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Verena Peters,
Erwin E W Jansen,
Cornelis Jakobs,
Eva Riedl, Bart Janssen,
Benito A Yard,
Johannes Wedel,
Georg F Hoffmann,
Johannes Zschocke,
Daniel Gotthardt,
Christine Fischer,
Hannes Köppel
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ABSTRACT: We reported an association of a particular allele of the carnosinase (CNDP1 Mannheim) gene with reduced serum carnosinase (CN1) activity and absence of nephropathy in diabetic patients. Carnosine protects against the adverse effects of high glucose levels but serum carnosine concentration was generally low.
We measured the concentration of two further histidine dipeptides, anserine and homocarnosine, via HPLC. CN1 activity was measured fluorometically and for concentration we developed a capture ELISA.
We found an association between the CNDP1 Mannheim allele and reduced serum CN1 activity for all three dipeptides but no correlation to serum concentrations although anserine and homocarnosine inhibited carnosinase activity. Patients with liver cirrhosis have low CN1 activity (0.24 ± 0.17 μmol/ml/h, n=7 males; normal range: 3.2 ± 1.1, n=104; p<0.05) and CN1 concentrations (2.3 ± 1.5 μg/ml; normal range: 24.9 ± 8.9, p<0.05) but surprisingly, histidine dipeptide concentrations in serum are not increased compared to controls.
Serum histidine dipeptide concentrations are not correlated to CN1 activity. The protective effect of low CN1 activity might be related either to turnover of CN1 substrates or a protective function of dipeptides might be localized in other tissues.
Clinica chimica acta; international journal of clinical chemistry 10/2010; 412(3-4):263-7. · 2.54 Impact Factor
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Antien L Mooyaart,
Ana Zutinic,
Stephan J L Bakker,
Diana C Grootendorst,
Nanne Kleefstra,
Irene G M van Valkengoed,
Stefan Böhringer,
Henk J G Bilo,
Friedo W Dekker,
Jan Anthonie Bruijn,
Gerjan Navis, Bart Janssen,
Hans J Baelde,
Emile De Heer
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ABSTRACT: The 5-5 homozygous CNDP1 (carnosinase) genotype is associated with a reduced risk of diabetic nephropathy. We investigated whether this association is sex specific and independent of susceptibility for type 2 diabetes.
Three separate groups of 114, 90, and 66 patients with type 2 diabetes and diabetic nephropathy were included in this study and compared with 93 patients with type 2 diabetes for >15 years without diabetic nephropathy and 472 population control subjects. The diabetes control group was used to determine an association in the three patient groups separately, and the population control group was used to estimate the genotype risk [odds ratio (CI)] for the population in a pooled analysis. The population control subjects were also compared with 562 patients with type 2 diabetes without diabetic nephropathy to determine whether the association was independent of type 2 diabetes. The CNDP1 genotype was determined by fragment analysis after PCR amplification.
The frequency of the 5-5 homozygous genotype was 28, 36, and 41% in the three diabetic nephropathy patient groups and 43 and 42% in the diabetic and population control subjects, respectively. The 5-5 homozygous genotype occurred significantly less frequently in women in all three patient groups compared with diabetic control subjects. The genotype risk for the population was estimated to be 0.5 (0.30-0.68) in women and 1.2 (0.77-1.69) in men. The 562 patients with type 2 diabetes without diabetic nephropathy did not differ from the general population (P = 0.23).
This study suggests that the association between the CNDP1 gene and diabetic nephropathy is sex specific and independent of susceptibility for type 2 diabetes.
Diabetes 03/2010; 59(6):1555-9. · 8.29 Impact Factor
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Alaa Alkhalaf,
Petra Zürbig,
Stephan J L Bakker,
Henk J G Bilo,
Marie Cerna,
Christine Fischer,
Sebastian Fuchs, Bart Janssen,
Karel Medek,
Harald Mischak,
Johannes M Roob,
Kasper Rossing,
Peter Rossing,
Ivan Rychlík,
Harald Sourij,
Beate Tiran,
Brigitte M Winklhofer-Roob,
Gerjan J Navis
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ABSTRACT: Urine proteome analysis is rapidly emerging as a tool for diagnosis and prognosis in disease states. For diagnosis of diabetic nephropathy (DN), urinary proteome analysis was successfully applied in a pilot study. The validity of the previously established proteomic biomarkers with respect to the diagnostic and prognostic potential was assessed on a separate set of patients recruited at three different European centers. In this case-control study of 148 Caucasian patients with diabetes mellitus type 2 and duration ≥5 years, cases of DN were defined as albuminuria >300 mg/d and diabetic retinopathy (n = 66). Controls were matched for gender and diabetes duration (n = 82).
