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Currie J, Budhwani S, Garza KH, Mallipudi M, Natarajan C, Sreenivasamurthy SGS, Krishnan B. Using FASS-LTP in postmortem mice brain tissues to assess pathological synaptic function. J Neurosci Methods 2024; 409:110219. [PMID: 39013526 DOI: 10.1016/j.jneumeth.2024.110219] [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: 05/17/2024] [Revised: 06/18/2024] [Accepted: 07/09/2024] [Indexed: 07/18/2024]
Abstract
BACKGROUND Study of synaptic integrity using conventional electrophysiology is a gold standard for quantitative assessment of neurodegeneration. Fluorescence assisted single-synapse long-term potentiation (FASS-LTP) provides a high throughput method to assess the synaptic integrity of neurotransmission within and between different brain regions as a measure of pharmacological efficacy in translational models. NEW METHOD We adapted the existing method to our purpose by adding a step during the thawing of frozen samples, by an extra step of placing them on a rocker at room temperature for 30 minutes immediately following thawing with constant mixing on a shaker. This allowed for gradual, uniform thawing, effectively separating the synaptosomes. Our study demonstrates FASS-LTP on four brain regions at 6- and 12-month periods in the 3xTg-AD mouse model, treating sibling cohorts with VU0155069 (a small molecule inhibitor) or vehicle (0.9 % saline). RESULTS Our findings demonstrate the robust ability of the FASS-LTP technique to characterize the functional synaptic integrity maintained by disease-treatment therapies in multiple brain regions longitudinally using frozen brain tissue. COMPARISON WITH EXISTING METHODS By providing a detailed, user-friendly protocol for this well-known analysis and including a recovery step improved the ability to robustly replicate the FASS-LTP between different brain regions. This may be extrapolated to a translational use on human clinical samples to improve understanding of the therapeutic impact on synaptic performance related to glutamate neurotransmission. CONCLUSIONS FASS-LTP method offers a robust analysis of synaptosomes isolated from frozen tissue samples, demonstrating greater reproducibility in rodent and human synapses in physiological and pathological states.
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Affiliation(s)
- Joshua Currie
- John Sealy School of Medicine, University of Texas Medical Branch at Galveston, USA; Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, USA
| | - Shaneilahi Budhwani
- Graduate School for Biomedical Sciences, University of Texas Medical Branch, USA; Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, USA
| | - Klarissa H Garza
- Department of Neurology, University of Texas Medical Branch, USA; Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, USA
| | - Malav Mallipudi
- Department of Neurology, University of Texas Medical Branch, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, USA; Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, USA
| | | | - Sravan Gopalkrishna Shetty Sreenivasamurthy
- Department of Neurology, University of Texas Medical Branch, USA; Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, USA
| | - Balaji Krishnan
- John Sealy School of Medicine, University of Texas Medical Branch at Galveston, USA; Graduate School for Biomedical Sciences, University of Texas Medical Branch, USA; Department of Neurology, University of Texas Medical Branch, USA; Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, USA.
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Busceti CL, Di Menna L, Castaldi S, D'Errico G, Taddeucci A, Bruno V, Fornai F, Pittaluga A, Battaglia G, Nicoletti F. Adaptive Changes in Group 2 Metabotropic Glutamate Receptors Underlie the Deficit in Recognition Memory Induced by Methamphetamine in Mice. eNeuro 2024; 11:ENEURO.0523-23.2024. [PMID: 38969501 PMCID: PMC11298959 DOI: 10.1523/eneuro.0523-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/27/2024] [Accepted: 06/04/2024] [Indexed: 07/07/2024] Open
Abstract
Cognitive dysfunction is associated with methamphetamine use disorder (MUD). Here, we used genetic and pharmacological approaches to examine the involvement of either Group 2 metabotropic glutamate (mGlu2) or mGlu3 receptors in memory deficit induced by methamphetamine in mice. Methamphetamine treatment (1 mg/kg, i.p., once a day for 5 d followed by 7 d of withdrawal) caused an impaired performance in the novel object recognition test in wild-type mice, but not in mGlu2-/- or mGlu3-/- mice. Memory deficit in wild-type mice challenged with methamphetamine was corrected by systemic treatment with selectively negative allosteric modulators of mGlu2 or mGlu3 receptors (compounds VU6001966 and VU0650786, respectively). Methamphetamine treatment in wild-type mice caused large increases in levels of mGlu2/3 receptors, the Type 3 activator of G-protein signaling (AGS3), Rab3A, and the vesicular glutamate transporter, vGlut1, in the prefrontal cortex (PFC). Methamphetamine did not alter mGlu2/3-mediated inhibition of cAMP formation but abolished the ability of postsynaptic mGlu3 receptors to boost mGlu5 receptor-mediated inositol phospholipid hydrolysis in PFC slices. Remarkably, activation of presynaptic mGlu2/3 receptors did not inhibit but rather amplified depolarization-induced [3H]-D-aspartate release in synaptosomes prepared from the PFC of methamphetamine-treated mice. These findings demonstrate that exposure to methamphetamine causes changes in the expression and function of mGlu2 and mGlu3 receptors, which might alter excitatory synaptic transmission in the PFC and raise the attractive possibility that selective inhibitors of mGlu2 or mGlu3 receptors (or both) may be used to improve cognitive dysfunction in individuals affected by MUD.
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Affiliation(s)
| | - Luisa Di Menna
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
| | - Sonia Castaldi
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
| | - Giovanna D'Errico
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
| | - Alice Taddeucci
- Department of Pharmacy, University of Genova, Genova 16148, Italy
| | - Valeria Bruno
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
| | - Francesco Fornai
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa 56126, Italy
| | - Anna Pittaluga
- Department of Pharmacy, University of Genova, Genova 16148, Italy
- IRCCS Ospedale Policlinico San Martino, Genova 16145, Italy
| | - Giuseppe Battaglia
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
| | - Ferdinando Nicoletti
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
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Tumurbaatar B, Fracassi A, Scaduto P, Guptarak J, Woltjer R, Jupiter D, Taglialatela G. Preserved autophagy in cognitively intact non-demented individuals with Alzheimer's neuropathology. Alzheimers Dement 2023; 19:5355-5370. [PMID: 37191183 PMCID: PMC10651802 DOI: 10.1002/alz.13074] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/27/2023] [Accepted: 03/08/2023] [Indexed: 05/17/2023]
Abstract
INTRODUCTION Growing evidence supports that dysfunctional autophagy, the major cell mechanism responsible for removing protein aggregates and a route of clearance for Tau in healthy neurons, is a major finding in demented Alzheimer's disease (AD) patients. However, the association of autophagy with maintenance of cognitive integrity in resilient individuals who have AD neuropathology but remain non-demented (NDAN) has not been evaluated. METHODS Using post mortem brain samples from age-matched healthy control, AD, and NDAN subjects, we evaluated autophagy in relation to Tau pathology using Western blot, immunofluorescence and RNA-seq. RESULTS Compared to AD patients, NDAN subjects had preserved autophagy and reduced tauopathy. Furthermore, expression of autophagy genes and AD-related proteins were significantly associated in NDAN compared to AD and control subjects. DISCUSSION Our results suggest preserved autophagy is a protective mechanism that maintains cognitive integrity in NDAN individuals. This novel observation supports the potential of autophagy-inducing strategies in AD therapeutics. HIGHLIGHTS NDAN subjects have preserved autophagic protein levels comparable with control subjects. Compared to control subjects, NDAN subjects have significantly reduced Tau oligomers and PHF Tau phosphorylation at synapses that negatively correlate with autophagy markers. Transcription of autophagy genes strongly associates with AD-related proteins in NDAN donors.
