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Jiang W, Fang J, Rastrick SPS, Samuelsen OB, Liang B, Mao Y, Strand Ø, Fang J, Jiang Z. CO 2-Induced Ocean Acidification Alters the Burrowing Behavior of Manila Clam Ruditapes philippinarum by Reversing GABA A Receptor Function. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37276348 DOI: 10.1021/acs.est.3c00707] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Biological burrowing behavior is an important driver shaping ecosystems that is being threatened by CO2-induced ocean acidification; however, the effects of ocean acidification on burrowing behavior and its neurological mechanism remain unclear. This study showed that elevated pCO2 significantly affected the burrowing behaviors of the Manila clam Ruditapes philippinarum, such as increased foot contraction, burrowing time, and intrabottom movement and decreased burrowing depth. Delving deeper into the mechanism, exposure to elevated pCO2 significantly decreased extracellular pH and increased [HCO3-]. Moreover, an indicator GABAA receptor, a neuroinhibitor for movement, was found to be closely associated with behavioral changes. In situ hybridization confirmed that the GABAA receptor was widely distributed in ganglia and foot muscles, and elevated pCO2 significantly increased the mRNA level and GABA concentration. However, the increase in GABAA receptor and its ligand did not suppress the foot movement, but rather sent "excitatory" signals for foot contraction. The destabilization of acid-base homeostasis was demonstrated to induce an increase in the reversal potential for GABAA receptor and an alteration in GABAA receptor function under elevated pCO2. This study revealed that elevated pCO2 affects the burrowing behavior of Manila clams by altering GABAA receptor function from inhibitory to excitatory.
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Affiliation(s)
- Weiwei Jiang
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Jinghui Fang
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao 266200, China
| | | | - Ole B Samuelsen
- Institute of Marine Research, Nordnes, Bergen NO-5817 1870, Norway
| | - Bo Liang
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
| | - Yuze Mao
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao 266200, China
| | - Øivind Strand
- Institute of Marine Research, Nordnes, Bergen NO-5817 1870, Norway
| | - Jianguang Fang
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao 266200, China
| | - Zengjie Jiang
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao 266200, China
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Wang J, Liu W, Xu W, Yang B, Cui M, Li Z, Zhang H, Jin C, Xue H, Zhang J. Comprehensive Analysis of the Oncogenic, Genomic Alteration, and Immunological Landscape of Cation-Chloride Cotransporters in Pan-Cancer. Front Oncol 2022; 12:819688. [PMID: 35372048 PMCID: PMC8968682 DOI: 10.3389/fonc.2022.819688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Background Assessing the phenotypic diversity underlying tumor progression requires the identification of variations in the respective molecular interaction in the tumor microenvironment (TME). Despite emerging studies focusing on the association between cation-chloride cotransporters (CCCs) and carcinogenesis, direct evidence that CCCs (KCC2 and NKCC1) mediate tumor progression in pan-cancer remains unclear. Methods We conducted a comprehensive assessment of the expression, DNA variation profiles, and prognostic and immunologic implications of CCCs based on a large-scale pan-cancer population, including 10,967 cancer patients from the Cancer Genome Atlas, 9,162 cancer patients from Genomics Expression Omnibus, 48,834 cancer patients from 188 independent studies, and 356 cancer patients from three real-world cohorts. Results In this study, we first found that CCCs were highly expressed in most tumors, and prominently associated with prognosis. Kaplan–Meier analysis and Cox regression analysis revealed that KCC2 and NKCC1 significantly predicted survival for patients with pan-cancer, suggesting that CCCs have inconsistent tumorigenesis regulatory mechanisms in cancers. Next, we examined the DNA variation landscape of KCC2 and NKCC1 and their prognostic implications in pan-cancer. The results demonstrated that UCEC patients with somatic copy number variation (CNV) of NKCC1 received significantly better outcomes (p < 0.05). Besides emphasizing the clinical implications of CNV of CCCs for cancer patients, we found that NKCC1MUT could prominently prolong progression-free survival (p = 2.59e-04), disease-specific survival (p = 0.019), and overall survival (p = 0.034) compared with NKCC1WT cancer patients possibly via regulation of cell proliferation and oncogenic stress pathways. Additionally, KCC2 positively correlated with the levels of tumor-infiltrating macrophages and CD4+ T cells, but NKCC1 showed a significantly widely negative association with tumor-infiltrated lymphocytes, suggesting an immune-excluded TME in cancers. Similarly, expression of KCC2, rather than NKCC1, was positively correlated with the immune checkpoint molecules, indicating its role as an immune regulator in a wide variety of cancers. Finally, to verify our hypothesis and altered expression of CCCs, we performed IHC analysis and revealed the staining distribution in tumor and adjacent normal tissues of glioma, clear cell renal cell carcinoma, papillary cell renal cell carcinoma, and hepatocellular and breast cancer from three real-world cohorts, and validated prominently prognostic implications of CCCs in patients with clear cell renal cell carcinoma. Conclusion This study first comprehensively investigated the molecular and clinical role of CCCs, and illustrated the significant association among KCC2/NKCC1 expression, DNA variation profiles prognosis, and TME of pan-cancer. The pan-cancer findings provided an in-depth understanding of potential oncogenic and immunologic of differential expression and DNA alteration of KCC2/NKCC1 cancers.
