Biology subjects

Wang, M.

Publications and source records attributed to Wang, M..

At least 289 records · Page 16Linked to original sources

bioRxiv2025

Comparison of Activities of Transcription Factor NF-κB from Two Jellyfish Models

Herein, transcription factor Nuclear Factor-kappaB (NF-{kappa}B) is characterized as the downstream effector of putative innate immune signaling pathways from two model jellyfish, Aurelia aurita (Aa) and Clytia hemisphaerica (Ch). Both jellyfish NF-{kappa}B proteins consist primarily of the N-terminal DNA-binding/dimerization domain, and they lack the C-terminal ankyrin repeat inhibitory domain found in vertebrate NF-{kappa}B proteins. Both jellyfish NF-{kappa}B proteins bind to a consensus mammalian NF-{kappa}B binding site, and their AlphaFold3-predicted structures on DNA are similar to that of mouse NF-{kappa}B p50. Neither Aa- nor Ch-NF-{kappa}B activated transcription of an NF-{kappa}B-site reporter gene in human cells; however, Aa-NF-{kappa}B did activate transcription from a GAL4-site reporter gene in yeast, whereas Ch-NF-{kappa}B did not. Aa- and Ch-NF-{kappa}B were both constitutively located in the nucleus when expressed in vertebrate cells. Homologs of I{kappa}B-like proteins from both species interacted with their corresponding NF-{kappa}B proteins in co-immunoprecipitation assays in HEK 293T cells. These I{kappa}B-like proteins influenced the subcellular localization of their cognate NF-{kappa}B proteins in vertebrate cells, and their ankyrin repeat domains were predicted to interact with Ch-NF-{kappa}B in a manner similar to mammalian I{kappa}B and NF-{kappa}B. RNA-sequencing data from Ch animals indicate that Ch-NF-{kappa}B is expressed at high levels in early developmental stages, when Ch-I{kappa}B expression is low, suggesting that active Ch-NF-{kappa}B controls an early developmental process. In contrast, in adult animals the expression of Ch-I{kappa}B is high, suggesting that Ch-NF-{kappa}B requires a signal in order to become active. Overall, these results provide comparative information on the structure, activity, and mRNA expression of jellyfish NF-{kappa}B pathway proteins among jellyfish, and they suggest roles for NF-{kappa}B in developing and adult jellyfish.

molecular biology↗

bioRxiv2025

Rosace-AA: Enhancing Interpretation of Deep Mutational Scanning Data with Amino Acid Substitution and Position-Specific Insights

Proteins are dynamic systems whose function and behavior are sensitive to environmental conditions and often involve multiple cellular roles. Deep mutational scanning (DMS) experiments generate extensive datasets to capture the functional consequences of mutations. However, the sheer volume of data presents challenges in visualization and interpretation. Current approaches often rely on heatmaps, but these methods fail to capture the nuanced effects of amino acid (AA) substitutions, which are essential for understanding mutational impact. To address this, we extend the Rosace framework with Rosace-AA, a model that incorporates both position-specific information and AA substitution trends. Using substitution matrices like BLOSUM90, Rosace-AA offers a flexible and interpretable approach to summarize DMS data oil both protein-level and position-level. We demonstrate its utility across datasets, including OCTI and MET kinase, showing that Rosace-AA highlights key positions where mutations deviate from expected substitution patterns and captures functionally relevant variation in protein behavior across multiple DMS screens. These results suggest that Rosace-AA enables more robust and interpretable analysis of complex DMS datasets.

bioinformatics↗

bioRxiv2025

Ptpn14 Knockout Mice Reveal Critical Female-Specific Roles for the Hippo Pathway

The Hippo pathway regulates many physiological processes, including development, tumor suppression, and wound healing. One understudied Hippo pathway component is PTPN14, an evolutionarily conserved tyrosine-phosphatase that inhibits YAP/TAZ. While an established tumor suppressor, PTPN14s role in tissue homeostasis has remained unclear. We thus generated Ptpn14-deficient mice and found that only [~]60% of Ptpn14-/- mice survived postnatally, highlighting the importance of PTPN14 for viability, while also enabling the discovery of PTPN14 physiological functions. Ptpn14-/-mice developed debilitating corneal lesions and the uterus defect, hydrometra, as well as heart and kidney abnormalities. Ptpn14-deficiency precipitated an impaired injury response in the cornea and dysregulated YAP signaling in the uterus. Notably, these phenotypes were female-specific, revealing sexually-dimorphic Hippo pathway function through PTPN14. Finally, analysis of human PTPN14 variants suggested that PTPN14s essential roles are conserved in humans, underscoring the importance of our insights for designing therapies to improve womens health.

