physiological state in human bronchial basal stem cells (BSCs) and progeny BEpiCs, rendering robust RIG-I to guard against the inactivation of RIG-I-STAT3 signaling by RSV nonstructural protein 2. In contrast, infant BEpiCs are vulnerable to such inactivation by RSV due to lower RIG-I levels. We show that acute respiratory viral infection in specific pathogen-free mice, rather than physical age, triggered sustained epigenetic and transcriptomic remodeling in BEpiCs that resembled age-associated changes in human BEpiCs. In addition, cytokine pretreatment of human neonatal BSCs induced an adult-like immune-poised state that was maintained in progeny BEpiCs to protect against RSV. Therefore, respiratory infection and inflammation during a lifetime imparts the effect of age to BSCs, which fortifies RIG-I in progeny cells to mediate RSV resistance.

microbiology↗

bioRxiv2025

Infant RSV infection desensitizes β2-adrenergic receptor via CXCL11-CXCR7 signaling in airway smooth muscle

RationaleAirflow obstruction refractory to {beta}2 adrenergic receptor ({beta}2AR) agonists is an important clinical feature of infant respiratory syncytial virus (RSV) bronchiolitis, with limited treatment options. This resistance is often linked to poor drug delivery and potential viral infection of airway smooth muscle cells (ASMCs). Whether RSV inflammation causes {beta}2AR desensitization in infant ASMCs is unknown. ObjectivesTo investigate the interaction of RSV inflammation with the {beta}2AR signaling pathway in infant ASMCs MethodsInfant precision-cut lung slices (PCLSs) and mouse pup models of RSV infection were subjected to airway physiological assays. Virus-free, conditioned media from RSV-infected infant bronchial epithelial cells in air-liquid interface (ALI) culture and nasopharyngeal aspirates (NPA) from infants with severe RSV bronchiolitis were collected and applied to infant PCLSs and ASMCs. Cytokines in these samples were profiled and assessed for the effects on {beta}2AR expression, cell surface distribution, and relaxant function in ASMCs. Measurements and Main ResultsConditioned media and NPA induced similar resistance to {beta}2AR agonists in ASMCs as RSV infection. Cytokine profiling identified CXCL11 as one of the most elevated signals following RSV infection. CXCL11 activated its receptor CXCR7 in a complex with {beta}2AR in ASMCs to promote {beta}2AR phosphorylation, internalization, and degradation. Blockade of CXCR7 partially restored airway relaxation in response to {beta}2AR agonists in infant PCLSs and mouse pup models of RSV infection. ConclusionsThe CXCL11-CXCR7 pathway plays a critical role in {beta}2AR desensitization in ASMCs during RSV infection and represents a potential therapeutic target in alleviating airflow obstruction in infant RSV bronchiolitis.

cell biology↗

bioRxiv2023

Age-related STAT3 signaling regulates severity of respiratory syncytial viral infection in human bronchial epithelial cells

Respiratory syncytial virus (RSV) can cause severe disease especially in infants; however, mechanisms of age-associated disease severity remain elusive. Here, employing human bronchial epithelium models generated from tracheal aspirate-derived basal stem cells of neonates and adults, we investigated whether age regulates RSV-epithelium interaction to determine disease severity. We show that following RSV infection, only neonatal epithelium model exhibited cytopathy and mucus hyperplasia, and neonatal epithelium had more robust viral spread and inflammatory responses than adult epithelium. Mechanistically, RSV-infected neonatal ciliated cells displayed age-related impairment of STAT3 activation, rendering susceptibility to apoptosis, which facilitated viral spread. In contrast, SARS-CoV-2 infection of ciliated cells had no effect on STAT3 activation and was not affected by age. Taken together, our findings identify an age-related and RSV-specific interaction with neonatal bronchial epithelium that critically contributes to severity of infection, and STAT3 activation offers a potential strategy to battle severe RSV disease in infants.

cell biology↗

bioRxiv2023

Overactivated epithelial NF-κB disrupts lung development in human and nitrofen CDH

Background & ObjectiveAbnormal lung development is the main cause of morbidity and mortality in neonates with congenital diaphragmatic hernia (CDH), a common birth defect (1:2500) of largely unknown pathobiology. Recent studies discovered that inflammatory processes, and specifically NF-{kappa}B associated pathways are enriched in human and experimental CDH. However, the molecular signaling of NF-{kappa}B in abnormal CDH lung development and its potential as a therapeutic target requires further investigation. Methods & ResultsUsing sections and hypoplastic lung explant cultures from the nitrofen rat model of CDH and human fetal CDH lungs, we demonstrate that NF-{kappa}B and its downstream transcriptional targets are hyperactive during abnormal lung formation in CDH. NF-{kappa}B activity was especially elevated in the airway epithelium of nitrofen and human CDH lungs at different developmental stages. Fetal rat lung explants had impaired pseudoglandular airway branching after exposure to nitrofen, together with increased phosphorylation and transcriptional activity of NF-{kappa}B. Dexamethasone, the broad and clinically applicable anti-inflammatory NF-{kappa}B antagonist, rescued lung branching and normalized NF-{kappa}B signaling in hypoplastic lung explants. Moreover, specific NF-{kappa}B inhibition with curcumenol similarly rescued ex vivo lung hypoplasia and restored NF-{kappa}B signaling. Lastly, we showed that prenatal intraperitoneal dexamethasone administration to pregnant rat dams carrying fetuses with hypoplastic lungs, significantly improves lung branching and normalizes NF-{kappa}B in vivo. Conclusions: Our results indicate that NF-{kappa}B is aberrantly activated in human and nitrofen CDH lungs. Anti-inflammatory treatment with dexamethasone and/ or specific NF-{kappa}B inhibition should be investigated further as a therapeutic avenue to target lung hypoplasia in CDH.

