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Cambridge, MA, United States

Breitenstein A.,University of Zurich | Stein S.,University of Zurich | Holy E.W.,University of Zurich | Camici G.G.,University of Zurich | And 8 more authors.
Cardiovascular Research | Year: 2011

AimsThe mammalian silent information regulator-two 1 (Sirt1) blunts the noxious effects of cardiovascular risk factors such as type 2 diabetes mellitus and obesity. Nevertheless, the role of Sirt1 in regulating the expression of tissue factor (TF), the key trigger of coagulation, and arterial thrombus formation remains unknown. Methods and resultsHuman as well as mouse cell lines were used for in vitro experiments, and C57Bl/6 mice for in vivo procedures. Sirt1 inhibition by splitomicin or sirtinol enhanced cytokine-induced endothelial TF protein expression as well as surface activity, while TF pathway inhibitor protein expression did not change. Sirt1 inhibition further enhanced TF mRNA expression, TF promoter activity, and nuclear translocation as well as DNA binding of the p65 subunit of nuclear factor-kappa B (NFκB/p65). Sirt1 siRNA enhanced TF protein and mRNA expression, and this effect was reduced in NFκB/p65-/- mouse embryonic fibroblasts reconstituted with non-acetylatable Lys310-mutant NFκB/p65. Activation of the mitogen-activated protein kinases p38, c-Jun NH2-terminal kinase, and p44/42 (ERK) remained unaffected. In vivo, mice treated with the Sirt1 inhibitor splitomicin exhibited enhanced TF activity in the arterial vessel wall and accelerated carotid artery thrombus formation in a photochemical injury model. ConclusionWe provide pharmacological and genetic evidence that Sirt1 inhibition enhances TF expression and activity by increasing NFκB/p65 activation in human endothelial cells. Furthermore, Sirt1 inhibition induces arterial thrombus formation in vivo. Hence, modulation of Sirt1 may offer novel therapeutic options for targeting thrombosis. © 2010 The Author. Source


Disch J.S.,Sirtris A GSK Company | Evindar G.,Glaxosmithkline | Chiu C.H.,Glaxosmithkline | Blum C.A.,Sirtris A GSK Company | And 14 more authors.
Journal of Medicinal Chemistry | Year: 2013

The sirtuins SIRT1, SIRT2, and SIRT3 are NAD+ dependent deacetylases that are considered potential targets for metabolic, inflammatory, oncologic, and neurodegenerative disorders. Encoded library technology (ELT) was used to affinity screen a 1.2 million heterocycle enriched library of DNA encoded small molecules, which identified pan-inhibitors of SIRT1/2/3 with nanomolar potency (e.g., 11c: IC50 = 3.6, 2.7, and 4.0 nM for SIRT1, SIRT2, and SIRT3, respectively). Subsequent SAR studies to improve physiochemical properties identified the potent drug like analogues 28 and 31. Crystallographic studies of 11c, 28, and 31 bound in the SIRT3 active site revealed that the common carboxamide binds in the nicotinamide C-pocket and the aliphatic portions of the inhibitors extend through the substrate channel, explaining the observable SAR. These pan SIRT1/2/3 inhibitors, representing a novel chemotype, are significantly more potent than currently available inhibitors, which makes them valuable tools for sirtuin research. © 2013 American Chemical Society. Source


Broom T.,Glaxosmithkline | Hughes M.,Glaxosmithkline | Szczepankiewicz B.G.,Sirtris A GSK Company | Ace K.,Glaxosmithkline | And 12 more authors.
Organic Process Research and Development | Year: 2014

A continuous flow process was developed for the synthesis of potassium bromomethyltrifluoroborate, a key precursor for Suzuki-Miyaura coupling reagents. The continuous flow process was used to produce potassium bromomethyltrifluoroborate on scales from grams to kilograms, and the successful process utilized a fraction of the resources required for the batch synthesis. In the plant, a team of three people produced approximately 100 kg of potassium bromomethyltrifluoroborate in less than 4 weeks. This process makes it both practical and economical to use potassium bromomethyltrifluoroborate and its derivatives for multikilogram-scale Suzuki-Miyaura couplings. © 2013 American Chemical Society. Source


Biason-Lauber A.,University of Fribourg | Boni-Schnetzler M.,University of Basel | Hubbard B.P.,Harvard University | Bouzakri K.,University of Geneva | And 33 more authors.
Cell Metabolism | Year: 2013

Type 1 diabetes is caused by autoimmune-mediated β cell destruction leading to insulin deficiency. The histone deacetylase SIRT1 plays an essential role in modulating several age-related diseases. Here we describe a family carrying a mutation in the SIRT1 gene, in which all five affected members developed an autoimmune disorder: four developed type 1 diabetes, and one developed ulcerative colitis. Initially, a 26-year-old man was diagnosed with the typical features of type 1 diabetes, including lean body mass, autoantibodies, T cell reactivity to β cell antigens, and a rapid dependence on insulin. Direct and exome sequencing identified the presence of a T-to-C exchange in exon 1 of SIRT1, corresponding to a leucine-to-proline mutation at residue 107. Expression of SIRT1-L107P in insulin-producing cells resulted in overproduction of nitric oxide, cytokines, and chemokines. These observations identify a role for SIRT1 in human autoimmunity and unveil a monogenic form of type 1 diabetes. © 2013 Elsevier Inc. Source


Szczepankiewicz B.G.,Sirtris A GSK Company | Dai H.,Sirtris A GSK Company | Koppetsch K.J.,Sirtris A GSK Company | Qian D.,HIGH-TECH | And 3 more authors.
Journal of Organic Chemistry | Year: 2012

Carba-NAD is a synthetic compound identical to NAD except for one substitution, where an oxygen atom adjacent to the anomeric linkage bearing nicotinamide is replaced with a methylene group. Because it is inert in nicotinamide displacement reactions, carba-NAD is an unreactive substrate analogue for NAD-consuming enzymes. SIRT3 and SIRT5 are NAD-consuming enzymes that are potential therapeutic targets for the treatment of metabolic diseases and cancers. We report an improved carba-NAD synthesis, including a pyrophosphate coupling method that proceeds in approximately 60% yield. We also disclose the X-ray crystal structures of the ternary complexes of SIRT3 and SIRT5 bound to a peptide substrate and carba-NAD. These X-ray crystal structures provide critical snapshots of the mechanism by which human sirtuins function as protein deacylation catalysts. © 2012 American Chemical Society. Source

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