Lake sediments are globally important carbon sinks, and play a critical role in the global carbon cycle. Although the fate of organic carbon in lake sediments depends mostly on sedimentary microorganisms, the environmental controls on the microbial community structure in lake sediments are still poorly understood. Here we investigate the relationships of lake trophic state, sediment redox chemistry, sediment organic matter (OM) sources and microbial community structure in sediment records across five lakes with different eutrophication histories and trophic states in central Switzerland. Our results show that, across all five lakes, bacterial and archaeal communities based on 16S rRNA gene sequencing analyses show similar sediment depth-dependent zonations at the phylum- and class-level, which appears to be primarily driven by vertical distributions of electron acceptors and secondarily by differences in the contributions of aquatic and terrestrial OM revealed by biomarkers. Yet, there are clear differences in microbial communities between lakes, most notably the higher abundances of putatively aerobic nitrifying Bacteria (Nitrospirae) and Archaea (Marine Group I, Thaumarchaeota) in anoxic sediments of oligotrophic Lake Lucerne. Furthermore, at the level of Zero-radius Operational Taxonomic Unit (ZOTU), eutrophication-related trends are more pronounced, in which microbial communities in the sediments of eutrophic lakes are more similar and share more ZOTUs with each other than with the oligotrophic lake. Notably, deep sediment layers of presently eutrophic lakes that were deposited prior to the era of eutrophication show high similarities in bacterial communities to equivalent depths in the oligotrophic lake. By contrast, archaeal communities are clearly differentiated according to trophic state only in recently deposited sediment layers, and independent of trophic state converge toward high similarities over time. Our study indicates a significant role of trophic status in driving lacustrine sediment microbial communities and reveals fundamental differences in the temporal responses of bacterial and archaeal communities to anthropogenic eutrophication.
We designed and synthesized a new series of fatty acid synthase (FASN) inhibitors with potential utility for the treatment of cancer. Extensive SAR studies led to highly active FASN inhibitors with good cellular activity and oral bioavailability, exemplified by compound 34. Compound 34 is a potent inhibitor of human FASN (IC50 = 28 nM) that effectively inhibits proliferation of A2780 ovarian cells (IC50= 13 nM) in lipid-reduced serum (LRS). This cellular activity can be rescued by addition of palmitate, consistent with an on-target effect. Compound 34 is also active in many other cell types, including PC3M (IC50 = 25 nM) and LnCaP-Vancouver prostate cells (IC50 = 66 nM), and is highly bioavailable (F 61%) with good exposure after oral administration. In a pharmacodynamics study in H460 lung xenograft-bearing mice, oral treatment with compound 34 results in elevated tumor levels of malonyl-CoA and decreased tumor levels of palmitate, fully consistent with the desired target engagement. (C) 2018 Elsevier Ltd. All rights reserved.
Abstract Fatty Acid Synthase (FASN) catalyzes the final step in palmitate (PA) synthesis, using acetyl-CoA, malonyl-CoA and NADPH. Most normal tissues express low levels of FASN and rely on uptake of fatty acids (FA) from the diet. It has been proposed that FASN overexpressing tumors including prostate and breast tumors depend on de novo FA synthesis, which is advantageous to tumors by providing lipids for membrane synthesis and increased growth factor receptor expression/signaling in lipid rafts. Overexpression of FASN leads to a higher amount of saturated lipids in membranes which can lead to resistance to cytotoxic chemotherapy. Lastly, NADPH consumption during PA synthesis keeps the redox balance in check. All of the above imply that FASN represents a potential therapeutic target for the treatment of multiple cancer types. At this AACR we report two novel chemical series (posters Connolly et al., Lu et al.). JNJ-53793220 and JNJ-54302833 potently and selectively (< 100nM) inhibit the FASN enzyme and proliferative activity in cells in lipid reduced medium (LRM). Using these, we investigated the underlying hypothesis that tumor cells do not utilize circulating FA and are dependent on de novo synthesis of FA. In a lipid reduced environment many cell lines, particularly of prostate, breast, ovarian or heme origin, proved to be sensitive to JNJ-53793220. However co-administration of PA dose-dependently reversed the anti-proliferative effects. Also androgen driven proliferation of LNCaP cells was potently blocked by JNJ-53793220 (EC50 30 nM), and decreased