Increased production of 27-hydroxycholesterol in human colorectal cancer advanced stage: Possible contribution to cancer cell survival and infiltration.

So far, the investigation in cancer cell lines of the modulation of cancer growth and progression by oxysterols, in particular 27-hydroxycholesterol (27HC), has yielded controversial results. The primary aim of this study was the quantitative evaluation of possible changes in 27HC levels during the different steps of colorectal cancer (CRC) progression in humans. A consistent increase in this oxysterol in CRC mass compared to the tumor-adjacent tissue was indeed observed, but only in advanced stages of progression (TNM stage III), a phase in which cancer has spread to nearby sites. To investigate possible pro-tumor properties of 27HC, its effects were studied in vitro in differentiated CaCo-2 cells. Relatively high concentrations of this oxysterol markedly increased the release of pro-inflammatory interleukins 6 and 8, monocyte chemoattractant protein-1, vascular endothelial growth factor, as well as matrix metalloproteinases 2 and 9. The up-regulation of all these molecules, which are potentially able to favor cancer progression, appeared to be dependent upon a net stimulation of Akt signaling exerted by supra-physiological amounts of 27HC.

CRISPR/Cas9-mediated knockout of Abcd1 and Abcd2 genes in BV-2 cells: novel microglial models for X-linked Adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD), the most frequent peroxisomal disorder, is associated with mutation in the ABCD1 gene which encodes a peroxisomal ATP-binding cassette transporter for very long-chain fatty acids (VLCFA). The biochemical hallmark of the disease is the accumulation of VLCFA. Peroxisomal defect in microglia being now considered a priming event in the pathology, we have therefore generated murine microglial cells mutated in the Abcd1 gene and its closest homolog, the Abcd2 gene. Using CRISPR/Cas9 gene editing strategy, we obtained 3 cell clones with a single or double deficiency. As expected, only the combined absence of ABCD1 and ABCD2 proteins resulted in the accumulation of VLCFA. Ultrastructural analysis by electron microscopy revealed in the double mutant cells the presence of lipid inclusions similar to those observed in brain macrophages of patients. These observations are likely related to the increased level of cholesterol and the accumulation of neutral lipids that we noticed in mutant cells. A preliminary characterization of the impact of peroxisomal defects on the expression of key microglial genes such as Trem2 suggests profound changes in microglial functions related to inflammation and phagocytosis. The expression levels of presumed modifier genes have also been found modified in mutant cells, making these novel cell lines relevant for use as in vitro models to better understand the physiopathogenesis of X-ALD and to discover new therapeutic targets.

A microglial cell model for acyl-CoA oxidase 1 deficiency.

Acyl-CoA oxidase 1 (ACOX1) deficiency is a rare and severe peroxisomal leukodystrophy associated with a very long-chain fatty acid (VLCFA) ß-oxidation defect. This neurodegenerative disease lacks relevant cell models to further decipher the pathomechanisms in order to identify novel therapeutic targets. Since peroxisomal defects in microglia appear to be a key component of peroxisomal leukodystrophies, we targeted the Acox1 gene in the murine microglial BV-2 cell line. Using CRISPR/Cas9 gene editing, we generated an Acox1-deficient cell line and validated the allelic mutations, which lead to the absence of ACOX1 protein and enzymatic activity. The activity of catalase, the enzyme degrading H2O2, was increased, likely in response to the alteration of redox homeostasis. The mutant cell line grew more slowly than control cells without obvious morphological changes. However, ultrastructural analysis revealed an increased number of peroxisomes and mitochondria associated with size reduction of mitochondria. Changes in the distribution of lipid droplets containing neutral lipids have been observed in mutant cells; lipid analysis revealed the accumulation of saturated and monounsaturated VLCFA. Besides, expression levels of genes encoding interleukin-1 beta and 6 (IL-1ß and IL-6), as well as triggering receptor expressed on myeloid cells 2 (Trem2) were found modified in the mutant cells suggesting modification of microglial polarization and phagocytosis ability. In summary, this Acox1-deficient cell line presents the main biochemical characteristics of the human disease and will serve as a promising model to further investigate the consequences of a specific microglial peroxisomal ß-oxidation defect on oxidative stress, inflammation and cellular functions.

