In patients with myocardial infarction (MI), the level of sphingolipids, such as ceramide (Cer), is elevated and is associated with an increased risk of progression towards heart failure (HF). Dihydroceramide desaturase 1 (DES1) catalyses the conversion of dihydroceramide (dhCer) into Cer in the de novo sphingolipid pathway. While pharmacological inhibition of DES1 has shown therapeutic benefits in metabolic disease and cancer models, its role in cardiac remodelling remains unclear. This study aimed to determine whether pharmacological inhibition of DES1 using the novel compound, CIN038, attenuates cardiac remodelling following ischemia-reperfusion (I/R) injury. Three-month-old male C57Bl/6 mice underwent I/R or sham surgery (n = 8) and were treated with vehicle or CIN038 (50 mg/kg/day, i.p.) for 28 days. Cardiac function, molecular changes, and lipid profiles in circulation and liver were assessed at the endpoint. CIN038 reduced infarct size and cardiac myocyte hypertrophy compared to the I/R + vehicle group. Profibrotic signalling was reduced in the infarcted hearts, as evidenced by reduced expression of Col1a1, Col3a1, and Tgfb mRNA and decreased levels of α-SMA and TGFβ1 protein expression. Inflammatory signalling was attenuated with reduced ERK and NFkB phosphorylation and suppression of Il-6-STAT axis. Despite these structural and molecular improvements, no changes were observed in cardiac function. Lipidomic analysis revealed selective alterations in circulating and hepatic lipid species, including plasmalogen phosphatidylethanolamines and ether-linked triglycerides, suggesting modulation of lipid metabolism. Collectively, these findings indicate that CIN038 attenuates post-ischemic cardiac remodelling by suppressing inflammatory and profibrotic signalling, highlighting DES1 as a potential therapeutic target following MI.

Fully substituted divinyl ketones (fsDVKs) have long been regarded as resistant to Nazarov cyclization (NC) unless they contain strategically positioned electronically activating substituents. Here, however, we show that fsDVKs bearing only electronically neutral alkyl or aryl groups actually undergo facile NC due to steric crowding in the pentadienyl cation intermediate, which raises its energy and reduces the barrier height to cyclization. Strongly ionizing and suitably bulky acid moieties further increase the energy of this intermediate cation, favoring cyclization. These features enable NCs of fsDVKs to be employed in the ready construction of multiple contiguous all-carbon quaternary stereocenters under mild conditions, in the absence of electronically activating groups.

This work describes the characterization of BNC210 (6-[(2,3-dihydro-1H-inden-2-yl)amino]-1-ethyl-3-(4-morpholinylcarbonyl)-1,8-naphthyridin-4(1H)-one), a selective, small molecule, negative allosteric modulator (NAM) of α7 nicotinic acetylcholine receptors (α7 nAChR). With the aim to discover a non-sedating, anxiolytic compound, BNC210 was identified during phenotypic screening of a focused medicinal chemistry library using the mouse Light Dark (LD) box to evaluate anxiolytic-like activity and the mouse Open Field (OF) (dark) test to detect sedative and/or motor effects. BNC210 exhibited anxiolytic-like activity with no measurable sedative or motor effects. Electrophysiology showed that BNC210 did not induce α7 nAChR currents by itself but inhibited EC80 agonist-evoked currents in recombinant GH4C1 cell lines stably expressing the rat or human α7 nAChR. BNC210 was not active when tested on cell lines expressing other members of the cys-loop ligand-gated ion channel family. Screening over 400 other targets did not reveal any activity for BNC210 confirming its selectivity for α7 nAChR. Oral administration of BNC210 to male mice and rats in several tests of behavior related to anxiety- and stress- related disorders, demonstrated significant reduction of these behaviors over a broad therapeutic range up to 500 times the minimum effective dose. Further testing for potential adverse effects in suitable rat and mouse tests showed that BNC210 did not produce sedation, memory and motor impairment or physical dependence, symptoms associated with current anxiolytic therapeutics. These data suggest that allosteric inhibition of α7 nAChR function may represent a differentiated approach to treating anxiety- and stress- related disorders with an improved safety profile compared to current treatments.

