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Guang D, Xiaofei Z, Yu M, Hui N, Min S, Xiaonan S. Pomiferin targeting SLC9A9 based on histone acetylation modification pattern is a potential therapeutical option for gastric cancer with high malignancy. Biochem Pharmacol 2024; 226:116333. [PMID: 38824966 DOI: 10.1016/j.bcp.2024.116333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
Changes in histone acetylation status are associated with gastric cancer (GC) progression. Pomiferin is a natural flavonoid, however, the specific role of pomiferin in the treatment of GC is still unclear, and its targets are not well clarified. In this work, the prognostic genes related with histone acetylation in GC were screened by univariate Cox analysis. Next, a risk model of was constructed using least absolute shrinkage and selection operator-Cox regression analyses, and multivariate Cox analysis was used for identifying the independent risk factor. Molecular docking was performed using AutoDock Vina to validate the interaction between solute carrier family 9 member A9 (SLC9A9) and pomiferin. In vitro and in vivo models were applied to investigate the tumor-suppressive role of pomiferin against GC. The inhibitory effects of pomiferin on EGFR/PI3K/AKT signaling were valdiated by Western blotting, immunofluorescence staining and qPCR. Here, a prognostic risk model based on histone acetylation regulators was established, and SLC9A9 was identified as a risk factor associated with histone acetylation status in GC. SLC9A9 expression was associated with abnormal immune microenvironment of tumor. Pomiferin had a high binding affinity with SLC9A9, and both pomiferin treatment and depletion of SLC9A9 repressed the malignant phenotypes of GC cells. Mechanistically, pomiferin inactivates EGFR/PI3K/AKT signaling in GC cells. In summary, SLC9A9, as a indicator of abnormal histone acetylation status of GC, functions as an oncogenic factor. Pomiferin binds with SLC9A9 to inactivate EGFR/PI3K/AKT pathway, to block GC progression, suggesting it is a promising drug for the patients with highly malignant GC.
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Affiliation(s)
- Deng Guang
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Zhang Xiaofei
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Meng Yu
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Niu Hui
- Department of Respiratory, Zhoukou City Central Hospital, Zhoukou 466000, Henan, China
| | - Song Min
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China.
| | - Shi Xiaonan
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China.
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2
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Zou J, Mitra K, Anees P, Oettinger D, Ramirez JR, Veetil AT, Gupta PD, Rao R, Smith JJ, Kratsios P, Krishnan Y. A DNA nanodevice for mapping sodium at single-organelle resolution. Nat Biotechnol 2024; 42:1075-1083. [PMID: 37735265 PMCID: PMC11004682 DOI: 10.1038/s41587-023-01950-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 08/15/2023] [Indexed: 09/23/2023]
Abstract
Cellular sodium ion (Na+) homeostasis is integral to organism physiology. Our current understanding of Na+ homeostasis is largely limited to Na+ transport at the plasma membrane. Organelles may also contribute to Na+ homeostasis; however, the direction of Na+ flow across organelle membranes is unknown because organellar Na+ cannot be imaged. Here we report a pH-independent, organelle-targetable, ratiometric probe that reports lumenal Na+. It is a DNA nanodevice containing a Na+-sensitive fluorophore, a reference dye and an organelle-targeting domain. By measuring Na+ at single endosome resolution in mammalian cells and Caenorhabditis elegans, we discovered that lumenal Na+ levels in each stage of the endolysosomal pathway exceed cytosolic levels and decrease as endosomes mature. Further, we find that lysosomal Na+ levels in nematodes are modulated by the Na+/H+ exchanger NHX-5 in response to salt stress. The ability to image subcellular Na+ will unveil mechanisms of Na+ homeostasis at an increased level of cellular detail.
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Affiliation(s)
- Junyi Zou
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Koushambi Mitra
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Palapuravan Anees
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA
| | - Daphne Oettinger
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Joseph R Ramirez
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Aneesh Tazhe Veetil
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Priyanka Dutta Gupta
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
| | - Rajini Rao
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jayson J Smith
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Paschalis Kratsios
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Yamuna Krishnan
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
- Neuroscience Institute, The University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
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3
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Identification of tumor antigens and immune subtypes of acute myeloid leukemia for mRNA vaccine development. Clin Transl Oncol 2023:10.1007/s12094-023-03108-6. [PMID: 36781600 PMCID: PMC9924891 DOI: 10.1007/s12094-023-03108-6] [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: 12/30/2022] [Accepted: 01/28/2023] [Indexed: 02/15/2023]
Abstract
BACKGROUND Acute myeloid leukemia (AML) is a highly aggressive hematological malignancy, and there has not been any significant improvement in therapy of AML over the past several decades. The mRNA vaccines have become a promising strategy against multiple cancers, however, its application on AML remains undefined. In this study, we aimed to identify novel antigens for developing mRNA vaccines against AML and explore the immune landscape of AML to select appropriate patients for vaccination. METHODS Genomic data and gene mutation data were retrieved from TCGA, GEO and cBioPortal, respectively. GEPIA2 was used to analyze differentially expressed genes. The single cell RNA-seq database Tumor Immune Single-cell Hub (TISCH) was used to explore the association between the potential tumor antigens and the infiltrating immune cells in the bone marrow. Consensus clustering analysis was applied to identify distinct immune subtypes. The correlation between the abundance of antigen presenting cells and the expression level of antigens was evaluated using Spearman correlation analysis. The characteristics of the tumor immune microenvironment in each subtype were investigated based on single-sample gene set enrichment analysis. RESULTS Five potential tumor antigens were identified for mRNA vaccine from the pool of overexpressed and mutated genes, including CDH23, LRP1, MEFV, MYOF and SLC9A9, which were associated with infiltration of antigen-presenting immune cells (APCs). AML patients were stratified into two immune subtypes Cluster1 (C1) and Cluster2 (C2), which were characterized by distinct molecular and clinical features. C1 subtype demonstrated an immune-hot and immunosuppressive phenotype, while the C1 subtype had an immune-cold phenotype. Furthermore, the two immune subtype showed remarkably different expression of immune checkpoints, immunogenic cell death modulators and human leukocyte antigens. CONCLUSION CDH23, LRP1, MEFV, MYOF and SLC9A9 were potential antigens for developing AML mRNA vaccine, and AML patients in immune subtype 1 were suitable for vaccination.
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Bernardazzi C, Sheikh IA, Xu H, Ghishan FK. The Physiological Function and Potential Role of the Ubiquitous Na +/H + Exchanger Isoform 8 (NHE8): An Overview Data. Int J Mol Sci 2022; 23:ijms231810857. [PMID: 36142772 PMCID: PMC9501935 DOI: 10.3390/ijms231810857] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/08/2022] [Accepted: 09/15/2022] [Indexed: 11/16/2022] Open
Abstract
The Na+/H+ exchanger transporters (NHE) play an important role in various biologic processes including Na+ absorption, intracellular pH homeostasis, cell volume regulation, proliferation, and apoptosis. The wide expression pattern and cellular localization of NHEs make these proteins pivotal players in virtually all human tissues and organs. In addition, recent studies suggest that NHEs may be one of the primeval transport protein forms in the history of life. Among the different isoforms, the most well-characterized NHEs are the Na+/H+ exchanger isoform 1 (NHE1) and Na+/H+ exchanger isoform 3 (NHE3). However, Na+/H+ exchanger isoform 8 (NHE8) has been receiving attention based on its recent discoveries in the gastrointestinal tract. In this review, we will discuss what is known about the physiological function and potential role of NHE8 in the main organ systems, including useful overviews that could inspire new studies on this multifaceted protein.