Safinamide Modulates Striatal Glutamatergic Signaling in a Rat Model of Levodopa-Induced Dyskinesia.

Safinamide (Xadago) is a novel dual-mechanism drug that has been approved in the European Union and United States as add-on treatment to levodopa in Parkinson's disease therapy. In addition to its selective and reversible monoamine oxidase B inhibition, safinamide through use-dependent sodium channel blockade reduces overactive glutamatergic transmission in basal ganglia, which is believed to contribute to motor symptoms and complications including levodopa-induced dyskinesia (LID). The present study investigated the effects of safinamide on the development of LID in 6-hydroxydopamine (6-OHDA)-lesioned rats, evaluating behavioral, molecular, and neurochemical parameters associated with LID appearance. 6-OHDA-lesioned rats were treated with saline, levodopa (6 mg/kg), or levodopa plus safinamide (15 mg/kg) for 21 days. Abnormal involuntary movements, motor performance, molecular composition of the striatal glutamatergic synapse, glutamate, and GABA release were analyzed. In the striatum, safinamide prevented the rearrangement of the subunit composition of N-methyl-d-aspartate receptors and the levodopa-induced increase of glutamate release associated with dyskinesia without affecting the levodopa-stimulated motor performance and dyskinesia. Overall, these findings suggest that the striatal glutamate-modulating component of safinamide's activity may contribute to its clinical effects, where its long-term use as levodopa add-on therapy significantly improves motor function and "on" time without troublesome dyskinesia.

Intestinal permeability and Ménière's disease.

PURPOSE: Ménière disease (MD) is a multifactorial chronic disabling condition characterized by episodic vertigo, ear fullness, and hearing loss. MD patients often complain of aspecific gastrointestinal symptoms associated with autonomic dysregulation, frequently outweighed by the otological manifestations. Dietary modifications have been reported to improve the typical MD symptoms in some cases. Our purpose was to test the urinary levels of lactulose and mannitol (double sugar test) and the fecal calprotectin, both markers of altered intestinal permeability, in subjects with definite MD in an active and inactive stage. MATERIALS AND METHODS: Twenty-six with definite unilateral MD were studied: 14 patients were symptomatic for at least 3months with moderate to severe vertigo spells and a functional level ≥4; 12 patients had been asymptomatic (no vertigo spells) for at least 3months and had a functional level=1 at the time of testing. Twenty healthy volunteers were recruited as "control group". RESULTS: Lactulose and mannitol absorption was significantly increased in the symptomatic M patients compared to the asymptomatic group (p<0.02 and p<0.004, respectively) and to the controls. FC were also higher than normal only in the symptomatic group. (p<0.01). CONCLUSIONS: An altered intestinal permeability, according to the two assays, was found only in symptomatic MD patients. The rationale for a possible relationship between MD and intestinal permeability is forwarded. The double-sugar test and FC quantification might be implemented in the MD diagnostic workup.

Safinamide: from molecular targets to a new anti-Parkinson drug.

Ideal treatment in Parkinson's disease (PD) aims at relieving symptoms and slowing disease progression. Of all remedies, levodopa remains the most effective for symptomatic relief, but the medical need for neuroprotectant drugs is still unfulfilled. Safinamide, currently in phase III clinical trials for the treatment of PD, is a unique molecule with multiple mechanisms of action and a very high therapeutic index. It combines potent, selective, and reversible inhibition of MAO-B with blockade of voltage-dependent Na+ and Ca2+ channels and inhibition of glutamate release. Safinamide has neuroprotective and neurorescuing effects in MPTP-treated mice, in the rat kainic acid, and in the gerbil ischemia model. Safinamide potentiates levodopa-mediated increase of DA levels in DA-depleted mice and reverses the waning motor response after prolonged levodopa treatment in 6-OHDA-lesioned rats. Safinamide has excellent bioavailability, linear kinetics, and is suitable for once-a-day administration. Therefore, safinamide may be used in PD to reduce l-dopa dosage and also represents a valuable therapeutic drug to test disease-modifying potential.

