1
|
Berliner JA, Lam MA, Najafi E, Hemley SJ, Bilston LE, Stoodley MA. Aquaporin-4 expression and modulation in a rat model of post-traumatic syringomyelia. Sci Rep 2023; 13:9662. [PMID: 37316571 PMCID: PMC10267129 DOI: 10.1038/s41598-023-36538-x] [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: 02/21/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023] Open
Abstract
Aquaporin-4 (AQP4) has been implicated in post-traumatic syringomyelia (PTS), a disease characterised by the formation of fluid-filled cysts in the spinal cord. This study investigated the expression of AQP4 around a mature cyst (syrinx) and the effect of pharmacomodulation of AQP4 on syrinx size. PTS was induced in male Sprague-Dawley rats by computerized spinal cord impact and subarachnoid kaolin injection. Immunofluorescence of AQP4 was carried out on mature syrinx tissue 12 weeks post-surgery. Increased AQP4 expression corresponded to larger, multiloculated cysts (R2 = 0.94), yet no localized changes to AQP4 expression in perivascular regions or the glia limitans were present. In a separate cohort of animals, at 6 weeks post-surgery, an AQP4 agonist (AqF026), antagonist (AqB050), or vehicle was administered daily over 4 days, with MRIs performed before and after the completion of treatment. Histological analysis was performed at 12 weeks post-surgery. Syrinx volume and length were not altered with AQP4 modulation. The correlation between increased AQP4 expression with syrinx area suggests that AQP4 or the glia expressing AQP4 are recruited to regulate water movement. Given this, further investigation should examine AQP4 modulation with dose regimens at earlier time-points after PTS induction, as these may alter the course of syrinx development.
Collapse
Affiliation(s)
- Joel A Berliner
- Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, Sydney, NSW, 2109, Australia.
| | - Magdalena A Lam
- The ANZAC Research Institute, Concord Repatriation General Hospital, Gate 3, Hospital Road, Sydney, NSW, 2139, Australia
| | - Elmira Najafi
- Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, Sydney, NSW, 2109, Australia
| | - Sarah J Hemley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, Sydney, NSW, 2109, Australia
| | - Lynne E Bilston
- Neuroscience Research Australia, Margarete Ainsworth Building, 139 Barker Street, Sydney, NSW, 2031, Australia
- Faculty of Medicine, School of Clinical Medicine, University of New South Wales, Sydney, NSW, 2031, Australia
| | - Marcus A Stoodley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, Sydney, NSW, 2109, Australia
| |
Collapse
|
2
|
Czorlich P, Schweingruber N, Göttsche J, Mader MM, Westphal M. Acute low-pressure hydrocephalus in aneurysmal subarachnoid hemorrhage. Neurosurg Focus 2023; 54:E5. [PMID: 37004138 DOI: 10.3171/2023.1.focus22639] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/17/2023] [Indexed: 04/03/2023]
Abstract
OBJECTIVE Acute and chronic hydrocephalus are common pathologies after aneurysmal subarachnoid hemorrhage (SAH). Generally, the presence of acute hydrocephalus is associated with elevated intracranial pressure (ICP) treated with a ventricular drain. Subsequently, however, pronounced hydrocephalus without elevated ICP may develop in some patients with SAH in the postacute phase. This is described as acute low-pressure hydrocephalus (aLPH), and there are very limited data in the literature of this pathology. The aim of this study was to evaluate the rate of and factors associated with aLPH and describe its clinical course. METHODS In this retrospective single-center cohort study, the frequency and clinical characteristics of SAH-associated aLPH were investigated. Acute LPH was defined as an increase in ventricular size as measured by the Evans index, ICP within the normal range (< 5 mm Hg) at the time of ventricular enlargement, and timely neurological improvement after indwelling ventricular CSF drainage with negative pressure up to 5 cm H2O below normal level. Demographic and SAH-specific factors in patients with SAH treated using an external ventricular drain were extracted from the electronic medical chart and further analyzed. RESULTS From November 2010 to May 2020, 15 (3.7.%) of 406 patients with SAH fulfilled the criteria for aLPH. Acute LPH was diagnosed after an average of 13.1 ± 7.7 days. The presence of IVH and its extension were associated with the occurrence of aLPH. After undergoing the transient phase of aLPH, these patients subsequently developed a chronic, typical malresorptive hydrocephalus requiring a ventriculoperitoneal shunt more often (66.7% vs 17.4%, p < 0.001) and stayed longer in the intensive care unit (27 vs 20.5 days, p = 0.043) and in the hospital (36.4 vs 26.3 days, p = 0.004). CONCLUSIONS Acute LPH is a rare pathology in patients with SAH and negatively impacts the clinical course. It should be especially considered in patients with a lack of neurological improvement, an increase in ventricular width, and normal ICP values, so that forced CSF drainage is implemented.
