L P van den Heuvel

Radboud University Nijmegen, Nymegen, Gelderland, Netherlands

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Publications (172)854.97 Total impact

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    ABSTRACT: The bioartificial kidney (BAK) aims at improving dialysis by developing 'living membranes' for cells-aided removal of uremic metabolites. Here, unique human conditionally immortalized proximal tubule epithelial cell (ciPTEC) monolayers were cultured on biofunctionalized MicroPES (polyethersulfone) hollow fiber membranes (HFM) and functionally tested using microfluidics. Tight monolayer formation was demonstrated by abundant zonula occludens-1 (ZO-1) protein expression along the tight junctions of matured ciPTEC on HFM. A clear barrier function of the monolayer was confirmed by limited diffusion of FITC-inulin. The activity of the organic cation transporter 2 (OCT2) in ciPTEC was evaluated in real-time using a perfusion system by confocal microscopy using 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP(+)) as a fluorescent substrate. Initial ASP(+) uptake was inhibited by a cationic uremic metabolites mixture and by the histamine H2-receptor antagonist, cimetidine. In conclusion, a 'living membrane' of renal epithelial cells on MicroPES HFM with demonstrated active organic cation transport was successfully established as a first step in BAK engineering.
    Preview · Article · Nov 2015 · Scientific Reports
  • J Engel · L Blanchet · B Bloemen · L.P. van den Heuvel · U.H.F. Engelke · R.A. Wevers · L.M.C. Buydens
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    ABSTRACT: Many advanced metabolomics experiments currently lead to data where a large number of response variables were measured while one or several factors were changed. Often the number of response variables vastly exceeds the sample size and well-established techniques such as multivariate analysis of variance (MANOVA) cannot be used to analyze the data. ANOVA simultaneous component analysis (ASCA) is an alternative to MANOVA for analysis of metabolomics data from an experimental design. In this paper, we show that ASCA assumes that none of the metabolites are correlated and that they all have the same variance. Because of these assumptions, ASCA may relate the wrong variables to a factor. This reduces the power of the method and hampers interpretation. We propose an improved model that is essentially a weighted average of the ASCA and MANOVA models. The optimal weight is determined in a data-driven fashion. Compared to ASCA, this method assumes that variables can correlate, leading to a more realistic view of the data. Compared to MANOVA, the model is also applicable when the number of samples is (much) smaller than the number of variables. These advantages are demonstrated by means of simulated and real data examples. The source code of the method is available from the first author upon request, and at the following github repository: https://github.com/JasperE/regularized-MANOVA.
    No preview · Article · Nov 2015 · Analytica chimica acta

