Biased agonism describes the ability of ligands to stabilize different conformations of a GPCR linked to distinct functional outcomes and offers the prospect of designing pathway-specific drugs that avoid on-target side effects. This mechanism is usually inferred from pharmacological data with the assumption that the confounding influences of observational (that is, assay dependent) and system (that is, cell background dependent) bias are excluded by experimental design and analysis. Here we reveal that 'kinetic context', as determined by ligand-binding kinetics and the temporal pattern of receptor-signalling processes, can have a profound influence on the apparent bias of a series of agonists for the dopamine D2 receptor and can even lead to reversals in the direction of bias. We propose that kinetic context must be acknowledged in the design and interpretation of studies of biased agonism.
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http://dx.doi.org/10.1038/ncomms10842 | DOI Listing |
J Immunother Cancer
January 2025
Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri, USA
Background: Treatment with immunotherapy can elicit varying responses across cancer types, and the mechanistic underpinnings that contribute to response vrsus progression remain poorly understood. However, to date there are few preclinical models that accurately represent these disparate disease scenarios.
Methods: Using combinatorial radio-immunotherapy consisting of PD-1 blockade, IL2Rβγ biased signaling, and OX40 agonism we were able to generate preclinical tumor models with conflicting responses, where head and neck squamous cell carcinoma (HNSCC) models respond and pancreatic ductal adenocarcinoma (PDAC) progresses.
Head Neck
December 2024
Cancer Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
Background: Head and neck squamous cell carcinoma (HNSCC) presents significant treatment challenges, particularly in cases unrelated to human papillomavirus (HPV). The chemokine receptor CXCR4, interacting with its ligand CXCL12, plays a crucial role in tumor proliferation, metastasis, and treatment resistance. This study explores the therapeutic potential of engineered monomeric and dimerized CXCL12 variants (CXCL12 and CXCL12, respectively) in HNSCC and evaluates potential additive effects when combined with radiation therapy.
View Article and Find Full Text PDFPharmacol Ther
December 2024
Cancer Center and Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States. Electronic address:
G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors in humans, playing a crucial role in regulating diverse cellular processes and serving as primary drug targets. Traditional drug design has primarily focused on ligands that uniformly activate or inhibit GPCRs. However, the concept of biased agonism-where ligands selectively stabilize distinct receptor conformations, leading to unique signaling outcomes-has introduced a paradigm shift in therapeutic development.
View Article and Find Full Text PDFPharmacol Ther
December 2024
Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA 30341, United States of America; Department of Biomedical Sciences, School of Medicine, Mercer University Health Sciences Center, Mercer University, Macon, GA 31207, United States of America. Electronic address:
Free-fatty acid receptor-4 (FFA4), previously known as GPR120, is a G protein-coupled receptor (GPCR) activated by medium-to-long chain free fatty acids (FFAs), including saturated, monounsaturated, and polyunsaturated fats, many of which (e.g., omega-3 fatty acids) are critical contributors to human health and disease.
View Article and Find Full Text PDFNat Commun
December 2024
Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, USA.
The cannabinoid receptor 1 (CBR) regulates synaptic transmission in the central nervous system, but also has important roles in the peripheral organs controlling cellular metabolism. While earlier generations of brain penetrant CBR antagonists advanced to the clinic for their effective treatment of obesity, such molecules were ultimately shown to exhibit negative effects on central reward pathways that thwarted their further therapeutic development. The peripherally restricted CBR inverse agonists MRI-1867 and MRI-1891 represent a new generation of compounds that retain the metabolic benefits of CBR inhibitors while sparing the negative psychiatric effects.
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