Adobe PDF - Supplementary_Data.pdf from BNC105: A Novel Tubulin Polymerization Inhibitor That Selectively Disrupts Tumor Vasculature and Displays Single-Agent Antitumor Efficacy

Polynucleotides, DNA and RNA (mRNA and non-coding RNAs) are critically involved in the molecular pathways of disease. Small molecule binding interactions with polynucleotides can modify functional polynucleotide topologies and/or their interactions with proteins. Current approaches to library design (lead-like or fragment-like libraries) are based on protein-ligand interactions and often include careful consideration of the 3-dimensional orientation of binding motifs and exclude π-rich compounds (polyfused aromatics) to avoid off-target R/DNA interactions. In contrast to proteins, where π,π-interactions are weak, polynucleotides can form strong π,π-interactions with suitable π-rich ligands. To assist in designing a polynucleotide-biased library, a scaffold-divergent synthesis approach to polyfused aromatic scaffolds has been undertaken. Initial screening hits that form moderately stable polynucleotide-ligand-protein ternary complexes can be further optimized through judicious incorporation of substituents on the scaffold to increase protein-ligand interactions. An example of this approach is given for topoisomerase-1 (TOP1), generating a novel TOP1 inhibitory chemotype.

Soft polymer nanoparticles designed to disassemble and release an antagonist of the neurokinin 1 receptor (NK1R) in endosomes provide efficacious yet transient relief from chronic pain. These micellar nanoparticles are unstable and rapidly release cargo, which may limit the duration of analgesia. We examined the efficacy of stable star polymer nanostars containing the NK1R antagonist aprepitant-amine for the treatment of chronic pain in mice. Nanostars continually released cargo for 24 h, trafficked through the endosomal system, and disrupted NK1R endosomal signaling. After intrathecal injection, nanostars accumulated in endosomes of spinal neurons. Nanostar-aprepitant reversed mechanical, thermal and cold allodynia and normalized nociceptive behavior more efficaciously than free aprepitant in preclinical models of neuropathic and inflammatory pain. Analgesia was maintained for >10 h. The sustained endosomal delivery of antagonists from slow-release nanostars provides effective and long-lasting reversal of chronic pain.

The level of sphingolipids such as ceramides (Cer) are dysregulated in patients with myocardial infarction (MI), leading to increased risk of progression towards heart failure. Dihydroceramide desaturase 1 (Des-1) is the enzyme responsible for the conversion of dihydroceramide (dhCer) into Cer in the de novo sphingolipids pathway. Its role in cardiac remodelling is unknown. This study aims to investigate the effects of a novel selective Des-1 inhibitor, CIN038, on cardiac remodelling in a mouse model of ischaemia-reperfusion (IR).

The iodocyclisation of alkynes bearing tethered nucleophiles is a highly effective method for the construction and diversification of heterocycles. A key limitation to this methodology is the 5-endo-dig iodocyclisation of alkynes that have an unfavourable electronic bias for electrophilic cyclisation. These tend to direct electrophilic attack of the iodonium atom to the wrong carbon for cyclisation, thus favouring competing addition reactions. Using our previously determined reaction conditions for the 5-endo-dig iodocyclisations of electronically resistant alkynes, we have achieved efficient synthetic access to 2-carboxy (and sulfoxy)-3-iodobenzo[b]thiophenes. The corresponding benzo[b]furans and indoles were not accessible under these conditions. This difference may arise due to the availability of a radical mechanism in the case of iodobenzo[b]thiophenes. The 2-carboxy functionality of the iodocyclised products can be further employed in iterative alkyne-coupling iodocyclisation reactions, where the carboxy group or an imine (Schiff base) partakes in a second iodocyclisation to generate a lactone or pyridine ring.

Non-dialysable protein-bound uremic toxins (PBUTs) contribute to the development of cardiovascular disease (CVD) in chronic kidney disease (CKD) and vice versa. PBUTs have been shown to alter sphingolipid imbalance. Dihydroceramide desaturase 1 (Des1) is an important gatekeeper enzyme which controls the non-reversible conversion of sphingolipids, dihydroceramide, into ceramide. The present study assessed the effect of Des1 inhibition on PBUT-induced cardiac and renal effects in vitro, using a selective Des1 inhibitor (CIN038). Des1 inhibition attenuated hypertrophy in neonatal rat cardiac myocytes and collagen synthesis in neonatal rat cardiac fibroblasts and renal mesangial cells induced by the PBUTs, indoxyl sulfate and p-cresol sulfate. This is at least attributable to modulation of NF-κB signalling and reductions in β-MHC, Collagen I and TNF-α gene expression. Lipidomic analyses revealed Des1 inhibition restored C16-dihydroceramide levels reduced by indoxyl sulfate. In conclusion, PBUTs play a critical role in mediating sphingolipid imbalance and inflammatory responses in heart and kidney cells, and these effects were attenuated by Des1 inhibition. Therefore, sphingolipid modifying agents may have therapeutic potential for the treatment of CVD and CKD and warrant further investigation.

