Publications (36)138.35 Total impact
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Article: Urine proteome analysis reflects atherosclerotic disease in an ApoE-/- mouse model and allows the discovery of new candidate biomarkers in mouse and human atherosclerosis.
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ABSTRACT: Noninvasive diagnosis of atherosclerosis via single biomarkers has been attempted but remains elusive. However, a previous polymarker or pattern approach of urine polypeptides in humans reflected coronary artery disease with high accuracy. The aim of the current study is to use urine proteomics in ApoE(-/-) mice to discover proteins with pathophysiological roles in atherogenesis and to identify urinary polypeptide patterns reflecting early stages of atherosclerosis. Urine of ApoE(-/-) mice either on high fat diet (HFD) or chow diet was collected over 12 weeks; urine of wild type mice on HFD was used to exclude diet-related proteome changes. Capillary electrophoresis coupled to mass spectrometry (CE-MS) of samples identified 16 polypeptides specific for ApoE(-/-) mice on HFD. In a blinded test set, these polypeptides allowed identification of atherosclerosis at a sensitivity of 90% and specificity of 100%, as well as monitoring of disease progression. Sequencing of the discovered polypeptides identified fragments of α(1)-antitrypsin, epidermal growth factor (EGF), kidney androgen-regulated protein, and collagen. Using immunohistochemistry, α(1)-antitrypsin, EGF, and collagen type I were shown to be highly expressed in atherosclerotic plaques of ApoE(-/-) mice on HFD. Urinary excretion levels of collagen and α(1)-antitrypsin fragments also significantly correlated with intraplaque collagen and α(1)-antitrypsin content, mirroring plaque protein expression in the urine proteome. To provide further confirmation that the newly identified proteins are relevant in humans, the presence of collagen type I, α(1)-antitrypsin, and EGF was also confirmed in human atherosclerotic disease. Urine proteome analysis in mice exemplifies the potential of a novel multimarker approach for the noninvasive detection of atherosclerosis and monitoring of disease progression. Furthermore, this approach represents a novel discovery tool for the identification of proteins relevant in murine and human atherosclerosis and thus also defines potential novel therapeutic targets.Molecular & Cellular Proteomics 02/2012; 11(7):M111.013847. · 7.40 Impact Factor -
Article: Urinary proteome analysis to exclude severe vesicoureteral reflux.
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ABSTRACT: High-grade vesicoureteral reflux (VUR, grade IV or V) is a risk factor for renal scarring, impaired renal function, and arterial hypertension. Voiding cystourethrography is the gold standard for detecting the severity of VUR. High-grade VUR is present in the minority of children with urinary tract infection (UTI), thus exposing the majority to invasive diagnostics that have no surgical consequence. We therefore aimed at establishing a noninvasive test to identify children with high-grade VUR. In a case-control study, a specific urinary proteome pattern was established by capillary electrophoresis coupled to mass spectrometry in 18 patients with primary VUR grade IV or V, distinguishing these from 19 patients without VUR after UTI. This proteome pattern was independently validated in a blinded cohort of 17 patients with VUR grade IV or V and 19 patients without VUR. Sensitivity in detecting VUR grade IV or V in the blinded study was 88%, specificity was 79%. The test's accuracy was independent of age, gender, and grade of VUR in the contralateral kidney. The odds ratio of suffering from VUR grade IV or V when tested positive was 28 (95% confidence interval: 4.5 to 176.0). This noninvasive test is ready for prospective validation in large cohorts with the aim of identifying those children with UTI and hydronephrosis in need of further invasive diagnostics, such as voiding cystourethrography, thus sparing most children without pathologic urinary proteome patterns from additional diagnostics.PEDIATRICS 02/2012; 129(2):e356-63. · 4.47 Impact Factor -
Article: Urinary proteome analysis for prostate cancer diagnosis: cost-effective application in routine clinical practice in Germany.
