1
|
Stark R. The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism. J Neuroendocrinol 2024; 36:e13382. [PMID: 38468186 DOI: 10.1111/jne.13382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/22/2024] [Accepted: 02/25/2024] [Indexed: 03/13/2024]
Abstract
Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.
Collapse
Affiliation(s)
- Romana Stark
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
2
|
Gu F, Zhao W, Duan X, Zhang Y, Luo X, Chen G, Jin X, Pan H, Gao F, Wu H. Association of hypocalcemia with in-hospital mortality in critically ill patients with intracerebral hemorrhage: A retrospective cohort study. Front Neurol 2023; 13:1054098. [PMID: 36698873 PMCID: PMC9868589 DOI: 10.3389/fneur.2022.1054098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Background and purpose There was little evidence to study the relationship between hypocalcemia and mortality among critically ill patients with intracerebral hemorrhage (ICH) aged ≥16 years. This study aimed to determine the potential association between hypocalcemia and in-hospital and ICU mortality in patients with ICH in the United States. Methods We analyzed 1,954 patients with ICH from the e-Intensive Care Unit Collaborative Research Database and divided them into hypocalcemia and non-hypocalcemia groups. Hypocalcemia was defined as albumin-adjusted total calcium below 8.4 mg/dl. The primary and secondary outcomes were hospital and ICU mortality, respectively. We performed multivariable regression and subgroup analyses to evaluate the association of hypocalcemia with hospital and ICU mortality. Cumulative survival rate analysis was performed using Kaplan-Meier curves with log-rank statistics. Results We enrolled 1,954 patients with ICH who had been hospitalized in ICU for >24 h and were older than 16 years (average age, 61.8 years; men, 56.7%). We noted that 373 (19%) hospital mortality occurred, including 235 (12%) ICU mortality. In this sample, 195 patients had hypocalcemia. Multivariable logistic regression analyses showed that hypocalcemia was associated with a 67% increased risk of in-hospital and a 72% increased risk of ICU mortality. This association was consistent across subgroup analyses. Conclusions Hypocalcemia was associated with a high risk of hospital and ICU mortality among critically ill patients with ICH. Future prospective, randomized, controlled studies are needed to confirm our results.
Collapse
Affiliation(s)
- Fang Gu
- Center for Reproductive Medicine, Department of Pediatrics, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Wenyan Zhao
- Center for General Practice Medicine, Department of General Practice Medicine, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Xiangjie Duan
- Department of Infectious Diseases, The First People's Hospital of Changde, Changde, Hunan, China
| | - Ying Zhang
- Center for Reproductive Medicine, Department of Pediatrics, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Xiaoming Luo
- Center for Reproductive Medicine, Department of Pediatrics, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Guoqing Chen
- Center for Reproductive Medicine, Department of Pediatrics, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Xiaoli Jin
- Center for Reproductive Medicine, Department of Pediatrics, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Hangli Pan
- Department of Pediatrics, Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Faliang Gao
- Center for Rehabilitation Medicine, Department of Neurosurgery, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China,Key Laboratory of Endocrine Gland Diseases of Zhejiang Province, Hangzhou, Zhejiang, China,Faliang Gao ✉
| | - Huadong Wu
- Center for Rehabilitation Medicine, Department of Neurology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, Zhejiang, China,*Correspondence: Huadong Wu ✉
| |
Collapse
|
3
|
Julliard AK, Al Koborssy D, Fadool DA, Palouzier-Paulignan B. Nutrient Sensing: Another Chemosensitivity of the Olfactory System. Front Physiol 2017; 8:468. [PMID: 28747887 PMCID: PMC5506222 DOI: 10.3389/fphys.2017.00468] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/19/2017] [Indexed: 12/31/2022] Open
Abstract
Olfaction is a major sensory modality involved in real time perception of the chemical composition of the external environment. Olfaction favors anticipation and rapid adaptation of behavioral responses necessary for animal survival. Furthermore, recent studies have demonstrated that there is a direct action of metabolic peptides on the olfactory network. Orexigenic peptides such as ghrelin and orexin increase olfactory sensitivity, which in turn, is decreased by anorexigenic hormones such as insulin and leptin. In addition to peptides, nutrients can play a key role on neuronal activity. Very little is known about nutrient sensing in olfactory areas. Nutrients, such as carbohydrates, amino acids, and lipids, could play a key role in modulating olfactory sensitivity to adjust feeding behavior according to metabolic need. Here we summarize recent findings on nutrient-sensing neurons in olfactory areas and delineate the limits of our knowledge on this topic. The present review opens new lines of investigations on the relationship between olfaction and food intake, which could contribute to determining the etiology of metabolic disorders.
