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Hartmann J, Bajaj T, Otten J, Klengel C, Ebert T, Gellner AK, Junglas E, Hafner K, Anderzhanova EA, Tang F, Missig G, Rexrode L, Trussell DT, Li KX, Pöhlmann ML, Mackert S, Geiger TM, Heinz DE, Lardenoije R, Dedic N, McCullough KM, Próchnicki T, Rhomberg T, Martinelli S, Payton A, Robinson AC, Stein V, Latz E, Carlezon WA, Hausch F, Schmidt MV, Murgatroyd C, Berretta S, Klengel T, Pantazopoulos H, Ressler KJ, Gassen NC. SKA2 regulated hyperactive secretory autophagy drives neuroinflammation-induced neurodegeneration. Nat Commun 2024; 15:2635. [PMID: 38528004 PMCID: PMC10963788 DOI: 10.1038/s41467-024-46953-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/15/2024] [Indexed: 03/27/2024] Open
Abstract
High levels of proinflammatory cytokines induce neurotoxicity and catalyze inflammation-driven neurodegeneration, but the specific release mechanisms from microglia remain elusive. Here we show that secretory autophagy (SA), a non-lytic modality of autophagy for secretion of vesicular cargo, regulates neuroinflammation-mediated neurodegeneration via SKA2 and FKBP5 signaling. SKA2 inhibits SA-dependent IL-1β release by counteracting FKBP5 function. Hippocampal Ska2 knockdown in male mice hyperactivates SA resulting in neuroinflammation, subsequent neurodegeneration and complete hippocampal atrophy within six weeks. The hyperactivation of SA increases IL-1β release, contributing to an inflammatory feed-forward vicious cycle including NLRP3-inflammasome activation and Gasdermin D-mediated neurotoxicity, which ultimately drives neurodegeneration. Results from protein expression and co-immunoprecipitation analyses of male and female postmortem human brains demonstrate that SA is hyperactivated in Alzheimer's disease. Overall, our findings suggest that SKA2-regulated, hyperactive SA facilitates neuroinflammation and is linked to Alzheimer's disease, providing mechanistic insight into the biology of neuroinflammation.
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Affiliation(s)
- Jakob Hartmann
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA.
| | - Thomas Bajaj
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
| | - Joy Otten
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Claudia Klengel
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Tim Ebert
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
| | - Anne-Kathrin Gellner
- Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
| | - Ellen Junglas
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
| | - Kathrin Hafner
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Elmira A Anderzhanova
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
- Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Fiona Tang
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Galen Missig
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Lindsay Rexrode
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Daniel T Trussell
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Katelyn X Li
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Max L Pöhlmann
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Sarah Mackert
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
| | - Thomas M Geiger
- Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, 64287, Darmstadt, Germany
| | - Daniel E Heinz
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany
- Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Roy Lardenoije
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Nina Dedic
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Kenneth M McCullough
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Tomasz Próchnicki
- Institute of Innate Immunity, University Hospital Bonn, 53127, Bonn, Germany
| | - Thomas Rhomberg
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Silvia Martinelli
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Antony Payton
- Division of Informatics, Imaging and Data Sciences, University of Manchester, Manchester, M13 9PL, UK
| | - Andrew C Robinson
- Division of Neuroscience, Faculty of Biology, Medicine and Health, School of Biological Sciences, The University of Manchester, Salford Royal Hospital, Salford, M6 8HD, UK
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre (MAHSC), Manchester, UK
| | - Valentin Stein
- Institute of Physiology II, University of Bonn, 53127, Bonn, Germany
| | - Eicke Latz
- Institute of Innate Immunity, University Hospital Bonn, 53127, Bonn, Germany
- Deutsches Rheuma Forschungszentrum Berlin (DRFZ), 10117, Berlin, Germany
| | - William A Carlezon
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Felix Hausch
- Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, 64287, Darmstadt, Germany
| | - Mathias V Schmidt
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - Chris Murgatroyd
- Department of Life Sciences, Manchester Metropolitan University, Manchester, M15 6BH, UK
| | - Sabina Berretta
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
| | - Torsten Klengel
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Harry Pantazopoulos
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Kerry J Ressler
- Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, 02478, USA.
| | - Nils C Gassen
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, 53127, Bonn, Germany.
