The manifestations of Parkinson’s disease are caused by reduced dopaminergic innervation of the striatum. Loss-of-function mutations in the
DJ-1 gene cause early-onset familial parkinsonism. To ...investigate a possible role for DJ-1 in the dopaminergic system, we generated a mouse model bearing a germline disruption of
DJ-1. Although
DJ-1
−/−
mice had normal numbers of dopaminergic neurons in the substantia nigra, evoked dopamine overflow in the striatum was markedly reduced, primarily as a result of increased reuptake. Nigral neurons lacking DJ-1 were less sensitive to the inhibitory effects of D2 autoreceptor stimulation. Corticostriatal long-term potentiation was normal in medium spiny neurons of
DJ-1
−/−
mice, but long-term depression (LTD) was absent. The LTD deficit was reversed by treatment with D2 but not D1 receptor agonists. Furthermore,
DJ-1
−/−
mice displayed hypoactivity in the open field. Collectively, our findings suggest an essential role for DJ-1 in dopaminergic physiology and D2 receptor-mediated functions.
We developed S1QEL1.719, a novel bioavailable S1QEL (suppressor of site IQ electron leak). S1QEL1.719 prevented superoxide/hydrogen peroxide production at site IQ of mitochondrial complex I in vitro. ...The free concentration giving half-maximal suppression (IC50) was 52 nM. Even at 50-fold higher concentrations S1QEL1.719 did not inhibit superoxide/hydrogen peroxide production from other sites. The IC50 for inhibition of complex I electron flow was 500-fold higher than the IC50 for suppression of superoxide/hydrogen peroxide production from site IQ. S1QEL1.719 was used to test the metabolic effects of suppressing superoxide/hydrogen peroxide production from site IQin vivo. C57BL/6J male mice fed a high-fat chow for one, two or eight weeks had increased body fat, decreased glucose tolerance, and increased fasting insulin concentrations, classic symptoms of metabolic syndrome. Daily prophylactic or therapeutic oral treatment of high-fat-fed animals with S1QEL1.719 decreased fat accumulation, strongly protected against decreased glucose tolerance and prevented or reversed the increase in fasting insulin level. Free exposures in plasma and liver at Cmax were 1–4 fold the IC50 for suppression of superoxide/hydrogen peroxide production at site IQ and substantially below levels that inhibit electron flow through complex I. These results show that the production of superoxide/hydrogen peroxide from mitochondrial site IQin vivo is necessary for the induction and maintenance of glucose intolerance caused by a high-fat diet in mice. They raise the possibility that oral administration of S1QELs may be beneficial in metabolic syndrome.
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•S1QELs suppress superoxide/H2O2 production at site IQ of mitochondrial complex I.•We introduce S1QEL1.719, an orally bioavailable S1QEL that is potent and specific.•Mice fed a high-fat diet become fat, glucose-intolerant and insulin-resistant.•S1QEL1.719 dosing protects fat-fed mice against these metabolic outcomes.
Cystic fibrosis (CF) is the most common monogenic autosomal recessive disease in Caucasians caused by pathogenic mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (
). ...Significant small molecule therapeutic advances over the past two decades have been made to target the defective CFTR protein and enhance its function. To address the most prevalent defect of the defective CFTR protein (i.e., F508del mutation) in CF, two biomolecular activities are required, namely, correctors to increase the amount of properly folded F508delCFTR levels at the cell surface and potentiators to allow the effective opening,
, function of the F508delCFTR channel. Combined, these activities enhance chloride ion transport yielding improved hydration of the lung surface and subsequent restoration of mucociliary clearance. To enhance clinical benefits to CF patients, a complementary triple combination therapy consisting of two corrector molecules, type 1 (C1) and type 2, with additive mechanisms along with a potentiator are being investigated in the clinic for maximum restoration of mutated CFTR function. We report the identification and in vitro biologic characterization of ABBV-2222/GLPG2222 (
),-a novel, potent, and orally bioavailable C1 corrector developed by AbbVie-Galapagos and currently in clinical trials-which exhibits substantial improvements over the existing C1 correctors. This includes improvements in potency and drug-drug interaction (DDI) compared with 3-(6-(1-(2,2-difluorobenzod1,3dioxol-5-yl)cyclopropanecarboxamido)-3-methylpyridin-2-yl)benzoic acid (VX-809, Lumacaftor) and improvements in potency and efficacy compared with 1-(2,2-difluoro-1,3-benzodioxol-5-yl)-N-1-(2R)-2,3-dihydroxypropyl-6-fluoro-2-(1-hydroxy-2-methylpropan-2-yl)indol-5-ylcyclopropane-1-carboxamide (VX-661, Tezacaftor). ABBV-2222/GLPG2222 exhibits potent in vitro functional activity in primary patient cells harboring F508del/F508del CFTR with an EC
value <10 nM. SIGNIFICANCE STATEMENT: To address the most prevalent defect of the defective CFTR protein (i.e., F508del mutation) in cystic fibrosis, AbbVie-Galapagos has developed ABBV-2222/GLPG2222, a novel, potent, and orally bioavailable C1 corrector of this protein. ABBV-2222/GLPG2222, which is currently in clinical trials, exhibits potent in vitro functional activity in primary patient cells harboring F508del/F508del CFTR and substantial improvements over the existing C1 correctors.