Cardiac fibrosis and myocyte hypertrophy play contributory roles in the progression of diseases such as heart Failure (HF) through what is collectively termed cardiac remodelling. The phosphoinositide 3- kinase (PI3K), protein kinase B (Akt) and mammalian target for rapamycin (mTOR) signalling pathway (PI3K/Akt- mTOR) is an important pathway in protein synthesis, cell growth, cell proliferation, and lipid metabolism. The sphingolipid, dihydrosphingosine 1 phosphate (dhS1P) has been shown to bind to high density lipids in plasma. Unlike its analog, spingosine 1 phosphate (S1P), the role of dhS1P in cardiac fibrosis is still being deciphered. This study was conducted to investigate the effect of dhS1P on PI3K/Akt signalling in primary cardiac fibroblasts and myocytes. Our findings demonstrate that inhibiting PI3K reduced collagen synthesis in neonatal cardiac fibroblasts (NCFs), and hypertrophy in neonatal cardiac myocytes (NCMs) induced by dhS1P, in vitro. Reduced activation of the PI3K/Akt- mTOR signalling pathway led to impaired translation of fibrotic proteins such as collagen 1 (Coll1) and transforming growth factor β (TGFβ) and inhibited the transcription and translation of tissue inhibitor of matrix metalloproteinase 1 (TIMP1). PI3K inhibition also affected the gene expression of S1P receptors and enzymes such as the dihydroceramide delta 4 desaturase (DEGS1) and sphingosine kinase 1 (SK1) in the de novo sphingolipid pathway. While in myocytes, PI3K inhibition reduced myocyte hypertrophy induced by dhS1P by reducing skeletal muscle α- actin (αSKA) mRNA expression, and protein translation due to increased glycogen synthase kinase 3β (GSK3β) mRNA expression. Our findings show a relationship between the PI3K/Akt- mTOR signalling cascade and exogenous dhS1P induced collagen synthesis and myocyte hypertrophy in primary neonatal cardiac cells.

The sphingolipid de novo synthesis pathway, encompassing the sphingolipids, the enzymes and the cell membrane receptors, are being investigated for their role in diseases and as potential therapeutic targets. The intermediate sphingolipids such as dihydrosphingosine (dhSph) and sphingosine (Sph) have not been investigated due to them being thought of as precursors to other more active lipids such as ceramide (Cer) and sphingosine 1 phosphate (S1P). Here we investigated their effects in terms of collagen synthesis in primary rat neonatal cardiac fibroblasts (NCFs). Our results in NCFs showed that both dhSph and Sph did not induce collagen synthesis, whilst dhSph reduced collagen synthesis induced by transforming growth factor β (TGFβ). The mechanisms of these inhibitory effects were associated with the increased activation of the de novo synthesis pathway that led to increased dihydrosphingosine 1 phosphate (dhS1P). Subsequently, through a negative feedback mechanism that may involve substrate-enzyme receptor interactions, S1P receptor 1 expression (S1PR1) was reduced.

Directed ortho-lithiation (DoL) has been developed as an effective method for the ortho-substitution of BINOL-phosphoric acid and BINOL-N-triflylphosphoramide (BINOL-P-acids). It can be employed in the rapid assembly of either mono- or disubstituted BINOL-P-acids, including unsymmetrical disubstitution through iterative DoL. Most significantly, DoL has proven to be highly effective in the diastereoselective desymmetrization of pseudo-C2-symmetric BINOL-N-triflylphosphoramide, affording a chiral P-group.

