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NDT Advance Access originally published online on September 26, 2007
Nephrology Dialysis Transplantation 2007 22(12):3487-3494; doi:10.1093/ndt/gfm300
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© The Author [2007]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org


Urinary excretion of endothelin-1 (ET-1), transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF165) in paediatric chronic kidney diseases: results of the ESCAPE trial

Ryszard Grenda1, Elke Wühl2, Mieczyslaw Litwin1, Roman Janas3, Joanna Sladowska1, Klaus Arbeiter4, Ulla Berg5, Alberto Caldas-Afonso6, Michel Fischbach7, Otto Mehls2, Peter Sallay8, Franz Schaefer2 and for the ESCAPE Trial group{dagger}

1Department of Nephrology, Kidney Transplantation and Hypertension, Children's Memorial Health Institute, Warsaw, Poland, 2Division of Pediatric Nephrology, Hospital for Pediatric and Adolescent Medicine, University of Heidelberg, Germany, 3Department of Radioimmunology, Children's Memorial Health Institute, Warsaw, Poland, 4Department of Pediatrics, Medical University Vienna, Austria, 5Karolinska Institute, Department of Pediatrics, Huddinge University Hospital, Sweden, 6Serviçio de Pediatria, Hospital de S. João, Porto, Portugal, 7CHU Hopital de Hautepierre, Service de Pédiatrie 3, Strasbourg, France and 8First Department of Pediatrics, Semmelweis University, Budapest, Hungary

Correspondence and offprint requests to: Ryszard Grenda, Department of Nephrology, Kidney Transplantation and Hypertension, The Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland. Email: r.grenda{at}czd.pl



   Abstract
Top
 Abstract
Background
 Methods
 Results
 Discussion
 Appendix
 Acknowledgements
 References
 
The severity and dynamics of renal tissue damage in chronic kidney disease (CKD) may be reflected by the urinary excretion of vasoactive and growth factors released by the damaged kidney. Urinary excretion of ET-1, TGF-β1 and VEGF165 was evaluated in 303 children with CKD stage II–IV (GFR 48 ± 22 ml/min/1.73 m2) and 81 age-matched healthy controls. Major renal disease groups were hypo-/dysplastic kidney disease (N = 183), obstructive uropathies (N = 47), glomerulopathies (N = 34), nephronophthisis (N = 19) and polycystic kidney disease (N = 20).

Results. The mean urinary excretion rates of each of the three putative biomarkers were significantly elevated in CKD patients compared to controls: 965 ± 2042 vs 216 ± 335 fmol/g creatinine for ET-1; 252 ± 338 vs 155 ± 158 ng/g for VEGF; 31.6 ± 37.0 vs 10.9 ± 9.8 ng/g for TGF-β1 (each P < 0.0001). The excretion of ET-1 and TGF-β1 was highest in patients with obstructive uropathies. In the patients, ET-1, TGF-β1 and VEGF excretion rates were inversely correlated with age (r = –0.22, –0.32 and –0.17, all P < 0.005) and renal function (r = –0.21, –0.13 and –0.15; P < 0.001; < 0.05; < 0.01; respectively) VEGF and TGF-β1 excretion rates were positively correlated both in patients and controls.

Conclusions. Children with CKD exhibit significantly elevated urinary excretion of ET-1, TGF-β1 and VEGF165 in comparison to healthy children. Urinary excretion of these biomarkers was most enhanced in patients with obstructive uropathies. A positive correlation between urinary TGF-β1 and VEGF165 excretion, shown both in patients and healthy controls, indicates an interdependent nature of their generation.

Keywords: adolescents; children; chronic kidney disease; ET-1; TGF-β1; urinary biomarkers excretion; VEGF165



   Background
Top
 Abstract
 Background
Methods
 Results
 Discussion
 Appendix
 Acknowledgements
 References
 
The spectrum of chronic kidney disease (CKD) in children differs markedly from the disorders typically seen in adults, with a preponderance of hypo- and dysplastic malformations frequently associated with reflux-related or obstructive anomalies of the urinary tract.

Ongoing renal tissue damage in the course of CKD is associated with local release of an array of biologically active factors, including endothelin-1 (ET-1), transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF).

ET-1, which is expressed in the kidney by endothelial, mesangial and tubular epithelial cells, can be stimulated by various factors such as angiotensin II, adrenalin, thrombin, interleukin-1 and TGFβ, and conditions such as mechanical stress, pressure and low shear stress. Other factors such as prostacyclin, nitric oxide, heparin and high shear stress decrease endothelin production. ET-1 participates in the perpetuation of tissue injury in CKD [1–5].

