@misc{HasanHocher2017,
  author    = {Hasan, Ahmed Abdallah Abdalrahman Mohamed and Hocher, Berthold},
  title     = {Role of soluble and membrane-bound dipeptidyl peptidase-4 in diabetic nephropathy},
  series = {Journal of Molecular Endocrinology},
  volume    = {59},
  journal   = {Journal of Molecular Endocrinology},
  publisher = {Bioscientifica LTD},
  address   = {Bristol},
  issn      = {0952-5041},
  doi       = {10.1530/JME-17-0005},
  pages     = {R1 -- R10},
  year      = {2017},
  abstract  = {Diabetic nephropathy is one of the most frequent, devastating and costly complications of diabetes. The available therapeutic approaches are limited. Dipeptidyl peptidase type 4 (DPP-4) inhibitors represent a new class of glucose-lowering drugs that might also have reno-protective properties. DPP-4 exists in two forms: a plasma membranebound form and a soluble form, and can exert many biological actions mainly through its peptidase activity and interaction with extracellular matrix components. The kidneys have the highest DPP-4 expression level in mammalians. DPP-4 expression and urinary activity are up-regulated in diabetic nephropathy, highlighting its role as a potential target to manage diabetic nephropathy. Preclinical animal studies and some clinical data suggest that DPP-4 inhibitors decrease the progression of diabetic nephropathy in a blood pressure-and glucose-independent manner. Many studies reported that these reno-protective effects could be due to increased half-life of DPP-4 substrates such as glucagon-like peptide-1 (GLP-1) and stromal derived factor-1 alpha (SDF-1a). However, the underlying mechanisms are far from being completely understood and clearly need further investigations.},
  language  = {en}
}
@article{GroopCooperPerkovicetal.2017,
  author    = {Groop, Per-Henrik and Cooper, Mark E. and Perkovic, Vlado and Hocher, Berthold and Kanasaki, Keizo and Haneda, Masakazu and Schernthaner, Guntram and Sharma, Kumar and Stanton, Robert C. and Toto, Robert and Cescutti, Jessica and Gordat, Maud and Meinicke, Thomas and Koitka-Weber, Audrey and Thiemann, Sandra and von Eynatten, Maximilian},
  title     = {Linagliptin and its effects on hyperglycaemia and albuminuria in patients with type 2 diabetes and renal dysfunction},
  series = {Diabetes obesity \& metabolism : a journal of pharmacology and therapeutics},
  volume    = {19},
  journal   = {Diabetes obesity \& metabolism : a journal of pharmacology and therapeutics},
  number    = {11},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1462-8902},
  doi       = {10.1111/dom.13041},
  pages     = {1610 -- 1619},
  year      = {2017},
  abstract  = {Aims: The MARLINA-T2D study (ClinicalTrials. gov, NCT01792518) was designed to investigate the glycaemic and renal effects of linagliptin added to standard-of-care in individuals with type 2 diabetes and albuminuria. Methods: A total of 360 individuals with type 2 diabetes, HbA1c 6.5\% to 10.0\% (48-86 mmol/ mol), estimated glomerular filtration rate (eGFR) >= 30 mL/min/1.73 m(2) and urinary albumin-tocreatinine ratio (UACR) 30-3000 mg/g despite single agent renin-angiotensin-system blockade were randomized to double-blind linagliptin (n = 182) or placebo (n = 178) for 24 weeks. The primary and key secondary endpoints were change from baseline in HbA1c at week 24 and time-weighted average of percentage change from baseline in UACR over 24 weeks, respectively. Results: Baseline mean HbA1c and geometric mean (gMean) UACR were 7.8\% +/- 0.9\% (62.2 +/- 9.6 mmol/mol) and 126 mg/g, respectively; 73.7\% and 20.3\% of participants had microalbuminuria or macroalbuminuria, respectively. After 24 weeks, the placebo-adjusted mean change in HbA1c from baseline was -0.60\% (-6.6 mmol/mol) (95\% confidence interval [CI], -0.78 to -0.43 [-8.5 to -4.7 mmol/mol]; P <.0001). The placebo-adjusted gMean for time-weighted average of percentage change in UACR from baseline was -6.0\% (95\% CI, -15.0 to 3.0; P =.1954). The adverse-event profile, including renal safety and change in eGFR, was similar between the linagliptin and placebo groups. Conclusions: In individuals at early stages of diabetic kidney disease, linagliptin significantly improved glycaemic control but did not significantly lower albuminuria. There was no significant change in placebo-adjusted eGFR. Detection of clinically relevant renal effects of linagliptin may require longer treatment, as its main experimental effects in animal studies have been to reduce interstitial fibrosis rather than alter glomerular haemodynamics.},
