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The tumor microenvironment is a barrier to breast cancer therapy. Cancer-associated fibroblast cells (CAFs) can support tumor proliferation, metastasis, and drug resistance by secreting various cytokines and growth factors. Abnormal angiogenesis provides sufficient nutrients for tumor proliferation. Considering that CAFs express the sigma receptor (which recognizes anisamide, AA), we developed a CAFs and breast cancer cells dual-targeting nano drug delivery system to transport the LightOn gene express system, a spatiotemporal controlled gene expression consisting of a light-sensitive transcription factor and a specific minimal promoter. We adopted RGD (Arg-Gly-Asp) to selectively bind to the αvβ3 integrin on activated vascular endothelial cells and tumor cells. After the LightOn system has reached the tumor site, LightOn gene express system can spatiotemporal controllably express toxic Pseudomonas exotoxin An under blue light irradiation. The LightOn gene express system, combined with multifunctional nanoparticles, achieved high targeting delivery efficiency both in vitro and in vivo. It also displayed strong tumor and CAFs inhibition, anti-angiogenesis ability and anti-metastasis ability, with good safety. Moreover, it improved survival rate, survival time, and lung metastasis rate in a mouse breast cancer model. This study proves the efficacy of combining the LightOn system with targeted multifunctional nanoparticles in tumor and anti-metastatic therapy and provides new insights into tumor microenvironment regulation. [Display omitted] • pPEA@mNP is a multi-functional gene delivery system, with high targetability and sensitive release profile • pPEA@mNP can spatiotemporally inhibits tumor cells, cancer associated fibroblasts and tumor angiogenesis • pPEA@mNP can eliminate breast cancer and regulate tumor microenvironment, providing a novel anti-metastatic therapy strategy [ABSTRACT FROM AUTHOR]

In Mycobacterium smegmatis, the transcriptional activity of the alternative sigma factor SigF is posttranslationally regulated by the partner switching system consisting of SigF, the anti-SigF RsbW1, and three anti-SigF antagonists (RsfA, RsfB, and RsbW3). We previously demonstrated that expression of the SigF regulon is strongly induced in the Δaa3 mutant of M. smegmatis lacking the aa3 cytochrome c oxidase, the major terminal oxidase in the respiratory electron transport chain. Here, we identified and characterized the RsfSR twocomponent system involved in regulating the phosphorylation state of the major anti-SigF antagonist RsfB. RsfS (MSMEG_6130) is a histidine kinase with the cyclase/histidine kinase-associated sensing extracellular 3 domain at its N terminus, and RsfR (MSMEG_6131) is a receiver domain-containing protein phosphatase 2C-type phosphatase that can dephosphorylate phosphorylated RsfB. We demonstrated that phosphorylation of RsfR on Asp74 by RsfS reduces the phosphatase activity of RsfR toward phosphorylated RsfB and that the cellular abundance of the active unphosphorylated RsfB is increased in the Δaa3 mutant relative to the WT strain. We also demonstrated that the RsfSR two-component system is required for induction of the SigF regulon under respirationinhibitory conditions such as inactivation of the cytochrome bcc1 complex and aa3 cytochrome c oxidase, as well as hypoxia, electron donor-limiting, high ionic strength, and low pH conditions. Collectively, our results reveal a key regulatory element involved in regulating the SigF signaling system by monitoring the state of the respiratory electron transport chain. [ABSTRACT FROM AUTHOR]

The effect of long-term administration of 3-di-o-tolylguanidine on cognitive functions and cerebral neurotransmitters in adult rats. [Display omitted] • 5-di-o-tolylguanidine exerts bi-phasic changes in spatial memory processes. • It impacts dopaminergic neurotransmission in certain brain regions. • It affects content of serine, histidine and glutamate in selected brain areas. The sigma-1 and sigma-2 (σ 1 and σ 2) receptors are found in high concentrations in the brain, and their altered expression leads to a variety of neuropsychiatric disorders. 3-di-tolylguanidine (DTG) stimulates the activity of both of these receptors. We assessed the effects of administering DTG to adult male Sprague Dawley rats on learning and memory consolidation processes and on the levels of neurotransmitters in selected brain structures. Spatial learning and memory were evaluated in the water maze test. The DTG was administered orally at daily doses of 3 mg/kg (DTG3), 10 mg/kg (DTG10) or 30 mg/kg (DTG30) for 10 weeks before and during the water-maze test. After completion of the experiment, the concentration of monoamines and their metabolites as well as amino acids in structures involved in cognitive performance – the hippocampus, prefrontal cortex, and striatum – were determined using high performance liquid chromatography (HPLC). The DTG10 group showed an improvement in memory processes related to the "new" platform location, whereas the DTG30 group was worse at finding the "old" platform location. Since the administration of DTG led to differences in dopaminergic transmission, it was assumed to influence memory processes in this way. Changes in histidine, serine, alanine, taurine, and glutamic acid levels in selected structures of the brains of rats with memory impairment were also observed. We conclude that long-term administration of DTG modulates spatial learning and memory in rats and changes the concentrations of neurotransmitters in the hippocampus, prefrontal cortex, and striatum.. [ABSTRACT FROM AUTHOR]

[Display omitted] In the past several decades, the field of cocrystal engineering has developed into a vital research topic in supramolecular chemistry, holding the foremost scope in crystal engineering, medicinal chemistry, materials chemistry, and the pharmaceutical industry. The medium of cocrystallization has been through the classic non-covalent interactions. However, cocrystallization through sigma hole (σ-hole)-based modern interactions is a breakthrough in crystal engineering. This σ-hole mediated non-covalent interaction uniquely contributes to supramolecular chemistry through different subgroups viz halogen bonding (XB), chalcogen bonding (ChB), pnictogen bonding (PnB), and tetrel bonding (TB). Despite much potential, chalcogen bonding, pnictogen bonding, and tetrel bonding are yet at an infancy stage compared to halogen bonding. Hence, we attempted to address the great potential of these non-covalent interactions (intra- and inter-molecular) and enlighten the ChB, PnB, and TB, as their outstanding contribution to the supramolecular domain needs to be communicated. Through this account, we promote these cooperative σ-hole-based interaction synthons as attractive toolboxes in supramolecular chemistry by addressing the strength and directionality of σ-hole potential, the role of steric hindrance, different modes of characterizations, application in distinct fields, etc. We hope this work will be the medium of a new direction in advancing σ-hole-assisted interactions in different research areas. Also, chalcogen, pnictogen, and tetrel bonding could get out of the shadow of halogen bonding and get their recognition in supramolecular chemistry. [ABSTRACT FROM AUTHOR]

[Display omitted] • New 2-(Piperidin-3-yl)phthalimides reduce inflammation in LPS-challenged cells. • Select materials also bind sigma and serotonin receptors linked to inflammation. • No appreciable thalidomide-like Cereblon binding observed for screened compounds. • Materials exceed 90% cellular viability at all concentrations tested. Herein, we report the synthesis of new 4-amino-2-(piperidin-3-yl)isoindoline-1,3-diones and their biological evaluation in a series of in vitro experiments. The synthetic production of these materials was initiated upon the condensation of appropriate nitrophthalic acid derivatives with various 3-aminopiperidines; subsequent reduction provided the final products in moderate to good yields. Readily available chiral pool reagents facilitated entry into optically enriched samples, while the piperidine scaffold furnished a variety of amide and alkylated entries. In total, 16 candidates were produced, and their ensuing treatment in LPS-challenged RAW cells effected slight reductions in secreted TNF-α but provided more robust and dose-dependent declines in nitrite and IL-6 levels relative to basal amounts, all concurrent with maintenance of cellular viability across the concentration ranges screened. The secondary amine cohort including rac - 6, (R) -7 , and (S) -8 rendered the most pronounced dose-dependent reductions in nitrite and IL-6. When dosed at 30 μM, (R) -7 demonstrated the most compelling effects, with decreases of 32 % and 40 % for nitrite and IL-6, respectively. Notable reductions in the inflammatory markers were also observed for 19 which effected declines in TNF-α (14 %), nitrite (19 %), and IL-6 (11 %) when treated at 30 μM. Additionally, four representative compounds were further evaluated against numerous CNS receptors, channels, and transporters, with 6 , 9 , and 19 demonstrating varying degrees of nanomolar-to-low-micromolar binding to the σ-1 and σ-2 receptors and also to serotonin receptors 5HT 2A , 5HT 2B and 5HT 3. In this regard, 6 displayed perhaps the most noteworthy affinities, with binding at σ-2 (K i = 2.2uM), 5HT 2B (K i = 561 nM) and 5HT 3 (K i = 536 nM). Furthermore, no pronounced or dose-dependent Cereblon/DDB1 binding was observed for the screened representative compounds 6 , 9 , 18 and 19. [ABSTRACT FROM AUTHOR]

