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Franchini L, Orlandi C. Deorphanization of G Protein Coupled Receptors (GPCRs): a historical perspective. Mol Pharmacol 2024:MOLPHARM-MR-2024-000900. [PMID: 38622017 DOI: 10.1124/molpharm.124.000900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/26/2024] [Accepted: 04/01/2024] [Indexed: 04/17/2024] Open
Abstract
Counting over 800 members, G Protein Coupled Receptors (GPCRs) form the largest family of membrane receptors encoded in the human genome. Since the discovery of G proteins and GPCRs in the late 1970s and early 1980s, a significant portion of the GPCR research has been focused on identifying ligand/receptor pairs in parallel to studies related to their signaling properties. Despite significant advancements, about a fourth of the ~400 non-odorant GPCRs are still considered orphan because their natural or endogenous ligands have yet to be identified. We should consider that every GPCR was once an orphan and that endogenous ligands have often been associated with biological effects without a complete understanding of the molecular identity of their target receptors. Within this framework, this review offers a historical perspective on deorphanization processes for representative GPCRs, including Ghrelin receptor, GABAB receptor, Apelin receptor, Cannabinoid receptors, and GPR15. It explores three main scenarios encountered in deorphanization efforts and discusses key questions and methodologies employed in elucidating ligand-receptor interactions, providing insights for future research endeavors. Significance Statement Understanding how scientists have historically approached the issue of GPCR deorphanization and pairing of biologically active ligands with their cognate receptors are relevant topics in pharmacology. In fact, the biology of each GPCR, including their pathophysiological involvement, has often been uncovered only after their deorphanization, illuminating druggable targets for various diseases. Furthermore, uncovered endogenous ligands have therapeutic value as many ligands - or derivates thereof - are developed into drugs.
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Affiliation(s)
- Luca Franchini
- Department of Pharmacology and Physiology, University of Rochester Medical Center, United States
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, United States
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Di Carli MF, Gormsen LC, Chareonthaitawee P, Johnson GB, Beanlands R, DeKemp R, Schindler T, Gropler R, Kulkarni H, McNeely P, Soman P, Oz O, Zaha V, Sorensen J, Harms H, Orlandi C, Vandenbroucke E, Udelson J. Rationale and design of the RAPID-WATER-FLOW trial: Radiolabeled perfusion to identify coronary artery disease using water to evaluate responses of myocardial FLOW. J Nucl Cardiol 2024; 31:101779. [PMID: 38215598 DOI: 10.1016/j.nuclcard.2023.101779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024]
Abstract
OBJECTIVES The objective of this study was to determine the diagnostic performance of 15O-water positron emission tomography (PET) myocardial perfusion imaging to detect coronary artery disease (CAD) using the truth-standard of invasive coronary angiography (ICA) with fractional flow reserve (FFR) or instantaneous wave-Free Ratio (iFR) or coronary computed tomography angiogram (CCTA). BACKGROUND 15O-water has a very high first-pass extraction that allows accurate quantification of myocardial blood flow and detection of flow-limiting CAD. However, the need for an on-site cyclotron and lack of automated production at the point of care and relatively complex image analysis protocol has limited its clinical use to date. METHODS The RAPID WATER FLOW study is an open-label, multicenter, prospective investigation of the accuracy of 15O-water PET to detect obstructive angiographic and physiologically significant stenosis in patients with suspected CAD. The study will include the use of an automated system for producing, dosing, and injecting 15O-water and enrolling approximately 215 individuals with suspected CAD at approximately 10 study sites in North America and Europe. The primary endpoint of the study is the diagnostic sensitivity and specificity of the 15O-water PET study using the truth-standard of ICA with FFR or iFR to determine flow-limiting stenosis, or CCTA to rule out CAD and incorporating a quantitative analytic platform developed for the 15O-water PET acquisitions. Sensitivity and specificity are to be considered positive if the lower bound of the 95% confidence interval is superior to the threshold of 60% for both, consistent with prior registration studies. Subgroup analyses include assessments of diagnostic sensitivity, specificity, and accuracy in female, obese, and diabetic individuals, as well as in those with multivessel disease. All enrolled individuals will be followed for adverse and serious adverse events for up to 32 hours after the index PET scan. The study will have >90% power (one-sided test, α = 0.025) to test the hypothesis that sensitivity and specificity of 15O-water PET are both >60%. CONCLUSIONS The RAPID WATER FLOW study is a prospective, multicenter study to determine the diagnostic sensitivity and specificity of 15O-water PET as compared to ICA with FFR/iFR or CCTA. This study will introduce several novel aspects to imaging registration studies, including a more relevant truth standard incorporating invasive physiologic indexes, coronary CTA to qualify normal individuals for eligibility, and a more quantitative approach to image analysis than has been done in prior pivotal studies. CLINICAL TRIAL REGISTRATION INFORMATION Clinical-Trials.gov (#NCT05134012).
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Affiliation(s)
- Marcelo F Di Carli
- Departments of Medicine and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Lars C Gormsen
- Department of Nuclear Medicine & PET Center, Aarhus University Hospital, Denmark
| | | | | | - Rob Beanlands
- National Cardiac PET Centre, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Canada
| | - Rob DeKemp
- National Cardiac PET Centre, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Canada
| | - Thomas Schindler
- Department of Radiology, Washington University, St Louis, MO, USA
| | - Robert Gropler
- Department of Radiology, Washington University, St Louis, MO, USA
| | | | - Parren McNeely
- Department of Radiology, University of Iowa, Iowa City, IA, USA
| | - Prem Soman
- Departments of Medicine and Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Orhan Oz
- Department of Radiology, UT Southwestern, Dallas, TX, USA
| | - Vlad Zaha
- Department of Radiology, UT Southwestern, Dallas, TX, USA
| | - Jens Sorensen
- PET Center, Uppsala University Hospital, Uppsala, Sweden
| | | | | | | | - James Udelson
- Division of Cardiology and the CardioVascular Center, Tufts Medical Center, Boston, MA, USA
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Alabdali R, Franchini L, Orlandi C. G α Protein Signaling Bias at Serotonin 1A Receptor. Mol Pharmacol 2023; 104:230-238. [PMID: 37567783 PMCID: PMC10586511 DOI: 10.1124/molpharm.123.000722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/11/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Serotonin 1A receptor (5-HT1AR) is a clinically relevant target because of its involvement in several central and peripheral functions, including sleep, temperature homeostasis, processing of emotions, and response to stress. As a G protein coupled receptor (GPCR) activating numerous Gα i/o/z family members, 5-HT1AR can potentially modulate multiple intracellular signaling pathways in response to different therapeutics. Here, we applied a cell-based bioluminescence resonance energy transfer assay to quantify how ten structurally diverse 5-HT1AR agonists exert biased signaling by differentially stimulating Gα i/o/z family members. Our concentration-response analysis of the activation of each Gα i/o/z protein revealed unique potency and efficacy profiles of selected agonists when compared with the reference 5-hydroxytryptamine, serotonin. Overall, our analysis of signaling bias identified groups of ligands sharing comparable G protein activation selectivity and also drugs with unique selectivity profiles. We observed, for example, a strong bias of F-15599 toward the activation of Gα i3 that was unique among the agonists tested: we found a biased factor of +2.19 when comparing the activation of Gα i3 versus Gα i2 by F-15599, while it was -0.29 for 8-hydroxy-2-(di-n-propylamino) tetralin. Similarly, vortioxetine showed a biased factor of +1.06 for Gα z versus Gα oA, while it was -1.38 for vilazodone. Considering that alternative signaling pathways are regulated downstream of each Gα protein, our data suggest that the unique pharmacological properties of the tested agonists could result in multiple unrelated cellular outcomes. Further investigation is needed to reveal how this type of ligand bias could affect cellular responses and to illuminate the molecular mechanisms underlying therapeutic profile and side effects of each drug. SIGNIFICANCE STATEMENT: Serotonin 1a receptor (5-HT1AR) activates several members of the Gi/o/z protein family. Here, we examined ten structurally diverse and clinically relevant agonists acting on 5-HT1AR and identified distinctive bias patterns among G proteins. Considering the diversity of their intracellular effectors and signaling properties, this data reveal novel mechanisms underlying both therapeutic and undesirable effects.
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Affiliation(s)
- Rana Alabdali
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY
| | - Luca Franchini
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY
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Franchini L, Orlandi C. Probing the orphan receptors: Tools and directions. Prog Mol Biol Transl Sci 2023; 195:47-76. [PMID: 36707155 DOI: 10.1016/bs.pmbts.2022.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The endogenous ligands activating a large fraction of the G Protein Coupled Receptor (GPCR) family members have yet to be identified. These receptors are commonly labeled as orphans (oGPCRs), and because of the absence of available pharmacological tools they are currently understudied. Nonetheless, genome wide association studies, together with research using animal models identified many physiological functions regulated by oGPCRs. Similarly, mutations in some oGPCRs have been associated with rare genetic disorders or with an increased risk of developing pathologies. The once underestimated pharmacological potential of targeting oGPCRs is increasingly being exploited by the development of novel tools to understand their biology and by drug discovery endeavors aimed at identifying new modulators of their activity. Here, we summarize recent advancements in the field of oGPCRs and future directions.
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Affiliation(s)
- Luca Franchini
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, United States
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, United States.
