http://hdl.handle.net/10993/98 Search this channel search https://orbilu.uni.lu/simple-search http://hdl.handle.net/10993/38664 Title: Lower plasma insulin levels during overnight closed loop in schoolchildren with type 1 diabetes: potential advantage? <br/> <br/>Author, co-author: Schierloh, Ulrike; Wilinska, M.; Pit-Ten Cate, Ineke; Baumann, P.; Hovorka, R.; de Beaufort, Carine <br/> <br/>Abstract: Background Studies have shown that overnight closed-loop insulin delivery can improve glucose control and reduce the risk of hypoglycemia and hence may improve metabolic outcomes and reduce burden for children with type 1 diabetes and their families. However, research so far has not reported insulin levels while comparing closed-loop to open-loop insulin delivery in children. Therefore, in this study we obtained glucose levels as well plasma insulin levels in children with type 1 diabetes to evaluate the efficacy of a model - based closed-loop algorithm compared to an open-loop administration. Methods Fifteen children with type 1 diabetes, 6-12 years, participated in this open-label single center study. We used a randomized cross over design in which we compared overnight closed-loop insulin delivery with sensor augmented pump therapy for two nights in both the hospital and at home (i.e., 1 night in-patient stay and at home per treatment condition). Only during the in-patient stay, hourly plasma insulin and blood glucose levels were assessed and are reported in this paper. Results Results of paired sample t-tests revealed that although plasma insulin levels were significantly lower during the closed-loop than in the open-loop (Mean difference 36.51 pmol/l; t(13)=2.13, p=.03, effect size d= 0.57), blood glucose levels did not vary between conditions (mean difference 0.76 mmol/l; t(13)=1.24, p=.12, d=0.37). The administered dose of insulin was significantly lower during the closed-loop compared with the open-loop (mean difference 0.10 UI; t(12)=2.45, p=.02, d=0.68). Conclusions Lower insulin doses were delivered in the closed-loop, resulting in lower plasma insulin levels , whereby glucose levels were not affected negatively. This suggests that the closed-loop administration is better targeted and hence could be more effective. http://hdl.handle.net/10993/38263 Title: A conserved phosphatase destroys toxic glycolytic side products in mammals and yeast <br/> <br/>Author, co-author: Collard, François; Baldin, Francesca; Gerin, Isabelle; Bolsée, Jennifer; Noël, Gaëtane; Graff, Julie; Veiga-da-Cunha, Maria; Stroobant, Vincent; Vertommen, Didier; Houddane, Amina; Rider, Mark H; Linster, Carole; Van Schaftingen, Emile; Bommer, Guido T <br/> <br/>Abstract: Metabolic enzymes are very specific. However, most of them show weak side activities toward compounds that are structurally related to their physiological substrates, thereby producing side products that may be toxic. In some cases, ‘metabolite repair enzymes’ eliminating side products have been identified. We show that mammalian glyceraldehyde 3-phosphate dehydrogenase and pyruvate kinase, two core glycolytic enzymes, produce 4-phosphoerythronate and 2-phospho-L-lactate, respectively. 4-Phosphoerythronate strongly inhibits an enzyme of the pentose phosphate pathway, whereas 2-phospho-L-lactate inhibits the enzyme producing the glycolytic activator fructose 2,6-bisphosphate. We discovered that a single, widely conserved enzyme, known as phosphoglycolate phosphatase (PGP) in mammals, dephosphorylates both 4-phosphoerythronate and 2-phospho-L-lactate, thereby preventing a block in the pentose phosphate pathway and glycolysis. Its yeast ortholog, Pho13, similarly dephosphorylates 4-phosphoerythronate and 2-phosphoglycolate, a side product of pyruvate kinase. Our work illustrates how metabolite repair enzymes can make up for the limited specificity of metabolic enzymes and permit high flux in central metabolic pathways. http://hdl.handle.net/10993/38261 Title: Nit1 is a metabolite repair enzyme that hydrolyzes deaminated glutathione <br/> <br/>Author, co-author: Peracchi, Alessio; Veiga-da-Cunha, Maria; Kuhara, Tomiko; Ellens, Kenneth W; Paczia, Nicole; Stroobant, Vincent; Seliga, Agnieszka K; Marlaire, Simon; Jaisson, Stephane; Bommer, Guido T; Sun, Jin; Huebner, Kay; Linster, Carole; Cooper, Arthur J.L.; Van Schaftingen, Emile <br/> <br/>Abstract: The mammalian gene Nit1 (nitrilase-like protein 1) encodes a protein that is highly conserved in eukaryotes and is thought to act as a tumor suppressor. Despite being ∼35% sequence identical to ω-amidase (Nit2), the Nit1 protein does not hydrolyze efficiently α-ketoglutaramate (a known physiological substrate of Nit2), and its actual enzymatic function has so far remained a puzzle. In the present study, we demonstrate that both the mammalian Nit1 and its yeast ortholog are amidases highly active toward deaminated glutathione (dGSH; i.e., a form of glutathione in which the free amino group has been replaced by a carbonyl group). We further show that Nit1-KO mutants of both human and yeast cells accumulate dGSH and the same compound is excreted in large amounts in the urine of Nit1-KO mice. Finally, we show that several mammalian aminotransferases (transaminases), both cytosolic and mitochondrial, can form dGSH via a common (if slow) side-reaction and provide indirect evidence that transaminases are mainly responsible for dGSH formation in cultured mammalian cells. Altogether, these findings delineate a typical instance of metabolite repair, whereby the promiscuous activity of some abundant enzymes of primary metabolism leads to the formation of a useless and potentially harmful compound, which needs a suitable “repair enzyme” to be destroyed or reconverted into a useful metabolite. The need for a dGSH repair reaction does not appear to be limited to eukaryotes: We demonstrate that Nit1 homologs acting as excellent dGSH amidases also occur in Escherichia coli and other glutathione-producing bacteria. http://hdl.handle.net/10993/38260 Title: Failure to eliminate a phosphorylated glucose analog leads to neutropenia in patients with G6PT and G6PC3 deficiency <br/> <br/>Author, co-author: Veiga-da-Cunha, Maria; Chevalier, Nathalie; Stephenne, Xavier; Defour, Jean-Philippe; Paczia, Nicole; Ferster, Alina; Achouri, Younes; Dewulf, Joseph P; Linster, Carole; Bommer, Guido T; Van Schaftingen, Emile <br/> <br/>Abstract: Neutropenia presents an important clinical problem in patients with G6PC3 or G6PT deficiency, yet why neutropenia occurs is unclear. We discovered that G6PC3 and G6PT collaborate to dephosphorylate a noncanonical metabolite (1,5anhydroglucitol-6-phosphate; 1,5AG6P) which is produced when glucose-phosphorylating enzymes erroneously act on 1,5-anhydroglucitol, a food-derived polyol present in blood. In patients or mice with G6PC3 or G6PT deficiency, 1,5AG6P accumulates and inhibits the first step of glycolysis. This is particularly detrimental in neutrophils, since their energy metabolism depends almost entirely on glycolysis. Consistent with our findings, we observed that treatment with a 1,5anhydroglucitol-lowering drug treats neutropenia in G6PC3deficient mice. Our findings highlight that the elimination of noncanonical side products by metabolite-repair enzymes makes an important contribution to mammalian physiology. http://hdl.handle.net/10993/32740 Title: Community- and mHealth-based integrated management of diabetes in primary healthcare in Rwanda (D²Rwanda): The study protocol <br/> <br/>Author, co-author: Uwizihiwe, Jean Paul; Lygidakis, Charilaos; Vögele, Claus; Condo, Jeanine; D'Ambrosio, Conchita; Kallestrup, Per <br/> <br/>Abstract: Introduction: The diabetes mellitus (DM) prevalence in Rwanda is estimated at 3.5%. In 2013, there were only one medical doctor and one nurse per 15,000 and 1,200 people respectively in Rwanda. A new programme employing frontline workers (Home-Based Community Practitioners (HBCPs)) is currently piloted, aiming at following-up patients with non-communicable diseases in their communities. We hypothesise that the management of