Escherichia coli RseP, a member of the site-2 protease family of intramembrane proteases, is involved in the activation of the sE extracytoplasmic stress response and elimination of signal peptides from the cytoplasmic membrane. However, whether RseP has additional cellular functions is unclear. In this study, we used mass spectrometry-based quantitative proteomic analysis to search for new substrates that might reveal unknown physiological roles for RseP. Our data showed that the levels of several Fec system proteins encoded by the fecABCDE operon (fec operon) were significantly decreased in an RsePdeficient strain. The Fec system is responsible for the uptake of ferric citrate, and the transcription of the fec operon is controlled by FecI, an alternative sigma factor, and its regulator FecR, a single-pass transmembrane protein. Assays with a fec operon expression reporter demonstrated that the proteolytic activity of RseP is essential for the ferric citrate-dependent upregulation of the fec operon. Analysis using the FecR protein and FecR-derived model proteins showed that FecR undergoes sequential processing at the membrane and that RseP participates in the last step of this sequential processing to generate the N-terminal cytoplasmic fragment of FecR that participates in the transcription of the fec operon with FecI. A shortened FecR construct was not dependent on RseP for activation, confirming this cleavage step is the essential and sufficient role of RseP. Our study unveiled that E. coli RseP performs the intramembrane proteolysis of FecR, a novel physiological role that is essential for regulating iron uptake by the ferric citrate transport system. [ABSTRACT FROM AUTHOR]

• Genetic depletion of GPx-1 potentiates cocaine-induced behavioral sensitization. • Signaling of σ-1 receptor-ERK-oxidative burden mediates the behavioral sensitization. • GPx-1 gene inhibits this signaling, and induces Nrf-2-related GSH system. We demonstrated that the gene of glutathione peroxidase-1 (GPx-1), a major antioxidant enzyme, is a potential protectant against the neurotoxicity and conditioned place preference induced by cocaine. Because the sigma (σ)-1 receptor is implicated in cocaine-induced drug dependence, we investigated whether the GPx-1 gene modulates the σ-1 receptor in the behavioral sensitization induced by cocaine. Cocaine-induced behavioral sensitization was more pronounced in GPx-1 knockout (KO) than wild-type (WT) mice and was less pronounced in GPx-1 overexpressing transgenic (GPx-1 TG) than non-TG mice. Cocaine treatment significantly enhanced the oxidative burden and reduced the GSH levels in the striatum of WT, GPx-1 KO, and non-TG mice but not in that of GPx-1 TG mice. In addition, cocaine significantly increased the nuclear translocation, its DNA binding activity of nuclear factor erythroid-2-related factor 2 (Nrf2) as well as the mRNA expression of γ-glutamylcysteine (GCL). The genetic depletion of GPx-1 inhibited the Nrf2-related glutathione system, whereas the genetic overexpression of GPx-1 activated this system against behavioral sensitization. BD1047, a σ-1 receptor antagonist, and U0126, an ERK inhibitor significantly induced the Nrf2-related antioxidant potential against behavioral sensitization. Unlike BD1047, U0126 did not affect the cocaine-induced σ-1 receptor immunoreactivity, suggesting that the σ-1 receptor is an upstream molecule for ERK signaling. Importantly, BD1047 and U0126 failed to affect the σ-1 receptor immunoreactivity and ERK phosphorylation induced by cocaine in GPx-1 TG mice. Our results suggest that GPx-1 is a critical mediator for the attenuation of cocaine-induced behavioral sensitization via modulating σ-1 receptor-mediated ERK activation by the induction of the Nrf2-related system. [ABSTRACT FROM AUTHOR]

The chaperone heat shock protein 70 (Hsp70) is crucial for avoiding protein misfolding under stress, but is also up-regulated in many kinds of cancers, where its ability to buffer cellular stress prevents apoptosis. Previous research has suggested Hsp70 interacts with pro-apoptotic Bcl-2 family proteins, including Bim and Bax. However, a definitive demonstration of this interaction awaits, and insights into the structural basis and molecular mechanism remain unclear. Earlier studies have identified a Bcl-2 homology 3 (BH3) domain present in Bcl-2 family members that engages receptors to stimulate apoptosis. We now show that Hsp70 physically interacts with pro-apoptotic multidomain and BH3-only proteins via a BH3 domain, thereby serving as a novel BH3 receptor, using in vitro fluorescent polarization (FP), isothermal titration calorimetry (ITC), and cell-based co-immunoprecipitation (co-IP) experiments, µH-15N-transverse relaxation optimized spectroscopy (TROSY-HSQC), trypsin proteolysis, ATPase activity, and denatured rhodanese aggregation measurements further demonstrated that BimBH3 binds to a novel allosteric site in the nucleotide-binding domain (NBD) of Hsp70, by which Bim acts as a positive co-chaperone to promote the ATPase activity and chaperone functions. A dual role of Hsp70's anti-apoptotic function was revealed that when it keeps Bim in check to inhibit apoptosis, it simultaneously stabilizes oncogenic clients including AKT and Raf-1 with the aid of Bim. Two faces of Bim in cell fate regulation were revealed that in opposite to its well-established pro-apoptotic activator role, Bim could help the folding of oncogenic proteins. [ABSTRACT FROM AUTHOR]

The bacterial protein WhiD belongs to the Wbl family of iron-sulfur [Fe-S] proteins present only in the actinomycetes. In Streptomyces coelicolor, it is required for the late stages of sporulation, but precisely how it functions is unknown. Here, we report results from in vitro and in vivo experiments with WhiD from Streptomyces venezuelae (SvWhiD), which differs from S. coelicolor WhiD (ScWhiD) only at the C terminus. We observed that, like ScWhiD and other Wbl proteins, SvWhiD binds a [4Fe-4S] cluster that is moderately sensitive to O2 and highly sensitive to nitric oxide (NO). However, although all previous studies have reported that Wbl proteins are monomers, we found that SvWhiD exists in a monomer-dimer equilibrium associated with its unusual C-terminal extension. Several Wbl proteins of Mycobacterium tuberculosis are known to interact with its principal sigma factor SigA. Using bacterial two-hybrid, gel filtration, and MS analyses, we demonstrate that SvWhiD interacts with domain 4 of the principal sigma factor of Streptomyces, σHrdB (σHrdB4). Using MS, we determined the dissociation constant (Kd) for the SvWhiD-σHrdB4 complex as ∼0.7 μm, consistent with a relatively tight binding interaction. We found that complex formation was cluster dependent and that a reaction with NO, which was complete at 8–10 NO molecules per cluster, resulted in dissociation into the separate proteins. The SvWhiD [4Fe-4S] cluster was significantly less sensitive to reaction with O2 and NO when SvWhiD was bound to σHrdB4, consistent with protection of the cluster in the complex. [ABSTRACT FROM AUTHOR]

• Dual promoters significantly enhanced gene expression levels both at log and stationary phases. • An efficient dual-promoter Pdual3 was attained via coupling the sigB- and sigA-type promoters and sequence optimization. • The yields of heterologous proteins and target metabolites were all significantly enhanced by means of promoter Pdual3. Promoter plays the critical role in regulating gene transcription, and dual-promoter has received the widespread attentions due to its high efficiency and continuity, here, we want to construct an efficient dual-promoter for protein production and metabolic pathway enhancement. Firstly, our results indicated that P43 promoter efficiently transcribed at logarithmic period, while the σB-type promoters (PylB, PgsiB, PykzA) were active at stationary phase. Then, several dual promoters were constructed by coupling these σB-type promoters with P43, and the attained dual-promoter PykzA-P43 showed the best performance, which led to 1.72-, 3.46- and 1.85-fold increases of green fluorescence intensity, red fluorescence intensity and α-amylase activity, compared with those of the recognized strong promoter P43, respectively. Furthermore, α-amylase activity was further increased to 389.65 U/mL by 32.20 % via optimizing sigma factor binding sites (-10 and -35 boxes) of PykzA-P43, attaining the optimized dual promoter Pdual3. Finally, Pdual3 was applied in metabolic pathway enhancement, and the yields of Poly γ-glutamic acid, acetoin and 2, 3-butanediol were respectively improved by 82.01 %, 17.09 % and 99.39 %. Our results indicated that dual-promoter significantly enhanced gene expression, and this study provided an energetic dual-promoter Pdual3 for efficient protein production and metabolic pathway enhancement in Bacillus licheniformis. [ABSTRACT FROM AUTHOR]

[Display omitted] • 456 HDES were evaluated for adsorption of short chain PFAS from water. • TOPO, T3623, TOAC, TOAB, TBAB were identified as the best HBA. • Camphor and L-arginine were identified as the best HBD. • Nonpolar interactions were dominant between HDES and PFAS. • Selected HDES and PFAS were characterized for their toxicity using VEGA model. In this study, our focus lies on hydrophobic deep eutectic solvents (HDES) as we explore their potential for the adsorption of short-chain per- and polyfluoroalkyl substances (PFAS) from water. This investigation utilizes Conductor-like Screening MOdel for Real Solvents (COSMO-RS) to fundamentally evaluate HDES for the adsorption of perfluorobutanesulfonic acid (PFBS), perfluorobutanoic acid (PFBA), perfluorohexanesulfonic acid (PFHxS), and perfluorohexanoic acid (PFHxA). By analyzing sigma surfaces, sigma profiles, and sigma potentials, it was observed that the PFAS compounds possess sufficiently strong nonpolar and hydrogen bond donating sites, having affinity towards hydrogen bond acceptor surfaces. According to the thermodynamic adsorption studies, short-chain PFAS exhibit higher affinity towards 5 main HBAs (trioctylphosphine oxide, tetrabutylammonium bromide, tetraoctylammonium chloride, tetraoctylammonium bromide, trihexyltetradecylphosphonium chloride) and 2 HBDs (camphor and L-arginine), with activity coefficients being as low as −13.07. Excess enthalpy analysis reveals that nonpolar interactions play a dominant role in the exchanges between HDES and PFAS compounds, suppressing hydrogen bonding interactions by an order of magnitude. TOPO: L-arginine (1:1) showed the lowest excess enthalpy of mixing for PFBS at −13.43 kJ/mol. The same HDES showed values of −10.60 kJ/mol, −15.14 kJ/mol, and −12.27 kJ/mol for PFBA, PFHxS, and PFHxA, respectively. Lastly, the best-performing solvent combinations underwent virtual models for property evaluation of chemicals within a global architecture (VEGA) analysis to assess their impact on human and environmental toxicity aspects such as mutagenicity, carcinogenicity, bioaccumulation, and acute toxicity. The outcome reveals that the best performing HDES components listed above present minimal toxicity and pose negligible environmental risks. [ABSTRACT FROM AUTHOR]