Collapse
Affiliation(s)
| | - Nils Schweingruber
- 2Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; and
| | | | - Marius M Mader
- Departments of1Neurosurgery and
- 3Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California
| | | |
Collapse
|
3
|
Altered Expression of AQP1 and AQP4 in Brain Barriers and Cerebrospinal Fluid May Affect Cerebral Water Balance during Chronic Hypertension. Int J Mol Sci 2022; 23:ijms232012277. [PMID: 36293145 PMCID: PMC9603298 DOI: 10.3390/ijms232012277] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/03/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2022] Open
Abstract
Hypertension is the leading cause of cardiovascular affection and premature death worldwide. The spontaneously hypertensive rat (SHR) is the most common animal model of hypertension, which is characterized by secondary ventricular dilation and hydrocephalus. Aquaporin (AQP) 1 and 4 are the main water channels responsible for the brain’s water balance. The present study focuses on defining the expression of AQPs through the time course of the development of spontaneous chronic hypertension. We performed immunofluorescence and ELISA to examine brain AQPs from 10 SHR, and 10 Wistar−Kyoto (WKY) rats studied at 6 and 12 months old. There was a significant decrease in AQP1 in the choroid plexus of the SHR-12-months group compared with the age-matched control (p < 0.05). In the ependyma, AQP4 was significantly decreased only in the SHR-12-months group compared with the control or SHR-6-months groups (p < 0.05). Per contra, AQP4 increased in astrocytes end-feet of 6 months and 12 months SHR rats (p < 0.05). CSF AQP detection was higher in the SHR-12-months group than in the age-matched control group. CSF findings were confirmed by Western blot. In SHR, ependymal and choroidal AQPs decreased over time, while CSF AQPs levels increased. In turn, astrocytes AQP4 increased in SHR rats. These AQP alterations may underlie hypertensive-dependent ventriculomegaly.
Collapse
|
4
|
Cellular Distribution of Brain Aquaporins and Their Contribution to Cerebrospinal Fluid Homeostasis and Hydrocephalus. Biomolecules 2022; 12:biom12040530. [PMID: 35454119 PMCID: PMC9025855 DOI: 10.3390/biom12040530] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 01/19/2023] Open
Abstract
Brain aquaporins facilitate the movement of water between the four water compartments: blood, cerebrospinal fluid, interstitial fluid, and intracellular fluid. This work analyzes the expression of the four most abundant aquaporins (AQPs) (AQP1, AQP4, AQP9, and AQP11) in the brains of mice and discuss their contribution to hydrocephalus. We analyzed available data from single-cell RNA sequencing of the central nervous system of mice to describe the expression of aquaporins and compare their distribution with that based on qPCR, western blot, and immunohistochemistry assays. Expression of AQP1 in the apical cell membrane of choroid plexus epithelial cells and of AQP4 in ependymal cells, glia limitans, and astrocyte processes in the pericapillary end foot is consistent with the involvement of both proteins in cerebrospinal fluid homeostasis. The expression of both aquaporins compensates for experimentally induced hydrocephalus in the animals. Recent data demonstrate that hypoxia in aged animals alters AQP4 expression in the choroidal plexus and cortex, increasing the ventricle size and intraventricular pressure. Cerebral distensibility is reduced in parallel with a reduction in cerebrospinal fluid drainage and cognitive deterioration. We propose that aged mice chronically exposed to hypoxia represent an excellent experimental model for studying the pathophysiological characteristics of idiopathic normal pressure hydrocephalus and roles for AQPs in such disease.
