The whole-body DWIBS protocol provided a fast whole-body examination with high specificity and NPV. One major bias of the study was the inclusion of patients with diffuse disease and advanced disease stage and the heterogeneity of the neoplastic diseases included.
Serotonin receptors play central roles in neuromodulation and are critical drug targets for psychiatric disorders. Optical control of serotonin receptor subtypes has the potential to greatly enhance our understanding of the spatiotemporal dynamics of receptor function. While other neuromodulatory receptors have been successfully rendered photoswitchable, reversible photocontrol of serotonin receptors has not been achieved, representing a major gap in GPCR photopharmacology. Herein, we develop the first tools that allow for such control. Azo5HT‐2 shows light‐dependent 5‐HT2AR agonism, with greater activity in the cis‐form. Based on docking and test compound analysis, we also develop photoswitchable orthogonal, remotely‐tethered ligands (PORTLs). These BG‐Azo5HTs provide rapid, reversible, and repeatable optical control following conjugation to SNAP‐tagged 5‐HT2AR. Overall, this study provides a foundation for the broad extension of photopharmacology to the serotonin receptor family.
Dopamine is a key catecholamine in the brain and the kidney, where it is involved in a number of physiological functions such as locomotion, cognition, emotion, endocrine regulation and renal function. As a membrane impermeant hormone and neurotransmitter, dopamine is thought to signal by binding and activating dopamine receptors, members of the G protein couple receptor (GPCR) family, only on the plasma membrane. Here, using novel nanobody-based biosensors, we demonstrate for the first time that the dopamine D1 receptor (D1DR), the primary mediator of dopaminergic signaling in the brain and kidney, not only functions on the plasma membrane but becomes activated at the Golgi apparatus in the presence of its ligand. We present evidence that activation of the Golgi pool of D1DR is dependent on Organic Cation Transporter 2 (OCT2), a dopamine transporter, providing an explanation for how the membrane impermeant dopamine accesses subcellular pools of D1DR. We further demonstrate that dopamine activates Golgi-D1DR in murine striatal medium spiny neurons (MSN) and this activity depends on OCT2 function. We also introduce a new approach to selectively interrogate compartmentalized D1DR signaling by inhibiting Gas coupling, using a nanobody-based chemical recruitment system. Using this strategy, we show that Golgi-localized D1DRs regulate cAMP production and mediate local protein kinase A activation. Together, our data suggest that spatially compartmentalized signaling hubs are previously unappreciated regulatory aspects of D1DR signaling. Our data provide further evidence for the role of transporters in regulating subcellular GPCR activity.
The serotonin receptor family of G protein-coupled receptors (GPCRs) and ligand-gated ion channels play central roles in neuromodulation and are critical drug targets for the treatment of psychiatric disorders. Optical control of serotonin receptor subtypes has the potential to greatly enhance our understanding of the spatiotemporal dynamics of receptor function both at the cellular level and within neural circuits. While other neuromodulatory receptors have been successfully rendered photoswitchable, reversible photocontrol of serotonin receptors has not been achieved, representing a major gap in GPCR photopharmacology. Herein, by designing and screening a family of azobenzene-conjugated serotonin analogues, we developed the first photopharmacological tools that allow for such control. Azo5HT-2 shows light-dependent 5-HT2AR agonism, inducing receptor-mediated calcium signaling in the light-activated cis-form. Based on computational docking and test compound analysis, we also synthesize and test photoswitchable orthogonal, remotely-tethered ligands (PORTLs). BG-Azo5HTn PORTLs provide rapid, reversible and repeatable optical control following conjugation to SNAP-tagged 5-HT2AR. Overall, this study both introduces new tools for the optical control of 5-HT2ARs and provides a foundation for the broad extension of photopharmacology to the serotonin receptor family.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.