Biology subjects

Jiang, Z.

Publications and source records attributed to Jiang, Z..

At least 91 records · Page 5Linked to original sources

bioRxiv2025

Allosteric inhibition rescues hydrocephalus caused by catalytically inactive Shp2

SHP2, a protein tyrosine phosphatase (PTP) crucial in Ras-MAPK signaling, is associated with various human congenital diseases and cancers. Here, we show that the catalytically inactive Shp2C459S mutation results in communicating hydrocephalus, similar to the catalytically activating Shp2E76K and Mek1DD mutants. Unlike previous mutants, however, Shp2C459S/+ mutation uniquely affects ciliary development rather than neurogenesis, leading to reduced cilia density and impaired ciliary motility. Differential scanning fluorimetry revealed that SHP2C459S, SHP2E76K and SHP2C459S/E76K mutations all induce an open SHP2 conformation, but only SHP2C459S leads to aberrant GAB1 phosphorylation in cells expressing wild-type SHP2. This distinctive signaling pattern correlates with our observations in brain ventricular tissues of Shp2C459S/+ mice, where Erk and Stat3 activities remain normal but Gab1 phosphorylation is elevated. Critically, we show that the hydrocephalus phenotype in Shp2C459S mice can be mitigated by allosteric inhibition of Shp2. These findings suggest that Shp2-associated hydrocephalus is driven by conformational changes rather than altered catalytic activity. Our results underscore the therapeutic potential of conformation-specific allosteric inhibitors in targeting both catalytically active and inactive SHP2 mutants.

pathology↗

bioRxiv2024

Establishment of bovine extraembryonic endoderm cells

Understanding the mechanisms of hypoblast development and its role in the implantation is critical for improving farm animal reproduction, but it is hampered by the lack of research models. Here we report that a chemical cocktail (FGF4, BMP4, IL-6, XAV939, and A83-01) enables de novo derivation and long-term culture of bovine extraembryonic endoderm cells (bXENs). Transcriptomic and epigenomic analyses confirmed the identity of bXENs and revealed that they are resemble hypoblast lineages of early bovine peri-implantation embryos. We showed that bXENs help maintain the stemness of bovine ESCs and prevent them from differentiation. In the presence of a signaling cocktail sustaining bXENs, the growth and progression of epiblasts are also facilitated in the developing pre-implantation embryo. Furthermore, through 3D assembly of bXENs with bovine ESCs and TSCs, we developed an improved bovine blastocyst like structure (bovine blastoid) that resembles blastocyst. The bovine XENs and blastoids established in this study represent accessible in vitro models for understanding hypoblast development and improving reproductive efficiency in livestock species.

developmental biology↗

bioRxiv2024

METTL7A improves bovine IVF embryo competence by attenuating oxidative stress

In vitro fertilization (IVF) is a widely used assisted reproductive technology to achieve a successful pregnancy. However, the acquisition of oxidative stress in embryo in vitro culture impairs its competence. Here, we demonstrated that a nuclear coding gene, methyltransferase- like protein 7A (METTL7A), improves the developmental potential of bovine embryos. We found that exogenous METTL7A modulates expression of genes involved in embryonic cell mitochondrial pathways and promotes trophectoderm development. Surprisingly, we discovered that METTL7A alleviates mitochondrial stress and DNA damage and promotes cell cycle progression during embryo cleavage. In summary, we have identified a novel mitochondria stress eliminating mechanism regulated by METTL7A that occurs during the acquisition of oxidative stress in embryo in vitro culture. This discovery lays the groundwork for the development of METTL7A as a promising therapeutic target for IVF embryo competence. Summary statement (Graphic abstract)We describe a molecule acts in the pre-implantation period to attenuate oxidative stress that enhances embryo development to the blastocyst stage and subsequent pregnancy in cattle. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/628915v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@12863c7org.highwire.dtl.DTLVardef@aec66aorg.highwire.dtl.DTLVardef@648ccaorg.highwire.dtl.DTLVardef@1572927_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2024