DM at community level will improve following the introduction of a HBCP programme with regular monthly assessments and disease management, coupled with integration of a mobile health (mHealth) application with patient diaries, notifications and educational material. Objective: The aim of the study is to determine the efficacy of such an integrated programme in Rwanda. Methods: The study is designed as a one-year, open-label cluster trial of two interventions (arm1: HBCP programme, arm2: HBCP programme + mHealth application) and usual care (control). The primary outcomes will be changes in glycated haemoglobin levels and health-related quality of life. Mortality, complications, health literacy, mental well-being and treatment adherence will be assessed as secondary outcomes. Measurements will be conducted at baseline, 6 and 12 months. An intention-to-treat approach will be used to evaluate outcomes. Before trial onset, ethical approval will be sought in Rwanda, Luxembourg and Denmark, and a cross-cultural adaptation of questionnaires and a pilot will be carried out. Relevance: The project will provide evidence on the efficacy of innovative approaches for integrated management of DM and may spur the development of similar solutions for other chronic diseases in low-resource settings. http://hdl.handle.net/10993/29204 Title: Comorbid depression in elderly with type 2 diabetes <br/> <br/>Author, co-author: Lygidakis, Charilaos; Altini, Chiara; Rigon, Sara; Spezia, Carlo; Luppi, Davide; Alice, Stefano <br/> <br/>Abstract: Aim: To evaluate the potential correlation between depression and type 2 diabetes mellitus (DM2) in patients aged 65 years and over accessing primary health care (PHC) units. Methods: During the last semester of 2008, 109 elderly patients with DM2 (mean age 74.86, sd = 5.72) were examined by GP trainees in PHC practices. Demographics, BMI, waist circumference, fasting blood glucose (FBG), HbA1c and medicine treatment were queried. Dietary and drug therapy compliance and weekly physical activity in recreational time were investigated; expended energy was measured using Metabolic Equivalents (METs). Depression was assessed with the 15-item Geriatric Depression Scale (GDS-15) and mental health was evaluated with the General Health Questionnaire – 12 (GHQ-12). For comparison purposes, a short interview comprising the GDS-15 and GHQ-12 was performed in 52 non diabetic, randomly selected patients. The two groups were properly adjusted for sex and age. Results: Moderate (GDS-15 scores 6–8) and severe depression (GDS-15 >9) were found in 33.9% and 17.4% of the diabetics respectively. Female patients seemed to have better FBG values (r = 0.33, p = 0.006) and more controlled HbA1c (<7%, r = 0.37, p = 0.003). However, only males with regular HbA1c showed significantly lower BMI (Mdn = 27.72, U = 128.00, p <0.001) and waist circumference (Mean = 91.84 cm, t = 3.32, p = 0.002). Diabetics without depression signs were triply likely to do moderate weekly exercise compared with depressed ones (OR = 3.01, 95%CI = 1.36–6.57). Lower GDS-15 and GHQ-12 scores were correlated with more scarce therapy compliance (r = 0.46, p <0.001; r = 0.43, p <0.001 respectively). Diabetics seemed to be 2.83 times more likely to suffer from moderate depression compared with the control patients (95%CI = 1.19–6.68). Conclusions: The findings of our study suggest that moderate depression is a common underlying comorbidity in DM2, affecting aspects of its management such as the physical activity and compliance of medical therapy. http://hdl.handle.net/10993/27743 Title: Model-based dietary optimization for late-stage, levodopa-treated, Parkinson’s disease patients <br/> <br/>Author, co-author: Ben Guebila, Marouen; Thiele, Ines <br/> <br/>Abstract: Levodopa has been the gold standard for Parkinson’s disease treatment for more than 40 years. Its bioavailability is hindered by dietary amino acids, leading to fluctuations in the motor response particularly in late-stage (stage 3 and 4 on Hoehn and Yahr