Proteome analysis was performed blinded using high-resolution capillary electrophoresis coupled with mass spectrometry (CE-MS). Data were evaluated employing the previously developed model for DN. Upon unblinding, the model for DN showed 93.8% sensitivity and 91.4% specificity, with an AUC of 0.948 (95% CI 0.898-0.978). Of 65 previously identified peptides, 60 were significantly different between cases and controls of this study. In <10% of cases and controls classification by proteome analysis not entirely resulted in the expected clinical outcome. Analysis of patient's subsequent clinical course revealed later progression to DN in some of the false positive classified DN control patients.
These data provide the first independent confirmation that profiling of the urinary proteome by CE-MS can adequately identify subjects with DN, supporting the generalizability of this approach. The data further establish urinary collagen fragments as biomarkers for diabetes-induced renal damage that may serve as earlier and more specific biomarkers than the currently used urinary albumin.
PLoS ONE 01/2010; 5(10):e13421. · 4.09 Impact Factor
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Verena Peters,
Moustafa Kebbewar,
Erwin W Jansen,
Cornelis Jakobs,
Eva Riedl,
Hannes Koeppel,
Dirk Frey,
Katja Adelmann,
Kristina Klingbeil,
Matthias Mack,
Georg F Hoffmann, Bart Janssen,
Johannes Zschocke,
Benito A Yard
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ABSTRACT: Activity of carnosinase (CN1), the only dipeptidase with substrate specificity for carnosine or homocarnosine, varies greatly between individuals but increases clearly and significantly with age. Surprisingly, the lower CN1 activity in children is not reflected by differences in CN1 protein concentrations. CN1 is present in different allosteric conformations in children and adults since all sera obtained from children but not from adults were positive in ELISA and addition of DTT to the latter sera increased OD450 values. There was no quantitative difference in the amount of monomeric CN1 between children and adults. Further, CN1 activity was dose dependently inhibited by homocarnosine. Addition of 80 microM homocarnosine lowered V (max) for carnosine from 440 to 356 pmol/min/microg and increased K (m) from 175 to 210 microM. The estimated K (i) for homocarnosine was higher (240 microM). Homocarnosine inhibits carnosine degradation and high homocarnosine concentrations in cerebrospinal fluid (CSF) may explain the lower carnosine degradation in CSF compared to serum. Because CN1 is implicated in the susceptibility for diabetic nephropathy (DN), our findings may have clinical implications for the treatment of diabetic patients with a high risk to develop DN. Homocarnosine treatment can be expected to reduce CN1 activity toward carnosine, resulting in higher carnosine levels.
Amino Acids 11/2009; 38(5):1607-15. · 3.25 Impact Factor
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ABSTRACT: Idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH) share important pathogenic and clinical features. BMPR2 mutations are important in the pathogenesis of IPAH, but little is known about the genetic background in CTEPH. Objective: To search for mutations and polymorphisms in genes involved in the BMPR2, serotonin and nitric oxide pathways possibly associated with pulmonary and cardiac disorders in IPAH and CTEPH.
In a cohort of Swiss patients with IPAH (n = 16) and CTEPH (n = 16), and in 24 controls with left heart disease without PH, polymorphisms in the BMPR2, 5-HHT, 5-HTR-2A and eNOS genes were analyzed and correlated with various clinical, functional and hemodynamic parameters.
We found a BMPR2 missense mutation in a patient with coronary artery disease (CAD) without PH but no BMPR2 mutations in our collective with late-onset sporadic PH. In patients with polymorphic variants of the BMPR2 gene, the number of blood platelets and oxygen saturation were increased. The c.600A-->C synonymous variant was associated with worse exercise capacity and decreased quality of life in PH. We found no significant differences for any measured parameter according to the eNOS, 5-HTR2A and the 5-HTT polymorphisms, although there was a higher allelic frequency of the 5-HTT long variant in IPAH than in CTEPH and controls.