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The sodium proton exchanger NHE9 regulates phagosome maturation and bactericidal activity in macrophages. J Biol Chem 2022; 298:102150. [PMID: 35716776 PMCID: PMC9293770 DOI: 10.1016/j.jbc.2022.102150] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/07/2022] [Accepted: 06/13/2022] [Indexed: 11/23/2022] Open
Abstract
Acidification of phagosomes is essential for the bactericidal activity of macrophages. Targeting machinery that regulates pH within the phagosomes is a prominent strategy employed by various pathogens that have emerged as major threats to public health. Nascent phagosomes acquire the machinery for pH regulation through a graded maturation process involving fusion with endolysosomes. In addition, meticulous coordination between proton pumping and leakage mechanisms is crucial for maintaining optimal pH within the phagosome. However, relative to mechanisms involved in acidifying the phagosome lumen, little is known about proton leakage pathways in this organelle. Sodium proton transporter NHE9 is a known proton leakage pathway located on the endosomes. As phagosomes acquire proteins through fusions with endosomes during maturation, NHE9 seemed a promising candidate for regulating proton fluxes on the phagosome. Here, using genetic and biophysical approaches, we show NHE9 is an important proton leakage pathway associated with the maturing phagosome. NHE9 is highly expressed in immune cells, specifically macrophages; however, NHE9 expression is strongly downregulated upon bacterial infection. We show that compensatory ectopic NHE9 expression hinders the directed motion of phagosomes along microtubules and promotes early detachment from the microtubule tracks. As a result, these phagosomes have shorter run lengths and are not successful in reaching the lysosome. In accordance with this observation, we demonstrate that NHE9 expression levels negatively correlate with bacterial survival. Together, our findings show that NHE9 regulates lumenal pH to affect phagosome maturation, and consequently, microbicidal activity in macrophages.
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6
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Anderegg MA, Gyimesi G, Ho TM, Hediger MA, Fuster DG. The Less Well-Known Little Brothers: The SLC9B/NHA Sodium Proton Exchanger Subfamily—Structure, Function, Regulation and Potential Drug-Target Approaches. Front Physiol 2022; 13:898508. [PMID: 35694410 PMCID: PMC9174904 DOI: 10.3389/fphys.2022.898508] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/04/2022] [Indexed: 12/15/2022] Open
Abstract
The SLC9 gene family encodes Na+/H+ exchangers (NHEs), a group of membrane transport proteins critically involved in the regulation of cytoplasmic and organellar pH, cell volume, as well as systemic acid-base and volume homeostasis. NHEs of the SLC9A subfamily (NHE 1–9) are well-known for their roles in human physiology and disease. Much less is known about the two members of the SLC9B subfamily, NHA1 and NHA2, which share higher similarity to prokaryotic NHEs than the SLC9A paralogs. NHA2 (also known as SLC9B2) is ubiquitously expressed and has recently been shown to participate in renal blood pressure and electrolyte regulation, insulin secretion and systemic glucose homeostasis. In addition, NHA2 has been proposed to contribute to the pathogenesis of polycystic kidney disease, the most common inherited kidney disease in humans. NHA1 (also known as SLC9B1) is mainly expressed in testis and is important for sperm motility and thus male fertility, but has not been associated with human disease thus far. In this review, we present a summary of the structure, function and regulation of expression of the SLC9B subfamily members, focusing primarily on the better-studied SLC9B paralog, NHA2. Furthermore, we will review the potential of the SLC9B subfamily as drug targets.
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Affiliation(s)
- Manuel A. Anderegg
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- *Correspondence: Manuel A. Anderegg,
| | - Gergely Gyimesi
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Membrane Transport Discovery Lab, Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Tin Manh Ho
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Matthias A. Hediger
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Membrane Transport Discovery Lab, Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Daniel G. Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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7
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Gao AYL, Lourdin-De Filippis E, Orlowski J, McKinney RA. Roles of Endomembrane Alkali Cation/Proton Exchangers in Synaptic Function and Neurodevelopmental Disorders. Front Physiol 2022; 13:892196. [PMID: 35547574 PMCID: PMC9081726 DOI: 10.3389/fphys.2022.892196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 03/30/2022] [Indexed: 12/25/2022] Open
Abstract
Endomembrane alkali cation (Na+, K+)/proton (H+) exchangers (eNHEs) are increasingly associated with neurological disorders. These eNHEs play integral roles in regulating the luminal pH, processing, and trafficking of cargo along the secretory (Golgi and post-Golgi vesicles) and endocytic (early, recycling, and late endosomes) pathways, essential regulatory processes vital for neuronal development and plasticity. Given the complex morphology and compartmentalization of multipolar neurons, the contribution of eNHEs in maintaining optimal pH homeostasis and cargo trafficking is especially significant during periods of structural and functional development and remodeling. While the importance of eNHEs has been demonstrated in a variety of non-neuronal cell types, their involvement in neuronal function is less well understood. In this review, we will discuss their emerging roles in excitatory synaptic function, particularly as it pertains to cellular learning and remodeling. We will also explore their connections to neurodevelopmental conditions, including intellectual disability, autism, and attention deficit hyperactivity disorders.
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Affiliation(s)
- Andy Y L Gao
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
| | | | - John Orlowski
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - R Anne McKinney
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
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8
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Ko M, Makena MR, Schiapparelli P, Suarez-Meade P, Mekile AX, Lal B, Lopez-Bertoni H, Kozielski KL, Green JJ, Laterra J, Quiñones-Hinojosa A, Rao R. The endosomal pH regulator NHE9 is a driver of stemness in glioblastoma. PNAS NEXUS 2022; 1:pgac013. [PMID: 35387234 PMCID: PMC8974362 DOI: 10.1093/pnasnexus/pgac013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 09/26/2021] [Accepted: 02/14/2022] [Indexed: 11/25/2022]
Abstract
A small population of self-renewing stem cells initiate tumors and maintain therapeutic resistance in glioblastoma (GBM). Given the limited treatment options and dismal prognosis for this disease, there is urgent need to identify drivers of stem cells that could be druggable targets. Previous work showed that the endosomal pH regulator NHE9 is upregulated in GBM and correlates with worse survival prognosis. Here, we probed for aberrant signaling pathways in patient-derived GBM cells and found that NHE9 increases cell surface expression and phosphorylation of multiple receptor tyrosine kinases (RTKs) by promoting their escape from lysosomal degradation. Downstream of NHE9-mediated receptor activation, oncogenic signaling pathways converged on the JAK2-STAT3 transduction axis to induce pluripotency genes Oct4 and Nanog and suppress markers of glial differentiation. We used both genetic and chemical approaches to query the role of endosomal pH in GBM phenotypes. Loss-of-function mutations in NHE9 that failed to alkalinize endosomal lumen did not increase self-renewal capacity of gliomaspheres in vitro. However, monensin, a chemical mimetic of Na+/H+ exchanger activity, and the H+ pump inhibitor bafilomycin bypassed NHE9 to directly alkalinize the endosomal lumen resulting in stabilization of RTKs and induction of Oct4 and Nanog. Using orthotopic models of primary GBM cells we found that NHE9 increased tumor initiation in vivo. We propose that NHE9 initiates inside-out signaling from the endosomal lumen, distinct from the established effects of cytosolic and extracellular pH on tumorigenesis. Endosomal pH may be an attractive therapeutic target that diminishes stemness in GBM, agnostic of specific receptor subtype.