TGF-β1 is centrally involved in chronic degenerative processes of parenchymal tissues. In the kidney, it promotes glomerular and tubulointerstitial fibrosis by stimulating the synthesis and suppressing the degradation of matrix proteins via multiple effects, including the transformation of tubular epithelial cells to a myofibroblastic phenotype. Moreover, TGF-β1 can induce apoptosis of endothelial cells, podocytes and tubular epithelial cells. Urinary TGF-β1 excretion has been proposed to reflect intrarenal production and activity of TGF-β1, hence potentially constituting a biomarker of the severity of tissue damage [6–9].

VEGF is a dimeric protein composed of subunits containing 121, 165, 189 or 206 amino acids. Whereas VEGF189 and VEGF206 are mostly bound to cell surfaces and extracellular matrix, VEGF121 and VEGF165 are soluble and secreted. In human kidneys VEGF165 is expressed by podocytes and tubular and collecting duct epithelia, as well as in glomerular and peritubular capillaries and pre- and post-glomerular vessels. The VEGF isoforms 121, 165 and 189 are also present in activated mesangial cells [10,11]. In renal tissue VEGF exerts various biological functions including neoangiogenesis, vascular and renal tissue remodelling and stimulation of proteinuria, mesangial collagen synthesis and the chemotactic attraction of monocytes.

Since ET-1, TGF-β1 and VEGF may be involved in progressive CKD in children, we have compared their urinary excretion in paediatric patients with mild to moderate CKD to healthy controls.



   Methods
Top
 Abstract
 Background
 Methods
Results
 Discussion
 Appendix
 Acknowledgements
 References
 
Subjects
Three hundred three children with CKD stage II to IV (GFR 48 ± 20 ml/min/1.73 m2) aged 11.5 ± 3.9 years followed in the ESCAPE (Efficacy of Strict Blood Pressure Control and Angiotensin Converting Enzyme Inhibition on the Progression of Chronic Renal Failure in PEdiatric Patients) trial were available for evaluation of urinary biomarker excretion. Their underlying kidney disorders were non-obstructive renal hypo/dysplasia (RHD) in 183 (55%, with associated vesicoureteral reflux in 119), post-obstructive RHD (due to posterior urethral valves, vesicoureteric or pelvicoureteric obstruction) in 47 (14%), glomerulopathies in 34 (10%), nephronophthisis (NPH) in 19 (6%) and polycystic kidney disease (PKD) in 20 patients (6%).

None of the patients was treated with renoprotective drugs at the time of the study and drugs inhibiting the renin–angiotensin–aldosteron system were withdrawn at least 2 months before urine collection.

The control group consisted of 81 age-matched healthy school children from Warsaw (mean age 12.3 ± 3.5 years) with normal renal function and albumin excretion of 0.16 ± 0.1 mg/mg of urine creatinine. Baseline clinical characteristics of patients and controls are given in Table 1.


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  		Table 1. Clinical characteristics of patients

 
The study protocol, including biochemical assessment, was designed in adherence to the Declaration of Helsinki and approved by local ethics committees. Written informed consent was obtained from all parents, and informed consent or assent from the patients and controls as appropriate.

Laboratory tests
Urine samples were collected according to the study protocol over 24 h whenever possible (83% of samples); otherwise spot urine samples were analysed. Samples were stored at –20 to –80°C until further processing. Serum and urine creatinine levels were measured using the routine Jaffe colorimetric method [12]. GFR was calculated using the Schwartz formula [13]. Proteinuria was measured by the Coomassie method [14]. The analysis of urinary biomarkers in patients and controls was performed at the laboratory of the Children's Memorial Health Institute in Warsaw, Poland. Prior to analysis urine samples were centrifuged at 3000 rpm for 10 min. Urinary excretion of ET-1 was assessed using a commercial ELISA (Biomedica, Austria), modified to increase sensitivity to 1 fmol/ml urine (normal range for urinary ET-1 in healthy urine: 0.1–0.5 fmol/ml; R&D Systems reference data). The samples with ET-1 levels under the detection limit were arbitrarily equated to 0.1 fmol/ml. The value of ET-1 excretion was expressed as fmol/g of creatinine excreted in urine.

Urinary excretion of TGF-β1 was assayed using ELISA kits from DRG Instruments GmbH, Marburg, Germany. The buffering capacity of the assay buffer was increased as a result of adding 10 ml 1 M Tris–HCl, pH 8.0 to 90 ml of the buffer. Prior to assay the standard and diluted aliquots of the urine samples (200 µl) were acidified by adding 20 µl 1 N HCl. The samples were mixed and incubated for 15–20 min at room temperature. After incubation the samples were neutralized with 20 µl 1 N NaOH and the urine samples were diluted 2 times with the assay buffer. The probes' pH was controlled using universal paper and ranged form 7.6 to 8.0. Further assay procedure was performed following manufacturer protocol. Intra- and inter-assay coefficient of variation was 8.5 and 14%, respectively. The sensitivity was 1.6 pg/ml.

