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 - Alter, Markus L. A1 - Ott, Ina M. A1 - von Websky, Karoline A1 - Tsuprykov, Oleg A1 - Sharkovska, Yuliya A1 - Krause-Relle, Katharina A1 - Raila, Jens A1 - Henze, Andrea A1 - Klein, Thomas A1 - Hocher, Berthold T1 - DPP-4 Inhibition on top of angiotensin receptor blockade offers a new therapeutic approach for diabetic nephropathy JF - Kidney & blood pressure research : official organ of the Gesellschaft für Nephrologie N2 - Background: The need for an improved treatment for diabetic nephropathy is greatest in patients who do not adequately respond to angiotensin II receptor blockers (ARBs). This study investigated the effect of the novel dipeptidyl peptidase-4 inhibitor linagliptin alone and in combination with the ARB telmisartan on the progression of diabetic nephropathy in diabetic endothelial nitric oxide synthase (eNOS) knockout mice. Methods: Sixty male eNOS knockout C57BL/6J mice were divided into four groups after receiving intraperitoneal high-dose streptozotocin: telmisartan (1 mg/kg), linagliptin (3 mg/kg), linagliptin + telmisartan (3 mg/kg + 1 mg/kg) and vehicle. Fourteen mice were used as non-diabetic controls. Results: After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan alone reduced systolic blood pressure by 5.9 mmHg versus diabetic controls (111.2 +/- 2.3 mmHg vs 117.1 +/- 2.2 mmHg; mean +/- SEM; P = 0.071). Combined treatment significantly reduced albuminuria compared with diabetic controls (71.7 +/- 15.3 mu g/24 h vs 170.8 +/- 34.2 mu g/24 h; P = 0.017), whereas the effects of single treatment with either telmisartan (97.8 +/- 26.4 mu g/24 h) or linagliptin (120.8 +/- 37.7 mu g/24 h) were not statistically significant. DPP-4 inhibition, alone and in combination, led to significantly lower plasma osteopontin levels compared with telmisartan alone. Histological analysis revealed reduced glomerulosclerosis after Linagliptin alone and in combination with telmisartan in comparison to non treated diabetic animals (p < 0.01 and p < 0.05). Kidney malonaldehyde immune-reactivity, a marker of oxidative stress, was significantly lower in animals treated with linagliptin. Conclusions: DPP-4 inhibition on top of ARB treatment significantly reduced urinary albumin excretion and oxidative stress in diabetic eNOS knockout mice. Linagliptin on top of an angiotensin II receptor blocker may offer a new therapeutic approach for patients with diabetic nephropathy. KW - Diabetic nephropathy KW - DPP-4 inhibitor KW - Linagliptin KW - Renin-angiotensin system Y1 - 2012 U6 - https://doi.org/10.1159/000341487 SN - 1420-4096 VL - 36 IS - 1 SP - 119 EP - 130 PB - Karger CY - Basel 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 - JOUR A1 - Ott, Ina M. A1 - Alter, Markus L. A1 - von Websky, Karoline A1 - Kretschmer, Axel A1 - Tsuprykov, Oleg A1 - Sharkovska, Yuliya A1 - Krause-Relle, Katharina A1 - Raila, Jens A1 - Henze, Andrea A1 - Stasch, Johannes-Peter A1 - Hocher, Berthold T1 - Effects of Stimulation of Soluble Guanylate Cyclase on Diabetic Nephropathy in Diabetic eNOS Knockout Mice on Top of Angiotensin II Receptor Blockade JF - PLOS ONE N2 - The prevalence of diabetes mellitus and its complications, such as diabetic nephropathy (DN), is rising worldwide and prevention and treatment are therefore becoming increasingly important. Therapy of DN is particularly important for patients who do not adequately respond to angiotensin receptor blocker (ARB) treatment. Novel approaches include the stimulation of soluble guanylate cyclase (sGC) as it is reported to have beneficial effects on cardiac and renal damage. We aimed to investigate the effects of the sGC stimulator riociguat and ARB telmisartan on kidney function and structure in a hypertensive model of diabetic nephropathy. Seventy-six diabetic male eNOS knockout C57BL/6J mice were randomly divided after having received streptozotocin: telmisartan (1 mg/kg/d), riociguat (3 mg/kg/d), riociguat+telmisartan (3+1 mg/kg/d), and vehicle. Fourteen mice were used as non-diabetic controls. Treatment duration was 11 weeks. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan insignificantly reduced blood pressure by 5.9 mmHg compared with diabetic controls (111.2 +/- 2.3 mmHg vs. 117.1 +/- 2.2 mmHg; p = 0.071). Treatment with riociguat both alone and in combination with telmisartan led to a significant reduction of blood pressure towards diabetic vehicle (105.2 +/- 2.5 mmHg and 105.0 +/- 3.2 mmHg, respectively, vs. 117.1 +/- 2.2 mmHg). Combined treatment also significantly decreased albuminuria compared with diabetic controls (47.3 +/- 9.6 mu g/24 h vs. 170.8 +/- 34.2 mu g/24 h; p = 0.002) reaching levels similar to those of non-diabetic controls (34.4 +/- 10.6 mu g/24 h), whereas the reduction by single treatment with either telmisartan (97.8 +/- 26.4 mu g/24 h) or riociguat (97.1 +/- 15.7 mu g/24 h) was not statistically significant. The combination treatment led to a significant (p < 0.01) decrease of tissue immunoreactivity of malondialdehyde, as consequence of reduced oxidative stress. In conclusion, stimulation of sGC significantly reduced urinary albumin excretion in diabetic eNOS knockout mice treated already with ARB. Thus, this new drug class on top of standard ARBs administration may offer a new therapeutic approach for patients resistant to ARB treatment. Y1 - 2012 U6 - https://doi.org/10.1371/journal.pone.0042623 SN - 1932-6203 VL - 7 IS - 8 PB - PUBLIC LIBRARY SCIENCE CY - SAN FRANCISCO 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 -