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Expression Analysis of Genes Involved in Transport Processes in Mice with MPTP-Induced Model of Parkinson’s Disease. Life (Basel) 2022; 12:life12050751. [PMID: 35629417 PMCID: PMC9146539 DOI: 10.3390/life12050751] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
Processes of intracellular and extracellular transport play one of the most important roles in the functioning of cells. Changes to transport mechanisms in a neuron can lead to the disruption of many cellular processes and even to cell death. It was shown that disruption of the processes of vesicular, axonal, and synaptic transport can lead to a number of diseases of the central nervous system, including Parkinson’s disease (PD). Here, we studied changes in the expression of genes whose protein products are involved in the transport processes (Snca, Drd2, Rab5a, Anxa2, and Nsf) in the brain tissues and peripheral blood of mice with MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)-induced models of PD. We detected changes in the expressions of Drd2, Anxa2, and Nsf at the earliest modeling stages. Additionally, we have identified conspicuous changes in the expression level of Anxa2 in the striatum and substantia nigra of mice with MPTP-induced models of PD in its early stages. These data clearly suggest the involvement of protein products in these genes in the earliest stages of the pathogenesis of PD.
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Vita DJ, Meier CJ, Broadie K. Neuronal fragile X mental retardation protein activates glial insulin receptor mediated PDF-Tri neuron developmental clearance. Nat Commun 2021; 12:1160. [PMID: 33608547 PMCID: PMC7896095 DOI: 10.1038/s41467-021-21429-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 01/08/2021] [Indexed: 01/31/2023] Open
Abstract
Glia engulf and phagocytose neurons during neural circuit developmental remodeling. Disrupting this pruning process contributes to Fragile X syndrome (FXS), a leading cause of intellectual disability and autism spectrum disorder in mammals. Utilizing a Drosophila FXS model central brain circuit, we identify two glial classes responsible for Draper-dependent elimination of developmentally transient PDF-Tri neurons. We find that neuronal Fragile X Mental Retardation Protein (FMRP) drives insulin receptor activation in glia, promotes glial Draper engulfment receptor expression, and negatively regulates membrane-molding ESCRT-III Shrub function during PDF-Tri neuron clearance during neurodevelopment in Drosophila. In this context, we demonstrate genetic interactions between FMRP and insulin receptor signaling, FMRP and Draper, and FMRP and Shrub in PDF-Tri neuron elimination. We show that FMRP is required within neurons, not glia, for glial engulfment, indicating FMRP-dependent neuron-to-glia signaling mediates neuronal clearance. We conclude neuronal FMRP drives glial insulin receptor activation to facilitate Draper- and Shrub-dependent neuronal clearance during neurodevelopment in Drosophila.
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Affiliation(s)
- Dominic J Vita
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Cole J Meier
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA.
- Kennedy Center for Research on Human Development, Nashville, TN, USA.
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, USA.
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3
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Suardi GAM, Haddad LA. FMRP ribonucleoprotein complexes and RNA homeostasis. ADVANCES IN GENETICS 2020; 105:95-136. [PMID: 32560791 DOI: 10.1016/bs.adgen.2020.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Fragile Mental Retardation 1 gene (FMR1), at Xq27.3, encodes the fragile mental retardation protein (FMRP), and displays in its 5'-untranslated region a series of polymorphic CGG triplet repeats that may undergo dynamic mutation. Fragile X syndrome (FXS) is the leading cause of inherited intellectual disability among men, and is most frequently due to FMR1 full mutation and consequent transcription repression. FMR1 premutations may associate with at least two other clinical conditions, named fragile X-associated primary ovarian insufficiency (FXPOI) and tremor and ataxia syndrome (FXTAS). While FXPOI and FXTAS appear to be mediated by FMR1 mRNA accumulation, relative reduction of FMRP, and triplet repeat translation, FXS is due to the lack of the RNA-binding protein FMRP. Besides its function as mRNA translation repressor in neuronal and stem/progenitor cells, RNA editing roles have been assigned to FMRP. In this review, we provide a brief description of FMR1 transcribed microsatellite and associated clinical disorders, and discuss FMRP molecular roles in ribonucleoprotein complex assembly and trafficking, as well as aspects of RNA homeostasis affected in FXS cells.