developmental biology↗

bioRxiv2025

The single amino acid change of R516K enables efficient generation of vesicular stomatitis virus-based Crimean-Congo hemorrhagic fever reporter virus

Crimean-Congo hemorrhagic fever virus (CCHFV) is a medically important tick-borne virus, causing severe hemorrhagic diseases in humans. There is no approved vaccines and therapeutics for CCHFV infection. The study of CCHFV authentic virus requires biosafety level 3 facilities, hindering the research and development of antivirals. Here we report the generation of a recombinant vesicular stomatitis virus (VSV) bearing both CCHFV glycoprotein precursor (GPC) and EGFP reporter (rVSV-CCHFV-GFP). We also find that the acquisition of an unexpected single R516K mutation in the GPC protein enables the packaging of high-titer pseudotyped particles. The replication-competent rVSV-CCHFV-GFP reporter virus resembles the entry properties of authentic virus and allows for rapid assessment of susceptible cell lines, neutralizing antibodies, and host entry factors such as heparan sulfate in fluorescence-based assays. This study provides valuable strategy for packaging of high-titer CCHFV pseudovirus, and the tool generated here can be served for the identification and evaluation of countermeasures against the cell entry of CCHFV.

microbiology↗

bioRxiv2025

YX0798 Is a Highly Potent, Selective, and Orally Effective CDK9 Inhibitor for Treating Aggressive Lymphoma

Non-genetic transcription evolution has been increasingly explored and recognized to drive tumor cell progression and therapeutic resistance. As the regulation hub of transcription machinery, cyclin-dependent kinase 9 (CDK9) is the gatekeeper of RNA polymerase II (Pol II) transcription, and CDK9 dysfunction results in transcriptomic reprogramming and tumor cell progression. We recently reported that the HSP90-MYC-CDK9 network drives therapeutic resistance in mantle cell lymphoma (MCL) through transcriptomic reprogramming. We also showed that targeting CDK9 by AZD4573 and enitociclib is a safe and effective treatment in preclinical MCL models, supporting CDK9 as a valid therapeutic target for MCL. However, current CDK9 inhibitors (CDK9i) under therapeutic development have room for improvement due to limited target selectivity and oral bioavailability. To this end, YX0798 was discovered to be a novel CDK9i through structural optimization. YX0798 demonstrated remarkable target selectivity and high affinity in binding to CDK9. Furthermore, YX0798 showed good oral bioavailability. YX0798, when administrated orally (5 mg/kg, daily), led to an efficacious anti-tumor activity in vivo and showed the potency in overcoming therapeutic resistance. Mechanistically, YX0798 downregulated the short-lived oncoprotein c-MYC and pro-survival protein MCL-1 as a common mechanism of CDK9 inhibition. Moreover, YX0798 disrupted the cell cycle and resulted in transcriptomic reprogramming, eventually leading to cell death. Together, these data demonstrate that YX0798 has oral bioavailability, exquisite selectivity, and anti-tumor potency that results from driving transcription reprogramming towards tumor cell killing. KEY POINTSO_LIYX0798 showed high selectivity, target binding affinity, and anti-tumor efficacy in overcoming resistance to various therapies. C_LIO_LIYX0798 had good oral pharmacokinetics and anti-tumor effects that resulted from transcription reprogramming towards tumor cell killing. C_LI

cancer biology↗

bioRxiv2025

Genomic feature of filled regions of telomere-to-telomere genomes in five model species