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Fu W, Franchini L, Orlandi C. Comprehensive Spatial Profile of the Orphan G Protein Coupled Receptor GPRC5B Expression in Mouse Brain. Front Neurosci 2022; 16:891544. [PMID: 35812210 PMCID: PMC9259939 DOI: 10.3389/fnins.2022.891544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Orphan G Protein Coupled Receptors (GPCRs) are GPCRs whose endogenous ligands are unknown or still debated. Due to the lack of pharmacological modulators, the physiological function of orphan GPCRs is understudied. However, relevant physiological roles associated with orphan GPCRs have been revealed by analysis of animal models and genome wide association studies illuminating an untapped potential for drug discovery. G Protein Coupled Receptor class C Group 5 Member B (GPRC5B) is among the most expressed GPCRs in the central nervous system. Thus, the expression profiling of GPRC5B is an essential step toward understanding GPRC5B function in health and disease. In this study, we generated new GPRC5B polyclonal antibodies and investigated the expression levels of GPRC5B across different organs and brain regions. We identified high levels of GPRC5B glycosylation both in transfected cells and in mouse brain. Moreover, in situ hybridization imaging analysis indicated that Gprc5b was expressed at the highest level in olfactory bulb, hippocampus, cerebellum, and pons. To dissect expression within various neuronal populations, we conducted a comprehensive spatial profiling of Gprc5b across excitatory and inhibitory neuronal types in medial prefrontal cortex, motor cortex, hippocampal regions, hypothalamus, and cerebellum. Overall, we discovered that GABAergic neurons displayed higher Gprc5b expression levels than glutamatergic neurons in most of the analyzed regions with the important exception of the hippocampal dentate gyrus. Overall, the expression analysis of GPRC5B in mouse brain will guide functional studies ultimately positioning GPRC5B in pathophysiological mechanisms and drug discovery.
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Fredi M, Orlandi C, Salvi M, Bazzani C, Nalli C, Andreoli L, Franceschini F. POS0117 DISEASE ACTIVITY AND CLINICAL REMISSION IN SYSTEMIC LUPUS ERYTHEMATOSUS: COMPARISON BETWEEN PATIENT AND PHYSICIAN PERSPECTIVES BY MEANS OF PATIENT REPORTED OUTCOMES (PROs). Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.2761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BackgroundIn daily clinical practice, it is not rare to observe a relevant discordance between patient’s global assessment (PGA) and physician’s global assessment (PhGA), because of different illness perceptions.ObjectivesTo evaluate the presence of PGA/PhGA discrepancy in patients with Systemic Lupus Erythematosus (SLE) who achieved clinical remission and to evaluate how this discrepancy affects PROs. In addition, to explore whether this discordance could be influenced by the presence of additional elements affecting patients’ quality of life, such as comorbidities, sleep disturbances and psycho-emotional factors.MethodsOur study included adult SLE patients consecutively followed in a single Lupus Clinic from March to July 2021 fulfilling at minimum the definition of clinical remission of treatment according to Zen et al. (1) (cSLEDAI=0, corticosteroids ≤5mg/die, stable dosage of DMARD). Medical records including demographic data, clinical characteristics and outcomes measures were collected. Pain assessment, PGA and PhGA were rated on a visual analogue scale (0-100 mm) on the same day of the clinical evaluation. To analyse the discrepancy between PGA and PhGA, the [PGA-PhGA] variable was calculated, considering as discordant a difference ≥ 25 mm as previously proposed (2) All the subjects completed the following questionnaires: Health Assessment Questionnaire (HAQ), SF36 Health Survey, State-Trait Anxiety Inventory (STAI-Y1/Y2), Self-rating Depression Scale (SDS Zung) and Insomnia Severity Index. Statistical analysis was performed to compare concordant and discordant groups.ResultsThe study included 106 patients, (93 women, 13 men) with a median age of 48 (41-58) and a median SLE duration 227 months (124-330). At the last evaluation median SLEDAI was 0 (0-2) and median SLICC was 1 (0-1). According to Zen definitions of remission, 51 patients (48%) and 20 (19%) also fulfilled the criteria of clinical remission off corticosteroids and complete remission respectively. Nevertheless, in 24 patients (22,7%) [PGA-PhGA]≥25. Patients in the discordant group were older (median 58 years, IQR 49-62 vs 46, IQR 39-57; p=0,0043) and less frequently achieved the definition of clinical remission off corticosteroids (n=4, 16,7% vs n=47, 57,3%,p<0.001;OR6,7; CI95%2.1-21) than concordant. No differences were found in gender, SLE duration, serology, disease activity or damage and other treatment. Data about differences in PROs between two groups are reported in Table 1: discordant patients had a worse performance in all the PROs included. At multivariate analysis SF-36 Physical Component Summary (PCS) resulted associated with [PGA-PhGA] ≥25 (p=<0,0001).Table 1.Data are expressed as median and interquartile range (IQR) and compared using Mann-Whitney test.TOTAL N=106 (%)CONCORDANT GROUP (PGA-PhGA) <25N=82 (%)DISCORDANT GROUP (PGA-PhGA) ≥25N=24 (%)P valueVAS-pain [0-100],10 (0-30)10 (0-20)50 (40-60)< 0.001SF-36 Physical Component Summary (PCS)50 (37,5-53)51 (44-54)30 (27,5-39)< 0.001SF-36 Mental Component Summary (PCS)48 (38-55)51 (40-55)40 (36-48,5)0,015STAI-Y1 [20-80]35 (30-47)33 (28,3-45,5)42 (36,5-49,5)0,013STAI-Y2 [20-80]37 (30-46)35 (29-43,3)42 (36-46)0,021Test di Zung [20-80]34,5 (29-43)33 (27-43)39 (35,5-44,5)0,008Insomnia severity index [0-28]6 (2-12)4 (1-9)9 (6,8-14,3)<0,0001HAQ0 (0-0,1)0 (0-0)0,38 (0-0,6)< 0.001ConclusionIn our study we found that, even in patients considered in remission, in more than 20% of patients there is a considerable discordance between the global disease assessment reported by patients and their physicians. Patients that had a higher PGA also presented worse score at PROs. Our data seems to confirm that potential causes for discordance could be more related to the presence of non-inflammatory processes, depression, or anxiety than clinical manifestations or damage related to SLE.References[1]Zen et al. Ann. Rheum. Dis. 2015;74:2117–2122[2]Neville C, et al. J Rheumatol 2000;27:675-9Disclosure of InterestsNone declared
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Franchini L, Watkins L, Orlandi C. Implementation of a method for analysis of Gi/o‐coupled orphan GPCR signaling. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.l7807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Lyndsay Watkins
- Integrated Research and Development LaboratoryMarshfield Clinic Research InstituteMarshfieldWI
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Packard RRS, Cooke CD, Van Train KF, Votaw JR, Sayre JW, Lazewatsky JL, Champagne KM, Orlandi C, Garcia EV, Maddahi J. Development, diagnostic performance, and interobserver agreement of a 18F-flurpiridaz PET automated perfusion quantitation system. J Nucl Cardiol 2022; 29:698-708. [PMID: 32895856 PMCID: PMC7936994 DOI: 10.1007/s12350-020-02335-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 01/11/2023]
Abstract
BACKGROUND Computerized methodologies standardize the myocardial perfusion imaging (MPI) interpretation process. METHODS To develop an automated relative perfusion quantitation approach for 18F-flurpiridaz, PET MPI studies from all phase III trial participants of 18F-flurpiridaz were divided into 3 groups. Count distributions were obtained in N = 40 normal patients undergoing pharmacological or exercise stress. Then, N = 90 additional studies were selected in a derivation group. Following receiver operating characteristic curve analysis, various standard deviations below the mean normal were used as cutoffs for significant CAD, and interobserver variability determined. Finally, diagnostic performance was compared between blinded visual readers and blinded derivations of automated relative quantitation in the remaining N = 548 validation patients. RESULTS Both approaches yielded comparable accuracies for the detection of global CAD, reaching 71% and 72% by visual reads, and 72% and 68% by automated relative quantitation, when using CAD ≥ 70% or ≥ 50% stenosis for significance, respectively. Similar results were observed when analyzing individual coronary territories. In both pharmacological and exercise stress, automated relative quantitation demonstrated significantly more interobserver agreement than visual reads. CONCLUSIONS Our automated method of 18F-flurpiridaz relative perfusion analysis provides a quantitative, objective, and highly reproducible assessment of PET MPI in normal and CAD subjects undergoing either pharmacological or exercise stress.
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Affiliation(s)
- René R Sevag Packard
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
| | - C David Cooke
- Department of Radiology and Imaging Sciences, Emory University Hospital, Emory University School of Medicine, Atlanta, GA, USA
- Syntermed, Inc., Atlanta, GA, USA
| | | | - John R Votaw
- Department of Radiology and Imaging Sciences, Emory University Hospital, Emory University School of Medicine, Atlanta, GA, USA
| | - James W Sayre
- Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles, CA, USA
| | | | | | | | - Ernest V Garcia
- Department of Radiology and Imaging Sciences, Emory University Hospital, Emory University School of Medicine, Atlanta, GA, USA
| | - Jamshid Maddahi
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Nuclear Medicine Clinic, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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Longo M, Cora S, Hussain S, Bignotto M, Orlandi C, Satariano N, Francescon P. Comparison of detectors performances in small field dosimetry of Versa HD flattened and flattening filter free beams. Phys Med 2021. [DOI: 10.1016/s1120-1797(22)00154-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Watkins LR, Orlandi C. In vitro profiling of orphan G protein coupled receptor (GPCR) constitutive activity. Br J Pharmacol 2021; 178:2963-2975. [PMID: 33784795 DOI: 10.1111/bph.15468] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 03/18/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE Members of the GPCR family are targeted by a significant fraction of the available FDA-approved drugs. However, the physiological role and pharmacological properties of many GPCRs remain unknown, representing untapped potential in drug design. Of particular interest are ~100 less-studied GPCRs known as orphans because their endogenous ligands are unknown. Intriguingly, disease-causing mutations identified in patients, together with animal studies, have demonstrated that many orphan receptors play crucial physiological roles and, thus, represent attractive drug targets. EXPERIMENTAL APPROACH The majority of deorphanized GPCRs demonstrate coupling to Gi/o . However, a limited number of techniques allow the detection of intrinsically small constitutive activity associated with Gi/o protein activation, which represents a significant barrier in our ability to study orphan GPCR signalling. Using luciferase reporter assays, we effectively detected constitutive Gs , Gq and G12/13 protein signalling by unliganded receptors and introducing various G protein chimeras, we provide a novel, highly sensitive tool capable of identifying Gi/o coupling in unliganded orphan GPCRs. KEY RESULTS Using this approach, we measured the constitutive activity of the entire class C GPCR family that includes eight orphan receptors and a subset of 20 prototypical class A GPCR members, including 11 orphans. Excitingly, this approach illuminated the G protein coupling profile of eight orphan GPCRs (GPR22, GPR137b, GPR88, GPR156, GPR158, GPR179, GPRC5D and GPRC6A) previously linked to pathophysiological processes. CONCLUSION AND IMPLICATIONS We provide a new platform that could be utilized in ongoing studies in orphan receptor signalling and de-orphanization efforts.
