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Query: "author" (Li Zheng) .

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1.
Quantitative assessment of the apical and basolateral membrane expression of VEGFR2 and NRP2 in VEGF-A-stimulated cultured human umbilical vein endothelial cells
Esmeralda K. Bosma, Shahan Darwesh, Jia Y. Zheng, Cornelis J. F. van Noorden, Reinier O. Schlingemann, Ingeborg Klaassen, 2022, original scientific article

Abstract: Endothelial cells (ECs) form a precisely regulated polarized monolayer in capillary walls. Vascular endothelial growth factor-A (VEGF-A) induces endothelial hyperpermeability, and VEGF-A applied to the basolateral side, but not the apical side, has been shown to be a strong barrier disruptor in blood–retinal barrier ECs. We show here that VEGF-A presented to the basolateral side of human umbilical vein ECs (HUVECs) induces higher permeability than apical stimulation, which is similar to results obtained with bovine retinal ECs. We investigated with immunocytochemistry and confocal imaging the distribution of VEGF receptor-2 (VEGFR2) and neuropilin-2 (NRP2) in perinuclear apical and basolateral membrane domains. Orthogonal z-sections of cultured HUVECs were obtained, and the fluorescence intensity at the apical and basolateral membrane compartments was measured. We found that VEGFR2 and NRP2 are evenly distributed throughout perinuclear apical and basolateral membrane compartments in unstimulated HUVECs grown on Transwell inserts, whereas basolateral VEGF-A stimulation induces a shift toward basolateral VEGFR2 and NRP2 localization. When HUVECs were grown on coverslips, the distribution of VEGFR2 and NRP2 across the perinuclear apical and basolateral membrane domains was different. Our findings demonstrate that HUVECs dynamically regulate VEGFR2 and NRP2 localization on membrane microdomains, depending on growth conditions and the polarity of VEGF-A stimulation.
Keywords: endotelijske celice, EGF, celična biologija
Published in DiRROS: 17.07.2024; Views: 2; Downloads: 2
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2.
Diferential roles of eNOS in late efects ofVEGF‑A on hyperpermeability in diferent types of endothelial cells
Esmeralda K. Bosma, Shahan Darwesh, Yasmin I. Habani, Maxime Cammeraat, Paola Serrano Martinez, Mathilda E. van Breest Smallenburg, JiaY. Zheng, Ilse M.C. Vogels, Cornelis J. F. van Noorden, Reinier O. Schlingemann, Ingeborg Klaassen, 2023, original scientific article

Abstract: Vascular endothelial growth factor (VEGF)-A induces endothelial hyperpermeability, but the molecular pathways remain incompletely understood. Endothelial nitric oxide synthase (eNOS) regulates acute efects of VEGF-A on permeability of endothelial cells (ECs), but it remains unknown whether and how eNOS regulates late efects of VEGF-A-induced hyperpermeability. Here we show that VEGF-A induces hyperpermeability via eNOS-dependent and eNOS-independent mechanisms at 2 days after VEGF-A stimulation. Silencing of expression of the eNOS gene (NOS3) reduced VEGF-A-induced permeability for dextran (70 kDa) and 766 Da-tracer in human dermal microvascular ECs (HDMVECs), but not in human retinal microvascular ECs (HRECs) and human umbilical vein ECs (HUVECs). However, silencing of NOS3 expression in HRECs increased permeability to dextran, BSA and 766 Da-tracer in the absence of VEGF-A stimulation, suggesting a barrier-protective function of eNOS. We also investigated how silencing of NOS3 expression regulates the expression of permeability-related transcripts, and found that NOS3 silencing downregulates the expression of PLVAP, a molecule associated with trans-endothelial transport via caveolae, in HDMVECs and HUVECs, but not in HRECs. Our fndings underscore the complexity of VEGF-A-induced permeability pathways in ECs and the role of eNOS therein, and demonstrate that diferent pathways are activated depending on the EC phenotype.
Keywords: endocytosis, RNAi, hyperpermeability
Published in DiRROS: 15.07.2024; Views: 47; Downloads: 18
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3.
Influence of test methodology on the characterization of the parallel-to-grain timber embedment strength and foundation modulus of dowels
Caroline D. Aquino, Rodrigues Leonardo G., Michael Schweigler, Meta Kržan, Zheng Li, Jorge M. Branco, 2024, original scientific article