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Affiliation(s)
- Jie Wang
- Department of Anesthesiology and Perioperative Medicine, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Wangrui Liu
- Department of Neurosurgery, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China
| | - Wenhao Xu
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Baofeng Yang
- Department of Anesthesiology and Perioperative Medicine, Affiliate Cancer Hospital of Zhengzhou University, Zhengzhou, China
| | - Mingzhu Cui
- Department of Anesthesiology and Perioperative Medicine, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Zhen Li
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Hailiang Zhang
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Chuntao Jin
- Department of Neurosurgery, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China
- *Correspondence: Jiaqiang Zhang, ; Huanzhou Xue, ; Chuntao Jin,
| | - Huanzhou Xue
- Department of Hepatobiliary Surgery, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
- *Correspondence: Jiaqiang Zhang, ; Huanzhou Xue, ; Chuntao Jin,
| | - Jiaqiang Zhang
- Department of Anesthesiology and Perioperative Medicine, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
- *Correspondence: Jiaqiang Zhang, ; Huanzhou Xue, ; Chuntao Jin,
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Dudok B, Klein PM, Soltesz I. Toward Understanding the Diverse Roles of Perisomatic Interneurons in Epilepsy. Epilepsy Curr 2021; 22:54-60. [PMID: 35233202 PMCID: PMC8832350 DOI: 10.1177/15357597211053687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Epileptic seizures are associated with excessive neuronal spiking. Perisomatic
γ-aminobutyric acid (GABA)ergic interneurons specifically innervate the subcellular
domains of postsynaptic excitatory cells that are critical for spike generation. With a
revolution in transcriptomics-based cell taxonomy driving the development of novel
transgenic mouse lines, selectively monitoring and modulating previously elusive
interneuron types is becoming increasingly feasible. Emerging evidence suggests that the
three types of hippocampal perisomatic interneurons, axo-axonic cells, along with
parvalbumin- and cholecystokinin-expressing basket cells, each follow unique activity
patterns in vivo, suggesting distinctive roles in regulating epileptic networks.
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Affiliation(s)
- Barna Dudok
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Peter M. Klein
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
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Auer T, Schreppel P, Erker T, Schwarzer C. Impaired chloride homeostasis in epilepsy: Molecular basis, impact on treatment, and current treatment approaches. Pharmacol Ther 2020; 205:107422. [DOI: 10.1016/j.pharmthera.2019.107422] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/07/2019] [Indexed: 12/14/2022]
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Jia Y, Chen L, Chi D, Cong D, Zhou P, Jin J, Ji H, Liang B, Gao S, Hu S. Photodynamic therapy combined with temozolomide inhibits C6 glioma migration and invasion and promotes mitochondrial-associated apoptosis by inhibiting sodium-hydrogen exchanger isoform 1. Photodiagnosis Photodyn Ther 2019; 26:405-412. [PMID: 31085295 DOI: 10.1016/j.pdpdt.2019.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 03/23/2019] [Accepted: 05/09/2019] [Indexed: 10/26/2022]
Abstract
OBJECTIVE As a targeted therapeutic technique for glioma inhibition, photodynamic therapy (PDT) has gradually become a focus of basic research related to glioma treatment. The capacity of PDT to kill glioma cells involves varieties of pathways. In glioma cells, activated sodium-hydrogen exchanger isoform 1 (NHE1) can inhibit the cytotoxic effect of temozolomide (TMZ), promote cell migration and invasion, and inhibit cell apoptosis by changing the acid-base equilibrium. The purpose of our study was to explore if PDT combined with TMZ can effectively inhibit glioma cells by influencing NHE1 in vitro. METHODS We analyzed the expression levels of proteins such as NHE1, ezrin, vimentin, Bcl-2, and Bax by Western blot analysis, we assessed the migration and invasion of rat C6 glioma cells by Transwell assay, and we evaluated C6 cell apoptosis in vitro by flow cytometry. RESULTS Western blot results indicated that NHE1, ezrin and vimentin were downregulated after cotreatment of C6 cells, and intracellular acidification was detected by a fluorometric intracellular pH assay. The migration and invasion capacities of C6 cells were significantly hindered after cotreatment, as shown by the Transwell assay. Experimental data also revealed a significant increase in cell apoptosis after cotreatment, as detected by flow cytometry; corresponding proapoptotic changes in Bcl-2, Bax and caspase-3 were also observed in vitro. CONCLUSION These results demonstrate that PDT combined with TMZ can inhibit C6 cell migration and invasion and promote mitochondrial-associated apoptosis by inhibiting NHE1. Therefore, this study provides supporting evidence for a potential method for the treatment of glioma.