Urinary excretion of bioactive VEGF165 was assayed using the BioLISA kit from Bender MedSystems (Vienna, Austria) for quantitative detection of human vascular endothelial growth factor A (VEGF). The manufacturer's assay procedure was applied, however the sample diluent was replaced by the following diluent: 125 mM Tris–HCl, 2.5% BSA, pH 8.0.

The value of VEGF excretion was expressed in pg/g of creatinine excreted in urine.

Statistical analysis
Statistical analysis was performed using SAS version 9.1 (SAS, Cary, NC). Results are expressed as means ± SD, means ± SEM or median and interquartile range as indicated in the referring legend.

All analysed urinary biomarkers were corrected for urinary creatinine excretion (ET-1/creatinine ratio, VEGF/creatinine ratio, TGF-β1/creatinine ratio) to exclude potential effect of gender, age or body surface area. Variables were assessed for Gaussian distribution by Shapiro–Wilk testing, and non-normally distributed parameters were log-transformed for parametric testing. Classification into five groups was used for comparison of biomarker excretion rates between underlying disease types (non-obstructive vs obstructive RHD vs GN vs PKD vs NPH). Between-group differences in continuous variables were assessed for significance by Student's t-test in the case of two, and by analysis of variance followed by Student's Newman–Keuls multiple comparison testing in the case of more than two groups. Spearman correlation coefficients were calculated for univariate analysis of associations between continuous variables.

For multiple linear regression analysis the following parameters were included in the model: age, gender, pubertal status, underlying renal disease, GFR and protein–creatinine ratio as independent variables.

A P-value <0.05 was regarded as significant.



   Results
Top
 Abstract
 Background
 Methods
 Results
Discussion
 Appendix
 Acknowledgements
 References
 
For all the three biomarkers analysed, urinary excretion was significantly higher in the patients compared to healthy controls. The median ET-1 excretion in the patient group was increased approximately 4-fold, that of VEGF 1.3-fold and TGF-β1 excretion 3-fold compared to healthy controls (Table 2). TGF-β1 and ET-1 urinary excretion were significantly increased compared to controls in each diagnosis category (Table 2, Figure 1).


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  		Table 2. Urinary biomarker excretion (ET-1, VEGF and TGF-β1) in patients compared to healthy controls

 

Figure 1
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  		Fig. 1. Log-transformed excretion of three urinary biomarkers for controls and patients according to underlying renal disease, respectively. (a) ET-1/creatinine-ratio, (b) VEGF/creatinine-ratio and (c) TGF-β1/creatinine-ratio. Superscript letters denote significant differences (P < 0.05): avs controls; bvs glomerulopathies; cvs hypo/dysplasia; dvs obstructive nephropathies; evs PKD; fvs NPH....... 25th and 75th percentiles for log-transformed analyte/creatinine ratios of healthy controls. PKD, polycystic kidney disease; NPH, Nephronophthisis.

 
Among the different aetiologies of CKD, ET-1 excretion was significantly higher in patients with obstructive uropathies (P < 0.005) (Figure 1a). TGF-β1 excretion was also higher in patients with obstructive uropathies compared to patients with hypodysplastic kidney disease or glomerulopathies (Figure 1c). VEGF excretion did not differ between the individual disease groups, but tended to be higher in the PKD and NPH patients (Figure 1b).

ET-1, TGF-β1 and VEGF excretion in the patient group were inversely correlated with age and, weakly, with GFR (Table 3). No correlation was observed with blood pressure. TGF-β1 excretion showed an inverse relationship with age also in the healthy controls, whereas ET-1 or VEGF excretion were unrelated to age (Figure 2a–c). VEGF and TGF-β1 excretion were interrelated both in patients (r = 0.41, P < 0.0001) and in the healthy controls (r = 0.45, P < 0.0005) (Figure 3).


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  		Table 3. Correlation between urinary biomarker excretion (analyte/creatinine ratios) and clinical and other variables

 

Figure 2
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  		Fig. 2. Correlation between age and urinary biomarker excretion for patients (blank circle and dashed line) and controls (filled square and solid line). (a) ET-1/creatinine ratio, (b) VEGF/creatinine ratio and (c) TGF-β1/creatinine ratio.

