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Theparambil SM, Begum G, Rose CR. pH regulating mechanisms of astrocytes: A critical component in physiology and disease of the brain. Cell Calcium 2024; 120:102882. [PMID: 38631162 DOI: 10.1016/j.ceca.2024.102882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/28/2024] [Accepted: 03/28/2024] [Indexed: 04/19/2024]
Abstract
Strict homeostatic control of pH in both intra- and extracellular compartments of the brain is fundamentally important, primarily due to the profound impact of free protons ([H+]) on neuronal activity and overall brain function. Astrocytes, crucial players in the homeostasis of various ions in the brain, actively regulate their intracellular [H+] (pHi) through multiple membrane transporters and carbonic anhydrases. The activation of astroglial pHi regulating mechanisms also leads to corresponding alterations in the acid-base status of the extracellular fluid. Notably, astrocyte pH regulators are modulated by various neuronal signals, suggesting their pivotal role in regulating brain acid-base balance in both health and disease. This review presents the mechanisms involved in pH regulation in astrocytes and discusses their potential impact on extracellular pH under physiological conditions and in brain disorders. Targeting astrocytic pH regulatory mechanisms represents a promising therapeutic approach for modulating brain acid-base balance in diseases, offering a potential critical contribution to neuroprotection.
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Affiliation(s)
- Shefeeq M Theparambil
- Faculty of Health and Medicine, Department of Biomedical and Life Sciences, Lancaster University, Lancaster, LA1 4YW, Lancaster, UK.
| | - Gulnaz Begum
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany
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2
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Du W, Yang J, Lou Y, You J, Wang Q. Relationship between baseline bicarbonate and 30-day mortality in patients with non-traumatic subarachnoid hemorrhage. Front Neurol 2024; 14:1310327. [PMID: 38234976 PMCID: PMC10793108 DOI: 10.3389/fneur.2023.1310327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/13/2023] [Indexed: 01/19/2024] Open
Abstract
Objective This study aimed to explore the relationship between baseline bicarbonate levels and 30-day mortality in individuals with non-traumatic subarachnoid hemorrhage (SAH). Methods Patients with non-traumatic SAH were chosen from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The relationship between baseline bicarbonate and 30-day mortality was examined using Cox regression models. Restricted cubic splines were used to test the hypothesis that there was an association between bicarbonate and mortality. With the use of Kaplan-Meier survival curve analysis, we looked deeper into the validity of these correlations. To find subgroups with differences, interaction tests were utilized. Results This retrospective cohort study consisted of 521 participants in total. Bicarbonate had a negative association with death at 30 days (HR = 0.93, 95%CI: 0.88-0.98, p = 0.004). Next, we divided bicarbonate into quartile groups. In comparison to the reference group Q1 (20 mEq/L), groups Q3 (23-25 mEq/L) and Q4 (26 mEq/L) had adjusted HR values of 0.47 (95%CI: 0.27-0.82, p = 0.007) and 0.56 (95%CI: 0.31-0.99, p = 0.047). No definite conclusions can be derived from this study, since there is no obvious curve link between baseline bicarbonate and 30-day mortality. Patients' 30-day mortality increased statistically significantly (p < 0.001, K-M analysis) in patients with low bicarbonate levels. The relationship between bicarbonate and 30-day mortality remained consistent in the stratified analysis, with no observed interactions. Conclusion Finally, 30-day mortality was negatively associated with baseline bicarbonate levels. Patients with non-traumatic SAH are more at risk of mortality if their bicarbonate levels are low.
