TY - JOUR A1 - Zebger-Gong, Hong A1 - Mueller, Dominik A1 - Diercke, Michaela A1 - Haffner, Dieter A1 - Hocher, Berthold A1 - Verberckmoes, Steven A1 - Schmidt, Sven A1 - D'Haese, Patrick C. A1 - Querfeld, Uwe T1 - 1,25-Dihydroxyvitamin D-3-induced aortic calcifications in experimental uremia: up-regulation of osteoblast markers, calcium-transporting proteins and osterix JF - Journal of hypertension N2 - Background and objective Whether treatment with vitamin D receptor activators contributes to cardiovascular disease in patients with chronic kidney disease is a matter of debate. We studied mechanisms involved in vitamin D-related vascular calcifications in vivo and in vitro. Methods Aortic calcifications were induced in subtotally nephrectomized (SNX) rats by treatment with a high dose (0.25 mu g/kg per day) of 1,25-dihydroxyvitamin D-3 (calcitriol) given for 6 weeks. Likewise, primary rat vascular smooth muscle cells (VSMCs) were incubated with calcitriol at concentrations ranging from 10(-11) to 10(-7) mol/l. Immunohistochemistry revealed that the aortic expression of osteopontin, osteocalcin and bone sialoprotein was significantly increased in calcitriol-treated SNX rats compared to untreated SNX controls. In addition, aortic expression of the transient receptor potential vanilloid calcium channel 6 (TRPV6) and calbindin D9k was significantly up-regulated by treatment with calcitriol. Furthermore, calcitriol significantly increased expression of the osteogenic transcription factor osterix. In-vitro studies showed similar results, confirming that these effects could be attributed to treatment with calcitriol. Conclusions High-dose calcitriol treatment induces an osteoblastic phenotype in VSMC both in SNX rats and in vitro, associated with up-regulation of proteins regulating mineralization and calcium transport, and of the osteogenic transcription factor osterix. KW - calbindin D9k KW - calcitriol KW - calcium transport KW - osteoblast KW - osterix KW - TRPV5 KW - TRPV6 KW - vascular calcification Y1 - 2011 U6 - https://doi.org/10.1097/HJH.0b013e328340aa30 SN - 0263-6352 VL - 29 IS - 2 SP - 339 EP - 348 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Hocher, Berthold A1 - Heimerl, Dirk A1 - Slowinski, Torsten A1 - Godes, Michael A1 - Halle, Horst A1 - Priem, Friedrich A1 - Pfab, Thiemo T1 - Birthweight and Fetal Glycosylated Hemoglobin at Birth in Newborns Carrying the GLUT1 XbaI Gene Polymorphism JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: Low birthweight is an independent risk factor of glucose intolerance and type 2 diabetes in later life. Genetically determined insulin resistance and subsequently impaired glucose uptake might explain both reduced fetal growth and elevated blood glucose. The glucose transporter 1 (GLUT!) plays an important role for fetal glucose uptake as well as for maternal-fetal glucose transfer, and it has been associated with insulin resistance in adults. The present study hypothesized that the common fetal GLUT1 XbaI polymorphism might reduce fetal insulin sensitivity and/or glucose supply in utero, thus affecting fetal blood glucose and fetal growth. Methods: A genetic association study was conducted at the obstetrics department of the Charite University Hospital, Berlin, Germany. 119.1 white women were included after delivery, and all newborns were genotyped for the GLUT1 XbaI polymorphism. Total glycosylated hemoglobin was quantified, serving as a surrogate of glycemia during the last weeks of pregnancy. Results: The analysis of this large population showed no significant differences in fetal glycosylated hemoglobin or birthweight for the different fetal GLUT1 XbaI genotypes. Only newborns carrying the mutated allele show the previously published inverse association between birthweight and glycosylated hemoglobin. Conclusions: The results suggest that there is no prenatal effect of the