Sodium channel activity and sigma binding of 2-aminopropanamide anticonvulsants.

Sodium channel blocking, anticonvulsant activity, and sigma (sigma) binding of selected leads in a series of alpha-amino amide anticonvulsants were examined. While anticonvulsant compounds were always endowed with low micromolar sodium (Na+) channel site-2 binding, compounds with low site-2 Na+ channel affinity failed to control seizures. No correlation could be drawn with sigma1 binding. Both anticonvulsant and Na+ channel blocking activities were independent of stereochemistry, while sigma1 binding seems to be favoured by an S-configuration on the aminoamide moiety.

Synthesis and preliminary biological evaluation of new alpha-amino amide anticonvulsants incorporating a dextromethorphan moiety.

Dextromethorphan 1 is an effective neuroprotectant in animal models of epilepsy and ischemia but showed side-effects during clinical trials limiting its potential use in a clinical setting. Here we describe the enantioselective and enantiospecific syntheses and the initial in vitro and in vivo biological evaluation of new hybrid structures between 1 and a previously disclosed alpha-amino amide anticonvulsant (3).

Biochemical and electrophysiological studies on the mechanism of action of PNU-151774E, a novel antiepileptic compound.

PNU-151774E [(S)-(+)-2-(4-(3-fluorobenzyloxy)benzylamino)propanamide methanesulfonate], a new anticonvulsant that displays a wide therapeutic window, has a potency comparable or superior to that of most classic anticonvulsants. PNU-151774E is chemically unrelated to current antiepileptics. In animal seizure models it possesses a broad spectrum of action. In the present study, the action mechanism of PNU-151774E has been investigated using electrophysiological and biochemical assays. Binding studies performed with rat brain membranes show that PNU-151774E has high affinity for binding site 2 of the sodium channel receptor, which is greater than that of phenytoin or lamotrigine (IC50, 8 microM versus 47 and 185 microM, respectively). PNU-151774E reduces sustained repetitive firing in a use-dependent manner without modifying the first action potential in hippocampal cultured neurons. In the same preparation PNU-151774E inhibits tetrodotoxin-sensitive fast sodium currents and high voltage-activated calcium currents under voltage-clamp conditions. These electrophysiological activities of PNU-151774E correlate with its ability to inhibit veratrine and KCl-induced glutamate release in rat hippocampal slices (IC50, 56.4 and 185.5 microM, respectively) and calcium inward currents in mouse cortical neurons. On the other hand, PNU-151774E does not affect whole-cell gamma-aminobutryic acid- and glutamate-induced currents in cultured mouse cortical neurons. These results suggest that PNU-151774E exerts its anticonvulsant activity, at least in part, through inhibition of sodium and calcium channels, stabilizing neuronal membrane excitability and inhibiting transmitter release. The possible relevance of these pharmacological properties to its antiepileptic potential is discussed.

Synthesis and antihypertensive activity of 2,4-dioxoimidazolidin-1-yl and perhydro-2,4-dioxopyrimidin-1-yl ergoline derivatives.

The synthesis and antihypertensive activity of a series of 2,4-dioxoimidazolidin-1-yl and perhydro-2,4-dioxopyrimidin-1-yl ergoline derivatives are reported. The oral antihypertensive activity was studied in spontaneously hypertensive rats (SHRs) by measuring systolic blood pressure by an indirect tail-cuff method at different times after treatment. The prolactin lowering activity (indirectly measured by the nidation test) in rats and the oral acute toxicity in mice were also studied. The results of this study revealed potent antihypertensive ergoline derivatives devoid of side-effects related to the dopaminergic stimulation and the importance of the delta 9,10 double bond for conferring high potency within these compounds.