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Affiliation(s)
- Wenyuan Du
- Department of Neurology, Shijiazhuang Traditional Chinese Medicine Hospital, Shijiazhuang, Hebei, China
| | - Jingmian Yang
- Department of Neurology, Shijiazhuang Traditional Chinese Medicine Hospital, Shijiazhuang, Hebei, China
| | - Yanfang Lou
- Department of Neurology, Shijiazhuang Traditional Chinese Medicine Hospital, Shijiazhuang, Hebei, China
| | - Jiahua You
- Department of Neurology, Shijiazhuang Traditional Chinese Medicine Hospital, Shijiazhuang, Hebei, China
| | - Qiang Wang
- Department of Cardiology, Shijiazhuang Traditional Chinese Medicine Hospital, Shijiazhuang, Hebei, China
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3
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Everaerts K, Thapaliya P, Pape N, Durry S, Eitelmann S, Roussa E, Ullah G, Rose CR. Inward Operation of Sodium-Bicarbonate Cotransporter 1 Promotes Astrocytic Na + Loading and Loss of ATP in Mouse Neocortex during Brief Chemical Ischemia. Cells 2023; 12:2675. [PMID: 38067105 PMCID: PMC10705779 DOI: 10.3390/cells12232675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 11/14/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
Ischemic conditions cause an increase in the sodium concentration of astrocytes, driving the breakdown of ionic homeostasis and exacerbating cellular damage. Astrocytes express high levels of the electrogenic sodium-bicarbonate cotransporter1 (NBCe1), which couples intracellular Na+ homeostasis to regulation of pH and operates close to its reversal potential under physiological conditions. Here, we analyzed its mode of operation during transient energy deprivation via imaging astrocytic pH, Na+, and ATP in organotypic slice cultures of the mouse neocortex, complemented with patch-clamp and ion-selective microelectrode recordings and computational modeling. We found that a 2 min period of metabolic failure resulted in a transient acidosis accompanied by a Na+ increase in astrocytes. Inhibition of NBCe1 increased the acidosis while decreasing the Na+ load. Similar results were obtained when comparing ion changes in wild-type and Nbce1-deficient mice. Mathematical modeling replicated these findings and further predicted that NBCe1 activation contributes to the loss of cellular ATP under ischemic conditions, a result confirmed experimentally using FRET-based imaging of ATP. Altogether, our data demonstrate that transient energy failure stimulates the inward operation of NBCe1 in astrocytes. This causes a significant amelioration of ischemia-induced astrocytic acidification, albeit at the expense of increased Na+ influx and a decline in cellular ATP.
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Affiliation(s)
- Katharina Everaerts
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany; (K.E.); (N.P.); (S.D.); (S.E.)
| | - Pawan Thapaliya
- Department of Physics, University of South Florida, Tampa, FL 33620, USA; (P.T.); (G.U.)
| | - Nils Pape
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany; (K.E.); (N.P.); (S.D.); (S.E.)
| | - Simone Durry
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany; (K.E.); (N.P.); (S.D.); (S.E.)
| | - Sara Eitelmann
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany; (K.E.); (N.P.); (S.D.); (S.E.)
| | - Eleni Roussa
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Albertstrasse 17, D-79104 Freiburg, Germany;
| | - Ghanim Ullah
- Department of Physics, University of South Florida, Tampa, FL 33620, USA; (P.T.); (G.U.)
| | - Christine R. Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany; (K.E.); (N.P.); (S.D.); (S.E.)
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4
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Huang X, Zhang Y. Relationship between serum bicarbonate levels and the risk of death within 30 days in ICU patients with acute ischemic stroke. Front Neurol 2023; 14:1125359. [PMID: 37292129 PMCID: PMC10246426 DOI: 10.3389/fneur.2023.1125359] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/17/2023] [Indexed: 06/10/2023] Open
Abstract
Aim To explore the relationship between baseline bicarbonate levels and their changes with 30-day mortality in patients with acute ischemic stroke who were admitted to the intensive care unit (ICU). Methods This cohort study collected the data of 4,048 participants from the Medical Information Mart for Intensive Care (MIMIC)-III and MIMIC-IV databases. Univariate and multivariable Cox proportional risk models were utilized to explore the relationship between bicarbonate T0 and Δbicarbonate with 30-day mortality in patients with acute ischemic stroke. The Kaplan-Meier curves were plotted to measure the 30-day survival probability of patients with acute ischemic stroke. Results The median follow-up time was 30 days. At the end of the follow-up, 3,172 patients survived. Bicarbonate T0 ≤ 21 mEq/L [hazard ratio (HR) = 1.24, a 95% confidence interval (CI): 1.02-1.50] or 21 mEq/L < bicarbonate T0 ≤ 23 mEq/L (HR = 1.29, 95%CI: 1.05-1.58) were associated with an increased risk of 30-day mortality in patients with acute ischemic stroke compared with bicarbonate T0 > 26 mEq/L. -2 mEq/L < Δbicarbonate ≤ 0 mEq/L (HR = 1.40, 95%CI: 1.14-1.71), 0 mEq/L < Δbicarbonate ≤ 2 mEq/L (HR = 1.44, 95%CI: 1.17-1.76), and Δbicarbonate >2 mEq/L (HR = 1.40, 95%CI: 1.15-1.71) were correlated with an elevated risk of 30-day mortality in acute ischemic stroke patients. The 30-day survival probability of acute ischemic stroke patients with 21 mEq/L < bicarbonate T0 ≤ 23 mEq/L, 23 mEq/L < bicarbonate T0 ≤ 26 mEq/L, or bicarbonate T0 >26 mEq/L was higher than that of patients with bicarbonate T0 ≤ 21 mEq/L. The 30-day survival probability was greater for patients in the Δbicarbonate ≤ -2 mEq/L group than for those in the Δbicarbonate >2 mEq/L group. Conclusion Low baseline bicarbonate levels and decreased bicarbonate levels during the ICU stay were associated with a high risk of 30-day mortality in acute ischemic stroke patients. Special interventions should be offered to those with low baseline and decreased bicarbonate levels during their ICU stay.