Ctenophores and parahoxozoans independently evolved complex and functionally diverse sets of voltage-gated K+ channels

The ctenophore species Mnemiopsis leidyi is known to have a large set of voltage-gated K+ channels, but little is known about the functional diversity of these channels or the evolutionary history of this gene family in other ctenophore species. Here, we searched the genomes of two additional ctenophore species, Beroe ovata and Hormiphora californensis, for voltage-gated K+ channels and functionally expressed a subset of M. leidyi channels. We found that the last common ancestor of these three disparate ctenophore lineages probably had at least 33 voltage-gated K+ channels. Two of these genes belong to the EAG family, and the remaining 31 belong to the Shaker family and form a single clade within the animal/choanoflagellate Shaker phylogeny. We additionally found evidence for 10 of these Shaker channels in a transcriptome of the early branching ctenophore lineage Euplokamis dunlapae, suggesting that the diversification of these channels was already underway early in ctenophore evolution. We functionally expressed 16 Mnemiopsis Shakers and found that they encode a functionally diverse array of voltage-gated K+ conductances with functional orthologs for many classic Shaker family subtypes found in cnidarians and bilaterians. Ctenophores therefore appear to have independently evolved much of the voltage-gated K+ channel diversity that is shared between cnidarians and bilaterians.

evolutionary biology↗

bioRxiv2024

Processing negative words in pun-humor: dynamic representation of mixed feelings blending amusement and negativity

This study aims to investigate whether amusement and negativity counteract each other or are jointly intensified during the online processing of negative keywords in pun-humor sentences, and how mixed feelings blending these two emotional states are dynamically experienced over time. Participants read three types of sentences that included the same negative words as keywords: pun-humor (negative words can generate humorous effects by resonating with the context), non-humor (negative words seamlessly align with the context), and nonsensical (negative words cannot be integrated with the context) sentences. The behavioral ratings revealed that compared with non-humor and nonsensical sentences, pun-humor sentences evoked stronger amusement and intensified negative feelings, indicating that pun-humor sentences containing negative keywords can effectively elicit mixed feelings that encompass conflicting emotional states. The ERP results showed that the N400 (300-500 ms) elicited by negative words in pun-humor sentences was comparable to that in non-humor sentences, suggesting that negative words were connected contextually in both sentence types. Besides, negative words elicited greater LPC (600-800 ms) in pun-humor sentences than in non-humor and nonsensical sentences, suggesting that pun-humor sentences require additional semantic processing and more elaborate emotional processing. Moreover, the representational similarity analysis (RSA) results revealed that in pun-humor sentences, the representation of negativity persisted for a longer duration, and it occurred and peaked earlier than that of amusement. This implies that within the dynamic representation of mixed feelings, negativity was experienced first, whereas amusement was subsequently felt within a brief period, during which negativity was not offset but rather continued to be represented over a longer time span, resulting in the simultaneous presence of both amused and negative feelings. Taken together, these findings show that mixed feelings elicited during the online processing of negative keywords in pun-humor sentences can be dynamically experienced in a way that aligns with the highly simultaneous pattern and that negativity can be experienced before amusement during the dynamic representation of mixed feelings.

neuroscience↗

bioRxiv2024

Alternative cGAS signaling promotes Herpes simplex encephalitis

During infection, foreign DNA is sensed by cyclic GMP-AMP synthase (cGAS) leading to the production of cGAMP, STING-dependent type I interferon and proinflammatory cytokine expression, and autophagy. To prevent a response to self-DNA, cGAS activity is tightly regulated. Dysregulation of cGAS underpins interferonopathies, such as Aicardi-Goutieres syndrome, as well as Lupus and neurodegenerative diseases like Parkinsons disease. Thus, cGAS and its product cGAMP are therapeutic targets. However, if cGAS functions independently of cGAMP signaling is undefined. Here, we identified an alternative signaling pathway that cGAS engages independent of cGAMP synthesis. We demonstrate that alternative cGAS signaling promotes hyperexpression of CXCL1 and enhanced neutrophil recruitment that facilitates viral dissemination during herpes simplex encephalitis. Our study is the first report of an alternative cGAS response independent of cGAMP highlighting a previously uncharacterized scaffold function for cGAS.

