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  1. Article ; Online: Mechanical Regulation of Limb Bud Formation

    Yvenn Sermeus / Jef Vangheel / Liesbet Geris / Bart Smeets / Przemko Tylzanowski

    Cells, Vol 11, Iss 420, p

    2022  Volume 420

    Abstract: Early limb bud development has been of considerable interest for the study of embryological development and especially morphogenesis. The focus has long been on biochemical signalling and less on cell biomechanics and mechanobiology. However, their ... ...

    Abstract Early limb bud development has been of considerable interest for the study of embryological development and especially morphogenesis. The focus has long been on biochemical signalling and less on cell biomechanics and mechanobiology. However, their importance cannot be understated since tissue shape changes are ultimately controlled by active forces and bulk tissue rheological properties that in turn depend on cell–cell interactions as well as extracellular matrix composition. Moreover, the feedback between gene regulation and the biomechanical environment is still poorly understood. In recent years, novel experimental techniques and computational models have reinvigorated research on this biomechanical and mechanobiological side of embryological development. In this review, we consider three stages of early limb development, namely: outgrowth, elongation, and condensation. For each of these stages, we summarize basic biological regulation and examine the role of cellular and tissue mechanics in the morphogenetic process.
    Keywords limb bud ; morphogenesis ; developmental mechanics ; Biology (General) ; QH301-705.5
    Subject code 571
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Glomerular endothelial glycocalyx-derived heparan sulfate inhibits glomerular leukocyte influx and attenuates experimental glomerulonephritis

    Marissa L. Maciej-Hulme / Jasper J. Van Gemst / Patience Sanderson / Angelique L. W. M. M. Rops / Jo H. Berden / Bart Smeets / I. Jonathan Amster / Ton J. Rabelink / Johan Van Der Vlag

    Frontiers in Molecular Biosciences, Vol

    2023  Volume 10

    Abstract: Proliferative forms of glomerulonephritis are characterized by the influx of leukocytes, albuminuria, and loss of kidney function. The glomerular endothelial glycocalyx is a thick carbohydrate layer that covers the endothelium and is comprised of heparan ...

    Abstract Proliferative forms of glomerulonephritis are characterized by the influx of leukocytes, albuminuria, and loss of kidney function. The glomerular endothelial glycocalyx is a thick carbohydrate layer that covers the endothelium and is comprised of heparan sulfate (HS), which plays a pivotal role in glomerular inflammation by facilitating endothelial-leukocyte trafficking. We hypothesize that the exogenous glomerular glycocalyx may reduce the glomerular influx of inflammatory cells during glomerulonephritis. Indeed, administration of mouse glomerular endothelial cell (mGEnC)-derived glycocalyx constituents, or the low-molecular-weight heparin enoxaparin, reduced proteinuria in mice with experimental glomerulonephritis. Glomerular influx of granulocytes and macrophages, as well as glomerular fibrin deposition, was reduced by the administration of mGEnC-derived glycocalyx constituents, thereby explaining the improved clinical outcome. HSglx also inhibited granulocyte adhesion to human glomerular endothelial cells in vitro. Notably, a specific HSglx fraction inhibited both CD11b and L-selectin binding to activated mGEnCs. Mass spectrometry analysis of this specific fraction revealed six HS oligosaccharides, ranging from tetra- to hexasaccharides with 2–7 sulfates. In summary, we demonstrate that exogenous HSglx reduces albuminuria during glomerulonephritis, which is possibly mediated via multiple mechanisms. Our results justify the further development of structurally defined HS-based therapeutics for patients with (acute) inflammatory glomerular diseases, which may be applicable to non-renal inflammatory diseases as well.
    Keywords heparan sulfate ; glomerulonephritis ; leukocyte ; glomerular endothelial cell ; inflammation ; glycocalyx ; Biology (General) ; QH301-705.5
    Subject code 616
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article: Parietal cells—new perspectives in glomerular disease

    Miesen, Laura / Eric Steenbergen / Bart Smeets

    Cell and tissue research. 2017 July, v. 369, no. 1

    2017  

    Abstract: In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman’s capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the ... ...