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Affiliation(s)
- Xia Huang
- Department of Neurology, Ninghai First Hospital, Ningbo, Zhejiang, China
| | - Yuanyuan Zhang
- Emergency Medicine Department, Affiliated Hospital of Yangzhou University (Yangzhou First People's Hospital), Yangzhou, Jiangsu, China
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5
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Guo X, Liu R, Jia M, Wang Q, Wu J. Ischemia Reperfusion Injury Induced Blood Brain Barrier Dysfunction and the Involved Molecular Mechanism. Neurochem Res 2023:10.1007/s11064-023-03923-x. [PMID: 37017889 DOI: 10.1007/s11064-023-03923-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 04/06/2023]
Abstract
Stroke is characterized by the abrupt failure of blood flow to a specific brain region, resulting in insufficient supply of oxygen and glucose to the ischemic tissues. Timely reperfusion of blood flow can rescue dying tissue but can also lead to secondary damage to both the infarcted tissues and the blood-brain barrier, known as ischemia/reperfusion injury. Both primary and secondary damage result in biphasic opening of the blood-brain barrier, leading to blood-brain barrier dysfunction and vasogenic edema. Importantly, blood-brain barrier dysfunction, inflammation, and microglial activation are critical factors that worsen stroke outcomes. Activated microglia secrete numerous cytokines, chemokines, and inflammatory factors during neuroinflammation, contributing to the second opening of the blood-brain barrier and worsening the outcome of ischemic stroke. TNF-α, IL-1β, IL-6, and other microglia-derived molecules have been shown to be involved in the breakdown of blood-brain barrier. Additionally, other non-microglia-derived molecules such as RNA, HSPs, and transporter proteins also participate in the blood-brain barrier breakdown process after ischemic stroke, either in the primary damage stage directly influencing tight junction proteins and endothelial cells, or in the secondary damage stage participating in the following neuroinflammation. This review summarizes the cellular and molecular components of the blood-brain barrier and concludes the association of microglia-derived and non-microglia-derived molecules with blood-brain barrier dysfunction and its underlying mechanisms.
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Affiliation(s)
- Xi Guo
- Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, 430070, China
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 10070, China
- China National Clinical Research Center for Neurological Diseases, Beijing, 10070, China
| | - Ru Liu
- Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, 430070, China
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 10070, China
- China National Clinical Research Center for Neurological Diseases, Beijing, 10070, China
| | - Meng Jia
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 10070, China
- China National Clinical Research Center for Neurological Diseases, Beijing, 10070, China
| | - Qun Wang
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
- China National Clinical Research Center for Neurological Diseases, Beijing, 10070, China
| | - Jianping Wu
- Hubei Key Laboratory of Nanomedicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan, 430070, China.
- Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China.
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 10070, China.
- China National Clinical Research Center for Neurological Diseases, Beijing, 10070, China.
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6
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Young JE, Goldstein LSB. Human-Induced Pluripotent Stem Cell (hiPSC)-Derived Neurons and Glia for the Elucidation of Pathogenic Mechanisms in Alzheimer's Disease. Methods Mol Biol 2023; 2561:105-133. [PMID: 36399267 DOI: 10.1007/978-1-0716-2655-9_6] [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: 11/19/2022]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder and a mechanistically complex disease. For the last decade, human models of AD using induced pluripotent stem cells (iPSCs) have emerged as a powerful way to understand disease pathogenesis in relevant human cell types. In this review, we summarize the state of the field and how this technology can apply to studies of both familial and sporadic studies of AD. We discuss patient-derived iPSCs, genome editing, differentiation of neural cell types, and three-dimensional organoids, and speculate on the future of this type of work for increasing our understanding of, and improving therapeutic development for, this devastating disease.