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Affiliation(s)
- Gabriela Aparecida Marcondes Suardi
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Luciana Amaral Haddad
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
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4
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Chatterjee M, Kurup PK, Lundbye CJ, Hugger Toft AK, Kwon J, Benedict J, Kamceva M, Banke TG, Lombroso PJ. STEP inhibition reverses behavioral, electrophysiologic, and synaptic abnormalities in Fmr1 KO mice. Neuropharmacology 2017; 128:43-53. [PMID: 28943283 DOI: 10.1016/j.neuropharm.2017.09.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/26/2017] [Accepted: 09/19/2017] [Indexed: 12/11/2022]
Abstract
Fragile X syndrome (FXS) is the leading cause of inherited intellectual disability, with additional symptoms including attention deficit and hyperactivity, anxiety, impulsivity, and repetitive movements or actions. The majority of FXS cases are attributed to a CGG expansion that leads to transcriptional silencing and diminished expression of fragile X mental retardation protein (FMRP). FMRP, an RNA binding protein, regulates the synthesis of dendritically-translated mRNAs by stalling ribosomal translation. Loss of FMRP leads to increased translation of some of these mRNAs, including the CNS-specific tyrosine phosphatase STEP (STriatal-Enriched protein tyrosine Phosphatase). Genetic reduction of STEP in Fmr1 KO mice have diminished audiogenic seizures and a reversal of social and non-social anxiety-related abnormalities. This study investigates whether a newly discovered STEP inhibitor (TC-2153) could attenuate the behavioral and synaptic abnormalities in Fmr1 KO mice. TC-2153 reversed audiogenic seizure incidences, reduced hyperactivity, normalized anxiety states, and increased sociability in Fmr1 KO mice. Moreover, TC-2153 reduced dendritic spine density and improved synaptic aberrations in Fmr1 KO neuronal cultures as well as in vivo. TC-2153 also reversed the mGluR-mediated exaggerated LTD in brain slices derived from Fmr1 KO mice. These studies suggest that STEP inhibition may have therapeutic benefit in FXS.
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Affiliation(s)
- Manavi Chatterjee
- Child Study Center, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States.
| | - Pradeep K Kurup
- Child Study Center, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States
| | - Camilla J Lundbye
- Institute of Biomedicine - Physiology, Aarhus University, Aarhus, 8000, Denmark
| | | | - Jeemin Kwon
- Child Study Center, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States
| | - Jessie Benedict
- Child Study Center, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States
| | - Marija Kamceva
- Child Study Center, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States
| | - Tue G Banke
- Institute of Biomedicine - Physiology, Aarhus University, Aarhus, 8000, Denmark
| | - Paul J Lombroso
- Child Study Center, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States; Department of Psychiatry, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States; Department of Neuroscience, Yale University, 230 South Frontage Rd, New Haven, CT, 06520, United States.
