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Tukacs V, Mittli D, Hunyadi-Gulyás É, Darula Z, Juhász G, Kardos J, Kékesi KA. Comparative analysis of hippocampal extracellular space uncovers widely altered peptidome upon epileptic seizure in urethane-anaesthetized rats. Fluids Barriers CNS 2024; 21:6. [PMID: 38212833 PMCID: PMC10782730 DOI: 10.1186/s12987-024-00508-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/31/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND The brain extracellular fluid (ECF), composed of secreted neurotransmitters, metabolites, peptides, and proteins, may reflect brain processes. Analysis of brain ECF may provide new potential markers for synaptic activity or brain damage and reveal additional information on pathological alterations. Epileptic seizure induction is an acute and harsh intervention in brain functions, and it can activate extra- and intracellular proteases, which implies an altered brain secretome. Thus, we applied a 4-aminopyridine (4-AP) epilepsy model to study the hippocampal ECF peptidome alterations upon treatment in rats. METHODS We performed in vivo microdialysis in the hippocampus for 3-3 h of control and 4-AP treatment phase in parallel with electrophysiology measurement. Then, we analyzed the microdialysate peptidome of control and treated samples from the same subject by liquid chromatography-coupled tandem mass spectrometry. We analyzed electrophysiological and peptidomic alterations upon epileptic seizure induction by two-tailed, paired t-test. RESULTS We detected 2540 peptides in microdialysate samples by mass spectrometry analysis; and 866 peptides-derived from 229 proteins-were found in more than half of the samples. In addition, the abundance of 322 peptides significantly altered upon epileptic seizure induction. Several proteins of significantly altered peptides are neuropeptides (Chgb) or have synapse- or brain-related functions such as the regulation of synaptic vesicle cycle (Atp6v1a, Napa), astrocyte morphology (Vim), and glutamate homeostasis (Slc3a2). CONCLUSIONS We have detected several consequences of epileptic seizures at the peptidomic level, as altered peptide abundances of proteins that regulate epilepsy-related cellular processes. Thus, our results indicate that analyzing brain ECF by in vivo microdialysis and omics techniques is useful for monitoring brain processes, and it can be an alternative method in the discovery and analysis of CNS disease markers besides peripheral fluid analysis.
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Affiliation(s)
- Vanda Tukacs
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
| | - Dániel Mittli
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
| | - Éva Hunyadi-Gulyás
- Laboratory of Proteomics Research, Biological Research Centre, Hungarian Research Network (HUN-REN), Temesvári Körút 62, Szeged, 6726, Hungary
| | - Zsuzsanna Darula
- Laboratory of Proteomics Research, Biological Research Centre, Hungarian Research Network (HUN-REN), Temesvári Körút 62, Szeged, 6726, Hungary
- Single Cell Omics Advanced Core Facility, Hungarian Centre of Excellence for Molecular Medicine, Temesvári Körút 62, Szeged, 6726, Hungary
| | - Gábor Juhász
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
- InnoScience Hungary Ltd., Bátori Út 9, Mátranovák, 3142, Hungary
| | - József Kardos
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary
| | - Katalin Adrienna Kékesi
- ELTE NAP Neuroimmunology Research Group, Department of Biochemistry, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary.
- Laboratory of Proteomics, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary.
- InnoScience Hungary Ltd., Bátori Út 9, Mátranovák, 3142, Hungary.
- Department of Physiology and Neurobiology, Institute of Biology, ELTE Eötvös Loránd University, Pázmány Péter Sétány 1/C, Budapest, 1117, Hungary.
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Llano DA, Devanarayan P, Devanarayan V. CSF peptides from VGF and other markers enhance prediction of MCI to AD progression using the ATN framework. Neurobiol Aging 2023; 121:15-27. [PMID: 36368195 DOI: 10.1016/j.neurobiolaging.2022.07.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 07/15/2022] [Accepted: 07/23/2022] [Indexed: 12/14/2022]
Abstract
The amyloid beta, tau, neurodegenerative markers framework has been proposed to serve as a system to classify and combine biomarkers for Alzheimer's Disease (AD). Although cerebrospinal (CSF) fluid AT (amyloid beta and tau)-based biomarkers have a well-established track record to distinguish AD from control subjects and to predict conversion from mild cognitive impairment (MCI) to AD, there is not an established non-tau based neurodegenerative ("N") marker from CSF. Here, we examine the ability of several candidate peptides in the CSF to serve as "N" markers to both classify disease state and predict MCI to AD conversion. We observed that although many putative N markers involved in synaptic processing and neuroinflammation were able to, when examined in isolation, distinguish MCI converters from non-converters, a derivative from VGF, when combined with AT markers, most strongly enhanced prediction of MCI to AD conversion. Low CSF VGF levels were also predictive of MCI to dementia conversion in the setting of normal AT markers, suggesting that it may serve as a very early predictor of dementia conversion. Other markers derived from neuronal pentraxin 2, GAP-43 and a 14-3-3 protein were also able to enhance MCI to AD prediction when used as a marker of neurodegeneration, but VGF had the highest predictive capacity. Thus, we propose that low levels of VGF in CSF may serve as "N" in the amyloid beta, tau, neurodegenerative markers framework to enhance the prediction of MCI to AD conversion.
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Affiliation(s)
- Daniel A Llano
- Department of Biomedical and Translational Sciences, Carle Illinois College of Medicine, Urbana, IL, USA; Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL, USA; Beckman Institute for Advanced Science and Technology, Urbana, IL, USA; Carle Neuroscience Institute, Urbana, IL, USA.
| | - Priya Devanarayan
- Department of Biology and Schreyer Honors College, Pennsylvania State University, University Park, PA, USA
| | - Viswanath Devanarayan
- Eisai, Inc., Nutley, NJ, USA; Department of Mathematics, Statistics and Computer Science, University of Illinois at Chicago, Chicago, IL, USA
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Wang Y, Qin X, Han Y, Li B. VGF: A prospective biomarker and therapeutic target for neuroendocrine and nervous system disorders. Biomed Pharmacother 2022; 151:113099. [PMID: 35594706 DOI: 10.1016/j.biopha.2022.113099] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/04/2022] [Accepted: 05/10/2022] [Indexed: 11/28/2022] Open
Abstract
Neuroendocrine regulatory polypeptide VGF (nerve growth factor inducible) was firstly found in the rapid induction of nerve growth factor on PC12 cells. It was selectively distributed in neurons and many neuroendocrine tissues. This paper reviewed the latest literatures on the gene structure, transcriptional regulation, protein processing, distribution and potential receptors of VGF. The neuroendocrine roles of VGF and its derived polypeptides in regulating energy, water electrolyte balance, circadian rhythm and reproductive activities were also summarized. Furthermore, based on the experimental evidence in vivo and in vitro, dysregulation of VGF in different neuroendocrine diseases and the possible mechanism mediated by VGF polypeptides were discussed. We next discussed the potential as the clinical diagnosis and therapy for VGF related diseases in the future.
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Affiliation(s)
- Yibei Wang
- Department of Thoracic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China; Department of Developmental Cell Biology, Key Laboratory of Medical Cell Biology, China Medical University, Shenyang, Liaoning Province, China.
| | - Xiaoxue Qin
- Department of Developmental Cell Biology, Key Laboratory of Medical Cell Biology, China Medical University, Shenyang, Liaoning Province, China.
| | - Yun Han
- Department of Thoracic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, China.
| | - Bo Li
- Department of Developmental Cell Biology, Key Laboratory of Medical Cell Biology, China Medical University, Shenyang, Liaoning Province, China.
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Sato H, Hatakeyama J, Iwasato T, Araki K, Yamamoto N, Shimamura K. Thalamocortical axons control the cytoarchitecture of neocortical layers by area-specific supply of VGF. eLife 2022; 11:67549. [PMID: 35289744 PMCID: PMC8959604 DOI: 10.7554/elife.67549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 03/12/2022] [Indexed: 11/13/2022] Open
Abstract
Neuronal abundance and thickness of each cortical layer are specific to each area, but how this fundamental feature arises during development remains poorly understood. While some of area-specific features are controlled by intrinsic cues such as morphogens and transcription factors, the exact influence and mechanisms of action by cues extrinsic to the cortex, in particular the thalamic axons, have not been fully established. Here, we identify a thalamus-derived factor, VGF, which is indispensable for thalamocortical axons to maintain the proper amount of layer 4 neurons in the mouse sensory cortices. This process is prerequisite for further maturation of the primary somatosensory area, such as barrel field formation instructed by a neuronal activity-dependent mechanism. Our results provide an actual case in which highly site-specific axon projection confers further regional complexity upon the target field through locally secreting signaling molecules from axon terminals.
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Affiliation(s)
- Haruka Sato
- Department of Brain Morphogenesis, Kumamoto University, Kumamoto, Japan
| | - Jun Hatakeyama
- Department of Brain Morphogenesis, Kumamoto University, Kumamoto, Japan
| | - Takuji Iwasato
- Laboratory of Mammalian Neural Circuits, National Institute of Genetics, Mishima, Japan
| | - Kimi Araki
- Department of Brain Morphogenesis, Kumamoto University, Kumamoto, Japan
| | - Nobuhiko Yamamoto
- Laboratory of Cellular and Molecular Neurobiology, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Kenji Shimamura
- Department of Brain Morphogenesis, Kumamoto University, Kumamoto, Japan
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Alqarni S, Alsebai M. Could VGF and/or its derived peptide act as biomarkers for the diagnosis of neurodegenerative diseases: A systematic review. Front Endocrinol (Lausanne) 2022; 13:1032192. [PMID: 36619561 PMCID: PMC9817138 DOI: 10.3389/fendo.2022.1032192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The increasing ageing population has led to an increase in the prevalence of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). However, as yet, there are no simple biomarkers to predict the onset of such diseases. Recently, VGF and its peptides have been highlighted in neurodegenerative diseases. VGF (non-acronymic) is a polypeptide induced in PC12 cells by neurotrophic factors. OBJECTIVE This systematic review aimed to determine whether VGF and/or its derived peptides can be used as biomarkers for the diagnosis of ALS, PD, and AD with specific attention to (1) the levels of VGF and/or its derived peptides, (2) amyloid-beta, (3) dopamine, and (4) cognitive score. METHODOLOGY A search was undertaken in the Ovid EMBASE, Cochrane Library, PubMed, Scopus, and Web of Science for observational studies. Publications that assessed the level of VGF and/or its derived peptides among people with neurodegenerative diseases and compared them with healthy people were included. The quality of the included studies was assessed using the National Heart, Lung, and Blood Institute Quality Assessment Tool. RESULT A search of the databases yielded 834 studies, of which, eight observational studies met the inclusion criteria with a total of 673 participants (51.7% males) aged >18 years. Seven studies showed significant decreases in VGF and its derived peptides in adults with AD, PD, and ALS compared to healthy controls (p<0.05). However, one study showed that there was no significant difference in VGF in AD compared to healthy control(p>0.05). Furthermore, only one study reported that VGF levels were positively correlated with those of tissue dopamine but not with Aβ1-42, and low levels of VGF were associated to cognitive deficits. CONCLUSION The use of VGF and its derivatives for the diagnosis of PD, ALS, AD remains unclear, so further investigation of the role of VGF in neurodegenerative diseases and pathophysiology is needed to provide new insights.