  • No preview · Conference Paper · Sep 2015
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    ABSTRACT: Dense deposit disease (DDD), a subtype of C3 glomerulopathy, is a rare disease affecting mostly children. Treatment options are limited. Debate exists whether eculizumab, a monoclonal antibody against complement factor C5, is effective in DDD. Reported data are scarce, especially in children. The authors analyzed clinical and histologic data of five pediatric patients with a native kidney biopsy diagnosis of DDD. Patients received eculizumab as therapy of last resort for severe nephritic or nephrotic syndrome with alternative pathway complement activation; this therapy was given only when the patients had not or only marginally responded to immunosuppressive therapy. Outcome measures were kidney function, proteinuria, and urine analysis. In all, seven disease episodes were treated with eculizumab (six episodes of severe nephritic syndrome [two of which required dialysis] and one nephrotic syndrome episode). Median age at treatment start was 8.4 (range, 5.9-13) years. For three treatment episodes, eculizumab was the sole immunosuppressive treatment. In all patients, both proteinuria and renal function improved significantly within 12 weeks of treatment (median urinary protein-to-creatinine ratio of 8.5 [range, 2.2-17] versus 1.1 [range, 0.2-2.0] g/g, P<0.005, and eGFR of 58 [range, 17-114] versus 77 [range, 50-129] ml/min per 1.73 m(2), P<0.01). A striking finding was the disappearance of leukocyturia within 1 week after the first eculizumab dose in all five episodes with leukocyturia at treatment initiation. In this case series of pediatric patients with DDD, eculizumab treatment was associated with reduction in proteinuria and increase in eGFR. Leukocyturia resolved within 1 week of initiation of eculizumab treatment. These results underscore the need for a randomized trial of eculizumab in DDD. Copyright © 2015 by the American Society of Nephrology.
    No preview · Article · Aug 2015 · Clinical Journal of the American Society of Nephrology
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    ABSTRACT: In renal failure, the systemic accumulation of uremic waste products is strongly associated with the development of a chronic inflammatory state. Here, the effect of cationic uremic toxins on the release of inflammatory cytokines and endothelin-1 (ET-1) was investigated in conditionally immortalized proximal tubule epithelial cells (ciPTEC). Additionally, we examined the effects of ET-1 on the cellular uptake mediated by organic cation transporters (OCTs). Exposure of ciPTEC to cationic uremic toxins initiated production of the inflammatory cytokines IL-6 (117 ± 3%, p < 0.001), IL-8 (122 ± 3%, p < 0.001), and ET-1 (134 ± 5%, p < 0.001). This was accompanied by a down-regulation of OCT mediated 4-(4-(dimethylamino)styryl)-N-methylpyridinium-iodide (ASP+) uptake in ciPTEC at 30 min (23 ± 4%, p < 0.001), which restored within 60 min of incubation. Exposure to ET-1 for 24 h increased the ASP+ uptake significantly (20 ± 5%, p < 0.001). These effects could be blocked by BQ-788, indicating activation of an ET-B-receptor-mediated signaling pathway. Downstream the receptor, iNOS inhibition by (N(G)‐monomethyl‐l‐arginine) l-NMMA acetate or aminoguanidine, as well as protein kinase C activation, ameliorated the short-term effects. These results indicate that uremia results in the release of cytokines and ET-1 from human proximal tubule cells, in vitro. Furthermore, ET-1 exposure was found to regulate proximal tubular OCT transport activity in a differential, time-dependent, fashion.
    Preview · Article · Jun 2015
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    ABSTRACT: COA6/C1orf31 is involved in cytochrome c oxidase (complex IV) biogenesis. We present a new pathogenic COA6 variant detected in a patient with neonatal hypertrophic cardiomyopathy and isolated complex IV deficiency. For the first time, clinical details about a COA6 deficient patient are given and patient fibroblasts are functionally characterized: COA6 protein is undetectable and steady state levels of complex IV and several of its subunits are reduced. The monomeric COX1 assembly intermediate accumulates. Using pulse-chase experiments, we demonstrate an increased turnover of mitochondrial encoded complex IV subunits. While monomeric complex IV is decreased in patient fibroblasts, the CI/CIII2/CIVn-supercomplexes remain unaffected. Copper supplementation shows a partial rescue of complex IV deficiency in patient fibroblasts. We conclude that COA6 is required for complex IV subunit stability. Furthermore, the proposed role in the copper delivery pathway to complex IV subunits is substantiated and a therapeutic lead for COA6 deficient patients is provided.This article is protected by copyright. All rights reserved
    No preview · Article · Jan 2015 · Human Mutation

  • No preview · Article · Sep 2014 · Pediatric Nephrology
  • J Jansen · M Fedecostante · M J Wilmer · L P van den Heuvel · J G Hoenderop · R Masereeuw
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    ABSTRACT: With the world-wide increase of patients with renal failure, the development of functional renal replacement therapies have gained significant interest and novel technologies are rapidly evolving. Currently used renal replacement therapies insufficiently remove accumulating waste products, resulting in the uremic syndrome. A more preferred treatment option is kidney transplantation, but the shortage of donor organs and the increasing number of patients waiting for a transplant warrant the development of novel technologies. The bioartificial kidney (BAK) is such promising biotechnological approach to replace essential renal functions together with the active secretion of waste products. The development of the BAK requires a multidisciplinary approach and evolves at the intersection of regenerative medicine and renal replacement therapy. Here we provide a concise review embracing a compact historical overview of bioartificial kidney development and highlighting the current state-of-the-art, including implementation of living-membranes and the relevance of extracellular matrices. We focus further on the choice of relevant renal epithelial cell lines versus the use of stem cells and co-cultures that need to be implemented in a suitable device. Moreover, the future of the BAK in regenerative nephrology is discussed.
    No preview · Article · Aug 2014 · Biotechnology Advances
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    Tri Q Nguyen · Roel Goldschmeding · Lambert P van den Heuvel