scale) patients. The routine dietary intervention consists of low-protein (<0.8 g/kg) diets or the redistribution of daily protein allowance to the last meal. Computational modeling was used to examine the fluctuation of gastrointestinal levodopa absorption under consideration of the diet by (i) identifying the group of patients that could benefit from dietary interventions, (ii) comparing existing diet recommendations for their impact on levodopa bioavailability, and (iii) suggesting a mechanism-based dietary intervention. We developed a multiscale computational model consisting of an ordinary differential equations-based advanced compartmentalized absorption and transit (ACAT) gut model and metabolic genome-scale small intestine epithelial cell model. We used this model to investigate complex spatiotemporal relationship between dietary amino acids and levodopa absorption. Our model predicted an improvement in bioavailability, as reflected by blood concentrations of levodopa with protein redistribution diet by 34% compared with a low-protein diet and by 11% compared with the ante cibum (a.c.) administration. These results are consistent with the reported better outcome in late-stage patients. A systematic analysis of the effect of different amino acids in the diet suggested that a serine-rich diet could improve the bioavailability by 22% compared with the a.c. administration. In addition, the slower gastric emptying rate in PD patients exacerbates the loss of levodopa due to competition. Optimizing dietary recommendations in quantity, composition, and intake time holds the promise to improve levodopa efficiency and patient’s quality of life based on highly detailed, mechanistic models of gut physiology endowed with improved extrapolative properties, thus paving the way for precision medical treatment. http://hdl.handle.net/10993/27304 Title: Decoding the dynamics of cellular metabolism and the action of 3-bromopyruvate and 2-deoxyglucose using pulsed stable isotope-resolved metabolomics <br/> <br/>Author, co-author: Mudrich Epouse Dorosz, Susann Antonia; Pietzke, Matthias; Zasada, Christin <br/> <br/>Abstract: Background Cellular metabolism is highly dynamic and continuously adjusts to the physiological program of the cell. The regulation of metabolism appears at all biological levels: (post-) transcriptional, (post-) translational, and allosteric. This regulatory information is expressed in the metabolome, but in a complex manner. To decode such complex information, new methods are needed in order to facilitate dynamic metabolic characterization at high resolution. Results Here, we describe pulsed stable isotope-resolved metabolomics (pSIRM) as a tool for the dynamic metabolic characterization of cellular metabolism. We have adapted gas chromatography-coupled mass spectrometric methods for metabolomic profiling and stable isotope-resolved metabolomics. In addition, we have improved robustness and reproducibility and implemented a strategy for the absolute quantification of metabolites. Conclusions By way of examples, we have applied this methodology to characterize central carbon metabolism of a panel of cancer cell lines and to determine the mode of metabolic inhibition of glycolytic inhibitors in times ranging from minutes to hours. Using pSIRM, we observed that 2-deoxyglucose is a metabolic inhibitor, but does not directly act on the glycolytic cascade. http://hdl.handle.net/10993/27289 Title: The ADP receptor P2RY12 regulates osteoclast function and pathologic bone remodeling <br/> <br/>Author, co-author: Su, X.; Floyd, D. H.; Hughes, A.; Xiang, J.; Schneider, Jochen; Uluckan, O.; Heller, E.; Deng, H.; Zou, W.; Craft, C. S.; Wu, K.; Hirbe, A. C.; Grabowska, D.; Eagleton, M. C.; Townsley, S.; Collins, L.; Piwnica-Worms, D.; Steinberg, T. H.; Novack, D. V.; Conley, P. B.; Hurchla, M. A.; Rogers, M.; Weilbaecher, K. N. <br/> <br/>Abstract: The adenosine diphosphate (ADP) receptor P2RY12 (purinergic receptor P2Y, G protein coupled, 12) plays a critical role in platelet aggregation, and