    Abstract In normal glomeruli, parietal epithelial cells (PECs) line the inside of Bowman’s capsule and form an inconspicuous sheet of flat epithelial cells in continuity with the proximal tubular epithelial cells (PTECs) at the urinary pole and with the podocytes at the vascular pole. PECs, PTECs and podocytes have a common mesenchymal origin and are the result of divergent differentiation during embryogenesis. Podocytes and PTECs are highly differentiated cells with well-established functions pertaining to the maintenance of the filtration barrier and transport, respectively. For PECs, no specific function other than a structural one has been known until recently. Possible important functions for PECs in the fate of the glomerulus in glomerular disease have now become apparent: (1) PECs may be involved in the replacement of lost podocytes; (2) PECs form the basis of extracapillary proliferative lesions and subsequent sclerosis in glomerular disease. In addition to the acknowledgement that PECs are crucial in glomerular disease, knowledge has been gained regarding the molecular processes driving the phenotypic changes and behavior of PECs. Understanding these molecular processes is important for the development of specific therapeutic approaches aimed at either stimulation of the regenerative function of PECs or inhibition of the pro-sclerotic action of PECs. In this review, we discuss recent advances pertaining to the role of PECs in glomerular regeneration and disease and address the major molecular processes involved.
    Keywords embryogenesis ; epithelial cells ; filtration ; phenotype ; sclerosis
    Language English
    Dates of publication 2017-07
    Size p. 237-244.
    Publishing place Springer Berlin Heidelberg
    Document type Article
    ZDB-ID 125067-x
    ISSN 1432-0878 ; 0302-766X
    ISSN (online) 1432-0878
    ISSN 0302-766X
    DOI 10.1007/s00441-017-2600-5
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Carbonic Anhydrase IX-Targeted α-Radionuclide Therapy with 225Ac Inhibits Tumor Growth in a Renal Cell Carcinoma Model

    Robin I. J. Merkx / Mark Rijpkema / Gerben M. Franssen / Annemarie Kip / Bart Smeets / Alfred Morgenstern / Frank Bruchertseifer / Eddie Yan / Michael P. Wheatcroft / Egbert Oosterwijk / Peter F. A. Mulders / Sandra Heskamp

    Pharmaceuticals, Vol 15, Iss 570, p

    2022  Volume 570

    Abstract: In this study, we compared the tumor-targeting properties, therapeutic efficacy, and tolerability of the humanized anti-CAIX antibody (hG250) labeled with either the α-emitter actinium-225 ( 225 Ac) or the β - -emitter lutetium-177 ( 177 Lu) in mice. ... ...

    Abstract In this study, we compared the tumor-targeting properties, therapeutic efficacy, and tolerability of the humanized anti-CAIX antibody (hG250) labeled with either the α-emitter actinium-225 ( 225 Ac) or the β - -emitter lutetium-177 ( 177 Lu) in mice. BALB/c nude mice were grafted with human renal cell carcinoma SK-RC-52 cells and intravenously injected with 30 µg [ 225 Ac] Ac-DOTA-hG250 ( 225 Ac-hG250) or 30 µg [ 177 Lu] Lu-DOTA-hG250 ( 177 Lu-hG250), followed by ex vivo biodistribution studies. Therapeutic efficacy was evaluated in mice receiving 5, 15, and 25 kBq of 225 Ac-hG250; 13 MBq of 177 Lu-hG250; or no treatment. Tolerability was evaluated in non-tumor-bearing animals. High tumor uptake of both radioimmunoconjugates was observed and increased up to day 7 (212.8 ± 50.2 %IA/g vs. 101.0 ± 18.4 %IA/g for 225 Ac-hG250 and 177 Lu-hG250, respectively). Survival was significantly prolonged in mice treated with 15 kBq 225 Ac-hG250, 25 kBq 225 Ac-hG250, and 13 MBq 177 Lu-hG250 compared to untreated control ( p < 0.05). Non-tumor-bearing mice that received single-dose treatment with 15 or 25 kBq 225 Ac-hG250 showed weight loss at the end of the experiment (day 126), and immunohistochemical analysis suggested radiation-induced nephrotoxicity. These results demonstrate the therapeutic potential of CAIX-targeted α-therapy in renal cell carcinoma. Future studies are required to find an optimal balance between therapeutic efficacy and toxicity.
    Keywords radioimmunotherapy ; RCC ; actinium-225 ; CAIX ; G250 ; Medicine ; R ; Pharmacy and materia medica ; RS1-441
    Language English
    Publishing date 2022-05-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Investigating the Molecular Mechanisms of Renal Hepcidin Induction and Protection upon Hemoglobin-Induced Acute Kidney Injury