Collapse
|
5
|
Castañeyra-Ruiz L, González-Marrero I, Hernández-Abad LG, Carmona-Calero EM, Pardo MR, Baz-Davila R, Lee S, Muhonen M, Borges R, Castañeyra-Perdomo A. AQP4 labels a subpopulation of white matter-dependent glial radial cells affected by pediatric hydrocephalus, and its expression increased in glial microvesicles released to the cerebrospinal fluid in obstructive hydrocephalus. Acta Neuropathol Commun 2022; 10:41. [PMID: 35346374 PMCID: PMC8962176 DOI: 10.1186/s40478-022-01345-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/11/2022] [Indexed: 01/16/2023] Open
Abstract
Hydrocephalus is a distension of the ventricular system associated with ventricular zone disruption, reactive astrogliosis, periventricular white matter ischemia, axonal impairment, and corpus callosum alterations. The condition's etiology is typically attributed to a malfunction in classical cerebrospinal fluid (CSF) bulk flow; however, this approach does not consider the unique physiology of CSF in fetal and perinatal patients. The parenchymal fluid contributes to the glymphatic system, and plays a fundamental role in pediatric hydrocephalus, with aquaporin 4 (AQP4) as the primary facilitator of these fluid movements. Despite the importance of AQP4 in the pathophysiology of hydrocephalus, it’s expression in human fetal life is not well-studied. This manuscript systematically defines the brain expression of AQP4 in human brain development under control (n = 13) and hydrocephalic conditions (n = 3). Brains from 8 postconceptional weeks (PCW) onward and perinatal CSF from control (n = 2), obstructive (n = 6) and communicating (n = 6) hydrocephalic samples were analyzed through immunohistochemistry, immunofluorescence, western blot, and flow cytometry. Our results indicate that AQP4 expression is observed first in the archicortex, followed by the ganglionic eminences and then the neocortex. In the neocortex, it is initially at the perisylvian regions, and lastly at the occipital and prefrontal zones. Characteristic astrocyte end-feet labeling surrounding the vascular system was not established until 25 PCW. We also found AQP4 expression in a subpopulation of glial radial cells with processes that do not progress radially but, rather, curve following white matter tracts (corpus callosum and fornix), which were considered as glial stem cells (GSC). Under hydrocephalic conditions, GSC adjacent to characteristic ventricular zone disruption showed signs of early differentiation into astrocytes which may affect normal gliogenesis and contribute to the white matter dysgenesis. Finally, we found that AQP4 is expressed in the microvesicle fraction (p < 0.01) of CSF from patients with obstructive hydrocephalus. These findings suggest the potential use of AQP4 as a diagnostic and prognostic marker of pediatric hydrocephalus and as gliogenesis biomarker.
Collapse
|
6
|
Purohit D, Finkel DA, Malfa A, Liao Y, Ivanova L, Kleinman GM, Hu F, Shah S, Thompson C, Joseph E, Wolin MS, Cairo MS, La Gamma EF, Vinukonda G. Human Cord Blood Derived Unrestricted Somatic Stem Cells Restore Aquaporin Channel Expression, Reduce Inflammation and Inhibit the Development of Hydrocephalus After Experimentally Induced Perinatal Intraventricular Hemorrhage. Front Cell Neurosci 2021; 15:633185. [PMID: 33897371 PMCID: PMC8062878 DOI: 10.3389/fncel.2021.633185] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Intraventricular hemorrhage (IVH) is a severe complication of preterm birth associated with cerebral palsy, intellectual disability, and commonly, accumulation of cerebrospinal fluid (CSF). Histologically, IVH leads to subependymal gliosis, fibrosis, and disruption of the ependymal wall. Importantly, expression of aquaporin channels 1 and 4 (AQP1 and AQP4) regulating respectively, secretion and absorption of cerebrospinal fluids is altered with IVH and are associated with development of post hemorrhagic hydrocephalus. Human cord blood derived unrestricted somatic stem cells (USSCs), which we previously demonstrated to reduce the magnitude of hydrocephalus, as having anti-inflammatory, and beneficial behavioral effects, were injected into the cerebral ventricles of rabbit pups 18 h after glycerol-induced IVH. USSC treated IVH pups showed a reduction in ventricular size when compared to control pups at 7 and 14 days (both, P < 0.05). Histologically, USSC treatment reduced cellular infiltration and ependymal wall disruption. In the region of the choroid plexus, immuno-reactivity for AQP1 and ependymal wall AQP4 expression were suppressed after IVH but were restored following USSC administration. Effects were confirmed by analysis of mRNA from dissected choroid plexus and ependymal tissue. Transforming growth factor beta (TGF-β) isoforms, connective tissue growth factor (CTGF) and matrix metalloprotease-9 (MMP-9) mRNA, as well as protein levels, were significantly increased following IVH and restored towards normal with USSC treatment (P < 0.05). The anti-inflammatory cytokine Interleukin-10 (IL-10) mRNA was reduced in IVH, but significantly recovered after USSC injection (P < 0.05). In conclusion, USSCs exerted anti-inflammatory effects by suppressing both TGF-β specific isoforms, CTGF and MMP-9, recovered IL-10, restored aquaporins expression towards baseline, and reduced hydrocephalus. These results support the possibility of the use of USSCs to reduce IVH consequences in prematurity.
