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Skauli N, Zohoorian N, Banitalebi S, Geiseler S, Salameh M, Rao SB, Morland C, Ottersen OP, Amiry-Moghaddam M. Aquaporin-4 deletion leads to reduced infarct volume and increased peri-infarct astrocyte reactivity in a mouse model of cortical stroke. J Physiol 2024; 602:3151-3168. [PMID: 38924526 DOI: 10.1113/jp284099] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 05/29/2024] [Indexed: 06/28/2024] Open
Abstract
Aquaporin-4 (AQP4) is the main water channel in brain and is enriched in perivascular astrocyte processes abutting brain microvessels. There is a rich literature on the role of AQP4 in experimental stroke. While its role in oedema formation following middle cerebral artery occlusion (MCAO) has been studied extensively, its specific impact on infarct volume remains unclear. This study investigated the effects of total and partial AQP4 deletion on infarct volume in mice subjected to distal medial cerebral artery (dMCAO) occlusion. Compared to MCAO, this model induces smaller infarcts confined to neocortex, and less oedema. We show that AQP4 deletion significantly reduced infarct volume as assessed 1 week after dMCAO, suggesting that the role of AQP4 in stroke goes beyond its effect on oedema formation and dissolution. The reduction in infarct volume was associated with increased astrocyte reactivity in the peri-infarct areas. No significant differences were observed in the number of microglia among the genotypes. These findings provide new insights in the role of AQP4 in ischaemic injury indicating that AQP4 affects both infarct volume and astrocyte reactivity in the peri-infarct zone. KEY POINTS: Aquaporin-4 (AQP4) is the main water channel in brain and is enriched in perivascular astrocyte processes abutting microvessels. A rich literature exists on the role of AQP4 in oedema formation following middle cerebral artery occlusion (MCAO). We investigated the effects of total and partial AQP4 deletion on infarct volume in mice subjected to distal medial cerebral artery occlusion (dMCAO), a model inducing smaller infarcts confined to neocortex and less oedema compared to MCAO. AQP4 deletion significantly reduced infarct volume 1 week after dMCAO, suggesting a broader role for AQP4 in stroke beyond oedema formation. The reduction in infarct volume was associated with increased astrocyte reactivity in the peri-infarct areas, while no significant differences were observed in the number of microglia among the genotypes. These findings provide new insights into the role of AQP4 in stroke, indicating that AQP4 affects both infarct volume and astrocyte reactivity in the peri-infarct zone.
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Affiliation(s)
- Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
| | - Negar Zohoorian
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
| | - Shervin Banitalebi
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
| | - Samuel Geiseler
- Cardiovascular Research Group IMB, Department of Medical Biology, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Maher Salameh
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
| | - Shreyas B Rao
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
| | - Cecilie Morland
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, The Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Ole P Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Oslo, Norway
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Li J, Jia S, Song Y, Xu W, Lin J. Ginkgolide B can alleviate spinal cord glymphatic system dysfunction and provide neuroprotection in painful diabetic neuropathy rats by inhibiting matrix metalloproteinase-9. Neuropharmacology 2024; 250:109907. [PMID: 38492884 DOI: 10.1016/j.neuropharm.2024.109907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/02/2024] [Accepted: 03/10/2024] [Indexed: 03/18/2024]
Abstract
The glymphatic system plays a crucial role in maintaining optimal central nervous system (CNS) function by facilitating the removal of metabolic wastes. Aquaporin-4 (AQP4) protein, predominantly located on astrocyte end-feet, is a key pathway for metabolic waste excretion. β-Dystroglycan (β-DG) can anchor AQP4 protein to the end-feet membrane of astrocytes and can be cleaved by matrix metalloproteinase (MMP)-9 protein. Studies have demonstrated that hyperglycemia upregulates MMP-9 expression in the nervous system, leading to neuropathic pain. Ginkgolide B (GB) exerts an inhibitory effect on the MMP-9 protein. In this study, we investigated whether inhibition of MMP-9-mediated β-DG cleavage by GB is involved in the regulation of AQP4 polarity within the glymphatic system in painful diabetic neuropathy (PDN) and exerts neuroprotective effects. The PDN model was established by injecting streptozotocin (STZ). Functional changes in the glymphatic system were observed using magnetic resonance imaging (MRI). The paw withdrawal threshold (PWT) was measured to assess mechanical allodynia. The protein expressions of MMP-9, β-DG, and AQP4 were detected by Western blotting and immunofluorescence. Our findings revealed significant decreases in the efficiency of contrast agent clearance within the spinal glymphatic system of the rats, accompanied by decreased PWT, increased MMP-9 protein expression, decreased β-DG protein expression, and loss of AQP4 polarity. Notably, GB treatment demonstrated the capacity to ameliorate spinal cord glymphatic function by modulating AQP4 polarity through MMP-9 inhibition, offering a promising therapeutic avenue for PDN.
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Affiliation(s)
- Jiang Li
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
| | - Shuaiying Jia
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
| | | | - Wenmei Xu
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
| | - Jingyan Lin
- Department of Anesthesiology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
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Bojarskaite L, Nafari S, Ravnanger AK, Frey MM, Skauli N, Åbjørsbråten KS, Roth LC, Amiry-Moghaddam M, Nagelhus EA, Ottersen OP, Bogen IL, Thoren AE, Enger R. Role of aquaporin-4 polarization in extracellular solute clearance. Fluids Barriers CNS 2024; 21:28. [PMID: 38532513 DOI: 10.1186/s12987-024-00527-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 03/02/2024] [Indexed: 03/28/2024] Open
Abstract
Waste from the brain has been shown to be cleared via the perivascular spaces through the so-called glymphatic system. According to this model the cerebrospinal fluid (CSF) enters the brain in perivascular spaces of arteries, crosses the astrocyte endfoot layer, flows through the parenchyma collecting waste that is subsequently drained along veins. Glymphatic clearance is dependent on astrocytic aquaporin-4 (AQP4) water channels that are highly enriched in the endfeet. Even though the polarized expression of AQP4 in endfeet is thought to be of crucial importance for glymphatic CSF influx, its role in extracellular solute clearance has only been evaluated using non-quantitative fluorescence measurements. Here we have quantitatively evaluated clearance of intrastriatally infused small and large radioactively labeled solutes in mice lacking AQP4 (Aqp4-/-) or lacking the endfoot pool of AQP4 (Snta1-/-). We confirm that Aqp4-/- mice show reduced clearance of both small and large extracellular solutes. Moreover, we find that the Snta1-/- mice have reduced clearance only for the 500 kDa [3H]dextran, but not 0.18 kDa [3H]mannitol suggesting that polarization of AQP4 to the endfeet is primarily important for clearance of large, but not small molecules. Lastly, we observed that clearance of 500 kDa [3H]dextran increased with age in adult mice. Based on our quantitative measurements, we confirm that presence of AQP4 is important for clearance of extracellular solutes, while the perivascular AQP4 localization seems to have a greater impact on clearance of large versus small molecules.
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Affiliation(s)
- Laura Bojarskaite
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
- Department of Neurology, Oslo University Hospital, Oslo, 0027, Norway
| | - Sahar Nafari
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Anne Katrine Ravnanger
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Mina Martine Frey
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, 0317, Norway
| | - Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, 0317, Norway
| | - Knut Sindre Åbjørsbråten
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Lena Catherine Roth
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, 0317, Norway
| | - Erlend A Nagelhus
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Ole Petter Ottersen
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Inger Lise Bogen
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
- Section for Drug Abuse Research, Department of Forensic Sciences, Oslo University Hospital, P.O. Box N-4950, Nydalen, Oslo, 0424, Norway
| | - Anna E Thoren
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway
| | - Rune Enger
- GliaLab and Letten Centre, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, P.O.B. 1103, Oslo, 0317, Norway.
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Moëlo C, Quillévéré A, Le Roy L, Timsit S. (S)-roscovitine, a CDK inhibitor, decreases cerebral edema and modulates AQP4 and α1-syntrophin interaction on a pre-clinical model of acute ischemic stroke. Glia 2024; 72:322-337. [PMID: 37828900 DOI: 10.1002/glia.24477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/22/2023] [Accepted: 09/07/2023] [Indexed: 10/14/2023]
Abstract
Cerebral edema is one of the deadliest complications of ischemic stroke for which there is currently no pharmaceutical treatment. Aquaporin-4 (AQP4), a water-channel polarized at the astrocyte endfoot, is known to be highly implicated in cerebral edema. We previously showed in randomized studies that (S)-roscovitine, a cyclin-dependent kinase inhibitor, reduced cerebral edema 48 h after induction of focal transient ischemia, but its mechanisms of action were unclear. In our recent blind randomized study, we confirmed that (S)-roscovitine was able to reduce cerebral edema by 65% at 24 h post-stroke (t test, p = .006). Immunofluorescence analysis of AQP4 distribution in astrocytes revealed that (S)-roscovitine decreased the non-perivascular pool of AQP4 by 53% and drastically increased AQP4 clusters in astrocyte perivascular end-feet (671%, t test p = .005) compared to vehicle. Non-perivascular and clustered AQP4 compartments were negatively correlated (R = -0.78; p < .0001), suggesting a communicating vessels effect between the two compartments. α1-syntrophin, AQP4 anchoring protein, was colocalized with AQP4 in astrocyte endfeet, and this colocalization was maintained in ischemic area as observed on confocal microscopy. Moreover, (S)-roscovitine increased AQP4/α1-syntrophin interaction (40%, MW p = .0083) as quantified by proximity ligation assay. The quantified interaction was negatively correlated with brain edema in both treated and placebo groups (R = -.57; p = .0074). We showed for the first time, that a kinase inhibitor modulated AQP4/α1-syntrophin interaction, and was implicated in the reduction of cerebral edema. These findings suggest that (S)-roscovitine may hold promise as a potential treatment for cerebral edema in ischemic stroke and as modulator of AQP4 function in other neurological diseases.
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Affiliation(s)
- Cloé Moëlo
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
| | - Alicia Quillévéré
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
| | - Lucas Le Roy
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
| | - Serge Timsit
- EFS, Université de Bretagne Occidentale, Inserm UMR 1078, GGB, Brest, France
- Neurology and Stroke Unit Department, CHRU de Brest, Inserm1078, Université de Bretagne Occidentale, Brest, France
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5
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Jazaeri SZ, Taghizadeh G, Babaei JF, Goudarzi S, Saadatmand P, Joghataei MT, Khanahmadi Z. Aquaporin 4 beyond a water channel; participation in motor, sensory, cognitive and psychological performances, a comprehensive review. Physiol Behav 2023; 271:114353. [PMID: 37714320 DOI: 10.1016/j.physbeh.2023.114353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/15/2023] [Accepted: 09/13/2023] [Indexed: 09/17/2023]
Abstract
Aquaporin 4 (AQP4) is a protein highly expressed in the central nervous system (CNS) and peripheral nervous system (PNS) as well as various other organs, whose different sites of action indicate its importance in various functions. AQP4 has a variety of essential roles beyond water homeostasis. In this article, we have for the first time summarized different roles of AQP4 in motor and sensory functions, besides cognitive and psychological performances, and most importantly, possible physiological mechanisms by which AQP4 can exert its effects. Furthermore, we demonstrated that AQP4 participates in pathology of different neurological disorders, various effects depending on the disease type. Since neurological diseases involve a spectrum of dysfunctions and due to the difficulty of obtaining a treatment that can simultaneously affect these deficits, it is therefore suggested that future studies consider the role of this protein in different functional impairments related to neurological disorders simultaneously or separately by targeting AQP4 expression and/or polarity modulation.