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Affiliation(s)
- Batbayar Tumurbaatar
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, Texas, 77555 USA
| | - Anna Fracassi
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, Texas, 77555 USA
| | - Pietro Scaduto
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, Texas, 77555 USA
| | - Jutatip Guptarak
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, Texas, 77555 USA
| | - Randall Woltjer
- Department of Pathology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR, USA
| | - Daniel Jupiter
- Department of Biostatistics & Data Science, Department of Orthopaedic Surgery and Rehabilitation, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, Texas, 77555 USA
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, Texas, 77555 USA
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Marcatti M, Jamison D, Fracassi A, Zhang WR, Limon A, Taglialatela G. A method to study human synaptic protein-protein interactions by using flow cytometry coupled to proximity ligation assay (Syn-FlowPLA). J Neurosci Methods 2023; 396:109920. [PMID: 37459899 DOI: 10.1016/j.jneumeth.2023.109920] [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: 03/13/2023] [Revised: 07/01/2023] [Accepted: 07/13/2023] [Indexed: 07/24/2023]
Abstract
BACKGROUND Synapses are highly specialized sites characterized by intricate networks of protein-protein interactions (PPIs) important to maintain healthy synapses. Therefore, mapping these networks could address unsolved questions about human cognition, synaptic plasticity, learning, and memory in physiological and pathological conditions. The limitation of analyzing synaptic interactions in living humans has led to the development of methods to isolate synaptic terminals (synaptosomes) from cryopreserved human brains. NEW METHOD Here, we established a method to detect synaptic PPIs by applying flow cytometric proximity ligation assay (FlowPLA) to synaptosomes isolated from frozen human frontal cortex (FC) and hippocampus (HP) (Syn-FlowPLA). RESULTS Applying this method in synaptosomes, we were able to detect the known post-synaptic interactions between distinct subtypes of N-methyl-D-aspartate glutamate receptors (NMDARs) and their anchoring postsynaptic density 95 protein (PSD95). Moreover, we detected the known pre-synaptic interactions between the SNARE complex proteins synaptosomal-associated protein of 25 kDa (SNAP25), synaptobrevin (VAMP2), and syntaxin 1a (STX1A). As a negative control, we analyzed the interaction between mitochondrial superoxide dismutase 2 (SOD2) and PSD95, which are not expected to be physically associated. COMPARISON WITH EXISTING METHODS PPIs have been studied in vitro primarily by co-immunoprecipitation, affinity chromatography, protein-fragment complementation assays (PCAs), and flow cytometry. All these are valid approaches; however, they require more steps or combination with other techniques. PLA technology identifies PPIs with high specificity and sensitivity. CONCLUSIONS The Syn-FlowPLA described here allows rapid analyses of PPIs, specifically within the synaptic compartment isolated from frozen autopsy specimens, achieving greater target sensitivity. Syn-FlowPLA, as presented here, is therefore a useful method to study human synaptic PPI in physiological and pathological conditions.
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Affiliation(s)
- Michela Marcatti
- Mitchell Center for Neurodegenerative Disease, Department of Neurology, University of Texas Medical Branch at Galveston, USA
| | - Danielle Jamison
- Mitchell Center for Neurodegenerative Disease, Department of Neurology, University of Texas Medical Branch at Galveston, USA; Department of Pharmacology and Toxicology, University of Texas Medical Branch at Galveston, USA
| | - Anna Fracassi
- Mitchell Center for Neurodegenerative Disease, Department of Neurology, University of Texas Medical Branch at Galveston, USA
| | - Wen-Ru Zhang
- Mitchell Center for Neurodegenerative Disease, Department of Neurology, University of Texas Medical Branch at Galveston, USA; Department of Pharmacology and Toxicology, University of Texas Medical Branch at Galveston, USA
| | - Agenor Limon
- Mitchell Center for Neurodegenerative Disease, Department of Neurology, University of Texas Medical Branch at Galveston, USA
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Disease, Department of Neurology, University of Texas Medical Branch at Galveston, USA.
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Fracassi A, Marcatti M, Tumurbaatar B, Woltjer R, Moreno S, Taglialatela G. TREM2-induced activation of microglia contributes to synaptic integrity in cognitively intact aged individuals with Alzheimer's neuropathology. Brain Pathol 2023; 33:e13108. [PMID: 35816404 PMCID: PMC9836373 DOI: 10.1111/bpa.13108] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/16/2022] [Indexed: 01/21/2023] Open
Abstract
The existence of individuals who remain cognitively intact despite presenting histopathological signs of Alzheimer's disease (AD), here referred to as "Nondemented with AD neuropathology" (NDAN), suggests that some mechanisms are triggered to resist cognitive impairment. Exposed phosphatidylserine (ePS) represents a neuronal "eat-me" signal involved in microglial-mediated phagocytosis of damaged synapses. A possible mediator of this process is TREM2, a microglial surface receptor activated by ligands including PS. Based on TREM2 role in the scavenging function of microglia, we hypothesize that an efficient microglial phagocytosis of damaged synapses underlies synaptic resilience in NDAN, thus protecting from memory deficits. Using immunofluorescence microscopy, we performed a comparative study of human post-mortem frontal cortices of aged-matched, AD and NDAN individuals. We studied the distribution of activated microglia (IBA1, IBA1+ /CD68+ cells) and phagocytic microglia-related proteins (TREM2, DAP12), demonstrating higher microglial activation and TREM2 expression in NDAN versus AD. A study of the preservation of synapses around plaques, assessed using MAP2 and βIII tubulin as dendritic and axonal markers, respectively, and PSD95 as a postsynaptic marker, revealed preserved axonal/dendritic structure around plaques in NDAN versus AD. Moreover, high levels of PSD95 around NDAN plaques and the colocalization of PSD95 with CD68 indicated a prompt removal of damaged synapses by phagocytic microglia. Furthermore, Annexin V assay on aged-matched, AD and NDAN individuals synaptosomes revealed increased levels of ePS in NDAN, confirming damaged synapses engulfment. Our results suggest a higher efficiency of TREM2-induced phagocytic microglia in removing damaged synapses, underlying synaptic resilience in NDAN individuals.
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Affiliation(s)
- Anna Fracassi
- Mitchell Center for Neurodegenerative Diseases, Department of NeurologyUniversity of Texas Medical Branch (UTMB)GalvestonTexasUSA
| | - Michela Marcatti
- Mitchell Center for Neurodegenerative Diseases, Department of NeurologyUniversity of Texas Medical Branch (UTMB)GalvestonTexasUSA
| | - Batbayar Tumurbaatar
- Mitchell Center for Neurodegenerative Diseases, Department of NeurologyUniversity of Texas Medical Branch (UTMB)GalvestonTexasUSA
| | - Randall Woltjer
- Department of PathologyOregon Health and Science UniversityPortlandOregonUSA
| | - Sandra Moreno
- Department of Science, LIMEUniversity Roma TreRomeItaly
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, Department of NeurologyUniversity of Texas Medical Branch (UTMB)GalvestonTexasUSA
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Kumar S, Orlov E, Gowda P, Bose C, Swerdlow RH, Lahiri DK, Reddy PH. Synaptosome microRNAs regulate synapse functions in Alzheimer's disease. NPJ Genom Med 2022; 7:47. [PMID: 35941185 PMCID: PMC9359989 DOI: 10.1038/s41525-022-00319-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 07/15/2022] [Indexed: 01/05/2023] Open
Abstract
MicroRNAs (miRNAs) are found in nerve terminals, synaptic vesicles, and synaptosomes, but it is unclear whether synaptic and cytosolic miRNA populations differ in Alzheimer's disease (AD) or if synaptosomal miRNAs affect AD synapse activity. To address these questions, we generated synaptosomes and cytosolic fractions from postmortem brains of AD and unaffected control (UC) samples and analyzed them using a global Affymetrix miRNAs microarray platform. A group of miRNAs significantly differed (P < 0.0001) with high fold changes variance (+/- >200-fold) in their expressions in different comparisons: (1) UC synaptosome vs UC cytosol, (2) AD synaptosomes vs AD cytosol, (3) AD cytosol vs UC cytosol, and (4) AD synaptosomes vs UC synaptosomes. MiRNAs data analysis revealed that some potential miRNAs were consistently different across sample groups. These differentially expressed miRNAs were further validated using AD postmortem brains, brains of APP transgenic (Tg2576), Tau transgenic (P301L), and wild-type mice. The miR-501-3p, miR-502-3p, and miR-877-5p were identified as potential synaptosomal miRNAs upregulated with disease progression based on AD Braak stages. Gene Ontology Enrichment and Ingenuity Pathway Analysis of synaptosomal miRNAs showed the involvement of miRNAs in nervous system development, cell junction organization, synapse assembly formation, and function of GABAergic synapse. This is the first description of synaptic versus cytosolic miRNAs in AD and their significance in synapse function.