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Affiliation(s)
- Myungjun Ko
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Neurosurgery, Mayo Clinic College of Medicine, Jacksonville, FL, 32224, USA
| | - Monish R Makena
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Paula Schiapparelli
- Department of Neurosurgery, Mayo Clinic College of Medicine, Jacksonville, FL, 32224, USA
| | - Paola Suarez-Meade
- Department of Neurosurgery, Mayo Clinic College of Medicine, Jacksonville, FL, 32224, USA
| | - Allatah X Mekile
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Bachchu Lal
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Hernando Lopez-Bertoni
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Kristen L Kozielski
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Electrical and Computer Engineering, Technical University of Munich, Munich, Germany
| | - Jordan J Green
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - John Laterra
- Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, USA
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | | | - Rajini Rao
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
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9
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Mir A, Almudhry M, Alghamdi F, Albaradie R, Ibrahim M, Aldurayhim F, Alhedaithy A, Alamr M, Bawazir M, Mohammad S, Abdelhay S, Bashir S, Housawi Y. SLC gene mutations and pediatric neurological disorders: diverse clinical phenotypes in a Saudi Arabian population. Hum Genet 2021; 141:81-99. [PMID: 34797406 DOI: 10.1007/s00439-021-02404-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 11/12/2021] [Indexed: 12/12/2022]
Abstract
The uptake and efflux of solutes across a plasma membrane is controlled by transporters. There are two main superfamilies of transporters, adenosine 5'-triphosphate (ATP) binding cassettes (ABCs) and solute carriers (SLCs). In the brain, SLC transporters are involved in transporting various solutes across the blood-brain barrier, blood-cerebrospinal fluid barrier, astrocytes, neurons, and other brain cell types including oligodendrocytes and microglial cells. SLCs play an important role in maintaining normal brain function. Hence, mutations in the genes that encode SLC transporters can cause a variety of neurological disorders. We identified the following SLC gene variants in 25 patients in our cohort: SLC1A2, SLC2A1, SLC5A1, SLC6A3, SLC6A5, SLC6A8, SLC9A6, SLC9A9, SLC12A6, SLC13A5, SLC16A1, SLC17A5, SLC19A3, SLC25A12, SLC25A15, SLC27A4, SLC45A1, SLC46A1, and SLC52A3. Eight patients harbored pathogenic or likely pathogenic mutations (SLC5A1, SLC9A6, SLC12A6, SLC16A1, SLC19A3, and SLC52A3), and 12 patients were found to have variants of unknown clinical significance (VOUS); these variants occurred in 11 genes (SLC1A2, SLC2A1, SLC6A3, SLC6A5, SLC6A8, SLC9A6, SLC9A9, SLC13A5, SLC25A12, SLC27A4, and SLC45A1). Five patients were excluded as they were carriers. In the remaining 20 patients with SLC gene variants, we identified 16 possible distinct neurological disorders. Based on the clinical presentation, we categorized them into genes causing intellectual delay (ID) or autism spectrum disorder (ASD), those causing epilepsy, those causing vitamin-related disorders, and those causing other neurological diseases. Several variants were detected that indicated possible personalized therapies: SLC2A1 led to dystonia or epilepsy, which can be treated with a ketogenic diet; SLC6A3 led to infantile parkinsonism-dystonia 1, which can be treated with levodopa; SLC6A5 led to hyperekplexia 3, for which unnecessary treatment with antiepileptic drugs should be avoided; SLC6A8 led to creatine deficiency syndrome type 1, which can be treated with creatine monohydrate; SLC16A1 led to monocarboxylate transporter 1 deficiency, which causes seizures that should not be treated with a ketogenic diet; SLC19A3 led to biotin-thiamine-responsive basal ganglia disease, which can be treated with biotin and thiamine; and SLC52A3 led to Brown-Vialetto-Van-Laere syndrome 1, which can be treated with riboflavin. The present study examines the prevalence of SLC gene mutations in our cohort of children with epilepsy and other neurological disorders. It highlights the diverse phenotypes associated with mutations in this large family of SLC transporter proteins, and an opportunity for personalized genomics and personalized therapeutics.
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Affiliation(s)
- Ali Mir
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia.
| | - Montaha Almudhry
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Fouad Alghamdi
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Raidah Albaradie
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Mona Ibrahim
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Fatimah Aldurayhim
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Abdullah Alhedaithy
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Mushari Alamr
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Maryam Bawazir
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Sahar Mohammad
- Department of Pediatric, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Salma Abdelhay
- Department of Pediatric, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
| | - Shahid Bashir
- Department of Pediatric Neurology, Neuroscience Center, King Fahad Specialist Hospital, Ammar Bin Thabit Street, Dammam, 31444, Kingdom of Saudi Arabia
| | - Yousef Housawi
- Genetic and Metabolic Department, King Fahad Specialist Hospital, Dammam, Kingdom of Saudi Arabia
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10
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Prasad H. Protons to Patients: targeting endosomal Na + /H + exchangers against COVID-19 and other viral diseases. FEBS J 2021; 288:5071-5088. [PMID: 34490733 PMCID: PMC8646450 DOI: 10.1111/febs.16163] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 12/15/2022]
Abstract
While there is undeniable evidence to link endosomal acid‐base homeostasis to viral pathogenesis, the lack of druggable molecular targets has hindered translation from bench to bedside. The recent identification of variants in the interferon‐inducible endosomal Na+/H+ exchanger 9 associated with severe coronavirus disease‐19 (COVID‐19) has brought a shift in the way we envision aberrant endosomal acidification. Is it linked to an increased susceptibility to viral infection or a propensity to develop critical illness? This review summarizes the genetic and cellular evidence linking endosomal Na+/H+ exchangers and viral diseases to suggest how they can act as a broad‐spectrum modulator of viral infection and downstream pathophysiology. The review also presents novel insights supporting the complex role of endosomal acid‐base homeostasis in viral pathogenesis and discusses the potential causes for negative outcomes of clinical trials utilizing alkalinizing drugs as therapies for COVID‐19. These findings lead to a pathogenic model of viral disease that predicts that nonspecific targeting of endosomal pH might fail, even if administered early on, and suggests that endosomal Na+/H+ exchangers may regulate key host antiviral defence mechanisms and mediators that act to drive inflammatory organ injury.