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Affiliation(s)
- Seyede Zohreh Jazaeri
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ghorban Taghizadeh
- Department of Occupational Therapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran.
| | - Javad Fahanik Babaei
- Electrophysiology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Sepideh Goudarzi
- Experimental Medicine Research Center, Tehran University of medical Sciences, Tehran, Iran
| | - Pegah Saadatmand
- Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Innovation in Medical Education, Faculty of Medicine, Ottawa University, Ottawa, Canada.
| | - Zohreh Khanahmadi
- Department of Occupational Therapy, School of Rehabilitation Services, Isfahan University of Medical Sciences, Isfahan, Iran
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6
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Kushwaha R, Li Y, Makarava N, Pandit NP, Molesworth K, Birukov KG, Baskakov IV. Reactive astrocytes associated with prion disease impair the blood brain barrier. Neurobiol Dis 2023; 185:106264. [PMID: 37597815 PMCID: PMC10494928 DOI: 10.1016/j.nbd.2023.106264] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/31/2023] [Accepted: 08/15/2023] [Indexed: 08/21/2023] Open
Abstract
BACKGROUND Impairment of the blood-brain barrier (BBB) is considered to be a common feature among neurodegenerative diseases, including Alzheimer's, Parkinson's and prion diseases. In prion disease, increased BBB permeability was reported 40 years ago, yet the mechanisms behind the loss of BBB integrity have never been explored. Recently, we showed that reactive astrocytes associated with prion diseases are neurotoxic. The current work examines the potential link between astrocyte reactivity and BBB breakdown. RESULTS In prion-infected mice, the loss of BBB integrity and aberrant localization of aquaporin 4 (AQP4), a sign of retraction of astrocytic endfeet from blood vessels, were noticeable prior to disease onset. Gaps in cell-to-cell junctions along blood vessels, together with downregulation of Occludin, Claudin-5 and VE-cadherin, which constitute tight and adherens junctions, suggested that loss of BBB integrity is linked with degeneration of vascular endothelial cells. In contrast to cells isolated from non-infected adult mice, endothelial cells originating from prion-infected mice displayed disease-associated changes, including lower levels of Occludin, Claudin-5 and VE-cadherin expression, impaired tight and adherens junctions, and reduced trans-endothelial electrical resistance (TEER). Endothelial cells isolated from non-infected mice, when co-cultured with reactive astrocytes isolated from prion-infected animals or treated with media conditioned by the reactive astrocytes, developed the disease-associated phenotype observed in the endothelial cells from prion-infected mice. Reactive astrocytes were found to produce high levels of secreted IL-6, and treatment of endothelial monolayers originating from non-infected animals with recombinant IL-6 alone reduced their TEER. Remarkably, treatment with extracellular vesicles produced by normal astrocytes partially reversed the disease phenotype of endothelial cells isolated from prion-infected animals. CONCLUSIONS To our knowledge, the current work is the first to illustrate early BBB breakdown in prion disease and to document that reactive astrocytes associated with prion disease are detrimental to BBB integrity. Moreover, our findings suggest that the harmful effects are linked to proinflammatory factors secreted by reactive astrocytes.
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Affiliation(s)
- Rajesh Kushwaha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Yue Li
- Lung Biology Research Program and Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Narayan P Pandit
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Kara Molesworth
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Konstantin G Birukov
- Lung Biology Research Program and Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, United States of America.
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Xiong J, Wang Z, Bai J, Cheng K, Liu Q, Ni J. Calcitonin gene-related peptide: a potential protective agent in cerebral ischemia-reperfusion injury. Front Neurosci 2023; 17:1184766. [PMID: 37529236 PMCID: PMC10387546 DOI: 10.3389/fnins.2023.1184766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 06/29/2023] [Indexed: 08/03/2023] Open
Abstract
Ischemic stroke is the most common type of cerebrovascular disease with high disability and mortality rates, which severely burdens patients, their families, and society. At present, thrombolytic therapy is mainly used for the treatment of ischemic strokes. Even though it can achieve a good effect, thrombolytic recanalization can cause reperfusion injury. Calcitonin gene-related peptide (CGRP) is a neuropeptide that plays a neuroprotective role in the process of ischemia-reperfusion injury. By combining with its specific receptors, CGRP can induce vasodilation of local cerebral ischemia by directly activating the cAMP-PKA pathway in vascular smooth muscle cells and by indirectly activating the NO-cGMP pathway in an endothelial cell-dependent manner,thus rapidly increasing ischemic local blood flow together with reperfusion. CGRP, as a key effector molecule of neurogenic inflammation, can reduce the activation of microglia, downregulates Th1 classical inflammation, and reduce the production of TNF-α, IL-2, and IFN-γ and the innate immune response of macrophages, leading to the reduction of inflammatory factors. CGRP can reduce the overexpression of the aquaporin-4 (AQP-4) protein and its mRNA in the cerebral ischemic junction, and play a role in reducing cerebral edema. CGRP can protect endothelial cells from angiotensin II by reducing the production of oxidants and protecting antioxidant defense. Furthermore, CGRP-upregulated eNOS can further induce VEGF expression, which then promotes the survival and angiogenesis of vascular endothelial cells. CGRP can also reduce apoptosis by promoting the expression of Bcl-2 and inhibiting the expression of caspase-3. These effects suggest that CGRP can reduce brain injury and repair damaged nerve function. In this review, we focused on the role of CGRP in cerebral ischemia-reperfusion injury.
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Affiliation(s)
- Jie Xiong
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Zhiyong Wang
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Junhui Bai
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Keling Cheng
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
| | - Qicai Liu
- Department of Reproductive Medicine Centre, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Jun Ni
- Department of Rehabilitation, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, China
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Stokum JA, Shim B, Negoita S, Tsymbalyuk N, Tsymbalyuk O, Ivanova S, Keledjian K, Bryan J, Blaustein MP, Jha RM, Kahle KT, Gerzanich V, Simard JM. Cation flux through SUR1-TRPM4 and NCX1 in astrocyte endfeet induces water influx through AQP4 and brain swelling after ischemic stroke. Sci Signal 2023; 16:eadd6364. [PMID: 37279286 PMCID: PMC10369355 DOI: 10.1126/scisignal.add6364] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 05/10/2023] [Indexed: 06/08/2023]
Abstract
Brain swelling causes morbidity and mortality in various brain injuries and diseases but lacks effective treatments. Brain swelling is linked to the influx of water into perivascular astrocytes through channels called aquaporins. Water accumulation in astrocytes increases their volume, which contributes to brain swelling. Using a mouse model of severe ischemic stroke, we identified a potentially targetable mechanism that promoted the cell surface localization of aquaporin 4 (AQP4) in perivascular astrocytic endfeet, which completely ensheathe the brain's capillaries. Cerebral ischemia increased the abundance of the heteromeric cation channel SUR1-TRPM4 and of the Na+/Ca2+ exchanger NCX1 in the endfeet of perivascular astrocytes. The influx of Na+ through SUR1-TRPM4 induced Ca2+ transport into cells through NCX1 operating in reverse mode, thus raising the intra-endfoot concentration of Ca2+. This increase in Ca2+ stimulated calmodulin-dependent translocation of AQP4 to the plasma membrane and water influx, which led to cellular edema and brain swelling. Pharmacological inhibition or astrocyte-specific deletion of SUR1-TRPM4 or NCX1 reduced brain swelling and improved neurological function in mice to a similar extent as an AQP4 inhibitor and was independent of infarct size. Thus, channels in astrocyte endfeet could be targeted to reduce postischemic brain swelling in stroke patients.
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Affiliation(s)
- Jesse A Stokum
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Bosung Shim
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Serban Negoita
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Natalya Tsymbalyuk
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Orest Tsymbalyuk
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Svetlana Ivanova
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Kaspar Keledjian
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Joseph Bryan
- Pacific Northwest Diabetes Research Institute, Seattle, WA 98122, USA
| | - Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Ruchira M Jha
- Department of Neurology, Barrow Neurological Institute and St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA
| | - Kristopher T Kahle
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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9
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Mohammed SR, Elmasry K, El-Gamal R, El-Shahat MA, Sherif RN. Alteration of Aquaporins 1 and 4 immunohistochemical and gene expression in the cerebellum of diabetic albino rat. Tissue Cell 2023; 82:102076. [PMID: 36989704 DOI: 10.1016/j.tice.2023.102076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023]
Abstract
Aquaporins (AQPs) are a family of transmembrane channel proteins. AQP1 and AQP4 are expressed in cerebellum amongst others. This study was designed to assess the effect of diabetes on AQP1 and AQP4 expression in cerebellum of rats. Diabetes was induced by a single intraperitoneal injection of Streptozotocin 45 mg/kg in 24 adult male Sprague Dawley rats. Six rats from control and diabetic groups were sacrificed at one, four, and eight weeks post diabetic confirmation. After eight weeks, measurement of malondialdehyde (MDA), reduced glutathione (GSH) concentrations, and cerebellar mRNA expression for AQP1 and AQP4 genes were performed. Immunohistochemical evaluation of AQP1, AQP4, and glial fibrillary acidic protein (GFAP) for cerebellar sections was performed for all groups. Diabetes caused degenerative changes in Purkinje cells with a significant increase in the cerebellar level of MDA and AQP1 immunoreactivity and a significant decrease in GSH level and AQP4 expression levels. However, the alteration in the AQP1 mRNA level was not statistically significant. GFAP immunoreactivity was increased in 8 W diabetic rats following its decrease in 1 W diabetic rats. Diabetes caused some alteration in the AQPs 1 and 4 expression in the cerebellum of diabetic rats which may contribute to diabetes-induced cerebellar complications.
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10
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Liu H, Chen L, Zhang C, Liu C, Li Y, Cheng L, Wei Z, Zhang Z, Lu H, van Zijl PCM, Iliff JJ, Xu J, Duan W. Interrogation of dynamic glucose-enhanced MRI and fluorescence-based imaging reveals a perturbed glymphatic network in Huntington's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535397. [PMID: 37066166 PMCID: PMC10103957 DOI: 10.1101/2023.04.03.535397] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder that presents with progressive motor, mental, and cognitive impairment leading to early disability and mortality. The accumulation of mutant huntingtin protein aggregates in neurons is a pathological hallmark of HD. The glymphatic system, a brain-wide perivascular network, facilitates the exchange of interstitial fluid (ISF) and cerebrospinal fluid (CSF), supporting interstitial solute clearance including abnormal proteins from mammalian brains. In this study, we employed dynamic glucose-enhanced (DGE) MRI to measure D-glucose clearance from CSF as a tool to assess CSF clearance capacity to predict glymphatic function in a mouse model of HD. Our results demonstrate significantly diminished CSF clearance efficiency in premanifest zQ175 HD mice. The impairment of CSF clearance of D-glucose, measured by DGE MRI, worsened with disease progression. These DGE MRI findings in compromised glymphatic function in HD mice were further confirmed with fluorescence-based imaging of glymphatic CSF tracer influx, suggesting an impaired glymphatic function in premanifest stage of HD. Moreover, expression of the astroglial water channel aquaporin-4 (AQP4) in the perivascular compartment, a key mediator of glymphatic function, was significantly diminished in both HD mouse brain as well as postmortem human HD brain. Our data, acquired using a clinically translatable MRI approach, indicate a perturbed glymphatic network in the HD brain as early as in the premanifest stage. Further validation of these findings in clinical studies should provide insights into potential of glymphatic clearance as a HD biomarker and for glymphatic functioning as a disease-modifying therapeutic target for HD.
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Kushwaha R, Li Y, Makarava N, Pandit NP, Molesworth K, Birukov KG, Baskakov IV. Reactive astrocytes associated with prion disease impair the blood brain barrier. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.533684. [PMID: 36993690 PMCID: PMC10055297 DOI: 10.1101/2023.03.21.533684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Background Impairment of the blood-brain barrier (BBB) is considered to be a common feature among neurodegenerative diseases, including Alzheimer's, Parkinson's and prion diseases. In prion disease, increased BBB permeability was reported 40 years ago, yet the mechanisms behind the loss of BBB integrity have never been explored. Recently, we showed that reactive astrocytes associated with prion diseases are neurotoxic. The current work examines the potential link between astrocyte reactivity and BBB breakdown. Results In prion-infected mice, the loss of BBB integrity and aberrant localization of aquaporin 4 (AQP4), a sign of retraction of astrocytic endfeet from blood vessels, were noticeable prior to disease onset. Gaps in cell-to-cell junctions along blood vessels, together with downregulation of Occludin, Claudin-5 and VE-cadherin, which constitute tight and adherens junctions, suggested that loss of BBB integrity is linked with degeneration of vascular endothelial cells. In contrast to cells isolated from non-infected adult mice, endothelial cells originating from prion-infected mice displayed disease-associated changes, including lower levels of Occludin, Claudin-5 and VE-cadherin expression, impaired tight and adherens junctions, and reduced trans-endothelial electrical resistance (TEER). Endothelial cells isolated from non-infected mice, when co-cultured with reactive astrocytes isolated from prion-infected animals or treated with media conditioned by the reactive astrocytes, developed the disease-associated phenotype observed in the endothelial cells from prion-infected mice. Reactive astrocytes were found to produce high levels of secreted IL-6, and treatment of endothelial monolayers originating from non-infected animals with recombinant IL-6 alone reduced their TEER. Remarkably, treatment with extracellular vesicles produced by normal astrocytes partially reversed the disease phenotype of endothelial cells isolated from prion-infected animals. Conclusions To our knowledge, the current work is the first to illustrate early BBB breakdown in prion disease and to document that reactive astrocytes associated with prion disease are detrimental to BBB integrity. Moreover, our findings suggest that the harmful effects are linked to proinflammatory factors secreted by reactive astrocytes.
