Increased synapse elimination by microglia in schizophrenia patient-derived models of synaptic pruning

Synapse density is reduced in postmortem cortical tissue from schizophrenia patients, which is suggestive of increased synapse elimination. Using a reprogrammed in vitro model of microglia-mediated synapse engulfment, we demonstrate increased synapse elimination in patient-derived neural cultures and isolated synaptosomes. This excessive synaptic pruning reflects abnormalities in both microglia-like cells and synaptic structures. Further, we find that schizophrenia risk-associated variants within the human complement component 4 locus are associated with increased neuronal complement deposition and synapse uptake; however, they do not fully explain the observed increase in synapse uptake. Finally, we demonstrate that the antibiotic minocycline reduces microglia-mediated synapse uptake in vitro and its use is associated with a modest decrease in incident schizophrenia risk compared to other antibiotics in a cohort of young adults drawn from electronic health records. These findings point to excessive pruning as a potential target for delaying or preventing the onset of schizophrenia in high-risk individuals.Postmortem studies indicate reduced synaptic density in schizophrenia. Sellgren et al. show increased synaptic pruning in patient-derived cell models and provide evidence that C4 risk variants increase engulfment, while minocycline decreases it.

[1]  M. Fava,et al.  Antidepressant response in patients with major depression exposed to NSAIDs: a pharmacovigilance study. , 2012, The American journal of psychiatry.

[2]  E. Erdfelder,et al.  Statistical power analyses using G*Power 3.1: Tests for correlation and regression analyses , 2009, Behavior research methods.

[3]  R. Shelton,et al.  Brain structure, function, and neurochemistry in schizophrenia and bipolar disorder—a systematic review of the magnetic resonance neuroimaging literature , 2017, npj Schizophrenia.

[4]  S. Stice,et al.  Human neural progenitor cells derived from embryonic stem cells in feeder-free cultures. , 2008, Differentiation; research in biological diversity.

[5]  Alexander Meissner,et al.  Highly efficient reprogramming to pluripotency and directed differentiation of human cells with synthetic modified mRNA. , 2010, Cell stem cell.

[6]  A. Meyer-Lindenberg,et al.  Regionally specific disturbance of dorsolateral prefrontal-hippocampal functional connectivity in schizophrenia. , 2005, Archives of general psychiatry.

[7]  Ben A. Barres,et al.  Microglia Sculpt Postnatal Neural Circuits in an Activity and Complement-Dependent Manner , 2012, Neuron.

[8]  J. Rosenbaum,et al.  Stratifying Risk for Renal Insufficiency Among Lithium-Treated Patients: An Electronic Health Record Study , 2016, Neuropsychopharmacology.

[9]  J. Hardy,et al.  Optimization of freezing, storage, and thawing conditions for the preparation of metabolically active synaptosomes from frozen rat and human brain. , 1986, Neurochemical pathology.

[10]  F. Turkheimer,et al.  Brain TSPO imaging and gray matter volume in schizophrenia patients and in people at ultra high risk of psychosis: An [11C]PBR28 study , 2017, Schizophrenia Research.

[11]  Tyrone D. Cannon.  How Schizophrenia Develops: Cognitive and Brain Mechanisms Underlying Onset of Psychosis , 2015, Trends in Cognitive Sciences.

[12]  H. Nagaraja,et al.  Sensitive and Specific Real-Time Polymerase Chain Reaction Assays to Accurately Determine Copy Number Variations (CNVs) of Human Complement C4A, C4B, C4-Long, C4-Short, and RCCX Modules: Elucidation of C4 CNVs in 50 Consanguineous Subjects with Defined HLA Genotypes1 , 2007, The Journal of Immunology.

[13]  A. Carvalho,et al.  Systematic review and meta-analysis of the efficacy and safety of minocycline in schizophrenia , 2017, CNS Spectrums.

[14]  M. Fava,et al.  Using electronic medical records to enable large-scale studies in psychiatry: treatment resistant depression as a model , 2011, Psychological Medicine.

[15]  Michael D. Cahalan,et al.  iPSC-Derived Human Microglia-like Cells to Study Neurological Diseases , 2017, Neuron.