    Laura E. Diepeveen / Gaby Stegemann / Erwin T. Wiegerinck / Rian Roelofs / Myrthe Naber / Olivier Lóreal / Bart Smeets / Frank Thévenod / Dorine W. Swinkels / Rachel P. L. van Swelm

    International Journal of Molecular Sciences, Vol 23, Iss 1352, p

    2022  Volume 1352

    Abstract: Hemolysis is known to cause acute kidney injury (AKI). The iron regulatory hormone hepcidin, produced by renal distal tubules, is suggested to exert a renoprotective role during this pathology. We aimed to elucidate the molecular mechanisms of renal ... ...

    Abstract Hemolysis is known to cause acute kidney injury (AKI). The iron regulatory hormone hepcidin, produced by renal distal tubules, is suggested to exert a renoprotective role during this pathology. We aimed to elucidate the molecular mechanisms of renal hepcidin synthesis and its protection against hemoglobin-induced AKI. In contrast to known hepatic hepcidin induction, incubation of mouse cortical collecting duct (mCCD cl1 ) cells with IL-6 or LPS did not induce Hamp1 mRNA expression, whereas iron (FeS) and hemin significantly induced hepcidin synthesis ( p < 0.05). Moreover, iron/heme-mediated hepcidin induction in mCCD cl1 cells was caused by the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, as indicated by increased nuclear Nrf2 translocation and induced expression of Nrf2 downstream targets GCLM ( p < 0.001), NQO1 ( p < 0.001), and TXNRD1 ( p < 0.005), which could be prevented by the known Nrf2 inhibitor trigonelline. Newly created inducible kidney-specific hepcidin KO mice demonstrated a significant reduction in renal Hamp1 mRNA expression. Phenylhydrazine (PHZ)-induced hemolysis caused renal iron loading and oxidative stress in both wildtype (Wt) and KO mice. PHZ treatment in Wt induced inflammatory markers ( IL-6 , TNFα ) but not Hamp1 . However, since PHZ treatment also significantly reduced systemic hepcidin levels in both Wt and KO mice (both p < 0.001), a dissection between the roles of systemic and renal hepcidin could not be made. Combined, the results of our study indicate that there are kidney-specific mechanisms in hepcidin regulation, as indicated by the dominant role of iron and not inflammation as an inducer of renal hepcidin, but also emphasize the complex interplay of various iron regulatory mechanisms during AKI on a local and systemic level.
    Keywords kidney ; iron ; hepcidin ; acute kidney injury ; hemoglobin ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Subject code 616
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Motile Cilia on Kidney Proximal Tubular Epithelial Cells Are Associated With Tubular Injury and Interstitial Fibrosis

    Jennifer Eymael / Brigith Willemsen / Joyce Xu / Fieke Mooren / Eric Steenbergen / Jack F. Wetzels / Henry Dijkman / Jitske Jansen / Johan Van der Vlag / Bart Smeets

    Frontiers in Cell and Developmental Biology, Vol

    2022  Volume 10

    Abstract: It is well established that mammalian kidney epithelial cells contain a single non-motile primary cilium (9 + 0 pattern). However, we noted the presence of multiple motile cilia with a central microtubular pair (9 + 2 pattern) in kidney biopsies of 11 ... ...

