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Bhuiyan P, Chen Y, Karim M, Dong H, Qian Y. Bidirectional communication between mast cells and the gut-brain axis in neurodegenerative diseases: Avenues for therapeutic intervention. Brain Res Bull 2021; 172:61-78. [PMID: 33892083 DOI: 10.1016/j.brainresbull.2021.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 03/02/2021] [Accepted: 04/17/2021] [Indexed: 12/12/2022]
Abstract
Although the global incidence of neurodegenerative diseases has been steadily increasing, especially in adults, there are no effective therapeutic interventions. Neurodegeneration is a heterogeneous group of disorders that is characterized by the activation of immune cells in the central nervous system (CNS) (e.g., mast cells and microglia) and subsequent neuroinflammation. Mast cells are found in the brain and the gastrointestinal tract and play a role in "tuning" neuroimmune responses. The complex bidirectional communication between mast cells and gut microbiota coordinates various dynamic neuro-cellular responses, which propagates neuronal impulses from the gastrointestinal tract into the CNS. Numerous inflammatory mediators from degranulated mast cells alter intestinal gut permeability and disrupt blood-brain barrier, which results in the promotion of neuroinflammatory processes leading to neurological disorders, thereby offsetting the balance in immune-surveillance. Emerging evidence supports the hypothesis that gut-microbiota exert a pivotal role in inflammatory signaling through the activation of immune and inflammatory cells. Communication between inflammatory cytokines and neurocircuits via the gut-brain axis (GBA) affects behavioral responses, activates mast cells and microglia that causes neuroinflammation, which is associated with neurological diseases. In this comprehensive review, we focus on what is currently known about mast cells and the gut-brain axis relationship, and how this relationship is connected to neurodegenerative diseases. We hope that further elucidating the bidirectional communication between mast cells and the GBA will not only stimulate future research on neurodegenerative diseases but will also identify new opportunities for therapeutic interventions.
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Affiliation(s)
- Piplu Bhuiyan
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, PR China
| | - Yinan Chen
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, PR China
| | - Mazharul Karim
- College of Pharmacy, Western University of Health Science, 309 East 2nd Street, Pomona, CA, 91766, USA
| | - Hongquan Dong
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, PR China.
| | - Yanning Qian
- Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, PR China.
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Abstract
Current experimental stroke research has evolved to focus on detailed understanding of the brain’s self-protective and restorative mechanisms, and harness this knowledge for development of new therapies. In this context, the role of peptidases and neuropeptides is of growing interest. In this focused review, peptidase neurolysin (Nln) and its extracellular peptide substrates are briefly discussed in relation to pathophysiology of ischemic stroke. Upregulation of Nln following stroke is viewed as a compensatory cerebroprotective mechanism in the acute phase of stroke, because the main neuropeptides inactivated by Nln are neuro/cerebrotoxic (bradykinin, substance P, neurotensin, angiotensin II, hemopressin), whereas the peptides generated by Nln are neuro/cerebroprotective (angiotensin-(1–7), Leu-/Met-enkephalins). This notion is confirmed by experimental studies documenting aggravation of stroke outcomes in mice after inhibition of Nln following stroke, and dramatic improvement of stroke outcomes in mice overexpressing Nln in the brain. The role of Nln in the (sub)chronic phase of stroke is less clear and it is likely, that this peptidase does not have a major role in neural repair mechanisms. This is because, the substrates of Nln are less uniform in modulating neurorestorative mechanisms in one direction, some appearing to have neural repair enhancing/stimulating potential, whereas others doing the opposite. Future studies focusing on the role of Nln in pathophysiology of stroke should determine its potential as a cerebroprotective target for stroke therapy, because its unique ability to modulate multiple neuropeptide systems critically involved in brain injury mechanisms is likely advantageous over modulation of one pathogenic pathway for stroke pharmacotherapy.
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Affiliation(s)
- Vardan T Karamyan
- Department of Pharmaceutical Sciences and Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, TX, USA
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Saiyasit N, Chunchai T, Apaijai N, Pratchayasakul W, Sripetchwandee J, Chattipakorn N, Chattipakorn SC. Chronic high-fat diet consumption induces an alteration in plasma/brain neurotensin signaling, metabolic disturbance, systemic inflammation/oxidative stress, brain apoptosis, and dendritic spine loss. Neuropeptides 2020; 82:102047. [PMID: 32327191 DOI: 10.1016/j.npep.2020.102047] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 02/06/2023]
Abstract
Chronic high-fat diet (HFD) consumption caused not only negative effects on obesity and metabolic disturbance, but also instigated several brain pathologies, including dendritic spine loss. In addition, alterations in plasma/brain neurotensin (NT) levels and NT signaling were observed in obesity. However, the mechanistic link between the NT levels in plasma and brain, NT signaling, and peripheral/brain pathologies following prolonged HFD consumption still needs to be elucidated. We hypothesized that an increase in peripheral/brain NT signaling were associated with peripheral/brain pathologies after prolonged HFD consumption. Male Wistar rats (n = 24) were given either a normal diet (ND) or a HFD for 12 and 40 weeks. At the end of each time course, metabolic parameters and plasma NT levels were measured. Rats were then decapitated and the brains were examined the levels of brain NT, hippocampal reactive oxygen species, the number of Iba-1 positive cells, the dendritic spine densities, and the expression of NT-, mitophagy-, autophagy-, and apoptotic-related proteins. The findings showed an increase in the level of plasma NT with dyslipidemia, metabolic disturbances, systemic inflammation/oxidative stress, and hippocampal pathologies in rats fed HFD for 12 and 40 weeks. The expression of brain NT signaling and brain apoptosis were markedly increased after 40 weeks of HFD feeding. These results indicated that the alteration in the level of circulating/brain NT and its downstream signaling were associated with central and peripheral pathologies after long-term HFD intake. Therefore, these alterations in NT level or its signaling could be considered as a therapeutic target in treating obesity.
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Affiliation(s)
- Napatsorn Saiyasit
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Titikorn Chunchai
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nattayaporn Apaijai
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Wasana Pratchayasakul
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Jirapas Sripetchwandee
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nipon Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Siriporn C Chattipakorn
- Neurophysiology Unit, Cardiac Electrophysiology Research, and Training Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Excellence in Cardiac Electrophysiology, Chiang Mai University, Chiang Mai 50200, Thailand; Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Chiang Mai 50200, Thailand.