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Arora S, Sharma D, Layek B, Singh J. A Review of Brain-Targeted Nonviral Gene-Based Therapies for the Treatment of Alzheimer's Disease. Mol Pharm 2021; 18:4237-4255. [PMID: 34705472 DOI: 10.1021/acs.molpharmaceut.1c00611] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diseases of the central nervous system (CNS) are difficult to treat owing to the complexity of the brain and the presence of a natural blood-brain-barrier (BBB). Alzheimer's disease (AD) is one of the major progressive and currently incurable neurodegenerative disorders of the CNS, which accounts for 60-80% of cases of dementia. The pathophysiology of AD involves the accumulation of amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) in the brain. Additionally, synaptic loss and imbalance of neuronal signaling molecules are characterized as important markers of AD. Existing treatments of AD help in the management of its symptoms and aim toward the maintenance of cognitive functions, behavior, and attenuation of gradual memory loss. Over the past decade, nonviral gene therapy has attracted increasing interest due to its various advantages over its viral counterparts. Moreover, advancements in nonviral gene technology have led to their increasing contributions in clinical trials. However, brain-targeted nonviral gene delivery vectors come across various extracellular and intracellular barriers, limiting their ability to transfer the therapeutic gene into the target cells. Chief barriers to nonviral gene therapy have been discussed briefly in this review. We have also highlighted the rapid advancement of several nonviral gene therapies for AD, which are broadly categorized into physical and chemical methods. These methods aim to modulate Aβ, beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), apolipoprotein E, or neurotrophic factors' expression in the CNS. Overall, this review discusses challenges and recent advancements of nonviral gene therapy for AD.
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Affiliation(s)
- Sanjay Arora
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Divya Sharma
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Buddhadev Layek
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo, North Dakota 58105, United States
| | - Jagdish Singh
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo, North Dakota 58105, United States
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Arora S, Singh J. In vitro and in vivo optimization of liposomal nanoparticles based brain targeted vgf gene therapy. Int J Pharm 2021; 608:121095. [PMID: 34543617 PMCID: PMC8574129 DOI: 10.1016/j.ijpharm.2021.121095] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/30/2021] [Accepted: 09/12/2021] [Indexed: 12/14/2022]
Abstract
Vgf (non-acronymic), a neurotrophin stimulated protein which plays a crucial role in learning, synaptic activity, and neurogenesis, is markedly downregulated in the brain of Alzheimer's disease (AD) patients. However, since vgf is a large polar protein, a safe and efficient gene delivery vector is critical for its delivery across the blood brain barrier (BBB). This research work demonstrates brain-targeted liposomal nanoparticles optimized for delivering plasmid encoding vgf across BBB and transfecting brain cells. Brain targeting was achieved by surface functionalization using glucose transporter-1 targeting ligand (mannose) and brain targeted cell-penetrating peptides (chimeric rabies virus glycoprotein fragment, rabies virus derived peptide, penetratin peptide, or CGNHPHLAKYNGT peptide). The ligands were conjugated to lipid via nucleophilic substitution reaction resulting in >75% binding efficiency. The liposomes were formed by film hydration technique demonstrating size <200 nm, positive zeta potential (15-20 mV), and polydispersity index <0.3. The bifunctionalized liposomes demonstrated ∼3 pg/µg protein vgf transfection across in vitro BBB, and ∼80 pg/mg protein in mice brain which was 1.5-2 fold (p < 0.05) higher compared to untreated control. The nanoparticles were also biocompatible in vitro and in vivo, suggesting a safe and efficient gene delivery system to treat AD.
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Affiliation(s)
- Sanjay Arora
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo 58105, ND, USA
| | - Jagdish Singh
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health Professions, North Dakota State University, Fargo 58105, ND, USA.
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VGF in Cerebrospinal Fluid Combined With Conventional Biomarkers Enhances Prediction of Conversion From MCI to AD. Alzheimer Dis Assoc Disord 2019; 33:307-314. [PMID: 31305322 DOI: 10.1097/wad.0000000000000328] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Previous work has suggested that the brain and cerebrospinal fluid (CSF) levels of a neural protein involved in synaptic transmission, VGF (a noninitialism), may be altered in mild cognitive impairment (MCI) and Alzheimer Disease (AD). The objective of the current work is to examine the potential of CSF levels of a peptide derived from VGF to predict conversion from MCI to AD. MATERIALS AND METHODS Using multivariate analytical approaches, the performance of the conventional biomarkers (CSF Aβ1-42 and phosphorylated tau +/- hippocampal volume) was compared with the same biomarkers combined with CSF VGF peptide levels in a large publicly available data set from human subjects. RESULTS It was observed that VGF peptides are lowered in CSF of patients with AD compared with controls and that combinations of CSF Aβ1-42 and phosphorylated tau, hippocampal volume, and VGF peptide levels outperformed conventional biomarkers alone (hazard ratio=2.2 vs. 3.9), for predicting MCI to AD conversion. CONCLUSIONS CSF VGF enhances the ability of conventional biomarkers to predict MCI to AD conversion. Future work will be needed to determine the specificity of VGF for AD versus other neurodegenerative diseases.
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VGF has Roles in the Pathogenesis of Major Depressive Disorder and Schizophrenia: Evidence from Transgenic Mouse Models. Cell Mol Neurobiol 2019; 39:721-727. [PMID: 31037515 DOI: 10.1007/s10571-019-00681-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/25/2019] [Indexed: 12/22/2022]
Abstract
Mental disorders, such as major depressive disorder and schizophrenia, are complex multigenetic conditions, but focused studies of single genes might reveal genes involved in the pathogenesis of mental disorders, including major depressive disorder and schizophrenia. Several candidate genes have been identified using transgenic mice. VGF nerve growth factor inducible (VGF) is a neuropeptide expression of which is induced by nerve growth factor (NGF). VGF is robustly and exclusively synthesized in neuronal and neuroendocrine cells. In central nervous system (CNS), VGF is extensively expressed especially in the cerebral cortex, hippocampus, and hypothalamus. VGF has many roles in the CNS, such as promotion of synaptic plasticity, neurogenesis, and neurite outgrowth. In clinical studies, altered expression and genetic mutations of VGF have been reported in patients with major depressive disorder and schizophrenia. On this basis, studies using transgenic mice to overexpress or knockout VGF have been performed to investigate the roles of upregulation or downregulation of VGF. In this review, we will discuss studies of the roles of VGF using transgenic mice and its relevance to pathologies in major depressive disorder and schizophrenia.
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Matsumoto T, Kawashima Y, Nagashio R, Kageyama T, Kodera Y, Jiang SX, Okayasu I, Kameya T, Sato Y. A New Possible Lung Cancer Marker: VGF Detection from the Conditioned Medium of Pulmonary Large Cell Neuroendocrine Carcinoma–Derived Cells using Secretome Analysis. Int J Biol Markers 2018; 24:282-5. [DOI: 10.1177/172460080902400411] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The prognosis of malignant neuroendocrine tumors of the lung is known to be very poor. Aiming to identify new markers of pulmonary neuroendocrine tumors in early stages and also differential diagnostic markers between large cell neuroendocrine carcinoma and small cell lung cancer, we comprehensively analyzed peptides which were secreted into conditioned medium by LCN1, a large cell neuroendocrine carcinoma cell line. Specific peaks in conditioned medium but not in used medium alone were detected using matrix-associated laser desorption/ionization time of flight mass spectrometry. Two peptide fragments of 40 and 19 amino acid residues were identified by matrix-associated laser desorption/ionization time of flight mass spectrometry. These two fragments were demonstrated to be parts of VGF nerve growth factor inducible (VGF), which is usually expressed in nerve cells or neuroendocrine cells. RT-PCR analysis of lung cancer cell lines showed that VGF mRNA was expressed only in neuroendocrine carcinoma–derived cells. Our data suggest that VGF can be used as a novel serological diagnostic marker of pulmonary neuroendocrine tumors.
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Affiliation(s)
- Toshihide Matsumoto
- Department of Cellular and Histo-Pathology, Graduate School of Medical Sciences, Kitasato University, Kanagawa
- Department of Molecular Diagnostics, School of Allied Health Sciences, Kitasato University, Kanagawa
| | - Yusuke Kawashima
- Department of Physics, School of Science, Kitasato University, Kanagawa
| | - Ryo Nagashio
- Department of Molecular Diagnostics, School of Allied Health Sciences, Kitasato University, Kanagawa
- Pathology Division, National Cancer Center Research Institute, Tokyo
| | - Taihei Kageyama
- Department of Cellular and Histo-Pathology, Graduate School of Medical Sciences, Kitasato University, Kanagawa
- Department of Molecular Diagnostics, School of Allied Health Sciences, Kitasato University, Kanagawa
| | - Yoshio Kodera
- Department of Physics, School of Science, Kitasato University, Kanagawa
| | - Shi-Xu Jiang
- Department of Cellular and Histo-Pathology, Graduate School of Medical Sciences, Kitasato University, Kanagawa
| | - Isao Okayasu
- Department of Cellular and Histo-Pathology, Graduate School of Medical Sciences, Kitasato University, Kanagawa
| | - Toru Kameya
- Pathology Division, Shizuoka Cancer Center Research Institute, Shizuoka - Japan
| | - Yuichi Sato
- Department of Molecular Diagnostics, School of Allied Health Sciences, Kitasato University, Kanagawa
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NERP-2 regulates gastric acid secretion and gastric emptying via the orexin pathway. Biochem Biophys Res Commun 2017; 485:409-413. [DOI: 10.1016/j.bbrc.2017.02.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 02/12/2017] [Indexed: 11/20/2022]
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Neuropeptide VGF Promotes Maturation of Hippocampal Dendrites That Is Reduced by Single Nucleotide Polymorphisms. Int J Mol Sci 2017; 18:ijms18030612. [PMID: 28287464 PMCID: PMC5372628 DOI: 10.3390/ijms18030612] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/03/2017] [Accepted: 03/08/2017] [Indexed: 12/13/2022] Open
Abstract
The neuropeptide VGF (non-acronymic) is induced by brain-derived neurotrophic factor and promotes hippocampal neurogenesis, as well as synaptic activity. However, morphological changes induced by VGF have not been elucidated. Developing hippocampal neurons were exposed to VGF through bath application or virus-mediated expression in vitro. VGF-derived peptide, TLQP-62, enhanced dendritic branching, and outgrowth. Furthermore, VGF increased dendritic spine density and the proportion of immature spines. Spine formation was associated with increased synaptic protein expression and co-localization of pre- and postsynaptic markers. Three non-synonymous single nucleotide polymorphisms (SNPs) were selected in human VGF gene. Transfection of N2a cells with plasmids containing these SNPs revealed no relative change in protein expression levels and normal protein size, except for a truncated protein from the premature stop codon, E525X. All three SNPs resulted in a lower proportion of N2a cells bearing neurites relative to wild-type VGF. Furthermore, all three mutations reduced the total length of dendrites in developing hippocampal neurons. Taken together, our results suggest VGF enhances dendritic maturation and that these effects can be altered by common mutations in the VGF gene. The findings may have implications for people suffering from psychiatric disease or other conditions who may have altered VGF levels.
