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Suárez V, Picotin R, Fassbender R, Gramespacher H, Haneder S, Persigehl T, Todorova P, Hackl MJ, Onur OA, Richter N, Burst V. Chronic Hyponatremia and Brain Structure and Function Before and After Treatment. Am J Kidney Dis 2024; 84:38-48.e1. [PMID: 38184092 DOI: 10.1053/j.ajkd.2023.11.007] [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: 05/24/2023] [Revised: 11/02/2023] [Accepted: 11/14/2023] [Indexed: 01/08/2024]
Abstract
RATIONALE & OBJECTIVE Hyponatremia is the most common electrolyte disorder and is associated with significant morbidity and mortality. This study investigated neurocognitive impairment, brain volume, and alterations in magnetic resonance imaging (MRI)-based measures of cerebral function in patients before and after treatment for hyponatremia. STUDY DESIGN Prospective cohort study. SETTING & PARTICIPANTS Patients with presumed chronic hyponatremia without signs of hypo- or hypervolemia treated in the emergency department of a German tertiary-care hospital. EXPOSURE Hyponatremia (ie, plasma sodium concentration [Na+]<125mmol/L) before and after treatment leading to [Na+]>130mmol/L. OUTCOMES Standardized neuropsychological testing (Mini-Mental State Examination, DemTect, Trail Making Test A/B, Beck Depression Inventory, Timed Up and Go) and resting-state MRI were performed before and after treatment of hyponatremia to assess total brain and white and gray matter volumes as well as neuronal activity and its synchronization. ANALYTICAL APPROACH Changes in outcomes after treatment for hyponatremia assessed using bootstrapped confidence intervals and Cohen d statistic. Associations between parameters were assessed using correlation analyses. RESULTS During a 3.7-year period, 26 patients were enrolled. Complete data were available for 21 patients. Mean [Na+]s were 118.4mmol/L before treatment and 135.5mmol/L after treatment. Most measures of cognition improved significantly. Comparison of MRI studies showed a decrease in brain tissue volumes, neuronal activity, and synchronization across all gray matter after normalization of [Na+]. Volume effects were particularly prominent in the hippocampus. During hyponatremia, synchronization of neuronal activity was negatively correlated with [Na+] (r=-0.836; 95% CI, -0.979 to-0.446) and cognitive function (Mini-Mental State Examination, r=-0.523; 95% CI, -0.805 to-0.069; DemTect, r=-0.744; 95% CI, -0.951 to-0.385; and Trail Making Test A, r=0.692; 95% CI, 0.255-0.922). LIMITATIONS Small sample size, insufficient quality of several MRI scans as a result of motion artifact. CONCLUSIONS Resolution of hyponatremia was associated with improved cognition and reductions in brain volumes and neuronal activity. Impaired cognition during hyponatremia is closely linked to increased neuronal activity rather than to tissue volumes. Furthermore, the hippocampus appears to be particularly susceptible to hyponatremia, exhibiting pronounced changes in tissue volume. PLAIN-LANGUAGE SUMMARY Hyponatremia is a common clinical problem, and patients often present with neurologic symptoms that are at least partially reversible. This study used neuropsychological testing and magnetic resonance imaging to examine patients during and after correction of hyponatremia. Treatment led to an improvement in patients' cognition as well as a decrease in their brain volumes, spontaneous neuronal activity, and synchronized neuronal activity between remote brain regions. Volume effects were particularly prominent in the hippocampus, an area of the brain that is important for the modulation of memory. During hyponatremia, patients with the lowest sodium concentrations had the highest levels of synchronized neuronal activity and the poorest cognitive test results.
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Affiliation(s)
- Victor Suárez
- Department II of Internal Medicine (Nephrology, Rheumatology, Diabetes, and General Internal Medicine) and Center for Molecular Medicine Cologne, Cologne, Germany; Emergency Department, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Rosanne Picotin
- Department of Neurology, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Ronja Fassbender
- Department of Neurology, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Hannes Gramespacher
- Department of Neurology, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Stefan Haneder
- Department of Diagnostic and Interventional Radiology, University of Cologne, Cologne, Germany
| | - Thorsten Persigehl
- Department of Diagnostic and Interventional Radiology, University of Cologne, Cologne, Germany
| | - Polina Todorova
- Department II of Internal Medicine (Nephrology, Rheumatology, Diabetes, and General Internal Medicine) and Center for Molecular Medicine Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Matthias Johannes Hackl
- Department II of Internal Medicine (Nephrology, Rheumatology, Diabetes, and General Internal Medicine) and Center for Molecular Medicine Cologne, Cologne, Germany; Emergency Department, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Oezguer A Onur
- Department of Neurology, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany
| | - Nils Richter
- Department of Neurology, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Volker Burst
- Department II of Internal Medicine (Nephrology, Rheumatology, Diabetes, and General Internal Medicine) and Center for Molecular Medicine Cologne, Cologne, Germany; Emergency Department, University of Cologne, Cologne, Germany; Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
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Sanicola HW, Stewart CE, Luther P, Yabut K, Guthikonda B, Jordan JD, Alexander JS. Pathophysiology, Management, and Therapeutics in Subarachnoid Hemorrhage and Delayed Cerebral Ischemia: An Overview. PATHOPHYSIOLOGY 2023; 30:420-442. [PMID: 37755398 PMCID: PMC10536590 DOI: 10.3390/pathophysiology30030032] [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: 07/20/2023] [Revised: 08/21/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023] Open
Abstract
Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke resulting from the rupture of an arterial vessel within the brain. Unlike other stroke types, SAH affects both young adults (mid-40s) and the geriatric population. Patients with SAH often experience significant neurological deficits, leading to a substantial societal burden in terms of lost potential years of life. This review provides a comprehensive overview of SAH, examining its development across different stages (early, intermediate, and late) and highlighting the pathophysiological and pathohistological processes specific to each phase. The clinical management of SAH is also explored, focusing on tailored treatments and interventions to address the unique pathological changes that occur during each stage. Additionally, the paper reviews current treatment modalities and pharmacological interventions based on the evolving guidelines provided by the American Heart Association (AHA). Recent advances in our understanding of SAH will facilitate clinicians' improved management of SAH to reduce the incidence of delayed cerebral ischemia in patients.
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Affiliation(s)
- Henry W. Sanicola
- Department of Neurology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - Caleb E. Stewart
- Department of Neurosurgery, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - Patrick Luther
- School of Medicine, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA; (P.L.); (K.Y.)
| | - Kevin Yabut
- School of Medicine, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA; (P.L.); (K.Y.)
| | - Bharat Guthikonda
- Department of Neurosurgery, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - J. Dedrick Jordan
- Department of Neurology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - J. Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA
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Abstract
Astrocyte endfeet enwrap the entire vascular tree within the central nervous system, where they perform important functions in regulating the blood-brain barrier (BBB), cerebral blood flow, nutrient uptake, and waste clearance. Accordingly, astrocyte endfeet contain specialized organelles and proteins, including local protein translation machinery and highly organized scaffold proteins, which anchor channels, transporters, receptors, and enzymes critical for astrocyte-vascular interactions. Many neurological diseases are characterized by the loss of polarization of specific endfoot proteins, vascular dysregulation, BBB disruption, altered waste clearance, or, in extreme cases, loss of endfoot coverage. A role for astrocyte endfeet has been demonstrated or postulated in many of these conditions. This review provides an overview of the development, composition, function, and pathological changes of astrocyte endfeet and highlights the gaps in our knowledge that future research should address.
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Affiliation(s)
- Blanca Díaz-Castro
- UK Dementia Research Institute and Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK;
| | - Stefanie Robel
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA;
| | - Anusha Mishra
- Department of Neurology Jungers Center for Neurosciences Research and Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA;
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Liu Y, Wang XR, Jiang YH, Li T, Ling S, Wang HY, Yu JW, Jia SW, Liu XY, Hou CM, Parpura V, Wang YF. Interactions between the Astrocytic Volume-Regulated Anion Channel and Aquaporin 4 in Hyposmotic Regulation of Vasopressin Neuronal Activity in the Supraoptic Nucleus. Cells 2023; 12:1723. [PMID: 37443757 PMCID: PMC10341125 DOI: 10.3390/cells12131723] [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: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
We assessed interactions between the astrocytic volume-regulated anion channel (VRAC) and aquaporin 4 (AQP4) in the supraoptic nucleus (SON). Acute SON slices and cultures of hypothalamic astrocytes prepared from rats received hyposmotic challenge (HOC) with/without VRAC or AQP4 blockers. In acute slices, HOC caused an early decrease with a late rebound in the neuronal firing rate of vasopressin neurons, which required activity of astrocytic AQP4 and VRAC. HOC also caused a persistent decrease in the excitatory postsynaptic current frequency, supported by VRAC and AQP4 activity in early HOC; late HOC required only VRAC activity. These events were associated with the dynamics of glial fibrillary acidic protein (GFAP) filaments, the late retraction of which was mediated by VRAC activity; this activity also mediated an HOC-evoked early increase in AQP4 expression and late subside in GFAP-AQP4 colocalization. AQP4 activity supported an early HOC-evoked increase in VRAC levels and its colocalization with GFAP. In cultured astrocytes, late HOC augmented VRAC currents, the activation of which depended on AQP4 pre-HOC/HOC activity. HOC caused an early increase in VRAC expression followed by a late rebound, requiring AQP4 and VRAC, or only AQP4 activity, respectively. Astrocytic swelling in early HOC depended on AQP4 activity, and so did the early extension of GFAP filaments. VRAC and AQP4 activity supported late regulatory volume decrease, the retraction of GFAP filaments, and subside in GFAP-VRAC colocalization. Taken together, astrocytic morphological plasticity relies on the coordinated activities of VRAC and AQP4, which are mutually regulated in the astrocytic mediation of HOC-evoked modulation of vasopressin neuronal activity.