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Affiliation(s)
- Jessica E Young
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA. .,Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA.
| | - Lawrence S B Goldstein
- Department of Cellular and Molecular Medicine, Department of Neurosciences, UC San Diego, La Jolla, CA, USA.,Sanford Consortium for Regenerative Medicine, La Jolla, CA, USA
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7
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Xue D, Wei C, Zhou Y, Wang K, Zhou Y, Chen C, Li Y, Sheng L, Lu B, Zhu Z, Cai W, Ning X, Li S, Qi T, Pi J, Lin S, Yan G, Huang Y, Yin W. TRIOL Inhibits Rapid Intracellular Acidification and Cerebral Ischemic Injury: The Role of Glutamate in Neuronal Metabolic Reprogramming. ACS Chem Neurosci 2022; 13:2110-2121. [PMID: 35770894 DOI: 10.1021/acschemneuro.2c00119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
As one of the key injury incidents, tissue acidosis in the brain occurs very quickly within several minutes upon the onset of ischemic stroke. Glutamate, an excitatory amino acid inducing neuronal excitotoxicity, has been reported to trigger the decrease in neuronal intracellular pH (pHi) via modulating proton-related membrane transporters. However, there remains a lack of clarity on the possible role of glutamate in neuronal acidosis via regulating metabolism. Here, we show that 200 μM glutamate treatment quickly promotes glycolysis and inhibits mitochondrial oxidative phosphorylation of primary cultured neurons within 15 min, leading to significant cytosolic lactate accumulation, which contributes to the rapid intracellular acidification and neuronal injury. The reprogramming of neuronal metabolism by glutamate is dependent on adenosine monophosphate-activated protein kinase (AMPK) signaling since the inhibition of AMPK activation by its selective inhibitor compound C significantly reverses these deleterious events in vitro. Moreover, 5α-androst-3β,5α,6β-TRIOL (TRIOL), a neuroprotectant we previously reported, can also remarkably reverse intracellular acidification and alleviate neuronal injury through the inhibition of AMPK signaling. Furthermore, TRIOL remarkably reduced the infarct volume and attenuated neurologic impairment in acute ischemic stroke models of middle cerebral artery occlusion in vivo. In summary, we reveal a novel role of glutamate in rapid intracellular acidification injury resulting from glutamate-induced lactate accumulation through AMPK-mediated neuronal reprogramming. Moreover, inhibition of the quick drop in neuronal pHi by TRIOL significantly reduces the cerebral damages, suggesting that it is a promising drug candidate for ischemic stroke.
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Affiliation(s)
- DongDong Xue
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - CaiLv Wei
- Department of Molecular Biology and Biochemistry, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - YueHan Zhou
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Kai Wang
- University College London, London WC1E 6BT, U.K
| | - YuWei Zhou
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Chen Chen
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Yuan Li
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - LongXiang Sheng
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - BingZheng Lu
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Zhu Zhu
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Wei Cai
- Department of Molecular Biology and Biochemistry, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - XinPeng Ning
- Department of Molecular Biology and Biochemistry, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - ShengLong Li
- Department of Molecular Biology and Biochemistry, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - TianYu Qi
- Department of Molecular Biology and Biochemistry, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - JiaKai Pi
- Guangzhou Foreign Language School, Guangzhou 511400, China
| | - SuiZhen Lin
- Guangzhou Cellprotek Pharmaceutical Co., Ltd., Guangzhou 510663, China
| | - GuangMei Yan
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - YiJun Huang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Wei Yin
- Department of Molecular Biology and Biochemistry, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
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8
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Ratko M, Habek N, Radmilović MD, Škokić S, Justić H, Barić A, Dugandžić A. Role of uroguanylin's signaling pathway in the development of ischemic stroke. Eur J Neurosci 2022; 56:3720-3737. [PMID: 35445449 PMCID: PMC9542124 DOI: 10.1111/ejn.15674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/30/2022] [Accepted: 04/17/2022] [Indexed: 11/28/2022]
Abstract
Stroke is one of the leading causes of mortality and disability worldwide. By affecting bradykinin function, activation of guanylate cyclase (GC)‐A has been shown to have a neuroprotective effect after ischaemic stroke, whereas the same has not been confirmed for GC‐B; therefore, we aimed to determine the possible role of GC‐C and its agonist, uroguanylin (UGN), in the development of stroke. In this study, middle cerebral artery occlusion (MCAO) was performed on wild‐type (WT), GC‐C KO and UGN KO mice. MR images were acquired before and 24 h after MCAO. On brain slices 48 h after MCAO, the Ca2+ response to UGN stimulation was recorded. Our results showed that the absence of GC‐C in GC‐C KO mice resulted in the development of smaller ischaemic lesions compared with WT littermates, which is an opposite effect compared with the effects of GC‐A agonists on brain lesions. WT and UGN KO animals showed a stronger Ca2+ response upon UGN stimulation in astrocytes of the peri‐ischaemic cerebral cortex compared with the same cortical region of the unaffected contralateral hemisphere. This stronger activation was not observed in GC‐C KO animals, which may be the reason for smaller lesion development in GC‐C KO mice. The reason why GC‐C might affect Ca2+ signalling in peri‐ischaemic astrocytes is that GC‐C is expressed in these cells after MCAO, whereas under normoxic conditions, it is expressed mainly in cortical neurons. Stronger activation of the Ca2+‐dependent signalling pathway could lead to the stronger activation of the Na+/H+ exchanger, tissue acidification and neuronal death.