• Microgels were prepared with HBPAK and GelMA by a microfluidic device. • H&G microgels efficiently eliminated typical ROS of DPPH and H 2 O 2. • H&G/ISP microgels effectively decreased inflammation of LPS-activated microglia. • ISP promoted SCs migration and NSCs neuronal differentiation tendency in microgels. • Stroke was efficiently recovered by H&G/ISP microgels in vivo. The glial scar forms a disadvantageous microenvironment for neurogenesis after stroke. Single treatment targeting glial scar suppression or neurogenesis promotion is insufficient for stroke repair. To improve the functional recovery post stroke, a synergistical therapy of reactive oxygen species (ROS)-scavenging polymers (hyperbranched poly(acrylate-capped thioketone-containing ethylene glycol, HBPAK) and chondroitin sulfate proteoglycans (CSPGs) receptor (protein tyrosine phosphatase σ, PTPσ) modulatory peptides (intracellular sigma peptide, ISP) was applied in a form of microgels for inflammation alleviation, glial scar inhibition and endogenous neuroblasts regulation. The microgels were prepared with a microfluidic device under UV irradiation. The microgels containing HBAPK displayed efficient elimination of typical ROS of 1-diphenyl-2-picryl hydrazyl radical (DPPH) and H 2 O 2. The microgels containing HBAPK and ISP peptides decreased inflammation response of lipopolysaccharide (LPS) activated BV2 microglia. Promoted cell migration and proliferation of Schwann cells (SCs) and strengthened cell stemness and neuronal differentiation of neural stem cells (NSCs) were shown when these cells were incubated within the microgels containing HBAPK and ISP peptides. Injection of the microgels in vivo achieved positive therapeutic effects with respect to motor dysfunction recovery promotion, inflammation alleviation and cell apoptosis reduction at 7 d, and astrocytic scar inhibition, neuroblasts promotion and axonal neurofilaments increase at 28 d post stroke, suggesting the effectiveness of this synergistical therapy for stroke. [ABSTRACT FROM AUTHOR]

Clostridioides difficile is a Gram-positive, anaerobic, and spore-forming bacterial member of the human gut microbiome. The primary virulence factors of C. difficile are toxin A and toxin B. These toxins damage the cell cytoskeleton and cause various diseases, from diarrhea to severe pseudomembranous colitis. Evidence suggests that bacteriophages can regulate the expression of the pathogenicity locus (PaLoc) genes of C. difficile. We previously demonstrated that the genome of the C. difficile RT027 strain NCKUH-21 contains a prophage-like DNA sequence, which was found to be markedly similar to that of the φCD38–2 phage. In the present study, we investigated the mechanisms underlying the φNCKUH-21-mediated regulation of the pathogenicity and the PaLoc genes expression in the lysogenized C. difficile strain R20291. The carriage of φNCKUH-21 in R20291 cells substantially enhanced toxin production, bacterial motility, biofilm formation, and spore germination in vitro. Subsequent mouse studies revealed that the lysogenized R20291 strain caused a more severe infection than the wild-type strain. We screened three φNCKUH-21 genes encoding DNA-binding proteins to check their effects on PaLoc genes expression. The overexpression of NCKUH-21_03890, annotated as a transcriptional regulator (phage transcriptional regulator X, PtrX), considerably enhanced toxin production, biofilm formation, and bacterial motility of R20291. Transcriptome analysis further confirmed that the overexpression of ptrX led to the upregulation of the expression of toxin genes, flagellar genes, and csrA. In the ptrX -overexpressing R20291 strain, PtrX influenced the expression of flagellar genes and the sigma factor gene sigD , possibly through an increased flagellar phase ON configuration ratio. [Display omitted] [ABSTRACT FROM AUTHOR]

The key role of chiral small molecules in drug discovery programs has been deeply investigated throughout last decades. In this context, our previous studies highlighted the influence of the absolute configuration of different stereocenters on the pharmacokinetic, pharmacodynamic and functional properties of promising Sigma receptor (SR) modulators. Thus, starting from the racemic SR ligand RC752 , we report herein the isolation of the enantiomers via enantioselective separation with both HPLC and SFC. After optimization of the eco-sustainable chiral SFC method, both enantiomers were obtained in sufficient amount (tens of mg) and purity (ee up to 95%) to allow their characterization and initial biological investigation. Both enantiomers a) displayed a high affinity for the S1R subtype (K i = 15.0 ± 1.7 and 6.0 ± 1.2 nM for the (S)- and (R)-enantiomer, respectively), but only negligible affinity toward the S2R (> 350 nM), and b) were rapidly metabolized when incubated with mouse and human hepatic microsomes. Furthermore, the activity on AQP-mediated water permeability indicated a different functional profile for the enantiomers in terms of modulatory effect on the peroxiporins gating. [Display omitted] • Enantioselective HPLC and SFC performed • Absolute configuration assigned by VCD • (R)-()- RC752 enantio-preference in binding and PK profile evidenced • Different functional profile of enantiomers in AQP-mediated H 2 O permeability assay [ABSTRACT FROM AUTHOR]

Food ingredients that can activate and improve immunological defense, against e.g., pathogens, have become a major field of research. Resistant starches (RSs) can resist enzymes in the upper gastrointestinal (GI) tract and induce health benefits. RS-3 physicochemical characteristics such as chain length (DP), A- or B-type crystal, and polydispersity index (PI) might be crucial for immunomodulation by activating human toll-like receptors (hTLRs). We hypothesize that crystal type, DP and PI, alone or in combination, impact the recognition of RS-3 preparations by hTLRs leading to different RS-3 immunomodulatory effects. We studied the activation of hTLR2, hTLR4, and hTLR5 by 0.5, 1 and 2 mg/mL of RS-3. We found strong activation of hTLR2-dependent NF-kB activation with PI <1.25, DP 18 as an A- or B-type crystal. At different doses, NF-kB activation was increased from 6.8 to 7.1 and 10-fold with A-type and 6.2 to 10.2 and 14.4-fold with B-type. This also resulted in higher cytokine production in monocytes. Molecular docking, using amylose-A and B, demonstrated that B-crystals bind hTLR2 promoting hTLR2-1 dimerization, supporting the stronger effects of B-type crystals. Immunomodulatory effects of RS-3 are predominantly hTLR2-dependent, and activation can be tailored by managing crystallinity, chain length, and PI. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel radio-complex 99mTc-THQ-DTPA has been developed for Sigma-2 receptor targeted triple negative breast tumor imaging. • Theoretical docking of THQ-DTPA with homology modelled Sigma-2 receptor protein reflects the potential of THQ-DTPA to bind with Sigma-2 receptor. • 99mTc-THQ-DTPA reflects high affinity towards Sigma-2 receptor with K d 16.32 ± 4.93 nM. • In vivo Biodistribution and SPECT imaging confirms the binding of 99mTc-THQ-DTPA towards Sigma-2 receptor in triple negative breast tumor. • High tumor/muscle and tumor/blood ratio confirm the specificity of ligand towards tumor. Over-expression of sigma-2 receptor in cancer cells provides an opportunity to develop molecular probes for diagnosis, even for non-receptor specific malignancies like triple negative breast cancers. In this work, a novel sigma-2 receptor ligand [THQ-DTPA] has been synthesized and characterized using 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (THQ) and diethylenetriaminepentaacetic acid (DTPA). The ligand is further chelated with 99mTc for application as metal based radiotracer [99mTc-THQ-DTPA]. Radiolabelling with 99mTc was achieved in an excellent yield of 98.0 ± 0.5% using stannous chloride as a reducing agent. The radioligand was found to be stable in human serum up-to 24 h, bio-compatible with less than 4% hemolysis, and exhibited high binding with sigma receptors isolated from rat liver membrane (K d of 16.32 ± 4.93 nM and Bmax of 0.5232 ± 0.06 pmol/mg). Bio-distribution studies in triple-negative breast tumor bearing nude mice showed high tumor uptake after 30 min of injection with tumor/muscle (T/M) ratio of 3.58 ± 0.09. At 240 min, the T/M ratio (2.84 ± 0.20) decreased by 35% when administered in sigma blocked tumor bearing mice (1.81 ± 0.16) suggesting the selectivity of the ligand. Tumor imaging in gamma camera indicated a contrast of 3.56 at 30 min p.i. The above findings indicate that the ligand 99mTc-THQ-DTPA binds to sigma-2 receptors with high affinity and has potential for triple-negative breast tumor imaging. [ABSTRACT FROM AUTHOR]