Synthesis and in vitro and in vivo evaluation of dopaminergic ergoline derivatives.

A series of ergoline-amides was synthesised in the discovery of new dopaminomimetic agents. Several compounds exhibited in vivo high prolactin lowering activity (indirectly measured by the nidation test) in rats. For the most active, the potential anti-Parkinson activity was evaluated by observation of the contralateral turning behaviour in 6-OH-DA lesioned rats. The acute toxicity by oral route in mice was also studied.

Serotonergic ergoline derivatives.

Novel classes of 13- and 14-tertbutyl-ergoline derivatives were prepared, and characterised in vitro for their affinity for adrenergic, dopaminergic and serotonergic binding sites. This study particularly examines the importance of the presence and the position of the tert-butyl group in conferring either significant 5-HT1A or 5-HT2 affinity and selectivity respectively.

Recombinant human IL-2 is cytotoxic to oligodendrocytes after in vitro self aggregation.

Interleukin 2 (IL-2) is a cytokine produced by activated T cells that plays a crucial role in the immune response and exerts multiple functions in different tissues including the nervous system. The present study was carried out to investigate the effect of recombinant human IL-2 (rhIL-2) on the survival of differnet glial cells type and of cortical neurons in culture. The results demonstrate that rhIL-2 is selectively cytotoxic to oligodendrocytes only if preincubated in aqueous solution (1200 U/ml) for at least two days before being added to the culture. Other glial and neuronal cells were unaffected. The cytotoxic effect was temperature- and concentration-dependent occurring only when rhIL-2 was reincubated at 37 degrees C and was dose-dependently neutralized by antibodies raised against IL-2 indicating that an immunoreactive IL-2 like compound is the active principle. Polyacrilamide gel electrophoresis under native (PAGE) and denaturing (SDS-PAGE) conditions and gel filtration analysis of the rhIL-2 incubated solution suggest that rhIL-2 is cytotoxic to oligodendrocytes only after association into soluble high weight molecular aggregates.

Phenylimidazolidin-2-one derivatives as selective 5-HT3 receptor antagonists and refinement of the pharmacophore model for 5-HT3 receptor binding.

A possible bioisosterism between the benzamido and the phenylimidazolidin-2-one moieties has been suggested on the basis of the similarity between the molecular electrostatic potential (MEP) of metoclopramide, a D2 receptor antagonist with weak 5-HT3 receptor antagonist properties, and zetidoline, a D2 receptor antagonist. Starting from this premise, a series of phenylimidazolidin-2-one derivatives bearing a basic azabicycloalkyl or an imidazolylalkyl moiety were synthesized and evaluated for 5-HT3 receptor radioligand binding affinity ([3H]-GR 43,694). In vitro 5-HT3 receptor antagonist activity was tested in the guinea pig ileum assay (GPI). A number of high-affinity ligands were shown to be potent 5-HT3 receptor antagonists in vivo as determined by inhibition of the Bezold--Jarisch reflex in the anesthetized rat. In general, the imidazolylalkyl derivatives were found to be more active than azabicycloalkyls. 1-(3,5-Dichlorophenyl)-3-[(5-methyl-1H-imidazol-4-yl)methyl]imidazoli din-2-one (58), in particular, displayed very high affinity for the 5-HT3 receptor (Ki of 0.038 nM) with a Kb of 5.62 nM in the GPI assay, being more potent than the reference compounds (ondansetron, tropisetron, granisetron, and BRL 46,470) tested. 58 showed an ID50 comparable to that of ondansetron (2.2 micrograms/kg i.v.) in the Bezold--Jarisch reflex. A molecular modeling study based on this structurally novel series of compounds allowed the refinement of previously reported 5-HT3 receptor antagonist pharmacophore models.

Structure-activity relationship studies on the 5-HT(1A) receptor affinity of 1-phenyl-4-[omega-(alpha- or beta-tetralinyl)alkyl]piperazines. 4.