Collapse
Affiliation(s)
- Deepti Purohit
- The Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, United States
| | - Dina A Finkel
- The Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, United States
| | - Ana Malfa
- The Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, United States
| | - Yanling Liao
- Department of Pediatrics, New York Medical College, Valhalla, NY, United States
| | - Larisa Ivanova
- Department of Pediatrics, New York Medical College, Valhalla, NY, United States
| | - George M Kleinman
- Department of Pathology, Westchester Medical Center, New York Medical College, Valhalla, NY, United States
| | - Furong Hu
- Department of Pediatrics, New York Medical College, Valhalla, NY, United States
| | - Shetal Shah
- The Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, United States
| | - Carl Thompson
- Department of Physiology, New York Medical College, Valhalla, NY, United States
| | - Etlinger Joseph
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, United States
| | - Michael S Wolin
- Department of Physiology, New York Medical College, Valhalla, NY, United States
| | - Mitchell S Cairo
- Department of Pediatrics, New York Medical College, Valhalla, NY, United States.,Departments of Medicine, Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY, United States
| | - Edmund F La Gamma
- The Regional Neonatal Center, Maria Fareri Children's Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, United States.,Department of Pediatrics, New York Medical College, Valhalla, NY, United States.,Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY, United States
| | - Govindaiah Vinukonda
- Department of Pediatrics, New York Medical College, Valhalla, NY, United States.,Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, United States
| |
Collapse
|
7
|
MR Elastography demonstrates reduced white matter shear stiffness in early-onset hydrocephalus. NEUROIMAGE-CLINICAL 2021; 30:102579. [PMID: 33631603 PMCID: PMC7905205 DOI: 10.1016/j.nicl.2021.102579] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/08/2020] [Accepted: 01/21/2021] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Hydrocephalus that develops early in life is often accompanied by developmental delays, headaches and other neurological deficits, which may be associated with changes in brain shear stiffness. However, noninvasive approaches to measuring stiffness are limited. Magnetic Resonance Elastography (MRE) of the brain is a relatively new noninvasive imaging method that provides quantitative measures of brain tissue stiffness. Herein, we aimed to use MRE to assess brain stiffness in hydrocephalus patients compared to healthy controls, and to assess its associations with ventricular size, as well as demographic, shunt-related and clinical outcome measures. METHODS MRE was collected at two imaging sites in 39 hydrocephalus patients and 33 healthy controls, along with demographic, shunt-related, and clinical outcome measures including headache and quality of life indices. Brain stiffness was quantified for whole brain, global white matter (WM), and lobar WM stiffness. Group differences in brain stiffness between patients and controls were compared using two-sample t-tests and multivariable linear regression to adjust for age, sex, and ventricular volume. Among patients, multivariable linear or logistic regression was used to assess which factors (age, sex, ventricular volume, age at first shunt, number of shunt revisions) were associated with brain stiffness and whether brain stiffness predicts clinical outcomes (quality of life, headache and depression). RESULTS Brain stiffness was significantly reduced in patients compared to controls, both unadjusted (p ≤ 0.002) and adjusted (p ≤ 0.03) for covariates. Among hydrocephalic patients, lower stiffness was associated with older age in temporal and parietal WM and whole brain (WB) (beta (SE): -7.6 (2.5), p = 0.004; -9.5 (2.2), p = 0.0002; -3.7 (1.8), p = 0.046), being female in global and frontal WM and WB (beta (SE): -75.6 (25.5), p = 0.01; -66.0 (32.4), p = 0.05; -73.2 (25.3), p = 0.01), larger ventricular volume in global, and occipital WM (beta (SE): -11.5 (3.4), p = 0.002; -18.9 (5.4), p = 0.0014). Lower brain stiffness also predicted worse quality of life and a higher likelihood of depression, controlling for all other factors. CONCLUSIONS Brain stiffness is reduced in hydrocephalus patients compared to healthy controls, and is associated with clinically-relevant functional outcome measures. MRE may emerge as a clinically-relevant biomarker to assess the neuropathological effects of hydrocephalus and shunting, and may be useful in evaluating the effects of therapeutic alternatives, or as a supplement, of shunting.
Collapse
|
8
|
Li YN, Gao ZW, Li R, Zhang YF, Zhu QS, Huang F. Aquaporin 4 regulation by ginsenoside Rb1 intervenes with oxygen-glucose deprivation/reoxygenation-induced astrocyte injury. Medicine (Baltimore) 2019; 98:e17591. [PMID: 31626131 PMCID: PMC6824638 DOI: 10.1097/md.0000000000017591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Spinal cord ischemia-reperfusion injury (SCII) is a common complication of spinal surgery as well as thoracic and abdominal surgery. Acute cytotoxic edema is the key pathogenic alteration. Therefore, avoiding or decreasing cellular edema has become the major target for SCII treatment. METHODS The antiedema activity of ginsenoside Rb1 on aquaporin (AQP) 4, nerve growth factor (NGF), and brain-derived neurotrophic factor expression was detected by western blot and real-time polymerase chain reaction under conditions of oxygen-glucose deprivation/reoxygenation (OGD/R) in a rat astrocyte model in vitro. In addition, the cellular membrane permeability of AQP4 overexpressing cells or AQP4 small interfering RNA-transfected cells was detected. RESULTS Ginsenoside Rb1 significantly prevented OGD/R-induced AQP4 downregulation in rat astrocytes. In addition, ginsenoside Rb1 treatment or AQP4 overexpression in rat astrocytes significantly attenuated the OGD/R-induced increase of cellular membrane permeability. Moreover, ginsenoside Rb1 obviously prevented the OGD/R-induced decrease of NGF and BDNT expression in rat astrocytes. CONCLUSION These findings demonstrate that ginsenoside Rb1 can relieve spinal cord edema and improve neurological function by increasing AQP4 expression.
