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Sigma 1 receptor

A Eraso-Pichot, R Larramona-Arcas, E Vicario-Orri, R Villalonga, L Pardo, E Galea, R Masgrau
Astrocytic excitability relies on cytosolic calcium increases as a key mechanism, whereby astrocytes contribute to synaptic transmission and hence learning and memory. While it is a cornerstone of neurosciences that experiences are remembered, because transmitters activate gene expression in neurons, long-term adaptive astrocyte plasticity has not been described. Here, we investigated whether the transcription factor CREB mediates adaptive plasticity-like phenomena in astrocytes. We found that activation of CREB-dependent transcription reduced the calcium responses induced by ATP, noradrenaline, or endothelin-1...
October 19, 2016: Cellular and Molecular Life Sciences: CMLS
Susan Z Lever, Kuo-Hsien Fan, John R Lever
INTRODUCTION: Aspects of radiopharmaceutical development are illustrated through preclinical studies of [(125)I]-(E)-1-(2-(2,3-dihydrobenzofuran-5-yl)ethyl)-4-(iodoallyl)piperazine ([(125)I]-E-IA-BF-PE-PIPZE), a radioligand for sigma-1 (σ1) receptors, coupled with examples from the recent literature. Findings are compared to those previously observed for [(125)I]-(E)-1-(2-(2,3-dimethoxy-5-yl)ethyl)-4-(iodoallyl)piperazine ([(125)I]-E-IA-DM-PE-PIPZE). METHODS: Syntheses of E-IA-BF-PE-PIPZE and [(125)I]-E-IA-BF-PE-PIPZE were accomplished by standard methods...
September 3, 2016: Nuclear Medicine and Biology
Edward C Lauterbach
Dextromethorphan (DM) may have ketamine-like rapid-acting, treatment-resistant, and conventional antidepressant effects.(1,2) This reports our initial experience with DM in unipolar Major Depressive Disorder (MDD). A patient with treatment-resistant MDD (failing adequate trials of citalopram and vortioxetine) with loss of antidepressant response (to fluoxetine and bupropion) twice experienced a rapid-acting antidepressant effect within 48 hours of DM administration and lasting 7 days, sustained up to 20 days with daily administration, then gradually developing labile loss of antidepressant response over the ensuing 7 days...
August 15, 2016: Psychopharmacology Bulletin
Minhan Ka, Yeon-Hee Kook, Ke Liao, Shilpa Buch, Woo-Yang Kim
Cocaine is a highly addictive narcotic associated with dendritic spine plasticity in the striatum. However, it remains elusive whether cocaine modifies spines in a cell type-specific or region-specific manner or whether it alters different types of synapses in the brain. In addition, there is a paucity of data on the regulatory mechanism(s) involved in cocaine-induced modification of spine density. In the current study, we report that cocaine exposure differentially alters spine density, spine morphology, and the types of synapses in hippocampal and cortical neurons...
October 13, 2016: Cell Death & Disease
Trent Conroy, Madhura Manohar, Yu Gong, Shane M Wilkinson, Michael Webster, Brian P Lieberman, Samuel D Banister, Tristan A Reekie, Robert H Mach, Louis M Rendina, Michael Kassiou
The sigma-1 receptor (S1R) has attracted a great deal of attention as a prospective drug target due to its involvement in numerous neurological disorders and, more recently, for its therapeutic potential in neuropathic pain. As there was no crystal structure of this membrane-bound protein reported until 2016, ligand generation was driven by pharmacophore refinements to the general model suggested by Glennon and co-workers. The generalised S1R pharmacophore comprises a central region where a basic amino group is preferred, flanked by two hydrophobic groups...
October 4, 2016: Organic & Biomolecular Chemistry
Attila Szabo, Attila Kovacs, Jordi Riba, Srdjan Djurovic, Eva Rajnavolgyi, Ede Frecska
N,N-dimethyltryptamine (DMT) is a potent endogenous hallucinogen present in the brain of humans and other mammals. Despite extensive research, its physiological role remains largely unknown. Recently, DMT has been found to activate the sigma-1 receptor (Sig-1R), an intracellular chaperone fulfilling an interface role between the endoplasmic reticulum (ER) and mitochondria. It ensures the correct transmission of ER stress into the nucleus resulting in the enhanced production of antistress and antioxidant proteins...
2016: Frontiers in Neuroscience
Mika Naganawa, Shu-Fei Lin, Keunpoong Lim, David Labaree, Jim Ropchan, Paul Harris, Yiyun Huang, Masanori Ichise, Richard E Carson, Gary W Cline
INTRODUCTION: (18)F-Fluoropropyl-(+)-dihydrotetrabenazine ((18)F-FP-(+)-DTBZ) is a vesicular monoamine transporter type 2 (VMAT2) radiotracer for positron emission tomography (PET) imaging to quantify human β-cell mass. Renal cortex and spleen have been suggested as reference regions, however, little is known about (18)F-FP-(+)-DTBZ binding in these regions including the fraction of radiometabolite. We compared the kinetics of (18)F-FP-(+)-DTBZ and its inactive enantiomer (18)F-FP-(-)-DTBZ in baboons, estimated the non-displaceable binding (VND) of the tracers, and used ex vivo studies to measure radiometabolite fractions...