    Preview · Article · Jul 2014 · Nephrology Dialysis Transplantation
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    Full-text · Article · Jun 2014 · European Journal of Vascular and Endovascular Surgery
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    ABSTRACT: Defects in complex II of the mitochondrial respiratory chain are a rare cause of mitochondrial disorders. Underlying autosomal-recessive genetic defects are found in most of the 'SDHx' genes encoding complex II (SDHA, SDHB, SDHC, and SDHD) and its assembly factors. Interestingly, SDHx genes also function as tumor suppressor genes in hereditary paragangliomas, pheochromocytomas, and gastrointestinal stromal tumors. In these cases, the affected patients are carrier of a heterozygeous SDHx germline mutation. Until now, mutations in SDHx associated with mitochondrial disease have not been reported in association with hereditary tumors and vice versa. Here, we characterize four patients with isolated complex II deficiency caused by mutations in SDHA presenting with multisystem mitochondrial disease including Leigh syndrome (LS) and/or leukodystrophy. Molecular genetic analysis revealed three novel mutations in SDHA. Two mutations (c.64-2A>G and c.1065-3C>A) affect mRNA splicing and result in loss of protein expression. These are the first mutations described affecting SDHA splicing. For the third new mutation, c.565T>G, we show that it severely affects enzyme activity. Its pathogenicity was confirmed by lentiviral complementation experiments on the fibroblasts of patients carrying this mutation. It is of special interest that one of our LS patients harbored the c.91C>T (p.Arg31*) mutation that was previously only reported in association with paragangliomas and pheochromocytomas, tightening the gap between these two rare disorders. As tumor screening is recommended for SDHx mutation carriers, this should also be considered for patients with mitochondrial disorders and their family members.European Journal of Human Genetics advance online publication, 30 April 2014; doi:10.1038/ejhg.2014.80.
    No preview · Article · Apr 2014 · European journal of human genetics: EJHG
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    ABSTRACT: Promising renal replacement therapies include the development of a bio-artificial kidney using functional human kidney cell models. In this study, human conditionally immortalized proximal tubular epithelial cell (ciPTEC) lines originating from kidney tissue (ciPTEC-T1 and ciPTEC-T2) were compared to ciPTEC previously isolated from urine (ciPTEC-U). Subclones of all ciPTEC isolates formed tight cell layers on Transwell inserts as determined by transepithelial resistance, inulin diffusion, E-cadherin expression and immunocytochemisty. Extracellular matrix genes collagen I and -IV α1 were highly present in both kidney tissue derived matured cell lines (p<0.001) compared to matured ciPTEC-U, whereas matured ciPTEC-U showed a more pronounced fibronectin I and laminin 5 gene expression (p<0.01 and p<0.05, respectively). Expression of the influx carrier Organic Cation Transporter 2 (OCT-2), and the efflux pumps P-glycoprotein (P-gp), Multidrug Resistance Protein 4 (MRP4) and Breast Cancer Resistance Protein (BCRP) were confirmed in the three cell lines using real-time PCR and Western blotting. The activities of OCT-2 and P-gp were sensitive to specific inhibition in all models (p<0.001). The highest activity of MRP4 and BCRP was demonstrated in ciPTEC-U (p<0.05). Finally, active albumin reabsorption was highest in ciPTEC-T2 (p<0.001), while Na(+)-dependent phosphate reabsorption was most abundant in ciPTEC-U (p<0.01). In conclusion, ciPTEC established from human urine or kidney tissue display comparable functional PTEC specific transporters and physiological characteristics, providing ideal human tools for bioartificial kidney development.
    Preview · Article · Feb 2014 · Experimental Cell Research
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    ABSTRACT: The complement system plays an important role in both the innate and adaptive immune system. Patients with inherited complement deficiencies have an increased risk of systemic bacterial infections. Deficiencies of the terminal complement pathway are especially associated with invasive meningococcal disease. Here, we report a case of a boy that presented with arthritis and recurrent bacterial and viral infections. Extensive analyses revealed decreased complement activity of both classical and alternative pathway, indicating a deficiency of C3 or one of the factors of the terminal complement pathway. Mutational analysis of the C6 gene identified two compound heterozygous mutations. An unknown missense aberration was found that involves the loss of a cysteine, possibly affecting the 3D structure of the protein. Furthermore, a known splice site variation was identified that results in a 14% shorter protein, due to transcription of amino acids that are normally intronic until a stop codon is reached (exon-intron boundary defect). It is known that the protein with this latter aberration is still functionally active when present with other C6 mutations and therefore, the consequences of the combination of the identified variations have been studied. Quantitative ELISAs showed that at least one allele produced a circulating C6 molecule that can be incorporated in the membrane attack complex, likely the truncated protein. In the present case we observed relapsing bacterial and viral infections, but no meningococcal disease. The reduced complement activity can be explained by the identified genetic variations in C6, as recombinant C6 supplementation corrected complement function in vitro.
    Full-text · Article · Dec 2013 · Molecular Immunology
  • D. Westra · L. P. van den Heuvel · J.A.E. van Wijk · J.F.M. Wetzels · N.C.A. van de Kar