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Jayaraman S, Al Shoyaib A, Kocot J, Villalba H, Alamri FF, Rashid M, Wangler NJ, Chowdhury EA, German N, Arumugam TV, Abbruscato TJ, Karamyan VT. Peptidase neurolysin functions to preserve the brain after ischemic stroke in male mice. J Neurochem 2019; 153:120-137. [PMID: 31486527 DOI: 10.1111/jnc.14864] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/26/2019] [Accepted: 08/28/2019] [Indexed: 12/13/2022]
Abstract
Previous studies documented up-regulation of peptidase neurolysin (Nln) after brain ischemia, however, the significance of Nln function in the post-stroke brain remained unknown. The aim of this study was to assess the functional role of Nln in the brain after ischemic stroke. Administration of a specific Nln inhibitor Agaricoglyceride A (AgaA) to mice after stroke in a middle cerebral artery occlusion model, dose-dependently aggravated injury measured by increased infarct and edema volumes, blood-brain barrier disruption, increased levels of interleukin 6 and monocyte chemoattractant protein-1, neurological and motor deficit 24 h after stroke. In this setting, AgaA resulted in inhibition of Nln in the ischemic hemisphere leading to increased levels of Nln substrates bradykinin, neurotensin, and substance P. AgaA lacked effects on several physiological parameters and appeared non-toxic to mice. In a reverse approach, we developed an adeno-associated viral vector (AAV2/5-CAG-Nln) to overexpress Nln in the mouse brain. Applicability of AAV2/5-CAG-Nln to transduce catalytically active Nln was confirmed in primary neurons and in vivo. Over-expression of Nln in the mouse brain was also accompanied by decreased levels of its substrates. Two weeks after in vivo transduction of Nln using the AAV vector, mice were subjected to middle cerebral artery occlusion and the same outcome measures were evaluated 72 h later. These experiments revealed that abundance of Nln in the brain protects animals from stroke. This study is the first to document functional significance of Nln in pathophysiology of stroke and provide evidence that Nln is an endogenous mechanism functioning to preserve the brain from ischemic injury.
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Affiliation(s)
- Srinidhi Jayaraman
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Abdullah Al Shoyaib
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Joanna Kocot
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Heidi Villalba
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Faisal F Alamri
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Mamoon Rashid
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Naomi J Wangler
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Ekram A Chowdhury
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Nadezhda German
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Thiruma V Arumugam
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Thomas J Abbruscato
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA.,Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
| | - Vardan T Karamyan
- Department of Pharmaceutical Sciences, School of Pharmacy, TTUHSC, Amarillo, Texas, USA.,Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, Texas, USA
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Karamyan VT. Peptidase neurolysin is an endogenous cerebroprotective mechanism in acute neurodegenerative disorders. Med Hypotheses 2019; 131:109309. [PMID: 31443781 DOI: 10.1016/j.mehy.2019.109309] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/06/2019] [Accepted: 07/12/2019] [Indexed: 12/28/2022]
Abstract
Stroke and traumatic brain injury (TBI) are significant clinical problems characterized by high rate of mortality and long-lasting disabilities, and an unmet need for new treatments. Current experimental stroke and TBI research are evolving to focus more on understanding the brain's self-protective mechanisms to meet the critical need of developing new therapies for these disorders. In this hypothesis-based manuscript, I provide several lines of evidence that peptidase neurolysin (Nln) is one of the brain's potent, self-protective mechanisms promoting preservation and recovery of the brain after acute injury. Based on published experimental observations and ongoing studies in our laboratory, I posit that Nln is a compensatory and cerebroprotective mechanism in the post-stroke/TBI brain that functions to process a diverse group of extracellular neuropeptides and by that to reduce excitotoxicity, oxidative stress, edema formation, blood brain barrier hyper-permeability, and neuroinflammation. If this hypothesis is correct, Nln could potentially serve as a single therapeutic target to modulate the function of multiple targets, the involved neuropeptide systems, critically involved in various mechanisms of brain injury and cerebroprotection/restoration. Such multi-pathway target would be highly desired for pharmacotherapy of stroke and TBI, because targeting one pathophysiological pathway has proven to be ineffective for such complex disorders.
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Affiliation(s)
- Vardan T Karamyan
- Department of Pharmaceutical Sciences and Center for Blood Brain Barrier Research, School of Pharmacy, TTUHSC, Amarillo, TX, United States.
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Muehlmann AM, Wolfman SL, Devine DP. The role of neurotensin in vulnerability for self-injurious behaviour: studies in a rodent model. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2018; 62:997-1007. [PMID: 30033601 DOI: 10.1111/jir.12519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 03/10/2018] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Self-injurious behaviour is a debilitating characteristic that is commonly expressed in people with autism and other neurodevelopmental disorders, but the neurobiological basis of this maladaptive behaviour is not understood. Abnormal dopaminergic and glutamatergic neurotransmission has been implicated, especially in relation to basal ganglia and mesocorticolimbic circuits. As neurotensin is an important modulator of dopamine and glutamate in these circuits, we investigated its potential role in vulnerability for self-injury, using the pemoline model in rats. METHODS Male Long-Evans rats were injected once daily with the psychostimulant pemoline or peanut oil vehicle on each of five consecutive days. Self-injury was quantified by measuring the area of injuries for each rat on each day of the experiment. Each brain was harvested on the sixth day, and the striatum and ventral tegmentum were dissected. Neurotensin-like immunoreactivity was quantified by radioimmunoassay from the dissected brain regions of some of the rats. Membrane and intracellular neurotensin receptor NTS1 were assayed from the striata of the remaining pemoline-treated or vehicle-treated rats by Western blot. In an additional experiment, male Long-Evans rats were treated with daily injections of vehicle or pemoline, and the NTS1 neurotensin receptor agonist PD149163 or the NTS1 receptor antagonist SR48692 (or respective vehicle solutions) was co-administered twice daily throughout the pemoline treatment regimen. The areas of injured tissue were measured, and the duration of self-injurious oral contact was quantified by video-recorded time samples throughout each day. RESULTS Striatal neurotensin immunoreactivity was found to be significantly higher in pemoline-treated than in vehicle-treated rats. Moreover, both membrane-bound and intracellular levels of NTS1 receptor were significantly higher in the striata of pemoline-treated rats than in the striata of the vehicle-treated controls. When the NTS1 receptor agonist PD149163 was co-administered during the pemoline treatment regimen, it prolonged the daily durations of self-injurious oral contact and increased the severity of the injuries in the self-injurious rats. Conversely, co-administration of the NTS1 receptor antagonist SR48692 diminished the daily durations of self-injurious oral contact and decreased the severity of the injuries. CONCLUSIONS The elevation of striatal neurotensin immunoreactivity during pemoline treatment, coupled with the effects of the NTS1 agonist and antagonist, suggests that neurotensin transmission in the striatum may be an important modulator of self-injurious behaviour in the pemoline model. Overall, the convergence of the behavioural and biochemical findings suggests that neurotensin signalling could be an important target for pharmacotherapeutic interventions for self-injurious behaviour.