P2RY12 inhibitors are used clinically to prevent cardiac and cerebral thrombotic events. Extracellular ADP has also been shown to increase osteoclast (OC) activity, but the role of P2RY12 in OC biology is unknown. Here, we examined the role of mouse P2RY12 in OC function. Mice lacking P2ry12 had decreased OC activity and were partially protected from age-associated bone loss. P2ry12-/- OCs exhibited intact differentiation markers, but diminished resorptive function. Extracellular ADP enhanced OC adhesion and resorptive activity of WT, but not P2ry12-/-, OCs. In platelets, ADP stimulation of P2RY12 resulted in GTPase Ras-related protein (RAP1) activation and subsequent αIIbβ3 integrin activation. Likewise, we found that ADP stimulation induced RAP1 activation in WT and integrin β3 gene knockout (Itgb3-/-) OCs, but its effects were substantially blunted in P2ry12-/- OCs. In vivo, P2ry12-/- mice were partially protected from pathologic bone loss associated with serum transfer arthritis, tumor growth in bone, and ovariectomy-induced osteoporosis: all conditions associated with increased extracellular ADP. Finally, mice treated with the clinical inhibitor of P2RY12, clopidogrel, were protected from pathologic osteolysis. These results demonstrate that P2RY12 is the primary ADP receptor in OCs and suggest that P2RY12 inhibition is a potential therapeutic target for pathologic bone loss. <br/> <br/>Commentary: in press http://hdl.handle.net/10993/27288 Title: Integrins and bone metastasis: integrating tumor cell and stromal cell interactions <br/> <br/>Author, co-author: Schneider, Jochen; Amend, S. R.; Weilbaecher, K. N. <br/> <br/>Abstract: Integrins on both tumor cells and the supporting host stromal cells in bone (osteoclasts, new blood vessels, inflammatory cells, platelets and bone marrow stromal cells) play key roles in enhancing bone metastasis. Tumor cells localize to specific tissues through integrin-mediated contacts with extracellular matrix and stromal cells. Integrin expression and signaling are perturbed in cancer cells, allowing them to "escape" from cell-cell and cell-matrix tethers, invade, migrate and colonize within new tissues and matrices. Integrin signaling through αvβ3 and VLA-4 on tumor cells can promote tumor metastasis to and proliferation in the bone microenvironment. Osteoclast (OC) mediated bone resorption is a critical component of bone metastasis and can promote tumor growth in bone and αvβ3 integrins are critical to OC function and development. Tumors in the bone microenvironment can recruit new blood vessel formation, platelets, pro-tumor immune cells and bone marrow stromal cells that promote tumor growth and invasion in bone. Integrins and their ligands play critical roles in platelet aggregation (αvβ3 and αIIbβ3), hematopoietic cell mobilization (VLA-4 and osteopontin), neoangiogenesis (αvβ3, αvβ5, α6β4, and β1 integrin) and stromal function (osteopontin and VLA-4). Integrins are involved in the pathogenesis of bone metastasis at many levels and further study to define integrin dysregulation by cancer will yield new therapeutic targets for the prevention and treatment of bone metastasis. http://hdl.handle.net/10993/27287 Title: Adiponectin Fails in Improving Angiogenic Repair in Streptozocin-Treated or Lepr db/db Mice after Hind Limb Ischemia <br/> <br/>Author, co-author: Belisle, Kurt; Andrassy, Martin; Schneider, Jochen; Schiekofer, Stephan <br/> <br/>Abstract: Type 1 and 2 diabetes carry risk factors for the development of microvascular diseases with associated impairment of angiogenic repair. Here, we investigated whether adiponectin, an adipocyte-specific adipocytokine with antiatherosclerotic and antidiabetic properties, regulates angiogenic repair in response to tissue ischemia in Leprdb/db and streptozocin-treated diabetic mouse models. Methods. Adenoviral vectors containing the gene for β-galactosidase, full-length mouse adiponectin, and dominant-negative AMPKα2 were used in streptozocin-treated male Leprdb/db mice, after which hind