Collapse
Affiliation(s)
- Ya-Nan Li
- Department of Pediatrics, The First Hospital of Jilin University
- Department of Molecular Biology, Basic Medical College of Jilin University
| | - Zhong-Wen Gao
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, PR China
| | - Ran Li
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, PR China
| | - Yun-Feng Zhang
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, PR China
| | - Qing-San Zhu
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, PR China
| | - Fei Huang
- Department of Orthopedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin, PR China
| |
Collapse
|
9
|
Hydrocephalus in Neurocysticercosis: Challenges for Clinical Practice and Basic Research Perspectives. World Neurosurg 2019; 126:264-271. [DOI: 10.1016/j.wneu.2019.03.071] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 11/19/2022]
|
10
|
AQP1 and AQP4 Contribution to Cerebrospinal Fluid Homeostasis. Cells 2019; 8:cells8020197. [PMID: 30813473 PMCID: PMC6406452 DOI: 10.3390/cells8020197] [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: 12/26/2018] [Revised: 02/19/2019] [Accepted: 02/21/2019] [Indexed: 12/23/2022] Open
Abstract
Aquaporin 1 (AQP1), expressed in epithelial cells of the choroid plexus, and aquaporin 4 (AQP4) present in ependymal cells and glia limitants have been proposed to play a significant role in cerebrospinal fluid (CSF) production and homeostasis. However, the specific contribution of each water channel to these functions remains unknown, being a subject of debate during the last years. Here, we analyzed in detail how AQP1 and AQP4 participate in different aspects of the CSF homeostasis such as the load and drainage of ventricles, and further explored if these proteins play a role in the ventricular compliance. To do that, we carried out records of intraventricular pressure and CSF outflow, and evaluated ventricular volume by magnetic resonance imaging in AQP1−/−, AQP4−/−, double AQP1−/−-AQP4−/− knock out and wild type mice controls. The analysis performed clearly showed that both AQPs have a significant participation in the CSF production, and additionally revealed that the double AQP1-AQP4 mutation alters the CSF drainage and the ventricular compliance. The data reported here indicate a significant extra-choroidal CSF formation mediated by AQP4, supporting the idea of an important and constant CSF production/absorption process, sustained by efflux/influx of water between brain capillaries and interstitial fluid. Moreover, our results suggest the participation of AQPs in structural functions also related with CSF homeostasis such as the distensibility capacity of the ventricular system.
Collapse
|
11
|
Sisto M, Ribatti D, Lisi S. Aquaporin water channels: New perspectives on the potential role in inflammation. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 116:311-345. [PMID: 31036295 DOI: 10.1016/bs.apcsb.2018.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Aquaporins (AQPs) are a family of membrane water channel proteins that osmotically modulate water fluid homeostasis in several tissues; some of them also transport small solutes such as glycerol. At the cellular level, the AQPs regulate not only cell migration and transepithelial fluid transport across membranes, but also common events that are crucial for the inflammatory response. Emerging data reveal a new function of AQPs in the inflammatory process, as demonstrated by their dysregulation in a wide range of inflammatory diseases including edematous states, cancer, obesity, wound healing and several autoimmune diseases. This chapter summarizes the discoveries made so far about the structure and functions of the AQPs and provides updated information on the underlying mechanisms of AQPs in several human inflammatory diseases. The discovery of new functions for AQPs opens new vistas offering promise for the discovery of mechanisms and therapeutic opportunities in inflammatory disorders.
Collapse
Affiliation(s)
- Margherita Sisto
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs (SMBNOS), Section of Human Anatomy and Histology, University of Bari "Aldo Moro", Bari, Italy.