    Abstract It is well established that mammalian kidney epithelial cells contain a single non-motile primary cilium (9 + 0 pattern). However, we noted the presence of multiple motile cilia with a central microtubular pair (9 + 2 pattern) in kidney biopsies of 11 patients with various kidney diseases, using transmission electron microscopy. Immunofluorescence staining revealed the expression of the motile cilia-specific markers Radial Spoke Head Protein 4 homolog A, Forkhead-box-protein J1 and Regulatory factor X3. Multiciliated cells were exclusively observed in proximal tubuli and a relative frequent observation in human kidney tissue: in 16.7% of biopsies with tubular injury and atrophy (3 of 18 tissues), in 17.6% of biopsies from patients with membranous nephropathy (3 of 17 tissues) and in 10% of the human kidney tissues derived from the unaffected pole after tumour nephrectomy (3 of 30 tissues). However, these particular tissues showed marked tubular injury and fibrosis. Further analysis showed a significant relation between the presence of multiciliated cells and an increased expression of alpha-smooth-muscle-actin (p-value < 0.01) and presence of Kidney-injury-molecule-1 (p-value < 0.01). Interestingly, multiciliated cells co-showed staining for the scattered tubular cell markers annexin A2, annexin A3, vimentin and phosphofructokinase platelet but not with cell senescence associated markers, like (p16) and degradation of lamin B. In conclusion, multiciliated proximal tubular cells with motile cilia were frequently observed in kidney biopsies and associated with tubular injury and interstitial fibrosis. These data suggest that proximal tubular cells are able to transdifferentiate into multiciliated cells.
    Keywords motile cilia ; multiciliated cells ; multiciliated differentiation ; kidney injury and repair ; interstitial fibrosis and tubular atrophy ; proximal tubular cells ; Biology (General) ; QH301-705.5
    Subject code 616
    Language English
    Publishing date 2022-03-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Kidney tubule iron loading in experimental focal segmental glomerulosclerosis

    Rachel P. L. van Swelm / Sanne Beurskens / Henry Dijkman / Erwin T. G. Wiegerinck / Rian Roelofs / Frank Thévenod / Johan van der Vlag / Jack F. M. Wetzels / Dorine W. Swinkels / Bart Smeets

    Scientific Reports, Vol 12, Iss 1, Pp 1-

    2022  Volume 12

    Abstract: Abstract Kidney iron deposition may play a role in the progression of tubulointerstitial injury during chronic kidney disease. Here, we studied the molecular mechanisms of kidney iron loading in experimental focal segmental glomerulosclerosis (FSGS) and ... ...

    Abstract Abstract Kidney iron deposition may play a role in the progression of tubulointerstitial injury during chronic kidney disease. Here, we studied the molecular mechanisms of kidney iron loading in experimental focal segmental glomerulosclerosis (FSGS) and investigated the effect of iron-reducing interventions on disease progression. Thy-1.1 mice were injected with anti-Thy-1.1 monoclonal antibody (mAb) to induce proteinuria. Urine, blood and tissue were collected at day (D)1, D5, D8, D15 and D22 after mAb injection. Thy-1.1 mice were subjected to captopril (CA), iron-deficient (ID) diet or iron chelation (deferoxamine; DFO). MAb injection resulted in significant albuminuria at all time points (p < 0.01). Kidney iron loading, predominantly in distal tubules, increased in time, along with urinary kidney injury molecule-1 and 24p3 concentration, as well as kidney mRNA expression of Interleukin-6 (Il-6) and Heme oxygenase-1 (Ho-1). Treatment with CA, ID diet or DFO significantly reduced kidney iron deposition at D8 and D22 (p < 0.001) and fibrosis at D22 (p < 0.05), but not kidney Il-6. ID treatment increased kidney Ho-1 (p < 0.001). In conclusion, kidney iron accumulation coincides with progression of tubulointerstitial injury in this model of FSGS. Reduction of iron loading halts disease progression. However, targeted approaches to prevent excessive kidney iron loading are warranted to maintain the delicate systemic and cellular iron balance.
    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2022-01-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Using human iPSC-derived kidney organoids to decipher SARS-CoV-2 pathology on single cell level

    Katharina C. Reimer / Jitske Jansen / Gijs J. Overheul / Pascal Miesen / Ronald P. van Rij / Sergio H. Triana / Bart Smeets / Rebekka K. Schneider / Rafael Kramann

    STAR Protocols, Vol 3, Iss 3, Pp 101612- (2022)

    2022  

    Abstract: Summary: We describe a protocol for single-cell RNA sequencing of SARS-CoV-2-infected human induced pluripotent stem cell (iPSC)-derived kidney organoids. After inoculation of kidney organoids with virus, we use mechanical and enzymatic disruption to ... ...