Abstract: A reliable determination of the embedment strength and foundation modulus of timber elements is critical for the design and safety assessment of joints in timber structures. However, the existence of various test configurations for characterising the embedding properties of large diameter steel fasteners in timber elements poses challenges in directly comparing and utilising available test data. This paper aims to provide an insight into the influence of embedment property test methods, comparing experimental results from different test setups within the guidelines of the EN 383 and ASTM D 5764-97a standards for European softwood species, Scots pine wood (Pinus sylvestris) and Norway spruce (Picea abies). In addition to the test guidelines, the thickness of the specimen and the application of the load was evaluated within the protocols. A comprehensive statistical analysis was performed to identify statistically significant differences between the groups evaluated. The results of the analysis revealed disagreement between the standards in the evaluation of the strength of the embedding, highlighting the potential bias inserted by the experimental setup and protocol. Furthermore, it was proven that the thickness of the specimens influences both the embedding strength and the foundation modulus of the wood species tested. Finally, no distinctions were observed between tensile and compressive loading within the guidelines of the EN 383 standard.
Keywords: embedment strength, foundation modulus, dowel-type connections, test methods
Published in DiRROS: 15.04.2024; Views: 233; Downloads: 117
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4.
Soil contamination in nearby natural areas mirrors that in urban greenspaces worldwide
Yu-Rong Liu, Marcel G. A. van der Heijden, Judith Riedo, Carlos Sanz-Lazaro, David J. Eldridge, Felipe Bastida, Eduardo Moreno-Jiménez, Xin-Quan Zhou, Hang-Wei Hu, Ji-Zheng He, Tine Grebenc, Tina Unuk Nahberger, 2023, original scientific article

Abstract: Soil contamination is one of the main threats to ecosystem health and sustainability. Yet little is known about the extent to which soil contaminants differ between urban greenspaces and natural ecosystems. Here we show that urban greenspaces and adjacent natural areas (i.e., natural/semi-natural ecosystems) shared similar levels of multiple soil contaminants (metal(loid)s, pesticides, microplastics, and antibiotic resistance genes) across the globe. We reveal that human influence explained many forms of soil contamination worldwide. Socio-economic factors were integral to explaining the occurrence of soil contaminants worldwide. We further show that increased levels of multiple soil contaminants were linked with changes in microbial traits including genes associated with environmental stress resistance, nutrient cycling, and pathogenesis. Taken together, our work demonstrates that human-driven soil contamination in nearby natural areas mirrors that in urban greenspaces globally, and highlights that soil contaminants have the potential to cause dire consequences for ecosystem sustainability and human wellbeing.
Keywords: soil contamination, urban greenspaces
Published in DiRROS: 28.03.2023; Views: 744; Downloads: 344
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6.
Global homogenization of the structure and function in the soil microbiome of urban greenspaces
Manuel Delgado-Baquerizo, David J. Eldridge, Yu-Rong Liu, Blessing Sokoya, Jun-Tao Wang, Hang-Wei Hu, Ji-Zheng He, Felipe Bastida, José L. Moreno, Adebola R. Bamigboye, Tine Grebenc, Tina Unuk Nahberger, 2021, original scientific article

Abstract: The structure and function of the soil microbiome of urban greenspaces remain largely undetermined. We conducted a global field survey in urban greenspaces and neighboring natural ecosystems across 56 cities from six continents, and found that urban soils are important hotspots for soil bacterial, protist and functional gene diversity, but support highly homogenized microbial communities worldwide. Urban greenspaces had a greater proportion of fast-growing bacteria, algae, amoebae, and fungal pathogens, but a lower proportion of ectomycorrhizal fungi than natural ecosystems. These urban ecosystems also showed higher proportions of genes associated with human pathogens, greenhouse gas emissions, faster nutrient cycling, and more intense abiotic stress than natural environments. City affluence, management practices, and climate were fundamental drivers of urban soil communities. Our work paves the way toward a more comprehensive global-scale perspective on urban greenspaces, which is integral to managing the health of these ecosystems and the well-being of human populations.
Keywords: soil biodiversity, structural diversity, functional diversity, urban soils
Published in DiRROS: 15.07.2021; Views: 1086; Downloads: 921
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