Biology subjects

Yue, H.

Publications and source records attributed to Yue, H..

At least 19 recordsLinked to original sources

bioRxiv2026

Engineering xylose metabolism for diverse polyhydroxyalkanoates synthesis in Halomonas TD

Engineering the biosynthesis of fully biodegradable polyhydroxyalkanoates (PHAs) from non-food and renewable feedstocks like lignocellulose is becoming an attractive strategy for sustainable biomanufacturing. However, the efficiency and diversity of PHA synthesis from lignocellulosic hydrolysate (LH), mainly containing glucose and xylose, still remains challenge. Here, Halomonas TD, a cost-effective PHA-producing chassis, was developed to utilize glucose and xylose (or LH) for effective production of poly-3-hydroxybutyrate (PHB) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] by engineering the phosphoketolase pathway-dependent xylose metabolism in the genome, yielding 50.1 g L-1 PHB and 42.6 g L-1 P(3HB-co- 11.4 mol% 4HB) under fed-batch condition. Subsequently, the introduction of Weimberg pathway was found be able to synthesize terpolymer consisting of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB) and 3-hydroxyvalerate (3HV), namely [P(3HB-co-4HB-co-3HV)], from glucose and xylose only due to the isoenzyme activity of keto-acid decarboxylase encoded by kivD, which converts xylose-derived intermediate 2,5-dioxopentanoate and -ketoglutarate into butanedial (4HB synthesis) and 2-ketobutyrate (3HV synthesis), respectively. Finally, a tailored-made xylose-induced system was constructed to achieve exquisite xylose transmembrane transportation control for improved synthesis of terpolymer P(3HB-co-4.5 mol% 4HB-co- 3.0 mol% 3HV), reaching to 6.3 g L-1 under shake-flask condition, together with the co-expression of fine-tuned phosphoketolase and Weimberg pathways. This study provides a feasible and sustainable alternative for lignocellulosic resources valorization powered by the engineered Halomonas TD capable of efficient xylose utilization and diverse PHAs synthesis.

bioengineering↗

bioRxiv2026

IID-KG: An ontology-aligned literature-derived knowledge graph for infectious and immune-mediated diseases

Infectious and immune-mediated diseases (IIDs) represent a broad and rapidly expanding biomedical literature domain in which scalable evidence extraction, disease ontology refinement, and interpretable knowledge integration are essential for biomedical discovery. We constructed an IID-specific biomedical knowledge graph (IID KG) from PubMed abstracts and PMC full-text articles by integrating nested named entity recognition, ontology-guided identifier assignment, full-text relation extraction, and relation-resolution strategies. A gold-standard corpus of 500 PubMed abstracts and 8 PMC full-text articles was manually annotated for nested biomedical entities across six entity types. The resulting models were applied to 30,128,068 PubMed abstracts and 1,385,500 IID-related PMC full-text articles. A unified IID ontology was developed from 411,341 disease terms using hierarchical text classification, large language model-based refinement, ontology cross-referencing, and expert review, yielding 179,657 confirmed MeSH mappings. The final IID KG contains approximately 1,837,513 unique entities and 16,295,390 unique relations across eight relation types. The resource was released publicly together with repurposing workflows, supporting ontology-aligned literature mining, disease mechanism analysis, and drug-repurposing hypothesis generation for IID research.

bioinformatics↗

bioRxiv2026

Regulator of G Protein Signaling 6 Negatively Regulates Platelet Activation and Arterial Thrombosis in Mice

