TY - JOUR A1 - Alter, Markus L. A1 - Kretschmer, Axel A1 - Von Websky, Karoline A1 - Tsuprykov, Oleg A1 - Reichetzeder, Christoph A1 - Simon, Alexandra A1 - Stasch, Johannes-Peter A1 - Hocher, Berthold T1 - Early urinary and plasma biomarkers for experimental diabetic Nephropathy JF - Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion N2 - Background: As the prevalence of diabetes rises, its complications such as diabetic nephropathy affect an increaseing number of patients. Consequently, the need for biomarkers in rodent models which reflect the stage and course of diabetic nephropathy is high. This article focuses on Heart-type fatty acid binding protein (H-FABP), osteopontin (OPN), nephrin, and Neutrophil gelatinase-associated lipocalin (NGAL) in urine, and kidney injury molecule (KIM)-1, clusterin, and tissue inhibitior of metalloproteinases (TIMP) 1 in plasma in uni-nephrectomized rats with streptocotozin-induced type 1 diabetes mellitus, a common animal model to explore renal impairment in the setting of diabetes mellitus. Methods: 23 male Wistar rats were uni-nephrectomized and subsequently divided into two study groups. The diabetic group received streptozotocin (STZ) via tail-vein injection, the non-diabetic group received citrate buffer without STZ. Subsequently, blood glucose, body weight, and blood pressure were checked regularly. After 18 weeks, animals were placed in metabolic cages, blood and urine obtained and subsequently organs were harvested after sacrifice. Results: Blood glucose levels were highly increased in diabetic animals throughout the experiment, whereas systolic blood pressure did not differ between the study groups. At study end, classical biomarkers such as urinary albumin and protein and plasma cystatin c were only slightly but not significantly different between groups indicating a very early disease state. In contrast, urinary excretion of H-FABP, OPN, nephrin, and NGAL were highly increased in diabetic animals with a highly significant p-value (p<0.01 each) compared to non-diabetic animals. In plasma, differences were found for calbindin, KIM-1, clusterin, TIMP-1, and OPN. These findings were confirmed by means of the area under the receiver operating characteristic curve (ROC-AUC) analysis. Conclusions: In summary, our study revealed elevated levels of new plasma and urinary biomarkers (urinary osteopontin, urinary nephrin, urinary NGAL, urinary H-FABP, plasma KIM-1, plasma TIMP-1) in uni-nephrectomized diabetic rats, an established rat model of diabetic nephropathy. These biomarkers appeared even before the classical biomarkers of diabetic nephropathy such as albuminuria and urinary protein excretion. The new biomarkers might offer advantage to urinary albumin and plasma cystatin c with respect to early detection. KW - diabetic nephropathy KW - urinary biomarker KW - blood biomarker KW - heart-type fatty acid binding protein KW - osteopontin KW - nephrin KW - neutrophil gelatinase-associated lipocalin KW - kidney injury molecule 1 KW - clusterin KW - tissue inhibitior of metalloproteinases 1 Y1 - 2012 U6 - https://doi.org/10.7754/Clin.Lab.2011.111010 SN - 1433-6510 VL - 58 IS - 7-8 SP - 659 EP - 671 PB - Clin Lab Publ., Verl. Klinisches Labor CY - Heidelberg ER - TY - JOUR A1 - Chaykovska, Lyubov A1 - Alter, Markus L. A1 - von Websky, Karoline A1 - Hohmann, Margarete A1 - Tsuprykov, Oleg A1 - Reichetzeder, Christoph A1 - Kutil, Barbara A1 - Kraft, Robin A1 - Klein, Thomas A1 - Hocher, Berthold T1 - Effects of telmisartan and linagliptin when used in combination on blood pressure and oxidative stress in rats with 2-kidney-1-clip hypertension JF - Journal of hypertension N2 - Objective:To investigate the effects of linagliptin alone and in combination