Among several potential applications, sigma receptors (σRs) can be used as neuroprotective agents, antiamnesic, antipsychotics and against other neurodegenerative disorders. On the other hands, antagonists of the GluN2b-subunit-containing-N-methyl-D-aspartate (NMDA) receptors are of major interest for the same purpose, being this subunit expressed in specific areas of the central nervous system and responsible for the excitatory regulation of nerve cells. Under these premises, we have synthesized and biologically tested novel hybrid derivatives obtained from the combination of phenyloxadiazolone and dihydroquinolinone scaffolds with different amine moieties, peculiar of σ2R ligands. Most of the new ligands exhibited a pan-affinity towards both σR subtypes and high affinity against GluN2b subunit. The most promising compounds belong to the dihydroquinolinone series, with the best affinity profile for the cyclohexylpiperazine derivative 28. Investigation on their biological activity showed that the new compounds were able to protect SH-SY5Y cells against oxidative stress induced by hydrogen peroxide treatment. These results proved that our dual σR/GluN2b ligands have beneficial effects in a model of neuronal oxidative stress and can represent strong candidate pharmacotherapeutic agents for minimizing oxidative stress-induced neuronal injuries. Image 1 • New hybrid derivatives as dual σR/GluN2b ligands were designed and synthesized. • Some of new derivatives showed pan-affinity for the sigma receptor. • In silico affinity evaluation confirmed the experimental data. • We evaluated the neuroprotective activity of the most interesting derivatives. • Compounds 24 and 28 displayed the best biological profile. [ABSTRACT FROM AUTHOR]

• The serotonin 2A receptor antagonist M100907 reduced methamphetamine-induced convulsions, seizures, and lethality. • The sigma 1 receptor antagonist BD1047 reduced methamphetamine-induced convulsions, seizures, and lethality • Neither agent given alone or in combination had any effect on methamphetamine-induced hyperthermia. • Combined administration of both agents was more effective than either agent alone in reducing methamphetamine-induced seizures and lethality. • These agents may have additive or synergistic effects in the reduction of methamphetamine overdose. There are no Food and Drug Administration approved pharmacotherapies for methamphetamine (METH) overdose, thus identifying novel drug targets to prevent this devastating adverse event is a public-health imperative. Previous research suggests that serotonin and sigma receptors may contribute to the adverse effects of METH. The present study assessed whether pretreatment with the 5-HT 2A receptor antagonist M100907 or the sigma 1 (σ 1) receptor antagonist BD 1047 attenuated METH-induced lethality, hyperthermia, convulsions, and seizures. Male, Swiss-Webster mice received intraperitoneal injections of M100907 (1 and 10 mg/kg), BD 1047 (10 mg/kg), or a combination of M100907 (1 mg/kg) and BD 1047 (10 mg/kg) prior to treatment with METH (78 mg/kg). Convulsions and lethality were assessed by observation, core body temperature was assessed by surgically implanted telemetric probes, and seizures were assessed by electroencephalography. M100907 reduced METH-elicited lethality from 67% to 33%, BD1047 reduced METH-elicited lethality from 67% to 50%, and combined administration of both agents eliminated lethality in all mice tested. Similarly, both agents and their combination reduced METH-elicited seizures and convulsions. None of the treatments decreased METH-induced hyperthermia. This research suggests that reducing METH-induced seizures is an important factor in reducing lethality associated with METH overdose. However, future studies should examine whether M100907 and BD 1047 modulate METH-induced hypertension and other adverse effects that may also contribute to METH overdose. Our data support the continued investigation of compounds that target 5-HT 2A and σ 1 receptors in METH-induced overdose, including their potential to yield emergency reversal agents. [ABSTRACT FROM AUTHOR]

A new set of 5-chlorobenzoxazole- and 5-chlorobenzothiazole-based derivatives containing the azepane ring as a basic moiety was designed, synthesized and evaluated through binding assays to measure their affinity and selectivity towards σ 1 and σ 2 receptors. Compounds 19 , 22 and 24 , with a four units spacer between the bicyclic scaffold and the azepane ring, showed nanomolar affinity towards both receptor subtype and the best K i values (K i σ 1 = 1.27, 2.30, and 0.78 and K i σ 2 = 7.9, 3.8, and 7.61 nM, respectively). Evaluation of cytotoxic and apoptotic effects in MCF-7 human cancer cells was useful to assess σ 2 receptor activity, while an in vivo mice model of inflammatory pain allowed to analyze σ 1 receptor pharmacological properties. In vitro and in vivo results suggested that compound 19 is a σ 1 /σ 2 agonist, compound 24 a σ 1 antagonist/σ 2 agonist, whereas compound 22 might act as σ 1 antagonist/σ 2 partial agonist. Due to their pharmacological profile, a potential therapeutic application in cancer of aforesaid novel σ 1 /σ 2 receptor ligands, especially 22 and 24 , is proposed. Image 1 • A new series of σ 1 and σ 2 receptor ligands was synthesized. • Novel ligands were able to bind to both receptors at low nanomolar concentration. • A four unit spacer was critical for affinity. • Agonism/antagonism properties were investigated for the most potent compounds. [ABSTRACT FROM AUTHOR]

Stress is one of the factors underlying drug seeking behavior that often goes in parallel with loss of appetite. We here demonstrate that orexin 1 receptors (OX 1 R) may form complexes with the corticotropin releasing factor CRF 2 receptor. Two specific features of the heteromer were a cross-antagonism and a blockade by CRF 2 of OX 1 R signaling. In cells expressing one of the receptors, agonist-mediated signal transduction mechanisms were potentiated by amphetamine. Sigma 1 (σ 1) and 2 (σ 2) receptors are targets of drugs of abuse and, despite sharing a similar name, the two receptors are structurally unrelated and their physiological role is not known. We here show that σ 1 receptors interact with CRF 2 receptors and that σ 2 receptors interact with OX 1 R. Moreover, we show that amphetamine effect on CRF 2 receptors was mediated by σ 1 R whereas the effect on OX 1 receptors was mediated by σ 2 R. Amphetamine did potentiate the negative cross-talk occurring within the CRF 2 -OX 1 receptor heteromer context, likely by a macromolecular complex involving the two sigma receptors and the two GPCRs. Finally, in vivo microdialysis experiments showed that amphetamine potentiated orexin A-induced dopamine and glutamate release in the ventral tegmental area (VTA). Remarkably, the in vivo orexin A effects were blocked by a selective CRF 2 R antagonist. These results show that amphetamine impacts on the OX 1 R-, CRF 2 R- and OX 1 R/CRF 2 R-mediated signaling and that cross-antagonism is instrumental for in vivo detection of GPCR heteromers. This article is part of the Special Issue entitled 'Receptor heteromers and their allosteric receptor-receptor interactions'. • Orexin 1 receptors (OX1R) may heteromerize with the corticotropin releasing factor CRF2 receptor. • Sigma1 receptors interact with CRF2 receptors and that sigma2 receptors interact with OX1R. • Amphetamine may impact on sigma1 and on sigma2 receptors. • Amphetamine effect on CRF2 is mediated by sigma1 and the effect on OX1 is mediated by sigma2. • In vivo cross-antagonism showed occurrence of OX1R/CRF2R-heteromer mediated signaling. [ABSTRACT FROM AUTHOR]

Our previous study has revealed 4-(4-(4-chlorophenyl)-1,4-diazepan-1-yl)-1-(4-fluorophenyl)butan-1-one·2HCl (SYA013) 1 as a sigma ligand with moderate selectivity for the sigma-2 receptor. Given the overexpression of sigma receptors in solid tumors and reports of sigma ligands with anticancer activities, we selected 1 for evaluation in several solid tumor cell lines. In addition, we have synthesized new analogs of 1 and now report that several of them bind preferentially at the sigma-2 receptor and have shown inhibition of several cancer cell lines including MDA-MB-231, MDA-MB-486, A549, PC-3, MIA PaCa-2 and Panc-1 cells. In particular, compounds 1 and 12 have demonstrated sub-micromolar activity against the Panc-1 cell line. It has also been observed that several of these compounds demonstrate selective toxicity toward cancer cells, when compared to normal cells. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Small interfering RNA (siRNA) has recently illustrated therapeutic potential for malignant disorders. However, the clinical application of siRNA-based therapeutics is significantly retarded by the paucity of successful delivery systems. Recently, multifunctional gold nanoparticles (AuNPs) as non-viral delivery carriers have shown promise for transporting chemotherapeutics, proteins/peptides, and genes. In this study, AuNPs capped with polyethylenimine (PEI) and PEGylated anisamide (a ligand known to target the sigma receptor) have been developed to produce a range of positively charged anisamide-targeted PEGylated AuNPs (namely Au-PEI-PEG-AA). The anisamide-targeted AuNPs effectively complexed siRNA via electrostatic interaction, and the resultant complex (Au 110 -PEI-PEG 5000 -AA.siRNA) illustrated favourable physicochemical characteristics, including particle size, surface charge, and stability. In vitro , anisamide-targeted AuNPs selectively bound to human prostate cancer PC-3 cells, inducing efficient endosomal escape of siRNA, and effective downregulation of the RelA gene. In vivo , prolonged systemic exposure of siRNA was achieved by anisamide-targeted AuNPs resulting in significant tumour growth suppression in a PC3 xenograft mouse model without an increase in toxicity. In addition, a combination of siRNA-mediated NF-κB knockdown using anisamide-targeted AuNPs with Paclitaxel produced a synergistic therapeutic response, thus providing a promising therapeutic strategy for the treatment of prostate cancer. [ABSTRACT FROM AUTHOR]