 

Figure 3
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  		Fig. 3. Correlation between TGF-β1 and VEGF/creatinine ratio for patients (blank circle and dashed line) and controls (filled square and solid line).

 
In a multivariate regression analysis model including age, gender, pubertal status, underlying renal disease, GFR and protein–creatinine ratio as independent variables, TGF-β1 excretion was independently predicted by age (β = –0.069, partial r2 = 0.102, P < 0.0001) and proteinuria (β = 0.077, partial r2 = 0.03, P = 0.098), VEGF excretion by age (β = –0.076, partial r2 = 0.049, P = 0.0009) and proteinuria (β = 0.174, partial r2 = 0.033, P < 0.005) and ET-1 excretion by age (β = –0.067, partial r2 = 0.052, P = 0.0003) and GFR (β = –0.012, partial r2 = 0.05, P = 0.0002).



   Discussion
Top
 Abstract
 Background
 Methods
 Results
 Discussion
Appendix
 Acknowledgements
 References
 
The key result of the study is the finding that in children with CKD, the urinary excretion of ET-1, TGF-β1 and VEGF165 was significantly elevated compared to age-matched healthy controls, and correlated with younger age and lower GFR. Moreover, the urinary excretion of TGF-β1 and VEGF165 was intercorrelated. In patients with CKD the urinary excretion of all the three biomarkers was also inversely age-related, while not in healthy controls for ET-1 and VEGF. Urinary excretion of ET-1 and TGF-β1 was significantly elevated in all major paediatric renal disease subgroups, most markedly so in children with obstructive uropathies. In contrast, VEGF excretion was only slightly increased relative to healthy controls, with no major differences between disease groups. To our knowledge, this is the first integrative assessment of the urinary excretion of ET-1, TGF-β1 and VEGF165 in a large paediatric population with CKD of different aetiologies. Most available reports, involving much smaller samples of patients and controls, concern proteinuric renal diseases and diabetic nephropathy in adult patients. There are also several urologic reports assessing urinary TGF-β1 excretion in obstructive uropathies, but biomarker studies in paediatric kidney disorders are scarce.

Worgall et al. [15] found ET-1 excretion to be inversely correlated with GFR in children with different renal pathologies. They also found that among healthy controls, urinary ET-1 excretion was constant across the paediatric age range. This observation is consistent with our data concerning healthy controls, but not patients, in whom a negative correlation was found between age and ET-1 urinary excretion. Age-dependent excretion of ET-1, TGF-β1 and VEGF may indicate age-related intensity of these biomarker turnovers in renal tissue. The activity of the renin–angiotensin system (RAS), as well as the risk of progressive fibrosis, have been found to be inversely related to age, both in experimental animals and in children. RAS activity plays a pivotal role in generation of ET-1, TGF-β1 and VEGF. We had the opportunity to study patients at the end of a washout period immediately before starting a renoprotective ACE inhibition treatment protocol, avoiding any bias by such medication. Considering that the most frequent underlying renal pathology in our patients were congenital anomalies of kidney and urinary tract (CAKUT), our data are consistent with the interpretation that progressive fibrosis with activated intrarenal generation of the three biomarkers develops at early age in renal malformations. This is also supported by the relatively greater excretion of ET-1 and TGF-β1 in children with obstructive nephropathy. These disorders lead to upper urinary tract destruction in utero, and significant fibrosis is observed early on.

The observed weak inverse relationship between urinary ET-1 excretion and GFR is in keeping with findings in adult CKD patients [16], although one study in IgA nephropathy patients suggested lower ET-1 excretion with advancing renal disease [17]. Wolf et al. [18] found increased urine excretion of ET-1 in patients with minimal change nephrotic syndrome, but not in patients with membrano-proliferative glomerulonephritis. The majority of available data concern highly proteinuric nephropathies. Our patients, including those from the glomerulopathy subgroup, had on average markedly lower proteinuria than the individuals studied in adult reports. Vlachojannis et al. [19] have found increased urinary ET-1 excretion in adult proteinuric patients compared to healthy controls. In tissue expression studies ET-1 localized not only to endothelial cells, but also to the cytoplasm of tubular epithelial cells, suggesting tubular uptake and/or local synthesis of ET-1 by tubular cells damaged by protein overload [19]. Indeed, Ohta et al. [20] have shown that in patients with renal disease urinary ET-1 derives mainly from renal tubular secretion, and any changes in tubular reabsorption or degradation of ET-1 in the course of kidney diseases may influence its renal handling.