T2T genome is a telomere-to-telomere high-quality genome with exceptional accuracy, continuity and integrity. It significantly filled some gaps of chromosome. However, the genomic features unique to the filled regions assembled in the T2T genome across species remain unclear. Here, we collected and compared T2T genomes with their older version from human (Homo sapiens), animal (Mus musculus), and plants (Arabidopsis thaliana, Musa acuminata, and Fragaria vesca). We explored the newly filled regions generated by the T2T genome in comparison to the old one, and focused on: (1) the comparison of their locations, (2) the distribution of genomic features, and (3) gene annotation and gene function for filled regions. Research indicated that the filled regions of the T2T genome ordinarily appear in the centromere and telomere regions, contain a great number of repetitive sequences. The T2T genome revealed the identification of a certain number of newly annotated genes, alongside significant variations in common annotated genes. Interestingly, the genomic features of filled regions exhibit distinct patterns between plants and human/animal. T2T genomes feature analysis serves as a crucial resource for studying pattern characteristics across diverse species and advancing the in-depth development of genomics.

genomics↗

bioRxiv2024

RNAGenesis: Foundation Model for Enhanced RNA Sequence Generation and Structural Insights

RNA molecules are central to gene regulation, catalysis, and molecular recognition, and offer broad opportunities for therapeutic applications. However, uncovering their complex sequence, structure, and function relationships, particularly for non-coding RNAs, remains a formidable challenge. Here, we introduce RNAGenesis, a Generalist RNA foundation model that integrates sequence representation, structural prediction, and de novo functional design within a single generative framework. Trained on diverse clustered non-coding RNAs, RNAGenesis leverages a BERT-style encoder, query-based latent compression, and a diffusion-guided decoder enhanced by inference-time alignment with gradient guidance and beam search strategies. Through comprehensive evaluations, RNAGenesis achieves state-of-the-art performance on 11 of 13 tasks in the BEACON benchmark and surpasses structure-aware models in inverse folding, 3D structure prediction, and de novo structure design. We further introduce RNATx-Bench, a dedicated benchmark for RNA therapeutics comprising over 100,000 experimentally validated sequences. RNAGenesis demonstrates strong predictive performance across ASOs, siRNAs, shRNAs, circRNAs, and untranslated region (UTR) variants. Furthermore, RNAGenesis enables functional RNA design, including aptamers targeting IGFBP3 and structurally constrained sgRNA scaffolds. Wet-lab validation confirms aptamer binding with KD values as low as 4.02 nM and up to 2.5-fold improvement in editing efficiency across CRISPR-Cas9, base editing, and prime editing systems. These results position RNAGenesis as a next-generation general-purpose RNA foundation model with broad utility for computational modeling and experimental therapeutic design.

bioinformatics↗

bioRxiv2024

Determination of Gaussian curvature modulus and spontaneous curvature via membrane buckling

The elastic properties of membranes are typically characterized by a few phenomenological parameters, including bending and Gaussian curvature moduli measuring the membrane rigidity against its deformation and topological change, as well as spontaneous curvature arising from the asymmetry between the two leaflets in the lipid bilayers. Though tether-based and fluctuation-based experiments are commonly utilized to measure the bending modulus, measuring the Gaussian curvature modulus and the spontaneous curvature of the membrane is considered to be much more difficult. In this paper, we study the buckling process of a circular membrane with nonzero spontaneous curvature under compressive stresses. It is found that when the stress exceeds a critical value, the circular membrane will transform from a spherical cap to a buckled shape, with its buckling degree enhanced with the increase of stress until its base is constricted to almost zero. As the stress-strain relationship of the buckled membrane strongly depends on the Gaussian curvature modulus and the spontaneous curvature,we therefore propose a method to determine the Gaussian curvature modulus and the spontaneous curvature simultaneously by measuring its stress-strain relationship during a buckling process.

biophysics↗

bioRxiv2024

A new class of penicillin-binding protein inhibitors to address drug-resistant Neisseria gonorrhoeae