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Affiliation(s)
- A M Muehlmann
- Department of Psychiatry, University of Florida, Gainesville, FL, USA
| | - S L Wolfman
- Department of Psychology, Behavioural and Cognitive Neuroscience Program, University of Florida, Gainesville, FL, USA
| | - D P Devine
- Department of Psychology, Behavioural and Cognitive Neuroscience Program, University of Florida, Gainesville, FL, USA
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Abstract
Hybrid compounds (also known as chimeras, designed multiple ligands, bivalent compounds) are chemical units where two active components, usually possessing affinity and selectivity for distinct molecular targets, are combined as a single chemical entity. The rationale for using a chimeric approach is well documented as such novel drugs are characterized by their enhanced enzymatic stability and biological activity. This allows their use at lower concentrations, increasing their safety profile, particularly when considering undesirable side effects. In the group of synthetic bivalent compounds, drugs combining pharmacophores having affinities toward opioid and neurokinin-1 receptors have been extensively studied as potential analgesic drugs. Indeed, substance P is known as a major endogenous modulator of nociception both in the peripheral and central nervous systems. Hence, synthetic peptide fragments showing either agonism or antagonism at neurokinin 1 receptor were both assigned with analgesic properties. However, even though preclinical studies designated neurokinin-1 receptor antagonists as promising analgesics, early clinical studies revealed a lack of efficacy in human. Nevertheless, their molecular combination with enkephalin/endomorphin fragments has been considered as a valuable approach to design putatively promising ligands for the treatment of pain. This paper is aimed at summarizing a 20-year journey to the development of potent analgesic hybrid compounds involving an opioid pharmacophore and devoid of unwanted side effects. Additionally, the legitimacy of considering neurokinin-1 receptor ligands in the design of chimeric drugs is discussed.
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Rouibi K, Bose P, Rompré PP, Warren RA. Ventral Midbrain NTS1 Receptors Mediate Conditioned Reward Induced by the Neurotensin Analog, D-Tyr[11]neurotensin. Front Neurosci 2015; 9:470. [PMID: 26733785 PMCID: PMC4686738 DOI: 10.3389/fnins.2015.00470] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 11/24/2015] [Indexed: 11/13/2022] Open
Abstract
The present study was aimed at characterizing the mechanisms by which neurotensin (NT) is acting within the ventral midbrain to induce a psychostimulant-like effect. In a first experiment, we determine which subtype(s) of NT receptors is/are involved in the reward-inducing effect of ventral midbrain microinjection of NT using the conditioned place-preference (CPP) paradigm. In a second study, we used in vitro patch clamp recording technique to characterize the NT receptor subtype(s) involved in the modulation of glutamatergic neurotransmission (excitatory post-synaptic current, EPSC) in ventral tegmental neurons that expressed (Ih+), or do not express (Ih-), a hyperpolarization-activated cationic current. Behavioral studies were performed with adult male Long-Evans rats while electrophysiological recordings were obtained from brain slices of rat pups aged between 14 and 21 days. Results show that bilateral ventral midbrain microinjections of 1.5 and 3 nmol of D-Tyr[11]NT induced a CPP that was respectively attenuated or blocked by co-injection with 1.2 nmol of the NTS1/NTS2 antagonist, SR142948, and the preferred NTS1 antagonist, SR48692. In electrophysiological experiments, D-Tyr[11]NT (0.01-0.5 μM) attenuated glutamatergic EPSC in Ih+ but enhanced it in Ih- neurons. The attenuation effect (Ih+ neurons) was blocked by SR142948 (0.1 μM) while the enhancement effect (Ih- neurons) was blocked by both antagonists (0.1 μM). These findings suggest that (i) NT is acting on ventral midbrain NTS1 receptors to induce a rewarding effect and (ii) that this psychostimulant-like effect could be due to a direct action of NT on dopamine neurons and/or an enhancement of glutamatergic inputs to non-dopamine (Ih-) neurons.
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Affiliation(s)
- Khalil Rouibi
- Department of Neurosciences, Université de MontréalMontréal, QC, Canada; FRQ-S Research Group in Behavioral Neurobiology, Department of Psychology, Concordia UniversityMontréal, QC, Canada
| | - Poulomee Bose
- Department of Psychiatry, Faculty of Medicine, Université de Montréal Montréal, QC, Canada
| | - Pierre-Paul Rompré
- Department of Neurosciences, Université de MontréalMontréal, QC, Canada; FRQ-S Research Group in Behavioral Neurobiology, Department of Psychology, Concordia UniversityMontréal, QC, Canada
| | - Richard A Warren
- Department of Psychiatry, Faculty of Medicine, Université de Montréal Montréal, QC, Canada
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Kleczkowska P, Kawalec M, Bujalska-Zadrozny M, Filip M, Zablocka B, Lipkowski AW. Effects of the Hybridization of Opioid and Neurotensin Pharmacophores on Cell Survival in Rat Organotypic Hippocampal Slice Cultures. Neurotox Res 2015; 28:352-60. [PMID: 26286504 DOI: 10.1007/s12640-015-9553-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/04/2015] [Accepted: 08/04/2015] [Indexed: 10/23/2022]
Abstract
Several neurotransmitter and neuromodulatory systems can control physiological glutamatergic activity. For example, opioid receptor ligands were shown to partially inhibit N-methyl-D-aspartic acid (NMDA) receptor-dependent glutamatergic excitotoxicity. Also, the endogenous tridecapeptide neurotensin (NT) was found to modulate excessive glutamate release and glutamate receptor activity in neurons. Alternatively to the one target-one drug approach, it has been well documented that hybrid compounds encompassing two pharmacophores in one molecular scaffold can represent more potent drugs. Moreover, such structures with dual activity can potentially enable a reduction of undesirable side effects and/or improved bioavailability. Herein, we describe the neuroprotective potential of an opioid-NT hybrid peptide (PK20), which was recently designed and synthesized within our group. The protective properties of PK20, assessed in an in vitro model of excitotoxic injury in organotypic hippocampal slice cultures subjected to NMDA, were compared to the effects caused by NT. Our results indicate that PK20 is a potent anti-neurodegenerative agent. Moreover, co-administered with NMDA, PK20 (25-100 ng/ml) dose-dependently reduced hippocampal cell death, determined by a decrease in the propidium iodide signal. We also report for the first time the significant NT-induced neuroprotective effect, as its application (50-100 ng/ml) to hippocampal slice cultures protected CA1 damage against neurotoxicity caused by NMDA.