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Affiliation(s)
- Subodh Kumar
- grid.416992.10000 0001 2179 3554Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Texas Tech University Health Sciences Center, 5001 El Paso Drive, El Paso, TX 79905 USA ,grid.416992.10000 0001 2179 3554Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA ,grid.416992.10000 0001 2179 3554Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, 5001 El Paso Drive, El Paso, TX 79905, USA
| | - Erika Orlov
- grid.416992.10000 0001 2179 3554Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA
| | - Prashanth Gowda
- grid.416992.10000 0001 2179 3554Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA
| | - Chhanda Bose
- grid.416992.10000 0001 2179 3554Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA
| | - Russell H. Swerdlow
- grid.266515.30000 0001 2106 0692Department of Neurology, the University of Kansas Medical Center, University of Kansas Alzheimer’s Disease Research Center, Fairway, KS 66205 USA
| | - Debomoy K. Lahiri
- grid.257413.60000 0001 2287 3919Laboratory of Molecular Neurogenetics’ Departments of Psychiatry and Medical & Molecular Genetics, Indiana University School of Medicine’ Indiana Alzheimer’s Disease Research Center, Stark Neuroscience Research Institute, Indianapolis, IN 46202 USA
| | - P. Hemachandra Reddy
- grid.416992.10000 0001 2179 3554Internal Medicine Department, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA ,grid.416992.10000 0001 2179 3554Department of Pharmacology & Neuroscience, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA ,grid.416992.10000 0001 2179 3554Department of Neurology, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA ,grid.416992.10000 0001 2179 3554Department of Public Health, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430 USA
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Petersen MH, Willert CW, Andersen JV, Madsen M, Waagepetersen HS, Skotte NH, Nørremølle A. Progressive Mitochondrial Dysfunction of Striatal Synapses in R6/2 Mouse Model of Huntington's Disease. J Huntingtons Dis 2022; 11:121-140. [PMID: 35311711 DOI: 10.3233/jhd-210518] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Huntington's disease (HD) is a neurodegenerative disorder characterized by synaptic dysfunction and loss of white matter volume especially in the striatum of the basal ganglia and to a lesser extent in the cerebral cortex. Studies investigating heterogeneity between synaptic and non-synaptic mitochondria have revealed a pronounced vulnerability of synaptic mitochondria, which may lead to synaptic dysfunction and loss. OBJECTIVE As mitochondrial dysfunction is a hallmark of HD pathogenesis, we investigated synaptic mitochondrial function from striatum and cortex of the transgenic R6/2 mouse model of HD. METHODS We assessed mitochondrial volume, ROS production, and antioxidant levels as well as mitochondrial respiration at different pathological stages. RESULTS Our results reveal that striatal synaptic mitochondria are more severely affected by HD pathology than those of the cortex. Striatal synaptosomes of R6/2 mice displayed a reduction in mitochondrial mass coinciding with increased ROS production and antioxidants levels indicating prolonged oxidative stress. Furthermore, synaptosomal oxygen consumption rates were significantly increased during depolarizing conditions, which was accompanied by a marked increase in mitochondrial proton leak of the striatal synaptosomes, indicating synaptic mitochondrial stress. CONCLUSION Overall, our study provides new insight into the gradual changes of synaptic mitochondrial function in HD and suggests compensatory mitochondrial actions to maintain energy production in the HD brain, thereby supporting that mitochondrial dysfunction do indeed play a central role in early disease progression of HD.
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Affiliation(s)
- Maria Hvidberg Petersen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Jens Velde Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Mette Madsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Niels Henning Skotte
- Proteomics Program, The Novo Nordisk Foundation Centre for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne Nørremølle
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
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Marcatti M, Fracassi A, Montalbano M, Natarajan C, Krishnan B, Kayed R, Taglialatela G. Aβ/tau oligomer interplay at human synapses supports shifting therapeutic targets for Alzheimer's disease. Cell Mol Life Sci 2022; 79:222. [PMID: 35377002 PMCID: PMC8979934 DOI: 10.1007/s00018-022-04255-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 03/08/2022] [Accepted: 03/17/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by progressive cognitive decline due to accumulating synaptic insults by toxic oligomers of amyloid beta (AβO) and tau (TauO). There is growing consensus that preventing these oligomers from interacting with synapses might be an effective approach to treat AD. However, recent clinical trial failures suggest low effectiveness of targeting Aβ in late-stage AD. Researchers have redirected their attention toward TauO as the levels of this species increase later in disease pathogenesis. Here we show that AβO and TauO differentially target synapses and affect each other's binding dynamics. METHODS Binding of labeled, pre-formed Aβ and tau oligomers onto synaptosomes isolated from the hippocampus and frontal cortex of mouse and postmortem cognitively intact elderly human brains was evaluated using flow-cytometry and western blot analyses. Binding of labeled, pre-formed Aβ and tau oligomers onto mouse primary neurons was assessed using immunofluorescence assay. The synaptic dysfunction was measured by fluorescence analysis of single-synapse long-term potentiation (FASS-LTP) assay. RESULTS We demonstrated that higher TauO concentrations effectively outcompete AβO and become the prevailing synaptic-associated species. Conversely, high concentrations of AβO facilitate synaptic TauO recruitment. Immunofluorescence analyses of mouse primary cortical neurons confirmed differential synaptic binding dynamics of AβO and TauO. Moreover, in vivo experiments using old 3xTgAD mice ICV injected with either AβO or TauO fully supported these findings. Consistent with these observations, FASS-LTP analyses demonstrated that TauO-induced suppression of chemical LTP was exacerbated by AβO. Finally, predigestion with proteinase K abolished the ability of TauO to compete off AβO without affecting the ability of high AβO levels to increase synaptic TauO recruitment. Thus, unlike AβO, TauO effects on synaptosomes are hampered by the absence of protein substrate in the membrane. CONCLUSIONS These results introduce the concept that TauO become the main synaptotoxic species at late AD, thus supporting the hypothesis that TauO may be the most effective therapeutic target for clinically manifest AD.
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Affiliation(s)
- Michela Marcatti
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Anna Fracassi
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Mauro Montalbano
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Chandramouli Natarajan
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Balaji Krishnan
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Rakez Kayed
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Giulio Taglialatela
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, TX 77555 USA
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Picone P, Palumbo FS, Federico S, Pitarresi G, Adamo G, Bongiovanni A, Chaves A, Cancemi P, Muccilli V, Giglio V, Vetri V, Anselmo S, Sancataldo G, Di Liberto V, Nuzzo D. Nano-structured myelin: new nanovesicles for targeted delivery to white matter and microglia, from brain-to-brain. Mater Today Bio 2021; 12:100146. [PMID: 34761196 PMCID: PMC8567303 DOI: 10.1016/j.mtbio.2021.100146] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 01/04/2023] Open
Abstract
Neurodegenerative diseases affect millions of people worldwide and the presence of various physiological barriers limits the accessibility to the brain and reduces the efficacy of various therapies. Moreover, new carriers having targeting properties to specific brain regions and cells are needed in order to improve therapies for the brain disorder treatment. In this study, for the first time, Myelin nanoVesicles (hereafter defined MyVes) from brain-extracted myelin were produced. The MyVes have an average diameter of 100–150 nm, negative zeta potential, spheroidal morphology, and contain lipids and the key proteins of the myelin sheath. Furthermore, they exhibit good cytocompatibility. The MyVes were able to target the white matter and interact mainly with the microglia cells. The preliminary results here presented allow us to suppose the employment of MyVes as potential carrier to target the white matter and microglia in order to counteract white matter microglia-related diseases. Bio-fabrication of brain tissue derived nanovesicles: myelin nanovesicles. Myelin nanovesicles contain the main proteins of the myelin sheath (myelin basic protein and myelin proteolipid protein). Myelin nanovesicles can lade a drug/molecule and cross a blood–brain barrier model. Myelin nanovesicles target white matter and microglia cells.