Increased urinary ET-1 concentration was also reported as a marker of altered urine flow, showing a correlation with the grade of vesico-renal reflux [21]. Taha et al. [22] reported increased urinary ET-1 excretion in children with uretero-pelvic obstruction, decreasing gradually during 12 months follow-up post-surgery. They also described that ET-1 excretion in these patients is age-dependent, with younger children exhibiting higher urinary ET-1 concentrations. This observation corresponds to our finding that ET-1 urine excretion was greatest in children with obstructive nephropathy. While it is tempting to speculate that elevated ET-1 excretion reflected ongoing mechanical injury of renal tissue in children with obstructive disorders, urodynamically relevant obstruction is usually detected and surgically corrected at an early postnatal age in this patient group. Another possible interpretation of our finding is that elevated ET-1 excretion reflects persistent tubular cell dysplasia secondary to prenatal urinary tract obstruction.

Urinary TGF-β1 excretion has been explored in various adult nephropathies and was found elevated in most disease entities, most markedly so in patients with gross proteinuria [23,24].

Increased urinary excretion of TGF-β1 has been correlated with markers of tubular injury in early type-I diabetic nephropathy, and with the degree of interstitial sclerosis in minimal change disease [23,24,26]. In the nephrotic state abundant TGF-β1 expression occurs within tubular epithelial cells, compatible with local activation of these cells by filtered protein towards increased TGF-β1 production [25]. The tubular abundance of TGF-β1, reabsorbed and/or produced locally in a paracrine/autocrine manner, is associated with various biological effects as it dissociates proximal tubule growth and Na+/H+ exchange activity, and reduces receptor-mediated endocytosis of albumin [27,28].

Whereas adult patients with chronic renal insufficiency were not demonstrated to have universally elevated TGF-β1 excretion [24], we observed an inverse relationship between GFR and urinary TGF-β1 normalized to creatinine excretion in the paediatric CKD cohort studies here. This discrepancy may be related to the different spectrum of underlying renal diseases in the paediatric CKD population, where congenital malformations of the kidneys and urinary tract are much more common. In children and adults with urinary tract obstruction, urinary TGF-β1 excretion was found almost universally elevated [29–34], with an 80–90% sensitivity in detecting a relevant obstruction of the ureteropelvic junction [30,31]. TGF-β1 excretion decreases, but does not completely normalize, within months after surgical correction [29]. In the experimental setting, tubular epithelial cells increase TGF-β1 synthesis under conditions resembling vesicoureteral reflux [35].

It is remarkable that TGF-β1 excretion was found higher in patients with obstructive uropathy even compared to children with glomerulopathies, despite markedly lower proteinuria. We speculate that TGF-β1 excretion reflects ongoing epithelial-mesenchymal transformation and tubulointerstitial scarring in post-obstructive, dysplastic kidneys, with local overproduction of TGF-β1 by invading inflammatory and/or activated tubular epithelial cells. TGF-β1 has experimentally been shown to be one of the key mediators of tubulointerstitial fibrosis, epithelial cell apoptosis and tubular atrophy in post-obstructed kidneys [36–38].

There are conflicting data on urinary VEGF excretion in patients with renal diseases. Matsumoto et al. [39] found elevated urinary VEGF excretion in proteinuric patients with MCNS and IgAN relative to healthy controls. VEGF excretion decreased in disease remission and was positively correlated with the degree of proteinuria. Honkanen et al. [40] observed increased urinary VEGF excretion in patients with FSGS and necrotizing GN but not in patients with MCNS or diabetic nephropathy. Urinary VEGF excretion did not correlate quantitatively with either GFR, serum VEGF concentrations or proteinuria. Kitamoto et al. [41] have demonstrated a negative correlation between creatinine clearance and urinary VEGF excretion in patients with CKD, suggesting that increased urinary VEGF excretion might reflect the degree of renal injury. This is consistent with our observation of an inverse association between GFR and urinary VEGF excretion. Some evidence from the experimental obstructive nephropathy model suggests that VEGF may be involved in the early local response to tubular injury, mediating neoangiogenic processes [42,43]. Stimulation of VEGF expression is one of the auto/paracrine actions of TGF-β1 in the kidney [44,45]. In line with this interpretation, we observed a positive correlation between urinary TGF-β1 and VEGF excretion.

An important consideration concerns the role of GFR in biomarker excretion in subjects with chronic renal failure. Our results and most cited studies suggest an increase of biomarker excretion with decreasing GFR, reflecting the impact of severe tubulointerstitial disease on overall renal function. On the other hand, since renal tubular and epithelial cells are considered the major source of ET-1, TGF1 and VEGF in the urine, one should assume that their excretion will eventually diminish in advanced chronic renal insufficiency. These opposing effects could explain the relatively weak correlation between excretion rates and GFR observed. A reversed relationship might have been observed if we had included patients with CKD stage 5.