fetal GLUT1 XbaI polymorphism on fetal insulin sensitivity, intrauterine fetal glucose supply or fetal growth. However, the polymorphism seems to modulate the inverse interaction between birthweight and fetal glycemia. KW - GLUT1 XbaI gene polymorphism KW - birthweight KW - total glycosylated hemoglobin KW - insulin resistance KW - fetal programming Y1 - 2011 SN - 1433-6510 VL - 57 IS - 9-10 SP - 651 EP - 657 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER - TY - JOUR A1 - Hocher, Berthold A1 - Heiden, S. A1 - von Websky, Karoline A1 - Rahnenführer, Jörg A1 - Kalk, Philipp A1 - Pfab, T. T1 - Dual endothelin-converting enzyme/neutral endopeptidase blockade in rats with D-galactosamine-induced liver failure JF - European journal of medical research : official organ "Deutsche AIDS-Gesellschaft" N2 - Secondary activation of the endothelin system is thought to be involved in toxic liver injury. This study tested the hypothesis that dual endothelin-converting enzyme / neutral endopeptidase blockade might: be able to attenuate acute toxic liver injury. Male Sprague-Dawley rats were implanted with subcutaneous minipumps to deliver the novel compound SLV338 (10 mg/kg*d) or vehicle. Four days later they received two intraperitoneal injections of D-galactosamine (1.3 g/kg each) or vehicle at an interval of 12 hours. The animals were sacrificed 48 hours after the first injection. Injection of D-galactosamine resulted in very severe liver injury, reflected by strongly elevated plasma liver enzymes, hepatic necrosis and inflammation, and a mortality rate of 42.9 %. SLV338 treatment did not show any significant effect on the extent of acute liver injury as judged from plasma parameters, hepatic histology and mortality. Plasma measurements of SLV338 confirmed adequate drug delivery. Plasma concentrations of big endothelin-1 and endothelin-1 were significantly elevated in animals with liver injury (5-fold and 62-fold, respectively). Plasma endothelin-1 was significantly correlated with several markers of liver injury. SLV338 completely prevented the rise of plasma big endothelin-1 (p<0.05) and markedly attenuated the rise of endothelin-1 (p = 0.055). In conclusion, dual endothelin-converting enzyme / neutral endopeptidase blockade by SLV338 did not significantly attenuate D-galactosamine-induced acute liver injury, although it largely prevented the activation of the endothelin system. An evaluation of SLV338 in a less severe model of liver injury would be of interest, since very severe intoxication might not be relevantly amenable to pharmacological interventions. KW - endothelin KW - endothelin-converting enzyme KW - neutral endopeptidase KW - D-galactosamine KW - acute liver failure Y1 - 2011 SN - 0949-2321 VL - 16 IS - 6 SP - 275 EP - 279 PB - Med. Scientific Publ. Holzapfel CY - München ER - TY - JOUR A1 - Chaykovska, Lyubov A1 - von Websky, Karoline A1 - Rahnenführer, Jan A1 - Alter, Markus L. A1 - Heiden, Susi A1 - Fuchs, Holger A1 - Runge, Frank A1 - Klein, Thomas A1 - Hocher, Berthold T1 - Effects of DPP-4 Inhibitors on the Heart in a Rat Model of Uremic Cardiomyopathy JF - PLoS one N2 - Background: Uremic cardiomyopathy contributes substantially to mortality in chronic kidney disease (CKD) patients. Glucagon-like peptide-1 (GLP-1) may improve cardiac function, but is mainly degraded by dipeptidyl peptidase-4 (DPP-4). Methodology/Principal Findings: In a rat model of chronic renal failure, 5/6-nephrectomized [5/6N] rats were treated orally with DPP-4 inhibitors (linagliptin, sitagliptin, alogliptin) or placebo once daily for 4 days from 8 weeks after surgery, to identify the most appropriate treatment for cardiac dysfunction associated with CKD. Linagliptin showed no significant change in blood level AUC(0-infinity) in 5/6N rats, but sitagliptin and alogliptin had significantly higher AUC(0-infinity) values; 41% and 28% (p=0.0001 and