limb blood flow was measured using a laser doppler blood flow analyzer. Results. The angiogenic repair of ischemic hind limbs was impaired in both streptozocin-treated and Leprdb/db mice compared to wild-type mice as evaluated by laser doppler flow and capillary density analyses. Adenovirus-mediated administration of adiponectin accelerated angiogenic repair after hind limb ischemia in WT mice, but not in Leprdb/db mice or mice treated with streptozocin. In vitro experiments using HUVECs highlighted the antiapoptotic and proangiogenic properties of adiponectin but could not demonstrate accelerated differentiation of endothelial cells into tube- like structures at elevated glucose levels. Conclusions. External administration of adiponectin at elevated glucose levels may not be useful in the treatment of diabetes mellitus-related vascular deficiency diseases. <br/> <br/>Commentary: Article ID 769092 http://hdl.handle.net/10993/27286 Title: Hedgehog signaling inhibition blocks growth of resistant tumors through effects on tumor microenvironment. <br/> <br/>Author, co-author: Heller, E.; Hurchla, M. A.; Xiang, J.; Chen, S.; Schneider, Jochen; Joeng, K.; Vidal, M.; Goldberg, L.; Deng, H.; Hornick, M. C.; Prior, J.; Piwnica-Worms, D. R.; Long, F.; Cagan, R.; Weilbaecher, K. <br/> <br/>Abstract: Hedgehog (Hh) signaling is implicated in bone development and cellular transformation. Here we demonstrate that inhibition of Hh pathway activity inhibits tumor growth through effects on the microenvironment. Pharmacological inhibition of the Hh effector Smoothened (Smo) increased trabecular bone in vivo and inhibited osteoclastogenesis in vitro. In addition, enhanced Hh signaling due to heterozygosity of the Hh inhibitory receptor Patched (Ptch1+/-) increased bone resorption, suggesting direct regulation of osteoclast activity by the Hh pathway. Ptch1+/- mice had increased bone metastatic and subcutaneous tumor growth, suggesting that increased Hh activation in host cells promoted tumor growth. Subcutaneous growth of Hh-resistant tumor cells was inhibited by LDE225, a novel orally bioavailable Smo antagonist, consistent with effects on tumor microenvironment. Knockdown of the Hh ligand Sonic Hh (SHH) in these cells decreased subcutaneous tumor growth and decreased stromal cell production of IL-6, indicating that tumor-derived Hh ligands stimulated tumor growth in a paracrine fashion. Together our findings demonstrate that inhibition of the Hh pathway can reduce tumor burden, regardless of tumor Hh responsiveness, through effects on tumor cells, osteoclasts and stromal cells within the tumor microenvironment. Hh may be a promising therapeutic target for solid cancers and bone metastases. <br/> <br/>Commentary: Published Online First December 20, 2011 http://hdl.handle.net/10993/27280 Title: Short-term akt activation in cardiac muscle cells improves contractile function in failing hearts <br/> <br/>Author, co-author: Shiojima, I.; Schiekofer, S.; Schneider, Jochen; Belisle, K.; Sato, K.; Andrassy, M.; Galasso, G.; Walsh, K. <br/> <br/>Abstract: Akt is a serine/threonine protein kinase that is activated by a variety of growth factors or cytokines in a phosphatidylinositol 3-kinase-dependent manner. By using a conditional transgenic system in which Akt signaling can be turned on or off in the adult heart, we previously showed that short-term Akt activation induces a physiological form of cardiac hypertrophy with enhanced coronary angiogenesis and maintained contractility. Here we tested the hypothesis that induction of physiological hypertrophy by short-term Akt activation might improve contractile function in failing hearts. When Akt signaling transiently was activated in murine hearts with impaired contractility, induced by pressure overload or doxorubicin treatment, contractile dysfunction was attenuated in both cases. Importantly, improvement of contractility was observed before the development of cardiac hypertrophy, indicating that Akt activation improves contractile function independently