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Affiliation(s)
- Patrycja Kleczkowska
- Department of Neuropeptides, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland. .,Department of Pharmacodynamics, Centre for Preclinical Research and Technology, CEPT, Medical University of Warsaw, 1B Banacha Str., 02-106, Warsaw, Poland.
| | - Maria Kawalec
- Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland
| | - Magdalena Bujalska-Zadrozny
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, CEPT, Medical University of Warsaw, 1B Banacha Str., 02-106, Warsaw, Poland
| | - Małgorzata Filip
- Department of Toxicology, Faculty of Pharmacy, Jagiellonian University, College of Medicum, 9 Medyczna Str., 30-688, Kraków, Poland.,Laboratory of Drug Addiction Pharmacology, Department of Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna Str., 31-343, Kraków, Poland
| | - Barbara Zablocka
- Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland
| | - Andrzej W Lipkowski
- Department of Neuropeptides, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawinskiego Str., 02-106, Warsaw, Poland
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Theoharides TC, Stewart JM, Panagiotidou S, Melamed I. Mast cells, brain inflammation and autism. Eur J Pharmacol 2015; 778:96-102. [PMID: 25941080 DOI: 10.1016/j.ejphar.2015.03.086] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/15/2015] [Accepted: 03/05/2015] [Indexed: 12/28/2022]
Abstract
Increasing evidence indicates that brain inflammation is involved in the pathogenesis of neuropsychiatric diseases. Mast cells (MCs) are located perivascularly close to neurons and microglia, primarily in the leptomeninges, thalamus, hypothalamus and especially the median eminence. Corticotropin-releasing factor (CRF) is secreted from the hypothalamus under stress and, together with neurotensin (NT), can stimulate brain MCs to release inflammatory and neurotoxic mediators that disrupt the blood-brain barrier (BBB), stimulate microglia and cause focal inflammation. CRF and NT synergistically stimulate MCs and increase vascular permeability; these peptides can also induce each other׳s surface receptors on MCs leading to autocrine and paracrine effects. As a result, brain MCs may be involved in the pathogenesis of "brain fog," headaches, and autism spectrum disorders (ASDs), which worsen with stress. CRF and NT are significantly increased in serum of ASD children compared to normotypic controls further strengthening their role in the pathogenesis of autism. There are no clinically affective treatments for the core symptoms of ASDs, but pilot clinical trials using natural-antioxidant and anti-inflammatory molecules reported statistically significant benefit.
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Affiliation(s)
- Theoharis C Theoharides
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, USA; Department of Internal Medicine, Tufts University School of Medicine and Tufts Medical Center, Boston, MA, USA; Department of Psychiatry, Tufts University School of Medicine and Tufts Medical Center, Boston, MA, USA.
| | - Julia M Stewart
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, USA
| | - Smaro Panagiotidou
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, USA
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Kritis AA, Stamoula EG, Paniskaki KA, Vavilis TD. Researching glutamate - induced cytotoxicity in different cell lines: a comparative/collective analysis/study. Front Cell Neurosci 2015; 9:91. [PMID: 25852482 PMCID: PMC4362409 DOI: 10.3389/fncel.2015.00091] [Citation(s) in RCA: 227] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 02/26/2015] [Indexed: 12/21/2022] Open
Abstract
Although glutamate is one of the most important excitatory neurotransmitters of the central nervous system, its excessive extracellular concentration leads to uncontrolled continuous depolarization of neurons, a toxic process called, excitotoxicity. In excitotoxicity glutamate triggers the rise of intracellular Ca2+ levels, followed by up regulation of nNOS, dysfunction of mitochondria, ROS production, ER stress, and release of lysosomal enzymes. Excessive calcium concentration is the key mediator of glutamate toxicity through over activation of ionotropic and metabotropic receptors. In addition, glutamate accumulation can also inhibit cystine (CySS) uptake by reversing the action of the CySS/glutamate antiporter. Reversal of the antiporter action reinforces the aforementioned events by depleting neurons of cysteine and eventually glutathione’s reducing potential. Various cell lines have been employed in the pursuit to understand the mechanism(s) by which excitotoxicity affects the cells leading them ultimately to their demise. In some cell lines glutamate toxicity is exerted mainly through over activation of NMDA, AMPA, or kainate receptors whereas in other cell lines lacking such receptors, the toxicity is due to glutamate induced oxidative stress. However, in the greatest majority of the cell lines ionotropic glutamate receptors are present, co-existing to CySS/glutamate antiporters and metabotropic glutamate receptors, supporting the assumption that excitotoxicity effect in these cells is accumulative. Different cell lines differ in their responses when exposed to glutamate. In this review article the responses of PC12, SH-SY5Y, HT-22, NT-2, OLCs, C6, primary rat cortical neurons, RGC-5, and SCN2.2 cell systems are systematically collected and analyzed.
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Affiliation(s)
- Aristeidis A Kritis
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Eleni G Stamoula
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Krystallenia A Paniskaki
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
| | - Theofanis D Vavilis
- Laboratory of Physiology, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki Greece
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Theoharides TC, Athanassiou M, Panagiotidou S, Doyle R. Dysregulated brain immunity and neurotrophin signaling in Rett syndrome and autism spectrum disorders. J Neuroimmunol 2014; 279:33-8. [PMID: 25669997 DOI: 10.1016/j.jneuroim.2014.12.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 11/18/2014] [Accepted: 12/02/2014] [Indexed: 12/21/2022]
Abstract
Rett syndrome is a neurodevelopmental disorder, which occurs in about 1:15,000 females and presents with neurologic and communication defects. It is transmitted as an X-linked dominant linked to mutations of the methyl-CpG-binding protein (MeCP2), a gene transcription suppressor, but its definitive pathogenesis is unknown thus hindering development of effective treatments. Almost half of children with Rett syndrome also have behavioral symptoms consistent with those of autism spectrum disorders (ASDs). PubMed was searched (2005-2014) using the terms: allergy, atopy, brain, brain-derived neurotrophic factor (BDNF), corticotropin-releasing hormone (CRH), cytokines, gene mutations, inflammation, mast cells (MCs), microglia, mitochondria, neurotensin (NT), neurotrophins, seizures, stress, and treatment. There are a number of intriguing differences and similarities between Rett syndrome and ASDs. Rett syndrome occurs in females, while ASDs more often in males, and the former has neurologic disabilities unlike ASDs. There is evidence of dysregulated immune system early in life in both conditions. Lack of microglial phagocytosis and decreased levels of BDNF appear to distinguish Rett syndrome from ASDs, in which there is instead microglia activation and/or proliferation and possibly defective BDNF signaling. Moreover, brain mast cell (MC) activation and focal inflammation may be more prominent in ASDs than Rett syndrome. The flavonoid luteolin blocks microglia and MC activation, provides BDNF-like activity, reverses Rett phenotype in mouse models, and has a significant benefit in children with ASDs. Appropriate formulations of luteolin or other natural molecules may be useful in the treatment of Rett syndrome.
