Synthesis of SMT022357 enantiomers and evaluation in a Duchenne muscular dystrophy mouse model.

Following on from ezutromid, the first-in-class benzoxazole utrophin modulator that progressed to Phase 2 clinical trials for the treatment of Duchenne muscular dystrophy, a new chemotype was designed to optimise its physicochemical and ADME profile. Herein we report the synthesis of SMT022357, a second generation utrophin modulator preclinical candidate, and an asymmetric synthesis of its constituent enantiomers. The pharmacological properties of both enantiomers were evaluated and .

From diagnosis to therapy in Duchenne muscular dystrophy.

Genetic approaches for the diagnosis and treatment of inherited muscle diseases have advanced rapidly in recent years. Many of the advances have occurred in the treatment of Duchenne muscular dystrophy (DMD), a muscle wasting disease where affected boys are typically wheelchair bound by age 12 years and generally die in their twenties from respiratory failure or cardiomyopathy. Dystrophin is a 421 kD protein which links F-actin to the extracellular matrix via the dystrophin-associated protein complex (DAPC) at the muscle membrane.

2-Arylbenzo[]oxazole Phosphinate Esters as Second-Generation Modulators of Utrophin for the Treatment of Duchenne Muscular Dystrophy.

Utrophin modulation is a promising therapeutic strategy for Duchenne muscular dystrophy (DMD), which should be applicable to all patient populations. Following on from ezutromid, the first-generation utrophin modulator, we describe the development of a second generation of utrophin modulators, based on the bioisosteric replacement of the sulfone group with a phosphinate ester and substitution of the metabolically labile naphthalene with a haloaryl substituent. The improved physicochemical and absorption, distribution, metabolism, and excretion (ADME) properties, further reflected in the enhanced pharmacokinetic profile of the most advanced compounds, and , led to significantly better exposure compared to ezutromid and alleviation of the dystrophic phenotype in mice.

The potential of utrophin and dystrophin combination therapies for Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a lethal neuromuscular disorder caused by loss of dystrophin. Several therapeutic modalities are currently in clinical trials but none will achieve maximum functional rescue and full disease correction. Therefore, we explored the potential of combining the benefits of dystrophin with increases of utrophin, an autosomal paralogue of dystrophin.

Micro-utrophin Improves Cardiac and Skeletal Muscle Function of Severely Affected D2/ Mice.

Duchenne muscular dystrophy (DMD) is an X-linked muscle-wasting disease caused by mutations in the dystrophin gene. DMD boys are wheelchair-bound around 12 years and generally survive into their twenties. There is currently no effective treatment except palliative care, although personalized treatments such as exon skipping, stop codon read-through, and viral-based gene therapies are making progress.

Embryonic myosin is a regeneration marker to monitor utrophin-based therapies for DMD.

Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. Constitutive utrophin expression, a structural and functional paralogue of dystrophin, can successfully prevent the dystrophic pathology in the dystrophin-deficient mdx mouse model. In dystrophic muscles, utrophin is increased as part of the repair process and localized at the sarcolemma of regenerating myofibers.

Identification of serum protein biomarkers for utrophin based DMD therapy.

Despite promising therapeutic avenues, there is currently no effective treatment for Duchenne muscular dystrophy (DMD), a lethal monogenic disorder caused by the loss of the large cytoskeletal protein, dystrophin. A highly promising approach to therapy, applicable to all DMD patients irrespective to their genetic defect, is to modulate utrophin, a functional paralogue of dystrophin, able to compensate for the primary defects of DMD restoring sarcolemmal stability. One of the major difficulties in assessing the effectiveness of therapeutic strategies is to define appropriate outcome measures.

Direct and indirect vitamin A supplementation strategies result in different plasma and tissue retinol kinetics in neonatal rats.

Many questions remain regarding vitamin A (VA) supplementation of infants. Herein we compared direct oral VA supplementation of the neonate and indirect treatment through maternal dietary VA (M-VA) treatment on VA status and kinetics in neonatal rats. Treatments included direct VA combined with retinoic acid (RA) [D-VARA; VA (6 mg/kg) + 10% RA, given orally to neonates on postnatal day (P)2 and P3] and indirect VA supplementation through increased M-VA, compared with each other and oil-treated neonates.

Perceptual and Brain Response to Odors Is Associated with Body Mass Index and Postprandial Total Ghrelin Reactivity to a Meal.

Animal studies have shown that olfactory sensitivity is greater when fasted than when fed. However, human research has generated inconsistent results. One possible explanation for these conflicting findings is metabolic health.

