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Xiangdong Wang

Publications and source records attributed to Xiangdong Wang.

At least 19 recordsLinked to original sources
PubMed2026

Synthetic community derived from the root core microbes of a desert shrub Caragana korshinskii enhances wheat drought tolerance.

BACKGROUND: Drought, intensified by climate change, poses a mounting threat to global food security by severely constraining crop productivity. While microbial inoculants offer promise for drought tolerance, their poor adaptability remains insufficient for extremely water-deficient environments. Desert plants host unique drought-adapted microbiomes that remain largely unexplored for agricultural applications. RESULTS: Here, we investigated the microbial community of the desert shrub Caragana korshinskii and identified a core set of drought-responsive strains. A synthetic microbial community (SynCom) derived from these strains significantly improved wheat growth under drought stress. Metagenomic analyses revealed that microbial functions related to biofilm formation, quorum sensing, and carbon metabolism were enriched, with Pseudomonas identified as a key functional taxon. Guided by inter-strain interactions in biofilm assembly, we streamlined the consortium into a five-member synthetic community, where quorum-sensing signals promoted community-wide biofilm formation. Community biofilm production improved strain colonization and conferred greater drought tolerance compared to monocultures. In plants, mechanistic investigations indicated that the simplified SynCom inoculation universally upregulated MAPK and jasmonic acid signaling pathways. Furthermore, carbohydrate metabolic pathways such as starch and sucrose metabolism were specifically activated, suggesting a multi-level mechanism underlying SynCom-mediated drought tolerance. CONCLUSIONS: These findings demonstrate that SynCom constructed on the endophytic flora of desert plants can significantly enhance crop drought tolerance. Our work highlights the pivotal role of community biofilm synthesis in facilitating root colonization and activating a multidimensional drought tolerance network in plants. This study not only gives an ecological perspective on desert microbiome adaptations but also offers a strategic framework for developing effective microbial inoculants for arid-region agriculture. Video Abstract.

Caragana↗
PubMed2025

Stereo-cell: Spatial enhanced-resolution single-cell sequencing with high-density DNA nanoball-patterned arrays.

Single-cell sequencing technologies have advanced our understanding of cellular heterogeneity and biological complexity. However, existing methods face limitations in throughput, capture uniformity, cell size flexibility, and technical extensibility. We present Stereo-cell, a spatial enhanced-resolution single-cell sequencing platform based on high-density DNA nanoball (DNB)-patterned arrays, which enables scalable and unbiased cell capture at a wide input range and supports high-fidelity transcriptome profiling. Stereo-cell further allows integration with imaging-based modalities and multiomics strategies, including immunofluorescence and epitope profiling. This platform is also compatible with profiling extracellular vesicles, microstructures, and large cells, whereas its spatial resolution facilitates in situ analysis of cell-cell interactions, cellular microenvironments, and subcellular transcript localization. Together, Stereo-cell provides a flexible framework for expanding single-cell research applications.

Animals↗
PubMed2006

In vivo imaging of hepatic growth hormone signaling.

We developed a system to noninvasively and repeatedly image in vivo hepatic GH signaling. GH regulates postnatal growth and metabolism. It affects numerous tissues, but has major effects in liver. We used nude mice for adenoviral-mediated delivery of a signal transducer and activator of transcription 5-dependent GH response element, a luciferase reporter to detect GH signaling pathway activation. We detected by noninvasive bioluminescence imaging GH-induced hepatic GH signaling serially within intact mice. Statistically significant effects of GH dose and time dependence were detected in the liver luciferase signal that peaked 3 h after GH injection. Codelivery of GH receptor significantly enhanced GH response, an effect that was further augmented by fasting. Our imaging system allows detailed in vivo analysis of GH signaling and action and may be a paradigm for studies of additional signaling pathways in liver and other tissues.

Adenoviridae↗
PubMed2006

Rat liver endothelial cells isolated by anti-CD31 immunomagnetic separation lack fenestrae and sieve plates.