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Affiliation(s)
- Yulong Jia
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Lei Chen
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Dapeng Chi
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Damin Cong
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Peng Zhou
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Jiaqi Jin
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Hang Ji
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Binbin Liang
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Shuai Gao
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China
| | - Shaoshan Hu
- Department of Neurological Surgery, The Second Affiliated Hospital of the Harbin Medical University, Harbin, 150001, China.
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Rahmanzadeh R, Mehrabi S, Barati M, Ahmadi M, Golab F, Kazmi S, Joghataei MT, Seifi M, Gholipourmalekabadi M. Effect of Co-administration of Bumetanide and Phenobarbital on Seizure Attacks in Temporal Lobe Epilepsy. Basic Clin Neurosci 2018; 9:408-416. [PMID: 30719255 PMCID: PMC6359685 DOI: 10.32598/bcn.9.6.408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 10/20/2016] [Accepted: 01/20/2018] [Indexed: 01/14/2023] Open
Abstract
Introduction: The resistance of temporal lobe epilepsy to classic drugs is thought to be due to disruption in the excitation/inhibition of this pathway. Two chloride transporters, NKCC1 and KCC2, are expressed differently for the excitatory state of Gamma-Amino Butyric Acid (GABA). The present study explored the effect of bumetanide as a selective NKCC1 inhibitor either alone or in combination with the phenobarbital in the pilocarpine model of epilepsy. Methods: An animal model of Status Epilepticus (SE) was induced with pilocarpine in Wistar male rats followed by phenobarbital and or bumetanide or saline administration for 45 days after the induction of SE by Intraperitoneal (IP) injection. The rats were monitored, their behavior was recorded, and after 24 hours they were sacrificed to study the expression of NKCC1 and KCC2 using real time PCR. Results: The data showed that the effects of a combination of bumetanide with phenobarbital on frequency rate and duration of seizure attack were more than those of the phenobarbital alone. In addition, in the bumetanide and combined treatment groups, NKCC1 expression decreased significantly, compared with untreated epileptic animals. A delayed decrement in NKCC1/KCC2 expression ratio after bumetanide application was also observed. Conclusion: The combination of bumetanide with phenobarbital increases the inhibition of SE and maximizes the potential of GABA signaling pathway, and can be considered as an effective therapeutic strategy in patients with epilepsy.
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Affiliation(s)
- Reza Rahmanzadeh
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Soraya Mehrabi
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahmood Barati
- Department of Biotechnology, School of Allied Medicine, Iran University of Medical Science, Tehran, Iran
| | - Milad Ahmadi
- Shefa Neuroscience Research Center, Tehran, Iran
| | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sareh Kazmi
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.,Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Morteza Seifi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mazaher Gholipourmalekabadi
- Department of Tissue Engineering & Regenerative Medicine, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
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Sizemore G, Lucke-Wold B, Rosen C, Simpkins JW, Bhatia S, Sun D. Temporal Lobe Epilepsy, Stroke, and Traumatic Brain Injury: Mechanisms of Hyperpolarized, Depolarized, and Flow-Through Ion Channels Utilized as Tri-Coordinate Biomarkers of Electrophysiologic Dysfunction. OBM NEUROBIOLOGY 2018; 2:009. [PMID: 29951646 PMCID: PMC6018002 DOI: 10.21926/obm.neurobiol.1802009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The brain is an integrated network of multiple variables that when compromised create a diseased state. The neuropathology of temporal lobe epilepsy (TLE), stroke, and traumatic brain injury (TBI) demonstrate both similarity and complexity that reflects this integrated variability; TLE with its live human tissue resection provides opportunity for translational science to demonstrate scale equivalent experimentation between the macroscopic world of clinical disease and the microscopic world of basic science. The extended value of this research is that the neuroinflammatory abnormalities that occur throughout astrocytes with hippocampal sclerosis and damaged or even reversed signaling pathways (inhibition to excitation such as with gaba-aminobutyric acid) are similar to those seen in post-stroke and TBI models. In evaluation of the epilepsy population this interconnectedness of pathology warrants further evaluation with collaborative efforts. This review summarizes patterns that could shift experimentation closer to the macro level of humanity, but still represent the micro world of genetics, epigenetics, and neuro-injury across etiologies of physiologic dysfunction such as TLE, stroke, and TBI with evaluation of cell function using electrophysiology. In conclusion we demonstrate the plausibility of electrophysiologic voltage and current measurement of brain tissue by patch clamp analysis to specify actual electrophysiologic function for comparison to electroencephalography in order to aid neurologic evaluation. Finally, we discuss the opportunity with multiscale modeling to display integration of the hyperpolarization cyclic-nucleotide gated channel, the depolarized calcium channels, and sodium-potassium-chloride-one/potassium-chloride-two co-transporter channels as potential mechanisms utilized as tri-coordinate biomarkers with these three forms of neurologic disease at a molecular scale of electrophysiologic pathology.