In summary, in children with CKD due to various underlying nephropathies, urinary excretion of ET-1, TGF-β1 and VEGF165 is significantly elevated relative to age-matched healthy controls. Elevated biomarker excretion depends on patient age and renal function Urinary biomarker excretion is most enhanced in patients with obstructive nephropathies. A positive correlation between urinary TGF-β1 and VEGF165 excretion, shown both in patients and healthy controls, indicates an interdependent nature of their generation.



   Appendix
Top
 Abstract
 Background
 Methods
 Results
 Discussion
 Appendix
Acknowledgements
 References
 
Members of the ESCAPE Trial Group: A. Anarat (Adana), A. Bakkaloglu, F.Ozaltin (Ankara), A. Peco-Antic (Belgrade), J. Gellermann, U. Querfeld (Berlin), P. Sallay (Budapest), D. Drozdz (Cracow), A.-M. Wingen, K.-E. Bonzel (Essen), A. Zurowska, I. Balasz (Gdansk), F. Perfumo, A. Canepa (Genoa), K. Zepf, D. E.Müller-Wiefel (Hamburg), G. Offner, B. Enke (Hannover), O. Mehls, F. Schaefer, E.Wühl, C. Hadtstein (Heidelberg), U. Berg, G. Celsi (Huddinge), S. Emre, A. Sirin, I. Bilge (Istanbul), S.Çaliskan (Istanbul-Cerrahpasa), S. Mir, E. Serdaroglu (Izmir), H. Eichstädt (Leipzig), K. Hohbach-Hohenfellner (Mainz), N. Jeck, G. Klaus (Marburg), G. Ardissino, S. Testa (Milano), G. Montini (Padova), M. Charbit, P. Niaudet (Paris), J. Dusek (Prague), A. Caldas-Afonso (Porto), S. Picca, M.C. Matteucci (Rome), M. Wigger (Rostock), M. Fischbach, J. Terzic (Strasbourg), T. Urasinski, J. Fydryk (Szczecin), L. Peruzzi, R. Coppo (Torino), A. Jankauskiene (Vilnius), M. Litwin, R. Grenda (Warszawa), K. Arbeiter (Vienna), T.J. Neuhaus (Zurich).



   Acknowledgements
Top
 Abstract
 Background
 Methods
 Results
 Discussion
 Appendix
 Acknowledgements
References
 
Support for this study was obtained from the European Commission (5th Framework Programme, QLG1-CT-2002-00908), the Boehringer Ingelheim Foundation, the Baxter Extramural Grant Program and the Kuratorium für Dialyse und Nierentransplantation e.V.

Conflict of interest statement. None declared.



   Notes
 
{dagger}Members of the ESCAPE Trial Group are listed in the appendix. Back



   References
Top
 Abstract
 Background
 Methods
 Results
 Discussion
 Appendix
 Acknowledgements
 References
 