The gold standard for the identification of sinusoidal endothelial cells (SEC) is the presence of fenestrae organized in sieve plates, which is characteristic of SEC in vivo. One of the methods currently in use to isolate SEC is immunomagnetic sorting for CD31. However, there is evidence to suggest that CD31 is not present on the surface of differentiated SEC. The present study used scanning electron microscopy to image rat hepatic endothelial cells isolated by anti-CD31 and immunomagnetic sorting and cells isolated by gradient centrifugation and centrifugal elutriation. Cells isolated by elutriation had well-developed fenestrae and sieve plates, whereas cells isolated by anti-CD31 and immunomagnetic sorting had significantly fewer fenestrae organized in sieve plates. In conclusion, cells isolated by anti-CD31 and immunomagnetic sorting lacked the hallmark features of SEC.

Animals↗
PubMed2006

Evaluation of excised lung gas volume measurements in animals with genetic or induced emphysema.

Emphysema, a leading cause of respiratory disability and mortality in humans, is characterized by destruction of alveolar walls and enlargement of airspaces. Animal studies are critical in understanding the pathogenesis of emphysema. However, current measurements of airspace enlargement and emphysema in small laboratory animals are labor intensive and may not be sensitive enough for measuring alterations in lung function and structure at the early stages of emphysema. In this study, we have investigated the excised lung gas volume (ELGV) measurement as a potential index for determining airspace enlargement in pallid mice with developing emphysema, in tight-skin mice with developed emphysema, or in Wistar rats with emphysema induced by an intratracheal instillation of pancreatic elastase. Our results showed that values of both ELGV per lung and per gram lung tissue were significantly increased in all three emphysema models, compared to control. The ELGV values were correlated well with morphometric evaluation of emphysema. Variations in transpulmonary pressures caused by different termination procedures were critical factors influencing the ELGV values. The present study demonstrates that ELGV measurement is a simple and sensitive method to monitor the development of emphysema.

Age Factors↗
PubMed2006

Janus kinase 2 influences growth hormone receptor metalloproteolysis.

GH signals through the GH receptor (GHR), a cytokine receptor superfamily member that couples to the cytoplasmic tyrosine kinase, Janus kinase 2 (JAK2). In addition to its role in signaling, we recently implicated JAK2 in the regulation of cell surface GHR abundance by modulation of GHR trafficking and mature GHR stability. GHR is a target for constitutive and inducible metalloprotease-mediated cleavage that alters surface GHR levels and can modulate GH signaling. We previously found that metalloprotease cleavage of GHR is dramatically lessened in fibroblasts derived from mice with targeted deletion of the zinc-binding domain of TNF-alpha-cleaving enzyme [TACE; ADAM17 (a disintegrin and metalloprotease)], implicating this transmembrane ectoenzyme as a GHR metalloprotease. In this study we used a human fibrosarcoma reconstitution system to compare the effects of RNA interference-mediated knockdown of TACE vs. a related metalloprotease, ADAM10. We found that TACE knockdown dramatically reduced both the pace and the degree of inducible GHR proteolysis and augmented the abundance of mature GHR, suggesting a role for TACE in constitutive receptor proteolysis in this system as well. Notably, ADAM10 knockdown also reduced inducible GHR proteolysis, although to a lesser degree than TACE knockdown, suggesting a contribution from this metalloprotease also. To determine whether JAK2 affects GHR proteolysis, we compared JAK2-deficient vs. JAK2-replete cells and found that phorbol 12-methyl 13-acetate-induced GHR proteolysis was significantly diminished in cells that lacked JAK2. Reconstitution with a GHR mutant that lacks the box 1 region (which mediates JAK2 association) resulted in phorbol 12-methyl 13-acetate-induced proteolysis similar in degree to that of the wild-type GHR in JAK2-deficient cells. Introduction of JAK2 did not affect the proteolysis of this box 1-deleted GHR, suggesting GHR-JAK2 association is required for JAK2 to affect GHR proteolysis. Additionally, the inhibitory effect of anti-GHRext-mAb, a conformation-sensitive GHR antibody, on receptor proteolysis was lost in cells that lacked JAK2. Our data indicate that the susceptibility of GHR to proteolysis is substantially affected by JAK2, suggesting yet another role for this kinase in determining GH sensitivity.