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Affiliation(s)
- Rajesh Kushwaha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
| | - Yue Li
- Lung Biology Research Program and Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, 21201
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
| | - Narayan P. Pandit
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
| | - Kara Molesworth
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
| | - Konstantin G. Birukov
- Lung Biology Research Program and Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, 21201
| | - Ilia V. Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States of America
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12
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Chen C, Fan P, Zhang L, Xue K, Hu J, Huang J, Lu W, Xu J, Xu S, Qiu G, Ran J, Gan S. Bumetanide Rescues Aquaporin-4 Depolarization via Suppressing β-Dystroglycan Cleavage and Provides Neuroprotection in Rat Retinal Ischemia-Reperfusion Injury. Neuroscience 2023; 510:95-108. [PMID: 36493910 DOI: 10.1016/j.neuroscience.2022.11.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/21/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Aquaporin-4 (AQP4) regulates retinal water homeostasis and participates in retinal oedema pathophysiology. β-dystroglycan (β-DG) is responsible for AQP4 polarization and can be cleaved by matrix metalloproteinase-9 (MMP9). Retinal oedema induced by ischemia-reperfusion (I/R) injury is an early complication. Bumetanide (BU) has potential efficacy against cytotoxic oedema. Our study investigated the effects of β-DG cleavage on AQP4 and the roles of BU in a rat retinal I/R injury model. The model was induced by applying 110 mm Hg intraocular pressure to the anterior eye chamber. BU and U0126 (a selective ERK inhibitor) were intraperitoneally administered 15 and 30 min, respectively, before I/R induction. Rhodamine isothiocyanate extravasation detection, quantitative real-time PCR, transmission electron microscopy, hematoxylin-eosin staining, immunofluorescence staining, western blotting, and TUNEL staining were performed. AQP4 lost its polarization in the retinal perivascular domain as a result of β-DG cleavage. BU rescued AQP4 depolarization, suppressed AQP4 protein expression, attenuated retinal cytotoxic oedema, and downregulated β-DG and AQP4 mRNA expression. BU suppressed glial responses and mitochondria-mediated apoptotic protein expression, including that of Caspase-3 and Cyto C, raised the Bcl-2/Bax ratio, and lowered the number of apoptotic cells in the retina. Both BU and U0126 downregulated p-ERK and MMP9 expression. Thus, BU treatment suppressed β-DG cleavage, recovered AQP4 polarization partially via inhibiting ERK/MMP9 signaling pathway, and possess potential neuroprotective efficacy in the rat retinal ischemia-reperfusion injury model.
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Affiliation(s)
- Chunyan Chen
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Ping Fan
- Department of Gynecology and Obstetrics of The Fifth People's Hospital of Chongqing, PR China
| | - Lirong Zhang
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Kaige Xue
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Jiaheng Hu
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Juan Huang
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Weitian Lu
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Jin Xu
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Shiye Xu
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Guoping Qiu
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Jianhua Ran
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China
| | - Shengwei Gan
- Institute of Neuroscience, Basic Medicine College of Chongqing Medical University, Chongqing, PR China.
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Chojnowski K, Opiełka M, Gozdalski J, Radziwon J, Dańczyszyn A, Aitken AV, Biancardi VC, Winklewski PJ. The Role of Arginine-Vasopressin in Stroke and the Potential Use of Arginine-Vasopressin Type 1 Receptor Antagonists in Stroke Therapy: A Narrative Review. Int J Mol Sci 2023; 24:ijms24032119. [PMID: 36768443 PMCID: PMC9916514 DOI: 10.3390/ijms24032119] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 01/25/2023] Open
Abstract
Stroke is a life-threatening condition in which accurate diagnoses and timely treatment are critical for successful neurological recovery. The current acute treatment strategies, particularly non-invasive interventions, are limited, thus urging the need for novel therapeutical targets. Arginine vasopressin (AVP) receptor antagonists are emerging as potential targets to treat edema formation and subsequent elevation in intracranial pressure, both significant causes of mortality in acute stroke. Here, we summarize the current knowledge on the mechanisms leading to AVP hyperexcretion in acute stroke and the subsequent secondary neuropathological responses. Furthermore, we discuss the work supporting the predictive value of measuring copeptin, a surrogate marker of AVP in stroke patients, followed by a review of the experimental evidence suggesting AVP receptor antagonists in stroke therapy. As we highlight throughout the narrative, critical gaps in the literature exist and indicate the need for further research to understand better AVP mechanisms in stroke. Likewise, there are advantages and limitations in using copeptin as a prognostic tool, and the translation of findings from experimental animal models to clinical settings has its challenges. Still, monitoring AVP levels and using AVP receptor antagonists as an add-on therapeutic intervention are potential promises in clinical applications to alleviate stroke neurological consequences.
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Affiliation(s)
- Karol Chojnowski
- Student Scientific Circle of the Department of Adult Neurology, Medical University of Gdansk, 17 Smoluchowskiego Street, 80-214 Gdansk, Poland
| | - Mikołaj Opiełka
- Student Scientific Circle of the Department of Adult Neurology, Medical University of Gdansk, 17 Smoluchowskiego Street, 80-214 Gdansk, Poland
| | - Jacek Gozdalski
- Department of Adult Neurology, Medical University of Gdansk, 17 Smoluchowskiego Street, 80-214 Gdansk, Poland
- Correspondence: (J.G.); (P.J.W.)
| | - Jakub Radziwon
- Student Scientific Circle of the Department of Adult Neurology, Medical University of Gdansk, 17 Smoluchowskiego Street, 80-214 Gdansk, Poland
| | - Aleksandra Dańczyszyn
- Student Scientific Circle of the Department of Adult Neurology, Medical University of Gdansk, 17 Smoluchowskiego Street, 80-214 Gdansk, Poland
| | - Andrew Vieira Aitken
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Center for Neurosciences Initiative, Auburn University, Auburn, AL 36849, USA
| | - Vinicia Campana Biancardi
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Center for Neurosciences Initiative, Auburn University, Auburn, AL 36849, USA
| | - Paweł Jan Winklewski
- Department of Human Physiology, Medical University of Gdansk, 15 Tuwima Street, 80-210 Gdansk, Poland
- 2nd Department of Radiology, Medical University of Gdansk, 17 Smoluchowskiego Street, 80-214 Gdansk, Poland
- Correspondence: (J.G.); (P.J.W.)
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14
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Li X, Yang B. Non-Transport Functions of Aquaporins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:65-80. [PMID: 36717487 DOI: 10.1007/978-981-19-7415-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although it has been more than 20 years since the first aquaporin was discovered, the specific functions of many aquaporins are still under investigation, because various mice lacking aquaporins have no significant phenotypes. And in many studies, the function of aquaporin is not directly related to its transport function. Therefore, this chapter will focus on some unexpected functions of aquaporins, such the decreased tumor angiogenesis in AQP1 knockout mice, and AQP1 promotes cell migration, possibly by accelerating the water transport in lamellipodia of migrating cells. AQP transports glycerol, and water regulates glycerol content in epidermis and fat, thereby regulating skin hydration/biosynthesis and fat metabolism. AQPs may also be involved in neural signal transduction, cell volume regulation, and organelle physiology. AQP1, AQP3, and AQP5 are also involved in cell proliferation. In addition, AQPs have also been reported to play roles in inflammation in various tissues and organs. The functions of these AQPs may not depend on the permeability of small molecules such as water and glycerol, suggesting AQPs may play more roles in different biological processes in the body.
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Affiliation(s)
- Xiaowei Li
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Baoxue Yang
- School of Basic Medical Sciences, Peking University, Beijing, China.
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15
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Yi T, Gao P, Hou M, Lv H, Huang M, Gao S, He J, Yang D, Chen W, Zhu T, Yu C, Liu F, Yin H, Jin S. The mechanisms underlying the actions of Xuefu Zhuyu decoction pretreatment against neurological deficits after ischemic stroke in mice: The mediation of glymphatic function by aquaporin-4 and its anchoring proteins. Front Pharmacol 2022; 13:1053253. [PMID: 36582539 PMCID: PMC9792381 DOI: 10.3389/fphar.2022.1053253] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 11/30/2022] [Indexed: 12/15/2022] Open
Abstract
Ischemic stroke (IS) has been associated with an impairment in glymphatic function. Xuefu Zhuyu Decoction (XFZYD) is widely used in the prevention and treatment of ischemic stroke. We hypothesized that Xuefu Zhuyu decoction pretreatment could attenuate early neurological deficits after ischemic stroke by enhancing the function of the glymphatic system. To prove our hypothesis, we carried out temporary middle cerebral artery occlusion and reperfusion surgery on C57BL/6 mice and then measured neurological score, infarct size and performed hematoxylin-eosin staining to assess stroke outcomes after 24 h of reperfusion. Subsequently, we injected fluorescent tracers in to the cisterna magna and evaluated tracer distribution in coronal brain sections. The polarization of aquaporin-4 (AQP4), colocalization of aquaporin-4, α-dystroglycan, β-dystroglycan and agrin were determined by immunofluorescence. Our research showed that pretreatment with Xuefu Zhuyu decoction significantly alleviated neurological scores, neurological deficits and pathological abnormalities in a mouse model of ischemic stroke. Importantly, Xuefu Zhuyu decoction pretreatment enhanced cerebrospinal fluid influx, protected aquaporin-4 depolarization and promoted the colocalization of aquaporin-4 with its anchoring proteins in the brain. Our findings highlight novel mechanisms underlying the neuroprotective effect of Xuefu Zhuyu decoction pretreatment on ischemic stroke-induced brain damage through the glymphatic system. Xuefu Zhuyu decoction pretreatment may offer a promising approach to slow the onset and progression of ischemic stroke.
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Affiliation(s)
- Ting Yi
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ping Gao
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Meng Hou
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Huan Lv
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Mengyuan Huang
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Shanshan Gao
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jinrong He
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dongdong Yang
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Weiyin Chen
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Tianmin Zhu
- School of Health and Rehabilitation, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Chang Yu
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fuyou Liu
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Haiyan Yin
- School of Acupuncture and Tuina, Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Haiyan Yin, ; Shuoguo Jin,
| | - Shuoguo Jin
- Department of Neurology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Haiyan Yin, ; Shuoguo Jin,
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16
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Dan Q, Ma Z, Tan Y, Visar B, Chen L. AQP4 knockout promotes neurite outgrowth via upregulating GAP43 expression in infant rats with hypoxic-ischemic brain injury. IBRAIN 2022; 8:324-337. [PMID: 37786741 PMCID: PMC10528973 DOI: 10.1002/ibra.12062] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 10/04/2023]
Abstract
Neonatal hypoxic-ischemic encephalopathy (NHIE) induces severe cerebral damage and neurological dysfunction, with seldom effective therapy. Aquaporin-4 (AQP4) is involved in aggravating brain damage induced by NHIE. This study aimed to investigate the role of AQP4 underlying the pathogenesis of NHIE. Neonatal Sprague-Dawley rats were used to establish neonatal hypoxic-ischemic (HI) models, and the expression of AQP4 in the cortex, hippocampus, and lung tissues was detected by real-time quantitative polymerase chain reaction as well as Western blot. Primary cortical neurons were cultured for the oxygen-glucose deprivation (OGD) model, and siRNA was used to silence the expression of AQP4. Immunostaining of Tuj1 was performed to observe the axonal growth. CRISPER/Cas9 technology was used to knock out AQP4. The results demonstrated that AQP4 was upregulated in the cortex, hippocampus, and lung tissues in neonatal rats with HI and OGD neurons. Besides, silencing AQP4 promoted axonal growth of OGD neurons, and AQP4 knockout notably improved long-term neurobehavioral impairment. Furthermore, GAP43 was found closely correlated with AQP4 via GeneMANIA prediction. Significant downregulation of GAP43 was induced in OGD neurons, while AQP4 knockout markedly upregulated its expression in rats. This indicated that the depletion of AQP4 may enhance axonal regeneration and promote the long-term neurobehavioral recovery associated with the upregulation of GAP43 expression.
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Affiliation(s)
- Qi‐Qin Dan
- National‐Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China HospitalSichuan UniversityChengduChina
| | - Zheng Ma
- National‐Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China HospitalSichuan UniversityChengduChina
| | - Ya‐Xin Tan
- National‐Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China HospitalSichuan UniversityChengduChina
| | - Belegu Visar
- Center for Epigenetics and Induced Pluripotent Stem Cells, Kennedy Krieger InstituteJohns Hopkins UniversityBaltimoreUSA
| | - Li Chen
- National‐Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China HospitalSichuan UniversityChengduChina
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17
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Gössweiner-Mohr N, Siligan C, Pluhackova K, Umlandt L, Koefler S, Trajkovska N, Horner A. The Hidden Intricacies of Aquaporins: Remarkable Details in a Common Structural Scaffold. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2202056. [PMID: 35802902 DOI: 10.1002/smll.202202056] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/09/2022] [Indexed: 06/15/2023]
Abstract
Evolution turned aquaporins (AQPs) into the most efficient facilitators of passive water flow through cell membranes at no expense of solute discrimination. In spite of a plethora of solved AQP structures, many structural details remain hidden. Here, by combining extensive sequence- and structural-based analysis of a unique set of 20 non-redundant high-resolution structures and molecular dynamics simulations of four representatives, key aspects of AQP stability, gating, selectivity, pore geometry, and oligomerization, with a potential impact on channel functionality, are identified. The general view of AQPs possessing a continuous open water pore is challenged and it is depicted that AQPs' selectivity is not exclusively shaped by pore-lining residues but also by the relative arrangement of transmembrane helices. Moreover, this analysis reveals that hydrophobic interactions constitute the main determinant of protein thermal stability. Finally, a numbering scheme of the conserved AQP scaffold is established, facilitating direct comparison of, for example, disease-causing mutations and prediction of potential structural consequences. Additionally, the results pave the way for the design of optimized AQP water channels to be utilized in biotechnological applications.
