A Novel Allosteric Activator of Free Fatty Acid 2 Receptor Displays Unique Gi-functional Bias.

The short chain fatty acid receptor FFA2 is able to stimulate signaling via both Gi- and Gq/G11-promoted pathways. These pathways are believed to control distinct physiological end points but FFA2 receptor ligands appropriate to test this hypothesis have been lacking. Herein, we characterize AZ1729, a novel FFA2 regulator that acts as a direct allosteric agonist and as a positive allosteric modulator, increasing the activity of the endogenously produced short chain fatty acid propionate in Gi-mediated pathways, but not at those transduced by Gq/G11 Using AZ1729 in combination with direct inhibitors of Gi and Gq/G11 family G proteins demonstrated that although both arms contribute to propionate-mediated regulation of phospho-ERK1/2 MAP kinase signaling in FFA2-expressing 293 cells, the Gq/G11-mediated pathway is predominant. We extend these studies by employing AZ1729 to dissect physiological FFA2 signaling pathways. The capacity of AZ1729 to act at FFA2 receptors to inhibit ß-adrenoreceptor agonist-promoted lipolysis in primary mouse adipocytes and to promote chemotaxis of isolated human neutrophils confirmed these as FFA2 processes mediated by Gi signaling, whereas, in concert with blockade by the Gq/G11 inhibitor FR900359, the inability of AZ1729 to mimic or regulate propionate-mediated release of GLP-1 from mouse colonic preparations defined this physiological response as an end point transduced via activation of Gq/G11.

Sublingual administration of atropine eyedrops in children with excessive drooling - a pilot study.

BACKGROUND: Drooling can be a severe disability and have high impact on daily life. Reversible treatment is preferable. AIM: To analyse whether sublingual administration of atropine eyedrops is a useful reversible treatment option for severe drooling in children with disabilities. DESIGN: The study had a prospective, single-system research design. The participants served as their own controls. The study period was 3 weeks without treatment, 4 weeks with atropine eyedrop solution 10 mg/mL one drop a day followed by 4 weeks of one drop twice a day. Parents' rating of their child's drooling was assessed on a 100-mm VAS, and unstimulated salivary secretion rate measurement was performed together with notations about side effects and practicality. RESULTS: Parents' VAS assessment of drooling decreased from a median (range) of 74 (40-98) at baseline to 48 (18-88) (P = 0.05) and 32 (12-85) (P = 0.004) after 4 weeks of atropine once a day and another 4 weeks of atropine twice a day, respectively (n = 11). Unstimulated salivary secretion rates decreased from baseline to end of study (P = 0.032). Several parents complained about difficult administration. No irreversible side effects were noted. CONCLUSIONS: Sublingual atropine eyedrops may be an alternative for treatment of severe drooling in children with disabilities.

Identification and design of a novel series of MGAT2 inhibitors.

[Acyl CoA]monoacylglycerol acyltransferase 2 (MGAT2) is of interest as a target for therapeutic treatment of diabetes, obesity and other diseases which together constitute the metabolic syndrome. In this Letter we report our discovery and optimisation of a novel series of MGAT2 inhibitors. The development of the SAR of the series and a detailed discussion around some key parameters monitored and addressed during the lead generation phase will be given. The in vivo results from an oral lipid tolerance test (OLTT) using the MGAT2 inhibitor (S)-10, shows a significant reduction (68% inhibition relative to naїve, p<0.01) in plasma triacylglycerol (TAG) concentration.

(R)-(3-amino-2-fluoropropyl) phosphinic acid (AZD3355), a novel GABAB receptor agonist, inhibits transient lower esophageal sphincter relaxation through a peripheral mode of action.