ADAM Proteins↗
PubMed2006

A mutant signal transducer and activator of transcription 5b, associated with growth hormone insensitivity and insulin-like growth factor-I deficiency, cannot function as a signal transducer or transcription factor.

CONTEXT: A natural missense mutation in the signal transducer and activator of transcription (STAT) 5b gene was recently identified in association with a female patient presenting with severe growth failure and immune dysfunction. The mutation results in an alanine to proline substitution at residue 630 (A630P) in the src-homology-2 domain, a region essential for docking of STATs to phospho-tyrosines on activated receptors, STAT dimerization, and stabilization of phospho-STAT-DNA interactions. OBJECTIVE: The purpose of this study was to explore the molecular mechanisms underlying the GH insensitivity and IGF-I deficiency caused by the A630P-mutated STAT5b. RESULTS: In reconstitution experiments using HEK293 cells, both GH and interferon-gamma were unable to activate mutant STAT5b (A630P), as demonstrated by lack of immunodetectable phospho-tyrosyl-STAT5b (A630P) and inability to drive luciferase reporter activity. However, the Src family of nonreceptor kinases [constitutively active v-src and epithelial growth factor-induced c-src] tyrosine-phosphorylated STAT5b(A630P). The v-src-induced phospho-STAT5b(A630P) translocated to the nucleus but, unlike wild-type Stat5b, was unable to bind DNA. CONCLUSIONS: The A630P mutation disrupts the src-homology-2 architecture such that: 1) mutant STAT5b most likely cannot dock to phospho-tyrosines on ligand-activated receptors; and 2) stable interactions with DNA are prevented. Because STAT5b (A630P) is an inefficient signal transducer and transcription factor, the detrimental impact on signaling pathways important for normal growth and immunity explains, in part, the complex clinical phenotype of GH insensitivity and immune dysfunction.

Adenoviridae↗
PubMed2006

Regulation of MUC5AC mucin secretion by depletion of AQP5 in SPC-A1 cells.

Airway mucus is regulated by many inflammatory mediators such as ILs, TNF-alpha, EGF, PGF2alpha, LT, and so on. Recently, the relationship between membrane ion channel and mucus production has been under investigation. The present study aimed to examine whether AQP5 was involved in modulation of mucin expression and secretion in airway submucosal gland cells (SPC-A1). A recombinant plasmid (pShAQP5) containing small hairpin RNA expression cassette targeting AQP5 sequence was constructed. In pShAQP5 transiently transfected cells, ELISA showed MUC5AC synthesis and secretion were increased by 57.9% and 85.3%, respectively, on day 5 after pShAQP5 transfection. While in five stably transfected clones (shAQP5-G1, G2, G3, A2, and A5), the upregulated levels of MUC5AC mRNA were 118%, 165%, 65%, 123%, and 38%, respectively. The elevated levels of MUC5AC synthesis and secretion varied from 59-156% and 33-166%, respectively. This is the first reliable investigation of the regulation of MUC5AC mucin secretion by silencing AQP5. Further study of the regulatory mechanism between AQPs and mucins may provide new strategies for development of novel antihypersecretory drugs in airway diseases.

Aquaporin 5↗
PubMed2006

Potential role of short hairpin RNA targeting epidermal growth factor receptor in growth and sensitivity to drugs of human lung adenocarcinoma cells.

Upregulation of expression and activation of epidermal growth factor receptor (EGFR) is involved in the development and progression of a wide range of human cancers. The present study aims at determining gene-silencing effects of vector-based short hairpin RNA (shRNA) targeting EGFR on receptor expression and cell growth and evaluating its modulation of responsiveness to drugs in human lung adenocarcinoma cells (HLAC). A vector-based polymerase 3-promotor system was used to express shRNA targeting EGFR in HLAC lines (A549 and SPC-A1). EGFR was detected by immunofluorescence staining and quantified by Western blot. The effect of shRNA targeting EGFR on tumor cell growth was assessed by colony formation assay, cell cycle and apoptosis by flow cytometry, and the responsiveness of HLAC lines to cytotoxic drugs by 3-[4,5-dimethylthiozol-2yl]-2,5-diphenyltetrazolium bromide [MTT] assay. Vectors expressing shRNA against EGFR significantly downregulated receptor expression by 74 and 85% and the colony number by 63 and 69% in A549 and SPC-A1, respectively. Vector-based shRNA against EGFR caused G1 arrest, induced apoptosis, and subsequently increased the sensitivity to cisplatin, doxorubicin and paclitaxel by about four- to seven-fold in both HLAC lines. Our data suggest that vector-based shRNA could be considered as an alternative to effectively inhibit EGFR expression in HLACs, probably with the higher efficacy in combination therapies with conventional chemotherapeutic drugs.

