201
|
Xia M, Abazyan S, Jouroukhin Y, Pletnikov M. Behavioral sequelae of astrocyte dysfunction: focus on animal models of schizophrenia. Schizophr Res 2016; 176:72-82. [PMID: 25468180 PMCID: PMC4439390 DOI: 10.1016/j.schres.2014.10.044] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 10/29/2014] [Accepted: 10/31/2014] [Indexed: 12/12/2022]
Abstract
Astrocytes regulate multiple processes in the brain ranging from trophic support of developing neurons to modulation of synaptic neurotransmission and neuroinflammation in adulthood. It is, therefore, understandable that pathogenesis and pathophysiology of major psychiatric disorders involve astrocyte dysfunctions. Until recently, there has been the paucity of experimental approaches to studying the roles of astrocytes in behavioral disease. A new generation of in vivo models allows us to advance our understanding of the roles of astrocytes in psychiatric disorders. This review will evaluate the recent studies that focus on the contribution of astrocyte dysfunction to behavioral alterations pertinent to schizophrenia and will propose the possible solutions of the limitations of the existing approaches.
Collapse
Affiliation(s)
- Meng Xia
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine,Preclinical College, Guangxi University of Chinese Medicine, Nanning, 530001, Guangxi Province, China,Chinese Medicine College, Hubei University for Nationalities, ENSHI, 445000, Hubei Province, China
| | - Sofya Abazyan
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine
| | - Yan Jouroukhin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine
| | - Mikhail Pletnikov
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, United States; Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, United States; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, United States; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, United States.
| |
Collapse
|
202
|
Aman NA, Nagarajan G, Kang SW, Hancock M, Kuenzel WJ. Differential responses of the vasotocin 1a receptor (V1aR) and osmoreceptors to immobilization and osmotic stress in sensory circumventricular organs of the chicken (Gallus gallus) brain. Brain Res 2016; 1649:67-78. [PMID: 27559012 DOI: 10.1016/j.brainres.2016.08.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 08/18/2016] [Accepted: 08/20/2016] [Indexed: 02/06/2023]
Abstract
Past studies have shown that the avian vasotocin 1a receptor (V1aR) is involved in immobilization stress. It is not known whether the receptor functions in osmotic stress, and if sensory circumventricular organs may be involved. An experiment was designed with four treatment groups including a 1h immobilization acute stress (AS) group, an unstressed acute control (AC), a third given an intraperitoneal (ip) hypertonic saline injection (HS) and isotonic saline controls (IC) administered ip. One set of chick brains was perfused for immunohistochemistry while a second was sampled for quantitative RT-PCR. Plasma corticosterone (CORT) and arginine vasotocin (AVT) concentrations were significantly increased in the immobilized and hypertonic saline groups (p<0.01) compared to controls. Intense staining of the V1aR occurred throughout the organum vasculosum of the lamina terminalis (OVLT) and subseptal organ (SSO)/subfornical organ (SFO). The immunostaining allowed the boundaries of the two circumventricular organs (CVOs) to be described for the first time in avian species. Both treatment groups showed marked morphological changes in glia within the OVLT and SSO/SFO. The avian V1aR, angiotensin II type 1 receptor (AT1R), and transient receptor potential vanilloid receptor 1 (TRPV1) mRNA levels were increased in the SSO/SFO in hypertonic saline treated birds compared to isotonic controls. In contrast, the latter two genes (AT1R and TRPV1) were significantly decreased in the OVLT of birds subjected to hyperosmotic stress, while all three genes were significantly up-regulated after immobilization. Taken together, results show a possible differential function for the same receptors in two anatomically adjacent CVOs.
Collapse
Affiliation(s)
- N Alphonse Aman
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Gurueswar Nagarajan
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Seong W Kang
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Megan Hancock
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Wayne J Kuenzel
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR, USA.
| |
Collapse
|
203
|
Astroglial calcium signalling in Alzheimer's disease. Biochem Biophys Res Commun 2016; 483:1005-1012. [PMID: 27545605 DOI: 10.1016/j.bbrc.2016.08.088] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/15/2016] [Indexed: 12/14/2022]
Abstract
Neuroglial contribution to Alzheimer's disease (AD) is pathologically relevant and highly heterogeneous. Reactive astrogliosis and activation of microglia contribute to neuroinflammation, whereas astroglial and oligodendroglial atrophy affect synaptic transmission and underlie the overall disruption of the central nervous system (CNS) connectome. Astroglial function is tightly integrated with the intracellular ionic signalling mediated by complex dynamics of cytosolic concentrations of free Ca2+ and Na+. Astroglial ionic signalling is mediated by plasmalemmal ion channels, mainly associated with ionotropic receptors, pumps and solute carrier transporters, and by intracellular organelles comprised of the endoplasmic reticulum and mitochondria. The relative contribution of these molecular cascades/organelles can be plastically remodelled in development and under environmental stress. In AD astroglial Ca2+ signalling undergoes substantial reorganisation due to an abnormal regulation of expression of Ca2+ handling molecular cascades.
Collapse
|
204
|
Cunha RA. How does adenosine control neuronal dysfunction and neurodegeneration? J Neurochem 2016; 139:1019-1055. [PMID: 27365148 DOI: 10.1111/jnc.13724] [Citation(s) in RCA: 312] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022]
Abstract
The adenosine modulation system mostly operates through inhibitory A1 (A1 R) and facilitatory A2A receptors (A2A R) in the brain. The activity-dependent release of adenosine acts as a brake of excitatory transmission through A1 R, which are enriched in glutamatergic terminals. Adenosine sharpens salience of information encoding in neuronal circuits: high-frequency stimulation triggers ATP release in the 'activated' synapse, which is locally converted by ecto-nucleotidases into adenosine to selectively activate A2A R; A2A R switch off A1 R and CB1 receptors, bolster glutamate release and NMDA receptors to assist increasing synaptic plasticity in the 'activated' synapse; the parallel engagement of the astrocytic syncytium releases adenosine further inhibiting neighboring synapses, thus sharpening the encoded plastic change. Brain insults trigger a large outflow of adenosine and ATP, as a danger signal. A1 R are a hurdle for damage initiation, but they desensitize upon prolonged activation. However, if the insult is near-threshold and/or of short-duration, A1 R trigger preconditioning, which may limit the spread of damage. Brain insults also up-regulate A2A R, probably to bolster adaptive changes, but this heightens brain damage since A2A R blockade affords neuroprotection in models of epilepsy, depression, Alzheimer's, or Parkinson's disease. This initially involves a control of synaptotoxicity by neuronal A2A R, whereas astrocytic and microglia A2A R might control the spread of damage. The A2A R signaling mechanisms are largely unknown since A2A R are pleiotropic, coupling to different G proteins and non-canonical pathways to control the viability of glutamatergic synapses, neuroinflammation, mitochondria function, and cytoskeleton dynamics. Thus, simultaneously bolstering A1 R preconditioning and preventing excessive A2A R function might afford maximal neuroprotection. The main physiological role of the adenosine modulation system is to sharp the salience of information encoding through a combined action of adenosine A2A receptors (A2A R) in the synapse undergoing an alteration of synaptic efficiency with an increased inhibitory action of A1 R in all surrounding synapses. Brain insults trigger an up-regulation of A2A R in an attempt to bolster adaptive plasticity together with adenosine release and A1 R desensitization; this favors synaptotocity (increased A2A R) and decreases the hurdle to undergo degeneration (decreased A1 R). Maximal neuroprotection is expected to result from a combined A2A R blockade and increased A1 R activation. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
Collapse
Affiliation(s)
- Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| |
Collapse
|
205
|
Ceyzériat K, Abjean L, Carrillo-de Sauvage MA, Ben Haim L, Escartin C. The complex STATes of astrocyte reactivity: How are they controlled by the JAK–STAT3 pathway? Neuroscience 2016; 330:205-18. [DOI: 10.1016/j.neuroscience.2016.05.043] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/19/2016] [Accepted: 05/19/2016] [Indexed: 01/05/2023]
|
206
|
Sica RE, Caccuri R, Quarracino C, Capani F. Are astrocytes executive cells within the central nervous system? ARQUIVOS DE NEURO-PSIQUIATRIA 2016; 74:671-8. [DOI: 10.1590/0004-282x20160101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 03/16/2016] [Indexed: 11/22/2022]
Abstract
ABSTRACT Experimental evidence suggests that astrocytes play a crucial role in the physiology of the central nervous system (CNS) by modulating synaptic activity and plasticity. Based on what is currently known we postulate that astrocytes are fundamental, along with neurons, for the information processing that takes place within the CNS. On the other hand, experimental findings and human observations signal that some of the primary degenerative diseases of the CNS, like frontotemporal dementia, Parkinson’s disease, Alzheimer’s dementia, Huntington’s dementia, primary cerebellar ataxias and amyotrophic lateral sclerosis, all of which affect the human species exclusively, may be due to astroglial dysfunction. This hypothesis is supported by observations that demonstrated that the killing of neurons by non-neural cells plays a major role in the pathogenesis of those diseases, at both their onset and their progression. Furthermore, recent findings suggest that astrocytes might be involved in the pathogenesis of some psychiatric disorders as well.
Collapse
|
207
|
Scofield MD, Li H, Siemsen B, Healey KL, Tran PK, Woronoff N, Boger HA, Kalivas PW, Reissner KJ. Cocaine Self-Administration and Extinction Leads to Reduced Glial Fibrillary Acidic Protein Expression and Morphometric Features of Astrocytes in the Nucleus Accumbens Core. Biol Psychiatry 2016; 80:207-15. [PMID: 26946381 PMCID: PMC4930433 DOI: 10.1016/j.biopsych.2015.12.022] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/02/2015] [Accepted: 12/17/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND As a more detailed picture of nervous system function emerges, diversity of astrocyte function becomes more widely appreciated. While it has been shown that cocaine experience impairs astroglial glutamate uptake and release in the nucleus accumbens (NAc), few studies have explored effects of self-administration on the structure and physiology of astrocytes. We investigated the effects of extinction from daily cocaine self-administration on astrocyte characteristics including glial fibrillary acidic protein (GFAP) expression, surface area, volume, and colocalization with a synaptic marker. METHODS Cocaine or saline self-administration and extinction were paired with GFAP Westerns, immunohistochemistry, and fluorescent imaging of NAc core astrocytes (30 saline-administering and 36 cocaine-administering male Sprague Dawley rats were employed). Imaging was performed using a membrane-tagged lymphocyte protein tyrosine kinase-green fluorescent protein (Lck-GFP) driven by the GFAP promoter, coupled with synapsin I immunohistochemistry. RESULTS GFAP expression was significantly reduced in the NAc core following cocaine self-administration and extinction. Similarly, we observed an overall smaller surface area and volume of astrocytes, as well as reduced colocalization with synapsin I, in cocaine-administering animals. Cocaine-mediated reductions in synaptic contact were reversed by the β-lactam antibiotic ceftriaxone. CONCLUSIONS Multiple lines of investigation indicate that NAc core astrocytes exist in a hyporeactive state following cocaine self-administration and extinction. Decreased association with synaptic elements may be particularly meaningful, as cessation of chronic cocaine use is associated with changes in synaptic strength and resistance to the induction of synaptic plasticity. We hypothesize that the reduced synaptic colocalization of astrocytes represents an important maladaptive cellular response to cocaine and the mechanisms underlying relapse vulnerability.