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VGF and Its C-Terminal Peptide TLQP-62 Regulate Memory Formation in Hippocampus via a BDNF-TrkB-Dependent Mechanism. J Neurosci 2015; 35:10343-56. [PMID: 26180209 DOI: 10.1523/jneurosci.0584-15.2015] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Regulated expression and secretion of BDNF, which activates TrkB receptor signaling, is known to play a critical role in cognition. Identification of additional modulators of cognitive behavior that regulate activity-dependent BDNF secretion and/or potentiate TrkB receptor signaling would therefore be of considerable interest. In this study, we show in the adult mouse hippocampus that expression of the granin family gene Vgf and secretion of its C-terminal VGF-derived peptide TLQP-62 are required for fear memory formation. We found that hippocampal VGF expression and TLQP-62 levels were transiently induced after fear memory training and that sequestering secreted TLQP-62 peptide in the hippocampus immediately after training impaired memory formation. Reduced VGF expression was found to impair learning-evoked Rac1 induction and phosphorylation of the synaptic plasticity markers cofilin and synapsin in the adult mouse hippocampus. Moreover, TLQP-62 induced acute, transient activation of the TrkB receptor and subsequent CREB phosphorylation in hippocampal slice preparations and its administration immediately after training enhanced long-term memory formation. A critical role of BDNF-TrkB signaling as a downstream effector in VGF/TLQP-62-mediated memory consolidation was further revealed by posttraining activation of BDNF-TrkB signaling, which rescued impaired fear memory resulting from hippocampal administration of anti-VGF antibodies or germline VGF ablation in mice. We propose that VGF is a critical component of a positive BDNF-TrkB regulatory loop and, upon its induced expression by memory training, the TLQP-62 peptide rapidly reinforces BDNF-TrkB signaling, regulating hippocampal memory consolidation. SIGNIFICANCE STATEMENT Identification of the cellular and molecular mechanisms that regulate long-term memory formation and storage may provide alternative treatment modalities for degenerative and neuropsychiatric memory disorders. The neurotrophin BDNF plays a prominent role in cognitive function, and rapidly and robustly induces expression of VGF, a secreted neuronal peptide precursor. VGF knock-out mice have impaired fear and spatial memory. Our study shows that VGF and VGF-derived peptide TLQP-62 are transiently induced after fear memory training, leading to increased BDNF/TrkB signaling, and that sequestration of hippocampal TLQP-62 immediately after training impairs memory formation. We propose that TLQP-62 is a critical component of a positive regulatory loop that is induced by memory training, rapidly reinforces BDNF-TrkB signaling, and is required for hippocampal memory consolidation.
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Carmel JB, Young W, Hart RP. Flipping the transcriptional switch from myelin inhibition to axon growth in the CNS. Front Mol Neurosci 2015; 8:34. [PMID: 26236189 PMCID: PMC4505142 DOI: 10.3389/fnmol.2015.00034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/06/2015] [Indexed: 01/01/2023] Open
Abstract
Poor regeneration of severed axons in the central nervous system (CNS) limits functional recovery. Regeneration failure involves interplay of inhibitory environmental elements and the growth state of the neuron. To find internal changes in gene expression that might overcome inhibitory environmental cues, we compared several paradigms that allow growth in the inhibitory environment. Conditions that allow axon growth by axotomized and cultured dorsal root ganglion (DRG) neurons on CNS myelin include immaturity (the first few postnatal days), high levels of cyclic adenosine mono phosphate (cAMP), and conditioning with a peripheral nerve lesion before explant. This shift from inhibition to growth depends on transcription. Seeking to understand the transcriptome changes that allow axon growth in the CNS, we collaborated with the Marie Filbin laboratory to identify several mRNAs that are functionally relevant, as determined by gain- and loss-of-function studies. In this Perspective, we review evidence from these experiments and discuss the merits of comparing multiple regenerative paradigms to identify a core transcriptional program for CNS axon regeneration.
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Affiliation(s)
- Jason B Carmel
- Brain Mind Research Institute and Departments of Pediatrics and Neurology, Weill Cornell Medical College New York, NY, USA ; Burke-Cornell Medical Research Institute White Plains, NY, USA
| | - Wise Young
- W.M. Keck Center for Collaborative Neuroscience and the Department of Cell Biology and Neuroscience, Rutgers University Piscataway, NJ, USA
| | - Ronald P Hart
- W.M. Keck Center for Collaborative Neuroscience and the Department of Cell Biology and Neuroscience, Rutgers University Piscataway, NJ, USA
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15
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Abstract
The vgf gene (non-acronymic) is highly conserved and was identified on the basis of its rapid induction in vitro by nerve growth factor, although can also be induced by brain-derived neurotrophic factor, and glial-derived growth factor. The VGF gene gives rise to a 68 kDa precursor polypeptide, which is induced robustly, relatively selectively and is synthesized exclusively in neuronal and neuroendocrine cells. Post-translational processing by neuroendocrine specific prohormone convertases in these cells results in the production of a number of smaller peptides. The VGF gene and peptides are widely expressed throughout the brain, particularly in the hypothalamus and hippocampus, in peripheral tissues including the pituitary gland, the adrenal glands, and the pancreas, and in the gastrointestinal tract in both the myenteric plexus and in endocrine cells. VGF peptides have been associated with a number of neuroendocrine roles, and in this review, we aim to describe these roles to highlight the importance of VGF as therapeutic target for a number of disorders, particularly those associated with energy metabolism, pain, reproduction, and cognition.
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Affiliation(s)
- Jo E. Lewis
- Queen’s Medical Centre, School of Life Sciences, University of Nottingham Medical School, Nottingham, UK
| | - John M. Brameld
- Division of Nutritional Sciences, School of Biosciences, University of Nottingham, Loughborough, UK
| | - Preeti H. Jethwa
- Division of Nutritional Sciences, School of Biosciences, University of Nottingham, Loughborough, UK
- *Correspondence: Preeti H. Jethwa, Division of Nutritional Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK e-mail:
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16
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Thakker-Varia S, Behnke J, Doobin D, Dalal V, Thakkar K, Khadim F, Wilson E, Palmieri A, Antila H, Rantamaki T, Alder J. VGF (TLQP-62)-induced neurogenesis targets early phase neural progenitor cells in the adult hippocampus and requires glutamate and BDNF signaling. Stem Cell Res 2014; 12:762-77. [PMID: 24747217 PMCID: PMC4991619 DOI: 10.1016/j.scr.2014.03.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 02/24/2014] [Accepted: 03/18/2014] [Indexed: 01/19/2023] Open
Abstract
The neuropeptide VGF (non-acronymic), which has antidepressant-like effects, enhances adult hippocampal neurogenesis as well as synaptic activity and plasticity in the hippocampus, however the interaction between these processes and the mechanism underlying this regulation remain unclear. In this study, we demonstrate that VGF-derived peptide TLQP-62 specifically enhances the generation of early progenitor cells in nestin-GFP mice. Specifically, TLQP-62 significantly increases the number of Type 2a neural progenitor cells (NPCs) while reducing the number of more differentiated Type 3 cells. The effect of TLQP-62 on proliferation rather than differentiation was confirmed using NPCs in vitro; TLQP-62 but not scrambled peptide PEHN-62 increases proliferation in a cell line as well as in primary progenitors from adult hippocampus. Moreover, TLQP-62 but not scrambled peptide increases Cyclin D mRNA expression. The proliferation of NPCs induced by TLQP-62 requires synaptic activity, in particular through NMDA and metabotropic glutamate receptors. The activation of glutamate receptors by TLQP-62 activation induces phosphorylation of CaMKII through NMDA receptors and protein kinase D through metabotropic glutamate receptor 5 (mGluR5). Furthermore, pharmacological antagonists to CaMKII and PKD inhibit TLQP-62-induced proliferation of NPCs indicating that these signaling molecules downstream of glutamate receptors are essential for the actions of TLQP-62 on neurogenesis. We also show that TLQP-62 gradually activates Brain-Derived Neurotrophic Factor (BDNF)-receptor TrkB in vitro and that Trk signaling is required for TLQP-62-induced proliferation of NPCs. Understanding the precise molecular mechanism of how TLQP-62 influences neurogenesis may reveal mechanisms by which VGF-derived peptides act as antidepressant-like agents.
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Affiliation(s)
- Smita Thakker-Varia
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Joseph Behnke
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - David Doobin
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Vidhi Dalal
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Keya Thakkar
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Farah Khadim
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Elizabeth Wilson
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Alicia Palmieri
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Hanna Antila
- Neuroscience Center, University of Helsinki, P.O. Box 56, Viikinkaari 4, 00014 Helsinki, Finland.
| | - Tomi Rantamaki
- Neuroscience Center, University of Helsinki, P.O. Box 56, Viikinkaari 4, 00014 Helsinki, Finland.
| | - Janet Alder
- Department of Neuroscience and Cell Biology, Rutgers University - Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
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17
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Karlsson O, Kultima K, Wadensten H, Nilsson A, Roman E, Andrén PE, Brittebo EB. Neurotoxin-induced neuropeptide perturbations in striatum of neonatal rats. J Proteome Res 2013; 12:1678-90. [PMID: 23410195 DOI: 10.1021/pr3010265] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The cyanobacterial toxin β-N-methylamino-l-alanine (BMAA) is suggested to play a role in neurodegenerative disease. We have previously shown that although the selective uptake of BMAA in the rodent neonatal striatum does not cause neuronal cell death, exposure during the neonatal development leads to cognitive impairments in adult rats. The aim of the present study was to characterize the changes in the striatal neuropeptide systems of male and female rat pups treated neonatally (postnatal days 9-10) with BMAA (40-460 mg/kg). The label-free quantification of the relative levels of endogenous neuropeptides using mass spectrometry revealed that 25 peptides from 13 neuropeptide precursors were significantly changed in the rat neonatal striatum. The exposure to noncytotoxic doses of BMAA induced a dose-dependent increase of neurosecretory protein VGF-derived peptides, and changes in the relative levels of cholecystokinin, chromogranin, secretogranin, MCH, somatostatin and cortistatin-derived peptides were observed at the highest dose. In addition, the results revealed a sex-dependent increase in the relative level of peptides derived from the proenkephalin-A and protachykinin-1 precursors, including substance P and neurokinin A, in female pups. Because several of these peptides play a critical role in the development and survival of neurons, the observed neuropeptide changes might be possible mediators of BMAA-induced behavioral changes. Moreover, some neuropeptide changes suggest potential sex-related differences in susceptibility toward this neurotoxin. The present study also suggests that neuropeptide profiling might provide a sensitive characterization of the BMAA-induced noncytotoxic effects on the developing brain.