immunology↗

bioRxiv2024

Deep Learning with Evolutionary Scale Modeling to discover Antibiotic-Resistance Drug against Klebsiella Pneumoniae

The development of effective antibiotics is crucial in combating antibiotic-resistant pathogens such as Klebsiella pneumoniae (KP). This study utilizes deep learning, specifically Evolutionary Scale Modeling (ESM), to identify potential drug candidates. By analyzing molecular similarities between known drugs and KP strains, we aim to accelerate the discovery of new treatments and reduce the risks associated with clinical trials. This approach may shed new lights in the field of drug repositioning.

bioinformatics↗

bioRxiv2024

Activating p53Y220C with a Mutant-Specific Small Molecule

TP53 is the most commonly mutated gene in cancer, but it remains recalcitrant to clinically meaningful therapeutic reactivation. We present here the discovery and characterization of a small molecule chemical inducer of proximity that activates mutant p53. We named this compound TRanscriptional Activator of p53 (TRAP-1) due to its ability to engage mutant p53 and BRD4 in a ternary complex, which potently activates mutant p53 and triggers robust p53 target gene transcription. Treatment of p53Y220C expressing pancreatic cell lines with TRAP-1 results in rapid upregulation of p21 and other p53 target genes and inhibits the growth of p53Y220C-expressing cell lines. Negative control compounds that are unable to form a ternary complex do not have these effects, demonstrating the necessity of chemically induced proximity for the observed pharmacology. This approach to activating mutant p53 highlights how chemically induced proximity can be used to restore the functions of tumor suppressor proteins that have been inactivated by mutation in cancer.

cancer biology↗

bioRxiv2024

Spatiotemporal dynamics and selectivity of mRNA translation during mouse pre-implantation development

Translational regulation is pivotal during preimplantation development. However, how mRNAs are selected for temporal regulation and their dynamic utilization and fate during this period are still unknown. Using a high-resolution ribosome profiling approach, we analyzed the transcriptome, as well as monosome- and polysome-bound RNAs of mouse oocytes and embryos, defining an unprecedented extent of spatiotemporal translational landscapes during this rapid developmental phase. We observed previously unknown mechanisms of translational selectivity, i.e., stage-wise deferral of loading monosome-bound mRNAs to polysome for active translation, continuous translation of both monosome and polysome-bound mRNAs at the same developmental stage, and priming to monosomes after initial activation. We showed that a eukaryotic initiation factor Eif1ad3, which is exclusively translated in the 2-Cell embryo, is required for ribosome biogenesis post embryonic genome activation. Our study thus provides genome-wide datasets and analyses of spatiotemporal translational dynamics accompanying mammalian germ cell and embryonic development and reveals the contribution of a novel translation initiation factor to mammalian pre-implantation development.