Collapse
Affiliation(s)
- Michael D. Scofield
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Hao Li
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Benjamin Siemsen
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Kati L. Healey
- Department of Psychology and Neuroscience, UNC Chapel Hill, Chapel Hill, NC
| | - Phuong K. Tran
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Nicholas Woronoff
- Department of Psychology and Neuroscience, UNC Chapel Hill, Chapel Hill, NC
| | - Heather A. Boger
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Peter W. Kalivas
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Kathryn J. Reissner
- Department of Psychology and Neuroscience, UNC Chapel Hill, Chapel Hill, NC,Department of Psychology and Neuroscience, UNC Chapel Hill, Chapel Hill, NC
| |
Collapse
|
208
|
Astrocyte Aquaporin Dynamics in Health and Disease. Int J Mol Sci 2016; 17:ijms17071121. [PMID: 27420057 PMCID: PMC4964496 DOI: 10.3390/ijms17071121] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/07/2016] [Accepted: 07/07/2016] [Indexed: 02/01/2023] Open
Abstract
The family of aquaporins (AQPs), membrane water channels, consists of diverse types of proteins that are mainly permeable to water; some are also permeable to small solutes, such as glycerol and urea. They have been identified in a wide range of organisms, from microbes to vertebrates and plants, and are expressed in various tissues. Here, we focus on AQP types and their isoforms in astrocytes, a major glial cell type in the central nervous system (CNS). Astrocytes have anatomical contact with the microvasculature, pia, and neurons. Of the many roles that astrocytes have in the CNS, they are key in maintaining water homeostasis. The processes involved in this regulation have been investigated intensively, in particular regulation of the permeability and expression patterns of different AQP types in astrocytes. Three aquaporin types have been described in astrocytes: aquaporins AQP1 and AQP4 and aquaglyceroporin AQP9. The aim here is to review their isoforms, subcellular localization, permeability regulation, and expression patterns in the CNS. In the human CNS, AQP4 is expressed in normal physiological and pathological conditions, but astrocytic expression of AQP1 and AQP9 is mainly associated with a pathological state.
Collapse
|
209
|
Astroglial connexin43 contributes to neuronal suffering in a mouse model of Alzheimer's disease. Cell Death Differ 2016; 23:1691-701. [PMID: 27391799 DOI: 10.1038/cdd.2016.63] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/19/2016] [Accepted: 05/25/2016] [Indexed: 01/15/2023] Open
Abstract
In Alzheimer's disease (AD), astrocyte properties are modified but their involvement in this pathology is only beginning to be appreciated. The expression of connexins, proteins forming gap junction channels and hemichannels, is increased in astrocytes contacting amyloid plaques in brains of AD patients and APP/PS1 mice. The consequences on their channel functions was investigated in a murine model of familial AD, the APPswe/PS1dE9 mice. Whereas gap junctional communication was not affected, we revealed that hemichannels were activated in astrocytes of acute hippocampal slices containing Aβ plaques. Such hemichannel activity was detected in all astrocytes, whatever their distance from amyloid plaques, but with an enhanced activity in the reactive astrocytes contacting amyloid plaques. Connexin43 was the main hemichannel contributor, however, a minor pannexin1 component was also identified in the subpopulation of reactive astrocytes in direct contact with plaques. Distinct regulatory pathways are involved in connexin and pannexin hemichannel activation. Inflammation triggered pannexin hemichannel activity, whereas connexin43 hemichannels were activated by the increase in resting calcium level of astrocytes. Importantly, hemichannel activation led to the release of ATP and glutamate that contributed to maintain a high calcium level in astrocytes placing them in the center of a vicious circle. The astroglial targeted connexin43 gene knocking-out in APPswe/PS1dE9 mice allowed to diminish gliotransmitter release and to alleviate neuronal damages, reducing oxidative stress and neuritic dystrophies in hippocampal neurons associated to plaques. Altogether, these data highlight the importance of astroglial hemichannels in AD and suggest that blocking astroglial hemichannel activity in astrocytes could represent an alternative therapeutic strategy in AD.
Collapse
|
210
|
De Simone U, Lonati D, Ronchi A, Coccini T. Brief exposure to nanosized and bulk titanium dioxide forms induces subtle changes in human D384 astrocytes. Toxicol Lett 2016; 254:8-21. [DOI: 10.1016/j.toxlet.2016.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/02/2016] [Accepted: 05/02/2016] [Indexed: 01/09/2023]
|
211
|
Yu S, Wang X, He X, Wang Y, Gao S, Ren L, Shi Y. Curcumin exerts anti-inflammatory and antioxidative properties in 1-methyl-4-phenylpyridinium ion (MPP(+))-stimulated mesencephalic astrocytes by interference with TLR4 and downstream signaling pathway. Cell Stress Chaperones 2016; 21:697-705. [PMID: 27164829 PMCID: PMC4908001 DOI: 10.1007/s12192-016-0695-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/12/2016] [Accepted: 04/23/2016] [Indexed: 01/01/2023] Open
Abstract
Neuroinflammation is closely associated with the pathophysiology of neurodegenerative diseases including Parkinson's disease (PD). Recent evidence indicates that astrocytes also play pro-inflammatory roles in the central nervous system (CNS) by activation with toll-like receptor (TLR) ligands. Therefore, targeting anti-inflammation may provide a promising therapeutic strategy for PD. Curcumin, a polyphenolic compound isolated from Curcuma longa root, has been commonly used for the treatment of neurodegenerative diseases. However, the details of how curcumin exerts neuroprotection remain uncertain. Here, we investigated the protective effect of curcumin on 1-methyl-4-phenylpyridinium ion-(MPP(+)-) stimulated primary astrocytes. Our results showed that MPP(+) stimulation resulted in significant production of tumor necrosis factor (TNF)-α, interleukin (IL-6), and reactive oxygen species (ROS) in primary mesencephalic astrocytes. Curcumin pretreatment decreased the levels of these pro-inflammatory cytokines while increased IL-10 expression in MPP(+)-stimulated astrocytes. In addition, curcumin increased the levels of antioxidant glutathione (GSH) and reduced ROS production. Our results further showed that curcumin decreased the levels of TLR4 and its downstream effectors including NF-κB, IRF3, MyD88, and TIRF that are induced by MPP(+) as well as inhibited the immunoreactivity of TLR4 and morphological activation in MPP(+)-stimulated astrocytes. Together, data suggest that curcumin might exert a beneficial effect on neuroinflammation in the pathophysiology of PD.
Collapse
Affiliation(s)
- Song Yu
- Department of Histology and Embryology, Liaoning University of Traditional Chinese Medicine, Shenyang, Liaoning, 110847, People's Republic of China
| | - Xu Wang
- Department of Histology and Embryology, Liaoning University of Traditional Chinese Medicine, Shenyang, Liaoning, 110847, People's Republic of China
| | - Xingliang He
- Department of Sports Medicine, Shenyang Sports University, Shenyang, Liaoning, 110102, People's Republic of China
| | - Yue Wang
- Department of Histology and Embryology, Liaoning University of Traditional Chinese Medicine, Shenyang, Liaoning, 110847, People's Republic of China
| | - Sujie Gao
- Department of Cardiac Function, The Second Staff Hospital of Liaohe Oilfield Company, Panjin, Liaoning, 124011, People's Republic of China
| | - Lu Ren
- Department of Mental Diseases, Liaoning University of Traditional Chinese Medicine, Shenyang, Liaoning, 110847, People's Republic of China
| | - Yan Shi
- Department of Internal Medicine of Traditional Chinese Medicine, Liaoning University of Traditional Chinese Medicine, 79 East Chongshan Road, Shenyang, Liaoning, 110847, People's Republic of China.
| |
Collapse
|
212
|
Blockade of Astrocytic Calcineurin/NFAT Signaling Helps to Normalize Hippocampal Synaptic Function and Plasticity in a Rat Model of Traumatic Brain Injury. J Neurosci 2016; 36:1502-15. [PMID: 26843634 DOI: 10.1523/jneurosci.1930-15.2016] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED Increasing evidence suggests that the calcineurin (CN)-dependent transcription factor NFAT (Nuclear Factor of Activated T cells) mediates deleterious effects of astrocytes in progressive neurodegenerative conditions. However, the impact of astrocytic CN/NFAT signaling on neural function/recovery after acute injury has not been investigated extensively. Using a controlled cortical impact (CCI) procedure in rats, we show that traumatic brain injury is associated with an increase in the activities of NFATs 1 and 4 in the hippocampus at 7 d after injury. NFAT4, but not NFAT1, exhibited extensive labeling in astrocytes and was found throughout the axon/dendrite layers of CA1 and the dentate gyrus. Blockade of the astrocytic CN/NFAT pathway in rats using adeno-associated virus (AAV) vectors expressing the astrocyte-specific promoter Gfa2 and the NFAT-inhibitory peptide VIVIT prevented the injury-related loss of basal CA1 synaptic strength and key synaptic proteins and reduced the susceptibility to induction of long-term depression. In conjunction with these seemingly beneficial effects, VIVIT treatment elicited a marked increase in the expression of the prosynaptogenic factor SPARCL1 (hevin), especially in hippocampal tissue ipsilateral to the CCI injury. However, in contrast to previous work on Alzheimer's mouse models, AAV-Gfa2-VIVIT had no effects on the levels of GFAP and Iba1, suggesting that synaptic benefits of VIVIT were not attributable to a reduction in glial activation per se. Together, the results implicate the astrocytic CN/NFAT4 pathway as a key mechanism for disrupting synaptic remodeling and homeostasis in the hippocampus after acute injury. SIGNIFICANCE STATEMENT Similar to microglia, astrocytes become strongly "activated" with neural damage and exhibit numerous morphologic/biochemical changes, including an increase in the expression/activity of the protein phosphatase calcineurin. Using adeno-associated virus (AAV) to inhibit the calcineurin-dependent activation of the transcription factor NFAT (Nuclear Factor of Activated T cells) selectively, we have shown that activated astrocytes contribute to neural dysfunction in animal models characterized by progressive/chronic neuropathology. Here, we show that the suppression of astrocytic calcineurin/NFATs helps to protect synaptic function and plasticity in an animal model in which pathology arises from a single traumatic brain injury. The findings suggest that at least some astrocyte functions impair recovery after trauma and may provide druggable targets for treating victims of acute nervous system injury.
