Jack F. M. Wetzels

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During chronic kidney disease (CKD), there is a progressive accumulation of toxic solutes due to inadequate renal clearance. Here, the interaction between uremic toxins and two important efflux pumps, viz. multidrug resistance protein 4 (MRP4) and breast cancer resistance protein (BCRP) was investigated. Membrane vesicles isolated from MRP4- or(More)
UNLABELLED In most types of peptide receptor radionuclide therapy, the maximum activity dose that can be administered is limited by high and persistent renal retention of the radiolabeled peptides, which is, at least partly, mediated by the megalin receptor. Several agents that interfere with renal reabsorption of radiolabeled peptides have been identified(More)
BACKGROUND Urine proteomics is one of the key emerging technologies to discover new biomarkers for renal disease, which may be used in the early diagnosis, prognosis and treatment of patients. In the present study, we validated surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) for biomarker discovery in patients(More)
Glycosylation has been shown to be important for proper routing and membrane insertion of a number of proteins. In the collecting duct, aquaporin-2 (AQP2) is inserted into the apical membrane after stimulation of vasopressin type-2 receptors and retrieved into an endosomal compartment after withdrawal of vasopressin. The extent of glycosylation of AQP2 in(More)
BACKGROUND Thy-1.1 transgenic mice, characterized by ectopic expression of the Thy-1.1 protein on podocytes, spontaneously develop proteinuria and focal glomerulosclerosis (FGS). Injection of a monoclonal antibody (mAb) directed against the Thy-1.1 protein in young transgenic mice induces a massive albuminuria that is followed by an accelerated FGS within 3(More)
Hepcidin-25, the bioactive form of hepcidin, is a key regulator of iron homeostasis as it induces internalization and degradation of ferroportin, a cellular iron exporter on enterocytes, macrophages and hepatocytes. Hepcidin levels are increased in chronic hemodialysis (HD) patients, but as of yet, limited information on factors associated with hepcidin-25(More)
BACKGROUND Chronic kidney disease (CKD) is characterized by the progressive accumulation of various potential toxic solutes. Furthermore, uremic plasma is a complex mixture hampering accurate determination of uremic toxin levels and the identification of novel uremic solutes. METHODS In this study, we applied (1)H-nuclear magnetic resonance (NMR)(More)
We describe a 50-year-old male patient with hyponatremia (serum sodium level, 128 mEq/L) discovered during routine follow-up for Henoch-Schönlein nephritis. The patient was known to have a generalized idiopathic epilepsy and was on 2,000 mg/day of sodium valproate. After exclusion of other causes such as hypothyroidism and adrenal insufficiency, we(More)
BACKGROUND Cardiovascular risk is increased in patients with chronic kidney disease (CKD). Fibroblast growth factor 23 (FGF23) has emerged as an important, independent predictor of outcome in CKD patients. High FGF23 may, however, be a reflection of renal tissue resistance to its actions, reflected by low fractional excretion of phosphate (FePi). We(More)
BACKGROUND Thy-1.1 transgenic mice develop hypercellular focal and segmental glomerulosclerosis (FSGS) lesions that mimic human collapsing FSGS, in 7 days after injection with anti-Thy-1.1 antibodies. These lesions consist of proliferating parietal epithelial cells (PECs). We questioned whether the angiotensin converting enzyme inhibitor (ACE), captopril,(More)