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Affiliation(s)
| | - Christine Siligan
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstr. 40, Linz, 4020, Austria
| | - Kristyna Pluhackova
- Stuttgart Center for Simulation Science, University of Stuttgart, Cluster of Excellence EXC 2075, Universitätsstr. 32, 70569, Stuttgart, Germany
| | - Linnea Umlandt
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstr. 40, Linz, 4020, Austria
| | - Sabina Koefler
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstr. 40, Linz, 4020, Austria
| | - Natasha Trajkovska
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstr. 40, Linz, 4020, Austria
| | - Andreas Horner
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstr. 40, Linz, 4020, Austria
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18
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Skauli N, Savchenko E, Ottersen OP, Roybon L, Amiry-Moghaddam M. Canonical Bone Morphogenetic Protein Signaling Regulates Expression of Aquaporin-4 and Its Anchoring Complex in Mouse Astrocytes. Front Cell Neurosci 2022; 16:878154. [PMID: 35518645 PMCID: PMC9067306 DOI: 10.3389/fncel.2022.878154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Aquaporin-4 (AQP4) is the predominant water channel in the brain; it is enriched in astrocytic foot processes abutting vessels where it is anchored through an interaction with the dystrophin-associated protein (DAP) complex. Enhanced expression with concomitant mislocalization of AQP4 along astrocyte plasma membranes is a hallmark of several neurological conditions. Thus, there is an urgent need to identify which signaling pathways dictate AQP4 microdistribution. Here we show that canonical bone morphogenetic proteins (BMPs), particularly BMP2 and 4, upregulate AQP4 expression in astrocytes and dysregulate the associated DAP complex by differentially affecting its individual members. We further demonstrate the presence of BMP receptors and Smad1/5/9 pathway activation in BMP treated astrocytes. Our analysis of adult mouse brain reveals BMP2 and 4 in neurons and in a subclass of endothelial cells and activated Smad1/5/9 in astrocytes. We conclude that the canonical BMP-signaling pathway might be responsible for regulating the expression of AQP4 and of DAP complex proteins that govern the subcellular compartmentation of this aquaporin.
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Affiliation(s)
- Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Ekaterina Savchenko
- Stem Cell Laboratory for CNS Disease Modeling, Department of Experimental Medical Science, BMC D10, Lund University, Lund, Sweden
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Karolinska Institutet, Stockholm, Sweden
| | - Laurent Roybon
- Stem Cell Laboratory for CNS Disease Modeling, Department of Experimental Medical Science, BMC D10, Lund University, Lund, Sweden
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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19
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Yu YH, Kim SW, Kang J, Song Y, Im H, Kim SJ, Yoo DY, Lee MR, Park DK, Oh JS, Kim DS. Phosphodiesterase-5 Inhibitor Attenuates Anxious Phenotypes and Movement Disorder Induced by Mild Ischemic Stroke in Rats. J Korean Neurosurg Soc 2022; 65:665-679. [PMID: 35430790 PMCID: PMC9452378 DOI: 10.3340/jkns.2021.0101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 02/03/2022] [Indexed: 11/27/2022] Open
Abstract
Objective Patients with mild ischemic stroke experience various sequela and residual symptoms, such as anxious behavior and deficits in movement. Few approaches have been proved to be effective and safe therapeutic approaches for patients with mild ischemic stroke by acute stroke. Sildenafil (SIL), a phosphodiesterase-5 inhibitor (PDE5i), is a known remedy for neurodegenerative disorders and vascular dementia through its angiogenesis and neurogenesis effects. In this study, we investigated the efficacy of PDE5i in the emotional and behavioral abnormalities in rats with mild ischemic stroke.
Methods We divided the rats into four groups as follows (n=20, respectively) : group 1, naïve; group 2, middle cerebral artery occlusion (MCAo30); group 3, MCAo30+SIL-pre; and group 4, MCAo30+SIL-post. In the case of drug administration groups, single dose of PDE5i (sildenafil citrate, 20 mg/kg) was given at 30-minute before and after reperfusion of MCAo in rats. After surgery, we investigated and confirmed the therapeutic effect of sildenafil on histology, immunofluorescence, behavioral assays and neural oscillations.
Results Sildenafil alleviated a neuronal loss and reduced the infarction volume. And results of behavior task and immunofluorescence shown possibility that anti-inflammation process and improve motor deficits sildenafil treatment after mild ischemic stroke. Furthermore, sildenafil treatment attenuated the alteration of theta-frequency rhythm in the CA1 region of the hippocampus, a known neural oscillatory marker for anxiety disorder in rodents, induced by mild ischemic stroke.
Conclusion PDE5i as effective therapeutic agents for anxiety and movement disorders and provide robust preclinical evidence to support the development and use of PDE5i for the treatment of mild ischemic stroke residual disorders.
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Mills WA, Woo AM, Jiang S, Martin J, Surendran D, Bergstresser M, Kimbrough IF, Eyo UB, Sofroniew MV, Sontheimer H. Astrocyte plasticity in mice ensures continued endfoot coverage of cerebral blood vessels following injury and declines with age. Nat Commun 2022; 13:1794. [PMID: 35379828 PMCID: PMC8980042 DOI: 10.1038/s41467-022-29475-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 03/11/2022] [Indexed: 01/30/2023] Open
Abstract
Astrocytes extend endfeet that enwrap the vasculature, and disruptions to this association which may occur in disease coincide with breaches in blood-brain barrier (BBB) integrity. Here we investigate if focal ablation of astrocytes is sufficient to disrupt the BBB in mice. Targeted two-photon chemical apoptotic ablation of astrocytes induced a plasticity response whereby surrounding astrocytes extended processes to cover vascular vacancies. In young animals, replacement processes occur in advance of endfoot retraction, but this is delayed in aged animals. Stimulation of replacement astrocytes results in constriction of pre-capillary arterioles, suggesting that replacement astrocytes are functional. Pharmacological inhibition of pSTAT3, as well as astrocyte specific deletion of pSTAT3, reduces astrocyte replacement post-ablation, without perturbations to BBB integrity. Similar endfoot replacement occurs following astrocyte cell death due to reperfusion in a stroke model. Together, these studies uncover the ability of astrocytes to maintain cerebrovascular coverage via substitution from nearby cells.
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Affiliation(s)
- William A. Mills
- grid.27755.320000 0000 9136 933XBrain, Immunology, and Glia Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XDepartment of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XRobert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.438526.e0000 0001 0694 4940Graduate Program in Translational Biology, Medicine, & Health, Virginia Polytechnic Institute and State University, Blacksburg, VA USA
| | - AnnaLin M. Woo
- grid.27755.320000 0000 9136 933XBrain, Immunology, and Glia Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XDepartment of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Shan Jiang
- grid.168010.e0000000419368956Department of Material Science and Engineering, Stanford University, Stanford, CA USA ,grid.168010.e0000000419368956Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA USA
| | - Joelle Martin
- grid.438526.e0000 0001 0694 4940Graduate Program in Translational Biology, Medicine, & Health, Virginia Polytechnic Institute and State University, Blacksburg, VA USA
| | - Dayana Surendran
- grid.27755.320000 0000 9136 933XBrain, Immunology, and Glia Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XDepartment of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Matthew Bergstresser
- grid.438526.e0000 0001 0694 4940School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA USA
| | - Ian F. Kimbrough
- grid.27755.320000 0000 9136 933XBrain, Immunology, and Glia Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XDepartment of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Ukpong B. Eyo
- grid.27755.320000 0000 9136 933XBrain, Immunology, and Glia Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XDepartment of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XRobert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA USA
| | - Michael V. Sofroniew
- grid.19006.3e0000 0000 9632 6718Department of Neurobiology, University of California, Los Angeles, CA USA
| | - Harald Sontheimer
- grid.27755.320000 0000 9136 933XBrain, Immunology, and Glia Center, University of Virginia School of Medicine, Charlottesville, VA USA ,grid.27755.320000 0000 9136 933XDepartment of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA USA
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21
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Abstract
The brain harbors a unique ability to, figuratively speaking, shift its gears. During wakefulness, the brain is geared fully toward processing information and behaving, while homeostatic functions predominate during sleep. The blood-brain barrier establishes a stable environment that is optimal for neuronal function, yet the barrier imposes a physiological problem; transcapillary filtration that forms extracellular fluid in other organs is reduced to a minimum in brain. Consequently, the brain depends on a special fluid [the cerebrospinal fluid (CSF)] that is flushed into brain along the unique perivascular spaces created by astrocytic vascular endfeet. We describe this pathway, coined the term glymphatic system, based on its dependency on astrocytic vascular endfeet and their adluminal expression of aquaporin-4 water channels facing toward CSF-filled perivascular spaces. Glymphatic clearance of potentially harmful metabolic or protein waste products, such as amyloid-β, is primarily active during sleep, when its physiological drivers, the cardiac cycle, respiration, and slow vasomotion, together efficiently propel CSF inflow along periarterial spaces. The brain's extracellular space contains an abundance of proteoglycans and hyaluronan, which provide a low-resistance hydraulic conduit that rapidly can expand and shrink during the sleep-wake cycle. We describe this unique fluid system of the brain, which meets the brain's requisites to maintain homeostasis similar to peripheral organs, considering the blood-brain-barrier and the paths for formation and egress of the CSF.
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Affiliation(s)
- Martin Kaag Rasmussen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Humberto Mestre
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
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22
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Banitalebi S, Skauli N, Geiseler S, Ottersen OP, Amiry-Moghaddam M. Disassembly and Mislocalization of AQP4 in Incipient Scar Formation after Experimental Stroke. Int J Mol Sci 2022; 23:ijms23031117. [PMID: 35163040 PMCID: PMC8835637 DOI: 10.3390/ijms23031117] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/10/2022] [Accepted: 01/17/2022] [Indexed: 12/04/2022] Open
Abstract
There is an urgent need to better understand the mechanisms involved in scar formation in the brain. It is well known that astrocytes are critically engaged in this process. Here, we analyze incipient scar formation one week after a discrete ischemic insult to the cerebral cortex. We show that the infarct border zone is characterized by pronounced changes in the organization and subcellular localization of the major astrocytic protein AQP4. Specifically, there is a loss of AQP4 from astrocytic endfoot membranes that anchor astrocytes to pericapillary basal laminae and a disassembly of the supramolecular AQP4 complexes that normally abound in these membranes. This disassembly may be mechanistically coupled to a downregulation of the newly discovered AQP4 isoform AQP4ex. AQP4 has adhesive properties and is assumed to facilitate astrocyte mobility by permitting rapid volume changes at the leading edges of migrating astrocytes. Thus, the present findings provide new insight in the molecular basis of incipient scar formation.
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Affiliation(s)
- Shervin Banitalebi
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
| | - Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
| | - Samuel Geiseler
- Cardiovascular Research Group IMB, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9019 Tromsø, Norway
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
- President's Office, Karolinska Institutet, Nobels väg 6, 171 77 Stockholm, Sweden
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
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23
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Przykaza Ł. Understanding the Connection Between Common Stroke Comorbidities, Their Associated Inflammation, and the Course of the Cerebral Ischemia/Reperfusion Cascade. Front Immunol 2021; 12:782569. [PMID: 34868060 PMCID: PMC8634336 DOI: 10.3389/fimmu.2021.782569] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/29/2021] [Indexed: 01/13/2023] Open
Abstract
Despite the enormous progress in the understanding of the course of the ischemic stroke over the last few decades, a therapy that effectively protects neurovascular units (NVUs) and significantly improves neurological functions in stroke patients has still not been achieved. The reasons for this state are unclear, but it is obvious that the cerebral ischemia and reperfusion cascade is a highly complex phenomenon, which includes the intense neuroinflammatory processes, and comorbid stroke risk factors strongly worsen stroke outcomes and likely make a substantial contribution to the pathophysiology of the ischemia/reperfusion, enhancing difficulties in searching of successful treatment. Common concomitant stroke risk factors (arterial hypertension, diabetes mellitus and hyperlipidemia) strongly drive inflammatory processes during cerebral ischemia/reperfusion; because these factors are often present for a long time before a stroke, causing low-grade background inflammation in the brain, and already initially disrupting the proper functions of NVUs. Broad consideration of this situation in basic research may prove to be crucial for the success of future clinical trials of neuroprotection, vasculoprotection and immunomodulation in stroke. This review focuses on the mechanism by which coexisting common risk factors for stroke intertwine in cerebral ischemic/reperfusion cascade and the dysfunction and disintegration of NVUs through inflammatory processes, principally activation of pattern recognition receptors, alterations in the expression of adhesion molecules and the subsequent pathophysiological consequences.
