Publications by authors named "Aimo Kannt"

46 Publications

Expanding the arsenal of E3 ubiquitin ligases for proximity-induced protein degradation.

Cell Chem Biol 2021 Apr 27. Epub 2021 Apr 27.

Fraunhofer Institute of Translational Medicine and Pharmacology ITMP, Theodor-Stern-Kai 7, 60596 Frankfurt am Main, Germany; Institute of Biochemistry II, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Straße 15, 60438 Frankfurt am Main, Germany; Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue Straße 3, 60438 Frankfurt am Main, Germany. Electronic address:

Efficacy and selectivity of molecules inducing protein degradation depend on their affinity to the target protein but also on the type of E3 ubiquitin ligase that is recruited to trigger proteasomal degradation. While tremendous progress has been made on the former, the latter-the arsenal of E3 ligases that can be hijacked for targeted protein degradation-is still largely unexplored. Only about 2% of the more than 600 E3 ligases have been utilized to date. Exploiting additional E3 ligases that are, for example, selectively expressed in specific tissues or cells, or regulated under certain conditions, can considerably broaden the applicability of molecular degraders as a therapeutic modality. Here, we provide an overview of major classes of E3 ligases, review the enzymes that have been exploited for induced protein degradation and approaches used to identify or design E3 ligands, and highlight challenges and opportunities for targeting new E3 ligases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chembiol.2021.04.007DOI Listing
April 2021

Effects of Whole-Body Adenylyl Cyclase 5 () Deficiency on Systemic Insulin Sensitivity and Adipose Tissue.

Int J Mol Sci 2021 Apr 21;22(9). Epub 2021 Apr 21.

Medical Center, Medical Department III-Endocrinology, Nephrology, Rheumatology, University of Leipzig, 04103 Leipzig, Germany.

Genome-wide association studies have identified adenylyl cyclase type 5 () as candidate gene for diabetes-related quantitative traits and an increased risk of type 2 diabetes. Mice with a whole-body deletion of do not develop obesity, glucose intolerance and insulin resistance, have improved cardiac function and increased longevity. Here, we investigated knockout mice () to test the hypothesis that changes in adipose tissue (AT) may contribute to the reported healthier phenotype. In contrast to previous reports, we found that deletion of did not confer any physiological or biochemical benefits. However, this unexpected finding allowed us to investigate the effects of depletion on AT independently of lower body weight and a metabolically healthier phenotype. mice exhibited an increased number of smaller adipocytes, lower mean adipocyte size and a distinct AT gene expression pattern with midline 1 () as the most significantly downregulated gene compared to control mice. Our model challenges previously described beneficial effects of deficiency and suggests that targeting Adcy5 does not improve insulin sensitivity and may therefore limit the relevance of ADCY5 as potential drug target.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms22094353DOI Listing
April 2021

Novel Inhibitors of Nicotinamide--Methyltransferase for the Treatment of Metabolic Disorders.

Molecules 2021 Feb 13;26(4). Epub 2021 Feb 13.

Sanofi-Aventis Deutschland Gmbh, Industriepark Hoechst, 65926 Frankfurt am Main, Germany.

Nicotinamide--methyltransferase (NNMT) is a cytosolic enzyme catalyzing the transfer of a methyl group from -adenosyl-methionine (SAM) to nicotinamide (Nam). It is expressed in many tissues including the liver, adipose tissue, and skeletal muscle. Its expression in several cancer cell lines has been widely discussed in the literature, and recent work established a link between NNMT expression and metabolic diseases. Here we describe our approach to identify potent small molecule inhibitors of NNMT featuring different binding modes as elucidated by X-ray crystallographic studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules26040991DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7918612PMC
February 2021

Activation of thyroid hormone receptor-β improved disease activity and metabolism independent of body weight in a mouse model of non-alcoholic steatohepatitis and fibrosis.

Br J Pharmacol 2021 Mar 3. Epub 2021 Mar 3.

Diabetes Research, Sanofi Research and Development, Frankfurt, Germany.

Background And Purpose: Activation of hepatic thyroid hormone receptor β (THR-β) is associated with systemic lipid lowering, increased bile acid synthesis, and fat oxidation. In patients with non-alcoholic steatohepatitis (NASH), treatment with THR-β agonists decreased hepatic steatosis and circulating lipids, and induced resolution of NASH. We chose resmetirom (MGL-3196), a liver-directed, selective THR-β agonist, as a prototype to investigate the effects of THR-β activation in mice with diet-induced obesity (DIO) and biopsy-confirmed advanced NASH with fibrosis.

Experimental Approach: C57Bl/6J mice were fed a diet high in fat, fructose, and cholesterol for 34 weeks, and only biopsy-confirmed DIO-NASH mice with fibrosis were included. Resmetirom was administered at a daily dose of 3 mg·kg p.o., for 8 weeks. Systemic and hepatic metabolic parameters, histological non-alcoholic fatty liver disease (NAFLD) activity and fibrosis scores, and liver RNA expression profiles were determined to assess the effect of THR-β activation.

Key Results: Treatment with resmetirom did not influence body weight but led to significant reduction in liver weight, hepatic steatosis, plasma alanine aminotransferase activity, liver and plasma cholesterol, and blood glucose. These metabolic effects translated into significant improvement in NAFLD activity score. Moreover, a lower content of α-smooth muscle actin and down-regulation of genes involved in fibrogenesis indicated a decrease in hepatic fibrosis.

Conclusion And Implications: Our model robustly reflected clinical observations of body weight-independent improvements in systemic and hepatic metabolism including anti-steatotic activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/bph.15427DOI Listing
March 2021

Effect of Mastiha supplementation on NAFLD: The MAST4HEALTH Randomised, Controlled Trial.

Mol Nutr Food Res 2021 Feb 24:e2001178. Epub 2021 Feb 24.

Cardiometabolic Risk Unit, Institute of Clinical Physiology, CNR, Pisa, Italy.

Scope: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease with poor therapeutic strategies. Mastiha possesses antioxidant/anti-inflammatory and lipid-lowering properties. The authors investigate the effectiveness of Mastiha as a nonpharmacological intervention in NAFLD.