[16]  S. Orlow,et al.  Oral Antibacterial Therapy for Acne Vulgaris: An Evidence-Based Review , 2017, American Journal of Clinical Dermatology.

[17]  Dennis Velakoulis,et al.  Progressive gray matter reduction of the superior temporal gyrus during transition to psychosis. , 2009, Archives of general psychiatry.

[18]  C. Spencer,et al.  Biological Insights From 108 Schizophrenia-Associated Genetic Loci , 2014, Nature.

[19]  D. Lewis,et al.  Decreased dendritic spine density on prefrontal cortical pyramidal neurons in schizophrenia. , 2000, Archives of general psychiatry.

[20]  J. Deleo,et al.  Minocycline decreases in vitro microglial motility, β1‐integrin, and Kv1.3 channel expression , 2007, Journal of neurochemistry.

[21]  J. Feldon,et al.  Preventive effects of minocycline in a neurodevelopmental two-hit model with relevance to schizophrenia , 2016, Translational Psychiatry.

[22]  Li-Huei Tsai,et al.  Efficient derivation of microglia-like cells from human pluripotent stem cells , 2016, Nature Medicine.

[23]  Tyrone D. Cannon,et al.  Progressive brain structural changes mapped as psychosis develops in ‘at risk’ individuals , 2009, Schizophrenia Research.

[24]  Alisha R Pollastri,et al.  Validation of electronic health record phenotyping of bipolar disorder cases and controls. , 2015, The American journal of psychiatry.

[25]  G. Šimić,et al.  Extraordinary neoteny of synaptic spines in the human prefrontal cortex , 2011, Proceedings of the National Academy of Sciences.

[26]  M. Giustetto,et al.  Synaptic Pruning by Microglia Is Necessary for Normal Brain Development , 2011, Science.

[27]  Sheng Ding,et al.  Scalable Production of iPSC-Derived Human Neurons to Identify Tau-Lowering Compounds by High-Content Screening , 2017, Stem cell reports.

[28]  J. Rosso.  Oral Doxycycline in the Management of Acne Vulgaris: Current Perspectives on Clinical Use and Recent Findings with a New Double-scored Small Tablet Formulation. , 2015 .

[29]  I. Kohane,et al.  Absence of evidence for increase in risk for autism or attention-deficit hyperactivity disorder following antidepressant exposure during pregnancy: a replication study , 2016, Translational psychiatry.

[30]  D. Hess,et al.  Optimal delivery of minocycline to the brain: implication for human studies of acute neuroprotection , 2004, Experimental Neurology.

[31]  Eric W. Danielson,et al.  SynPAnal: Software for Rapid Quantification of the Density and Intensity of Protein Puncta from Fluorescence Microscopy Images of Neurons , 2014, PloS one.

[32]  S. Hersch,et al.  Minocycline is protective in a mouse model of Huntington's disease , 2003, Annals of neurology.

[33]  A. Meyer-Lindenberg,et al.  Microglia Activation and Schizophrenia: Lessons From the Effects of Minocycline on Postnatal Neurogenesis, Neuronal Survival and Synaptic Pruning. , 2016, Schizophrenia bulletin.

[34]  Michael Cooper,et al.  High-throughput phagocytosis assay utilizing a pH-sensitive fluorescent dye. , 2005, BioTechniques.

[35]  Giulio Genovese,et al.  Schizophrenia risk from complex variation of complement component 4 , 2016, Nature.

[36]  Stephen J. Smith,et al.  Astrocytes mediate synapse elimination through MEGF10 and MERTK pathways , 2013, Nature.

[37]  R. Kahn,et al.  Progressive structural brain changes during development of psychosis. , 2012, Schizophrenia bulletin.

[38]  Karl J. Friston,et al.  Reduced frontotemporal functional connectivity in schizophrenia associated with auditory hallucinations , 2002, Biological Psychiatry.

[39]  S. Haggarty,et al.  Epigenetic Characterization of the FMR1 Gene and Aberrant Neurodevelopment in Human Induced Pluripotent Stem Cell Models of Fragile X Syndrome , 2011, PloS one.