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Affiliation(s)
- Theoharis C Theoharides
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA; Department of Internal Medicine, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA; Tufts Medical Center, Boston, MA, USA; Department of Psychiatry, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA.
| | - Marianna Athanassiou
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA
| | - Smaro Panagiotidou
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA, USA
| | - Robert Doyle
- Pediatric Psychopharmacology Unit, Massachusetts General Hospital, Boston MA, USA; Harvard Medical School, Boston MA, USA
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Keiser AA, Matazel KS, Esser MK, Feifel D, Prus AJ. Systemic administration of the neurotensin NTS₁-receptor agonist PD149163 improves performance on a memory task in naturally deficient male brown Norway rats. Exp Clin Psychopharmacol 2014; 22:541-7. [PMID: 25222546 PMCID: PMC4250335 DOI: 10.1037/a0037912] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Agonists for the neurotensin NTS₁ receptor consistently exhibit antipsychotic effects in animal models without producing catalepsy, suggesting that NTS₁-receptor agonists may be a novel class of drugs to treat schizophrenia. Moreover, studies utilizing NTS₁ agonists have reported improvements in some aspects of cognitive functioning, including prepulse inhibition and learning procedures, which suggest an ability of NTS₁-receptor agonists to diminish neurocognitive deficits. The present study sought to assess both baseline delay-induced memory performance and the effects of NTS₁-receptor activation on learning and memory consolidation in male Long-Evans and Brown Norway rats using a delayed nonmatch-to-position task radial arm-maze task. In the absence of drugs, Brown Norway rats displayed a significant increase in spatial memory errors following 3-, 7-, and 24-hr delay, whereas Long-Evans rats exhibited an increase in spatial memory errors following only a 7-, and 24-hr delay. With Brown Norway rats, administration of PD149163 before or after an information trial significantly reduced errors during a retention trial after a 24 hr delay. Administration of the NTS(1/2)-receptor antagonist SR142948 prior to the information trial did not affect retention-trial errors. These data are consistent with previous findings that Brown Norway rats have natural cognitive deficits and that they may be useful for assessing putative antipsychotic drugs for cognitive efficacy. Moreover, the results of this study support previous findings suggesting that NTS₁-receptor agonists may improve some aspects of cognitive functioning.
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Hypothalamic neurotensin projections promote reward by enhancing glutamate transmission in the VTA. J Neurosci 2013; 33:7618-26. [PMID: 23637156 DOI: 10.1523/jneurosci.2588-12.2013] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The lateral hypothalamus (LH) sends a dense glutamatergic and peptidergic projection to dopamine neurons in the ventral tegmental area (VTA), a cell group known to promote reinforcement and aspects of reward. The role of the LH to VTA projection in reward-seeking behavior can be informed by using optogenetic techniques to dissociate the actions of LH neurons from those of other descending forebrain inputs to the VTA. In the present study, we identify the effect of neurotensin (NT), one of the most abundant peptides in the LH to VTA projection, on excitatory synaptic transmission in the VTA and reward-seeking behavior. Mice displayed robust intracranial self-stimulation of LH to VTA fibers, an operant behavior mediated by NT 1 receptors (Nts1) and NMDA receptors. Whole-cell patch-clamp recordings of VTA dopamine neurons demonstrated that NT (10 nm) potentiated NMDA-mediated EPSCs via Nts1. Results suggest that NT release from the LH into the VTA activates Nts1, thereby potentiating NMDA-mediated EPSCs and promoting reward. The striking behavioral and electrophysiological effects of NT and glutamate highlight the LH to VTA pathway as an important component of reward.
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Bashir S, AL-Ayadhi L. Role of serum levels of neurotensin in children with autism spectrum disorder. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.npbr.2013.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Ferraro L, O'Connor WT, Beggiato S, Tomasini MC, Fuxe K, Tanganelli S, Antonelli T. Striatal NTS1 , dopamine D2 and NMDA receptor regulation of pallidal GABA and glutamate release--a dual-probe microdialysis study in the intranigral 6-hydroxydopamine unilaterally lesioned rat. Eur J Neurosci 2011; 35:207-20. [PMID: 22211865 DOI: 10.1111/j.1460-9568.2011.07949.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The current microdialysis study elucidates a functional interaction between the striatal neurotensin NTS(1) receptor and the striatal dopamine D(2) and N-methyl-d-aspartic acid (NMDA) receptors in the regulation of striatopallidal gamma-aminobutyric acid (GABA) and glutamate levels after an ipsilateral intranigral 6-hydroxydopamine-induced lesion of the ascending dopamine pathways to the striatum. Lateral globus pallidus GABA levels were higher in the lesioned group while no change was observed in striatal GABA and glutamate levels. The 6-hydroxydopamine-induced lesion did not alter the ability of intrastriatal NT (10 nm) to counteract the decrease in pallidal GABA and glutamate levels induced by the dopamine D(2) -like receptor agonist quinpirole (10 μm). A more pronounced increase in the intrastriatal NMDA- (10 μm) induced increase in pallidal GABA levels was observed in the lesioned group while it attenuated the increase in striatal glutamate levels and amplified the increase in pallidal glutamate levels compared with that observed in the controls. NT enhanced the NMDA-induced increase in pallidal GABA and glutamate and striatal glutamate levels; these effects were counteracted by the NTS(1) antagonist SR48692 (100 nm) in both groups. These findings demonstrate an inhibitory striatal dopamine D(2) and an excitatory striatal NMDA receptor regulation of striatopallidal GABA transmission in both groups. These actions are modulated by NT via antagonistic NTS(1) /D(2) and facilitatory NTS(1) /NMDA receptor-receptor interactions, leading to enhanced glutamate drive of the striatopallidal GABA neurons associated with motor inhibition, effects which all are counteracted by SR48692. Thus, NTS(1) antagonists in combination with conventional treatments may provide a novel therapeutic strategy in Parkinson's disease.
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Affiliation(s)
- Luca Ferraro
- Department of Clinical and Experimental Medicine, Pharmacology Section and LTTA Centre, University of Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy.