p=0.0324), respectively. No correlation of markers of renal tubular and glomerular function with AUC was observed for linagliptin, which required no dose adjustment in uremic rats. Linagliptin 7 mu mol/kg caused a 2-fold increase in GLP-1 (AUC 201.0 ng/l*h) in 5/6N rats compared with sham-treated rats (AUC 108.6 ng/l*h) (p=0.01). The mRNA levels of heart tissue fibrosis markers were all significantly increased in 5/6N vs control rats and reduced/normalized by linagliptin. Conclusions/Significance: DPP-4 inhibition increases plasma GLP-1 levels, particularly in uremia, and reduces expression of cardiac mRNA levels of matrix proteins and B-type natriuretic peptides (BNP). Linagliptin may offer a unique approach for treating uremic cardiomyopathy in CKD patients, with no need for dose-adjustment. Y1 - 2011 U6 - https://doi.org/10.1371/journal.pone.0027861 SN - 1932-6203 VL - 6 IS - 11 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Schildroth, Janice A1 - Rettig-Zimmermann, Juliane A1 - Kalk, Philipp A1 - Steege, Andreas A1 - Faehling, Michael A1 - Sendeski, Mauricio A1 - Paliege, Alexander A1 - Lai, En Yin A1 - Bachmann, Sebastian A1 - Persson, Pontus B. A1 - Hocher, Berthold A1 - Patzak, Andreas T1 - Endothelin type A and B receptors in the control of afferent and efferent arterioles in mice JF - Nephrology, dialysis, transplantation N2 - Background. Endothelin 1 contributes to renal blood flow control and pathogenesis of kidney diseases. The differential effects, however, of endothelin 1 (ET-1) on afferent (AA) and efferent arterioles (EA) remain to be established. Methods. We investigated endothelin type A and B receptor (ETA-R, ETB-R) functions in the control of AA and EA. Arterioles of ETB-R deficient, rescued mice [ETB (-/-)] and wild types [ETB(+/+)] were microperfused. Results. ET-1 constricted AA stronger than EA in ETB (-/-) and ETB(+/+) mice. Results in AA: ET-1 induced similar constrictions in ETB(-/-) and ETB(+/+) mice. BQ-123 (ETA-R antagonist) inhibited this response in both groups. ALA-ET-1 and IRL1620 (ETB-R agonists) had no effect on arteriolar diameter. L-NAME did neither affect basal diameters nor ET-1 responses. Results in EA: ET-1 constricted EA stronger in ETB(+/+) compared to ETB(-/-). BQ-123 inhibited the constriction completely only in ETB(-/-). ALA-ET-1 and IRL1620 constricted only arterioles of ETB(+/+) mice. L-NAME decreased basal diameter in ETB(+/+), but not in ETB(-/-) mice and increased the ET-1 response similarly in both groups. The L-NAME actions indicate a contribution of ETB-R in basal nitric oxide (NO) release in EA and suggest dilatory action of ETA-R in EA. Conclusions. ETA-R mediates vasoconstriction in AA and contributes to vasoconstriction in EA in this mouse model. ETB-R has no effect in AA but mediates basal NO release and constriction in EA. The stronger effect of ET-1 on AA supports observations of decreased glomerular filtration rate to ET-1 and indicates a potential contribution of ET-1 to the pathogenesis of kidney diseases. KW - endothelin KW - ETB receptor-deficient mouse KW - glomerular arterioles KW - renal haemodynamics Y1 - 2011 U6 - https://doi.org/10.1093/ndt/gfq534 SN - 0931-0509 VL - 26 IS - 3 SP - 779 EP - 789 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Vignon-Zellweger, Nicolas A1 - Relle, Katharina A1 - Kienlen, Elodie A1 - Alter, Markus L. A1 - Seider, Patrick A1 - Sharkovska, Juliya A1 - Heiden, Susi A1 - Kalk, Philipp A1 - Schwab, Karima A1 - Albrecht-Kuepper, Barbara A1 - Theuring, Franz A1 - Stasch, Johannes-Peter A1 - Hocher, Berthold T1 - Endothelin-1 overexpression restores diastolic function in eNOS knockout mice JF - Journal of hypertension N2 - Background The cardiac nitric oxide and endothelin-1 (ET-1) systems are closely linked and play a critical role in cardiac physiology. The balance between both systems is often disturbed in cardiovascular diseases. To