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Affiliation(s)
- Gina Sizemore
- Department of Clinical and Translational Science, West Virginia School of Medicine, Morgantown, WV
| | - Brandon Lucke-Wold
- Department of Neurosurgery, West Virginia School of Medicine, Morgantown, WV
| | - Charles Rosen
- Department of Neurosurgery, West Virginia School of Medicine, Morgantown, WV
| | - James W. Simpkins
- Center for Basic and Translational Stroke Research, West Virginia School of Medicine, Morgantown, WV
| | - Sanjay Bhatia
- Department of Neurosurgery, West Virginia School of Medicine, Morgantown, WV
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA
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Cong D, Zhu W, Kuo JS, Hu S, Sun D. Ion transporters in brain tumors. Curr Med Chem 2016; 22:1171-81. [PMID: 25620102 DOI: 10.2174/0929867322666150114151946] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 01/05/2015] [Accepted: 01/08/2015] [Indexed: 11/22/2022]
Abstract
Ion transporters are important in regulation of ionic homeostasis, cell volume, and cellular signal transduction under physiological conditions. They have recently emerged as important players in cancer progression. In this review, we discussed two important ion transporter proteins, sodium-potassium-chloride cotransporter isoform 1 (NKCC-1) and sodium-hydrogen exchanger isoform 1 (NHE-1) in Glioblastoma multiforme (GBM) and other malignant tumors. NKCC-1 is a Na(+)- dependent Cl(-) transporter that mediates the movement of Na(+), K(+), and Cl(-) ions across the plasma membrane and maintains cell volume and intracellular K(+) and Cl(-) homeostasis. NHE-1 is a ubiquitously expressed cell membrane protein which regulates intracellular pH (pH(i)) and extracellular pH (pH(e)) homeostasis and cell volume. Here, we summarized recent pre-clinical experimental studies on NKCC-1 and NHE-1 in GBM and other malignant tumors, such as breast cancer, hepatocellular carcinoma, and lung cancer cells. These studies illustrated that pharmacological inhibition or down-regulation of these ion transporter proteins reduces proliferation, increases apoptosis, and suppresses migration and invasion of cancer cells. These new findings reveal the potentials of these ion transporters as new targets for cancer diagnosis and/or treatment.
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Affiliation(s)
| | | | | | | | - Dandan Sun
- Department of Neurology, University of Pittsburgh Medical School, S-598 South Biomedical Science Tower (BST), 3500 Terrace St., Pittsburgh, PA 15213, USA.
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9
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Lykke K, Töllner K, Feit PW, Erker T, MacAulay N, Löscher W. The search for NKCC1-selective drugs for the treatment of epilepsy: Structure-function relationship of bumetanide and various bumetanide derivatives in inhibiting the human cation-chloride cotransporter NKCC1A. Epilepsy Behav 2016; 59:42-9. [PMID: 27088517 DOI: 10.1016/j.yebeh.2016.03.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/11/2016] [Accepted: 03/12/2016] [Indexed: 11/30/2022]
Abstract
The Na(+)-K(+)-Cl(-) cotransporter NKCC1 plays a major role in the regulation of intraneuronal Cl(-) concentration. Abnormal functionality of NKCC1 has been implicated in several brain disorders, including epilepsy. Bumetanide is the only available selective NKCC1 inhibitor, but also inhibits NKCC2, which can cause severe adverse effects during treatment of brain disorders. A NKCC1-selective bumetanide derivative would therefore be a desirable option. In the present study, we used the Xenopus oocyte heterologous expression system to compare the effects of bumetanide and several derivatives on the two major human splice variants of NKCCs, hNKCC1A and hNKCC2A. The derivatives were selected from a series of ~5000 3-amino-5-sulfamoylbenzoic acid derivatives, covering a wide range of structural modifications and diuretic potencies. To our knowledge, such structure-function relationships have not been performed before for NKCC1. Half maximal inhibitory concentrations (IC50s) of bumetanide were 0.68 (hNKCC1A) and 4.0μM (hNKCC2A), respectively, indicating that this drug is 6-times more potent to inhibit hNKCC1A than hNKCC2A. Side chain substitutions in the bumetanide molecule variably affected the potency to inhibit hNKCC1A. This allowed defining the minimal structural requirements necessary for ligand interaction. Unexpectedly, only a few of the bumetanide derivatives examined were more potent than bumetanide to inhibit hNKCC1A, and most of them also inhibited hNKCC2A, with a highly significant correlation between IC50s for the two NKCC isoforms. These data indicate that the structural requirements for inhibition of NKCC1 and NKCC2 are similar, which complicates development of bumetanide-related compounds with high selectivity for NKCC1.