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Affiliation(s)
- Hari Prasad
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
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11
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Decreased Brain pH and Pathophysiology in Schizophrenia. Int J Mol Sci 2021; 22:ijms22168358. [PMID: 34445065 PMCID: PMC8395078 DOI: 10.3390/ijms22168358] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/30/2021] [Accepted: 07/30/2021] [Indexed: 12/26/2022] Open
Abstract
Postmortem studies reveal that the brain pH in schizophrenia patients is lower than normal. The exact cause of this low pH is unclear, but increased lactate levels due to abnormal energy metabolism appear to be involved. Schizophrenia patients display distinct changes in mitochondria number, morphology, and function, and such changes promote anaerobic glycolysis, elevating lactate levels. pH can affect neuronal activity as H+ binds to numerous proteins in the nervous system and alters the structure and function of the bound proteins. There is growing evidence of pH change associated with cognition, emotion, and psychotic behaviors. Brain has delicate pH regulatory mechanisms to maintain normal pH in neurons/glia and extracellular fluid, and a change in these mechanisms can affect, or be affected by, neuronal activities associated with schizophrenia. In this review, we discuss the current understanding of the cause and effect of decreased brain pH in schizophrenia based on postmortem human brains, animal models, and cellular studies. The topic includes the factors causing decreased brain pH in schizophrenia, mitochondria dysfunction leading to altered energy metabolism, and pH effects on the pathophysiology of schizophrenia. We also review the acid/base transporters regulating pH in the nervous system and discuss the potential contribution of the major transporters, sodium hydrogen exchangers (NHEs), and sodium-coupled bicarbonate transporters (NCBTs), to schizophrenia.
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12
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Lizarraga SB, Ma L, Maguire AM, van Dyck LI, Wu Q, Ouyang Q, Kavanaugh BC, Nagda D, Livi LL, Pescosolido MF, Schmidt M, Alabi S, Cowen MH, Brito-Vargas P, Hoffman-Kim D, Gamsiz Uzun ED, Schlessinger A, Jones RN, Morrow EM. Human neurons from Christianson syndrome iPSCs reveal mutation-specific responses to rescue strategies. Sci Transl Med 2021; 13:13/580/eaaw0682. [PMID: 33568516 DOI: 10.1126/scitranslmed.aaw0682] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 06/04/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022]
Abstract
Christianson syndrome (CS), an X-linked neurological disorder characterized by postnatal attenuation of brain growth (postnatal microcephaly), is caused by mutations in SLC9A6, the gene encoding endosomal Na+/H+ exchanger 6 (NHE6). To hasten treatment development, we established induced pluripotent stem cell (iPSC) lines from patients with CS representing a mutational spectrum, as well as biologically related and isogenic control lines. We demonstrated that pathogenic mutations lead to loss of protein function by a variety of mechanisms: The majority of mutations caused loss of mRNA due to nonsense-mediated mRNA decay; however, a recurrent, missense mutation (the G383D mutation) had both loss-of-function and dominant-negative activities. Regardless of mutation, all patient-derived neurons demonstrated reduced neurite growth and arborization, likely underlying diminished postnatal brain growth in patients. Phenotype rescue strategies showed mutation-specific responses: A gene transfer strategy was effective in nonsense mutations, but not in the G383D mutation, wherein residual protein appeared to interfere with rescue. In contrast, application of exogenous trophic factors (BDNF or IGF-1) rescued arborization phenotypes across all mutations. These results may guide treatment development in CS, including gene therapy strategies wherein our data suggest that response to treatment may be dictated by the class of mutation.
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Affiliation(s)
- Sofia B Lizarraga
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.,Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC 29208, USA
| | - Li Ma
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
| | - Abbie M Maguire
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Hassenfeld Child Health Innovation Institute, Brown University, Providence, RI 02912, USA
| | - Laura I van Dyck
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Qing Wu
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA.,Center for Computational Molecular Biology, Brown University, Providence, RI 02912, USA
| | - Qing Ouyang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
| | - Brian C Kavanaugh
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA.,Hassenfeld Child Health Innovation Institute, Brown University, Providence, RI 02912, USA.,Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA
| | - Dipal Nagda
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Liane L Livi
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA
| | - Matthew F Pescosolido
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA.,Hassenfeld Child Health Innovation Institute, Brown University, Providence, RI 02912, USA.,Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA.,Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA.,Hassenfeld Child Health Innovation Institute, Brown University, Providence, RI 02912, USA.,Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA
| | - Shanique Alabi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mara H Cowen
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.,Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC 29208, USA
| | - Paul Brito-Vargas
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.,Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC 29208, USA
| | - Diane Hoffman-Kim
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA.,Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA.,Center for Biomedical Engineering, Brown University, Providence, RI 02912, USA
| | - Ece D Gamsiz Uzun
- Center for Computational Molecular Biology, Brown University, Providence, RI 02912, USA.,Department of Pathology and Laboratory Medicine, Warren Alpert Medical School of Brown University, Providence, RI 02912, USA
| | - Avner Schlessinger
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Richard N Jones
- Quantitative Sciences Program, Department of Psychiatry and Human Behavior and Department of Neurology, Warren Alpert Medical School of Brown University, Providence, RI 02912, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA. .,Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA.,Hassenfeld Child Health Innovation Institute, Brown University, Providence, RI 02912, USA.,Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA
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13
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Impaired Intestinal Sodium Transport in Inflammatory Bowel Disease: From the Passenger to the Driver's Seat. Cell Mol Gastroenterol Hepatol 2021; 12:277-292. [PMID: 33744482 PMCID: PMC8165433 DOI: 10.1016/j.jcmgh.2021.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/22/2022]
Abstract
Although impaired intestinal sodium transport has been described for decades as a ubiquitous feature of inflammatory bowel disease (IBD), whether and how it plays a pivotal role in the ailment has remained uncertain. Our identification of dominant mutations in receptor guanylyl cyclase 2C as a cause of IBD-associated familial diarrhea syndrome brought a shift in the way we envision impaired sodium transport. Is this just a passive collateral effect resulting from intestinal inflammation, or is it a crucial regulator of IBD pathogenesis? This review summarizes the mutational spectrum and underlying mechanisms of monogenic IBD associated with congenital sodium diarrhea. We constructed a model proposing that impaired sodium transport is an upstream pathogenic factor in IBD. The review also synthesized emerging insights from microbiome and animal studies to suggest how sodium malabsorption can serve as a unifying mediator of downstream pathophysiology. Further investigations into the mechanisms underlying salt and water transport in the intestine will provide newer approaches for understanding the ion-microbiome-immune cross-talk that serves as a driver of IBD. Model systems, such as patient-derived enteroids or induced pluripotent stem cell models, are warranted to unravel the role of individual genes regulating sodium transport and to develop more effective epithelial rescue and repair therapies.