developmental biology↗

bioRxiv2024

Recursive Cleaning for Large-scale Protein Data via Multimodal Learning

AO_SCPLOWBSTRACTC_SCPLOWReliable datasets and high-performance models work together to drive significant advancements in protein representation learning in the era of Artificial Intelligence. The size of protein models and datasets has grown exponentially in recent years. However, the quality of protein knowledge and model training has suffered from the lack of accurate and efficient data annotation and cleaning methods. To address this challenge, we introduce ProtAC, which corrects large Protein datasets with a scalable Automatic Cleaning framework that leverages both sequence and functional information through multimodal learning. To fulfill data cleaning, we propose the Sequence-Annotation Matching (SAM) module in the model, which filters the functional annotations that are more suitable for the corresponding sequences. Our approach is a cyclic process consisting of three stages: first pretraining the model on a large noisy dataset, then finetuning the model on a small manually annotated dataset, and finally cleaning the noisy dataset using the finetuned model. Through multiple rounds of "train-finetune-clean" cycles, we observe progressive improvement in protein function prediction and sequenceannotation matching. As a result, we achieve (1) a state-of-the-art (SOTA) model that outperforms competitors with fewer than 100M parameters, evaluated on multiple function-related downstream tasks, and (2) a cleaned UniRef50 dataset containing [~]50M proteins with well-annotated functions. Performing extensive biological analysis on a cleaned protein dataset, we demonstrate that our model is able to understand the relationships between different functional annotations in proteins and that proposed functional annotation revisions are reasonable.

bioengineering↗

bioRxiv2024

Development of potent and selective CK1α Molecular Glue Degraders

Molecular glue degraders (MGDs) are small molecules that facilitate proximity between a target protein and an E3 ubiquitin ligase thereby inducing target protein degradation. Glutarimide-containing compounds are MGDs that bind to cereblon (CRBN) and recruit neosubstrates. Through explorative synthesis of a glutarimide-based library, we discovered a series of molecules that induce casein kinase 1 alpha (CK1) degradation. By scaffold hopping and rational modification of the chemical scaffold, we identified an imidazo[1,2-a]pyrimidine compound that induces potent and selective CK1 degradation. A structure-activity relationship study of the lead compound, QXG-6442, identified the structural features that contribute to degradation potency and selectivity compared to other frequently observed neosubstrates. The glutarimide library screening and structure activity relationship medicinal chemistry approach we employed is generally useful for developing new molecular glue degraders towards new targets of interest.

biochemistry↗

bioRxiv2024

Discovery of electrophilic degraders that exploit SNAr chemistry

Targeted covalent inhibition (TCI) and targeted protein degradation (TPD) have proven effective in pharmacologically addressing formerly undruggable targets. Integration of both methodologies has resulted in the development of electrophilic degraders where recruitment of a suitable E3 ubiquitin ligase is achieved through formation of a covalent bond with a cysteine nucleophile. Expanding the scope of electrophilic degraders requires the development of electrophiles with tempered reactivity that enable selective ligase recruitment and reduce cross-reactivity with other cellular nucleophiles. In this study, we report the use of chemical moieties that enable nucleophilic aromatic substitution (SNAr) reactions in the rational design of electrophilic protein degraders. Appending an SNAr covalent warhead to several preexisting small molecule inhibitors transformed them into degraders, obviating the need for a defined E3 ligase recruiter. The SNAr covalent warhead is versatile; it can recruit various E3 ligases, including DDB1 and CUL4 associated factor 11 (DCAF11), DDB1 and CUL4 associated factor 16 (DCAF16), and possibly others. The incorporation of an SNAr covalent warhead into the BRD4 inhibitor led to the discovery of degraders with low picomolar degradation potency. Furthermore, we demonstrate the broad applicability of this approach through rational functional switching from kinase inhibitors into potent degraders.

biochemistry↗

bioRxiv2024

Comprehensive proteolytic profiling of Aedes aegypti mosquito midgut extracts: Unraveling the blood meal protein digestion system