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Affiliation(s)
- Kasper Lykke
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Peter W Feit
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Thomas Erker
- Department of Medicinal Chemistry, University of Vienna, Vienna, Austria
| | - Nanna MacAulay
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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Sullivan CR, Funk AJ, Shan D, Haroutunian V, McCullumsmith RE. Decreased chloride channel expression in the dorsolateral prefrontal cortex in schizophrenia. PLoS One 2015; 10:e0123158. [PMID: 25826365 PMCID: PMC4380350 DOI: 10.1371/journal.pone.0123158] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 02/17/2015] [Indexed: 12/17/2022] Open
Abstract
Alterations in GABAergic neurotransmission are implicated in several psychiatric illnesses, including schizophrenia. The Na-K-Cl and K-Cl cotransporters regulate intracellular chloride levels. Abnormalities in cotransporter expression levels could shift the chloride electrochemical gradient and impair GABAergic transmission. In this study, we performed Western blot analysis to investigate whether the Na-K-Cl and K-Cl cotransporter protein is abnormally expressed in the dorsal lateral prefrontal cortex and the anterior cingulate cortex in patients with schizophrenia versus a control group. We found decreased K-Cl cotransporter protein expression in the dorsal lateral prefrontal cortex, but not the anterior cingulate cortex, in subjects with schizophrenia, supporting the hypothesis of region level abnormal GABAergic function in the pathophysiology of schizophrenia. Subjects with schizophrenia off antipsychotic medication at the time of death had decreased K-Cl cotransporter protein expression compared to both normal controls and subjects with schizophrenia on antipsychotics. Our results provide evidence for KCC2 protein abnormalities in schizophrenia and suggest that antipsychotic medications might reverse deficits of this protein in the illness.
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Affiliation(s)
- Courtney R. Sullivan
- University of Cincinnati College of Medicine, Neuroscience Graduate Program, Cincinnati, Ohio, United States of America
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Adam J. Funk
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Dan Shan
- Department of Nephrology, University of Alabama Birmingham, Birmingham, Alabama, United States of America
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, New York, New York, United States of America
- James J Peters Veterans Affairs Medical Center, New York, New York, United States of America
| | - Robert E. McCullumsmith
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
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Silbert BI, Heaton AE, Cash RFH, James I, Dunne JW, Lawn ND, Silbert PL, Mastaglia FL, Thickbroom GW. Evidence for an excitatory GABAA response in human motor cortex in idiopathic generalised epilepsy. Seizure 2015; 26:36-42. [PMID: 25799900 DOI: 10.1016/j.seizure.2015.01.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/28/2014] [Accepted: 01/23/2015] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Impaired GABAergic inhibition has been implicated in the pathophysiology of epilepsy. The possibility of a paradoxical excitatory effect of GABA in epilepsy has been suggested, but has not been investigated in vivo. We investigated pre- and post-synaptic GABAergic mechanisms in patients with idiopathic generalised epilepsy (IGE). METHOD In 10 patients and 12 control subjects we explored short- and long-interval intracortical inhibition (SICI, LICI; post-synaptic GABAA and GABAB-mediated respectively) and long-interval intracortical facilitation (LICF; pre-synaptic disinhibition) using transcranial magnetic stimulation. RESULTS While post-synaptic GABAB-mediated inhibition was unchanged in IGE (p=0.09), LICF was reduced compared to controls (controls: 141±17% of baseline; untreated patients: 107±12%, p=0.2; treated patients: 79±10%, p=0.003). GABAA-mediated inhibition was reduced in untreated patients (response amplitude 56±4% of baseline vs. 26±6% in controls, p=0.004) and normalised with treatment (37±12%, p=0.5 vs. controls). When measured during LICI, GABAA-mediated inhibition became excitatory in untreated IGE (response amplitude 120±10% of baseline, p=0.017), but not in treated patients. CONCLUSION Pre- and post-synaptic GABA-mediated inhibitory mechanisms are altered in IGE. The findings lend in vivo support to evidence from experimental models and in vitro studies of human epileptic brain tissue that GABA may have a paradoxical excitatory role in ictogenesis.