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Affiliation(s)
- Yang Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Xiao-Ran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Yun-Hao Jiang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
- Neuroscience Laboratory for Translational Medicine, School of Mental Health, Qiqihar Medical University, Qiqihar 161006, China
| | - Shuo Ling
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Hong-Yang Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Jia-Wei Yu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Shu-Wei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Xiao-Yu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Chun-Mei Hou
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Vladimir Parpura
- International Translational Neuroscience Research Institute, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
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Wei Y, Khalaf AT, Rui C, Abdul Kadir SY, Zainol J, Oglah Z. The Emergence of TRP Channels Interactome as a Potential Therapeutic Target in Pancreatic Ductal Adenocarcinoma. Biomedicines 2023; 11:biomedicines11041164. [PMID: 37189782 DOI: 10.3390/biomedicines11041164] [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: 03/05/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Integral membrane proteins, known as Transient Receptor Potential (TRP) channels, are cellular sensors for various physical and chemical stimuli in the nervous system, respiratory airways, colon, pancreas, bladder, skin, cardiovascular system, and eyes. TRP channels with nine subfamilies are classified by sequence similarity, resulting in this superfamily's tremendous physiological functional diversity. Pancreatic Ductal Adenocarcinoma (PDAC) is the most common and aggressive form of pancreatic cancer. Moreover, the development of effective treatment methods for pancreatic cancer has been hindered by the lack of understanding of the pathogenesis, partly due to the difficulty in studying human tissue samples. However, scientific research on this topic has witnessed steady development in the past few years in understanding the molecular mechanisms that underlie TRP channel disturbance. This brief review summarizes current knowledge of the molecular role of TRP channels in the development and progression of pancreatic ductal carcinoma to identify potential therapeutic interventions.
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Affiliation(s)
- Yuanyuan Wei
- Basic Medical College, Chengdu University, Chengdu 610106, China
| | | | - Cao Rui
- Basic Medical College, Chengdu University, Chengdu 610106, China
| | - Samiah Yasmin Abdul Kadir
- Faculty of Medicine, Widad University College, BIM Point, Bandar Indera Mahkota, Kuantan 25200, Malaysia
| | - Jamaludin Zainol
- Faculty of Medicine, Widad University College, BIM Point, Bandar Indera Mahkota, Kuantan 25200, Malaysia
| | - Zahraa Oglah
- School of Science, Auckland University of Technology (AUT), 55 Wellesley Street, Auckland 1010, New Zealand
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Jiang YH, Li T, Liu Y, Liu X, Jia S, Hou C, Chen G, Wang H, Ling S, Gao Q, Wang XR, Wang YF. Contribution of inwardly rectifying K + channel 4.1 of supraoptic astrocytes to the regulation of vasopressin neuronal activity by hypotonicity. Glia 2023; 71:704-719. [PMID: 36408843 DOI: 10.1002/glia.24306] [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: 07/08/2022] [Revised: 11/06/2022] [Accepted: 11/12/2022] [Indexed: 11/22/2022]
Abstract
Astrocytic morphological plasticity and its modulation of adjacent neuronal activity are largely determined by astrocytic volume regulation, in which glial fibrillary acidic protein (GFAP), aquaporin 4 (AQP4), and potassium channels including inwardly rectifying K+ channel 4.1 (Kir4.1) are essential. However, associations of astrocyte-dominant Kir4.1 with other molecules in astrocytic volume regulation and the subsequent influence on neuronal activity remain unclear. Here, we report our study on these issues using primary cultures of rat pups' hypothalamic astrocytes and male adult rat brain slices. In astrocyte culture, hyposmotic challenge (HOC) significantly decreased GFAP monomer expression and astrocytic volume at 1.5 min and increased Kir4.1 expression and inwardly rectifying currents (IRCs) at 10 min. BaCl2 (100 μmol/l) suppressed the HOC-increased IRCs, which was simulated by VU0134992 (2 μmol/l), a Kir4.1 blocker. Preincubation of the astrocyte culture with TGN-020 (10 μmol/l, a specific AQP4 blocker) made the HOC-increased Kir4.1 currents insignificant. In hypothalamic brain slices, HOC initially decreased and then increased the firing rate of vasopressin (VP) neurons in the supraoptic nucleus. In the presence of BaCl2 or VU0134992, HOC-elicited rebound increase in VP neuronal activity was blocked. GFAP was molecularly associated with Kir4.1, which was increased by HOC at 20 min; this increase was blocked by BaCl2 . These results suggest that HOC-evoked astrocytic retraction or decrease in the volume and length of its processes is associated with increased Kir4.1 activity. Kir4.1 involvement in HOC-elicited astrocytic retraction is associated with AQP4 activity and GFAP plasticity, which together determines the rebound excitation of VP neurons.
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Affiliation(s)
- Yun-Hao Jiang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China.,Neuroelectrophysiology Laboratory, School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Yang Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Chunmei Hou
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Guichuan Chen
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Hongyang Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuo Ling
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Qiang Gao
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiao-Ran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
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Sucha P, Hermanova Z, Chmelova M, Kirdajova D, Camacho Garcia S, Marchetti V, Vorisek I, Tureckova J, Shany E, Jirak D, Anderova M, Vargova L. The absence of AQP4/TRPV4 complex substantially reduces acute cytotoxic edema following ischemic injury. Front Cell Neurosci 2022; 16:1054919. [PMID: 36568889 PMCID: PMC9773096 DOI: 10.3389/fncel.2022.1054919] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
Introduction Astrocytic Aquaporin 4 (AQP4) and Transient receptor potential vanilloid 4 (TRPV4) channels form a functional complex that likely influences cell volume regulation, the development of brain edema, and the severity of the ischemic injury. However, it remains to be fully elucidated whether blocking these channels can serve as a therapeutic approach to alleviate the consequences of having a stroke. Methods and results In this study, we used in vivo magnetic resonance imaging (MRI) to quantify the extent of brain lesions one day (D1) and seven days (D7) after permanent middle cerebral artery occlusion (pMCAO) in AQP4 or TRPV4 knockouts and mice with simultaneous deletion of both channels. Our results showed that deletion of AQP4 or TRPV4 channels alone leads to a significant worsening of ischemic brain injury at both time points, whereas their simultaneous deletion results in a smaller brain lesion at D1 but equal tissue damage at D7 when compared with controls. Immunohistochemical analysis 7 days after pMCAO confirmed the MRI data, as the brain lesion was significantly greater in AQP4 or TRPV4 knockouts than in controls and double knockouts. For a closer inspection of the TRPV4 and AQP4 channel complex in the development of brain edema, we applied a real-time iontophoretic method in situ to determine ECS diffusion parameters, namely volume fraction (α) and tortuosity (λ). Changes in these parameters reflect alterations in cell volume, and tissue structure during exposure of acute brain slices to models of ischemic conditions in situ, such as oxygen-glucose deprivation (OGD), hypoosmotic stress, or hyperkalemia. The decrease in α was comparable in double knockouts and controls when exposed to hypoosmotic stress or hyperkalemia. However, during OGD, there was no decrease in α in the double knockouts as observed in the controls, which suggests less swelling of the cellular components of the brain. Conclusion Although simultaneous deletion of AQP4 and TRPV4 did not improve the overall outcome of ischemic brain injury, our data indicate that the interplay between AQP4 and TRPV4 channels plays a critical role during neuronal and non-neuronal swelling in the acute phase of ischemic injury.