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Neuro-inflammation, blood-brain barrier, seizures and autism. J Neuroinflammation 2011; 8:168. [PMID: 22129087 PMCID: PMC3293070 DOI: 10.1186/1742-2094-8-168] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 11/30/2011] [Indexed: 12/15/2022] Open
Abstract
Many children with Autism Spectrum Diseases (ASD) present with seizure activity, but the pathogenesis is not understood. Recent evidence indicates that neuro-inflammation could contribute to seizures. We hypothesize that brain mast cell activation due to allergic, environmental and/or stress triggers could lead to focal disruption of the blood-brain barrier and neuro-inflammation, thus contributing to the development of seizures. Treating neuro-inflammation may be useful when anti-seizure medications are ineffective.
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Ferraro L, Beggiato S, Tomasini MC, Fuxe K, Tanganelli S, Antonelli T. Neurotensin regulates cortical glutamate transmission by modulating N-methyl-D-aspartate receptor functional activity: an in vivo microdialysis study. J Neurosci Res 2011; 89:1618-26. [PMID: 21656844 DOI: 10.1002/jnr.22686] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 04/05/2011] [Accepted: 04/11/2011] [Indexed: 12/30/2022]
Abstract
The aim of the present in vivo microdialysis study was to investigate whether the tridecapeptide neurotensin (NT) influences the N-methyl-D-aspartate (NMDA) receptor-mediated increase of cortical glutamate transmission in freely moving rats. Intracortical perfusion with NT influenced local extracellular glutamate levels in a bell-shaped, concentration-dependent manner. One hundred and three hundred nanomolar NT concentrations increased glutamate levels (151% ± 7% and 124% ± 3% of basal values, respectively). Higher (1,000 nM) and lower (10 nM) NT concentrations did not alter extracellular glutamate levels. The NT receptor antagonist SR48692 (100 nM) prevented the NT (100 nM)-induced increase in glutamate levels. NMDA (100 and 500 μM) perfusion induced a concentration-dependent increase in extracellular glutamate levels, the lower 10 μM NMDA concentration being ineffective. When NT (10 nM, a concentration by itself ineffective) was added in combination with NMDA (100 μM) to the perfusion medium, a significant greater increase in extracellular glutamate levels (169% ± 7%) was observed with respect to the increase induced by NMDA (100 μM) alone (139% ± 4%). SR48692 (100 nM) counteracted the increase in glutamate levels induced by the treatment with NT (10 nM) plus NMDA (100 μM). The enhancement of cortical glutamate levels induced by NMDA (100 and 500 μM) was partially antagonized by the presence of SR48692, at a concentration (100 nM) that by itself was ineffective in modulating glutamate release. These findings indicate that NT plays a relevant role in the regulation of cortical glutamatergic transmission, especially by modulating the functional activity of cortical NMDA receptors. A possible role in glutamate-mediated neurotoxicity is suggested.
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Affiliation(s)
- Luca Ferraro
- Department of Clinical and Experimental Medicine, Pharmacology Section and LTTA Centre, Universityof Ferrara, Ferrara, Italy.
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Ghanizadeh A. Targeting neurotensin as a potential novel approach for the treatment of autism. J Neuroinflammation 2010; 7:58. [PMID: 20920308 PMCID: PMC2958902 DOI: 10.1186/1742-2094-7-58] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 10/01/2010] [Indexed: 12/26/2022] Open
Abstract
The pathophysiology of autism remains obscure. Recently, serum neurotensin levels in children with autistic disorder have been found to be higher than those of normal children. Neurotensin is known to intensify neuronal NMDA-mediated glutamate signaling, which may cause apoptosis in autism. Further, an imbalance of glutamate/GABAergic system in autism has been described. These observations lead to a postulate that neurotensin may accentuate the hyperglutaminergic state in autism, leading to apoptosis. Targeting neurotensin might be a possible novel approach for the treatment of autism.
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Affiliation(s)
- Ahmad Ghanizadeh
- Research Center for Psychiatry and Behavioral Sciences, Shiraz University of Medical Sciences, Hafez Hospital, Shiraz, Iran.
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Gandou C, Ohtani A, Senzaki K, Shiga T. Neurotensin promotes the dendrite elongation and the dendritic spine maturation of the cerebral cortex in vitro. Neurosci Res 2010; 66:246-55. [DOI: 10.1016/j.neures.2009.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/16/2009] [Accepted: 11/17/2009] [Indexed: 01/07/2023]
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Stolakis V, Kalafatakis K, Botis J, Zarros A, Liapi C. The regulatory role of neurotensin on the hypothalamic-anterior pituitary axons: emphasis on the control of thyroid-related functions. Neuropeptides 2010; 44:1-7. [PMID: 19878995 DOI: 10.1016/j.npep.2009.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 09/29/2009] [Accepted: 09/30/2009] [Indexed: 12/14/2022]
Abstract
Neurotensin (NT) is a 13 amino acid neurohormone and/or neuromodulator, located in the synaptic vesicles and released from the neuronal terminals in a calcium-dependent manner. This peptide is present among mammalian and nonmammalian species, mainly in the central nervous system and the gastrointestinal tract. Due to its neuroendocrine activity, NT has been related to the pathophysiology of a series of disorders, such as schizophrenia, drug-abuse, Parkinson's disease, cancer, stroke, eating disorders and other neurodegenerative conditions. Moreover, NT participates in the physiology of pain-induction, central blood pressure control and inflammation. NT also plays an important interactive role in all components of the hypothalamic-anterior pituitary circuit, which is mediated by an endocrine, paracrine or/and autocrine manner, towards most of the anatomical regions that define this circuit. A considerable amount of data implicates NT in thyroid-related regulation through this circuit, the exact mechanisms of which should be further investigated for the potential development of more targeted approaches towards the treatment of thyroid-related endocrine diseases. The aim of this study was to provide an up-to-date review of the literature concerning the regulatory role of NT on the hypothalamic-anterior pituitary axons, with an emphasis on the control of thyroid-related functions.