Collapse
|
213
|
Sadigh-Eteghad S, Majdi A, Mahmoudi J, Golzari SEJ, Talebi M. Astrocytic and microglial nicotinic acetylcholine receptors: an overlooked issue in Alzheimer's disease. J Neural Transm (Vienna) 2016; 123:1359-1367. [PMID: 27262818 DOI: 10.1007/s00702-016-1580-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/27/2016] [Indexed: 02/01/2023]
Abstract
It is increasingly recognized that astrocytes and microglia-associated dysfunction contribute to AD pathology. In addition, glial nicotinic acetylcholine receptors (nAChRs) play a role in AD-related phenomena, such as neuron survival, synaptic plasticity, and memory. From mechanistic point of view, the glial regulation of pro-inflammatory cytokines, as common contributors in AD, is modulated by nAChRs. Astrocytic and microglial nAChRs contribute to Aβ metabolism, including Aβ phagocytosis and degradation as well as Aβ-related oxidative stress and neurotoxicity. These receptors are also involved in neurotransmission and gliotransmission through indirect interaction with N-Methyl-D-aspartate (NMDA) and a-amino-3-hydroxy-5-methyl-4 isoxazolepropionic acid (AMPA) receptors as well as gamma-aminobutyric acid (GABA) and intracellular calcium regulation. In addition, glial nAChRs participate in trophic factors-induced neuroprotection. This review gathers the most recent advances along with the previous data on astrocytic and microglial nAChRs role in AD pathogenesis.
Collapse
Affiliation(s)
- Saeed Sadigh-Eteghad
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alireza Majdi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Javad Mahmoudi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Samad E J Golzari
- Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahnaz Talebi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
214
|
Kaminsky N, Bihari O, Kanner S, Barzilai A. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders. GENOMICS, PROTEOMICS & BIOINFORMATICS 2016; 14:155-165. [PMID: 27245308 PMCID: PMC4936608 DOI: 10.1016/j.gpb.2016.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/19/2022]
Abstract
The DNA damage response (DDR) is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to genomic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evidence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes). Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a "hostile" environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit.
Collapse
Affiliation(s)
- Natalie Kaminsky
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ofer Bihari
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sivan Kanner
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Ari Barzilai
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
| |
Collapse
|
215
|
Fukushi I, Takeda K, Yokota S, Hasebe Y, Sato Y, Pokorski M, Horiuchi J, Okada Y. Effects of arundic acid, an astrocytic modulator, on the cerebral and respiratory functions in severe hypoxia. Respir Physiol Neurobiol 2016; 226:24-9. [DOI: 10.1016/j.resp.2015.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 12/18/2022]
|
216
|
Ajit D, Simonyi A, Li R, Chen Z, Hannink M, Fritsche KL, Mossine VV, Smith RE, Dobbs TK, Luo R, Folk WR, Gu Z, Lubahn DB, Weisman GA, Sun GY. Phytochemicals and botanical extracts regulate NF-κB and Nrf2/ARE reporter activities in DI TNC1 astrocytes. Neurochem Int 2016; 97:49-56. [PMID: 27166148 DOI: 10.1016/j.neuint.2016.05.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/29/2016] [Accepted: 05/03/2016] [Indexed: 11/19/2022]
Abstract
The increase in oxidative stress and inflammatory responses associated with neurodegenerative diseases has drawn considerable attention towards understanding the transcriptional signaling pathways involving NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and Nrf2 (Nuclear Factor Erythroid 2-like 2). Our recent studies with immortalized murine microglial cells (BV-2) demonstrated effects of botanical polyphenols to inhibit lipopolysaccharide (LPS)-induced nitric oxide (NO) and enhance Nrf2-mediated antioxidant responses (Sun et al., 2015). In this study, an immortalized rat astrocyte (DI TNC1) cell line expressing a luciferase reporter driven by the NF-κB or the Nrf2/Antioxidant Response Element (ARE) promoter was used to assess regulation of these two pathways by phytochemicals such as quercetin, rutin, cyanidin, cyanidin-3-O-glucoside, as well as botanical extracts from Withania somnifera (Ashwagandha), Sutherlandia frutescens (Sutherlandia) and Euterpe oleracea (Açaí). Quercetin effectively inhibited LPS-induced NF-κB reporter activity and stimulated Nrf2/ARE reporter activity in DI TNC1 astrocytes. Cyanidin and the glycosides showed similar effects but only at much higher concentrations. All three botanical extracts effectively inhibited LPS-induced NF-κB reporter activity. These extracts were capable of enhancing ARE activity by themselves and further enhanced ARE activity in the presence of LPS. Quercetin and botanical extracts induced Nrf2 and HO-1 protein expression. Interestingly, Ashwagandha extract was more active in inducing Nrf2 and HO-1 expression in DI TNC1 astrocytes as compared to Sutherlandia and Açaí extracts. In summary, this study demonstrated NF-kB and Nrf2/ARE promoter activities in DI TNC1 astrocytes, and further showed differences in ability for specific botanical polyphenols and extracts to down-regulate LPS-induced NF-kB and up-regulate the NRF2/ARE activities in these cells.
Collapse
Affiliation(s)
- Deepa Ajit
- Biochemistry Department, University of Missouri, Columbia, MO, USA
| | - Agnes Simonyi
- Biochemistry Department, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | - Runting Li
- Biochemistry Department, University of Missouri, Columbia, MO, USA
| | - Zihong Chen
- Biochemistry Department, University of Missouri, Columbia, MO, USA
| | - Mark Hannink
- Biochemistry Department, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | - Kevin L Fritsche
- Department of Animal Sciences, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | - Valeri V Mossine
- Biochemistry Department, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | | | | | - Rensheng Luo
- Department of Chemistry and Biochemistry, University of Missouri, St. Louis, MO, USA
| | - William R Folk
- Biochemistry Department, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | - Zezong Gu
- Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | - Dennis B Lubahn
- Biochemistry Department, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA
| | - Gary A Weisman
- Biochemistry Department, University of Missouri, Columbia, MO, USA
| | - Grace Y Sun
- Biochemistry Department, University of Missouri, Columbia, MO, USA; Center for Botanical Interaction Studies, University of Missouri, Columbia, MO, USA.
| |
Collapse
|
217
|
Astrocytes in physiological aging and Alzheimer’s disease. Neuroscience 2016; 323:170-82. [DOI: 10.1016/j.neuroscience.2015.01.007] [Citation(s) in RCA: 266] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/02/2015] [Accepted: 01/06/2015] [Indexed: 12/20/2022]
|
218
|
Nardin P, Zanotto C, Hansen F, Batassini C, Gasparin MS, Sesterheim P, Gonçalves CA. Peripheral Levels of AGEs and Astrocyte Alterations in the Hippocampus of STZ-Diabetic Rats. Neurochem Res 2016; 41:2006-16. [PMID: 27084774 DOI: 10.1007/s11064-016-1912-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 12/25/2022]
Abstract
Diabetic patients and streptozotocin (STZ)-induced diabetes mellitus (DM) models exhibit signals of brain dysfunction, evidenced by neuronal damage and memory impairment. Astrocytes surrounding capillaries and synapses modulate many brain activities that are connected to neuronal function, such as nutrient flux and glutamatergic neurotransmission. As such, cognitive changes observed in diabetic patients and experimental models could be related to astroglial alterations. Herein, we investigate specific astrocyte changes in the rat hippocampus in a model of DM induced by STZ, particularly looking at glial fibrillary acidic protein (GFAP), S100B protein and glutamate uptake, as well as the content of advanced glycated end products (AGEs) in serum and cerebrospinal fluid (CSF), as a consequence of elevated hyperglycemia and the content of receptor for AGEs in the hippocampus. We found clear peripheral alterations, including hyperglycemia, low levels of proinsulin C-peptide, elevated levels of AGEs in serum and CSF, as well as an increase in RAGE in hippocampal tissue. We found specific astroglial abnormalities in this brain region, such as reduced S100B content, reduced glutamate uptake and increased S100B secretion, which were not accompanied by changes in GFAP. We also observed an increase in the glucose transporter, GLUT-1. All these changes may result from RAGE-induced inflammation; these astroglial alterations together with the reduced content of GluN1, a subunit of the NMDA receptor, in the hippocampus may be associated with the impairment of glutamatergic communication in diabetic rats. These findings contribute to understanding the cognitive deficits in diabetic patients and experimental models.
Collapse
Affiliation(s)
- Patrícia Nardin
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil.
| | - Caroline Zanotto
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Fernanda Hansen
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Cristiane Batassini
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Manuela Sangalli Gasparin
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| | - Patrícia Sesterheim
- Centro de Desenvolvimento Científico e Tecnológico, Fundação Estadual de Produção e Pesquisa em Saúde, Porto Alegre, Brazil
| | - Carlos-Alberto Gonçalves
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600-Anexo, Porto Alegre, RS, 90035-003, Brazil
| |
Collapse
|
219
|
Wang LL, Shi DL, Gu HY, Zheng MZ, Hu J, Song XH, Shen YL, Chen YY. Resveratrol attenuates inflammatory hyperalgesia by inhibiting glial activation in mice spinal cords. Mol Med Rep 2016; 13:4051-7. [PMID: 27035673 DOI: 10.3892/mmr.2016.5027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 03/04/2016] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to investigate the effect of resveratrol on inflammatory pain. Mice were injected intraperitoneally with lipopolysaccharide (LPS) for 5 consecutive days to induce subacute systemic inflammation. Acetic acid‑induced writhing tests and tail‑flick tests were performed following the final LPS injection. Glial fibrillary acidic protein (GFAP; an astrocyte‑specific activation marker), ionized calcium binding adapter molecule 1 (Iba‑1; a microglia‑specific activation marker) and sirtuin 1 (SIRT1) protein expression levels were detected using immunohistochemistry analysis or western blotting. Following administration of LPS for 5 days, the number of writhes increased and the tail‑flick latency decreased. Resveratrol (10 or 20 mg/kg) partly inhibited LPS‑induced hyperalgesia and prevented the increase in tumor necrosis factor‑α and interleukin 6 levels induced by LPS. LPS injection reduced the SIRT1 protein expression and increased the number of GFAP‑positive and Iba‑1‑positive cells in the spinal cord. Resveratrol increased the SIRT1 protein expression levels and decreased the number of GFAP‑positive and Iba‑1‑positive cells in LPS‑treated mice. The protective effect of resveratrol was partly blocked by a selective SIRT1 inhibitor, EX‑257. Results from the present study suggest that subacute treatment with LPS induced the activation of glial cells and hyperalgesia. Resveratrol was demonstrated to inhibit the activation of glial cells and attenuate inflammatory hyperalgesia in a SIRT1‑dependent manner.