Our first report of a BMPR2 mutation in a patient with CAD without PH is interesting and warrants further investigation. Our study may reflect the clinical status and genetic background in a typical PH cohort as seen in a single tertiary care referral center.
Respiration 10/2009; 79(4):279-87. · 2.26 Impact Factor
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Ekkehard Grünig,
Sylvia Weissmann,
Nicola Ehlken,
Anna Fijalkowska,
Christine Fischer,
Thierry Fourme,
Nazzareno Galié,
Ardeschir Ghofrani,
Rachel E Harrison,
Sandrine Huez, [......],
Robert Naeije,
Horst Olschewski,
Steeve Provencher,
Frank Reichenberger,
Kathleen Retailleau,
Guido Rocchi,
Gérald Simonneau,
Adam Torbicki,
Richard Trembath,
Werner Seeger
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ABSTRACT: This large, prospective, multicentric study was performed to analyze the distribution of tricuspid regurgitation velocity (TRV) values during exercise and hypoxia in relatives of patients with idiopathic and familial pulmonary arterial hypertension (PAH) and in healthy control subjects. We tested the hypothesis that relatives of idiopathic/familial PAH patients display an enhanced frequency of hypertensive TRV response to stress and that this response is associated with mutations in the bone morphogenetic protein receptor II (BMPR2) gene.
TRV was estimated by Doppler echocardiography during supine bicycle exercise in normoxia and during 120 minutes of normobaric hypoxia (FIO(2)=12%; approximately 4500 m) in 291 relatives of 109 PAH patients and in 191 age-matched control subjects. Mean maximal TRVs were significantly higher in PAH relatives during both exercise and hypoxia. During exercise, 10% of control subjects but 31.6% of relatives (P<0.0001) exceeded the 90% quantile of mean maximal TRV seen in control subjects. Hypoxia revealed hypertensive TRV in 26% of relatives (P=0.0029). Among control subjects, TRV at rest was not related to age, sex, body mass index, systemic blood pressure, smoking status, or heart rate. Within kindreds identified as harboring deleterious mutations of the BMPR2 gene, a hypertensive TRV response occurred significantly more often compared with those without detected mutations.
Pulmonary hypertensive response to exercise and hypoxia in idiopathic/familial PAH relatives appears as a genetic trait with familial clustering, being correlated to but not caused by a BMPR2 mutation. The suitability of this trait to predict manifest PAH development should be addressed in long-term follow-up studies.
Circulation 05/2009; 119(13):1747-57. · 14.74 Impact Factor
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ABSTRACT: Patients with Angelman syndrome (OMIM # 105830) are generally thought to have normal brain imaging studies except for occasional minor cerebral atrophy. We report 9 patients with genetically proven Angelman syndrome, who were examined by magnetic resonance imaging (MRI) between the ages of 7.5 months and 5 years. MRI in the 5 patients examined during infancy revealed myelination delay and a deficit of white matter. Retarded and/or abnormal myelination in Angelman syndrome seems to be a common finding that may be diagnostically misleading. This is particularly important in the evaluation of infants with possible Angelman syndrome, who present with nonspecific clinical features and have not yet developed the characteristic behavioural, language, and movement abnormalities.
European journal of paediatric neurology: EJPN: official journal of the European Paediatric Neurology Society 07/2008; 13(3):271-6. · 2.01 Impact Factor
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ABSTRACT: Recently, we demonstrated that a polymorphism in exon 2 of the serum carnosinase (CNDP1) gene is associated with susceptibility to developing diabetic nephropathy. Based on the number of CTG repeats in the signal peptide, five different alleles coding for 4, 5, 6, 7, or 8 leucines (4L-8L) are known. Diabetic patients without nephropathy are homozygous for the 5L allele more frequently than those with nephropathy. Since serum carnosinase activity correlates with CNDP1 genotype, we hypothesized in the present study that secretion of serum carnosinase is determined by the CNDP1 genotype. To test this hypothesis, we transfected Cos-7 cells with different CNDP1 constructs varying in CTG repeats and assessed the expression of CNDP1 protein in cell extracts and supernatants. Our results demonstrate that CNDP1 secretion is significantly higher in cells expressing variants with more than five leucines in the signal peptide. Hence, our data might explain why individuals homozygous for the 5L allele have low serum carnosinase activity. Because carnosine, the natural substrate for carnosinase, exerts antioxidative effects and inhibits ACE activity and advanced glycation end product formation, our results support the finding that diabetic patients homozygous for CNDP1 5L are protected against diabetic nephropathy.