PSA levels. Both effects were partially rescued by the addition of PA. While the rescue of tumor cells by PA confirmed the on-target activity of the compounds, it also suggested that cancer cells are capable of using external FA. To extend these findings, we screened more than 400 cell lines in lipid containing medium (LCM) for their sensitivity to JNJ-53793220. In LCM sensitivity to FASN inhibition was lower than in LRM conditions. In most, but not all, cases the addition of PA reverted the antiproliferative effects of JNJ-53793220, although target engagement was not reduced in LCM conditions. The EC50 of 14C-acetate incorporation in lipids of ∼30 nM corresponded well with enzymatic and anti-proliferative effects in LRM (27 and 13 nM respectively). Furthermore, growth of pre-established LNCaP xenografts in vivo was not blocked significantly by JNJ-53793220, even though malonyl-CoA levels were increased as expected upon FASN inhibition in the tumor. While circulating lipids in vivo are likely culprits for the lack of efficacy, other factors may play a role as well. In a 3D culture model (poster Vidic et al.) the growth of LNCaP and PC346c spheroids was blocked by JNJ-54302833 (1µM), but growth of PC346c spheroids co-cultured with cancer associated fibroblasts was not inhibited. Taken together our data suggest that the outcome of FASN inhibition is influenced by the tumor environment. Citation Format: Karine A. Smans, Sabine De Breucker, Norbert Esser, Erwin Fraiponts, Ron Gilissen, Ralph Graeser, Boudewijn Janssen, Lieven Meerpoel, Danielle Peeters, Geert Van Hecke, Luc Van Nuffel, Yolanda Chong, Peter Vermeulen, Gilles Bignan, James Bischoff, Peter Connolly, Bruce Grasberger, Tianbao Lu, Donald Ludovici, Carsten Schubert, Michael Parker, Christophe Meyer, Suzana Vidic. Sensitivity of cell lines to Fatty Acid Synthase inhibitors depends on the lipid content in the cellular environment. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 801. doi:10.1158/1538-7445.AM2014-801
AbstractEin Indikator für den Sauerstoffgehalt im Tiefenwasser von Seen ist das Verhältnis von Mangan zu Eisen in Sedimenten. Die Elementzusammensetzung der Sedimente ist mit Röntgenfluoreszenz messbar und zeigt auch die Umweltveränderungen der Vergangenheit.
Abstract Fatty Acid Synthase (FASN) is a multi-domain protein that carries out de novo fatty acid (palmitate) synthesis from acetate and malonate in mammalian cells. FASN is up-regulated in cancer cells, providing fatty acid building blocks for rapid cell growth and cell division. Increased FASN expression is correlated with disease progression and poor prognosis in many cancers including prostate, breast, ovary, colon, and lung. FASN has been demonstrated to play an important role in carcinogenesis by protecting cells from apoptosis. Herein we report a new series of potent, selective and orally bioavailable FASN inhibitors. Recent publications disclose several FASN inhibitor chemotypes that share a common pharmacophore, wherein an aromatic group and an acylated cyclic amine are attached to a central scaffold. We postulated that a spirocyclic imidazolinone core would be an acceptable and drug-like scaffold, inspired by the precedent of irbesartan, an approved antihypertensive drug in which a spirocyclopentyl-imidazolinone core replaces the substituted imidazole ring of losartan, an older approved agent from the same drug class. This hypothesis led to a new spirocyclic imidazolinone based FASN inhibitors. Extensive SAR efforts resulted in FASN inhibitors with potent enzyme and cell activity, selectivity, and oral bioavailability exemplified by JNJ-54302833. JNJ-54302833 is a potent inhibitor of human FASN (IC50 = 28 nM) and also potently inhibits proliferation of A2780 ovarian cells (IC50 = 13 nM) in lipid-reduced medium. This cellular activity can be rescued by addition of palmitate, demonstrating on-target effects. JNJ-54302833 is also potent in many other cells, including PC3M (IC50 = 25 nM) and LnCaP-Vancouver prostate cells (IC50 = 66 nM), and is highly bioavailable (F 61%) with good exposures. In a pharmacodynamics study in H460 lung xenograft-bearing mice, oral treatment with JNJ-54302833 resulted in elevated tumor levels of malonyl-CoA and decreased tumor levels of palmitate. This novel series potently inhibits the FASN KR domain (IC50 = 54 nM for JNJ-54302833); specific binding to KR was confirmed by crystal structures.In summary, we have designed and discovered a new series of FASN inhibitors that are potent both in enzyme and in cell proliferation assays, are highly bioavailable, and bind to KR domain. Additionally, palmitate rescue of lipid-reduced cellular activity suggests selectivity and pharmacodynamics studies confirm target engagement. Citation Format: Tianbao Lu, Richard Alexander, Gilles Bignan, James Bischoff, Peter Connolly, Max Cummings, Sabine De Breucker, Norbert Esser, Erwin Fraiponts, Ron Gilissen, Bruce Grasberger, Boudewijn Janssens, Donald Ludovici, Lieven Meerpoel, Christophe Meyer, Michael Parker, Danielle Peeters, Carsten Schubert, Karine Smans, Luc Van Nuffel, Peter Vermeulen. Design and synthesis of a series highly potent and bioavailable FASN KR domain inhibitors for cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4747. doi:10.1158/1538-7445.AM2014-4747