Protein-bound uremic toxins (PBUTs) have adverse effects on vascular function, which is imperative in the progression of cardiovascular and renal diseases. The role of sphingolipids in PBUT-mediated vasculo-endothelial pathophysiology is unclear. This study assessed the therapeutic potential of dihydroceramide desaturase 1 (Des1) inhibition, the last enzyme involved in de novo ceramide synthesis, to mitigate the vascular effects of the PBUT indoxyl sulfate (IS). Rat aortic rings were isolated and vascular reactivity was assessed in organ bath experiments followed by immunohistochemical analyses. Furthermore, cultured human aortic endothelial cells were assessed for phenotypic and mechanistic changes. Inhibition of Des1 by a selective inhibitor CIN038 (0.1 to 0.3 μM) improved IS-induced impairment of vasorelaxation and modulated immunoreactivity of oxidative stress markers. Des1 inhibition also reversed IS-induced reduction in endothelial cell migration (1.0 μM) by promoting the expression of angiogenic cytokines and reducing inflammatory and oxidative stress markers. These effects were associated with a reduction of TIMP1 and the restoration of Akt phosphorylation. In conclusion, Des1 inhibition improved vascular relaxation and endothelial cell migration impaired by IS overload. Therefore, Des1 may be a suitable intracellular target to mitigate PBUT-induced adverse vascular effects.

Cardiac fibrosis and myocyte hypertrophy are hallmarks of the cardiac remodelling process in cardiomyopathies such as heart failure (HF). Dyslipidemia or dysregulation of lipids contribute to HF. The dysregulation of high density lipoproteins (HDL) could lead to altered levels of other lipid metabolites that are bound to it such as sphingosine-1- phosphate (S1P). Recently, it has been shown that S1P and its analogue dihydrosphingosine-1-phosphate (dhS1P) are bound to HDL in plasma. The effects of dhS1P on cardiac cells have been obscure. In this study, we show that extracellular dhS1P is able to increase collagen synthesis in neonatal rat cardiac fibroblasts (NCFs) and cause hypertrophy of neonatal cardiac myocytes (NCMs). The janus kinase/signal transducer and activator (JAK/STAT) signalling pathway was involved in the increased collagen synthesis by dhS1P, through sustained increase of tissue inhibitor of matrix metalloproteinase 1 (TIMP1). Extracellular dhS1P increased phosphorylation levels of STAT1 and STAT3 proteins, also caused an early increase in gene expression of transforming growth factor-β (TGFβ), and sustained increase in TIMP1. Inhibition of JAKs led to inhibition of TIMP1 and TGFβ gene and protein expression. We also show that dhS1P is able to cause NCM hypertrophy through S1P-receptor-1 (S1PR1) signalling which is opposite to that of its analogue, S1P. Taken together, our results show that dhS1P increases collagen synthesis in cardiac fibroblasts causing fibrosis through dhS1P-JAK/STAT-TIMP1 signalling.

Cardiac fibrosis is one of the hallmarks of cardiac remodelling in cardiomyopathies such as heart Failure (HF). Dyslipidemia plays a role in the progression of HF. The sphingolipid, dihydrosphingosine 1 phosphate (dhS1P) has been shown to bind to high density lipids in plasma. Unlike its analog, spingosine 1 phosphate (S1P), the role of dhS1P in cardiac fibrosis is not known. The aim of this study is to determine the role dhS1P plays in cardiac fibrosis through the PI3K/Akt- mTOR pathway. Neonatal rat cardiac fibroblasts (NCF) were isolated from 1-2 day old pups with enzymic digestion. After pre-treating with the PI3K inhibitor, Wortmannin (W, 0.1 – 10.0μM), cells were stimulated with dhS1P for 48 hours. NCF collagen synthesis was determined by 3H-proline incorporation. NCF were also treated for protein and gene expression analysis. Exogenous addition of 3 μM dhS1P stimulated significant increase in collagen synthesis (p<0.005) which was dose dependently inhibited by W (p<0.0001, Fig. 1A). Western blot analysis showed that W reduced Akt, mTOR, and S6 activation in the presence of dhS1P. dhS1P also increased protein levels of TGFβ, Coll 1 and TIMP1. W reduced dhS1P elevated TIMP1, and SK1, but not TGFβ1 gene expression (Fig. 1B). Our study demonstrates for the first time that dhS1P can cause cardiac cellular fibrosis via PI3K/Akt- mTOR pathway. Its inhibition may represent a novel therapeutic strategy for cardiac fibrosis.