{beta}-Lactams are the most widely used antibiotics for the treatment of bacterial infections because of their proven track record of safety and efficacy. However, susceptibility to {beta}-lactam antibiotics is continually eroded by resistance mechanisms. Emerging multidrug-resistant (MDR) Neisseria gonorrhoeae strains possessing altered penA alleles (encoding PBP2) pose a global health emergency as they threaten the utility of ceftriaxone, the last remaining outpatient antibiotic. Here we disclose a novel benzoxaborinine-based penicillin-binding protein inhibitor series (boro-PBPi) that is envisioned to address penA-mediated resistance while offering protection against evolution and expansion of {beta}-lactamases. Optimization of boro-PBPi led to the identification of compound 21 (VNRX-14079) that exhibits potent antibacterial activity against MDR N. gonorrhoeae achieved by high affinity binding to the PBP2 target. Boro-PBPi/PBP2 complex structures confirmed covalent interaction of the boron atom with Ser310 and the importance of the {beta}3-{beta}4 loop for improved affinity. 21 elicits bactericidal activity, a low frequency of resistance, a good safety profile, suitable pharmacokinetic properties, and in vivo efficacy in a murine infection model against ceftriaxone-resistant N. gonorrhoeae. 21 is a promising anti-gonorrhea agent poised for further advancement.

microbiology↗

bioRxiv2024

Phages-bacteria interactions underlying the dynamics of polyhydroxyalkanoates-producing mixed microbial cultures via meta-omics study

The dynamics of the structure of polyhydroxyalkanoates-producing mixed microbial cultures (PHA-MMCs) during enrichment and maintenance is an unsolved problem. The effect of phages has been proposed as a cause of dynamic changes in community structure, but evidence is lacking. To address this question, we enriched five PHA-MMCs and sampled temporally to study the interactions between phage and prokaryotic members by combining metagenomics and metatranscriptomics. 963 metagenome-assemble genomes and 4294 phage operational taxonomic units were assembled from bulk metagenomic data. There were complex interactions between the phages in Casadabanvirus and Unclassified Hendrixvirinae and the dominant species in Azomonas, Paracoccus, Thauera and Breundimonas. The dynamic change of the structure of phage and prokaryotic communities were remarkably consistent. Further structural equation modeling analysis showed that phage communities could significantly affect the activity and community structure of prokaryotic microorganisms. In addition, seven key auxiliary metabolic genes (phaC, fadJ, acs, ackA, phbB, acdAB and fadD) in the PHA synthesis pathway were identified from phage sequences. Importantly, these auxiliary metabolic genes were expressed at the transcriptional level, indicating that they were in an active functional state. This meta-analysis provides the first catalog of phages in PHA-MMCs and the auxiliary metabolic genes they carry, as well as how they play a role in the dynamic changes of prokaryotic communities. This study provides a reference for subsequent studies on understanding and regulating the microbial community structure of artificial open microbial systems. ImportanceThe synthesis of biodegradable plastic PHA from organic waste through mixed microbial cultures (MMCs), with extremely low cost, has the potential for expanded production. However, there is a gap of understanding of the dynamics of dominant species in MMCs to better control community structure. Our results demonstrate for the first time the impact of phages on the structure of prokaryotic communities in the MMCs. There are complex interactions between the PHA producers (Azomonas, Paracoccus, Thauera) and phages (Casadabanvirus and Unclassified Hendrixvirinae). Phage communities can negatively regulate the activity and structure of prokaryotic communities. In addition, the auxiliary metabolic genes in the PHA synthesis pathways carried by phages may promote the PHA synthesis ability of prokaryotic members. This study highlights the impact of phages on prokaryotic community structure, suggesting that phages have the potential to become a tool for better controlling the microbial community structure of PHA-MMCs.

microbiology↗

bioRxiv2024

Cardiac Pacemaker Cells Harness Stochastic Resonance to Ensure Fail-Safe Operation at Low Rates Bordering on Sinus Arrest

