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Bioorganic & Medicinal Chemistry Letters Jan 2024Screening a library of >100,000 compounds identified the substituted tetrazole compound 1 as a selective TRPML1 agonist. Both enantiomers of compound 1 were separated...
Screening a library of >100,000 compounds identified the substituted tetrazole compound 1 as a selective TRPML1 agonist. Both enantiomers of compound 1 were separated and profiled in vitro and in vivo. Their selectivity, ready availability and CNS penetration should enable them to serve as the tool compounds of choice in future TRPML1 channel activation studies. SAR studies on conformationally locked macrocyclic analogs further improved the TRPML1 agonist potency while retaining the selectivity.
Topics: Transient Receptor Potential Channels; Structure-Activity Relationship; Tetrazoles
PubMed: 38141860
DOI: 10.1016/j.bmcl.2023.129595 -
Molecules (Basel, Switzerland) Oct 2021Activated opioid receptors transmit internal signals through two major pathways: the G-protein-mediated pathway, which exerts analgesia, and the β-arrestin-mediated...
Activated opioid receptors transmit internal signals through two major pathways: the G-protein-mediated pathway, which exerts analgesia, and the β-arrestin-mediated pathway, which leads to unfavorable side effects. Hence, G-protein-biased opioid agonists are preferable as opioid analgesics. Rubiscolins, the spinach-derived naturally occurring opioid peptides, are selective δ opioid receptor agonists, and their p.o. administration exhibits antinociceptive effects. Although the potency and effect of rubiscolins as G-protein-biased molecules are partially confirmed, their in vitro profiles remain unclear. We, therefore, evaluated the properties of rubiscolins, in detail, through several analyses, including the CellKey assay, cADDis cAMP assay, and PathHunter β-arrestin recruitment assay, using cells stably expressing µ, δ, κ, or µ/δ heteromer opioid receptors. In the CellKey assay, rubiscolins showed selective agonistic effects for δ opioid receptor and little agonistic or antagonistic effects for µ and κ opioid receptors. Furthermore, rubiscolins were found to be G-protein-biased δ opioid receptor agonists based on the results obtained in cADDis cAMP and PathHunter β-arrestin recruitment assays. Finally, we found, for the first time, that they are also partially agonistic for the µ/δ dimers. In conclusion, rubiscolins could serve as attractive seeds, as δ opioid receptor-specific agonists, for the development of novel opioid analgesics with reduced side effects.
Topics: GTP-Binding Proteins; Gene Expression Regulation; HEK293 Cells; Humans; Molecular Structure; Opioid Peptides; Peptide Fragments; Receptors, Opioid, delta; Receptors, Opioid, mu; Ribulose-Bisphosphate Carboxylase; Signal Transduction; Spinacia oleracea; beta-Arrestins
PubMed: 34641621
DOI: 10.3390/molecules26196079 -
Reviews in the Neurosciences Aug 2020In this review, a series of experiments is presented, in which γ-amino butyric acid (GABA)ergic and glutamatergic effects on dopamine function in the rat nigrostriatal... (Review)
Review
In this review, a series of experiments is presented, in which γ-amino butyric acid (GABA)ergic and glutamatergic effects on dopamine function in the rat nigrostriatal and mesolimbic system was systematically assessed after pharmacological challenge with GABAA receptor (R) and and N-methyl d-aspartate (NMDA)R agonists and antagonists. In these studies, [123I]iodobenzamide binding to the D2/3R was mesured in nucleus accumbens (NAC), caudateputamen (CP), substantia nigra/ventral tegmental area (SN/VTA), frontal (FC), motor (MC) and parietal cortex (PC) as well as anterior (aHIPP) and posterior hippocampus (pHIPP) with small animal SPECT in baseline and after injection of either the GABAAR agonist muscimol (1 mg/kg), the GABAAR antagonist bicuculline (1 mg/kg), the NMDAR agonist d-cycloserine (20 mg/kg) or the NMDAR antagonist amantadine (40 mg/kg). Muscimol reduced D2/3R binding in NAC, CP, SN/VTA, THAL and pHIPP, while, after amantadine, decreases were confined to NAC, CP and THAL. In contrast, d-cycloserine elevated D2/3R binding in NAC, SN/VTA, THAL, frontal cortex, motor cortex, PC, aHIPP and pHIPP, while, after bicuculline, increases were confined to CP and THAL. Taken together, similar actions on regional dopamine levels were exterted by the GABAAR agonist and the NMDAR antagonist on the one side and by the GABAAR antagonist and the NMDAR agonist on the other, with agonistic action, however, affecting more brain regions. Thereby, network analysis suggests different roles of GABAARs and NMDARs in the mediation of nigrostriatal, nigrothalamocortical and mesolimbocortical dopamine function.