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Affiliation(s)
- Martina Ratko
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.,Centre of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Nikola Habek
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | | | - Siniša Škokić
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Helena Justić
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Anja Barić
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Aleksandra Dugandžić
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.,Centre of Excellence for Basic, Clinical and Translational Neuroscience, School of Medicine, University of Zagreb, Zagreb, Croatia.,Department of Physiology, School of Medicine, University of Zagreb, Zagreb, Croatia
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9
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Li XD, Li MM. A novel nomogram to predict mortality in patients with stroke: a survival analysis based on the MIMIC-III clinical database. BMC Med Inform Decis Mak 2022; 22:92. [PMID: 35387672 PMCID: PMC8988376 DOI: 10.1186/s12911-022-01836-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 03/28/2022] [Indexed: 11/27/2022] Open
Abstract
Background Stroke is a disease characterized by sudden cerebral ischemia and is the second leading cause of death worldwide. We aimed to develop and validate a nomogram model to predict mortality in intensive care unit patients with stroke. Methods All data involved in this study were extracted from the Medical Information Mart for Intensive Care III database (MIMIC-III). The data were analyzed using multivariate Cox regression, and the performance of the novel nomogram, which assessed the patient’s overall survival at 30, 180, and 360 days after stroke, was evaluated using Harrell’s concordance index (C-index) and the area under the receiver operating characteristic curve. A calibration curve and decision curve were introduced to test the clinical value and effectiveness of our prediction model. Results A total of 767 patients with stroke were randomly divided into derivation (n = 536) and validation (n = 231) cohorts at a 7:3 ratio. Multivariate Cox regression showed that 12 independent predictors, including age, weight, ventilation, cardiac arrhythmia, metastatic cancer, explicit sepsis, Oxford Acute Severity of Illness Score or OASIS score, diastolic blood pressure, bicarbonate, chloride, red blood cell and white blood cell counts, played a significant role in the survival of individuals with stroke. The nomogram model was validated based on the C-indices, calibration plots, and decision curve analysis results. Conclusions The plotted nomogram accurately predicted stroke outcomes and, thus may contribute to clinical decision-making and treatment as well as consultation services for patients. Supplementary Information The online version contains supplementary material available at 10.1186/s12911-022-01836-3.
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Affiliation(s)
- Xiao-Dan Li
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, 510630, People's Republic of China
| | - Min-Min Li
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Jinan University, Guangzhou, 510630, People's Republic of China.
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10
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Neuroprotective Potential of Mild Uncoupling in Mitochondria. Pros and Cons. Brain Sci 2021; 11:brainsci11081050. [PMID: 34439669 PMCID: PMC8392724 DOI: 10.3390/brainsci11081050] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 02/07/2023] Open
Abstract
There has been an explosion of interest in the use of uncouplers of oxidative phosphorylation in mitochondria in the treatment of several pathologies, including neurological ones. In this review, we analyzed all the mechanisms associated with mitochondrial uncoupling and the metabolic and signaling cascades triggered by uncouplers. We provide a full set of positive and negative effects that should be taken into account when using uncouplers in experiments and clinical practice.
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11
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van Putten MJ, Fahlke C, Kafitz KW, Hofmeijer J, Rose CR. Dysregulation of Astrocyte Ion Homeostasis and Its Relevance for Stroke-Induced Brain Damage. Int J Mol Sci 2021; 22:5679. [PMID: 34073593 PMCID: PMC8198632 DOI: 10.3390/ijms22115679] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
Ischemic stroke is a leading cause of mortality and chronic disability. Either recovery or progression towards irreversible failure of neurons and astrocytes occurs within minutes to days, depending on remaining perfusion levels. Initial damage arises from energy depletion resulting in a failure to maintain homeostasis and ion gradients between extra- and intracellular spaces. Astrocytes play a key role in these processes and are thus central players in the dynamics towards recovery or progression of stroke-induced brain damage. Here, we present a synopsis of the pivotal functions of astrocytes at the tripartite synapse, which form the basis of physiological brain functioning. We summarize the evidence of astrocytic failure and its consequences under ischemic conditions. Special emphasis is put on the homeostasis and stroke-induced dysregulation of the major monovalent ions, namely Na+, K+, H+, and Cl-, and their involvement in maintenance of cellular volume and generation of cerebral edema.