BACKGROUNDThe sinoatrial node (SAN) is the primary pacemaker of the heart. Recent high-resolution imaging showed that synchronized action potentials (APs) exiting the SAN emerge from heterogeneous signals, including subthreshold signals in non-firing (dormant) cells. This raises a new question in cardiac biology: how do these signals contribute to heartbeat generation? Here, we tested the hypothesis that pacemaker cells harness stochastic resonance to ensure fail-safe operation, especially at low rates bordering on sinus arrest. METHODSMembrane potential and Ca signals were measured using perforated-patch recordings in rabbit SAN cells exposed to sine-wave or white-noise currents. Additionally, we imaged Ca signals in intact mouse SAN tissue and performed multiscale model simulations at the subcellular, cellular, and tissue levels. RESULTSIn addition to classical synchronized Ca transients, SAN tissue exhibited heterogeneous local Ca signals of different kinetics. Noise currents, mimicking the heterogeneous natural cell environment, restored AP firing in dormant cells and substantially improved the rate and rhythm of those firing infrequently and irregularly. The benefit followed a bell-shaped curve: the performance improved but then declined, demonstrating a hallmark of stochastic resonance. Rhythmic AP generation in response to sine-wave currents of different frequencies defined a resonance spectrum in SAN cells, reflecting their ability to respond via stochastic resonance to specific frequency components embedded in noise. Cholinergic stimulation shifted the resonance spectrum and responses to noise toward lower frequencies across all amplitudes tested, rendering cells unresponsive to higher-frequency signals while enabling more effective processing of slower signals. Both the numerical models and simultaneous recordings of membrane potential and Ca dynamics demonstrated that stochastic resonance is amplified by coupled electrical and Ca signaling, enhancing AP generation at low noise levels. Adding noise currents to the cell and tissue models allowed firing under conditions where they otherwise would have stopped. CONCLUSIONSSAN cells harness stochastic resonance amplified by coupled membrane-Ca signaling to ensure rhythmic heartbeat initiation, especially at low rates. This new signaling mechanism could help avoid sinus arrest when heart slows but noise increases, such as during parasympathetic stimulation, bradyarrhythmia, or aging.

biophysics↗

bioRxiv2024

Deficiency of DDI2 suppresses liver cancer progression byworsening cell survival conditions

The levels of reactive oxygen species (ROS) and the extent of ensuing DNA damage significantly influence cancer initiation and progression. Of crucial importance, the aspartate protease DDI2 has been proposed to play a pivotal role in monitoring intracellular ROS levels (to trigger oxidative eustress or distress), as well as in the oxidative DNA damage repair, through redox homeostasis-determining factor Nrf1 (encoded by NFE2L1). However, the specific role of DDI2 in the multi-step process resulting in the development and progression of liver cancer remains elusive to date. In the present study, we employed the CRISPR/Cas9 gene editing system to create two nuanced lines of DDI2 knockout (i.e., DDI2-/- and DDI2insG/-) from liver cancer cells. Subsequent experiments indicate that the knockout of DDI2 leads to increased ROS levels in hepatoma cells by downregulating two major antioxidant transcription factors Nrf1 and Nrf2 (encoded by NFE2L2), exacerbating endogenous DNA damages caused by ROS and not-yet-identified factors, thereby inhibiting cell proliferation and promoting apoptosis, and ultimately hindering in vivo malignant growth of xenograft tumor cells. Conversely, the restoration of DDI2 expression reverses the accumulation of ROS and associated DNA damage caused by DDI2 knockout, eliminating the subsequent inhibitory effects of DDI2 deficiency on both in vitro and in vivo growth of liver cancer cells. Collectively, these findings demonstrate that DDI2 deficiency impedes liver tumor growth by disrupting its survival environment, suggesting that DDI2 may serve as a novel therapeutic target for anti-cancer strategies aimed at modulating ROS or DNA damage processes.

cancer biology↗

bioRxiv2024

Adaptation to cystine limitation stress promotes PDAC tumor growth and metastasis through translational upregulation of OxPPP