Cystic fibrosis (CF) is a genetic disorder that affects multiple tissues and organs. CF is caused by mutations in the CFTR gene, resulting in insufficient or impaired cystic fibrosis transmembrane ...conductance regulator (CFTR) protein. The deletion of phenylalanine at position 508 of the protein (F508del-CFTR) is the most common mutation observed in CF patients. The most effective treatments of these patients employ two CFTR modulator classes, correctors and potentiators. CFTR correctors increase protein levels at the cell surface; CFTR potentiators enable the functional opening of CFTR channels at the cell surface. Triple-combination therapies utilize two distinct corrector molecules (C1 and C2) to further improve the overall efficacy. We identified the need to develop a C2 corrector series that had the potential to be used in conjunction with our existing C1 corrector series and provide robust clinical efficacy for CF patients. The identification of a pyrrolidine series of CFTR C2 correctors and the structure–activity relationship of this series is described. This work resulted in the discovery and selection of (2S,3R,4S,5S)-3-(tert-butyl)-4-((2-methoxy-5-(trifluoromethyl)pyridin-3-yl)methoxy)-1-((S)-tetrahydro-2H-pyran-2-carbonyl)-5-(o-tolyl)pyrrolidine-2-carboxylic acid (ABBV/GLPG-3221), which was advanced to clinical trials.
A novel series of N-type calcium channel inhibitors have been discovered. Optimization of potency and HT-ADME properties provides 4-aminocyclopentapyrrolidines with analgesic efficacy after oral ...dosing.
Blockade of voltage-gated Ca
2+ channels on sensory nerves attenuates neurotransmitter release and membrane hyperexcitability associated with chronic pain states. Identification of small molecule Ca
...2+ channel blockers that produce significant antinociception in the absence of deleterious hemodynamic effects has been challenging. In this report, two novel structurally related compounds, A-686085 and A-1048400, were identified that potently block N-type (IC
50
=
0.8
μM and 1.4
μM, respectively) and T-type (IC
50
=
4.6
μM and 1.2
μM, respectively) Ca
2+ channels in FLIPR based Ca
2+ flux assays. A-686085 also potently blocked L-type Ca
2+ channels (EC
50
=
0.6
μM), however, A-1048400 was much less active in blocking this channel (EC
50
=
28
μM). Both compounds dose-dependently reversed tactile allodynia in a model of capsaicin-induced secondary hypersensitivity with similar potencies (EC
50
=
300–365
ng/ml). However, A-686085 produced dose-related decreases in mean arterial pressure at antinociceptive plasma concentrations in the rat, while A-1048400 did not significantly alter hemodynamic function at supra-efficacious plasma concentrations. Electrophysiological studies demonstrated that A-1048400 blocks native N- and T-type Ca
2+ currents in rat dorsal root ganglion neurons (IC
50
=
3.0
μM and 1.6
μM, respectively) in a voltage-dependent fashion. In other experimental pain models, A-1048400 dose-dependently attenuated nociceptive, neuropathic and inflammatory pain at doses that did not alter psychomotor or hemodynamic function. The identification of A-1048400 provides further evidence that voltage-dependent inhibition of neuronal Ca
2+ channels coupled with pharmacological selectivity vs. L-type Ca
2+ channels can provide robust antinociception in the absence of deleterious effects on hemodynamic or psychomotor function.