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ABSTRACT: ObjectIVES: Capillary electrophoresis mass spectrometry urinary proteome analysis for prostate cancer has been shown to be highly accurate in the detection of prostate cancer. The aim of the present study was to report our experience with routine application of this test in clinical practice and its cost-effectiveness. The urinary proteome analysis for prostate cancer test was carried out in 211 patients in outpatient centers. In 184 of them, data about their follow up and the test results were available for analysis. Prostate cancer was detected in 49 cases. The test correctly recognized 42 out of 49 tumor patients, showing a sensitivity of 86% (95% confidence interval 73-94). Of 135 prostate cancer-negative patients, 79 had a negative urinary proteome analysis for prostate cancer test (specificity 59% [79/135 95% confidence interval 50-66]). Negative and positive predictive values were 92% (95% confidence interval 84-96) and 43% (95% confidence interval 33-53), respectively. A statistically significant (P<0.0005) improvement in terms of diagnostic accuracy was observed in comparison with serum prostate-specific antigen and percent-free prostate-specific antigen. Whereas the urinary proteome analysis for prostate cancer test results agreed in 65.7% with follow-up reference results, prostate-specific antigen achieved 33.3% and percent-free prostate-specific antigen achieved 42.7%. Cost-effectiveness analysis showed that the urinary proteome analysis for prostate cancer strategy outperformed the biopsy approach as well as prostate-specific antigen tests. The non-invasive urinary proteome analysis for prostate cancer test appears to be a helpful addition to prostate cancer diagnostics for patients with suspicious prostate-specific antigen and/or digital-rectal examination.International Journal of Urology 11/2011; 19(2):118-25. · 1.75 Impact Factor -
Article: Diagnosis of subclinical and clinical acute T-cell-mediated rejection in renal transplant patients by urinary proteome analysis.
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ABSTRACT: Noninvasive diagnosis of acute renal allograft rejection may be advantageous compared with the allograft biopsy. In this study, a multi-marker classification model for rejection was defined on a training set of 39 allograft patients by statistical comparison of capillary electrophoresis mass spectrometry (CE-MS) peptide spectra in urine samples from 16 cases with subclinical acute T-cell-mediated tubulointerstitial rejection and 23 nonrejection controls. Application of the rejection model to a blinded validation set (n=64) resulted in an AUC value of 0.91 (95% CI: 0.82-0.97, p=0.0001). In total, 16 out of 18 subclinical and 10 out of 10 clinical rejections (BANFF grades Ia/Ib), and 28 out of 36 controls without rejection were correctly classified. Acute tubular injury in the biopsies or concomitant urinary tract infection did not interfere with CE-MS-based diagnosis. Sequence information of identified altered collagen α(I) and α (III) chain fragments in rejection samples suggested an involvement of matrix metalloproteinase-8 (MMP-8). Biopsy stainings revealed matrix metalloproteinase-8 exclusively in neutrophils located within peritubular capillaries and sparsely, in the tubulointerstitium during rejection. The established marker set contains peptides related to tubulointerstitial infiltration seen in acute rejection. The set of urinary peptide markers will be used for early diagnosis of acute kidney allograft rejection marker in a multicenter phase III prospective study.PROTEOMICS - CLINICAL APPLICATIONS 06/2011; 5(5-6):322-33. · 1.81 Impact Factor -
Article: Bile proteomic profiles differentiate cholangiocarcinoma from primary sclerosing cholangitis and choledocholithiasis.
