-
Journal of Immunotherapy (Hagerstown,... Jun 2023Toll-like receptor (TLR) 7/8 and 9 agonists stimulate an innate immune response that supports the development of tumor-specific immunity. Previous studies showed that...
Toll-like receptor (TLR) 7/8 and 9 agonists stimulate an innate immune response that supports the development of tumor-specific immunity. Previous studies showed that either agonist individually could cure mice of small tumors and that when used in combination, they could prevent the progression of larger tumors (>300 mm 3 ). To examine whether these agents combined could control metastatic disease, syngeneic mice were challenged with the highly aggressive 66cl4 triple-negative breast tumor cell line. Treatment was not initiated until pulmonary metastases were established, as verified by bioluminescent imaging of luciferase-tagged tumor cells. Results show that combined therapy with TLR7/8 and TLR9 agonists delivered to both primary and metastatic tumor sites significantly reduced tumor burden and extended survival. The inclusion of cyclophosphamide and anti-PD-L1 resulted in optimal tumor control, characterized by a 5-fold increase in the average duration of survival.
Topics: Mice; Animals; Toll-Like Receptor 9; Immunotherapy; Cell Line; Adjuvants, Immunologic; Lung Neoplasms
PubMed: 37103328
DOI: 10.1097/CJI.0000000000000467 -
Phytomedicine : International Journal... Jun 2022Bombesin Receptor Subtype-3 (BRS-3, Bombesin-like receptor, BB) is an orphan G-protein coupled receptor (GPCR). Recent studies have shown that BRS-3 played a vital role...
BACKGROUND
Bombesin Receptor Subtype-3 (BRS-3, Bombesin-like receptor, BB) is an orphan G-protein coupled receptor (GPCR). Recent studies have shown that BRS-3 played a vital role in glucose regulation, insulin secretion, and energy homeostasis. Therefore, discovering more novel exogenous ligands with diverse structures for BRS-3 will be of great importance for target validation and drug development.
PURPOSE
In this study, we aim to discover new agonists of BRS-3 from our natural compound libraries, providing a new probe to study the function of BRS-3.
STUDY DESIGN
Multiple cell-based assays and in vivo experiments were performed to identify the new ligand.
METHODS
BRS-3 overexpression cells were coupled with FLIPR assay, homogeneous time-resolved fluorescence (HTRF) IP-ONE assay, dynamic mass redistribution (DMR) assay, β-arrestin2 recruitment assay, and western blot to determine receptor activation and downstream signaling events. To further validate the target of BRS-3, a series of in vitro and in vivo experiences were conducted, including glucose uptake, glucose transporter type 4 (GLUT4) transportation in C2C12, and oral glucose tolerance test (OGTT) in mice.
RESULTS
We discovered and identified oridonin as a novel small molecule agonist of BRS-3, with a moderate affinity (EC of 2.236 × 10 M in calcium mobilization assay), specificity, and subtype selectivity. Further in vitro and in vivo tests demonstrated that oridonin exerted beneficial effects in glucose homeostasis through activating BRS-3.
CONCLUSIONS
Oridonin, as the discovered new ligand of BRS-3, provides a valuable tool compound to investigate BRS-3's function, especially for target validation in type 2 diabetes and obesity. Oridonin is promising as a lead compound in the treatment of metabolic disorders. Compared to the known agonists of BRS-3, we can take advantage of the multiple reported pharmacological activities of ODN as a natural product and assess whether these pharmacological activities are regulated by BRS-3. This may facilitate the discovery of novel functions of BRS-3.
Topics: Animals; Diabetes Mellitus, Type 2; Diterpenes, Kaurane; Glucose; Ligands; Mice; Receptors, Bombesin
PubMed: 35405616
DOI: 10.1016/j.phymed.2022.154085 -
European Journal of Medicinal Chemistry Dec 2021GPR27 belongs, with GPR85 and GPR173, to a small subfamily of three receptors called "Super-Conserved Receptors Expressed in the Brain" (SREB). It has been postulated to...