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Fritsch B, Mayer M, Reis J, Gellner AK. Safety of ipsilesional anodal transcranial direct current stimulation in acute photothrombotic stroke: implications for early neurorehabilitation. Sci Rep 2024; 14:2501. [PMID: 38291061 PMCID: PMC10827716 DOI: 10.1038/s41598-024-51839-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/10/2024] [Indexed: 02/01/2024] Open
Abstract
Early rehabilitation in the acute phase of stroke, that bears unique neuroplastic properties, is the current standard to reduce disability. Anodal transcranial direct current stimulation can augment neurorehabilitation in chronic stroke. Studies in the acute phase are sparse and held back by inconclusive preclinical data pointing towards potential negative interaction of the excitability increasing tDCS modality with stroke-induced glutamate toxicity. In this present study, we aimed to evaluate structural and behavioral safety of anodal tDCS applied in the acute phase of stroke. Photothrombotic stroke including the right primary motor cortex was induced in rats. 24 h after stroke anodal tDCS was applied for 20 min ipsilesionally at one of four different current densities in freely moving animals. Effects on the infarct volume and on stroke induced neuroinflammation were assessed. Behavioral consequences were monitored. Infarct volume and the modified Neurological Severity Score were not affected by anodal tDCS. Pasta handling, a more sensitive task for sensorimotor deficits, and microglia reactivity indicated potentially harmful effects at the highest tDCS current density tested (47.8 A/m2), which is more than 60 times higher than intensities commonly used in humans. Compared to published safety limits of anodal tDCS in healthy rats, recent stroke does not increase the sensitivity of the brain to anodal tDCS, as assessed by lesion size and neuroinflammatory response. Behavioral deficits only occurred at the highest intensity, which was associated with increased neuroinflammation. When safety limits of commonly used clinical tDCS are met, augmentation of early neurorehabilitation after stroke by anodal tDCS appears to be feasible.
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Affiliation(s)
- Brita Fritsch
- Department of Neurology, University Hospital Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - Marleen Mayer
- Department of Neurology, University Hospital Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - Janine Reis
- Department of Neurology, University Hospital Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - Anne-Kathrin Gellner
- Department of Neurology, University Hospital Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
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Gellner AK, Reis J, Fiebich BL, Fritsch B. Cx3cr1 deficiency interferes with learning- and direct current stimulation-mediated neuroplasticity of the motor cortex. Eur J Neurosci 2024; 59:177-191. [PMID: 38049944 DOI: 10.1111/ejn.16206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 10/18/2023] [Accepted: 11/12/2023] [Indexed: 12/06/2023]
Abstract
Microglia are essential contributors to synaptic transmission and stability and communicate with neurons via the fractalkine pathway. Transcranial direct current stimulation [(t)DCS], a form of non-invasive electrical brain stimulation, modulates cortical excitability and promotes neuroplasticity, which has been extensively demonstrated in the motor cortex and for motor learning. The role of microglia and their fractalkine receptor CX3CR1 in motor cortical neuroplasticity mediated by DCS or motor learning requires further elucidation. We demonstrate the effects of pharmacological microglial depletion and genetic Cx3cr1 deficiency on the induction of DCS-induced long-term potentiation (DCS-LTP) ex vivo. The relevance of microglia-neuron communication for DCS response and structural neuroplasticity underlying motor learning are assessed via 2-photon in vivo imaging. The behavioural consequences of impaired CX3CR1 signalling are investigated for both gross and fine motor learning. We show that DCS-mediated neuroplasticity in the motor cortex depends on the presence of microglia and is driven in part by CX3CR1 signalling ex vivo and provide the first evidence of microglia interacting with neurons during DCS in vivo. Furthermore, CX3CR1 signalling is required for motor learning and underlying structural neuroplasticity in concert with microglia interaction. Although we have recently demonstrated the microglial response to DCS in vivo, we now provide a link between microglial integrity and neuronal activity for the expression of DCS-dependent neuroplasticity. In addition, we extend the knowledge on the relevance of CX3CR1 signalling for motor learning and structural neuroplasticity. The underlying molecular mechanisms and the potential impact of DCS in rescuing CX3CR1 deficits remain to be addressed in the future.