Methods And Results: Ninety-eight patients with NAFLD in three countries (Greece, Italy, Serbia) are randomly allocated to either Mastiha or Placebo for 6 months, as part of a multicenter, randomized, double-blind, placebo-controlled, parallel-group clinical trial. The authors assess NAFLD severity via magnetic resonance imaging (MRI) scanning and LiverMultiScan technique and evaluate the effectiveness of Mastiha through medical, anthropometric, biochemical, metabolomic, and microbiota assessment. Mastiha is not superior to Placebo on changes in iron-corrected T1 (cT1) and Liver Inflammation Fibrosis score (LIF) in entire patient population; however, after BMI stratification (BMI ≤ 35 kg m and BMI > 35 kg m ), severely obese patients show an improvement in cT1 and LIF in Mastiha versus Placebo. Mastiha increases dissimilarity of gut microbiota, as shown by the Bray-Curtis index, downregulates Flavonifractor, a known inflammatory taxon and decreases Lysophosphatidylcholines-(LysoPC) 18:1, Lysophosphatidylethanolamines-(LysoPE) 18:1, and cholic acid compared to Placebo.

Conclusion: Mastiha supplementation improves microbiota dysbiosis and lipid metabolite levels in patients with NAFLD, although it reduces parameters of liver inflammation/fibrosis only in severely obese patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mnfr.202001178DOI Listing
February 2021

AMPKβ1 and AMPKβ2 define an isoform-specific gene signature in human pluripotent stem cells, differentially mediating cardiac lineage specification.

J Biol Chem 2020 12;295(51):17659-17671

Research & Development, Sanofi-Aventis Deutschland GmbH, Frankfurt/Main, Germany. Electronic address:

AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism that phosphorylates a wide range of proteins to maintain cellular homeostasis. AMPK consists of three subunits: α, β, and γ. AMPKα and β are encoded by two genes, the γ subunit by three genes, all of which are expressed in a tissue-specific manner. It is not fully understood, whether individual isoforms have different functions. Using RNA-Seq technology, we provide evidence that the loss of AMPKβ1 and AMPKβ2 lead to different gene expression profiles in human induced pluripotent stem cells (hiPSCs), indicating isoform-specific function. The knockout of AMPKβ2 was associated with a higher number of differentially regulated genes than the deletion of AMPKβ1, suggesting that AMPKβ2 has a more comprehensive impact on the transcriptome. Bioinformatics analysis identified cell differentiation as one biological function being specifically associated with AMPKβ2. Correspondingly, the two isoforms differentially affected lineage decision toward a cardiac cell fate. Although the lack of PRKAB1 impacted differentiation into cardiomyocytes only at late stages of cardiac maturation, the availability of PRKAB2 was indispensable for mesoderm specification as shown by gene expression analysis and histochemical staining for cardiac lineage markers such as cTnT, GATA4, and NKX2.5. Ultimately, the lack of AMPKβ1 impairs, whereas deficiency of AMPKβ2 abrogates differentiation into cardiomyocytes. Finally, we demonstrate that AMPK affects cellular physiology by engaging in the regulation of hiPSC transcription in an isoform-specific manner, providing the basis for further investigations elucidating the role of dedicated AMPK subunits in the modulation of gene expression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.RA120.013990DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7762962PMC
December 2020

A 3D Human Liver Model of Nonalcoholic Steatohepatitis.

J Clin Transl Hepatol 2020 Dec 15;8(4):359-370. Epub 2020 Dec 15.

Translational Sciences, Sanofi, 1 Avenue Pierre Brossolette, Chilly-Mazarin, France.

To better understand nonalcoholic steatohepatitis (NASH) disease progression and to evaluate drug targets and compound activity, we undertook the development of an 3D model to mimic liver architecture and the NASH environment. We have developed an preclinical 3D NASH model by coculturing primary human hepatocytes, human stellate cells, liver endothelial cells and Kupffer cells embedded in a hydrogel of rat collagen on a 96-well plate. A NASH-like environment was induced by addition of medium containing free fatty acids and tumor necrosis factor-α. This model was then characterized by biochemical, imaging and transcriptomics analyses. We succeeded in defining suitable culture conditions to maintain the 3D coculture for up to 10 days , with the lowest level of steatosis and reproducible low level of inflammation and fibrosis. NASH disease was induced with a custom medium mimicking NASH features. The cell model exhibited the key NASH disease phenotypes of hepatocyte injury, steatosis, inflammation, and fibrosis. Hepatocyte injury was highlighted by a decrease of CYP3A4 expression and activity, without loss of viability up to day 10. Moreover, the model was able to stimulate a stable inflammatory and early fibrotic environment, with expression and secretion of several cytokines. A global gene expression analysis confirmed the NASH induction. This is a new model of NASH disease consisting of four human primary cell-types that exhibits most features of the disease. The 10-day cell viability and cost effectiveness of the model make it suitable for medium throughput drug screening and provide attractive avenues to better understand disease physiology and to identify and characterize new drug targets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14218/JCTH.2020.00015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7782122PMC
December 2020

Triantennary GalNAc Molecular Imaging Probes for Monitoring Hepatocyte Function in a Rat Model of Nonalcoholic Steatohepatitis.

Adv Sci (Weinh) 2020 Dec 9;7(24):2002997. Epub 2020 Nov 9.

Industriepark Höchst 65926 Frankfurt Germany.

Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease that can lead to irreversible liver cirrhosis and cancer. Early diagnosis of NASH is vital to detect disease before it becomes life-threatening, yet noninvasively differentiating NASH from simple steatosis is challenging. Herein, bifunctional probes have been developed that target the hepatocyte-specific asialoglycoprotein receptor (ASGPR), the expression of which decreases during NASH progression. The results show that the probes allow longitudinal, noninvasive monitoring of ASGPR levels by positron emission tomography in the newly developed rat model of NASH. The probes open new possibilities for research into early diagnosis of NASH and development of drugs to slow or reverse its progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/advs.202002997DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7739951PMC
December 2020

The Novel Phosphate and Bile Acid Sequestrant Polymer SAR442357 Delays Disease Progression in a Rat Model of Diabetic Nephropathy.

