Beware of your Cre-Ation: lacZ expression impairs neuronal integrity and hippocampus-dependent memory.
Expression of the lacZ-sequence is a widely used reporter-tool to assess the transgenic and/or transfection efficacy of a target gene in mice. Once activated, lacZ is permanently expressed. However, protein accumulation is one of the hallmarks of neurodegenerative diseases. Furthermore, the protein product of the bacterial lacZ gene is ß-galactosidase, an analog to the mammalian senescence-associated ß-galactosidase, a molecular marker for aging. Therefore we studied the behavioral, structural and molecular consequences of lacZ expression in distinct neuronal sub-populations. lacZ expression in cortical glutamatergic neurons resulted in severe impairments in hippocampus-dependent memory accompanied by marked structural alterations throughout the CNS. In contrast, GFP expression or the expression of the ChR2/YFP fusion product in the same cell populations did not result in either cognitive or structural deficits. GABAergic lacZ expression caused significantly decreased hyper-arousal and mild cognitive deficits. Attenuated structural and behavioral consequences of lacZ expression could also be induced in adulthood, and lacZ transfection in neuronal cell cultures significantly decreased their viability. Our findings provide a strong caveat against the use of lacZ reporter mice for phenotyping studies and point to a particular sensitivity of the hippocampus formation to detrimental consequences of lacZ expression. © 2016 Wiley Periodicals, Inc.
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.|Department of Molecular Pharmacology, Albert Einstein College of Medicine, 10461, Bronx, New York.
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Reichel
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.|Core Unit Neuroimaging, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Bedenk
Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Gassen
Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Hafner
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Bura
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Almeida-Correa
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Genewsky
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Dedic
Institute of Developmental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, Neuherberg, D-85764, Germany.
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Giesert
The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland.
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Agarwal
Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, 37075, Germany.
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Nave
Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Rein
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.|Core Unit Neuroimaging, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Czisch
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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JM
Deussing
Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany. wotjak@mpipsykl.mpg.de.
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Wotjak
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression; D018698:Glutamic Acid / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D007763:Lac Operon; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008568:Memory / Q000502:physiology*; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D001426:Bacterial Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; C045073:Cre recombinase; D019426:Integrases; D001616:beta-Galactosidase
cognition; hippocampus; memory impairment; neurodegeneration; neurotoxicity; transgenic; volume loss