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ABSTRACT: Early detection of malignant biliary tract diseases, especially cholangiocarcinoma (CC) in patients with primary sclerosing cholangitis (PSC), is very difficult and often comes too late to give the patient a therapeutic benefit. We hypothesize that bile proteomic analysis distinguishes CC from nonmalignant lesions. We used capillary electrophoresis mass spectrometry (CE-MS) to identify disease-specific peptide patterns in patients with choledocholithiasis (n = 16), PSC (n = 18), and CC (n = 16) in a training set. A model for differentiation of choledocholithiasis from PSC and CC (PSC/CC model) and another model distinguishing CC from PSC (CC model) were subsequently validated in independent cohorts (choledocholithiasis [n = 14], PSC [n = 18] and CC [n = 25]). Peptides were characterized by sequencing. Application of the PSC/CC model in the independent test cohort resulted in correct exclusion of 12/14 bile samples from patients with choledocholithiasis and identification of 40/43 patients with PSC or CC (86% specificity, 93% sensitivity). The corresponding receiver operating characteristic (ROC) analysis revealed an area under the curve (AUC) of 0.93 (95% confidence interval [CI]: 0.82-0.98, P = 0.0001). The CC model succeeded in an accurate detection of 14/18 bile samples from patients with PSC and 21/25 samples with CC (78% specificity, 84% sensitivity) in the independent cohort, resulting in an AUC value of 0.87 (95% CI: 0.73-0.95, P = 0.0001) in ROC analysis. Eight out of 10 samples of patients with CC complicating PSC were identified. CONCLUSION: Bile proteomic analysis discriminates benign conditions from CC accurately. This method may become a diagnostic tool in future as it offers a new possibility to diagnose malignant bile duct disease and thus enables efficient therapy particularly in patients with PSC.Hepatology 03/2011; 53(3):875-84. · 11.66 Impact Factor -
Article: Markers of vascular disease in plasma from patients with chronic kidney disease identified by proteomic analysis.
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ABSTRACT: Chronic kidney disease (CKD) patients belong to the group of patients with a high prevalence of cardiovascular disease (CVD). Arterial calcification and aortic stiffness are currently used as surrogates for vascular alterations. However, still little is known about prediction and the patho-physiologic mechanisms leading to CVD. We applied capillary electrophoresis coupled mass spectrometry profiling to blood specimens collected from 34 CKD stage 5D patients suffering from vascular alterations to allow insights into the molecular pathology of the disease. Statistical comparison of plasma profiles from mild and severe CVD cases according to either arterial calcification or aortic stiffness unveiled 13 novel biomarkers for vascular disease. Tandem mass spectrometry identified four of these as fragments of collagen alpha-1 type I and III and one as fragment of apolipoprotein CIII. Integrated in a distinct pattern the candidates were validated using the moderate CVD cases among the 34 CKD patients (N=11) and an additional independent blinded cohort of CKD stage 4-5 patients (N=21), who all had not been considered during biomarker discovery. The panel distinguished mild and severe CVD with sensitivity of 89% and specificity of 67% in this independent cohort. This diagnostic phase I/II study supports the notion that vascular alterations are reflected by distinct changes in plasma profiles of CKD patients.Journal of hypertension 02/2011; 29(4):783-90. · 4.02 Impact Factor -
Article: Effect of fenofibrate treatment on the low molecular weight urinary proteome of healthy volunteers.
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ABSTRACT: Urinary peptidome changes and discrimination for potential renal glomerular and tubular damage after 6 wk of fenofibrate treatment were evaluated in 26 healthy subjects. Peptide profiling was performed in urine samples before and after treatment using high-resolution capillary electrophoresis coupled with electrospray ionization mass spectrometry. A panel of 88 fenofibrate-sensitive peptides was detected with a frequency of ≥50% before and after treatment. This was reduced to 36 peptides by repeating the comparison ten times by randomly excluding samples at each time-point. Nineteen peptides were consistent and reliable biomarkers after an additional comparison with an age and sex-matched subject control group. Levels of peptides identified as fragments of Collagen α-1 (I), Collagen α-1 (XVII), Collagen α-2 (VIII) or sodium/potassium-transporting ATPase subunit gamma were reduced after fenofibrate treatment. Classification scores for renal tubular and glomerular damages determined by support vector machine based biomarker models increased after treatment but remained below pathological score cutoff values. Fenofibrate treatment led to minor modifications of the urinary proteomic profile in a way that does not create safety issues affecting glomerular and tubular functions. Urinary peptide profiling proved to be appropriate to monitor drug pharmacological effects in a clinical setting.PROTEOMICS - CLINICAL APPLICATIONS 02/2011; 5(3-4):159-66. · 1.81 Impact Factor -
Article: Urinary excretion of twenty peptides forms an early and accurate diagnostic pattern of acute kidney injury.