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Affiliation(s)
- Łukasz Przykaza
- Laboratory of Experimental and Clinical Neurosurgery, Mossakowski Medical Research Institute, Polish Academy of Sciences, Warsaw, Poland
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24
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Patabendige A, Singh A, Jenkins S, Sen J, Chen R. Astrocyte Activation in Neurovascular Damage and Repair Following Ischaemic Stroke. Int J Mol Sci 2021; 22:4280. [PMID: 33924191 PMCID: PMC8074612 DOI: 10.3390/ijms22084280] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 04/11/2021] [Accepted: 04/15/2021] [Indexed: 12/11/2022] Open
Abstract
Transient or permanent loss of tissue perfusion due to ischaemic stroke can lead to damage to the neurovasculature, and disrupt brain homeostasis, causing long-term motor and cognitive deficits. Despite promising pre-clinical studies, clinically approved neuroprotective therapies are lacking. Most studies have focused on neurons while ignoring the important roles of other cells of the neurovascular unit, such as astrocytes and pericytes. Astrocytes are important for the development and maintenance of the blood-brain barrier, brain homeostasis, structural support, control of cerebral blood flow and secretion of neuroprotective factors. Emerging data suggest that astrocyte activation exerts both beneficial and detrimental effects following ischaemic stroke. Activated astrocytes provide neuroprotection and contribute to neurorestoration, but also secrete inflammatory modulators, leading to aggravation of the ischaemic lesion. Astrocytes are more resistant than other cell types to stroke pathology, and exert a regulative effect in response to ischaemia. These roles of astrocytes following ischaemic stroke remain incompletely understood, though they represent an appealing target for neurovascular protection following stroke. In this review, we summarise the astrocytic contributions to neurovascular damage and repair following ischaemic stroke, and explore mechanisms of neuroprotection that promote revascularisation and neurorestoration, which may be targeted for developing novel therapies for ischaemic stroke.
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Affiliation(s)
- Adjanie Patabendige
- Brain Barriers Group, School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2321, Australia;
- Priority Research Centre for Stroke and Brain Injury, and Priority Research Centre for Brain & Mental Health, University of Newcastle, Callaghan, NSW 2321, Australia
- Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
- Institute of Infection & Global Health, University of Liverpool, Liverpool L7 3EA, UK
| | - Ayesha Singh
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK;
| | - Stuart Jenkins
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK; (S.J.); (J.S.)
- Neural Tissue Engineering: Keele (NTEK), Keele University, Staffordshire ST5 5BG, UK
| | - Jon Sen
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK; (S.J.); (J.S.)
- Clinical Informatics and Neurosurgery Fellow, The Cleveland Clinic, 33 Grosvenor Square, London SW1X 7HY, UK
| | - Ruoli Chen
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK;
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25
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Rao SB, Skauli N, Jovanovic N, Katoozi S, Frigeri A, Froehner SC, Adams ME, Ottersen OP, Amiry-Moghaddam M. Orchestrating aquaporin-4 and connexin-43 expression in brain: Differential roles of α1- and β1-syntrophin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183616. [PMID: 33872576 DOI: 10.1016/j.bbamem.2021.183616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/22/2021] [Accepted: 03/25/2021] [Indexed: 01/09/2023]
Abstract
Aquaporin-4 (AQP4) water channels and gap junction proteins (connexins) are two classes of astrocytic membrane proteins critically involved in brain water and ion homeostasis. AQP4 channels are anchored by α1-syntrophin to the perivascular astrocytic endfoot membrane domains where they control water flux at the blood-brain interface while connexins cluster at the lateral aspects of the astrocytic endfeet forming gap junctions that allow water and ions to dissipate through the astrocyte syncytium. Recent studies have pointed to an interdependence between astrocytic AQP4 and astrocytic gap junctions but the underlying mechanism remains to be explored. Here we use a novel transgenic mouse line to unravel whether β1-syntrophin (coexpressed with α1-syntrophin in astrocytic plasma membranes) is implicated in the expression of AQP4 isoforms and formation of gap junctions in brain. Our results show that while the effect of β1-syntrophin deletion is rather limited, double knockout of α1- and β1-syntrophin causes a downregulation of the novel AQP4 isoform AQP4ex and an increase in the number of astrocytic gap junctions. The present study highlight the importance of syntrophins in orchestrating specialized functional domains of brain astrocytes.
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Affiliation(s)
- Shreyas B Rao
- Laboratory of Molecular Neuroscience, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317 Oslo, Norway.
| | - Nadia Skauli
- Laboratory of Molecular Neuroscience, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317 Oslo, Norway.
| | - Nenad Jovanovic
- Laboratory of Molecular Neuroscience, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317 Oslo, Norway
| | - Shirin Katoozi
- Laboratory of Molecular Neuroscience, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317 Oslo, Norway
| | - Antonio Frigeri
- School of Medicine, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari Aldo Moro, Bari, Italy.
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195-7290, USA.
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195-7290, USA.
| | - Ole Petter Ottersen
- Laboratory of Molecular Neuroscience, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317 Oslo, Norway.
| | - Mahmood Amiry-Moghaddam
- Laboratory of Molecular Neuroscience, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317 Oslo, Norway.
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26
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Ramadhanti J, Yamada T, Yasui M, Nuriya M. Differentially regulated pools of aquaporin-4 (AQP4) proteins in the cerebral cortex revealed by biochemical fractionation analyses. J Pharmacol Sci 2021; 146:58-64. [PMID: 33858656 DOI: 10.1016/j.jphs.2021.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 11/29/2022] Open
Abstract
Aquaporin-4 (AQP4) is a predominant water channel in the central nervous system. It regulates water movement in the brain and has been suggested to play critical roles in various pathological conditions. However, the molecular mechanisms underlying its regulation are not yet well understood. In this study, we biochemically characterized AQP4 in the brain using acute cortical brain slices prepared from mice. Using biochemical fractionation, we found that AQP4 is enriched in the detergent-resistant membrane (DRM) fraction that is not soluble in 1% Triton X-100. In contrast, β-dystroglycan and syntrophin, which are part of the dystrophin complex in the brain, primarily reside in the non-DRM fraction. DRM enrichment of AQP4 is insensitive to cholesterol depletion, suggesting that it is not tightly associated with lipid rafts. Furthermore, AQP4 in the DRM fraction is more enriched in the M23 isoform than in the non-DRM fraction. Finally, by employing oxygen-glucose deprivation (OGD), an in vitro model of ischemia, we examined the molecular changes of AQP4. Under OGD conditions, a reduction in AQP4 in the DRM fraction was observed before the total AQP4 protein level dropped. Our data therefore highlight the characteristics of two pools of AQP4 that are distinctly regulated under ischemic conditions.
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Affiliation(s)
- Julia Ramadhanti
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; Department of Biomedical Science, Medical Faculty, Universitas Padjadjaran, Jalan Professor Eijkman no.38, Bandung, 40161, Indonesia
| | - Tomoko Yamada
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Masato Yasui
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; Keio Advanced Research Center for Water Biology and Medicine, Keio University, 2-15-45 Mita, Minato-ku, Tokyo, 108-8345, Japan
| | - Mutsuo Nuriya
- Department of Pharmacology School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; Graduate School of Environment and Information Sciences, Yokohama National University, Kanagawa, 240-8501, Japan; Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama, 332-0012, Japan; Keio Advanced Research Center for Water Biology and Medicine, Keio University, 2-15-45 Mita, Minato-ku, Tokyo, 108-8345, Japan.
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27
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Chau S, Fujii A, Wang Y, Vandebroek A, Goda W, Yasui M, Abe Y. Di-lysine motif-like sequences formed by deleting the C-terminal domain of aquaporin-4 prevent its trafficking to the plasma membrane. Genes Cells 2021; 26:152-164. [PMID: 33474763 DOI: 10.1111/gtc.12829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/17/2021] [Accepted: 01/17/2021] [Indexed: 11/30/2022]
Abstract
Aquaporin-4 is a transmembrane water channel protein, the C-terminal domain of which is facing the cytosol. In the process of investigating the role of the C-terminal domain of aquaporin-4 with regard to intracellular trafficking, we observed that a derivative of aquaporin-4, in which the C-terminal 53 amino acids had been removed (Δ271-323), was localized to intracellular compartments, including the endoplasmic reticulum, but was not expressed on the plasma membranes. This was determined by immunofluorescence staining and labeling of the cells with monoclonal antibody specifically recognizing the extracellular domain of aquaporin-4, followed by confocal microscopy and flow cytometry. Deletion of additional amino acids in the C-terminal domain of aquaporin-4 led to its redistribution to the plasma membrane. This suggests that the effect of the 53-amino acid deletion on the subcellular localization of aquaporin-4 could be attributed to the formation of a signal at the C terminus that retained aquaporin-4 in intracellular compartments, rather than the loss of a signal required for plasma membrane targeting. Substitution of the lysine at position 268 with alanine could rescue the Δ271-323-associated retention in the cytosol, suggesting that the C-terminal sequence of the mutant served as a signal similar to a di-lysine motif.
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Affiliation(s)
- Simon Chau
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
| | - Atsushi Fujii
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
| | - Yingqi Wang
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
| | - Arno Vandebroek
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
| | - Wakami Goda
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
| | - Masato Yasui
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan.,Center for Water Biology & Medicine, Keio University Global Research Institute, Tokyo, Japan
| | - Yoichiro Abe
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan.,Center for Water Biology & Medicine, Keio University Global Research Institute, Tokyo, Japan
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28
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Belmaati Cherkaoui M, Vacca O, Izabelle C, Boulay AC, Boulogne C, Gillet C, Barnier JV, Rendon A, Cohen-Salmon M, Vaillend C. Dp71 contribution to the molecular scaffold anchoring aquaporine-4 channels in brain macroglial cells. Glia 2020; 69:954-970. [PMID: 33247858 DOI: 10.1002/glia.23941] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 02/06/2023]
Abstract
Intellectual disability in Duchenne muscular dystrophy has been associated with the loss of dystrophin-protein 71, Dp71, the main dystrophin-gene product in the adult brain. Dp71 shows major expression in perivascular macroglial endfeet, suggesting that dysfunctional glial mechanisms contribute to cognitive impairments. In the present study, we investigated the molecular alterations induced by a selective loss of Dp71 in mice, using semi-quantitative immunogold analyses in electron microscopy and immunofluorescence confocal analyses in brain sections and purified gliovascular units. In macroglial pericapillary endfeet of the cerebellum and hippocampus, we found a drastic reduction (70%) of the polarized distribution of aquaporin-4 (AQP4) channels, a 50% reduction of β-dystroglycan, and a complete loss of α1-syntrophin. Interestingly, in the hippocampus and cortex, these effects were not homogeneous: AQP4 and AQP4ex isoforms were mostly lost around capillaries but preserved in large vessels corresponding to pial arteries, penetrating cortical arterioles, and arterioles of the hippocampal fissure, indicating the presence of Dp71-independent pools of AQP4 in these vascular structures. In conclusion, the depletion of Dp71 strongly alters the distribution of AQP4 selectively in macroglial perivascular endfeet surrounding capillaries. This effect likely affects water homeostasis and blood-brain barrier functions and may thus contribute to the synaptic and cognitive defects associated with Dp71 deficiency.
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Affiliation(s)
| | - Ophélie Vacca
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, Gif-sur-Yvette, France
| | - Charlotte Izabelle
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, Gif-sur-Yvette, France
| | - Anne-Cécile Boulay
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, Unité Mixte de Recherche 7241CNRS, Unité 1050 INSERM, PSL Research University, Paris, France
| | - Claire Boulogne
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Cynthia Gillet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Jean-Vianney Barnier
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, Gif-sur-Yvette, France
| | - Alvaro Rendon
- UPMC Université Paris 06, INSERM, CNRS, Institut de la Vision, Sorbonne Universités, Paris, France
| | - Martine Cohen-Salmon
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, Unité Mixte de Recherche 7241CNRS, Unité 1050 INSERM, PSL Research University, Paris, France
| | - Cyrille Vaillend
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, Gif-sur-Yvette, France
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29
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Pro-Inflammatory Role of AQP4 in Mice Subjected to Intrastriatal Injections of the Parkinsonogenic Toxin MPP. Cells 2020; 9:cells9112418. [PMID: 33167342 PMCID: PMC7694382 DOI: 10.3390/cells9112418] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/01/2020] [Accepted: 11/02/2020] [Indexed: 12/28/2022] Open
Abstract
Aquaporin-4 (AQP4) is critically involved in brain water and volume homeostasis and has been implicated in a wide range of pathological conditions. Notably, evidence has been accrued to suggest that AQP4 plays a proinflammatory role by promoting release of astrocytic cytokines that activate microglia and other astrocytes. Neuroinflammation is a hallmark of Parkinson’s disease (PD), and we have previously shown that astrocytes in substantia nigra (SN) are enriched in AQP4 relative to cortical astrocytes, and that their complement of AQP4 is further increased following treatment with the parkinsonogenic toxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). Here, we investigated the effect of Aqp4 deletion on microglial activation in mice subjected to unilateral intrastriatal injection of 1-methyl-4-phenylpyridinium (MPP+, the toxic metabolite of MPTP). Our results show that MPP+ injections lead to a pronounced increase in the expression level of microglial activating genes in the ventral mesencephalon of wild type (WT) mice, but not Aqp4−/− mice. We also show, in WT mice, that MPP+ injections cause an upregulation of nigral AQP4 and swelling of astrocytic endfeet. These findings are consistent with the idea that AQP4 plays a pro-inflammatory role in Parkinson’s disease, secondary to the dysregulation of astrocytic volume homeostasis.
