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Merrild C, Pedersen GA, Antonsen KW, Madsen MG, Keller AK, Møller HJ, Nejsum LN, Mutsaers HAM, Nørregaard R. A human tissue-based model of renal inflammation. Exp Cell Res 2024; 443:114309. [PMID: 39476943 DOI: 10.1016/j.yexcr.2024.114309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 10/23/2024] [Accepted: 10/27/2024] [Indexed: 11/05/2024]
Abstract
Inflammation plays a key role in both the onset and progression of various kidney diseases. However, the specific molecular and cellular mechanisms by which inflammation drives kidney diseases from different etiologies remain to be elucidated. To enhance our understanding of these mechanisms, a reliable and translational human model of renal inflammation is needed. Here, we aim to establish such a model using human precision-cut kidney slices (PCKS). The PCKS were prepared from fresh, macroscopically healthy kidney tissue and cultured for 3h-48h with or without tumor necrosis factor-α (TNFα), or its inhibitor Etanercept. The ensuing inflammatory response in the slices was evaluated using both qPCR and a cytokine array. Furthermore, the presence of immune cells was visualized using immunofluorescent staining, and the activation potential of tissue-resident macrophages was examined with ELISA. We observed a culture-induced inflammatory response, reflected by increased expression of pro-inflammatory genes TNF, IL1B, CCL2, and IL6. This response could be partially inhibited by Etanercept, indicating that TNFα plays a role in the observed response. Moreover, we found that TNFα stimulation further increased the gene expression of TNF, IL1B, CCL2, and IL6, as well as the production of several chemokines and cytokines, including CXCL5, MCP1, MCP3, and IL-6. Lastly, we observed the presence of CD14- and HLA-DR-positive cells, as well as proliferating (CD68- and PCNA-positive) and activated macrophages in the slices during incubation. In conclusion, this study presents a novel human model for investigating renal inflammation.
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Elsborg SH, Pedersen GA, Madsen MG, Keller AK, Nørregaard R, Nejsum LN. Multiplex immunofluorescence staining of coverslip-mounted paraffin-embedded tissue sections. APMIS 2023. [PMID: 37211896 DOI: 10.1111/apm.13329] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 04/27/2023] [Indexed: 05/23/2023]
Abstract
Animal and human tissues are used extensively in physiological and pathophysiological research. Due to both ethical considerations and low availability, it is essential to maximize the use of these tissues. Therefore, the aim was to develop a new method allowing for multiplex immunofluorescence (IF) staining of kidney sections in order to reuse the same tissue section multiple times. The paraffin-embedded kidney sections were placed onto coated coverslips and multiplex IF staining was performed. Five rounds of staining were performed where each round consisted of indirect antibody labelling, imaging on a widefield epifluorescence microscope, removal of the antibodies using a stripping buffer, and then re-staining. In the final round, the tissue was stained with hematoxylin/eosin. Using this method, tubular segments in the nephron, blood vessels, and interstitial cells were labeled. Furthermore, by placing the tissue on coverslips, confocal-like resolution was obtained using a conventional widefield epifluorescence microscope and a 60x oil objective. Thus, using standard reagents and equipment, paraffin-embedded tissue was used for multiplex IF staining with increased Z-resolution. In summary, this method offers time-saving multiplex IF staining and allows for the retrieval of both quantitative and spatial expressional information of multiple proteins and subsequently for an assessment of the tissue morphology. Due to the simplicity and integrated effectivity of this multiplex IF protocol, it holds the potential to supplement standard IF staining protocols and maximize use of tissue.
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Login FH, Jensen HH, Pedersen GA, Koffman JS, Kwon TH, Parsons M, Nejsum LN. Aquaporins differentially regulate cell‐cell adhesion in MDCK cells. FASEB J 2019; 33:6980-6994. [DOI: 10.1096/fj.201802068rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Jensen HH, Pedersen GA, Morgen JJ, Parsons M, Pedersen SF, Nejsum LN. The Na + /H + exchanger NHE1 localizes as clusters to cryptic lamellipodia and accelerates collective epithelial cell migration. J Physiol 2018; 597:849-867. [PMID: 30471113 DOI: 10.1113/jp277383] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Exogenous Na+ /H+ exchanger 1 (NHE1) expression stimulated the collective migration of epithelial cell sheets Stimulation with epidermal growth factor, a key morphogen, primarily increased migration of the front row of cells, whereas NHE1 increased that of submarginal cell rows, and the two stimuli were additive Accordingly, NHE1 localized not only to the leading edges of leader cells, but also in cryptic lamellipodia in submarginal cell rows NHE1 expression disrupted the morphology of epithelial cell sheets and three-dimensional cysts ABSTRACT: Collective cell migration plays essential roles in embryonic development, in normal epithelial repair processes, and in many diseases including cancer. The Na+ /H+ exchanger 1 (NHE1, SLC9A1) is an important regulator of motility in many cells and has been widely studied for its roles in cancer, although its possible role in collective migration of normal epithelial cells has remained unresolved. In the present study, we show that NHE1 expression in MDCK-II kidney epithelial cells accelerated collective cell migration. NHE1 localized to the leading edges of leader cells, as well as to cryptic lamellipodia in submarginal cell rows. Epidermal growth factor, a kidney morphogen, increased displacement of the front row of collectively migrating cells and reduced the number of migration fingers. NHE1 expression increased the number of migration fingers and increased displacement of submarginal cell rows, resulting in additive effects of NHE1 and epidermal growth factor. Finally, NHE1 expression resulted in disorganized development of MDCK-II cell cysts. Thus, NHE1 contributes to collective migration and epithelial morphogenesis, suggesting roles for the transporter in embryonic and early postnatal development.