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Affiliation(s)
- Anne-Kathrin Gellner
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
- Department of Neurology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Institute of Physiology II, Medical Faculty, University of Bonn, Bonn, Germany
| | - Janine Reis
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
| | - Bernd L Fiebich
- Neurochemistry and Neuroimmunology Research Group, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Brita Fritsch
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
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Abstract
Neuropsychiatric disorders, such as major depression, anxiety disorders, and post-traumatic stress disorder, tend to be long-term conditions in whose development and maintenance stress are central pathogenic factors. Translational mouse models are widely used in neuropsychiatric research, exploiting social and non-social stressors to investigate the mechanisms underlying their detrimental effects. However, most studies focus on the short-term consequences of chronic stress, whereas only a few are interested in the long-term course. This is counterintuitive given the human conditions that preclinical models are designed to mimic. In this review, we have summarized the limited work to date on long-term effects of chronic stress in mice models. First, the different models are presented and a definition of short- vs. long-term sequelae is proposed. On this basis, behavioral, endocrine, and vegetative effects are addressed before examining data on cellular and molecular alterations in the brain. Finally, future directions for research on the long-term effects of stress are discussed.
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Affiliation(s)
- Inès Tran
- Institute of Physiology II, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anne-Kathrin Gellner
- Institute of Physiology II, Medical Faculty, University of Bonn, Bonn, Germany.
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany.
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Hartmann J, Bajaj T, Otten J, Klengel C, Gellner AK, Junglas E, Hafner K, Anderzhanova EA, Tang F, Missig G, Rexrode L, Li K, Pöhlmann ML, Heinz DE, Lardenoije R, Dedic N, McCullough KM, Próchnicki T, Rhomberg T, Martinelli S, Payton A, Robinson AC, Stein V, Latz E, Carlezon WA, Schmidt MV, Murgatroyd C, Berretta S, Klengel T, Pantazopoulos H, Ressler KJ, Gassen NC. SKA2 regulated hyperactive secretory autophagy drives neuroinflammation-induced neurodegeneration. bioRxiv 2023:2023.04.03.534570. [PMID: 37066393 PMCID: PMC10103985 DOI: 10.1101/2023.04.03.534570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
High levels of proinflammatory cytokines induce neurotoxicity and catalyze inflammation-driven neurodegeneration, but the specific release mechanisms from microglia remain elusive. We demonstrate that secretory autophagy (SA), a non-lytic modality of autophagy for secretion of vesicular cargo, regulates neuroinflammation-mediated neurodegeneration via SKA2 and FKBP5 signaling. SKA2 inhibits SA-dependent IL-1β release by counteracting FKBP5 function. Hippocampal Ska2 knockdown in mice hyperactivates SA resulting in neuroinflammation, subsequent neurodegeneration and complete hippocampal atrophy within six weeks. The hyperactivation of SA increases IL-1β release, initiating an inflammatory feed-forward vicious cycle including NLRP3-inflammasome activation and Gasdermin D (GSDMD)-mediated neurotoxicity, which ultimately drives neurodegeneration. Results from protein expression and co-immunoprecipitation analyses of postmortem brains demonstrate that SA is hyperactivated in Alzheimer's disease. Overall, our findings suggest that SKA2-regulated, hyperactive SA facilitates neuroinflammation and is linked to Alzheimer's disease, providing new mechanistic insight into the biology of neuroinflammation.
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Gellner AK, Frase S, Reis J, Fritsch B. Direct current stimulation increases blood flow and permeability of cortical microvasculature in vivo. Eur J Neurol 2023; 30:362-371. [PMID: 36305221 DOI: 10.1111/ene.15616] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/08/2022] [Accepted: 10/12/2022] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE Transcranial direct current stimulation (DCS) structurally and functionally modulates neuronal networks and microglia dynamics. Neurovascular coupling adapts regional cerebral blood flow to neuronal activity and metabolic demands. METHODS In this study, we examined effects of anodal DCS on vessel morphology, blood flow parameters, permeability of cortical microvasculature, and perivascular microglia motility by time-lapse two-photon microscopy in anaesthetized mice. RESULTS Low-intensity DCS significantly increased vessel diameter and blood flow parameters. These effects were transient and dependent on the spontaneous vasomotion characteristics of the individual vessel. Vessel leakage increased significantly after DCS at 1.1 and was more pronounced at 2.2 A/m2 , indicating a dose-dependent increase in vascular permeability. Perivascular microglia exhibited increased soma motility post-DCS at both intensities, potentially triggered by the extravasation of intravascular substrates. CONCLUSIONS Our findings demonstrate that DCS affected only vessels with spontaneous vasomotion. This rapid vascular response may occur as an adaptation of regional blood supply to neuronal excitability altered by DCS or as a direct effect on the vessel wall. In contrast to these immediate effects during stimulation, increases in cortical vessel permeability and perivascular microglia motility appeared after the stimulation had ended.