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Affiliation(s)
- Vasileios Stolakis
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Petkova-Kirova P, Rakovska A, Della Corte L, Zaekova G, Radomirov R, Mayer A. Neurotensin modulation of acetylcholine, GABA, and aspartate release from rat prefrontal cortex studied in vivo with microdialysis. Brain Res Bull 2008; 77:129-35. [PMID: 18721670 DOI: 10.1016/j.brainresbull.2008.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Accepted: 04/14/2008] [Indexed: 11/17/2022]
Abstract
The effects of the peptide transmitter neurotensin (NT) on the release of acetylcholine (ACh), gamma-aminobutyric acid (GABA), glutamate (Glu), aspartate (Asp), and taurine from the prefrontal cortex (PFC) of freely moving rats were studied by transversal microdialysis. Neurotensin (0.2 and 1 microM) administered locally in the PFC produced a concentration-dependent increase in the extracellular levels of ACh, GABA, and Asp, but not of Glu or taurine. The increase produced by 1 microM NT reached a maximum of about 240% for ACh, 370% for GABA, and 380% for Asp. Lower doses of NT (0.05 microM) did not cause a significant change in ACh, GABA, or Asp output in the PFC. Higher concentrations of NT (2 microM) did not induce further increases in the level of neurotransmitters. A high-affinity selective neurotensin receptor (NTR1) antagonist SR 48692 (0.5 microM) perfused locally blocked neurotensin (1 microM)-evoked ACh, GABA, and Asp release. Local infusion of the sodium channel blocker tetrodotoxin (TTX) (1 microM) decreased the release of ACh, had no significant effect on GABA or Asp release, and prevented the 1 microM neurotensin-induced increase in ACh, GABA, and Asp output. Removal of calcium from the Ringer's solution prevented the peptide from having any effects on the neurotransmitters. Thus, in vivo NT plays a modulatory role in the PFC by interacting with cortical neurons releasing GABA and Asp and with ACh-containing neurons projecting to the PFC. The NT effects are of neural origin, as they are TTX-sensitive, and mediated by the NTR1 receptor, as they are antagonized by SR 48692.
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Affiliation(s)
- Polina Petkova-Kirova
- Institute of Biophysics, Bulgarian Academy of Sciences, Acad. G. Bonchev Street, bl. 21, 1113 Sofia, Bulgaria.
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Antonelli T, Tomasini MC, Fournier J, Mazza R, Tanganelli S, Pirondi S, Fuxe K, Ferraro L, Luca F. Neurotensin receptor involvement in the rise of extracellular glutamate levels and apoptotic nerve cell death in primary cortical cultures after oxygen and glucose deprivation. Cereb Cortex 2007; 18:1748-57. [PMID: 18063561 DOI: 10.1093/cercor/bhm217] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In view of the ability of neurotensin (NT) to increase glutamate release, the role of NT receptor mechanisms in oxygen-glucose deprivation (OGD)-induced neuronal degeneration in cortical cultures has been evaluated by measuring lactate dehydrogenase (LDH) levels, mitochondrial dehydrogenase activity with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide levels, and microtubule-associated protein 2 (MAP2) immunoreactivity. Apoptotic nerve cell death was analyzed measuring chromatin condensation with Hoechst 33258, annexin V staining, and caspase-3 activity. Furthermore, the involvement of glutamate excitotoxicity in the neurodegeneration-enhancing actions of NT was analyzed by measurement of extracellular glutamate levels. NT enhanced the OGD-induced increase of LDH, endogenous extracellular glutamate levels, and apoptotic nerve cell death. In addition, the peptide enhanced the OGD-induced loss of mitochondrial functionality and increase of MAP2 aggregations. These effects were blocked by the neurotensin receptor 1 (NTR1) antagonist SR48692. Unexpectedly, the antagonist at 100 nM counteracted not only the NT effects but also some OGD-induced biochemical and morphological alterations. These results suggest that NTR1 receptors may participate in neurodegenerative events induced by OGD in cortical cultures, used as an in vitro model of cortical ischemia. The NTR1 receptor antagonists could provide a new tool to explore the clinical possibilities and thus to move from chemical compound to effective drug.
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Affiliation(s)
- Tiziana Antonelli
- Department of Clinical and Experimental Medicine, Pharmacology Section, University of Ferrara, 44100 Ferrara, Italy
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Ferraro L, Tomasini MC, Mazza R, Fuxe K, Fournier J, Tanganelli S, Antonelli T. Neurotensin receptors as modulators of glutamatergic transmission. ACTA ACUST UNITED AC 2007; 58:365-73. [PMID: 18096238 DOI: 10.1016/j.brainresrev.2007.11.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 11/02/2007] [Accepted: 11/05/2007] [Indexed: 12/22/2022]
Abstract
Functional studies have provided evidence supporting the concept that the tridecapeptide neurotensin (NT) acts in the central nervous system as a classical neurotransmitter and/or as an important modulator of neuronal signalling. The role of NT in the regulation of the striatal amino acidergic transmission, mainly by antagonising D2 receptor function, will be analysed. In addition, in different rat brain regions, including the basal ganglia, the contribution of NT receptors in modulating and reinforcing glutamate signalling will be shown including the involvement of interactions between NT and NMDA receptors. Since the enhancement of glutamate transmission and in particular the excessive activation of NMDA receptors, has been postulated to be an important factor in the induction of glutamate-mediated neuronal damage, the involvement of NT in the glutamate-induced neurodegenerative effects will be discussed. Moving from these observations and in order to further investigate this issue, results from preliminary behavioural, functional and biochemical experiments will be presented on the putative neuroprotective effect obtained by the blockade of NT receptor 1 (NTS1) via the systemic administration of the selective NTS1 antagonist SR48692 in an in vivo animal model of Parkinson's disease [unilateral nigral 6-hydroxydopamine (6-OHDA) induced lesion of the nigrostriatal pathway].
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Affiliation(s)
- Luca Ferraro
- Department of Clinical and Experimental Medicine, Section of Pharmacology, University of Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
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Yamauchi R, Wada E, Kamichi S, Yamada D, Maeno H, Delawary M, Nakazawa T, Yamamoto T, Wada K. Neurotensin type 2 receptor is involved in fear memory in mice. J Neurochem 2007; 102:1669-1676. [PMID: 17697051 DOI: 10.1111/j.1471-4159.2007.04805.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Neurotensin receptor subtype 2 (Ntsr2) is a levocabastine-sensitive neurotensin receptor expressed diffusely throughout the mouse brain. Previously, we found that Ntsr2-deficient mice have an abnormality in the processing of thermal nociception. In this study, to examine the involvement of Ntsr2 in mouse behavior, we performed a fear-conditioning test in Ntsr2-deficient mice. In the contextual fear-conditioning test, the freezing response was significantly reduced in Ntsr2-deficient mice compared with that of wild-type mice. This reduction was observed from 1 h to 3 weeks after conditioning, and neither shock sensitivity nor locomotor activity was altered in Ntsr2-deficient mice. In addition, we found that Ntsr2 mRNA was predominantly expressed in cultured astrocytes and weakly expressed in cultured neurons derived from mouse brain. The combination of in situ hybridization and immunohistochemistry showed that Ntsr2 mRNA was dominantly expressed in glial fibrillary acidic protein positive cells in many brain regions including the hypothalamus, while Ntsr2 gene was co-expressed with neuron-specific microtubule associated protein-2 in limited numbers of cells. These results suggest that Ntsr2 in astrocytes and neurons may have unique function like a modulation of fear memory in the mouse brain.