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ABSTRACT: Early and accurate detection of acute kidney injury (AKI) is needed to prevent the progression to chronic kidney disease and to improve outcome. Here we used capillary electrophoresis-mass spectrometry to identify urinary peptides predictive of AKI in a training set of 87 urine samples longitudinally collected from patients in an intensive care unit. Within this patient cohort, 16 developed AKI while 14 maintained normal renal function. The sequence of twenty peptides significantly associated with AKI was identified. They were found to be degradation products of six proteins. These formed a diagnostic pattern. Peptides of albumin, α-1-antitrypsin, and β-2-microglobulin were upregulated but fragments of fibrinogen α and collagens 1 α(I) and 1 α(III) were downregulated in AKI. After cross-validation of the training set, a good diagnostic performance of the marker pattern was found with an area under the ROC curve of 0.91. This was confirmed in a blinded validation set of 20 patients in the intensive care unit and 31 allogeneic hematopoietic stem cell transplantation patients, of which 13 had and 18 had not experienced an episode of AKI. In comparison to more established markers of AKI such as serum cystatin C and urinary kidney injury molecule-1, interleukin-18, and neutrophil gelatinase associated-lipocalin, the proteomic marker pattern was found to be of superior prognostic value, detecting AKI up to 5 days in advance of the rise in serum creatinine.Kidney International 12/2010; 78(12):1252-62. · 6.61 Impact Factor -
Article: Urinary proteomic diagnosis of coronary artery disease: identification and clinical validation in 623 individuals.
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ABSTRACT: We studied the urinary proteome in a total of 623 individuals with and without coronary artery disease (CAD) in order to characterize multiple biomarkers that enable prediction of the presence of CAD. Urine samples were analyzed by capillary electrophoresis coupled online to micro time-of-flight mass spectrometry. We defined a pattern of 238 CAD-specific polypeptides from comparison of 586 spot urine samples from 408 individuals. This pattern identified patients with CAD in a blinded cohort of 138 urine samples (71 patients with CAD and 67 healthy individuals) with high sensitivity and specificity (area under the receiver operator characteristic curve 87%, 95% confidence interval 81-92) and was superior to previously developed 15-marker (area under the receiver operator characteristic curve 68%, P < 0.0001) and 17-marker panels (area under the receiver operator characteristic curve 77%, P < 0.0001). The sequences of the discriminatory polypeptides include fragments of alpha-1-antitrypsin, collagen types 1 and 3, granin-like neuroendocrine peptide precursor, membrane-associated progesterone receptor component 1, sodium/potassium-transporting ATPase gamma chain and fibrinogen-alpha chain. Several biomarkers changed significantly toward the healthy signature following 2-year treatment with irbesartan, whereas short-term treatment with irbesartan did not significantly affect the polypeptide pattern. Urinary proteomics identifies CAD with high confidence and might also be useful for monitoring the effects of therapeutic interventions.Journal of hypertension 11/2010; 28(11):2316-22. · 4.02 Impact Factor -
Article: Naturally occurring human urinary peptides for use in diagnosis of chronic kidney disease.