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Activity Induces Fmr1-Sensitive Synaptic Capture of Anterograde Circulating Neuropeptide Vesicles. J Neurosci 2017; 36:11781-11787. [PMID: 27852784 DOI: 10.1523/jneurosci.2212-16.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/22/2016] [Accepted: 09/26/2016] [Indexed: 12/21/2022] Open
Abstract
Synaptic neuropeptide and neurotrophin stores are maintained by constitutive bidirectional capture of dense-core vesicles (DCVs) as they circulate in and out of the nerve terminal. Activity increases DCV capture to rapidly replenish synaptic neuropeptide stores following release. However, it is not known whether this is due to enhanced bidirectional capture. Here experiments at the Drosophila neuromuscular junction, where DCVs contain neuropeptides and a bone morphogenic protein, show that activity-dependent replenishment of synaptic neuropeptides following release is evident after inhibiting the retrograde transport with the dynactin disruptor mycalolide B or photobleaching DCVs entering a synaptic bouton by retrograde transport. In contrast, photobleaching anterograde transport vesicles entering a bouton inhibits neuropeptide replenishment after activity. Furthermore, tracking of individual DCVs moving through boutons shows that activity selectively increases capture of DCVs undergoing anterograde transport. Finally, upregulating fragile X mental retardation 1 protein (Fmr1, also called FMRP) acts independently of futsch/MAP-1B to abolish activity-dependent, but not constitutive, capture. Fmr1 also reduces presynaptic neuropeptide stores without affecting activity-independent delivery and evoked release. Therefore, presynaptic motoneuron neuropeptide storage is increased by a vesicle capture mechanism that is distinguished from constitutive bidirectional capture by activity dependence, anterograde selectivity, and Fmr1 sensitivity. These results show that activity recruits a separate mechanism than used at rest to stimulate additional synaptic capture of DCVs for future release of neuropeptides and neurotrophins. SIGNIFICANCE STATEMENT Synaptic release of neuropeptides and neurotrophins depends on presynaptic accumulation of dense-core vesicles (DCVs). At rest, DCVs are captured bidirectionally as they circulate through Drosophila motoneuron terminals by anterograde and retrograde transport. Here we show that activity stimulates further synaptic capture that is distinguished from basal capture by its selectivity for anterograde DCVs and its inhibition by overexpression of the fragile X retardation protein Fmr1. Fmr1 dramatically lowers DCV numbers in synaptic boutons. Therefore, activity-dependent anterograde capture is a major determinant of presynaptic peptide stores.
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Broek JAC, Lin Z, de Gruiter HM, van 't Spijker H, Haasdijk ED, Cox D, Ozcan S, van Cappellen GWA, Houtsmuller AB, Willemsen R, de Zeeuw CI, Bahn S. Synaptic vesicle dynamic changes in a model of fragile X. Mol Autism 2016; 7:17. [PMID: 26933487 PMCID: PMC4772588 DOI: 10.1186/s13229-016-0080-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 02/20/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fragile X syndrome (FXS) is a single-gene disorder that is the most common heritable cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorders (ASD). FXS is caused by an expansion of trinucleotide repeats in the promoter region of the fragile X mental retardation gene (Fmr1). This leads to a lack of fragile X mental retardation protein (FMRP), which regulates translation of a wide range of messenger RNAs (mRNAs). The extent of expression level alterations of synaptic proteins affected by FMRP loss and their consequences on synaptic dynamics in FXS has not been fully investigated. METHODS Here, we used an Fmr1 knockout (KO) mouse model to investigate the molecular mechanisms underlying FXS by monitoring protein expression changes using shotgun label-free liquid-chromatography mass spectrometry (LC-MS(E)) in brain tissue and synaptosome fractions. FXS-associated candidate proteins were validated using selected reaction monitoring (SRM) in synaptosome fractions for targeted protein quantification. Furthermore, functional alterations in synaptic release and dynamics were evaluated using live-cell imaging, and interpretation of synaptic dynamics differences was investigated using electron microscopy. RESULTS Key findings relate to altered levels of proteins involved in GABA-signalling, especially in the cerebellum. Further exploration using microscopy studies found reduced synaptic vesicle unloading of hippocampal neurons and increased vesicle unloading in cerebellar neurons, which suggests a general decrease of synaptic transmission. CONCLUSIONS Our findings suggest that FMRP is a regulator of synaptic vesicle dynamics, which supports the role of FMRP in presynaptic functions. Taken together, these studies provide novel insights into the molecular changes associated with FXS.