BackgroundPlatelet activation via G protein-coupled receptors (GPCRs) is central to arterial thrombosis. P2Y12 is a canonical Gi-coupled receptor mediating ADP-dependent platelet activation, yet the role of Regulator of G protein Signaling 6 (RGS6), a modulator of Gi signaling, in platelet function and thrombosis remains unclear. ObjectivesTo determine the role of RGS6 in platelet activation and arterial thrombosis and to define its impact on P2Y12/Gi signaling. MethodsArterial thrombosis was assessed using a FeCl{square}-induced carotid artery injury model in wild-type (WT) and Rgs6-/- mice. Platelet aggregation was measured ex vivo. Signaling pathways were analyzed by Western blot in ADP-stimulated platelets. P2Y12/Gi signaling was further evaluated using a cAMP-responsive luciferase reporter assay in HEK293 cells. ResultsMale Rgs6-/- mice exhibited significantly accelerated thrombosis compared with WT controls. Rgs6-/- platelets showed enhanced ADP-induced aggregation, whereas collagen-induced aggregation was unchanged. In ADP-stimulated platelets, RGS6 deficiency altered signaling kinetics, characterized by delayed Akt phosphorylation and reduced PKA and VASP phosphorylation. In a heterologous cAMP-luciferase assay, RGS6 attenuated P2Y12/Gi-mediated suppression of cAMP. Two-way ANOVA demonstrated significant effects of ADP and RGS6 expression on luciferase activity, with no interaction, indicating that RGS6 modulates signaling magnitude rather than agonist sensitivity. Pharmacologic inhibition of P2Y12 with clopidogrel abolished the genotype-dependent difference in thrombosis in vivo. ConclusionsRGS6 acts as a negative regulator of platelet P2Y12/Gi signaling and thrombus formation. Loss of RGS6 enhances ADP-dependent platelet activation and accelerates arterial thrombosis, establishing RGS6 as an endogenous brake on platelet activation.

cell biology↗

bioRxiv2026

Dynamic engagement of dual-role regulators by the Sin3 complex

Gene expression is governed by dynamic switches between repressive and activating transcriptional states1,2. Among the molecules mediating these transitions, chromatin readers and transcription factors play pivotal roles3,4. However, how they assemble with regulatory machineries to enable crosstalk between gene repression and activation remains unknown. Here, we use an integrative structural dynamics approach - combining cryo-EM, crosslinking mass spectrometry, fragment-resolved protein interactome mapping and crystallography - to show how the dual-role chromatin reader Cti6 and transcription factors Ash1 and Ume6 engage the Sin3 deacetylase complex, a major regulatory hub in eukaryotes5. We find that Cti6 competes with Ash1 to drive its dynamic recruitment to a shared peripheral module, while Ume6 engages the Sin3 scaffold through a defined, minimal interface. Using high-throughput mutational scanning, we reveal deleterious and gain-of-function mutations in Sin3, identifying evolutionarily conserved residues essential for anchoring transcription factors. Together, these results provide structural and functional insights into how dual-role regulators engage the central Sin3 complex, revealing subtle assembly principles that may facilitate crosstalk between gene repression and activation. They also establish an integrative multidisciplinary framework to dissect the dynamics of macromolecular assemblies across biological systems.

molecular biology↗

bioRxiv2025

Thymidine Phosphorylase Drives SARS-CoV-2 Spike Protein-Induced Lung Tumorigenesis

Rationale and ObjectivesCOVID-19 survivors exhibit increased interstitial lung fibrosis, a known risk factor for lung cancer. We investigated whether SARS-CoV-2 Spike protein (SP)-induced lung injury and elevated thymidine phosphorylase (TYMP) promote lung tumorigenesis. MethodsA TriNetX retrospective cohort analysis was combined with mechanistic studies in K18-hACE2TG and K18-hACE2TG/Tymp-/- mice. Mice received intratracheal SP or control lysate followed by a urethane-induced lung cancer protocol. Lung injury, inflammation, thrombosis, fibrosis, STAT3 activation, cytokine profiles, and tumor burden were assessed. In vitro assays evaluated SP- and RBD-induced ACE2 processing. ResultsPropensity score-matched TriNetX cohorts demonstrated an increased lung cancer risk after COVID-19, particularly among current smokers (n = 166,807; RR 1.22; HR 1.50; P < .001). In mice, SP induced acute lung injury, neutrophil infiltration, and microthrombi, which were reduced in TYMP-deficient mice. SP markedly increased lung tumor incidence and aggressiveness, whereas TYMP deficiency reduced tumor formation from 50% to 18% of lung lobes. SP-induced STAT3 upregulation and collagen deposition were significantly attenuated in K18-hACE2TG/Tymp-/- mice. Cytokine profiling revealed a tumor-promoting, myeloid-dominant inflammatory milieu in K18-hACE2TG mice, in contrast to a T cell-inflamed, anti-tumor profile in K18-hACE2TG/Tymp-/- mice. SP and RBD altered ACE2 processing, generating lower-molecular-weight fragments consistent with enhanced turnover. ConclusionsSARS-CoV-2 SP drives lung injury, fibrosis, and tumorigenesis through a TYMP-dependent mechanism involving STAT3 signaling and inflammatory microenvironment remodeling. COVID-19 significantly increases lung cancer risk, especially in current smokers. TYMP represents a potential therapeutic target to mitigate long-term pulmonary consequences of COVID-19.