J Pharmacol Exp Ther 2021 02 17;376(2):190-203. Epub 2020 Nov 17.

R&D Diabetes (T.R.C., R.E., A.Ka., A.Ko., P.J.L., C.A., T.H.), Integrated Drug Discovery (M.M.), Biomarkers and Clinical Bioanalysis (U.S.), Translational In Vivo Models, Global Discovery Pathology (P.S.), and Global Research Project Management (M.F.), Sanofi-Aventis Deutschland GmbH, Industriepark Höchst, Frankfurt, Germany; C&BD Haverhill Operations, Sanofi GB Genzyme Limited, Haverhill, Suffolk, United Kingdom (I.D.); R&D Translational Sciences France, Bioinformatics, Sanofi, Chilly-Mazarin Cedex, France (C.R.); Translational In Vivo Models, Global Discovery Pathology, Framingham, Massachusetts (K.S., D.S.B.); and Pharmaceutical Development Platform, Sanofi Global R&D, Waltham, Massachusetts (P.K.D.)

As a gut-restricted, nonabsorbed therapy, polymeric bile acid sequestrants (BAS) play an important role in managing hyperlipidemia and hyperglycemia. Similarly, nonabsorbable sequestrants of dietary phosphate have been used for the management of hyperphosphatemia in end-stage renal disease. To evaluate the potential utility of such polymer sequestrants to treat type 2 diabetes (T2D) and its associated renal and cardiovascular complications, we synthesized a novel polymeric sequestrant, SAR442357, possessing optimized bile acid (BA) and phosphate sequestration characteristics. Long-term treatment of T2D obese Zucker fatty/Spontaneously hypertensive heart failure F1 hybrid (ZSF1) with SAR442357 resulted in enhanced sequestration of BAs and phosphate in the gut, improved glycemic control, lowering of serum cholesterol, and attenuation of diabetic kidney disease (DKD) progression. In comparison, colesevelam, a BAS with poor phosphate binding properties, did not prevent DKD progression, whereas losartan, an angiotensin II receptor blocker that is widely used to treat DKD, showed no effect on hyperglycemia. Analysis of hepatic gene expression levels of the animals treated with SAR442357 revealed upregulation of genes responsible for the biosynthesis of cholesterol and BAs, providing clear evidence of target engagement and mode of action of the new sequestrant. Additional hepatic gene expression pathway changes were indicative of an interruption of the enterohepatic BA cycle. Histopathological analysis of ZSF1 rat kidneys treated with SAR442357 further supported its nephroprotective properties. Collectively, these findings reveal the pharmacological benefit of simultaneous sequestration of BAs and phosphate in treating T2D and its associated comorbidities and cardiovascular complications. SIGNIFICANCE STATEMENT: A new nonabsorbed polymeric sequestrant with optimum phosphate and bile salt sequestration properties was developed as a treatment option for DKD. The new polymeric sequestrant offered combined pharmacological benefits including glucose regulation, lipid lowering, and attenuation of DKD progression in a single therapeutic agent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1124/jpet.120.000285DOI Listing
February 2021

Short-term variability of the human serum metabolome depending on nutritional and metabolic health status.

Sci Rep 2020 10 1;10(1):16310. Epub 2020 Oct 1.

Sanofi Research and Development, Frankfurt, Germany.

The intra-individual variability of the human serum metabolome over a period of 4 weeks and its dependence on metabolic health and nutritional status was investigated in a single-center study under tightly controlled conditions in healthy controls, pre-diabetic individuals and patients with type-2 diabetes mellitus (T2DM, n = 10 each). Untargeted metabolomics in serum samples taken at three different days after overnight fasts and following intake of a standardized mixed meal showed that the human serum metabolome is remarkably stable: The median intra-class correlation coefficient (ICC) across all metabolites and all study participants was determined as 0.65. ICCs were similar for the three different health groups, before and after meal intake, and for different metabolic pathways. Only 147 out of 1438 metabolites (10%) had an ICC below 0.4 indicating poor stability over time. In addition, we confirmed previously identified metabolic signatures differentiating healthy, pre-diabetic and diabetic individuals. To our knowledge, this is the most comprehensive study investigating the temporal variability of the human serum metabolome under such tightly controlled conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-72914-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7530737PMC
October 2020

Protective effect of Soluble Epoxide Hydrolase Inhibition in Retinal Vasculopathy associated with Polycystic Kidney Disease.

Theranostics 2020 22;10(17):7857-7871. Epub 2020 Jun 22.

5th Medical Department, Medical Faculty Mannheim, University of Heidelberg, D-68167 Mannheim, Germany.

Vasoregression secondary to glial activation develops in various retinal diseases, including retinal degeneration and diabetic retinopathy. Photoreceptor degeneration and subsequent retinal vasoregression, characterized by pericyte loss and acellular capillary formation in the absence diabetes, are also seen in transgenic rats expressing the polycystic kidney disease (PKD) gene. Activated Müller glia contributes to retinal vasodegeneration, at least in part via the expression of the soluble epoxide hydrolase (sEH). Given that an increase in sEH expression triggered vascular destabilization in diabetes, and that vasoregression is similar in diabetic mice and PKD rats, the aim of the present study was to determine whether sEH inhibition could prevent retinal vasoregression in the PKD rat. One-month old male homozygous transgenic PKD rats were randomly allocated to receive vehicle or a sEH inhibitor (sEH-I; Sar5399, 30 mg/kg) for four weeks. Wild-type Sprague-Dawley (SD) littermates received vehicle as controls. Retinal sEH expression and activity were measured by Western blotting and LC-MS, and vasoregression was quantified in retinal digestion preparations. Microglial activation and immune response cytokines were assessed by immunofluorescence and quantitative PCR, respectively. 19,20-dihydroxydocosapentaenoic acid (19,20-DHDP) mediated Notch signaling, microglial activation and migration were assessed and . This study demonstrates that sEH expression and activity were increased in PKD retinae, which led to elevated production of 19,20-DHDP and the depression of Notch signaling. The latter changes elicited pericyte loss and the recruitment of CD11b/CD74 microglia to the perivascular region. Microglial activation increased the expression of immune-response cytokines, and reduced levels of Notch3 and delta-like ligand 4 (Dll4). Treatment with Sar5399 decreased 19,20-DHDP generation and increased Notch3 expression. Sar5399 also prevented vasoregression by reducing pericyte loss and suppressed microglial activation as well as the expression of immune-response cytokines. Mechanistically, the activation of Notch signaling by Dll4 maintained a quiescent microglial cell phenotype, i.e. reduced both the surface presentation of CD74 and microglial migration. In contrast, in retinal explants, 19,20-DHDP and Notch inhibition both promoted CD74 expression and reversed the Dll4-induced decrease in migration. Our data indicate that 19,20-DHDP-induced alterations in Notch-signaling result in microglia activation and pericyte loss and contribute to retinal vasoregression in polycystic kidney disease. Moreover, sEH inhibition can ameliorate vasoregression through reduced activity of inflammatory microglia. sEH inhibition is thus an attractive new therapeutic approach to prevent retinal vasoregression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7150/thno.43154DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7359083PMC
May 2021