The synthesis of 1-phenylpiperazines, linked in the alpha or beta position of the tetralin moiety on the terminal part of the N-4 alkyl chain, and their radioligand binding affinities for 5-HT(1A), 5-HT(2A), D-1, D-2, alpha1, and alpha2 receptors along with SAR studies on the 5-HT(1A) receptor are reported. Several changes have been carried out on previous structures of type 2, by inserting the alkyl chain with variable length in the alpha or beta position of the tetralin moiety and by changing the position of the methoxy group on the aromatic ring of the tetralin nucleus. The highest affinity (IC50 = 0.50 nM) and selectivity for the 5-HT(1A) receptor were showed by 1-phenylpiperazine 2a with a three-membered alkyl chain bearing a 5-methoxytetralin-1-yl ring in the omega position.

1-aryl-4-[(1-tetralinyl)alkyl]piperazines: alkylamido and alkylamino derivatives. Synthesis, 5-HT1A receptor affinity, and selectivity. 3.

The synthesis and binding profile on 5-HT1A, 5-HT2, D-1, D-2, alpha 1, and alpha 2 receptors of the N-4 long-chain arylpiperazines 22-40 are reported, where an amino or amido function is inserted into the intermediate chain linked to the alpha position of the tetralin nucleus. Unlike the buspirone analogues, for the amido derivatives studied in this paper, the terminal amide function of long-chain piperazines is not important for 5-HT1A receptor affinity binding, and its removal yields high-affinity 5-HT1A receptor agents.

Dopamine receptors status after unilateral nigral 6-OHDA lesion. Autoradiographic and in situ hybridization study in the rat brain.

The physiological effects of dopamine (DA) are mediated by several distinct receptor subtypes. The effects of unilateral nigral 6-hydroxydopamine (6-OHDA) lesions on DA receptors were investigated by receptor autoradiography using the D1 selective ligand [3H]SCH 23390 as well as the D2 ligand [3H]spiroperidol. mRNA distribution was studied by in situ hybridization. Lesioned rats were sacrificed at different time intervals. Receptor binding studies were performed on tissue sections using selective ligands. [35S]UTP labeled RNA probes were prepared from the different cDNA (D1, D2, D3) and used for in situ hybridization. A specific loss of receptor binding sites and mRNA hybridization was found in the lesioned substantia nigra pars compacta (SNc) at all times examined. Receptor binding studies revealed a different time-dependent increase in both D1 and D2 receptors. In situ hybridization showed that only D2 receptor mRNA increased in the caudate-putamen (CPu) of the lesioned side 15 d after 6-OHDA. No changes were observed in D1 and D3 receptor mRNA during the entire time-course.

FCE 23884, substrate-dependent interaction with the dopaminergic system. I. Preclinical behavioral studies.

FCE 23884, a newly synthetized ergoline derivative, shows dopamine (DA) agonist or antagonist properties depending on the functional state of the biological substrate. The compound behaves as a full DA antagonist in normal animals, but shows full agonist properties in denervated models in the same dose range. In normal animals, FCE 23884 impairs Sidmans avoidance in rats, reduces spontaneous locomotion in mice and monkeys and antagonizes apomorphine-induced climbing behavior in mice, yawning in rats, emesis in dogs and amphetamine-induced toxicity in grouped mice. After experimental procedures resulting in severe DA depletion, FCE 23884 behaves as a powerful DA-agonist mainly at D-1 receptors. FCE 23884 induces contralateral turning behavior in 6-hydroxydopamine-lesioned rats and reverses 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced akinesia in monkeys and reserpine-induced hypokinesia in mice. These results indicate that the antagonist or agonist activity of FCE 23884 is substrate-dependent and mostly related to the presence or absence of DA. This leads to the apparently paradoxical suggestion that the compound could be useful both in psychotic states and extrapyramidal diseases, i.e., in clinical conditions characterized by either excessive or impaired DAergic neurotransmission.