| | - Domenico Ribatti
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs (SMBNOS), Section of Human Anatomy and Histology, University of Bari "Aldo Moro", Bari, Italy
| | - Sabrina Lisi
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs (SMBNOS), Section of Human Anatomy and Histology, University of Bari "Aldo Moro", Bari, Italy
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Li Y, Hu H, Liu J, Zhu Q, Gu R. Effects of aquaporin 4 and inward rectifier potassium channel 4.1 on medullospinal edema after methylprednisolone treatment to suppress acute spinal cord injury in rats. Acta Cir Bras 2018. [PMID: 29513816 DOI: 10.1590/s0102-865020180020000009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To investigate the effects of aquaporin 4 (AQP4) and inward rectifier potassium channel 4.1 (Kir4.1) on medullospinal edema after treatment with methylprednisolone (MP) to suppress acute spinal cord injury (ASCI) in rats. METHODS Sprague Dawley rats were randomly divided into control, sham, ASCI, and MP-treated ASCI groups. After the induction of ASCI, we injected 30 mg/kg MP via the tail vein at various time points. The Tarlov scoring method was applied to evaluate neurological symptoms, and the wet-dry weights method was applied to measure the water content of the spinal cord. RESULTS The motor function score of the ASCI group was significantly lower than that of the sham group, and the spinal water content was significantly increased. In addition, the levels of AQP4 and Kir4.1 were significantly increased, as was their degree of coexpression. Compared with that in the ASCI group, the motor function score and the water content were significantly increased in the MP group; in addition, the expression and coexpression of AQP4 and Kir4.1 were significantly reduced. CONCLUSION Methylprednisolone inhibited medullospinal edema in rats with acute spinal cord injury, possibly by reducing the coexpression of aquaporin 4 and Kir4.1 in medullospinal tissues.
Collapse
Affiliation(s)
- Ye Li
- Associate Professor, Department of Orthopaedics, China-Japan Union Hospital, Jilin University, Changchun, China. Conception, design, intellectual and scientific content of the study; acquisition of data; manuscript writing; critical revision
| | - Haifeng Hu
- Attending Doctor, Department of Orthopaedics, China-Japan Union Hospital, Jilin University, Changchun, China. Acquisition of data, manuscript writing
| | - Jingchen Liu
- Professor, Department of Orthopaedics, China-Japan Union Hospital, Jilin University, Changchun, China. Scientific content of the study, acquisition of data, manuscript writing
| | - Qingsan Zhu
- Professor, Department of Orthopaedics, China-Japan Union Hospital, Jilin University, Changchun, China. Acquisition of data
| | - Rui Gu
- Professor, Department of Orthopaedics, China-Japan Union Hospital, Jilin University, Changchun, China. Intellectual, scientific, conception and design of the study; critical revision
| |
Collapse
|
14
|
Jeon T, Park KS, Park SH, Hwang JH, Hwang SK. Expression of Aquaporin 1 and 4 in the Choroid Plexus and Brain Parenchyma of Kaolin-Induced Hydrocephalic Rats. Korean J Neurotrauma 2017; 13:68-75. [PMID: 29201837 PMCID: PMC5702761 DOI: 10.13004/kjnt.2017.13.2.68] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/09/2017] [Accepted: 07/14/2017] [Indexed: 11/15/2022] Open
Abstract
Objective Aquaporin (AQP) is a recently discovered protein that regulates water homeostasis. The present study examines changes in AQP 1 and 4 in kaolin induced experimental hydrocephalic rats to elucidate the pathophysiology of water homeostasis in the disease. Methods Hydrocephalus was induced by percutaneous intracisternal injection of kaolin. The brain parenchyma and choroid plexus were obtained at 3, 7, 14 and 30 days after injection. Protein expressions of AQP 1 and 4 were measured by western blot, immunohistochemistry (IHC) and immunofluorescence (IF) stains. Results In the choroid plexus of the kaolin-induced hydrocephalus group, AQP 1 expression identified by western blot exhibited sharp decrease in the early stage (55% by the 3rd day and 22% by the 7th day), but indicated a 2.2-fold increase in the later stage (30th day) in comparison with control groups. In the parenchyma, a quantitative measurement of AQP 4 expression revealed variable results on the 3rd and 7th days, but indicated expression 2.1 times higher than the control in the later stage (30th day). In addition, the IHC and IF findings supported the patterns of expression of AQP 1 in the choroid plexus and AQP 4 in the parenchyma. Conclusion Expression of AQP 1 decreased sharply in the choroid plexus of acute hydrocephalus rats and increased at later stages. Expression of AQP 4 in the brain parenchyma was variable in the early stage in the hydrocephalus group, but was higher than in the control in the later stage. These findings suggest a compensating role of AQPs in water physiology in hydrocephalus.