define the cardiac effect of excessive ET-1 in a status of nitric oxide deficiency, we compared left ventricular function and morphology in wild-type mice, ET-1 transgenic (ET+/+) mice, endothelial nitric oxide synthase knockout (eNOS(-/-)) mice, and ET(+/+)eNOS(-/-) mice. Methods and results eNOS(-/-) and ET(+/+)eNOS(-/-) mice developed high blood pressure compared with wild-type and ET+/+ mice. Left ventricular catheterization showed that eNOS(-/-) mice, but not ET(+/+)eNOS(-/-), developed diastolic dysfunction characterized by increased end-diastolic pressure and relaxation constant tau. To elucidate the causal molecular mechanisms driving the rescue of diastolic function in ET(+/+)eNOS(-/-) mice, the cardiac proteome was analyzed. Two-dimensional gel electrophoresis coupled to mass spectrometry offers an appropriate hypothesis-free approach. ET-1 overexpression on an eNOS(-/-) background led to an elevated abundance and change in posttranslational state of antioxidant enzymes (e. g., peroxiredoxin-6, glutathione S-transferase mu 2, and heat shock protein beta 7). In contrast to ET(+/+)eNOS(-/-) mice, eNOS(-/-) mice showed an elevated abundance of proteins responsible for sarcomere disassembly (e. g., cofilin-1 and cofilin-2). In ET(+/+)eNOS(-/-) mice, glycolysis was favored at the expense of fatty acid oxidation. Conclusion eNOS(-/-) mice developed diastolic dysfunction; this was rescued by ET-1 transgenic overexpression. This study furthermore suggests that cardiac ET-1 overexpression in case of eNOS deficiency causes specifically the regulation of proteins playing a role in oxidative stress, myocytes contractility, and energy metabolism. KW - cardiovascular diseases KW - endothelin KW - nitric oxide Y1 - 2011 U6 - https://doi.org/10.1097/HJH.0b013e3283450770 SN - 0263-6352 SN - 1473-5598 VL - 29 IS - 5 SP - 961 EP - 970 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Kalk, Philipp A1 - Sharkovska, Yuliya A1 - Kashina, Elena A1 - von Websky, Karoline A1 - Relle, Katharina A1 - Pfab, Thiemo A1 - Alter, Markus L. A1 - Guillaume, Philippe A1 - Provost, Daniel A1 - Hoffmann, Katrin A1 - Fischer, Yvan A1 - Hocher, Berthold T1 - Endothelin-Converting Enzyme/Neutral Endopeptidase Inhibitor SLV338 Prevents Hypertensive Cardiac Remodeling in a Blood Pressure-Independent Manner JF - HYPERTENSION N2 - Hypertensive heart disease is a major contributor to cardiovascular mortality. Endothelin is a potent vasoconstrictive and profibrotic mediator produced by the endothelin-converting enzyme (ECE), whereas natriuretic peptides, degraded by the neutral endopeptidase (NEP), have diuretic, vasodilatory, and antifibrotic properties. Thus, combined ECE/NEP inhibition may halt hypertensive cardiac remodeling. This study examined effects of SLV338, a novel ECE/NEP inhibitor, on cardiac protection in experimental renovascular hypertension (2-kidney, 1-clip [2K1C]). Male rats were allocated to 5 groups: sham-operated rats, untreated animals with 2K1C, 2K1C animals treated with oral SLV338 (30 and 100 mg/kg per day), and 2K1C animals treated with oral losartan (20 mg/kg per day). Treatment duration was 12 weeks. Blood pressure was assessed every 4 weeks. At study end, hearts were taken for histology/computer-aided histomorphometry/immunohistochemistry. Pharmacological properties of SLV338 are described. SLV338 is a dual ECE/NEP inhibitor, as demonstrated both in vitro and in vivo. In the 2K1C study, losartan lowered blood pressure by <= 46 mm Hg, whereas both dosages of SLV338 had no effect. However, SLV338 (both dosages) completely normalized cardiac interstitial fibrosis, perivascular fibrosis, myocyte diameter, and media: lumen ratio of cardiac arteries, as did losartan. Cardiac transforming growth factor-beta 1 expression was significantly enhanced in untreated 2K1C rats versus controls, whereas treatment with SLV338 and losartan prevented this effect. Taken together, dual ECE/NEP inhibitor SLV338 prevents cardiac remodeling to the same extent as losartan, but in a blood pressure-independent manner, in a rat model of renovascular hypertension. This effect is at least partially mediated via suppression of cardiac transforming growth factor-beta 1 expression. (Hypertension. 