September 2, 2016: Nuclear Medicine and Biology
Fadil M Hannan, Valerie N Babinsky, Rajesh V Thakker
The extracellular calcium (Ca(2+) o)-sensing receptor (CaSR) is a family C G protein-coupled receptor, which detects alterations in Ca(2+) o concentrations and modulates parathyroid hormone secretion and urinary calcium excretion. The central role of the CaSR in Ca(2+) o homeostasis has been highlighted by the identification of mutations affecting the CASR gene on chromosome 3q21.1. Loss-of-function CASR mutations cause familial hypocalciuric hypercalcaemia (FHH), whereas gain-of-function mutations lead to autosomal dominant hypocalcaemia (ADH)...
October 2016: Journal of Molecular Endocrinology
Alejandro Horga, Pedro J Tomaselli, Michael A Gonzalez, Matilde Laurà, Francesco Muntoni, Adnan Y Manzur, Michael G Hanna, Julian C Blake, Henry Houlden, Stephan Züchner, Mary M Reilly
OBJECTIVE: To describe the genetic and clinical features of a simplex patient with distal hereditary motor neuropathy (dHMN) and lower limb spasticity (Silver-like syndrome) due to a mutation in the sigma nonopioid intracellular receptor-1 gene (SIGMAR1) and review the phenotypic spectrum of mutations in this gene. METHODS: We used whole-exome sequencing to investigate the proband. The variants of interest were investigated for segregation in the family using Sanger sequencing...
September 14, 2016: Neurology
Lukas Pfeifer, Keary M Engle, George W Pidgeon, Hazel A Sparkes, Amber L Thompson, John M Brown, Véronique Gouverneur
Hydrogen bonding with fluoride is a key interaction encountered when analyzing the mode of action of 5'-fluoro-5'-deoxyadenosine synthase, the only known enzyme capable of catalyzing the formation of a C-F bond from F(-). Further understanding of the effect of hydrogen bonding on the structure and reactivity of complexed fluoride is therefore important for catalysis and numerous other applications, such as anion supramolecular chemistry. Herein we disclose a detailed study examining the structure of 18 novel urea-fluoride complexes in the solid state, by X-ray and neutron diffraction, and in solution phase and explore the reactivity of these complexes as a fluoride source in SN2 chemistry...
October 4, 2016: Journal of the American Chemical Society
Jessica L Hastie, Kyle B Williams, Lindsey L Bohr, Jon C Houtman, Lokesh Gakhar, Craig D Ellermeier
σ factors provide RNA polymerase with promoter specificity in bacteria. Some σ factors require activation in order to interact with RNA polymerase and transcribe target genes. The Extra-Cytoplasmic Function (ECF) σ factor, σV, is encoded by several Gram-positive bacteria and is specifically activated by lysozyme. This activation requires the proteolytic destruction of the anti-σ factor RsiV via a process of regulated intramembrane proteolysis (RIP). In many cases proteases that cleave at site-1 are thought to directly sense a signal and initiate the RIP process...
September 2016: PLoS Genetics
Sheu-Ran Choi, Soon-Gu Kwon, Hoon-Seong Choi, Ho-Jae Han, Alvin James Beitz, Jang-Hern Lee
We recently demonstrated that activation of spinal sigma-1 receptors (Sig-1Rs) induces pain hypersensitivity via the activation of neuronal nitric oxide synthase (nNOS) and NADPH oxidase 2 (Nox2). However, the potential direct interaction between nNOS-derived nitric oxide (NO) and Nox2-derived reactive oxygen species (ROS) is poorly understood, particularly with respect to the potentiation of NMDA receptor activity in the spinal cord associated with the development of central sensitization. Thus, the main purpose of this study was to investigate whether Sig-1R-induced and nNOS-derived NO modulates spinal Nox2 activation leading to an increase in ROS production and ultimately to the potentiation of NMDA receptor activity and pain hypersensitivity...
September 7, 2016: Biological & Pharmaceutical Bulletin
Iljung Lee, Brian P Lieberman, Shihong Li, Catherine Hou, Mehran Makvandi, Robert H Mach
INTRODUCTION: Nine novel analogues were synthesized including a 6-carbon spacer analogue of ISO-1 (7). They have moderate binding affinity for sigma-2 (σ2) receptors and high selectivity for σ2 receptors relative to sigma-1 (σ1) receptors. METHODS: ([(18)F]7) was synthesized and evaluated as a candidate ligand for positron emission (PET) imaging of the σ2 receptor in tumors. Radioligand [(18)F]7 was radiolabeled with (18)F via displacement of the corresponding mesylate precursor with [(18)F]fluoride...