    No preview · Article · Dec 2013 · Molecular Immunology
  • D. Westra · R.A.J. Kurvers · L. P. van den Heuvel · R. Wurzner · N.C.A. van de Kar · A. Warris

    No preview · Article · Dec 2013 · Molecular Immunology
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    ABSTRACT: Bartter syndrome encompasses a variety of inheritable renal tubular transport disorders characterized by hypokalemia and hypochloremic metabolic alkalosis. Bartter syndrome Type III is caused by genetic alterations in the chloride channel kidney B (CLCNKB) gene and often presents in the first 2 years of life, known as classic Bartter syndrome. However, in rare cases Bartter syndrome Type III has an antenatal presentation with polyhydramnios, premature delivery and severe dehydration in the first weeks of life. Associations between congenital anomalies of the kidney and urinary tract and Bartter syndrome are extremely rare. This case report presents a girl with Bartter syndrome Type III due to a homozygous CLCNKB mutation and bilateral congenital anomalies of the kidney and urinary tract. In addition, we describe the antenatal presentation as well as its perinatal management.
    Full-text · Article · Dec 2012 · Clinical nephrology
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    ABSTRACT: A multicentre comparison of mitochondrial respiratory chain and complex V enzyme activity tests was performed. The average reproducibility of the enzyme assays is 16% in human muscle samples. In a blinded diagnostic accuracy test in patient fibroblasts and SURF1 knock-out mouse muscle, each lab made the correct diagnosis except for two complex I results. We recommend that enzyme activities are evaluated based on ratios, e.g. with complex IV or citrate synthase activity. In spite of large variations in observed enzyme activities, we show that inter-laboratory comparison of patient sample test results is possible by using normalization against a control sample.
    No preview · Article · Nov 2012 · Mitochondrion
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    ABSTRACT: During chronic kidney disease (CKD), drug metabolism is affected leading to changes in drug disposition. Furthermore, there is a progressive accumulation of uremic retention solutes due to impaired renal clearance. Here, we investigated whether uremic toxins can influence the metabolic functionality of human conditionally immortalized renal proximal tubule epithelial cells (ciPTEC) with the focus on UDP-glucuronosyltransferases (UGTs) and mitochondrial activity. Our results showed that ciPTEC express a wide variety of metabolic enzymes, including UGTs. These enzymes were functionally active as demonstrated by the glucuronidation of 7-hydroxycoumarin (7-OHC; K(m) of 12±2μM and a V(max) of 76±3pmol/min/mg) and p-cresol (K(m) of 33±13μM and a V(max) of 266±25pmol/min/mg). Furthermore, a wide variety of uremic toxins, including indole-3-acetic acid, indoxyl sulfate, phenylacetic acid and kynurenic acid, reduced 7-OHC glucuronidation with more than 30% as compared with controls (p<0.05), whereas UGT1A and UGT2B protein expressions remained unaltered. In addition, our results showed that several uremic toxins inhibited mitochondrial succinate dehydrogenase (i.e. complex II) activity with more than 20% as compared with controls (p<0.05). Moreover, indole-3-acetic acid decreased the reserve capacity of the electron transport system with 18% (p<0.03). In conclusion, this study shows that multiple uremic toxins inhibit UGT activity and mitochondrial activity in ciPTEC, thereby affecting the metabolic capacity of the kidney during CKD. This may have a significant impact on drug and uremic retention solute disposition in CKD patients.
    Full-text · Article · Sep 2012 · Biochimica et Biophysica Acta