of its growth-promoting effects. To gain mechanistic insights into Akt-mediated positive inotropic effects, transcriptional profiles in the heart were determined in a pressure overload-induced heart failure model. Biological network analysis of differentially expressed transcripts revealed significant alterations in the expression of genes associated with cell death, and these alterations were reversed by short-term Akt activation. Thus, short-term Akt activation improves contractile function in failing hearts. This beneficial effect of Akt on contractility is hypertrophy-independent and may be mediated in part by inhibition of cell death associated with heart failure. <br/> <br/>Commentary: in press http://hdl.handle.net/10993/27276 Title: Method Validation for Preparing Serum and Plasma Samples from Human Blood for Downstream Proteomic, Metabolomic, and Circulating Nucleic Acid-Based Applications <br/> <br/>Author, co-author: Ammerlaan, Wim; Trezzi, Jean-Pierre; Lescuyer, Pierre; Mathay,, Conny; Hiller, Karsten; Betsou, Fay http://hdl.handle.net/10993/26945 Title: New hepatic fat activates PPARalpha to maintain glucose, lipid, and cholesterol homeostasis <br/> <br/>Author, co-author: Chakravarthy, M. V.; Pan, Z.; Zhu, Y.; Tordjman, K.; Schneider, Jochen; Coleman, T.; Turk, J.; Semenkovich, C. F. <br/> <br/>Abstract: De novo lipogenesis is an energy-expensive process whose role in adult mammals is poorly understood. We generated mice with liver-specific inactivation of fatty-acid synthase (FAS), a key lipogenic enzyme. On a zero-fat diet, FASKOL (FAS knockout in liver) mice developed hypoglycemia and fatty liver, which were reversed with dietary fat. These phenotypes were also observed after prolonged fasting, similarly to fasted PPARalpha-deficiency mice. Hypoglycemia, fatty liver, and defects in expression of PPARalpha target genes in FASKOL mice were corrected with a PPARalpha agonist. On either zero-fat or chow diet, FASKOL mice had low serum and hepatic cholesterol levels with elevated SREBP-2, decreased HMG-CoA reductase expression, and decreased cholesterol biosynthesis; these were also corrected with a PPARalpha agonist. These results suggest that products of the FAS reaction regulate glucose, lipid, and cholesterol metabolism by serving as endogenous activators of distinct physiological pools of PPARalpha in adult liver http://hdl.handle.net/10993/26943 Title: De Novo Lipogenesis Maintains Vascular Homeostasis through Endothelial Nitric-oxide Synthase (eNOS) Palmitoylation <br/> <br/>Author, co-author: Wei, Xiaochao; Schneider, Jochen; Shenouda, Sherene M.; Lee, Ada; Towler, Dwight A.; Chakravarthy, Manu V.; Vita, Joseph A.; Semenkovich, Clay F. <br/> <br/>Abstract: Endothelial dysfunction leads to lethal vascular complications in diabetes and related metabolic disorders. Here, we demonstrate that de novo lipogenesis, an insulin-dependent process driven by the multifunctional enzyme fatty-acid synthase (FAS), maintains endothelial function by targeting endothelial nitric-oxide synthase (eNOS) to the plasma membrane. In mice with endothelial inactivation of FAS (FASTie mice), eNOS membrane content and activity were decreased. eNOS and FAS were physically associated; eNOS palmitoylation was decreased in FAS-deficient cells, and incorporation of labeled carbon into eNOS-associated palmitate was FAS-dependent. FASTie mice manifested a proinflammatory state reflected as increases in vascular permeability, endothelial inflammatory markers, leukocyte migration, and susceptibility to LPS-induced death that was reversed with an NO donor. FAS-deficient endothelial cells showed deficient migratory capacity, and angiogenesis was decreased in FASTie mice subjected to hindlimb ischemia. Insulin induced FAS in endothelial cells freshly isolated from humans, and eNOS palmitoylation was decreased in mice with insulin-deficient or insulin-resistant diabetes. Thus, disrupting eNOS bioavailability through impaired lipogenesis identifies a novel mechanism coordinating nutritional status