Gastroesophageal reflux disease (GERD) affects >10% of the Western population. Conventionally, GERD is treated by reducing gastric acid secretion, which is effective in most patients but inadequate in a significant minority. We describe a new therapeutic approach for GERD, based on inhibition of transient lower esophageal sphincter relaxation (TLESR) with a proposed peripherally acting GABA(B) receptor agonist, (R)-(3-amino-2-fluoropropyl)phosphinic acid (AZD3355). AZD3355 potently stimulated recombinant human GABA(B) receptors and inhibited TLESR in dogs, with a biphasic dose-response curve. In mice, AZD3355 produced considerably less central side effects than the prototypical GABA(B) receptor agonist baclofen but evoked hypothermia at very high doses (blocked by a GABA(B) receptor antagonist and absent in GABA(B)-/- mice). AZD3355 and baclofen differed markedly in their distribution in rat brain; AZD3355, but not baclofen, was concentrated in circumventricular organs as a result of active uptake (shown by avid intracellular sequestration) and related to binding of AZD3355 to native GABA transporters in rat cerebrocortical membranes. AZD3355 was also shown to be transported by all four recombinant human GABA transporters. AR-H061719 [(R/S)-(3-amino-2-fluoropropyl)phosphinic acid], (the racemate of AZD3355) inhibited the response of ferret mechanoreceptors to gastric distension, further supporting its peripheral site of action on TLESR. In summary, AZD3355 probably inhibits TLESR through stimulation of peripheral GABA(B) receptors and may offer a potential new approach to treatment of GERD.

Recent advances in non-competitive mGlu5 receptor antagonists and their potential therapeutic applications.

Extensive research into the functions of glutamate and glutamate receptors in the central nervous system (CNS) has shown an essential role of metabotropic glutamate (mGlu) receptors in normal brain functions, but also in neurological and psychiatric disorders. The precise functions of these receptors remain undefined, and progress toward understanding their functions has been hampered by the lack of selective ligands with appropriate pharmacokinetic properties. The Group I mGlu receptor, mGlu5, is well positioned to regulate and fine-tune neuronal excitability and synaptic transmission through its modulation of various signal transduction pathways and interactions with other transmitter systems. Therefore, the mGlu5 receptor may be an important therapeutic target for the treatment of disorders of the central nervous system. The discovery of MPEP 3, a non-competitive mGlu5 receptor antagonist, provided a potent, selective, systemically active tool compound for proof of concept studies in animal models of various disease states. These studies have led to greater understanding of possible therapeutic applications of mGlu5 receptor antagonists in recent years, suggesting their use in a number of disease states, including chronic pain, various psychiatric and neurological disorders, substance abuse and withdrawal, obesity and gastroesophageal reflux disease (GERD). Together, these findings have intensified efforts to find other non-competitive mGlu5 receptor antagonists and have led to the discovery of several second-generation compounds, a few of which are in preclinical evaluations. There have been several recent reviews on mGlu receptor. This article highlights recent efforts on the design, synthesis and development of novel, non-competitive mGlu5 receptor antagonists and studies to understand their in vitro mechanisms of action and in vivo pharmacological profiles. Emphasis is also given to recent advances in the potential therapeutic applications of non-competitive mGlu5 receptor antagonists.

Effects of (2R)-(3-amino-2-fluoropropyl)sulphinic acid (AFPSiA) on transient lower oesophageal sphincter relaxation in dogs and mechanism of hypothermic effects in mice.

