@article{HasanvonWebskyReichetzederetal.2019, author = {Hasan, Ahmed Abdallah Abdalrahman Mohamed and von Websky, Karoline and Reichetzeder, Christoph and Tsuprykov, Oleg and Gaballa, Mohamed Mahmoud Salem Ahmed and Guo, Jingli and Zeng, Shufei and Delic, Denis and Tammen, Harald and Klein, Thomas and Kleuser, Burkhard and Hocher, Berthold}, title = {Mechanisms of GLP-1 receptor-independent renoprotective effects of the dipeptidyl peptidase type 4 inhibitor linagliptin in GLP-1 receptor knockout mice with 5/6 nephrectomy}, series = {Kidney international : official journal of the International Society of Nephrology}, volume = {95}, journal = {Kidney international : official journal of the International Society of Nephrology}, number = {6}, publisher = {Elsevier}, address = {New York}, issn = {0085-2538}, doi = {10.1016/j.kint.2019.01.010}, pages = {1373 -- 1388}, year = {2019}, abstract = {Dipeptidyl peptidase type 4 (DPP-4) inhibitors were reported to have beneficial effects in experimental models of chronic kidney disease. The underlying mechanisms are not completely understood. However, these effects could be mediated via the glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP1R) pathway. Here we investigated the renal effects of the DPP-4 inhibitor linagliptin in Glp1r-/- knock out and wild-type mice with 5/6 nephrectomy (5/6Nx). Mice were allocated to groups: sham + wild type + placebo; 5/6Nx+ wild type + placebo; 5/6Nx+ wild type + linagliptin; sham + knock out+ placebo; 5/6Nx + knock out+ placebo; 5/6Nx + knock out+ linagliptin. 5/6Nx caused the development of renal interstitial fibrosis, significantly increased plasma cystatin C and creatinine levels and suppressed renal gelatinase/collagenase, matrix metalloproteinase-1 and -13 activities; effects counteracted by linagliptin treatment in wildtype and Glp1r-/- mice. Two hundred ninety-eight proteomics signals were differentially regulated in kidneys among the groups, with 150 signals specific to linagliptin treatment as shown by mass spectrometry. Treatment significantly upregulated three peptides derived from collagen alpha-1(I), thymosin beta 4 and heterogeneous nuclear ribonucleoprotein Al (HNRNPA1) and significantly downregulated one peptide derived from Y box binding protein-1 (YB-1). The proteomics results were further confirmed using western blot and immunofluorescence microscopy. Also, 5/6Nx led to significant up-regulation of renal transforming growth factor-beta 1 and pSMAD3 expression in wild type mice and linagliptin significantly counteracted this up-regulation in wild type and GIplr-/- mice. Thus, the renoprotective effects of linagliptin cannot solely be attributed to the GLP-1/GLP1R pathway, highlighting the importance of other signaling pathways (collagen I homeostasis, HNRNPA1,YB-1,thymosin beta 4 and TGF-beta 1) influenced by DPP-4 inhibition.}, language = {en} } @article{PrommerMaurervonWebskyetal.2018, author = {Prommer, Hans-Ulrich and Maurer, Johannes and von Websky, Karoline and Freise, Christian and Sommer, Kerstin and Nasser, Hamoud and Samapati, Rudi and Reglin, Bettina and Guimaraes, Pedro and Pries, Axel Radlach and Querfeld, Uwe}, title = {Chronic kidney disease induces a systemic microangiopathy, tissue hypoxia and dysfunctional angiogenesis}, series = {Scientific reports}, volume = {8}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-018-23663-1}, pages = {14}, year = {2018}, abstract = {Chronic kidney disease (CKD) is associated with excessive mortality from cardiovascular disease (CVD). Endothelial dysfunction, an early manifestation of CVD, is consistently observed in CKD patients and might be linked to structural defects of the microcirculation including microvascular rarefaction. However, patterns of microvascular rarefaction in CKD and their relation to functional deficits in perfusion and oxygen delivery are currently unknown. In this in-vivo microscopy study of the cremaster muscle microcirculation in BALB/c mice with moderate to severe uremia, we show in two experimental models (adenine feeding or subtotal nephrectomy), that serum urea levels associate incrementally with a distinct microangiopathy. Structural changes were characterized by a heterogeneous pattern of focal microvascular rarefaction with loss of coherent