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Affiliation(s)
- Petra Sucha
- Second Faculty of Medicine, Charles University, Prague, Czechia,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Zuzana Hermanova
- Second Faculty of Medicine, Charles University, Prague, Czechia,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Martina Chmelova
- Second Faculty of Medicine, Charles University, Prague, Czechia,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Denisa Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Sara Camacho Garcia
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Valeria Marchetti
- Second Faculty of Medicine, Charles University, Prague, Czechia,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Ivan Vorisek
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
| | - Eyar Shany
- Department of Diagnostic and Interventional Radiology, Institute of Clinical and Experimental Medicine, Prague, Czechia
| | - Daniel Jirak
- Department of Diagnostic and Interventional Radiology, Institute of Clinical and Experimental Medicine, Prague, Czechia,First Faculty of Medicine, Institute of Biophysics and Informatics, Charles University, Prague, Czechia
| | - Miroslava Anderova
- Second Faculty of Medicine, Charles University, Prague, Czechia,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia,*Correspondence: Miroslava Anderova,
| | - Lydia Vargova
- Second Faculty of Medicine, Charles University, Prague, Czechia,Department of Cellular Neurophysiology, Institute of Experimental Medicine of the CAS, Prague, Czechia
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Park A, Croset V, Otto N, Agarwal D, Treiber CD, Meschi E, Sims D, Waddell S. Gliotransmission of D-serine promotes thirst-directed behaviors in Drosophila. Curr Biol 2022; 32:3952-3970.e8. [PMID: 35963239 PMCID: PMC9616736 DOI: 10.1016/j.cub.2022.07.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/04/2022] [Accepted: 07/15/2022] [Indexed: 12/13/2022]
Abstract
Thirst emerges from a range of cellular changes that ultimately motivate an animal to consume water. Although thirst-responsive neuronal signals have been reported, the full complement of brain responses is unclear. Here, we identify molecular and cellular adaptations in the brain using single-cell sequencing of water-deprived Drosophila. Water deficiency primarily altered the glial transcriptome. Screening the regulated genes revealed astrocytic expression of the astray-encoded phosphoserine phosphatase to bi-directionally regulate water consumption. Astray synthesizes the gliotransmitter D-serine, and vesicular release from astrocytes is required for drinking. Moreover, dietary D-serine rescues aay-dependent drinking deficits while facilitating water consumption and expression of water-seeking memory. D-serine action requires binding to neuronal NMDA-type glutamate receptors. Fly astrocytes contribute processes to tripartite synapses, and the proportion of astrocytes that are themselves activated by glutamate increases with water deprivation. We propose that thirst elevates astrocytic D-serine release, which awakens quiescent glutamatergic circuits to enhance water procurement.
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Affiliation(s)
- Annie Park
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Vincent Croset
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK; Department of Biosciences, Durham University, Durham DH1 3LE, UK.
| | - Nils Otto
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Devika Agarwal
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK; MRC Computational Genomics Analysis and Training Programme (CGAT), MRC Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Christoph D Treiber
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - Eleonora Meschi
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK
| | - David Sims
- MRC Computational Genomics Analysis and Training Programme (CGAT), MRC Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Scott Waddell
- Centre for Neural Circuits & Behaviour, University of Oxford, Oxford OX1 3TA, UK.
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The Water Transport System in Astrocytes–Aquaporins. Cells 2022; 11:cells11162564. [PMID: 36010640 PMCID: PMC9406552 DOI: 10.3390/cells11162564] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Highlights (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes, including those of astrocytes. The expression and subcellular localization of AQPs in astrocytes are highly dynamic under physiological and pathological conditions. Besides their primary function in water homeostasis, AQPs participate in many ancillary functions including glutamate clearance in tripartite synapses and cell migration.
Abstract Astrocytes have distinctive morphological and functional characteristics, and are found throughout the central nervous system. Astrocytes are now known to be far more than just housekeeping cells in the brain. Their functions include contributing to the formation of the blood–brain barrier, physically and metabolically supporting and communicating with neurons, regulating the formation and functions of synapses, and maintaining water homeostasis and the microenvironment in the brain. Aquaporins (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes. Various subtypes of AQPs (AQP1, AQP3, AQP4, AQP5, AQP8 and AQP9) have been reported to be expressed in astrocytes, and the expressions and subcellular localizations of AQPs in astrocytes are highly correlated with both their physiological and pathophysiological functions. This review describes and summarizes the recent advances in our understanding of astrocytes and AQPs in regard to controlling water homeostasis in the brain. Findings regarding the features of different AQP subtypes, such as their expression, subcellular localization, physiological functions, and the pathophysiological roles of astrocytes are presented, with brain edema and glioma serving as two representative AQP-associated pathological conditions. The aim is to provide a better insight into the elaborate “water distribution” system in cells, exemplified by astrocytes, under normal and pathological conditions.
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10
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Elsherbini DMA, Ghoneim FM, El-Mancy EM, Ebrahim HA, El-Sherbiny M, El-Shafey M, Al-Serwi RH, Elsherbiny NM. Astrocytes profiling in acute hepatic encephalopathy: Possible enrolling of glial fibrillary acidic protein, tumor necrosis factor-alpha, inwardly rectifying potassium channel (Kir 4.1) and aquaporin-4 in rat cerebral cortex. Front Cell Neurosci 2022; 16:896172. [PMID: 36060277 PMCID: PMC9428715 DOI: 10.3389/fncel.2022.896172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Hepatic encephalopathy (HE) is a neurological disarray manifested as a sequel to chronic and acute liver failure (ALF). A potentially fatal consequence of ALF is brain edema with concomitant astrocyte enlargement. This study aims to outline the role of astrocytes in acute HE and shed light on the most critical mechanisms driving this role. Rats were allocated into two groups. Group 1, the control group, received the vehicle. Group 2, the TAA group, received TAA (300 mg/kg) for 3 days. Serum AST, ALT, and ammonia were determined. Liver and cerebral cortical sections were processed for hematoxylin and eosin staining. Additionally, mRNA expression and immunohistochemical staining of cortical GFAP, TNFα, Kir4.1, and AQP4 were performed. Cortical sections from the TAA group demonstrated neuropil vacuolation and astrocytes enlargement with focal gliosis. GFAP, TNFα, and AQP4 revealed increased mRNA expression, positive immunoreactivity, and a positive correlation to brain water content. In contrast, Kir 4.1 showed decreased mRNA expression and immunoreactivity and a negative correlation to brain water content. In conclusion, our findings revealed altered levels of TNFα, Kir 4.1, GFAP, and AQP4 in HE-associated brain edema. A more significant dysregulation of Kir 4.1 and TNFα was observed compared to AQP4 and GFAP.
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Affiliation(s)
- Dalia Mahmoud Abdelmonem Elsherbini
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, Saudi Arabia
- Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- *Correspondence: Dalia Mahmoud Abdelmonem Elsherbini,
| | - Fatma M. Ghoneim
- Department of Histology and Cell Biology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Eman Mohammed El-Mancy
- Deanship of Common First Year, Jouf University, Sakaka, Saudi Arabia
- Department of Zoology, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, Egypt
| | - Hasnaa Ali Ebrahim
- Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Mohamed El-Sherbiny
- Department of Basic Medical Sciences, College of Medicine, AlMaarefa University, Riyadh, Saudi Arabia
- Mohamed El-Sherbiny,
| | - Mohamed El-Shafey
- Department of Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- Department of Physiological Sciences, Fakeeh College for Medical Sciences, Jeddah, Saudi Arabia
| | - Rasha Hamed Al-Serwi
- Department of Basic Dental Sciences, College of Dentistry, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Nehal M. Elsherbiny
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
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11
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Zhang Y, Lei L, Zhou H, Lu X, Cai F, Li T. Roles of Micro Ribonucleic Acids in Astrocytes After Cerebral Stroke. Front Cell Neurosci 2022; 16:890762. [PMID: 35755778 PMCID: PMC9218061 DOI: 10.3389/fncel.2022.890762] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
Cerebral stroke is one of the highest-ranking causes of death and the leading cause of disability globally, particularly with an increasing incidence and prevalence in developing countries. Steadily more evidence has indicated that micro ribonucleic acids (miRNAs) have important regulatory functions in gene transcription and translation in the course of cerebral stroke. It is beyond arduous to understand the pathophysiology of cerebral stroke, due in part to the perplexity of influencing the network of the inflammatory response, brain edema, autophagy and neuronal apoptosis. The recent research shows miRNA plays a key role in regulating aquaporin 4 (AQP4), and many essential pathological processes after cerebral stroke. This article reviews the recent knowledge on how miRNA influences the inflammatory response, brain edema, infarction size, and neuronal injury after cerebral stroke. In addition, some miRNAs may serve as potential biomarkers in stroke diagnosis and therapy since the expression of some miRNAs in the blood is stable after cerebral stroke.