Diabetes 10/2007; 56(9):2410-3. · 8.29 Impact Factor
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ABSTRACT: Standard methods used for genomic methylation analysis allow the detection of complete absence of either methylated or non-methylated alleles but are usually unable to detect changes in the proportion of methylated and unmethylated alleles. We compare two methods for quantitative methylation analysis, using the chromosome 15q11-q13 imprinted region as model. Absence of the non-methylated paternal allele in this region leads to Prader-Willi syndrome (PWS) whilst absence of the methylated maternal allele results in Angelman syndrome (AS). A proportion of AS is caused by mosaic imprinting defects which may be missed with standard methods and require quantitative analysis for their detection. Sequence-based quantitative methylation analysis (SeQMA) involves quantitative comparison of peaks generated through sequencing reactions after bisulfite treatment. It is simple, cost-effective and can be easily established for a large number of genes. However, our results support previous suggestions that methods based on bisulfite treatment may be problematic for exact quantification of methylation status. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) avoids bisulfite treatment. It detects changes in both CpG methylation as well as copy number of up to 40 chromosomal sequences in one simple reaction. Once established in a laboratory setting, the method is more accurate, reliable and less time consuming.
Molecular and Cellular Probes 07/2007; 21(3):208-15. · 2.08 Impact Factor
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Barry I Freedman,
Pamela J Hicks,
Michele M Sale,
Eric D Pierson,
Carl D Langefeld,
Stephen S Rich,
Jianzhao Xu,
Caitrin McDonough, Bart Janssen,
Benito A Yard,
Fokko J van der Woude,
Donald W Bowden
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ABSTRACT: Four linkage analyses have identified a region on chromosome 18q22-23 that appears to harbour a diabetic nephropathy (DN) susceptibility locus. A trinucleotide repeat sequence in exon 2 of the carnosinase gene (CNDP1) residing on 18q22.3 was subsequently associated with DN in European Caucasians and Arabs.
We evaluated the role of the CNDP1 5 leucine/5 leucine (5-5) polymorphism (CNDP1 Mannheim) in diabetic end-stage renal disease (ESRD) susceptibility in 858 European Americans: 294 with type 2 DN-associated ESRD (DN-ESRD), 258 with diabetes mellitus (DM) lacking nephropathy and 306 healthy controls.
Subjects with DM lacking nephropathy were significantly more likely to be homozygous for the 5-leucine repeat CNDP1 genotype (5-5), compared with those with DN-ESRD (P=0.02). Healthy controls were also more likely to be homozygous for the 5-5 genotype, compared with those with DN-ESRD (P=0.008). No significant difference in 5-5 genotype frequency was observed between healthy controls and DM cases without nephropathy (P=0.74).
European Americans homozygous for the 5-5 leucine repeat polymorphism in the CNDP1 gene are at significantly reduced risk for developing diabetic ESRD. This replicates the CNDP1 gene association with DN that was initially detected in European Caucasians and in Arabs, and further demonstrates that the CNDP1 gene and carnosine pathway appear to play a role in susceptibility to DN.