[40]  J. Coyle,et al.  Prefrontal cortical dendritic spine pathology in schizophrenia and bipolar disorder. , 2014, JAMA psychiatry.

[41]  Karl J. Friston,et al.  Dysconnection in Schizophrenia: From Abnormal Synaptic Plasticity to Failures of Self-monitoring , 2009, Schizophrenia bulletin.

[42]  Tyrone D. Cannon,et al.  Progressive Reduction in Cortical Thickness as Psychosis Develops: A Multisite Longitudinal Neuroimaging Study of Youth at Elevated Clinical Risk , 2015, Biological Psychiatry.

[43]  John D. Lambris,et al.  The Classical Complement Cascade Mediates CNS Synapse Elimination , 2007, Cell.

[44]  Ping Wang,et al.  A novel method to determine the engulfment of apoptotic cells by macrophages using pHrodo succinimidyl ester. , 2009, Journal of immunological methods.

[45]  John Suckling,et al.  For personal use. Only reproduce with permission from The Lancet Publishing Group. Effect of sunlight and season on serotonin turnover in the brain , 2002 .

[46]  D. Maric,et al.  Differentiation of human and murine induced pluripotent stem cells to microglia-like cells , 2017, Nature Neuroscience.

[47]  Hongjun Song,et al.  Modeling synaptogenesis in schizophrenia and autism using human iPSC derived neurons , 2016, Molecular and Cellular Neuroscience.

[48]  D. Lewis,et al.  Dendritic spine pathology in schizophrenia , 2013, Neuroscience.

[49]  James A Daniel,et al.  Analysis of synaptic vesicle endocytosis in synaptosomes by high-content screening , 2012, Nature Protocols.

[50]  R. Perlis,et al.  Patient-specific models of microglia-mediated engulfment of synapses and neural progenitors , 2016, Molecular psychiatry.

[51]  Edgar Erdfelder,et al.  G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences , 2007, Behavior research methods.

[52]  Philip K. McGuire,et al.  Reductions in frontal, temporal and parietal volume associated with the onset of psychosis , 2008, Schizophrenia Research.

[53]  Baptiste N. Jaeger,et al.  An environment-dependent transcriptional network specifies human microglia identity , 2017, Science.

[54]  D. Sheehan,et al.  The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. , 1998, The Journal of clinical psychiatry.

[55]  R. Veerhuis,et al.  Minocycline does not affect amyloid β phagocytosis by human microglial cells , 2007, Neuroscience Letters.

[56]  Y. Ikegaya,et al.  Microglia engulf viable newborn cells in the epileptic dentate gyrus , 2016, Glia.

[57]  K. Woltjen,et al.  Engineering the AAVS1 locus for consistent and scalable transgene expression in human iPSCs and their differentiated derivatives. , 2016, Methods.

[58]  F. C. Bennett,et al.  New tools for studying microglia in the mouse and human CNS , 2016, Proceedings of the National Academy of Sciences.

[59]  J. Deleo,et al.  Inhibition of Microglial Activation Attenuates the Development but Not Existing Hypersensitivity in a Rat Model of Neuropathy , 2003, Journal of Pharmacology and Experimental Therapeutics.

[60]  Noémie Elhadad,et al.  Identifying and mitigating biases in EHR laboratory tests , 2014, J. Biomed. Informatics.

[61]  R. Perlis,et al.  Pre‐birth cohort study of atopic dermatitis and severe bronchiolitis during infancy , 2016, Pediatric allergy and immunology : official publication of the European Society of Pediatric Allergy and Immunology.

[62]  Nich Wattanasin,et al.  The Biobank Portal for Partners Personalized Medicine: A Query Tool for Working with Consented Biobank Samples, Genotypes, and Phenotypes Using i2b2 , 2016, Journal of personalized medicine.

[63]  Woong Sun,et al.  Rapid induction and long-term self-renewal of primitive neural precursors from human embryonic stem cells by small molecule inhibitors , 2011, Proceedings of the National Academy of Sciences.

[64]  S. Haneuse,et al.  A General Framework for Considering Selection Bias in EHR-Based Studies: What Data Are Observed and Why? , 2016, EGEMS.