GPR27 belongs, with GPR85 and GPR173, to a small subfamily of three receptors called "Super-Conserved Receptors Expressed in the Brain" (SREB). It has been postulated to participate in key physiological processes such as neuronal plasticity, energy metabolism, and pancreatic β-cell insulin secretion and regulation. Recently, we reported the first selective GPR27 agonist, 2,4-dichloro-N-(4-(N-phenylsulfamoyl)phenyl)benzamide (I, pEC 6.34, E 100%). Here, we describe the synthesis and structure-activity relationships of a series of new derivatives and analogs of I. All products were evaluated for their ability to activate GPR27 in an arrestin recruitment assay. As a result, agonists were identified with a broad range of efficacies including partial and full agonists, showing higher efficacies than the lead compound I. The most potent agonist was 4-chloro-2,5-difluoro-N-(4-(N-phenylsulfamoyl)phenyl)benzamide (7y, pEC 6.85, E 37%), and the agonists with higher efficacies were 4-chloro-2-methyl-N-(4-(N-phenylsulfamoyl)phenyl)benzamide (7p, pEC 6.04, E 123%), and 2-bromo-4-chloro-N-(4-(N-phenylsulfamoyl)phenyl)benzamide (7r, pEC 5.99, E 123%). Docking studies predicted the putative binding site and interactions of agonist 7p with GPR27. Selected potent agonists were found to be soluble and devoid of cellular toxicity within the range of their pharmacological activity. Therefore, they represent important new tools to further characterize the (patho)physiological roles of GPR27.
Topics: Benzamides; Cell Survival; Dose-Response Relationship, Drug; HEK293 Cells; Humans; Models, Molecular; Molecular Structure; Receptors, G-Protein-Coupled; Structure-Activity Relationship
PubMed: 34454125
DOI: 10.1016/j.ejmech.2021.113777 -
Scientific Reports Nov 2019Agonists of β adrenergic receptors (βAR) and glucocorticoid receptors (GR) are prescribed to treat pulmonary diseases. Since ozone effects are mediated through the...
Agonists of β adrenergic receptors (βAR) and glucocorticoid receptors (GR) are prescribed to treat pulmonary diseases. Since ozone effects are mediated through the activation of AR and GR, we hypothesized that the treatment of rats with relevant therapeutic doses of long acting βAR agonist (LABA; clenbuterol; CLEN) and/or GR agonist (dexamethasone; DEX) would exacerbate ozone-induced pulmonary and systemic changes. In the first study, male 12-week-old Wistar-Kyoto rats were injected intraperitoneally with vehicle (saline), CLEN (0.004 or 0.02 mg/kg), or DEX (0.02 or 0.1 mg/kg). Since dual therapy is commonly used, in the second study, rats received either saline or combined CLEN + DEX (each at 0.005 or 0.02 mg/kg) one day prior to and on both days of exposure (air or 0.8ppm ozone, 4 hr/day x 2-days). In air-exposed rats CLEN, DEX or CLEN + DEX did not induce lung injury or inflammation, however DEX and CLEN + DEX decreased circulating lymphocytes, spleen and thymus weights, increased free fatty acids (FFA) and produced hyperglycemia and glucose intolerance. Ozone exposure of vehicle-treated rats increased bronchoalveolar lavage fluid protein, albumin, neutrophils, IL-6 and TNF-α. Ozone decreased circulating lymphocytes, increased FFA, and induced hypeerglycemia and glucose intolerance. Drug treatment did not reverse ozone-induced ventillatory changes, however, lung effects (protein and albumin leakage, inflammation, and IL-6 increase) were exacerbated by CLEN and CLEN + DEX pre-treatment in a dose-dependent manner (CLEN > CLEN + DEX). Systemic effects induced by DEX and CLEN + DEX but not CLEN in air-exposed rats were analogous to and more pronounced than those induced by ozone. These data suggest that adverse air pollution effects might be exacerbated in people receiving LABA or LABA plus glucocorticoids.