Topics: Animals; Bicuculline; Dopamine; Humans; Muscimol; Nucleus Accumbens; Rats; Receptors, GABA-A; Receptors, N-Methyl-D-Aspartate
PubMed: 32619197
DOI: 10.1515/revneuro-2019-0112 -
Organic & Biomolecular Chemistry Jan 2024The STING pathway is critical to innate immunity and is being investigated as a potential therapeutic target. Existing agents targeting STING suffer from several...
The STING pathway is critical to innate immunity and is being investigated as a potential therapeutic target. Existing agents targeting STING suffer from several undesirable effects, particularly the possibility of systematic activation, which increases the risk of autoimmune disorders. In this proof-of-concept study, we report the development of a light-activated STING agonist, based on the potent compound SR-717. We first screened the activity of the non-caged agonist toward 5 human STING variants to identify the most viable target. A photocaged agonist was designed and synthesized in order to block an essential interaction between the carboxy acid group of the ligand with the R238 residue of the STING protein. We then investigated the selective activation of STING with the photocaged agonist, demonstrating an irradiation-dependent response. The development and characterization of this selective agonist expands the growing toolbox of conditionally controlled STING agonists to avoid systematic immune activation.
Topics: Humans; Immunity, Innate; Membrane Proteins
PubMed: 38054844
DOI: 10.1039/d3ob01578e -
Current Pharmaceutical Design 2023The most frequent mutated oncogene KRAS in lung cancer is targeted by KRAS G12C-directed drugs, such as Sotorasib and Adagrasib. Still, other alleles frequently...
The most frequent mutated oncogene KRAS in lung cancer is targeted by KRAS G12C-directed drugs, such as Sotorasib and Adagrasib. Still, other alleles frequently expressed in pancreatic and colon cancer may be attacked indirectly by hitting the guanine nucleotide exchange factor (GEF) SOS1 that loads and activates KRAS. The first modulators of SOS1 were found to act as agonists and defined a hydrophobic pocket at the catalytic site. High throughput screenings resulted in the detection of SOS1 inhibitors Bay-293 and BI-3406 comprising amino quinazoline scaffolds optimized for binding to the pocket by various substituents. The first inhibitor, BI-1701963, is in clinical studies alone or in combination with a KRAS inhibitor, a MAPK inhibitor or chemotherapeutics. An optimized agonist, VUBI-1, shows activity against tumor cells by destructive overactivation of cellular signaling. This agonist was used to formulate a proteolysis targeting chimera (PROTAC), that labels SOS1 for degradation by proteasomal degradation through a linked VHL E3 ligase ligand. This PROTAC exhibited the highest SOS1-directed activity due to target destruction, recycling and removal of SOS1 as a scaffolding protein. Although other first PROTACs have entered clinical trials, each conjugate must be meticulously adapted as an efficient clinical drug.
Topics: Humans; High-Throughput Screening Assays; Proteolysis; Proteolysis Targeting Chimera; Proto-Oncogene Proteins p21(ras); Ubiquitin-Protein Ligases; SOS1 Protein
PubMed: 37073657
DOI: 10.2174/1381612829666230418114520 -
Drug Discovery Today Feb 2022ROR-γt, the master regulator of Th-17 cells, is activated by the binding of small molecules at its orthosteric site, followed by the recruitment of co-activators or... (Review)
Review
ROR-γt, the master regulator of Th-17 cells, is activated by the binding of small molecules at its orthosteric site, followed by the recruitment of co-activators or co-repressors in the ligand binding domain (LBD). Th-17 cells provide immune-dependent protection against cancers and pathogens. Their dysregulation causes inflammation and is therefore implicated in various autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, and psoriasis. Consequently, there is enormous interest in the development of ROR-γt modulators, both agonist and inverse-agonists. Here, we review advances in the development of ROR-γt modulators that have been made over the past decade, focusing on the rich crystallography landscape for ROR-γt co-crystals that has delineated the relationship between the binding patterns of modulators and the resulting biological activities.
Topics: Arthritis, Rheumatoid; Crystallography; Humans; Inflammation; Nuclear Receptor Subfamily 1, Group F, Member 3; Th17 Cells
PubMed: 34838728
DOI: 10.1016/j.drudis.2021.11.022 -
Bioorganic & Medicinal Chemistry May 2023Farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)γ are nuclear receptor 1 superfamily of transcription factors. FXR and PPARγ agonists...
Farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)γ are nuclear receptor 1 superfamily of transcription factors. FXR and PPARγ agonists have been individually investigated in clinical trial of anti-diabetic agents in the patients with nonalcoholic fatty liver disease (NAFLD). Regarding recent agonist development, the partial agonists for FXR and PPARγ are drawing attention from the standpoint of avoiding overactive responses caused by full agonists. In this article, we report that 18 with a benzimidazole scaffold possesses FXR/PPARγ dual partial agonistic activity. In addition, 18 shares the ability to reduce cyclin-dependent kinase 5-mediated phosphorylation of PPARγ-Ser273 and the metabolic stability in mouse liver microsome assay. To date, there are no published reports on FXR/PPARγ dual partial agonists with biological profiles similar to 18. Thus, the analog would be a feasible candidate as an unprecedented approach to NAFLD associated with type 2 diabetes mellitus.