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Affiliation(s)
- Jantine A C Broek
- Cambridge Centre for Neuropsychiatric Research, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Zhanmin Lin
- Department of Neurosciences, Erasmus MC, Rotterdam, The Netherlands
| | | | - Heleen van 't Spijker
- Cambridge Centre for Neuropsychiatric Research, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Elize D Haasdijk
- Department of Neurosciences, Erasmus MC, Rotterdam, The Netherlands
| | - David Cox
- Cambridge Centre for Neuropsychiatric Research, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Sureyya Ozcan
- Cambridge Centre for Neuropsychiatric Research, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | | | | | - Rob Willemsen
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Chris I de Zeeuw
- Department of Neurosciences, Erasmus MC, Rotterdam, The Netherlands.,Netherlands Institute for Neurosciences, Royal Academy for Arts and Sciences, Amsterdam, The Netherlands
| | - Sabine Bahn
- Cambridge Centre for Neuropsychiatric Research, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.,Department of Neurosciences, Erasmus MC, Rotterdam, The Netherlands
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Tillmaand EG, Yang N, Kindt CAC, Romanova EV, Rubakhin SS, Sweedler JV. Peptidomics and Secretomics of the Mammalian Peripheral Sensory-Motor System. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:2051-2061. [PMID: 26392278 PMCID: PMC4655166 DOI: 10.1007/s13361-015-1256-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/30/2015] [Accepted: 08/10/2015] [Indexed: 06/01/2023]
Abstract
The dorsal root ganglion (DRG) and its anatomically and functionally associated spinal nerve and ventral and dorsal roots are important components of the peripheral sensory-motor system in mammals. The cells within these structures use a number of peptides as intercellular signaling molecules. We performed a variety of mass spectrometry (MS)-based characterizations of peptides contained within and secreted from these structures, and from isolated and cultured DRG cells. Liquid chromatography-Fourier transform MS was utilized in DRG and nerve peptidome analysis. In total, 2724 peptides from 296 proteins were identified in tissue extracts. Neuropeptides are among those detected, including calcitonin gene-related peptide I, little SAAS, and known hemoglobin-derived peptides. Solid phase extraction combined with direct matrix-assisted laser desorption/ionization time-of-flight MS was employed to investigate the secretome of these structures. A number of peptides were detected in the releasate from semi-intact preparations of DRGs and associated nerves, including neurofilament- and myelin basic protein-related peptides. A smaller set of analytes was observed in releasates from cultured DRG neurons. The peptide signals observed in the releasates have been mass-matched to those characterized and identified in homogenates of entire DRGs and associated nerves. This data aids our understanding of the chemical composition of the mammalian peripheral sensory-motor system, which is involved in key physiological functions such as nociception, thermoreception, itch sensation, and proprioception.
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Affiliation(s)
- Emily G Tillmaand
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Ning Yang
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Callie A C Kindt
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Elena V Romanova
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Stanislav S Rubakhin
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Jonathan V Sweedler
- Department of Chemistry and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
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8
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Maki AE, Morris KA, Catherman K, Chen X, Hatcher NG, Gold PE, Sweedler JV. Fibrinogen α-chain-derived peptide is upregulated in hippocampus of rats exposed to acute morphine injection and spontaneous alternation testing. Pharmacol Res Perspect 2014; 2:e00037. [PMID: 24855564 PMCID: PMC4024393 DOI: 10.1002/prp2.37] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Fibrinogen is a secreted glycoprotein that is synthesized in the liver, although recent in situ hybridization data support its expression in the brain. It is involved in blood clotting and is released in the brain upon injury. Here, we report changes in the extracellular levels of fibrinogen α-chain-derived peptides in the brain after injections of saline and morphine. More specifically, in order to assess hippocampus-related working memory, an approach pairing in vivo microdialysis with mass spectrometry was used to characterize extracellular peptide release from the hippocampus of rats in response to saline or morphine injection coupled with a spontaneous alternation task. Two fibrinopeptide A-related peptides derived from the fibrinogen α-chain – fibrinopeptide A (ADTGTTSEFIEAGGDIR) and a fibrinopeptide A-derived peptide (DTGTTSEFIEAGGDIR) – were shown to be consistently elevated in the hippocampal microdialysate. Fibrinopeptide A was significantly upregulated in rats exposed to morphine and spontaneous alternation testing compared with rats exposed to saline and spontaneous alternation testing (P < 0.001), morphine alone (P < 0.01), or saline alone (P < 0.01), respectively. The increase in fibrinopeptide A in rats subjected to morphine and a memory task suggests that a complex interaction between fibrinogen and morphine takes place in the hippocampus.