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Affiliation(s)
- Oskar Karlsson
- Department of Pharmaceutical Biosciences, Uppsala University , SE-751 24 Uppsala, Sweden
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18
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Neto FL, Borges G, Torres-Sanchez S, Mico JA, Berrocoso E. Neurotrophins role in depression neurobiology: a review of basic and clinical evidence. Curr Neuropharmacol 2012; 9:530-52. [PMID: 22654714 PMCID: PMC3263450 DOI: 10.2174/157015911798376262] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Revised: 08/18/2010] [Accepted: 08/09/2010] [Indexed: 01/02/2023] Open
Abstract
Depression is a neuropsychiatric disorder affecting a huge percentage of the active population especially in developed countries. Research has devoted much of its attention to this problematic and many drugs have been developed and are currently prescribed to treat this pathology. Yet, many patients are refractory to the available therapeutic drugs, which mainly act by increasing the levels of the monoamines serotonin and noradrenaline in the synaptic cleft. Even in the cases antidepressants are effective, it is usually observed a delay of a few weeks between the onset of treatment and remission of the clinical symptoms. Additionally, many of these patients who show remission with antidepressant therapy present a relapse of depression upon treatment cessation. Thus research has focused on other possible molecular targets, besides monoamines, underlying depression. Both basic and clinical evidence indicates that depression is associated with
several structural and neurochemical changes where the levels of neurotrophins, particularly of brain-derived neurotrophic factor (BDNF), are altered. Antidepressants, as well as other therapeutic strategies, seem to restore these levels. Neuronal atrophy, mostly detected in limbic structures that regulate mood and cognition, like the hippocampus, is observed in depressed patients and in animal behavioural paradigms for depression. Moreover, chronic antidepressant treatment enhances adult hippocampal neurogenesis, supporting the notion that this event underlies antidepressants effects. Here we review some of the preclinical and clinical studies, aimed at disclosing the role of neurotrophins in the pathophysiological
mechanisms of depression and the mode of action of antidepressants, which favour the neurotrophic/neurogenic hypothesis.
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Affiliation(s)
- Fani L Neto
- Instituto de Histologia e Embriologia, Faculdade de Medicina e IBMC, Universidade do Porto, 4200-319, Porto, Portugal
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19
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VGF: an inducible gene product, precursor of a diverse array of neuro-endocrine peptides and tissue-specific disease biomarkers. J Chem Neuroanat 2011; 42:249-61. [PMID: 21621608 DOI: 10.1016/j.jchemneu.2011.05.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/10/2011] [Accepted: 05/12/2011] [Indexed: 12/13/2022]
Abstract
The vgf gene (non-acronymic) is induced in vivo by neurotrophins including Nerve Growth Factor (NGF), Brain Derived Growth Factor (BDNF) and Glial Derived Growth Factor (GDNF), by synaptic activity and by homeostatic and other stimuli. Post-translational processing of a single VGF precursor gives raise to a varied multiplicity of neuro-endocrine peptides, some of which are secreted upon stimulation both in vitro and in vivo. Several VGF peptides, accounting for ∼20% of the VGF precursor sequence, have shown biological roles including regulation of food intake, energy balance, reproductive and homeostatic mechanisms, synaptic strengthening, long-term potentiation (LTP) and anti-depressant activity. From a further ∼50% of VGF derive multiple "fragments", largely identified in the human cerebro-spinal fluid by proteomic studies searching for disease biomarkers. These represent an important starting point for discovery of further VGF products relevant to neuronal brain functions, as well as to neurodegenerative and psychiatric disease conditions. A distinct feature of VGF peptides is their cell type specific diversity in all neuroendocrine organs studied so far. Selective differential profiles are found across the cell populations of pituitary, adrenal medulla and pancreatic islets, and in gastric neuroendocrine as well as some further mucosal cells, and are yet to be investigated in neuronal systems. At the same time, specific VGF peptide/s undergo selective modulation in response to organ or cell population relevant stimuli. Such pattern argues for a multiplicity of roles for VGF peptides, including endocrine functions, local intercellular communication, as well as the possible mediation of intracellular mechanisms.
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20
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Chronic hyperoxia alters the expression of neurotrophic factors in the carotid body of neonatal rats. Respir Physiol Neurobiol 2010; 175:220-7. [PMID: 21094282 DOI: 10.1016/j.resp.2010.11.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 11/12/2010] [Accepted: 11/14/2010] [Indexed: 12/12/2022]
Abstract
Chronic exposure to hyperoxia alters the postnatal development and innervation of the rat carotid body. We hypothesized that this plasticity is related to changes in the expression of neurotrophic factors or related proteins. Rats were reared in 60% O(2) from 24 to 36h prior to birth until studied at 3d of age (P3). Protein levels for brain-derived neurotrophic factor (BDNF) were significantly reduced (-70%) in the P3 carotid body, while protein levels for its receptor, tyrosine kinase B, and for glial cell line-derived neurotrophic factor (GDNF) were unchanged. Transcript levels in the carotid body were downregulated for the GDNF receptor Ret (-34%) and the neuropeptide Vgf (-67%), upregulated for Cbln1 (+205%), and unchanged for Fgf2; protein levels were not quantified for these genes. Immunohistochemical analysis revealed that Vgf and Cbln1 proteins are expressed within the carotid body glomus cells. These data suggest that BDNF, and perhaps other neurotrophic factors, contribute to abnormal carotid body function following perinatal hyperoxia.
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21
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Cocco C, D'Amato F, Noli B, Ledda A, Brancia C, Bongioanni P, Ferri GL. Distribution of VGF peptides in the human cortex and their selective changes in Parkinson's and Alzheimer's diseases. J Anat 2010; 217:683-93. [PMID: 21039478 DOI: 10.1111/j.1469-7580.2010.01309.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
VGF mRNA and its precursor-derived products are selectively expressed in certain neurons and promptly respond to neurotrophins and to neural/electrical activity. Proteomic studies have previously revealed a reduction in some VGF peptides in the cerebrospinal fluid of patients affected by Alzheimer's disease and other conditions, suggesting their potential diagnostic and clinical significance. As the presence of VGF peptides within the human cortex has been somewhat elucidated, they were studied postmortem in the frontal, parietal, and temporal cortex areas of control subjects and patients affected by Parkinson's disease, and in parietal cortex samples from patients with Alzheimer's disease. We raised antibodies to the C-/N-terminal portions of the proVGF precursor protein, to the TPGH and TLQP sequences and to the neuroendocrine regulatory peptide (NERP)-1, all used for enzyme-linked immunosorbent assay coupled with gel chromatography and for immunohistochemistry. In the control brain samples, the levels of TPGH and C-terminus peptides were about 130-200 and 700-2000 pmol g⁻¹, respectively, the N-terminus and NERP-1 peptides were less represented (about 10-30 and 4-20 pmol g⁻¹, respectively), and the TLQP peptides were below detection limits. Upon gel chromatography, the VGF antisera mainly revealed small molecular weight forms (i.e. about 0.8-1.3 kDa), whereas VGF immunolocalisation was found within different types of neuron in rat and bovine brain cortices. In the Parkinson's disease samples, a clear-cut decrease was revealed in the parietal cortex only, exclusively for TPGH and NERP-1 peptides, whereas in the Alzheimer's disease samples, a reduction in all of the VGF peptides was shown. The results suggest the involvement of VGF in the physiological or pathophysiological mechanisms occurring in the parietal cortex of patients with Parkinson's and Alzheimer's diseases.
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Affiliation(s)
- Cristina Cocco
- Department of Cytomorphology, University of Cagliari, Monserrato, Cagliari, Italy.
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22
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Toshinai K, Yamaguchi H, Kageyama H, Matsuo T, Koshinaka K, Sasaki K, Shioda S, Minamino N, Nakazato M. Neuroendocrine regulatory peptide-2 regulates feeding behavior via the orexin system in the hypothalamus. Am J Physiol Endocrinol Metab 2010; 299:E394-401. [PMID: 20551287 DOI: 10.1152/ajpendo.00768.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Neuroendocrine regulatory peptide (NERP)-1 and NERP-2 are derived from distinct regions of VGF, a neurosecretory protein. Vgf(-/-) mice exhibit dwarfism and hypermetabolic rates, suggesting that VGF or VGF-derived peptides play important roles in energy metabolism. Here, we examined the role of NERPs in the central regulation of feeding and energy homeostasis. We attempted to identify NERPs expressing neurons in rats by immunohistochemistry. We studied the effects of intracerebroventricular (icv) administration of NERP-2 on feeding, body temperature, oxygen consumption, and locomotor activity in rats and mice. Intracerebroventricular administration of NERP-2, but not NERP-1 or a form of NERP-2 bearing a COOH-terminal glycine extension, increased food intake in rats. We investigated the downstream signal of NERP-2 on the basis of studies of NERP-2-induced feeding with neutralization of orexins, neuropeptide Y, or agouti-related protein. NERP-2 expression localized to the lateral hypothalamus (LH) and the dorsomedial perifornical hypothalamus in rats, colocalizing with orexins that activate feeding behavior and arousal. NERP-2 administration induced Fos protein, a marker of neuronal activation, in the orexin-immunoreactive neurons. Vgf mRNA levels were upregulated in the rat LH upon food deprivation. Intracerebroventricular administration of NERP-2 also increased body temperature, oxygen consumption, and locomotor activity in rats. Treatment with anti-NERP-2 IgG decreased food intake. NERP-2-induced bioactivities could be abrogated by administration of anti-orexins IgG or orexin receptor antagonists. NERP-2 did not induce food intake or locomotor activity in orexin-deficient mice. Our findings indicate that hypothalamic NERP-2 plays a role in the control of food intake and energy homeostasis via the orexin pathway. Thus, VGF serves as a precursor of multiple bioactive peptides exerting a diverse set of neuroendocrine functions.
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Cattaneo A, Sesta A, Calabrese F, Nielsen G, Riva MA, Gennarelli M. The expression of VGF is reduced in leukocytes of depressed patients and it is restored by effective antidepressant treatment. Neuropsychopharmacology 2010; 35:1423-8. [PMID: 20164831 PMCID: PMC3055467 DOI: 10.1038/npp.2010.11] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Major depression is a disease characterized by an inability of neuronal systems to show appropriate adaptive plasticity especially under challenging conditions, such as stress. Conversely, pharmacological intervention may normalize such defects through the modulation of factors that might act in concert for the functional recovery of depressed patients, like the neuropeptide VGF, which has previously shown to possess antidepressant like activity. We analyzed VGF mRNA levels in the brain of rodents exposed to stress or treated with antidepressant drugs. In addition, we assessed VGF expression in leukocytes obtained from 25 drug-free depressed patients before and during antidepressant treatment. We found a persistent reduction of VGF expression after exposure to prenatal stress and an upregulation of its levels following chronic treatment with different antidepressant drugs. Moreover, VGF mRNA levels were significantly reduced in drug-free depressed patients, as compared with controls, and were modulated in response to effective antidepressant treatment. Our data provide further support to the role of VGF in mood disorders and suggest that VGF could be a more specific biomarker for treatment responsiveness.
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Affiliation(s)
- Annamaria Cattaneo
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy,Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Antonella Sesta
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy,Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Francesca Calabrese
- Department of Pharmacological Sciences, Center of Neuropharmacology, Università degli studi di Milano, Milan, Italy
| | - Gabriela Nielsen
- Psychiatric Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Marco Andrea Riva
- Department of Pharmacological Sciences, Center of Neuropharmacology, Università degli studi di Milano, Milan, Italy,Center of Excellence on Neurodegenerative Diseases, Università degli studi di Milano, Milan, Italy
| | - Massimo Gennarelli
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy,Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy,Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies, University of Brescia, Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Viale Europa 11, Brescia 25123, Italy, Tel: +39 030 3501453, Fax: +39 030 3501592, E-mail:
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Moss A, Ingram R, Koch S, Theodorou A, Low L, Baccei M, Hathway GJ, Costigan M, Salton SR, Fitzgerald M. Origins, actions and dynamic expression patterns of the neuropeptide VGF in rat peripheral and central sensory neurones following peripheral nerve injury. Mol Pain 2008; 4:62. [PMID: 19077191 PMCID: PMC2614976 DOI: 10.1186/1744-8069-4-62] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Accepted: 12/10/2008] [Indexed: 11/15/2022] Open
Abstract
Background The role of the neurotrophin regulated polypeptide, VGF, has been investigated in a rat spared injury model of neuropathic pain. This peptide has been shown to be associated with synaptic strengthening and learning in the hippocampus and while it is known that VGFmRNA is upregulated in dorsal root ganglia following peripheral nerve injury, the role of this VGF peptide in neuropathic pain has yet to be investigated. Results Prolonged upregulation of VGF mRNA and protein was observed in injured dorsal root ganglion neurons, central terminals and their target dorsal horn neurons. Intrathecal application of TLQP-62, the C-terminal active portion of VGF (5–50 nmol) to naïve rats caused a long-lasting mechanical and cold behavioral allodynia. Direct actions of 50 nM TLQP-62 upon dorsal horn neuron excitability was demonstrated in whole cell patch recordings in spinal cord slices and in receptive field analysis in intact, anesthetized rats where significant actions of VGF were upon spontaneous activity and cold evoked responses. Conclusion VGF expression is therefore highly modulated in nociceptive pathways following peripheral nerve injury and can cause dorsal horn cell excitation and behavioral hypersensitivity in naïve animals. Together the results point to a novel and powerful role for VGF in neuropathic pain.