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Affiliation(s)
- Lyndsay R Watkins
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, USA
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, USA
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Packard RRS, Lazewatsky JL, Orlandi C, Maddahi J. Diagnostic Performance of PET Versus SPECT Myocardial Perfusion Imaging in Patients with Smaller Left Ventricles: A Substudy of the 18F-Flurpiridaz Phase III Clinical Trial. J Nucl Med 2020; 62:849-854. [PMID: 33246979 DOI: 10.2967/jnumed.120.252007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/04/2020] [Indexed: 12/16/2022] Open
Abstract
The performance of SPECT myocardial perfusion imaging (MPI) may deteriorate in smaller hearts, primarily because of the lower resolution of conventional Anger cameras. 18F-flurpiridaz is a novel PET MPI agent with superior image and defect resolution. We sought to determine the diagnostic performance of 99mTc-labeled SPECT MPI compared with 18F-flurpiridaz PET MPI according to left ventricle (LV) size. Methods: We conducted a substudy of the phase III clinical trial of flurpiridaz (n = 750) and stratified diagnostic performance according to the median PET LV end-diastolic volume (LVEDV), with smaller LVs defined as having an LVEDV of less than 113 mL (n = 369) and larger LVs defined as having an LVEDV of at least 113 mL (n = 381). Images were interpreted by the majority rule of 3 independent masked readers. The reference standard was quantitative invasive angiography, with at least 50% stenosis in at least 1 coronary artery considered significant. Results: SPECT performance decreased significantly from an area under the curve (AUC) of 0.75 in larger LVs to 0.67 in smaller LVs (P = 0.03), whereas PET performance was similar in larger and smaller LVs (AUC, 0.79 vs. 0.77, P = 0.49). Accordingly, in smaller LVs, PET had a higher AUC (0.77) than the SPECT AUC (0.67) (P < 0.0001), a phenomenon driven by female patients (P < 0.0001). In smaller LVs, there was a degradation of SPECT sensitivity that was highly significant (P < 0.001), whereas there was no significant change in PET sensitivity according to LV size (P = 0.07). Overall, PET had significantly higher sensitivity than SPECT in both smaller LVs (67% vs. 43%, P < 0.001) and larger LVs (76% vs. 61%, P < 0.001). The specificities of PET and SPECT were similar in larger LVs (76% vs. 83%, P = 0.11). Although SPECT specificity improved in smaller compared with larger LVs (90% vs. 83%, P = 0.03), the PET specificity did not change with LV size (76% vs. 76%, P = 0.9). Conclusion: The diagnostic performance of 18F-flurpiridaz PET MPI is not affected by LV size and is superior to SPECT MPI in patients with smaller LVs, highlighting the importance of appropriate test selection in these patients.
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Affiliation(s)
| | | | - Cesare Orlandi
- Lantheus Medical Imaging, North Billerica, Massachusetts; and
| | - Jamshid Maddahi
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California.,Nuclear Medicine Clinic, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California
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Kessler L, Schlitter AM, Krönke M, von Werder A, Tauber R, Maurer T, Robinson S, Orlandi C, Herz M, Yousefi BH, Nekolla SG, Schwaiger M, Eiber M, Rischpler C. First Experience Using 18F-Flubrobenguane PET Imaging in Patients with Suspected Pheochromocytoma or Paraganglioma. J Nucl Med 2020; 62:479-485. [PMID: 32859709 DOI: 10.2967/jnumed.120.248021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/20/2020] [Indexed: 11/16/2022] Open
Abstract
Pheochromocytomas and paragangliomas are a rare tumor entity originating from adrenomedullary chromaffin cells in the adrenal medulla or in sympathetic, paravertebral ganglia outside the medulla. Small lesions are especially difficult to detect by conventional CT or MRI and even by SPECT with the currently available radiotracers (e.g., metaiodobenzylguanidine [MIBG]). The novel PET radiotracer 18F-flubrobenguane could change the diagnostic paradigm in suspected pheochromocytomas and paragangliomas because of its homology with MIBG and the general advantages of PET imaging. The aim of this retrospective analysis was to evaluate 18F-flubrobenguane in pheochromocytomas and paragangliomas and to investigate the biodistribution in patients. Methods: Twenty-three patients with suspected pheochromocytoma or paraganglioma underwent PET/CT or PET/MRI at 63 ± 24 min after injection of 256 ± 33 MBq of 18F-flubrobenguane. The SUVmean and SUVmax of organs were measured with spheric volumes of interest. Threshold-segmented volumes of interest were used to measure the SUVmean or SUVmax of the tumor lesions. One reader evaluated all cross-sectional imaging datasets (CT or MRI) separately, as well as the PET hybrid datasets, and reported the lesion number and size. The diagnostic certainty for a positive lesion was scored on a 3-point scale. Results: 18F-flubrobenguane showed a reproducible, stable biodistribution, with the highest SUVmax and SUVmean being in the thyroid gland (30.3 ± 2.2 and 22.5 ± 1.6, respectively), pancreas (12.2 ± 0.8 and 9.5 ± 0.7, respectively), and tumor lesions (16.8 ± 1.7 and 10.1 ± 1.1, respectively) and the lowest SUVmax and SUVmean being in muscle (1.1 ± 0.06 and 0.7 ± 0.04, respectively) and the lung (2.5 ± 0.17 and 1.85 ± 0.13, respectively). In a subgroup analysis, a significantly higher average SUVmean was seen for both pheochromocytoma and paraganglioma than for healthy adrenal glands (11.9 ± 2.0 vs. 9.9 ± 1.5 vs. 3.7 ± 0.2, respectively). In total, 47 lesions were detected. The reader reported more and smaller lesions with higher certainty in PET hybrid imaging than in conventional imaging; however, statistical significance was not reached. Of the 23 (23/47, 49%) lesions smaller than 1 cm, 61% (14/23) were found on hybrid imaging only. Conclusion: Our preliminary data suggest 18F-flubrobenguane PET to be a new, effective staging tool for patients with suspected pheochromocytoma or paraganglioma. Major advantages are the fast acquisition and high spatial resolution of PET imaging and the intense uptake in tumor lesions, facilitating detection. Further studies are warranted to define the role of 18F-flubrobenguane PET, particularly in comparison to standard diagnostic procedures such as MRI or 123I-MIBG SPECT/CT.
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Affiliation(s)
- Lukas Kessler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Anna M Schlitter
- Institute of Pathology, Technical University Munich, Munich, Germany
| | - Markus Krönke
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Alexander von Werder
- Department of Gastroenterology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Robert Tauber
- Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Tobias Maurer
- Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Simon Robinson
- Discovery Research, Lantheus Medical Imaging, North Billerica, Massachusetts; and
| | - Cesare Orlandi
- Discovery Research, Lantheus Medical Imaging, North Billerica, Massachusetts; and
| | - Michael Herz
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Behrooz H Yousefi
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Nuclear Medicine, Philipps University of Marburg, Marburg, Germany
| | - Stephan G Nekolla
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Markus Schwaiger
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Matthias Eiber
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Christoph Rischpler
- Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany .,Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
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13
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Abstract
G protein coupled receptors (GPCRs) are the main mediators of signal transduction in the central nervous system. Therefore, it is not surprising that many GPCRs have long been investigated for their role in the development of anxiety and mood disorders, as well as in the mechanism of action of antidepressant therapies. Importantly, the endogenous ligands for a large group of GPCRs have not yet been identified and are therefore known as orphan GPCRs (oGPCRs). Nonetheless, growing evidence from animal studies, together with genome wide association studies (GWAS) and post-mortem transcriptomic analysis in patients, pointed at many oGPCRs as potential pharmacological targets. Among these discoveries, we summarize in this review how emotional behaviors are modulated by the following oGPCRs: ADGRB2 (BAI2), ADGRG1 (GPR56), GPR3, GPR26, GPR37, GPR50, GPR52, GPR61, GPR62, GPR88, GPR135, GPR158, and GPRC5B.
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Affiliation(s)
| | - Cesare Orlandi
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY 14642, USA;
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14
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Wang D, Stoveken HM, Zucca S, Dao M, Orlandi C, Song C, Masuho I, Johnston C, Opperman KJ, Giles AC, Gill MS, Lundquist EA, Grill B, Martemyanov KA. Using
C. elegans
Genetics to Identify Regulators of μ‐Opioid Receptor Signaling. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.04078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Zelt JGE, Mielniczuk LM, Orlandi C, Robinson S, Hadizad T, Walter O, Garrard L, Beanlands RSB, deKemp RA. Correction to: PET imaging of sympathetic innervation with [ 18F]Flubrobenguane vs [ 11C]mHED in a patient with ischemic cardiomyopathy. J Nucl Cardiol 2020; 27:702. [PMID: 31898001 DOI: 10.1007/s12350-019-02018-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
At time of initial publication, the USAN Council had assigned the generic name for LMI1195 as Flurobenguan. However, the Council has since changed and finalized this compound name as Flubrobenguane which is recommended as the generic name to be used in the future.
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Affiliation(s)
- Jason G E Zelt
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Lisa M Mielniczuk
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | | | | | - Tayebeh Hadizad
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
| | - Olga Walter
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
| | - Linda Garrard
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
| | - Rob S B Beanlands
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Robert A deKemp
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.