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Affiliation(s)
- Benjamin I Silbert
- Western Australian Neuroscience Research Institute, University of Western Australia, 4th Floor, A Block, QEII Medical Centre, Verdun Street, Nedlands, Perth, Western Australia 6009, Australia
| | - Alexandra E Heaton
- Western Australian Neuroscience Research Institute, University of Western Australia, 4th Floor, A Block, QEII Medical Centre, Verdun Street, Nedlands, Perth, Western Australia 6009, Australia
| | - Robin F H Cash
- Western Australian Neuroscience Research Institute, University of Western Australia, 4th Floor, A Block, QEII Medical Centre, Verdun Street, Nedlands, Perth, Western Australia 6009, Australia; Division of Brain, Imaging and Behaviour - Systems Neuroscience, Toronto Western Research Institute, University Health Network, 339 Bathurst Street, MP14-324, Toronto, Ontario M5T 2S8, Canada
| | - Ian James
- Centre for Clinical Immunology and Biomedical Statistics, Institute for Immunology and Infectious Diseases, Murdoch University, Building 390, Discovery Way, Murdoch, Perth, Western Australia 6150, Australia
| | - John W Dunne
- Department of Neurology, Royal Perth Hospital, Level 8, A Block, GPO Box X2213, Perth, Western Australia 6001, Australia
| | - Nicholas D Lawn
- Department of Neurology, Royal Perth Hospital, Level 8, A Block, GPO Box X2213, Perth, Western Australia 6001, Australia
| | - Peter L Silbert
- Department of Neurology, Royal Perth Hospital, Level 8, A Block, GPO Box X2213, Perth, Western Australia 6001, Australia
| | - Frank L Mastaglia
- Western Australian Neuroscience Research Institute, University of Western Australia, 4th Floor, A Block, QEII Medical Centre, Verdun Street, Nedlands, Perth, Western Australia 6009, Australia
| | - Gary W Thickbroom
- Western Australian Neuroscience Research Institute, University of Western Australia, 4th Floor, A Block, QEII Medical Centre, Verdun Street, Nedlands, Perth, Western Australia 6009, Australia.
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Abstract
Knowledge of the nature, prognosis, and ways to treat brain lesions in neonatal infants has increased remarkably. Neonatal hypoxic-ischaemic encephalopathy (HIE) in term infants, mirrors a progressive cascade of excito-oxidative events that unfold in the brain after an asphyxial insult. In the laboratory, this cascade can be blocked to protect brain tissue through the process of neuroprotection. However, proof of a clinical effect was lacking until the publication of three positive randomised controlled trials of moderate hypothermia for term infants with HIE. These results have greatly improved treatment prospects for babies with asphyxia and altered understanding of the theory of neuroprotection. The studies show that moderate hypothermia within 6 h of asphyxia improves survival without cerebral palsy or other disability by about 40% and reduces death or neurological disability by nearly 30%. The search is on to discover adjuvant treatments that can further enhance the effects of hypothermia.
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13
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Combined effect of bumetanide, bromide, and GABAergic agonists: an alternative treatment for intractable seizures. Epilepsy Behav 2011; 20:147-9. [PMID: 21167788 DOI: 10.1016/j.yebeh.2010.10.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 10/26/2010] [Accepted: 10/27/2010] [Indexed: 11/22/2022]
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Kahle KT, Simard JM, Staley KJ, Nahed BV, Jones PS, Sun D. Molecular mechanisms of ischemic cerebral edema: role of electroneutral ion transport. Physiology (Bethesda) 2009; 24:257-65. [PMID: 19675357 DOI: 10.1152/physiol.00015.2009] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The brain achieves homeostasis of its intracellular and extracellular fluids by precisely regulating the transport of solute and water across its major cellular barriers: endothelia of the blood-brain barrier (BBB), choroid plexus epithelia, and neuroglial cell membranes. Cerebral edema, the pathological accumulation of fluid in the brain's intracellular and extracellular spaces, is a major cause of morbidity and mortality following stroke and other forms of ischemic brain injury. Until recently, mechanisms of cerebral edema formation have been obscure; consequently, its treatment has been empiric and suboptimal. Here, we provide a paradigm for understanding ischemic cerebral edema, showing that its molecular pathogenesis is a complex yet step-wise process that results largely from impaired astrocytic cell volume regulation and permeability alterations in the cerebral microvasculature, both of which arise from pathological changes in the activities of specific ion channels and transporters. Recent data has implicated the bumetanide-sensitive NKCC1, an electroneutral cotransporter expressed in astrocytes and the BBB, in cerebral edema formation in several different rodent models of stroke. Pharmacological inhibition or genetic deficiency of NKCC1 decreases ischemia-induced cell swelling, BBB breakdown, cerebral edema, and neurotoxicity. Combination pharmacological strategies that include NKCC1 as a target might thus prove beneficial for the treatment of ischemic, and potentially other types of, cerebral edema.