To sustain the gonotrophic cycle, the Aedes aegypti mosquito must acquire a blood meal from a human or other vertebrate host. However, in the process of blood feeding, the mosquito may facilitate the transmission of several bloodborne viral pathogens (e.g., dengue, Zika, and chikungunya). The blood meal is essential as it contains proteins that are digested into polypeptides and amino acid nutrients that are eventually used for egg production. These proteins are digested by several midgut proteolytic enzymes. As such, the female mosquitos reliance on blood may serve as a potential target for vector and viral transmission control. However, this strategy may prove to be challenging since midgut proteolytic activity is a complex process dependent on several exo- and endo-proteases. Therefore, to understand the complexity of Ae. aegypti blood meal digestion, we used Multiplex Substrate Profiling by Mass Spectrometry (MSP-MS) to generate global proteolytic profiles of sugar- and blood-fed midgut tissue extracts, along with substrate profiles of recombinantly expressed midgut proteases. Our results reveal a shift from high exoproteolytic activity in sugar-fed mosquitoes to an expressive increase in endoproteolytic activity in blood-fed mosquitoes. This approach allowed for the identification of 146 cleaved peptide bonds (by the combined 6 h and 24 h blood-fed samples) in the MSP-MS substrate library, and of these 146, 99 (68%) were cleaved by the five recombinant proteases evaluated. These reveal the individual contribution of each recombinant midgut protease to the overall blood meal digestion process of the Ae. aegypti mosquito. Further, our molecular docking simulations support the substrate specificity of each recombinant protease. Therefore, the present study provides key information of midgut proteases and the blood meal digestion process in mosquitoes, which may be exploited for the development of potential inhibitor targets for vector and viral transmission control strategies. Author SummaryThe Aedes aegypti mosquito is a vector of viral pathogens that can be transmitted directly to humans. For instance, the transmission of dengue, Zika, or chikungunya viruses may happen during the Ae. aegypti acquisition of an infected blood meal. This blood meal is important for the anautogenous mosquito because without the digestion of blood proteins the mosquito will not obtain the necessary nutrients needed for egg production. After imbibing a blood meal, midgut digestive enzymes (proteases) are expressed and secreted into the lumen. To fully understand their roles in blood meal digestion, we used a special technique called Multiplex Substrate Profiling by Mass Spectrometry (MSP-MS). This method allows us to generate global proteolytic activity profiles of Ae. aegypti midgut tissue extracts that were fed with sugar or blood. In addition, we generated substrate cleavage profiles of recombinantly expressed midgut proteases allowing us to understand the enzyme preferences for blood proteins. Therefore, utilizing this approach, we found the contribution of each individual recombinant protease tested relative to the global activity profile of blood-fed midgut tissue extracts. This may be a starting point for the validation of midgut protease inhibition and the development of a new potential vector control strategy.

biochemistry↗

bioRxiv2024

Somatic Transthyretin-Related Proteins in C. elegans Govern Reproductive Longevity by Sustaining Sperm Integrity and Timely Ovulation

The decline in reproductive capability during adult life is critical for health, but its mechanism is elusive. We systematically analyzed the developmental role of an expanded TTR family of proteins, structurally analogous to mammalian thyroid hormone-transporting Transthyretin, and identified three paralogous proteins, TTR-15, TTR-16, and TTR-17, differentially expressed in somatic cells of the gonads and secreted around gametes in C. elegans. Simultaneous inactivation of TTR-15, TTR-16, and TTR-17 leads to a rapid reduction in reproductive capacity in middle age. While oocyte and sperm production remain unaffected in the triple mutants, late-onset infertility results from stalled ovulation. Mechanistically, the absence of TTR-15, TTR-16, and TTR-17 causes sperm to prematurely deplete the cytoplasmic pool of major sperm protein (MSP), released via non-conventional vesicle budding as a signal for ovulation. We propose that the somatic gonads play a central role in maintaining sperm integrity post-production and determining the duration of the reproductive age. HighlightsO_LISystematic analysis of TTR family proteins reveals diverse expression and critical functions. C_LIO_LITTR-15, TTR-16, and TTR-17 are secreted around gametes in C. elegans. C_LIO_LITTR-15/16/17 triple KO exhibits middle-age onset infertility due to stalled ovulation. C_LIO_LIMSP, a signal for ovulation, is prematurely depleted from sperm in the absence of TTR-15/16/17. C_LI