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Affiliation(s)
- Andrew Moss
- UCL Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
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25
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The neurotrophin-inducible gene Vgf regulates hippocampal function and behavior through a brain-derived neurotrophic factor-dependent mechanism. J Neurosci 2008; 28:9857-69. [PMID: 18815270 DOI: 10.1523/jneurosci.3145-08.2008] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
VGF is a neurotrophin-inducible, activity-regulated gene product that is expressed in CNS and PNS neurons, in which it is processed into peptides and secreted. VGF synthesis is stimulated by BDNF, a critical regulator of hippocampal development and function, and two VGF C-terminal peptides increase synaptic activity in cultured hippocampal neurons. To assess VGF function in the hippocampus, we tested heterozygous and homozygous VGF knock-out mice in two different learning tasks, assessed long-term potentiation (LTP) and depression (LTD) in hippocampal slices from VGF mutant mice, and investigated how VGF C-terminal peptides modulate synaptic plasticity. Treatment of rat hippocampal slices with the VGF-derived peptide TLQP62 resulted in transient potentiation through a mechanism that was selectively blocked by the BDNF scavenger TrkB-Fc, the Trk tyrosine kinase inhibitor K252a (100 nm), and tPA STOP, an inhibitor of tissue plasminogen activator (tPA), an enzyme involved in pro-BDNF cleavage to BDNF, but was not blocked by the NMDA receptor antagonist APV, anti-p75(NTR) function-blocking antiserum, or previous tetanic stimulation. Although LTP was normal in slices from VGF knock-out mice, LTD could not be induced, and VGF mutant mice were impaired in hippocampal-dependent spatial learning and contextual fear conditioning tasks. Our studies indicate that the VGF C-terminal peptide TLQP62 modulates hippocampal synaptic transmission through a BDNF-dependent mechanism and that VGF deficiency in mice impacts synaptic plasticity and memory in addition to depressive behavior.
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Thakker-Varia S, Alder J. Neuropeptides in depression: role of VGF. Behav Brain Res 2008; 197:262-78. [PMID: 18983874 DOI: 10.1016/j.bbr.2008.10.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 10/05/2008] [Indexed: 12/20/2022]
Abstract
The monoamine hypothesis of depression is increasingly called into question by newer theories that revolve around changes in neuronal plasticity, primarily in the hippocampus, at both the structural and the functional levels. Chronic stress negatively regulates hippocampal function while antidepressants ameliorate the effects of stress on neuronal morphology and activity. Both stress and antidepressants have been shown to affect levels of brain-derived neurotrophic factor (BDNF) whose transcription is dependent on cAMP response element binding protein (CREB). BDNF itself has antidepressant-like actions and can induce transcription of a number of molecules. One class of genes regulated by both BDNF and serotonin (5-HT) are neuropeptides including VGF (non-acryonimic) which has a novel role in depression. Neuropeptides are important modulators of neuronal function but their role in affective disorders is just emerging. Recent studies demonstrate that VGF, which is also a CREB-dependent gene, is upregulated by antidepressant drugs and voluntary exercise and is reduced in animal models of depression. VGF enhances hippocampal synaptic plasticity as well as neurogenesis in the dentate gyrus but the mechanisms of antidepressant-like actions of VGF in behavioral paradigms are not known. We summarize experimental data describing the roles of BDNF, VGF and other neuropeptides in depression and how they may be acting through the generation of new neurons and altered synaptic activity. Understanding the molecular and cellular changes that underlie the actions of neuropeptides and how these adaptations result in antidepressant-like effects will aid in developing drugs that target novel pathways for major depressive disorders.
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Affiliation(s)
- Smita Thakker-Varia
- Department of Neuroscience and Cell Biology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, 683 Hoes Lane West, Robert Wood Johnson-School of Public Health 357A, Piscataway, NJ 08854-5635, United States
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27
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The neuropeptide VGF produces antidepressant-like behavioral effects and enhances proliferation in the hippocampus. J Neurosci 2007; 27:12156-67. [PMID: 17989282 DOI: 10.1523/jneurosci.1898-07.2007] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is upregulated in the hippocampus by antidepressant treatments, and BDNF produces antidepressant-like effects in behavioral models of depression. In our previous work, we identified genes induced by BDNF and defined their specific roles in hippocampal neuronal development and plasticity. To identify genes downstream of BDNF that may play roles in psychiatric disorders, we examined a subset of BDNF-induced genes also regulated by 5-HT (serotonin), which includes the neuropeptide VGF (nonacronymic). To explore the function of VGF in depression, we first investigated the expression of the neuropeptide in animal models of depression. VGF was downregulated in the hippocampus after both the learned helplessness and forced swim test (FST) paradigms. Conversely, VGF infusion in the hippocampus of mice subjected to FST reduced the time spent immobile for up to 6 d, thus demonstrating a novel role for VGF as an antidepressant-like agent. Recent evidence indicates that chronic treatment of rodents with antidepressants increases neurogenesis in the adult dentate gyrus and that neurogenesis is required for the behavioral effects of antidepressants. Our studies using [(3)H]thymidine and bromodeoxyuridine as markers of DNA synthesis indicate that chronic VGF treatment enhances proliferation of hippocampal progenitor cells both in vitro and in vivo with survival up to 21 d. By double immunocytochemical analysis of hippocampal neurons, we demonstrate that VGF increases the number of dividing cells that express neuronal markers in vitro. Thus, VGF may act downstream of BDNF and exert its effects as an antidepressant-like agent by enhancing neurogenesis in the hippocampus.
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Bartolomucci A, Possenti R, Levi A, Pavone F, Moles A. The role of the vgf gene and VGF-derived peptides in nutrition and metabolism. GENES & NUTRITION 2007; 2:169-80. [PMID: 18850173 PMCID: PMC2474945 DOI: 10.1007/s12263-007-0047-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 10/24/2006] [Indexed: 12/01/2022]
Abstract
Energy homeostasis is a complex physiological function coordinated at multiple levels. The issue of genetic regulation of nutrition and metabolism is attracting increasing interest and new energy homeostasis-regulatory genes are continuously identified. Among these genes, vgf is gaining increasing interest following two observations: (1) VGF-/- mice have a lean and hypermetabolic phenotype; (2) the first VGF-derived peptide involved in energy homeostasis, named TLQP-21, has been identified. The aim of this review will be to discuss the role of the vgf gene and VGF derived peptides in metabolic and nutritional functions. In particular we will: (1) provide a brief overview on the central systems regulating energy homeostasis and nutrition particularly focusing on the melanocortin system; (2) introduce the structure and molecular characteristic of vgf; (3) describe the phenotype of VGF deficient mice; (4) present recent data on the metabolic role of VGF-derived peptides, particularly focusing on one peptide named TLQP-21.
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Affiliation(s)
- Alessandro Bartolomucci
- Institute of Neuroscience, CNR, Via del Fosso di Fiorano 64, 00143 Rome, Italy
- Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, V.le G.P. Usberti 11A, 43100 Parma, Italy
| | - Roberta Possenti
- Department of Neuroscience, University of Roma II-Tor Vergata, Rome, Italy
- Institute of Neurobiology and Molecular Medicine, CNR, Rome, Italy
| | - Andrea Levi
- Institute of Neurobiology and Molecular Medicine, CNR, Rome, Italy
| | - Flaminia Pavone
- Institute of Neuroscience, CNR, Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Anna Moles
- Institute of Neuroscience, CNR, Via del Fosso di Fiorano 64, 00143 Rome, Italy
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Rindi G, Licini L, Necchi V, Bottarelli L, Campanini N, Azzoni C, Favret M, Giordano G, D'Amato F, Brancia C, Solcia E, Ferri GL. Peptide products of the neurotrophin-inducible gene vgf are produced in human neuroendocrine cells from early development and increase in hyperplasia and neoplasia. J Clin Endocrinol Metab 2007; 92:2811-5. [PMID: 17440014 DOI: 10.1210/jc.2007-0035] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Although the neurotrophin-inducible gene vgf is expressed in mammalian neurons and endocrine cells, limited data is available in man. AIM The objective of the study was to map proVGF peptides in human endocrine cells during development, adulthood, hyperplasia, and tumors. METHODS Antisera were generated against peptides related to internal cleavage or cleavage-amidation sites (rat proVGF(422-430) and human proVGF(298-306)-NH2) and the proVGF C-terminal ending (human proVGF(607-615)). Developing and normal adult endocrine cells, hyperplastic endocrine lesions (thyroid, parathyroid, lung, and stomach), and 120 tumors (102 endocrine) were studied. Immunogold electron microscopy was performed on normal adult pancreas and gut, and Western blotting was performed on extracts of control tissues and endocrine tumors. RESULTS proVGF fragments were revealed in developing pituitary, gut, pancreas, and adrenal medulla from 10 gestational weeks, in normal adult pituitary and adrenal medulla, pancreatic glucagon, and insulin cells and gut serotonin cells, in hyperplastic thyroid calcitonin cells, lung P cells, gastric enterochromaffin-like cells, and gastrin cells, and in 88 of 102 endocrine tumors. At electron microscopy proVGF immunoreactivity was restricted to electron-dense granules. Western blotting revealed large molecular weight forms and cleavage fragments in both control tissues and tumor extracts. CONCLUSIONS proVGF-related peptides are present in endocrine cells early during development and adulthood and increase in hyperplasia and tumors, and proVGF fragments could be novel diagnostic tools for endocrine cells and related lesions, including tumors.
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Affiliation(s)
- Guido Rindi
- Department of Pathology and Laboratory Medicine, University of Parma, 43100 Parma, Italy.