cell biology↗

bioRxiv2025

RBM15 promotes lung adenocarcinoma progression and palbociclib sensitivity via m6A-mediated STIL activation and downstream cyclin D1/CDK4 signaling

RNA-binding motif protein 15 (RBM15), an N6-methyladenosine (m6A) methyltransferase, plays a crucial role in the progression of lung adenocarcinoma (LUAD); however, the underlying mechanisms remain insufficiently defined. In this study, we investigated the contribution of RBM15-mediated m6A modification to LUAD pathogenesis. Our data showed that RBM15 was highly expressed in LUAD tissues and cell lines. Notably, its expression levels were positively correlated with tumor TNM staging and negatively correlated with differentiation status. The overexpression of RBM15 enhanced cell proliferation, migration, invasion, and cell cycle progression, while simultaneously inhibiting apoptosis. Conversely, RBM15 knockdown reversed these phenotypes and induced G2/M-phase arrest. In vivo experiments further confirmed that RBM15 knockdown led to the suppression of tumor growth. RNA sequencing, MeRIP sequencing, and bioinformatics analyses identified STIL as a gene directly regulated by RBM15 through m6A modification, a finding subsequently validated by luciferase reporter assays. Western blot and rescue experiments demonstrated that RBM15 and STIL cooperatively activate the cyclin D1/CDK4 signaling pathway, thereby promoting LUAD progression. However, this effect was markedly attenuated by CDK4/6 inhibitor application. Collectively, these findings indicated that the RBM15-STIL-cyclin D1/CDK4 axis represents a promising therapeutic target for LUAD.

cancer biology↗

bioRxiv2025

ALK1-BMPRII agonism by clustering bispecific antibodies treats hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is characterized by arteriovenous malformations (AVMs) and severe bleeding caused by loss-of-function mutations in the ALK1 receptor pathway. We developed clustering agonist bispecific antibodies (BsAbs) targeting ALK1 and its activating partner, the Ser/Thr receptor kinase BMPRII. These BsAbs induced ALK1-BMPRII proximity association, stimulated the downstream Smad1/5/8 signaling cascade, and treated HHT pathologies in various mouse models. BsAb treatment reduced AVM burden by up to 95% in HHT mice, preventing anemia, cardiomegaly, and premature death. The BsAbs also enhanced Smad1/5/8 signaling in endothelial cells derived from HHT patients with ALK1 mutations and prevented retinal AVMs in a newly developed knock-in mouse carrying an HHT-causing ALK1 mutation. These findings establish ALK1-BMPRII agonism as a promising therapeutic strategy for HHT.

cell biology↗

bioRxiv2025

REINDEER2: practical abundance index at scale

Recent advances in biological sequence indexing have enabled the efficient querying of sequence presence across massive genomic data repositories. While presence queries have become tractable at petabyte scale, retrieving quantitative information such as sequence abundances remains a significant algorithmic challenge. Existing abundance-aware indexes are mostly static, difficult to scale, and often trade off completeness, precision, or updatability. We describe a novel discrete abundance index designed for scalability, dynamic updates, and tunable precision. We combine an inverted index with probabilistic and exact structures to support fast, memory-efficient construction and precise high-throughput queries across thousands of RNA datasets. Our experiments demonstrate that our method REINDEER2 achieves one to two orders of magnitude speedup in construction compared to existing methods, while maintaining comparable or better memory use. Despite using approximate structures for scalability, REINDEER2 achieves sub-1% error on abundance recovery and correlates strongly with reference quantifiers like Kallisto. It also supports sequence-level queries in seconds over thousands of datasets. Code and experiments github.com/Yohan-HernandezCourbevoie/REINDEER2

bioinformatics↗

bioRxiv2025

Decoding protein-peptide interactions using a large, target-agnostic yeast surface display library