Collapse
Affiliation(s)
- Lin-Lin Wang
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Dong-Ling Shi
- Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Hui-Yao Gu
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Ming-Zhi Zheng
- Department of Pharmacology, Zhejiang Medical College, Hangzhou, Zhejiang 310053, P.R. China
| | - Jue Hu
- Department of Pharmacology, Zhejiang Medical College, Hangzhou, Zhejiang 310053, P.R. China
| | - Xing-Hui Song
- Core Facilities, Department of Basic Medical Sciences, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Yue-Liang Shen
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Ying-Ying Chen
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| |
Collapse
|
220
|
Impact of Plant-Derived Flavonoids on Neurodegenerative Diseases. Neurotox Res 2016; 30:41-52. [PMID: 26951456 DOI: 10.1007/s12640-016-9600-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/24/2015] [Accepted: 01/21/2016] [Indexed: 12/27/2022]
Abstract
Neurodegenerative disorders have a common characteristic that is the involvement of different cell types, typically the reactivity of astrocytes and microglia, characterizing gliosis, which in turn contributes to the neuronal dysfunction and or death. Flavonoids are secondary metabolites of plant origin widely investigated at present and represent one of the most important and diversified among natural products phenolic groups. Several biological activities are attributed to this class of polyphenols, such as antitumor activity, antioxidant, antiviral, and anti-inflammatory, among others, which give significant pharmacological importance. Our group have observed that flavonoids derived from Brazilian plants Dimorphandra mollis Bent., Croton betulaster Müll. Arg., e Poincianella pyramidalis Tul., botanical synonymous Caesalpinia pyramidalis Tul. also elicit a broad spectrum of responses in astrocytes and neurons in culture as activation of astrocytes and microglia, astrocyte associated protection of neuronal progenitor cells, neuronal differentiation and neuritogenesis. It was observed the flavonoids also induced neuronal differentiation of mouse embryonic stem cells and human pluripotent stem cells. Moreover, with the objective of seeking preclinical pharmacological evidence of these molecules, in order to assess its future use in the treatment of neurodegenerative disorders, we have evaluated the effects of flavonoids in preclinical in vitro models of neuroinflammation associated with Parkinson's disease and glutamate toxicity associated with ischemia. In particular, our efforts have been directed to identify mechanisms involved in the changes in viability, morphology, and glial cell function induced by flavonoids in cultures of glial cells and neuronal cells alone or in interactions and clarify the relation with their neuroprotective and morphogetic effects.
Collapse
|
221
|
Elmann A, Telerman A, Erlank H, Ofir R, Kashman Y, Beit-Yannai E. Achillolide A Protects Astrocytes against Oxidative Stress by Reducing Intracellular Reactive Oxygen Species and Interfering with Cell Signaling. Molecules 2016; 21:301. [PMID: 26950103 PMCID: PMC6274406 DOI: 10.3390/molecules21030301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 11/17/2022] Open
Abstract
Achillolide A is a natural sesquiterpene lactone that we have previously shown can inhibit microglial activation. In this study we present evidence for its beneficial effects on astrocytes under oxidative stress, a situation relevant to neurodegenerative diseases and brain injuries. Viability of brain astrocytes (primary cultures) was determined by lactate dehydrogenase (LDH) activity, intracellular ROS levels were detected using 2',7'-dichlorofluorescein diacetate, in vitro antioxidant activity was measured by differential pulse voltammetry, and protein phosphorylation was determined using specific ELISA kits. We have found that achillolide A prevented the H₂O₂-induced death of astrocytes, and attenuated the induced intracellular accumulation of reactive oxygen species (ROS). These activities could be attributed to the inhibition of the H₂O₂-induced phosphorylation of MAP/ERK kinase 1 (MEK1) and p44/42 mitogen-activated protein kinases (MAPK), and to the antioxidant activity of achillolide A, but not to H₂O₂ scavenging. This is the first study that demonstrates its protective effects on brain astrocytes, and its ability to interfere with MAPK activation. We propose that achillolide A deserves further evaluation for its potential to be developed as a drug for the prevention/treatment of neurodegenerative diseases and brain injuries where oxidative stress is part of the pathophysiology.
Collapse
Affiliation(s)
- Anat Elmann
- Department of Food Quality and Safety, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel.
| | - Alona Telerman
- Department of Food Quality and Safety, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel.
| | - Hilla Erlank
- Department of Food Quality and Safety, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel.
| | - Rivka Ofir
- Dead Sea & Arava Science Center and Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheba 84105, Israel.
| | - Yoel Kashman
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of chemistry, Tel Aviv University, Ramat Aviv 69978, Israel.
| | - Elie Beit-Yannai
- Clinical Biochemistry and Pharmacology Department, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheba 84105, Israel.
| |
Collapse
|
222
|
Astrocytes: a central element in neurological diseases. Acta Neuropathol 2016; 131:323-45. [PMID: 26671410 DOI: 10.1007/s00401-015-1513-1] [Citation(s) in RCA: 531] [Impact Index Per Article: 66.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/28/2015] [Accepted: 11/21/2015] [Indexed: 12/18/2022]
Abstract
The neurone-centred view of the past disregarded or downplayed the role of astroglia as a primary component in the pathogenesis of neurological diseases. As this concept is changing, so is also the perceived role of astrocytes in the healthy and diseased brain and spinal cord. We have started to unravel the different signalling mechanisms that trigger specific molecular, morphological and functional changes in reactive astrocytes that are critical for repairing tissue and maintaining function in CNS pathologies, such as neurotrauma, stroke, or neurodegenerative diseases. An increasing body of evidence shows that the effects of astrogliosis on the neural tissue and its functions are not uniform or stereotypic, but vary in a context-specific manner from astrogliosis being an adaptive beneficial response under some circumstances to a maladaptive and deleterious process in another context. There is a growing support for the concept of astrocytopathies in which the disruption of normal astrocyte functions, astrodegeneration or dysfunctional/maladaptive astrogliosis are the primary cause or the main factor in neurological dysfunction and disease. This review describes the multiple roles of astrocytes in the healthy CNS, discusses the diversity of astroglial responses in neurological disorders and argues that targeting astrocytes may represent an effective therapeutic strategy for Alexander disease, neurotrauma, stroke, epilepsy and Alzheimer's disease as well as other neurodegenerative diseases.
Collapse
|
223
|
Reactive gliosis in the pathogenesis of CNS diseases. Biochim Biophys Acta Mol Basis Dis 2016; 1862:483-91. [DOI: 10.1016/j.bbadis.2015.11.014] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 01/11/2023]
|
224
|
Bowers MS, Jackson A, Maldoon PP, Damaj MI. N-acetylcysteine decreased nicotine reward-like properties and withdrawal in mice. Psychopharmacology (Berl) 2016; 233:995-1003. [PMID: 26676982 PMCID: PMC4819399 DOI: 10.1007/s00213-015-4179-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/02/2015] [Indexed: 12/26/2022]
Abstract
RATIONALE N-acetylcysteine can increase extrasynaptic glutamate and reduce nicotine self-administration in rats and smoking rates in humans. OBJECTIVES The aim of this study was to determine if N-acetylcysteine modulates the development of nicotine place conditioning and withdrawal in mice. METHODS N-acetylcysteine was given to nicotine-treated male ICR mice. Experiment 1: reward-like behavior. N-acetylcysteine (0, 5, 15, 30, or 60 mg/kg, i.p.) was given 15 min before nicotine (0.5 mg/kg, s.c.) or saline (10 ml/kg, s.c.) in an unbiased conditioned place preference (CPP) paradigm. Conditioning for highly palatable food served as control. Experiment 2: spontaneous withdrawal. The effect of N-acetylcysteine (0, 15, 30, 120 mg/kg, i.p.) on anxiety-like behavior, somatic signs, and hyperalgesia was measured 18-24 h after continuous nicotine (24 mg/kg/day, 14 days). Experiment 3: mecamylamine-precipitated, withdrawal-induced aversion. The effect of N-acetylcysteine (0, 15, 30, 120 mg/kg, i.p.) on mecamylamine (3.5 mg/kg, i.p.)-precipitated withdrawal was determined after continuous nicotine (24 mg/kg, i.p., 28 days) using the conditioned place aversion (CPA) paradigm. RESULTS Dose-related reductions in the development of nicotine CPP, somatic withdrawal signs, hyperalgesia, and CPA were observed after N-acetylcysteine pretreatment. No effect of N-acetylcysteine was found on palatable food CPP, anxiety-like behavior, or motoric capacity (crosses between plus maze arms). Finally, N-acetylcysteine did not affect any measure in saline-treated mice at doses effective in nicotine-treated mice. CONCLUSIONS These are the first data suggesting that N-acetylcysteine blocks specific mouse behaviors associated with nicotine reward and withdrawal, which adds to the growing appreciation that N-acetylcysteine may have high clinical utility in combating nicotine dependence.
Collapse
Affiliation(s)
- M S Bowers
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA.
- Virginia Institute for Psychiatric and Behavioral Genetics Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, 23298, USA.
| | - A Jackson
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - P P Maldoon
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - M I Damaj
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| |
Collapse
|
225
|
Glutamate and ATP at the Interface Between Signaling and Metabolism in Astroglia: Examples from Pathology. Neurochem Res 2016; 42:19-34. [PMID: 26915104 DOI: 10.1007/s11064-016-1848-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/17/2022]
Abstract
Glutamate is the main excitatory transmitter in the brain, while ATP represents the most important energy currency in any living cell. Yet, these chemicals play an important role in both processes, enabling them with dual-acting functions in metabolic and intercellular signaling pathways. Glutamate can fuel ATP production, while ATP can act as a transmitter in intercellular signaling. We discuss the interface between glutamate and ATP in signaling and metabolism of astrocytes. Not only do glutamate and ATP cross each other's paths in physiology of the brain, but they also do so in its pathology. We present the fabric of this process in (patho)physiology through the discussion of synthesis and metabolism of ATP and glutamate in astrocytes as well as by providing a general description of astroglial receptors for these molecules along with the downstream signaling pathways that may be activated. It is astroglial receptors for these dual-acting molecules that could hold a key for medical intervention in pathological conditions. We focus on two examples disclosing the role of activation of astroglial ATP and glutamate receptors in pathology of two kinds of brain tissue, gray matter and white matter, respectively. Interventions at the interface of metabolism and signaling show promise for translational medicine.
Collapse
|
226
|
Souza DG, Bellaver B, Hansel G, Arús BA, Bellaver G, Longoni A, Kolling J, Wyse ATS, Souza DO, Quincozes-Santos A. Characterization of Amino Acid Profile and Enzymatic Activity in Adult Rat Astrocyte Cultures. Neurochem Res 2016; 41:1578-86. [PMID: 26915106 DOI: 10.1007/s11064-016-1871-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/01/2016] [Accepted: 02/11/2016] [Indexed: 10/22/2022]
Abstract
Astrocytes are multitasking players in brain complexity, possessing several receptors and mechanisms to detect, participate and modulate neuronal communication. The functionality of astrocytes has been mainly unraveled through the study of primary astrocyte cultures, and recently our research group characterized a model of astrocyte cultures derived from adult Wistar rats. We, herein, aim to characterize other basal functions of these cells to explore the potential of this model for studying the adult brain. To characterize the astrocytic phenotype, we determined the presence of GFAP, GLAST and GLT 1 proteins in cells by immunofluorescence. Next, we determined the concentrations of thirteen amino acids, ATP, ADP, adenosine and calcium in astrocyte cultures, as well as the activities of Na(+)/K(+)-ATPase and acetylcholine esterase. Furthermore, we assessed the presence of the GABA transporter 1 (GAT 1) and cannabinoid receptor 1 (CB 1) in the astrocytes. Cells demonstrated the presence of glutamine, consistent with their role in the glutamate-glutamine cycle, as well as glutamate and D-serine, amino acids classically known to act as gliotransmitters. ATP was produced and released by the cells and ADP was consumed. Calcium levels were in agreement with those reported in the literature, as were the enzymatic activities measured. The presence of GAT 1 was detected, but the presence of CB 1 was not, suggesting a decreased neuroprotective capacity in adult astrocytes under in vitro conditions. Taken together, our results show cellular functionality regarding the astrocytic role in gliotransmission and neurotransmitter management since they are able to produce and release gliotransmitters and to modulate the cholinergic and GABAergic systems.