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Affiliation(s)
- Pasquale Picone
- Istituto per la Ricerca e l’Innovazione Biomedica, CNR, via U. La Malfa 153, 90146, Palermo, Italy
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy
- Corresponding author.
| | - Fabio Salvatore Palumbo
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy
| | - Salvatore Federico
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy
| | - Giovanna Pitarresi
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy
| | - Giorgia Adamo
- Istituto per la Ricerca e l’Innovazione Biomedica, CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Antonella Bongiovanni
- Istituto per la Ricerca e l’Innovazione Biomedica, CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Antonio Chaves
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Festa del Perdono 7, 20122, Milano, Italy
| | - Patrizia Cancemi
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy
| | - Vera Muccilli
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria, 6, I-95125, Catania, Italy
| | - Valentina Giglio
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria, 6, I-95125, Catania, Italy
| | - Valeria Vetri
- Dipartimento di Fisica e Chimica-Emilio Segrè, Università degli studi di Palermo, Viale delle Scienze edificio 18, 90128, Palermo, Italy
| | - Sara Anselmo
- Dipartimento di Fisica e Chimica-Emilio Segrè, Università degli studi di Palermo, Viale delle Scienze edificio 18, 90128, Palermo, Italy
| | - Giuseppe Sancataldo
- Dipartimento di Fisica e Chimica-Emilio Segrè, Università degli studi di Palermo, Viale delle Scienze edificio 18, 90128, Palermo, Italy
| | - Valentina Di Liberto
- Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata, Università di Palermo, Corso Tukory 129, 90134, Palermo, Italy
| | - Domenico Nuzzo
- Istituto per la Ricerca e l’Innovazione Biomedica, CNR, via U. La Malfa 153, 90146, Palermo, Italy
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università di Palermo, Viale delle Scienze, 90128, Palermo, Italy
- Corresponding author.
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10
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Singh A, Allen D, Fracassi A, Tumurbaatar B, Natarajan C, Scaduto P, Woltjer R, Kayed R, Limon A, Krishnan B, Taglialatela G. Functional Integrity of Synapses in the Central Nervous System of Cognitively Intact Individuals with High Alzheimer's Disease Neuropathology Is Associated with Absence of Synaptic Tau Oligomers. J Alzheimers Dis 2021; 78:1661-1678. [PMID: 33185603 PMCID: PMC7836055 DOI: 10.3233/jad-200716] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Certain individuals, here referred to as Non-Demented with Alzheimer Neuropathology (NDAN), do not show overt neurodegeneration (N-) and remain cognitively intact despite the presence of plaques (A+) and tangles (T+) that would normally be consistent with fully symptomatic Alzheimer's disease (AD). OBJECTIVE The existence of NDAN (A + T+N-) subjects suggests that the human brain utilizes intrinsic mechanisms that can naturally evade cognitive decline normally associated with the symptomatic stages of AD (A + T+N+). Deciphering the underlying mechanisms would prove relevant to develop complementing therapeutics to prevent progression of AD-related cognitive decline. METHODS Previously, we have reported that NDAN present with preserved neurogenesis and synaptic integrity paralleled by absence of amyloid oligomers at synapses. Using postmortem brain samples from age-matched control subjects, demented AD patients and NDAN individuals, we performed immunofluorescence, western blots, micro transplantation of synaptic membranes in Xenopus oocytes followed by twin electrode voltage clamp electrophysiology and fluorescence assisted single synaptosome-long term potentiation studies. RESULTS We report decreased tau oligomers at synapses in the brains of NDAN subjects. Furthermore, using novel approaches we report, for the first time, that such absence of tau oligomers at synapses is associated with synaptic functional integrity in NDAN subjects as compared to demented AD patients. CONCLUSION Overall, these results give further credence to tau oligomers as primary actors of synaptic destruction underscoring cognitive demise in AD and support their targeting as a viable therapeutic strategy for AD and related tauopathies.
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Affiliation(s)
- Ayush Singh
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Dyron Allen
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Anna Fracassi
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Batbayar Tumurbaatar
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Chandramouli Natarajan
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Pietro Scaduto
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Randy Woltjer
- Department of Pathology, Oregon Health and Science University, Portland, OR, USA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Agenor Limon
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA
| | - Balaji Krishnan
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA,Correspondence to: Giulio Taglialatela, PhD, Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA. Tel.: +1 409 772 1679; Fax: +1 409 772 0015; E-mail: . and Balaji Krishnan, PhD, Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA. Tel.: +1 409 772 8069; Fax: +1 409 772 0015; E-mail:
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA,Correspondence to: Giulio Taglialatela, PhD, Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA. Tel.: +1 409 772 1679; Fax: +1 409 772 0015; E-mail: . and Balaji Krishnan, PhD, Mitchell Center for Neurodegenerative Diseases, Department of Neurology, UTMB Galveston, TX, USA. Tel.: +1 409 772 8069; Fax: +1 409 772 0015; E-mail:
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11
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Busceti CL, Ginerete RP, Di Menna L, D'Errico G, Cisani F, Di Pietro P, Imbriglio T, Bruno V, Battaglia G, Fornai F, Monn JA, Pittaluga A, Nicoletti F. Behavioural and biochemical responses to methamphetamine are differentially regulated by mGlu2 and mGlu3 metabotropic glutamate receptors in male mice. Neuropharmacology 2021; 196:108692. [PMID: 34217776 DOI: 10.1016/j.neuropharm.2021.108692] [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] [Received: 02/17/2021] [Revised: 06/04/2021] [Accepted: 06/27/2021] [Indexed: 01/09/2023]
Abstract
Group II metabotropic glutamate receptors (mGlu2 and mGlu3 receptors) shape mechanisms of methamphetamine addiction, but the individual role played by the two subtypes is unclear. We measured methamphetamine-induced conditioned place preference (CPP) and motor responses to single or repeated injections of methamphetamine in wild-type, mGlu2-/-, and mGlu3-/-mice. Only mGlu3-/-mice showed methamphetamine preference in the CPP test. Motor response to the first methamphetamine injection was dramatically reduced in mGlu2-/-mice, unless these mice were treated with the mGlu5 receptor antagonist, MTEP. In contrast, methamphetamine-induced sensitization was increased in mGlu3-/-mice compared to wild-type mice. Only mGlu3-/-mice sensitized to methamphetamine showed increases in phospho-ERK1/2 levels in the nucleus accumbens (NAc) and free radical formation in the NAc and medial prefrontal cortex. These changes were not detected in mGlu2-/-mice. We also measured a series of biochemical parameters related to the mechanism of action of methamphetamine in naïve mice to disclose the nature of the differential behavioural responses of the three genotypes. We found a reduced expression and activity of dopamine transporter (DAT) and vesicular monoamine transporter-2 in the NAc and striatum of mGlu2-/-and mGlu3-/-mice, whereas expression of the DAT adaptor, syntaxin 1A, was selectively increased in the striatum of mGlu3-/-mice. Methamphetamine-stimulated dopamine release in striatal slices was largely reduced in mGlu2-/-, but not in mGlu3-/-, mice. These findings suggest that drugs that selectively enhance mGlu3 receptor activity or negatively modulate mGlu2 receptors might be beneficial in the treatment of methamphetamine addiction and associated brain damage.
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Affiliation(s)
| | | | | | | | | | | | | | - Valeria Bruno
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, University Sapienza, Roma, Italy
| | - Giuseppe Battaglia
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, University Sapienza, Roma, Italy
| | - Francesco Fornai
- IRCCS Neuromed, Pozzilli, Italy; Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - Anna Pittaluga
- Department of Pharmacy, University of Genova, Genova, Italy; IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Ferdinando Nicoletti
- IRCCS Neuromed, Pozzilli, Italy; Department of Physiology and Pharmacology, University Sapienza, Roma, Italy.
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12
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Chronic Low Dose Neutron Exposure Results in Altered Neurotransmission Properties of the Hippocampus-Prefrontal Cortex Axis in Both Mice and Rats. Int J Mol Sci 2021; 22:ijms22073668. [PMID: 33915974 PMCID: PMC8036585 DOI: 10.3390/ijms22073668] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 03/29/2021] [Accepted: 03/31/2021] [Indexed: 12/18/2022] Open
Abstract
The proposed deep space exploration to the moon and later to Mars will result in astronauts receiving significant chronic exposures to space radiation (SR). SR exposure results in multiple neurocognitive impairments. Recently, our cross-species (mouse/rat) studies reported impaired associative memory formation in both species following a chronic 6-month low dose exposure to a mixed field of neutrons (1 mGy/day for a total dose pf 18 cGy). In the present study, we report neutron exposure induced synaptic plasticity in the medial prefrontal cortex, accompanied by microglial activation and significant synaptic loss in the hippocampus. In a parallel study, neutron exposure was also found to alter fluorescence assisted single synaptosome LTP (FASS-LTP) in the hippocampus of rats, that may be related to a reduced ability to insert AMPAR into the post-synaptic membrane, which may arise from increased phosphorylation of the serine 845 residue of the GluA1 subunit. Thus, we demonstrate for the first time, that low dose chronic neutron irradiation impacts homeostatic synaptic plasticity in the hippocampal-cortical circuit in two rodent species, and that the ability to successfully encode associative recognition memory is a dynamic, multicircuit process, possibly involving compensatory changes in AMPAR density on the synaptic surface.