developmental biology↗

bioRxiv2024

CRISPR editing of candidate host factors that impact influenza A virus infection

Influenza A virus (IAV) is a respiratory pathogen with a segmented negative-sense RNA genome that can cause epidemics and pandemics. The host factors required for the complete IAV infectious cycle have not been fully identified. Here, we examined select host factors that were identified by independent CRISPR screens as candidate contributors to IAV infectivity. We performed CRISPR-mediated knockout of cytidine monophosphate N-acetylneuraminic acid synthetase (CMAS) as well as CRISPR-mediated overexpression of beta-1,4 N-acetylgalactosaminyltransferase 2 (B4GALNT2) and adenosine deaminase acting on RNA 1 (ADAR1) in the human bronchial epithelial A549 cell line and evaluated IAV infectivity. We confirmed that the knockout of CMAS or overexpression of B4GALNT2 restricts IAV infection by diminishing binding to the cell surface but has no effect on vesicular stomatitis virus infection. While ADAR1 overexpression does not significantly inhibit IAV replication, it has a pro-viral effect with coxsackie B virus (CVB) infection. This pro-viral effect is not likely secondary to reduced type I interferon (IFN) production, as the induction of the IFN-stimulated genes ISG15 and CXCL10 is negligible in both parent and ADAR1-overexpressing A549 cells following CVB challenge. In contrast, ISG15 and CXCL10 production is robust and equal for parent and ADAR1-overexpressing A549 cells challenged with IAV. Taken together, these data provide insight into how host factors identified in CRISPR screens can be further explored to understand the dynamics of pro- and anti-viral factors. ImportanceInfluenza A virus (IAV) remains a global threat due to its ability to cause pandemics, making the identification of host factors essential for developing new antiviral strategies. In this study, we utilized CRISPR-based techniques to investigate host factors identified in screens as reducing IAV infectivity. Knockout of CMAS, a key enzyme in sialic acid biosynthesis, significantly reduced IAV binding and infection by disrupting sialic acid production on the cell surface. Overexpression of B4GALNT2 had similar effects, conferring resistance to IAV infection through diminished cell-surface binding. While overexpression of ADAR1, known for its role in RNA editing and immune regulation, slightly reduced IAV replication, it increased coxsackie B virus replication. Such findings reveal the diverse roles of host factors in viral infection, offering insights for targeted therapeutic development against IAV and other pathogens.

immunology↗

bioRxiv2024

Repurposing the plant-derived compound apigenin for senomorphic effect in antiaging pipelines

Cellular senescence is a cell fate triggered by inherent or environmental stress and characterized by stable cell cycle arrest accompanied by a hypersecretory feature, termed as the senescence-associated secretory phenotype (SASP). Senescent cell burden increases with natural aging, functionally contributing to age-related organ dysfunction and multiple disorders. In this study, we performed a large scale screening of a natural product library for senotherapeutic candidates by assessing their effects on human senescent cells. Apigenin, a dietary flavonoid previously reported with antioxidant and anti-inflammatory activities, exhibited a prominent capacity in targeting senescent cells as a senomorphic agent. In senescent cells, apigenin blocks the interactions between ATM/p38 and HSPA8, thus preventing transition of the acute stress-associated phenotype (ASAP) towards the SASP. Mechanistically, apigenin targets peroxiredoxin 6 (PRDX6), an intracellular redox-active molecule, suppressing the iPLA2 activity of PRDX6 and disrupting downstream reactions underlying the SASP development. Without reversing cellular senescence, apigenin deprives cancer cells of malignancy acquired from senescent stromal cells in culture, while reducing chemoresistance upon combination with chemotherapy in anticancer regimens. In preclinical trials, apigenin administration improves physical function of animals prematurely aged after whole body irradiation, alleviating physical frailty and cognitive impairment. Overall, our study demonstrates the potential of exploiting a naturally derived compound with senomorphic capacity to achieve geroprotective effects by modulating the SASP, thus providing a research platform for future exploration of novel natural agents against age-related conditions.