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Affiliation(s)
- Kristopher T Kahle
- Departments of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
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15
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Ellens DJ, Hong E, Giblin K, Singleton MJ, Bashyal C, Englot DJ, Mishra AM, Blumenfeld H. Development of spike-wave seizures in C3H/HeJ mice. Epilepsy Res 2009; 85:53-9. [PMID: 19409755 DOI: 10.1016/j.eplepsyres.2009.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 12/17/2008] [Accepted: 01/18/2009] [Indexed: 11/26/2022]
Abstract
C3H/HeJ mice have been reported to have relatively early onset of spike-wave discharges (SWD), and a defective AMPA receptor subunit Gria4 as the genetic cause. We investigated the time course of SWD development through serial EEG recordings in C3H/HeJ mice to better characterize this model. We found that at immature postnatal ages of 5-15 days, rare SWD-like events were observed at an average rate of 3 per hour, and with relatively broad spikes, irregular rhythm, slow frequency (5-6 Hz), and short duration (mean 1.75 s). This was followed by a transitional period of increasing SWD incidence, which then stabilized in mature animals at age 26-62 days, with SWD at an average rate of 45 per hour, narrower spike morphology, regular rhythm, higher frequency (7-8 Hz), and longer duration (mean 3.40s). This sequence of maturational changes in SWD development suggests that effects of early intervention could be tested in C3H/HeJ mice over the course of a few weeks, rather than a few months as in rats, greatly facilitating future research on anti-epileptogenesis.
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Affiliation(s)
- Damien J Ellens
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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16
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Kahle KT, Staley KJ. The bumetanide-sensitive Na-K-2Cl cotransporter NKCC1 as a potential target of a novel mechanism-based treatment strategy for neonatal seizures. Neurosurg Focus 2009; 25:E22. [PMID: 18759624 DOI: 10.3171/foc/2008/25/9/e22] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Seizures that occur during the neonatal period do so with a greater frequency than at any other age, have profound consequences for cognitive and motor development, and are difficult to treat with the existing series of antiepileptic drugs. During development, gamma-aminobutyric acid (GABA)ergic neurotransmission undergoes a switch from excitatory to inhibitory due to a reversal of neuronal chloride (Cl()) gradients. The intracellular level of chloride ([Cl()](i)) in immature neonatal neurons, compared with mature adult neurons, is about 20-40 mM higher due to robust activity of the chloride-importing Na-K-2Cl cotransporter NKCC1, such that the binding of GABA to ligand-gated GABA(A) receptor-associated Cl() channels triggers Cl() efflux and depolarizing excitation. In adults, NKCC1 expression decreases and the expression of the genetically related chloride-extruding K-Cl cotransporter KCC2 increases, lowering [Cl()](i) to a level such that activation of GABA(A) receptors triggers Cl() influx and inhibitory hyperpolarization. The excitatory action of GABA in neonates, while playing an important role in neuronal development and synaptogenesis, accounts for the decreased seizure threshold, increased seizure propensity, and poor efficacy of GABAergic anticonvulsants in this age group. Bumetanide, a furosemide-related diuretic already used to treat volume overload in neonates, is a specific inhibitor of NKCC1 at low doses, can switch the GABA equilibrium potential of immature neurons from depolarizing to hyperpolarizing, and has recently been shown to inhibit epileptic activity in vitro and in vivo in animal models of neonatal seizures. The fundamental role of NKCC1 in establishing excitatory GABAergic neurotransmission in the neonate makes it a tempting target of a novel mechanism-based anticonvulsant strategy that could utilize the well-known pharmacology of bumetanide to help treat neonatal seizures.