Protein-peptide interactions underlie key biological processes and are commonly utilized in biomedical research and therapeutic discovery. It is often desirable to identify peptide sequence properties that confer high-affinity binding to a target protein. However, common approaches to such characterization are typically low throughput and only sample regions of sequence space near an initial hit. To overcome these challenges, we built a yeast surface displayed library representing [~]6.1 x 109 unique peptides. We then performed screens against diverse protein targets, including two antibodies, an E3 ubiquitin ligase, and an essential membrane-bound bacterial enzyme. In each case, we observed motifs that appear to drive peptide binding and we identified multiple novel, high-affinity clones. These results highlight the librarys utility as a robust and versatile tool for discovering peptide ligands and for characterizing protein-peptide binding interactions more generally. To enable further studies, we will make the library freely available upon request.

bioengineering↗

bioRxiv2024

Ternary complex formation of VCP, VCPIP1 and p47 facilitates Golgi reassembly

VCP/p97 regulates a wide range of cellular processes, including post-mitotic Golgi reassembly. In this context, VCP is assisted by p47, an adapter protein, and VCPIP1, a deubiquitinase (DUB). However, how they organize into a functionally competent complex and promote reassembly remains unknown. Here, we use cryo-EM to characterize VCP-VCPIP1 and VCP-VCPIP1-p47 complexes. We show that VCPIP1 engages VCP through two interfaces: one involving the N-domain of VCP and the UBX domain of VCPIP1, and the other involving the VCP D2 domains and a region of VCPIP1 we refer to as VCPID. The p47 UBX domain competitively binds to the VCP N-domain, while not affecting VCPID binding. We show that VCPID is critical for VCP-mediated enhancement of DUB activity and Golgi reassembly.

biochemistry↗

bioRxiv2024

YTHDF1 Facilitates Lung Adenocarcinoma Progression via Promotion of EEF1G Translation in a m6A-Dependent Manner

Lung adenocarcinoma (LUAD) is a malignant tumor with high morbidity and mortality worldwide, and overall survival rates for LUAD patients remain unimproved. RNA modification is a key process in post-transcriptional gene regulation in epigenetics, with N6-methyladenosine (m6A) being a common RNA modification. The molecular mechanisms of LUAD are unclear, but evidence suggests that m6A RNA methylation plays a significant role. This study aimed to clarify the role of YTHDF1 in LUAD development and pathogenesis. These findings confirmed that YTHDF1, a m6A reader protein, is highly expressed in LUAD tissues and is correlated with tumor differentiation and TNM stage. The results of functional loss experiments in LUAD cell lines revealed that downregulating YTHDF1 inhibits proliferation, migration, and invasion and induces apoptosis, with opposite effects observed upon YTHDF1 upregulation. In vivo, YTHDF1 knockout suppressed LUAD xenograft growth. RNA-seq, MeRIP-seq, RIP-seq, and bioinformatics analyses identified EEF1G as a downstream target of YTHDF1 in LUAD, and high expression of EEF1G was confirmed. The interaction between YTHDF1 and EEF1G was validated through RIP-qPCR, Co-IP and Co-IF assays. The overexpression of EEF1G in LUAD cells partially counteracts the tumor suppression induced by YTHDF1 silencing, and the knockdown of EEF1G has the opposite effect, further confirming the regulatory relationship. In summary, this study describes a novel YTHDF1/EEF1G regulatory pathway in which YTHDF1 promotes LUAD progression by recognizing and binding to the m6A-modified mRNA of EEF1G, accelerating its translation, suggesting that YTHDF1 may be a potential biomarker and therapeutic target.