The effects of the novel GABA analogue (2R)-(3-amino-2-fluoropropyl)sulphinic acid (AFPSiA) on transient lower oesophageal sphincter relaxations (TLOSRs) were studied in the dog. In addition, the GABA(A)/GABA(B) selectivity was determined in vitro and in vivo, and the pharmacokinetics and the metabolism of the compound were studied in the dog and rat. TLOSRs were reduced by 55 +/- 8% after intragastric administration of AFPSiA at 14 mumol kg(-1) and did not decrease further at higher doses. When evaluated 2 and 4 h after administration, the effect declined to 37 +/- 6 and 16 +/- 9%, respectively. Spontaneous swallowing was only significantly inhibited at 100 micromol kg(-1). The oral availability of AFPSiA was 52 +/- 17 and 71 +/- 4% in the dog and rat, respectively. A fraction of AFPSiA was oxidised to the corresponding sulphonate, (2R)-(3-amino-2-fluoropropyl)sulphonic acid (AFPSoA) after oral administration to the rat and dog. In rat brain membranes, AFPSiA was found to have ten times higher affinity for rat brain GABA(B) (K(i) =47 +/- 4.4 nM) compared to GABA(A) (K(i) = 430 +/- 46 nM) binding sites. The compound was a full agonist at human recombinant GABA(B(1a,2)) receptors (EC(50) = 130 +/- 10 nM). In contrast, the metabolite AFPSoA was considerably more selective for binding to rat brain GABA(A) (K(i) = 37 +/- 3.1 nM) vs GABA(B) (K(i) = 6800 +/- 280 nM) receptors. In the mouse, high doses (1-8 mmol kg(-1)) of AFPSiA induced a rapid and mild hypothermia followed by a profound and sustained hypothermia at the higher doses tested (6 and 8 mmol kg(-1)). This effect was unaffected by the selective GABA(B) receptor antagonist CGP62349. AFPSoA (1 and 2 mmol kg(-1)) produced transient and moderate hypothermia while the hypothermic response was considerably larger at 4 mmol kg(-1).It is concluded that AFPSiA inhibits but does not abolish TLOSRs in the dog. High doses of the compound induce hypothermia in the mouse, which probably is attributable to activation of the GABA(A) receptor. The latter effect may be caused both by AFPSiA and its oxidised sulphonic acid metabolite AFPSoA.

Transient lower esophageal sphincter relaxations in dogs are inhibited by a metabotropic glutamate receptor 5 antagonist.

Transient lower esophageal sphincter relaxation is the major mechanism for gastroesophageal reflux. The present study was initiated to investigate the potential effect of the metabotropic glutamate 5 (mGlu5) receptor antagonist, 2-methyl-6-(phenylethynyl)-pyridine (MPEP), on transient lower esophageal sphincter relaxations in the conscious dog. MPEP (1.4-8.7 micromol/kg i.v.) produced a dose-dependent inhibition of transient lower esophageal sphincter relaxations (59+/-11% inhibition at 8.7 micromol/kg). In addition, there was a reduction of the number of reflux episodes and an increase in latency time to the occurrence of the first transient lower esophageal sphincter relaxation. No effect was seen on basal lower esophageal sphincter pressure or on swallowing. It is concluded that the mGlu5 receptor antagonist MPEP potently inhibits transient lower esophageal sphincter relaxations and that the mGlu5 receptor is a potential target for treatment of gastroesophageal reflux disease.

The Use of 15 N NMR Spectroscopy To Resolve the "Higher Order Cyanocuprate" Controversy: 15 N, 6 Li, and 13 C NMR Spectroscopic Investigations of CuCN-Derived Butyl Cuprates.

Structure 1 is the major component obtained by the reaction of two equivalents of RLi and one equivalent of CuCN; other proposed structures can now be ruled out on the basis of 15 N NMR spectroscopic and theoretical studies. Thus, these useful synthetic reagents should be considered as cyano-Gilman reagents R2 CuLi⋅LiCN and not "higher order cyanocuprates" R2 Cu(CN)Li2 .

A novel panel of biomarkers predicts radioresistance in patients with squamous cell carcinoma of the head and neck.

PURPOSE: Global gene expression analysis was performed on pre-treatment biopsies from patients with squamous cell carcinoma of the head and neck (SCCHN) to discover biomarkers that can predict outcome of radiation based therapy. METHODS: We initially evaluated RNA expression using cDNA microarray analysis of 38 patients that received radiotherapy (RT). The five strongest candidates (VEGF, BCL-2, CLAUDIN-4, YAP-1 and c-MET) were then analysed in pre-treatment biopsies in a second group of 86 patients who received radiation based treatment using immunohistochemical staining (IHC), prepared by tissue microarray. RESULTS: In the first population, 13 of 38 (34%) had no (NR) or partial response (PR) to RT. cDNA microarrays revealed 60 genes that were linked to response to therapy. In the second series, 12 of 86 patients (14%) experienced NR or PR to CRT. Cause specific survival (CSS) and recurrence free survival (RFS) at 2 years was 85% and 90% and at 3 years 81% and 84%, respectively. Biomarkers predictive for NR/PR were increased expression of vascular endothelial growth factor (VEGF) (p=0.02), Yes-associated protein (YAP-1) (p<0.01), CLAUDIN-4 (p<0.01), c-MET (p<0.01) and BCL-2 (p=0.02). Biomarkers predictive of poor RFS were YAP-1 (p=0.01) and BCL-2 (p<0.01). Biomarkers predictive of poor CSS were YAP-1 (p=0.04), VEGF (p=0.03) and CLAUDIN-4 (p=0.03). Furthermore, when YAP-1 and c-MET expression levels were combined the prediction of radio-resistance was increased. CONCLUSION: All five biomarkers were predictive of poor response to radiation based therapy. In particular, YAP-1 and c-MET have synergistic power and could be used to make treatment decisions.