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30
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Jin J, Wang H, Zheng X, Xie S, Zheng L, Zhan R. Inhibition of LncRNA MALAT1 Attenuates Cerebral Ischemic Reperfusion Injury via Regulating AQP4 Expression. Eur Neurol 2020; 83:581-590. [PMID: 33130678 DOI: 10.1159/000511238] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/25/2020] [Indexed: 01/05/2023]
Abstract
Stroke is one of the leading causes of mortality and disability worldwide. Long noncoding RNAs (lncRNAs) including MALAT1 have been shown to have critical roles in cerebral ischemia reperfusion injury (CIRI). However, the underlying mechanism of MALAT1 in CIRI has not been elucidated. The present study aimed to investigate the function and potential regulatory mechanism of MALAT1 in cerebral ischemic reperfusion injury. We established the middle cerebral artery occlusion (MCAO) model and oxygen-glucose deprivation/reoxygenation (OGD/RX) model in vivo and in vitro, and then Cell Counting Kit-8 (CCK-8), RT-qPCR, flow cytometry analysis, lactate dehydrogenase (LDH) analysis, and 2,3,5-triphenyltetrazolium chloride (TTC) staining were used to examine cell viability, MALAT1, aquaporin-4 (AQP4) expression, LDH release, and infarct volume, respectively. The level of AQP4 was remarkably upregulated in CIRI 24 h/48 h or OGD/RX 24 h/48 h compared with the sham group. Knockdown of AQP4 could alleviate OGD/RX-induced injury through enhancing cell viability and reducing LDH release and the rate of apoptotic cells. Furthermore, we found that MALAT1 was also increased in OGD/RX 24 h/48 h and silencing of MALAT1 could decrease AQP4. Inhibition of MALAT1 could also protect OGD/RX-induced injury, while the protective effect of MALAT1 siRNA on cerebral ischemic reperfusion was disappeared after transfection with AQP4 plasmid, indicating that MALAT1 may play a protective role in brain stroke through regulating AQP4. Taken together, our study provides evidence that MALAT1 is involved in ischemic stroke by inhibiting AQP4. Therefore, MALAT1 may serve as a potential target for therapeutic intervention in ischemic brain injury.
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Affiliation(s)
- Jing Jin
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
| | - Hongwei Wang
- Department of Anesthesiology, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Xiaoxiao Zheng
- Cancer Institute of Integrated Traditional Chinese and Western Medicine, Zhejiang Academy of Traditional Chinese Medicine, Tongde Hospital of Zhejiang Province, Hangzhou, China.,Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Shangzhi Xie
- Cancer Institute of Integrated Traditional Chinese and Western Medicine, Zhejiang Academy of Traditional Chinese Medicine, Tongde Hospital of Zhejiang Province, Hangzhou, China.,Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Li Zheng
- Cancer Institute of Integrated Traditional Chinese and Western Medicine, Zhejiang Academy of Traditional Chinese Medicine, Tongde Hospital of Zhejiang Province, Hangzhou, China.,Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, China
| | - Renya Zhan
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China,
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Cohen-Salmon M, Slaoui L, Mazaré N, Gilbert A, Oudart M, Alvear-Perez R, Elorza-Vidal X, Chever O, Boulay AC. Astrocytes in the regulation of cerebrovascular functions. Glia 2020; 69:817-841. [PMID: 33058289 DOI: 10.1002/glia.23924] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/18/2022]
Abstract
Astrocytes are the most numerous type of neuroglia in the brain and have a predominant influence on the cerebrovascular system; they control perivascular homeostasis, the integrity of the blood-brain barrier, the dialogue with the peripheral immune system, the transfer of metabolites from the blood, and blood vessel contractility in response to neuronal activity. These regulatory processes occur in a specialized interface composed of perivascular astrocyte extensions that almost completely cover the cerebral blood vessels. Scientists have only recently started to study how this interface is formed and how it influences cerebrovascular functions. Here, we review the literature on the astrocytes' role in the regulation of the cerebrovascular system. We cover the anatomy and development of the gliovascular interface, the known gliovascular functions, and molecular factors, the latter's implication in certain pathophysiological situations, and recent cutting-edge experimental tools developed to examine the astrocytes' role at the vascular interface. Finally, we highlight some open questions in this field of research.
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Affiliation(s)
- Martine Cohen-Salmon
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Leila Slaoui
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Noémie Mazaré
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Alice Gilbert
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Marc Oudart
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Rodrigo Alvear-Perez
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Xabier Elorza-Vidal
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
| | - Oana Chever
- Normandie University, UNIROUEN, INSERM, DC2N, IRIB, Rouen, France
| | - Anne-Cécile Boulay
- Physiology and Physiopathology of the Gliovascular Unit Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS Unité Mixte de Recherche 724, INSERM Unité 1050, Labex Memolife, PSL Research University, Paris, France
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32
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Drug development in targeting ion channels for brain edema. Acta Pharmacol Sin 2020; 41:1272-1288. [PMID: 32855530 PMCID: PMC7609292 DOI: 10.1038/s41401-020-00503-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/02/2020] [Indexed: 12/18/2022] Open
Abstract
Cerebral edema is a pathological hallmark of various central nervous system (CNS) insults, including traumatic brain injury (TBI) and excitotoxic injury such as stroke. Due to the rigidity of the skull, edema-induced increase of intracranial fluid significantly complicates severe CNS injuries by raising intracranial pressure and compromising perfusion. Mortality due to cerebral edema is high. With mortality rates up to 80% in severe cases of stroke, it is the leading cause of death within the first week. Similarly, cerebral edema is devastating for patients of TBI, accounting for up to 50% mortality. Currently, the available treatments for cerebral edema include hypothermia, osmotherapy, and surgery. However, these treatments only address the symptoms and often elicit adverse side effects, potentially in part due to non-specificity. There is an urgent need to identify effective pharmacological treatments for cerebral edema. Currently, ion channels represent the third-largest target class for drug development, but their roles in cerebral edema remain ill-defined. The present review aims to provide an overview of the proposed roles of ion channels and transporters (including aquaporins, SUR1-TRPM4, chloride channels, glucose transporters, and proton-sensitive channels) in mediating cerebral edema in acute ischemic stroke and TBI. We also focus on the pharmacological inhibitors for each target and potential therapeutic strategies that may be further pursued for the treatment of cerebral edema.
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33
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Guo H, Yin A, Ma Y, Fan Z, Tao L, Tang W, Ma Y, Hou W, Cai G, Zhuo L, Zhang J, Li Y, Xiong L. Astroglial N-myc downstream-regulated gene 2 protects the brain from cerebral edema induced by stroke. Glia 2020; 69:281-295. [PMID: 32652708 PMCID: PMC7754347 DOI: 10.1002/glia.23888] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 06/16/2020] [Accepted: 06/26/2020] [Indexed: 01/14/2023]
Abstract
Brain edema is a grave complication of brain ischemia and is the main cause of herniation and death. Although astrocytic swelling is the main contributor to cytotoxic edema, the molecular mechanism involved in this process remains elusive. N‐myc downstream‐regulated gene 2 (NDRG2), a well‐studied tumor suppressor gene, is mainly expressed in astrocytes in mammalian brains. Here, we found that NDRG2 deficiency leads to worsened cerebral edema, imbalanced Na+ transfer, and astrocyte swelling after ischemia. We also found that NDRG2 deletion in astrocytes dramatically changed the expression and distribution of aquaporin‐4 and Na+‐K+‐ATPase β1, which are strongly associated with cell polarity, in the ischemic brain. Brain edema and astrocyte swelling were significantly alleviated by rescuing the expression of astrocytic Na+‐K+‐ATPase β1 in NDRG2‐knockout mouse brains. In addition, the upregulation of astrocytic NDRG2 by lentiviral constructs notably attenuated brain edema, astrocytic swelling, and blood–brain barrier destruction. Our results indicate a particular role of NDRG2 in maintaining astrocytic polarization to facilitate Na+ and water transfer balance and to protect the brain from ischemic edema. These findings provide insight into NDRG2 as a therapeutic target in cerebral edema.
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Affiliation(s)
- Hang Guo
- Department of Anesthesiology, The Seventh Medical Center of Chinese PLA General Hospital, Beijing, China.,Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China
| | - Anqi Yin
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China.,Department of Anesthesiology, Jinling Hospital, Nanjing, China
| | - Yulong Ma
- Anesthesia and Operation Center, The First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Ze Fan
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China
| | - Liang Tao
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China
| | - Wenhong Tang
- Department of Anesthesiology, The 960th Hospital of PLA, Jinan, China
| | - Yaqun Ma
- Department of Anesthesiology, The Seventh Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Wugang Hou
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China
| | - Guohong Cai
- Institute of Neuroscience, The Air Force Military Medical University, Xi'an, China
| | - Lixia Zhuo
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Jian Zhang
- Department of Biochemistry and Molecular Biology, The Air Force Military Medical University, Xi'an, China
| | - Yan Li
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China.,Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Lize Xiong
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, The Air Force Military Medical University, Xi'an, China.,Department of Anesthesiology & Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital, Tongji University School of Medicine, Shanghai, China
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34
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Wang H, Chen H, Jin J, Liu Q, Zhong D, Li G. Inhibition of the NLRP3 inflammasome reduces brain edema and regulates the distribution of aquaporin-4 after cerebral ischaemia-reperfusion. Life Sci 2020; 251:117638. [PMID: 32251636 DOI: 10.1016/j.lfs.2020.117638] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/24/2020] [Accepted: 04/01/2020] [Indexed: 12/19/2022]
Abstract
AIMS Brain edema is a common threat to life in ischaemic brain injury. The NLRP3 inflammasome promotes the inflammatory injury after ischaemic stroke. Previous studies have shown that aquaporin-4 (AQP4) modulates brain water transport and endothelin-1 (ET-1) induces cerebral edema. However, the contribution of the NLRP3 inflammasome to regulation of brain edema and blood-brain barrier (BBB) disruption in cerebral ischaemia-reperfusion is elusive. The aim of this study is to investigate the effect of inhibition of the NLRP3 inflammasome by MCC950 on regulation of cerebral edema, BBB disruption and the expression of AQP4 and ET-1 in cerebral ischaemia-reperfusion. MAIN METHODS The male C57BL/6 mice were used to establish the experimental transient middle cerebral artery occlusion (tMCAO) model. The mice were intraperitoneally injected with MCC950. Changes in NLRP3, IL-1β, IL-18, the pyroptosis protein gasdermin D (GSDMD), brain water content, AQP4 and ET-1 in brain tissue were detected. KEY FINDINGS MCC950 inhibited NLRP3 and GSDMD after tMCAO. MCC950 improved cerebral edema and alleviated the damage of BBB after tMCAO. The levels of AQP4 and ET-1 were decreased by MCC950. In addition, MCC950 regulated the distribution of AQP4 after tMCAO in mice. SIGNIFICANCE The NLRP3 inflammasome facilitated brain edema and BBB disruption after cerebral ischaemia-reperfusion in mice, and NLRP3 inflammasome inhibition with MCC950 regulated the expression and distribution of AQP4 in the infarct area. Hence, the NLRP3 inflammasome is considered to be an important target for the treatment of brain edema in cerebral ischaemia-reperfusion, and MCC950 has potential value for ischaemic stroke treatment.
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Affiliation(s)
- Haining Wang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, China
| | - Hongping Chen
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, China
| | - Jing Jin
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, China
| | - Qingqing Liu
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, China
| | - Di Zhong
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, China.
| | - Guozhong Li
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, China.
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35
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Katoozi S, Rao SB, Skauli N, Froehner SC, Ottersen OP, Adams ME, Amiry-Moghaddam M. Functional specialization of retinal Müller cell endfeet depends on an interplay between two syntrophin isoforms. Mol Brain 2020; 13:40. [PMID: 32178707 PMCID: PMC7074989 DOI: 10.1186/s13041-020-00581-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 03/06/2020] [Indexed: 11/10/2022] Open
Abstract
Retinal Müller cells are highly polarized macroglial cells with accumulation of the aquaporin-4 (AQP4) water channel and the inwardly rectifying potassium channel Kir4.1 at specialized endfoot membrane domains abutting microvessels and corpus vitreum. Proper water and potassium homeostasis in retina depends on these membrane specializations. Here we show that targeted deletion of β1-syntrophin leads to a partial loss of AQP4 from perivascular Müller cell endfeet and that a concomitant deletion of both α1- and β1-syntrophin causes a near complete loss of AQP4 from both perivascular and subvitreal endfoot membranes. α1-syntrophin is normally very weakly expressed in Müller cell endfeet but β1-syntrophin knockout mice display an increased amount of α1-syntrophin at these sites. We suggest that upregulation of perivascular α1-syntrophin restricts the effect of β1-syntrophin deletion. The present findings indicate that β1-syntrophin plays an important role in maintaining the functional polarity of Müller cells and that α1-syntrophin can partially substitute for β1-syntrophin in AQP4 anchoring. Functional polarization of Müller cells thus depends on an interplay between two syntrophin isoforms.