Abstract Sigma receptors (σRs) are considered to be a significant and valid target for developing new medications to address several diseases. Their potential involvement in numerous central nervous system disorders, neuropathic pain, addiction, and cancer has been extensively reported. In particular, the σ 2 R has been identified as potential target for the development of pharmaceutical agents intended to treat the negative effects associated with drugs of abuse. As a continuation of our previous efforts to develop new selective σ 2 R ligands, a series of benzimidazolone derivatives were designed, synthesized, and characterized. The newly synthesized ligands were evaluated through in vitro radioligand binding assays to determine their affinity and selectivity towards both σ 1 and σ 2 receptors. Several derivatives displayed high affinity for the σ 2 R (K i = 0.66–68.5 nM) and varied from preferring to selective, compared to σ 1 R (σ 1 /σ 2 = 5.8–1139). Among them, compound 1-{4-[4-(4-fluorophenyl)piperazin-1-yl]butyl}-3-propyl-1,3-dihydrobenzimidazol-2-one dihydrochloride (14) displayed the ability to produce a dose-dependent reduction in the convulsive effects of cocaine in a rodent model after injecting 10 mg/kg (i.p.). These preliminary results support the use of selective σ 2 R ligands in the development of useful pharmacological tools or potential pharmacotherapies for cocaine toxicity. Graphical abstract Image 1 Highlights • A series of benzimidazolone derivatives as highly selective σ 2 R ligands were prepared and characterized. • Bioisosteric replacement of the heterocyclic scaffolds increased σ 2 selectivity. • 1-(4-fluorophenyl)piperazine as the cyclic amine motif is preferred for σ 2 selectivity. • n-propyl and n-pentyl group at N -3 position are optimal for affinity and selectivity for the σ 2 R. • Selective σ 2 R ligands might attenuate cocaine-induced convulsions. [ABSTRACT FROM AUTHOR]

Highlights • Neuroimaging of σ receptors in the brain will shed new light on AD pathophysiology. • It provides tools for efficacy monitoring of novel AD therapeutic strategies. • Neuroimaging of σ 1 and σ 2 receptors may provide new biomarkers for AD diagnosis. Abstract The sigma-1 (σ 1) receptor is a chaperone protein located on the mitochondria-associated membrane of the endoplasmic reticulum, while the sigma-2 receptor (σ 2) is an endoplasmic reticulum-resident membrane protein. Recent evidence indicates that both of these receptors figure prominently in the pathophysiology of Alzheimer's disease (AD) and thus are targets for the development of novel, disease-modifying therapeutic strategies. Radioligand-based molecular imaging technique such as positron emission tomography (PET) imaging is a powerful tool for the investigation of protein target expression and function in living subjects. In this review, we survey the development of PET radioligands for the σ 1 or σ 2 receptors and assess their potential for human imaging applications. The availability of PET imaging with σ 1 or σ 2 receptor-specific radioligands in humans will allow the investigation of these receptors in vivo and lead to further understanding of their respective roles in AD pathogenesis and progression. Moreover, PET imaging can be used in target occupancy studies to assess target engagement and correlate receptor occupancy and therapeutic response of σ 1 receptor agonists and σ 2 receptor antagonists currently in clinical trials. It is expected that neuroimaging of σ 1 and σ 2 receptors in the brain will shed new light on AD pathophysiology and may provide us with new biomarkers for diagnosis of AD and efficacy monitoring of emerging AD therapeutic strategies. [ABSTRACT FROM AUTHOR]

Abstract Dorsal root injury commonly results in irreversible loss of sensory functions because of the limited intrinsic regenerative capacity of adult sensory axons and the growth-inhibitory environment at the dorsal root entry zone (DREZ) between the dorsal root and the spinal cord. Chondroitin sulfate proteoglycans (CSPGs) are the dominant suppressors of axonal regeneration, acting via neuronal receptors including protein tyrosine phosphatase-σ (PTPσ). ISP (Intracellular Sigma Peptide) is a small peptide mimetic of the PTPσ wedge region that has been developed to target PTPσ and relieve CSPG inhibition. Extracellular regulated kinases (Erks) and cAMP response element binding protein (CREB) are signaling molecules downstream of CSPGs and PTPσ; they are expressed in neurons and essential for axon growth. In this study, we observed that ISP administration could promote sensory function restoration in adult rats after dorsal spinal root crush injury. Our results show that systemic ISP administration would not only significantly increase sensory axon regeneration and functional recovery, but also activate Erk and CREB signaling pathway. Furthermore, ISP has also been verified to increase dorsal root ganglion axonal remyelination in vitro. These results suggest that modulation of PTPσ by ISP represents a promising therapeutic strategy for sensory neuronal injuries. Highlights • ISP (Intracellular Sigma Peptide) promotes axonal regeneration into the spinal cord. • ISP promotes axonal regeneration in the dorsal root entry zone (DREZ). • Treatment with ISP promotes sensory functional recovery. • Systematic ISP treatment activates Erk/CREB pathway. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New piperidine-based alkylacetamide derivatives as σR ligands were synthesized. • Two out of fifteen of new derivatives showed high affinity and selectivity. • SAR study was carried out in order to investigate the chemical features. • Cytotoxic assay of new derivatives was performed towards 2 cancer cell lines. • Compound with the best σ2R affinity/selectivity, resulted to be σ2R agonist. Abstract The sigma receptor (σR) family has been considered mysterious for a long time. In fact, the σ2R subtype has been cloned only recently, revealing its identity as TMEM97, a NPC1-binding protein involved in cholesterol biosynthesis and implicated in the pathogenesis of cancer and neurologic disorders. With the aim of developing new chemical entities gifted with σR affinity, herein we report the design and synthesis of new piperidine-based alkylacetamide derivatives with mixed affinity towards both σ1 and σ2R subtypes. [ABSTRACT FROM AUTHOR]

Abstract In this manuscript we report on the design, synthesis and evaluation of dual Sigma 1 Receptor (S1R) modulators/Acetylcholinesterase (AChE) inhibitors endowed with antioxidant and neurotrophic properties, potentially able to counteract neurodegeneration. The compounds based on arylalkylaminoketone scaffold integrate the pharmacophoric elements of RRC-33, a S1R modulator developed by us, donepezil, a well-known AChE inhibitor, and curcumin, a natural antioxidant compound with neuroprotective properties. A small library of compounds was synthesized and preliminary in vitro screening performed. Some compounds showed good S1R binding affinity, selectivity towards S2R and N -Methyl- d -Aspartate (NMDA) receptor, AChE relevant inhibiting activity and are potentially able to bypass the BBB, as predicted by the in silico study. For the hits 10 and 20 , the antioxidant profile was assessed in SH-SY5Y human neuroblastoma cell lines by evaluating their protective effect against H 2 O 2 cytotoxicity and reactive oxygen species (ROS) production. Tested compounds resulted effective in decreasing ROS production, thus ameliorating the cellular survival. Moreover, compounds 10 and 20 showed to be effective in promoting the neurite elongation of Dorsal Root Ganglia (DRG), thus demonstrating a promising neurotrophic activity. Of note, the tested compounds did not show any cytotoxic effect at the concentration assayed. Relying on these encouraging results, both compounds will undergo a structure optimization program for the development of therapeutic candidates for neurodegenerative diseases treatment. Graphical abstract Image 1 Highlights • Some neurodegenerative diseases have a multifactorial origin. • Sigma 1 Receptor is a molecular target involved in neurodegenerative diseases. • Acetylcholinesterase inhibitors restore cholinergic system impairments. • Molecules endowed with antioxidant properties may limit central oxidative damages. • Small molecules, active as neurotrophic agents, are promising tools for the treatment of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

In this work we describe neurogenic and neuroprotective donepezil-flavonoid hybrids (DFHs), exhibiting nanomolar affinities for the sigma-1 receptor (σ 1 R) and inhibition of key enzymes in Alzheimer's disease (AD), such as acetylcholinesterase (AChE), 5-lipoxygenase (5-LOX), and monoamine oxidases (MAOs). In general, new compounds scavenge free radical species, are predicted to be brain-permeable, and protect neuronal cells against mitochondrial oxidative stress. N -(2-(1-Benzylpiperidin-4-yl)ethyl)-6,7-dimethoxy-4-oxo-4 H -chromene-2-carboxamide ( 18 ) is highlighted due to its interesting biological profile in σ 1 R, AChE, 5-LOX, MAO-A and MAO-B. In phenotypic assays, it protects a neuronal cell line against mitochondrial oxidative stress and promotes maturation of neural stem cells into a neuronal phenotype, which could contribute to the reparation of neuronal tissues. Molecular modelling studies of 18 in AChE, 5-LOX and σ 1 R revealed the main interactions with these proteins, which will be further exploited in the optimization of new, more efficient DFHs. [ABSTRACT FROM AUTHOR]