developmental biology↗

bioRxiv2022

A tracheal aspirate-derived airway basal cell model reveals a pro-inflammatory epithelial defect in congenital diaphragmatic hernia

RationaleCongenital diaphragmatic hernia (CDH) is characterized by incomplete closure of the diaphragm and lung hypoplasia. The pathophysiology of lung defects in CDH is poorly understood. ObjectivesTo establish a translational model of human airway epithelium in CDH for pathogenic investigation and therapeutic testing. MethodsWe developed a robust methodology of epithelial progenitor derivation from tracheal aspirates of newborns. Basal stem cells (BSCs) from CDH patients and preterm and term, non-CDH controls were derived and analyzed by bulk RNA-sequencing, ATAC-sequencing, and air-liquidinterface differentiation. Lung sections from fetal human CDH samples and the nitrofen rat model of CDH were subjected to histological assessment of epithelial defects. Therapeutics to restore epithelial differentiation were evaluated in human epithelial cell culture and the nitrofen rat model of CDH. Measurements and Main ResultsTranscriptomic and epigenetic profiling of CDH and non-CDH basal stem cells reveals a disease-specific, proinflammatory signature independent of severity or hernia size. In addition, CDH basal stem cells exhibit defective epithelial differentiation in vitro that recapitulates epithelial phenotypes found in fetal human CDH lung samples and fetal tracheas of the nitrofen rat model of CDH. Furthermore, steroid treatment normalizes epithelial differentiation phenotypes of human CDH basal stem cells in vitro and in nitrofen rat tracheas in vivo. ConclusionsOur findings have identified an underlying proinflammatory signature and BSC differentiation defects as a potential therapeutic target for airway epithelial defects in CDH.

developmental biology↗

bioRxiv2021

Analysis of the Genetic Structure and Diversity of Upland Cotton Groups in Different Planting Areas Based on SNP Markers

Genetic diversity, kinship and population genetic structure analyses of Gossypium hirsutum germplasm can provide a better understanding of the origin and evolution of G. hirsutum biodiversity. In this study, 1313331 SNP molecular markers were used to construct a phylogenetic tree of each sample using MEGAX, to perform population structure analysis by ADMIXTURE software and principal component analysis (PCA) by EIGENSOFT software, and to estimate relatedness using SPAGeDi. ADMIXTURE software divided the experimental cotton population into 16 subgroups, and the Gossypium hirsutum samples could be roughly clustered according to source place, but there were some overlapping characteristics among samples. The experimental cotton population was divided into six groups according to source to calculate the genetic diversity index (H), and the obtained value (0.306) was close to that for germplasm collected by others in China. Cluster 4 had a relatively high genetic diversity level (0.390). The degrees of genetic differentiation within the experimental cotton population groups were low (the population differentiation indexes ranged from 0.02368 to 0.10664). The genetic distance among cotton accessions varied from 0.000332651 to 0.562664014, with an average of 0.25240429. The results of this study may provide a basis for mining elite alleles and using them for subsequent association analysis.

genomics↗

bioRxiv2020

Hippo signaling promotes Ets21c-dependent apical cell extrusion in the Drosophila wing disc

Cell extrusion is a crucial regulator of epithelial tissue development and homeostasis. Epithelial cells undergoing apoptosis, bearing pathological mutations, and possessing developmental defects are actively extruded toward elimination. However, the molecular mechanisms of Drosophila epithelial cell extrusion are not fully understood. Here, we report that activation of the conserved Hippo (Hpo) signaling pathway induces both apical and basal cell extrusion in the Drosophila wing disc epithelia. We show that canonical Yorki targets Diap1, and that dMyc and Cyclin E are not required for either apical or basal cell extrusion induced by activation of this pathway. Another target gene, bantam, is only involved in basal cell extrusion, suggesting novel Hpo-regulated apical cell extrusion mechanisms. Using RNA-Seq analysis, we found that JNK signaling is activated in the extruding cells. We provide genetic evidence that JNK signaling activation is both sufficient and necessary for Hpo-regulated cell extrusion. Furthermore, we demonstrate that the ETS-domain transcription factor Ets21c, an ortholog of proto-oncogenes FLI1 and ERG, acts downstream of JNK signaling to mediate apical cell extrusion. Our findings reveal a novel molecular link between Hpo signaling and cell extrusion. SUMMARY STATEMENTActivation of Hippo signaling induces cell extrusion in the Drosophila wing epithelia, in which bantam mediates basal cell extrusion and Ets21c mediates apical cell extrusion.

developmental biology↗