Collapse
Affiliation(s)
- Débora Guerini Souza
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil.
| | - Bruna Bellaver
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Gisele Hansel
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Bernardo Assein Arús
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Gabriela Bellaver
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Aline Longoni
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Janaina Kolling
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Angela T S Wyse
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - Diogo Onofre Souza
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| | - André Quincozes-Santos
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, 2600, Anexo, PO Box: 90035-003, Porto Alegre, RS, Brazil
| |
Collapse
|
227
|
Abstract
A cardinal feature of early stages of human brain development centers on the sensory, cognitive, and emotional experiences that shape neuronal-circuit formation and refinement. Consequently, alterations in these processes account for many psychiatric and neurodevelopmental disorders. Neurodevelopment disorders affect 3-4% of the world population. The impact of these disorders presents a major challenge to clinicians, geneticists, and neuroscientists. Mutations that cause neurodevelopmental disorders are commonly found in genes encoding proteins that regulate synaptic function. Investigation of the underlying mechanisms using gain or loss of function approaches has revealed alterations in dendritic spine structure, function, and plasticity, consequently modulating the neuronal circuit formation and thereby raising the possibility of neurodevelopmental disorders resulting from synaptopathies. One such gene, SYNGAP1 (Synaptic Ras-GTPase-activating protein) has been shown to cause Intellectual Disability (ID) with comorbid Autism Spectrum Disorder (ASD) and epilepsy in children. SYNGAP1 is a negative regulator of Ras, Rap and of AMPA receptor trafficking to the postsynaptic membrane, thereby regulating not only synaptic plasticity, but also neuronal homeostasis. Recent studies on the neurophysiology of SYNGAP1, using Syngap1 mouse models, have provided deeper insights into how downstream signaling proteins and synaptic plasticity are regulated by SYNGAP1. This knowledge has led to a better understanding of the function of SYNGAP1 and suggests a potential target during critical period of development when the brain is more susceptible to therapeutic intervention.
Collapse
Affiliation(s)
- Nallathambi Jeyabalan
- Narayana Nethralaya Post-Graduate Institute of Ophthalmology, Narayana Nethralaya Foundation, Narayana Health City Bangalore, India
| | - James P Clement
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research Bangalore, India
| |
Collapse
|
228
|
Di Benedetto B, Malik VA, Begum S, Jablonowski L, Gómez-González GB, Neumann ID, Rupprecht R. Fluoxetine Requires the Endfeet Protein Aquaporin-4 to Enhance Plasticity of Astrocyte Processes. Front Cell Neurosci 2016; 10:8. [PMID: 26869881 PMCID: PMC4735422 DOI: 10.3389/fncel.2016.00008] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 01/11/2016] [Indexed: 01/12/2023] Open
Abstract
Morphological alterations in astrocytes are characteristic for post mortem brains of patients affected by major depressive disorder (MDD). Recently, a significant reduction in the coverage of blood vessels (BVs) by aquaporin-4 (AQP-4)-positive astrocyte endfeet has been shown in the prefrontal cortex (PFC) of MDD patients, suggesting that either alterations in the morphology of endfeet or in AQP-4 distribution might be responsible for the disease phenotype or constitute a consequence of its progress. Antidepressant drugs (ADs) regulate the expression of several proteins, including astrocyte-specific ones. Thus, they may target AQP-4 to induce morphological changes in astrocytes and restore their proper shape or relocate AQP-4 to endfeet. Using an animal model of depression, rats selectively bred for high anxiety-like behavior (HAB), we confirmed a reduced coverage of BVs in the adult PFC by AQP-4-immunoreactive (AQP-4-IR) astrocyte processes with respect to non-selected Wistar rats (NAB), thereby validating it for our study. A further evaluation of the morphology of astrocyte in brain slices (ex vivo) and in vitro using an antibody against the astrocyte-specific cytoskeletal protein glial fibrillary acidic protein (GFAP) revealed that HAB astrocytes extended less processes than NAB cells. Furthermore, short-term drug treatment in vitro with the AD fluoxetine (FLX) was sufficient to increase the plasticity of astrocyte processes, enhancing their number in NAB-derived cells and recovering their basal number in HAB-derived cells. This enhanced FLX-dependent plasticity occurred, however, only in the presence of intact AQP-4, as demonstrated by the lack of effect after the downregulation of AQP-4 with RNAi in both NAB and HAB cells. Nonetheless, a similar short-term treatment did neither modulate the coverage of BVs with AQP-4-positive astrocyte endfeet in NAB nor in HAB rats, although dosage and time of treatment were sufficient to fully recover GFAP expression in HAB brains. Thus, we suggest that longer treatment regimes may be needed to properly restore the coverage of BVs or to relocate AQP-4 to astrocyte endfeet. In conclusion, FLX requires AQP-4 to modulate the plasticity of astrocyte processes and this effect might be essential to re-establish a functional glia-vasculature interface necessary for a physiological communication between bloodstream and brain parenchyma.
Collapse
Affiliation(s)
- Barbara Di Benedetto
- Laboratory of Neuro-Glia Pharmacology, Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
| | - Victoria A Malik
- Laboratory of Neuro-Glia Pharmacology, Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
| | - Salina Begum
- Laboratory of Neuro-Glia Pharmacology, Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
| | - Lena Jablonowski
- Laboratory of Neuro-Glia Pharmacology, Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
| | - Gabriela B Gómez-González
- Laboratory of Neuro-Glia Pharmacology, Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
| | - Inga D Neumann
- Department of Neurobiology, University of Regensburg Regensburg, Germany
| | - Rainer Rupprecht
- Laboratory of Neuro-Glia Pharmacology, Department of Psychiatry and Psychotherapy, University of Regensburg Regensburg, Germany
| |
Collapse
|
229
|
Jeanson T, Pondaven A, Ezan P, Mouthon F, Charvériat M, Giaume C. Antidepressants Impact Connexin 43 Channel Functions in Astrocytes. Front Cell Neurosci 2016; 9:495. [PMID: 26778961 PMCID: PMC4703821 DOI: 10.3389/fncel.2015.00495] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/09/2015] [Indexed: 12/20/2022] Open
Abstract
Glial cells, and in particular astrocytes, are crucial to maintain neuronal microenvironment by regulating energy metabolism, neurotransmitter uptake, gliotransmission, and synaptic development. Moreover, a typical feature of astrocytes is their high expression level of connexins, a family of membrane proteins that form gap junction channels allowing intercellular exchanges and hemichannels that provide release and uptake pathways for neuroactive molecules. Interestingly, several studies have revealed unexpected changes in astrocytes from depressive patients and rodent models of depressive-like behavior. Moreover, changes in the expression level of the astroglial connexin 43 (Cx43) have been reported in a depressive context. On the other hand, antidepressive drugs have also been shown to impact the expression of this connexin in astrocytes. However, so far there is little information concerning the functional consequence of these changes, i.e., the status of gap junctional communication and hemichannel activity in astrocytes exposed to antidepressants. In the present work we focused our attention on the action of seven antidepressants from four different therapeutic classes and tested their effects on Cx43 expression and on the two connexin-based channels functions studied in cultured astrocytes. We here report that when used at non-toxic and clinically relevant concentrations they have no effects on Cx43 expression but differential effects on Cx43 gap junction channels. Moreover, all tested antidepressants inhibit Cx43 hemichannel with different efficiency depending on their therapeutic classe. By studying the impact of antidepressants on the functional status of astroglial connexin channels, contributing to dynamic neuroglial interactions, our observations should help to better understand the mechanism by which these drugs provide their effect in the brain.
Collapse
Affiliation(s)
- Tiffany Jeanson
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France; TheranexusLyon, France
| | - Audrey Pondaven
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| | - Pascal Ezan
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| | | | | | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050Paris, France; University Pierre et Marie CurieParis, France; MemoLife Laboratory of Excellence and Paris Science Lettre Research UniversityParis, France
| |
Collapse
|
230
|
Verkhratsky A, Steardo L, Peng L, Parpura V. Astroglia, Glutamatergic Transmission and Psychiatric Diseases. ADVANCES IN NEUROBIOLOGY 2016; 13:307-326. [PMID: 27885635 DOI: 10.1007/978-3-319-45096-4_12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Astrocytes are primary homeostatic cells of the central nervous system. They regulate glutamatergic transmission through the removal of glutamate from the extracellular space and by supplying neurons with glutamine. Glutamatergic transmission is generally believed to be significantly impaired in the contexts of all major neuropsychiatric diseases. In most of these neuropsychiatric diseases, astrocytes show signs of degeneration and atrophy, which is likely to be translated into reduced homeostatic capabilities. Astroglial glutamate uptake/release and glutamate homeostasis are affected in all forms of major psychiatric disorders and represent a common mechanism underlying neurotransmission disbalance, aberrant connectome and overall failure on information processing by neuronal networks, which underlie pathogenesis of neuropsychiatric diseases.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, 48011, Spain.