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Affiliation(s)
- Agatha E Maki
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
| | - Kenneth A Morris
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
| | - Kasia Catherman
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
| | - Xian Chen
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
| | - Nathan G Hatcher
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
| | - Paul E Gold
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
| | - Jonathan V Sweedler
- Beckman Institute (A.E.M., K.C., X.C., N.G.H., J.V.S.), Neuroscience Program (A.E.M., K.A.M., J.V.S.), and Department of Chemistry (K.C., X.C., N.G.H., J.V.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Biology, Syracuse University, Syracuse, New York (P.E.G.)
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Gelman JS, Dasgupta S, Berezniuk I, Fricker LD. Analysis of peptides secreted from cultured mouse brain tissue. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2408-17. [PMID: 23402728 DOI: 10.1016/j.bbapap.2013.01.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 01/25/2013] [Accepted: 01/29/2013] [Indexed: 01/02/2023]
Abstract
Peptides represent a major class of cell-cell signaling molecules. Most peptidomic studies have focused on peptides present in brain or other tissues. For a peptide to function in intercellular signaling, it must be secreted. The present study was undertaken to identify the major peptides secreted from mouse brain slices that were cultured in oxygenated buffer for 3-4h. Approximately 75% of the peptides identified in extracts of cultured slices matched the previously reported peptide content of heat-inactivated mouse brain tissue, whereas only 2% matched the peptide content of unheated brain tissue; the latter showed a large number of postmortem changes. As found with extracts of heat-inactivated mouse brain, the extracts of cultured brain slices represented secretory pathway peptides as well as peptides derived from intracellular proteins such as those present in the cytosol and mitochondria. A subset of the peptides detected in the extracts of the cultured slices was detected in the culture media. The vast majority of secreted peptides arose from intracellular proteins and not secretory pathway proteins. The peptide RVD-hemopressin, a CB1 cannabinoid receptor agonist, was detected in culture media, which is consistent with a role for RVD-hemopressin as a non-classical neuropeptide. Taken together with previous studies, the present results show that short-term culture of mouse brain slices is an appropriate system to study peptide secretion, especially the non-conventional pathway(s) by which peptides produced from intracellular proteins are secreted. This article is part of a Special Issue entitled: An Updated Secretome.
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Affiliation(s)
- Julia S Gelman
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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10
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Hou X, Xie F, Sweedler JV. Relative quantitation of neuropeptides over a thousand-fold concentration range. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2012; 23:2083-93. [PMID: 22993045 PMCID: PMC3515743 DOI: 10.1007/s13361-012-0481-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/16/2012] [Accepted: 08/17/2012] [Indexed: 05/23/2023]
Abstract
Neuropeptides are essential cell-to-cell signaling molecules that influence diverse regulatory and behavioral functions within biological systems. Differing in their amino acid sequences and post-translational modifications, hundreds of neuropeptides are produced via a series of enzymatic processing steps, and their levels vary with location, time, and physiological condition. Due to their wide range of endogenous concentrations and inherent chemical complexity, using mass spectrometry (MS) to accurately quantify changes in peptide levels can be challenging. Here we evaluate three different MS systems for their ability to accurately measure neuropeptide levels: capillary liquid chromatography-electrospray ionization-ion trap (CapLC-ESI-IT) MS, ultraperformance liquid chromatography-electrospray ionization-quadrupole-time-of-flight (UPLC-LC-ESI-Q-TOF) MS, and matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) MS. Specifically, eight sample mixtures composed of five neuropeptide standards, with four technical replicates of each, were labeled with H(4)/D(4)-succinic anhydride, followed by relative peptide quantitation using the three MS platforms. For these samples, the CapLC-ESI-IT MS platform offered the most robust ability to accurately quantify peptides over a concentration range of 1200-fold, although it required larger sample sizes than the other two platforms. Both the UPLC-ESI-Q-TOF MS and the MALDI-TOF MS systems had lower limits of quantification, with the MALDI-TOF having the lowest. By implementing several data acquisition schemes and optimizing the data analysis approaches, we were able to accurately quantify peptides over a three orders of magnitude concentration range using either the UPLC or MALDI-TOF platforms. Overall these results increase our understanding of both the capabilities and limits of using MS-based approaches to measure peptides.