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Affiliation(s)
- Michel J.A.M. van Putten
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands; (M.J.A.M.v.P.); (J.H.)
| | - Christoph Fahlke
- Institut für Biologische Informationsprozesse, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Karl W. Kafitz
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Jeannette Hofmeijer
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands; (M.J.A.M.v.P.); (J.H.)
| | - Christine R. Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
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12
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Giannaki M, Schrödl-Häußel M, Khakipoor S, Kirsch M, Roussa E. STAT3-dependent regulation of the electrogenic Na +/ HCO 3- cotransporter 1 (NBCe1) functional expression in cortical astrocytes. J Cell Physiol 2021; 236:2036-2050. [PMID: 32761631 DOI: 10.1002/jcp.29990] [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: 05/08/2020] [Revised: 07/03/2020] [Accepted: 07/21/2020] [Indexed: 01/10/2023]
Abstract
The electrogenic Na+ /HCO3- cotransporter (NBCe1) in astrocytes is crucial in regulation of acid-base homeostasis in the brain. Since many pathophysiological conditions in the brain have been associated with pH shifts we exposed primary mouse cortical and hippocampal astrocytes to prolonged low or high extracellular pH (pHo ) at constant extracellular bicarbonate concentration and investigated activation of astrocytes and regulation of NBCe1 by immunoblotting, biotinylation of surface proteins, and intracellular H+ recordings. High pHo at constant extracellular bicarbonate caused upregulation of NBCe1 protein, surface expression and activity via upregulation of the astrocytic activation markers signal transducer and activator of transcription 3 (STAT3) signaling and glial fibrillary acidic protein expression. High pHo -induced increased NBCe1 protein expression was prevented in astrocytes from Stat3flox/flox ::GfapCre/+ mice. In vitro, basal and high pHo -induced increased NBCe1 functional expression was impaired following inhibition of STAT3 phosphorylation. These results provide a novel regulation mode of NBCe1 protein and activity, highlight the importance of astrocyte reactivity on regulation of NBCe1 and implicate roles for NBCe1 in altering/modulating extracellular pH during development as well as of the microenvironment at sites of brain injuries and other pathophysiological conditions.
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Affiliation(s)
- Marina Giannaki
- Department of Molecular Embryology, Medical Faculty, Institute of Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Magdalena Schrödl-Häußel
- Department of Molecular Embryology, Medical Faculty, Institute of Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Shokoufeh Khakipoor
- Department of Molecular Embryology, Medical Faculty, Institute of Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Matthias Kirsch
- Department of Neuroanatomy, Medical Faculty, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Eleni Roussa
- Department of Molecular Embryology, Medical Faculty, Institute of Anatomy and Cell Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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13
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Song S, Luo L, Sun B, Sun D. Roles of glial ion transporters in brain diseases. Glia 2019; 68:472-494. [PMID: 31418931 DOI: 10.1002/glia.23699] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/22/2019] [Accepted: 07/26/2019] [Indexed: 12/21/2022]
Abstract
Glial ion transporters are important in regulation of ionic homeostasis, cell volume, and cellular signal transduction under physiological conditions of the central nervous system (CNS). In response to acute or chronic brain injuries, these ion transporters can be activated and differentially regulate glial functions, which has subsequent impact on brain injury or tissue repair and functional recovery. In this review, we summarized the current knowledge about major glial ion transporters, including Na+ /H+ exchangers (NHE), Na+ /Ca2+ exchangers (NCX), Na+ -K+ -Cl- cotransporters (NKCC), and Na+ -HCO3 - cotransporters (NBC). In acute neurological diseases, such as ischemic stroke and traumatic brain injury (TBI), these ion transporters are rapidly activated and play significant roles in regulation of the intra- and extracellular pH, Na+ , K+ , and Ca2+ homeostasis, synaptic plasticity, and myelin formation. However, overstimulation of these ion transporters can contribute to glial apoptosis, demyelination, inflammation, and excitotoxicity. In chronic brain diseases, such as glioma, Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), glial ion transporters are involved in the glioma Warburg effect, glial activation, neuroinflammation, and neuronal damages. These findings suggest that glial ion transporters are involved in tissue structural and functional restoration, or brain injury and neurological disease development and progression. A better understanding of these ion transporters in acute and chronic neurological diseases will provide insights for their potential as therapeutic targets.