Collapse
Affiliation(s)
- A-Karyn Julliard
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/Centre National de la Recherche Scientifique UMR5292 Team Olfaction: From Coding to MemoryLyon, France
| | - Dolly Al Koborssy
- Department of Biological Science, Florida State UniversityTallahassee, FL, United States.,Program in Neuroscience, Florida State UniversityTallahassee, FL, United States
| | - Debra A Fadool
- Department of Biological Science, Florida State UniversityTallahassee, FL, United States.,Program in Neuroscience, Florida State UniversityTallahassee, FL, United States.,Institute of Molecular Biophysics, Florida State UniversityTallahassee, FL, United States
| | - Brigitte Palouzier-Paulignan
- Univ Lyon, Université Claude Bernard Lyon1, Centre de Recherche en Neurosciences de Lyon (CRNL), INSERM U1028/Centre National de la Recherche Scientifique UMR5292 Team Olfaction: From Coding to MemoryLyon, France
| |
Collapse
|
4
|
Voltage Dependence of a Neuromodulator-Activated Ionic Current. eNeuro 2016; 3:eN-NWR-0038-16. [PMID: 27257619 PMCID: PMC4874538 DOI: 10.1523/eneuro.0038-16.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/18/2016] [Accepted: 04/25/2016] [Indexed: 02/07/2023] Open
Abstract
The neuromodulatory inward current (IMI) generated by crab Cancer borealis stomatogastric ganglion neurons is an inward current whose voltage dependence has been shown to be crucial in the activation of oscillatory activity of the pyloric network of this system. It has been previously shown that IMI loses its voltage dependence in conditions of low extracellular calcium, but that this effect appears to be regulated by intracellular calmodulin. Voltage dependence is only rarely regulated by intracellular signaling mechanisms. Here we address the hypothesis that the voltage dependence of IMI is mediated by intracellular signaling pathways activated by extracellular calcium. We demonstrate that calmodulin inhibitors and a ryanodine antagonist can reduce IMI voltage dependence in normal Ca(2+), but that, in conditions of low Ca(2+), calmodulin activators do not restore IMI voltage dependence. Further, we show evidence that CaMKII alters IMI voltage dependence. These results suggest that calmodulin is necessary but not sufficient for IMI voltage dependence. We therefore hypothesize that the Ca(2+)/calmodulin requirement for IMI voltage dependence is due to an active sensing of extracellular calcium by a GPCR family calcium-sensing receptor (CaSR) and that the reduction in IMI voltage dependence by a calmodulin inhibitor is due to CaSR endocytosis. Supporting this, preincubation with an endocytosis inhibitor prevented W7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride)-induced loss of IMI voltage dependence, and a CaSR antagonist reduced IMI voltage dependence. Additionally, myosin light chain kinase, which is known to act downstream of the CaSR, seems to play a role in regulating IMI voltage dependence. Finally, a Gβγ-subunit inhibitor also affects IMI voltage dependence, in support of the hypothesis that this process is regulated by a G-protein-coupled CaSR.