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Affiliation(s)
| | | | - Jonathan V. Sweedler
- Address reprint requests to: Jonathan V. Sweedler, Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, 63-5, Urbana, Il 61801, Ph: 217-244-7359, Fax: 217-265-6290,
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11
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Multiple approaches to investigate the transport and activity-dependent release of BDNF and their application in neurogenetic disorders. Neural Plast 2012; 2012:203734. [PMID: 22720171 PMCID: PMC3375105 DOI: 10.1155/2012/203734] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/14/2012] [Accepted: 04/15/2012] [Indexed: 01/01/2023] Open
Abstract
Studies utilizing genetic and pharmacological manipulations in rodent models and neuronal cultures have revealed myriad roles of brain-derived neurotrophic factor (BDNF). Currently, this knowledge of BDNF function is being translated into improvement strategies for several debilitating neurological disorders in which BDNF abnormalities play a prominent role. Common among the BDNF-related disorders are irregular trafficking and release of mature BDNF (mBDNF) and/or its prodomain predecessor, proBDNF. Thus, investigating the conditions required for proper trafficking and release of BDNF is an essential step toward understanding and potentially improving these neurological disorders. This paper will provide examples of disorders related to BDNF release and serve as a review of the techniques being used to study the trafficking and release of BDNF.
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Cellular Mechanisms for the Biogenesis and Transport of Synaptic and Dense-Core Vesicles. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 299:27-115. [DOI: 10.1016/b978-0-12-394310-1.00002-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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13
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Gelman JS, Sironi J, Castro LM, Ferro ES, Fricker LD. Peptidomic analysis of human cell lines. J Proteome Res 2011; 10:1583-92. [PMID: 21204522 DOI: 10.1021/pr100952f] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Peptides have been proposed to function in intracellular signaling within the cytosol. Although cytosolic peptides are considered to be highly unstable, a large number of peptides have been detected in mouse brain and other biological samples. In the present study, we evaluated the peptidome of three diverse cell lines: SH-SY5Y, MCF7, and HEK293 cells. A comparison of the peptidomes revealed considerable overlap in the identity of the peptides found in each cell line. The majority of the observed peptides are not derived from the most abundant or least stable proteins in the cell, and approximately half of the cellular peptides correspond to the N- or C- termini of the precursor proteins. Cleavage site analysis revealed a preference for hydrophobic residues in the P1 position. Quantitative peptidomic analysis indicated that the levels of most cellular peptides are not altered in response to elevated intracellular calcium, suggesting that calpain is not responsible for their production. The similarity of the peptidomes of the three cell lines and the lack of correlation with the predicted cellular degradome implies the selective formation or retention of these peptides, consistent with the hypothesis that they are functional in the cells.