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Affiliation(s)
- Shirin Katoozi
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway
| | - Shreyas B Rao
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway
| | - Nadia Skauli
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195-7290, USA
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway.,Present Address: President's office, Karolinska Institutet, Nobels väg 6, 171 77, Stockholm, Sweden
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195-7290, USA
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Post box 1105, Blindern, 0317, Oslo, Norway.
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36
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Hoddevik EH, Rao SB, Zahl S, Boldt HB, Ottersen OP, Amiry-Moghaddam M. Organisation of extracellular matrix proteins laminin and agrin in pericapillary basal laminae in mouse brain. Brain Struct Funct 2020; 225:805-816. [PMID: 32072250 PMCID: PMC7046580 DOI: 10.1007/s00429-020-02036-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 01/29/2020] [Indexed: 01/08/2023]
Abstract
Evidence suggests that extracellular matrix molecules of perivascular basal laminae help orchestrate the molecular assemblies at the gliovascular interface. Specifically, laminin and agrin are thought to tether the dystrophin-associated protein (DAP) complex to the astrocytic basal lamina. This complex includes α-syntrophin (α-Syn), which is believed to anchor aquaporin-4 (AQP4) to astrocytic endfoot membrane domains. We have previously shown that the size of the perivascular AQP4 pool differs considerably between brain regions in an α-Syn-dependent manner. Also, both AQP4 and α-Syn occur at higher densities in endfoot membrane domains facing pericytes than in endfoot membrane domains facing endothelial cells. The heterogeneous distribution of AQP4 at the regional and capillary level has been attributed to a direct interaction between AQP4 and α-Syn. This would be challenged (1) if the microdistributions of laminin and agrin fail to align with those of DAP and AQP4 and (2) if targeted deletion of α-Syn leads to a loss of laminin and/or agrin. Here, we provide the first detailed and quantitative analysis of laminin and agrin in brain basal laminae of mice. We show that the microdistributions of these molecules vary in a fashion that is well aligned with the previously reported microdistribution of AQP4. We also demonstrate that the expression patterns of laminin and agrin are insensitive to targeted deletion of α-Syn, suggesting that α-Syn deletion affects AQP4 directly and not indirectly via laminin or agrin. These data fill remaining voids in the current model of how key molecules are assembled and tethered at the gliovascular interface.
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Affiliation(s)
- Eystein Hellstrøm Hoddevik
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Post box 1105, 0317, Oslo, Norway
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - Shreyas Balachandra Rao
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Post box 1105, 0317, Oslo, Norway
| | - Soulmaz Zahl
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Post box 1105, 0317, Oslo, Norway
| | - Henning Bünsow Boldt
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Post box 1105, 0317, Oslo, Norway
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - Ole Petter Ottersen
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Post box 1105, 0317, Oslo, Norway
- President's Office, Karolinska Institutet, Nobels väg 6, 171 77, Stockholm, Sweden
| | - Mahmood Amiry-Moghaddam
- Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Blindern, Post box 1105, 0317, Oslo, Norway.
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37
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Rauen K, Pop V, Trabold R, Badaut J, Plesnila N. Vasopressin V 1a Receptors Regulate Cerebral Aquaporin 1 after Traumatic Brain Injury. J Neurotrauma 2020; 37:665-674. [PMID: 31547764 PMCID: PMC7045352 DOI: 10.1089/neu.2019.6653] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Brain edema formation contributes to secondary brain damage and unfavorable outcome after traumatic brain injury (TBI). Aquaporins (AQP), highly selective water channels, are involved in the formation of post-trauma brain edema; however, their regulation is largely unknown. Because vasopressin receptors are involved in AQP-mediated water transport in the kidney and inhibition of V1a receptors reduces post-trauma brain edema formation, we hypothesize that cerebral AQPs may be regulated by V1a receptors. Cerebral Aqp1 and Aqp4 messenger ribonucleic acid (mRNA) and AQP1 and AQP4 protein levels were quantified in wild-type and V1a receptor knockout (V1a-/-) mice before and 15 min, 1, 3, 6, 12, or 24 h after experimental TBI by controlled cortical impact. In non-traumatized mice, we found AQP1 and AQP4 expression in cortical neurons and astrocytes, respectively. Experimental TBI had no effect on Aqp4 mRNA or AQP4 protein expression, but increased Aqp1 mRNA (p < 0.05) and AQP1 protein expression (p < 0.05) in both hemispheres. The Aqp1 mRNA and AQP1 protein regulation was blunted in V1a receptor knockout mice. The V1a receptors regulate cerebral AQP1 expression after experimental TBI, thereby unraveling the molecular mechanism by which these receptors may mediate brain edema formation after TBI.
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Affiliation(s)
- Katrin Rauen
- Laboratory of Experimental Neurosurgery, Department of Neurosurgery & Institute for Surgical Research, University of Munich Medical Center, Munich, Germany
- Institute for Stroke and Dementia Research (ISD), University of Munich Medical Center, Munich, Germany
- University Hospital of Psychiatry Zurich, Department of Geriatric Psychiatry & Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Viorela Pop
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, California
| | - Raimund Trabold
- Laboratory of Experimental Neurosurgery, Department of Neurosurgery & Institute for Surgical Research, University of Munich Medical Center, Munich, Germany
| | - Jerome Badaut
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, California
- Aquitaine Institute for Cognitive and Integrative Neuroscience, University of Bordeaux, Bordeaux, France
| | - Nikolaus Plesnila
- Laboratory of Experimental Neurosurgery, Department of Neurosurgery & Institute for Surgical Research, University of Munich Medical Center, Munich, Germany
- Institute for Stroke and Dementia Research (ISD), University of Munich Medical Center, Munich, Germany
- Munich Cluster for Systems Neurology (Synergy), Munich, Germany
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38
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Uncoupling of the Astrocyte Syncytium Differentially Affects AQP4 Isoforms. Cells 2020; 9:cells9020382. [PMID: 32046059 PMCID: PMC7072498 DOI: 10.3390/cells9020382] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/29/2020] [Accepted: 02/04/2020] [Indexed: 11/25/2022] Open
Abstract
The water channel protein aquaporin-4 (AQP4) and the gap junction forming proteins connexin-43 (Cx43) and connexin-30 (Cx30) are astrocytic proteins critically involved in brain water and ion homeostasis. While AQP4 is mainly involved in water flux across the astrocytic endfeet membranes, astrocytic gap junctions provide syncytial coupling allowing intercellular exchange of water, ions, and other molecules. We have previously shown that mice with targeted deletion of Aqp4 display enhanced gap junctional coupling between astrocytes. Here, we investigate whether uncoupling of the astrocytic syncytium by deletion of the astrocytic connexins Cx43 and Cx30 affects AQP4 membrane localization and expression. By using quantitative immunogold cytochemistry, we show that deletion of astrocytic connexins leads to a substantial reduction of perivascular AQP4, concomitant with a down-regulation of total AQP4 protein and mRNA. Isoform expression analysis shows that while the level of the predominant AQP4 M23 isoform is reduced in Cx43/Cx30 double deficient hippocampal astrocytes, the levels of M1, and the alternative translation AQP4ex isoform protein levels are increased. These findings reveal a complex interdependence between AQP4 and connexins, which are both significantly involved in homeostatic functions and astrogliopathologies.
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39
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Heterogeneity of Astrocytes in Grey and White Matter. Neurochem Res 2019; 46:3-14. [PMID: 31797158 DOI: 10.1007/s11064-019-02926-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 11/21/2019] [Accepted: 11/28/2019] [Indexed: 02/07/2023]
Abstract
Astrocytes are a diverse and heterogeneous type of glial cells. The major task of grey and white matter areas in the brain are computation of information at neuronal synapses and propagation of action potentials along axons, respectively, resulting in diverse demands for astrocytes. Adapting their function to the requirements in the local environment, astrocytes differ in morphology, gene expression, metabolism, and many other properties. Here we review the differential properties of protoplasmic astrocytes of grey matter and fibrous astrocytes located in white matter in respect to glutamate and energy metabolism, to their function at the blood-brain interface and to coupling via gap junctions. Finally, we discuss how this astrocytic heterogeneity might contribute to the different susceptibility of grey and white matter to ischemic insults.
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40
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Maroli N, Kalagatur NK, Bhasuran B, Jayakrishnan A, Manoharan RR, Kolandaivel P, Natarajan J, Kadirvelu K. Molecular Mechanism of T-2 Toxin-Induced Cerebral Edema by Aquaporin-4 Blocking and Permeation. J Chem Inf Model 2019; 59:4942-4958. [DOI: 10.1021/acs.jcim.9b00711] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | | | | | | | | | - Jeyakumar Natarajan
- Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore 641046, Tamil Nadu, India
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41
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Glibenclamide and Therapeutic Hypothermia Have Comparable Effect on Attenuating Global Cerebral Edema Following Experimental Cardiac Arrest. Neurocrit Care 2019; 29:119-127. [PMID: 29150777 DOI: 10.1007/s12028-017-0479-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Cerebral edema is one of the major causes of mortality following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). A subunit of the sulfonylurea receptor 1-transient receptor potential M4 (Sur1-TRPM4) channel has been implicated in the pathogenesis of ischemia-evoked cerebral edema. In this study, we examined whether glibenclamide (GBC), a Sur1-TRPM4 channel inhibitor, attenuates cerebral edema following CA/CPR and further examined the efficacy of GBC combined with therapeutic hypothermia. METHODS Isoflurane-anesthetized adult male wild-type C57Bl/6 mice subjected to 7-min CA/CPR were randomized into five groups: sham operation, control with normothermia, GBC with normothermia, control with hypothermia, and GBC with hypothermia. The primary outcome was to evaluate regional brain water content; the secondary outcome was to measure blood glucose level, Sur1-TRPM4 expression, and pro-inflammatory factor expression. RESULTS Compared with normothermia, GBC treatment or hypothermia significantly attenuated brain water content in mice subjected to CA/CPR. GBC combined with hypothermia had no additional effects on attenuating cerebral edema. Pro-inflammatory factor messenger RNA expression (TNF-α and IL-6), NFκβ activation, and SUR1-TRPM4 levels were upregulated after CA/CPR. Compared with normothermia, hypothermia, but not GBC, partly suppressed these factors' expression. CONCLUSIONS GBC attenuated cerebral edema following CA/CPR by blocking Sur1-TRPM4 channels upregulated by CA insult. The effect of GBC was comparable with that of therapeutic hypothermia alone. These results suggest that GBC is an alternative approach for treating CA-evoked cerebral edema.
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Mages B, Aleithe S, Blietz A, Krueger M, Härtig W, Michalski D. Simultaneous alterations of oligodendrocyte-specific CNP, astrocyte-specific AQP4 and neuronal NF-L demarcate ischemic tissue after experimental stroke in mice. Neurosci Lett 2019; 711:134405. [PMID: 31374325 DOI: 10.1016/j.neulet.2019.134405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/11/2019] [Accepted: 07/27/2019] [Indexed: 12/16/2022]
Abstract
Ischemic stroke not only affects neurons, but also glial and vascular elements. The development of novel neuroprotective strategies thus requires an improved pathophysiological understanding of ischemia-affected cell types that comprise the 'neurovascular unit' (NVU). To explore spatiotemporal alterations of oligodendrocytes, astrocytes and neurons after experimental ischemic stroke, we applied a permanent middle cerebral artery occlusion model in mice for 4 and 24 h. Using fluorescence microscopy, the oligodendrocyte marker 2',3'-cyclic nucleotide phosphodiesterase (CNP), the neuronal neurofilament light chain (NF-L) and the astroglial aquaporin-4 (AQP4) were analyzed in regional relation to one another. Immunofluorescence intensities of CNP and NF-L were simultaneously increased in the ischemic neocortex and striatum. AQP4 immunoreactivity was decreased in the ischemic striatum, which represents the initial and potentially strongest affected site of infarction. The more distant ischemic neocortex and infarct border zones exhibited areas with alternately increased or decreased AQP4 immunoreactivity, leading to an increase of fluorescence intensity in total. Further, deformed CNP-immunopositive processes were found around axonal spheroids, indicating a combined affection of oligodendrocytes and neurons due to ischemia. Importantly, altered AQP4 immunosignals were not limited to the ischemic core, but were also detectable in penumbral areas. This applies for CNP and NF-L also, since altered immunosignals of all three markers coincided regionally at both time points. In conclusion, the present study provides evidence for a simultaneous affection of oligodendrocytes, astrocytes and neurons after experimental focal cerebral ischemia. Consequently, CNP, AQP4 and NF-L immunofluorescence alterations can be utilized to identify ischemia-affected tissue. The simultaneity of the described alterations further strengthens the concept of interdependent NVU components and distinguishes NF-L, CNP and AQP4 as highly ischemia-sensitive elements. Consequently, future therapeutic approaches might influence stroke evolution via strategies simultaneously addressing both neuronal and glial functions.