microvascular networks resulting in large avascular areas. Corresponding microvascular dysfunction was evident by significantly diminished blood flow velocity, vascular tone, and oxygen uptake. Microvascular rarefaction in the cremaster muscle paralleled rarefaction in the myocardium, which was accompanied by a decrease in transcription levels not only of the transcriptional regulator HIF-1 alpha, but also of its target genes Angpt-2, TIE-1 and TIE-2, Flkt-1 and MMP-9, indicating an impaired hypoxia-driven angiogenesis. Thus, experimental uremia in mice associates with systemic microvascular disease with rarefaction, tissue hypoxia and dysfunctional angiogenesis.}, language = {en} } @article{vonWebskyHasanReichetzederetal.2018, author = {von Websky, Karoline and Hasan, Ahmed Abdallah Abdalrahman Mohamed and Reichetzeder, Christoph and Tsuprykov, Oleg and Hocher, Berthold}, title = {Impact of vitamin D on pregnancy-related disorders and on offspring outcome}, series = {The Journal of Steroid Biochemistry and Molecular Biology}, volume = {180}, journal = {The Journal of Steroid Biochemistry and Molecular Biology}, publisher = {Elsevier}, address = {Oxford}, issn = {0960-0760}, doi = {10.1016/j.jsbmb.2017.11.008}, pages = {51 -- 64}, year = {2018}, abstract = {Observational studies from all over the world continue to find high prevalence rates of vitamin D insufficiency and deficiency in many populations, including pregnant women. Beyond its classical function as a regulator of calcium and phosphate metabolism, vitamin D elicits numerous effects in the human body. Current evidence highlights a vital role of vitamin D in mammalian gestation. During pregnancy, adaptations in maternal vitamin D metabolism lead to a physiologic increase of vitamin D levels, mainly because of an increased renal production, although other potential sources like the placenta are being discussed. A sufficient supply of mother and child with calcium and vitamin D during pregnancy ensures a healthy bone development of the fetus, whereas lack of either of these nutrients can lead to the development of rickets in the child. Moreover, vitamin D insufficiency during pregnancy has consistently been associated with adverse maternal and neonatal pregnancy outcomes. In multitudinous studies, low maternal vitamin D status was associated with a higher risk for pre-eclampsia, gestational diabetes mellitus and other gestational diseases. Likewise, several negative consequences for the fetus have been reported, including fetal growth restriction, increased risk of preterm birth and a changed susceptibility for later-life diseases. However, study results are diverging and causality has not been proven so far. Meta-analyses on the relationship between maternal vitamin D status and pregnancy outcomes revealed a wide heterogeneity of studied populations and the applied methodology in vitamin D assessment. Until today, clinical guidelines for supplementation cannot be based on high-quality evidence and it is not clear if the required intake for pregnant women differs from non-pregnant women. Long-term safety data of vitamin D supplementation in pregnant women has not been established and overdosing of vitamin D might have unfavorable effects, especially in mothers and newborns with mutations of genes involved in vitamin D metabolism. Reliable data from large observational and interventional randomized control trials are urgently needed as a basis for any detailed and safe recommendations for supplementation in the general population and, most importantly, in pregnant women. This is of utmost importance, as ensuring a sufficient vitamin D-supply of mother and child implies a great potential for the prevention of birth complications and development of diseases.