Nephrology Dialysis Transplantation 05/2007; 22(4):1131-5. · 3.40 Impact Factor
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ABSTRACT: Carnosine, a cytoprotective dipeptide found at very high concentrations in skeletal muscle, heart and brain, is cleaved in blood by serum carnosinase which is encoded by the CNDP1 gene. We recently found that homozygosity of a 5-leucine variant in the leader peptide of this enzyme protects diabetes mellitus patients against nephropathy. Hypothesising that the same allele could also be associated with longevity or a reduced incidence of cardiovascular problems, we examined the frequency of CNDP1 alleles in German centenarians, patients with premature coronary heart disease, and matched controls. A total of 1382 individuals was investigated. The 5-leucine allele was the most common allele in all groups investigated. There was no difference in allele or genotype frequency between centenarians and their control group, or between cardiovascular patients and their control group. The recently identified functional carnosinase variant therefore does neither contribute to longevity nor protect against coronary heart disease in our probands. In addition to the known trinucleotide repeat alleles in the CNDP1 gene, we detected a rare 8-leucine allele, a rare duplication, p.L13_V15dup, and a more common frameshift deletion, L17fsX20. Homozygosity for L17fsX20, estimated to have a prevalence of approximately 1:20,000, would be expected to cause carnosinaemia, an autosomal recessive trait with uncertain clinical relevance.
Mechanisms of Ageing and Development 12/2006; 127(11):817-20. · 3.44 Impact Factor
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Rajiv D Machado,
Rolf Koehler,
Eric Glissmeyer,
Colin Veal,
Jay Suntharalingam,
Miryoung Kim,
John Carlquist,
Margaret Town,
C Gregory Elliott,
Marius Hoeper,
Anna Fijalkowska,
Marcin Kurzyna,
Jennifer R Thomson,
Simon R Gibbs,
Martin R Wilkins,
Werner Seeger,
Nicholas W Morrell,
Ekkehard Gruenig,
Richard C Trembath, Bart Janssen
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ABSTRACT: The bone morphogenetic receptor type II gene is the major genetic determinant for the inherited form of pulmonary arterial hypertension. However, deleterious mutations of this gene are not observed in the majority of subjects who develop the condition spontaneously and familial disease displays age- and sex-dependent penetrance, indicating the requirement for additional environmental and/or genetic modifiers for disease development.
We investigated polymorphic variation of the serotonin transporter gene, a biological candidate for predisposition to this vascular disorder.
No significant evidence of association between alleles of the serotonin transporter gene and pulmonary hypertension was detected, nor did we observe a relationship with age of onset in familial and idiopathic disease.
Variation of the serotonin transporter gene appears unlikely to confer significant susceptibility to pulmonary arterial hypertension. This study emphasizes the need for adequately powered cohorts for association analyses to identify not only genetic determinants of disease susceptibility but also inherited modifiers for disease development.
American Journal of Respiratory and Critical Care Medicine 05/2006; 173(7):793-7. · 11.08 Impact Factor
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Rajiv D Machado,
Micheala A Aldred,
Victoria James,
Rachel E Harrison,
Bhakti Patel,
Edward C Schwalbe,
Ekkehard Gruenig, Bart Janssen,
Rolf Koehler,
Werner Seeger, [......],
Shingo Kyotani,
Norifumi Nakanishi,
Takayuki Morisaki,
Marc Humbert,
Gerald Simonneau,
Olivier Sitbon,
Florent Soubrier,
Florence Coulet,
Nicholas W Morrell,
Richard C Trembath
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ABSTRACT: Pulmonary arterial hypertension (PAH) is clinically characterized by a sustained elevation in mean pulmonary artery pressure leading to significant morbidity and mortality. The disorder is typically sporadic, and in such cases the term idiopathic PAH (IPAH) is used. However, cases that occur within families (familial PAH (FPAH)) display similar clinical and histopathological features, suggesting a common etiology. Heterozygous mutations of a type II member of the TGF-beta cell signaling superfamily known as BMPR2 on chromosome 2q33 have been identified in many kindreds with FPAH, yet display both reduced penetrance and sex bias. This report presents the compilation of data for 144 distinct mutations that alter the coding sequence of the BMPR2 gene identified in 210 independent PAH subjects. This large data set characterizes the extent of sequence variation and reveals that the majority (71%) of mutations in FPAH and IPAH comprise nonsense, frameshift, and splice-site defects, and gene rearrangements. These predict premature termination of the transcript with likely loss through the process of nonsense-mediated decay (NMD). A total of 44 missense mutations were identified that substitute amino acid residues at highly conserved sites within recognized functional domains of the mature receptor. We assess this category of mutations in the context of their heterogeneous effects on cell signaling when assayed by in vitro cell-based systems. Disease-causing mutation hot-spots within BMPR2 are summarized. Taken together, these observations are likely to aid in the development of targeted mutation detection strategies relevant for patient management. Finally, we examine the age- and sex-dependent reduced penetrance of BMPR2 mutations by reviewing bmpr2 animal models and the requirement for additional genetic and/or environmental modifiers of disease. In conclusion, these data provide compelling genetic evidence that haploinsufficiency is the predominant molecular mechanism underlying disease predisposition, and support the concept of a critical threshold of signaling activity below which disease may be precipitated.