Adenocarcinoma↗
PubMed2006

The role of PDE4 in pulmonary inflammation and goblet cell hyperplasia in allergic rats.

Phosphodiesterase 4 (PDE4) has been suggested to a critical factor in the pathogenesis of inflammation by metabolizing cAMP in human leukocytes, endothelium and epithelium. The present study aimed at evaluating the PDE4 activity and expression, the relationship between the inflammation and cAMP- activity in the lungs, and potential interventions of PDE inhibitors and antiinflammatory drugs in the reduction of lung inflammation and goblet cell hyperplasia in allergic rats. The total leukocyte number and eosinophil number in bronchoalveolar lavegar fluid and infiltration of inflammatory cells in the perivascular and peribronchial spaces, structure changes and goblet cell hyperplasia in the OVA-sensitized and challenged allergic rats. A significant correlation was observed between the increases in cAMP-PDE activity and inflammation in the lung. Those OVA-induced changes were prevented by pretreatment with PDE inhibitor in a dose-related patterns and with glucocorticosteriod. We found an increase in the proportion of PDE4 and PDE4 gene expression, while a decrease in the proportion of PDE3 in the lung of the allergic rats. Incubation with different PDE inhibitors down-regulated OVA-induced cAMP hydrolysis. Our data suggest that PDE4C may play an important role in the airway inflammation, remodeling and goblet cell hyperplasia after repeated challenge of sensitized rats.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2006

Epithelial proteomics in multiple organs and tissues: similarities and variations between cells, organs, and diseases.

Epithelial cells play an important role in physiological and pathophysiological situations, with organ-, tissue-, type-, and function-specific patterns. Proteome analysis has been used to study epithelial-origin diseases and identify novel prognostic, diagnostic, and therapeutic markers. The present review compares the variation of sample preparation for epithelial proteomic analysis, search similarities, and differences of epithelial proteomics between different cells, locations, and diseases. We focus on specificity of proteomic markers for epithelial-involved diseases. Proteomic alterations in epithelial cell lines were mapped to understand protein patterns, differentiation, oncogenesis, and pathogenesis of epithelial-origin diseases. Changes of proteomic patterns depend on different epithelial cell lines, challenges, and preparation. Epithelial protein profiles associated with intracellular locations and protein function. Epithelial proteomics has been greatly developed to link clinical questions, e.g., disease severity, biomarkers for disease diagnosis, and drug targets. There is an exciting and attractive start to link epithelial proteomics with histology of clinical samples. From the present review, we can find that most of disease-associated investigation of epithelial proteomics has been focused on epithelial-origin cancer. There is a significant gap of epithelial proteomics between acute and chronic organ injury, inflammation, and multiple organ dysfunction. Epithelial proteomics will provide powerful information on the relationships between biological molecules and disease mechanisms. Epithelial proteomics strategies and approaches should become more global, multidimensional, and systemic.

Biomarkers, Tumor↗
PubMed2006

Better understanding of organ dysfunction requires proteomic involvement.

Organ dysfunction is defined as a systemic consequence of acute and chronic diseases, a critical and important phase of disease development. The mortality of patients with severe illness is highly correlated with the number and duration of dysfunctional organs. There is still not an efficient and specific therapy to improve the prognosis of patients with organ dysfunction, due to the complexity and severity of the disease. There is a great need to understand molecular mechanisms of the disease, identify disease-related biomarkers, and validate therapeutic effects. Thus, it is important to have a special attention from proteomic scientists to explore the combination between advanced proteomic biotechnology, clinical proteomics, tissue imaging and profiling, and organ dysfunction score systems, to improve the clinical outcomes of these patients.