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Affiliation(s)
- Anne-Kathrin Gellner
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
- Department of Neurology and Neuroscience, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sibylle Frase
- Department of Neurology and Neuroscience, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Janine Reis
- Department of Neurology and Neuroscience, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Brita Fritsch
- Department of Neurology and Neuroscience, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Komorowska-Müller JA, Gellner AK, Ravichandran KA, Bilkei-Gorzo A, Zimmer A, Stein V. Chronic low-dose Δ 9-tetrahydrocannabinol (THC) treatment stabilizes dendritic spines in 18-month-old mice. Sci Rep 2023; 13:1390. [PMID: 36697430 PMCID: PMC9877016 DOI: 10.1038/s41598-022-27146-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 12/27/2022] [Indexed: 01/26/2023] Open
Abstract
Cognitive functions decline during aging. This decline could be caused by changes in dendritic spine stability and altered spine dynamics. Previously, we have shown that a low dose chronic THC treatment improves learning abilities in old whereas impairs learning abilities in young mice. The mechanism underlying this age-dependent effect is not known. Dendritic spine stability is a key for memory formation, therefore we hypothesized that THC affects spine dynamics in an age-dependent manner. We applied longitudinal 2-photon in vivo imaging to 3- and 18-month-old mice treated with 3 mg/kg/day of THC for 28 days via an osmotic pump. We imaged the same dendritic segments before, during and after the treatment and assessed changes in spine density and stability. We now show that in old mice THC improved spine stability resulting in a long-lasting increase in spine density. In contrast, in young mice THC transiently increased spine turnover and destabilized the spines.
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Affiliation(s)
| | - Anne-Kathrin Gellner
- Medical Faculty, Institute of Physiology II, University of Bonn, Bonn, Germany.,Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
| | - Kishore Aravind Ravichandran
- Medical Faculty, Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany.,Medical Faculty, Institute of Physiology II, University of Bonn, Bonn, Germany
| | - Andras Bilkei-Gorzo
- Medical Faculty, Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany
| | - Andreas Zimmer
- Medical Faculty, Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany.
| | - Valentin Stein
- Medical Faculty, Institute of Physiology II, University of Bonn, Bonn, Germany.
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8
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Serradas ML, Stein V, Gellner AK. Long-term changes of parvalbumin- and somatostatin-positive interneurons of the primary motor cortex after chronic social defeat stress depend on individual stress-vulnerability. Front Psychiatry 2022; 13:946719. [PMID: 35966477 PMCID: PMC9366473 DOI: 10.3389/fpsyt.2022.946719] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Chronic stress is a major risk factor for developing mental illnesses and cognitive deficiencies although stress-susceptibility varies individually. In a recent study, we established the connection between chronic social defeat stress (CSDS) and impaired motor learning abilities accompanied by chronically disturbed structural neuroplasticity in the primary motor cortex (M1) of mice. In this study, we further investigated the long-term effects of CSDS exposure on M1, focusing on the interneuronal cell population. We used repeated CSDS to elicit effects across behavioral, endocrinological, and metabolic parameters in mice. Susceptible and resilient phenotypes were discriminated by symptom load and motor learning abilities were assessed on the rotarod. Structural changes in interneuronal circuits of M1 were studied by immunohistochemistry using parvalbumin (PV+) and somatostatin (SST+) markers. Stress-susceptible mice had a blunted stress hormone response and impaired motor learning skills. These mice presented reduced numbers of both interneuron populations in M1 with layer-dependent distribution, while alterations in cell size and immunoreactivity were found in both susceptible and resilient individuals. These results, together with our previous data, suggest that stress-induced cell loss and degeneration of the GABAergic interneuronal network of M1 could underlay impaired motor learning, due to their role in controlling the excitatory output and spine dynamics of principal neurons required for this task. Our study further highlights the importance of long-term outcomes of chronically stressed individuals which are translationally important due to the long timecourses of stress-induced neuropsychiatric disorders.