Collapse
|
5
|
Pak HJ, Riew TR, Shin YJ, Choi JH, Jin X, Lee MY. Enhanced expression of the calcium-sensing receptor in reactive astrocytes following ischemic injury in vivo and in vitro. J Neurol Sci 2016; 366:102-109. [PMID: 27288786 DOI: 10.1016/j.jns.2016.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 11/19/2022]
Abstract
We recently demonstrated that the G protein-coupled calcium-sensing receptor (CaSR) is associated with the pathogenesis of ischemic stroke and may be involved in vascular remodeling and astrogliosis. To further substantiate the involvement of CaSR in the astroglial reaction common to ischemic insults, we investigated the temporal and cell type-specific expression patterns of CaSR in the hippocampus after transient forebrain ischemia. CaSR was constitutively expressed in neurons of the pyramidal and granule cell layers, whereas increased CaSR immunoreactivity was observed in reactive astrocytes, but not in activated microglia or macrophages, in the CA1 region of the post-ischemic hippocampus. Astroglial induction of CaSR expression was evident on days 3-7 after reperfusion and appeared to increase progressively through day 28, at which time CaSR expression was prominent in astrocytes with a highly reactive hypertrophic phenotype and elevated levels of glial fibrillary acidic protein. This expression pattern was supported by results of immunoblot analyses. Furthermore, CaSR expression was upregulated in rat primary cortical astrocytes exposed to oxygen-glucose deprivation, which undergo reactive gliosis-like changes. Thus, our results demonstrate that selective and long-lasting astroglial induction of CaSR expression is a common characteristic of ischemic injury and suggest its involvement in the ischemia-induced astroglial reaction.
Collapse
Affiliation(s)
- Ha-Jin Pak
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Yoo-Jin Shin
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Jeong-Heon Choi
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Xuyan Jin
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 137-701, Seoul, Korea.
| |
Collapse
|
6
|
Jones BL, Smith SM. Calcium-Sensing Receptor: A Key Target for Extracellular Calcium Signaling in Neurons. Front Physiol 2016; 7:116. [PMID: 27065884 PMCID: PMC4811949 DOI: 10.3389/fphys.2016.00116] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/14/2016] [Indexed: 12/14/2022] Open
Abstract
Though both clinicians and scientists have long recognized the influence of extracellular calcium on the function of muscle and nervous tissue, recent insights reveal that the mechanisms allowing changes in extracellular calcium to alter cellular excitability have been incompletely understood. For many years the effects of calcium on neuronal signaling were explained only in terms of calcium entry through voltage-gated calcium channels and biophysical charge screening. More recently however, it has been recognized that the calcium-sensing receptor is prevalent in the nervous system and regulates synaptic transmission and neuronal activity via multiple signaling pathways. Here we review the multiplicity of mechanisms by which changes in extracellular calcium alter neuronal signaling and propose that multiple mechanisms are required to describe the full range of experimental observations.
Collapse
Affiliation(s)
- Brian L. Jones
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science UniversityPortland, OR, USA
| | - Stephen M. Smith
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science UniversityPortland, OR, USA
- Section of Pulmonary and Critical Care Medicine, VA Portland Health Care SystemPortland, OR, USA
| |
Collapse
|
7
|
Noh JS, Pak HJ, Shin YJ, Riew TR, Park JH, Moon YW, Lee MY. Differential expression of the calcium-sensing receptor in the ischemic and border zones after transient focal cerebral ischemia in rats. J Chem Neuroanat 2015; 66-67:40-51. [DOI: 10.1016/j.jchemneu.2015.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/20/2015] [Accepted: 05/15/2015] [Indexed: 10/23/2022]
|
8
|
Cozzolino M, Tomlinson J, Walsh L, Bellasi A. Emerging drugs for secondary hyperparathyroidism. Expert Opin Emerg Drugs 2015; 20:197-208. [PMID: 25702624 DOI: 10.1517/14728214.2015.1018177] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Secondary hyperparathyroidism (SHPT), a common, serious, and progressive complication of chronic kidney disease (CKD), is characterized by elevated serum parathyroid hormone (PTH), parathyroid gland hyperplasia, and mineral metabolism abnormalities. These disturbances may result in CKD-mineral and bone disorder (CKD-MBD), which is associated with poor quality of life and short life expectancy. AREAS COVERED The goal of SHPT treatment is to maintain PTH, calcium, and phosphorus within accepted targeted ranges. This review highlights the pathogenesis of SHPT and current SHPT therapeutic approaches, including the use of low-phosphate diets, phosphate binders, 1,25-dihydroxyvitamin D3 (calcitriol) and its analogs, calcimimetics, and parathyroidectomy in addition to discussing emerging drugs in development for SHPT. EXPERT OPINION Numerous studies indicate that mineral abnormalities occur early in the course of CKD, are prevalent by the time patients enter dialysis, and foreshadow a risk of cardiovascular and all-cause mortality. Several newly developed compounds may potentially overcome the limitations of current SHPT therapies. If emerging therapies can reduce PTH, normalize mineral metabolism, promote treatment adherence, and reduce the risk of side effects, they may provide the requisite features for improving long-term outcomes in patients with SHPT receiving dialysis and reduce the risks of CKD-MBD.