August 9, 2016: Nuclear Medicine and Biology
Sheu-Ran Choi, Dae-Hyun Roh, Seo-Yeon Yoon, Soon-Gu Kwon, Hoon-Seong Choi, Ho-Jae Han, Alvin J Beitz, Jang-Hern Lee
We have previously shown using a spinal cord injury (SCI) model that gap junctions contribute to the early spread of astrocyte activation in the lumbar spinal cord and that this astrocyte communication plays critical role in the induction of central neuropathic pain. Sigma-1 receptors (Sig-1Rs) have been implicated in spinal astrocyte activation and the development of peripheral neuropathic pain, yet their contribution to central neuropathic pain remains unknown. Thus, we investigated whether SCI upregulates spinal Sig-1Rs, which in turn increase the expression of the astrocytic gap junction protein, connexin 43 (Cx43) leading to the induction of central neuropathic pain...
December 2016: Neuropharmacology
Hermia N Ikome, Fidele Ntie-Kang, Moses N Ngemenya, Zhude Tu, Robert H Mach, Simon M N Efange
BACKGROUND: Sigma (σ) receptors are membrane-bound proteins characterised by an unusual promiscuous ability to bind a wide variety of drugs and their high affinity for typical neuroleptic drugs, such as haloperidol, and their potential as alternative targets for antipsychotic agents. Sigma receptors display diverse biological activities and represent potential fruitful targets for therapeutic development in combating many human diseases. Therefore, they present an interesting avenue for further exploration...
2016: Chemistry Central Journal
Heather Kang, Pojeong Park, Zuner A Bortolotto, Simon D Brandt, Tristan Colestock, Jason Wallach, Graham L Collingridge, David Lodge
To avoid legislation based on chemical structure, research chemicals, frequently used for recreational purposes, are continually being synthesized. N-Ethyl-1,2-diphenylethanamine (ephenidine) is a diarylethylamine that has recently become popular with recreational users searching for dissociative hallucinogenic effects. In the present study, the pharmacological basis of its neural actions has been investigated, initially by assessing its profile in central nervous system receptor binding assays and subsequently in targeted electrophysiological studies...
August 9, 2016: Neuropharmacology
Michal Geva, Rebecca Kusko, Holly Soares, Kevin D Fowler, Tal Birnberg, Steve Barash, Avia Merenlender -Wagner, Tania Fine, Andrew Lysaght, Brian Weiner, Yoonjeong Cha, Sarah Kolitz, Fadi Towfic, Aric Orbach, Ralph Laufer, Ben Zeskind, Iris Grossman, Michael R Hayden
Pridopidine has demonstrated improvement in Huntington Disease (HD) motor symptoms as measured by secondary endpoints in clinical trials. Originally described as a dopamine stabilizer, this mechanism is insufficient to explain the clinical and preclinical effects of pridopidine. This study therefore explored pridopidine's potential mechanisms of action. The effect of pridopidine versus sham treatment on genome-wide expression profiling in the rat striatum was analysed and compared to the pathological expression profile in Q175 knock-in (Q175 KI) vs Q25 WT mouse models...
July 27, 2016: Human Molecular Genetics
Yasuharu Shinoda, Hideaki Tagashira, Md Shenuarin Bhuiyan, Hideyuki Hasegawa, Hiroshi Kanai, Kohji Fukunaga
Haloperidol is an antipsychotic drug that inhibits the dopamine D2 receptor among others. Haloperidol also binds the sigma-1 receptor (σ1R) and inhibits it irreversibly. A serious outcome of haloperidol treatment of schizophrenia patients is death due to sudden cardiac failure. Although the cause remains unclear, we hypothesized that these effects were mediated by chronic haloperidol inhibition of cardiac σ1R. To test this, we treated neonatal rat cardiomyocytes with haloperidol, exposed them to angiotensin II and assessed hypertrophy, σ1R expression, mitochondrial Ca(2+) transport and ATP levels...
July 2016: Journal of Pharmacological Sciences
Adrian Y C Wong, Elitza Hristova, Nina Ahlskog, Louis-Alexandre Tasse, Johnny K Ngsee, Prakash Chudalayandi, Richard Bergeron
The sigma-1 receptor (σ-1R) is an endoplasmic reticulum resident chaperone protein involved in a plethora of cellular functions, and whose disruption has been implicated in a wide range of diseases. Genetic analysis has revealed two σ-1R mutants involved in neuromuscular disorders. A point mutation (E102Q) in the ligand-binding domain results in the juvenile form of amyotrophic lateral sclerosis (ALS16), and a 20 amino-acid deletion (Δ31-50) in the putative cytosolic domain leads to a form of distal hereditary motor neuropathy...
September 2016: Molecular Pharmacology
Maninder Malik, Claudia Rangel-Barajas, Robert H Mach, Robert R Luedtke
Several receptor mediated pathways have been shown to modulate the murine head twitch response (HTR). However, the role of sigma receptors in the murine (±)-2,5-dimethoxy-4-iodoamphetamine (DOI)-induced HTR has not been previously investigated. We examined the ability of LS-1-137, a novel sigma-1 vs. sigma-2 receptor selective phenylacetamide, to modulate the DOI-induced HTR in DBA/2J mice. We also assessed the in vivo efficacy of reference sigma-1 receptor antagonists and agonists PRE-084 and PPCC. The effect of the sigma-2 receptor selective antagonist RHM-1-86 was also examined...
September 2016: Pharmacology, Biochemistry, and Behavior
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