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Affiliation(s)
- Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Lanxin Luo
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania.,School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China.,School of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China
| | - Baoshan Sun
- School of Functional Food and Wine, Shenyang Pharmaceutical University, Shenyang, China.,Pólo Dois Portos, Instituto National de Investigação Agrária e Veterinária, Dois Portos, Portugal
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania.,Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, Pennsylvania
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14
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Intracellular pH Regulation in iPSCs-derived Astrocytes from Subjects with Chronic Mountain Sickness. Neuroscience 2018; 375:25-33. [PMID: 29438800 DOI: 10.1016/j.neuroscience.2018.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 11/22/2022]
Abstract
Chronic Mountain Sickness (CMS) occurs in high-altitude residents with major neurological symptoms such as migraine headaches, dizziness and cognitive deficits. Recent work demonstrated that highlanders have increased intracellular pH (pHi) in their brain cells, perhaps for the sake of adaptation to hypoxemia and help to facilitate glycolysis, DNA synthesis, and cell cycle progression. Since there are well adapted (non-CMS) and maladapted (CMS) high-altitude dwellers, it is not clear whether pHi is differently regulated in these two high-altitude populations. In this work, we obtained induced pluripotent stem cell (iPSC)-derived astrocytes from both CMS and non-CMS highlanders who live in the Peruvian Andes (>14,000 ft) and studied pHi regulation in these astrocytes using pH-sensitive dye BCECF. Our results show that the steady-state pHi (ss pHi) is lower in CMS astrocytes compared with non-CMS astrocytes. In addition, the acid extrusion following an acid loading is faster and the pHi dependence of H+ flux rate becomes steeper in CMS astrocytes. Furthermore, the Na+ dependency of ss pHi is stronger in CMS astrocytes and the Na+/H+ exchanger (NHE) inhibitors blunted the acid extrusion in both CMS and non-CMS astrocytes. We conclude that (a) NHE contributes to the ss pHi stabilization and mediates active acid extrusion during the cytosolic acidosis in highlanders; (b) acid extrusion becomes less pHi sensitive in non-CMS (versus CMS) astrocytes which may prevent NHE from over-activated in the hypoxia-induced intracellular acidosis and render the non-CMS astrocytes more resistant to hypoxemia challenges.
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15
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Wu W, Yao H, Zhao HW, Wang J, Haddad GG. Down-regulation of Inwardly Rectifying K + Currents in Astrocytes Derived from Patients with Monge's Disease. Neuroscience 2018; 374:70-79. [PMID: 29355592 DOI: 10.1016/j.neuroscience.2018.01.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 01/04/2018] [Indexed: 12/25/2022]
Abstract
Chronic mountain sickness (CMS) or Monge's disease is a disease in highlanders. These patients have a variety of neurologic symptoms such as migraine, mental fatigue, confusion, dizziness, loss of appetite, memory loss and neuronal degeneration. The cellular and molecular mechanisms underlying CMS neuropathology is not understood. In the previous study, we demonstrated that neurons derived from CMS patients' fibroblasts have a decreased expression and altered gating properties of voltage-gated sodium channel. In this study, we further characterize the electrophysiological properties of iPSC-derived astrocytes from CMS patients. We found that the current densities of the inwardly rectifying potassium (Kir) channels in CMS astrocytes (-5.7 ± 2.2 pA/pF at -140 mV) were significantly decreased as compared to non-CMS (-28.4 ± 3.4 pA/pF at -140 mV) and sea level subjects (-28.3 ± 5.3 pA/pF at -140 mV). We further demonstrated that the reduced Kir current densities in CMS astrocytes were caused by their decreased protein expression of Kir4.1 and Kir2.3 channels, while single channel properties (i.e., Po, conductance) of Kir channel in CMS astrocytes were not altered. In addition, we found no significant differences of outward potassium currents between CMS and non-CMS astrocytes. As compared to non-CMS and sea level subjects, the K+ uptake ability in CMS astrocytes was significantly decreased. Taken together, our results suggest that down-regulation of Kir channels and the resulting decreased K+ uptake ability in astrocytes could be one of the major molecular mechanisms underlying the neurologic manifestations in CMS patients.
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Affiliation(s)
- Wei Wu
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, United States
| | - Hang Yao
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, United States
| | - Helen W Zhao
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, United States
| | - Juan Wang
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, United States
| | - Gabriel G Haddad
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, United States; Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, United States; Rady Children's Hospital-San Diego, San Diego, CA 92123, United States.