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14
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Abstract
Extracellular acidification is a well-known driver of tumorigenesis that has been extensively studied. In contrast, the role of endosomal pH is novel and relatively unexplored. There is emerging evidence from a growing number of studies showing that the pH of endosomal compartments controls proliferation, migration, stemness, and sensitivity to chemoradiation therapy in a variety of tumors. Endosomes are a crucial hub, mediating cellular communication with the external environment. By finely regulating the sorting and trafficking of vesicular cargo for degradation or recycling, endosomal pH determines the fate of plasma membrane proteins, lipids, and extracellular signals including growth factor receptors and their ligands. Several critical regulators of endosomal pH have been identified, including multiple isoforms of the family of electroneutral Na+/H+ exchangers (NHE) such as NHE6 and NHE9. Recent studies have shed light on molecular mechanisms linking endosomal pH to cancer malignancy. Manipulating endosomal pH by epigenetic reprogramming, small molecules, or nanoparticles may offer promising new options in cancer therapy. In this review, we summarize evidence linking endosomal pH to cancer, with a focus on the role of endosomal Na+/H+ exchangers and how they affect the prognosis of cancer patients, and also suggest how regulation of endosomal pH may be exploited to develop new cancer therapies.
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15
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Winklemann I, Matsuoka R, Meier PF, Shutin D, Zhang C, Orellana L, Sexton R, Landreh M, Robinson CV, Beckstein O, Drew D. Structure and elevator mechanism of the mammalian sodium/proton exchanger NHE9. EMBO J 2020; 39:e105908. [PMID: 33118634 PMCID: PMC7737618 DOI: 10.15252/embj.2020105908] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 12/21/2022] Open
Abstract
Na+ /H+ exchangers (NHEs) are ancient membrane-bound nanomachines that work to regulate intracellular pH, sodium levels and cell volume. NHE activities contribute to the control of the cell cycle, cell proliferation, cell migration and vesicle trafficking. NHE dysfunction has been linked to many diseases, and they are targets of pharmaceutical drugs. Despite their fundamental importance to cell homeostasis and human physiology, structural information for the mammalian NHE was lacking. Here, we report the cryogenic electron microscopy structure of NHE isoform 9 (SLC9A9) from Equus caballus at 3.2 Å resolution, an endosomal isoform highly expressed in the brain and associated with autism spectrum (ASD) and attention deficit hyperactivity (ADHD) disorders. Despite low sequence identity, the NHE9 architecture and ion-binding site are remarkably similar to distantly related bacterial Na+ /H+ antiporters with 13 transmembrane segments. Collectively, we reveal the conserved architecture of the NHE ion-binding site, their elevator-like structural transitions, the functional implications of autism disease mutations and the role of phosphoinositide lipids to promote homodimerization that, together, have important physiological ramifications.
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Affiliation(s)
- Iven Winklemann
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
| | - Rei Matsuoka
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
| | - Pascal F Meier
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
| | - Denis Shutin
- Department of ChemistryUniversity of OxfordOxfordUK
| | - Chenou Zhang
- Department of PhysicsCenter for Biological PhysicsArizona State UniversityTempeAZUSA
| | - Laura Orellana
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
| | - Ricky Sexton
- Department of PhysicsCenter for Biological PhysicsArizona State UniversityTempeAZUSA
| | - Michael Landreh
- Department of Microbiology, Tumor and Cell BiologyKarolinska InstituteStockholmSweden
| | | | - Oliver Beckstein
- Department of PhysicsCenter for Biological PhysicsArizona State UniversityTempeAZUSA
| | - David Drew
- Department of Biochemistry and BiophysicsStockholm UniversityStockholmSweden
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16
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Prasad H, Rao R. Endosomal Acid-Base Homeostasis in Neurodegenerative Diseases. Rev Physiol Biochem Pharmacol 2020; 185:195-231. [PMID: 32737755 PMCID: PMC7614123 DOI: 10.1007/112_2020_25] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Neurodegenerative disorders are debilitating and largely untreatable conditions that pose a significant burden to affected individuals and caregivers. Overwhelming evidence supports a crucial preclinical role for endosomal dysfunction as an upstream pathogenic hub and driver in Alzheimer's disease (AD) and related neurodegenerative disorders. We present recent advances on the role of endosomal acid-base homeostasis in neurodegeneration and discuss evidence for converging mechanisms. The strongest genetic risk factor in sporadic AD is the ε4 allele of Apolipoprotein E (ApoE4), which potentiates pre-symptomatic endosomal dysfunction and prominent amyloid beta (Aβ) pathology, although how these pathways are linked mechanistically has remained unclear. There is emerging evidence that the Christianson syndrome protein NHE6 is a prominent ApoE4 effector linking endosomal function to Aβ pathologies. By functioning as a dominant leak pathway for protons, the Na+/H+ exchanger activity of NHE6 limits endosomal acidification and regulates β-secretase (BACE)-mediated Aβ production and LRP1 receptor-mediated Aβ clearance. Pathological endosomal acidification may impact both Aβ generation and clearance mechanisms and emerges as a promising therapeutic target in AD. We also offer our perspective on the complex role of endosomal acid-base homeostasis in the pathogenesis of neurodegeneration and its therapeutic implications for neuronal rescue and repair strategies.
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Affiliation(s)
- Hari Prasad
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India, Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Rajini Rao
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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17
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Patak J, Faraone SV, Zhang-James Y. Sodium hydrogen exchanger 9 NHE9 (SLC9A9) and its emerging roles in neuropsychiatric comorbidity. Am J Med Genet B Neuropsychiatr Genet 2020; 183:289-305. [PMID: 32400953 DOI: 10.1002/ajmg.b.32787] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 12/09/2019] [Accepted: 02/22/2020] [Indexed: 12/16/2022]
Abstract
Variations in SLC9A9 gene expression and protein function are associated with multiple human diseases, which range from Attention-deficit/hyperactivity disorder (ADHD) to glioblastoma multiforme. In an effort to determine the full spectrum of human disease associations with SLC9A9, we performed a systematic review of the literature. We also review SLC9A9's biochemistry, protein structure, and function, as well as its interacting partners with the goal of identifying mechanisms of disease and druggable targets. We report gaps in the literature regarding the genes function along with consistent trends in disease associations that can be used to further research into treating the respective diseases. We report that SLC9A9 has strong associations with neuropsychiatric diseases and various cancers. Interestingly, we find strong overlap in SLC9A9 disease associations and propose a novel role for SLC9A9 in neuropsychiatric comorbidity. In conclusion, SLC9A9 is a multifunctional protein that, through both its endosome regulatory function and its protein-protein interaction network, has the ability to modulate signaling axes, such as the PI3K pathway, among others.
