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 - TY - JOUR A1 - Collenburg, Lena A1 - Walter, Tim A1 - Burgert, Anne A1 - Mueller, Nora A1 - Seibel, Juergen A1 - Japtok, Lukasz A1 - Kleuser, Burkhard A1 - Sauer, Markus A1 - Schneider-Schaulies, Sibylle T1 - A Functionalized Sphingolipid Analogue for Studying Redistribution during Activation in Living T Cells JF - The journal of immunology N2 - Sphingolipids are major components of the plasma membrane. In particular, ceramide serves as an essential building hub for complex sphingolipids, but also as an organizer of membrane domains segregating receptors and signalosomes. Sphingomyelin breakdown as a result of sphingomyelinase activation after ligation of a variety of receptors is the predominant source of ceramides released at the plasma membrane. This especially applies to T lymphocytes where formation of ceramide-enriched membrane microdomains modulates TCR signaling. Because ceramide release and redistribution occur very rapidly in response to receptor ligation, novel tools to further study these processes in living T cells are urgently needed. To meet this demand, we synthesized nontoxic, azido-functionalized ceramides allowing for bio-orthogonal click-reactions to fluorescently label incorporated ceramides, and thus investigate formation of ceramide-enriched domains. Azido-functionalized C-6-ceramides were incorporated into and localized within plasma membrane microdomains and proximal vesicles in T cells. They segregated into clusters after TCR, and especially CD28 ligation, indicating efficient sorting into plasma membrane domains associated with T cell activation; this was abolished upon sphingomyelinase inhibition. Importantly, T cell activation was not abrogated upon incorporation of the compound, which was efficiently excluded from the immune synapse center as has previously been seen in Ab-based studies using fixed cells. Therefore, the functionalized ceramides are novel, highly potent tools to study the subcellular redistribution of ceramides in the course of T cell activation. Moreover, they will certainly also be generally applicable to studies addressing rapid stimulation-mediated ceramide release in living cells. Y1 - 2016 U6 - https://doi.org/10.4049/jimmunol.1502447 SN - 0022-1767 SN - 1550-6606 VL - 196 SP - 3951 EP - 3962 PB - American Assoc. of Immunologists CY - Bethesda ER - TY - JOUR A1 - Huston, Joseph P. A1 - Kornhuber, Johannes A1 - Muehle, Christiane A1 - Japtok, Lukasz A1 - Komorowski, Mara A1 - Mattern, Claudia A1 - Reichel, Martin A1 - Gulbins, Erich A1 - Kleuser, Burkhard A1 - Topic, Bianca A1 - Silva, Maria A. De Souza A1 - Mueller, Christian P. T1 - A sphingolipid mechanism for behavioral extinction JF - Journal of neurochemistry N2 - Reward-dependent instrumental behavior must continuously be re-adjusted according to environmental conditions. Failure to adapt to changes in reward contingencies may incur psychiatric disorders like anxiety and depression. When an expected reward is omitted, behavior undergoes extinction. While extinction involves active re-learning, it is also accompanied by emotional behaviors indicative of frustration, anxiety, and despair (extinction-induced depression). Here, we report evidence for a sphingolipid mechanism in the extinction of behavior. Rapid extinction, indicating efficient re-learning, coincided with a decrease in the activity of the enzyme acid sphingomyelinase (ASM), which catalyzes turnover of sphingomyelin to ceramide, in the dorsal hippocampus of rats. The stronger the decline in ASM activity, the more rapid was the extinction. Sphingolipid-focused lipidomic analysis showed that this results in a decline of local ceramide species in the dorsal hippocampus. Ceramides shape the fluidity of lipid rafts in synaptic membranes and by that way can control neural plasticity. We also found that aging modifies activity of enzymes and ceramide levels in selective brain regions. Aging also changed how the chronic treatment with corticosterone (stress) or intranasal dopamine modified regional enzyme activity and ceramide levels, coinciding with rate of extinction. These data provide first evidence for a functional ASM-ceramide pathway in the brain involved in the extinction of learned behavior. This finding extends the known cellular mechanisms underlying behavioral plasticity to a new class of membrane-located molecules, the sphingolipids, and their regulatory enzymes, and may offer new treatment targets for extinction- and learning-related psychopathological conditions. KW - acid sphingomyelinase KW - ceramide KW - extinction KW - hippocampus KW - operant behavior KW - sphingomyelin Y1 - 2016 U6 - https://doi.org/10.1111/jnc.13537 SN - 0022-3042 SN - 1471-4159 VL - 137 SP - 589 EP - 603 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Hecht, Eva A1 - Freise, Christian A1 - von Websky, Karoline A1 - Nasser, Hamoud A1 - Kretzschmar, Nadja A1 - Stawowy, Philipp A1 - Hocher, Berthold A1 - Querfeld, Uwe T1 - The matrix metalloproteinases 2 and 9 initiate uraemic vascular calcifications JF - Nephrology, dialysis, transplantation N2 - 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. KW - chronic kidney disease KW - matrix