Collapse
Affiliation(s)
- Mario Cozzolino
- University of Milan, San Paolo Hospital, School of Medicine, Renal Division, Department of Health Sciences , Milan , Italy +39 02 81844381 ;
| | | | | | | |
Collapse
|
9
|
Vinas-Rios JM, Sanchez-Aguilar M, Sanchez-Rodriguez JJ, Gonzalez-Aguirre D, Heinen C, Meyer F, Kretschmer T. Hypocalcaemia as a prognostic factor of early mortality in moderate and severe traumatic brain injury. Neurol Res 2013; 36:102-6. [PMID: 24139087 DOI: 10.1179/1743132813y.0000000272] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Our main objective was to evaluate whether serum hypocalcaemia on the third day [defined as < 2.1 mmol/l (8.5 mg/dl)] is a prognostic factor for early mortality after moderate and severe traumatic brain injury (TBI). METHODS We developed an ambispective comparative case control study. We evaluated clinical profiles from included patients from January 2005 to July 2009 and we prospectively recruited additional patients from August 2009 to July 2011. Patients were between 1 and 89 years old and had a Glasgow Coma Scale of 3-12 points following TBI. RESULTS We calculated an Odds Ratio of 5.2 (Confidence Intervals 95%: 4.48 to 6.032) for hypocalcaemia on day three, which was associated with death. Retrospectively (January 2005 to July 2009) we compiled data from 81 patients. Prospectively (August 2009 to July 2011) we recruited 41 patients. The adjusted variables in the logistic regression final model were: serum calcium on day three (Odds Ratio 3.5, Confidence Intervals 95%: 1·12 to 13·61, P < 0·028) and anisocoria (Odds Ratio 8·24, Confidence Intervals 95%: 1·3 to 67·35, P < 0·019) obtaining an adjusted R2 of 0·22 (P < 0·005). DISCUSSION The serum levels of calcium on day three could be useful for the prediction of mortality in patients with moderate and severe TBI.
Collapse
|
10
|
Martin KJ, Bell G, Pickthorn K, Huang S, Vick A, Hodsman P, Peacock M. Velcalcetide (AMG 416), a novel peptide agonist of the calcium-sensing receptor, reduces serum parathyroid hormone and FGF23 levels in healthy male subjects. Nephrol Dial Transplant 2013; 29:385-92. [PMID: 24235081 PMCID: PMC3910343 DOI: 10.1093/ndt/gft417] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CONTEXT Velcalcetide, also known as AMG 416, is a novel, long-acting selective peptide agonist of the calcium sensing receptor. It is being developed as an intravenous treatment of secondary hyperparathyroidism (SHPT) in hemodialysis patients with chronic kidney disease-mineral and bone disorder. OBJECTIVE To assess the safety, tolerability, pharmacokinetics and pharmacodynamics of velcalcetide in healthy male volunteers. METHODS The study was a double-blind, randomized, placebo-controlled, single-dose, dose-escalation study in healthy males aged 18-45 years conducted at a single center. Each cohort included eight subjects randomized 6:2 to velcalcetide or placebo. INTERVENTION Velcalcetide at 0.5, 2, 5 and 10 mg or placebo was administered intravenously. OUTCOMES Measurements included plasma ionized calcium (iCa), serum total calcium, intact parathyroid hormone (iPTH), phosphorus and fibroblast growth factor-23 (FGF23), 1,25-dihydroxyvitamin D, calcitonin and urine creatinine, calcium and phosphorus and plasma pharmacokinetics for velcalcetide. Vital signs, safety biochemical and hematological indices, and adverse events were monitored throughout the study. RESULTS Intravenous administration of velcalcetide was well tolerated with no adverse reaction of nausea, vomiting or diarrhea reported. Velcalcetide mediated dose-dependent decreases in serum iPTH at 30 min, FGF23 at 24 h and iCa at 12 h post dose (P<0.05) and in urine fractional excretion of phosphorus and increases in tubular reabsorption of phosphorus. Velcalcetide plasma exposure increased in a dose-related manner and the terminal elimination of half-life was comparable across the dose range evaluated and ranged from 18.4 to 20.0 h. CONCLUSION Single IV doses of velcalcetide were well tolerated and associated with rapid, sustained, dose-dependent reductions in serum PTH. The results support further evaluation of velcalcetide as a treatment for SHPT in hemodialysis patients.