Activation of Adenosine Monophosphate-Activated Protein Kinase Reduces the Onset of Diet-Induced Hepatocellular Carcinoma in Mice.

Hepatol Commun 2020 Jul 15;4(7):1056-1072. Epub 2020 May 15.

Sanofi R&D Frankfurt Germany.

The worldwide obesity and type 2 diabetes epidemics have led to an increase in nonalcoholic fatty liver disease (NAFLD). NAFLD covers a spectrum of hepatic pathologies ranging from simple steatosis to nonalcoholic steatohepatitis, characterized by fibrosis and hepatic inflammation. Nonalcoholic steatohepatitis predisposes to the onset of hepatocellular carcinoma (HCC). Here, we characterized the effect of a pharmacological activator of the intracellular energy sensor adenosine monophosphate-activated protein kinase (AMPK) on NAFLD progression in a mouse model. The compound stimulated fat oxidation by activating AMPK in both liver and skeletal muscle, as revealed by indirect calorimetry. This translated into an ameliorated hepatic steatosis and reduced fibrosis progression in mice fed a diet high in fat, cholesterol, and fructose for 20 weeks. Feeding mice this diet for 80 weeks caused the onset of HCC. The administration of the AMPK activator for 12 weeks significantly reduced tumor incidence and size. Pharmacological activation of AMPK reduces NAFLD progression to HCC in preclinical models.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hep4.1508DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7327225PMC
July 2020

Incretin combination therapy for the treatment of non-alcoholic steatohepatitis.

Diabetes Obes Metab 2020 08 12;22(8):1328-1338. Epub 2020 Apr 12.

Sanofi Research and Development, Frankfurt, Germany.

Aims: To test specific mono-agonists to the glucagon-like peptide-1 receptor (GLP-1R), glucagon receptor (GCGR) and glucose-dependent insulinotropic peptide receptor (GIPR), individually and in combination, in a mouse model of diet-induced non-alcoholic steatohepatitis (NASH) and fibrosis in order to decipher the contribution of their activities and potential additive effects to improving systemic and hepatic metabolism.

Materials And Methods: We induced NASH by pre-feeding C57BL/6J mice a diet rich in fat, fructose and cholesterol for 36 weeks. This was followed by 8 weeks of treatment with the receptor-specific agonists 1-GCG (20 μg/kg twice daily), 2-GLP1 (3 μg/kg twice daily) or 3-GIP (30 μg/kg twice daily), or the dual (1 + 2) or triple (1 + 2 + 3) combinations thereof. A dual GLP-1R/GCGR agonistic peptide, 4-dual-GLP1/GCGR (30 μg/kg twice daily), and liraglutide (100 μg/kg twice daily) were included as references.

Results: Whereas low-dose 1-GCG or 3-GIP alone did not influence body weight, liver lipids and histology, their combination with 2-GLP1 provided additional weight loss, reduction in liver triglycerides and improvement in histological disease activity score. Notably, 4-dual-GLP-1R/GCGR and the triple combination of selective mono-agonists led to a significantly stronger reduction in the histological non-alcoholic fatty liver disease activity score compared to high-dose liraglutide, at the same extent of body weight loss.

Conclusions: GCGR and GIPR agonism provide additional, body weight-independent improvements on top of GLP-1R agonism in a murine model of manifest NASH with fibrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/dom.14035DOI Listing
August 2020

Novel Biomarkers for Change in Renal Function in People With Dysglycemia.

Diabetes Care 2020 02 14;43(2):433-439. Epub 2019 Nov 14.

Sanofi Aventis Deutschland GmbH Research and Development, Frankfurt, Germany.

Objective: Diabetes is a major risk factor for renal function decline and failure. The availability of multiplex panels of biochemical markers provides the opportunity to identify novel biomarkers that can better predict changes in renal function than routinely available clinical markers.

Research Design And Methods: The concentration of 239 biochemical markers was measured in stored serum from participants in the biomarker substudy of Outcome Reduction With Initial Glargine Intervention (ORIGIN) trial. Repeated-measures mixed-effects models were used to compute the annual change in eGFR (measured as mL/min/1.73 m/year) for the 7,482 participants with a recorded baseline and follow-up eGFR. Linear regression models using forward selection were used to identify the independent biomarker determinants of the annual change in eGFR after accounting for baseline HbA, baseline eGFR, and routinely measured clinical risk factors. The incidence of the composite renal outcome (i.e., renal replacement therapy, renal death, renal failure, albuminuria progression, doubling of serum creatinine) and death within each fourth of change in eGFR predicted from these models was also estimated.

Results: During 6.2 years of median follow-up, the median annual change in eGFR was -0.18 mL/min/1.73 m/year. Fifteen biomarkers independently predicted eGFR decline after accounting for cardiovascular risk factors, as did 12 of these plus 1 additional biomarker after accounting for renal risk factors. Every 0.1 mL/min/1.73 m predicted annual fall in eGFR predicted a 13% (95% CI 12, 14%) higher mortality.