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ABSTRACT: Because of its availability, ease of collection, and correlation with physiology and pathology, urine is an attractive source for clinical proteomics/peptidomics. However, the lack of comparable data sets from large cohorts has greatly hindered the development of clinical proteomics. Here, we report the establishment of a reproducible, high resolution method for peptidome analysis of naturally occurring human urinary peptides and proteins, ranging from 800 to 17,000 Da, using samples from 3,600 individuals analyzed by capillary electrophoresis coupled to MS. All processed data were deposited in an Structured Query Language (SQL) database. This database currently contains 5,010 relevant unique urinary peptides that serve as a pool of potential classifiers for diagnosis and monitoring of various diseases. As an example, by using this source of information, we were able to define urinary peptide biomarkers for chronic kidney diseases, allowing diagnosis of these diseases with high accuracy. Application of the chronic kidney disease-specific biomarker set to an independent test cohort in the subsequent replication phase resulted in 85.5% sensitivity and 100% specificity. These results indicate the potential usefulness of capillary electrophoresis coupled to MS for clinical applications in the analysis of naturally occurring urinary peptides.Molecular & Cellular Proteomics 11/2010; 9(11):2424-37. · 7.40 Impact Factor -
Article: Urinary proteome analysis identifies infants but not older children requiring pyeloplasty.
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ABSTRACT: One out of every five children suffering from ureteropelvic junction obstruction (UPJO) requires pyeloplasty. This prevalence indicates an urgent necessity to identify high-grade UPJO as early as possible to avoid renal damage. A novel non-invasive proteomic urine test has recently been introduced that is able to detect these patients at an early stage. In the study reported here, we tested this approach to assess its use in our centre and to expand its application to older children. Twenty-seven children (median age 0.4 years, range 0.1-8.8 years) with hydronephrosis who had been scheduled a nuclear diuretic renal scan (DR) to identify urodynamically relevant UPJO were included in our prospective study. Patients with prior surgery of the urinary tract were excluded. The urinary proteome pattern was analysed using capillary electrophoresis coupled to mass spectrometry. Of the 27 children, 11 had a relevant UPJO diagnosed by the DR. In 19 children <1 year of age, urinary proteome analysis predicted obstruction with a sensitivity of 83% (5/6) and a specificity of 92% (12/13). However, in older patients, the sensitivity decreased to 20% (1/5) and specificity to 66% (2/3). Based on our results, the proteome pattern established by Decramer and co-workers predicts the need for surgery in infants but not in older children with UPJO.Pediatric Nephrology 02/2010; 25(9):1673-8. · 2.52 Impact Factor -
Article: Urinary collagen fragments are significantly altered in diabetes: a link to pathophysiology.
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ABSTRACT: The pathogenesis of diabetes mellitus (DM) is variable, comprising different inflammatory and immune responses. Proteome analysis holds the promise of delivering insight into the pathophysiological changes associated with diabetes. Recently, we identified and validated urinary proteomics biomarkers for diabetes. Based on these initial findings, we aimed to further validate urinary proteomics biomarkers specific for diabetes in general, and particularity associated with either type 1 (T1D) or type 2 diabetes (T2D). Therefore, the low-molecular-weight urinary proteome of 902 subjects from 10 different centers, 315 controls and 587 patients with T1D (n = 299) or T2D (n = 288), was analyzed using capillary-electrophoresis mass-spectrometry. The 261 urinary biomarkers (100 were sequenced) previously discovered in 205 subjects were validated in an additional 697 subjects to distinguish DM subjects (n = 382) from control subjects (n = 315) with 94% (95% CI: 92-95) accuracy in this study. To identify biomarkers that differentiate T1D from T2D, a subset of normoalbuminuric patients with T1D (n = 68) and T2D (n = 42) was employed, enabling identification of 131 biomarker candidates (40 were sequenced) differentially regulated between T1D and T2D. These biomarkers distinguished T1D from T2D in an independent validation set of normoalbuminuric patients (n = 108) with 88% (95% CI: 81-94%) accuracy, and in patients with impaired renal function (n = 369) with 85% (95% CI: 81-88%) accuracy. Specific collagen fragments were associated with diabetes and type of diabetes indicating changes in collagen turnover and extracellular matrix as one hallmark of the molecular pathophysiology of diabetes. Additional biomarkers including inflammatory processes and pro-thrombotic alterations were observed. These findings, based on the largest proteomic study performed to date on subjects with DM, validate the previously described biomarkers for DM, and pinpoint differences in the urinary proteome of T1D and T2D, indicating significant differences in extracellular matrix remodeling.PLoS ONE 01/2010; 5(9). · 4.09 Impact Factor -
Chapter: Capillary Electrophoresis Coupled to Mass Spectrometry for Urinary Proteome Analysis
12/2009: pages 321 - 332; , ISBN: 9783527628612 -
Article: Prediction of muscle-invasive bladder cancer using urinary proteomics.