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    ABSTRACT: Background: The hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy leading to acute kidney injury in children. In most cases it is triggered by an infection caused by Shiga-like toxin-producing Escherichia coli (STEC). Endothelial damage plays a central role in the pathogenesis of disease. Hemophilia A is a genetic disorder leading to factor VIII (FVIII) deficiency, an important factor in the coagulation system. Case: Here we describe a hemophilia A patient who developed HUS due to a STEC O26 infection. The patient developed not only acute kidney injury, but also severe gastro-intestinal and neurological complications. Increased amounts of recombinant FVIII (rFVIII) had to be administered during the acute phase of the disease to reach acceptable blood levels of FVIII, in order to control the hemorrhagic colitis and to prevent severe neurological complications. Conclusion: The patient's treatment schedule of rFVIII during the HUS period was a serious challenge, and we cannot exclude that it contributed to the severity of the HUS by enhancing the thrombotic microangiopathic process. The role of factor VIII administration in the severe outcome of this disease is discussed.
    No preview · Article · Sep 2012 · Pediatric Nephrology
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    ABSTRACT: Atypical HUS (aHUS) is a severe renal disorder that is associated with mutations in the genes encoding proteins of the complement alternative pathway. Previously, we identified pathogenic variations in genes encoding complement regulators (CFH, CFI, and MCP) in our aHUS cohort. In this study, we screened for mutations in the alternative pathway regulator CFHR5 in 65 aHUS patients by means of PCR on genomic DNA and sequence analysis. Potential pathogenicity of genetic alterations was determined by published data on CFHR5 variants, evolutionary conservation, and in silico mutation prediction programs. Detection of serum CFHR5 was performed by western blot analysis and ELISA. A potentially pathogenic sequence variation was found in CFHR5 in three patients (4.6%). All variations were located in SCRs that might be involved in binding to C3b, heparin, or CRP. The identified CFHR5 mutations require functional studies to determine their relevance to aHUS, but they might be candidates for an altered genetic profile predisposing to the disease.
    Full-text · Article · May 2012 · Journal of Human Genetics

Publication Stats

13k Citations
854.97 Total Impact Points

Institutions

  • 1988-2015
    • Radboud University Nijmegen
      • • Department of Pediatrics
      • • Laboratory of Pediatrics and Neurology
      • • Medical Centre
      • • Department of Biochemistry
      Nymegen, Gelderland, Netherlands
  • 1996-2014
    • Radboud University Medical Centre (Radboudumc)
      • • Department of Human Genetics
      • • Department of Neurology
      Nymegen, Gelderland, Netherlands
    • HagaZiekenhuis van Den Haag
      's-Gravenhage, South Holland, Netherlands
  • 2012
    • Universitair Ziekenhuis Leuven
      • Department of Pedriatrics
      Louvain, Flanders, Belgium
  • 2010
    • Universitair Ziekenhuis Ghent
      Gand, Flanders, Belgium
  • 2007
    • Aristotle University of Thessaloniki
      • Department of Pediatrics II
      Saloníki, Central Macedonia, Greece
  • 2002
    • Erasmus Universiteit Rotterdam
      Rotterdam, South Holland, Netherlands
  • 2001
    • University of Iowa Children's Hospital
      Iowa City, Iowa, United States
  • 1997-2000
    • University of Amsterdam
      Amsterdamo, North Holland, Netherlands
  • 1998
    • University of Groningen
      Groningen, Groningen, Netherlands
  • 1995
    • Leiden University
      Leyden, South Holland, Netherlands