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, 48940, Spain.
| | - Luca Steardo
- Department of Psychiatry, University of Naples SUN, Largo Madonna delle Grazie, Naples, Italy
| | - Liang Peng
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy & Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL, 35294, USA
| |
Collapse
|
231
|
Verkhratsky A, Parpura V. Astrogliopathology in neurological, neurodevelopmental and psychiatric disorders. Neurobiol Dis 2016; 85:254-261. [PMID: 25843667 PMCID: PMC4592688 DOI: 10.1016/j.nbd.2015.03.025] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/20/2015] [Accepted: 03/26/2015] [Indexed: 12/17/2022] Open
Abstract
Astroglial cells represent a main element in the maintenance of homeostasis and providing defense to the brain. Consequently, their dysfunction underlies many, if not all, neurological, neurodevelopmental and neuropsychiatric disorders. General astrogliopathy is evident in diametrically opposing morpho-functional changes in astrocytes, i.e. their hypertrophy along with reactivity or atrophy with asthenia. Neurological disorders with astroglial participation can be genetic, of which Alexander disease is a primary sporadic astrogliopathy, environmentally caused, such as heavy metal encephalopathies, or neurodevelopmental in origin. Astroglia contribute to neurodegenerative processes seen in amyotrophic lateral sclerosis, Alzheimer's and Huntington's diseases. Furthermore, astroglia also play a role in major neuropsychiatric disorders, ranging from schizophrenia to depression, as well as in addictive disorders.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 429, Birmingham, AL 35294-0021, USA; Department of Biotechnology, University of Rijeka, Radmile Matejčić 2, 51000 Rijeka, Croatia.
| |
Collapse
|
232
|
Evidence for alterations of the glial syncytial function in major depressive disorder. J Psychiatr Res 2016; 72:15-21. [PMID: 26519765 PMCID: PMC5813495 DOI: 10.1016/j.jpsychires.2015.10.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 09/25/2015] [Accepted: 10/13/2015] [Indexed: 11/21/2022]
Abstract
BACKGROUND Glial cells are essential in maintaining synaptic function. In glutamatergic synapses astrocytes remove the products of neural activity, (i.e. potassium, glutamate and excess water) from the synaptic cleft and redistribute them across the glial network; these products of neural activity can then be recycled for neuronal use or released into the vascular compartment. This type of highly coupled cell network -or syncytium-maintains the balance of synaptic activity by restoring the basal levels of such molecules in the synaptic cleft. Previous studies have reported alterations of glia related genes in Major Depressive Disorder, including some genes related to syncytial function. METHODS We used RNA isolated from hippocampal tissues of 13 MDD subjects and 10 healthy controls to broadly examine gene expression using microarrays. Hippocampal RNA samples were isolated by laser capture microdissection from human tissue sections carefully avoiding contamination from neighboring structures. Once RNA quality was validated RNA was labeled and hybridized to microarrays. RESULTS Analysis of microarray data identified mRNA transcripts involved in glial syncytial function that were downregulated in MDD subjects compared to controls, including potassium and water channels (KCNJ10, AQP4), gap junction proteins (GJA1) and glutamate transporters (SLC1A2, SLC1A3). These gene expression differences were confirmed by qPCR. CONCLUSIONS The downregulation of these genes related to the syncytial network activity of glial cells is consistent with the hypothesis that synaptic homeostasis is disrupted thereby disrupting hippocampal synaptic function in MDD patients. Such glial gene expression changes could contribute either to the onset or perpetuation of depressive symptoms and hence, represent targets for novel therapeutics.
Collapse
|
233
|
Verkhratsky A, Zorec R, Rodriguez JJ, Parpura V. PATHOBIOLOGY OF NEURODEGENERATION: THE ROLE FOR ASTROGLIA. OPERA MEDICA ET PHYSIOLOGICA 2016; 1:13-22. [PMID: 27308639 PMCID: PMC4905715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The common denominator of neurodegenerative diseases, which mainly affect humans, is the progressive death of neural cells resulting in neurological and cognitive deficits. Astroglial cells are the central elements of the homoeostasis, defence and regeneration of the central nervous system, and their malfunction or reactivity contribute to the pathophysiology of neurodegenerative diseases. Pathological remodelling of astroglia in neurodegenerative context is multifaceted. Both astroglial atrophy with a loss of function and astroglial reactivity have been identified in virtually all the forms of neurodegenerative disorders. Astroglia may represent a novel target for therapeutic strategies aimed at preventing and possibly curing neurodegenerative diseases.
Collapse
Affiliation(s)
- Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, M13 9PT, UK
- University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain & Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Robert Zorec
- University of Ljubljana, Institute of Pathophysiology, Laboratory of Neuroendocrinology and Molecular Cell Physiology, Zaloska cesta 4; SI-1000, Ljubljana, Slovenia
- Celica, BIOMEDICAL, Technology Park 24, 1000 Ljubljana, Slovenia
| | - Jose J. Rodriguez
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain & Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, 1719 6th Avenue South, CIRC 429, University of Alabama, Birmingham, AL 35294-0021, USA
| |
Collapse
|
234
|
A Tribute to Mary C. McKenna: Glutamate as Energy Substrate and Neurotransmitter-Functional Interaction Between Neurons and Astrocytes. Neurochem Res 2015; 42:4-9. [PMID: 26721512 DOI: 10.1007/s11064-015-1813-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/16/2015] [Accepted: 12/18/2015] [Indexed: 10/22/2022]
Abstract
Glutamate metabolism in the brain is extremely complex not only involving a large variety of enzymes but also a tight partnership between neurons and astrocytes, the latter cells being in control of de novo synthesis of glutamate. This review provides an account of the processes involved, i.e. pyruvate carboxylation and recycling as well as the glutamate-glutamine cycle, focusing on the many seminal contributions from Dr. Mary McKenna. The ramification of the astrocytic end feet allowing contact and control of hundreds of thousands of synapses at the same time obviously puts these cells in a prominent position to regulate neural activity. Additionally, the astrocytes take active part in the neurotransmission processes by releasing a variety of gliotransmitters including glutamate. Hence, the term "the tripartite synapse", in which there is an active and dynamic interplay between the pre- and post-synaptic neurons and the ensheathing astrocytes, has been coined. The studies of Mary McKenna and her colleagues over several decades have been of paramount importance for the elucidation of compartmentation in astrocytes and synaptic terminals and the intricate metabolic processes underlying the glutamatergic neurotransmission process.
Collapse
|
235
|
Park H, Ahn KJ, Lee Kang J, Choi YH. Protein-protein interaction between caveolin-1 and SHP-2 is dependent on the N-SH2 domain of SHP-2. BMB Rep 2015; 48:184-9. [PMID: 25672415 PMCID: PMC4453023 DOI: 10.5483/bmbrep.2015.48.3.249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Indexed: 11/20/2022] Open
Abstract
Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) is known to protect neurons from neurodegeneration during ischemia/reperfusion injury. We recently reported that ROS-mediated oxidative stress promotes phosphorylation of endogenous SHP-2 in astrocytes and complex formation between caveolin-1 and SHP-2 in response to oxidative stress. To examine the region of SHP-2 participating in complex formation with caveolin-1, we generated three deletion mutant constructs and six point mutation constructs of SHP-2. Compared with wild-type SHP-2, binding of the N-SH2 domain deletion mutant of SHP-2 to p-caveolin-1 was reduced greatly, using flow cytometric competitive binding assays and surface plasmon resonance (SPR). Moreover, deletion of the N-SH2 domain of SHP-2 affected H2O2-mediated ERK phosphorylation and Src phosphorylation at Tyr 419 in primary astrocytes, suggesting that N-SH2 domain of SHP-2 is responsible for the binding of caveolin-1 and contributes to the regulation of Src phosphorylation and activation following ROS-induced oxidative stress in brain astrocytes.
Collapse
Affiliation(s)
- Hyunju Park
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul 158-710, Korea
| | - Keun Jae Ahn
- Department of Science Education, Jeju National University, Jeju 690-756, Korea
| | - Jihee Lee Kang
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul 158-710, Korea
| | - Youn-Hee Choi
- Department of Physiology, Tissue Injury Defense Research Center, Ewha Womans University School of Medicine, Seoul 158-710, Korea
| |
Collapse
|
236
|
Kleiderman S, Sá JV, Teixeira AP, Brito C, Gutbier S, Evje LG, Hadera MG, Glaab E, Henry M, Sachinidis A, Alves PM, Sonnewald U, Leist M. Functional and phenotypic differences of pure populations of stem cell-derived astrocytes and neuronal precursor cells. Glia 2015; 64:695-715. [DOI: 10.1002/glia.22954] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Susanne Kleiderman
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| | - João V. Sá
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Ana P. Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Catarina Brito
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Simon Gutbier
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| | - Lars G. Evje
- Department of Earth Science, University of Bergen; Allégaten 41 5007 Bergen Norway
| | - Mussie G. Hadera
- Department of Pharmacy; College of Health Sciences; Mekelle University, Tigray Ethiopia
| | - Enrico Glaab
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg; Belvaux L-4366 Luxembourg
| | - Margit Henry
- Institute of Neurophysiology and Center for Molecular Medicine, Cologne (CMMC), University of Cologne; Cologne Germany
| | - Agapios Sachinidis
- Institute of Neurophysiology and Center for Molecular Medicine, Cologne (CMMC), University of Cologne; Cologne Germany
| | - Paula M. Alves
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Ursula Sonnewald
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; Copenhagen Denmark
- Department of Neuroscience; Norwegian University of Science and Technology; Faculty of Medicine; Trondheim Norway
| | - Marcel Leist
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| |
Collapse
|
237
|
Gap Junction Intercellular Communication Mediates Ammonia-Induced Neurotoxicity. Neurotox Res 2015; 29:314-24. [PMID: 26646155 DOI: 10.1007/s12640-015-9581-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/20/2015] [Accepted: 11/24/2015] [Indexed: 12/21/2022]
Abstract
Astrocytes are important brain targets of ammonia, a neurotoxin implicated in the development of hepatic encephalopathy. During hyperammonemia, the pivotal role of astrocytes in brain function and homeostasis is impaired. These cells are abundantly interconnected by gap junctions (GJ), which are intercellular channels that allow the exchange of signaling molecules and metabolites. This communication may also increase cellular vulnerability during injuries, while GJ uncoupling could limit the extension of a lesion. Therefore, the current study was performed to investigate whether astrocyte coupling through GJ contributes to ammonia-induced cytotoxicity. We found that carbenoxolone (CBX), an effective GJ blocker, prevented the following effects induced by ammonia in astrocyte primary cultures: (1) decrease in cell viability and membrane integrity; (2) increase in reactive oxygen species production; (3) decrease in GSH intracellular levels; (4) GS activity; (5) pro-inflammatory cytokine release. On the other hand, CBX had no effect on C6 astroglial cells, which are poorly coupled via GJ. To our knowledge, this study provides the first evidence that GJ play a role in ammonia-induced cytotoxicity. Although more studies in vivo are required to confirm our hypothesis, our data suggest that GJ communication between astrocytes may transmit damage signals and excitotoxic components from unhealthy to normal cells, thereby contributing to the propagation of the neurotoxicity of ammonia.