Collapse
Affiliation(s)
- Kevin J Martin
- Division of Nephrology, Saint Louis University School of Medicine, Saint Louis, MO 63103, USA
| | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
The calcium sensing receptor (CaSR) is expressed by subpopulations of neuronal and glial cells throughout the brain and is activated by extracellular calcium [Formula: see text] . During development, the CaSR regulates neuronal cell growth and migration as well as oligodendroglial maturation and function. Emerging evidence suggests that in nerve terminals, CaSR is implicated in synaptic plasticity and neurotransmission. In this review, we analyze the roles attributed to CaSR in regulating diverse brain functions, including central regulation of body fluid composition and blood pressure. We also discuss the potential relevance of Ca(2+)-sensing in brain by other family C G protein-coupled receptors. Finally, evidence that the CaSR contributes to the pathogenesis of various brain disorders raises the possibility that pharmacological modulators of the CaSR may have therapeutic benefit.
Collapse
Affiliation(s)
- Martial Ruat
- CNRS-UPR-3294, Laboratory of Neurobiology and Development, Institute of Neurobiology, Alfred Fessard IFR2118, Signal Transduction and Developmental Neuropharmacology Team, 1 Avenue de la Terrasse, F-91198, Gif-sur-Yvette, France.
| | | |
Collapse
|
12
|
Walter S, Baruch A, Dong J, Tomlinson JE, Alexander ST, Janes J, Hunter T, Yin Q, Maclean D, Bell G, Mendel DB, Johnson RM, Karim F. Pharmacology of AMG 416 (Velcalcetide), a Novel Peptide Agonist of the Calcium-Sensing Receptor, for the Treatment of Secondary Hyperparathyroidism in Hemodialysis Patients. J Pharmacol Exp Ther 2013; 346:229-40. [DOI: 10.1124/jpet.113.204834] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
13
|
Torres A, Wang F, Xu Q, Fujita T, Dobrowolski R, Willecke K, Takano T, Nedergaard M. Extracellular Ca²⁺ acts as a mediator of communication from neurons to glia. Sci Signal 2012; 5:ra8. [PMID: 22275221 DOI: 10.1126/scisignal.2002160] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Defining the pathways through which neurons and astrocytes communicate may contribute to the elucidation of higher central nervous system functions. We investigated the possibility that decreases in extracellular calcium ion concentration ([Ca(2+)](e)) that occur during synaptic transmission might mediate signaling from neurons to glia. Using noninvasive photolysis of the photolabile Ca(2+) buffer diazo-2 {N-[2-[2-[2-[bis(carboxymethyl)amino]-5-(diazoacetyl)phenoxy]ethoxy]-4-methylphenyl]-N-(carboxymethyl)-, tetrapotassium salt} to reduce [Ca(2+)](e) or caged glutamate to simulate glutamatergic transmission, we found that a local decline in extracellular Ca(2+) triggered astrocytic adenosine triphosphate (ATP) release and astrocytic Ca(2+) signaling. In turn, activation of purinergic P2Y1 receptors on a subset of inhibitory interneurons initiated the generation of action potentials by these interneurons, thereby enhancing synaptic inhibition. Thus, astrocytic ATP release evoked by an activity-associated decrease in [Ca(2+)](e) may provide a negative feedback mechanism that potentiates inhibitory transmission in response to local hyperexcitability.