}, language = {en} } @article{LuReichetzederPrehnetal.2018, author = {Lu, Yong-Ping and Reichetzeder, Christoph and Prehn, Cornelia and von Websky, Karoline and Slowinski, Torsten and Chen, You-Peng and Yin, Liang-Hong and Kleuser, Burkhard and Yang, Xue-Song and Adamski, Jerzy and Hocher, Berthold}, title = {Fetal serum metabolites are independently associated with Gestational diabetes mellitus}, series = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology}, volume = {45}, journal = {Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry and pharmacology}, number = {2}, publisher = {Karger}, address = {Basel}, issn = {1015-8987}, doi = {10.1159/000487119}, pages = {625 -- 638}, year = {2018}, abstract = {Background/Aims: Gestational diabetes (GDM) might be associated with alterations in the metabolomic profile of affected mothers and their offspring. Until now, there is a paucity of studies that investigated both, the maternal and the fetal serum metabolome in the setting of GDM. Mounting evidence suggests that the fetus is not just passively affected by gestational disease but might play an active role in it. Metabolomic studies performed in maternal blood and fetal cord blood could help to better discern distinct fetal from maternal disease interactions. Methods: At the time of birth, serum samples from mothers and newborns (cord blood samples) were collected and screened for 163 metabolites utilizing tandem mass spectrometry. The cohort consisted of 412 mother/child pairs, including 31 cases of maternal GDM. Results: An initial non-adjusted analysis showed that eight metabolites in the maternal blood and 54 metabolites in the cord blood were associated with GDM. After Benjamini-Hochberg (BH) procedure and adjustment for confounding factors for GDM, fetal phosphatidylcholine acyl-alkyl C 32:1 and proline still showed an independent association with GDM. Conclusions: This study found metabolites in cord blood which were associated with GDM, even after adjustment for established risk factors of GDM. To the best of our knowledge, this is the first study demonstrating an independent association between fetal serum metabolites and maternal GDM. Our findings might suggest a potential effect of the fetal metabolome on maternal GDM. (c) 2018 The Author(s) Published by S. Karger AG, Basel}, language = {en} } @misc{LuReichetzederPrehnetal.2018, author = {Lu, Yong-Ping and Reichetzeder, Christoph and Prehn, Cornelia and von Websky, Karoline and Slowinski, Torsten and Chen, You-Peng and Yin, Liang-Hong and Kleuser, Burkhard and Yang, Xue-Song and Adamski, Jerzy and Hocher, Berthold}, title = {Fetal serum metabolites are independently associated with Gestational diabetes mellitus}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {637}, issn = {1866-8372}, doi = {10.25932/publishup-42458}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424585}, pages = {14}, year = {2018}, abstract = {Background/Aims: Gestational diabetes (GDM) might be associated with alterations in the metabolomic profile of affected mothers and their offspring. Until now, there is a paucity of studies that investigated both, the maternal and the fetal serum metabolome in the setting of GDM. Mounting evidence suggests that the fetus is not just passively affected by gestational disease but might play an active role in it. Metabolomic studies performed in maternal blood and fetal cord blood could help to better discern distinct fetal from maternal disease interactions. Methods: At the time of birth, serum samples from mothers and newborns (cord blood samples) were collected and screened for 163 metabolites utilizing tandem mass spectrometry. The cohort consisted of 412 mother/child pairs, including 31 cases of maternal GDM. Results: An initial non-adjusted analysis showed that eight metabolites in the maternal blood and 54 metabolites in the cord blood were associated with GDM. After Benjamini-Hochberg (BH) procedure and adjustment for confounding factors for GDM, fetal phosphatidylcholine acyl-alkyl C 32:1 and proline still showed an independent association with GDM. Conclusions: This study found metabolites in cord blood which were associated with GDM, even after adjustment for established risk factors of GDM. To the best of our knowledge, this is the first study demonstrating an independent association between fetal serum metabolites and maternal GDM. Our findings might suggest a potential effect of the fetal metabolome on maternal GDM. (c) 2018 The Author(s) Published by S. Karger AG, Basel}, language = {en} } @article{ReichetzedervonWebskyTsuprykovetal.2017, author = {Reichetzeder, Christoph and von Websky, Karoline and Tsuprykov, Oleg and Samarin, Azadeh Mohagheghi and Falke, Luise Gabriele and Putra, Sulistyo Emantoko Dwi and Hasan, Ahmed Abdallah Abdalrahman