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Login FH, Jensen HH, Pedersen GA, Amieva MR, Nejsum LN. The soluble extracellular domain of E-cadherin interferes with EPEC adherence via interaction with the Tir:intimin complex. FASEB J 2018; 32:fj201800651. [PMID: 29920220 DOI: 10.1096/fj.201800651] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Enteropathogenic Escherichia coli (EPEC) causes watery diarrhea when colonizing the surface of enterocytes. The translocated intimin receptor (Tir):intimin receptor complex facilitates tight adherence to epithelial cells and formation of actin pedestals beneath EPEC. We found that the host cell adherens junction protein E-cadherin (Ecad) was recruited to EPEC microcolonies. Live-cell and confocal imaging revealed that Ecad recruitment depends on, and occurs after, formation of the Tir:intimin complex. Combinatorial binding experiments using wild-type EPEC, isogenic mutants lacking Tir or intimin, and E. coli expressing intimin showed that the extracellular domain of Ecad binds the bacterial surface in a Tir:intimin-dependent manner. Finally, addition of the soluble extracellular domain of Ecad to the infection medium or depletion of Ecad extracellular domain from the cell surface reduced EPEC adhesion to host cells. Thus, the soluble extracellular domain of Ecad may be used in the design of intervention strategies targeting EPEC adherence to host cells.-Login, F. H., Jensen, H. H., Pedersen, G. A., Amieva, M. R., Nejsum, L. N. The soluble extracellular domain of E-cadherin interferes with EPEC adherence via interaction with the Tir:intimin complex.
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Jensen HH, Pedersen HN, Stenkjær E, Pedersen GA, Login FH, Nejsum LN. Tir Is Essential for the Recruitment of Tks5 to Enteropathogenic Escherichia coli Pedestals. PLoS One 2015; 10:e0141871. [PMID: 26536015 PMCID: PMC4633291 DOI: 10.1371/journal.pone.0141871] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 10/14/2015] [Indexed: 11/24/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is a bacterial pathogen that infects the epithelial lining of the small intestine and causes diarrhea. Upon attachment to the intestinal epithelium, EPEC uses a Type III Secretion System to inject its own high affinity receptor Translocated intimin receptor (Tir) into the host cell. Tir facilitates tight adhesion and recruitment of actin-regulating proteins leading to formation of an actin pedestal beneath the infecting bacterium. The pedestal has several similarities with podosomes, which are basolateral actin-rich extensions found in some migrating animal cells. Formation of podosomes is dependent upon the early podosome-specific scavenger protein Tks5, which is involved in actin recruitment. Although Tks5 is expressed in epithelial cells, and podosomes and EPEC pedestals share many components in their structure and mechanism of formation, the potential role of Tks5 in EPEC infections has not been studied. The aim of this study was to determine the subcellular localization of Tks5 in epithelial cells and to investigate if Tks5 is recruited to the EPEC pedestal. In an epithelial MDCK cell line stably expressing Tks5-EGFP, Tks5 localized to actin bundles. Upon infection, EPEC recruited Tks5-EGFP. Tir, but not Tir phosphorylation was essential for the recruitment. Time-lapse microscopy revealed that Tks5-EGFP was recruited instantly upon EPEC attachment to host cells, simultaneously with actin and N-WASp. EPEC infection of cells expressing a ΔPX-Tks5 deletion version of Tks5 showed that EPEC was able to both infect and form pedestals when the PX domain was deleted from Tks5. Future investigations will clarify the role of Tks5 in EPEC infection and pedestal formation.