  1. Benigni A, Zoja C, Corna D, et al. A specific subtype A receptor antagonist protects against injury in renal disease progression. Kidney Int (1993) 44:440–444.[Web of Science][Medline]
  2. Kohan DE. Endothelins in the normal and diseased kidney. Am J Kidney Dis (1997) 29:2–26.[Web of Science][Medline]
  3. Yanashigawa M, Kurihara H, Kimura S, et al. A novel potent vasoconstrictor peptide produced by vascular endothelial cells. Nature (1998) 332:411–415.
  4. Arai H, Hori S, Aramori I, Ohkubo H, Nakanishi S. Cloning and expression of a cDNA encoding an endothelin receptor. Nature (1990) 348:730–732.[CrossRef][Medline]
  5. Hunley TE, Kon V. Update of endothelins: biology and clinical implications. Pediatr Nephrol (2001) 16:752–762.[CrossRef][Web of Science][Medline]
  6. Border WA, Noble NA. TGF-β1 in kidney fibrosis: a target for gene therapy. Kidney Int (1997) 51:1388–1396.[Web of Science][Medline]
  7. Border WA, Noble NAL. Interactions of transforming growth factor β and angiotensin II in renal fibrosis. Hypertension (1998) 31:181–188.[Abstract/Free Full Text]
  8. Murakami K, Takamura T, Hino S, Yoshioka K. Urinary transforming growth factor β1 in patients with glomerular diseases. Pediatr Nephrol (1997) 11:334–336.[CrossRef][Web of Science][Medline]
  9. Böttinger EP, Bitzer M. TGF-β signaling in renal disease. J Am Soc Nephrol (2002) 13:2600–2610.[Abstract/Free Full Text]
  10. Ferrara N, Houck KA, Jakeman LB, et al. The vascular endothelial growth factor family of polypeptides. J Cell Biochem (1991) 47:211–218.[CrossRef][Web of Science][Medline]
  11. Kang DH, Kanellis J, Hugo C, et al. Role of microvascular endothelium in progressive renal disease. J Am Soc Nephrol (2002) 13:806–816.[Abstract/Free Full Text]
  12. Bartels H, Bohmer M. Eine mikrometode zur kreatinin bestimmung. Clin Chim Acta (1971) 32:81–85.[CrossRef][Web of Science][Medline]
  13. Schwartz GJ, Haycock GB, Edelmann CM Jr, Spitzer A. A simple estimate of glomerular filtration rate in children derived from body length and plasma creatinine. Pediatrics (1976) 58:259–263.[Abstract/Free Full Text]
  14. Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of proteins utilising the principle of protein - dye binding. Anal Biochem (1976) 72:248–254.[CrossRef][Web of Science][Medline]
  15. Worgall S, Manz F, Kleschin K, Feth F, Rascher W. Elevated urinary excretion of endothelin-like immunoreactivity in children with renal disease is related to urine flow rate. Clin Nephrol (1994) 41:331–337.[Web of Science][Medline]
  16. Cantaro S, Milan Manani S, Marcon R, et al. Urinary excretion of vasoactive substances in chronic renal failure. Clin Nephrol (2001) 55:393–399.[Web of Science][Medline]
  17. Roccatello D, Mosso R, Ferro M, et al. Urinary endothelin-1 in glomerulonephritis patients with normal renal function. Clin Nephrol (1994) 41:323–330.[Web of Science][Medline]
  18. Wolf SC, Smoltczyk H, Brehm BR, Erley CM, Risler T. Endothelin-1 and endothelin-3 levels in different types of glomerulonephritis. J Cardiovasc Pharmacol (1998) 31:S482–S485.[CrossRef][Web of Science][Medline]
  19. Vlachojannis JG, Tsakas S, Petropoulou C, Goumenos DS, Alexandri S. Endothelin-1 in the kidney and urine of patients with glomerular disease and proteinuria. Clin Nephrol (2002) 58:337–343.[Web of Science][Medline]
  20. Ohta K, Hirata Y, Shichiri M, et al. Urinary excretion of endothelin-1 in normal subjects and patients with renal disease. Kidney Int (1991) 39:301–311.[CrossRef][Web of Science][Medline]
  21. Takeda M, Komeyama T, Katayama Y, et al. Measurment of urinary endothelin-1-like immunoreactivity and comparison with other urinary parameters in patients with primary vesicoureteral reflux. Eur Urol (1994) 25:326–320.[Web of Science][Medline]
  22. Taha MA, Shokeir AA, Osman HG, El-Aziz A, Farahat SE. Diagnosis of ureteropelvic junction obstruction in children: role of endothelin-1 in voided urine. Urology (2007) 69:560–565.[CrossRef][Web of Science][Medline]
  23. Honkanen E, Teppo A-M, Törnroth T, Groop PH, Grönhagen-Riska C. Urinary transforming β1 in membranous glomerulonephritis. Nephrol Dial Transplant (1997) 12:2562–2568.[Abstract/Free Full Text]
  24. De Muro P, Faedda R, Fresu P, et al. Urinary transforming growth factor β1 in various types of nephropathy. Pharmacol Res (2004) 49:293–209.[CrossRef][Web of Science][Medline]
  25. Goumenos DS, Tsakas S, El Nahas AM, et al. Transforming growth factor-β1 in the kidney and urine of patients with glomerular disease and proteinuria. Nephrol Dial Transplant (2002) 17:2145–2152.[Abstract/Free Full Text]