Collapse
Affiliation(s)
- Arnulfo Torres
- Center for Translational Neuromedicine, Division of Glial Disease and Therapeutics, University of Rochester Medical School, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Compelling evidence of a cell surface receptor sensitive to extracellular calcium was observed as early as the 1980s and was finally realized in 1993 when the calcium-sensing receptor (CaR) was cloned from bovine parathyroid tissue. Initial studies relating to the CaR focused on its key role in extracellular calcium homeostasis, but as the amount of information about the receptor grew it became evident that it was involved in many biological processes unrelated to calcium homeostasis. The CaR responds to a diverse array of stimuli extending well beyond that merely of calcium, and these stimuli can lead to the initiation of a wide variety of intracellular signaling pathways that in turn are able to regulate a diverse range of biological processes. It has been through the examination of the molecular characteristics of the CaR that we now have an understanding of how this single receptor is able to convert extracellular messages into specific cellular responses. Recent CaR-related reviews have focused on specific aspects of the receptor, generally in the context of the CaR's role in physiology and pathophysiology. This review will provide a comprehensive exploration of the different aspects of the receptor, including its structure, stimuli, signalling, interacting protein partners, and tissue expression patterns, and will relate their impact on the functionality of the CaR from a molecular perspective.
Collapse
Affiliation(s)
- Aaron L Magno
- Department of Endocrinology and Diabetes, First Floor, C Block, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands 6009, Western Australia, Australia
| | | | | |
Collapse
|
15
|
Kobayashi-Torii M, Takahashi Y, Sunanaga J, Fujita M, Lee EY, Ichimaru Y, Fujita T, Kanmura Y, Kuwaki T. Possible participation of extracellular calcium-sensing receptor in blood pressure regulation in rats. Brain Res 2011; 1367:181-7. [DOI: 10.1016/j.brainres.2010.10.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 10/02/2010] [Accepted: 10/05/2010] [Indexed: 11/26/2022]
|
16
|
Bandyopadhyay S, Tfelt-Hansen J, Chattopadhyay N. Diverse roles of extracellular calcium-sensing receptor in the central nervous system. J Neurosci Res 2010; 88:2073-82. [PMID: 20336672 DOI: 10.1002/jnr.22391] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The G-protein-coupled calcium-sensing receptor (CaSR), upon activation by Ca(2+) or other physiologically relevant polycationic molecules, performs diverse functions in the brain. The CaSR is widely expressed in the central nervous system (CNS) and is characterized by a robust increase in its expression during postnatal brain development over adult levels throughout the CNS. Developmental increases in CaSR levels in brain correlate with myelinogenesis. Indeed, neural stem cells differentiating to the oligodendrocyte lineage exhibit the highest CaSR expression compared with those differentiating to astrocytic or neuronal lineages. In adult CNS, CaSR has broad relevance in maintaining local ionic homeostasis. CaSR shares an evolutionary relationship with the metabotropic glutamate receptor and forms heteromeric complexes with the type B-aminobutyric acid receptor subunits that affects its cell surface expression, activation, signaling, and functions. In normal physiology as well as in pathologic conditions, CaSR is activated by signals arising from mineral ions, amino acids, polyamines, glutathione, and amyloid-beta in conjunction with Ca(2+) and other divalent cationic ligands. CaSR activation regulates membrane excitability of neurons and glia and affects myelination, olfactory and gustatory signal integration, axonal and dendritic growth, and gonadotrophin-releasing hormonal-neuronal migration. Insofar as the CaSR is a clinically important therapeutic target for parathyroid disorders, development of its agonists or antagonists as therapeutics for CNS disorder could be a major breakthrough.
Collapse
Affiliation(s)
- Sanghamitra Bandyopadhyay
- Developmental Toxicology, Indian Institute of Toxicology Research (Council of Scientific and Industrial Rsearch; CSIR), Lucknow, India
| | | | | |
Collapse
|