Despite advances in treatment, chronic heart failure (CHF) still remains a major health burden. Novel strategies are urgently required to improve mortality, morbidity and quality of life. Sphingolipids (SLs) are known to play important roles in health and diseases and are therefore potential therapeutic targets. The aim of this study is to investigate the circulating levels of SL and the therapeutic potential of a novel SLs modifying agent, MIPS247, in cardiac cells. Lipidomic analysis was performed with CHF, acute decompensated HF (ADHF), ADHF follow-up (FU-ADHF) patients and healthy volunteers (HV, n=10 / group) as well as neonatal rat cardiac myocytes (NCM) and fibroblasts (NCF) samples using LC/MS/MS with internal controls. NCM and NCF were stimulated with angiotensin II (AngII, 100nM) with or without pre-treatment of MIPS247 (1 or 3μM). NCM hypertrophy and NCF collagen synthesis were also determined. The detectable SL levels were altered in HF as compared to HV (examples Fig A). AngII stimulation altered SL levels in NCM (Fig B) and NCF (Fig C) which were reversed by MIPS247 treatment. MIPS247 also inhibited AngII stimulated NCM hypertrophy and NCF collagen synthesis. Circulation levels of SLs are altered in HF which may be biomarkers for disease monitoring. AngII-induced changes of SLs are reversed by SL modifying agent MIPS247 which may represent a novel therapy for heart diseases.

Polyfused chalcogenophenes are prepared in one step through polyelectrophilic cyclization of polyynes using the ambiphilic reagent MeACl (A = S, Se, or Te). Up to four new rings have been generated under mild conditions, including thiophenes, selenophenes, and tellurophenes.

Background: Cardiac fibrosis is one of the hallmarks of cardiac remodelling in cardiomyopathies such as heart Failure (HF). Dyslipidemia plays a role in the progression of HF. The sphingolipid, dihydrosphingosine 1 phosphate (dhS1P) has been shown to bind to high density lipids in plasma. Unlike its analog, spingosine 1 phosphate (S1P), the role of dhS1P in cardiac fibrosis is not known. The aim of this study is to determine the role dhS1P plays in cardiac fibrosis through the PI3K/Akt- mTOR pathway. Method: Neonatal rat cardiac fibroblasts (NCF) were isolated from 1-2 day old pups with enzymic digestion. After pre-treating with the PI3K inhibitor, Wortmannin (W, 0.1 - 10.0μM), cells were stimulated with dhS1P for 48 hours. NCF collagen synthesis was determined by 3H-proline incorporation. NCF were also treated for protein and gene expression analysis. Results: Exogenous addition of 3 μM dhS1P stimulated significant increase in collagen synthesis (p<0.005) which was dose dependently inhibited by W (p < 0.0001, Fig. 1A). Western blot analysis showed that W reduced Akt, mTOR, and S6 activation in the presence of dhS1P. dhS1P also increased protein levels of TGFβ, Coll 1 and TIMP1. W reduced dhS1P elevated TIMP1, and SK1, but not TGFβ1 gene expression (Fig. 1B). Conclusion: Our study demonstrates for the first time that dhS1P can cause cardiac cellular fibrosis via PI3K/Akt- mTOR pathway. Its inhibition may represent a novel therapeutic strategy for cardiac fibrosis.

Readily accessible 3-aryl-2-carboxypropenones (by Knoevenagel condensation) undergo acid promoted cyclodehydration with nucleophile incorporation to form highly substituted indenes. For stronger nucleophiles, nucleophile incorporation precedes cyclodehydration in a nucleophilic-addition-cyclodehydration (NAC) sequence. For weaker nucleophiles, cyclodehydration precedes nucleophile incorporation in a cyclodehydrative-nucleophilic-trapping (CNT) sequence, involving a reactive allyl cation intermediate. The substrate scope and preferred cyclization pathway (NAC or CNT) has been studied with respect to 3-aryl-2-carboxypropenone and the nature of the nucleophile. Also, for 1,3-diaryl-2-carboxypropenones, which can also undergo Nazarov cyclization, delineation between competing Nazarov and CNT pathways is controlled by the nature of the acid catalyst.

Ox-activated divinyl ketones undergo torquoselective Nazarov cyclization to give cyclopentanoids containing up to three new contiguous quaternary (4°) stereocentres.