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Monje FJ, Cicvaric A, Acevedo Aguilar JP, Elbau I, Horvath O, Diao W, Glat M, Pollak DD. Disrupted Ultradian Activity Rhythms and Differential Expression of Several Clock Genes in Interleukin-6-Deficient Mice. Front Neurol 2017; 8:99. [PMID: 28382017 PMCID: PMC5360714 DOI: 10.3389/fneur.2017.00099] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [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: 12/19/2016] [Accepted: 02/28/2017] [Indexed: 12/14/2022] Open
Abstract
The characteristics of the cycles of activity and rest stand out among the most intensively investigated aspects of circadian rhythmicity in humans and experimental animals. Alterations in the circadian patterns of activity and rest are strongly linked to cognitive and emotional dysfunctions in severe mental illnesses such as Alzheimer’s disease (AD) and major depression (MDD). The proinflammatory cytokine interleukin 6 (IL-6) has been prominently associated with the pathogenesis of AD and MDD. However, the potential involvement of IL-6 in the modulation of the diurnal rhythms of activity and rest has not been investigated. Here, we set out to study the role of IL-6 in circadian rhythmicity through the characterization of patterns of behavioral locomotor activity in IL-6 knockout (IL-6 KO) mice and wild-type littermate controls. Deletion of IL-6 did not alter the length of the circadian period or the amount of locomotor activity under either light-entrained or free-running conditions. IL-6 KO mice also presented a normal phase shift in response to light exposure at night. However, the temporal architecture of the behavioral rhythmicity throughout the day, as characterized by the quantity of ultradian activity bouts, was significantly impaired under light-entrained and free-running conditions in IL-6 KO. Moreover, the assessment of clock gene expression in the hippocampus, a brain region involved in AD and depression, revealed altered levels of cry1, dec2, and rev-erb-beta in IL-6 KO mice. These data propose that IL-6 participates in the regulation of ultradian activity/rest rhythmicity and clock gene expression in the mammalian brain. Furthermore, we propose IL-6-dependent circadian misalignment as a common pathogenetic principle in some neurodegenerative and neuropsychiatric disorders.
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Affiliation(s)
- Francisco J Monje
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
| | - Ana Cicvaric
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
| | - Juan Pablo Acevedo Aguilar
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
| | - Immanuel Elbau
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria; Max Planck Institute of Psychiatry, Munich, Germany
| | - Orsolya Horvath
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
| | - Weifei Diao
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
| | - Micaela Glat
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
| | - Daniela D Pollak
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna , Vienna , Austria
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Cicvaric A, Yang J, Krieger S, Khan D, Kim EJ, Dominguez-Rodriguez M, Cabatic M, Molz B, Acevedo Aguilar JP, Milicevic R, Smani T, Breuss JM, Kerjaschki D, Pollak DD, Uhrin P, Monje FJ. The brain-tumor related protein podoplanin regulates synaptic plasticity and hippocampus-dependent learning and memory. Ann Med 2016; 48:652-668. [PMID: 27558977 PMCID: PMC5125287 DOI: 10.1080/07853890.2016.1219455] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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] [Indexed: 01/15/2023] Open
Abstract
INTRODUCTION Podoplanin is a cell-surface glycoprotein constitutively expressed in the brain and implicated in human brain tumorigenesis. The intrinsic function of podoplanin in brain neurons remains however uncharacterized. MATERIALS AND METHODS Using an established podoplanin-knockout mouse model and electrophysiological, biochemical, and behavioral approaches, we investigated the brain neuronal role of podoplanin. RESULTS Ex-vivo electrophysiology showed that podoplanin deletion impairs dentate gyrus synaptic strengthening. In vivo, podoplanin deletion selectively impaired hippocampus-dependent spatial learning and memory without affecting amygdala-dependent cued fear conditioning. In vitro, neuronal overexpression of podoplanin promoted synaptic activity and neuritic outgrowth whereas podoplanin-deficient neurons exhibited stunted outgrowth and lower levels of p-Ezrin, TrkA, and CREB in response to nerve growth factor (NGF). Surface Plasmon Resonance data further indicated a physical interaction between podoplanin and NGF. DISCUSSION This work proposes podoplanin as a novel component of the neuronal machinery underlying neuritogenesis, synaptic plasticity, and hippocampus-dependent memory functions. The existence of a relevant cross-talk between podoplanin and the NGF/TrkA signaling pathway is also for the first time proposed here, thus providing a novel molecular complex as a target for future multidisciplinary studies of the brain function in the physiology and the pathology. Key messages Podoplanin, a protein linked to the promotion of human brain tumors, is required in vivo for proper hippocampus-dependent learning and memory functions. Deletion of podoplanin selectively impairs activity-dependent synaptic strengthening at the neurogenic dentate-gyrus and hampers neuritogenesis and phospho Ezrin, TrkA and CREB protein levels upon NGF stimulation. Surface plasmon resonance data indicates a physical interaction between podoplanin and NGF. On these grounds, a relevant cross-talk between podoplanin and NGF as well as a role for podoplanin in plasticity-related brain neuronal functions is here proposed.
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Affiliation(s)
- Ana Cicvaric
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Jiaye Yang
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Sigurd Krieger
- b Clinical Institute of Pathology , Medical University of Vienna , Vienna , Austria
| | - Deeba Khan
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Eun-Jung Kim
- c Paik Institute for Clinical Research, Inje University College of Medicine , Busan , Republic of Korea
| | - Manuel Dominguez-Rodriguez
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Maureen Cabatic
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Barbara Molz
- d Psychology University of York , Heslington York , UK
| | - Juan Pablo Acevedo Aguilar
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Radoslav Milicevic
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Tarik Smani
- e Grupo de Fisiopatología Cardiovascular, Instituto de Biomedicina de Sevilla (IBiS) , Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla , Seville , Spain
| | - Johannes M Breuss
- f Department of Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Dontscho Kerjaschki
- b Clinical Institute of Pathology , Medical University of Vienna , Vienna , Austria
| | - Daniela D Pollak
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Pavel Uhrin
- f Department of Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
| | - Francisco J Monje
- a Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology , Medical University of Vienna , Vienna , Austria
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