cancer biology↗

bioRxiv2024

Unveiling the hidden interactome of CRBN molecular glues with chemoproteomics

Targeted protein degradation and induced proximity refer to strategies that leverage the recruitment of proteins to facilitate their modification, regulation or degradation. As prospective design of glues remains challenging, unbiased discovery methods are needed to unveil hidden chemical targets. Here we establish a high throughput affinity purification mass spectrometry workflow in cell lysates for the unbiased identification of molecular glue targets. By mapping the targets of 20 CRBN-binding molecular glues, we identify 298 protein targets and demonstrate the utility of enrichment methods for identifying novel targets overlooked using established methods. We use a computational workflow to estimate target confidence and perform a biochemical screen to identify a lead compound for the new non-ZF target PPIL4. Our study provides a comprehensive inventory of targets chemically recruited to CRBN and delivers a robust and scalable workflow for identifying new drug-induced protein interactions in cell lysates.

cancer biology↗

bioRxiv2024

Galvanotactic directionality of cell groups depends on group size

Motile cells migrate directionally in the electric field in a process known as galvanotaxis, important and under-investigated phenomenon in wound healing and development. We previously reported that individual fish keratocyte cells migrate to the cathode in electric fields, that inhibition of PI3 kinase reverses single cells to the anode, and that large cohesive groups of either unperturbed or PI3K-inhibited cells migrate to the cathode. Here we find that small uninhibited cell groups move to the cathode, while small groups of PI3K-inhibited cells move to the anode. Small groups move faster than large groups, and groups of unperturbed cells move faster than PI3K-inhibited cell groups of comparable sizes. Shapes and sizes of large groups change little when they start migrating, while size and shapes of small groups change significantly, lamellipodia disappear from the rear edges of these groups, and their shapes start to resemble giant single cells. Our results are consistent with the computational model, according to which cells inside and at the edge of the groups pool their propulsive forces to move but interpret directional signals differently. Namely, cells in the group interior are directed to the cathode independently of their chemical state. Meanwhile, the edge cells behave like individual cells: they are directed to the cathode/anode in uninhibited/PI3K-inhibited groups, respectively. As a result, all cells drive uninhibited groups to the cathode, while larger PI3K-inhibited groups are directed by cell majority in the group interior to the cathode, while majority of the edge cells in small groups win the tug-of-war driving these groups to the anode. Significance statementMotile cells migrate directionally in electric fields. This behavior - galvanotaxis - is important in many physiological phenomena. Individual fish keratocytes migrate to the cathode, while inhibition of PI3K reverses single cells to the anode. Uninhibited cell groups move to the cathode. Surprisingly, groups of PI3K-inhibited cells exhibit bidirectional behavior: larger/smaller groups move to the cathode/anode, respectively. A mechanical model suggests that inner and outer cells interpret directional signals differently, and that a tug-of-war between the outer and inner cells directs the cell groups. These results shed light on general principles of collective cell migration.

cell biology↗

bioRxiv2024

Discovery of Potent Degraders of the Dengue Virus Envelope Protein

Targeted protein degradation has been widely adopted as a new approach to eliminate both established and previously recalcitrant therapeutic targets. Here we report the development of small molecule degraders of the envelope (E) protein of dengue virus. We developed two classes of bivalent E-degraders, linking two previously reported E-binding small molecules, GNF-2 and CVM-2-12-2, to a glutarimide-based recruiter of the CRL4CRBN ligase to effect proteosome-mediated degradation of the E protein. ZXH-2-107 (based on GNF-2) is an E degrader with ABL inhibition while ZXH-8-004 (based on CVM-2-12-2) is a selective and potent E-degrader. These two compounds provide proof-of-concept that difficult-to-drug targets such as a viral envelope protein can be effectively eliminated using a bivalent degrader and provide starting points for the future development of a new class antiviral drugs.

biochemistry↗

bioRxiv2024

Sodium/Potassium ATPase Alpha 1 Subunit Fine-tunes Platelet GPCR Signaling Function and is Essential for Thrombosis