Increasing evidences have implicated that sigma-2 receptor is a biomarker and significantly over-expressed in many proliferative cancer cells with no or low expression in normal cells. Sigma-2 receptor selective ligands have been successfully used as valuable tools to study its pharmacological functions, tumor imaging, and cancer therapeutics or adjuvants. 6,7-Dimethoxy-1,2,3,4-tetrahydroisoquinolinylalkyl benzamides are among a few categories of structures that have demonstrated high affinities and selectivities for sigma-2 receptor and been used extensively as study tools in various tumor imaging and therapy. As a continuous effort, we have synthesized a new series of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives and evaluated their affinities for both sigma-1 and sigma-2 receptors. Most of these newly developed analogs showed good to excellent binding affinities for sigma-2 receptor with no or low affinities for sigma-1 receptor. In particular, compounds 3b , 3e , 4b , and 4e demonstrated K i values of 5–6 nM affinities and excellent selectivities for sigma-2 receptor. In addition, these analogs also demonstrated moderate anticancer activities against human liver Huh-7 tumor cells and human esophagus KYSE-140 cancer cells. But their cytotoxicities seem not to be correlated with their sigma-2 receptor affinities. [ABSTRACT FROM AUTHOR]

The sigma-1 receptor (S1R) is a molecular chaperone which activity modulates several intracellular signals including calcium mobilization at mitochondria-associated endoplasmic reticulum membranes. S1R agonists are potent neuroprotectants against neurodegenerative insults and particularly in rodent models of Alzheimer's disease (AD). We here analyzed whether S1R inactivation modifies vulnerability to amyloid toxicity in AD models. Two strategies were used: (1) amyloid β[25-35] (Aβ 25-35 ) peptide (1, 3, 9 nmol) was injected intracerebroventricularly in mice treated repeatedly with the S1R antagonist NE-100 or in S1RKO mice, and (2) WT, APP SweInd , S1RKO, and APP SweInd /S1RKO mice were created and female littermates analyzed at 8 months of age. Learning deficits, oxidative stress, Bax level and BDNF content in the hippocampus were analyzed. Aβ 25-35 induced learning impairment, oxidative stress, Bax induction and BDNF alteration at lower dose in NE-100-treated mice or S1RKO mice as compared to WT animals. The extent of learning deficits and biochemical alterations were also higher in APP SweInd /S1RKO mice as compared to WT, APP SweInd , and S1RKO animals. S1R inactivation or altered S1R expression augmented the pathological status in pharmacologic and genetic AD mouse models. These observations, in relation with the well-known protective effects of S1R agonists, are coherent with a role of signal amplifier in neurodegeneration and neuroprotection proposed for S1R in AD and related neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

The aggressiveness of pancreatic cancer urgently requires more efficient treatment options. Because the sigma-2 (σ 2 ) receptor was recently proposed as a promising target for pancreatic cancer therapy, we explored our previously developed multifunctional thiosemicarbazones, designed to synergistically impair cell energy levels, by targeting σ 2 and P-gp proteins and chelating Iron. A deconstruction approach was herein applied by removing one function at a time from the potent multifunctional thiosemicarbazones 1 and 2 , to investigate the contribution to cytotoxicity of each target involved. The results from in vitro (panel of pancreatic tumor cells) and in vivo experiments (C57BL/6 bearing KP02 tumor), suggest that while the multifunctional activity was not required for the antitumor activity of these thiosemicarbazones, σ 2 -targeting appeared to allow alternative tumor cell death mechanisms, leading to potent and less toxic off-targets toxicities compared to other thiosemicarbazones devoid of σ 2 -targeting. [ABSTRACT FROM AUTHOR]

The sigma 2 receptor (σ 2 R), which is identical to transmembrane protein 97 (TMEM97), is attracting increasing interest as a possible therapeutic target for various indications in neuroscience. In continuation of a program to identify novel compounds that bind with high affinity and selectivity to σ 2 R/TMEM97, we performed structure-affinity-relationship (SAfiR) studies of several sets of σ 2 R/TMEM97 ligands having a B-norbenzomorphan ring core. Binding data for σ 2 R/TMEM97 and σ 1 R of several enantiomeric pairs of piperazine-substituted norbenzomorphans show the (1 S ,5 R)-enantiomers have affinities (K i = 9–75 nM) for σ 2 R/TMEM97 that are 2–3-fold higher than their enantiomorphic (1 R ,5 S)-analogs; however, there is no clear trend for selectivity for σ 2 R/TMEM97 vs σ 1 R. A series of N- alkyl piperazino (1 S, 5 R)-norbenzomorphans was then evaluated, and with the exception of compounds having N- alkyl groups substituted with oxygen or amino groups at C (2) of an ethylene chain, K i values for σ 2 R/TMEM97 are less than 25 nM, and several compounds have good selectivities (ca 7–16-fold) for σ 2 R/TMEM97 vs σ 1 R. Mono-substituted carbobenzyloxy analogs have K i values for σ 2 R/TMEM97 comparable to the unsubstituted parent (K i = ca 7–27 nM), but replacing the N -acyloxy group with N -acyl or N -arylsulfonyl groups provides analogs having lower affinity and selectivity. Some congeners with bioisosteric replacements of the piperazine group on the (1 S, 5 R)-norbenzomorphan core have high affinity (K i = <30 nM) for σ 2 R/TMEM97, but selectivities are modest. Computational docking studies for racemic pairs of piperazino norbenzomorphans show that individual (1 S ,5 R)- and (1 R ,5 S)-enantiomers adopt distinct poses upon binding to σ 2 R/TMEM97, whereas ligands belongingto the same enantiomeric series adopt closely similar binding poses. The protonated amino group in each of the enantiomorphic ligands engages in highly conserved salt bridges with Asp29 and cation-π interactions with Tyr150 that are the primary determinants of binding affinity. There is no correlation between any of the computational parameter outputs and K i values, but this is unsurprising given the small energetic differences involved. Modeling also suggest sthat some compounds can extend deeper into σ 2 R/TMEM97 binding pocket forming salt bridges with Glu73. [Display omitted] • (1 S ,5 R)-piperazine-substituted norbenzomorphans higher affinity than (1 R ,5 S)-isomer. • Substituents on norbenzomorphan can be varied and maintain high affinity. • Docking studies predict (1 S ,5 R)- and (1 R ,5 S)-norbenzomorphans bind differently. • Docking studies predict some ligands can interact with Glu73. [ABSTRACT FROM AUTHOR]

• Anxiety putative causal gene expression levels were characterized in human brain tissue. • Gene targets of novel drug mechanisms of action groups were enriched in anxiety-associated genes. • Drug compounds ditolylguanidine and LY-2140023 demonstrated high therapeutical potential. Anxiety disorders are a group of prevalent and heritable neuropsychiatric diseases. We previously conducted a genome-wide association study (GWAS) which identified genomic loci associated with anxiety; however, the biological consequences underlying the genetic associations are largely unknown. Integrating GWAS and functional genomic data may improve our understanding of the genetic effects on intermediate molecular phenotypes such as gene expression. This can provide an opportunity for the discovery of drug targets for anxiety via drug repurposing. We used the GWAS summary statistics to determine putative causal genes for anxiety using MAGMA and colocalization analyses. A transcriptome-wide association study was conducted to identify genes with differential genetically regulated levels of gene expression in human brain tissue. The genes were integrated with a large drug-gene expression database (Connectivity Map), discovering compounds that are predicted to "normalise" anxiety-associated expression changes. The study identified 64 putative causal genes associated with anxiety (35 genes upregulated; 29 genes downregulated). Drug mechanisms adrenergic receptor agonists, sigma receptor agonists, and glutamate receptor agonists gene targets were enriched in anxiety-associated genetic signal and exhibited an opposing effect on the anxiety-associated gene expression signature. The significance of the project demonstrated genetic links for novel drug candidates to potentially advance anxiety therapeutics. [ABSTRACT FROM AUTHOR]

As sigma receptors are abundantly expressed on different types of cancer cells, several radiolabeled sigma receptor ligands have been developed for cancer imaging and therapy. Previously, we synthesized and evaluated radioiodinated aza-vesamicol derivatives, [125I] p IC 3 NV, [125I] m IC 2 N5V, and [125I] m IC 3 N5V. They accumulated in tumors, and [125I] m IC 2 N5V and [125I] m IC 3 N5V showed higher tumor to non-target tissue ratios than [125I] p IC 3 NV. Therefore, we synthesized and evaluated the corresponding 211At-labeled compounds, [211At] m AtC 2 N5V and [211At] m AtC 3 N5V, for targeted alpha therapy (TAT). [211At] m AtC 2 N5V and [211At] m AtC 3 N5V were prepared by the standard method of electrophilic astatodestannylation of the corresponding trimethylstannyl precursors. Cellular uptake experiments, and biodistribution experiments and therapeutic experiments in tumor-bearing mice were performed. The radiochemical yields of [211At] m AtC 2 N5V and [211At] m AtC 3 N5V were 45.5 ± 14.4% and 56.9 ± 13.8%, respectively. After HPLC purification, their radiochemical purities were over 95%. [211At] m AtC 2 N5V and [211At] m AtC 3 N5V showed high uptake in DU-145 cells. They demonstrated high accumulation in tumors (6.9 ± 1.4%injected dose/g and 5.1 ± 1.4%injected dose/g at 1 h, respectively) and similar biodistribution tendencies compared with the corresponding 125I-labeled compounds. A single injection of [211At] m AtC 2 N5V (0.48 MBq) or [211At] m AtC 3 N5V (0.48 MBq) significantly inhibited tumor growth. These results indicated that [211At] m AtC 2 N5V and [211At] m AtC 3 N5V could be potential candidates for TAT. [Display omitted] [ABSTRACT FROM AUTHOR]

