Biology subjects

Wu, X.-J.

Publications and source records attributed to Wu, X.-J..

6 recordsLinked to original sources

bioRxiv2026

A TSST 1 structural motif disrupts endothelial programs required for vascular regeneration.

Staphylococcus aureus causes profound vascular damage during infection, where it inflicts vascular injury across organs and generates lesions that fail to heal. Superantigens are major virulence factors in S. aureus infections, yet their direct effects on vascular repair remain unclear. We provide evidence that TSST-1 disrupts endothelial regeneration through coordinated mechanisms. TSST-1 interferes with collective directed migration, impairing endothelial cell directional persistence and preventing re-endothelialization in vitro. These defects stem from cytoskeletal disorganization, characterized by stress fiber accumulation and loss of lamellipodia, and broad suppression of motility-associated secreted factors. In an ex vivo aortic ring assay, TSST-1 suppresses angiogenic sprouting and generates dysmorphic vascular networks. Proteomic profiling reveals a shift toward matrix rigidity, adhesion stabilization, and overall suppression of angiogenesis. These activities map to a conserved dodecapeptide motif. Hence, TSST-1 suppression of vascular repair may convert sites of tissue injury into persistently non-healing niches suited for S. aureus persistence.

cell biology↗

bioRxiv2024

The GPR4 antagonist NE-52-QQ57 increases survival, mitigates the hyperinflammatory response and reduces viral load in SARS-CoV-2-infected K18-hACE2 transgenic mice

COVID-19 (Coronavirus disease 19) is caused by infection with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) in the respiratory system and other organ systems. Tissue injuries resulting from viral infection and host hyperinflammatory responses may lead to moderate to severe pneumonia, systemic complications, and even death. While anti-inflammatory agents have been used to treat patients with severe COVID-19, their therapeutic effects are limited. GPR4 (G protein-coupled receptor 4) is a pro-inflammatory receptor expressed on vascular endothelial cells, regulating leukocyte infiltration and inflammatory responses. In this study, we evaluated the effects of a GPR4 antagonist, NE-52-QQ57, in the SARS-CoV-2-infected K18-hACE2 transgenic mouse model. Our results demonstrated that GPR4 antagonist treatment increased the survival rate in this severe COVID-19 mouse model. The inflammatory response, characterized by proinflammatory cytokines and chemokines, was reduced in the GPR4 antagonist group compared with the vehicle group. Additionally, both SARS-CoV-2 RNA copy numbers and infectious viral titers in the mouse lung were decreased in the GPR4 antagonist group. The percentage of SARS-CoV-2 antigen-positive mouse brains was also decreased in the GPR4 antagonist group compared to the vehicle group. Furthermore, the GPR4 antagonist inhibited SARS-CoV-2 propagation in Vero E6 cells. Together, these results suggest that GPR4 antagonism may be explored as a novel approach for the treatment of COVID-19 and other similar viral diseases.

pharmacology and toxicology↗

bioRxiv2022

Pathogen effector-associated nuclear-localization of RPW8.2 amplifies its expression to boost immunity in Arabidopsis

RESISTANCE TO POWDERY MILDEW 8 (RPW8) defines a unique N-terminal coiled-coil domain of nucleotide-binding and leucine-rich repeat immune receptors required for immune signaling in plants. Arabidopsis RPW8.2 is specifically induced by the powdery mildew (PM) fungus (Golovinomyces cichoracearum) in the infected epidermal cells to activate immunity. The mechanism of RPW8.2-induction is not well understood. Here, we identify a G. cichoracearum factor delivered to the nucleus of the host cell, named Gc-RPW8.2 interacting protein 1 (GcR8IP1). Ectopic expression of GcR8IP1 in Arabidopsis or Nicotiana benthamiana suppressed host immune responses and enhanced susceptibility to PM. Host-induced gene silencing of GcR8IP1 compromised PM infectivity in susceptible Arabidopsis plants. Co-expression of GcR8IP1 with RPW8.2 increased nuclear localization of RPW8.2, which in turn, promoted transcriptional amplification of RPW8.2. Thus, RPW8.2-dependent defense strengthening is due to altered partitioning of RPW8.2 by an effector of a PM fungus, which exemplifies an atypical form of effector-triggered immunity.