Collapse
Affiliation(s)
- Taehyung Jeon
- Department of Neurosurgery, Kyungpook National Univeristy Hospital, Daegu, Korea
| | - Ki-Su Park
- Department of Neurosurgery, Kyungpook National Univeristy Hospital, Daegu, Korea
| | - Seong-Hyun Park
- Department of Neurosurgery, Kyungpook National Univeristy Hospital, Daegu, Korea
| | - Jeong-Hyun Hwang
- Department of Neurosurgery, Kyungpook National Univeristy Hospital, Daegu, Korea
| | - Sung Kyoo Hwang
- Department of Neurosurgery, Kyungpook National Univeristy Hospital, Daegu, Korea
| |
Collapse
|
15
|
The Neuroepithelium Disruption Could Generate Autoantibodies against AQP4 and Cause Neuromyelitis Optica and Hydrocephalus. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:580572. [PMID: 27379319 PMCID: PMC4897238 DOI: 10.1155/2014/580572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 09/11/2014] [Accepted: 09/14/2014] [Indexed: 12/02/2022]
Abstract
Neuromyelitis optica is an inflammatory disease characterized by neuritis and myelitis of the optic nerve. Its physiopathology is connected with the aquaporin-4 water channel, since antibodies against aquaporin-4 have been found in the cerebrospinal fluid and blood of neuromyelitis optica patients. The seropositivity for aquaporin-4 antibodies is used for the diagnosis of neuromyelitis optica or neuromyelitis optica spectrum disease. On the other hand, aquaporin-4 is expressed in astrocyte feet in the brain-blood barrier and subventricular zones of the brain ventricles. Aquaporin-4 expression is high in cerebrospinal fluid in hydrocephalus. Furthermore, neuroepithelial denudation precedes noncommunicating hydrocephalus and this neuroepithelial disruption could allow aquaporin-4 to reach anomalous brain areas where it is unrecognized and induce the generation of aquaporin-4 antibodies which could cause the neuromyelitis optica and certain types of hydrocephalus.
Collapse
|
16
|
Shim JW, Sandlund J, Madsen JR. VEGF: a potential target for hydrocephalus. Cell Tissue Res 2014; 358:667-83. [PMID: 25146955 DOI: 10.1007/s00441-014-1978-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 07/28/2014] [Indexed: 12/13/2022]
Abstract
Growth factors are primarily responsible for the genesis, differentiation and proliferation of cells and maintenance of tissues. Given the central role of growth factors in signaling between cells in health and in disease, it is understandable that disruption of growth factor-mediated molecular signaling can cause diverse phenotypic consequences including cancer and neurological conditions. This review will focus on the specific questions of enlarged cerebral ventricles and hydrocephalus. It is also well known that angiogenic factors, such as vascular endothelial growth factor (VEGF), affect tissue permeability through activation of receptors and adhesion molecules; hence, recent studies showing elevations of this factor in pediatric hydrocephalus led to the demonstration that VEGF can induce ventriculomegaly and altered ependyma when infused in animals. In this review, we discuss recent findings implicating the involvement of biochemical and biophysical factors that can induce a VEGF-mimicking effect in communicating hydrocephalus and pay particular attention to the role of the VEGF system as a potential pharmacological target in the treatment of some cases of hydrocephalus. The source of VEGF secretion in the cerebral ventricles, in periventricular regions and during pathologic events including hydrocephalus following hypoxia and hemorrhage is sought. The review is concluded with a summary of potential non-surgical treatments in preclinical studies suggesting several molecular targets including VEGF for hydrocephalus and related neurological disorders.
Collapse
Affiliation(s)
- Joon W Shim
- Department of Biology, Indiana University-Purdue University Indianapolis, 723 W. Michigan Street SL354, Indianapolis, IN, 46202, USA
| | | | | |
Collapse
|
17
|
Ordered disorder of the astrocytic dystrophin-associated protein complex in the norm and pathology. PLoS One 2013; 8:e73476. [PMID: 24014171 PMCID: PMC3754965 DOI: 10.1371/journal.pone.0073476] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/19/2013] [Indexed: 12/13/2022] Open
Abstract
The abundance and potential functional roles of intrinsically disordered regions in aquaporin-4, Kir4.1, a dystrophin isoforms Dp71, α-1 syntrophin, and α-dystrobrevin; i.e., proteins constituting the functional core of the astrocytic dystrophin-associated protein complex (DAPC), are analyzed by a wealth of computational tools. The correlation between protein intrinsic disorder, single nucleotide polymorphisms (SNPs) and protein function is also studied together with the peculiarities of structural and functional conservation of these proteins. Our study revealed that the DAPC members are typical hybrid proteins that contain both ordered and intrinsically disordered regions. Both ordered and disordered regions are important for the stabilization of this complex. Many disordered binding regions of these five proteins are highly conserved among vertebrates. Conserved eukaryotic linear motifs and molecular recognition features found in the disordered regions of five protein constituting DAPC likely enhance protein-protein interactions that are required for the cellular functions of this complex. Curiously, the disorder-based binding regions are rarely affected by SNPs suggesting that these regions are crucial for the biological functions of their corresponding proteins.