  language  = {en}
}
@misc{vonWebskyReichetzederHocher2014,
  author    = {von Websky, Karoline and Reichetzeder, Christoph and Hocher, Berthold},
  title     = {Physiology and pathophysiology of incretins in the kidney},
  series = {Current opinion in nephrology and hypertension : reviews of all advances, evaluations of key references, comprehensive listing of papers},
  volume    = {23},
  journal   = {Current opinion in nephrology and hypertension : reviews of all advances, evaluations of key references, comprehensive listing of papers},
  number    = {1},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {1062-4821},
  doi       = {10.1097/01.mnh.0000437542.77175.a0},
  pages     = {54 -- 60},
  year      = {2014},
  abstract  = {Purpose of reviewIncretin-based therapy with glucagon-like peptide-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors is considered a promising therapeutic option for type 2 diabetes mellitus. Cumulative evidence, mainly from preclinical animal studies, reveals that incretin-based therapies also may elicit beneficial effects on kidney function. This review gives an overview of the physiology, pathophysiology, and pharmacology of the renal incretin system.Recent findingsActivation of GLP-1R in the kidney leads to diuretic and natriuretic effects, possibly through direct actions on renal tubular cells and sodium transporters. Moreover, there is evidence that incretin-based therapy reduces albuminuria, glomerulosclerosis, oxidative stress, and fibrosis in the kidney, partially through GLP-1R-independent pathways. Molecular mechanisms by which incretins exert their renal effects are understood incompletely, thus further studies are needed.SummaryThe GLP-1R and DPP-4 are expressed in the kidney in various species. The kidney plays an important role in the excretion of incretin metabolites and most GLP-1R agonists and DPP-4 inhibitors, thus special attention is required when applying incretin-based therapy in renal impairment. Preclinical observations suggest direct renoprotective effects of incretin-based therapies in the setting of hypertension and other disorders of sodium retention, as well as in diabetic and nondiabetic nephropathy. Clinical studies are needed in order to confirm translational relevance from preclinical findings for treatment options of renal diseases.},
  language  = {en}
}
@article{SharkovskaReichetzederAlteretal.2014,
  author    = {Sharkovska, Yuliya and Reichetzeder, Christoph and Alter, Markus L. and Tsuprykov, Oleg and Bachmann, Sebastian and Secher, Thomas and Klein, Thomas and Hocher, Berthold},
  title     = {Blood pressure and glucose independent renoprotective effects of dipeptidyl peptidase-4 inhibition in a mouse model of type-2 diabetic nephropathy},
  series = {Journal of hypertension},
  volume    = {32},
  journal   = {Journal of hypertension},
  number    = {11},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {0263-6352},
  doi       = {10.1097/HJH.0000000000000328},
  pages     = {2211 -- 2223},
  year      = {2014},
  abstract  = {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.},
  language  = {en}
}
@article{AlterKretschmerVonWebskyetal.2012,
  author    = {Alter, Markus L. and Kretschmer, Axel and Von Websky, Karoline and Tsuprykov, Oleg and Reichetzeder, Christoph and Simon, Alexandra and Stasch, Johannes-Peter and Hocher, Berthold},
  title     = {Early urinary and plasma biomarkers for experimental diabetic Nephropathy},
  series = {Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion},
  volume    = {58},
  journal   = {Clinical laboratory : the peer reviewed journal for clinical laboratories and laboratories related to blood transfusion},
  number    = {7-8},
  publisher = {Clin Lab Publ., Verl. Klinisches Labor},
  address   = {Heidelberg},
  issn      = {1433-6510},
  doi       = {10.7754/Clin.Lab.2011.111010},
  pages     = {659 -- 671},
  year      = {2012},
  abstract  = {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.},
  language  = {en}
}