Human Mutation 03/2006; 27(2):121-32. · 5.69 Impact Factor
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Chest 01/2006; 128(6 Suppl):619S. · 5.25 Impact Factor
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Chest 01/2006; 128(6 Suppl):630S-633S. · 5.25 Impact Factor
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Bart Janssen,
Daniela Hohenadel,
Paul Brinkkoetter,
Verena Peters,
Nina Rind,
Christine Fischer,
Ivan Rychlik,
Marie Cerna,
Marianna Romzova,
Emile de Heer, [......],
Moin A Saleem,
Jochen Meyer,
Hannes Köppel,
Sibylle Sauerhoefer,
Claus R Bartram,
Peter Nawroth,
Hans-Peter Hammes,
Benito A Yard,
Johannes Zschocke,
Fokko J van der Woude
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ABSTRACT: The risk of diabetic nephropathy is partially genetically determined. Diabetic nephropathy is linked to a gene locus on chromosome 18q22.3-q23. We aimed to identify the causative gene on chromosome 18 and to study the mechanism by which the product of this gene could be involved in the development of diabetic nephropathy. DNA polymorphisms were determined in 135 case (diabetic nephropathy) and 107 control (diabetes without nephropathy) subjects. The effect of carnosine on the production of extracellular matrix components and transforming growth factor-beta (TGF-beta) after exposure to 5 and 25 mmol/l d-glucose was studied in cultured human podocytes and mesangial cells, respectively. A trinucleotide repeat in exon 2 of the CNDP1 gene, coding for a leucine repeat in the leader peptide of the carnosinase-1 precursor, was associated with nephropathy. The shortest allelic form (CNDP1 Mannheim) was more common in the absence of nephropathy (P = 0.0028, odds ratio 2.56 [95% CI 1.36-4.84]) and was associated with lower serum carnosinase levels. Carnosine inhibited the increased production of fibronectin and collagen type VI in podocytes and the increased production of TGF-beta in mesangial cells induced by 25 mmol/l glucose. Diabetic patients with the CNDP1 Mannheim variant are less susceptible for nephropathy. Carnosine protects against the adverse effects of high glucose levels on renal cells.
Diabetes 09/2005; 54(8):2320-7. · 8.29 Impact Factor
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ABSTRACT: We have tested for large BRCA1 gene rearrangements in German high-risk breast and ovarian cancer families previously screened negative for point mutations by dHPLC and sequencing. Using the novel MLPA method, two deletions of exons 1A, 1B and 2 and exon 17, respectively, were detected in four out of 75 families investigated in Southern Germany. An identical exon 17 deletion with the same breakpoints and a deletion of exons 1A, 1B and 2 were found by fluorescent multiplex PCR in two out of 30 families investigated in Northern Germany. Combining both populations, genomic rearrangements were found in 6% of the mutation-negative families and 3% of all high-risk families and account for 8% of all BRCA1 mutations. Our data indicate that the exon 17 deletion may be a founder mutation in the German population. The prevalence of BRCA1 gene deletions or duplications in our patients is similar to previous reports from Germany and France. Genomic quantification by MLPA is a useful method for molecular diagnostics in high-risk breast cancer families.
