@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{RailaSchweigertKohn2014, author = {Raila, Jens and Schweigert, Florian J. and Kohn, Barbara}, title = {Relationship between urinary Tamm-Horsfall protein excretion and renal function in dogs with naturally occurring renal disease}, series = {Veterinary clinical pathology}, volume = {43}, journal = {Veterinary clinical pathology}, number = {2}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0275-6382}, doi = {10.1111/vcp.12143}, pages = {261 -- 265}, year = {2014}, abstract = {Background Tamm-Horsfall protein (THP) is physiologically excreted in urine, but little is known about the role of THP in the diagnosis of renal disease in dogs. Objective The aim of this study was to evaluate to which extent naturally occurring renal disease affects the urinary excretion of THP. Methods Dogs were divided into 5 groups according to plasma creatinine concentration, urinary protein-to-creatinine ratio (UP/UC), and exogenous plasma creatinine clearance (P-ClCr) rates: Group A (healthy control dogs; n=8), nonazotemic and nonproteinuric dogs, with P-ClCr rates > 90mL/min/m2; group B (n=25), nonazotemic and nonproteinuric dogs with reduced P-ClCr rates (51-89mL/min/m2); group C (n=7), nonazotemic but proteinuric dogs with P-ClCr rates 53-98mL/min/m2; group D (n=8), azotemic and borderline proteinuric dogs (P-ClCr rates: 22-45mL/min/m2); and group E (n=15), azotemic and proteinuric dogs (not tested for P-ClCr). THP was measured by quantitative Western blot analysis, and the ratio of THP-to-urinary creatinine (THP/UC) was calculated. Results The THP/UC concentrations were not different among dogs of groups A-D, but were reduced in dogs of group E (P<.001). THP/UC correlated negatively with serum creatinine (P<.01) and UP/UC (P<.01), but was not significantly associated with P-ClCr. Conclusions Decreased levels of THP/UC were present in moderately to severely azotemic and proteinuric dogs. This suggests tubular injury in these dogs and that THP might be useful as urinary marker to study the pathogenesis of renal disease.}, language = {en} } @article{NairHocherVerkaartetal.2012, author = {Nair, Anil V. and Hocher, Berthold and Verkaart, Sjoerd and van Zeeland, Femke and Pfab, Thiemo and Slowinski, Torsten and Chen, You-Peng and Schlingmann, Karl Peter and Schaller, Andre and Gallati, Sabina and Bindels, Rene J. and Konrad, Martin and H{\"o}nderop, Joost G.}, title = {Loss of insulin-induced activation of TRPM6 magnesium channels results in impaired glucose tolerance during pregnancy}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {28}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1113811109}, pages = {11324 -- 11329}, year = {2012}, abstract = {Hypomagnesemia affects insulin resistance and is a risk factor for diabetes mellitus type 2 (DM2) and gestational diabetes mellitus (GDM). Two single nucleotide polymorphisms (SNPs) in the epithelial magnesium channel TRPM6 ((VI)-I-1393, (KE)-E-1584) were predicted to confer susceptibility for DM2. Here, we show using patch clamp analysis and total internal reflection fluorescence microscopy, that insulin stimulates TRPM6 activity via a phosphoinositide 3-kinase and Rac1-mediated elevation of cell surface expression of TRPM6. Interestingly, insulin failed to activate the genetic variants TRPM6 ((VI)-I-1393) and TRPM6((KE)-E-1584), which is likely due to the inability of the insulin signaling pathway to phosphorylate TRPM6(T-1391) and TRPM6(S-1583). Moreover, by measuring total glycosylated hemoglobin (TGH) in 997 pregnant women as a measure of glucose control, we demonstrate that TRPM6((VI)-I-1393) and TRPM6((KE)-E-1584) are associated with higher TGH and confer a higher likelihood of developing GDM. The impaired response of TRPM6((VI)-I-1393) and TRPM6((KE)-E-1584) to insulin represents a unique molecular pathway leading to GDM where the defect is located in TRPM6.}, language = {en} }