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ABSTRACT: Minimally invasive methods of predicting the risk of muscle-invasive urothelial bladder carcinoma may expedite appropriate therapy and reduce morbidity and cost. Here, capillary electrophoresis coupled mass spectrometry was used to identify urinary polypeptide bladder cancer biomarkers in 127 patients. These markers were used to construct a panel discriminating muscle-invasive from noninvasive disease, which was refined in 297 additional samples from healthy volunteers, patients with malignant and nonmalignant genitourinary conditions. Sequencing of panel polypeptides was then done. Finally, the ability of the panel to predict muscle-invasive disease was evaluated prospectively in 130 bladder carcinoma patients. Four sequenced polypeptides formed a panel predictive of muscle-invasive disease. Prospective evaluation of this panel revealed a sensitivity of 81% [95% confidence interval (CI), 69-90] and specificity of 57% (95% CI, 45-69) for muscle-invasive disease. Multivariate analysis revealed the panel (P < 0.0001) and tumor grade (P = 0.0001), but not urine cytology, predict muscle invasion. A model including grade and panel polypeptide levels improved sensitivity [92% (95% CI, 82-97)] and specificity [68% (95% CI, 55-79)] for muscle-invasive disease. A model score of >0.88 provided a negative predictive value of 77% and positive predictive value of 90% for muscle invasion. Use of urinary peptides seems promising in estimating the probability a patient harbors muscle-invasive urothelial bladder cancer. These peptides may also shed novel insights into the biology of bladder tumor progression not obtainable by other methods. Clinical trials seem warranted to evaluate the effect of this approach on practice.Clinical Cancer Research 08/2009; 15(15):4935-43. · 7.74 Impact Factor -
Article: Urinary proteome pattern in children with renal Fanconi syndrome.
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ABSTRACT: The renal Fanconi syndrome (FS) is characterized by renal glucosuria, loss of electrolytes, bicarbonate and lactate, generalized hyperaminoaciduria and low-molecular-weight proteinuria. We studied the urinary low-molecular-weight proteome to identify excreted peptides indicative of a pathogenetic mechanism leading to tubular dysfunction. We established a urinary proteome pattern using capillary electrophoresis mass spectrometry (CE-MS) of 7 paediatric patients with cystinosis and 6 patients with ifosfamide-induced FS as the study group, and 54 healthy volunteers and 45 patients suffering from other renal diseases such as lupus nephritis (n = 8), focal segmental glomerulosclerosis (n = 27), minimal change disease (n = 7) and membranous glomerulonephritis (n = 3) as controls. Consequently, we conducted a blinded study consisting of 11 FS patients and 9 patients with renal disease other than FS. Additionally, we applied this pattern to 294 previously measured samples of patients with different renal diseases. Amino acid sequences of some marker proteins were obtained. Specificity for detecting FS was 89% and sensitivity was 82%. The marker peptides constituting the proteome pattern are fragments derived from osteopontin, uromodulin and collagen alpha-1. CE-MS can be used to diagnose FS in paediatric patients and might be a future tool for the non-invasive diagnosis of FS. The reduced amount of the marker proteins osteopontin and uromodulin indicates loss of function of tubular excretion in all patients suffering from FS regardless of the underlying cause. In addition, the six different fragments of the collagen alpha-1 (I) chain were either elevated or reduced in the urine. This indicates a change of proteases in collagen degradation as observed in interstitial fibrosis. These changes were prominent irrespectively of the stages of FS. This indicates fibrosis as an early starting pathogenetic reason for the development of renal insufficiency in FS patients.Nephrology Dialysis Transplantation 03/2009; 24(7):2161-9. · 3.40 Impact Factor -
Article: Evaluation of urinary biomarkers for coronary artery disease, diabetes, and diabetic kidney disease.