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13
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Fracassi A, Marcatti M, Zolochevska O, Tabor N, Woltjer R, Moreno S, Taglialatela G. Oxidative Damage and Antioxidant Response in Frontal Cortex of Demented and Nondemented Individuals with Alzheimer's Neuropathology. J Neurosci 2021; 41:538-554. [PMID: 33239403 PMCID: PMC7821866 DOI: 10.1523/jneurosci.0295-20.2020] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by progressive neurodegeneration in the cerebral cortex, histopathologically hallmarked by amyloid β (Aβ) extracellular plaques and intracellular neurofibrillary tangles, constituted by hyperphosphorylated tau protein. Correlation between these pathologic features and dementia has been challenged by the emergence of "nondemented with Alzheimer's neuropathology" (NDAN) individuals, cognitively intact despite displaying pathologic features of AD. The existence of these subjects suggests that some unknown mechanisms are triggered to resist Aβ-mediated detrimental events. Aβ accumulation affects mitochondrial redox balance, increasing oxidative stress status, which in turn is proposed as a primary culprit in AD pathogenesis. To clarify the relationship linking Aβ, oxidative stress, and cognitive impairment, we performed a comparative study on AD, NDAN, and aged-matched human postmortem frontal cortices of either sex. We quantitatively analyzed immunofluorescence distribution of oxidative damage markers, and of SOD2 (superoxide dismutase 2), PGC1α [peroxisome proliferator-activated receptor (PPAR) γ-coactivator 1α], PPARα, and catalase as key factors in antioxidant response, as well as the expression of miRNA-485, as a PGC1α upstream regulator. Our results confirm dramatic redox imbalance, associated with impaired antioxidant defenses in AD brain. By contrast, NDAN individuals display low oxidative damage, which is associated with high levels of scavenging systems, possibly resulting from a lack of PGC1α miRNA-485-related inhibition. Comparative analyses in neurons and astrocytes further highlighted cell-specific mechanisms to counteract redox imbalance. Overall, our data emphasize the importance of transcriptional and post-transcriptional regulation of antioxidant response in AD. This suggests that an efficient PGC1α-dependent "safety mechanism" may prevent Aβ-mediated oxidative stress, supporting neuroprotective therapies aimed at ameliorating defects in antioxidant response pathways in AD patients.
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Affiliation(s)
- Anna Fracassi
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), Galveston, Texas 77550
| | - Michela Marcatti
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), Galveston, Texas 77550
| | - Olga Zolochevska
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), Galveston, Texas 77550
| | - Natalie Tabor
- Neuroscience Summer Undergraduate Program, University of Texas Medical Branch, Galveston, Texas 77555
| | - Randall Woltjer
- Department of Pathology, Oregon Health and Science University, Portland, Oregon 97239-3098
| | - Sandra Moreno
- Department of Science, LIME, University Roma Tre, 00146 Rome, Italy
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch (UTMB), Galveston, Texas 77550
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14
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Picone P, Porcelli G, Bavisotto CC, Nuzzo D, Galizzi G, Biagio PLS, Bulone D, Di Carlo M. Synaptosomes: new vesicles for neuronal mitochondrial transplantation. J Nanobiotechnology 2021; 19:6. [PMID: 33407593 PMCID: PMC7789323 DOI: 10.1186/s12951-020-00748-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/05/2020] [Indexed: 12/19/2022] Open
Abstract
Background Mitochondrial dysfunction is a critical factor in the onset and progression of neurodegenerative diseases. Recently, mitochondrial transplantation has been advised as an innovative and attractive strategy to transfer and replace damaged mitochondria. Here we propose, for the first time, to use rat brain extracted synaptosomes, a subcellular fraction of isolated synaptic terminal that contains mitochondria, as mitochondrial delivery systems. Results Synaptosome preparation was validated by the presence of Synaptophysin and PSD95. Synaptosomes were characterized in terms of dimension, zeta potential, polydispersity index and number of particles/ml. Nile Red or CTX-FITCH labeled synaptosomes were internalized in LAN5 recipient cells by a mechanism involving specific protein–protein interaction, as demonstrated by loss of fusion ability after trypsin treatment and using different cell lines. The loading and release ability of the synaptosomes was proved by the presence of curcumin both into synaptosomes and LAN5 cells. The vitality of mitochondria transferred by Synaptosomes was demonstrated by the presence of Opa1, Fis1 and TOM40 mitochondrial proteins and JC-1 measurements. Further, synaptosomes deliver vital mitochondria into the cytoplasm of neuronal cells as demonstrated by microscopic images, increase of TOM 40, cytochrome c, Hexokinase II mitochondrial proteins, and presence of rat mitochondrial DNA. Finally, by using synaptosomes as a vehicle, healthy mitochondria restored mitochondrial function in cells containing rotenone or CCCp damaged mitochondria. Conclusions Taken together these results suggest that synaptosomes can be a natural vehicle for the delivery of molecules and organelles to neuronal cells. Further, the replacement of affected mitochondria with healthy ones could be a potential therapy for treating neuronal mitochondrial dysfunction-related diseases.![]()
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Affiliation(s)
- Pasquale Picone
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Gaetana Porcelli
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Celeste Caruso Bavisotto
- Istituto di Biofisica (IBF) (sez. Palermo) CNR, via U. La Malfa, 153, 90146, Palermo, Italy.,Dipartimento di Biomedicina, Neuroscienze, e Diagnostica Avanzata (BIND) (Sez. Anatomia Umana), Università di Palermo, via del Vespro 129, 90127, Palermo, Italy.,Istituto Euro-Mediterraneo di Scienze e Tecnologie (IEMEST), via M. Miraglia, 20, 90139, Palermo, Italy
| | - Domenico Nuzzo
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Giacoma Galizzi
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy
| | - Pier Luigi San Biagio
- Istituto di Biofisica (IBF) (sez. Palermo) CNR, via U. La Malfa, 153, 90146, Palermo, Italy
| | - Donatella Bulone
- Istituto di Biofisica (IBF) (sez. Palermo) CNR, via U. La Malfa, 153, 90146, Palermo, Italy
| | - Marta Di Carlo
- Istituto per la Ricerca e l' Innovazione Biomedica (IRIB) CNR, via U. La Malfa 153, 90146, Palermo, Italy.
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15
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Cisani F, Roggeri A, Olivero G, Garrone B, Tongiani S, Di Giorgio FP, Pittaluga A. Acute Low Dose of Trazodone Recovers Glutamate Release Efficiency and mGlu2/3 Autoreceptor Impairments in the Spinal Cord of Rats Suffering From Chronic Sciatic Ligation. Front Pharmacol 2020; 11:1108. [PMID: 32765286 PMCID: PMC7379891 DOI: 10.3389/fphar.2020.01108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/08/2020] [Indexed: 11/16/2022] Open
Abstract
We investigated whether chronic sciatic ligation modifies the glutamate release in spinal cord nerve endings (synaptosomes) as well as the expression and the function of presynaptic release-regulating mGlu2/3 autoreceptors and 5-HT2A heteroreceptors in these particles. Synaptosomes were from the spinal cord of animals suffering from the sciatic ligation that developed on day 6 post-surgery a significant decrease of the force inducing paw-withdrawal in the lesioned paw. The exocytosis of glutamate (quantified as release of preloaded [3H]D-aspartate, [3H]D-Asp) elicited by a mild depolarizing stimulus (15 mM KCl) was significantly increased in synaptosomes from injured rats when compared to controls (uninjured rats). The mGlu2/3 agonist LY379268 (1000 pM) significantly inhibited the 15 mM KCl-evoked [3H]D-Asp overflow from control synaptosomes, but not in terminals isolated from injured animals. Differently, a low concentration (10 nM) of (±) DOI, unable to modify the 15 mM KCl-evoked [3H]D-Asp overflow in control spinal cord synaptosomes, significantly reduced the glutamate exocytosis in nerve endings isolated from the injured rats. Acute oral trazodone (TZD, 0.3 mg/kg on day 7 post-surgery) efficiently recovered glutamate exocytosis as well as the efficiency of LY379268 in inhibiting this event in spinal cord synaptosomes from injured animals. The sciatic ligation significantly reduced the expression of mGlu2/3, but not of 5-HT2A, receptor proteins in spinal cord synaptosomal lysates. Acute TZD recovered this parameter. Our results support the use of 5-HT2A antagonists for restoring altered spinal cord glutamate plasticity in rats suffering from sciatic ligation.