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Affiliation(s)
- Yuansheng Zhang
- Department of Neurosurgery, The Affiliated Hospital of Medical College, Kunming University of Science and Technology, The First People's Hospital of Yunnan Province, Kunming, China
| | - Li Lei
- Department of Neurosurgery, The Affiliated Hospital of Medical College, Kunming University of Science and Technology, The First People's Hospital of Yunnan Province, Kunming, China
| | - Hu Zhou
- Department of Neurosurgery, The Affiliated Hospital of Medical College, Kunming University of Science and Technology, The First People's Hospital of Yunnan Province, Kunming, China
| | - Xiaoyang Lu
- Translational Neurosurgery and Neurobiology, University Hospital Aachen, RWTH Aachen, Aachen, Germany
| | - Feifei Cai
- Department of Radiology, Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Shaoxing, China
| | - Tao Li
- Department of Neurosurgery, The Affiliated Hospital of Medical College, Kunming University of Science and Technology, The First People's Hospital of Yunnan Province, Kunming, China
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12
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Li D, Cui D, Jia S, Liu X, Wang X, Qiu D, Wang YF. Involvement of Supraoptic Astrocytes in Basilar Artery Occlusion-Evoked Differential Activation of Vasopressin Neurons and Vasopressin Secretion in Rats. Neurochem Res 2021; 46:2651-2661. [PMID: 33532897 DOI: 10.1007/s11064-021-03246-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/02/2021] [Accepted: 01/12/2021] [Indexed: 10/22/2022]
Abstract
Vasopressin (VP) is a key factor in the development of brain injury in ischemic stroke. However, the regulation of VP secretion in basilar artery occlusion (BAO) remains unclear. To clarify the regulation of VP secretion in BAO and the underlying mechanisms, we performed this study in a rat model of BAO with (BC) or without common carotid artery occlusion (CCAO). The results showed that BAO and BC time-dependently increased neurological scores and that BC also increased water contents in the medulla at 2 h and in the pontine at 8 h. Moreover, plasma VP level increased significantly at BAO-8 h, CCAO and BC-2 h but not at BC-8 h; however, VP expressions increased in the supraoptic nucleus (SON) at BC-8 h. The neurological scores were highly correlated with pontine water contents and plasma VP levels. The number of phosphorylated extracellular signal-regulated protein kinase1/2-positive VP neurons increased significantly in the SON at BC-8 h. Similarly, the number of c-Fos-positive VP neurons increased significantly in the SON at BAO-8 h and BC-8 h. In addition, the length of glial fibrillary acidic protein (GFAP) filaments increased significantly in BC compared to BAO only. Aquaporin 4 (AQP4) puncta around VP neurons increased significantly at BC-8 h relative to BC-2 h, which had negative correlation with plasma VP levels. These findings indicate that BAO facilitates VP secretion and increases VP neuronal activity in the SON. The peripheral VP release is possibly under a negative feedback regulation of central VP neuronal activity through increasing GFAP and AQP4 expression in astrocytic processes.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China.
- Department of Physiology, Hainan Medical University, Haikou, China.
| | - Dan Cui
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Delai Qiu
- Department of Physiology and Pathophysiology, College of Medicine, Yanbian University, Yanji, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China.
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13
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Li D, Li T, Yu J, Liu X, Jia S, Wang X, Wang P, Wang YF. Astrocytic Modulation of Supraoptic Oxytocin Neuronal Activity in Rat Dams with Pup-Deprivation at Different Stages of Lactation. Neurochem Res 2021; 46:2601-2611. [PMID: 32930948 DOI: 10.1007/s11064-020-03129-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/05/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023]
Abstract
Appropriate interactions between astrocytes and oxytocin neurons in the hypothalamo- neurohypophysial system are essential for normal lactation. To further explore the mechanisms underlying astrocytic modulation of oxytocin neuronal activity, we observed astrocytic plasticity in the supraoptic nucleus of lactating rats with intermittent pup-deprivation (PD, 20 h/day) at early (day 1-5) and middle (day 8-12) stages of lactation. PD at both stages decreased suckling duration and litter's body weight gain. They also significantly increased the expression of glial fibrillary acidic protein (GFAP) in Western blots while increased GFAP filaments and the colocalization of GFAP filaments with aquaporin 4 (AQP4) puncta in astrocyte processes surrounding oxytocin neuronal somata in immunohistochemistry in the supraoptic nucleus. Suckling between adjacent milk ejections but not shortly after them decreased molecular association between GFAP and AQP4. In hypothalamic slices from male rats, oxytocin treatment (0.1 nmol/L, 10 min) significantly reduced the length of GFAP filaments and AQP4 puncta in the processes but increased GFAP staining in the somata. These oxytocin effects were blocked by pretreatment of the slices with N-(1,3,4-Thiadiazolyl) nicotinamide (TGN-020, inhibitor of AQP4, 10 µmol/L, 5 min before oxytocin). In addition, inhibition of AQP4 with TGN-020 blocked excitation in oxytocin neurons evoked by prostaglandin E2, a downstream signal of oxytocin receptor and mediator of oxytocin-evoked burst firing, in whole-cell patch-clamp recordings. These results indicate that AQP4-associated astrocytic plasticity is essential for normal oxytocin neuronal activity during lactation and that PD-evoked hypogalactia is associated with astrocytic process expansion following increased GFAP and AQP4 expressions.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Jiawei Yu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China
| | - Ping Wang
- Department of Genetics, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150081, China.
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14
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Cui D, Jia S, Yu J, Li D, Li T, Liu Y, Chang J, Wang X, Liu X, Wang YF. Alleviation of Cerebral Infarction of Rats With Middle Cerebral Artery Occlusion by Inhibition of Aquaporin 4 in the Supraoptic Nucleus. ASN Neuro 2021; 12:1759091420960550. [PMID: 32985231 PMCID: PMC7545515 DOI: 10.1177/1759091420960550] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In ischemic stroke, vasopressin hypersecretion is a critical factor of cerebral swelling and brain injury. To clarify neural mechanisms underlying ischemic stroke-evoked vasopressin hypersecretion, we observed the effect of unilateral permanent middle cerebral artery occlusion (MCAO) in rats on astrocytic plasticity and vasopressin neuronal activity in the supraoptic nucleus (SON) as well as their associated cerebral injuries. MCAO for 8 hr caused cerebral infarction in the MCAO side where water contents also increased. Immunohistochemical examination revealed that the percentage of phosphorylated extracellular signal-regulated protein kinase 1/2 (pERK1/2)-positive vasopressin neurons in the SON of MCAO side was significantly higher than that in non-MCAO side and in sham group. In the cortex, pERK1/2 and aquaporin 4 expressions increased significantly in the infarction area, while glial fibrillary acidic protein (GFAP) reduced significantly compared with the noninfarction side in brain cortex. Microinjection of N-(1,3,4-Thiadiazolyl)nicotinamide-020 [TGN-020, a specific blocker of aquaporin 4] into the SON blocked MCAO-evoked increases in pERK1/2 in the SON as well as the reduction of GFAP and the increase in pERK1/2 and aquaporin 4 in the infarction area of the cortex. Finally, oxygen and glucose deprivation reduced GFAP expression and the colocalization and molecular association of GFAP with aquaporin 4 in the SON in brain slices. These effects were blocked by TGN-020 and/or phloretin, a blocker of astrocytic volume-regulated anion channels. These findings indicate that blocking aquaporin 4 in the SON may reduce the activation of vasopressin neurons and brain injuries elicited by vasopressin during ischemic stroke.
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Affiliation(s)
- Dan Cui
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Jiawei Yu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yang Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Jinlong Chang
- The Seventh Affiliated Hospital, Sun Yat-sen Universtiy, Shenzhen, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
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15
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Stackhouse TL, Mishra A. Neurovascular Coupling in Development and Disease: Focus on Astrocytes. Front Cell Dev Biol 2021; 9:702832. [PMID: 34327206 PMCID: PMC8313501 DOI: 10.3389/fcell.2021.702832] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/09/2021] [Indexed: 12/14/2022] Open
Abstract
Neurovascular coupling is a crucial mechanism that matches the high energy demand of the brain with a supply of energy substrates from the blood. Signaling within the neurovascular unit is responsible for activity-dependent changes in cerebral blood flow. The strength and reliability of neurovascular coupling form the basis of non-invasive human neuroimaging techniques, including blood oxygen level dependent (BOLD) functional magnetic resonance imaging. Interestingly, BOLD signals are negative in infants, indicating a mismatch between metabolism and blood flow upon neural activation; this response is the opposite of that observed in healthy adults where activity evokes a large oversupply of blood flow. Negative neurovascular coupling has also been observed in rodents at early postnatal stages, further implying that this is a process that matures during development. This rationale is consistent with the morphological maturation of the neurovascular unit, which occurs over a similar time frame. While neurons differentiate before birth, astrocytes differentiate postnatally in rodents and the maturation of their complex morphology during the first few weeks of life links them with synapses and the vasculature. The vascular network is also incomplete in neonates and matures in parallel with astrocytes. Here, we review the timeline of the structural maturation of the neurovascular unit with special emphasis on astrocytes and the vascular tree and what it implies for functional maturation of neurovascular coupling. We also discuss similarities between immature astrocytes during development and reactive astrocytes in disease, which are relevant to neurovascular coupling. Finally, we close by pointing out current gaps in knowledge that must be addressed to fully elucidate the mechanisms underlying neurovascular coupling maturation, with the expectation that this may also clarify astrocyte-dependent mechanisms of cerebrovascular impairment in neurodegenerative conditions in which reduced or negative neurovascular coupling is noted, such as stroke and Alzheimer’s disease.