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16
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Abstract
Oncotic cell death or oncosis represents a major mechanism of cell death in ischaemic stroke, occurring in many central nervous system (CNS) cell types including neurons, glia and vascular endothelial cells. In stroke, energy depletion causes ionic pump failure and disrupts ionic homeostasis. Imbalance between the influx of Na+ and Cl- ions and the efflux of K+ ions through various channel proteins and transporters creates a transmembrane osmotic gradient, with ensuing movement of water into the cells, resulting in cell swelling and oncosis. Oncosis is a key mediator of cerebral oedema in ischaemic stroke, contributing directly through cytotoxic oedema, and indirectly through vasogenic oedema by causing vascular endothelial cell death and disruption of the blood-brain barrier (BBB). Hence, inhibition of uncontrolled ionic flux represents a novel and powerful strategy in achieving neuroprotection in stroke. In this review, we provide an overview of oncotic cell death in the pathology of stroke. Importantly, we summarised the therapeutically significant pathways of water, Na+, Cl- and K+ movement across cell membranes in the CNS and their respective roles in the pathobiology of stroke.
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17
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Modeling neurological diseases using iPSC-derived neural cells : iPSC modeling of neurological diseases. Cell Tissue Res 2017; 371:143-151. [PMID: 29079884 DOI: 10.1007/s00441-017-2713-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 10/13/2017] [Indexed: 12/14/2022]
Abstract
Developing efficient models for neurological diseases enables us to uncover disease mechanisms and develop therapeutic strategies to treat them. Discovery of reprogramming somatic cells to induced pluripotent stem cells (iPSCs) has revolutionized the way of modeling human diseases, especially neurological diseases. Currently almost all types of neural cells, including but not limited to neural stem cells, neurons, astrocytes, oligodendrocytes and microglia, can be derived from iPSCs following developmental principles. These iPSC-derived neural cells provide valuable tools for studying neurological disease mechanisms, developing potential therapies, and deepening our understanding of the nervous system.
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18
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Khakipoor S, Ophoven C, Schrödl‐Häußel M, Feuerstein M, Heimrich B, Deitmer JW, Roussa E. TGF-β signaling directly regulates transcription and functional expression of the electrogenic sodium bicarbonate cotransporter 1, NBCe1 (SLC4A4), via Smad4 in mouse astrocytes. Glia 2017; 65:1361-1375. [PMID: 28568893 PMCID: PMC5518200 DOI: 10.1002/glia.23168] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 04/27/2017] [Accepted: 05/04/2017] [Indexed: 02/06/2023]
Abstract
The electrogenic sodium bicarbonate cotransporter NBCe1 (SLC4A4) expressed in astrocytes regulates intracellular and extracellular pH. Here, we introduce transforming growth factor beta (TGF-β) as a novel regulator of NBCe1 transcription and functional expression. Using hippocampal slices and primary hippocampal and cortical astrocyte cultures, we investigated regulation of NBCe1 and elucidated the underlying signaling pathways by RT-PCR, immunoblotting, immunofluorescence, intracellular H(+ ) recording using the H(+ ) -sensitive dye 2',7'-bis-(carboxyethyl)-5-(and-6)-carboxyfluorescein, mink lung epithelial cell (MLEC) assay, and chromatin immunoprecipitation. Activation of TGF-β signaling significantly upregulated transcript, protein, and surface expression of NBCe1. These effects were TGF-β receptor-mediated and suppressed following inhibition of JNK and Smad signaling. Moreover, 4-aminopyridine (4AP)-dependent NBCe1 regulation requires TGF-β. TGF-β increased the rate and amplitude of intracellular H+ changes upon challenging NBCe1 in wild-type astrocytes but not in cortical astrocytes from Slc4a4-deficient mice. A Smad4 binding sequence was identified in the NBCe1 promoter and Smad4 binding increased after activation of TGF-β signaling. The data show for the first time that NBCe1 is a direct target of TGF-β/Smad4 signaling. Through activation of the canonical pathway TGF-β acts directly on NBCe1 by binding of Smad4 to the NBCe1 promoter and regulating its transcription, followed by increased protein expression and transport activity.
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Affiliation(s)
- Shokoufeh Khakipoor
- Department of Molecular EmbryologyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
| | - Christian Ophoven
- Department of Molecular EmbryologyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
| | - Magdalena Schrödl‐Häußel
- Department of Molecular EmbryologyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
| | - Melanie Feuerstein
- Department of Molecular EmbryologyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
| | - Bernd Heimrich
- Department of NeuroanatomyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
| | - Joachim W. Deitmer
- Department of General ZoologyFB Biology, University of KaiserslauternP.B. 3049D‐67653KaiserslauternGermany
| | - Eleni Roussa
- Department of Molecular EmbryologyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
- Department of NeuroanatomyInstitute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgAlbertstrasse 17D‐79104FreiburgGermany
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