scholarly journals In vitro and in vivo sigma 1 receptor imaging studies in different disease states

2020 ◽  
Author(s):  
Hebaalla Agha ◽  
Christopher R. McCurdy

Molecular imaging studies have paved the road for the development of successful σ1R ligands currently in clinical trials.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jose A. Morales-Garcia ◽  
Javier Calleja-Conde ◽  
Jose A. Lopez-Moreno ◽  
Sandra Alonso-Gil ◽  
Marina Sanz-SanCristobal ◽  
...  

Abstract N,N-dimethyltryptamine (DMT) is a component of the ayahuasca brew traditionally used for ritual and therapeutic purposes across several South American countries. Here, we have examined, in vitro and vivo, the potential neurogenic effect of DMT. Our results demonstrate that DMT administration activates the main adult neurogenic niche, the subgranular zone of the dentate gyrus of the hippocampus, promoting newly generated neurons in the granular zone. Moreover, these mice performed better, compared to control non-treated animals, in memory tests, which suggest a functional relevance for the DMT-induced new production of neurons in the hippocampus. Interestingly, the neurogenic effect of DMT appears to involve signaling via sigma-1 receptor (S1R) activation since S1R antagonist blocked the neurogenic effect. Taken together, our results demonstrate that DMT treatment activates the subgranular neurogenic niche regulating the proliferation of neural stem cells, the migration of neuroblasts, and promoting the generation of new neurons in the hippocampus, therefore enhancing adult neurogenesis and improving spatial learning and memory tasks.


2010 ◽  
Author(s):  
◽  
Kuo-Hsien Fan

Sigma receptors are unique binding sites located in the central nervous system (CNS) and peripheral organs. Two sigma receptor subtypes ([signma]1 and [sigma]2) have been described so far. It is known that the [sigma]1 receptor is involved in a number of CNS disorders and the [sigma]2 receptor is involved in tumor proliferation among others. Because of the important biological functions of the [sigma] receptor, development of structure activity relationships (SAR) can aid in the identification of potential medications and imaging agents. Three series of analogs based on three lead compounds have been synthesized and evaluated for their in vitro affinity and selectivity for the [sigma]1 and [sigma]2 subtypes. Lead I is a selective [sigma]1 receptor ligand with anti-cocaine activity, but its in vivo distribution is unknown. Our in vitro binding results showed that all the Lead I analogs are potent [sigma]1 receptor ligands. Furthermore, one of the Lead I analogs was radioiodinated and evaluated for its in vivo distribution. In vivo evaluation of the radioiodinated Lead I analog has shown high brain uptake and specific binding to [sigma]1 receptor of the radioligand. Lead II is also a selective [sigma]1 receptor ligand and radioiodinated Lead II has been shown to be a potential imaging agent for the [sigma]1 receptor. Two of the Lead II analogs were shown to be potent [sigma]1 receptor ligands. The radioiodinated Lead II analogs were demonstrated to be potential imaging agents for [sigma]1 receptor in vivo. Lead III is one of the most selective [sigma]2 receptor ligands known to date. Only one of the newly synthesized Lead III analogs was found to be a selective [sigma]2 receptor ligand. The SAR study of Lead III analogs successfully indentified the important structural features in Lead III for [sigma]2 receptor binding. To summarize, the SAR studies based on the lead compounds have generated useful information and three potential [sigma]1 imaging agents were prepared in the studies.


Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 211 ◽  
Author(s):  
Maximilian Christ ◽  
Heike Huesmann ◽  
Heike Nagel ◽  
Andreas Kern ◽  
Christian Behl

Dysfunction of autophagy and disturbed protein homeostasis are linked to the pathogenesis of human neurodegenerative diseases and the modulation of autophagy as the protein clearance process has become one key pharmacological target. Due to the role of sigma-1 receptors (Sig-1R) in learning and memory, and the described pleiotropic neuroprotective effects in various experimental paradigms, Sig-1R activation is recognized as one potential approach for prevention and therapy of neurodegeneration and, interestingly, in amyotrophic lateral sclerosis associated with mutated Sig-1R, autophagy is disturbed. Here we analyzed the effects of tetrahydro-N,N-dimethyl-2,2-diphenyl-3-furanmethanamine hydrochloride (ANAVEX2-73), a muscarinic receptor ligand and Sig-1R agonist, on autophagy and proteostasis. We describe, at the molecular level, for the first time, that pharmacological Sig-1R activation a) enhances the autophagic flux in human cells and in Caenorhabditis elegans and b) increases proteostasis capacity, ultimately ameliorating paralysis caused by protein aggregation in C. elegans. ANAVEX2-73 is already in clinical investigation for the treatment of Alzheimer’s disease, and the novel activities of this compound on autophagy and proteostasis described here may have consequences for the use and further development of the Sig-1R as a drug target in the future. Moreover, our study defines the Sig-1R as an upstream modulator of canonical autophagy, which may have further implications for various conditions with dysfunctional autophagy, besides neurodegeneration.


2014 ◽  
Vol 559 ◽  
pp. 174-178 ◽  
Author(s):  
Yoko Ono ◽  
Hirotaka Tanaka ◽  
Masafumi Takata ◽  
Yuki Nagahara ◽  
Yasuhiro Noda ◽  
...  

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S655-S655
Author(s):  
James M Stone ◽  
Erik Arstad ◽  
Kjell Erlandsson ◽  
Rikki N Waterhouse ◽  
Peter J Ell ◽  
...  
Keyword(s):  

2020 ◽  
Vol 21 (10) ◽  
pp. 955-964 ◽  
Author(s):  
Mengjie Liu ◽  
John Wade ◽  
Mohammed Akhter Hossain

: Ghrelin is a 28-amino acid octanoylated peptide hormone that is implicated in many physiological and pathophysiological processes. Specific visualization of ghrelin and its cognate receptor using traceable ligands is crucial in elucidating the localization, functions, and expression pattern of the peptide’s signaling pathway. Here 12 representative radio- and fluorescently-labeled peptide-based ligands are reviewed for in vitro and in vivo imaging studies. In particular, the focus is on their structural features, pharmacological properties, and applications in further biochemical research.


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