Collapse
|
238
|
Watanabe K, Uemura K, Asada M, Maesako M, Akiyama H, Shimohama S, Takahashi R, Kinoshita A. The participation of insulin-like growth factor-binding protein 3 released by astrocytes in the pathology of Alzheimer's disease. Mol Brain 2015; 8:82. [PMID: 26637371 PMCID: PMC4670528 DOI: 10.1186/s13041-015-0174-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 11/30/2015] [Indexed: 01/02/2023] Open
Abstract
Background Alzheimer’s disease (AD) is characterized by senile plaques, extracellular deposits composed primarily of amyloid–beta (Aβ), and neurofibrillary tangles, which are abnormal intracellular inclusions containing hyperphosphorylated tau. The amyloid cascade hypothesis posits that the deposition of Aβ in the brain parenchyma initiates a sequence of events that leads to dementia. However, the molecular process by which the extracellular accumulation of Aβ peptides promotes intracellular pathologic changes in tau filaments remains unclear. To elucidate this process, we presumed that astrocytes might trigger neuronal reactions, leading to tau phosphorylation. In this study, we examined AD pathology from the perspective of the astrocyte-neuron interaction. Results A cytokine-array analysis revealed that Aβ stimulates astrocytes to release several chemical mediators that are primarily related to inflammation and cell adhesion. Among those mediators, insulin-like growth factor (IGF)-binding protein 3 (IGFBP-3) was highly upregulated. In AD brains, the expression of IGFBP-3 was found to be increased by western blot analysis, and increased expression of IGFBP-3 was observed in astrocytes via fluorescence microscopy. In addition, we reproduced the increase in IGFBP-3 after treatment with Aβ using human astrocytoma cell lines and found that IGFBP-3 was expressed via calcineurin. In AD brains, the activated forms of calcineurin were found to be increased by western blot analysis, and increased expression of calcineurin was observed in astrocytes via fluorescence microscopy. When Ser9 of glycogen synthase kinase-3β (GSK-3β) is phosphorylated, GSK-3β is controlled and tau phosphorylation is suppressed. Aβ suppresses the phosphorylation of GSK-3β, leading to tau phosphorylation. In this study, we found that IGF-Ι suppressed tau phosphorylation induced by Aβ, although IGFBP-3 inhibited this property of IGF-Ι. As a result, IGFBP-3 contributed to tau phosphorylation and cell death induced by Aβ. Conclusions Our study suggested that calcineurin in astrocytes was activated by Aβ, leading to IGFBP-3 release. We further demonstrated that IGFBP-3 produced by astrocytes induced tau phosphorylation in neurons. Our study provides novel insights into the role of astrocytes in the induction of tau phosphorylation and suggests that IGFBP-3 could be an important link between Aβ and tau pathology and an important therapeutic target. Electronic supplementary material The online version of this article (doi:10.1186/s13041-015-0174-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kiwamu Watanabe
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Kengo Uemura
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Megumi Asada
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan. .,School of Human Health Sciences Faculty of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Masato Maesako
- School of Human Health Sciences Faculty of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Haruhiko Akiyama
- Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
| | - Shun Shimohama
- Department of Neurology, Sapporo Medical University School of Medicine, 16 Minami-1-jyo-Nishi, Chuo-ku, Sapporo, 060-8543, Japan.
| | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Ayae Kinoshita
- School of Human Health Sciences Faculty of Medicine, Kyoto University, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
| |
Collapse
|
239
|
Mongin AA. Volume-regulated anion channel--a frenemy within the brain. Pflugers Arch 2015; 468:421-41. [PMID: 26620797 DOI: 10.1007/s00424-015-1765-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/16/2015] [Accepted: 11/20/2015] [Indexed: 10/22/2022]
Abstract
The volume-regulated anion channel (VRAC) is a ubiquitously expressed yet highly enigmatic member of the superfamily of chloride/anion channels. It is activated by cellular swelling and mediates regulatory cell volume decrease in a majority of vertebrate cells, including those in the central nervous system (CNS). In the brain, besides its crucial role in cellular volume regulation, VRAC is thought to play a part in cell proliferation, apoptosis, migration, and release of physiologically active molecules. Although these roles are not exclusive to the CNS, the relative significance of VRAC in the brain is amplified by several unique aspects of its physiology. One important example is the contribution of VRAC to the release of the excitatory amino acid neurotransmitters glutamate and aspartate. This latter process is thought to have impact on both normal brain functioning (such as astrocyte-neuron signaling) and neuropathology (via promoting the excitotoxic death of neuronal cells in stroke and traumatic brain injury). In spite of much work in the field, the molecular nature of VRAC remained unknown until less than 2 years ago. Two pioneer publications identified VRAC as the heterohexamer formed by the leucine-rich repeat-containing 8 (LRRC8) proteins. These findings galvanized the field and are likely to result in dramatic revisions to our understanding of the place and role of VRAC in the brain, as well as other organs and tissues. The present review briefly recapitulates critical findings in the CNS and focuses on anticipated impact on the LRRC8 discovery on further progress in neuroscience research.
Collapse
Affiliation(s)
- Alexander A Mongin
- Center for Neuropharmacology and Neuroscience, Albany Medical College, 47 New Scotland Ave., Albany, NY, 12208, USA.
| |
Collapse
|
240
|
Ibi D, Yamada K. Therapeutic Targets for Neurodevelopmental Disorders Emerging from Animal Models with Perinatal Immune Activation. Int J Mol Sci 2015; 16:28218-29. [PMID: 26633355 PMCID: PMC4691039 DOI: 10.3390/ijms161226092] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 11/17/2015] [Accepted: 11/20/2015] [Indexed: 01/02/2023] Open
Abstract
Increasing epidemiological evidence indicates that perinatal infection with various viral pathogens enhances the risk for several psychiatric disorders. The pathophysiological significance of astrocyte interactions with neurons and/or gut microbiomes has been reported in neurodevelopmental disorders triggered by pre- and postnatal immune insults. Recent studies with the maternal immune activation or neonatal polyriboinosinic polyribocytidylic acid models of neurodevelopmental disorders have identified various candidate molecules that could be responsible for brain dysfunction. Here, we review the functions of several candidate molecules in neurodevelopment and brain function and discuss their potential as therapeutic targets for psychiatric disorders.
Collapse
Affiliation(s)
- Daisuke Ibi
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, 150 Yagotoyama, Tenpaku-ku, Nagoya 468-8503, Japan.
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan.
| | - Kiyofumi Yamada
- Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Nagoya 466-8560, Japan.
| |
Collapse
|
241
|
Mu S, Liu B, Ouyang L, Zhan M, Chen S, Wu J, Chen J, Wei X, Wang W, Zhang J, Lei W. Characteristic Changes of Astrocyte and Microglia in Rat Striatum Induced by 3-NP and MCAO. Neurochem Res 2015; 41:707-14. [PMID: 26586406 DOI: 10.1007/s11064-015-1739-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/28/2015] [Accepted: 10/12/2015] [Indexed: 01/01/2023]
Abstract
Our previous studies had confirmed that both 3-NP and MCAO induced the behavioral defect as well as striatal neuronal injury and loss in experimental rats. This study aimed to examine different response forms of striatal astrocyte and microglia in 3-NP and MCAO rat models. The present results showed that the immunoreaction for GFAP was extremely weak in the lesioned core of striatum, but in the transition zone of 3-NP model and the penumbra zone of MCAO model, GFAP+ cells showed strong hypertrophic and proliferative changes. Statistical analysis for the number, size and integral optical density (IOD) of GFAP+ cells showed significant differences when compared with their controls and compared between the core and the transition zone or the penumbra zone, respectively, but no differences between the 3-NP and MCAO groups. However, Iba-1+ cells showed obvious hypertrophy and proliferation in the injured striatum in the 3-NP and the MCAO models, especially in the transition zone of 3-NP model and the penumbra zone of MCAO model. These Iba-1+ cells displayed two characteristic forms as branching cells with thick processes and amoeboid cells with thin processes. Statistical analysis showed that the number, size and IOD of Iba-1+ cells were significantly increased in the cores and the transition zone of 3-NP group and the penumbra zone of MCAO group than that of the controls, and the immune response of Iba-1 was stronger in the MCAO group than in the 3-NP group. The present results suggested that characteristic responses of astrocyte and microglia in the 3-NP and the MCAO models display their different effects on the pathological process of brain injury.
Collapse
Affiliation(s)
- Shuhua Mu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Bingbing Liu
- Department of Anesthesiology, Guangdong No. 2 Provincial People's Hospital, Guangdong Provincial Emergency Hospital, Guangzhou, China
| | - Lisi Ouyang
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Mali Zhan
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Si Chen
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Jiajia Wu
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Jiachang Chen
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Xianyou Wei
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Weiping Wang
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China
| | - Jian Zhang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, China. .,School of Medicine, Shenzhen University, Nanhai Ave 3688, Shenzhen, 518060, China.
| | - Wanlong Lei
- Department of Anatomy, Zhongshan School of Medicine, SUN Yat-sen University, 74 Zhongshan Rd 2, Guangzhou, 510080, China.
| |
Collapse
|
242
|
Jakovcevski M, Akbarian S, Di Benedetto B. Pharmacological modulation of astrocytes and the role of cell type-specific histone modifications for the treatment of mood disorders. Curr Opin Pharmacol 2015; 26:61-6. [PMID: 26515273 DOI: 10.1016/j.coph.2015.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Revised: 10/01/2015] [Accepted: 10/02/2015] [Indexed: 01/01/2023]
Abstract
Astrocytes orchestrate arrangement and functions of neuronal circuits and of the blood-brain barrier. Dysfunctional astrocytes characterize mood disorders, here showcased by deregulation of the astrocyte end-feet protein Aquaporin-4 around blood vessels and, hypothetically, of the astrocyte-specific phagocytic protein MEGF10 to shape synapses. Development of mood disorders is often a result of 'gene × environment' interactions, regulated among others by histone modifications and related modulator enzymes, which rapidly promote adaptive responses. Thus, they represent ideal targets of drugs aimed at inducing stable effects with quick onsets. One of the prevalent features of histone modifications and their modulators is their cell-type specificity. Investigating cell type-specific epigenetic modulations upon drug administration might therefore help to implement therapeutic treatments.
Collapse
Affiliation(s)
| | - Schahram Akbarian
- Department of Psychiatry and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Barbara Di Benedetto
- Department of Psychiatry and Psychotherapy, University Clinic of Regensburg, Regensbrug, Germany.
| |
Collapse
|
243
|
Johnson KM, Crocker SJ. TIMP-1 couples RhoK activation to IL-1β-induced astrocyte responses. Neurosci Lett 2015; 609:165-70. [PMID: 26484505 DOI: 10.1016/j.neulet.2015.10.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/21/2015] [Accepted: 10/13/2015] [Indexed: 12/27/2022]
Abstract
Interleukin-1β (IL-1β) is a pleotropic cytokine known to influence the central nervous system (CNS) responses to injury or infection. IL-1β also directly induces astrocytic expression of tissue inhibitor of metalloproteinases (TIMP)-1, a potent trophic factor and regulator of matrix metalloproteinase activity. In this study, we examined the functional relationship between IL-1β and TIMP-1 and determined that the behavior of astrocytes in response to IL-1β is determined by TIMP-1 expression. Using primary astrocytes from C57Bl/6 mice, we found astrocytes from wildtype (Wt) mice exhibited a robust wound healing response to a scratch wound that was arrested in response to IL-1β. In contrast, TIMP-1 knockout (TIMP-1KO) astrocytes, exhibited minimal response to the scratch wound but an accelerated response following IL-1β-treatment. We also determined that the scratch wound effect in Wt cultures was attenuated by inhibition of Rho kinase but amplified in the TIMP-1KO cultures. We propose that the specific induction of TIMP-1 from astrocytes in response to IL-1β reflects a previously unrecognized physiological relationship where the directionality of astrocytic behavior is determined by the actions of TIMP‑1. These findings may provide additional insight into glial responses in the context of neuropathology where expression of TIMP-1 may vary and astrocytic responses may be impacted by the inflammatory milieu of the CNS.