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16
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Francescon P, Kilby W, Noll JM, Satariano N, Orlandi C. Small field dosimetry correction factors for circular and MLC shaped fields with the CyberKnife M6 System: evaluation of the PTW 60023 microSilicon detector. Phys Med Biol 2020; 65:01NT01. [PMID: 31829983 DOI: 10.1088/1361-6560/ab6154] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The PTW 60023 microSilicon is a new unshielded diode detector for small-field photon dosimetry. It provides improved water equivalence and a slightly larger sensitive region diameter in comparison to previous diode detectors in this range. In this study we evaluated the correction factors relevant to commissioning a CyberKnife System with this detector by Monte Carlo simulation and verified this data by multi-detector measurement comparison. The correction factors required for output factor determination were substantially closer to unity at small field sizes than for previous diode versions (e.g. [Formula: see text] = 0.981 at 5 mm field size which compares with corrections of 5%-6% with other stereotactic diodes). Because of these differences we recommend that corrections to small field output factor measurements generated specifically for the microSilicon detector rather than generic data taken from other diode types should be used with this new detector. For depth-dose measurements the microSilicon is consistent with a microDiamond detector to <1% (global), except at depths <10 mm where the diode gives a significantly lower measurement, by 6%-8% at the surface. For profile measurements, the microSilicon requires negligible corrections except in the low dose region outside the beam, where it underestimates off-axis-ratio (OAR) for small fields and overestimates for large fields. Where this effect is most noticeable at the largest field size and depth (115 mm × 100 mm and 300 mm depth) the microSilicon overestimates OAR by 2.3% (global) in the profile tail. This is consistent with other unshielded diodes.
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Affiliation(s)
- P Francescon
- Department of Radiation Oncology, Ospedale Di Vicenza, I-36100 Vicenza, Italy
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17
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Orlandi C, Omori Y, Wang Y, Cao Y, Ueno A, Roux MJ, Condomitti G, de Wit J, Kanagawa M, Furukawa T, Martemyanov KA. Transsynaptic Binding of Orphan Receptor GPR179 to Dystroglycan-Pikachurin Complex Is Essential for the Synaptic Organization of Photoreceptors. Cell Rep 2020; 25:130-145.e5. [PMID: 30282023 PMCID: PMC6203450 DOI: 10.1016/j.celrep.2018.08.068] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 08/16/2018] [Accepted: 08/23/2018] [Indexed: 01/05/2023] Open
Abstract
Establishing synaptic contacts between neurons is paramount for nervous system function. This process involves transsynaptic interactions between a host of cell adhesion molecules that act in cooperation with the proteins of the extracellular matrix to specify uniquephysiological propertiesofindividual synaptic connections. However, understanding of the molecular mechanisms that generate functional diversity in an input-specific fashion is limited. In this study, we identify that major components of the extracellular matrix proteins present in the synaptic cleft—members oftheheparansulfateproteoglycan (HSPG) family—associate with the GPR158/179 group of orphan receptors. Using the mammalian retina as a model system, we demonstrate that the HSPG member Pikachurin, released by photoreceptors, recruits a key post-synaptic signaling complex of downstream ON-bipolar neurons in coordination with the presynaptic dystroglycan glycoprotein complex. We further demonstrate that this transsynaptic assembly plays an essential role in synaptic transmission of photoreceptor signals. Orlandi et al. identify transsynaptic assembly at photoreceptor synapses involving pre-synaptic dystrophindystroglycan complex and the postsynaptic orphan receptor GPR179 bridged by HSPG protein Pikachurin in the cleft and demonstrate its role in shaping transmission of photoreceptor signals.
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Affiliation(s)
- Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Yoshihiro Omori
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Yuchen Wang
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Yan Cao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Akiko Ueno
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Michel J Roux
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Centre National de la Recherche Scientifique, UMR7104, INSERM, U1258, Illkirch, France
| | - Giuseppe Condomitti
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Herestraat 49, 3000 Leuven, Belgium
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Herestraat 49, 3000 Leuven, Belgium
| | - Motoi Kanagawa
- Division of Molecular Brain Science, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan
| | - Takahisa Furukawa
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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18
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Dunn HA, Orlandi C, Martemyanov KA. Beyond the Ligand: Extracellular and Transcellular G Protein-Coupled Receptor Complexes in Physiology and Pharmacology. Pharmacol Rev 2019; 71:503-519. [PMID: 31515243 DOI: 10.1124/pr.119.018044] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
G protein-coupled receptors (GPCRs) remain one of the most successful targets of U.S. Food and Drug Administration-approved drugs. GPCR research has predominantly focused on the characterization of the intracellular interactome's contribution to GPCR function and pharmacology. However, emerging evidence uncovers a new dimension in the biology of GPCRs involving their extracellular and transcellular interactions that critically impact GPCR function and pharmacology. The seminal examples include a variety of adhesion GPCRs, such as ADGRLs/latrophilins, ADGRBs/brain angiogenesis inhibitors, ADGRG1/GPR56, ADGRG6/GPR126, ADGRE5/CD97, and ADGRC3/CELSR3. However, recent advances have indicated that class C GPCRs that contain large extracellular domains, including group III metabotropic glutamate receptors (mGluR4, mGluR6, mGluR7, mGluR8), γ-aminobutyric acid receptors, and orphans GPR158 and GPR179, can also participate in this form of transcellular regulation. In this review, we will focus on a variety of identified extracellular and transcellular GPCR-interacting partners, including teneurins, neurexins, integrins, fibronectin leucine-rich transmembranes, contactin-6, neuroligin, laminins, collagens, major prion protein, amyloid precursor protein, complement C1q-likes, stabilin-2, pikachurin, dystroglycan, complement decay-accelerating factor CD55, cluster of differentiation CD36 and CD90, extracellular leucine-rich repeat and fibronectin type III domain containing 1, and leucine-rich repeat, immunoglobulin-like domain and transmembrane domains. We provide an account on the diversity of extracellular and transcellular GPCR complexes and their contribution to key cellular and physiologic processes, including cell migration, axon guidance, cellular and synaptic adhesion, and synaptogenesis. Furthermore, we discuss models and mechanisms by which extracellular GPCR assemblies may regulate communication at cellular junctions. SIGNIFICANCE STATEMENT: G protein-coupled receptors (GPCRs) continue to be the prominent focus of pharmacological intervention for a variety of human pathologies. Although the majority of GPCR research has focused on the intracellular interactome, recent advancements have identified an extracellular dimension of GPCR modulation that alters accepted pharmacological principles of GPCRs. Herein, we describe known endogenous allosteric modulators acting on GPCRs both in cis and in trans.
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Affiliation(s)
- Henry A Dunn
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida
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19
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Zelt JGE, Mielniczuk LM, Orlandi C, Robinson S, Hadizad T, Walter O, Garrard L, Beanlands RSB, deKemp RA. PET imaging of sympathetic innervation with [ 18F]Flurobenguan vs [ 11C]mHED in a patient with ischemic cardiomyopathy. J Nucl Cardiol 2019; 26:2151-2153. [PMID: 30456496 DOI: 10.1007/s12350-018-01527-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 11/24/2022]
Affiliation(s)
- Jason G E Zelt
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Lisa M Mielniczuk
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | | | | | - Tayebeh Hadizad
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
| | - Olga Walter
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
| | - Linda Garrard
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
| | - Rob S B Beanlands
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Robert A deKemp
- Division of Cardiology, Department of Medicine, Molecular Function and Imaging Program, The National Cardiac PET Centre, University of Ottawa Heart Institute and University of Ottawa, 40 Ruskin Street, Ottawa, ON, K1Y 4W7, Canada.
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20
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Sutton LP, Muntean BS, Ostrovskaya O, Zucca S, Dao M, Orlandi C, Song C, Xie K, Martemyanov KA. NF1-cAMP signaling dissociates cell type-specific contributions of striatal medium spiny neurons to reward valuation and motor control. PLoS Biol 2019; 17:e3000477. [PMID: 31600280 PMCID: PMC6805008 DOI: 10.1371/journal.pbio.3000477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 10/22/2019] [Accepted: 09/17/2019] [Indexed: 12/11/2022] Open
Abstract
The striatum plays a fundamental role in motor learning and reward-related behaviors that are synergistically shaped by populations of D1 dopamine receptor (D1R)- and D2 dopamine receptor (D2R)-expressing medium spiny neurons (MSNs). How various neurotransmitter inputs converging on common intracellular pathways are parsed out to regulate distinct behavioral outcomes in a neuron-specific manner is poorly understood. Here, we reveal that distinct contributions of D1R-MSNs and D2R-MSNs towards reward and motor behaviors are delineated by the multifaceted signaling protein neurofibromin 1 (NF1). Using genetic mouse models, we show that NF1 in D1R-MSN modulates opioid reward, whereas loss of NF1 in D2R-MSNs delays motor learning by impeding the formation and consolidation of repetitive motor sequences. We found that motor learning deficits upon NF1 loss were associated with the disruption in dopamine signaling to cAMP in D2R-MSN. Restoration of cAMP levels pharmacologically or chemogenetically rescued the motor learning deficits seen upon NF1 loss in D2R-MSN. Our findings illustrate that multiplex signaling capabilities of MSNs are deployed at the level of intracellular pathways to achieve cell-specific control over behavioral outcomes. A mouse genetic study reveals that the multifaceted signaling protein neurofibromin (known for its role in the human genetic disease neurofibromatosis type 1) plays a key role in differential routing of motor and reward signals in populations of striatal medium spiny neurons.