with the angiotensin II receptor blocker (ARB), telmisartan on blood pressure (BP), kidney function, heart morphology and oxidative stress in rats with renovascular hypertension.Methods:Fifty-seven male Wistar rats underwent unilateral surgical stenosis of the renal artery [2-kidney-1-clip (2k1c) method]. Animals were randomly divided into four treatment groups (n=14-18 per group) receiving: telmisartan (10mg/kg per day in drinking water), linagliptin (89ppm in chow), combination (linagliptin 89ppm+telmisartan 10mg/kg per day) or placebo. An additional group of 12 rats underwent sham surgery. BP was measured one week after surgery. Hypertensive animals entered a 16-week dosing period. BP was measured 2, 4, 8, 12 and 16 weeks after the initiation of treatment. Blood and urine were tested for assessment of kidney function and oxidative stress 6, 10, 14 and 18 weeks after surgery. Blood and urine sampling and organ harvesting were finally performed.Results:Renal stenosis caused an increase in meanSD systolic BP as compared with the sham group (157.7 +/- 29.3 vs. 106.2 +/- 20.5mmHg, respectively; P<0.001). Telmisartan alone and in combination with linagliptin, normalized SBP (111.1 +/- 24.3mmHg and 100.4 +/- 13.9mmHg, respectively; P<0.001 vs. placebo). Telmisartan alone and in combination with linagliptin significantly prevented cardiac hypertrophy, measured by heart weight and myocyte diameter. Renal function measured by cystatin C was not affected by 2k1c surgery. Telmisartan significantly increased plasma concentration of cystatin C. 2k1c surgery initiated fibrosis in both kidneys. Telmisartan promoted further fibrotic changes in the clipped kidney, as measured by protein expression of Col1a1 and histology for interstitial fibrosis and glomerulosclerosis. In non-clipped kidneys, telmisartan demonstrated antifibrotic properties, reducing Col1a1 protein expression. Plasma levels of oxidized low-density lipoprotein were higher in the placebo-treated 2k1c rats as compared to sham-operated animals. The increase was abolished by linagliptin alone (P=0.03 vs. placebo) and in combination with telmisartan (P=0.02 vs. placebo). Combination therapy also significantly reduced plasma concentration of carbonyl proteins (P=0.04 vs. placebo).Conclusion:Inhibition of type 4 dipeptidyl peptidase with linagliptin did not counter BP-lowering effects of ARB in 2k1c rats. Linagliptin reduced lipid and protein oxidation in 2k1c rats, and this effect was BP-independent. KW - 2k1c renovascular hypertension KW - blood pressure KW - DPP4 inhibition KW - linagliptin KW - oxidative stress Y1 - 2013 U6 - https://doi.org/10.1097/HJH.0b013e3283649b4d SN - 0263-6352 SN - 1473-5598 VL - 31 IS - 11 SP - 2290 EP - 2299 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Hocher, Berthold A1 - Reichetzeder, Christoph A1 - Alter, Markus L. T1 - Renal and cardiac effects of DPP-4 inhibitors - from preclinical development to clinical research JF - Kidney & blood pressure research : official organ of the Gesellschaft für Nephrologie N2 - Inhibitors of type 4 dipeptidyl peptidase (DDP-4) were developed and approved for the oral treatment of type 2 diabetes. Its mode of action is to inhibit the degradation of incretins, such as type 1 glucagon like peptide (GLP-1), and GIP. GLP-1 stimulates glucose-dependent insulin secretion from pancreatic beta-cells and suppresses glucagon release from alpha-cells, thereby improving glucose control. Besides its action on the pancreas type 1 glucagon like peptide has direct effects on the heart, vessels and kidney mainly via the type 1 glucagon like peptide receptor (GLP-1R). Moreover, there are substrates of DPP-4 beyond incretins that have proven renal and cardiovascular effects such as