Topics: Adrenergic beta-2 Receptor Agonists; Animals; Clenbuterol; Dexamethasone; Drug Interactions; Fatty Acids; Glucocorticoids; Glucose; Interleukin-6; Lung; Lymphocytes; Male; Ozone; Rats; Rats, Wistar; Spleen; Thymus Gland; Tumor Necrosis Factor-alpha
PubMed: 31784596
DOI: 10.1038/s41598-019-54269-w -
JAMA Aug 2023
Topics: Humans; Narcolepsy; Orexins; Sleep; Treatment Outcome; Patient Safety; Clinical Trials as Topic
PubMed: 37531144
DOI: 10.1001/jama.2023.13621 -
Epilepsy Research Aug 2023The study intends to repurpose FDA drugs and investigate the mechanism of (5HTR) activation by comprehending inter-residue interactions. The 5HTR is a novel thread, and...
The study intends to repurpose FDA drugs and investigate the mechanism of (5HTR) activation by comprehending inter-residue interactions. The 5HTR is a novel thread, and its role in reducing seizures in Dravet syndrome is emerging. The crystal structure (5HTR) is a chimera with mutations; hence 3D-structure is modeled (4IB4: 5HTR). The structure is cross-validated to simulate the human receptor using enrichment analysis (ROC: 0.79) and SAVESv6.0. Virtual screening of 2456 approved drugs yielded the best hits that are subjected to MM/GBSA and molecular dynamic (MD) simulations. The 2 top drugs Cabergoline (-53.44 kcal/mol) and Methylergonovine (-40.42 kcal/mol), display strong binding affinity, and ADMET/SAR analysis also suggests their non-mutagenic or non-carcinogenic nature. Methylergonovine has a weaker binding affinity and lower potency than standards [Ergotamine (agonist) and Methysergide (antagonist)] due to its higher K (1.32 M) and K (6.44 ×10 M) values. Compared to standards, Cabergoline has moderate binding affinity and potency [K = 0.85 M and K = 5.53 × 10-8 M]. The top 2 drugs primarily interact with conserved residues (ASP135, LEU209, GLY221, ALA225, and THR140) as in agonists, unlike the antagonist. The top 2 drugs, upon binding to the 5HTR modify the helices VI, V, and III and shift the RMSD 2.48 Å and 3.07 Å. LEU209 forms a latch with residues 207-214 (forms a lid) in the 5HTR receptor, which enhances agonist binding and prevents drug escape. Methylergonovine and Cabergoline interact more stongly with ALA225 than the antagonist. The post-MD analysis of Cabergoline suggests a better MM/GBSA value (-89.21 kcal/mol) than Methylergonovine (-63.54 kcal/mol). In this study, Cabergoline and Methylergonovine's agonistic mechanism and solid binding properties suggest their strong role in regulating the 5HTR and might target drug-resistant epilepsy.
Topics: Humans; Cabergoline; Methylergonovine; Drug Repositioning; Molecular Dynamics Simulation; Epilepsy
PubMed: 37302343
DOI: 10.1016/j.eplepsyres.2023.107168 -
JAMA Network Open May 2024
Topics: Humans; Diabetes Mellitus, Type 2; Glucagon-Like Peptide-1 Receptor; Obesity; Male; Female; Middle Aged; Hypoglycemic Agents; Aged; Adult
PubMed: 38787563
DOI: 10.1001/jamanetworkopen.2024.13172 -
Bioorganic & Medicinal Chemistry Letters Oct 2023G protein-coupled receptor 3 (GPR3) is an orphan receptor potentially involved in many important physiological processes such as drug abuse, neuropathic pain, and...