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Affiliation(s)
- Laurie P. Sutton
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Brian S. Muntean
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Olga Ostrovskaya
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Stefano Zucca
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Maria Dao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Chenghui Song
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Keqiang Xie
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
| | - Kirill A. Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, United States of America
- * E-mail:
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21
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Wang D, Stoveken HM, Zucca S, Dao M, Orlandi C, Song C, Masuho I, Johnston C, Opperman KJ, Giles AC, Gill MS, Lundquist EA, Grill B, Martemyanov KA. Genetic behavioral screen identifies an orphan anti-opioid system. Science 2019; 365:1267-1273. [PMID: 31416932 DOI: 10.1126/science.aau2078] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 02/22/2019] [Accepted: 08/05/2019] [Indexed: 12/12/2022]
Abstract
Opioids target the μ-opioid receptor (MOR) to produce unrivaled pain management, but their addictive properties can lead to severe abuse. We developed a whole-animal behavioral platform for unbiased discovery of genes influencing opioid responsiveness. Using forward genetics in Caenorhabditis elegans, we identified a conserved orphan receptor, GPR139, with anti-opioid activity. GPR139 is coexpressed with MOR in opioid-sensitive brain circuits, binds to MOR, and inhibits signaling to heterotrimeric guanine nucleotide-binding proteins (G proteins). Deletion of GPR139 in mice enhanced opioid-induced inhibition of neuronal firing to modulate morphine-induced analgesia, reward, and withdrawal. Thus, GPR139 could be a useful target for increasing opioid safety. These results also demonstrate the potential of C. elegans as a scalable platform for genetic discovery of G protein-coupled receptor signaling principles.
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Affiliation(s)
- Dandan Wang
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hannah M Stoveken
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Stefano Zucca
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Maria Dao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Chenghui Song
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Caitlin Johnston
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Karla J Opperman
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Andrew C Giles
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Matthew S Gill
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Erik A Lundquist
- Department of Molecular Biosciences, The University of Kansas, Lawrence, KS 66045, USA
| | - Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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22
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Song C, Orlandi C, Sutton LP, Martemyanov KA. The signaling proteins GPR158 and RGS7 modulate excitability of L2/3 pyramidal neurons and control A-type potassium channel in the prelimbic cortex. J Biol Chem 2019; 294:13145-13157. [PMID: 31311860 DOI: 10.1074/jbc.ra119.007533] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 07/11/2019] [Indexed: 12/18/2022] Open
Abstract
Stress profoundly affects physiological properties of neurons across brain circuits and thereby increases the risk for depression. However, the molecular and cellular mechanisms mediating these effects are poorly understood. In this study, we report that chronic physical restraint stress in mice decreases excitability specifically in layer 2/3 of pyramidal neurons within the prelimbic subarea of the prefrontal cortex (PFC) accompanied by the induction of depressive-like behavioral states. We found that a complex between G protein-coupled receptor (GPCR) 158 (GPR158) and regulator of G protein signaling 7 (RGS7), a regulatory GPCR signaling node recently discovered to be a key modulator of affective behaviors, plays a key role in controlling stress-induced changes in excitability in this neuronal population. Deletion of GPR158 or RGS7 enhanced excitability of layer 2/3 PFC neurons and prevented the impact of stress. Investigation of the underlying molecular mechanisms revealed that the A-type potassium channel Kv4.2 subunit is a molecular target of the GPR158-RGS7 complex. We further report that GPR158 physically associates with Kv4.2 channel and promotes its function by suppressing inhibitory modulation by cAMP-protein kinase A (PKA)-mediated phosphorylation. Taken together, our observations reveal a critical mechanism that adjusts neuronal excitability in L2/3 pyramidal neurons of the PFC and may thereby modulate the effects of stress on depression.
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Affiliation(s)
- Chenghui Song
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458
| | - Laurie P Sutton
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458.
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Dunn HA, Dao M, Orlandi C, Zucca S, Martemyanov KA. Trans‐synaptic regulation of group III mGluR pharmacology by endogenous allosteric modulators implicated in neuropsychiatric disease. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.503.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Henry A. Dunn
- Department of NeuroscienceThe Scripps Research InstituteJupiterFL
| | - Maria Dao
- Department of NeuroscienceThe Scripps Research InstituteJupiterFL
| | - Cesare Orlandi
- Department of NeuroscienceThe Scripps Research InstituteJupiterFL
| | - Stefano Zucca
- Department of NeuroscienceThe Scripps Research InstituteJupiterFL
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24
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Orlandi C, Omori Y, Wang Y, Cao Y, Ueno A, Condomitti G, De Wit J, Furukawa T, Martemyanov K. Orphan receptors organizing trans‐synaptic complexes: The case of GPR179 in the retina. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.669.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Yoshihiro Omori
- Molecular and Developmental BiologyOsaka UniversityOsakaJapan
| | - Yuchen Wang
- The Scripps Research Institute (TSRI)JupiterFL
| | - Yan Cao
- The Scripps Research Institute (TSRI)JupiterFL
| | - Akiko Ueno
- Molecular and Developmental BiologyOsaka UniversityOsakaJapan
| | | | - Joris De Wit
- KU Leuven ‐ VIB Center for Brain & Disease ResearchLeuvenBelgium
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25
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Orlandi C, Sutton LP, Muntean BS, Song C, Martemyanov KA. Homeostatic cAMP regulation by the RGS7 complex controls depression-related behaviors. Neuropsychopharmacology 2019; 44:642-653. [PMID: 30546127 PMCID: PMC6333837 DOI: 10.1038/s41386-018-0238-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 01/27/2023]
Abstract
Affective disorders arise from abnormal responses of the brain to prolonged exposure to challenging environmental stimuli. Recent work identified the orphan receptor GPR158 as a molecular link between chronic stress and depression. Here we reveal a non-canonical mechanism by which GPR158 exerts its effects on stress-induced depression by the complex formation with Regulator of G protein Signaling 7 (RGS7). Chronic stress promotes membrane recruitment of RGS7 via GPR158 in the medial prefrontal cortex (mPFC). The resultant complex suppresses homeostatic regulation of cAMP by inhibitory GPCRs in the region. Accordingly, RGS7 loss in mice induces an antidepressant-like phenotype and resiliency to stress, whereas its restoration within the mPFC is sufficient to rescue this phenotype in a GPR158-dependent way. These findings mechanistically link the unusual orphan receptor-RGS complex to a major stress mediator, the cAMP system and suggest new avenues for pharmacological interventions in affective disorders.
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Affiliation(s)
- Cesare Orlandi
- 0000000122199231grid.214007.0Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458 USA
| | - Laurie P. Sutton
- 0000000122199231grid.214007.0Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458 USA
| | - Brian S. Muntean
- 0000000122199231grid.214007.0Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458 USA
| | - Chenghui Song
- 0000000122199231grid.214007.0Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458 USA
| | - Kirill A. Martemyanov
- 0000000122199231grid.214007.0Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458 USA
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26
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Francescon P, Kilby W, Satariano N, Orlandi C, Elshamndy S. The impact of inter-unit variations on small field dosimetry correction factors, with application to the CyberKnife system. Phys Med Biol 2019; 64:035006. [PMID: 30561377 DOI: 10.1088/1361-6560/aaf971] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Small field dosimetry correction factors are usually determined from calculations or measurements using one specific example of a treatment system. The sensitivity of the corrections to inter-unit variation is therefore not evaluated. We propose two methods for this evaluation that could be applied to any system. We use them to assess the variability in [Formula: see text] for the CyberKnife System caused by design changes between pre-M6 and M6 versions, and to the variability in [Formula: see text] and [Formula: see text] resulting from measured beam-data variations across 139 units. We also perform measurements to investigate the differences in [Formula: see text] reported for microchambers in a CyberKnife-specific study versus TRS-483. The results show that [Formula: see text] is smaller for the M6 version than pre-M6 versions by 0.4% for a Farmer chamber, and 0.1% for shorter chambers. The presence or absence of a lead filter within the treatment head had no significant impact on [Formula: see text]. The beam-data analysis showed inter-unit variations in [Formula: see text] of ±0.8% (2 s.d.) for Farmer chambers and ⩽ ±0.5% for shorter cavities (<10 mm) pre-M6, reducing to 0.4% and 0.2% respectively with M6. Inter-unit [Formula: see text] variations for microDiamond and microchambers were ⩽ ±1% at 5 mm field size, except for microchambers with axis perpendicular to the beam where this was > ±2%. Differences of up to 9% were confirmed between Output Factors measured using a microchamber and corrected using TRS-483 [Formula: see text], and a consensus dataset for the same treatment unit determined using multiple detectors and Monte Carlo simulation. A set of practical recommendations for small field dosimetry with the CyberKnife System is derived from these results.
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Affiliation(s)
- P Francescon
- Department of Radiation Oncology, Ospedale Di Vicenza, I-36100 Vicenza, Italy
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27
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Condomitti G, Wierda KD, Schroeder A, Rubio SE, Vennekens KM, Orlandi C, Martemyanov KA, Gounko NV, Savas JN, de Wit J. An Input-Specific Orphan Receptor GPR158-HSPG Interaction Organizes Hippocampal Mossy Fiber-CA3 Synapses. Neuron 2018; 100:201-215.e9. [PMID: 30290982 DOI: 10.1016/j.neuron.2018.08.038] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 07/02/2018] [Accepted: 08/29/2018] [Indexed: 12/20/2022]
Abstract
Pyramidal neuron dendrites integrate synaptic input from multiple partners. Different inputs converging on the same dendrite have distinct structural and functional features, but the molecular mechanisms organizing input-specific properties are poorly understood. We identify the orphan receptor GPR158 as a binding partner for the heparan sulfate proteoglycan (HSPG) glypican 4 (GPC4). GPC4 is enriched on hippocampal granule cell axons (mossy fibers), whereas postsynaptic GPR158 is restricted to the proximal segment of CA3 apical dendrites receiving mossy fiber input. GPR158-induced presynaptic differentiation in contacting axons requires cell-surface GPC4 and the co-receptor LAR. Loss of GPR158 increases mossy fiber synapse density but disrupts bouton morphology, impairs ultrastructural organization of active zone and postsynaptic density, and reduces synaptic strength of this connection, while adjacent inputs on the same dendrite are unaffected. Our work identifies an input-specific HSPG-GPR158 interaction that selectively organizes synaptic architecture and function of developing mossy fiber-CA3 synapses in the hippocampus.