Mohamed and Antonenko, Viktoriia and Curato, Caterina and Rippmann, Joerg and Klein, Thomas and Hocher, Berthold}, title = {Head-to-head comparison of structurally unrelated dipeptidyl peptidase 4 inhibitors in the setting of renal ischemia reperfusion injury}, series = {British journal of pharmacology : journal of The British Pharmacological Society}, volume = {174}, journal = {British journal of pharmacology : journal of The British Pharmacological Society}, publisher = {Wiley}, address = {Hoboken}, issn = {0007-1188}, doi = {10.1111/bph.13822}, pages = {2273 -- 2286}, year = {2017}, abstract = {BACKGROUND AND PURPOSE Results regarding protective effects of dipeptidyl peptidase 4 (DPP4) inhibitors in renal ischaemia-reperfusion injury (IRI) are conflicting. Here we have compared structurally unrelated DPP4 inhibitors in a model of renal IRI. EXPERIMENTAL APPROACH IRI was induced in uninephrectomizedmale rats by renal artery clamping for 30 min. The shamgroup was uninephrectomized but not subjected to IRI. DPP4 inhibitors or vehicle were given p. o. once daily on three consecutive days prior to IRI: linagliptin (1.5 mg.kg(-1).day(-1)), vildagliptin (8mg.kg(-1).day(-1)) and sitagliptin (30 mg.kg(-1).day(-1)). An additional group received sitagliptin until study end (before IRI: 30 mg.kg(-1).day(-1); after IRI: 15mg.kg(-1).day(-1)). KEY RESULTS Plasma-active glucagon-like peptide type 1 (GLP(-1)) increased threefold to fourfold in all DPP4 inhibitor groups 24 h after IRI. Plasma cystatin C, a marker of GFR, peaked 48 h after IRI. Compared with the placebo group, DPP4 inhibition did not reduce increased plasma cystatin C levels. DPP4 inhibitors ameliorated histopathologically assessed tubular damage with varying degrees of drug-specific efficacies. Renal osteopontin expression was uniformly reduced by all DPP4 inhibitors. IRI-related increased renal cytokine expression was not decreased by DPP4 inhibition. Renal DPP4 activity at study end was significantly inhibited in the linagliptin group, but only numerically reduced in the prolonged/dose-adjusted sitagliptin group. Active GLP(-1) plasma levels at study end were increased only in the prolonged/dose-adjusted sitagliptin treatment group. CONCLUSIONS AND IMPLICATIONS In rats with renal IRI, DPP4 inhibition did not alter plasma cystatin C, a marker of glomerular function, but may protect against tubular damage.}, language = {en} } @article{HechtFreisevonWebskyetal.2016, author = {Hecht, Eva and Freise, Christian and von Websky, Karoline and Nasser, Hamoud and Kretzschmar, Nadja and Stawowy, Philipp and Hocher, Berthold and Querfeld, Uwe}, title = {The matrix metalloproteinases 2 and 9 initiate uraemic vascular calcifications}, series = {Nephrology, dialysis, transplantation}, volume = {31}, journal = {Nephrology, dialysis, transplantation}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0931-0509}, doi = {10.1093/ndt/gfv321}, pages = {789 -- 797}, year = {2016}, abstract = {The matrix metalloproteinases (MMP) MMP-2 and MMP-9 are physiological regulators of vascular remodelling. Their dysregulation could contribute to vascular calcification. We examined the role of the MMP-2 and MMP-9 in uraemic vascular calcification in vivo and in vitro. The impact of pharmacological MMP inhibition on the development of media calcifications was explored in an aggressive animal model of uraemic calcification. In addition, the selective effects of addition and inhibition, respectively, of MMP-2 and MMP-9 on calcium-/phosphate-induced calcifications were studied in a murine cell line of vascular smooth muscle cells (VSMCs). High-dose calcitriol treatment of uraemic rats given a high phosphate diet induced massive calcifications, apoptosis and increased gene expressions of MMP-2, MMP-9 and of osteogenic transcription factors and proteins in aortic VSMC. The MMP inhibitor doxycycline prevented the VSMC transdifferentiation to osteoblastic cells, suppressed transcription of mediators of matrix remodelling and almost completely blocked aortic calcifications while further increasing apoptosis. Similarly, specific inhibitors of either MMP-2 or -9, or of both gelatinases (Ro28-2653) and a selective knockdown of MMP-2/-9 mRNA expression blocked calcification of murine VSMC induced by calcification medium (CM). In contrast to MMP inhibition, recombinant MMP-2 or MMP-9 enhanced CM-induced calcifications and the secretion of gelatinases. These data indicate that both gelatinases provide essential signals for phenotypic VSMC conversion, matrix remodelling and the initiation of vascular calcification. Their inhibition seems a promising strategy in the prevention of vascular calcifications.