Discovery of agonists of cannabinoid receptor 1 with restricted central nervous system penetration aimed for treatment of gastroesophageal reflux disease.

Agonists of the cannabinoid receptor 1 (CB1) have been suggested as possible treatments for a range of medical disorders including gastroesophageal reflux disease (GERD). While centrally acting cannabinoid agonists are known to produce psychotropic effects, it has been suggested that the CB1 receptors in the periphery could play a significant role in reducing reflux. A moderately potent and highly lipophilic series of 2-aminobenzamides was identified through focused screening of GPCR libraries. Development of this series focused on improving potency and efficacy at the CB1 receptor, reducing lipophilicity and limiting the central nervous system (CNS) exposure while maintaining good oral absorption. Improvement of the series led to compounds having excellent potency at the CB1 receptor and high levels of agonism, good physical and pharmacokinetic properties, and low penetration into the CNS. A range of compounds demonstrated a dose-dependent inhibition of transient lower esophageal sphincter relaxations in a dog model.

Synthesis and pharmacological evaluation of novel gamma-aminobutyric acid type B (GABAB) receptor agonists as gastroesophageal reflux inhibitors.

We have previously demonstrated that the prototypical GABA B receptor agonist baclofen inhibits transient lower esophageal sphincter relaxations (TLESRs), the most important mechanism for gastroesophageal reflux. Thus, GABA B agonists could be exploited for the treatment of gastroesophageal reflux disease. However, baclofen, which is used as an antispastic agent, and other previously known GABA B agonists can produce CNS side effects such as sedation, dizziness, nausea, and vomiting at higher doses. We now report the discovery of atypical GABA B agonists devoid of classical GABA B agonist related CNS side effects at therapeutic doses and the optimization of this type of compound for inhibition of TLESRs, which has resulted in a candidate drug ( R)- 7 (AZD3355) that is presently being evaluated in man.

Phenyl ureas of creatinine as mGluR5 antagonists. A structure-activity relationship study of fenobam analogues.

Fenobam (1) was developed by McNeil Laboratories as an anxiolytic agent with an unknown molecular target in the late 1970s. In a recent publication, it was revealed that fenobam is a non-competitive mGluR5 antagonist. Herein, we present the structure-activity relationship of fenobam and its analogues and similarities between the SAR of mGluR5 antagonism and the SAR of CNS properties originally reported by McNeil are discussed.

Structure-activity relationship of thiopyrimidines as mGluR5 antagonists.

Structure-activity relationship investigations of the thiopyrimidine (1), an HTS hit with micromolar activity as a metabotropic glutamate receptor 5 (mGluR5) antagonist, led to compounds with sub-micromolar activity.

A new series of pyridinyl-alkynes as antagonists of the metabotropic glutamate receptor 5 (mGluR5).

Synthesis and some structure-activity relationships for a new series of propargyl ethers as mGluR5 antagonists are reported.

Structure-activity relationships for the linker in a series of pyridinyl-alkynes that are antagonists of the metabotropic glutamate receptor 5 (mGluR5).

Studies of structure-activity relationships for the linker in a new series of metabotropic glutamate receptor 5 antagonists are presented together with in vitro and in vivo pharmacokinetic data.