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Biology subjects

Chen, Y. C.

Publications and source records attributed to Chen, Y. C..

4 recordsLinked to original sources

Patient-specific "Physical Twin" artery-on-chip platform reveals complex flow-dependent VWF mechanobiology and guides personalized antithrombotic therapy

Ischemic stroke triggered by carotid atherosclerosis remains unpredictable because the thrombosis embolization is governed by patient-specific vascular geometry and hemodynamics that cannot be recapitulated in conventional models. Here, we engineered "Physical Twin" artery-on-chip platforms that reproduce individualized carotid anatomy with humanized subendothelial matrix composition and arterial endothelial phenotype under physiological flow patterns. We then established thrombotic microenvironments following laser-induced injury. Computational fluid dynamics-guided experiments across distinct patient geometries reveal that local shear dictates a mechanobiological hierarchy: high-shear bifurcations ([~]3,000 s-{superscript 1}) produce von Willebrand factor (VWF) A1-dependent thrombi suppressible by conformationally sensitive inhibitors, whereas low-shear stenoses generate fragile aggregates where VWF-integrin IIb{beta} coupling governs embolization overgrowth. Pulsatile flow suppresses thrombotic growth independent of mean shear. Molecular dynamics simulations reveal why conformationally sensitive nanobodies (caplacizumab) outperform shear-independent aptamers (ARC1172) in high-shear bifurcation flow zones. This Physical Twin platform provides a mechanistic blueprint for geometry-informed, personalized antithrombotic therapy selection.

bioengineering↗

Arabidopsis UGT76B1 glycosylates N-hydroxy-pipecolic acid and inactivates systemic acquired resistance in tomato

Systemic acquired resistance (SAR) is a mechanism that plants utilize to connect a local pathogen infection to global defense responses. N-hydroxy-pipecolic acid (NHP) and a glycosylated derivative are produced during SAR, yet their individual roles in the response have not yet been elucidated. Here we report that Arabidopsis thaliana UGT76B1 can generate glycosylated NHP (NHP-Glc) in vitro and when transiently expressed alongside Arabidopsis NHP biosynthetic genes in two Solanaceous plants. During infection, Arabidopsis ugt76b1 mutants do not accumulate NHP-Glc and accumulate less glycosylated salicylic acid (SA-Glc) than wild type plants. The metabolic changes in ugt76b1 mutant plants are accompanied by enhanced defense to the bacterial pathogen Pseudomonas syringae, suggesting that glycosylation of SAR molecules NHP and SA by UGT76B1 plays an important role in defense modulation. Transient expression of Arabidopsis UGT76B1 with the Arabidopsis NHP biosynthesis genes ALD1 and FMO1 in tomato increases NHP-Glc production and reduces NHP accumulation in local tissue, and abolishes the systemic resistance seen when expressing NHP-biosynthetic genes alone. These findings reveal that the glycosylation of NHP by UGT76B1 alters defense priming in systemic tissue and provide further evidence for the role of the NHP aglycone as the active metabolite in SAR signaling.

plant biology↗

Conservation of N-hydroxy-pipecolic acid-mediated systemic acquired resistance in crop plants

Signal propagation and the coordination of whole-organism responses in plants rely heavily on small molecules. Systemic acquired resistance (SAR) is one such process in which long-distance signaling activates immune responses in uninfected tissue as a way to limit the spread of a primary, localized infection. Recently, N-hydroxy pipecolic acid (NHP) was discovered and shown to coordinate SAR in Arabidopsis. Here, we provide metabolic and biochemical evidence that NHP is conserved across the plant kingdom and demonstrate a role for NHP in mediating SAR responses in tomato and pepper. We reconstituted the NHP biosynthetic pathway in planta and show that transient expression of two NHP biosynthetic genes in tomato induces enhanced resistance to a bacterial pathogen in distal tissue. Our results suggest engineering strategies to induce NHP-mediated SAR are a promising route to improve broad-spectrum pathogen resistance in crops. IN BRIEFEngineering NHP production is a promising strategy to enhance disease resistance in crops. HIGHLIGHTSO_LIArabidopsis N-hydroxy-pipecolic acid (NHP) pathway is conserved across the plant kingdom C_LIO_LIApplication of NHP to tomato and pepper plants induces a robust SAR response C_LIO_LIMetabolic engineering of the Arabidopsis NHP pathway in Solanum lycopersicum leads to enhanced NHP production and defense priming C_LIO_LIGenetic engineering for enhanced NHP production is a promising strategy to protect crop plants from multiple pathogens C_LI

plant biology↗

N-hydroxy-pipecolic acid is a mobile signal that induces systemic disease resistance in Arabidopsis

Systemic acquired resistance (SAR) is a global response in plants induced at the site of infection that leads to long-lasting and broad-spectrum disease resistance at distal, uninfected tissues. Despite the importance of this priming mechanism, the identity of the mobile defense signal that moves systemically throughout plants to initiate SAR has remained elusive. In this paper, we describe a new metabolite, N-hydroxy-pipecolic acid (N-OH-Pip), and provide evidence that this molecule is a mobile signal that plays a central role in initiating SAR signal transduction in Arabidopsis thaliana. We demonstrate that FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1), a key regulator of SAR-associated defense priming, can synthesize N-OH-Pip from pipecolic acid in planta, and exogenously applied N-OH-PIP moves systemically in Arabidopsis and can rescue the SAR-deficiency of fmo1 mutants. We also demonstrate that N-OH-Pip treatment causes systemic changes in the expression of pathogenesis-related genes and metabolic pathways throughout the plant, and enhances resistance to a bacterial pathogen. This work provides new insight into the chemical nature of a mobile signal for SAR and also suggests that the N-OH-Pip pathway is a promising target for metabolic engineering to enhance disease resistance.

plant biology↗