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Affiliation(s)
- Giuseppe Condomitti
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Keimpe D Wierda
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Anna Schroeder
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Sara E Rubio
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Kristel M Vennekens
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Natalia V Gounko
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium; Electron Microscopy Platform & VIB BioImaging Core, Herestraat 49, 3000 Leuven, Belgium
| | - Jeffrey N Savas
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Herestraat 49, 3000 Leuven, Belgium.
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28
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Prodi G, De Giovanni C, Galli MC, Gola G, Grilli S, Rocchetta R, Orlandi C. 17β-estradiol, 5α-Dihydrotestosterone, Progesterone and Cortisol Receptors in Normal and Neoplastic Human Endometrium. Tumori 2018; 65:241-53. [PMID: 462576 DOI: 10.1177/030089167906500214] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Using the value of 0.24 fmoles/μg DNA as breaking point between high and low binding capacities, we quantified receptors for 17β-estradiol (ER), 5α-dihydrotestosterone (DHTR), progesterone (PR) and cortisol (CR) in normal and neoplastic human uterine tissues. Concerning receptors occurrence, significant relationships were observed between ER and PR, ER and DHTR, and DHTR and PR. A direct correlation between the presence of ER and tumor grading was found: PR was less frequent in grade II and absent in grade III endometrial carcinoma, however this was not a significant correlation. In endometrial carcinoma at least 1 of the receptors was detected in 67-91% of the cases, 3 receptors (ER, DHTR, PR) in 56%, and all 4 receptors in 45%. The simultaneous detection of multiple receptors could play an important role in determining hormone response.
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Abstract
Serum CA-125 was determind in 60 patients with variously extended ovarian cancer and monitored during and after chemotherapy. The study indicates that: 1) prechemotherapy CA-125 shows the presence of an active disease with an accuracy > 85%. The antigen is elevated in 97% of patients with > 2 cm disease, but sensitivity is low (67%) in patients with minimal residual disease (< 2 cm); 2) changes in CA-125 correspond well with the response to chemotherapy. CA-125 becomes negative in every patient having clinical CR and increases in every patient with progressive disease. These changes can indicate the type of response some months ahead of time; 3) CA-125 indicates in advance the recurrence of the disease after an objective remission: 4) In the conditions studied CA-125 basal levels do not seem to have prognostic value as regarding either response or survival.
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Affiliation(s)
- A Martoni
- Division of Oncology, University of Bologna
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Sarria I, Cao Y, Wang Y, Ingram NT, Orlandi C, Kamasawa N, Kolesnikov AV, Pahlberg J, Kefalov VJ, Sampath AP, Martemyanov KA. LRIT1 Modulates Adaptive Changes in Synaptic Communication of Cone Photoreceptors. Cell Rep 2018; 22:3562-3573. [PMID: 29590623 PMCID: PMC5902029 DOI: 10.1016/j.celrep.2018.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/10/2018] [Accepted: 02/28/2018] [Indexed: 12/15/2022] Open
Abstract
Cone photoreceptors scale dynamically the sensitivity of responses to maintain responsiveness across wide range of changes in luminance. Synaptic changes contribute to this adaptation, but how this process is coordinated at the molecular level is poorly understood. Here, we report that a cell adhesion-like molecule, LRIT1, is enriched selectively at cone photoreceptor synapses where it engages in a trans-synaptic interaction with mGluR6, the principal receptor in postsynaptic ON-bipolar cells. The levels of LRIT1 are regulated by the neurotransmitter release apparatus that controls photoreceptor output. Knockout of LRIT1 in mice increases the sensitivity of cone synaptic signaling while impairing its ability to adapt to background light without overtly influencing the morphology or molecular composition of photoreceptor synapses. Accordingly, mice lacking LRIT1 show visual deficits under conditions requiring temporally challenging discrimination of visual signals in steady background light. These observations reveal molecular mechanisms involved in scaling synaptic communication in the retina.
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Affiliation(s)
- Ignacio Sarria
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Yan Cao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Yuchen Wang
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Norianne T Ingram
- Department of Ophthalmology, Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA 90095, USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Naomi Kamasawa
- Electron Microscopy Core Facility, Max Planck Florida Institute, Jupiter, FL 33458, USA
| | - Alexander V Kolesnikov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Johan Pahlberg
- Department of Ophthalmology, Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA 90095, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alapakkam P Sampath
- Department of Ophthalmology, Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA 90095, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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31
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Sutton LP, Orlandi C, Song C, Oh WC, Muntean BS, Xie K, Filippini A, Xie X, Satterfield R, Yaeger JDW, Renner KJ, Young SM, Xu B, Kwon H, Martemyanov KA. Orphan receptor GPR158 controls stress-induced depression. eLife 2018; 7:33273. [PMID: 29419376 PMCID: PMC5823542 DOI: 10.7554/elife.33273] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 02/06/2018] [Indexed: 01/23/2023] Open
Abstract
Stress can be a motivational force for decisive action and adapting to novel environment; whereas, exposure to chronic stress contributes to the development of depression and anxiety. However, the molecular mechanisms underlying stress-responsive behaviors are not fully understood. Here, we identified the orphan receptor GPR158 as a novel regulator operating in the prefrontal cortex (PFC) that links chronic stress to depression. GPR158 is highly upregulated in the PFC of human subjects with major depressive disorder. Exposure of mice to chronic stress also increased GPR158 protein levels in the PFC in a glucocorticoid-dependent manner. Viral overexpression of GPR158 in the PFC induced depressive-like behaviors. In contrast GPR158 ablation, led to a prominent antidepressant-like phenotype and stress resiliency. We found that GPR158 exerts its effects via modulating synaptic strength altering AMPA receptor activity. Taken together, our findings identify a new player in mood regulation and introduce a pharmacological target for managing depression.
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Affiliation(s)
- Laurie P Sutton
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Chenghui Song
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Won Chan Oh
- Max Planck Florida Institute for Neuroscience, Jupiter, United States
| | - Brian S Muntean
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Keqiang Xie
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Alice Filippini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Xiangyang Xie
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | | | - Jazmine D W Yaeger
- Center for Brain and Behavior Research, University of South Dakota, Vermillion, United States.,Department of Biology, University of South Dakota, Vermillion, United States
| | - Kenneth J Renner
- Center for Brain and Behavior Research, University of South Dakota, Vermillion, United States.,Department of Biology, University of South Dakota, Vermillion, United States
| | - Samuel M Young
- Max Planck Florida Institute for Neuroscience, Jupiter, United States.,Department of Anatomy and Cell Biology, University of Iowa, Iowa, United States.,Aging Mind and Brain Initiative, University of Iowa, Iowa, United States.,Department of Otolaryngology, Carver College of Medicine, University of Iowa, Iowa, United States
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
| | - Hyungbae Kwon
- Max Planck Florida Institute for Neuroscience, Jupiter, United States.,Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, United States
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Aguado C, Orlandi C, Fajardo-Serrano A, Gil-Minguez M, Martemyanov KA, Luján R. Cellular and Subcellular Localization of the RGS7/Gβ5/R7BP Complex in the Cerebellar Cortex. Front Neuroanat 2016; 10:114. [PMID: 27965545 PMCID: PMC5127842 DOI: 10.3389/fnana.2016.00114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 11/10/2016] [Indexed: 11/13/2022] Open
Abstract
A member of regulator of G-protein signaling family, RGS7, is an essential modulator of signaling through GABAB receptors. RGS7 functions as a macromolecular complex with type 5 G protein β (Gβ5) and R7 binding protein (R7BP) to control the localization and function of the resultant heterotrimeric complexes. Here, we used co-immunoprecipitation, in situ hybridization, histoblot and immunohistochemical techniques at the light and electron microscopic level to advance understanding of RGS7-Gβ5-R7BP complexes in the central nervous system, focusing on distinct neuronal populations in the cerebellar cortex. Histoblot analysis showed that RGS7, Gβ5 and R7BP proteins were widely expressed in the brain, with mostly an overlapping pattern and showing a high expression level in the molecular layer of the cerebellar cortex. Co-immunoprecipitation experiments established that the RGS7/Gβ5 forms complexes with R7BP in the cerebellum. At the cellular level, RGS7 and R7BP mRNAs were expressed at the highest level in Purkinje cells (PCs) and Golgi cells, and at low levels in granule cells. Immunohistochemistry confirmed that labeling for RGS7, Gβ5 and R7BP were present in the three neuronal populations and concentrated in dendrites and spines. At the electron microscopic level, immunolabeling for RGS7, Gβ5 and R7BP proteins was found both at postsynaptic and presynaptic sites and showed similar distribution patterns. Immunoreactivity for the three proteins was mostly localized along the extrasynaptic plasma membrane of dendritic shafts and spines of PCs and to a lesser extent, in axon terminals (AT) establishing excitatory synapses. Quantitative analysis of immunogold particles for RGS7, Gβ5 and R7BP revealed that they are non-uniformly distributed along the surface of PCs, and show enrichment around excitatory synapses on dendritic spines. We further report that deletion of R7BP in mice reduced the targeting of both RGS7 and Gβ5 to the plasma membrane. Altogether, these data support the existence of macromolecular complexes composed of RGS7-Gβ5-R7BP in PCs. The location at post- and pre-synaptic sites in PCs spines-parallel fiber synapses suggests their involvement in the modulation of glutamatergic neurotransmission in the cerebellar cortex.