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ABSTRACT: In this study we sought to validate urinary biomarkers for diabetes and two common complications, coronary artery disease (CAD) and diabetic nephropathy (DN). A CAD score calculated by summing the product of a classification coefficient and signal amplitude of 15 urinary polypeptides was previously developed. Five sequences of biomarkers in the panel were identified as fragments of collagen alpha-1(I) and alpha-1(III). Prospectively collected urine samples available for analysis from 19 out of 20 individuals with CAD (15 with type 1 diabetes [T1D] and four without diabetes) and age-, sex-, and diabetes-matched controls enrolled in the Coronary Artery Calcification in Type 1 Diabetes study were analyzed for the CAD score using capillary electrophoresis and electrospray ionization mass spectrometry. Two panels of biomarkers that were previously defined to distinguish diabetes status were analyzed to determine their relationship to T1D. Three biomarker panels developed to distinguish DN (DNS) and two biomarker panels developed to distinguish renal disease (RDS) were examined to determine their relationship with renal function. The CAD score was associated with CAD (odds ratio with 95% confidence interval, 2.2 [1.3-5.2]; P = 0.0016) and remained significant when adjusted individually for age, albumin excretion rate (AER), blood pressure, waist circumference, intraabdominal fat, glycosylated hemoglobin, and lipids. DNS and RDS were significantly correlated with AER, cystatin C, and serum creatinine. The biomarker panels for diabetes were both significantly associated with T1D status (P < 0.05 for both). We validated a urinary proteome pattern associated with CAD and urinary proteome patterns associated with T1D and DN.Diabetes Technology & Therapeutics 02/2009; 11(1):1-9. · 1.93 Impact Factor -
Article: Capillary electrophoresis coupled to mass spectrometry for proteomic profiling of human urine and biomarker discovery.
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ABSTRACT: Currently, the main focus of clinical proteome analysis is on detection and identification of polypeptides that significantly change owing to pathological changes. Capillary electrophoresis coupled online to an electrospray ionization time of flight mass spectrometer (CE-MS) allows the differential display of a large number of polypeptides in a single, reproducible, and time-limited step and enables the comparison of different protein profiles for biomarker discovery. In addition to the reproducibility of the CE-MS setup, many further steps including data processing and mining, usage of biomarkers for diagnosis, and biomarker sequencing are necessary to answer the demands of biomarker discovery of clinical significance. In this chapter, we discuss materials and methods for CE-MS-based clinical proteomics allowing the reproducible profiling of urine.Methods in molecular biology (Clifton, N.J.) 02/2009; 564:105-21. -
Article: Evaluation of urine proteome pattern analysis for its potential to reflect coronary artery atherosclerosis in symptomatic patients.
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ABSTRACT: Coronary artery disease (CAD) is a major cause of mortality and morbidity. Noninvasive proteome analysis could guide clinical evaluation and early/preventive treatment. Under routine clinical conditions, urine of 67 patients presenting with symptoms suspicious for CAD were analyzed by capillary electrophoresis directly coupled with mass spectrometry (CE-MS). All patients were subjected to coronary angiography and either assigned to a CAD or non-CAD group. A training set of 29 patients was used to establish CAD and non-CAD-associated proteome patterns of plasma as well as urine. Significant discriminatory power was achieved in urine but not in plasma. Therefore, urine proteomic analysis of further 38 patients was performed in a blinded study. A combination of 17 urinary polypeptides allowed separation of both groups in the test set with a sensitivity of 81%, a specificity of 92%, and an accuracy of 84%. Sequencing of urinary marker peptides identified fragments of collagen alpha1 (I and III), which we furthermore demonstrated to be expressed in atherosclerotic plaques of human aorta. In conclusion, specific CE-MS polypeptide patterns in urine were associated with significant CAD in patients with angina-typical symptoms. These promising findings need to be further evaluated in regard to reliability of a urine-based screening method with the potential of improving the diagnostic approaches for CAD.Journal of Proteome Research 12/2008; 8(1):335-45. · 5.11 Impact Factor -
Article: Quantitative urinary proteome analysis for biomarker evaluation in chronic kidney disease.