We investigated the role(s) of the damage-inducible SOS response dinB and imuBC gene products in the generation of ciprofloxacin-resistance mutations in the important human opportunistic bacterial pathogen, Pseudomonas aeruginosa. We found that the overall numbers of ciprofloxacin resistant (CipR) mutants able to be recovered under conditions of selection were significantly reduced when the bacterial cells concerned carried a defective dinB gene, but could be elevated to levels approaching wild-type when these cells were supplied with the dinB gene on a plasmid vector; in turn, firmly establishing a role for the dinB gene product, error-prone DNA polymerase IV, in the generation of CipR mutations in P. aeruginosa. Further, we report that products of the SOS-regulated imuABC gene cassette of this organism, ImuB and the error-prone ImuC DNA polymerase, are also involved in generating CipR mutations in this organism, since the yields of CipR mutations were substantially decreased in imuB - or imuC -defective cells compared to wild-type. Intriguingly, we found that the mutability of a dinB -defective strain could not be rescued by overexpression of the imuBC genes. And similarly, overexpression of the dinB gene either only modestly or else failed to restore CipR mutations in imuB - or imuC -defective cells, respectively. Combined, these results indicated that the products of the dinB and imuBC genes were acting in the same pathway leading to the generation of CipR mutations in P. aeruginosa. In addition, we provide evidence indicating that the general stress response sigma factor σs, RpoS, is required for mutagenesis in this organism and is in part at least modulating the dinB (DNA polymerase IV)-dependent mutational process. Altogether, these data provide further insight into the complexity and multifaceted control of the mutational mechanism(s) contributing to the generation of ciprofloxacin-resistance mutations in P. aeruginosa. • The generation of ciprofloxacin-resistance mutations in Pseudomonas aeruginosa involves the dinB and imuBC gene products. • The products of the dinB and imuBC genes appear to be acting in the same pathway leading to the generation of CipR mutations. • The stress response factor, RpoS, is potentially modulating the DinB- dependent mutational process. [ABSTRACT FROM AUTHOR]

A 3D quantitative structure-activity relationship (3D-QSAR) model for predicting the σ 2 receptor affinity has been constructed with the aim of providing a useful tool for the identification, design, and optimization of novel σ 2 receptor ligands. The model has been built using a set of 500 selective σ 2 receptor ligands recovered from the sigma-2 receptor selective ligand database (S2RSLDB) and developed with the software Forge. The present model showed high statistical quality as confirmed by its robust predictive potential and satisfactory descriptive capability. The drawn up 3D map allows for a prompt visual comprehension of the electrostatic, hydrophobic, and shaping features underlying σ 2 receptor ligands interaction. A theoretic approach for the generation of new lead compounds with optimized σ 2 receptor affinity has been performed by means of scaffold hopping analysis. Obtained results further confirmed the validity of our model being some of the identified moieties have already been successfully employed in the development of potent σ 2 receptor ligands. For the first time is herein reported a 3D-QSAR model which includes a number of chemically diverse σ 2 receptor ligands and well accounts for the individual ligands affinities. These features will ensure prospectively advantageous applications to speed up the identification of new potent and selective σ 2 receptor ligands. [ABSTRACT FROM AUTHOR]

The vesicular acetylcholine transporter (VAChT) is an important target for in vivo imaging of neurodegenerative processes using positron emission tomography (PET). So far the development of VAChT PET radioligands is based on the single known lead compound vesamicol. In this study we investigated a recently published spiroindoline based compound class (Sluder et al., 2012), which was suggested to have potential in the development of VAChT ligands. Therefore, we synthesized a small series of N , N -substituted spiro[indoline-3,4′-piperidine] derivatives and determined their in vitro binding affinities toward the VAChT. In order to investigate the selectivity, the off-target binding toward σ 1 and σ 2 receptors was determined. The compounds possessed VAChT affinities with K i values in the range of 39–376 nM. Binding affinities toward the σ 1 and σ 2 receptors are in a similar range indicating that the strong structural difference between the spiroindolines and vesamicol did not improve the selectivity. The observed potential to additionally bind to σ receptors let us assume that the herein investigated spiroindolines are not suitable to replace vesamicol as lead compound for the development of VAChT ligands. [ABSTRACT FROM AUTHOR]

For the first time in sigma-2 (σ 2 ) receptor field, a quantitative structure–activity relationship (QSAR) model has been built using p K i values of the whole set of known selective σ 2 receptor ligands (548 compounds), taken from the Sigma-2 Receptor Selective Ligands Database (S2RSLDB) ( http://www.researchdsf.unict.it/S2RSLDB/ ), through the Monte Carlo technique and employing the software CORAL. The model has been developed by using a large and structurally diverse set of compounds, allowing for a prediction of different populations of chemical compounds endpoint (σ 2 receptor p K i ). The statistical quality reached, suggested that model for p K i determination is robust and possesses a satisfactory predictive potential. The statistical quality is high for both visible and invisible sets. The screening of the FDA approved drugs, external to our dataset, suggested that sixteen compounds might be repositioned as σ 2 receptor ligands (predicted p K i ≥ 8). A literature check showed that six of these compounds have already been tested for affinity at σ 2 receptor and, of these, two (Flunarizine and Terbinafine) have shown an experimental σ 2 receptor p K i > 7. This suggests that this QSAR model may be used as focusing screening filter in order to prospectively find or repurpose new drugs with high affinity for the σ 2 receptor, and overall allowing for an enhanced hit rate respect to a random screening. [ABSTRACT FROM AUTHOR]

Nowadays sigma-1 receptors are considered as new therapeutic objectives for central nervous system neurodegenerative diseases. Among different molecules, alpha lipoic acid has been identified as a natural potent antioxidant drug, whose therapeutic efficacy is limited by its many drawbacks, such as fast metabolism, poor bioavailability and high physico-chemical instability. Alfa-lipoic acid derivatives have been recently developed demonstrating their neuroprotective activity and effectiveness in different types of oxidative stress. In this work, two derivatives containing an amide or an ester functional group with different lipophilicity, were selected for their important affinity for sigma-1 receptors. Herein, in order to improve the in vitro stability and antioxidant effectiveness of alpha-lipoic acid derivatives, we focused our efforts in the nanoencapsulation strategies. Aqueous-core nanocapsules for the delivery of the hydrophilic compound and nanostructured lipid carrier for the lipophilic derivative, were properly designed and prepared using a direct or inverse eco-friendly organic solvent-free procedure. All nanosystems were characterized in terms of mean size, polydispersity, stability, morphology, encapsulation efficiency and in vitro release profiles. In order to evaluate the nanocarriers biocompatibility and antioxidant effectiveness, in vitro biological studies (cell viability, total antioxidant capacity and total oxidative status) were developed on primary human whole blood cell cultures, on both unloaded and derivatives-loaded nanodevices. [ABSTRACT FROM AUTHOR]

Background Sigma receptors (σ 1 R) are expressed both in neurons and microglia and can be considered as a promising target for developing pharmacological strategies for neuroprotection in various experimental models. The aim of the present study was to test the effect of (+)-pentazocine, a putative σ 1 R agonist, in an in vitro model of neuron/microglia crosstalk following hypoxia/reoxygenation. Methods Microglia (BV2 cells) was exposed (3 h) to 1% oxygen and reoxygenation was allowed for 24 h. Conditioned media obtained from this experimental condition was used to treat neuroblast-like cell line (SH-SY5Y cells) in the presence or absence of (+)-pentazocine (25 μM). Cell viability was measured by cytofluorimetric analysis, whereas inflammation and oxidative stress were evaluated by the expression of Hsp70, GAD, SOD and p65. Microglial cell migration was also evaluated by Xcelligence technology. Results Our results showed that (+)-pentazocine was able to increase SH-SY5Y cell viability following exposure to microglial-conditioned medium. Furthermore, (+)-pentazocine was also able to inhibit microglial cell toward neuron treated with hypoxic conditioned medium. Finally, pharmacological treatment reduced the expression of inflammatory and oxidative stress markers (GAD, SOD and p65). Interestingly, hypoxic medium was able to reduce the expression of Hsp70 and such effect was prevented by (+)-pentazocine treatment. Conclusions (+)-Pentazocine exhibits significant neuroprotective effects in our in vitro model of SH-SY5Y/microglial crosstalk thus suggesting that σ 1 R may represent a possible strategy for neuroprotection. [ABSTRACT FROM AUTHOR]

Sigma Receptor (SR) modulators are involved in different signal transduction pathways, representing important pharmacological/therapeutic tools in several pathological conditions, such as neurodegenerative diseases and cancers. To this purpose, numerous compounds have been developed in order to target selectively one of the two subtypes (S1R and S2R) as chemotherapeutic agent. However, experiments have also shown that ligands which are able to bind both SR subtypes can be useful for the diagnosis and/or the treatment of cancers. Therefore, the discovery of compounds with good affinity towards both S1R and S2R (‘pan-modulators’) is also of great interest and still represents a challenge up to now. For this reason, we synthesized novel arylalkylamines with the aim to obtain compounds with S1R and S2R affinity in the nM range and, by modeling quantitative structure–activity relationships (QSARs), we identified the essential structural features to obtain promising pan-compounds. [ABSTRACT FROM AUTHOR]