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Ghiani CA, Beltran-Parrazal L, Sforza DM, Malvar JS, Seksenyan A, Cole R, Smith DJ, Charles A, Ferchmin PA, de Vellis J. Genetic program of neuronal differentiation and growth induced by specific activation of NMDA receptors. Neurochem Res 2006; 32:363-76. [PMID: 17191130 DOI: 10.1007/s11064-006-9213-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2006] [Accepted: 10/23/2006] [Indexed: 12/31/2022]
Abstract
Glutamate and its receptors are expressed very early during development and may play important roles in neurogenesis, synapse formation and brain wiring. The levels of glutamate and activity of its receptors can be influenced by exogenous factors, leading to neurodevelopmental disorders. To investigate the role of NMDA receptors on gene regulation in a neuronal model, we used primary neuronal cultures developed from embryonic rat cerebri in serum-free medium. Using Affymetrix Gene Arrays, we found that genes known to be involved in neuronal plasticity were differentially expressed 24 h after a brief activation of NMDA receptors. The upregulation of these genes was accompanied by a sustained induction of CREB phosphorylation, and an increase in synaptophysin immunoreactivity. We conclude that NMDA receptor activation elicits expression of genes whose downstream products are involved in the regulation of early phases of the process leading to synaptogenesis and its consolidation, at least in part through sustained CREB phosphorylation.
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Affiliation(s)
- Cristina A Ghiani
- Mental Retardation Research Center, Jane and Terry Semel Institute for Neuroscience and Human Behaviour, Department of Neurobiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
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31
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Bouwman J, Spijker S, Schut D, Wächtler B, Ylstra B, Smit AB, Verhage M. Reduced expression of neuropeptide genes in a genome-wide screen of a secretion-deficient mouse. J Neurochem 2006; 99:84-96. [PMID: 16987237 DOI: 10.1111/j.1471-4159.2006.04041.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Activity-dependent changes in synapses rely on functional changes in resident proteins and on gene expression. We addressed the relationship between synapse activity and the expression of synaptic genes by comparing RNA levels in the neocortex of normal mice versus secretion-deficient and therefore synaptically silent munc18-1 (mammalian homologue of Caenorhabditis elegans uncoordinated locomotion-18) null mutants, using microarray expression analysis, real-time quantitative PCR and northern blotting. We hypothesized that genes under the control of synaptic activity would be differentially expressed between mutants and controls. We found that few synaptic genes were differentially expressed. However, most neuropeptide genes with detectable expression on the microarray were differentially expressed, being expressed 3-20-fold higher in control cortex. Several other secreted proteins were also differentially expressed, but genes encoding their receptors and many other synaptic components were not. Differential expression was confirmed by real-time quantitative PCR analysis. In situ hybridization indicated that the difference in neuropeptide expression was uniform and not due to the loss of specific cells in the mutant. In primary sensory neurons, which do not depend on synaptic activity for their input, the differential expression of neuropeptides was not observed. These data argue against a general relationship between the activity of synapses and the expression of their resident proteins, but suggest a link between secretion and the expression of genes encoding the secreted products.
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Affiliation(s)
- J Bouwman
- Department of Functional Genomics, Centre for Neurogenomics and Cognitive Research (CNCR), Vrije Universiteit Amsterdam (VUA) and VU Medical Centre (VUmc), Amsterdam, the Netherlands
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Wibrand K, Messaoudi E, Håvik B, Steenslid V, Løvlie R, Steen VM, Bramham CR. Identification of genes co-upregulated with Arc during BDNF-induced long-term potentiation in adult rat dentate gyrus in vivo. Eur J Neurosci 2006; 23:1501-11. [PMID: 16553613 DOI: 10.1111/j.1460-9568.2006.04687.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a critical regulator of transcription-dependent adaptive neuronal responses, such as long-term potentiation (LTP). Brief infusion of BDNF into the dentate gyrus of adult anesthetized rats triggers stable LTP at medial perforant path-granule synapses that is transcription-dependent and requires induction of the immediate early gene Arc. Rather than acting alone, Arc is likely to be part of a larger BDNF-induced transcriptional program. Here, we used cDNA microarray expression profiling to search for genes co-upregulated with Arc 3 h after BDNF-LTP induction. Of nine cDNAs encoding for known genes and up-regulated more than four-fold, we selected five genes, Narp, neuritin, ADP-ribosylation factor-like protein-4 (ARL4L), TGF-beta-induced immediate early gene-1 (TIEG1) and CARP, for further validation. Real-time PCR confirmed robust up-regulation of these genes in an independent set of BDNF-LTP experiments, whereas infusion of the control protein cytochrome C had no effect. In situ hybridization histochemistry further revealed up-regulation of all five genes in somata of post-synaptic granule cells following both BDNF-LTP and high-frequency stimulation-induced LTP. While Arc synthesis is critical for local actin polymerization and stable LTP formation, several of the co-upregulated genes have known functions in excitatory synaptogenesis, axon guidance and glutamate receptor clustering. These results provide novel insight into gene expression responses underlying BDNF-induced synaptic consolidation in the adult brain in vivo.
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Affiliation(s)
- Karin Wibrand
- Department of Biomedicine and Bergen Mental Health Research Center, Section for Physiology, University of Bergen, Jonas Liens vei 91, N-5009 Bergen, Norway
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Chakraborty TR, Tkalych O, Nanno D, Garcia AL, Devi LA, Salton SRJ. Quantification of VGF- and pro-SAAS-derived peptides in endocrine tissues and the brain, and their regulation by diet and cold stress. Brain Res 2006; 1089:21-32. [PMID: 16631141 DOI: 10.1016/j.brainres.2006.02.124] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Revised: 12/13/2005] [Accepted: 02/26/2006] [Indexed: 11/23/2022]
Abstract
Two novel granin-like polypeptides, VGF and pro-SAAS, which are stored in and released from secretory vesicles and are expressed widely in nervous, endocrine, and neuroendocrine tissues, play roles in the regulation of body weight, feeding, and energy expenditure. Both VGF and pro-SAAS are cleaved into peptide fragments, several of which are biologically active. We utilized a highly sensitive and specific radioimmunoassay (RIA) to immunoreactive, pro-SAAS-derived PEN peptides, developed another against immunoreactive, VGF-derived AQEE30 peptides, and quantified these peptides in various mouse tissues and brain regions. Immunoreactive AQEE30 was most abundant in the pituitary, while brain levels were highest in hypothalamus, striatum, and frontal cortex. Immunoreactive PEN levels were highest in the pancreas and spinal cord, and in brain, PEN was most abundant in striatum, hippocampus, pons and medulla, and cortex. Since both peptides were expressed in hypothalamus, a region of the brain that controls feeding and energy expenditure, double label immunofluorescence studies were employed. These demonstrated that 42% of hypothalamic arcuate neurons coexpress VGF and SAAS peptides, and that the intracellular distributions of these peptides in arcuate neurons differed. By RIA, cold stress increased immunoreactive AQEE30 and PEN peptide levels in female but not male hypothalamus, while a high fat diet increased AQEE30 and PEN peptide levels in female but not male hippocampus. VGF and SAAS-derived peptides are therefore widely expressed in endocrine, neuroendocrine, and neural tissues, can be accurately quantified by RIA, and are differentially regulated in the brain by diet and cold stress.
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Affiliation(s)
- Tandra R Chakraborty
- Fishberg Department of Neuroscience, Mount Sinai School of Medicine, New York, NY 10029, USA
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Saleri R, Cavalli V, Grasselli F, Tamanini C. Growth hormone expression and secretion in pig pituitary and median eminence slices are not influenced by the VGF protein. Neuroendocrinology 2006; 83:89-96. [PMID: 16804334 DOI: 10.1159/000094149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Accepted: 05/09/2006] [Indexed: 12/16/2022]
Abstract
Body homeostasis is maintained by a complex system that involves the brain and the periphery via many circulating hormones. In recent years the VGF protein has been indicated as an important peptide affecting the regulation of body composition. We examined the effects of VGF on growth hormone (GH) expression and secretion in porcine pituitary slices, incubated alone (group 1) or with stalk median eminence (SME) (group 2). After 2 h (time 0), medium was removed and replaced with a fresh one; tissues were challenged with VGF (10(-6) M, 10(-8) M) alone or with ghrelin (10(-8) M) or growth hormone-releasing hormone (GHRH) (10(-8) M). Medium was replaced again 2 h (+2) and 6 h (+6) later. None of the VGF concentrations influenced GH secretion in either group; the association with GHRH or ghrelin appeared ineffective in influencing GH secretion as compared with the effects of GH mRNA expression and was not influenced by VGF treatments. The presence of SME had an additive effect on GH expression. Collectively, our results confirm previous findings on GH regulation; however, further investigations are needed to establish whether the modulation of GH secretion in the absence of nutrients involves the balance of GHRH/ghrelin receptors at pituitary levels. As for VGF, a crucial aspect to clarify is whether its lack of effects depends on our experimental conditions or, alternatively, it is not effective at all.
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Affiliation(s)
- Roberta Saleri
- Department of Animal Production, Veterinary Biotechnology and Food Safety, Section of Veterinary Physiology, University of Parma, Parma, Italy.
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35
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Hughes-Davis EJ, Cogen JP, Jakowec MW, Cheng HW, Grenningloh G, Meshul CK, McNeill TH. Differential regulation of the growth-associated proteins GAP-43 and superior cervical ganglion 10 in response to lesions of the cortex and substantia nigra in the adult rat. Neuroscience 2005; 135:1231-9. [PMID: 16165289 DOI: 10.1016/j.neuroscience.2005.07.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2005] [Revised: 06/15/2005] [Accepted: 07/03/2005] [Indexed: 11/23/2022]
Abstract
Investigation of the elements underlying synapse replacement after brain injury is essential for predicting the neural compensation that can be achieved after various types of damage. The growth-associated proteins superior cervical ganglion-10 and growth-associated protein-43 have previously been linked with structural changes in the corticostriatal system in response to unilateral deafferentation. To examine the regulation of this response, unilateral cortical aspiration lesion was carried out in combination with ipsilateral 6-hydroxydopamine lesion of the substantia nigra, and the time course of the contralateral cortical molecular response was followed. Unilateral cortical aspiration lesion in rats corresponds with an upregulation of superior cervical ganglion-10 mRNA at 3 and 10 days post-lesion, and protein, sustained from three to at least 27 days following lesion. With the addition of substantia nigra lesion, the response shifts to an upregulation of growth-associated protein-43 mRNA at 3 and 10 days post-lesion, and protein after 10 days. Nigral lesion alone does not alter contralateral expression of either gene. Likewise, motor function assessment using the rotorod test revealed no significant long-term deficits in animals that sustained only nigrostriatal damage, but cortical lesion was associated with a temporary deficit which was sustained when nigrostriatal input was also removed. Growth-associated protein-43 and superior cervical ganglion-10, two presynaptic genes that are postulated to play roles in lesion-induced sprouting, are differentially upregulated in corticostriatal neurons after cortical versus combined cortical/nigral lesions. The shift in contralateral gene response from superior cervical ganglion-10 to growth-associated protein-43 upregulation and associated behavioral deficit following combined cortical and nigral denervation suggest that nigrostriatal afferents regulate cortical lesion-induced gene expression and ultimate functional outcome.
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Affiliation(s)
- E J Hughes-Davis
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA.