Biomarkers↗
PubMed2006

Immune status and inflammatory response differ locally and systemically in severe acute pancreatitis.

OBJECTIVE: Acute pancreatitis (AP) is an inflammatory disorder that develops a complex cascade of immunological events. The local and systemic immune status and inflammatory response might contribute to the understanding of underlying pathophysiological mechanisms and potential treatment. MATERIAL AND METHODS: Severe AP was induced by intraductal perfusion of 5% sodium taurodeoxycholate in rats. mRNA expression of cytokines and chemokines was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) and NF-kappaB activation was assessed by electrophoretic mobility shift assay in fresh pancreatic acini and circulating monocytes 1, 3, 6 or 9 h after sham operation, induction of AP or N-acetylcysteine (NAC) pretreatment. Flow cytometry was performed on cells obtained from the peripheral blood. RESULTS: An inverse relationship in pancreatic and circulating monocytic NF-kappaB activation was detected 6 and 9 h after induction of AP. NAC further suppressed monocytic NF-kappaB activation induced by AP as seen 9 h after induction of AP. A marked constitutive increase in the expression of IL-6, CINC and MCP-1 was seen in pancreatic acini, whereas no change in mRNA expression of inflammatory mediators was observed in circulating monocytes 6 h after induction of AP. Flow cytometry further confirmed the altered function of circulating monocytes. CONCLUSIONS: The different immune status and inflammatory response in the pancreas and circulating monocytes improve the understanding of the mechanisms by which systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS) develop in severe AP. A potential therapeutic approach could be to restore the functional capacity of the immune system in AP. The use of an NF-kappaB inhibitor, preferentially reaching the local inflammatory foci, could be a potential future way of intervention.

Acetylcysteine↗
PubMed2006

[Prevalence of sensitization to aeroallergens in Beijing patients with allergic rhinitis].

OBJECTIVES: The purpose of this study was to determine which aeroallergens were prevalent in patients with allergic rhinitis in Beijing. METHOD: A total of 554 cases (female: 212, male: 342, aged between 4-69 years) who were diagnosed with allergic rhinitis by history and clinical presentation, underwent a skin prick test with 20 standardized aeroallergens, and the important sensitizing allergens were assessed. The samples were stratified on two age groups: 4-18-year-olds (children group, n = 81) and 19-60-year-olds (adults group, n = 401). Difference of SPT responses of the two groups was investigated. RESULT: The percent of patients with positive skin tests were follow:D. farinae (64.6%), D. pteronyssinus (64.3%), Flowers pollen (28.7%), Herbs (26.5%), Lamb's Quarters (13.7%) ,Tree II (13.5%), Giant Ragweed (12.5%). Tree I (12.5%) There were significantly higher sensitivity to dust mite among children group compared to adults group (P < 0.01). CONCLUSION: The study shows that the dust mite, Flowers pollen and Herbs are the most important three aeroallergens in Beijing region.

Adolescent↗
PubMed2005

Evaluation of nasal barrier dysfunction at acute- and late-phase reactions in a guinea pig model of allergic rhinitis.

Allergic rhinitis is a common disease characterized by the symptoms of pruritus, sneezing, hypersecretion and nasal blockage. Increased mucosal barrier permeability has been suggested to be an indicator for the severity of allergic rhinitis. This study investigates the passage of radiolabelled albumin from the nasal mucosal circulation into the lumen in guinea pigs intraperitoneally sensitized and intranasally challenged with antigen. In order to characterize the allergic rhinitis model, we evaluated a number of potential influencing factors in nasal plasma exudation, including antigen doses, volumes of antigen solution used, and animal position during the nasal lavage, and the conditions of nasal lavage. The number of eosinophils and levels of histamine and leukotriene B4 in the nasal lavage and eosinophils in the nasal mucosa were determined at the early and late phases after antigen challenge. We also compared the effects of topical nasal treatments for allergic rhinitis on nasal inflammatory responses. Our results demonstrate that, in the guinea pig nasal mucosa, topical challenge with antigens induces plasma exudation and histamine release at the acute-phase reaction, and plasma exudation and eosinophil infiltration at the late-phase reaction. These changes are similar to those reported in human allergic rhinitis. Alterations of nasal plasma exudation, histamine release and eosinophil influx were dependent upon the concentrations and volumes of antigens. An antihistamine inhibited the acute-phase reaction partially, whereas budesonide inhibited effects at the late-phase reaction. We suggest that this model of guinea pig allergic rhinitis with the early and late responses may be useful for high-throughout screening of new drugs.