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Affiliation(s)
- Teresa L Stackhouse
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States
| | - Anusha Mishra
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health & Science University, Portland, OR, United States.,Knight Cardiovascular Institute, Oregon Health & Sciences University, Portland, OR, United States
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16
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Wang X, Li T, Liu Y, Jia S, Liu X, Jiang Y, Wang P, Parpura V, Wang Y. Aquaporin 4 differentially modulates osmotic effects on vasopressin neurons in rat supraoptic nucleus. Acta Physiol (Oxf) 2021; 232:e13672. [PMID: 33978309 DOI: 10.1111/apha.13672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/28/2021] [Accepted: 05/06/2021] [Indexed: 12/24/2022]
Abstract
AIM Glial fibrillary acidic protein (GFAP) molecularly associates with aquaporin 4 (AQP4) in astrocytic plasticity. Here, we further examined how AQP4 modulates osmotic effects on vasopressin (VP) neurons in rat supraoptic nucleus (SON) through interactions with GFAP in astrocytes. METHODS Brain slices from adult male rats were kept under osmotic stimulation. Western blot, co-immunoprecipitation, immunohistochemistry and patch-clamp recordings were used for analysis of expressions and interactions between GFAP and AQP4, astrocyte-specific proteins in the SON, as well as their influence on VP neuronal activity. Data were analysed using SPSS software. RESULTS Hyposmotic challenge (HOC) of acute SON slices caused an early (within 5 minutes) and transient increase in the colocalization of AQP4 with GFAP filaments. This effect was prominent at astrocytic processes surrounding VP neuron somata and was accompanied by inhibition of VP neuronal activity. Similar HOC effect was seen in the SON isolated from rats subjected to in vivo HOC, wherein a transiently increased molecular association between GFAP and AQP4 was detected using co-immunoprecipitation. The late stage rebound excitation (10 minutes) of VP neurons in brain slices subjected to HOC and the associated astrocytic GFAP's 'return to normal' were both hampered by 2-(nicotinamide)-1,3,4-thiadiazole, a specific AQP4 channel blocker that itself did not influence VP neuronal activity. Moreover, this agent prevented hyperosmotic stress-evoked excitation of VP neurons and associated reduction in GFAP filaments. CONCLUSION These findings indicate that osmotically driven increase in VP neuronal activity requires the activation of AQP4, which determines a retraction of GFAP filaments.
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Affiliation(s)
- Xiaoran Wang
- Department of Physiology Harbin Medical University Harbin China
| | - Tong Li
- Department of Physiology Harbin Medical University Harbin China
| | - Yang Liu
- Department of Physiology Harbin Medical University Harbin China
| | - Shuwei Jia
- Department of Physiology Harbin Medical University Harbin China
| | - Xiaoyu Liu
- Department of Physiology Harbin Medical University Harbin China
| | - Yunhao Jiang
- Department of Physiology Harbin Medical University Harbin China
| | - Ping Wang
- Department of Genetics Harbin Medical University Harbin China
| | - Vladimir Parpura
- Department of Neurobiology The University of Alabama at Birmingham Birmingham AL USA
| | - Yu‐Feng Wang
- Department of Physiology Harbin Medical University Harbin China
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17
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Shi XY, Cai MT, Shen H, Zhang JX. Central pontine myelinolysis mimicking glioma in diabetes: A case report. World J Clin Cases 2021; 9:4837-4843. [PMID: 34222456 PMCID: PMC8223854 DOI: 10.12998/wjcc.v9.i18.4837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/09/2021] [Accepted: 03/31/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Central pontine myelinolysis (CPM) usually occurs during rapid correction of serum osmolality, typically with brainstem lesions presenting uniform signals following enhancement on magnetic resonance imaging (MRI). We report a case of CPM caused by diabetes, which was characterized by glioma-like imaging features and the patient responded well to corticosteroids.
CASE SUMMARY A 49-year-old man with type 2 diabetes was admitted due to numbness and weakness for 6 mo with progressive aggravation for 2 wk. His complete blood count, serum electrolytes, renal and liver function parameters were within the normal range. MRI showed mass lesions in the brainstem, with unusually inhomogeneous signal intensity after contrast-enhanced scans. His symptoms worsened after hypoglycemic therapy. Due to his clinical history and examination results, CPM was considered the most likely diagnosis. Treatment with corticosteroids was administered with a methylprednisolone pulse in the acute phase followed by dose tapering. During the 8-mo follow-up period, his clinical symptoms and imaging features significantly improved.
CONCLUSION Diabetes could rarely be accompanied by CPM, and patients who experience this neurological complication could benefit from corticosteroid treatment. Clinicians should recognize the special relationship between diabetes and CPM, and improve awareness of early identification and appropriate treatment.
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Affiliation(s)
- Xiao-Yong Shi
- Department of Brain Center, Affiliated Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou 310000, Zhejiang Province, China
| | - Meng-Ting Cai
- Department of Neurology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310000, Zhejiang Province, China
| | - Hao Shen
- Department of Neurology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou 310000, Zhejiang Province, China
| | - Jin-Xia Zhang
- Department of Clinical Psychology (Sleep Medical Center), Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou 310000, Zhejiang Province, China
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18
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Filippenkov IB, Dergunova LV, Limborska SA, Myasoedov NF. Neuroprotective Effects of Peptides in the Brain: Transcriptome Approach. BIOCHEMISTRY (MOSCOW) 2021; 85:279-287. [PMID: 32564732 DOI: 10.1134/s0006297920030037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The importance of studying the action mechanisms of drugs based on natural regulatory peptides is commonly recognized. Particular attention is paid to the peptide drugs that contribute to the restoration of brain functions after acute cerebrovascular accidents (stroke), which for many years continues to be one of the main problems and threats to human health. However, molecular genetic changes in the brain in response to ischemia, as well as the mechanisms of protective effects of peptides, have not been sufficiently studied. This limits the use of neuroprotective peptides and makes it difficult to develop new, more efficient drugs with targeted action on brain functions. Transcriptome analysis is a promising approach for studying the mechanisms of the damaging effects of cerebral ischemia and neuroprotective action of peptide drugs. Beside investigating the role of mRNAs in protein synthesis, the development of new neuroprotection strategies requires studying the involvement of regulatory RNAs in ischemia. Of greatest interest are microRNAs (miRNAs) and circular RNAs (circRNAs), which are expressed predominantly in the brain. CircRNAs can interact with miRNAs and diminish their activity, thereby inhibiting miRNA-mediated repression of mRNAs. It has become apparent that analysis of the circRNA/miRNA/mRNA system is essential for deciphering the mechanisms of brain damage and repair. Here, we present the results of studies on the ischemia-induced changes in the activity of genes and peptide-mediated alterations in the transcriptome profiles in experimental ischemia and formulate the basic principles of peptide regulation in the ischemia-induced damage.
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Affiliation(s)
- I B Filippenkov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia.
| | - L V Dergunova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - S A Limborska
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - N F Myasoedov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
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19
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Wang SC, Parpura V, Wang YF. Astroglial Regulation of Magnocellular Neuroendocrine Cell Activities in the Supraoptic Nucleus. Neurochem Res 2020; 46:2586-2600. [PMID: 33216313 DOI: 10.1007/s11064-020-03172-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/02/2020] [Accepted: 11/09/2020] [Indexed: 01/02/2023]
Abstract
Studies on the interactions between astrocytes and neurons in the hypothalamo-neurohypophysial system have significantly facilitated our understanding of the regulation of neural activities. This has been exemplified in the interactions between astrocytes and magnocellular neuroendocrine cells (MNCs) in the supraoptic nucleus (SON), specifically during osmotic stimulation and lactation. In response to changes in neurochemical environment in the SON, astrocytic morphology and functions change significantly, which further modulates MNC activity and the secretion of vasopressin and oxytocin. In osmotic regulation, short-term dehydration or water overload causes transient retraction or expansion of astrocytic processes, which increases or decreases the activity of SON neurons, respectively. Prolonged osmotic stimulation causes adaptive change in astrocytic plasticity in the SON, which allows osmosensory neurons to reserve osmosensitivity at new levels. During lactation, changes in neurochemical environment cause retraction of astrocytic processes around oxytocin neurons, which increases MNC's ability to secrete oxytocin. During suckling by a baby/pup, astrocytic processes in the mother/dams exhibit alternative retraction and expansion around oxytocin neurons, which mirrors intermittently synchronized activation of oxytocin neurons and the post-excitation inhibition, respectively. The morphological and functional plasticities of astrocytes depend on a series of cellular events involving glial fibrillary acidic protein, aquaporin 4, volume regulated anion channels, transporters and other astrocytic functional molecules. This review further explores mechanisms underlying astroglial regulation of the neuroendocrine neuronal activities in acute processes based on the knowledge from studies on the SON.
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Affiliation(s)
- Stephani C Wang
- Division of Cardiology, Department of Medicine, University of California-Irvine, Irvine, CA, USA
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, 35242, USA.
| | - Yu-Feng Wang
- Department of Physiology School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin, 150086, China.