Collapse
|
18
|
Nabiuni M, Nazari Z, Safaeinejad Z, Delfan B, Miyan JA. Curcumin downregulates aquaporin-1 expression in cultured rat choroid plexus cells. J Med Food 2013; 16:504-10. [PMID: 23735000 DOI: 10.1089/jmf.2012.0208] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Aquaporin-1 (AQP1) is a water channel that is highly expressed on the apical side of the choroid plexus epithelium (CP) and thought to be one of the major pathways for the high water permeability of this structure. Blockade of AQP1 in the CP reduce the production of cerebrospinal fluid (CSF). Downregulation of AQP1 might be protective against some neurological disorders correlated with increased intracranial pressure and/or poor drainage of CSF. Curcumin, the major constituent of the rhizome of Curcuma longa, has been shown to inhibit potassium channels, Na⁺-K⁺ ATPase, as well as AQP3 in some cells. We therefore speculated that curcumin might be a useful tool to inhibit and/or decrease AQP1, and thus might be useful in the regulation of CSF production in pathophysiological conditions, including traumatic brain injury, hydrocephalus, stroke, systemic hyponatremia, acute cerebral edema, and hypertension. Choroidal epithelial cells of the lateral ventricle of Wistar rats were isolated and grown in in-vitro cultures for 24 h. Curcumin was then added to the medium at different concentrations, and the cell viability tested by the (3,4,5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay. Additional wells of cells were tested for AQP1 protein expression using immunocytochemistry, immunoblotting, and flow cytometry. Our results showed that curcumin treatment decreases AQP1 expression in rat choroid epithelium cells in a dose-dependent manner. We conclude that curcumin may be a useful tool to regulate CSF production in pathophysiological conditions such as hydrocephalus, systemic hyponatremia, hypertension, and other neurological conditions.
Collapse
Affiliation(s)
- Mohammad Nabiuni
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University-TMU, Tehran, Iran
| | | | | | | | | |
Collapse
|
19
|
Castañeyra-Ruiz L, González-Marrero I, González-Toledo JM, Castañeyra-Ruiz A, de Paz-Carmona H, Castañeyra-Perdomo A, Carmona-Calero EM. Aquaporin-4 expression in the cerebrospinal fluid in congenital human hydrocephalus. Fluids Barriers CNS 2013; 10:18. [PMID: 23659378 PMCID: PMC3651869 DOI: 10.1186/2045-8118-10-18] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 04/25/2013] [Indexed: 11/21/2022] Open
Abstract
Background Aquaporin-4 (AQP4) is a water channel mainly located in the ventricular ependymal cells (brain-CSF barrier), the sub-ependymal glia, glia limitans and in end-feet of astrocytes in at the blood–brain barrier (BBB). Methods In the present work, the expression of AQP4 in the cerebrospinal fluid (CSF) in control and congenital human hydrocephalus infants (obstructive and communicating), was analysed by Western-blot and enzyme immunoassay (ELISA). Results AQP4 was found to be high compared to the control in the CSF in congenital hydrocephalus patients. Western-blot showed higher values for AQP4 than controls in communicating hydrocephalus (communicating: 38.3%, control: 6.9% p < 0.05) although the increase was not significant in obstructive hydrocephalus (obstructive: 14.7%). The AQP4 quantification by ELISA also showed that, the mean concentration of AQP4 in CSF was significantly higher in communicating hydrocephalus (communicating: 11.32 ± 0.69 ng/ml, control: 8.61 ± 0.31 ng/ml; p < 0.05). However, there was no increase over control in obstructive hydrocephalus (obstructive: 8.65 ± 0.80 ng/ml). Conclusions AQP4 has a modulatory effect on ependyma stability and acts in CSF production and reabsorption. Therefore, the increase of AQP4 in the CSF in congenital hydrocephalus could be due to the fact that AQP4 passes from the parenchyma to the CSF and this AQP4 movement may be a consequence of ependyma denudation.
Collapse
Affiliation(s)
- Leandro Castañeyra-Ruiz
- Departamento de Anatomía, Facultad de Medicina, Universidad de La Laguna, La Laguna, Tenerife, Canary Island, Spain.
| | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
The aquaporins (AQPs) are plasma membrane water-transporting proteins. AQP4 is the principal member of this protein family in the CNS, where it is expressed in astrocytes and is involved in water movement, cell migration and neuroexcitation. AQP1 is expressed in the choroid plexus, where it facilitates cerebrospinal fluid secretion, and in dorsal root ganglion neurons, where it tunes pain perception. The AQPs are potential drug targets for several neurological conditions. Astrocytoma cells strongly express AQP4, which may facilitate their infiltration into the brain, and the neuroinflammatory disease neuromyelitis optica is caused by AQP4-specific autoantibodies that produce complement-mediated astrocytic damage.
Collapse
Affiliation(s)
- Marios C Papadopoulos
- Academic Neurosurgery Unit, St. George's, University of London, Tooting, London, SW17 0RE, UK. mpapadop@sgul. ac.uk
| | | |
Collapse
|