Conclusions: Adding up to 16 biomarkers to routinely measured clinical risk factors improves the prediction of annual change in eGFR in people with dysglycemia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/dc19-1604DOI Listing
February 2020

Vasodilation of rat skeletal muscle arteries by the novel BK channel opener GoSlo is mediated by the simultaneous activation of BK and K 7 channels.

Br J Pharmacol 2020 03 26;177(5):1164-1186. Epub 2020 Jan 26.

Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.

Background And Purpose: BK channels play important roles in various physiological and pathophysiological processes and thus have been the target of several drug development programmes focused on creating new efficacious BK channel openers, such as the GoSlo-SR compounds. However, the effect of GoSlo-SR compounds on vascular smooth muscle has not been studied. Therefore, we tested the hypothesis that GoSlo-SR compounds dilate arteries exclusively by activating BK channels.

Experimental Approach: Experiments were performed on rat Gracilis muscle, saphenous, mesenteric and tail arteries using isobaric and isometric myography, sharp microelectrodes, digital droplet PCR and the patch-clamp technique.

Key Results: GoSlo-SR compounds dilated isobaric and relaxed and hyperpolarised isometric vessel preparations and their effects were abolished after (a) functionally eliminating K channels by pre-constriction with 50 mM KCl or (b) blocking all K channels known to be expressed in vascular smooth muscle. However, these effects were not blocked when BK channels were inhibited. Surprisingly, the K 7 channel inhibitor XE991 reduced their effects considerably, but neither K 1 nor K 2 channel blockers altered the inhibitory effects of GoSlo-SR. However, the combined blockade of BK and K 7 channels abolished the GoSlo-SR-induced relaxation. GoSlo-SR compounds also activated K 7.4 and K 7.5 channels expressed in HEK 293 cells.

Conclusion And Implications: This study shows that GoSlo-SR compounds are effective relaxants in vascular smooth muscle and mediate their effects by a combined activation of BK and K 7.4/K 7.5 channels. Activation of K 1, K 2 or K 7.1 channels or other vasodilator pathways seems not to be involved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/bph.14910DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7042121PMC
March 2020

Mastiha (Pistacia lentiscus) Improves Gut Microbiota Diversity, Hepatic Steatosis, and Disease Activity in a Biopsy-Confirmed Mouse Model of Advanced Non-Alcoholic Steatohepatitis and Fibrosis.

Mol Nutr Food Res 2019 12 23;63(24):e1900927. Epub 2019 Oct 23.

Foundation for the Promotion of Health and Biomedical Research (FISABIO), 46035, Valencia, Spain.

Scope: As a result of the obesity epidemic, the prevalence of non-alcoholic steatohepatitis (NASH) is increasing. No drug is approved for the treatment of NASH. In this study, the effect of a nutritional supplement, Mastiha or Chios mastic gum, on metabolic and histological parameters and on the gut microbiome in mice with NASH and fibrosis was investigated.

Methods And Results: Advanced NASH was induced by feeding C57BL/6J mice a diet rich in fat, sucrose, and cholesterol for 41 weeks. After randomization, animals received the NASH-inducing diet with or without 0.2% (w/w) Mastiha for a further 8 weeks. Disease activity was assessed by liver histology and determination of plasma transaminase activities. Fecal microbiota DNA extraction and 16S rRNA amplicon sequencing were used to determine the composition of the gut microbiome. Mastiha supplementation led to a significant reduction in circulating alanine aminotransferase (ALT) activity, improvement in hepatic steatosis and collagen content, and a reduction in NAFLD activity score. Furthermore, it resulted in a partial but significant recovery of gut microbiota diversity and changes in identity and abundance of specific taxa.

Conclusion: This is the first study demonstrating an improvement in disease activity in mice with advanced NASH with fibrosis by a diet containing Mastiha.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mnfr.201900927DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7003480PMC
December 2019

High-Affinity Alkynyl Bisubstrate Inhibitors of Nicotinamide -Methyltransferase (NNMT).

J Med Chem 2019 11 25;62(21):9837-9873. Epub 2019 Oct 25.

Jubilant Biosys Ltd. , Yeshwantpur, Bangalore , 560 022 Karnataka , India.

Nicotinamide -methyltransferase (NNMT) is a metabolic enzyme that methylates nicotinamide (NAM) using cofactor -adenosylmethionine (SAM). NNMT overexpression has been linked to diabetes, obesity, and various cancers. In this work, structure-based rational design led to the development of potent and selective alkynyl bisubstrate inhibitors of NNMT. The reported nicotinamide-SAM conjugate (named NS1) features an alkyne as a key design element that closely mimics the linear, 180° transition state geometry found in the NNMT-catalyzed SAM → NAM methyl transfer reaction. NS1 was synthesized in 14 steps and found to be a high-affinity, subnanomolar NNMT inhibitor. An X-ray cocrystal structure and SAR study revealed the ability of an alkynyl linker to span the methyl transfer tunnel of NNMT with ideal shape complementarity. The compounds reported in this work represent the most potent and selective NNMT inhibitors reported to date. The rational design principle described herein could potentially be extended to other methyltransferase enzymes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jmedchem.9b01238DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7955893PMC
November 2019

A Therapeutic Silencing RNA Targeting Hepatocyte TAZ Prevents and Reverses Fibrosis in Nonalcoholic Steatohepatitis in Mice.

Hepatol Commun 2019 Sep 23;3(9):1221-1234. Epub 2019 Jul 23.

Department of Medicine Columbia University Irving Medical Center New York NY.