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Pivnenko K, Pedersen GA, Eriksson E, Astrup TF. Bisphenol A and its structural analogues in household waste paper. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 44:39-47. [PMID: 26194879 DOI: 10.1016/j.wasman.2015.07.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/13/2015] [Accepted: 07/13/2015] [Indexed: 05/26/2023]
Abstract
Bisphenol A (BPA) is an industrial chemical produced in large volumes. Its main use is associated with polycarbonate plastic, epoxy resins and thermal paper. In contrast to other applications, thermal paper contains BPA in its un-reacted form as an additive, which is subjected to migration. Receiving a significant amount of attention from the scientific community and beyond, due to its controversial endocrine-disrupting effects, the industry is attempting to substitute BPA in variety of applications. Alternative phenolic compounds have been proposed for use in thermal paper; however, information to what extent BPA alternatives have been used in paper is sparse. The aim of the present work was to quantify BPA and its alternatives (bisphenol S (BPS), bisphenol E (BPE), bisphenol B (BPB), 4-cumylphenol (HPP) and bisphenol F (BPF)) in waste paper and board from Danish households, thermal paper receipts, non-carbon copy paper and conventional printer paper. BPA was found in all waste paper samples analysed, while BPS was identified in 73% of them. Only BPB was not identified in any of the samples. BPA and BPS were found in the majority of the receipts, which contained no measurable concentrations of the remaining alternatives. Although receipts showed the highest concentrations of BPA and BPS, office paper, flyers and corrugated boxes, together with receipts, represented the major flux of the two compounds in waste paper streams.
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Marlar S, Arnspang EC, Pedersen GA, Koffman JS, Nejsum LN. Measuring localization and diffusion coefficients of basolateral proteins in lateral versus basal membranes using functionalized substrates and kICS analysis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2404-11. [DOI: 10.1016/j.bbamem.2014.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 06/03/2014] [Accepted: 06/09/2014] [Indexed: 11/17/2022]
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Kristensen SH, Pedersen GA, Nejsum LN, Sutherland DS. Protein Adsorption at Nanopatterned Surfaces Studied by Quartz Crystal Microbalance with Dissipation and Surface Plasmon Resonance. J Phys Chem B 2013; 117:10376-83. [DOI: 10.1021/jp4038528] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Kristensen SH, Pedersen GA, Ogaki R, Bochenkov V, Nejsum LN, Sutherland DS. Complex protein nanopatterns over large areas via colloidal lithography. Acta Biomater 2013; 9:6158-68. [PMID: 23333875 DOI: 10.1016/j.actbio.2013.01.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 11/20/2012] [Accepted: 01/01/2013] [Indexed: 11/15/2022]
Abstract
The patterning of biomolecules at the nanoscale provides a powerful method to investigate cellular adhesion processes. A novel method for patterning is presented that is based on colloidal monolayer templating combined with multiple and angled deposition steps. Patterns of gold and SiO2 layers are used to generate complex protein nanopatterns over large areas. Simple circular patches or more complex ring structures are produced in addition to hierarchical patterns of smaller patches. The gold regions are modified through alkanethiol chemistry, which enables the preparation of extracellular matrix proteins (vitronectin) or cellular ligands (the extracellular domain of E-cadherin) in the nanopatterns, whereas the selective poly(l-lysine)-poly(ethylene glycol) functionalization of the SiO2 matrix renders it protein repellent. Cell studies, as a proof of principle, demonstrate the potential for using sets of systematically varied samples with simpler or more complex patterns for studies of cellular adhesive behavior and reveal that the local distribution of proteins within a simple patch critically influences cell adhesion.
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Kristensen SH, Pedersen GA, Nejsum LN, Sutherland DS. Nanoscale E-cadherin ligand patterns show threshold size for cellular adhesion and adherence junction formation. NANO LETTERS 2012; 12:2129-2133. [PMID: 22385254 DOI: 10.1021/nl300514v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The role of ligand spatial distribution on the formation of cadherin mediated cell-cell contacts is studied utilizing nanopatterns of E-cadherin ligands. Protein patches ranging in size from 100 to 800 nm prepared by colloidal lithography critically influence adhesion, spreading, and formation of adherence junctions in epithelial cells. Cells at 100 nm patterns show poor adhesion, while larger pattern sizes show good adhesion, significant spreading, and defined cortical actin. We estimate a threshold of 0.03 μm(2) for epithelial cellular attachment via E-Cadherin.