BNP/ANP, NPY, PYY or SDF-1 alpha. Preclinical evidence suggests that DPP-4 inhibitors may be effective in acute and chronic renal failure as well as in cardiac diseases like myocardial infarction and heart failure. Interestingly, large cardiovascular meta-analyses of combined Phase II/III clinical trials with DPP-4 inhibitors point all in the same direction: a potential reduction of cardiovascular events in patients treated with these agents. A pooled analysis of pivotal Phase III, placebo-controlled, registration studies of linagliptin further showed a significant reduction of urinary albumin excretion after 24 weeks of treatment. The observation suggests direct renoprotective effects of DPP-4 inhibition that may go beyond its glucose-lowering potential. Type 4 dipeptidyl peptidase inhibitors have been shown to be very well tolerated in general, but for those excreted via the kidney dose adjustments according to renal function are needed to avoid side effects. In conclusion, the direct cardiac and renal effects seen in preclinical studies as well as meta-analysis of clinical trials may offer additional potentials - beyond improvement of glycemic control - for this newer class of drugs, such as acute kidney failure, chronic kidney failure as well as acute myocardial infarction and heart failure. KW - DDP-4 inhibition KW - Diabetes KW - GLP-1 KW - Cardiovascular effects KW - Myocardial infarction KW - Kidney KW - Diabetic nephropathy KW - Acute renal failure Y1 - 2012 U6 - https://doi.org/10.1159/000339028 SN - 1420-4096 VL - 36 IS - 1 SP - 65 EP - 84 PB - Karger CY - Basel ER - TY - CHAP A1 - Hocher, Berthold A1 - Tsuprykov, Oleg A1 - Alter, Markus L. A1 - von Websky, Karoline A1 - Chaykovska, Lyubov A1 - Antonenko, V. A1 - Rahnenführer, Jan A1 - Klein, T. A1 - Reichetzeder, Christoph T1 - Linagliptin and the angiotensin II receptor blocker telmisartan show comparable efficacy but different renoprotective pathways in rats with 5/6 nephrectomy T2 - Diabetologia : journal of the European Association for the Study of Diabetes (EASD) Y1 - 2013 SN - 0012-186X SN - 1432-0428 VL - 56 IS - 15-16 SP - S66 EP - S66 PB - Springer CY - New York ER - TY - CHAP A1 - Sharkovska, Y. A1 - Alter, Markus L. A1 - Reichetzeder, Christoph A1 - Tsuprykov, Oleg A1 - Klein, T. A1 - Hocher, Berthold T1 - DPP-4 inhibition with linagliptin delays the progression of diabetic nephropathy in db/db mice T2 - Diabetologia : journal of the European Association for the Study of Diabetes (EASD) Y1 - 2012 SN - 0012-186X SN - 1432-0428 VL - 55 IS - 5 SP - S20 EP - S20 PB - Springer CY - New York ER - TY - JOUR A1 - Sharkovska, Yuliya A1 - Reichetzeder, Christoph A1 - Alter, Markus L. A1 - Tsuprykov, Oleg A1 - Bachmann, Sebastian A1 - Secher, Thomas A1 - Klein, Thomas A1 - Hocher, Berthold T1 - Blood pressure and glucose independent renoprotective effects of dipeptidyl peptidase-4 inhibition in a mouse model of type-2 diabetic nephropathy JF - Journal of hypertension N2 - Background: Despite the beneficial effects of type 4 dipeptidyl peptidase (DPP-4) inhibitors on glucose levels, its effects on diabetic nephropathy remain unclear. Method: This study examined the long-term renoprotective effects of DPP-4 inhibitor linagliptin in db/db mice, a model of type 2 diabetes. Results were compared with the known beneficial effects of renin-angiotensin system blockade by enalapril. Ten-week-old male diabetic db/db mice were treated for 3 months with either vehicle (n = 10), 3 mg linagliptin/kg per day (n = 8), or 20 mg enalapril/kg per day (n = 10). Heterozygous db/m mice treated with vehicle served as healthy controls (n = 8). Results: Neither linagliptin nor enalapril had significant effects on the parameters of glucose metabolism or blood