2011;57:755-763.) KW - renovascular hypertension KW - cardiac remodeling KW - endothelin-converting enzyme KW - neutral endopeptidase KW - TGF-beta 1 Y1 - 2011 U6 - https://doi.org/10.1161/HYPERTENSIONAHA.110.163972 SN - 0194-911X VL - 57 IS - 4 SP - 755 EP - 763 PB - LIPPINCOTT WILLIAMS & WILKINS CY - PHILADELPHIA ER - TY - JOUR A1 - Espe, Katharina M. A1 - Raila, Jens A1 - Henze, Andrea A1 - Krane, Vera A1 - Schweigert, Florian J. A1 - Hocher, Berthold A1 - Wanner, Christoph A1 - Drechsler, Christiane T1 - Impact of vitamin A on clinical outcomes in haemodialysis patients JF - Nephrology, dialysis, transplantation N2 - Background. Patients on maintenance haemodialysis treatment experience an excessive risk of cardiovascular disease and mortality. The vitamin A concentration is known to be higher in these patients compared to the general population where elevated vitamin A concentrations are associated with adverse outcome. The impact of vitamin A on morbidity and mortality in end-stage renal disease patients is controversial and is the topic of this study. Methods. We analysed plasma retinol and retinol-binding protein 4 (RBP4) in 1177 diabetic haemodialysis patients, who participated in the German Diabetes and Dialysis Study (median follow-up 4 years). By Cox regression analyses hazard ratios (HRs) were determined for pre-specified, adjudicated end points according to baseline concentrations. Results. Patients had a mean age of 66 +/- 8 years, mean retinol and RBP4 concentrations of 3.28 (0.71-7.44) and 4.02 (1.28-10.1) mu mol/L, respectively. Patients with retinol concentrations in the first quartile (<2.6 mu mol/L) had an almost 2-fold increased risk of all-cause mortality compared to patients of the fourth quartile [>3.9 mu mol/L; HR 1.81, 95% confidence interval (CI) 1.43-2.30]. There was a strong association between low retinol and the risk of sudden cardiac death (SCD, HR 2.22, 95% CI 1.41-3.50) and fatal infection (HR 2.19, 95% CI 1.26-3.82). Patients with RBP4 concentrations in the lowest quartile (<3.0 mu mol/L) were more likely to die of any cause (HR 1.43, 95% CI 1.14-1.80), experience SCD (HR 1.97, 95% CI 1.28-3.03) and cardiovascular events (HR 1.43, 95% CI 1.10-1.85). Conclusion. This large cohort study shows a strong association of low retinol and RBP4 concentrations with SCD and all-cause mortality in diabetic haemodialysis patients. KW - haemodialysis KW - mortality KW - retinol KW - retinol-binding protein 4 KW - sudden death Y1 - 2011 U6 - https://doi.org/10.1093/ndt/gfr171 SN - 0931-0509 VL - 26 IS - 12 SP - 4054 EP - U583 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Li, Jian A1 - Wang, Zi-Neng A1 - Schlemm, Ludwig A1 - Pfab, Thiemo A1 - Xiao, Xiao-Min A1 - Chen, You-Peng A1 - Hocher, Berthold T1 - Low birth weight and elevated head-to-abdominal circumference ratio are associated with elevated fetal glycated serum protein concentrations JF - Journal of hypertension N2 - Objective To analyze the association between low birth weight, head-to-abdominal circumference ratio, and insulin resistance in early life. Method and results Glycated serum proteins (GSPs) were quantified at delivery in 612 Chinese mother/child pairs serving as a surrogate of maternal and fetal glycemia. Differential ultrasound examination of the fetal's body (head circumference, biparietal diameter, pectoral diameter, abdominal circumference, and femur length) was done in average 1 week prior to delivery. Multivariable regression analysis considering gestational age at delivery, the child's sex, maternal BMI, maternal