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Affiliation(s)
- Maria L Serradas
- Institute of Physiology II, Medical Faculty, University of Bonn, Bonn, Germany
| | - Valentin Stein
- Institute of Physiology II, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anne-Kathrin Gellner
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
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9
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Gellner AK, Reis J, Fiebich BL, Fritsch B. Electrified microglia: Impact of direct current stimulation on diverse properties of the most versatile brain cell. Brain Stimul 2021; 14:1248-1258. [PMID: 34411753 DOI: 10.1016/j.brs.2021.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 08/07/2021] [Accepted: 08/09/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Transcranial direct current stimulation [(t)DCS], modulates cortical excitability and promotes neuroplasticity. Microglia has been identified to respond to electrical currents as well as neuronal activity, but its response to DCS is mostly unknown. OBJECTIVE This study addresses effects of DCS applied in vivo to the sensorimotor cortex on physiological microglia properties and neuron-microglia communication. METHODS Time lapse in vivo 2-photon microscopy in anaesthetized mice was timely coupled with DCS of the sensorimotor cortex to observe microglia dynamics on a population-based and single cell level. Neuron-microglia communication during DCS was investigated in mice with a functional knock out of the fractalkine receptor CX3CR1. Moreover, the role of voltage gated microglial channels and DCS effects on phagocytosis were studied. RESULTS DCS promoted several physiological microglia properties, depending on the glial activation state and stimulation intensity. On a single cell level, process motility was predominantly enhanced in ramified cells whereas horizontal soma movement and galvanotaxis was pronounced in reactive microglia. Blockage of voltage sensitive microglial channels suppressed DCS effects in vivo and in vitro. Microglial motility changes were partially driven by the fractalkine signaling pathway. Moreover, phagocytosis increased after DCS in vitro. CONCLUSION Microglia dynamics are rapidly influenced by DCS. This is the first in vivo demonstration of a direct effect of electrical currents on microglia and indirect effects potentially driven by neuronal activity via the fractalkine pathway.
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Affiliation(s)
- Anne-Kathrin Gellner
- Department of Neurology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Janine Reis
- Department of Neurology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - Bernd L Fiebich
- Neurochemistry and Neuroimmunology Research Group, Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstrasse 5, 79104, Freiburg, Germany
| | - Brita Fritsch
- Department of Neurology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
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10
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Martinelli S, Anderzhanova EA, Bajaj T, Wiechmann S, Dethloff F, Weckmann K, Heinz DE, Ebert T, Hartmann J, Geiger TM, Döngi M, Hafner K, Pöhlmann ML, Jollans L, Philipsen A, Schmidt SV, Schmidt U, Maccarrone G, Stein V, Hausch F, Turck CW, Schmidt MV, Gellner AK, Kuster B, Gassen NC. Stress-primed secretory autophagy promotes extracellular BDNF maturation by enhancing MMP9 secretion. Nat Commun 2021; 12:4643. [PMID: 34330919 PMCID: PMC8324795 DOI: 10.1038/s41467-021-24810-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/07/2021] [Indexed: 11/23/2022] Open
Abstract
The stress response is an essential mechanism for maintaining homeostasis, and its disruption is implicated in several psychiatric disorders. On the cellular level, stress activates, among other mechanisms, autophagy that regulates homeostasis through protein degradation and recycling. Secretory autophagy is a recently described pathway in which autophagosomes fuse with the plasma membrane rather than with lysosomes. Here, we demonstrate that glucocorticoid-mediated stress enhances secretory autophagy via the stress-responsive co-chaperone FK506-binding protein 51. We identify the matrix metalloproteinase 9 (MMP9) as one of the proteins secreted in response to stress. Using cellular assays and in vivo microdialysis, we further find that stress-enhanced MMP9 secretion increases the cleavage of pro-brain-derived neurotrophic factor (proBDNF) to its mature form (mBDNF). BDNF is essential for adult synaptic plasticity and its pathway is associated with major depression and posttraumatic stress disorder. These findings unravel a cellular stress adaptation mechanism that bears the potential of opening avenues for the understanding of the pathophysiology of stress-related disorders.