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Sadgrove MP, Chad JE, Gray WP. Kainic acid induces rapid cell death followed by transiently reduced cell proliferation in the immature granule cell layer of rat organotypic hippocampal slice cultures. Brain Res 2005; 1035:111-9. [PMID: 15722051 DOI: 10.1016/j.brainres.2004.11.059] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Revised: 11/19/2004] [Accepted: 11/19/2004] [Indexed: 11/26/2022]
Abstract
Brain injury due to seizures results in transiently increased cell proliferation and neurogenesis in the subgranular zone of the adult dentate gyrus. In contrast, the immature postnatal brain appears to be more resistant to cell death after seizure-induced brain injury and paradoxically reacts to seizures by reducing SGZ proliferation. Organotypic hippocampal slice cultures are a useful paradigm for modelling the early postnatal hippocampus. We have investigated the temporal relationship between cell death and cell proliferation after kainate in the granule cell layer of rat organotypic hippocampal slice cultures equivalent to post natal day 11 animals. We found stable numbers and densities of mature thionine stained cells in the granule cell layer over 72 h in control cultures grown in defined medium. We also found a slowly declining cell proliferation rate over the same time period under control conditions. We report evidence of early cell death in the granule cell layer after just 2 h exposure to 5 microM kainate, followed by a significant decrease in cell proliferation in the granule cell layer at 24 h. In contrast to control conditions, cell proliferation rose significantly in the kainate exposed cultures by 72 h back to levels seen at 2 h. There were no significant changes in cell labelling with antibody to activated caspase-3 between kainate treated and control cultures at any time point examined. Our results suggest that kainate-induced injury in the early postnatal hippocampus damages precursor cells contributing to a reduction in granule layer cell proliferation.
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Affiliation(s)
- Matthew Paul Sadgrove
- Division of Clinical Neurosciences, Southampton Neurosciences Group, School of Medicine, University of Southampton, Room 6207, Level 6, Biomedical Sciences Building, Bassett Crescent East, Southampton SO16 7PX, UK
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Carroll SL, Byer SJ, Dorsey DA, Watson MA, Schmidt RE. Ganglion-specific patterns of diabetes-modulated gene expression are established in prevertebral and paravertebral sympathetic ganglia prior to the development of neuroaxonal dystrophy. J Neuropathol Exp Neurol 2004; 63:1144-54. [PMID: 15581182 DOI: 10.1093/jnen/63.11.1144] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In both humans and animal models, diabetic sympathetic autonomic neuropathy is associated with the selective development of markedly enlarged distal axons and nerve terminals (neuroaxonal dystrophy, NAD). NAD occurs in the prevertebral superior mesenteric and celiac ganglia (SMG-CG), but not in the paravertebral superior cervical ganglion (SCG). To identify molecular differences between these ganglia that may explain their selective vulnerability to NAD, we have examined global gene expression patterns in control and diabetic rat sympathetic ganglia before and after the onset of structural evidence of NAD. As predicted, major differences in transcriptional profiles exist between SCG and SMG-CG in normal young adult animals including, but not limited to, known differences in neurotransmitter-related gene expression. Gene expression patterns of diabetic SMG-CG and SCG, prior to the development of NAD lesions, also differ from their age-matched non-diabetic counterparts. However, diabetes has ganglion-specific effects on gene expression; of approximately 110 transcripts that were differentially expressed between diabetic and control sympathetic ganglia, only 5 were differentially expressed as a result of diabetes in both SCG and SMG-CG. Genes involving synapse and mitochondrial structure and function, oxidative stress, and glycolysis were highly represented in the differentially expressed gene set. Differences in the number of synapse-related gene alterations in diabetic SMG-CG (18 genes) versus SCG (2 genes) prior to the onset of NAD may also well explain the selective development of NAD in the SMG-CG. These results provide support for the specificity of diabetes-modulated gene expression for selected neuronal subpopulations of sympathetic noradrenergic neurons.
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Affiliation(s)
- Steven L Carroll
- Department of Pathology, The University of Alabama School of Medicine, Birmingham, Alabama, USA
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Levi A, Ferri GL, Watson E, Possenti R, Salton SRJ. Processing, distribution, and function of VGF, a neuronal and endocrine peptide precursor. Cell Mol Neurobiol 2004; 24:517-33. [PMID: 15233376 DOI: 10.1023/b:cemn.0000023627.79947.22] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
1. The vgf gene encodes a neuropeptide precursor with a restricted pattern of expression that is limited to a subset of neurons in the central and peripheral nervous systems and to specific populations of endocrine cells in the adenohypophysis, adrenal medulla, gastrointestinal tract, and pancreas. In responsive neurons, vgf transcription is upregulated by neurotrophins. the basis for the original identification of VGF as nerve growth factor- (NGF) inducible in PC12 cells (A. Levi, J. D. Eldridge, and B. M. Paterson, Science 229:393-395, 1985). 2. In this review, we shall summarize data concerning the transcriptional regulation of vgf in vitro, the structural organization of the vgf promoter as well as the transcription factors which regulate its activity. 3. On the basis of in situ hybridization and immunohistochemical studies, the in vivo tissue-specific expression of VGF during differentiation and in the adult will be summarized. 4. Parallel biochemical data will be reviewed, addressing the proteolytical processing of the pro-VGF precursor within the secretory compartment of neuroendocrine cells. 5. Finally, analysis of the phenotype of VGF knockout mice will be discussed, implying a nonredundant role of VGF products in the regulation of energy storage and expenditure.
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Affiliation(s)
- Andrea Levi
- Department of Neuroscience, University of Tor Vergata, Rome, Italy
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Brain-derived neurotrophic factor-induced gene expression reveals novel actions of VGF in hippocampal synaptic plasticity. J Neurosci 2003. [PMID: 14645472 DOI: 10.1523/jneurosci.23-34-10800.2003] [Citation(s) in RCA: 210] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synaptic strengthening induced by brain-derived neurotrophic factor (BDNF) is associated with learning and is coupled to transcriptional activation. However, identification of the spectrum of genes associated with BDNF-induced synaptic plasticity and the correlation of expression with learning paradigms in vivo has not yet been studied. Transcriptional analysis of BDNF-induced synaptic strengthening in cultured hippocampal neurons revealed increased expression of the immediate early genes (IEGs), c-fos, early growth response gene 1 (EGR1), activity-regulated cytoskeletal-associated protein (Arc) at 20 min, and the secreted peptide VGF (non-acronymic) protein precursor at 3 hr. The induced genes served as prototypes to decipher mechanisms of both BDNF-induced transcription and plasticity. BDNF-mediated gene expression was tyrosine kinase B and mitogen-activated protein kinase-dependent, as demonstrated by pharmacological studies. Single-cell transcriptional analysis of Arc after whole-cell patch-clamp recordings indicated that increased gene expression correlated with enhancement of synaptic transmission by BDNF. Increased expression in vitro predicted elevations in vivo: VGF and the IEGs increased after trace eyeblink conditioning, a hippocampal-dependent learning paradigm. VGF protein was also upregulated by BDNF treatment and was expressed in a punctate manner in dissociated hippocampal neurons. Collectively, these findings suggested that the VGF neuropeptides may regulate synaptic function. We found a novel function for VGF by applying VGF peptides to neurons. C-terminal VGF peptides acutely increased synaptic charge in a dose-dependent manner, whereas N-terminal peptide had no effect. These observations indicate that gene profiling in vitro can reveal new mechanisms of synaptic strengthening associated with learning and memory.
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Abstract
Electroconvulsive seizure therapy (ECS) is a clinically proven treatment for depression and is often effective even in patients resistant to chemical antidepressants. However, the molecular mechanisms underlying the therapeutic efficacy of ECS are not fully understood. One theory that has gained attention is that ECS and other antidepressants increase the expression of select neurotrophic factors that could reverse or block the atrophy and cell loss resulting from stress and depression. To further address this topic, we examined the expression of other neurotrophic-growth factors and related signaling pathways in the hippocampus in response to ECS using a custom growth factor microarray chip. We report the regulation of several genes that are involved in growth factor and angiogenic-endothelial signaling, including neuritin, stem cell factor, vascular endothelial growth factor (VEGF), VGF (nonacronymic), cyclooxygenase-2, and tissue inhibitor of matrix metalloproteinase-1. Some of these, as well as other growth factors identified, including VEGF, basic fibroblast growth factor, and brain-derived neurotrophic factor, have roles in mediating neurogenesis and cell proliferation in the adult brain. We also examined gene expression in the choroid plexus and found several growth factors that are enriched in this vascular tissue as well as regulated by ECS. These data suggest that an amplification of growth factor signaling combined with angiogenic mechanisms could have an important role in the molecular action of ECS. This study demonstrates the applicability of custom-focused microarray technology in addressing hypothesis-driven questions regarding the action of antidepressants.
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McNeill TH, Brown SA, Hogg E, Cheng HW, Meshul CK. Synapse replacement in the striatum of the adult rat following unilateral cortex ablation. J Comp Neurol 2003; 467:32-43. [PMID: 14574678 DOI: 10.1002/cne.10907] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Defining the selective pattern of synapse replacement that occurs in different areas of the damaged brain is essential for predicting the limits of functional compensation that can be achieved after various types of brain injury. Here we describe the time course of dendritic reorganization, spine loss and recovery, and synapse replacement in the striatum following a unilateral cortex ablation. We found that the time course for the transient loss and recovery of dendritic spines on medium spiny I (MSI) neurons, the primary postsynaptic target for corticostriatal axons, paralleled the time course for the removal of degenerating axon terminals from the neuropil and the formation of new synapses on MSI neurons. Reinnervation of the deafferented striatum occurred chiefly by axon terminals that formed asymmetric synapses with dendritic spines of MSI neurons, and the mean density of asymmetric synapses recovered to 86% of the sham-operated rat value by 30 days postlesion. In addition, the synaptic circuitry of the reconstructed striatum was characterized by an increase in the number of multiple synaptic boutons (MSBs), i.e., presynaptic axon terminals that make contact with more than one dendritic spine. Whether the postsynaptic contacts of MSBs are formed with the dendritic spines of the same or a different parent dendrite in the striatum is unknown. Nevertheless, these data suggest that the formation of MSBs is an essential part of the compensatory response to the loss of input from the ipsilateral cortex following the aspiration lesion and may serve to modulate activity-dependent adaptive changes in the reconstructed striatum that can lead to functional recovery.
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Affiliation(s)
- Thomas H McNeill
- Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, Los Angeles, California 90033, USA.
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Costigan M, Befort K, Karchewski L, Griffin RS, D'Urso D, Allchorne A, Sitarski J, Mannion JW, Pratt RE, Woolf CJ. Replicate high-density rat genome oligonucleotide microarrays reveal hundreds of regulated genes in the dorsal root ganglion after peripheral nerve injury. BMC Neurosci 2002; 3:16. [PMID: 12401135 PMCID: PMC139981 DOI: 10.1186/1471-2202-3-16] [Citation(s) in RCA: 420] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2002] [Accepted: 10/25/2002] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Rat oligonucleotide microarrays were used to detect changes in gene expression in the dorsal root ganglion (DRG) 3 days following sciatic nerve transection (axotomy). Two comparisons were made using two sets of triplicate microarrays, naïve versus naïve and naïve versus axotomy. RESULTS Microarray variability was assessed using the naïve versus naïve comparison. These results support use of a P < 0.05 significance threshold for detecting regulated genes, despite the large number of hypothesis tests required. For the naïve versus axotomy comparison, a 2-fold cut off alone led to an estimated error rate of 16%; combining a >1.5-fold expression change and P < 0.05 significance reduced the estimated error to 5%. The 2-fold cut off identified 178 genes while the combined >1.5-fold and P < 0.05 criteria generated 240 putatively regulated genes, which we have listed. Many of these have not been described as regulated in the DRG by axotomy. Northern blot, quantitative slot blots and in situ hybridization verified the expression of 24 transcripts. These data showed an 83% concordance rate with the arrays; most mismatches represent genes with low expression levels reflecting limits of array sensitivity. A significant correlation was found between actual mRNA differences and relative changes between microarrays (r2 = 0.8567). Temporal patterns of individual genes regulation varied. CONCLUSIONS We identify parameters for microarray analysis which reduce error while identifying many putatively regulated genes. Functional classification of these genes suggest reorganization of cell structural components, activation of genes expressed by immune and inflammatory cells and down-regulation of genes involved in neurotransmission.