}, language = {en} } @article{TsuprykovAndoReichetzederetal.2016, author = {Tsuprykov, Oleg and Ando, Ryotaro and Reichetzeder, Christoph and von Websky, Karoline and Antonenko, Viktoriia and Sharkovska, Yuliya and Chaykovska, Lyubov and Rahnenfuehrer, Jan and Hasan, Ahmed Abdallah Abdalrahman Mohamed and Tammen, Harald and Alter, Markus L. and Klein, Thomas and Ueda, Seiji and Yamagishi, Sho-ichi and Okuda, Seiya and Hocher, Berthold}, title = {The dipeptidyl peptidase inhibitor linagliptin and the angiotensin II receptor blocker telmisartan show renal benefit by different pathways in rats with 5/6 nephrectomy}, series = {Kidney international : official journal of the International Society of Nephrology}, volume = {89}, journal = {Kidney international : official journal of the International Society of Nephrology}, publisher = {Nature Publ. Group}, address = {New York}, issn = {0085-2538}, doi = {10.1016/j.kint.2016.01.016}, pages = {1049 -- 1061}, year = {2016}, abstract = {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/).}, language = {en} } @inproceedings{ReichetzedervonWebskyTsuprykovetal.2015, author = {Reichetzeder, Christoph and von Websky, Karoline and Tsuprykov, Oleg and Antonenko, V. and Samarin, Azin Mohagheghi and Hocher, Berthold}, title = {Effects of DPP-4 inhibition on glomerular and tubular function in a rat model of ischaemia-reperfusion injury}, series = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, volume = {58}, booktitle = {Diabetologia : journal of the European Association for the Study of Diabetes (EASD)}, publisher = {Springer}, address = {New York}, issn = {0012-186X}, pages = {S34 -- S35}, year = {2015}, language = {en} } @misc{OngvonWebskyHocher2015, author = {Ong, Albert C. M. and von Websky, Karoline and Hocher, Berthold}, title = {Endothelin and Tubulointerstitial Renal Disease}, series = {Seminars in nephrology}, volume = {35}, journal = {Seminars in nephrology}, number = {2}, publisher = {Elsevier}, address = {Philadelphia}, issn = {0270-9295}, doi = {10.1016/j.semnephrol.2015.03.004}, pages = {197 -- 207}, year = {2015}, abstract = {All components of the endothelin (ET) system are present in renal tubular cells. In this review, we summarize current knowledge about ET and the most common tubular diseases: acute kidney injury (AKI) and polycystic kidney disease. AKI originally was called acute tubular necrosis, pointing to the most prominent morphologic findings. Similarly, cysts in polycystic kidney disease, and especially in autosomal-dominant polycystic kidney disease, are of tubular origin. Preclinical studies have indicated that the ET system and particularly ETA receptors are involved in the pathogenesis of ischemia-reperfusion injury, although these findings have not been translated to clinical studies. The ET system also has been implicated in radiocontrast-dye-induced AKI, however, ET-receptor blockade in a large human study was not successful. The ET system is activated in sepsis models of AKI; the effectiveness of ET blocking agents in preclinical studies is variable depending on the model and the ET-receptor antagonist used. Numerous studies have shown that the ET system plays an important role in the complex pathophysiology associated with cyst formation and disease progression in polycystic kidney disease. However, results from selective targeting of ET-receptor subtypes in animal models of polycystic kidney disease have proved disappointing and do not support clinical trials. These studies have shown that a critical balance between ETA and ETB receptor action is necessary to maintain structure and function in the cystic kidney. In summary, ETs have been implicated in the pathogenesis of several renal tubulointerstitial diseases, however, experimental animal findings have not yet led to use of ET blockers in human beings. (C) 2015 Elsevier Inc. All rights reserved.}, language = {en} }