Biology subjects

Chen, X.-H.

Publications and source records attributed to Chen, X.-H..

7 recordsLinked to original sources

bioRxiv2026

Elevated procoagulant platelets driven by necroptosis and pyroptosis aggravate pulmonary thrombosis via suppressing monocyte efferocytosis in severe pneumonia

BACKGROUND: Severe influenza pneumonia with secondary bacterial infection is complicated by progressive pulmonary thrombus exacerbation, a key contributor to respiratory failure, yet anticoagulant therapies show limited efficacy and bleeding risks. Although platelet-monocyte crosstalk initiates thrombosis, whether and how it drives thrombus exacerbation via procoagulant platelets and monocyte efferocytosis remains unclear. METHODS: Clinical samples, mouse models, and isolated platelets challenged with influenza A virus followed by methicillin-resistant Staphylococcus aureus (MRSA) were analyzed. Procoagulant platelet, platelet programmed cell death and monocyte efferocytosis were assessed, and pharmacological inhibition, platelet depletion and systemic/platelet-specific Gsdmd knockout were used. Platelet proteomics and exogenous C1qa supplementation identified C1qa as a key mediator. RESULTS: We showed that elevated procoagulant platelet-driven thrombus exacerbation, rather than initial thrombus formation, was a critical driver of disease progression in influenza pneumonia with secondary bacterial infection, whereas influenza alone caused milder illness. Procoagulant platelet formation was induced via MLKL-mediated necroptosis and GSDMD-mediated pyroptosis. These platelets exacerbated pulmonary thrombosis and lung injury by inhibiting monocyte efferocytosis via complement C1qa. Platelet depletion reduced monocyte efferocytosis and worsened pneumonia, while pharmacological inhibition or platelet-specific Gsdmd knockout decreased procoagulant platelet levels, restored monocyte efferocytosis, and alleviated thrombotic and pulmonary injury. Mechanistically, C1qa impaired efferocytosis both by directly suppressing monocyte function and by reducing the proportion of reparative (M2-like) monocytes. Clinical relevance was confirmed by detection of MLKL/GSDMD-dependent procoagulant platelets and reduced efferocytosis receptor levels on monocytes in bronchoalveolar lavage fluid from severe pneumonia patients. CONCLUSIONS: Necroptosis/pyroptosis-driven procoagulant platelets exacerbate pulmonary thrombosis by suppressing monocyte efferocytosis in a C1qa-dependent manner. These findings extend platelet-monocyte crosstalk from thrombus initiation to thrombus exacerbation, identifying modulation of the interaction between procoagulant platelets and monocyte efferocytosis as a potential therapeutic strategy for thrombus-exacerbating diseases, especially in subpopulations of patients with severe pneumonia and progressive pulmonary thrombosis.

cell biology↗

bioRxiv2026

The Ser83, Arg85, Tyr88, Asn124, Lys192 of C-terminal Lipid-associated membrane hemagglutinin affecting Mycoplasma synoviae agglutination of erythrocyte

Mycoplasma synoviae is an avian pathogen that causes respiratory disease and synovitis, and its hemagglutinin plays a critical role in host cell adhesion. However, the key residues and structural mechanisms underlying hemagglutination remain unclear. In this study, domain analysis of the hemagglutinin family of Mycoplasma synoviae revealed that it contains long-chain and short-chain types, among which LAM HA (VY93_RS01465) was selected as the bait protein due to its complete C-terminal conserved domain. Through yeast two-hybrid screening, 18 host proteins interacting with LAM HA were identified. Furthermore, five key amino acid residues S83, R85, Y88, N124, and K192 were found to mediate hemagglutination activity. Deletion of these residues reduced the hemagglutination titer of LAM HA under acidic conditions. Secondary structure analysis showed that the deletion mutation decreased the -helix content while increasing the proportions of {beta}-sheet and random coil. Molecular dynamics simulations revealed that the mutant exhibited generally higher root mean square deviation and root mean square fluctuation values than the wild-type under different pH conditions, with a marked decrease in structural stability particularly at pH 5.0 and 6.0. These findings indicate that LAM HA, as a critical adhesin, exerts its hemagglutination function dependent on specific key residues and pH-sensitive conformational stability. IMPORTANCEMycoplasma synoviae (M. synoviae) causes significant economic losses to the poultry industry worldwide. Lipid-related membrane protein hemagglutinin (LAM HA) is a surface adhesin essential for host cell attachment, but its precise amino acid residues and structural features have not been defined. In this study, five key residues (S83, R85, Y88, N124, and K192) were identified as critical for LAM HA-mediated hemagglutination activity. Deletion of these residues altered the secondary structure composition, reduced conformational stability under acidic pH conditions, and decreased hemagglutination activity. These findings reveal a previously unknown structure-function relationship of M. synoviae LAM HA, demonstrating that its hemagglutination activity depends on specific residues and pH-sensitive structural integrity. This provides new insights into the molecular mechanisms of M. synoviae adhesion and offers potential targets for the development of novel intervention strategies against avian mycoplasmosis.