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Affiliation(s)
- Francesca Cisani
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Alessandra Roggeri
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Guendalina Olivero
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Beatrice Garrone
- Angelini RR&D (Research, Regulatory & Development), Angelini Pharma S.p.A., Rome, Italy
| | - Serena Tongiani
- Angelini RR&D (Research, Regulatory & Development), Angelini Pharma S.p.A., Rome, Italy
| | | | - Anna Pittaluga
- Department of Pharmacy, DIFAR, Pharmacology and Toxicology Section and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genova, Italy
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16
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Selected microRNAs Increase Synaptic Resilience to the Damaging Binding of the Alzheimer's Disease Amyloid Beta Oligomers. Mol Neurobiol 2020; 57:2232-2243. [PMID: 31997075 PMCID: PMC7170988 DOI: 10.1007/s12035-020-01868-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 01/06/2020] [Indexed: 01/30/2023]
Abstract
Alzheimer’s disease (AD) is marked by synaptic loss (at early stages) and neuronal death (at late stages). Amyloid beta (Aβ) and tau oligomers can target and disrupt synapses thus driving cognitive decay. Non-demented individuals with Alzheimer’s neuropathology (NDAN) are capable of withstanding Aβ and tau toxicity, thus remaining cognitively intact despite presence of AD neuropathology. Understanding the involved mechanism(s) would lead to development of novel effective therapeutic strategies aimed at promoting synaptic resilience to amyloid toxicity. NDAN have a unique hippocampal post-synaptic proteome when compared with AD and control individuals. Potential upstream modulators of such unique proteomic profile are miRNA-485, miRNA-4723 and miRNA-149, which we found differentially expressed in AD and NDAN vs. control. We thus hypothesized that these miRNAs play an important role in promoting either synaptic resistance or sensitization to Aβ oligomer binding. Using an in vivo mouse model, we found that administration of these miRNAs affected key synaptic genes and significantly decreased Aβ binding to the synapses. Our findings suggest that miRNA regulation and homeostasis are crucial for Aβ interaction with synaptic terminals and support that a unique miRNA regulation could be driving synaptic resistance to Aβ toxicity in NDAN, thus contributing to their preserved cognitive abilities.
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17
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Zolochevska O, Bjorklund N, Woltjer R, Wiktorowicz JE, Taglialatela G. Postsynaptic Proteome of Non-Demented Individuals with Alzheimer's Disease Neuropathology. J Alzheimers Dis 2019; 65:659-682. [PMID: 30103319 PMCID: PMC6130411 DOI: 10.3233/jad-180179] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Some individuals, here referred to as Non-Demented with Alzheimer’s Neuropathology (NDAN), retain their cognitive function despite the presence of amyloid plaques and tau tangles typical of symptomatic Alzheimer’s disease (AD). In NDAN, unlike AD, toxic amyloid-β oligomers do not localize to the postsynaptic densities (PSDs). Synaptic resistance to amyloid-β in NDAN may thus enable these individuals to remain cognitively intact despite the AD-like pathology. The mechanism(s) responsible for this resistance remains unresolved and understanding such protective biological processes could reveal novel targets for the development of effective treatments for AD. The present study uses a proteomic approach to compare the hippocampal postsynaptic densities of NDAN, AD, and healthy age-matched persons to identify protein signatures characteristic for these groups. Subcellular fractionation followed by 2D gel electrophoresis and mass spectrometry were used to analyze the PSDs. We describe fifteen proteins which comprise the unique proteomic signature of NDAN PSDs, thus setting them apart from control subjects and AD patients.
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Affiliation(s)
- Olga Zolochevska
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Nicole Bjorklund
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
| | - Randall Woltjer
- Department of Pathology, Oregon Health and Science University, Portland, OR, USA
| | - John E Wiktorowicz
- Department of Biochemistry and Molecular Biology, Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Giulio Taglialatela
- Department of Neurology, University of Texas Medical Branch, Galveston, TX, USA
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18
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Micci MA, Krishnan B, Bishop E, Zhang WR, Guptarak J, Grant A, Zolochevska O, Tumurbaatar B, Franklin W, Marino C, Widen SG, Luthra A, Kernie SG, Taglialatela G. Hippocampal stem cells promotes synaptic resistance to the dysfunctional impact of amyloid beta oligomers via secreted exosomes. Mol Neurodegener 2019; 14:25. [PMID: 31200742 PMCID: PMC6570890 DOI: 10.1186/s13024-019-0322-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/03/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Adult hippocampal neurogenesis plays an important role in synaptic plasticity and cogntive function. We reported that higher numbers of neural stem cells (NSC) in the hippocampus of cognitively-intact individuals with high Alzheimer's disease (AD) pathology (plaques and tangles) is associated with decreased synaptic amyloid beta oligomers (Aβο), an event linked to onset of dementia in AD. While these findings suggest a link between NSC and synaptic resistance to Aβο, the involved mechanism remains to be determined. With this goal in mind, here we investigated the ability of exosomes secreted from hippocampal NSC to promote synaptic resilience to Aβo. METHODS Exosomes isolated from media of hippocampus NSC (NSC-exo) or mature hippocampal neuronal (MN-exo) cultures were delivered intracerebroventricularly (ICV) to mice before assessment of Aβο-induced suppression of hippocampal long-term potentiation (LTP) and memory deficits. Aβο binding to synapses was assessed in cultured hippocampal neurons and on synaptosomes isolated from hippocampal slices from wild type mice and from an inducible mouse model of NSC ablation (Nestin-δ-HSV-TK mice) treated with exosomes. Expression of CaMKII and of AMPA and NMDA glutamate receptor subunits in synaptosomes was measured by western blot. Small RNA Deep sequencing was performed to identify microRNAs enriched in NSC-exo as compared to MN-exo. Mimics of select miRNAs were injected ICV. RESULTS NSC-exo, but not MN-exo, abolished Aβo-induced suppression of LTP and subsequent memory deficits. Furthermore, in hippocampal slices and cultured neurons, NSC-exo significantly decreased Aβo binding to the synapse. Similarly, transgenic ablation of endogenous NSC increased synaptic Aβo binding, which was reversed by exogenous NSC-exo. Phosphorylation of synaptic CaMKII was increased by NSC-exo, while AMPA and NMDA receptors were not affected. Lastly, we identified a set of miRNAs enriched in NSC-exo that, when injected ICV, protected the synapses from Aβo-binding and Aβo-induced LTP inhibition. CONCLUSIONS These results identify a novel mechanism linking NSC-exo and synaptic susceptibility to Aβo that may underscore cognitive resilience of certain individuals with increased neurogenesis in spite of AD neuropathology and unmask a novel target for the development of a new treatment concept for AD centered on promoting synaptic resilience to toxic amyloid proteins.
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Affiliation(s)
- Maria-Adelaide Micci
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Balaji Krishnan
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Elizabeth Bishop
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Wen-Ru Zhang
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Jutatip Guptarak
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Auston Grant
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Olga Zolochevska
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Batbayar Tumurbaatar
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Whitney Franklin
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Claudia Marino
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Steven G. Widen
- Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555 USA
| | - Arjun Luthra
- Pressent address: The University of Texas at Austin, Austin, TX 78712 USA
| | - Steven G. Kernie
- Department of Pediatrics and Pathology & Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032 USA
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, TX 77555 USA
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Franklin W, Krishnan B, Taglialatela G. Chronic synaptic insulin resistance after traumatic brain injury abolishes insulin protection from amyloid beta and tau oligomer-induced synaptic dysfunction. Sci Rep 2019; 9:8228. [PMID: 31160730 PMCID: PMC6546708 DOI: 10.1038/s41598-019-44635-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/14/2019] [Indexed: 02/07/2023] Open
Abstract
Traumatic brain injury (TBI) is a risk factor for Alzheimer's disease (AD), although the mechanisms contributing to this increased risk are unknown. Insulin resistance is an additional risk factor for AD whereby decreased insulin signaling increases synaptic sensitivity to amyloid beta (Aβ) and tau. Considering this, we used rats that underwent a lateral fluid percussion injury at acute and chronic time-points to investigate whether decreased insulin responsiveness in TBI animals is playing a role in synaptic vulnerability to AD pathology. We detected acute and chronic decreases in insulin responsiveness in isolated hippocampal synaptosomes after TBI. In addition to assessing both Aβ and tau binding on synaptosomes, we performed electrophysiology to assess the dysfunctional impact of Aβ and tau oligomers as well as the protective effect of insulin. While we saw no difference in binding or degree of LTP inhibition by either Aβ or tau oligomers between sham and TBI animals, we found that insulin treatment was able to block oligomer-induced LTP inhibition in sham but not in TBI animals. Since insulin treatment has been discussed as a therapy for AD, this gives valuable insight into therapeutic implications of treating AD patients based on one's history of associated risk factors.