  26. Korpinen E, Teppo A-M, Hukkanen L, Akerblom H, Gronhagen-Riska C, Vaarala O. Urinary transforming growth factor-β1 and {alpha}1-macroglobulin in children and adolescents with type-1 diabetes. Diabetes Care (2000) 23:664–668.[Abstract/Free Full Text]
  27. Johnson DW, Saunders HJ, Brew BK, et al. TGF-β1 dissociates human proximal tubule cell growth and Na+ – H+ exchange activity. Kidney Int (1998) 53:1601–1607.[CrossRef][Web of Science][Medline]
  28. Gekle M, Knaus P, Nielsen R, et al. Transforming growth factor-β1 reduces megalin- and cubilin-mediated endocytosis of albumin in proximal tubule-derived opossum kidney cells. J Physiol (2003) 552:471–481.[Abstract/Free Full Text]
  29. Taha MA, Shokeir AA, Osman HG, El-Aziz A, Farahat SE. Pelvi-ureteric junction obstruction in children: the role of transforming growth factor-β and epidermal growth factor. BJU Int (2007) 99:899–903.[CrossRef][Web of Science][Medline]
  30. Furness PD, Maizels M, Han SW, Cohn RA, Cheng EY. Elevated bladder urine concentration of transforming growth factor- beta1 correlates with upper urinary tract obstruction in children. J Urol (1999) 162:1033–1036.[CrossRef][Web of Science][Medline]
  31. El-Sherbiny MT, Mousa OM, Shokeir AA, Ghoneim MA. Role of urinary transforming growth factor- beta1 concentration in the diagnosis of upper urinary tract obstruction in children. J Urol (2002) 168:1798–1800.[CrossRef][Web of Science][Medline]
  32. Palmer LS, Maizels M, Kaplan WE, Firlit CF, Cheng EY. Urine levels of transforming growth factor- beta1 in children with ureteropelvic junction-obstruction. J Urol (1997) 50:769–773.[CrossRef]
  33. Monga M, Gabal-Shehab LL, Stein P. Urinary transforming growth factor- beta1 levels correlated with bladder outlet obstruction. Int J Urol (2001) 8:487–489.[CrossRef][Web of Science][Medline]
  34. MacRae Dell K, Hoffman BB, Leonard MB, Ziyadeh FN, Schulman SL. Increased urinary transforming growth factor- beta1 excretion in children with posterior urethral valve. Urology (2000) 56:311–314.[CrossRef][Web of Science][Medline]
  35. Maruyama T, Hayashi Y, Nakane A, Sasaki S, Kohri K. Intermittent pressure-loading increases transforming growth factor-beta-1 secretion from renal tubular epithelial cells: in vitro vesicoureteral reflux model. Urol Int (2005) 75:150–158.[CrossRef][Web of Science][Medline]
  36. Sutaria PM, Ohebshalom M, McCaffrey TA, Vaughan ED, Felsen D. Transforming growth factor-beta receptor types I and II are expressed in renal tubules and are increased after chronic unilateral obstruction. Life Sci (1998) 62:1965–1972.[CrossRef][Web of Science][Medline]
  37. Misseri R, Rink RC, Meldrum DR, Meldrum KK. Inflammatory mediators and growth factors in obstructive renal injury. J Surg Res (2004) 119:149–159.[CrossRef][Web of Science][Medline]
  38. Miyajuma A, Chen J, Lawrence C, et al. Antibody to transforming growth factor-beta ameliorates tubular apoptosis in unilateral ureteral obstruction. Kidney Int (2000) 58:2301–2310.[CrossRef][Web of Science][Medline]
  39. Matsumoto K, Kanmatsuse K. Elevated vascular endothelial growth factor levels in the urine of patients with minimal change nephrotic syndrome. Clin Nephrol (2001) 55:269–274.[Web of Science][Medline]
  40. Honkanen EO, Teppo AM, Gronhagen-Riska C. Decreased urinary excretion of vascular endothelial growth factor in idiopathic membranous glomerulonephritis. Kidney Int (2000) 57:2343–2340.[CrossRef][Web of Science][Medline]
  41. Kitamoto Y, Matsuo K, Tomita K. Different response of urinary excretion of VEGF in patients with chronic and acute renal disease. Kidney Int (2001) 59:385–386.[CrossRef][Web of Science][Medline]
  42. Burt LE, Forbes MS, Thornhill BA, Kiley SC, Chevalier RL. Renal vascular endothelial growth factor in neonatal obstructive nephropathy. I. Endogenous VEGF. Am J Pysiol Renal Physiol (2007) 292:F158–F167.
  43. Ohashi R, Shimizu A, Masuda Y, et al. Peritubular capillary regression during the progression of experimental obstructive nephropathy. J Am Soc Nephrol (2002) 13:1795–1805.[Abstract/Free Full Text]
  44. Nakagawa T, Lan HY, Zhu HJ, Kang DH, Schreiner GF, Johnson RJ. Differential regulation of VEGF by TGFβ and hypoxia in rat proximal tubular cells. Am J Physiol Renal Physiol (2004) 287:F658–F664.[Abstract/Free Full Text]
  45. Kitamura S, Maeshima Y, Sugaya T, Sugiyama H, Yamasaki Y, Makino K. Transforming growth factor β1 induces cascular endothelial growth factor espression in murine proximal tubular epithelial cells. Nephron Exp Nephrol (2003) 95:79–86.[CrossRef]

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