Human Mutation 01/2005; 24(6):534. · 5.69 Impact Factor
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Ekkehard Grünig,
Rolf Koehler,
Gabriel Miltenberger-Miltenyi,
Rainer Zimmermann,
Matthias Gorenflo,
Derliz Mereles,
Karlin Arnold,
Barbara Naust,
Heinrike Wilkens,
Andreas Benz,
Albrecht von Hippel,
Herbert E Ulmer,
Wolfgang Kübler,
Hugo A Katus,
Claus R Bartram,
Dietmar Schranz, Bart Janssen
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ABSTRACT: Mutations of the bone morphogenetic protein receptor II (BMPR2) gene on chromosome 2q33 can cause familial primary pulmonary hypertension (PPH) and may occur in 26% adult patients with sporadic disease. Other disease-related genes have been localized to chromosomes 2q31 (PPH2) and 12q13 (ALK1). The genetic background in affected children remains unclear. Thirteen children (age at diagnosis, 6 mo to 13 y; mean, 5.6 +/- 3.9 y) with invasively confirmed PPH were screened for BMPR2 mutations using denaturing HPLC and sequence analysis. In addition, all children were scanned for BMPR2 deletions by Southern blot analysis. Pulmonary artery pressure was assessed using echocardiography at rest and during exercise in 57 family members of six infants. The six families were subjected to linkage analysis. None of the 13 children had a BMPR2 mutation or deletion. Linkage to chromosome 2 or 12 could not be confirmed in any of the families investigated. In all assessed families, both parents of the index patient and/or members of both branches revealed an abnormal pulmonary artery systolic pressure (PASP)-response to exercise. PPH in children may have a different genetic background than in adults. We postulate a recessive mode of inheritance in a proportion of infantile cases.
Pediatric Research 11/2004; 56(4):571-8. · 2.70 Impact Factor
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John H Newman,
Richard C Trembath,
Jane A Morse,
Ekkehard Grunig,
James E Loyd,
Serge Adnot,
Fabio Coccolo,
Carlo Ventura,
John A Phillips,
James A Knowles, Bart Janssen,
Oliver Eickelberg,
Saadia Eddahibi,
Phillipe Herve,
William C Nichols,
Gregory Elliott
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ABSTRACT: Mutations in two receptors of the transforming growth factor-beta family have recently been shown to be present in the majority of cases of inherited (familial) pulmonary arterial hypertension (PAH). Study of the biology of these receptors, bone morphogenetic protein receptor type-2 (BMPR2), and activin-like kinase type-1 (ALK-1) will certainly reveal pathogenic mechanisms of disease. Exonic mutations in BMPR2 are found in about 50% of patients with familial PAH, and ALK1 mutations are found in a minority of patients with hereditary hemorrhagic telangiectasia and co-existent PAH. Because familial PAH is highly linked to chromosome 2q33, it is likely that the remaining 50% of family cases without exonic mutations have either intronic BMPR2 abnormalities or alterations in the promoter or regulatory genes. Also, only about 10% of patients with "sporadic" idiopathic PAH have identifiable BMPR2 mutations. Mutations in BMPR2 confer a 15% to 20% chance of developing PAH in a carrier's lifetime. Thus, there must be gene-gene or gene-environment interactions that either enhance or prevent the development of the vascular disease in persons carrying a mutation, and there must be other patterns of susceptibility based on genetic makeup. To elucidate the genetic basis of PAH further, investigations are needed, including genome scanning for major and minor genes, analysis of genetic profiles of patients for candidate genes likely to modify risk for disease (e.g., serotonin transporter alleles, nitric oxide-synthases), proteomics, transgenic mice, and altered signal transduction. Advances in genetic testing, presymptomatic screening, and biomarkers should permit early detection of disease in those at risk of PAH and allow trials of preventive therapy in carriers.
Journal of the American College of Cardiology 07/2004; 43(12 Suppl S):33S-39S. · 14.16 Impact Factor
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ABSTRACT: Diabetic nephropathy (DN) is the most common cause of renal failure in the western hemisphere. Epidemiological studies have suggested a genetic susceptibility for DN. Linkage analysis showed evidence for a locus on chromosome 18q22.3-q23 in Turkish families. We report the construction of a transcript map of the target region on chromosome 18q22.3-q23 and analysis of the candidate gene ZNF236. By using recent publications, human genome databases, and a multitude of available protein-predicting programs, we obtained a detailed map of this 4.7-Mb-spanning region. We sequenced ZNF236 in patients with diabetic nephropathy and diabetes without nephropathy, as well as in unaffected controls. We observed multiple splice forms in all individuals but no mutation in any of the patients. It seems improbable, therefore, that ZNF236 is a gene that confers DN susceptibility.
Genomics 10/2003; 82(3):406-11. · 3.02 Impact Factor