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Affiliation(s)
- Carolina Aguado
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha Albacete, Spain
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute Jupiter, FL, USA
| | - Ana Fajardo-Serrano
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha Albacete, Spain
| | - Mercedes Gil-Minguez
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha Albacete, Spain
| | | | - Rafael Luján
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha Albacete, Spain
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Xie K, Colgan LA, Dao MT, Muntean BS, Sutton LP, Orlandi C, Boye SL, Boye SE, Shih CC, Li Y, Xu B, Smith RG, Yasuda R, Martemyanov KA. NF1 Is a Direct G Protein Effector Essential for Opioid Signaling to Ras in the Striatum. Curr Biol 2016; 26:2992-3003. [PMID: 27773571 DOI: 10.1016/j.cub.2016.09.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 08/24/2016] [Accepted: 09/07/2016] [Indexed: 01/19/2023]
Abstract
It is well recognized that G-protein-coupled receptors (GPCRs) can activate Ras-regulated kinase pathways to produce lasting changes in neuronal function. Mechanisms by which GPCRs transduce these signals and their relevance to brain disorders are not well understood. Here, we identify a major Ras regulator, neurofibromin 1 (NF1), as a direct effector of GPCR signaling via Gβγ subunits in the striatum. We find that binding of Gβγ to NF1 inhibits its ability to inactivate Ras. Deletion of NF1 in striatal neurons prevents the opioid-receptor-induced activation of Ras and eliminates its coupling to Akt-mTOR-signaling pathway. By acting in the striatal medium spiny neurons of the direct pathway, NF1 regulates opioid-induced changes in Ras activity, thereby sensitizing mice to psychomotor and rewarding effects of morphine. These results delineate a novel mechanism of GPCR signaling to Ras pathways and establish a critical role of NF1 in opioid addiction.
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Affiliation(s)
- Keqiang Xie
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Lesley A Colgan
- Max Planck Florida Institute for Neuroscience, 1 Max Planck Way, Jupiter, FL 33458, USA
| | - Maria T Dao
- Department of Metabolism and Aging, The Scripps Research Institute, 120 Scripps Way, Jupiter, FL 33458, USA
| | - Brian S Muntean
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Laurie P Sutton
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida, 1395 Center Drive, Gainesville, FL 32610, USA
| | - Shannon E Boye
- Department of Ophthalmology, University of Florida, 1395 Center Drive, Gainesville, FL 32610, USA
| | - Chien-Cheng Shih
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yuqing Li
- Department of Neurology, University of Florida, 1600 SW Archer Road, Gainesville, FL 32610, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Roy G Smith
- Department of Metabolism and Aging, The Scripps Research Institute, 120 Scripps Way, Jupiter, FL 33458, USA
| | - Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, 1 Max Planck Way, Jupiter, FL 33458, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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34
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Sutton LP, Ostrovskaya O, Dao M, Xie K, Orlandi C, Smith R, Wee S, Martemyanov KA. Regulator of G-Protein Signaling 7 Regulates Reward Behavior by Controlling Opioid Signaling in the Striatum. Biol Psychiatry 2016; 80:235-45. [PMID: 26364547 PMCID: PMC4753143 DOI: 10.1016/j.biopsych.2015.07.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 07/02/2015] [Accepted: 07/27/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Morphine mediates its euphoric and analgesic effects by acting on the μ-opioid receptor (MOR). MOR belongs to the family of G-protein coupled receptors whose signaling efficiency is controlled by the regulator of G-protein signaling (RGS) proteins. Our understanding of the molecular diversity of RGS proteins that control MOR signaling, their circuit specific actions, and underlying cellular mechanisms is very limited. METHODS We used genetic approaches to ablate regulator of G-protein signaling 7 (RGS7) both globally and in specific neuronal populations. We used conditioned place preference and self-administration paradigms to examine reward-related behavior and a battery of tests to assess analgesia, tolerance, and physical dependence to morphine. Electrophysiology approaches were applied to investigate the impact of RGS7 on morphine-induced alterations in neuronal excitability and plasticity of glutamatergic synapses. At least three animals were used for each assessment. RESULTS Elimination of RGS7 enhanced reward, increased analgesia, delayed tolerance, and heightened withdrawal in response to morphine administration. RGS7 in striatal neurons was selectively responsible for determining the sensitivity of rewarding and reinforcing behaviors to morphine without affecting analgesia, tolerance, and withdrawal. In contrast, deletion of RGS7 in dopaminergic neurons did not influence morphine reward. RGS7 exerted its effects by controlling morphine-induced changes in excitability of medium spiny neurons in nucleus accumbens and gating the compositional plasticity of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and N-methyl-D-aspartate receptors. CONCLUSIONS This study identifies RGS7 as a novel regulator of MOR signaling by dissecting its circuit specific actions and pinpointing its role in regulating morphine reward by controlling the activity of nucleus accumbens neurons.
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Affiliation(s)
- Laurie P. Sutton
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Olga Ostrovskaya
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Maria Dao
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458 USA,Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Keqiang Xie
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Roy Smith
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Sunmee Wee
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458 USA
| | - Kirill A. Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458 USA,Corresponding author: Dr. Kirill Martemyanov, Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, 3C2, Jupiter, FL 33458, Phone: (561) 228-2770,
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35
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Bateman TM, Maddahi J, Udelson J, Beanlands R, Knuuti J, Heller G, Berman D, Lazewatsky J, Orlandi C. IMPROVED ASSESSMENT OF CAD IN OBESE SUBJECTS WITH FLURPIRIDAZ F18 PET MYOCARDIAL PERFUSION IMAGING: A SUBSET ANALYSIS OF THE FLURPIRIDAZ F18 301 PHASE 3 STUDY. J Am Coll Cardiol 2016. [DOI: 10.1016/s0735-1097(16)31579-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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36
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Tayou J, Wang Q, Jang GF, Pronin AN, Orlandi C, Martemyanov KA, Crabb JW, Slepak VZ. Regulator of G Protein Signaling 7 (RGS7) Can Exist in a Homo-oligomeric Form That Is Regulated by Gαo and R7-binding Protein. J Biol Chem 2016; 291:9133-47. [PMID: 26895961 DOI: 10.1074/jbc.m115.694075] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Indexed: 11/06/2022] Open
Abstract
RGS (regulator of G protein signaling) proteins of the R7 subfamily (RGS6, -7, -9, and -11) are highly expressed in neurons where they regulate many physiological processes. R7 RGS proteins contain several distinct domains and form obligatory dimers with the atypical Gβ subunit, Gβ5 They also interact with other proteins such as R7-binding protein, R9-anchoring protein, and the orphan receptors GPR158 and GPR179. These interactions facilitate plasma membrane targeting and stability of R7 proteins and modulate their activity. Here, we investigated RGS7 complexes using in situ chemical cross-linking. We found that in mouse brain and transfected cells cross-linking causes formation of distinct RGS7 complexes. One of the products had the apparent molecular mass of ∼150 kDa on SDS-PAGE and did not contain Gβ5 Mass spectrometry analysis showed no other proteins to be present within the 150-kDa complex in the amount close to stoichiometric with RGS7. This finding suggested that RGS7 could form a homo-oligomer. Indeed, co-immunoprecipitation of differentially tagged RGS7 constructs, with or without chemical cross-linking, demonstrated RGS7 self-association. RGS7-RGS7 interaction required the DEP domain but not the RGS and DHEX domains or the Gβ5 subunit. Using transfected cells and knock-out mice, we demonstrated that R7-binding protein had a strong inhibitory effect on homo-oligomerization of RGS7. In contrast, our data indicated that GPR158 could bind to the RGS7 homo-oligomer without causing its dissociation. Co-expression of constitutively active Gαo prevented the RGS7-RGS7 interaction. These results reveal the existence of RGS protein homo-oligomers and show regulation of their assembly by R7 RGS-binding partners.
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Affiliation(s)
- Junior Tayou
- From the Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Qiang Wang
- From the Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Geeng-Fu Jang
- the Cole Eye Institute Cleveland Clinic, Cleveland, Ohio 44195, and
| | - Alexey N Pronin
- From the Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Cesare Orlandi
- the Department of Neuroscience, Scripps Research Institute, Jupiter, Florida 33458
| | - Kirill A Martemyanov
- the Department of Neuroscience, Scripps Research Institute, Jupiter, Florida 33458
| | - John W Crabb
- the Cole Eye Institute Cleveland Clinic, Cleveland, Ohio 44195, and
| | - Vladlen Z Slepak
- From the Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida 33136,
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37
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Lorenzon L, Donatiello S, Cannatà V, Garganese M, Giannone G, Orlandi C, Pacilio M, Genovese E. Accurate measurements of low activity for calibration of a RIA gamma counter used in red marrow dosimetry. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.01.372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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38
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Donatiello S, Genovese E, Orlandi C, Cannata' V. Determination of attenuation properties of materials used in protective devices against diagnostic medical X-radiation following the new CEI EN 61331-1. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.01.408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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39
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Genovese E, Pimpinella M, Guerra A, De Coste V, Marinelli M, Rinati GV, Donatiello S, Orlandi C, Romanzo A, Cozza R, Cannata V. Verification of dose distribution from CCX RU-106 eye-plaques by using a microDiamond dosimeter. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.01.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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40
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Genovese E, Napolitano A, Donatiello S, Orlandi C, Toma' P, Campanella F, Calcagnini G, Censi F. Safety for MRI patients with implanted medical devices. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.01.441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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41
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Genovese E, Napolitano A, Donatiello S, Orlandi C, Toma' P, Cannata' V. MRI ferromagnetic detector system for patients' and operators' safety: Experience in opbg. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.01.442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Cao Y, Sarria I, Fehlhaber KE, Kamasawa N, Orlandi C, James KN, Hazen JL, Gardner MR, Farzan M, Lee A, Baker S, Baldwin K, Sampath AP, Martemyanov KA. Mechanism for Selective Synaptic Wiring of Rod Photoreceptors into the Retinal Circuitry and Its Role in Vision. Neuron 2015; 87:1248-1260. [PMID: 26402607 PMCID: PMC4583715 DOI: 10.1016/j.neuron.2015.09.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/11/2015] [Accepted: 08/31/2015] [Indexed: 01/06/2023]
Abstract
In the retina, rod and cone photoreceptors form distinct connections with different classes of downstream bipolar cells. However, the molecular mechanisms responsible for their selective connectivity are unknown. Here we identify a cell-adhesion protein, ELFN1, to be essential for the formation of synapses between rods and rod ON-bipolar cells in the primary rod pathway. ELFN1 is expressed selectively in rods where it is targeted to the axonal terminals by the synaptic release machinery. At the synapse, ELFN1 binds in trans to mGluR6, the postsynaptic receptor on rod ON-bipolar cells. Elimination of ELFN1 in mice prevents the formation of synaptic contacts involving rods, but not cones, allowing a dissection of the contributions of primary and secondary rod pathways to retinal circuit function and vision. We conclude that ELFN1 is necessary for the selective wiring of rods into the primary rod pathway and is required for high sensitivity of vision.