Collapse
Affiliation(s)
- Kasey M Johnson
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Stephen J Crocker
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, United States.
| |
Collapse
|
244
|
Fluteau A, Ince PG, Minett T, Matthews FE, Brayne C, Garwood CJ, Ratcliffe LE, Morgan S, Heath PR, Shaw PJ, Wharton SB, Simpson JE. The nuclear retention of transcription factor FOXO3a correlates with a DNA damage response and increased glutamine synthetase expression by astrocytes suggesting a neuroprotective role in the ageing brain. Neurosci Lett 2015; 609:11-7. [PMID: 26455863 PMCID: PMC4674771 DOI: 10.1016/j.neulet.2015.10.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 10/01/2015] [Accepted: 10/01/2015] [Indexed: 01/14/2023]
Abstract
The accumulation of reactive oxygen species leading to oxidative damage and cell death plays an important role in a number of neurodegenerative disorders. FOXO3a, the main isoform of FOXO transcription factors, mediates the cellular response to oxidative stress by regulating the expression of genes involved in DNA repair and glutamine metabolism, including glutamine synthetase (GS). Immunohistochemical investigation of the population-based neuropathology cohort of the Medical Research Council's Cognitive Function and Ageing Study (MRC CFAS) demonstrates that nuclear retention of FOXO3a significantly correlates with a DNA damage response and with GS expression by astrocytes. Furthermore, we show that GS expression correlates with increasing Alzheimer-type pathology in this ageing cohort. Our findings suggest that in response to oxidative stress, the nuclear retention of FOXO3a in astrocytes upregulates expression of GS as a neuroprotective mechanism. However, the activity of GS may be compromised by increasing levels of oxidative stress in the ageing brain resulting in dysfunctional enzyme activity, neuronal excitotoxic damage and cognitive impairment.
Collapse
Affiliation(s)
- Adeline Fluteau
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom; MRC Human Genetics Unit, University of Edinburgh, United Kingdom
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Thais Minett
- Institute of Public Health, University of Cambridge, United Kingdom; Department of Radiology, University of Cambridge, United Kingdom
| | - Fiona E Matthews
- MRC Biostatistics Unit, Cambridge, United Kingdom; Institute of Health and Society, University of Newcastle, United Kingdom; Faculty of Life Sciences, University of Manchester, United Kingdom
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, United Kingdom
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Laura E Ratcliffe
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Sarah Morgan
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom.
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, United Kingdom
| | | |
Collapse
|
245
|
Guanosine inhibits LPS-induced pro-inflammatory response and oxidative stress in hippocampal astrocytes through the heme oxygenase-1 pathway. Purinergic Signal 2015; 11:571-80. [PMID: 26431832 DOI: 10.1007/s11302-015-9475-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/24/2015] [Indexed: 12/12/2022] Open
Abstract
Guanosine, a guanine-based purine, is an extracellular signaling molecule that is released from astrocytes and has been shown to promote central nervous system defenses in several in vivo and in vitro injury models. Our group recently demonstrated that guanosine exhibits glioprotective effects in the C6 astroglial cell line by associating the heme oxygenase-1 (HO-1) signaling pathway with protection against azide-induced oxidative stress. Astrocyte overactivation contributes to the triggering of brain inflammation, a condition that is closely related to the development of many neurological disorders. These cells sense and amplify inflammatory signals from microglia and/or initiate the release of inflammatory mediators that are strictly related to transcriptional factors, such as nuclear factor kappa B (NFκB), that are modulated by HO-1. Astrocytes also express toll-like receptors (TLRs); TLRs specifically recognize lipopolysaccharide (LPS), which has been widely used to experimentally study inflammatory response. This study was designed to understand the glioprotective mechanism of guanosine against the inflammatory and oxidative damage induced by LPS exposure in primary cultures of hippocampal astrocytes. Treatment of astrocytes with LPS resulted in deleterious effects, including the augmentation of pro-inflammatory cytokine levels, NFκB activation, mitochondrial dysfunction, increased levels of oxygen/nitrogen species, and decreased levels of antioxidative defenses. Guanosine was able to prevent these effects, protecting the hippocampal astrocytes against LPS-induced cytotoxicity through activation of the HO-1 pathway. Additionally, the anti-inflammatory effects of guanosine were independent of the adenosinergic system. These results highlight the potential role of guanosine against neuroinflammatory-related diseases.
Collapse
|
246
|
Olivera-Bravo S, Barbeito L. A role of astrocytes in mediating postnatal neurodegeneration in Glutaric acidemia-type 1. FEBS Lett 2015; 589:3492-7. [DOI: 10.1016/j.febslet.2015.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/02/2015] [Accepted: 09/08/2015] [Indexed: 01/12/2023]
|
247
|
A new minimally-invasive method for microinjection into the mouse spinal dorsal horn. Sci Rep 2015; 5:14306. [PMID: 26387932 PMCID: PMC4585681 DOI: 10.1038/srep14306] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/24/2015] [Indexed: 12/30/2022] Open
Abstract
Noninvasive gene delivery to the spinal dorsal horn (SDH) remains challenging because existing methods to directly microinject vectors require laminectomy, which leads to tissue damage and inflammation. Such responses might hamper accurate readouts of cellular and behavioural effects of an introduced gene. Here we develop a new minimally-invasive SDH microinjection technique without the need of laminectomy in which a microcapillary is inserted into the SDH parenchyma through an intervertebral space. Using this method, we microinjected adeno-associated virus with an astrocytic promoter into the SDH and achieved efficient gene expression in an astrocyte-specific manner without gliosis, neuronal loss or inflammation. Furthermore, astrocytic loss- and gain-of-function of the transcription factor STAT3 by expressing a dominant-negative form and a constitutive-active form of STAT3, respectively, demonstrated the necessity and sufficiency of astrocytic STAT3 in the maintenance of neuropathic pain following peripheral nerve injury, a debilitating chronic pain state in which currently available treatments are frequently ineffective. Thus, our technique enables manipulation of gene expression in cell type- and spatial-specific manners without adverse effects, and may be useful for research in SDH physiology and pathology.
Collapse
|
248
|
Adrover E, Pallarés ME, Baier CJ, Monteleone MC, Giuliani FA, Waagepetersen HS, Brocco MA, Cabrera R, Sonnewald U, Schousboe A, Antonelli MC. Glutamate neurotransmission is affected in prenatally stressed offspring. Neurochem Int 2015; 88:73-87. [DOI: 10.1016/j.neuint.2015.05.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 05/12/2015] [Accepted: 05/19/2015] [Indexed: 11/16/2022]
|
249
|
Hoppe J, Salbego CG, Cimarosti H. SUMOylation: Novel Neuroprotective Approach for Alzheimer's Disease? Aging Dis 2015; 6:322-30. [PMID: 26425387 DOI: 10.14336/ad.2014.1205] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 12/05/2014] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized in the brain by the formation of amyloid-beta (Aβ)-containing plaques and neurofibrillary tangles containing the microtubule-associated protein tau. Neuroinflammation is another feature of AD and astrocytes are receiving increasing attention as key contributors. Although some progress has been made, the molecular mechanisms underlying the pathophysiology of AD remain unclear. Interestingly, some of the main proteins involved in AD, including amyloid precursor protein (APP) and tau, have recently been shown to be SUMOylated. The post-translational modification by SUMO (small ubiquitin-like modifier) has been shown to regulate APP and tau and may modulate other proteins implicated in AD. Here we present an overview of recent studies suggesting that protein SUMOylation might be involved in the underlying pathogenic mechanisms of AD and discuss how this could be exploited for therapeutic intervention.
Collapse
Affiliation(s)
| | - Christianne G Salbego
- 1 Laboratory of Neuroprotection and Cell Signaling, Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, 90035-003, Brazil
| | - Helena Cimarosti
- 2 Reading School of Pharmacy, University of Reading, Reading, RG6 6UB, UK
| |
Collapse
|
250
|
Garwood CJ, Ratcliffe LE, Morgan SV, Simpson JE, Owens H, Vazquez-Villaseñor I, Heath PR, Romero IA, Ince PG, Wharton SB. Insulin and IGF1 signalling pathways in human astrocytes in vitro and in vivo; characterisation, subcellular localisation and modulation of the receptors. Mol Brain 2015; 8:51. [PMID: 26297026 PMCID: PMC4546315 DOI: 10.1186/s13041-015-0138-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/02/2015] [Indexed: 12/20/2022] Open
Abstract
Background The insulin/IGF1 signalling (IIS) pathways are involved in longevity regulation and are dysregulated in neurons in Alzheimer’s disease (AD). We previously showed downregulation in IIS gene expression in astrocytes with AD-neuropathology progression, but IIS in astrocytes remains poorly understood. We therefore examined the IIS pathway in human astrocytes and developed models to reduce IIS at the level of the insulin or the IGF1 receptor (IGF1R). Results We determined IIS was present and functional in human astrocytes by immunoblotting and showed astrocytes express the insulin receptor (IR)-B isoform of Ir. Immunocytochemistry and cell fractionation followed by western blotting revealed the phosphorylation status of insulin receptor substrate (IRS1) affects its subcellular localisation. To validate IRS1 expression patterns observed in culture, expression of key pathway components was assessed on post-mortem AD and control tissue using immunohistochemistry. Insulin signalling was impaired in cultured astrocytes by treatment with insulin + fructose and resulted in decreased IR and Akt phosphorylation (pAkt S473). A monoclonal antibody against IGF1R (MAB391) induced degradation of IGF1R receptor with an associated decrease in downstream pAkt S473. Neither treatment affected cell growth or viability as measured by MTT and Cyquant® assays or GFAP immunoreactivity. Discussion IIS is functional in astrocytes. IR-B is expressed in astrocytes which differs from the pattern in neurons, and may be important in differential susceptibility of astrocytes and neurons to insulin resistance. The variable presence of IRS1 in the nucleus, dependent on phosphorylation pattern, suggests the function of signalling molecules is not confined to cytoplasmic cascades. Down-regulation of IR and IGF1R, achieved by insulin + fructose and monoclonal antibody treatments, results in decreased downstream signalling, though the lack of effect on viability suggests that astrocytes can compensate for changes in single pathways. Changes in signalling in astrocytes, as well as in neurons, may be important in ageing and neurodegeneration. Electronic supplementary material The online version of this article (doi:10.1186/s13041-015-0138-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Claire J Garwood
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Laura E Ratcliffe
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Sarah V Morgan
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Helen Owens
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Irina Vazquez-Villaseñor
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Paul R Heath
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Ignacio A Romero
- Biomedical Research Network, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - Paul G Ince
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, The University of Sheffield, 385a Glossop Road, Sheffield, S10 2HQ, UK.
| |
Collapse
|