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Affiliation(s)
- Silvia Martinelli
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany.
| | - Elmira A Anderzhanova
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Thomas Bajaj
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Svenja Wiechmann
- Chair of Proteomics and Bioanalytics, Technical University of Munich, Emil-Erlenmeyer-Forum 5, Freising, Germany
- German Cancer Consortium (DKTK), Munich, Germany
- German Cancer Center (DKFZ), Heidelberg, Germany
| | - Frederik Dethloff
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
- Metabolomics Core Facility, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Katja Weckmann
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Daniel E Heinz
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Tim Ebert
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Jakob Hartmann
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, USA
| | - Thomas M Geiger
- Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Darmstadt, Germany
| | - Michael Döngi
- Institut für Physiologie II, University of Bonn, Bonn, Germany
| | - Kathrin Hafner
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Max L Pöhlmann
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, Munich, Germany
| | - Lee Jollans
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Alexandra Philipsen
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | | | - Ulrike Schmidt
- Research Group Molecular and Clinical Psychotraumatology, Department of Psychiatry and Psychotherapy, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
- Research Group Traumatic Stress & Neurodegeneration & PTSD Treatment Unit, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
- Department of Psychiatry and Neuropsychology, Maastricht University Medical Centre, School for Mental Health and Neuroscience, Maastricht, The Netherlands
| | - Giuseppina Maccarrone
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Valentin Stein
- Institut für Physiologie II, University of Bonn, Bonn, Germany
| | - Felix Hausch
- Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Darmstadt, Germany
| | - Christoph W Turck
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
| | - Mathias V Schmidt
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, Munich, Germany
| | - Anne-Kathrin Gellner
- Institut für Physiologie II, University of Bonn, Bonn, Germany
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Bernhard Kuster
- Chair of Proteomics and Bioanalytics, Technical University of Munich, Emil-Erlenmeyer-Forum 5, Freising, Germany
- German Cancer Consortium (DKTK), Munich, Germany
- German Cancer Center (DKFZ), Heidelberg, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Freising, Germany
| | - Nils C Gassen
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany.
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany.
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11
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Gellner AK, Voelter J, Schmidt U, Beins EC, Stein V, Philipsen A, Hurlemann R. Molecular and neurocircuitry mechanisms of social avoidance. Cell Mol Life Sci 2020; 78:1163-1189. [PMID: 32997200 PMCID: PMC7904739 DOI: 10.1007/s00018-020-03649-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/09/2020] [Accepted: 09/15/2020] [Indexed: 12/11/2022]
Abstract
Humans and animals live in social relationships shaped by actions of approach and avoidance. Both are crucial for normal physical and mental development, survival, and well-being. Active withdrawal from social interaction is often induced by the perception of threat or unpleasant social experience and relies on adaptive mechanisms within neuronal networks associated with social behavior. In case of confrontation with overly strong or persistent stressors and/or dispositions of the affected individual, maladaptive processes in the neuronal circuitries and its associated transmitters and modulators lead to pathological social avoidance. This review focuses on active, fear-driven social avoidance, affected circuits within the mesocorticolimbic system and associated regions and a selection of molecular modulators that promise translational potential. A comprehensive review of human research in this field is followed by a reflection on animal studies that offer a broader and often more detailed range of analytical methodologies. Finally, we take a critical look at challenges that could be addressed in future translational research on fear-driven social avoidance.
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Affiliation(s)
- Anne-Kathrin Gellner
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Jella Voelter
- Department of Psychiatry, School of Medicine and Health Sciences, University of Oldenburg, Hermann-Ehlers-Str. 7, 26160, Bad Zwischenahn, Germany
| | - Ulrike Schmidt
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.,Department of Psychiatry Und Psychotherapy, University of Göttingen, Von-Siebold-Str. 5, 37075, Göttingen, Germany
| | - Eva Carolina Beins
- Institute of Human Genetics, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Valentin Stein
- Institute of Physiology II, University Hospital Bonn, 53115, Bonn, Germany
| | - Alexandra Philipsen
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - René Hurlemann
- Division of Medical Psychology, Department of Psychiatry, University Hospital, Venusberg-Campus 1, 53127, Bonn, Germany. .,Department of Psychiatry, School of Medicine and Health Sciences, University of Oldenburg, Hermann-Ehlers-Str. 7, 26160, Bad Zwischenahn, Germany. .,Research Center Neurosensory Science, University of Oldenburg, 26129, Oldenburg, Germany.