Administration, Topical↗
PubMed2005

Protein kinase C modulates the pulmonary inflammatory response in acute pancreatitis.

The present study aims at evaluating the role of protein kinase C (PKC) in the development of acute lung injury, production of inflammatory mediators and expression of adhesion molecules on leukocytes after induction of acute pancreatitis (AP). AP was induced by the intraductal infusion of 5% sodium taurodeoxycholate in the rat. The animals had the PKC inhibitor polymyxin B administered intraperitoneally 30min prior to induction of AP. Levels of protein content, protease activity, cytokines and chemokines in bronchoalveolar lavage fluid (BALF) were assessed 1 and 6h after AP induction. Adhesion molecule expression on leukocytes were measured by flowcytometry. Pretreatment with polymyxin B prevented against acute pancreatitis-induced lung injury and the otherwise occurring increases in TNF-alpha, IL-1beta, MCP-1 and IL-10, as well as against the decreases in IL-2, IFNgamma and TIMP-1, decreased protease activity and down-regulation of CD31, CD54 and CD62L on recruited neutrophils and macrophages in BALF. The results indicate that the leukocyte response in acute pancreatitis vary depending on leukocyte subpopulation. It seems that activation of the PKC signalling pathway may play an important role in pancreatitis-associated lung injury.

Animals↗
PubMed2005

Janus kinase 2 enhances the stability of the mature growth hormone receptor.

The abundance of surface GH receptor (GHR) is an important determinant of cellular GH sensitivity and is regulated at both transcriptional and posttranscriptional levels. In previous studies of GHR-expressing Janus kinase 2 (JAK2)-deficient human fibrosarcoma cells (gamma2A-GHR), we demonstrated that stable transfection with JAK2 resulted in increased steady-state levels of mature GHR (endoH-resistant; relative molecular mass, 115-140 kDa) relative to precursor GHR (endoH-sensitive; relative molecular mass, 100 kDa). We now examine further the effects of JAK2 on GHR trafficking by comparing gamma2A-GHR to gamma2A-GHR cells stably reconstituted with JAK2 (C14 cells). In the presence of JAK2, GHR surface expression was increased, as assessed by surface biotinylation, 125I-labeled human GH cell surface binding, and immunofluorescence microscopy assays. Although the absence of JAK2 precluded GH-stimulated signaling, GH-induced GHR disulfide linkage (a proxy for the GH-induced conformational changes in the GHR dimer) proceeded independent of JAK2 expression, indicating that the earliest steps in GH-induced GHR triggering are not prevented by the absence of JAK2. RNA interference-mediated knockdown of JAK2 in C14 cells resulted in a decreased mature to precursor ratio, supporting a primary role for JAK2 either in enhancing GHR biogenesis or dampening mature GHR degradation. To address these potential mechanisms, metabolic pulse-chase labeling experiments and experiments in which the fate of previously synthesized GHR was followed by anti-GHR immunoblotting after cycloheximide treatment (cycloheximide chase experiments) were performed. These indicated that the presence of JAK2 conferred modest enhancement (1.3- to 1.5-fold) in GHR maturation but substantially prolonged the t1/2 of the mature GHR, suggesting a predominant effect on mature GHR stability. Cycloheximide chase experiments with metalloprotease, proteasome, and lysosome inhibitors indicated that the enhanced stability of mature GHR conferred by JAK2 is not related to effects on constitutive receptor metalloproteolysis but rather is a result of reduced constitutive endosomal/lysosomal degradation of the mature GHR. These results are discussed in the context of emerging information on how JAK-family members modulate surface expression of other cytokine receptors.

Ammonium Chloride↗