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Affiliation(s)
- Julia S Gelman
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, United States
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Fulks JL, O’Bryhim BE, Wenzel SK, Fowler SC, Vorontsova E, Pinkston JW, Ortiz AN, Johnson MA. Dopamine Release and Uptake Impairments and Behavioral Alterations Observed in Mice that Model Fragile X Mental Retardation Syndrome. ACS Chem Neurosci 2010; 1:679-690. [PMID: 21116467 PMCID: PMC2992329 DOI: 10.1021/cn100032f] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 07/27/2010] [Indexed: 11/29/2022] Open
Abstract
In this study we evaluated the relationship between amphetamine-induced behavioral alterations and dopamine release and uptake characteristics in Fmr1 knockout (Fmr1 KO) mice, which model fragile X syndrome. The behavioral analyses, obtained at millisecond temporal resolution and 2 mm spatial resolution using a force-plate actometer, revealed that Fmr1 KO mice express a lower degree of focused stereotypy compared to wild type (WT) control mice after injection with 10 mg/kg (ip) amphetamine. To identify potentially related neurochemical mechanisms underlying this phenomenon, we measured electrically-evoked dopamine release and uptake using fast-scan cyclic voltammetry at carbon-fiber microelectrodes in striatal brain slices. At 10 weeks of age, dopamine release per pulse, which is dopamine release corrected for differences in uptake, was unchanged. However, at 15 (the age of behavioral testing) and 20 weeks of age, dopamine per pulse and the maximum rate of dopamine uptake was diminished in Fmr1 KO mice compared to WT mice. Dopamine uptake measurements, obtained at different amphetamine concentrations, indicated that dopamine transporters in both genotypes have equal affinities for amphetamine. Moreover, dopamine release measurements from slices treated with quinpirole, a D2-family receptor agonist, rule out enhanced D2 autoreceptor sensitivity as a mechanism of release inhibition. However, dopamine release, uncorrected for uptake and normalized against the corresponding pre-drug release peaks, increased in Fmr1 KO mice, but not in WT mice. Collectively, these data are consistent with a scenario in which a decrease in extracellular dopamine levels in the striatum result in diminished expression of focused stereotypy in Fmr1 KO mice.
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Affiliation(s)
- Jenny L. Fulks
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
- Ralph N. Adams Institute of Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
| | - Bliss E. O’Bryhim
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
| | - Sara K. Wenzel
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
| | - Stephen C. Fowler
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, Kansas 66045-7582
- Neuroscience Program, University of Kansas, Lawrence, Kansas 66045-7582
| | - Elena Vorontsova
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, Kansas 66045-7582
| | - Jonathan W. Pinkston
- Department of Pharmacology and Toxicology, University of Kansas, Lawrence, Kansas 66045-7582
| | - Andrea N. Ortiz
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
- Ralph N. Adams Institute of Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
| | - Michael A. Johnson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
- Ralph N. Adams Institute of Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045-7582
- Neuroscience Program, University of Kansas, Lawrence, Kansas 66045-7582
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Romanova EV, Lee JE, Kelleher NL, Sweedler JV, Gulley JM. Mass spectrometry screening reveals peptides modulated differentially in the medial prefrontal cortex of rats with disparate initial sensitivity to cocaine. AAPS JOURNAL 2010; 12:443-54. [PMID: 20490734 DOI: 10.1208/s12248-010-9204-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 05/03/2010] [Indexed: 01/06/2023]
Abstract
To better understand why certain individuals are more vulnerable to cocaine abuse and addiction, we identify peptide markers associated with individual variation in sensitivity to the behavioral effects of cocaine. Previous studies in rats show that low, compared to high, cocaine responders are more sensitive to cocaine-induced behavioral plasticity (sensitization), exhibit enhanced conditioning to cocaine's rewarding effects, and are more motivated to self administer cocaine. In the current study, we combine matrix-assisted laser desorption/ionization mass spectrometry with multivariate statistical methods to analyze tissue extracts from rat dorsal striatum, nucleus accumbens, and medial prefrontal cortex (mPFC) to examine trends in peptide changes that coincide with behavioral phenotype. Peptide profiles of these three regions from individual animals were characterized via mass spectrometry. Resulting mass peaks that were statistically different between these groups were identified using principal component analysis. The mass peaks were then identified in pooled samples via multistage liquid chromatography mass spectrometry. A total of 74 peptides from 28 proteins were sequenced from defined brain regions. Statistically significant changes in peak intensities for seven peptides were found in the mPFC of rats given a single injection of 10 mg/kg cocaine, with low cocaine responders showing approximately 2-fold increase in peak intensities for the acetylated N terminus peptides of stathmin and Hint 1, as well as truncated ATP synthase. These results suggest that distinct peptide profiles in the mPFC are associated with individuals that exhibit reduced sensitivity to the behavioral effects of cocaine.