Nonalcoholic steatohepatitis (NASH) is emerging as a major public health issue and is associated with significant liver-related morbidity and mortality. At present, there are no approved drug therapies for NASH. The transcriptional coactivator with PDZ-binding motif (TAZ; encoded by WW domain-containing transcription regulator 1 []) is up-regulated in hepatocytes in NASH liver from humans and has been shown to causally promote inflammation and fibrosis in mouse models of NASH. As a preclinical test of targeting hepatocyte TAZ to treat NASH, we injected stabilized TAZ small interfering RNA (siRNA) bearing the hepatocyte-specific ligand N-acetylgalactosamine (GalNAc-siTAZ) into mice with dietary-induced NASH. As a preventative regimen, GalNAc-siTAZ inhibited inflammation, hepatocellular injury, and the expression of profibrogenic mediators, accompanied by decreased progression from steatosis to NASH. When administered to mice with established NASH, GalNAc-siTAZ partially reversed hepatic inflammation, injury, and fibrosis. : Hepatocyte-targeted siTAZ is potentially a novel and clinically feasible treatment for NASH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hep4.1405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6719739PMC
September 2019

Characterization of Glycolytic Enzymes and Pyruvate Kinase M2 in Type 1 and 2 Diabetic Nephropathy.

Diabetes Care 2019 07 10;42(7):1263-1273. Epub 2019 May 10.

Joslin Diabetes Center, Boston, MA

Objective: Elevated glycolytic enzymes in renal glomeruli correlated with preservation of renal function in the Medalist Study, individuals with ≥50 years of type 1 diabetes. Specifically, pyruvate kinase M2 (PKM2) activation protected insulin-deficient diabetic mice from hyperglycemia-induced glomerular pathology. This study aims to extend these findings in a separate cohort of individuals with type 1 and type 2 diabetes and discover new circulatory biomarkers for renal protection through proteomics and metabolomics of Medalists' plasma. We hypothesize that increased glycolytic flux and improved mitochondrial biogenesis will halt the progression of diabetic nephropathy.

Research Design And Methods: Immunoblots analyzed selected glycolytic and mitochondrial enzymes in postmortem glomeruli of non-Medalists with type 1 diabetes ( = 15), type 2 diabetes ( = 19), and no diabetes ( = 5). Plasma proteomic (SOMAscan) ( = 180) and metabolomic screens ( = 214) of Medalists with and without stage 3b chronic kidney disease (CKD) were conducted and significant markers validated by ELISA.

Results: Glycolytic (PKM1, PKM2, and ENO1) and mitochondrial (MTCO2) enzymes were significantly elevated in glomeruli of CKD- versus CKD+ individuals with type 2 diabetes. Medalists' plasma PKM2 correlated with estimated glomerular filtration rate ( = 0.077; = 0.0002). Several glucose and mitochondrial enzymes in circulation were upregulated with corresponding downregulation of toxic metabolites in CKD-protected Medalists. Amyloid precursor protein was also significantly upregulated, tumor necrosis factor receptors downregulated, and both confirmed by ELISA.

Conclusions: Elevation of enzymes involved in the metabolism of intracellular free glucose and its metabolites in renal glomeruli is connected to preserving kidney function in both type 1 and type 2 diabetes. The renal profile of elevated glycolytic enzymes and reduced toxic glucose metabolites is reflected in the circulation, supporting their use as biomarkers for endogenous renal protective factors in people with diabetes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/dc18-2585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609957PMC
July 2019

Smoking and Other Risk Factors in Type 2 Diabetes.

Authors:
Aimo Kannt

N Engl J Med 2018 Dec;379(26):2574

Sanofi, Franfurt, Germany

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1056/NEJMc1812842DOI Listing
December 2018

Genetic Nicotinamide -Methyltransferase () Deficiency in Male Mice Improves Insulin Sensitivity in Diet-Induced Obesity but Does Not Affect Glucose Tolerance.

Diabetes 2019 03 14;68(3):527-542. Epub 2018 Dec 14.

Sanofi Research and Development, Frankfurt am Main, Germany

Antisense oligonucleotide knockdown (ASO-KD) of nicotinamide -methyltransferase (NNMT) in high-fat diet (HFD)-fed mice has been reported to reduce weight gain and plasma insulin levels and to improve glucose tolerance. Using NNMT-ASO-KD or NNMT knockout mice (NNMT), we tested the hypothesis that deletion protects against diet-induced obesity and its metabolic consequences in males and females on obesity-inducing diets. We also examined samples from a human weight reduction (WR) study for adipose (a) expression and plasma 1-methylnicotinamide (MNAM) levels. In Western diet (WD)-fed female mice, NNMT-ASO-KD reduced body weight, fat mass, and insulin level and improved glucose tolerance. Although NNMT mice fed a standard diet had no obvious phenotype, NNMT males fed an HFD showed strongly improved insulin sensitivity (IS). Furthermore, NNMT females fed a WD showed reduced weight gain, less fat, and lower insulin levels. However, no improved glucose tolerance was observed in NNMT mice. Although expression in human fat biopsy samples increased during WR, corresponding plasma MNAM levels significantly declined, suggesting that other mechanisms besides a expression modulate circulating MNAM levels during WR. In summary, upon NNMT deletion or knockdown in males and females fed different obesity-inducing diets, we observed sex- and diet-specific differences in body composition, weight, and glucose tolerance and estimates of IS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/db18-0780DOI Listing
March 2019

Team Players or Opponents: Coadministration of Selective Glucagon and GLP-1 Receptor Agonists in Obese Diabetic Monkeys.

Endocrinology 2018 08;159(8):3105-3119

Sanofi-Aventis Deutschland GmbH, Industriepark Höchst, Frankfurt, German.

We assessed the therapeutic contribution of the individual components of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) agonists alone and in combination upon energy homeostasis and glycemic control in diet-induced obese, diabetic nonhuman primates. The pharmacological active dose ranges of selective agonists were established through a dose-finding study, followed by a 6-week chronic study. Repeated subcutaneous administration of a selective GCGR agonist (30 µg/kg once daily) did not affect food intake or body weight, whereas the selective GLP-1R agonist (3 µg/kg once daily) alone decreased energy intake by 18% and body weight by 3.8% ± 0.9%. Combination of both agonists reduced significantly cumulative food intake by 27% and body weight by 6.6% ± 0.9%. Fasting plasma glucose (FPG) was improved by GLP-1R agonist (baseline vs end of study, 176.7 ± 34.0 vs 115.9 ± 16.1 mg/dL). In contrast, groups exposed to GCGR agonist experienced nonsignificant elevations of FPG. More accurate assessment of therapeutic interventions on glucose homeostasis was tested by an IV glucose tolerance test. Glucose excursion was significantly elevated by chronic GCGR agonist administration, whereas it was significantly decreased in GLP-1R agonist-treated monkeys. In the combination group, a nonsignificant increase of glucose excursion was seen, concomitantly with significantly increased insulin secretion. We conclude that chronic glucagon agonism does not affect energy homeostasis in nonhuman primates. In combination with GLP-1R agonism, glucagon agonism synergistically enhances negative energy balance with resulting larger body weight loss. However, adding GCGR to GLP-1R agonism diminishes glycemic control in diabetic monkeys. Therefore, long-term therapeutic implications of using GLP-1R/GCGR coagonists for weight management in diabetes warrants further scrutiny.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/en.2018-00399DOI Listing
August 2018

Running on mixed fuel-dual agonistic approach of GLP-1 and GCG receptors leads to beneficial impact on body weight and blood glucose control: A comparative study between mice and non-human primates.