    Abstract Summary: We describe a protocol for single-cell RNA sequencing of SARS-CoV-2-infected human induced pluripotent stem cell (iPSC)-derived kidney organoids. After inoculation of kidney organoids with virus, we use mechanical and enzymatic disruption to obtain single cell suspensions. Next, we process the organoid-derived cells into sequencing-ready SARS-CoV-2-targeted libraries. Subsequent sequencing analysis reveals changes in kidney cells after virus infection. The protocol was designed for kidney organoids cultured in a 6-well transwell format but can be adapted to organoids with different organ backgrounds.For complete details on the use and execution of this protocol, please refer to Jansen et al. (2022). : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
    Keywords Cell biology ; Single cell ; Microbiology ; Stem cells ; Organoids ; Science (General) ; Q1-390
    Language English
    Publishing date 2022-09-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: The role of actin protrusion dynamics in cell migration through a degradable viscoelastic extracellular matrix

    Tommy Heck / Diego A Vargas / Bart Smeets / Herman Ramon / Paul Van Liedekerke / Hans Van Oosterwyck

    PLoS Computational Biology, Vol 16, Iss 1, p e

    Insights from a computational model.

    2020  Volume 1007250

    Abstract: Actin protrusion dynamics plays an important role in the regulation of three-dimensional (3D) cell migration. Cells form protrusions that adhere to the surrounding extracellular matrix (ECM), mechanically probe the ECM and contract in order to displace ... ...

    Abstract Actin protrusion dynamics plays an important role in the regulation of three-dimensional (3D) cell migration. Cells form protrusions that adhere to the surrounding extracellular matrix (ECM), mechanically probe the ECM and contract in order to displace the cell body. This results in cell migration that can be directed by the mechanical anisotropy of the ECM. However, the subcellular processes that regulate protrusion dynamics in 3D cell migration are difficult to investigate experimentally and therefore not well understood. Here, we present a computational model of cell migration through a degradable viscoelastic ECM. This model is a 2D representation of 3D cell migration. The cell is modeled as an active deformable object that captures the viscoelastic behavior of the actin cortex and the subcellular processes underlying 3D cell migration. The ECM is regarded as a viscoelastic material, with or without anisotropy due to fibrillar strain stiffening, and modeled by means of the meshless Lagrangian smoothed particle hydrodynamics (SPH) method. ECM degradation is captured by local fluidization of the material and permits cell migration through the ECM. We demonstrate that changes in ECM stiffness and cell strength affect cell migration and are accompanied by changes in number, lifetime and length of protrusions. Interestingly, directly changing the total protrusion number or the average lifetime or length of protrusions does not affect cell migration. A stochastic variability in protrusion lifetime proves to be enough to explain differences in cell migration velocity. Force-dependent adhesion disassembly does not result in faster migration, but can make migration more efficient. We also demonstrate that when a number of simultaneous protrusions is enforced, the optimal number of simultaneous protrusions is one or two, depending on ECM anisotropy. Together, the model provides non-trivial new insights in the role of protrusions in 3D cell migration and can be a valuable contribution to increase the understanding of ...
    Keywords Biology (General) ; QH301-705.5
    Subject code 612
    Language English
    Publishing date 2020-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article: A discrete element approach for modelling the compression of crop stems

    Leblicq, Tom / Bart Smeets / Herman Ramon / Wouter Saeys

    Computers and electronics in agriculture. 2016 Apr., v. 123

    2016  

    Abstract: The discrete element method (DEM) offers a powerful tool for simulating the interactions of large numbers of particles. Recently, DEM was used to simulate the interactions of tubular particles. While the existing linear elastic and Hertzian contact ... ...

    Abstract The discrete element method (DEM) offers a powerful tool for simulating the interactions of large numbers of particles. Recently, DEM was used to simulate the interactions of tubular particles. While the existing linear elastic and Hertzian contact models can approximate the reversible compression for small deformations, they are inadequate for larger deformations. Here, the force–deformation behaviour is highly non-linear and plastic. In this study, data based contact models were developed for crop stems. These models combine realistic deformation behaviour with a minimal number of model parameters. Furthermore, the effect of plastic deformation and damage was incorporated in the model. The contact models were successfully used to validate, through comparison of simulations and measurements, individual stem and bulk compression. A good agreement was found between both. These validated DEM contact models for compression of crop stems allow to simulate the processing of large numbers of crop stems.
    Keywords models ; plastic deformation ; stems
    Language English
    Dates of publication 2016-04
    Size p. 80-88.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 395514-x
    ISSN 0168-1699
    ISSN 0168-1699
    DOI 10.1016/j.compag.2016.02.018
    Database NAL-Catalogue (AGRICOLA)

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