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12
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Abstract
Transcranial electrical brain stimulation can modulate cortical excitability and plasticity in humans and rodents. The most common form of stimulation in humans is transcranial direct current stimulation (tDCS). Less frequently, transcranial alternating current stimulation (tACS) or transcranial random noise stimulation (tRNS), a specific form of tACS using an electrical current applied randomly within a pre-defined frequency range, is used. The increase of noninvasive electrical brain stimulation research in humans, both for experimental and clinical purposes, has yielded an increased need for basic, mechanistic, safety studies in animals. This article describes a model for transcranial electrical brain stimulation (tES) through the intact skull targeting the motor system in alert rodents. The protocol provides step-by-step instructions for the surgical set-up of a permanent epicranial electrode socket combined with an implanted counter electrode on the chest. By placing a stimulation electrode into the epicranial socket, different electrical stimulation types, comparable to tDCS, tACS, and tRNS in humans, can be delivered. Moreover, the practical steps for tES in alert rodents are introduced. The applied current density, stimulation duration, and stimulation type may be chosen depending on the experimental needs. The caveats, advantages, and disadvantages of this set-up are discussed, as well as safety and tolerability aspects.
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Affiliation(s)
- Brita Fritsch
- Department of Neurology, Albert-Ludwigs-University Freiburg;
| | | | - Janine Reis
- Department of Neurology, Albert-Ludwigs-University Freiburg
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13
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Gellner AK, Reis J, Fritsch B. Glia: A Neglected Player in Non-invasive Direct Current Brain Stimulation. Front Cell Neurosci 2016; 10:188. [PMID: 27551261 PMCID: PMC4976108 DOI: 10.3389/fncel.2016.00188] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/19/2016] [Indexed: 12/21/2022] Open
Abstract
Non-invasive electrical brain stimulation by application of direct current (DCS) promotes plasticity in neuronal networks in vitro and in in vivo. This effect has been mainly attributed to the direct modulation of neurons. Glia represents approximately 50% of cells in the brain. Glial cells are electrically active and participate in synaptic plasticity. Despite of that, effects of DCS on glial structures and on interaction with neurons are only sparsely investigated. In this perspectives article we review the current literature, present own dose response data and provide a framework for future research from two points of view: first, the direct effects of DCS on glia and second, the contribution of glia to DCS related neuronal plasticity.
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Affiliation(s)
| | - Janine Reis
- Department of Neurology, University Hospital Freiburg Freiburg, Germany
| | - Brita Fritsch
- Department of Neurology, University Hospital Freiburg Freiburg, Germany
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14
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Weltin A, Kieninger J, Enderle B, Gellner AK, Fritsch B, Urban GA. Polymer-based, flexible glutamate and lactate microsensors for in vivo applications. Biosens Bioelectron 2014; 61:192-9. [PMID: 24880657 DOI: 10.1016/j.bios.2014.05.014] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 12/28/2022]
Abstract
We present a flexible microsensor, based on a polymer substrate, for multiparametric, electrochemical in vivo monitoring. The sensor strip with a microelectrode array at the tip was designed for insertion into tissue, for fast and localized online monitoring of physiological parameters. The microsystem fabrication on a wafer-level is based on a polyimide substrate and includes the patterning of platinum microelectrodes as well as epoxy and dry-film-resist insulation in a cost-effective thin-film and laminate process. A stable, electrodeposited silver/silver chloride reference electrode on-chip and a perm-selective membrane as an efficient interference rejection scheme are integrated on a wafer-level. Amperometric, electrochemical, enzyme-based biosensors for the neurotransmitter L-glutamate and the energy metabolite L-lactate have been developed. Hydrogel membranes or direct cross-linking as stable concepts for the enzyme immobilization are shown. Sensor performance including high selectivity, tailoring of sensitivity and long-term stability is discussed. For glutamate, a high sensitivity of 2.16 nAmm(-2) µM(-1) was found. For lactate, a variation in sensitivity between 2.6 and 32 nAmm(-2)mM(-1) was achieved by different membrane compositions. The in vivo application in an animal model is demonstrated by glutamate measurements in the brain of rats. Local glutamate alterations in the micromolar range and in nanoliter-range volumes can be detected and quantified with high reproducibility and temporal resolution. A novel, versatile platform for the integration of various electrochemical sensors on a small, flexible sensor strip for a variety of in vivo applications is presented.