microbiology↗

bioRxiv2026

Indazolone-Based Molecular Glue Degraders as a Tunable Platform for Reprogramming Cereblon Substrate Specificity

Molecular glue degraders (MGDs) represent a transformative modality in drug discovery, with the cereblon (CRBN)-MGD axis offering a strategic gateway to systematically address the historically undruggable proteome. However, the limited chemical diversity of existing CRBN-mediated MGDs has constrained the full exploration of the degradable landscape. Here, we introduce an innovative indazolone-based platform that extends beyond canonical isoindolinone-glutarimide scaffolds, significantly expanding the accessible chemical space for CRBN modulation. Guided by mechanistic insights into CRBN-MGD complex conformational plasticity, we rationally designed indazolone architectures as novel CRBN ligands, developing diverse MGDs with potent ligase binding and exceptional substrate programmability. This platform enables fine-tuned control over neo-substrate recognition, supporting diverse degradation profiles ranging from the broad targeting of critical proteins (IKZF1/3, ZFP91, and LIMD1) to the exquisitely selective degradation of CK1 and IKZF2. Beyond expanding the chemical landscape for intractable targets, our indazolone-based MGDs exhibit favorable pharmacokinetic properties, offering robust promise for therapeutic development. Collectively, the remarkable tunability and exceptional neo-substrate programmability of the indazolone-based platform provide a highly transformative blueprint for next-generation MGD discovery, enabling systematic exploration of the vast CRBN-accessible proteome. Furthermore, as superior CRBN ligands, this platform holds immense potential for PROTAC discovery to systematically address previously intractable targets.

biochemistry↗

bioRxiv2025

StCEL-based platform enables detection and sequencing of native sialoglycoRNA

Glycosylated RNAs (glycoRNAs) are an emerging class of biomolecules characterized by glycans attached to RNA molecules. Currently, glycoRNA detection remains largely confined to cellular models, substantially impeding its functional characterization and clinical translation. Here, we developed sialyltransferase-mediated chemical enzymatic labeling (StCEL), in which azido-modified sialic acid was transferred to the natural sialic acid on sialoglycoRNA, enabling the detection of native sialoglycoRNA across diverse biological samples with high specificity and sensitivity. Using StCEL, we found that sialoglycoRNA was significantly upregulated in multiple cancer types. StCEL combined with a microplate reader was applied to detect sialoglycoRNA in large-scale samples, revealing that elevated sialoglycoRNA levels correlate positively with tumor malignancy and poor patient prognosis. Furthermore, StCEL-based sialoglycoRNA enrichment and sequencing identified dysregulated sialoglycoRNAs in tumor tissues. Collectively, StCEL establishes a multifunctional platform that enables sensitive and specific detection of sialoglycoRNA, alongside sequencing analysis, demonstrating significant potential for clinical translation.

molecular biology↗

bioRxiv2025

Visible-Light-Controlled Residue-Selective Cross-Linking for Deciphering Protein Complexes and Dynamic Protein-Protein Interactions in Live Cells