Cystine/cysteine is critical for antioxidant response and sulfur metabolism in cancer cells and is one of the most depleted amino acids in the microenvironment of pancreatic ductal adenocarcinoma (PDAC). The effects of cystine limitation stress (CLS) on PDAC progression are poorly understood. Here we report that adaptation to CLS (CLSA) promotes PDAC cell proliferation and tumor growth through translational upregulation of the oxidative pentose phosphate pathway (OxPPP). OxPPP activates the de novo synthesis of nucleotides and fatty acids to support tumor growth. On the other hand, CLSA-mediated lipidomic reprogramming depends on triacylglycerides synthesis and lipid droplet formation to mitigate lipotoxicity. Through drug screening, we identify lomitapide as an inhibitor of CLSA PDAC tumor growth and a potent sensitizer of chemotherapy. Lomitapide inhibits triacylglycerides synthesis to interfere with CLSA and chemotherapy-induced lipidomic reprogramming. Taken together, we demonstrate that CLSA promotes PDAC tumor growth through metabolic reprogramming and lomitapide could be used to target the dysregulated lipid metabolism in PDAC.

cancer biology↗

bioRxiv2024

A genetic safeguard for eliminating target genes in synthetic probiotics in a gut environment

Following the development of therapeutic probiotics, there is an emerging demand for constraining engineered microbial activities to ensure biosafety. Many biocontainment studies developed genetic devices that involve cell death and growth inhibition on the engineered microbes, which often create basal levels of cytotoxicity that hamper cell fitness and performance on therapeutic functions; furthermore, these toxic pathways may promote genetic instability that leads to mutations and breakdown of biocontainment circuit. To address this issue, here we explore a circuit design that destroys the engineered genetic materials in a probiotic strain, instead of killing these cells, under non-permissive conditions. Our safeguard circuit involves a two-layered transcriptional regulatory circuit to control the expression of a CRISPR system that targets the engineered genes for degradation. In Escherichia coli Nissle 1917 (EcN), the biocontainment system continuously scavenged and destroyed the target until no engineered cellular function could be detected, suggesting this strategy has the potential to avoid escapee formation. Additionally, this safeguard circuit did not affect EcN cell fitness. We further demonstrated that the engineered probiotics inhabited in mouse guts and continued the engineered activities for at least 7 days when the permissive signal was supplied constantly; when the permissive signal was not provided, the engineered activities became undetectable within two days. Together, these studies support that our safeguard design is feasible for synthetic probiotic applications. HIGHLIGHTSO_LIOur safeguard system only destroys target genes and does not kill the host microbes C_LIO_LIIt terminated engineered activities in guts in response to a loss of a signal C_LIO_LIThis safeguard allowed synthetic probiotics to inhabit in guts for at least a week C_LIO_LICellobiose has great potential to serve as a continuous genetic signal in guts C_LI

synthetic biology↗

bioRxiv2024

Multimodal single-cell analyses reveal molecular markers of neuronal senescence in human drug-resistant epilepsy

The histopathological neurons in the brain tissue of drug-resistant epilepsy exhibit aberrant cytoarchitecture and imbalanced synaptic circuit function. However, the gene expression changes of these neurons remain unknown, making it difficult for the diagnosis or to dissect the mechanism of drug-resistant epilepsy. By integrating whole-cell patch clamp recording and single-cell RNA sequencing approaches, we identified a transcriptionally distinct subset of cortical pyramidal neurons. These neurons highly expressed genes CDKN1A (P21), CCL2 and NFKBIA that associated with mTOR pathway, inflammatory response and cellular senescence. We confirmed the expression of senescent marker genes in a subpopulation of cortical pyramidal neurons with enlarged soma size in the brain tissue of drug-resistant epilepsy. We further revealed the expression of senescent cell markers P21, P53, COX2, {gamma}-H2AX, {beta}-Gal and reduction of nuclear integrity marker Lamin B1 in histopathological neurons in the brain tissue of drug-resistant epilepsy patients with different pathologies, but not in control brain tissue with no history of epilepsy. Additionally, chronic, but not acute, epileptic seizures induced senescent markers expression in cortical neurons in mouse models of drug-resistant epilepsy. These results provide important molecular markers for histopathological neurons and new insights into the pathophysiological mechanisms of drug-resistant epilepsy.

neuroscience↗

bioRxiv2024

deepBlastoid: A Deep Learning-Based High-Throughput Classifier for Human Blastoids Using Brightfield Images with Confidence Assessment