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Affiliation(s)
- Andreas Weltin
- Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany.
| | - Jochen Kieninger
- Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany
| | - Barbara Enderle
- Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany
| | | | - Brita Fritsch
- Department of Neurology, University of Freiburg, Germany
| | - Gerald A Urban
- Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, Germany
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15
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Pachmann K, Camara O, Kroll T, Gajda M, Gellner AK, Wotschadlo J, Runnebaum IB. Efficacy control of therapy using circulating epithelial tumor cells (CETC) as "liquid biopsy": trastuzumab in HER2/neu-positive breast carcinoma. J Cancer Res Clin Oncol 2011. [PMID: 21739182 DOI: 10.1007/s00432‐011‐1000‐6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE The majority of targeted personalized cancer therapies are effective only in part of the patients, and most of these drugs are excessively expensive. Therefore, methods are urgently required, which reveal already early during treatment, whether the therapy is effective. In the present report, monitoring of circulating epithelial tumor cells (CETC) was used as a timely control of trastuzumab therapy in patients with HER2/neu-positive breast cancer. METHODS Seventy-nine sequential HER2/neu-positive breast cancer patients, 35 without trastuzumab, and 36 treated with 1 year of trastuzumab treatment were included. CETC from unseparated white blood cells stained with FITC-anti-EpCAM were analyzed repeatedly during chemotherapy and between 2 and 10 times during 1 year of maintenance treatment or observation. RESULTS Patients treated with trastuzumab had a better relapse-free survival than patients without trastuzumab treatment during the first 2-4 years of follow-up. Decrease in numbers or no change versus highly variable numbers or increase (fivefold or more) allowed to discriminate highly significantly and clearly (P < 0.0001, hazard ratio 5.5) between patients with a low or high risk of relapse. An increase in CETC was accompanied by an increasing portion of cells containing a very high number of HER2/neu gene amplificates. CONCLUSIONS Analysis of the behavior of CETC can, in the future, contribute to evaluate the efficacy of targeted therapy early during the course of the disease, sparing patients unnecessary treatment but also to reduce the costs for the health system and to downsize the extent and length of clinical studies.
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Affiliation(s)
- Katharina Pachmann
- Department of Experimental Hematology and Oncology, Clinic for Internal Medicine II, Friedrich Schiller University, Jena, Erlanger Allee 101, 07747, Jena, Germany.
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16
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Pachmann K, Camara O, Kroll T, Gajda M, Gellner AK, Wotschadlo J, Runnebaum IB. Efficacy control of therapy using circulating epithelial tumor cells (CETC) as "liquid biopsy": trastuzumab in HER2/neu-positive breast carcinoma. J Cancer Res Clin Oncol 2011; 137:1317-27. [PMID: 21739182 PMCID: PMC3155034 DOI: 10.1007/s00432-011-1000-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 06/20/2011] [Indexed: 12/24/2022]
Abstract
Purpose The majority of targeted personalized cancer therapies are effective only in part of the patients, and most of these drugs are excessively expensive. Therefore, methods are urgently required, which reveal already early during treatment, whether the therapy is effective. In the present report, monitoring of circulating epithelial tumor cells (CETC) was used as a timely control of trastuzumab therapy in patients with HER2/neu-positive breast cancer. Methods Seventy-nine sequential HER2/neu-positive breast cancer patients, 35 without trastuzumab, and 36 treated with 1 year of trastuzumab treatment were included. CETC from unseparated white blood cells stained with FITC-anti-EpCAM were analyzed repeatedly during chemotherapy and between 2 and 10 times during 1 year of maintenance treatment or observation. Results Patients treated with trastuzumab had a better relapse-free survival than patients without trastuzumab treatment during the first 2–4 years of follow-up. Decrease in numbers or no change versus highly variable numbers or increase (fivefold or more) allowed to discriminate highly significantly and clearly (P < 0.0001, hazard ratio 5.5) between patients with a low or high risk of relapse. An increase in CETC was accompanied by an increasing portion of cells containing a very high number of HER2/neu gene amplificates. Conclusions Analysis of the behavior of CETC can, in the future, contribute to evaluate the efficacy of targeted therapy early during the course of the disease, sparing patients unnecessary treatment but also to reduce the costs for the health system and to downsize the extent and length of clinical studies.
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Affiliation(s)
- Katharina Pachmann
- Department of Experimental Hematology and Oncology, Clinic for Internal Medicine II, Friedrich Schiller University, Jena, Erlanger Allee 101, 07747, Jena, Germany.
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