BackgroundThrombosis is a major cause of myocardial infarction and ischemic stroke. The sodium/potassium ATPase (NKA), comprising and {beta} subunits, is crucial in maintaining intracellular sodium and potassium gradients. However, the role of NKA in platelet function and thrombosis remains unclear. MethodsWe utilized wild-type (WT, 1+/+) and NKA 1 heterozygous (1+/-) mice, aged 8 to 16 weeks, of both sexes. An intravital microscopy-based, FeCl3-induced carotid artery injury thrombosis model was employed for in vivo thrombosis assessment. Platelet transfusion assays were used to evaluate platelet NKA 1 function on thrombosis. Human platelets isolated from healthy donors and heart failure patients treated with/without digoxin were used for platelet function and signaling assay. Complementary molecular approaches were used for mechanistic studies. ResultsNKA 1 haplodeficiency significantly reduced its expression on platelets without affecting sodium homeostasis. It significantly inhibited 7.5% FeCl3-induced thrombosis in male but not female mice without disturbing hemostasis. Transfusion of 1+/-, but not 1+/+, platelets to thrombocytopenic WT mice substantially prolonged thrombosis. Treating WT mice with low-dose ouabain or marinobufagenin, both binding NKA 1 and inhibiting its ion-transporting function, markedly inhibited thrombosis in vivo. NKA 1 formed complexes with leucine-glycine-leucine (LGL)-containing platelet receptors, including P2Y12, PAR4, and thromboxane A2 receptor. This binding was significantly attenuated by LGL>SFT mutation or LGL peptide. Haplodeficiency of NKA 1 in mice or ouabain treatment of human platelets notably inhibited ADP-induced platelet aggregation. While not affecting 10% FeCl3-induced thrombosis, NKA 1 haplodeficiency significantly prolonged thrombosis time in mice treated with an ineffective dose of clopidogrel. ConclusionNKA 1 plays an essential role in enhancing platelet activation through binding to LGL-containing platelet GPCRs. NKA 1 haplodeficiency or inhibition with low-dose ouabain and marinobufagenin significantly inhibited thrombosis and sensitized clopidogrels anti-thrombotic effect. Targeting NKA 1 emerges as a promising antiplatelet and antithrombotic therapeutic strategy.

cell biology↗

bioRxiv2024

ROS Mediated the Photodynamic Antibacterial of Vibrio vulnificus by a DNA-Targeted Molecular Rotor Probe

Vibrio vulnificus, a highly pathogenic Gram-negative bacterium, is capable of inducing sepsis, necrotizing fasciitis, and skin and soft tissue infections through contact with wounds. Currently, the majority of V. vulnificus strains have developed resistance to multiple drugs, highlighting the critical necessity for the development of novel therapeutics capable of effectively targeting and eradicating this bacterium. In recent years, material molecules have emerged as promising antimicrobial agents. This study introduces a novel molecular fluorescent probe, BDTP, which demonstrates a wide-ranging antimicrobial effect against both Gram-negative and Gram-positive bacteria while exhibiting minimal toxicity to normal mammalian cells. Of particular significance is BDTPs ability to rapidly detect V. vulnificus, bind to bacterial DNA, and exhibit fluorescence monitoring behavior. Furthermore, BDTP displays enhanced photodynamic antibacterial activity when exposed to white light irradiation. Under a low dose of white light (15mW cm-2), the killing efficiency of V. vulnificus irradiated with 4uM for 10 minutes was more than 99.8%. Moreover, it could significantly inhibit and eliminate the biofilm formed by V. vulnificus. It can induce the production of reactive oxygen species (ROS) in V. vulnificus cells, leading to bacterial cell damage. More importantly, BDTP significantly promoted the healing of infected wounds in an animal model of V. vulnificus infection. Therefore, BDTP shows great promise as a potent antibacterial agent against V. vulnificus infection.

microbiology↗

bioRxiv2024

Thymidine Phosphorylase Promotes the Formation of Abdominal Aortic Aneurysm in Mice Fed a Western Diet