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Binderup ML, Pedersen GA, Vinggaard AM, Rasmussen ES, Rosenquist H, Cederberg T. Toxicity testing and chemical analyses of recycled fibre-based paper for food contact. FOOD ADDITIVES AND CONTAMINANTS 2002; 19 Suppl:13-28. [PMID: 11962701 DOI: 10.1080/02652030110089878] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Food-contact materials, including paper, have to comply with a basic set of criteria concerning safety. This means that paper for food contact should not give rise to migration of components, which can endanger human health. The objectives of this pilot study were, first, to compare paper of different qualities as food-contact materials and to perform a preliminary evaluation of their suitability, from a safety point of view, and, second, to evaluate the use of different in vitro toxicity tests for screening of paper and board. Paper produced from three different categories of recycled fibres (B-D) and a raw material produced from virgin fibres (A) were obtained from industry, and extracts were examined by chemical analyses and diverse in vitro toxicity test systems. The products tested were either based on different raw materials or different treatments were applied. Paper category B was made from 40% virgin fibres, 40% unprinted cuttings from newspapers, and 20% de-inked newspapers and magazines. Paper categories C and D were based on newspapers and magazines. However, paper D was de-inked, whereas C was not. To identify constituents of the papers with a potential to migrate into foodstuff, samples of the paper products were extracted with either 99% ethanol or water. Potential migrants in the extracts were identified and semiquantified by GC-IR-MS or GC-HRMS. In parallel to the chemical analyses, a battery of four different in vitro toxicity tests with different endpoints were applied to the same extracts. (1) a cytotoxicity test using normal human skin fibroblasts. The test was based on measurements of the reduction of resazurin to resorufin by cellular redox processes and used as a screening test for acute or general toxicity; (2) a Salmonella/microsome assay (Ames test) as a screening test for mutagenic and potentially carcinogenic compounds; (3) a recombinant yeast cell bioassay as a screening test for compounds with oestrogenic activity; (4) an aryl hydrocarbon (Ah)-receptor assay (CALUX assay) as a screening test for compounds with dioxin-like activity. In addition, the papers were testedfor microbial content and, in general, the microbiological load was quite low. The following microorganisms were counted and identified on both surface and homogenized pulp samples: the total number of aerobic bacteria, the number of aerobic and anaerobic spore formers, the number of Bacillus cereus/thuringiensis, and the number of yeast and moulds. The chemical analyses showed a significantly higher amount and different composition pattern of chemicals extracted with ethanol compared with water. Analyses of the ethanol extracts showed a distinctly smaller number and lower concentrations of chemicals in extracts prepared from sample A compared with extracts of samples B-D. The compounds identified in B-D were similar, but the amounts were lower in B compared with C and D. In accordance with the chemical analyses, the water extracts were less cytotoxic than the ethanol extracts. The extract prepared from virgin fibres was less cytotoxic than the extracts prepared from paper made from recycled fibres, and extracts prepared from C was the most cytotoxic. None of the extracts showed mutagenic activity. No conclusion about the oestrogenic activity could be made, because all extracts were cytotoxic to the test organism (yeast cells). Ethanol extracts of A and B showed a negligible positive response in the Ah-receptor assay at the highest nontoxic concentration, whereas C and D showed a more pronounced effect with C being the most potent. A comparable weak effect of water extracts of samples B-D was observed, too. However, the active compound(s) was not identified by chemical analyses.
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Berg T, Petersen A, Pedersen GA, Petersen J, Madsen C. The release of nickel and other trace elements from electric kettles and coffee machines. FOOD ADDITIVES AND CONTAMINANTS 2000; 17:189-96. [PMID: 10827900 DOI: 10.1080/026520300283441] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The release of nickel, chromium and lead from electric kettles to water under conditions simulating regular household use was investigated. Ten out of 26 kettles sold on the Danish market released more than 50 micrograms/l nickel to water, whereas neither lead nor chromium was released in any significant amount. Fifty micrograms/l of nickel in water was chosen as the threshold of action, because concentrations below this value were considered unlikely to provide outbreaks of eczema for those consumers suffering from contact allergy to nickel, who are also sensitive to the content of nickel in the diet. This first part of the study was followed up by a dialogue between the kettle producers and the Danish authorities, leading to a change of construction or design for those kettles that did not comply with the criteria. As a follow-up study another ten kettles were studied to check whether compliance was improved. Two of these ten kettles still released more than 50 micrograms/l nickel to water under the test conditions. These two kettles, however, were subsequently withdrawn from the market. Coffee machines tested similarly did not release aluminium, lead, chromium or nickel in quantities of any significance.
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Pedersen GA, Mortensen GK, Larsen EH. Beverages as a source of toxic trace element intake. FOOD ADDITIVES AND CONTAMINANTS 1994; 11:351-63. [PMID: 7926169 DOI: 10.1080/02652039409374234] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Beverages of different kinds have been investigated for their content of lead, cadmium, nickel, chromium, arsenic and mercury. About a ten times higher lead concentration was found in wine than in most other beverages. Cocoa was high in cadmium and nickel and some vegetable juices contained high levels of nickel. The daily intake of trace elements from beverages was estimated. Wine was still the most significant source of lead even if the bottles did not have lead capsules. By consumption of half a bottle per day the daily intake of lead would be doubled and it would contribute 12% of Provisional Tolerable Weekly Intake. Cocoa is an important source of cadmium and nickel, and consumption of tea as well as vegetable juices could increase the nickel intake significantly. The data are compared to Danish maximum limits on lead and cadmium.
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