plant biology↗

bioRxiv2021

Insights into the susceptibility of rice to a floral disease

Crop floral diseases are economically important as they reduce grain yield and quality and even introduce food toxins. Rice false smut has emerged as a serious floral disease producing mycotoxins. However, very little is known on the interaction mechanisms between rice flower and the causal fungus Ustilaginoidea virens. Here we show that a conserved anti-fungal immunity in rice flower is disarmed by U. virens via a secreted protein UvChi1. UvChi1 functioned as an essential virulence factor and directly interacted with the chitin receptor CEBiP and co-receptor CERK1 in rice to disrupt their oligomerizations and subsequent immune responses. Moreover, intraspecific-conserved UvChi1 could target OsCEBiP/OsCERK1 receptor complex in at least 98.5% of 5232 surveyed rice accessions. These results demonstrate that U. virens utilizes a crucial virulence factor to subvert chitin-triggered flower immunity in most rice varieties, providing new insights into the susceptibility of rice to false smut disease. One Sentence SummaryThe fungal pathogen Ustilaginoidea virens disarms chitin-triggered immunity in rice flower via a secreted chitinase.

plant biology↗

bioRxiv2020

Establishment of a stable transgenic g6pdM1315-1443 zebrafish line with glucose-6-phosphate dehydrogenase deficiency

ABSTRACTGlucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common inherited enzymopathy in humans and is associated with a predisposition to hemolysis. However, there are few animal models to that adequately mimic associated human disease states that could be used to evaluate strategies to address clinical syndromes attributable to G6PD deficiency. In the present study, we aimed to establish a stable transgenic zebrafish model of G6PD deficiency that recapitulates the clinical manifestations of G6PD deficiency. We incorporated a stable transgene of G6PD lacking nucleotides from 1315 to 1443 denoted Tg(zgata1:g6pdM1315-1443-egfp). Functional analysis showed that Tg(zgata1:g6pdM1315-1443-egfp) transgenic zebrafish demonstrate a decrease in g6pd activity, reduced GSH levels and hemoglobin content, and increases in pericardial edema in response to α-naphthol exposure, similar to human subjects with G6PD deficiency. We detected no other significant phenotypic abnormalities compared to controls. Taken together, these observations indicate that the Tg(zgata1:g6pdM1315-1443-egfp) zebrafish line mirrors key clinical manifestations of G6PD deficiency in humans. This model may facilitate mechanistic studies and promote translational research related to G6PD deficiency.Competing Interest StatementThe authors have declared no competing interest.View Full Text

zoology↗

bioRxiv2018

Uric acid lowering treatment alleviates perivascular carotid collar placement induced neointimal lesions in Uricase knockout mice

Hyperuricemia (HU) is a cause of gout. Clinical studies show a link between HU and cardiovascular disease. However, the role of soluble serum urate on atherosclerosis development remains elusive. We aimed to use a new HU mouse model (Uricase/Uox knockout (KO)) to further investigate the relationship between HU and atherosclerosis. Mouse model of induced carotid atherosclerosis was established in the novel spontaneous HU Uox-KO mouse and their wild type littermates (C57BL/6J background). Mice were implanted with a perivascular collar placement around the right carotid artery in combination with a western-type diet. To investigate urate-lowering treatment (ULT) effects on intima, the mice were gavaged daily from the age of 6 weeks with allopurinol. Human umbilical vein endothelial cells (HUVECs) were co-incubated with soluble urate, with and without probenecid, to study the mechanism of urate-related atherosclerosis. The Uox-KO mice had significantly elevated serum urate levels combined with higher blood urea nitrogen and serum creatinine. Western blot analysis showed enhanced levels of atherosclerosis inflammatory response proteins. However, there were no other risk indicators for the pathogenesis of atherosclerosis, including increased fasting glucose, altered lipid and atherosclerosis characterized cardiovascular and histological manifestations. In contrast, collar placement Uox-KO mice showed severe neointimal changes in histology staining consistent with increases in intimal area and increases in proliferating cell nuclear antigen (PCNA) - and F4/80-positive cells. Allopurinol reduced neointimal areas induced by the perivascular collar in hyperuricemic mice accompanied by decreased expression of PCNA- and F4/80-positive cells (P< 0.05). ULT alleviated atherosclerosis inflammatory response factors and reactive oxygen species intensities in both collar placement Uox-KO mice and urate-stimulated HUVECs. In vitro results using HUVECs showed ROS was induced by urate and ROS induction was abrogated using antioxidants. These data demonstrate that urate per se does not trigger atherosclerosis intima lesions in mice. Urate worsens carotid neointimal lesions induced by the perivascular collar and urate-lowering therapy partially abrogates the effects. The current study warrants the further human based study on the possible benefits of urate-lowering therapy in atherosclerosis patients with HU.\n\nSummary statementWe generated a carotid collar placement atherosclerosis model in the novel spontaneous HU Uox-KO mouse and demonstrate that urate plays a contributing rather than a causal role in the carotid neointimal lesions, while urate-lowering treatment may bring additional benefits in this HU mouse model.

physiology↗