Diabetes Obes Metab 2018 Aug 25;20(8):1836-1851. Epub 2018 Jun 25.

Sanofi-Aventis Deutschland GmbH, Frankfurt, Germany.

Aim: We performed acute and chronic studies in healthy and diet-induced obese animals using mouse-specific or monkey-specific dual GLP-1R/GCGR agonists to investigate their effects on food intake, body weight, blood glucose control and insulin secretion. The selective GLP-1R agonist liraglutide was used as comparator.

Methods: The mouse-specific dual agonist and liraglutide were tested in lean wild type, GLP-1R knockout and diet-induced obese mice at different doses. A chronic study was performed in DIO mice to investigate the effect on body weight, food consumption and total energy expenditure (TEE) in obese and diabetic monkeys with a focus on body weight and energy intake.

Results: The mouse-specific dual agonist and liraglutide similarly affected glycaemic control. A higher loss in body weight was measured in dual agonist-treated obese mice. The dual agonist significantly enhanced plasma glucose excursion in overnight fed GLP-1R mice, probably reflecting a potent GCGR agonist activity. It increased TEE and enhanced fat and carbohydrate oxidation, while liraglutide produced no effect on TEE. In obese and diabetic monkeys, treatment with the monkey-specific dual agonist reduced total energy intake to 60%-70% of baseline TEI during chronic treatment. A decrease in body weight and significant improvement in glucose tolerance was observed.

Conclusions: In DIO mice and non-human primates, dual agonists elicited robust glycaemic control, similar to the marketed GLP-1R agonist, while eliciting greater effects on body weight. Results from DIO mice suggest that the increase in TEE is caused not only by increased fat oxidation but also by an increase in carbohydrate oxidation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/dom.13212DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6055720PMC
August 2018

Identification and characterisation of carnostatine (SAN9812), a potent and selective carnosinase (CN1) inhibitor with in vivo activity.

Amino Acids 2019 Jan 20;51(1):7-16. Epub 2018 Jun 20.

Sanofi Research and Development, Frankfurt am Main, Germany.

Carnosinase 1 (CN1) has been postulated to be a susceptibility factor for developing diabetic nephropathy (DN). Although its major substrate, carnosine, is beneficial in rodent models of DN, translation of these findings to humans has been hampered by high CN1 activity in human serum resulting in rapid degradation of carnosine. To overcome this hurdle, we screened a protease-directed small-molecule library for inhibitors of human recombinant CN1. We identified SAN9812 as a potent and highly selective inhibitor of CN1 activity with a K of 11 nM. It also inhibited CN1 activity in human serum and serum of transgenic mice-overexpressing human CN1. Subcutaneous administration of 30 mg/kg SAN9812 led to a sustained reduction in circulating CN1 activity in human CN1 transgenic (TG) mice. Simultaneous administration of carnosine and SAN9812 increased carnosine levels in plasma and kidney by up to 100-fold compared to treatment-naïve CN1-overexpressing mice. To our knowledge, this is the first study reporting on a potent and selective CN1 inhibitor with in vivo activity. SAN9812, also called carnostatine, may be used to increase renal carnosine concentration as a potential therapeutic modality for renal diseases linked to glycoxidative conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00726-018-2601-zDOI Listing
January 2019

A small molecule inhibitor of Nicotinamide N-methyltransferase for the treatment of metabolic disorders.

Sci Rep 2018 02 26;8(1):3660. Epub 2018 Feb 26.

Jubilant Biosys Ltd, Bangalore, 560022, India.

Nicotinamide N-methyltransferase (NNMT) is a cytosolic enzyme that catalyzes the transfer of a methyl group from the co-factor S-adenosyl-L-methionine (SAM) onto the substrate, nicotinamide (NA) to form 1-methyl-nicotinamide (MNA). Higher NNMT expression and MNA concentrations have been associated with obesity and type-2 diabetes. Here we report a small molecule analog of NA, JBSNF-000088, that inhibits NNMT activity, reduces MNA levels and drives insulin sensitization, glucose modulation and body weight reduction in animal models of metabolic disease. In mice with high fat diet (HFD)-induced obesity, JBSNF-000088 treatment caused a reduction in body weight, improved insulin sensitivity and normalized glucose tolerance to the level of lean control mice. These effects were not seen in NNMT knockout mice on HFD, confirming specificity of JBSNF-000088. The compound also improved glucose handling in ob/ob and db/db mice albeit to a lesser extent and in the absence of weight loss. Co-crystal structure analysis revealed the presence of the N-methylated product of JBSNF-000088 bound to the NNMT protein. The N-methylated product was also detected in the plasma of mice treated with JBSNF-000088. Hence, JBSNF-000088 may act as a slow-turnover substrate analog, driving the observed metabolic benefits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-018-22081-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5826917PMC
February 2018

Novel nicotinamide analog as inhibitor of nicotinamide N-methyltransferase.

Bioorg Med Chem Lett 2018 03 31;28(5):922-925. Epub 2018 Jan 31.