• CircHIPK2-SIGMAR1 axis regulated astrocytic inflammation. • Astrocytic inflammation was associated with autophagy. • Abundant autophagy promoted circHIPK2 degradation. • There was mutual accommodation between autophagy and circHIPK2-SIGMAR1 axis. Circular RNAs (circRNAs) are a subclass of noncoding RNAs and widely involve in the occurrence of multiple human diseases. It is an urgent task to clarify circRNA upstream regulation mechanism and seek their biofunction. Our previous study has confirmed that circular RNA HIPK2 (circHIPK2) promotes astrocyte activation via SIGMAR1, sigma non-opioid intracellular receptor 1, in a mouse model of single high-dose lipopolysaccharide (LPS) injection. However, what mechanism circHIPK2 is regulated by and whether it is involved in the inflammatory response of astrocytes remain unclear. In this study, we reported that circHIPK2 and SIGMAR1 were significantly increased in mouse prefrontal cortex after multiple intraperitoneal injection of LPS, with the elevation of inflammatory mediators. Knockdown circHIPK2 in primary astrocytes suppressed the SIGMAR1 expression and inflammation. Pretreatment of autophagy inducer rapamycin on astrocytes suppressed the circHIPK2 expression and inactivated inflammatory response. These results implied that autophagy inducer rapamycin could suppress astrocytic inflammation by inactivating circHIPK2-SIGMAR1 axis. Autophagy may be a promising upstream administrator of circHIPK2 and therapeutic target for central nervous system inflammation. [ABSTRACT FROM AUTHOR]

Steam explosion coupling high-temperature short-time sterilization (SE-HTST) was exploited to modify cellulosic biomass medium properties and promote high-solid fermentation (HSF). Biomass characterization analysis showed that SE-HTST enlarged microstructural pores and cavities in solid media, providing more effective space for microbial growth. Meanwhile, SE-HTST helped to release glucose from the cellulose with 35.8 ± 4.5, 20.0 ± 2.3, and 12.3 ± 5.7 mg glucose/g dry medium at 24, 48, and 72 h of fermentation, which were 3.1, 2.3, and 1.5 times higher than that in medium from conventional thermal sterilization (CTS), respectively. SE-HTST increased the viable cell and spore number of Bacillus subtilis by 1.8 and 1.6 times at 72 h of fermentation compared to CTS. Moreover, the expressions of master transcriptional gene spo0A and the early sigma factors of sigF and sigE genes gradually increased in the SE-HTST medium, showing enhanced sporulation in HSF. Therefore, SE-HTST is an effective strategy for facilitating cellulose degradation, improving glucose nutrients in biomass medium, and promoting sporulation-regulatory gene expression during high-solid fermentation, which enhances the production of microbial ecological agents using B. subtilis significantly. • SE-HTST facilitated cellulose degradation and improved nutrients in biomass media. • High levels of spo0A, sigF, and sigE expression with SE-HTST indicated enhanced sporulation. • SE-HTST presented a porous medium and effective contact space for microbial cells. • The proposed model well elucidated microstructural changes of cellulosic biomass media. • SE-HTST improved biomass medium properties and facilitated fermentation performance. [ABSTRACT FROM AUTHOR]

The discovery of ketamine as a rapid-acting antidepressant spurred significant research to understand its underlying mechanisms of action and to identify other novel compounds that may act similarly. Serotonergic psychedelics (SPs) have shown initial promise in treating depression, though the challenge of conducting randomized controlled trials with SPs and the necessity of long-term clinical observation are important limitations. This review summarizes the similarities and differences between the psychoactive effects associated with both ketamine and SPs and the mechanisms of action of these compounds, with a focus on the monoaminergic, glutamatergic, gamma-aminobutyric acid (GABA)-ergic, opioid, and inflammatory systems. Both molecular and neuroimaging aspects are considered. While their main mechanisms of action differ—SPs increase serotonergic signaling while ketamine is a glutamatergic modulator—evidence suggests that the downstream mechanisms of action of both ketamine and SPs include mechanistic target of rapamycin complex 1 (mTORC1) signaling and downstream GABA A receptor activity. The similarities in downstream mechanisms may explain why ketamine, and potentially SPs, exert rapid-acting antidepressant effects. However, research on SPs is still in its infancy compared to the ongoing research that has been conducted with ketamine. For both therapeutics, issues with regulation and proper controls should be addressed before more widespread implementation. This article is part of the Special Issue on "Ketamine and its Metabolites". • Ketamine and psychedelics have different initial mechanisms of action. • Parallel downstream mechanisms may account for therapeutic similarities. • Monoamines, opioid and sigma receptors, and inflammation are all promising targets. • More research on psychedelics is needed compared to ketamine. • Consideration of regulatory issues is crucial to implementation. [ABSTRACT FROM AUTHOR]

Dynamic stability has become a major constraint to static random access memory (SRAM) circuits design. In this paper, the relationship between the read/write delay and corresponding yield will be given by our CharTM, an unified memory yield analysis method by modeling the tail of performance distribution. In charTM, we design an efficient weighted regression-based high-dimensional meta-model to collect the tail samples without running simulations and construct the tail distribution by generalized Pareto distribution (GPD) with an adaptive tail fraction selection strategy to improve the accuracy in the high-sigma region. The effectiveness of CharTM is verified on bit cell, read, and write critical paths of an SRAM. The results show that the efficiency of CharTM exceeds that of a commercial yield analysis tool by 5.3–16.5 times on our validation cases with the same level of accuracy, and exceeds that of state-of-the-art methods by 13–82 times with much higher accuracy, especially on read and write paths. [ABSTRACT FROM AUTHOR]

• Showcased the analytical performance of 6 next generation chemistry assays on the Abbott ARCHITECT system. • Evaluated the assays' precision, linearity, method comparison and accuracy. • The 6 next generation ARCHITECT assays demonstrated ≥ 6 Sigma performance. We evaluated analytical and Sigma performance for 6 next generation chemistry assays on the Abbott Architect c8000 system. Albumin with bromocresol purple or green, amylase, cholesterol, total protein, and urea nitrogen were analyzed using photometric technology. Analytical performance goals were defined based on Accreditation Canada Diagnostics (ACD) and Clinical Laboratory Improvement Amendments (CLIA). Precision study consisted of testing 2 quality control concentrations and 3 patient serum sample pools, twice a day in quintuplicate over 5 days. Linearity testing consisted of 5–6 concentrations of commercial linearity materials. We tested a minimum of 120 serum/plasma specimens on the new and current Architect methods for comparison. We assessed accuracy with reference materials for 5 assays, and a calibration standard for cholesterol. Bias from the reference standard target value was used for Sigma metric analysis. Observed total imprecision of the assays ranged from 0.5 to 4%, meeting pre-defined goals. Linearity was acceptable over the tested range. Measurements on the new and current Architect methods were comparable. Accuracy ranged from 0 to 2.0% absolute mean difference from target value. All 6 next generation clinical chemistry assays demonstrated Six Sigma quality, using CLIA standards. Applying ACD recommendations, 5 assays showed Six Sigma, while cholesterol showed Five Sigma performance. [ABSTRACT FROM AUTHOR]

Ochratoxin A (OTA), a secondary fungal metabolite with nephrotoxicity, is widespread in numerous kinds of feeds and foodstuffs. Ursolic acid (UA), a water-insoluble pentacyclic triterpene acid, exists in a wide range of food materials and medicinal plants. Our earlier researches provided preliminary evidence that mitochondria- and mitochondria-associated endoplasmic reticulum membranes (MAMs)-located stress-responsive Lon protease 1 (Lonp1) had a protective function in OTA-induced nephrotoxicity, and the renoprotective function of UA against OTA partially due to Lonp1. However, whether other MAMs-located protiens, such as endoplasmic reticulum stress (ERS)-responsive Sigma 1-type opioid receptor (Sig-1R), contribute to the protection of UA against OTA-induced nephrotoxicity together with Lonp1 needs further investigation. In this study, the cell viability, reactive oxygen species, and protein expressions of human proximal tubule epithelial-originated kidney-2 (HK-2) cells varied with OTA and/or UA/CDDO-me/AVex-73/Sig-1R siRNA treatments were determined. Results indicated that a 24 h-treatment of 5 μM OTA could significantly induce mitochondrial-mediated apoptosis via repressing Lonp1 and Sig-1R, thereby enhancing the protein expressions of GRP78, p-PERK, p-eIF2α, CHOP, IRE1α, and Bax, and inhibiting the protein expression of Bcl-2 in HK-2 cells, which could be remarkably relieved by a 2 h-pre-treatment of 4 μM UA (P < 0.05). In conclusion, through mutual promotion between Lonp1 and Sig-1R, UA could effectively relieve OTA-induced apoptosis in vitro and break the vicious cycle between oxidative stress and ERS, which activated the mitochondrial apoptosis pathway. [Display omitted] • Ochratoxin A (OTA) triggered mitochondrial-mediated apoptosis. • Ursolic acid (UA) could effectively relieve OTA-induced mitochondrial apoptosis. • Lonp1 and Sig-1R contribute to the relief of UA against OTA-induced apoptosis. [ABSTRACT FROM AUTHOR]