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Affiliation(s)
- Jameson Patak
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA.,College of Medicine, MD Program, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Stephen V Faraone
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA.,Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Yanli Zhang-James
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, New York, USA
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18
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Cao B, Xia Z, Liu C, Fan W, Zhang S, Liu Q, Xiang Z, Zhao A. New Insights into the Structure-Function Relationship of the Endosomal-Type Na +, K +/H + Antiporter NHX6 from Mulberry ( Morus notabilis). Int J Mol Sci 2020; 21:ijms21020428. [PMID: 31936580 PMCID: PMC7014192 DOI: 10.3390/ijms21020428] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 01/05/2020] [Accepted: 01/06/2020] [Indexed: 01/31/2023] Open
Abstract
The endosomal-type Na+, K+/H+ antiporters (NHXs) play important roles in K+, vesicle pH homeostasis, and protein trafficking in plant. However, the structure governing ion transport mechanism and the key residues related to the structure–function of the endosomal-type NHXs remain unclear. Here, the structure-function relationship of the only endosomal-type NHX from mulberry, MnNHX6, was investigated by homology modeling, mutagenesis, and localization analyses in yeast. The ectopic expression of MnNHX6 in arabidopsis and Nhx1 mutant yeast can enhance their salt tolerance. MnNHX6’s three-dimensional structure, established by homology modeling, was supported by empirical, phylogenetic, and experimental data. Structure analysis showed that MnNHX6 contains unusual 13 transmembrane helices, but the structural core formed by TM5-TM12 assembly is conserved. Localization analysis showed that MnNHX6 has the same endosomal localization as yeast Nhx1/VPS44, and Arg402 is important for protein stability of MnNHX6. Mutagenesis analysis demonstrated MnNHX6 contains a conserved cation binding mechanism and a similar charge-compensated pattern as NHE1, but shares a different role in ion selectivity than the vacuolar-type NHXs. These results improve our understanding of the role played by the structure–function related key residues of the plant endosomal-type NHXs, and provide a basis for the ion transport mechanism study of endosomal-type NHXs.
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Affiliation(s)
| | | | | | | | | | | | | | - Aichun Zhao
- Correspondence: ; Tel.: +86-23-6825-1803; Fax: +86-23-6825-1128
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19
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Warnau J, Wöhlert D, Okazaki KI, Yildiz Ö, Gamiz-Hernandez AP, Kaila VRI, Kühlbrandt W, Hummer G. Ion Binding and Selectivity of the Na +/H + Antiporter MjNhaP1 from Experiment and Simulation. J Phys Chem B 2020; 124:336-344. [PMID: 31841344 PMCID: PMC6970264 DOI: 10.1021/acs.jpcb.9b08552] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Cells employ membrane-embedded
antiporter proteins to control their
pH, salt concentration, and volume. The large family of cation/proton
antiporters is dominated by Na+/H+ antiporters
that exchange sodium ions against protons, but homologous K+/H+ exchangers have recently been characterized. We show
experimentally that the electroneutral antiporter NhaP1 of Methanocaldococcus jannaschii (MjNhaP1) is highly selective
for Na+ ions. We then characterize the ion selectivity
in both the inward-open and outward-open states of MjNhaP1 using classical
molecular dynamics simulations, free energy calculations, and hybrid
quantum/classical (QM/MM) simulations. We show that MjNhaP1 is highly
selective for binding of Na+ over K+ in the
inward-open state, yet it is only weakly selective in the outward-open
state. These findings are consistent with the function of MjNhaP1
as a sodium-driven deacidifier of the cytosol that maintains a high
cytosolic K+ concentration in environments of high salinity.
By combining experiment and computation, we gain mechanistic insight
into the Na+/H+ transport mechanism and help
elucidate the molecular basis for ion selectivity in cation/proton
exchangers.
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Affiliation(s)
- Judith Warnau
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , 60438 Frankfurt am Main , Germany.,Department Chemie , Technische Universität München , 85748 Garching , Germany
| | - David Wöhlert
- Department of Structural Biology , Max Planck Institute of Biophysics , 60438 Frankfurt am Main , Germany
| | - Kei-Ichi Okazaki
- Department of Theoretical and Computational Molecular Science, Institute for Molecular Science , National Institutes of Natural Science , Okazaki , 444-8585 , Japan
| | - Özkan Yildiz
- Department of Structural Biology , Max Planck Institute of Biophysics , 60438 Frankfurt am Main , Germany
| | - Ana P Gamiz-Hernandez
- Department Chemie , Technische Universität München , 85748 Garching , Germany.,Department of Biochemistry and Biophysics , Stockholm University , 10691 Stockholm , Sweden
| | - Ville R I Kaila
- Department Chemie , Technische Universität München , 85748 Garching , Germany.,Department of Biochemistry and Biophysics , Stockholm University , 10691 Stockholm , Sweden
| | - Werner Kühlbrandt
- Department of Structural Biology , Max Planck Institute of Biophysics , 60438 Frankfurt am Main , Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics , Max Planck Institute of Biophysics , 60438 Frankfurt am Main , Germany.,Institute of Biophysics , Goethe University Frankfurt , 60438 Frankfurt am Main , Germany
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20
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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21
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Bernardino RL, Carrageta DF, Sousa M, Alves MG, Oliveira PF. pH and male fertility: making sense on pH homeodynamics throughout the male reproductive tract. Cell Mol Life Sci 2019; 76:3783-3800. [PMID: 31165202 PMCID: PMC11105638 DOI: 10.1007/s00018-019-03170-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 04/24/2019] [Accepted: 05/29/2019] [Indexed: 02/07/2023]
Abstract
In the male reproductive tract, ionic equilibrium is essential to maintain normal spermatozoa production and, hence, the reproductive potential. Among the several ions, HCO3- and H+ have a central role, mainly due to their role on pH homeostasis. In the male reproductive tract, the major players in pH regulation and homeodynamics are carbonic anhydrases (CAs), HCO3- membrane transporters (solute carrier 4-SLC4 and solute carrier 26-SLC26 family transporters), Na+-H+ exchangers (NHEs), monocarboxylate transporters (MCTs) and voltage-gated proton channels (Hv1). CAs and these membrane transporters are widely distributed throughout the male reproductive tract, where they play essential roles in the ionic balance of tubular fluids. CAs are the enzymes responsible for the production of HCO3- which is then transported by membrane transporters to ensure the maturation, storage, and capacitation of the spermatozoa. The transport of H+ is carried out by NHEs, Hv1, and MCTs and is essential for the electrochemical balance and for the maintenance of the pH within the physiological limits along the male reproductive tract. Alterations in HCO3- production and transport of ions have been associated with some male reproductive dysfunctions. Herein, we present an up-to-date review on the distribution and role of the main intervenient on pH homeodynamics in the fluids throughout the male reproductive tract. In addition, we discuss their relevance for the establishment of the male reproductive potential.
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Affiliation(s)
- Raquel L Bernardino
- Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar and Unit for Multidisciplinary Research in Biomedicine, University of Porto, Porto, Portugal
| | - David F Carrageta
- Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar and Unit for Multidisciplinary Research in Biomedicine, University of Porto, Porto, Portugal
| | - Mário Sousa
- Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar and Unit for Multidisciplinary Research in Biomedicine, University of Porto, Porto, Portugal
| | - Marco G Alves
- Institute of Biomedical Sciences Abel Salazar and Unit for Multidisciplinary Research in Biomedicine, University of Porto, Porto, Portugal
| | - Pedro F Oliveira
- Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar and Unit for Multidisciplinary Research in Biomedicine, University of Porto, Porto, Portugal.
- i3S-Institute for Innovation and Health Research, University of Porto, Porto, Portugal.
- Department of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal.