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Affiliation(s)
- Rena Yamauchi
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Etsuko Wada
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Sari Kamichi
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Daisuke Yamada
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Hiroshi Maeno
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Mina Delawary
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Takanobu Nakazawa
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Tadashi Yamamoto
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Keiji Wada
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, JapanJapan Society for Promotion of Science, Chiyoda-ku, Tokyo, JapanCREST, Japan Science and Technology Agency, Kawaguchi, Saitama, JapanDivision of Oncology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
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27
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Antonelli T, Fuxe K, Tomasini MC, Mazzoni E, Agnati LF, Tanganelli S, Ferraro L. Neurotensin receptor mechanisms and its modulation of glutamate transmission in the brain: relevance for neurodegenerative diseases and their treatment. Prog Neurobiol 2007; 83:92-109. [PMID: 17673354 DOI: 10.1016/j.pneurobio.2007.06.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 05/18/2007] [Accepted: 06/19/2007] [Indexed: 11/30/2022]
Abstract
The extracellular accumulation of glutamate and the excessive activation of glutamate receptors, in particular N-methyl-D-aspartate (NMDA) receptors, have been postulated to contribute to the neuronal cell death associated with chronic neurodegenerative disorders such as Parkinson's disease. Findings are reviewed indicating that the tridecaptide neurotensin (NT) via activation of NT receptor subtype 1 (NTS1) promotes and reinforces endogenous glutamate signalling in discrete brain regions. The increase of striatal, nigral and cortical glutamate outflow by NT and the enhancement of NMDA receptor function by a NTS1/NMDA interaction that involves the activation of protein kinase C may favour the depolarization of NTS1 containing neurons and the entry of calcium. These results strengthen the hypothesis that NT may be involved in the amplification of glutamate-induced neurotoxicity in mesencephalic dopamine and cortical neurons. The mechanisms involved may include also antagonistic NTS1/D2 interactions in the cortico-striatal glutamate terminals and in the nigral DA cell bodies and dendrites as well as in the nigro-striatal DA terminals. The possible increase in NT levels in the basal ganglia under pathological conditions leading to the NTS1 enhancement of glutamate signalling may contribute to the neurodegeneration of the nigro-striatal dopaminergic neurons found in Parkinson's disease, especially in view of the high density of NTS1 receptors in these neurons. The use of selective NTS1 antagonists together with conventional drug treatments could provide a novel therapeutic approach for treatment of Parkinson's disease.
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Affiliation(s)
- T Antonelli
- Department of Clinical and Experimental Medicine, Section of Pharmacology, University of Ferrara, 44100 Ferrara, Italy
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Chen L, Yung KKL, Yung WH. Neurotensin selectively facilitates glutamatergic transmission in globus pallidus. Neuroscience 2006; 141:1871-8. [PMID: 16814931 DOI: 10.1016/j.neuroscience.2006.05.049] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2006] [Revised: 05/19/2006] [Accepted: 05/22/2006] [Indexed: 11/26/2022]
Abstract
The tridecapeptide neurotensin has been demonstrated to modulate neurotransmission in a number of brain regions. There is evidence that neurotensin receptors exist in globus pallidus presynaptically and postsynaptically. Whole-cell patch-clamp recordings were used to investigate the modulatory effects of neurotensin on glutamate and GABA transmission in this basal ganglia nucleus in rats. Neurotensin at 1 microM significantly increased the frequency of glutamate receptor-mediated miniature excitatory postsynaptic currents. In contrast, neurotensin had no effect on GABA(A) receptor-mediated miniature inhibitory postsynaptic currents. The presynaptic facilitation of neurotensin on glutamatergic transmission could be mimicked by the C-terminal fragment, neurotensin (8-13), but not by the N-terminal fragment, neurotensin (1-8). The selective neurotensin type-1 receptor antagonist, SR48692 {2-[(1-(7-chloro-4-quinolinyl)-5-2(2,6-dimethoxyphenyl)pyrazol-3-yl)carbonylamino]-tricyclo(3.3.1.1.(3.7))-decan-2-carboxylic acid}, blocked this facilitatory effect of neurotensin, and which itself had no effect on miniature excitatory postsynaptic currents. The specific phospholipase C inhibitor, U73122 {1-[6-[[17beta-3-methoyyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1H-pyrrole-2,5-dione}, significantly inhibit neurotensin-induced facilitation on glutamate release. Taken together with the reported postsynaptic depolarization of neurotensin in globus pallidus, it is suggested that neurotensin excites the globus pallidus neurons by multiple mechanisms which may provide a rationale for further investigations into its involvement in motor disorders originating from the basal ganglia.
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Affiliation(s)
- L Chen
- Department of Physiology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
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Onn SP, Wang XB. Differential modulation of anterior cingulate cortical activity by afferents from ventral tegmental area and mediodorsal thalamus. Eur J Neurosci 2005; 21:2975-92. [PMID: 15978009 DOI: 10.1111/j.1460-9568.2005.04122.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A distinct increase in cell firing activity is reported in prefrontal cortex during working memory tasks. The afferents that modulate this activity are not yet identified. Using in vivo intracellular recording and labelling of prefrontal cortical pyramidal neurons in anaesthetized rats, we systematically evaluated the influences of afferent projections arising from the ventral tegmental area (VTA) and mediodorsal thalamus (MD) by phasic electrical stimulation with a range of stimulus frequencies. Both VTA- and MD-responsive pyramidal neurons exhibited extensive intracortical axon arborization. Neither single shocks to the VTA at 0.2 Hz, nor low frequency trains of stimuli at 1-4 Hz (< 5 Hz) interrupted the periodicity of membrane bistability in bistable pyramidal neurons. However, high-frequency VTA-train stimulation (10-50 Hz) interrupted the bistability, and produced sustained membrane depolarizations accompanied by intense tonic firing in a frequency-dependent manner. Electrical stimulation of MD (10-50 Hz) did not produce sustained activity in the same PFC neurons. Thus, the sustained activity induced by high-frequency VTA trains is input selective. This effect of VTA-train stimulation was attenuated by systemic injection of the D1 receptor antagonist, SCH 23390, and blocked by acute dopamine (DA) depletion produced via alpha-methyl-para-tyrosine pre-treatment, suggesting that sustained cortical activity is mediated by DA. Chemical stimulation of VTA via intra-VTA infusion of NMDA induced sustained activity similar to VTA-train stimulation. Thus, while both VTA- and MD-responsive pyramidal neurons exhibited extensive intracortical axon arborization, VTA synapses (as opposed to MD synapses) may be critically positioned in the dendritic arborizations of anterior cingulate cortical pyramidal neurons, which may allow their modulation of sustained activity in prefrontal bistable neurons.
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Affiliation(s)
- Shao-Pii Onn
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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