AimsThe precise molecular drivers of abdominal aortic aneurysm (AAA) remain unclear. Thymidine phosphorylase (TYMP) contributes to increased platelet activation, thrombosis, and inflammation, all of which are key factors in AAA development. Additionally, TYMP suppresses the proliferation of vascular smooth muscle cells (VSMCs), which are central to the development and progression of AAA. We hypothesize that TYMP plays a key role in AAA development. Methods and ResultsWe conducted a histological study using human AAA samples and normal abdominal aortas, revealing heightened levels of TYMP in human AAA vessel walls. To validate this observation, we utilized an Ang II perfusion-induced AAA model in wild-type C57BL/6J (WT) and Tymp-/-mice, feeding them a Western diet (TD.88137) starting from 4 weeks of age. We found that Tymp-/-mice were protected from Ang II perfusion-induced AAA formation. Furthermore, by using TYMP-expressing VSMCs as well as primarily cultured VSMCs from WT and Tymp-/- mice, we elucidated the essential role of TYMP in regulating MMP2 expression and activation. TYMP deficiency or inhibition by tipiracil, a selective TYMP inhibitor, led to reduced MMP2 production, release, and activation in VSMCs. Additionally, TYMP was found to promote pro-inflammatory cytokine expression systemically, and its absence attenuates TNF--stimulated activation of MMP2 and AKT. By co-culturing VSMCs and platelets, we observed that TYMP-deficient platelets had a reduced inhibitory effect on VSMC proliferation compared to WT platelets. Moreover, TYMP appeared to enhance the expression of activated TGF{beta}1 in cultured VSMCs in vitro and in human AAA vessel walls in vivo. TYMP also boosted the activation of thrombospondin-1 type 1 repeat domain-enhanced TGF{beta}1 signaling, resulting in increased connective tissue growth factor production. ConclusionOur findings collectively demonstrated that TYMP serves as a novel regulatory force in vascular biology, exerting influence over VSMC functionality and inflammatory responses that promote the development of AAA. Translational PerspectiveThymidine phosphorylase (TYMP) is increased in the vessel walls of patients with abdominal aortic aneurysm (AAA), and TYMP deficiency in mice reduces the incidence of AAA, suggesting that TYMP plays a crucial role in AAA development. This could be attributed to TYMPs role in enhancing systemic inflammation and thrombosis, inhibiting vascular smooth muscle cell function, increasing the activation of matrix metalloproteinase and AKT, as well as enhancing the expression of TGF{beta}1 and connective tissue growth factor. Tipiracil is an FDA-approved drug known to inhibit TYMP-enhanced thrombosis. Targeting TYMP with tipiracil could represent a promising new therapeutic strategy for AAA development.

cell biology↗

bioRxiv2024

Thymidine Phosphorylase Mediates SARS-CoV-2 Spike Protein Enhanced Thrombosis in K18-hACE2TG Mice

COVID-19, caused by SARS-CoV-2, is associated with arterial and venous thrombosis, thereby increasing mortality. SARS-CoV-2 spike protein (SP), a viral envelope structural protein, is implicated in COVID-19-associated thrombosis. However, the underlying mechanisms remain unknown. Thymidine phosphorylase (TYMP), a newly identified prothrombotic protein, is upregulated in the plasma, platelets, and lungs of patients with COVID-19 but its role in COVID-19-associated thrombosis is not defined. In this study, we found that wild-type SARS-CoV-2 SP significantly promoted arterial thrombosis in K18-hACE2TG mice. SP-accelerated thrombosis was attenuated by inhibition or genetic ablation of TYMP. SP increased the expression of TYMP, resulting in the activation of signal transducer and activator of transcription 3 (STAT3) in BEAS-2B cells, a human bronchial epithelial cell line. A siRNA-mediated knockdown of TYMP inhibited SP-enhanced activation of STAT3. Platelets derived from SP-treated K18-hACE2TG mice also showed increased STAT3 activation, which was reduced by TYMP deficiency. Activated STAT3 is known to potentiate glycoprotein VI signaling in platelets. While SP did not influence ADP- or collagen-induced platelet aggregation, it significantly shortened activated partial thromboplastin time and this change was reversed by TYMP knockout. Additionally, platelet factor 4 (PF4) interacts with SP, which also complexes with TYMP. TYMP enhanced the formation of the SP/PF4 complex, which may potentially augment the prothrombotic and procoagulant effects of PF4. We conclude that SP upregulates TYMP expression, and TYMP inhibition or knockout mitigates SP-enhanced thrombosis. These findings indicate that inhibition of TYMP may be a novel therapeutic strategy for COVID-19-associated thrombosis. Key PointsO_LISARS-CoV-2 spike protein, thymidine phosphorylase, and platelet factor 4 form a complex that may promote clot formation. C_LIO_LIInhibiting thymidine phosphorylase attenuates SARS-CoV-2 spike protein-enhanced thrombosis, platelet activation, and coagulation. C_LI

cell biology↗