Abstract De novo synthesis of fatty acids in mammalian cells is catalyzed by Fatty Acid Synthase (FASN), a complex dimeric protein with seven catalytic domains that processes acetyl-CoA and malonyl-CoA into palmitic acid. Palmitate and other fatty acids are essential for normal physiological processes like energy storage and production and are key intermediates in the biosynthesis of hormones and other essential biomolecules. The role of FASN in cancer has been well documented over the past decade. While FASN is expressed at low levels in most normal tissue (except liver and adipose tissue), it is highly expressed in many tumors including prostate, breast, and colon. FASN overexpression and activity is correlated with poor prognosis and disease progression. Numerous publications describing anti-cancer effects of small molecule FASN inhibitors have appeared in the scientific and patent literature. Recently, several groups reported anticancer and antiviral activities of N-benzoyl arylpiperidine FASN inhibitors. In this work we describe the discovery of novel N-benzoyl arylpiperidine and arylazetidine compounds that potently inhibit FASN enzymatic activity in vitro and antiproliferative activity in FASN-sensitive cell lines. We conducted focused structure-activity (SAR) studies exploring the benzoyl group and the aryl substituent on the piperidine or azetidine heterocycle to optimize potency, improve properties and oral bioavailability, and achieve in vivo FASN-driven pharmacodynamic (PD) activity. X-ray crystal structures of these molecules confirm a unique binding mode within the KR subdomain of FASN. Using structural information and molecular modeling, we were able to rationalize SAR trends and design FASN inhibitors with excellent in vitro potency and cellular activity. These efforts resulted in the discovery of compounds exemplified by JNJ-54380482, a potent FASN inhibitor (IC50 = 26 nM) that inhibits proliferation of A2780 ovarian cells in lipid-reduced medium (LRM, IC50 = 8.9 nM). Engagement of FASN in cellular assays is confirmed by rescue of proliferation upon addition of palmitate. JNJ-54380482 is orally bioavailable in mice (F% = 51) and exhibits excellent plasma exposure when dosed at 10 mg/kg (Cmax = 2.6 µM, T1/2 = 5 h). In a PD study using H460 lung xenograft-bearing mice, oral treatment with 30 mg/kg of JNJ-54380482 results in 36-fold higher tumor levels of malonyl-CoA vs vehicle. In summary, we synthesized several hundred compounds having the N-benzoyl arylpiperidine and arylazetidine chemotypes. Utilizing structural information from X-ray co-crystals to understand SAR and guide the design of more potent molecules, we identified >100 analogs with highly potent FASN enzymatic (IC50 ≤ 50 nM) and antiproliferative activities in A2780 cells in LRM (IC50 ≤ 100 nM). Key examples from these series have good in vitro properties, are orally bioavailable, and demonstrate FASN target engagement in a mouse PD model. Citation Format: Peter J. Connolly, Gilles Bignan, James Bischoff, Sabine De Breucker, Norbert Esser, Erwin Fraiponts, Ron Gilissen, Bruce Grasberger, Boudewijn Janssens, Tianbao Lu, Donald Ludovici, Lieven Meerpoel, Christophe Meyer, Michael Parker, Danielle Peeters, Carsten Schubert, Karine Smans, Luc Van Nuffel, Peter Vermeulen. Structure-activity relationships of novel N-benzoyl arylpiperidine and arylazetidine FASN inhibitors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2535. doi:10.1158/1538-7445.AM2014-2535
Structure–activity relationship (SAR) studies on a highly potent series of arylamide FMS inhibitors were carried out with the aim of improving FMS kinase selectivity, particularly over KIT. Potent compound 17r (FMS IC50 0.7nM, FMS cell IC50 6.1nM) was discovered that had good PK properties and a greater than fivefold improvement in selectivity for FMS over KIT kinase in a cellular assay relative to the previously reported clinical candidate 4. This improved selectivity was manifested in vivo by no observed decrease in circulating reticulocytes, a measure of bone safety, at the highest studied dose. Compound 17r was highly active in a mouse pharmacodynamic model and demonstrated disease-modifying effects in a dose-dependent manner in a strep cell wall-induced arthritis model of rheumatoid arthritis in rats.