Weighing the evidence: Variance in brain responses to milkshake receipt is predictive of eating behavior.

Variations in brain responses to sensory stimuli are typically considered to lack information content and treated as "noise". Alternatively, variable response patterns may reflect the adjustment of biological parameters to external factors. We used functional magnetic resonance imaging in healthy non-dieting individuals to test whether intra-individual variation in brain response to the receipt of milkshake is associated with a range of behavioral and metabolic parameters.

Temporal transcriptomics suggest that twin-peaking genes reset the clock.

The mammalian suprachiasmatic nucleus (SCN) drives daily rhythmic behavior and physiology, yet a detailed understanding of its coordinated transcriptional programmes is lacking. To reveal the finer details of circadian variation in the mammalian SCN transcriptome we combined laser-capture microdissection (LCM) and RNA-seq over a 24 hr light / dark cycle. We show that 7-times more genes exhibited a classic sinusoidal expression signature than previously observed in the SCN.

Basolateral amygdala response to food cues in the absence of hunger is associated with weight gain susceptibility.

In rodents, food-predictive cues elicit eating in the absence of hunger (Weingarten, 1983). This behavior is disrupted by the disconnection of amygdala pathways to the lateral hypothalamus (Petrovich et al., 2002).

Second-generation compound for the modulation of utrophin in the therapy of DMD.

Duchenne muscular dystrophy (DMD) is a lethal, X-linked muscle-wasting disease caused by lack of the cytoskeletal protein dystrophin. There is currently no cure for DMD although various promising approaches are progressing through human clinical trials. By pharmacologically modulating the expression of the dystrophin-related protein utrophin, we have previously demonstrated in dystrophin-deficient mdx studies, daily SMT C1100 treatment significantly reduced muscle degeneration leading to improved muscle function.

Functional correction in mouse models of muscular dystrophy using exon-skipping tricyclo-DNA oligomers.

Antisense oligonucleotides (AONs) hold promise for therapeutic correction of many genetic diseases via exon skipping, and the first AON-based drugs have entered clinical trials for neuromuscular disorders. However, despite advances in AON chemistry and design, systemic use of AONs is limited because of poor tissue uptake, and recent clinical reports confirm that sufficient therapeutic efficacy has not yet been achieved. Here we present a new class of AONs made of tricyclo-DNA (tcDNA), which displays unique pharmacological properties and unprecedented uptake by many tissues after systemic administration.

The Cellular Processing Capacity Limits the Amounts of Chimeric U7 snRNA Available for Antisense Delivery.

Many genetic diseases are induced by mutations disturbing the maturation of pre-mRNAs, often affecting splicing. Antisense oligoribonucleotides (AONs) have been used to modulate splicing thereby circumventing the deleterious effects of mutations. Stable delivery of antisense sequences is achieved by linking them to small nuclear RNA (snRNAs) delivered by viral vectors, as illustrated by studies where therapeutic exon skipping was obtained in animal models of Duchenne muscular dystrophy (DMD).

Rescue of severely affected dystrophin/utrophin-deficient mice through scAAV-U7snRNA-mediated exon skipping.

Duchenne muscular dystrophy (DMD) is a severe neuromuscular disorder caused by mutations in the dystrophin gene that result in the absence of functional protein. Antisense-mediated exon skipping is one of the most promising approaches for the treatment of DMD and recent clinical trials have demonstrated encouraging results. However, antisense oligonucleotide-mediated exon skipping for DMD still faces major hurdles such as extremely low efficacy in the cardiac muscle, poor cellular uptake and relatively rapid clearance from circulation, which means that repeated administrations are required to achieve some therapeutic efficacy.

Engineering multiple U7snRNA constructs to induce single and multiexon-skipping for Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disorder caused by mutations in the dystrophin gene. Antisense-mediated exon skipping is one of the most promising approaches for the treatment of DMD but still faces personalized medicine challenges as different mutations found in DMD patients require skipping of different exons. However, 70% of DMD patients harbor dystrophin gene deletions in a mutation-rich area or "hot-spot" in the central genomic region.

Diaphragm rescue alone prevents heart dysfunction in dystrophic mice.

Duchenne muscular dystrophy (DMD) is an X-linked recessive disease caused, in most cases, by the complete absence of the 427 kDa cytoskeletal protein, dystrophin. There is no effective treatment, and affected individuals die from respiratory failure and cardiomyopathy by age 30. Here, we investigated whether cardiomyopathy could be prevented in animal models of DMD by increasing diaphragm utrophin or dystrophin expression and thereby restoring diaphragm function.