age at delivery, maternal body weight, and pregnancyinduced hypertension revealed that fetal GSP was inversely associated with birth weight (R(2) = 0.416; P < 0.001). Fetal GSP was furthermore positively associated with the head-to-abdominal circumference ratio, whereas the maternal GSP was negatively correlated with the offspring's head-to-abdominal circumference ratio (R(2) = 0.285; P = 0.010 and R(2) = 0.261; P = 0.020, respectively). The increased head-to-abdominal circumference ratio in newborns with higher fetal GSP is mainly due to a reduced abdominal circumference rather than reduced growth of the brain. Conclusion The disproportional intrauterine growth is in line with the concept of so-called brain sparing, a mechanism maintaining the intrauterine growth of the brain at the expense of trunk growth. Our data suggest that the low birth weight phenotype, linked to cardiovascular diseases like hypertension in later life, might be a phenotype of disproportional intrauterine growth retardation and early life insulin resistance. KW - disproportional intrauterine growth retardation KW - insulin resistance KW - low birth weight KW - ultrasound Y1 - 2011 U6 - https://doi.org/10.1097/HJH.0b013e328349a2e6 SN - 0263-6352 VL - 29 IS - 9 SP - 1712 EP - 1718 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Wengenmayer, Christina A1 - Krikov, Maxim A1 - Mueller, Susanne A1 - Lucht, Kristin A1 - Villringer, Arno A1 - Hocher, Berthold A1 - Unger, Thomas A1 - Thoene-Reineke, Christa T1 - Novel therapy approach in primary stroke prevention simultaneous inhibition of endothelin converting enzyme and neutral endopeptidase in spontaneously hypertensive, stroke-prone rats improves survival JF - Neurological research : a journal of progress in neurosurgery and neurosciences N2 - Objectives: Stroke, frequently a consequence of hypertension, is one of the leading causes of death and neurological disabilities worldwide. In the ischemic brain, levels of endothelin-1, one of the most potent vasoconstrictors, are raised. Anti-inflammatory and neuroprotective effects of endothelin antagonists after stroke have been described in literature. Based on these findings, we investigated the protective effect of the endothelin converting enzyme/neutral endopeptidase blocker, SLV 338, in salt-loaded, stroke-prone, spontaneously hypertensive rats. Methods: Male, 8-week-old spontaneously hypertensive stroke-prone rats were put on a high salt diet and treated with either 30 mg/kg or 100 mg/kg SLV 338 or vehicle for 27 weeks. Blood pressure, neurological outcome, body weight, and mortality were investigated throughout treatment. In weeks 1 and 9, animals were housed in metabolic cages for collection of urinary and blood samples and assessment of salt water and food intake. In weeks 22 and 27, additional blood samples were taken. At the end of the study, all brains were analyzed using magnetic resonance imaging. Results: SLV 338 was well tolerated in all animals. Neurological outcome and infarct size were similar in all groups. Albuminuria was considerably delayed and the incidence of stroke significantly lowered in treated animals. In spontaneously hypertensive stroke-prone rats, treatment with SLV 338 significantly (P=0.01) improved survival in comparison to the vehicle treated group in a blood pressure-independent manner. Discussion: Our data in spontaneously hypertensive stroke-prone rats demonstrate that combined endothelin converting enzyme/neutral endopeptidase inhibition could offer a new therapeutic approach for primary stroke prevention and improvement of mortality. The mechanism seems to be blood pressure-independent. KW - Endothelin KW - Hypertension KW - Natriuretic peptides KW - Stroke Y1 - 2011 U6 - https://doi.org/10.1179/016164111X12881719352534 SN - 0161-6412 VL - 33 IS - 2 SP - 201 EP - 207 PB - Routledge, Taylor & Francis Group CY - Leeds ER -