Recent advances in human blastoids have opened new avenues for modeling early human development and implantation. Human blastoids can be generated in large numbers, making them suitable for high-throughput screening, which often involves analyzing vast numbers of images. However, automated methods for evaluating and characterizing blastoid morphology are still underdeveloped. We developed a deep-learning model capable of recognizing and classifying blastoid brightfield images into five distinct quality categories. The model processes 53.2 images per second with an average accuracy of 87%, without signs of overfitting or batch eHects. By integrating a Confidence Rate (CR) metric, the accuracy was further improved to 97%, with low-CR images flagged for human review. In a comparison with human experts, the model matched their accuracy while significantly outperforming them in throughput. We demonstrate the value of the model in two real-world applications: (1) systematic assessment of the eHect of lysophosphatidic acid (LPA) concentration on blastoid formation, and (2) evaluating the impact of dimethyl sulfoxide (DMSO) on blastoids for drug screening. In the applications involving over 10,000 images, the model identified significant eHects of LPA and DMSO, which may have been overlooked in manual assessments. The deepBlastoid model is publicly available and researchers can train their own model according to their imaging conditions and blastoid culture protocol. deepBlastoid thus oHers a precise, automated approach for blastoid classification, with significant potential for advancing mechanism research, drug screening, and clinical in vitro fertilization (IVF) applications.

developmental biology↗

bioRxiv2024

Engineered human lymph node stroma model for examining interstitial fluid flow and T cell egress

The lymph node (LN) performs essential roles in immunosurveillance throughout the body. Developing in vitro models of this key tissue is of great importance to enhancing physiological relevance in immunoengineering. The LN consists of stromal populations and immune cells, which are highly organized and bathed in constant interstitial flow. The stroma, notably the fibroblastic reticular cells (FRCs) and the lymphatic endothelial cells (LECs), play crucial roles in guiding T cell migration and are known to be sensitive to fluid flow. During inflammation, interstitial fluid flow rates drastically increase in the LN. It is unknown how these altered flow rates impact crosstalk and cell behavior in the LN, and most existing in vitro models focus on the interactions between T cells, B cells, and dendritic cells rather than with the stroma. To address this gap, we developed a human engineered model of the LN stroma consisting of FRC-laden hydrogel above a monolayer of LECs in a tissue culture insert with gravity-driven interstitial flow. We found that FRCs had enhanced coverage and proliferation in response to high flow rates, while LECs experienced decreased barrier integrity. We added CD4+ and CD8+ T cells and found that their egress was significantly decreased in the presence of interstitial flow, regardless of magnitude. Interestingly, 3.0 {micro}m/s flow, but not 0.8 {micro}m/s flow, correlated with enhanced inflammatory cytokine secretion in the LN stroma. Overall, we demonstrate that interstitial flow is an essential consideration in the lymph node for modulating LN stroma morphology, T cell migration, and inflammation.

bioengineering↗

bioRxiv2024

The Landscape of Sex- and APOE Genotype-Specific Transcriptional Changes in Alzheimer's Disease at the Single Cell Level

Alzheimers disease (AD) is the most common form of dementia, with approximately two-thirds of AD patients are females. Basic and clinical research studies show evidence supporting sex-specific differences contributing to the complexity of AD. There is also strong evidence supporting sex-specific interaction between the primary genetic risk factor of AD, APOE4 and AD-associated neurodegenerative processes. Recent studies by us and others have identified sex and/or APOE4 specific differentially expressed genes in AD based on the bulk tissue RNA-sequencing data of postmortem human brain samples in AD. However, there lacks a comprehensive investigation of the interplay between sex and APOE genotypes at the single cell level. In the current study, we systematically explore sex and APOE genotype differences in single cell transcriptomics in AD. Our work provides a comprehensive overview of sex and APOE genotype-specific transcriptomic changes across 54 high-resolution cell types in AD and highlights individual genes and brain cell types that show significant differences between sexes and APOE genotypes. This study lays the groundwork for exploring the complex molecular mechanisms of AD and will inform the development of effective sex- and APOE-stratified interventions for AD.

genomics↗