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22
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Pall AE, Juratli L, Guntur D, Bandyopadhyay K, Kondapalli KC. A gain of function paradox: Targeted therapy for glioblastoma associated with abnormal NHE9 expression. J Cell Mol Med 2019; 23:7859-7872. [PMID: 31532058 PMCID: PMC6815843 DOI: 10.1111/jcmm.14665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/13/2019] [Accepted: 08/13/2019] [Indexed: 01/16/2023] Open
Abstract
Glioblastoma (GBM) is the most frequent and inevitably lethal primary brain cancer in adults. It is recognized that the overexpression of the endosomal Na+ /H+ exchanger NHE9 is a potent driver of GBM progression. Patients with NHE9 overexpression have a threefold lower median survival relative to GBM patients with normal NHE9 expression, using available treatment options. New treatment strategies tailored for this GBM subset are much needed. According to the prevailing model, NHE9 overexpression leads to an increase in plasma membrane density of epidermal growth factor receptors (EGFRs) which consequently enhances GBM cell proliferation and migration. However, this increase is not specific to EGFRs. In fact, the hallmark of NHE9 overexpression is a pan-specific increase in plasma membrane receptors. Paradoxically, we report that this gain of function in NHE9 can be exploited to effectively target GBM cells for destruction. When exposed to gold nanoparticles, NHE9 overexpressing GBM cells accumulated drastically high amounts of gold via receptor-mediated endocytosis, relative to control. Irradiation of these cells with near-infrared light led to apoptotic tumour cell death. A major limitation for delivering therapeutics to GBM cells is the blood-brain barrier (BBB). Here, we demonstrate that macrophages loaded with gold nanoparticles can cross the BBB, deliver the gold nanoparticles and effect the demise of GBM cells. In combination with receptor tyrosine kinase inhibition, we show this approach holds great promise for a new GBM-targeted therapy.
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Affiliation(s)
- Ashley E Pall
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
| | - Lena Juratli
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
| | - Dhyana Guntur
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
| | | | - Kalyan C Kondapalli
- Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI, USA
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23
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Vilidaite G, Norcia AM, West RJH, Elliott CJH, Pei F, Wade AR, Baker DH. Autism sensory dysfunction in an evolutionarily conserved system. Proc Biol Sci 2019; 285:20182255. [PMID: 30963913 PMCID: PMC6304042 DOI: 10.1098/rspb.2018.2255] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
There is increasing evidence for a strong genetic basis for autism, with many genetic models being developed in an attempt to replicate autistic symptoms in animals. However, current animal behaviour paradigms rarely match the social and cognitive behaviours exhibited by autistic individuals. Here, we instead assay another functional domain—sensory processing—known to be affected in autism to test a novel genetic autism model in Drosophila melanogaster. We show similar visual response alterations and a similar development trajectory in Nhe3 mutant flies (total n = 72) and in autistic human participants (total n = 154). We report a dissociation between first- and second-order electrophysiological visual responses to steady-state stimulation in adult mutant fruit flies that is strikingly similar to the response pattern in human adults with ASD as well as that of a large sample of neurotypical individuals with high numbers of autistic traits. We explain this as a genetically driven, selective signalling alteration in transient visual dynamics. In contrast to adults, autistic children show a decrease in the first-order response that is matched by the fruit fly model, suggesting that a compensatory change in processing occurs during development. Our results provide the first animal model of autism comprising a differential developmental phenotype in visual processing.
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Affiliation(s)
- Greta Vilidaite
- 1 Department of Psychology, Stanford University , Stanford, CA 94305 , USA
| | - Anthony M Norcia
- 1 Department of Psychology, Stanford University , Stanford, CA 94305 , USA
| | - Ryan J H West
- 3 Department of Biology, University of York , York YO10 5DD , UK
| | | | - Francesca Pei
- 2 Department of Psychiatry, Stanford University , Stanford, CA 94305 , USA
| | - Alex R Wade
- 3 Department of Biology, University of York , York YO10 5DD , UK.,4 Department of Psychology, University of York , York YO10 5DD , UK
| | - Daniel H Baker
- 4 Department of Psychology, University of York , York YO10 5DD , UK
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24
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Tamtaji OR, Mirzaei H, Shamshirian A, Shamshirian D, Behnam M, Asemi Z. New trends in glioma cancer therapy: Targeting Na + /H + exchangers. J Cell Physiol 2019; 235:658-665. [PMID: 31250444 DOI: 10.1002/jcp.29014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 06/10/2019] [Indexed: 12/20/2022]
Abstract
Glioma is the oneof the most prevalent primarybrain tumors. There is a variety of oxidative stresses, inflammatory pathways, apoptosis signaling, and Na+ /H + exchangers (NHEs) involved in the pathophysiology of glioma. Previous studies have indicated a relationship between NHEs and some molecular pathways in glioma. NHEs, including NHE1, NHE5, and NHE9 affect apoptosis, tumor-associated macrophage inflammatory pathways, matrix metalloproteinases, cancer-cell growth, invasion, and migration of glioma. Also, inhibition of NHEs contributes to increased survival in animal models of glioma. Limited studies, however, have assessed the relationship between NHEs and molecular pathways in glioma. This review summarizes current knowledge and evidence regarding the relationship between NHEs and glioma, and the mechanisms involved.
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Affiliation(s)
- Omid Reza Tamtaji
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
| | - Amir Shamshirian
- Department of Medical Laboratory Sciences, Student Research Committee, School of Allied Medical Sciences, Mazandaran University of Medical Sciences, Sari, Iran
| | - Danial Shamshirian
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran
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25
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Katz M, Corson F, Keil W, Singhal A, Bae A, Lu Y, Liang Y, Shaham S. Glutamate spillover in C. elegans triggers repetitive behavior through presynaptic activation of MGL-2/mGluR5. Nat Commun 2019; 10:1882. [PMID: 31015396 PMCID: PMC6478929 DOI: 10.1038/s41467-019-09581-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 03/20/2019] [Indexed: 01/08/2023] Open
Abstract
Glutamate is a major excitatory neurotransmitter, and impaired glutamate clearance following synaptic release promotes spillover, inducing extra-synaptic signaling. The effects of glutamate spillover on animal behavior and its neural correlates are poorly understood. We developed a glutamate spillover model in Caenorhabditis elegans by inactivating the conserved glial glutamate transporter GLT-1. GLT-1 loss drives aberrant repetitive locomotory reversal behavior through uncontrolled oscillatory release of glutamate onto AVA, a major interneuron governing reversals. Repetitive glutamate release and reversal behavior require the glutamate receptor MGL-2/mGluR5, expressed in RIM and other interneurons presynaptic to AVA. mgl-2 loss blocks oscillations and repetitive behavior; while RIM activation is sufficient to induce repetitive reversals in glt-1 mutants. Repetitive AVA firing and reversals require EGL-30/Gαq, an mGluR5 effector. Our studies reveal that cyclic autocrine presynaptic activation drives repetitive reversals following glutamate spillover. That mammalian GLT1 and mGluR5 are implicated in pathological motor repetition suggests a common mechanism controlling repetitive behaviors. Katz and colleagues examine glutamate spillover effects on C. elegans behaviour. They show that impaired synaptic glutamate clearance in glial glutamate transporter mutants, causes presynaptic mgl-2/mGluR5 activation, generating postsynaptic neural activity oscillations driving repetitive behaviour.