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Affiliation(s)
- Kristopher T Kahle
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
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Price TJ, Cervero F, Gold MS, Hammond DL, Prescott SA. Chloride regulation in the pain pathway. BRAIN RESEARCH REVIEWS 2009; 60:149-70. [PMID: 19167425 PMCID: PMC2903433 DOI: 10.1016/j.brainresrev.2008.12.015] [Citation(s) in RCA: 191] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/29/2008] [Indexed: 12/18/2022]
Abstract
Melzack and Wall's Gate Control Theory of Pain laid the theoretical groundwork for a role of spinal inhibition in endogenous pain control. While the Gate Control Theory was based on the notion that spinal inhibition is dynamically regulated, mechanisms underlying the regulation of inhibition have turned out to be far more complex than Melzack and Wall could have ever imagined. Recent evidence indicates that an exquisitely sensitive form of regulation involves changes in anion equilibrium potential (E(anion)), which subsequently impacts fast synaptic inhibition mediated by GABA(A), and to a lesser extent, glycine receptor activation, the prototypic ligand gated anion channels. The cation-chloride co-transporters (in particular NKCC1 and KCC2) have emerged as proteins that play a critical role in the dynamic regulation of E(anion) which in turn appears to play a critical role in hyperalgesia and allodynia following peripheral inflammation or nerve injury. This review summarizes the current state of knowledge in this area with particular attention to how such findings relate to endogenous mechanisms of hyperalgesia and allodynia and potential applications for therapeutics based on modulation of intracellular Cl(-) gradients or pharmacological interventions targeting GABA(A) receptors.
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Affiliation(s)
| | - Fernando Cervero
- McGill University, Department of Anesthesia, McGill Centre for Research on Pain,
| | | | - Donna L Hammond
- University of Iowa, Department of Anesthesia, Department of Pharmacology,
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Nardou R, Ben-Ari Y, Khalilov I. Bumetanide, an NKCC1 antagonist, does not prevent formation of epileptogenic focus but blocks epileptic focus seizures in immature rat hippocampus. J Neurophysiol 2009; 101:2878-88. [PMID: 19297515 DOI: 10.1152/jn.90761.2008] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Excitatory GABA action induced by high [Cl(-)](i) is thought to contribute to seizure generation in neonatal neurons although the mechanism of this effect remains unclear. We report that bumetanide, a NKCC1 antagonist, reduces driving force of GABA-mediated currents (DF(GABA)) in neonatal hippocampal neurons and blocks the giant depolarizing potentials (GDPs), a spontaneous pattern of network activity. In the preparation composed of two intact interconnected hippocampi, bumetanide did not prevent generation of kainate-induced seizures, their propagation to the contralateral hippocampus, and formation of an epileptogenic mirror focus. However, in the isolated mirror focus, bumetanide effectively blocked spontaneous epileptiform activity transforming it to the GDP-like activity pattern. Bumetanide partially reduced DF(GABA) and therefore the excitatory action of GABA in epileptic neurons. Therefore bumetanide is a potent anticonvulsive agent although it cannot prevent formation of the epileptogenic mirror focus. We suggest that an additional mechanism other than NKCC1-mediated contributes to the persistent increase of DF(GABA) in epileptic neurons.
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Affiliation(s)
- Romain Nardou
- Institut de Neurobiologie de la Mediterranee, Institut National de la Santé et de la Recherche Médicale Unité 901, 13273 Marseille Cedex 09, France
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Mathews GC. Rational polypharmacy: when two old drugs are better than one. Epilepsy Curr 2008; 8:133-5. [PMID: 18852837 DOI: 10.1111/j.1535-7511.2008.00268.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Bumetanide Enhances Phenobarbital Efficacy in a Neonatal Seizure Model. Dzhala VI, Brumback AC, Staley KJ. Ann Neurol 2008;63(2):222–235. OBJECTIVES: High levels of expression of the Na+-K+-2Cl- (NKCC1) cotransporter in immature neurons cause the accumulation of intracellular chloride and, therefore, a depolarized Cl- equilibrium potential (ECl). This results in the outward flux of Cl- through GABAA channels, the opposite direction compared with mature neurons, in which GABAA receptor activation is inhibitory because Cl- flows into the cell. This outward flow of Cl- in neonatal neurons is excitatory and contributes to a greater seizure propensity and poor electroencephalographic response to GABAergic anticonvulsants such as phenobarbital and benzodiazepines. Blocking the NKCC1 transporter with bumetanide prevents outward Cl- flux and causes a more negative GABA equilibrium potential (EGABA) in immature neurons. We therefore tested whether bumetanide enhances the anticonvulsant action of phenobarbital in the neonatal brain. METHODS: Recurrent seizures were induced in the intact hippocampal preparation in vitro by continuous 5-hour exposure to low-Mg2+ solution. The anticonvulsant efficacy of phenobarbital, bumetanide, and the combination of these drugs was studied. RESULTS: Phenobarbital failed to abolish or depress recurrent seizures in 70% of hippocampi. In contrast, phenobarbital in combination with bumetanide abolished seizures in 70% of hippocampi and significantly reduced the frequency, duration, and power of seizures in the remaining 30%. INTERPRETATION: Thus, alteration of Cl- transport by bumetanide enables the anticonvulsant action of phenobarbital in immature brain. This is a mechanistic demonstration of rational anticonvulsant polypharmacy. The combination of these agents may comprise an effective therapy for early-life seizures.
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