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Affiliation(s)
- Elena V Romanova
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA
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Fricker LD. Analysis of mouse brain peptides using mass spectrometry-based peptidomics: implications for novel functions ranging from non-classical neuropeptides to microproteins. MOLECULAR BIOSYSTEMS 2010; 6:1355-65. [PMID: 20428524 DOI: 10.1039/c003317k] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Peptides are known to play many important physiological roles in signaling. A large number of peptides have been detected in mouse brain extracts using mass spectrometry-based peptidomics studies, and 850 peptides have been identified. Half of these peptides are derived from secretory pathway proteins and many are known bioactive neuropeptides which activate G protein-coupled receptors; these are termed "classical neuropeptides". In addition, 427 peptides were identified that are derived from non-secretory pathway proteins; the majority are cystosolic, and the remainder are mitochondrial, nuclear, lysosomal, or membrane proteins. Many of these peptides represent the N- or C-terminus of the protein, rather than internal fragments, raising the possibility that they are formed by selective processing rather than protein degradation. In addition to consideration of the cleavage site required to generate the intracellular peptides, their potential functions are discussed. Several of the cytosolic peptides were previously found to interact with receptors and/or otherwise influence cellular activity; examples include hemorphins, hemopressins, diazepam binding inhibitor, and hippocampal cholinergic neurostimulating peptide. The possibility that these peptides are secreted from cells and function in cell-cell signaling is discussed. If these intracellular peptides can be shown to be secreted in levels sufficient to produce a biological effect, they would appropriately be called "non-classical neuropeptides" by analogy with non-classical neurotransmitters such as nitric oxide and anandamide. It is also possible that intracellular peptides function as "microproteins" and modulate protein-protein interactions; evidence for this function is discussed, along with future directions that are needed to establish this and other possible functions for peptides.
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Affiliation(s)
- Lloyd D Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Gelman JS, Fricker LD. Hemopressin and other bioactive peptides from cytosolic proteins: are these non-classical neuropeptides? AAPS JOURNAL 2010; 12:279-89. [PMID: 20383670 DOI: 10.1208/s12248-010-9186-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Accepted: 03/22/2010] [Indexed: 12/31/2022]
Abstract
Peptides perform many roles in cell-cell signaling; examples include neuropeptides, hormones, and growth factors. Although the vast majority of known neuropeptides are produced in the secretory pathway, a number of bioactive peptides are derived from cytosolic proteins. For example, the hemopressins are a family of peptides derived from alpha and beta hemoglobin which bind to the CB1 cannabinoid receptor, functioning as agonists or antagonists/inverse agonists depending on the size of the peptide. However, the finding that peptides derived from cytosolic proteins can affect receptors does not prove that these peptides are true endogenous signaling molecules. In order for the hemopressins and other peptides derived from cytosolic proteins to be considered neuropeptide-like signaling molecules, they must be synthesized in brain, they must be secreted in levels sufficient to produce effects, and either their synthesis or secretion should be regulated. If these criteria are met, we propose the name "non-classical neuropeptide" for this category of cytosolic bioactive peptide. This would be analogous to the non-classical neurotransmitters, such as nitric oxide and anandamide, which are not stored in secretory vesicles and released upon stimulation but are synthesized upon stimulation and constitutively released. We review some examples of cytosolic peptides from various protein precursors, describe potential mechanisms of their biosynthesis and secretion, and discuss the possibility that these peptides are signaling molecules in the brain, focusing on the criteria that these peptides would have to fill in order to be considered non-classical neuropeptides.
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Affiliation(s)
- Julia S Gelman
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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