[[(Arylpiperazinyl)alkyl]thio]thieno[2,3-<i>d</i>]pyrimidinone Derivatives as High-Affinity, Selective 5-HT_1A Receptor Ligands^†

A series of 2-[[(4-aryl-1-piperazinyl)alkyl]thio]thieno[2,3-d]pyrimidin-4(1H)-one and 3-substituted 2-[[(4-aryl-1-piperazinyl)alkyl]thio]thieno[2,3-d]pyrimidin-4(3H)-one derivatives was prepared and evaluated for in vitro 5-HT1A receptor affinity by radioligand binding assays; the selectivity for 5-HT1A receptors rather than α1-adrenoceptors was also examined (ratio of the IC50 α1 to IC50 5-HT1A). The binding tests gave indications about the best features of the [(arylpiperazinyl)alkyl]thio moiety and of the substituents on the thiophene and pyrimidinone rings for efficacious and selective 5-HT1A ligands. The most effective derivative for displacing [3H]-8-OH-DPAT from rat hippocampal membranes was the 3-amino-2-[[3-[4-(2-methoxyphenyl)-1-piperazinyl]propyl]thio]-5,6-dimethylthieno[2,3-d]pyrimidin-4(3H)-one (70) (IC50 = 0.3 nM) with selectivity of 24 for the 5-HT1A over the α1-adrenoceptor. Compound 73, where the 2-methoxyphenyl on the N4 piperazine ring was replaced with a pyrimidine group, showed the best selectivity, with a ratio of 74, while its affinity IC50 for 5-HT1A was 6.8 nM. These results, compared to those for compounds 46 (IC50 24 nM; selectivity 2) and 49 (IC50 226 nM; selectivity 5), N3 unsubstituted analogues of derivatives 70 and 73, show the importance of an amino group in position 3 of the thienopyrimidine system for the interaction with 5-HT1A receptor binding sites, although this fragment can affect the affinity and selectivity only if linked to the (arylpiperazinyl)alkyl moiety. The better selectivity of piperidine 74 (IC50 0.8; selectivity 45) compared to the analogous piperazine 70 is also noteworthy. Twenty of the 30 molecules used for determining the binding affinity to 5-HT1A and α1-adrenergic receptors were selected for QSAR analysis using a series of molecular descriptors and calculated with the TSAR software

MOESM1 of Human Skeletal Muscle Stem Cell Antiinflammatory Activity Ameliorates Clinical Outcome in Amyotrophic Lateral Sclerosis Models

Human Skeletal Muscle Stem Cell Antiinflammatory Activity Ameliorates Clinical Outcome in Amyotrophic Lateral Sclerosis Model

Proteomic Profiling of Cervical and Lumbar Spinal Cord Reveals Potential Protective Mechanisms in the Wobbler Mouse, a Model of Motor Neuron Degeneration

The wobbler mouse is a model of selective motor neuron degeneration in the cervical spinal cord. Comparing cervical and lumbar tracts of control and diseased mice at the early stage of pathology by proteomic analysis, we identified 31 proteins by peptide mass fingerprint after tryptic digestion and MALDI-TOF analysis, that were differently represented among the four experimental groups. In healthy mice, patterns of protein expression differed between cervical and lumbar tract: proteins of cellular energetic metabolism pathway showed lower expression in the cervical tract, while cellular trafficking proteins were overrepresented. In wobbler mice, these differences disappeared and the expression pattern was similar between cervical and lumbar spinal cord. We found that most of the proteins differentially regulated in wobbler with respect to control cervical tract were related to astrogliosis or involved in glutamate-glutamine cycle, energy transduction and redox functions. Proteins overrepresented in the wobbler lumbar spinal cord were cytoskeleton proteins and cellular transport proteins, in particular the vesicle fusing ATPase and the isoform 2 of syntaxin-binding protein 1, involved in vesicle trafficking. We suggest that overexpression of proteins involved in vesicle trafficking, together with proteins counteracting mitochondrial dysfunction can have neuroprotective effects, preserving lumbar spinal cord motor neurons in wobbler mice

Synthesis of New Molecular Probes for Investigation of Steroid Biosynthesis Induced by Selective Interaction with Peripheral Type Benzodiazepine Receptors (PBR)^†

In the present study, we have synthesized and tested novel pyridopyrrolo- and pyrrolobenzoxazepine derivatives, as novel and selective peripheral type benzodiazepine receptor (PBR) ligands, and their ability to modulate steroid biosynthesis has been investigated. A subset of new ligands bind the PBR (rat brain and testis) with picomolar affinity, representing the most potent ligands that have been identified to date, and elicited effects on endogenous rate of steroidogenesis in MA10 Leydig cells, having similar potency and effect as PK11195. Several compounds, differently substituted at C-7, were used as molecular yardsticks to probe the spatial dimension of the lipophilic pocket L4 in the receptor binding site

Neuropathologic and biochemical changes during disease progression in liver X receptor beta-/- mice, a model of adult neuron disease.

