Synthesis and Structure-Affinity Relationships of Spirocyclic Benzopyrans with Exocyclic Amino Moiety

\u3c31 and/or \u3c32 receptors play a crucial role in pathological conditions such as pain, neurodegenerative disorders, and cancer. A set of spirocyclic cyclohexanes with diverse O-heterocycles and amino moieties (general structure III) was prepared and pharmacologically evaluated. In structure-activity relationships studies, the \u3c31 receptor affinity and \u3c31:\u3c32 selectivity were correlated with the stereochemistry, the kind and substitution pattern of the O-heterocycle, and the substituents at the exocyclic amino moiety. cis-configured 2-benzopyran cis-11b bearing a methoxy group and a tertiary cyclohexylmethylamino moiety showed the highest \u3c31 affinity ( Ki = 1.9 nM) of this series of compounds. In a Ca2+ influx assay, cis-11b behaved as a \u3c31 antagonist. cis-11b reveals high selectivity over \u3c32 and opioid receptors. The interactions of the novel \u3c31 ligands were analyzed on the molecular level using the recently reported X-ray crystal structure of the \u3c31 receptor protein. The protonated amino moiety forms a persistent salt bridge with E172. The spiro[benzopyran-1,1'-cyclohexane] scaffold and the cyclohexylmethyl moiety occupy two hydrophobic pockets. Exchange of the N-cyclohexylmethyl moiety by a benzyl group led unexpectedly to potent and selective \u3bc-opioid receptor ligands

Rigidity versus flexibility: is this an issue in S1 (sigma-1) receptor ligand affinity and activity?

A set of stereoisomeric 2,5-diazabicyclo[2.2.2]octanes 14 and 15 was prepared in a chiral-pool synthesis starting from (S)- or (R)-aspartate. The key step in the synthesis was a Dieckmann-analogous cyclization of (dioxopiperazinyl)acetates 8, which involved trapping uf the intermediate hemiketal anion with Me3SiCl. The \u3c31 affinity was tested using membrane preparations from animal (guinea pig) and human origin. The binding of bicyclic compounds was analyzed by molecular dynamics simulations based on a 3D homology model of the \u3c31 receptor. The good correlation between Ki values observed in the \u3c31 assays and calculated free binding energy, coupled with the identification of four crucial ligand/receptor interactions allowed the formulation of structure affinity relationships. In an in vitro antitumor assay with seven human tumor cell lines, the bicyclic compounds inhibited selectively the growth of the cell line A427, which is due to induction of apoptosis. In this assay, the compounds behave like the known \u3c31 receptor antagonist haloperidol

An extended association screen in multiple sclerosis using 202 microsatellite markers targeting apoptosis-related genes does not reveal new predisposing factors

Apoptosis, the programmed death of cells, plays a distinct role in the etiopathogenesis of Multiple sclerosis (MS), a common disease of the central nervous system with complex genetic background. Yet, it is not clear whether the impact of apoptosis is due to altered apoptotic behaviour caused by variations of apoptosis-related genes. Instead, apoptosis in MS may also represent a secondary response to cellular stress during acute inflammation in the central nervous system. Here, we screened 202 apoptosis-related genes for association by genotyping 202 microsatellite markers in initially 160 MS patients and 160 controls, both divided in 4 sets of pooled DNA samples, respectively. When applying Bonferroni correction, no significant differences in allele frequencies were detected between MS patients and controls. Nevertheless, we chose 7 markers for retyping in individual DNA samples, thereby eliminating 6 markers from the list of candidates. The remaining candidate, the ERBB3 gene microsatellite, was genotyped in additional 245 MS patients and controls. No association of the ERBB3 marker with the disease was detected in these additional cohorts. In consequence, we did not find further evidence for apoptosis-related genes as predisposition factors in MS

Evaluation of a Structured Screening Assessment to Detect Isolated Rapid Eye Movement Sleep Behavior Disorder

ABSTRACT: Background: Isolated rapid eye movement(REM) sleep behavior disorder (iRBD) cohorts have providedinsights into the earliest neurodegenerative processes inα-synucleinopathies. Even though polysomnography (PSG)remains the gold standard for diagnosis, an accuratequestionnaire-based algorithm to identify eligible subjectscould facilitate efficient recruitment in research.Objective: This study aimed to optimize the identificationof subjects with iRBD from the general population.Methods: Between June 2020 and July 2021, we placednewspaper advertisements, including the single-questionscreen for RBD (RBD1Q). Participants’ evaluationsincluded a structured telephone screening consisting ofthe RBD screening questionnaire (RBDSQ) and additionalsleep-related questionnaires. We examined anamnesticinformation predicting PSG-proven iRBD using logisticregressions and receiver operating characteristic curves.Results: Five hundred forty-three participants answeredthe advertisements, and 185 subjects fulfilling inclusionand exclusion criteria were screened. Of these,124 received PSG after expert selection, and 78 (62.9%)were diagnosed with iRBD. Selected items of theRBDSQ, the Pittsburgh Sleep Quality Index, the STOPBangquestionnaire, and age predicted iRBD with highaccuracy in a multiple logistic regression model (areaunder the curve >80%). When comparing the algorithmto the sleep expert decision, 77 instead of 124 polysomnographies(62.1%) would have been carried out,and 63 (80.8%) iRBD patients would have been identified;32 of 46 (69.6%) unnecessary PSG examinationscould have been avoided.Conclusions: Our proposed algorithm displayed highdiagnostic accuracy for PSG-proven iRBD costeffectivelyand may be a convenient tool for research andclinical settings. External validation sets are warranted toprove reliability. © 2023 The Authors. Movement Disorderspublished by Wiley Periodicals LLC on behalf ofInternational Parkinson and Movement Disorder Society.Key Words: general population; Parkinson’s disease;prediction; questionnaire; rapid eye movement sleepbehavior disorde