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Affiliation(s)
- Bianca Mages
- Department of Neurology, University of Leipzig, Germany; Institute of Anatomy, University of Leipzig, Germany.
| | | | | | | | - Wolfgang Härtig
- Paul Flechsig Institute of Brain Research, University of Leipzig, Germany
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Tong F, Zou Y, Liang Y, Lei H, Lopsong T, Liu Y, Le Grange JM, He G, Zhou Y. The Water Diffusion of Brain Following Hypoglycemia in Rats – A Study with Diffusion Weighted Imaging and Neuropathologic Analysis. Neuroscience 2019; 409:58-68. [DOI: 10.1016/j.neuroscience.2019.04.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 01/26/2023]
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Adrenergic receptor antagonism induces neuroprotection and facilitates recovery from acute ischemic stroke. Proc Natl Acad Sci U S A 2019; 116:11010-11019. [PMID: 31097598 DOI: 10.1073/pnas.1817347116] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spontaneous waves of cortical spreading depolarization (CSD) are induced in the setting of acute focal ischemia. CSD is linked to a sharp increase of extracellular K+ that induces a long-lasting suppression of neural activity. Furthermore, CSD induces secondary irreversible damage in the ischemic brain, suggesting that K+ homeostasis might constitute a therapeutic strategy in ischemic stroke. Here we report that adrenergic receptor (AdR) antagonism accelerates normalization of extracellular K+, resulting in faster recovery of neural activity after photothrombotic stroke. Remarkably, systemic adrenergic blockade before or after stroke facilitated functional motor recovery and reduced infarct volume, paralleling the preservation of the water channel aquaporin-4 in astrocytes. Our observations suggest that AdR blockers promote cerebrospinal fluid exchange and rapid extracellular K+ clearance, representing a potent potential intervention for acute stroke.
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Mamtilahun M, Tang G, Zhang Z, Wang Y, Tang Y, Yang GY. Targeting Water in the Brain: Role of Aquaporin-4 in Ischemic Brain Edema. Curr Drug Targets 2019; 20:748-755. [DOI: 10.2174/1389450120666190214115309] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 01/21/2023]
Abstract
Brain edema primarily occurs as a consequence of various cerebral injuries including
ischemic stroke. Excessive accumulation of brain water content causes a gradual expansion of brain
parenchyma, decreased blood flow and increased intracranial pressure and, ultimately, cerebral herniation
and death. Current clinical treatment for ischemic edema is very limited, therefore, it is urgent to
develop novel treatment strategies. Mounting evidence has demonstrated that AQP4, a water channel
protein, is closely correlated with brain edema and could be an optimal therapeutic target for the reduction
of ischemic brain edema. AQP4 is prevalently distributed in the central nervous system, and
mainly regulates water flux in brain cells under normal and pathological conditions. This review focuses
on the underlying mechanisms of AQP4 related to its dual role in edema formation and elimination.
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Affiliation(s)
- Muyassar Mamtilahun
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Guanghui Tang
- Institute of Molecular Health Sciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Zhijun Zhang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yongting Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yaohui Tang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Guo-Yuan Yang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
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Bothwell SW, Janigro D, Patabendige A. Cerebrospinal fluid dynamics and intracranial pressure elevation in neurological diseases. Fluids Barriers CNS 2019; 16:9. [PMID: 30967147 PMCID: PMC6456952 DOI: 10.1186/s12987-019-0129-6] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/19/2019] [Indexed: 01/09/2023] Open
Abstract
The fine balance between the secretion, composition, volume and turnover of cerebrospinal fluid (CSF) is strictly regulated. However, during certain neurological diseases, this balance can be disrupted. A significant disruption to the normal CSF circulation can be life threatening, leading to increased intracranial pressure (ICP), and is implicated in hydrocephalus, idiopathic intracranial hypertension, brain trauma, brain tumours and stroke. Yet, the exact cellular, molecular and physiological mechanisms that contribute to altered hydrodynamic pathways in these diseases are poorly defined or hotly debated. The traditional views and concepts of CSF secretion, flow and drainage have been challenged, also due to recent findings suggesting more complex mechanisms of brain fluid dynamics than previously proposed. This review evaluates and summarises current hypotheses of CSF dynamics and presents evidence for the role of impaired CSF dynamics in elevated ICP, alongside discussion of the proteins that are potentially involved in altered CSF physiology during neurological disease. Undoubtedly CSF secretion, absorption and drainage are important aspects of brain fluid homeostasis in maintaining a stable ICP. Traditionally, pharmacological interventions or CSF drainage have been used to reduce ICP elevation due to over production of CSF. However, these drugs are used only as a temporary solution due to their undesirable side effects. Emerging evidence suggests that pharmacological targeting of aquaporins, transient receptor potential vanilloid type 4 (TRPV4), and the Na+-K+-2Cl- cotransporter (NKCC1) merit further investigation as potential targets in neurological diseases involving impaired brain fluid dynamics and elevated ICP.
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Affiliation(s)
- Steven William Bothwell
- Brain Barriers Group, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Medical Sciences Building, University Drive, Callaghan, NSW 2308 Australia
| | - Damir Janigro
- FloTBI Inc., Cleveland, OH USA
- Department of Physiology, Case Western Reserve University, Cleveland, OH USA
| | - Adjanie Patabendige
- Brain Barriers Group, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Medical Sciences Building, University Drive, Callaghan, NSW 2308 Australia
- Hunter Medical Research Institute, Newcastle, NSW Australia
- The Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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Bursting at the Seams: Molecular Mechanisms Mediating Astrocyte Swelling. Int J Mol Sci 2019; 20:ijms20020330. [PMID: 30650535 PMCID: PMC6359623 DOI: 10.3390/ijms20020330] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/10/2019] [Accepted: 01/11/2019] [Indexed: 01/31/2023] Open
Abstract
Brain swelling is one of the most robust predictors of outcome following brain injury, including ischemic, traumatic, hemorrhagic, metabolic or other injury. Depending on the specific type of insult, brain swelling can arise from the combined space-occupying effects of extravasated blood, extracellular edema fluid, cellular swelling, vascular engorgement and hydrocephalus. Of these, arguably the least well appreciated is cellular swelling. Here, we explore current knowledge regarding swelling of astrocytes, the most abundant cell type in the brain, and the one most likely to contribute to pathological brain swelling. We review the major molecular mechanisms identified to date that contribute to or mitigate astrocyte swelling via ion transport, and we touch upon the implications of astrocyte swelling in health and disease.
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Trillo-Contreras JL, Ramírez-Lorca R, Hiraldo-González L, Sánchez-Gomar I, Galán-Cobo A, Suárez-Luna N, Sánchez de Rojas-de Pedro E, Toledo-Aral JJ, Villadiego J, Echevarría M. Combined effects of aquaporin-4 and hypoxia produce age-related hydrocephalus. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3515-3526. [PMID: 30293570 DOI: 10.1016/j.bbadis.2018.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/01/2018] [Accepted: 08/05/2018] [Indexed: 10/28/2022]
Abstract
Aquaporin-4, present in ependymal cells, in glia limiting and abundantly in pericapillary astrocyte foot processes, and aquaporin-1, expressed in choroid plexus epithelial cells, play an important role in cerebrospinal fluid production and may be involved in the pathophysiology of age-dependent hydrocephalus. The finding that brain aquaporins expression is regulated by low oxygen tension led us to investigate how hypoxia and elevated levels of cerebral aquaporins may result in an increase in cerebrospinal fluid production that could be associated with a hydrocephalic condition. Here we have explored, in young and aged mice exposed to hypoxia, whether aquaporin-4 and aquaporin-1 participate in the development of age-related hydrocephalus. Choroid plexus, striatum, cortex and ependymal tissue were analyzed separately both for mRNA and protein levels of aquaporins. Furthermore, parameters such as total ventricular volume, intraventricular pressure, cerebrospinal fluid outflow rate, ventricular compliance and cognitive function were studied in wild type, aquaporin-1 and aquaporin-4 knock-out animals subjected to hypoxia or normoxia. Our data demonstrate that hypoxia is involved in the development of age-related hydrocephalus by a process that depends on aquaporin-4 channels as a main route for cerebrospinal fluid movement. Significant increases in aquaporin-4 expression that occur over the course of animal aging, together with a reduced cerebrospinal fluid outflow rate and ventricular compliance, contribute to produce more severe hydrocephalus related to hypoxic events in aged mice, with a notable impairment in cognitive function. These results indicate that physiological events and/or pathological conditions presenting with cerebral hypoxia/ischemia contribute to the development of chronic adult hydrocephalus.
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Affiliation(s)
- José Luis Trillo-Contreras
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain
| | - Reposo Ramírez-Lorca
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain
| | - Laura Hiraldo-González
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain
| | - Ismael Sánchez-Gomar
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain
| | - Ana Galán-Cobo
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain
| | - Nela Suárez-Luna
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain
| | - Eva Sánchez de Rojas-de Pedro
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain
| | - Juan José Toledo-Aral
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Spain
| | - Javier Villadiego
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Spain.
| | - Miriam Echevarría
- Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital. (HUVR)/Spanish National Research Council (CSIC)/University of Seville, Seville 41013, Spain; Department of Physiology and Biophysics, University of Seville, Seville 41009, Spain.
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Anzabi M, Ardalan M, Iversen NK, Rafati AH, Hansen B, Østergaard L. Hippocampal Atrophy Following Subarachnoid Hemorrhage Correlates with Disruption of Astrocyte Morphology and Capillary Coverage by AQP4. Front Cell Neurosci 2018; 12:19. [PMID: 29445328 PMCID: PMC5797792 DOI: 10.3389/fncel.2018.00019] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 01/15/2018] [Indexed: 01/08/2023] Open
Abstract
Despite successful management of ruptured intracranial aneurysm following subarachnoid hemorrhage (SAH), delayed cerebral ischemia (DCI) remains the main cause of high mortality and morbidity in patients who survive the initial bleeding. Astrocytes play a key role in neurovascular coupling. Therefore, changes in the neurovascular unit including astrocytes following SAH may contribute to the development of DCI and long-term complications. In this study, we characterized morphological changes in hippocampal astrocytes following experimental SAH, with special emphasis on glia-vascular cross-talk and hippocampal volume changes. Four days after induction of SAH or sham-operation in mice, their hippocampal volumes were determined by magnetic resonance imaging (MRI) and histological/stereological methods. Glial fibrillary acid protein (GFAP) immunostained hippocampal sections were examined by stereological techniques to detect differences in astrocyte morphology, and global spatial sampling method was used to quantify the length density of Aquaporin-4 (AQP4) positive capillaries. Our results indicated that hippocampal volume, as measured both by MRI and by histological approaches, was significantly lower in SAH animals than in the sham-operated group. Accordingly, in this animal model of SAH, hippocampal atrophy existed already at the time of DCI onset in humans. SAH induced retraction of GFAP positive astrocyte processes, accompanied by a significant reduction in the length density of AQP4 positive capillaries as well as narrowing of hippocampal capillaries. Meanwhile, astrocyte volume was higher in SAH mice compared with the sham-operated group. Morphological changes in hippocampal astrocytes seemingly disrupt glia-vascular interactions early after SAH and may contribute to hippocampal atrophy. We speculate that astrocytes and astrocyte-capillary interactions may provide targets for the development of therapies to improve the prognosis of SAH.
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Affiliation(s)
- Maryam Anzabi
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University, Aarhus, Denmark
| | - Maryam Ardalan
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University, Aarhus, Denmark.,Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Nina K Iversen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University, Aarhus, Denmark
| | - Ali H Rafati
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark.,Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Brian Hansen
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University, Aarhus, Denmark
| | - Leif Østergaard
- Department of Clinical Medicine, Center of Functionally Integrative Neuroscience and MINDLab, Aarhus University, Aarhus, Denmark
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Price BR, Norris CM, Sompol P, Wilcock DM. An emerging role of astrocytes in vascular contributions to cognitive impairment and dementia. J Neurochem 2018; 144:644-650. [PMID: 29222909 DOI: 10.1111/jnc.14273] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 10/30/2017] [Accepted: 11/23/2017] [Indexed: 01/15/2023]
Abstract
Vascular contributions to cognitive impairment and dementia (VCID) is understood to be the second most common cause of dementia after Alzheimer's disease, and is also a frequent comorbidity with Alzheimer's disease. While VCID is widely acknowledged as a key contributor to dementia, the mechanistic underpinnings of VCID remain poorly understood. In this review, we address the potential role of astrocytes in the pathophysiology of VCID. The vast majority of the blood vessels in the brain are surrounded by astrocytic end-feet. Given that astrocytes make up a significant proportion of the cells in the brain, and that astrocytes are usually passively connected to one another through gap junctions, we hypothesize that astrocytes are key mediators of cognitive impairment because of cerebrovascular disease. In this review, we discuss the existing body of literature regarding the role of astrocytes at the vasculature in the brain, and the known consequences of their dysfunction, as well as our hypotheses regarding the role astrocytes play in VCID. This article is part of the Special Issue "Vascular Dementia".
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Affiliation(s)
- Brittani R Price
- Department of Physiology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
| | - Christopher M Norris
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Pradoldej Sompol
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Donna M Wilcock
- Department of Physiology, Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
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