Topics: Mice; Animals; PPAR gamma; Non-alcoholic Fatty Liver Disease; Diabetes Mellitus, Type 2; Transcription Factors; Hypoglycemic Agents
PubMed: 37028120
DOI: 10.1016/j.bmc.2023.117238 -
Immunity Feb 2024Antibodies can block immune receptor engagement or trigger the receptor machinery to initiate signaling. We hypothesized that antibody agonists trigger signaling by...
Antibodies can block immune receptor engagement or trigger the receptor machinery to initiate signaling. We hypothesized that antibody agonists trigger signaling by sterically excluding large receptor-type protein tyrosine phosphatases (RPTPs) such as CD45 from sites of receptor engagement. An agonist targeting the costimulatory receptor CD28 produced signals that depended on antibody immobilization and were sensitive to the sizes of the receptor, the RPTPs, and the antibody itself. Although both the agonist and a non-agonistic anti-CD28 antibody locally excluded CD45, the agonistic antibody was more effective. An anti-PD-1 antibody that bound membrane proximally excluded CD45, triggered Src homology 2 domain-containing phosphatase 2 recruitment, and suppressed systemic lupus erythematosus and delayed-type hypersensitivity in experimental models. Paradoxically, nivolumab and pembrolizumab, anti-PD-1-blocking antibodies used clinically, also excluded CD45 and were agonistic in certain settings. Reducing these agonistic effects using antibody engineering improved PD-1 blockade. These findings establish a framework for developing new and improved therapies for autoimmunity and cancer.
Topics: Protein Tyrosine Phosphatases; Signal Transduction; CD28 Antigens; Receptors, Immunologic
PubMed: 38354703
DOI: 10.1016/j.immuni.2024.01.007 -
Pharmacological Research May 2023Considerable progress has been made in recent years towards the identification and characterisation of novel subtype-selective modulators of nicotinic acetylcholine... (Review)
Review
Considerable progress has been made in recent years towards the identification and characterisation of novel subtype-selective modulators of nicotinic acetylcholine receptors (nAChRs). In particular, this has focussed on modulators of α7 nAChRs, a nAChR subtype that has been identified as a target for drug discovery in connection with a range of potential therapeutic applications. This review focusses upon α7-selective modulators that bind to receptor sites other than the extracellular 'orthosteric' agonist binding site for the endogenous agonist acetylcholine (ACh). Such compounds include those that are able to potentiate responses evoked by orthosteric agonists such as ACh (positive allosteric modulators; PAMs) and those that are able to activate α7 nAChRs by direct allosteric activation in the absence of an orthosteric agonist (allosteric agonists or 'ago-PAMs'). There has been considerable debate about the mechanism of action of α7-selective PAMs and allosteric agonists, much of which has centred around identifying the location of their binding sites on α7 nAChRs. Based on a variety of experimental evidence, including recent structural data, there is now clear evidence indicating that at least some α7-selective PAMs bind to an inter-subunit site located in the transmembrane domain. In contrast, there are differing hypotheses about the site or sites at which allosteric agonists bind to α7 nAChRs. It will be argued that the available evidence supports the conclusion that direct allosteric activation by allosteric agonists/ago-PAMs occurs via the same inter-subunit transmembrane site that has been identified for several α7-selective PAMs.
Topics: alpha7 Nicotinic Acetylcholine Receptor; Allosteric Regulation; Binding Sites; Receptors, Nicotinic; Acetylcholine
PubMed: 37023990
DOI: 10.1016/j.phrs.2023.106759 -
Pharmacogenomics Apr 2023To analyze roles of single nucleotide variants (SNVs) on weight loss with US FDA-approved medications. We searched the literature up until November 2022. Preferred... (Meta-Analysis)
Meta-Analysis Review
To analyze roles of single nucleotide variants (SNVs) on weight loss with US FDA-approved medications. We searched the literature up until November 2022. Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were followed. 14 studies were included in qualitative analysis and seven in meta-analysis. SNVs in , , , , , , and were evaluated relative to weight loss with glucagon-like peptide-1 agonists (13 studies) or naltrexone-bupropion (one study). gene (rs1049353), gene (rs6923761, rs10305420), gene (rs7903146) were associated with weight loss in at least one study involving glucagon-like peptide-1 agonist(s). The meta-analysis did not identify any consistent effect of SNVs. Pharmacogenetic interactions for exenatide, liraglutide, naltrexone-bupropion and weight loss were identified, but the directionality was inconsistent.
Topics: Adult; Humans; Hypoglycemic Agents; Pharmacogenetics; Naltrexone; Bupropion; Peptides; Venoms; Glucagon-Like Peptide 1; Weight Loss; Glucagon-Like Peptide-1 Receptor; Diabetes Mellitus, Type 2; Protein Serine-Threonine Kinases
PubMed: 36999540
DOI: 10.2217/pgs-2022-0192