Synthesis, Pharmacological Evaluation, and σ₁ Receptor Interaction Analysis of Hydroxyethyl Substituted Piperazines

Starting from (<i>S</i>)- or (<i>R</i>)-aspartate, three synthetic strategies were explored to prepare hydroxyethyl substituted piperazines with different substituents at the N-atoms. σ receptor affinity was recorded using receptor material from both animal and human origin. σ₁ affinities determined with guinea pig brain and human RPMI 8226 tumor cell lines differed slightly but showed the same tendency. (<i>S</i>)-2-[4-(Cyclohexylmethyl)-1-(naphthalene-2-ylmethyl)­piperazin-2-yl]­ethanol (<b>7c</b>) revealed the highest affinity at human σ₁ receptors (<i>K</i>_i = 6.8 nM). The potent σ₁ receptor ligand <b>7c</b> was able to inhibit selectively the growth of three human tumor cell lines with IC₅₀ values in the low micromolar range. The reduced growth of the RPMI-8226 cell line was caused by apoptosis. The interaction of <b>7c</b> with the σ₁ receptor was analyzed in detail using the 3D homology model of the σ₁ receptor. The calculated free binding energies of all hydroxyethylpiperazines nicely correlate with their recorded affinities toward the human σ₁ receptor

Rigidity versus Flexibility: Is This an Issue in σ₁ Receptor Ligand Affinity and Activity?

Stereoisomeric 2,5-diazabicyclo[2.2.2]­octanes <b>14</b> and <b>15</b> were prepared in a chiral-pool synthesis starting from (<i>S</i>)- or (<i>R</i>)-aspartate. The key step in the synthesis was a Dieckmann-analogous cyclization of (dioxopiperazinyl)­acetates <b>8</b>, which involved trapping of the intermediate hemiketal anion with Me₃SiCl. The σ₁ affinity was tested using membrane preparations from animal (guinea pig) and human origin. The binding of bicyclic compounds was analyzed by molecular dynamics simulations based on a 3D homology model of the σ₁ receptor. The good correlation between <i>K</i>_i values observed in the σ₁ assays and calculated free binding energy, coupled with the identification of four crucial ligand/receptor interactions, allowed the formulation of structure–affinity relationships. In an in vitro antitumor assay with seven human tumor cell lines, the bicyclic compounds inhibited selectively the growth of the cell line A427, which is due to induction of apoptosis. In this assay, the compounds behave like the known σ₁ receptor antagonist haloperidol

Blockade of TNF-α rapidly inhibits pain responses in the central nervous system

There has been a consistent gap in understanding how TNF-α neutralization affects the disease state of arthritis patients so rapidly, considering that joint inflammation in rheumatoid arthritis is a chronic condition with structural changes. We thus hypothesized that neutralization of TNF-α acts through the CNS before directly affecting joint inflammation. Through use of functional MRI (fMRI), we demonstrate that within 24 h after neutralization of TNF-α, nociceptive CNS activity in the thalamus and somatosensoric cortex, but also the activation of the limbic system, is blocked. Brain areas showing blood-oxygen level-dependent signals, a validated method to assess neuronal activity elicited by pain, were significantly reduced as early as 24 h after an infusion of a monoclonal antibody to TNF-α. In contrast, clinical and laboratory markers of inflammation, such as joint swelling and acute phase reactants, were not affected by anti-TNF-α at these early time points. Moreover, arthritic mice overexpressing human TNF-α showed an altered pain behavior and a more intensive, widespread, and prolonged brain activity upon nociceptive stimuli compared with wild-type mice. Similar to humans, these changes, as well as the rewiring of CNS activity resulting in tight clustering in the thalamus, were rapidly reversed after neutralization of TNF-α. These results suggest that neutralization of TNF-α affects nociceptive brain activity in the context of arthritis, long before it achieves anti-inflammatory effects in the joints

Cellular Importin-α3 Expression Dynamics in the Lung Regulate Antiviral Response Pathways against Influenza A Virus Infection.

Importin-α adaptor proteins orchestrate dynamic nuclear transport processes involved in cellular homeostasis. Here, we show that importin-α3, one of the main NF-κB transporters, is the most abundantly expressed classical nuclear transport factor in the mammalian respiratory tract. Importin-α3 promoter activity is regulated by TNF-α-induced NF-κB in a concentration-dependent manner. High-level TNF-α-inducing highly pathogenic avian influenza A viruses (HPAIVs) isolated from fatal human cases harboring human-type polymerase signatures (PB2 627K, 701N) significantly downregulate importin-α3 mRNA expression in primary lung cells. Importin-α3 depletion is restored upon back-mutating the HPAIV polymerase into an avian-type signature (PB2 627E, 701D) that can no longer induce high TNF-α levels. Importin-α3-deficient mice show reduced NF-κB-activated antiviral gene expression and increased influenza lethality. Thus, importin-α3 plays a key role in antiviral immunity against influenza. Lifting the bottleneck in importin-α3 availability in the lung might provide a new strategy to combat respiratory virus infections