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Affiliation(s)
- Whitney Franklin
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, Texas, 77555, USA
- Department of Neuroscience, Cell Biology & Anatomy, University of Texas Medical Branch, Galveston, Texas, 77555, USA
| | - Balaji Krishnan
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, Texas, 77555, USA
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, University of Texas Medical Branch, Galveston, Texas, 77555, USA.
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Petersen MH, Willert CW, Andersen JV, Waagepetersen HS, Skotte NH, Nørremølle A. Functional Differences between Synaptic Mitochondria from the Striatum and the Cerebral Cortex. Neuroscience 2019; 406:432-443. [PMID: 30876983 DOI: 10.1016/j.neuroscience.2019.02.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/08/2019] [Accepted: 02/28/2019] [Indexed: 12/16/2022]
Abstract
Mitochondrial dysfunction has been shown to play a major role in neurodegenerative disorders such as Huntington's disease, Alzheimer's disease and Parkinson's disease. In these and other neurodegenerative disorders, disruption of synaptic connectivity and impaired neuronal signaling are among the early signs. When looking for potential causes of neurodegeneration, specific attention is drawn to the function of synaptic mitochondria, as the energy supply from mitochondria is crucial for normal synaptic function. Mitochondrial heterogeneity between synaptic and non-synaptic mitochondria has been described, but very little is known about possible differences between synaptic mitochondria from different brain regions. The striatum and the cerebral cortex are often affected in neurodegenerative disorders. In this study we therefore used isolated nerve terminals (synaptosomes) from female mice, striatum and cerebral cortex, to investigate differences in synaptic mitochondrial function between these two brain regions. We analyzed mitochondrial mass, citrate synthase activity, general metabolic activity and mitochondrial respiration in resting as well as veratridine-activated synaptosomes using glucose and/or pyruvate as substrate. We found higher mitochondrial oxygen consumption rate in both resting and activated cortical synaptosomes compared to striatal synaptosomes, especially when using pyruvate as a substrate. The higher oxygen consumption rate was not caused by differences in mitochondrial content, but instead corresponded with a higher proton leak in the cortical synaptic mitochondria compared to the striatal synaptic mitochondria. Our results show that the synaptic mitochondria of the striatum and cortex differently regulate respiration both in response to activation and variations in substrate conditions.
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Affiliation(s)
- Maria Hvidberg Petersen
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
| | | | - Jens Velde Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, 2100 Copenhagen Ø, Denmark
| | | | - Niels Henning Skotte
- Proteomics Program, The Novo Nordisk Foundation Centre for Protein Research, Faculty of Health Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Anne Nørremølle
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark.
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21
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Kulas JA, Franklin WF, Smith NA, Manocha GD, Puig KL, Nagamoto-Combs K, Hendrix RD, Taglialatela G, Barger SW, Combs CK. Ablation of amyloid precursor protein increases insulin-degrading enzyme levels and activity in brain and peripheral tissues. Am J Physiol Endocrinol Metab 2019; 316:E106-E120. [PMID: 30422705 PMCID: PMC6417684 DOI: 10.1152/ajpendo.00279.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The amyloid precursor protein (APP) is a type I transmembrane glycoprotein widely studied for its role as the source of β-amyloid peptide, accumulation of which is causal in at least some cases of Alzheimer's disease (AD). APP is expressed ubiquitously and is involved in diverse biological processes. Growing bodies of evidence indicate connections between AD and somatic metabolic disorders related to type 2 diabetes, and App-/- mice show alterations in glycemic regulation. We find that App-/- mice have higher levels of insulin-degrading enzyme (IDE) mRNA, protein, and activity compared with wild-type controls. This regulation of IDE by APP was widespread across numerous tissues, including liver, skeletal muscle, and brain as well as cell types within neural tissue, including neurons, astrocytes, and microglia. RNA interference-mediated knockdown of APP in the SIM-A9 microglia cell line elevated IDE levels. Fasting levels of blood insulin were lower in App-/- than App+/+ mice, but the former showed a larger increase in response to glucose. These low basal levels may enhance peripheral insulin sensitivity, as App-/- mice failed to develop impairment of glucose tolerance on a high-fat, high-sucrose ("Western") diet. Insulin levels and insulin signaling were also lower in the App-/- brain; synaptosomes prepared from App-/- hippocampus showed diminished insulin receptor phosphorylation compared with App+/+ mice when stimulated ex vivo. These findings represent a new molecular link connecting APP to metabolic homeostasis and demonstrate a novel role for APP as an upstream regulator of IDE in vivo.
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Affiliation(s)
- Joshua A Kulas
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Whitney F Franklin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch , Galveston, Texas
| | - Nicholas A Smith
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Gunjan D Manocha
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Kendra L Puig
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Rachel D Hendrix
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock Arkansas
| | - Giulio Taglialatela
- Department of Neurology, University of Texas Medical Branch , Galveston, Texas
| | - Steven W Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences , Little Rock Arkansas
- Geriatric Research, Education and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
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22
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Comerota MM, Tumurbaatar B, Krishnan B, Kayed R, Taglialatela G. Near Infrared Light Treatment Reduces Synaptic Levels of Toxic Tau Oligomers in Two Transgenic Mouse Models of Human Tauopathies. Mol Neurobiol 2018; 56:3341-3355. [PMID: 30120733 PMCID: PMC6476871 DOI: 10.1007/s12035-018-1248-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/15/2018] [Indexed: 12/16/2022]
Abstract
Tau oligomers are emerging as a key contributor to the synaptic dysfunction that drives cognitive decline associated with the clinical manifestation and progression of Alzheimer’s disease (AD). Accordingly, there is ample consensus that interventions that target tau oligomers may slow or halt the progression of AD. With this ultimate goal in mind, in the present study, we investigated tau oligomer accumulation and its synaptic and behavioral consequences after an in vivo treatment with near infrared (NIR) light (600–1000 nm) in two transgenic mouse models, overexpressing human tau either alone (hTau mice) or in combination with amyloid beta (3xTgAD mice). We found that a 4-week exposure to NIR light (90 s/day/5 days a week) significantly reduced levels of endogenous total and oligomeric tau in both synaptosomes and total protein extracts from the hippocampus and cortex of hTau mice and improved deteriorating memory function. Similar results were observed in the 3xTgAD mice, which further displayed reduced synaptic Aβ after NIR light treatment. On the other hand, ex vivo binding of tau oligomers in isolated synaptosomes as well as tau oligomer-induced depression of long-term potentiation (LTP) in hippocampal slices from NIR light-treated wt mice were unaffected. Finally, levels of proteins critically involved in two mechanisms associated with clearance of misfolded tau, inducible HSP70 and autophagy, were upregulated in NIR light treated mice. Collectively, these results show that NIR light decreases levels of endogenous toxic tau oligomers and alleviate associated memory deficits, thus furthering the development of NIR light as a possible therapeutic for AD.
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Affiliation(s)
- Michele M Comerota
- University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-1045, USA
| | - Batbayar Tumurbaatar
- University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-1045, USA
| | - Balaji Krishnan
- University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-1045, USA
| | - Rakez Kayed
- University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-1045, USA
| | - Giulio Taglialatela
- University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555-1045, USA.