pressure in diabetic db/db mice. However, linagliptin treatment reduced albuminuria and attenuated kidney injury. In addition, expression of podocyte marker podocalyxin was normalized. We also analysed DPP-4 expression by immunofluorescence in human kidney biopsies and detected upregulation of DPP-4 in the glomeruli of patients with diabetic nephropathy, suggesting that our findings might be of relevance for human kidney disease as well. Conclusion: Treatment with DPP-4 inhibitor linagliptin delays the progression of diabetic nephropathy damage in a glucose-independent and blood-pressure-independent manner. The observed effects may be because of the attenuation of podocyte injury and inhibition of myofibroblast transformation. KW - diabetic nephropathy KW - DPP-4 inhibitors KW - linagliptin Y1 - 2014 U6 - https://doi.org/10.1097/HJH.0000000000000328 SN - 0263-6352 SN - 1473-5598 VL - 32 IS - 11 SP - 2211 EP - 2223 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Tsuprykov, Oleg A1 - Ando, Ryotaro A1 - Reichetzeder, Christoph A1 - von Websky, Karoline A1 - Antonenko, Viktoriia A1 - Sharkovska, Yuliya A1 - Chaykovska, Lyubov A1 - Rahnenfuehrer, Jan A1 - Hasan, Ahmed Abdallah Abdalrahman Mohamed A1 - Tammen, Harald A1 - Alter, Markus L. A1 - Klein, Thomas A1 - Ueda, Seiji A1 - Yamagishi, Sho-ichi A1 - Okuda, Seiya A1 - Hocher, Berthold T1 - The dipeptidyl peptidase inhibitor linagliptin and the angiotensin II receptor blocker telmisartan show renal benefit by different pathways in rats with 5/6 nephrectomy JF - Kidney international : official journal of the International Society of Nephrology N2 - Dipeptidyl peptidase (DPP)-4 inhibitors delay chronic kidney disease (CKD) progression in experimental diabetic nephropathy in a glucose-independent manner. Here we compared the effects of the DPP-4 inhibitor linagliptin versus telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. Animals were allocated to 1 of 4 groups: sham operated plus placebo; 5/6 nephrectomy plus placebo; 5/6 nephrectomy plus linagliptin; and 5/6 nephrectomy plus telmisartan. Interstitial fibrosis was significantly decreased by 48% with linagliptin but a non-significant 24% with telmisartan versus placebo. The urine albumin-to-creatinine ratio was significantly decreased by 66% with linagliptin and 92% with telmisartan versus placebo. Blood pressure was significantly lowered by telmisartan, but it was not affected by linagliptin. As shown by mass spectrometry, the number of altered peptide signals for linagliptin in plasma was 552 and 320 in the kidney. For telmisartan, there were 108 peptide changes in plasma and 363 in the kidney versus placebo. Linagliptin up-regulated peptides derived from collagen type I, apolipoprotein C1, and heterogeneous nuclear ribonucleoproteins A2/B1, a potential downstream target of atrial natriuretic peptide, whereas telmisartan up-regulated angiotensin II. A second study was conducted to confirm these findings in 5/6 nephrectomy wild-type and genetically deficient DPP-4 rats treated with linagliptin or placebo. Linagliptin therapy in wild-type rats was as effective as DPP-4 genetic deficiency in terms of albuminuria reduction. Thus, linagliptin showed comparable efficacy to telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. However, the underlying pathways seem to be different. Copyright (C) 2016, International Society of Nephrology. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). KW - albuminuria KW - angiotensin receptor blockers KW - chronic kidney disease KW - DPP-4 inhibition KW - proteinuria KW - proteomic analysis Y1 - 2016 U6 - https://doi.org/10.1016/j.kint.2016.01.016 SN - 0085-2538 SN - 1523-1755 VL - 89 SP - 1049 EP - 1061 PB - Nature Publ. Group CY - New York ER -