Department of Medicinal Chemistry, Jubilant Biosys Ltd, Bangalore 560022, India. Electronic address:

Nicotinamide N-methyltransferase (NNMT) has been linked to obesity and diabetes. We have identified a novel nicotinamide (NA) analog, compound 12 that inhibited NNMT enzymatic activity and reduced the formation of 1-methyl-nicotinamide (MNA), the primary metabolite of NA by ∼80% at 2 h when dosed in mice orally at 50 mg/kg.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bmcl.2018.01.058DOI Listing
March 2018

Crystal structures of monkey and mouse nicotinamide N-methyltransferase (NNMT) bound with end product, 1-methyl nicotinamide.

Biochem Biophys Res Commun 2017 09 15;491(2):416-422. Epub 2017 Jul 15.

Sanofi Research and Development, Industriepark Hoechst, H823, D-65926 Frankfurt am Main, Germany; Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.

Nicotinamide N-methyltransferase (NNMT) is a S-adenosyl-l-methionine (SAM)-dependent enzyme that catalyzes N-methylation of nicotinamide (NA) and other pyridines to form N-methyl pyridinium ions. Here we report the first ternary complex X-ray crystal structures of monkey NNMT and mouse NNMT in bound form with the primary endogenous product, 1-methyl nicotinamide (MNA) and demethylated cofactor, S-adenosyl-homocysteine (SAH) determined at 2.30 Å and 1.88 Å respectively. The structural fold of these enzymes is identical to human NNMT. It is known that the primary endogenous product catalyzed by NNMT, MNA is a specific inhibitor of NNMT. Our data clearly indicates that the MNA binds to the active site and it would be trapped in the active site due to the formation of the bridge between the pole (long helix, α3) and long C-terminal loop. This might explain the mechanism of MNA acting as a feedback inhibitor of NNMT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbrc.2017.07.087DOI Listing
September 2017

Pyruvate kinase M2 activation may protect against the progression of diabetic glomerular pathology and mitochondrial dysfunction.

Nat Med 2017 Jun 24;23(6):753-762. Epub 2017 Apr 24.

Research Division, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA.

Diabetic nephropathy (DN) is a major cause of end-stage renal disease, and therapeutic options for preventing its progression are limited. To identify novel therapeutic strategies, we studied protective factors for DN using proteomics on glomeruli from individuals with extreme duration of diabetes (ł50 years) without DN and those with histologic signs of DN. Enzymes in the glycolytic, sorbitol, methylglyoxal and mitochondrial pathways were elevated in individuals without DN. In particular, pyruvate kinase M2 (PKM2) expression and activity were upregulated. Mechanistically, we showed that hyperglycemia and diabetes decreased PKM2 tetramer formation and activity by sulfenylation in mouse glomeruli and cultured podocytes. Pkm-knockdown immortalized mouse podocytes had higher levels of toxic glucose metabolites, mitochondrial dysfunction and apoptosis. Podocyte-specific Pkm2-knockout (KO) mice with diabetes developed worse albuminuria and glomerular pathology. Conversely, we found that pharmacological activation of PKM2 by a small-molecule PKM2 activator, TEPP-46, reversed hyperglycemia-induced elevation in toxic glucose metabolites and mitochondrial dysfunction, partially by increasing glycolytic flux and PGC-1α mRNA in cultured podocytes. In intervention studies using DBA2/J and Nos3 (eNos) KO mouse models of diabetes, TEPP-46 treatment reversed metabolic abnormalities, mitochondrial dysfunction and kidney pathology. Thus, PKM2 activation may protect against DN by increasing glucose metabolic flux, inhibiting the production of toxic glucose metabolites and inducing mitochondrial biogenesis to restore mitochondrial function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nm.4328DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5575773PMC
June 2017

Managing risks in drug discovery: reproducibility of published findings.

Naunyn Schmiedebergs Arch Pharmacol 2016 Apr 17;389(4):353-60. Epub 2016 Feb 17.

Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.

In spite of tremendous advances in biopharmaceutical science and technology, the productivity of pharmaceutical research and development has been steadily declining over the last decades. The reasons for this decline are manifold and range from improved standard of care that is more and more difficult to top to inappropriate management of technical and translational risks along the R&D value chain. In this short review, major types of risks in biopharmaceutical R&D and means to address them will be described. A special focus will be on a risk, i.e., the lack of reproducibility of published information, that has so far not been fully appreciated and systematically analyzed. Measures to improve reproducibility and trust in published information will be discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00210-016-1216-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785199PMC
April 2016

Characterization of RA839, a Noncovalent Small Molecule Binder to Keap1 and Selective Activator of Nrf2 Signaling.

J Biol Chem 2015 Nov 12;290(47):28446-28455. Epub 2015 Oct 12.

R&D, Sanofi, 65926 Frankfurt, Germany. Electronic address:

The activation of the transcription factor NF-E2-related factor 2 (Nrf2) maintains cellular homeostasis in response to oxidative stress by the regulation of multiple cytoprotective genes. Without stressors, the activity of Nrf2 is inhibited by its interaction with the Keap1 (kelch-like ECH-associated protein 1). Here, we describe (3S)-1-[4-[(2,3,5,6-tetramethylphenyl) sulfonylamino]-1-naphthyl]pyrrolidine-3-carboxylic acid (RA839), a small molecule that binds noncovalently to the Nrf2-interacting kelch domain of Keap1 with a Kd of ∼6 μM, as demonstrated by x-ray co-crystallization and isothermal titration calorimetry. Whole genome DNA arrays showed that at 10 μM RA839 significantly regulated 105 probe sets in bone marrow-derived macrophages. Canonical pathway mapping of these probe sets revealed an activation of pathways linked with Nrf2 signaling. These pathways were also activated after the activation of Nrf2 by the silencing of Keap1 expression. RA839 regulated only two genes in Nrf2 knock-out macrophages. Similar to the activation of Nrf2 by either silencing of Keap1 expression or by the reactive compound 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid methyl ester (CDDO-Me), RA839 prevented the induction of both inducible nitric-oxide synthase expression and nitric oxide release in response to lipopolysaccharides in macrophages. In mice, RA839 acutely induced Nrf2 target gene expression in liver. RA839 is a selective inhibitor of the Keap1/Nrf2 interaction and a useful tool compound to study the biology of Nrf2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.M115.678136DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4653701PMC
November 2015