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Affiliation(s)
- Michael Costigan
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Katia Befort
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Laurie Karchewski
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Robert S Griffin
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | | | - Andrew Allchorne
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Joanne Sitarski
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - James W Mannion
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Richard E Pratt
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, MA 02115, USA
| | - Clifford J Woolf
- Neural Plasticity Research Group, Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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Regional differences in neurotrophin availability regulate selective expression of VGF in the developing limbic cortex. J Neurosci 2002. [PMID: 11717365 DOI: 10.1523/jneurosci.21-23-09315.2001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Gene and protein expression patterns in the cerebral cortex are complex and often change spatially and temporally through development. The signals that regulate these patterns are primarily unknown. In the present study, we focus on the regulation of VGF expression, which is limited to limbic cortical areas early in development but later expands into sensory and motor areas. We isolated neurons from embryonic day 17 rat cortex and demonstrate that the profile of VGF expression in perirhinal (expressing) and occipital (nonexpressing) populations in vitro is similar to that in the perinatal cortex in vivo. The addition of neutralizing neurotrophin antibodies indicates that endogenous brain-derived neurotrophic factor (BDNF) is necessary for the normal complement of VGF-expressing neurons in the perirhinal cortex, although endogenous neurotrophin-3 (NT-3) regulates the expression of VGF in a subpopulation of cells. ELISA analysis demonstrates that there is significantly more BDNF present in the perirhinal cortex compared with the occipital cortex in the perinatal period. However, the total amount of NT-3 is similar between the two regions and, moreover, there is considerably more NT-3 than BDNF in both areas, a finding seemingly in conflict with regional VGF expression. Quantification of the extracellular levels of neurotrophins in perirhinal and occipital cultures using ELISA in situ analysis indicates that perirhinal neurons release significantly more BDNF than the occipital population. Furthermore, the amount of NT-3 released by the perirhinal neurons is significantly less than the amount of BDNF. Local injection of BDNF in vivo into a normally negative VGF region results in robust ectopic expression of VGF. These data suggest that the local availability of specific neurotrophins for receptor occupation, rather than the total amount of neurotrophin, is a critical parameter in determining the selective expression of VGF in the developing limbic cortex.
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Abstract
Sleep and waking differ significantly in terms of behavior, metabolism, and neuronal activity. Recent evidence indicates that sleep and waking also differ with respect to the expression of certain genes. To systematically investigate such changes, we used mRNA differential display and cDNA microarrays to screen approximately 10000 transcripts expressed in the cerebral cortex of rats after 8 h of sleep, spontaneous waking, or sleep deprivation. We found that 44 genes had higher mRNA levels after waking and/or sleep deprivation relative to sleep, while 10 were upregulated after sleep. Known genes that were upregulated in waking and sleep deprivation can be grouped into the following categories: immediate early genes/transcription factors (Arc, CHOP, IER5, NGFI-A, NGFI-B, N-Ras, Stat3), genes related to energy metabolism (glucose type I transporter Glut1, Vgf), growth factors/adhesion molecules (BDNF, TrkB, F3 adhesion molecule), chaperones/heat shock proteins (BiP, ERP72, GRP75, HSP60, HSP70), vesicle- and synapse-related genes (chromogranin C, synaptotagmin IV), neurotransmitter/hormone receptors (adrenergic receptor alpha(1A) and beta(2), GABA(A) receptor beta(3), glutamate NMDA receptor 2A, glutamate AMPA receptor GluR2 and GluR3, nicotinic acetylcholine receptor beta(2), thyroid hormone receptor TRbeta), neurotransmitter transporters (glutamate/aspartate transporter GLAST, Na(+)/Cl(-) transporter NTT4/Rxt1), enzymes (aryl sulfotransferase, c-jun N-terminal kinase 1, serum/glucocorticoid-induced serine/threonine kinase), and a miscellaneous group (calmodulin, cyclin D2, LMO-4, metallothionein 3). Several other genes that were upregulated in waking and all the genes upregulated in sleep, with the exception of the one coding for membrane protein E25, did not match any known sequence. Thus, significant changes in gene expression occur across behavioral states, which are likely to affect basic cellular functions such as RNA and protein synthesis, neural plasticity, neurotransmission, and metabolism.
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Affiliation(s)
- C Cirelli
- The Neurosciences Institute, 10640 John J. Hopkins Drive, San Diego, CA 92121, USA
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Salton SR, Ferri GL, Hahm S, Snyder SE, Wilson AJ, Possenti R, Levi A. VGF: a novel role for this neuronal and neuroendocrine polypeptide in the regulation of energy balance. Front Neuroendocrinol 2000; 21:199-219. [PMID: 10882540 DOI: 10.1006/frne.2000.0199] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insight into the mechanisms of action of neurotrophic growth factors has been obtained through the identification and characterization of gene products that are regulated or modified at the transcriptional, translational, and/or posttranslational level in response to neurotrophin treatment. VGF (non-acronymic) was identified approximately 15 years ago as a nerve growth factor (NGF)-regulated transcript in rat PC12 pheochromocytoma cells. Subsequent studies have demonstrated that neurotrophins such as NGF and brain-derived neurotrophic factor induce vgf gene expression relatively rapidly in PC12 cells and cultured cortical neurons, respectively, in comparison to less robust regulation by epidermal growth factor (EGF) and insulin, growth factors which do not trigger the neuronal differentiation of PC12 cells. vgf gene expression is stimulated in vitro by NGF and the ras/map kinase signaling cascade through a CREB-dependent mechanism, while in vivo, VGF mRNA levels are regulated by neuronal activity, including long-term potentiation, seizure, and injury. Both the mRNA and encoded approximately 68-kDa protein (VGF) are selectively synthesized in neuroendocrine and neuronal cells. The predicted VGF sequence is rich in paired basic amino acid residues that are potential sites for proteolytic processing, and VGF undergoes regulated release from dense core secretory vesicles. Although VGF mRNA is synthesized widely, by neurons in the brain, spinal cord, and peripheral nervous system, its expression is particularly abundant in the hypothalamus. In addition, VGF peptides are found in hypophysial, adrenal medullary, gastrointestinal, and pancreatic endocrine cells, suggesting important neuroendocrine functions. Recent analysis of VGF knockout mice indeed demonstrates that VGF plays a critical role in the control of energy homeostasis. VGF knockout mice are thin, small, hypermetabolic, hyperactive, and relatively infertile, with markedly reduced leptin levels and fat stores and altered hypothalamic pro-opiomelanocortin, neuropeptide Y, and agouti-related peptide expression. Coupled with the demonstration that VGF mRNA levels are induced in the normal mouse hypothalamic arcuate nuclei in response to fasting, important central and peripheral roles for VGF in the regulation of metabolism are suggested. Here we review previous studies of VGF in the broader context of its newly recognized role in the control of energy balance and propose several models and experimental approaches that may better define the mechanisms of action of VGF.
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Affiliation(s)
- S R Salton
- Fishberg Research Center for Neurobiology, Mount Sinai School of Medicine, New York, New York, 10029, USA.
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Abstract
Several studies support the hypothesis that after stroke, specific features of brain function revert to those seen at an early stage of development, with the subsequent process of recovery recapitulating ontogeny in many ways. Many clinical characteristics of stroke recovery resemble normal development, particularly in the motor system. Consistent with this, brain-mapping studies after an ischemic insult suggest re-emergence of childhood organizational patterns: recovery being associated with a return to adult patterns. Experimental animal studies demonstrate increased levels of developmental proteins, particularly in the area surrounding an infarct, suggesting an active process of reconditioning in response to cerebral ischemia. Understanding the patterns of similarity between normal development and stroke recovery might be of value in its treatment.
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Affiliation(s)
- S C Cramer
- Dept of Neurology, University of Washington, Seattle, WA 98195, USA
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Hahm S, Mizuno TM, Wu TJ, Wisor JP, Priest CA, Kozak CA, Boozer CN, Peng B, McEvoy RC, Good P, Kelley KA, Takahashi JS, Pintar JE, Roberts JL, Mobbs CV, Salton SR. Targeted deletion of the Vgf gene indicates that the encoded secretory peptide precursor plays a novel role in the regulation of energy balance. Neuron 1999; 23:537-48. [PMID: 10433265 DOI: 10.1016/s0896-6273(00)80806-5] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
To determine the function of VGF, a secreted polypeptide that is synthesized by neurons, is abundant in the hypothalamus, and is regulated in the brain by electrical activity, injury, and the circadian clock, we generated knockout mice lacking Vgf. Homozygous mutants are small, hypermetabolic, hyperactive, and infertile, with markedly reduced leptin levels and fat stores and altered hypothalamic proopiomelanocortin (POMC), neuropeptide Y (NPY), and agouti-related peptide (AGRP) expression. Furthermore, VGF mRNA synthesis is induced in the hypothalamic arcuate nuclei of fasted normal mice. VGF therefore plays a critical role in the regulation of energy homeostasis, suggesting that the study of lean VGF mutant mice may provide insight into wasting disorders and, moreover, that pharmacological antagonism of VGF action(s) might constitute the basis for treatment of obesity.
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Affiliation(s)
- S Hahm
- Fishberg Research Center for Neurobiology, Mount Sinai School of Medicine, New York, New York 10029, USA
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Wolansky MJ, Paratcha GC, Ibarra GR, Azcurra JM. Nerve growth factor preserves a critical motor period in rat striatum. JOURNAL OF NEUROBIOLOGY 1999; 38:129-36. [PMID: 10027568 DOI: 10.1002/(sici)1097-4695(199901)38:1<129::aid-neu10>3.0.co;2-t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We previously found the occurrence of a critical motor period during rat postnatal development where circling training starting the 7-day schedule at 30 days-but not before or after-induces a lifetime drop in the binding to cholinergic muscarinic receptors (mAChRs) in striatum. Here, we studied whether nerve growth factor (NGF) participates in this restricted period of muscarinic sensitivity. For this purpose, we administered mouse salival gland 2.5S NGF (1.4 or 0.4 microg/day, infused by means of ALZA minipumps) by intrastriatal unilateral route between days 25 and 39, and then trained rats starting at 40 days. Under these conditions, NGF induced a long-term reduction in the striatal [3H] quinuclidilbenzylate (QNB) binding sites despite the fact that motor training was carried out beyond the natural critical period. Thus, at day 70, measurement of specific QNB binding in infused striata of trained rats showed decreases of 42% (p < .0004) and 33% (p < .02) after administration of the higher and lower NGF doses, respectively, with respect to trained rats treated with cytochrome C, for control. Noncannulated striata of the NGF-treated rats also showed a decrease in QNB binding sites (44%; p < .0001) only at the higher infusion rate. This effect was not found in the respective control groups. Our observations show that NGF modulates the critical period in which activity-dependent mAChR setting takes place during rat striatal maturation.
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Affiliation(s)
- M J Wolansky
- Proyecto IPON, Cátedra de Biología Celular, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Universidad de Buenos Aires, Argentina
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