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ABSTRACT: A limitation of proteomic methods with respect to their clinical applicability is the lack of possibilities to directly deduce the amount of a protein or peptide from a particular mass spectrometry (MS) spectrum. For quantification of chronic kidney disease (CKD)-specific urinary polypeptides in capillary electrophoresis coupled with mass spectrometry (CE-MS), we compared signal intensity calibration methods based on either urinary creatinine or stable isotope labeled synthetic marker analogues (absolute quantification) with those based on ion counting using highly abundant collagen fragments as nonmarker references (relative quantification). Our results indicate that relative quantification of biomarker excretion based on ion counts in reference to endogenous "housekeeping" peptides is sufficient for the determination of urinary polypeptide levels. The calculation of absolute concentrations via exogenous stable isotope-labeled peptide standards is of no additional benefit.Journal of Proteome Research 12/2008; 8(1):268-81. · 5.11 Impact Factor -
Article: Proteins induced by telomere dysfunction and DNA damage represent biomarkers of human aging and disease.
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ABSTRACT: Telomere dysfunction limits the proliferative capacity of human cells by activation of DNA damage responses, inducing senescence or apoptosis. In humans, telomere shortening occurs in the vast majority of tissues during aging, and telomere shortening is accelerated in chronic diseases that increase the rate of cell turnover. Yet, the functional role of telomere dysfunction and DNA damage in human aging and diseases remains under debate. Here, we identified marker proteins (i.e., CRAMP, stathmin, EF-1alpha, and chitinase) that are secreted from telomere-dysfunctional bone-marrow cells of late generation telomerase knockout mice (G4mTerc(-/-)). The expression levels of these proteins increase in blood and in various tissues of aging G4mTerc(-/-) mice but not in aging mice with long telomere reserves. Orthologs of these proteins are up-regulated in late-passage presenescent human fibroblasts and in early passage human cells in response to gamma-irradiation. The study shows that the expression level of these marker proteins increases in the blood plasma of aging humans and shows a further increase in geriatric patients with aging-associated diseases. Moreover, there was a significant increase in the expression of the biomarkers in the blood plasma of patients with chronic diseases that are associated with increased rates of cell turnover and telomere shortening, such as cirrhosis and myelodysplastic syndromes (MDS). Analysis of blinded test samples validated the effectiveness of the biomarkers to discriminate between young and old, and between disease groups (MDS, cirrhosis) and healthy controls. These results support the concept that telomere dysfunction and DNA damage are interconnected pathways that are activated during human aging and disease.Proceedings of the National Academy of Sciences 09/2008; 105(32):11299-304. · 9.68 Impact Factor
Top co-authors
Top Journals
Institutions
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2009–2012
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Medizinische Hochschule Hannover
Hannover, Lower Saxony, Germany -
Mahidol University
Bangkok, Bangkok, Thailand -
University of Colorado Denver
- Barbara Davis Center for Childhood Diabetes
Denver, CO, USA
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2006–2011
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Mosaiques Diagnostics and Therapeutics AG
Hannover, Lower Saxony, Germany
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2010
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University of Wisconsin, Madison
- Department of Chemistry
Madison, MS, USA
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2008
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Johns Hopkins University
Baltimore, MD, USA -
University of Virginia
- Department of Urology
Charlottesville, VA, USA
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