metalloproteinases KW - vascular calcification KW - vascular smooth muscle cells Y1 - 2016 U6 - https://doi.org/10.1093/ndt/gfv321 SN - 0931-0509 SN - 1460-2385 VL - 31 SP - 789 EP - 797 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Niehoff, Ann-Christin A1 - Schulz, Jacqueline A1 - Soltwisch, Jens A1 - Meyer, Soren A1 - Kettling, Hans A1 - Sperling, Michael A1 - Jeibmann, Astrid A1 - Dreisewerd, Klaus A1 - Francesconi, Kevin A. A1 - Schwerdtle, Tanja A1 - Karst, Uwe T1 - Imaging by Elemental and Molecular Mass Spectrometry Reveals the Uptake of an Arsenolipid in the Brain of Drosophila melanogaster JF - Analytical chemistry N2 - Arsenic-containing lipids (arsenolipids) are natural products of marine organisms such as fish, invertebrates, and algae, many of which are important seafoods. A major group of arsenolipids, namely, the arsenic-containing hydrocarbons (AsHC), have recently been shown to be cytotoxic to human liver and bladder cells, a result that has stimulated interest in the chemistry and toxicology of these compounds. In this study, elemental laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) and molecular matrix-assisted laser desorption/ionization (MALDI-)MS were used to image and quantify the uptake of an AsHC in the model organism Drosophila melanogaster. Using these two complementary methods, both an enrichment of arsenic and the presence of the AsHC in the brain were revealed, indicating that the intact arsenolipid had crossed the blood-brain barrier. Simultaneous acquisition of quantitative elemental concentrations and molecular distributions could allow new insight into organ-specific enrichment and possible transportation processes of arsenic-containing bioactive compounds in living organisms. Y1 - 2016 U6 - https://doi.org/10.1021/acs.analchem.6b00333 SN - 0003-2700 SN - 1520-6882 VL - 88 SP - 5258 EP - 5263 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Manowsky, Julia A1 - Camargo, Rodolfo Gonzalez A1 - Kipp, Anna Patricia A1 - Henkel, Janin A1 - Püschel, Gerhard Paul T1 - Insulin-induced cytokine production in macrophages causes insulin resistance in hepatocytes JF - American journal of physiology : Endocrinology and metabolism N2 - Overweight and obesity are associated with hyperinsulinemia, insulin resistance, and a low-grade inflammation. Although hyperinsulinemia is generally thought to result from an attempt of the beta-cell to compensate for insulin resistance, there is evidence that hyperinsulinaemia itself may contribute to the development of insulin resistance and possibly the low-grade inflammation. To test this hypothesis, U937 macrophages were exposed to insulin. In these cells, insulin induced expression of the proinflammatory cytokines IL-1 beta, IL-8, CCL2, and OSM. The insulin-elicited induction of IL-1 beta was independent of the presence of endotoxin and most likely mediated by an insulin-dependent activation of NF-kappa B. Supernatants of the insulin-treated U937 macrophages rendered primary cultures of rat hepatocytes insulin resistant; they attenuated the insulin-dependent induction of glucokinase by 50%. The cytokines contained in the supernatants of insulin-treated U937 macrophages activated ERK1/2 and IKK beta, resulting in an inhibitory serine phosphorylation of the insulin receptor substrate. In addition, STAT3 was activated and SOCS3 induced, further contributing to the interruption of the insulin receptor signal chain in hepatocytes. These results indicate that hyperinsulinemia per se might contribute to the low-grade inflammation prevailing in overweight and obese patients and thereby promote the development of insulin resistance particularly in the liver, because the insulin concentration in the portal circulation is much higher than in all other tissues. KW - metabolic syndrome KW - type 2 diabetes KW - inflammation KW - macrophage KW - insulin KW - cytokines Y1 - 2016 U6 - https://doi.org/10.1152/ajpendo.00427.2015 SN - 0193-1849 SN - 1522-1555 VL - 310 SP - E938 EP - E946 PB - American Chemical Society CY - Bethesda ER - TY - JOUR A1 - Bijleveld, Catrien A1 - Huschek, Doreen A1 - Liefbroer, Aart C. T1 - Parental criminality and entry into parenthood among sons and daughters JF - Advances in life course research N2 - In this article, we examined to what extent parental offending influences the timing of entry into parenthood of children. Based on a literature review, we hypothesized that children of delinquent parents would be more likely to enter into parenthood at a relatively young age, and that part of that association could be explained by differences between children of delinquent and non-delinquent parents in the timing of entry into marriage and in their own delinquent behaviour. Using data from a five-generation study of high risk families in the Netherlands, we found that parental delinquency increases the chance of early childbearing among daughters, but not among sons. Among sons, parental delinquency increased son's delinquency, suggesting that parental delinquency has different consequences for the life courses of their sons and daughters. KW - Intergenerational effects KW - Offending KW - Parenthood KW - Demographic transitions KW - Delinquency Y1 - 2016 U6 - https://doi.org/10.1016/j.alcr.2016.03.006 SN - 1569-4909 SN - 1879-6974 VL - 28 SP - 81 EP - 90 PB - Elsevier CY - Oxford ER - TY - GEN A1 - Bijleveld, Catrien A1 - Zoutewelle-Terovan, Mioara A1 - Huschek, Doreen A1 - Liefbroer, Aart C. T1 - Criminal careers and demographic outcomes: An introduction to the special issue T2 - Advances in life course research Y1 - 2016 U6 - https://doi.org/10.1016/j.alcr.2016.05.001 SN - 1569-4909 SN - 1879-6974 VL - 28 SP - 1 EP - 5 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Reichetzeder, Christoph A1 - Putra, S. E. Dwi A1 - Pfab, T. A1 - Slowinski, T. A1 - Neuber, Corinna A1 - Kleuser, Burkhard A1 - Hocher, Berthold T1 - Increased global placental DNA methylation levels are associated with gestational diabetes JF - Clinical epigenetics N2 - Background: Gestational diabetes mellitus (GDM) is associated with adverse pregnancy outcomes. It is known that GDM is associated with an altered placental function and changes in placental gene regulation. More recent studies demonstrated an involvement of epigenetic mechanisms. So far, the focus regarding placental epigenetic changes in GDM was set on gene-specific DNA methylation analyses. Studies that robustly investigated placental global DNA methylation are lacking. However, several studies showed that tissue-specific alterations in global DNA methylation are independently associated with type 2 diabetes. Thus, the aim of this study was to characterize global placental DNA methylation by robustly measuring placental DNA 5-methylcytosine (5mC) content and to examine whether differences in placental global DNA methylation are associated with GDM. Methods: Global DNA methylation was quantified by the current gold standard method, LC-MS/MS. In total, 1030 placental samples were analyzed in this single-center birth cohort study. Results: Mothers with GDM displayed a significantly increased global placental DNA methylation (3.22 +/- 0.63 vs. 3.00 +/- 0.46 %; p = 0.013; +/- SD). Bivariate logistic regression showed a highly significant positive correlation between global placental DNA methylation and the presence of GDM (p = 0.0009). Quintile stratification according to placental DNA 5mC levels revealed that the frequency of GDM was evenly distributed in quintiles 1-4 (2.9-5.3 %), whereas the frequency in the fifth quintile was significantly higher (10.7 %; p = 0.003). Bivariate logistic models adjusted for maternal age, BMI, ethnicity, recurrent miscarriages, and familiar diabetes predisposition clearly demonstrated an independent association between global placental DNA hypermethylation and GDM. Furthermore, an ANCOVA model considering known predictors of DNA methylation substantiated an independent association between GDM and placental DNA methylation. Conclusions: This is the first study that employed a robust quantitative assessment of placental global DNA methylation in over a thousand placental samples. The study provides large scale evidence that placental global DNA hypermethylation is associated with GDM, independent of established risk factors. KW - Placenta KW - Gestational diabetes KW - Insulin resistance KW - LC-MS/MS KW - Global DNA methylation KW - Epigenetics KW - Hypermethylation Y1 - 2016 U6 - https://doi.org/10.1186/s13148-016-0247-9 SN - 1868-7083 VL - 8 PB - BioMed Central CY - London ER - TY - JOUR A1 - Castro, José Pedro A1 - Grune, Tilman A1 - Speckmann, Bodo T1 - The two faces of reactive oxygen species (ROS) in adipocyte function and dysfunction JF - Biological chemistry N2 - White adipose tissue (WAT) is actively involved in the regulation of whole-body energy homeostasis via storage/ release of lipids and adipokine secretion. Current research links WAT dysfunction to the development of metabolic syndrome (MetS) and type 2 diabetes (T2D). The expansion of WAT during oversupply of nutrients prevents ectopic fat accumulation and requires proper preadipocyte-to-adipocyte differentiation. An assumed link between excess levels of reactive oxygen species (ROS), WAT dysfunction and T2D has been discussed controversially. While oxidative stress conditions have conclusively been detected in WAT of T2D patients and related animal models, clinical trials with antioxidants failed to prevent T2D or to improve glucose homeostasis. Furthermore, animal studies yielded inconsistent results regarding the role of oxidative stress in the development of diabetes. Here, we discuss the contribution of ROS to the (patho) physiology of adipocyte function and differentiation, with particular emphasis on sources and nutritional modulators of adipocyte ROS and their functions in signaling mechanisms controlling adipogenesis and functions of mature fat cells. We propose a concept of ROS balance that is required for normal functioning of WAT. We explain how both excessive and diminished levels of ROS, e. g. resulting from over supplementation with antioxidants, contribute to WAT dysfunction and subsequently insulin resistance. KW - adipogenesis KW - adipose tissue dysregulation KW - antioxidants KW - metabolic disorders KW - oxidative stress Y1 - 2016 U6 - https://doi.org/10.1515/hsz-2015-0305 SN - 1431-6730 SN - 1437-4315 VL - 397 SP - 709 EP - 724 PB - De Gruyter CY - Berlin ER -