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20
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Endoplasmic reticulum chaperone BiP/GRP78 knockdown leads to autophagy and cell death of arginine vasopressin neurons in mice. Sci Rep 2020; 10:19730. [PMID: 33184425 PMCID: PMC7661499 DOI: 10.1038/s41598-020-76839-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022] Open
Abstract
The immunoglobulin heavy chain binding protein (BiP), also referred to as 78-kDa glucose-regulated protein (GRP78), is a pivotal endoplasmic reticulum (ER) chaperone which modulates the unfolded protein response under ER stress. Our previous studies showed that BiP is expressed in arginine vasopressin (AVP) neurons under non-stress conditions and that BiP expression is upregulated in proportion to the increased AVP expression under dehydration. To clarify the role of BiP in AVP neurons, we used a viral approach in combination with shRNA interference for BiP knockdown in mouse AVP neurons. Injection of a recombinant adeno-associated virus equipped with a mouse AVP promoter and BiP shRNA cassette provided specific BiP knockdown in AVP neurons of the supraoptic (SON) and paraventricular nuclei (PVN) in mice. AVP neuron-specific BiP knockdown led to ER stress and AVP neuronal loss in the SON and PVN, resulting in increased urine volume due to lack of AVP secretion. Immunoelectron microscopy of AVP neurons revealed that autophagy was activated through the process of AVP neuronal loss, whereas no obvious features characteristic of apoptosis were observed. Pharmacological inhibition of autophagy by chloroquine exacerbated the AVP neuronal loss due to BiP knockdown, indicating a protective role of autophagy in AVP neurons under ER stress. In summary, our results demonstrate that BiP is essential for the AVP neuron system.
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Cui D, Jia S, Li T, Li D, Wang X, Liu X, Wang YF. Alleviation of brain injury by applying TGN-020 in the supraoptic nucleus via inhibiting vasopressin neurons in rats of focal ischemic stroke. Life Sci 2020; 264:118683. [PMID: 33127515 DOI: 10.1016/j.lfs.2020.118683] [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: 08/13/2020] [Revised: 10/17/2020] [Accepted: 10/25/2020] [Indexed: 12/27/2022]
Abstract
AIMS To understand mechanisms underlying vasopressin hypersecretion in stroke and its association with brain injury, we investigated effects of blocking aquaporin 4 (AQP4) in the supraoptic nucleus (SON) on vasopressin neuronal activity and cerebral injuries in male rats of unilateral middle cerebral artery occlusion (MCAO). MAIN METHODS Establishing MCAO model without or with microinjection of TGN-020 into the SON, performing Western blots and immunohistochemistry and analyzing the expression levels and spatial distribution of functional proteins in the SON and/or the cerebral cortex. KEY FINDINGS MCAO increased plasma vasopressin levels, caused neurological damage and increased glycogen synthase kinase 3β (GSK-3β) in the SON and the cortex of MCAO side. In the SON, MCAO significantly increased c-Fos in vasopressin neurons and astrocytic somata in the ventral glial lamina. MCAO significantly reduced glial fibrillary acidic protein (GFAP) and AQP4 around vasopressin neurons, which accompanied separation of GFAP from AQP4. By contrast, blocking AQP4 by microinjection of TGN-020 into the SON blocked MCAO-evoked GSK-3β increase as well as the reduction of AQP4 relative to GFAP around vasopressin neurons in the SON. In the cortex, TGN-020 in the SON also blocked MCAO-evoked increase in GSK-3β while reduced neurological damages. SIGNIFICANCE These findings indicate that MCAO disrupts interactions of GFAP with AQP4 in astrocytic processes in the SON, which increases vasopressin neuronal activity. Blocking AQP4 in the SON can block abnormal activation of vasopressin neurons and alleviate ischemic brain injury, which provides novel targets for alleviating ischemic brain injury.
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Affiliation(s)
- Dan Cui
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China.
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22
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Jin J, Ji W, Li L, Zhao G, Wu W, Wei H, Ma F, Jiang Y, Mao L. Electrochemically Probing Dynamics of Ascorbate during Cytotoxic Edema in Living Rat Brain. J Am Chem Soc 2020; 142:19012-19016. [PMID: 33108734 DOI: 10.1021/jacs.0c09011] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cytotoxic edema is the initial and most important step in the sequence that almost inevitably leads to brain damage. Exploring the neurochemical disturbances in this process is of great significance in providing a measurable biological parameter for signaling specific pathological conditions. Here, we present an electrochemical system that pinpoints a critical neurochemical involved in cytotoxic edema. Specially, we report a molecularly tailored brain-implantable ascorbate sensor (CFEAA2.0) featuring excellent selectivity and spatiotemporal resolution that assists the first observation of release of ascorbate induced by cytotoxic edema in vivo. Importantly, we reveal that this release is associated with an increase in the amount of cytotoxic edema-inducing agent and that blockage of cytotoxic edema abolishes ascorbate release, further supporting that ascorbate efflux is cytotoxic edema-dependent. Our study holds the promise for understanding the molecular basis of cytotoxic edema that can lead to the discovery of biomarkers or potential therapeutic strategies of brain diseases.
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Affiliation(s)
- Jing Jin
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecule Science, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenliang Ji
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecule Science, Beijing 100190, China
| | - Lijuan Li
- Department of Otorhinolaryngology, Peking University Third Hospital, Beijing 100083, China
| | - Gang Zhao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecule Science, Beijing 100190, China
| | - Wenjie Wu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecule Science, Beijing 100190, China
| | - Huan Wei
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecule Science, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Furong Ma
- Department of Otorhinolaryngology, Peking University Third Hospital, Beijing 100083, China
| | - Ying Jiang
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Lanqun Mao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecule Science, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
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Dergunova LV, Filippenkov IB, Limborska SA, Myasoedov NF. Pharmacotranscriptomics of peptide drugs with neuroprotective properties. Med Res Rev 2020; 41:754-769. [PMID: 32638434 DOI: 10.1002/med.21704] [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: 04/07/2020] [Revised: 06/18/2020] [Accepted: 06/20/2020] [Indexed: 01/05/2023]
Abstract
Here we present a review of studies on the effects of peptides with neuroprotective properties on gene transcription in nerve cells. The few published works in this area clearly demonstrate massive changes in cell transcriptomes induced by peptides under normal conditions and under conditions of experimental brain ischemia. These changes significantly affect signaling and metabolic pathways, affecting various body systems and confirming the multiple target actions of peptides. The importance of noncoding RNAs in the regulation of these processes is shown, and we discuss the prospects of research for determining the main mechanisms of peptide regulation, which is necessary for the further development of drugs with targeted neuroprotective effects.
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Affiliation(s)
- Lyudmila V Dergunova
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Ivan B Filippenkov
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Svetlana A Limborska
- Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Nikolai F Myasoedov
- Department of Chemistry of Physiologically Active Compounds, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
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24
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Chemically Functionalized Water-Soluble Single-Walled Carbon Nanotubes Obstruct Vesicular/Plasmalemmal Recycling in Astrocytes Down-Stream of Calcium Ions. Cells 2020; 9:cells9071597. [PMID: 32630262 PMCID: PMC7408470 DOI: 10.3390/cells9071597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/24/2020] [Accepted: 06/27/2020] [Indexed: 01/24/2023] Open
Abstract
We used single-walled carbon nanotubes chemically functionalized with polyethylene glycol (SWCNT-PEG) to assess the effects of this nanomaterial on astrocytic endocytosis and exocytosis. We observed that the SWCNT-PEG do not affect the adenosine triphosphate (ATP)-evoked Ca2+ elevations in astrocytes but significantly reduce the Ca2+-dependent glutamate release. There was a significant decrease in the endocytic load of the recycling dye during constitutive and ATP-evoked recycling. Furthermore, SWCNT-PEG hampered ATP-evoked exocytotic release of the loaded recycling dye. Thus, by functionally obstructing evoked vesicular recycling, SWCNT-PEG reduced glutamate release from astrocytes via regulated exocytosis. These effects implicate SWCNT-PEG as a modulator of Ca2+-dependent exocytosis in astrocytes downstream of Ca2+, likely at the level of vesicle fusion with/pinching off the plasma membrane.
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25
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Channels that Cooperate with TRPV4 in the Brain. J Mol Neurosci 2020; 70:1812-1820. [PMID: 32524421 DOI: 10.1007/s12031-020-01574-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 04/27/2020] [Indexed: 12/26/2022]
Abstract
Transient receptor potential vanilloid 4 (TRPV4) is a nonselective Ca2+-permeable cation channel that is a member of the TRP channel family. It is clear that TRPV4 channels are broadly expressed in the brain. As they are expressed on the plasma membrane, they interact with other channels and play a crucial role in nervous system activity. Under some pathological conditions, TRPV4 channels are upregulated and sensitized via cellular signaling pathways, and this can cause nervous system diseases. In this review, we focus on receptors that cooperate with TRPV4, including large-conductance Ca2+-activated K+(BKca) channels, N-methyl-D-aspartate receptors (NMDARs), α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptors (AMPARs), inositol 1,4,5-trisphosphate receptors (IP3Rs), ryanodine receptors (RyRs), aquaporin 4 (AQP4), and other potential cooperative receptors in the brain. The data demonstrate how these channels work together to cause nervous system diseases under pathological conditions. The aim of this review was to discuss the receptors and signaling pathways related to TRPV4 based on recent data on the important physiological functions of TRPV4 channels to provide new clues for future studies and prospective therapeutic targets for related brain diseases.