Prevention of dystrophic pathology in severely affected dystrophin/utrophin-deficient mice by morpholino-oligomer-mediated exon-skipping.

Duchenne muscular dystrophy (DMD) is a severe neuromuscular disorder caused by mutations in the dystrophin gene that result in the absence of functional protein. Antisense-mediated exon-skipping is one of the most promising approaches for the treatment of DMD because of its capacity to correct the reading frame and restore dystrophin expression, which has been demonstrated in vitro and in vivo. In particular, peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs) have recently been shown to induce widespread high levels of dystrophin expression in the mdx mouse model.

Enhanced exon-skipping induced by U7 snRNA carrying a splicing silencer sequence: Promising tool for DMD therapy.

Duchenne muscular dystrophy (DMD) is a fatal muscle wasting disorder caused by mutations in the dystrophin gene. In most cases, the open-reading frame is disrupted which results in the absence of functional protein. Antisense-mediated exon skipping is one of the most promising approaches for the treatment of DMD and has recently been shown to correct the reading frame and restore dystrophin expression in vitro and in vivo.

5-HT(1A) activation counteracts cardiovascular but not hypophagic effects of sibutramine in rats.

The noradrenaline (NA) and serotonin reuptake inhibitor, sibutramine, gives effective weight loss, but full efficacy cannot be attained at approved doses due to cardiovascular side effects. We assessed in rats the contributions of NA and serotonin transporters to sibutramine's hypophagic and cardiovascular effects, and whether selective 5-hydroxytryptamine (5-HT(1A)) receptor activation could counteract the latter without affecting the former. Food intake was assessed in freely feeding rats and cardiovascular parameters in conscious telemetered rats.

PSNCBAM-1, a novel allosteric antagonist at cannabinoid CB1 receptors with hypophagic effects in rats.

Background And Purpose: Rimonabant (Acomplia, SR141716A), a cannabinoid CB1 receptor inverse agonist, has recently been approved for the treatment of obesity. There are, however, concerns regarding its side effect profile. Developing a CB1 antagonist with a different pharmacological mechanism may lead to a safer alternative.

A dominant mutation in Snap25 causes impaired vesicle trafficking, sensorimotor gating, and ataxia in the blind-drunk mouse.

The neuronal soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex is essential for synaptic vesicle exocytosis, but its study has been limited by the neonatal lethality of murine SNARE knockouts. Here, we describe a viable mouse line carrying a mutation in the b-isoform of neuronal SNARE synaptosomal-associated protein of 25 kDa (SNAP-25). The causative I67T missense mutation results in increased binding affinities within the SNARE complex, impaired exocytotic vesicle recycling and granule exocytosis in pancreatic beta-cells, and a reduction in the amplitude of evoked cortical excitatory postsynaptic potentials.

Deorphanization of a G protein-coupled receptor for oleoylethanolamide and its use in the discovery of small-molecule hypophagic agents.

The endogenous lipid signaling agent oleoylethanolamide (OEA) has recently been described as a peripherally acting agent that reduces food intake and body weight gain in rat feeding models. This paper presents evidence that OEA is an endogenous ligand of the orphan receptor GPR119, a G protein-coupled receptor (GPCR) expressed predominantly in the human and rodent pancreas and gastrointestinal tract and also in rodent brain, suggesting that the reported effects of OEA on food intake may be mediated, at least in part, via the GPR119 receptor. Furthermore, we have used the recombinant receptor to discover novel selective small-molecule GPR119 agonists, typified by PSN632408, which suppress food intake in rats and reduce body weight gain and white adipose tissue deposition upon subchronic oral administration to high-fat-fed rats.

Pharmacological characterisation of a cell line expressing GABA B1b and GABA B2 receptor subunits.

The gamma-aminobutyric acid (GABA(B)) receptor has been shown to be a heterodimer consisting of two receptor subunits, GABA(B1) and GABA(B2). We have stably co-expressed these two subunits in a CHO cell line, characterised its pharmacology and compared it to the native receptor in rat brain membranes. Radioligand binding using [3H]CGP54626A demonstrated a similar rank order of potency between recombinant and native receptors: CGP62349>CGP54626A>SCH 50911>3-aminopropylphosphinicacid(3-APPA)>GABA>baclofen>saclofen>phaclofen.