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Affiliation(s)
- Yan Cao
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Ignacio Sarria
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Katherine E Fehlhaber
- Jules Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095, USA
| | - Naomi Kamasawa
- Electron Microscopy Core Facility, Max Planck Florida Institute, 1 Max Planck Way, Jupiter, FL 33458, USA
| | - Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Kiely N James
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92121, USA
| | - Jennifer L Hazen
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92121, USA
| | - Matthew R Gardner
- Department of Infectious Disease, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Michael Farzan
- Department of Infectious Disease, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
| | - Sheila Baker
- Department of Biochemistry, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
| | - Kristin Baldwin
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92121, USA
| | - Alapakkam P Sampath
- Jules Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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Orlandi C, Xie K, Masuho I, Fajardo-Serrano A, Lujan R, Martemyanov KA. Orphan Receptor GPR158 Is an Allosteric Modulator of RGS7 Catalytic Activity with an Essential Role in Dictating Its Expression and Localization in the Brain. J Biol Chem 2015; 290:13622-39. [PMID: 25792749 DOI: 10.1074/jbc.m115.645374] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Indexed: 11/06/2022] Open
Abstract
Regulators of G protein signaling control the duration and extent of signaling via G protein-coupled receptor (GPCR) pathways by accelerating the GTP hydrolysis on G protein α subunits thereby promoting termination of GPCR signaling. A member of this family, RGS7, plays a critical role in the nervous system where it regulates multiple neurotransmitter GPCRs that mediate vision, memory, and the action of addictive drugs. Previous studies have established that in vivo RGS7 forms mutually exclusive complexes with the membrane protein RGS7-binding protein or the orphan receptor GPR158. In this study, we examine the impact of GPR158 on RGS7 in the brain. We report that knock-out of GPR158 in mice results in marked post-transcriptional destabilization of RGS7 and substantial loss of its association with membranes in several brain regions. We further identified the RGS7-binding site in the C terminus of GPR158 and found that it shares significant homology with the RGS7-binding protein. The proximal portion of the GPR158 C terminus additionally contained a conserved sequence that was capable of enhancing RGS7 GTPase-activating protein activity in solution by an allosteric mechanism acting in conjunction with the regulators of the G protein signaling-binding domain. The distal portion of the GPR158 C terminus contained several phosphodiesterase E γ-like motifs and selectively recruited G proteins in their activated state. The results of this study establish GPR158 as an essential regulator of RGS7 in the native nervous system with a critical role in controlling its expression, membrane localization, and catalytic activity.
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Affiliation(s)
- Cesare Orlandi
- From the Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458 and
| | - Keqiang Xie
- From the Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458 and
| | - Ikuo Masuho
- From the Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458 and
| | - Ana Fajardo-Serrano
- the Instituto de Investigación en Descapacidades Neuronales (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
| | - Rafael Lujan
- the Instituto de Investigación en Descapacidades Neuronales (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain
| | - Kirill A Martemyanov
- From the Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458 and
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Abdelmoneim S, Lowe T, Hibberd M, Bhat G, Miller P, Orlandi C, Mulvagh S. STRESS ECHOCARDIOGRAPHY WITH AND WITHOUT ULTRASOUND CONTRAST AGENT USE IN 26,716 IN-PATIENTS: A PROPENSITY-MATCHED COHORT STUDY EVALUATING LENGTH OF STAY AND HOSPITALIZATION COST. Can J Cardiol 2014. [DOI: 10.1016/j.cjca.2014.07.469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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45
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Abstract
Vasopressin antagonists have been studied in a variety of clinical settings, including patients with acute and chronic heart failure. The clinical trials published to date have sought to describe the clinical and physiologic effects of these agents in an effort to prove clinical efficacy and safety. A variety of agents with varying effects on V2 and V1a vasopressin receptor subtype have been studied. They have been shown to reduce bodyweight and improve serum sodium without worsening renal function. They may also decrease the need for loop diuretic use and may be particularly useful in patients with hyponatremia in the setting of volume overload. Further studies are underway that are powered to assess for morbidity and mortality benefits. The beneficial effects have been well documented but, until outcomes are understood more fully, the use of these agents should be limited to currently approved indications. In the USA, this includes only the treatment of euvolemic hyponatremia.
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Affiliation(s)
- Joseph Rossi
- Northwestern University, Feinberg School of Medicine, 251 E. Huron Galter 10-240, Chicago IL 60611, USA.
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Orlandi C, Cao Y, Martemyanov KA. Orphan receptor GPR179 forms macromolecular complexes with components of metabotropic signaling cascade in retina ON-bipolar neurons. Invest Ophthalmol Vis Sci 2013; 54:7153-61. [PMID: 24114537 DOI: 10.1167/iovs.13-12907] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE In the mammalian retina, synaptic transmission between light-excited rod photoreceptors and downstream ON-bipolar neurons is indispensable for dim vision, and disruption of this process leads to congenital stationary night blindness in human patients. The ON-bipolar neurons use the metabotropic signaling cascade, initiated by the mGluR6 receptor, to generate depolarizing responses to light-induced changes in neurotransmitter glutamate release from the photoreceptor axonal terminals. Evidence for the identity of the components involved in transducing these signals is growing rapidly. Recently, the orphan receptor, GPR179, a member of the G protein-coupled receptor (GPCR) superfamily, has been shown to be indispensable for the synaptic responses of ON-bipolar cells. In our study, we investigated the interaction of GPR179 with principle components of the signal transduction cascade. METHODS We used immunoprecipitation and proximity ligation assays in transfected cells and native retinas to characterize the protein-protein interactions involving GPR179. The influence of cascade components on GPR179 localization was examined through immunohistochemical staining of the retinas from genetic mouse models. RESULTS We demonstrated that, in mouse retinas, GPR179 forms physical complexes with the main components of the metabotropic cascade, recruiting mGluR6, TRPM1, and the RGS proteins. Elimination of mGluR6 or RGS proteins, but not TRPM1, detrimentally affects postsynaptic targeting or GPR179 expression. CONCLUSIONS These observations suggest that the mGluR6 signaling cascade is scaffolded as a macromolecular complex in which the interactions between the components ensure the optimal spatiotemporal characteristics of signal transduction.
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Affiliation(s)
- Cesare Orlandi
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida
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Orlandi C, Masuho I, Posokhova E, Cao Y, Ray T, Hasan N, Gregg R, Martemyanov K. GPR158 and GPR179: a subfamily of orphan GPCRs as a new class of G protein signaling modulators. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1095.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Ikuo Masuho
- NeuroscienceThe Scripps Research InstituteJupiterFL
| | | | - Yan Cao
- NeuroscienceThe Scripps Research InstituteJupiterFL
| | - Thomas Ray
- Biochemistry and Molecular BiologyUniversity of LouisvilleLouisvilleKY
| | - Nazarul Hasan
- Biochemistry and Molecular BiologyUniversity of LouisvilleLouisvilleKY
| | - Ronald Gregg
- Biochemistry and Molecular BiologyUniversity of LouisvilleLouisvilleKY
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48
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Ignácio F, Bergfelt D, Mendes D, Orlandi C, Araújo G, Oliveira J, Montechiesi D, Carvalho L, Meira C. Ovarian response to porcine FSH in association with ablation-induced or spontaneous follicular wave development during the estrous cycle in crossbred and Brazilian Warmblood mares. Anim Reprod Sci 2013; 137:82-7. [DOI: 10.1016/j.anireprosci.2012.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 12/03/2012] [Accepted: 12/07/2012] [Indexed: 11/29/2022]
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49
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Abraham WT, Hensen J, Gross PA, Bichet DG, Josiassen RC, Chafekar DS, Orlandi C. Lixivaptan safely and effectively corrects serum sodium concentrations in hospitalized patients with euvolemic hyponatremia. Kidney Int 2012; 82:1223-30. [DOI: 10.1038/ki.2012.275] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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50
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La Via L, Bonini D, Russo I, Orlandi C, Barlati S, Barbon A. Modulation of dendritic AMPA receptor mRNA trafficking by RNA splicing and editing. Nucleic Acids Res 2012; 41:617-31. [PMID: 23166306 PMCID: PMC3592400 DOI: 10.1093/nar/gks1223] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
RNA trafficking to dendrites and local translation are crucial processes for superior neuronal functions. To date, several α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) mRNAs have been detected in dendrites and are subject to local protein synthesis. Here, we report the presence of all AMPAR GluA1-4 mRNAs in hippocampal and cortical rat synaptic spines by synaptoneurosomes analysis. In particular, we showed that dendritic AMPAR mRNAs are present in the Flip versions in the cortex and hippocampus. To further confirm these data, we demonstrate, using in situ hybridization, the dendritic localization of the GluA2 Flip isoform in vitro and in vivo, whereas the Flop variant is restricted mainly to the soma. In addition, we report that dendritic AMPA mRNAs are edited at low levels at their R/G sites; this result was also supported with transfection experiments using chimeric GluA2 DNA vectors, showing that transcripts carrying an unedited nucleotide at the R/G site, in combination with the Flip exon, are more efficiently targeted to dendrites when compared with the edited-Flip versions. Our data show that post-transcriptional regulations such as RNA splicing, editing and trafficking might be mutually coordinated and that the localization of different AMPAR isoforms in dendrites might play a functional role in the regulation of neuronal transmission.
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Affiliation(s)
- Luca La Via
- Department of Biomedical Sciences and Biotechnology, Division of Biology and Genetics, National Institute of Neuroscience, University of Brescia, Viale Europa 11, Brescia 25123, Italy
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