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23
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Krishnan B, Kayed R, Taglialatela G. Elevated phospholipase D isoform 1 in Alzheimer's disease patients' hippocampus: Relevance to synaptic dysfunction and memory deficits. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2018; 4:89-102. [PMID: 29560412 PMCID: PMC5857521 DOI: 10.1016/j.trci.2018.01.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Introduction Phospholipase D (PLD), a lipolytic enzyme that breaks down membrane phospholipids, is also involved in signaling mechanisms downstream of seven transmembrane receptors. Abnormally elevated levels of PLD activity are well-established in Alzheimer's disease (AD), implicating the two isoforms of mammalian phosphatidylcholine cleaving PLD (PC-PLD1 and PC-PLD2). Therefore, we took a systematic approach of investigating isoform-specific expression in human synaptosomes and further investigated the possibility of therapeutic intervention using preclinical studies. Methods Synaptosomal Western blot analyses on the postmortem human hippocampus, temporal cortex, and frontal cortex of AD patient brains/age-matched controls and the 3XTg-AD mice hippocampus (mouse model with overexpression of human amyloid precursor protein, presenilin-1 gene, and microtubule-associated protein tau causing neuropathology progressing comparable to that in human AD patients) were used to detect the levels of neuronal PLD1 expression. Mouse hippocampal long-term potentiation of PLD1-dependent changes was studied using pharmacological approaches in ex vivo slice preparations from wild-type and transgenic mouse models. Finally, PLD1-dependent changes in novel object recognition memory were assessed following PLD1 inhibition. Results We observed elevated synaptosomal PLD1 in the hippocampus/temporal cortex from postmortem tissues of AD patients compared to age-matched controls and age-dependent hippocampal PLD1 increases in 3XTg-AD mice. PLD1 inhibition blocked effects of oligomeric amyloid β or toxic oligomeric tau species on high-frequency stimulation long-term potentiation and novel object recognition deficits in wild-type mice. Finally, PLD1 inhibition blocked long-term potentiation deficits normally observed in aging 3XTg-AD mice. Discussion Using human studies, we propose a novel role for PLD1-dependent signaling as a critical mechanism underlying oligomer-driven synaptic dysfunction and consequent memory disruption in AD. We, further, provide the first set of preclinical studies toward future therapeutics targeting PLD1 in slowing down/stopping the progression of AD-related memory deficits as a complementary approach to immunoscavenging clinical trials that are currently in progress.
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Affiliation(s)
- Balaji Krishnan
- Corresponding author. Tel.: 409 772 8069; Fax: 409 747 0015.
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25
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Near infrared light decreases synaptic vulnerability to amyloid beta oligomers. Sci Rep 2017; 7:15012. [PMID: 29118388 PMCID: PMC5678170 DOI: 10.1038/s41598-017-15357-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/25/2017] [Indexed: 02/07/2023] Open
Abstract
Synaptic dysfunction due to the disrupting binding of amyloid beta (Aβ) and tau oligomers is one of the earliest impairments in Alzheimer’s Disease (AD), driving initial cognitive deficits and clinical manifestation. Consequently, there is ample consensus that preventing early synaptic dysfunction would be an effective therapeutic strategy for AD. With this goal in mind, we investigated the effect of a treatment of mice with near infrared (NIR) light on synaptic vulnerability to Aβ oligomers. We found that Aβ oligomer binding to CNS synaptosomes isolated from wild type (wt) mice treated with NIR light was significantly reduced and the resulting suppression of long term potentiation (LTP) by Aβ oligomers was prevented. Similarly, APP transgenic mice treated with NIR showed a significant reduction of endogenous Aβ at CNS synapses. We further found that these phenomena were accompanied by increased synaptic mitochondrial membrane potential in both wt and Tg2576 mice. This study provides evidence that NIR light can effectively reduce synaptic vulnerability to damaging Aβ oligomers, thus furthering NIR light therapy as a viable treatment for AD.
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26
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The Study of Postmortem Human Synaptosomes for Understanding Alzheimer's Disease and Other Neurological Disorders: A Review. Neurol Ther 2017; 6:57-68. [PMID: 28733958 PMCID: PMC5520816 DOI: 10.1007/s40120-017-0070-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Indexed: 12/12/2022] Open
Abstract
Synaptic dysfunction is thought to play important roles in the pathophysiology of many neurological diseases, including Alzheimer’s disease, Parkinson’s disease, and schizophrenia. Over the past few decades, there have been systematic efforts to collect postmortem brain tissues via autopsies, leading to the establishment of dozens of human brain banks around the world. From cryopreserved human brain tissues, it is possible to isolate detached-and-resealed synaptic terminals termed synaptosomes, which remain metabolically and enzymatically active. Synaptosomes have become important model systems for studying human synaptic functions, being much more accessible than ex vivo brain slices or primary neuronal cultures. Here we review recent advances in the establishment of human brain banks, the isolation of synaptosomes, their biological activities, and various analytical techniques for investigating their biochemical and ultrastructural properties. There are unique insights to be gained by directly examining human synaptosomes, which cannot be substituted by animal models. We will also discuss how human synaptosome research has contributed to better understanding of neurological disorders, especially Alzheimer’s disease.
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27
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Hsu WCJ, Wildburger NC, Haidacher SJ, Nenov MN, Folorunso O, Singh AK, Chesson BC, Franklin WF, Cortez I, Sadygov RG, Dineley KT, Rudra JS, Taglialatela G, Lichti CF, Denner L, Laezza F. PPARgamma agonists rescue increased phosphorylation of FGF14 at S226 in the Tg2576 mouse model of Alzheimer's disease. Exp Neurol 2017; 295:1-17. [PMID: 28522250 DOI: 10.1016/j.expneurol.2017.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/13/2017] [Accepted: 05/13/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Cognitive impairment in humans with Alzheimer's disease (AD) and in animal models of Aβ-pathology can be ameliorated by treatments with the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARγ) agonists, such as rosiglitazone (RSG). Previously, we demonstrated that in the Tg2576 animal model of AD, RSG treatment rescued cognitive deficits and reduced aberrant activity of granule neurons in the dentate gyrus (DG), an area critical for memory formation. METHODS We used a combination of mass spectrometry, confocal imaging, electrophysiology and split-luciferase assay and in vitro phosphorylation and Ingenuity Pathway Analysis. RESULTS Using an unbiased, quantitative nano-LC-MS/MS screening, we searched for potential molecular targets of the RSG-dependent rescue of DG granule neurons. We found that S226 phosphorylation of fibroblast growth factor 14 (FGF14), an accessory protein of the voltage-gated Na+ (Nav) channels required for neuronal firing, was reduced in Tg2576 mice upon treatment with RSG. Using confocal microscopy, we confirmed that the Tg2576 condition decreased PanNav channels at the AIS of the DG, and that RSG treatment of Tg2576 mice reversed the reduction in PanNav channels. Analysis from previously published data sets identified correlative changes in action potential kinetics in RSG-treated T2576 compared to untreated and wildtype controls. In vitro phosphorylation and mass spectrometry confirmed that the multifunctional kinase GSK-3β, a downstream target of insulin signaling highly implicated in AD, phosphorylated FGF14 at S226. Assembly of the FGF14:Nav1.6 channel complex and functional regulation of Nav1.6-mediated currents by FGF14 was impaired by a phosphosilent S226A mutation. Bioinformatics pathway analysis of mass spectrometry and biochemistry data revealed a highly interconnected network encompassing PPARγ, FGF14, SCN8A (Nav 1.6), and the kinases GSK-3 β, casein kinase 2β, and ERK1/2. CONCLUSIONS These results identify FGF14 as a potential PPARγ-sensitive target controlling Aβ-induced dysfunctions of neuronal activity in the DG underlying memory loss in early AD.
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Affiliation(s)
- Wei-Chun J Hsu
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Biochemistry and Molecular Biology Graduate Program, Graduate School of Biomedical Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; M.D./Ph.D. Combined Degree Program, Graduate School of Biomedical Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Norelle C Wildburger
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Neuroscience Graduate Program, Graduate School of Biomedical Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Department of Neurology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, United States
| | - Sigmund J Haidacher
- Department of Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Miroslav N Nenov
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Oluwarotimi Folorunso
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Aditya K Singh
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Brent C Chesson
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Whitney F Franklin
- Neuroscience Graduate Program, Graduate School of Biomedical Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Department of Neurology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Ibdanelo Cortez
- Neuroscience Graduate Program, Graduate School of Biomedical Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Rovshan G Sadygov
- Biochemistry and Molecular Biology Graduate Program, Graduate School of Biomedical Sciences, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Sealy Center for Molecular Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Kelly T Dineley
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Department of Neurology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Center for Addiction Research, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Jay S Rudra
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Giulio Taglialatela
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Department of Neurology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Cheryl F Lichti
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Larry Denner
- Sealy Center for Molecular Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Department of Internal Medicine, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Center for Addiction Research, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Fernanda Laezza
- Department of Pharmacology & Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Center for Addiction Research, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States; Center for Biomedical Engineering, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States.
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