G protein-coupled receptor 3 (GPR3) is an orphan receptor potentially involved in many important physiological processes such as drug abuse, neuropathic pain, and anxiety and depression related disorders. Pharmacological studies of GPR3 have been limited due to the restricted number of known agonists and inverse agonists for this constitutively active receptor. In this medicinal chemistry study, we report the discovery of GPR3 agonists based off the diphenyleneiodonium (DPI) scaffold. The most potent full agonist was the 3-trifluoromethoxy analog (32) with an EC of 260 nM and 90% efficacy compared to DPI. Investigation of a homology model of GPR3 from multiple sequence alignment resulted in the finding of a binding site rich in potential π-π and π-cation interactions stabilizing DPI-scaffold agonists. MMGBSA free energy analysis showed a good correlation with trends in observed ECs. DPI analogs retained the same high receptor selectivity for GPR3 over GPR6 and GPR12 as observed with DPI. Collectively, the DPI analog series shows that order of magnitude improvements in potency with the scaffold were attainable; however, attempts to replace the iodonium ion to make the scaffold more druggable failed.
Topics: Receptors, G-Protein-Coupled; Drug Inverse Agonism; Onium Compounds; Binding Sites
PubMed: 37541631
DOI: 10.1016/j.bmcl.2023.129427 -
ChemMedChem Feb 2021TGR5, a G-protein-coupled receptor (GPCR), plays an important role in several physiological functions. TGR5 activation through bile acids induces an increase in energy...
TGR5, a G-protein-coupled receptor (GPCR), plays an important role in several physiological functions. TGR5 activation through bile acids induces an increase in energy expenditure. Therefore, synthetic TGR5 ligands could be useful for the treatment of obesity or dyslipidemia. In this study, we designed and synthesized a set of TGR5 ligands with a 5,6,7,8-tetrahydro-5,5,8,8-tetramethylnaphthalene (TMN) skeleton, and evaluated their TGR5 agonistic activity. We also investigated the selectivity of the synthesized compounds for TGR5 relative to the farnesoid X receptor (FXR) and retinoic acid receptor (RAR). Our results show that compound 4 b [N-(2-chlorophenyl)-5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenecarboxamide] exhibited potent TGR5 agonist activity with an IC value of 8.4 nM without significant cytotoxicity. In addition, compound 4 b showed only slight agonistic activity toward FXR and RAR at 1 μM treatment. These data indicate that compound 4 b is a selective TGR5 agonist, and could be a promising therapeutic agent for dyslipidemia.
Topics: Dose-Response Relationship, Drug; Drug Development; Humans; Ligands; Molecular Structure; Receptors, G-Protein-Coupled; Structure-Activity Relationship
PubMed: 32969181
DOI: 10.1002/cmdc.202000567 -
Scientific Reports Sep 2020Proper determination of agonist efficacy is indispensable in the evaluation of agonist selectivity and bias to activation of specific signalling pathways. The...
Proper determination of agonist efficacy is indispensable in the evaluation of agonist selectivity and bias to activation of specific signalling pathways. The operational model (OM) of pharmacological agonism is a useful means for achieving this goal. Allosteric ligands bind to receptors at sites that are distinct from those of endogenous agonists that interact with the orthosteric domain on the receptor. An allosteric modulator and an orthosteric agonist bind simultaneously to the receptor to form a ternary complex, where the allosteric modulator affects the binding affinity and operational efficacy of the agonist. Allosteric modulators are an intensively studied group of receptor ligands because of their selectivity and preservation of physiological space-time pattern of the signals they modulate. We analysed the operational model of allosterically-modulated agonism (OMAM) including modulation by allosteric agonists. Similar to OM, several parameters of OMAM are inter-dependent. We derived equations describing mutual relationships among parameters of the functional response and OMAM. We present a workflow for the robust fitting of OMAM to experimental data using derived equations.
Topics: Allosteric Regulation; Animals; Drug Synergism; Humans; Kinetics; Ligands; Protein Binding; Receptors, G-Protein-Coupled
PubMed: 32879329
DOI: 10.1038/s41598-020-71228-y