cell biology↗

bioRxiv2024

Enhancing Photosynthesis under Salt Stress via Directed Evolution in Cyanobacteria

A key aspect of enhancing photosynthesis is improving its recycling kinetics, enabling swift resumption of photochemical quenching following environmental disruptions or stress. Salt stress exacerbates high light stress in cyanobacteria and leads to severe yield losses in crop plants. Genetic traits that confer salt tolerance without compromising photosynthetic performance are essential for improving photosynthesis under these conditions. Here we applied accelerated evolution in Synechococcus elongatus PCC 7942 by conditionally suppressing its methyl-directed mismatch repair system to obtain beneficial genetic traits for enhanced photosynthesis under salt stress. Screening over 10,000 mutants, we isolated eight strains with increased biomass or sucrose productivity under salt stress. Genome sequencing revealed an average of 8-20 single nucleotide polymorphisms (SNPs) or indels per genome. Notably, mutations in the photosystem II (PSII) reaction center D1 gene, resulting in the amino acid changes L353F, I358N, and H359N at the carboxyl terminus of the pre-D1 (pD1) protein, improve photosynthesis under salt and combined salt and light stress by potentially accelerating D1 maturation during PSII repair. Phylogenetic analysis of pD1 across cyanobacteria and red algae highlights the broad significance of these adaptive genetic traits, underscoring the importance of leveraging evolutionary insights to improve photosynthesis under stress or fluctuating environments.

plant biology↗

bioRxiv2024

Gasdermin D deficiency attenuates development of ascending aortic dissections in a novel mouse model

BackgroundThoracic aortic dissection (TAD) is a silent killer. Approximately two-thirds of the cases occur in the ascending aorta (i.e. type A dissection) and majority of them are unrelated to genetic mutations. However, animal models of spontaneous type A dissection are not widely available. In the present study, a novel mouse TAD model was created. Further, the role of gasdermin D (GSDMD) in TAD development was evaluated. MethodsTADs were created by treating ascending aorta of adult mice (C57BL/6J) with active elastase (40.0 U/ml) and {beta}-aminopropionitrile (Act E+BAPN). The temporal progress of the TAD pathology was rigorously characterized by histological evaluation and scanning electron microscopy, while potential mechanisms explored with bulk RNA sequencing of specimens collected at multiple timepoints. With this novel TAD model, further experiments were performed with Gsdmd-/- mice to evaluate its impact on TAD formation. ResultsThe ascending aorta challenged with Act E+BAPN developed pathology characterized by an early onset of intimomedial tears (complete penetration) and intramural hematoma, followed by progressive medial loss and aortic dilation. Ingenuity Pathway Analysis and functional annotation of differentially expressed genes suggested that a unique inflammatory micro-environment, rather than general inflammation, promoted the onset of TADs by specifically recruiting neutrophils to the aortic wall, while the pathology at the advanced stage was driven by T-cell mediated immune injury. Gsdmd-/- attenuated medial loss, adventitial fibrosis, and dilation of TADs. This protective effect was associated with a reduced number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) positive cells and T-cells in TADs. ConclusionsA novel mouse TAD model was created in the ascending aorta. It produces a unique microenvironment to activate different immune cell subsets, promoting onset and subsequent remodeling of TADs. Consistently, Gsdmd-/- attenuates TAD development, with modulation of cell death and T-cell response likely acting as the underlying mechanism. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=173 HEIGHT=200 SRC="FIGDIR/small/609270v1_ufig1.gif" ALT="Figure 1"> View larger version (91K): org.highwire.dtl.DTLVardef@173a620org.highwire.dtl.DTLVardef@19f8f01org.highwire.dtl.DTLVardef@65bcb9org.highwire.dtl.DTLVardef@1492f88_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