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26
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Li D, Liu X, Liu T, Liu H, Tong L, Jia S, Wang YF. Neurochemical regulation of the expression and function of glial fibrillary acidic protein in astrocytes. Glia 2019; 68:878-897. [PMID: 31626364 DOI: 10.1002/glia.23734] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/27/2019] [Accepted: 09/17/2019] [Indexed: 12/30/2022]
Abstract
Glial fibrillary acidic protein (GFAP), a type III intermediate filament, is a marker of mature astrocytes. The expression of GFAP gene is regulated by many transcription factors (TFs), mainly Janus kinase-2/signal transducer and activator of transcription 3 cascade and nuclear factor κ-light-chain-enhancer of activated B cell signaling. GFAP expression is also modulated by protein kinase and other signaling molecules that are elicited by neuronal activity and hormones. Abnormal expression of GFAP proteins occurs in neuroinflammation, neurodegeneration, brain edema-eliciting diseases, traumatic brain injury, psychiatric disorders and others. GFAP, mainly in α-isoform, is the major component of cytoskeleton and the scaffold of astrocytes, which is essential for the maintenance of astrocytic structure and shape. GFAP also has highly morphological plasticity because of its quick changes in assembling and polymerizing states in response to environmental challenges. This plasticity and its corresponding cellular morphological changes endow astrocytes the functions of physical barrier between adjacent neurons and stabilizer of extracellular environment. Moreover, GFAP colocalizes and even molecularly associates with many functional molecules. This feature allows GFAP to function as a platform for direct interactions between different molecules. Last, GFAP involves transportation and localization of other functional proteins and thus serves as a protein transport guide in astrocytes. This guiding role of GFAP involves an elastic retraction and extension cytoskeletal network that couples with GFAP reassembling, transporting, and membrane protein recycling machinery. This paper reviews our current understanding of the expression and functions of GFAP as well as their regulation.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Tianming Liu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Haitao Liu
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Li Tong
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, Harbin Medical University, Harbin, China
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27
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Wang YF, Gao YJ. 2019 Academic Annual Meeting and the Frontier Seminar on "Glial Cell Function and Disease" (Nantong, China). ASN Neuro 2019; 11:1759091419863576. [PMID: 31342775 PMCID: PMC6659189 DOI: 10.1177/1759091419863576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The contribution of glial activities to the functions, diseases, and repair of
the central nervous system has received increasing attention in neuroscience
studies. To promote the research of glial cells and increase cooperation with
peers, the 2019 Academic Annual Meeting and the Frontier Seminar on “Glial Cell
Function and Disease” was held in Nantong City, Jiangsu Province, China from May
24 to 26. The meeting was organized by Drs. Yong-Jing Gao and Jia-Wei Zhou of
the Chinese Society of Neuroscience Glia Branch. The conference focused on the
physiological and pathological functions of astrocytes, microglia, and
oligodendrocytes with 25 speakers in two plenary speeches and five sections of
more than 180 participants engaged in glial cell research. In the two plenary
lectures, Yutian Wang from the University of British Columbia and Xia Zhang from
the University of Ottawa presented “Development of NMDAR (N-methyl-D-aspartic
acid receptor)-positive allosteric modulators as novel therapeutics for brain
disorders” and “Mechanisms underlying cannabinoid regulation of brain function
and disease,” respectively. The five sections included microglia and disease,
astrocytes and disease, glioma treatment and glial imaging, oligodendrocytes and
disease, and glial–neuronal interactions and disease. This meeting allowed
extensive and in-depth academic exchanges on the latest research and
experimental techniques, represented the highest achievements of Chinese
scholars on glial cells, and promoted the cooperation between peers in the
fields of glia studies.
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Affiliation(s)
- Yu-Feng Wang
- 1 Department of Physiology, Harbin Medical University, China
| | - Yong-Jing Gao
- 2 Institute of Pain Medicine, Institute of Special Environmental Medicine, Nantong University, China
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28
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Gao L, Zhang Z, Lu J, Pei G. Mitochondria Are Dynamically Transferring Between Human Neural Cells and Alexander Disease-Associated GFAP Mutations Impair the Astrocytic Transfer. Front Cell Neurosci 2019; 13:316. [PMID: 31327963 PMCID: PMC6636397 DOI: 10.3389/fncel.2019.00316] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 06/27/2019] [Indexed: 12/22/2022] Open
Abstract
Mitochondria are the critical organelles for energy metabolism and cell survival in eukaryotic cells. Recent studies demonstrated that mitochondria can intercellularly transfer between mammalian cells. In neural cells, astrocytes transfer mitochondria into neurons in a CD38-dependent manner. Here, using co-culture system of neural cell lines, primary neural cells, and human pluripotent stem cell (hPSC)-derived neural cells, we further revealed that mitochondria dynamically transferred between astrocytes and also from neuronal cells into astrocytes, to which CD38/cyclic ADP-ribose signaling and mitochondrial Rho GTPases (MIRO1 and MIRO2) contributed. The transfer consequently elevated mitochondrial membrane potential in the recipient cells. By introducing Alexander disease (AxD)-associated hotspot mutations (R79C, R239C) into GFAP gene of hPSCs and subsequently inducing astrocyte differentiation, we found that GFAP mutations impaired mitochondrial transfer from astrocytes and reduced astrocytic CD38 expression. Thus, our study suggested that mitochondria dynamically transferred between neural cells and revealed that AxD-associated mutations in GFAP gene disrupted the astrocytic transfer, providing a potential pathogenic mechanism in AxD.
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Affiliation(s)
- Longfei Gao
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Zhen Zhang
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Jing Lu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Gang Pei
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.,Shanghai Key Laboratory of Signaling and Disease Research, Collaborative Innovation Center for Brain Science, School of Life Sciences and Technology, Tongji University, Shanghai, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
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29
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Dardiotis E, Siokas V, Aloizou AM, Karampinis E, Brotis AG, Grigoriadis S, Paterakis K, Dardioti M, Komnos A, Kapsalaki E, Fountas K, Hadjigeorgiou GM. Effect of integrin AV and B8 gene polymorphisms in patients with traumatic brain injury. Brain Inj 2019; 33:836-845. [PMID: 31033358 DOI: 10.1080/02699052.2019.1606444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background: Α few genetic variants are associated with the outcome after traumatic brain injury (TBI). Integrins are glycoprotein receptors that play an important role in the integrity of microvasculature of the brain. Objective: To examine the role of integrin-AV (ITGAV) and integrin-B8 (ITGB8) tag single nucleotide polymorphisms (SNPs) on the outcome of patients with TBI. Methods: 363 participants were included and genotyped for 11 SNPs for ITGAV and 11 for ITGB8 gene. SNPs were tested for associations with the 6-month outcome after TBI, the presence of a hemorrhagic event after TBI, and the initial TBI severity after adjustment for TBI's main predictors. Results: The ITGAV rs3911239 CC and rs7596996 GG genotypes were associated with an unfavorable outcome after TBI, compared to the TT and AA genotypes, respectively. The ITGB8 rs10239099 CC and rs3757727 CC genotypes were associated with increased risk of any cerebral hemorrhagic event after TBI compared to GG and TT respectively. The ITGAV rs7589470 and rs7565633 were associated with the TBI's initial severity. Conclusions: ITGAV gene SNPs may be implicated in the outcome after TBI, as well as in the initial TBI severity, and also of ITGB8 gene SNPs in the risk of hemorrhagic event after a TBI.