A high-resolution structure of a ligand-bound, soluble form of human monoglyceride lipase (MGL) is presented. The structure highlights a novel conformation of the regulatory lid-domain present in the lipase family as well as the binding mode of a pharmaceutically relevant reversible inhibitor. Analysis of the structure lacking the inhibitor indicates that the closed conformation can accommodate the native substrate 2-arachidonoyl glycerol. A model is proposed in which MGL undergoes conformational and electrostatic changes during the catalytic cycle ultimately resulting in its dissociation from the membrane upon completion of the cycle. In addition, the study outlines a successful approach to transform membrane associated proteins, which tend to aggregate upon purification, into a monomeric and soluble form.
A class of potent inhibitors of colony-stimulating factor-1 receptor (CSF-1R or FMS), as exemplified by 8 and 21, was optimized to improve pharmacokinetic and pharmacodynamic properties and potential toxicological liabilities. Early stage absorption, distribution, metabolism, and excretion assays were employed to ensure the incorporation of druglike properties resulting in the selection of several compounds with good activity in a pharmacodynamic screening assay in mice. Further investigation, utilizing the type II collagen-induced arthritis model in mice, culminated in the selection of anti-inflammatory development candidate JNJ-28312141 (23, FMS IC(50) = 0.69 nM, cell assay IC(50) = 2.6 nM). Compound 23 also demonstrated efficacy in rat adjuvant and streptococcal cell wall-induced models of arthritis and has entered phase I clinical trials.
During efforts to improve the bioavailability of FMS kinase inhibitors 1 and 2, a series of saturated and aromatic 4-heterocycles of reduced basicity were prepared and evaluated in an attempt to also improve the cardiovascular safety profile over lead arylamide 1, which possessed ion channel activity. The resultant compounds retained excellent potency and exhibited diminished ion channel activity.
A series of pyrido[2,3-d]pyrimidin-5-ones has been synthesized and evaluated as inhibitors of the kinase domain of macrophage colony-stimulating factor-1 receptor (FMS). FMS inhibitors may be useful in treating rheumatoid arthritis and other chronic inflammatory diseases. Structure-based optimization of the lead amide analogue 10 led to hydroxamate analogue 37, which possessed excellent potency and an improved pharmacokinetic profile. During the chronic phase of streptococcal cell wall-induced arthritis in rats, compound 37 (10, 3, and 1 mg/kg) was highly effective at reversing established joint swelling. In an adjuvant-induced arthritis model in rats, 37 prevented joint swelling partially at 10 mg/kg. In this model, osteoclastogenesis and bone erosion were prevented by low doses (1 or 0.33 mg/kg) that had minimal impact on inflammation. These data underscore the potential of FMS inhibitors to prevent erosions and reduce symptoms in rheumatoid arthritis.
HTS campaigns push functional assays to their limits for multiple reasons. As such, labeled substrates and secondary detection methods that minimize interference issues are often employed. Fluorescent labeling of a substrate results in the generation of a substrate that no longer resembles the physiological target. Secondary or tertiary detection techniques often result in an assay where initial velocity requirements are lost. In an ideal world, one would the physiological substrates requiring the implementation of label‐free system. The reality of label free‐detection are the amplification of interference issues and/or use substrate concentrations well above the KM‐value. The coupling of high‐throughput mass spectroscopy (HTMS) in a functional assay eliminates these issues and as such one can use substrates that more closely reflect the in vivo condition. HTMS assays are sensitive and they eliminate complications from secondary detection methods. HTMS allows for the examination of the substrates and products from multi‐functional enzymes reactions independently. In the present study, functional assays are coupled with a label‐free biophysical binding assay (ThermofluorTM). The overlap between these orthogonal in vitro technologies enables rapid lead generation and lead optimization of compounds that can progress into full development.