and tissue repair that may contribute to diabetic vascular disease. http://hdl.handle.net/10993/21182 Title: Non-targeted mass isotopolome analysis to gain insights into cancer cell metabolism <br/> <br/>Author, co-author: Weindl, Daniel http://hdl.handle.net/10993/20928 Title: Combining multiple viewpoints on genetically modified foods <br/> <br/>Author, co-author: König, Ariane http://hdl.handle.net/10993/18547 Title: Molecular and Clinical Evidence for an ARMC5 Tumor Syndrome: Concurrent Inactivating Germline and Somatic Mutations are Associated with both Primary Macronodular Adrenal Hyperplasia and Meningioma <br/> <br/>Author, co-author: Eibelt, Ulf; Trovato, Alissa; Kloth, Michael; Gentz, Enno; Finke, Reinhard; Spranger, Joachim; Galas, David J.; Weber, Susanne; Wolf, Cristina-Alexandra; König, Katharina; Arlt, Wiebke; Büttner, Reinhard; May, Patrick; Allolio, Bruno; Schneider, Jochen <br/> <br/>Abstract: Context:Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushing's syndrome (CS), which may present in the context of different familial multitumor syndromes. Heterozygous inactivating germline mutations of armadillo repeat containing 5 (ARMC5) have very recently been described as cause for sporadic PMAH. Whether this genetic condition also causes familial PMAH in association with other neoplasias is unclear. Objective: The aim of the present study was to delineate the molecular cause in a large family with PMAH and other neoplasias. Patients and Methods: Whole genome sequencing and comprehensive clinical and biochemical phenotyping was performed in members of a PMAH affected family. Nodules derived from adrenal surgery and pancreatic and meningeal tumor tissue were analysed for accompanying somatic mutations in the identified target genes. Results: PMAH presenting either as overt or subclinical CS was accompanied by a heterozygous germline mutation in ARMC5 (p.A110fs*9) located on chromosome 16. Analysis of tumor tissue showed different somatic ARMC5 mutations in adrenal nodules supporting a “second hit” hypothesis with inactivation of a tumor suppressor gene. A damaging somatic ARMC5 mutation was also found in a concomitant meningioma (p.R502fs) but not in a pancreatic tumor suggesting biallelic inactivation of ARMC5 as causal also for the intracranial meningioma. Conclusions: Our analysis further confirms inherited inactivating ARMC5 mutations as a cause of familial PMAH and suggests an additional role for the development of concomitant intracranial meningiomas. http://hdl.handle.net/10993/4559 Title: PPARγ population shift produces disease-related changes in molecular networks associated with metabolic syndrome <br/> <br/>Author, co-author: Jurkowski, Wiktor; Roomp, Kirsten; Crespo, Isaac; Schneider, Jochen; del Sol Mesa, Antonio <br/> <br/>Abstract: Peroxisome proliferator-activated receptor gamma (PPARγ) is a key regulator of adipocyte differentiation and has an important role in metabolic syndrome. Phosphorylation of the receptor's ligand-binding domain at serine 273 has been shown to change the expression of a large number of genes implicated in obesity. The difference in gene expression seen when comparing wild-type phosphorylated with mutant non-phosphorylated PPARγ may have important consequences for the cellular molecular network, the state of which can be shifted from the healthy to a stable diseased state. We found that a group of differentially expressed genes are involved in bi-stable switches and form a core network, the state of which changes with disease progression. These findings support the idea that bi-stable switches may be a mechanism for locking the core gene network into a diseased state and for efficiently propagating perturbations to more distant regions of the network. A structural analysis of the PPARγ-RXRα dimer complex supports the hypothesis of a major structural change between the two states, and this may represent an important mechanism leading to the differential expression observed in the core network. <br/> <br/>Commentary: e192