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Affiliation(s)
- Efthimios Dardiotis
- a Department of Neurology, Laboratory of Neurogenetics , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Vasileios Siokas
- a Department of Neurology, Laboratory of Neurogenetics , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Athina-Maria Aloizou
- a Department of Neurology, Laboratory of Neurogenetics , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Emmanouil Karampinis
- a Department of Neurology, Laboratory of Neurogenetics , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Alexandros G Brotis
- b Department of Neurosurgery , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Savas Grigoriadis
- c Second Department of Neurosurgery , Hippokration University Hospital, Aristotle University of Thessaloniki , Thessaloniki , Greece
| | - Konstantinos Paterakis
- b Department of Neurosurgery , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Maria Dardioti
- a Department of Neurology, Laboratory of Neurogenetics , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Apostolos Komnos
- d Intensive Care Unit , General Hospital of Larissa , Larissa , Greece
| | - Eftychia Kapsalaki
- e Department of Radiology , University of Thessaly, School of Medicine , Larissa , Greece
| | - Kostas Fountas
- b Department of Neurosurgery , University of Thessaly, University Hospital of Larissa , Larissa , Greece
| | - Georgios M Hadjigeorgiou
- a Department of Neurology, Laboratory of Neurogenetics , University of Thessaly, University Hospital of Larissa , Larissa , Greece.,f Department of Neurology , Medical School, University of Cyprus , Nicosia , USA
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Largeau B, Le Tilly O, Sautenet B, Salmon Gandonnière C, Barin-Le Guellec C, Ehrmann S. Arginine Vasopressin and Posterior Reversible Encephalopathy Syndrome Pathophysiology: the Missing Link? Mol Neurobiol 2019; 56:6792-6806. [PMID: 30924075 DOI: 10.1007/s12035-019-1553-y] [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] [Received: 12/25/2018] [Accepted: 03/13/2019] [Indexed: 12/12/2022]
Abstract
Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity characterized by a typical brain edema. Its pathogenesis is still debated through hypoperfusion and hyperperfusion theories, which have many limitations. As PRES occurs almost exclusively in clinical situations with arginine vasopressin (AVP) hypersecretion, such as eclampsia and sepsis, we hypothesize that AVP plays a central pathophysiologic role. In this review, we discuss the genesis of PRES and its symptoms through this novel approach. We theorize that AVP axis stimulation precipitates PRES development through an increase in AVP secretion or AVP receptor density. Activation of vasopressin V1a receptors leads to cerebral vasoconstriction, causing endothelial dysfunction and cerebral ischemia. This promotes cytotoxic edema through hydromineral transglial flux dysfunction and may increase endothelial permeability, leading to subsequent vasogenic brain edema. If our hypothesis is confirmed, it opens new perspectives for better patient monitoring and therapies targeting the AVP axis in PRES.
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Affiliation(s)
- Bérenger Largeau
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France.
| | - Olivier Le Tilly
- CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France
| | - Bénédicte Sautenet
- Université de Tours, Université de Nantes, INSERM, Methods in patients-centered outcomes and health research (SPHERE) - UMR 1246, CHRU de Tours, Service de Néphrologie-Hypertension artérielle, Dialyses et Transplantation Rénale, Tours, France
| | | | - Chantal Barin-Le Guellec
- Université de Tours, Université de Limoges, INSERM, Individual profiling and prevention of risks with immunosuppressive therapies and transplantation (IPPRITT) - UMR 1248, CHRU de Tours, Laboratoire de Biochimie et Biologie Moléculaire, Tours, France
| | - Stephan Ehrmann
- Université de Tours, INSERM, Centre d'étude des pathologies respiratoires (CEPR) - UMR 1100, CHRU de Tours, Service de Médecine Intensive Réanimation, CIC 1415, réseau CRICS-TRIGGERSEP, Tours, France
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Fuentes-Santamaría V, Alvarado JC, Rodríguez-de la Rosa L, Juiz JM, Varela-Nieto I. Neuroglial Involvement in Abnormal Glutamate Transport in the Cochlear Nuclei of the Igf1 -/- Mouse. Front Cell Neurosci 2019; 13:67. [PMID: 30881288 PMCID: PMC6405628 DOI: 10.3389/fncel.2019.00067] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 02/11/2019] [Indexed: 12/25/2022] Open
Abstract
Insulin-like growth factor 1 (IGF-1) is a powerful regulator of synaptic activity and a deficit in this protein has a profound impact on neurotransmission, mostly on excitatory synapses in both the developing and mature auditory system. Adult Igf1−/− mice are animal models for the study of human syndromic deafness; they show altered cochlear projection patterns into abnormally developed auditory neurons along with impaired glutamate uptake in the cochlear nuclei, phenomena that probably reflect disruptions in neuronal circuits. To determine the cellular mechanisms that might be involved in regulating excitatory synaptic plasticity in 4-month-old Igf1−/− mice, modifications to neuroglia, astroglial glutamate transporters (GLTs) and metabotropic glutamate receptors (mGluRs) were assessed in the cochlear nuclei. The Igf1−/− mice show significant decreases in IBA1 (an ionized calcium-binding adapter) and glial fibrillary acidic protein (GFAP) mRNA expression and protein accumulation, as well as dampened mGluR expression in conjunction with enhanced glutamate transporter 1 (GLT1) expression. By contrast, no differences were observed in the expression of glutamate aspartate transporter (GLAST) between these Igf1−/− mice and their heterozygous or wildtype littermates. These observations suggest that congenital IGF-1 deficiency may lead to alterations in microglia and astrocytes, an upregulation of GLT1, and the downregulation of groups I, II and III mGluRs. Understanding the molecular, biochemical and morphological mechanisms underlying neuronal plasticity in a mouse model of hearing deficits will give us insight into new therapeutic strategies that could help to maintain or even improve residual hearing when human deafness is related to IGF-1 deficiency.
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Affiliation(s)
- Veronica Fuentes-Santamaría
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Juan C Alvarado
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Lourdes Rodríguez-de la Rosa
- Grupo de Neurobiología de la Audición, Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), CIBER MP, Instituto de Salud Carlos III, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Universitario La Paz (IdiPAZ), Madrid, Spain
| | - José M Juiz
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad de Castilla-La Mancha, Albacete, Spain
| | - Isabel Varela-Nieto
- Grupo de Neurobiología de la Audición, Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), CIBER MP, Instituto de Salud Carlos III, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Universitario La Paz (IdiPAZ), Madrid, Spain
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Zhang J, Wang Y, Zheng Z, Sun X, Chen T, Li C, Zhang X, Guo J. Intracellular ion and protein nanoparticle-induced osmotic pressure modify astrocyte swelling and brain edema in response to glutamate stimuli. Redox Biol 2019; 21:101112. [PMID: 30685709 PMCID: PMC6351271 DOI: 10.1016/j.redox.2019.101112] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/02/2019] [Accepted: 01/14/2019] [Indexed: 12/28/2022] Open
Abstract
Intracellular tension activity plays a crucial role in cytotoxic brain edema and astrocyte swelling. Here, a few genetically encoded FRET-based tension probes were designed to detect cytoskeletal structural tension optically, including their magnitude and vectors. The astrocyte swelling resulted in GFAP tension increment, which is associated with the antagonistic effect of inward microfilaments (MFs) and microtubules (MTs) forces. In glutamate-induced astrocyte swelling, GFAP tension rise resulted from outward ion and protein nanoparticle-induced osmotic pressure (PN-OP) increases, where PN-OP could be elicited by MF and MT depolymerization, protein nanoparticle production, and activation of cofilin and stathmin-1. Attenuation of both ion osmotic pressure and PN-OP by drug combinations, together with free-radical scavenger, relieved cerebral edema in vivo. The study suggests that intracellular osmotic pressure (especially PN-OP) has a pivotal role in glutamate-induced astrocyte swelling and brain edema. Recovery of cytoplasmic potential is a promising target to develop new drugs and cure brain edema.
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Affiliation(s)
- JiaRui Zhang
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - YuXuan Wang
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - ZiHui Zheng
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - XiaoHe Sun
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - TingTing Chen
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - Chen Li
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - XiaoLong Zhang
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China
| | - Jun Guo
- State Key Laboratory Cultivation Base For TCM Quality and Efficacy, School of Medicine and Life Science, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; Key Laboratory of Drug Target and Drug for Degenerative Disease, Nanjing University of Chinese Medicine, Nanjing, PR China; Jiangsu Key Laboratory of Pediatric Respiratory Disease, Institute of Pediatrics, Nanjing University of Chinese Medicine, Nanjing, PR China.
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Chapman CAR, Aristovich K, Donega M, Fjordbakk CT, Stathopoulou TR, Viscasillas J, Avery J, Perkins JD, Holder D. Electrode fabrication and interface optimization for imaging of evoked peripheral nervous system activity with electrical impedance tomography (EIT). J Neural Eng 2018; 16:016001. [PMID: 30444215 DOI: 10.1088/1741-2552/aae868] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Non-invasive imaging techniques are undoubtedly the ideal methods for continuous monitoring of neural activity. One such method, fast neural electrical impedance tomography (EIT) has been developed over the past decade in order to image neural action potentials with non-penetrating electrode arrays. APPROACH The goal of this study is two-fold. First, we present a detailed fabrication method for silicone-based multiple electrode arrays which can be used for epicortical or neural cuff applications. Secondly, we optimize electrode material coatings in order to achieve the best accuracy in EIT reconstructions. MAIN RESULTS The testing of nanostructured electrode interface materials consisting of platinum, iridium oxide, and PEDOT:pTS in saline tank experiments demonstrated that the PEDOT:pTS coating used in this study leads to more accurate reconstruction dimensions along with reduced phase separation between recording channels. The PEDOT:pTS electrodes were then used in vivo to successfully image and localize the evoked activity of the recurrent laryngeal fascicle from within the cervical vagus nerve. SIGNIFICANCE These results alongside the simple fabrication method presented here position EIT as an effective method to image neural activity.
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Affiliation(s)
- Christopher A R Chapman
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
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