Cross-linking mass spectrometry (XL-MS) has emerged as an attractive technology for investigating protein complexes and protein-protein interactions (PPIs). However, commonly used cross-linking strategies present significant challenges for precise analysis of protein complexes and dynamic PPIs in native biological environments. Here we present the visible-light-controlled lysine-selective cross-linking (VL-XL) strategy for in-depth analysis of protein complexes and dynamic PPIs both in vitro and in live cells, building on light-induced primary amines and o-nitrobenzyl alcohols cyclization (PANAC) chemistry. We demonstrate that the VL-XL strategy effectively explores the dynamic dimerization of PD-L1 stimulated by exogenous modulators. Moreover, the VL-XL strategy successfully profiles the time-resolved EGF-stimulated EGFR interactome, providing valuable insights into the regulatory mechanisms of EGFR signaling and intracellular trafficking. Importantly, the VL-XL strategy efficiently deciphers the molecular glue (MG) induced dynamic PPIs and substrate profile of MG degrader, opening an innovative avenue for identifying neo-substrates. By harnessing the advantages of temporal controllability, good biocompatibility, and lysine selectivity, the VL-XL method simplifies MS data analysis and facilitates the acquisition of accurate structural information of protein complexes and the elucidation of elusive PPIs in live cells. Overall, the VL-XL strategy expands the XL-MS toolbox, and realizes in-depth analysis of protein complexes and dynamic PPIs, which will inspire innovative solutions for protein interactomes research and structural systems biology.

biochemistry↗

bioRxiv2022

Nanosecond pulsed electric field ablates rabbit VX2 liver tumors in a non-thermal manner versus radiofrequency ablation

BackgroundLiver tumor remains an important cause of cancer-related death. Nanosecond pulsed electric fields (nsPEFs) are advantageous in the treatment of melanoma and pancreatic cancer, but their therapeutic application on liver tumors need to be further studied. MethodsHep3B cells were treated with nsPEFs. The biological behaviors of cells were detected by Cell Counting Kit-8, 5-ethynyl-20-deoxyuridine, and transmission electron microscopy (TEM) assays. In vivo, rabbit VX2 liver tumor models were ablated by ultrasound-guided nsPEFs and radiofrequency ablation (RFA). Contrast-enhanced ultrasound (CEUS) was used to evaluate the ablation effect. HE staining and Masson staining were used to evaluate the tissue morphology after ablation. Immunohistochemistry was performed to determine the expression of Ki67, proliferating cell nuclear antigen, and -smooth muscle actin at different time points after ablation. ResultsThe cell viability of Hep3B cells was continuously lower than that of the control group within 3 days after pulse treatment. The proliferation of Hep3B cells was significantly affected by nsPEFs. TEM showed that Hep3B cells underwent significant morphological changes after pulse treatment. In vivo, CEUS imaging showed that nsPEFs could completely ablate model rabbit VX2 liver tumors. After nsPEFs ablation, the area of tumor fibrosis and the expression of Ki67, proliferating cell nuclear antigen, and -smooth muscle actin were decreased. However, after RFA, rabbit VX2 liver tumor tissue showed complete necrosis, but the expression of PCNA and -smooth muscle actin did not decrease compared to the tumor group. ConclusionsnsPEFs can induce Hep3B cells apoptosis and ablate rabbit VX2 liver tumors in a non-thermal manner versus RFA. The ultrasound contrast agent can monitor immediate effect of nsPEF ablation. This study provides a basis for the clinical study of nsPEFs ablation of liver cancer.

cancer biology↗

bioRxiv2019

Novel Small Molecules Targeting the Intrinsically Disordered Structural Ensemble of α-Synuclein Protect Against Diverse α-Synuclein Mediated Dysfunctions

The over-expression and aggregation of -synuclein (Syn) are linked to the onset and pathology of Parkinsons disease. Native monomeric Syn exists in an intrinsically disordered ensemble of interconverting conformations, which has made its therapeutic targeting by small molecules highly challenging. Nonetheless, here we successfully target the monomeric structural ensemble of Syn and thereby identify novel drug-like small molecules that impact multiple pathogenic processes. Using a surface plasmon resonance high-throughput screen, in which monomeric Syn is incubated with microchips arrayed with tethered compounds, we identified novel Syn interacting drug-like compounds. Because these small molecules could impact a variety of Syn forms present in the ensemble, we tested representative hits for impact on multiple Syn malfunctions in vitro and in cells including aggregation and perturbation of vesicular dynamics. We thereby identified a compound that inhibits Syn misfolding and is neuroprotective, multiple compounds that restore phagocytosis impaired by Syn overexpression, and a compound blocking cellular transmission of Syn. Our studies demonstrate that drug-like small molecules that interact with native Syn can impact a variety of its pathological processes. Thus, targeting the intrinsically disordered ensemble of Syn offers a unique approach to the development of small molecule research tools and therapeutics for Parkinsons disease.

neuroscience↗