A series of 2-aminopyrimidines was synthesized as ligands of the histamine H4 receptor (H4R). Working in part from a pyrimidine hit that was identified in an HTS campaign, SAR studies were carried ...out to optimize the potency, which led to compound 3, 4-tert-butyl-6-(4-methylpiperazin-1-yl)pyrimidin-2-ylamine. We further studied this compound by systematically modifying the core pyrimidine moiety, the methylpiperazine at position 4, the NH2 at position 2, and positions 5 and 6 of the pyrimidine ring. The pyrimidine 6 position benefited the most from this optimization, especially in analogs in which the 6-tert-butyl was replaced with aromatic and secondary amine moieties. The highlight of the optimization campaign was compound 4, 4-2-amino-6-(4-methylpiperazin-1-yl)pyrimidin-4-ylbenzonitrile, which was potent in vitro and was active as an anti-inflammatory agent in an animal model and had antinociceptive activity in a pain model, which supports the potential of H4R antagonists in pain.
Salvinorin A is a naturally occurring hallucinogenic diterpenoid from the plant Salvia divinorum that selectively and potently activates κ-opioid receptors (KORs). Salvinorin A is unique in that it ...is the only known lipid-like molecule that selectively and potently activates a G-protein coupled receptor (GPCR), which has as its endogenous agonist a peptide; salvinorin A is also the only known non-nitrogenous opioid receptor agonist. In this paper, we identify key residues in KORs responsible for the high binding affinity and agonist efficacy of salvinorin A. Surprisingly, we discovered that salvinorin A was stabilized in the binding pocket by interactions with tyrosine residues in helix 7 (Tyr313 and Tyr320) and helix 2 (Tyr119). Intriguingly, activation of KORs by salvinorin A required interactions with the helix 7 tyrosines Tyr312, Tyr313, and Tyr320 and with Tyr139 in helix 3. In contrast, the prototypical nitrogenous KOR agonist U69593 and the endogenous peptidergic agonist dynorphin A (1−13) showed differential requirements for these three residues for binding and activation. We also employed a novel approach, whereby we examined the effects of cysteine-substitution mutagenesis on the binding of salvinorin A and an analogue with a free sulfhydryl group, 2-thiosalvinorin B. We discovered that residues predicted to be in close proximity, especially Tyr313, to the free thiol of 2-thiosalvinorin B when mutated to Cys showed enhanced affinity for 2-thiosalvinorin B. When these findings are taken together, they imply that the diterpenoid salvinorin A utilizes unique residues within a commonly shared binding pocket to selectively activate KORs.
Acute activation of Galpha(i/o)-coupled D2 dopamine receptors inhibits A2A adenosine receptor stimulation of adenylate cyclase. This antagonistic interaction between D2 dopamine and A2A adenosine ...receptors has been well documented; however, the effects of persistent activation of D2 dopamine receptors on subsequent A2A adenosine receptor signaling have not been explored. The present study investigated the effects of short-term (3-h) and long-term (18-h) activation of D2L dopamine receptors on subsequent A2A adenosine receptor stimulation of adenylate cyclase in CAD-D2L and NS20Y-D2L neuroblastoma cells. Short- and long-term activation of D2L dopamine receptors markedly increased 5'-N-methylcarboxamidoadenosine (MECA)-stimulated cyclic AMP accumulation 1.4-fold and 1.7-fold, respectively. D2L receptor-induced sensitization of A2A-stimulated cyclic AMP accumulation was blocked by the D2 antagonist spiperone and pertussis toxin pretreatment. In addition, persistent activation of A2A adenosine receptors resulted in 50% desensitization of subsequent MECA-stimulated cyclic AMP accumulation; however, MECA-induced desensitization of A2A adenosine receptors did not prevent completely quinpirole-induced sensitization of adenylate cyclase. These studies revealed a novel mode of regulation between D2L dopamine and A2A adenosine receptors and suggest a cooperative interaction in the regulation of cyclic AMP signaling.
cis-4-(Piperazin-1-yl)-5,6,7a,8,9,10,11,11a-octahydrobenzofuro2,3-hquinazolin-2-amine, 4 (A-987306) is a new histamine H4 antagonist. The compound is potent in H4 receptor binding assays (rat H4, K i ...= 3.4 nM, human H4 K i = 5.8 nM) and demonstrated potent functional antagonism in vitro at human, rat, and mouse H4 receptors in cell-based FLIPR assays. Compound 4 also demonstrated H4 antagonism in vivo in mice, blocking H4-agonist induced scratch responses, and showed anti-inflammatory activity in mice in a peritonitis model. Most interesting was the high potency and efficacy of this compound in blocking pain responses, where it showed an ED50 of 42 μmol/kg (ip) in a rat post-carrageenan thermal hyperalgesia model of inflammatory pain.
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