In amyotrophic lateral sclerosis (ALS), there is selective degeneration of motor neurons that leads to paralysis and death. Although the etiology of ALS is unclear, its heterogeneity suggests that a combination of factors (endogenous and/or environmental) may induce progressive motor neuron stress that results in the activation of different cell death pathways. Alterations of brain cholesterol homeostasis have recently been considered as possible cofactors in many neurodegenerative disorders, including ALS. The liver X receptor beta (LXRbeta) receptor is involved in lipogenesis and cholesterol metabolism, and we previously found that adult-onset motor neuron pathology occurs in LXRbeta mice. Here, we investigated neuromuscular alterations of LXRbeta mice from ages 3 to 24 months. Increased cholesterol levels, gliosis, and inflammation preceded motor neuron loss and clinical disease onset; the mice showed progressivemotor neuron deficits starting from age 7 months. The numbers ofmotor neurons and neuromuscular junctions were decreased in 24-month-old mice, but neither paralysis nor reduced life span was observed. Moreover, other spinal neurons were also lost in these mice. These results suggest that LXRbeta may inhibit neuroinflammation and maintain cholesterol homeostasis, and that LXRbeta mice represent a potential model for investigating the role of cholesterol in ALS and other neurodegenerative disorders

Novel Sigma Receptor Ligands: Synthesis and Biological Profile

The aim of the present study was to investigate the biological profile of new substituted 1-phenyl-2-cyclopropylmethylamines. High affinity for both σ subtypes was achieved when 4-phenylpiperidin-4-ol (4a−e) and 4-benzylpiperidine moieties were present (5a−e). (1R,2S/1S,2R)-2-[4-Hydroxy-4-phenylpiperidin-1-yl)methyl]-1-(4-methylphenyl)cyclopropanecarboxylate (4b) showed high affinity for the σ1 sites (Ki = 1.5 nM) and the most favorable σ1/σ2 selectivity (Ki(σ2)/Ki(σ1) = 33.9). Binding affinity studies showed that 4b binding on N-methyl-d-aspartate (NMDA), dopaminergic (D1, D2, D3), muscarinic, histaminergic H1, adrenergic (α1, α2), serotoninergic (5-HT2A, 5-HT2C, 5-HT3, 5-HT4, 5-HT6), DA (DAT), and 5-HT (SERT) transporters was not significant. Interestingly, σ ligands differently induced the expression of tissue transglutaminase (TG-2) in primary astroglial cell cultures. We suggest that 4b may act as a σ1/σ2 agonist and that the σ ligands may modulate TG-2 differently

Synthesis of 3-Arylpiperazinylalkylpyrrolo[3,2-<i>d</i>]pyrimidine-2,4-dione Derivatives as Novel, Potent, and Selective α₁-Adrenoceptor Ligands^‡

Novel compounds characterized by a pyrrolo[3,2-d]pyrimidine-2,4-dione (PPm) system connected through an alkyl chain to a phenylpiperazine (PPz) residue were designed as structural analogues of the α1-adrenoceptor (α1-AR) ligand RN5 (1). In this new series of derivatives an arylpyrrolo moiety has replaced the indole nucleus of RN5. Several structural modifications were performed on the PPm and PPz moieties and the connecting alkyl chain. These compounds were synthesized and tested in radioligand binding experiments where many of them showed interesting binding profiles. Some compounds, including 31, 34, and 36, displayed substantial α1-AR selectivity with respect to serotoninergic 5-HT1A and dopaminergic D1 and D2 receptors. Two different molecular modeling approaches (pharmacophoric mapping and quantitative structure−affinity relationship analysis) have been applied to rationalize, at a quantitative level, the relationships between affinity toward α1-ARs and the structure of the studied compounds. Several QSAR models have been reported and described, accounting for the influence of various molecular portions on such affinity data

Synthesis of New Arylpiperazinylalkylthiobenzimidazole, Benzothiazole, or Benzoxazole Derivatives as Potent and Selective 5-HT_1A Serotonin Receptor Ligands

A series of new compounds containing a benzimidazole, benzothiazole, or benzoxazole nucleus linked to an arylpiperazine by different thioalkyl chains was prepared. They were tested in radioligand binding experiments to evaluate their affinity for 5-HT1A and 5-HT2A serotonergic, α1 adrenergic, D1, and D2 dopaminergic receptors. Many of tested compounds showed an interesting binding profile; in particular, 36 displayed very high 5-HT1A receptor affinity and selectivity over all the other investigated receptors. Selected compounds, evaluated in functional assays, showed antagonistic or partial agonistic activity at 5-HT1A receptor. An extensive conformational research using both NMR and modeling techniques indicated that extended conformations predominated in vacuum, in solution and during interactions with 5-HT1A receptor. Finally, the elaborated binding mode of selected compounds at 5-HT1A receptor was used to explain the influence of spacer length on ligands affinity

MOESM1 of Neuroprotective Effects of Toll-Like Receptor 4 Antagonism in Spinal Cord Cultures and in a Mouse Model of Motor Neuron Degeneration

Neuroprotective Effects of Toll-Like Receptor 4 Antagonism in Spinal Cord Cultures and in a Mouse Model of Motor Neuron Degeneratio

Endogenous erythropoietin as part of the cytokine network in the pathogenesis of experimental autoimmune encephalomyelitis

Erythropoietin (EPO) is of great interest as a therapy for many of the central nervous system (CNS) diseases and its administration is protective in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Endogenous EPO is induced by hypoxic/ischemic injury, but little is known about its expression in other CNS diseases. We report here that EPO expression in the spinal cord is induced in mouse models of chronic or relapsing-remitting EAE, and is prominently localized to motoneurons. We found a parallel increase of hypoxia-inducible transcription factor (HIF)-1 alpha, but not HIF-2 alpha, at the mRNA level, suggesting a possible role of non-hypoxic factors in EPO induction. EPO mRNA in the spinal cord was co-expressed with interferon (IFN)-gamma and tumor necrosis factor (TNF), and these cytokines inhibited EPO production in vitro in both neuronal and glial cells. Given the known inhibitory effect of EPO on neuroinflammation, our study indicates that EPO should be viewed as part of the inflammatory/anti-inflammatory network in MS