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Affiliation(s)
- Menachem Katz
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Francis Corson
- Laboratoire de Physique Statistique, Ecole Normale Supérieure, CNRS, Université Pierre et Marie Curie, Université Paris Diderot, 75005, Paris, France
| | - Wolfgang Keil
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.,Center for Studies in Physics and Biology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Anupriya Singhal
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Andrea Bae
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Yun Lu
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Yupu Liang
- Research Bioinformatics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
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26
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Zhang-James Y, Vaudel M, Mjaavatten O, Berven FS, Haavik J, Faraone SV. Effect of disease-associated SLC9A9 mutations on protein-protein interaction networks: implications for molecular mechanisms for ADHD and autism. ACTA ACUST UNITED AC 2019; 11:91-105. [PMID: 30927234 DOI: 10.1007/s12402-018-0281-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/27/2018] [Indexed: 12/20/2022]
Abstract
Na+/H+ Exchanger 9 (NHE9) is an endosomal membrane protein encoded by the Solute Carrier 9A, member 9 gene (SLC9A9). SLC9A9 has been implicated in attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), epilepsy, multiple sclerosis and cancers. To better understand the function of NHE9 and the effects of disease-associated variants on protein-protein interactions, we conducted a quantitative analysis of the NHE9 interactome using co-immunoprecipitation and isobaric labeling-based quantitative mass spectrometry. We identified 100 proteins that interact with NHE9. These proteins were enriched in known functional pathways for NHE9: the endocytosis, protein ubiquitination and phagosome pathways, as well as some novel pathways including oxidative stress, mitochondrial dysfunction, mTOR signaling, cell death and RNA processing pathways. An ADHD-associated mutation (A409P) significantly altered NHE9's interactions with a subset of proteins involved in caveolae-mediated endocytosis and MAP2K2-mediated downstream signaling. An ASD nonsense mutation in SLC9A9, R423X, produced no-detectable amount of NHE9, suggesting the overall loss of NHE9 functional networks. In addition, seven of the NHE9 interactors are products of known autism candidate genes (Simons Foundation Autism Research Initiative, SFARI Gene) and 90% of the NHE9 interactome overlap with SFARI protein interaction network PIN (p < 0.0001), supporting the role of NHE9 interactome in ASDs molecular mechanisms. Our results provide a detailed understanding of the functions of protein NHE9 and its disrupted interactions, possibly underlying ADHD and ASDs. Furthermore, our methodological framework proved useful for functional characterization of disease-associated genetic variants and suggestion of druggable targets.
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Affiliation(s)
- Yanli Zhang-James
- Departments of Psychiatry, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Marc Vaudel
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Olav Mjaavatten
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Frode S Berven
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Jan Haavik
- Department of Biomedicine, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.,Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Stephen V Faraone
- Departments of Psychiatry, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, 13210, USA. .,Neuroscience and Physiology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, 13210, USA.
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27
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Zhang L, Qin Y, Gong X, Peng R, Cai C, Zheng Y, Du Y, Wang H. A promoter variant in ZNF804A decreasing its expression increases the risk of autism spectrum disorder in the Han Chinese population. Transl Psychiatry 2019; 9:31. [PMID: 30670685 PMCID: PMC6342935 DOI: 10.1038/s41398-019-0369-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/10/2018] [Accepted: 01/02/2019] [Indexed: 12/15/2022] Open
Abstract
Synaptic pathology may be one of the cellular substrates underlying autism spectrum disorder (ASD). ZNF804A is a transcription factor that can affect or regulate the expression of many candidate genes involved in ASD. It also localizes at synapses and regulates neuronal and synaptic morphology. So far, few reports have addressed possible associations between ZNF804A polymorphisms and ASD. This study aimed to investigate whether ZNF804A genetic variants contribute to ASD susceptibility and its possible pathological role in the disorder. We analyzed the relationship of two polymorphisms (rs10497655 and rs34714481) in ZNF804A promoter region with ASD in 854 cases versus 926 controls. The functional analyses of rs10497655 were then performed using real-time quantitative polymerase chain reaction, electrophoretic mobility shift assays, chromatin immunoprecipitation and dual-luciferase assays. The variant rs10497655 was significantly associated with ASD (P = 0.007851), which had a significant effect on ZNF804A expression, with the T risk allele homozygotes related with reduced ZNF804A expression in human fetal brains. HSF2 acted as a suppressor by down-regulating ZNF804A expression and had a stronger binding affinity for the T allele of rs10497655 than for the C allele. This was the first experiment to elucidate the process in which a disease-associated SNP affects the level of ZNF804A expression by binding with the upstream regulation factor HSF2. This result indicates that the rs10497655 allelic expression difference of ZNF804A during the critical period of brain development may have an effect on postnatal phenotypes of ASD. It reveals new roles of ZNF804A polymorphisms in the pathogenesis of psychiatric disorders.
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Affiliation(s)
- Linna Zhang
- Department of Child & Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China
| | - Yue Qin
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Institute of Reproduction and Development, Fudan University, Shanghai, 200011, China
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xiaohong Gong
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Institute of Reproduction and Development, Fudan University, Shanghai, 200011, China
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Rui Peng
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Institute of Reproduction and Development, Fudan University, Shanghai, 200011, China
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Chunquan Cai
- Department of Neurosurgery, Tianjin Children's Hospital, Tianjin, 300134, China
| | - Yufang Zheng
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Institute of Reproduction and Development, Fudan University, Shanghai, 200011, China
| | - Yasong Du
- Department of Child & Adolescent Psychiatry, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China.
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Institute of Reproduction and Development, Fudan University, Shanghai, 200011, China.
- Key Laboratory of Reproduction Regulation of NPFPC, Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, 200032, China.
- Children's Hospital of Fudan University, Shanghai, 201102, China.
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28
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Amyloid clearance defect in ApoE4 astrocytes is reversed by epigenetic correction of endosomal pH. Proc Natl Acad Sci U S A 2018; 115:E6640-E6649. [PMID: 29946028 DOI: 10.1073/pnas.1801612115] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Endosomes have emerged as a central hub and pathogenic driver of Alzheimer's disease (AD). The earliest brain cytopathology in neurodegeneration, occurring decades before amyloid plaques and cognitive decline, is an expansion in the size and number of endosomal compartments. The strongest genetic risk factor for sporadic AD is the ε4 allele of Apolipoprotein E (ApoE4). Previous studies have shown that ApoE4 potentiates presymptomatic endosomal dysfunction and defective endocytic clearance of amyloid beta (Aβ), although how these two pathways are linked at a cellular and mechanistic level has been unclear. Here, we show that aberrant endosomal acidification in ApoE4 astrocytes traps the low-density lipoprotein receptor-related protein (LRP1) within intracellular compartments, leading to loss of surface expression and Aβ clearance. Pathological endosome acidification is caused by ε4 risk allele-selective down-regulation of the Na+/H+ exchanger isoform NHE6, which functions as a critical leak pathway for endosomal protons. In vivo, the NHE6 knockout (NHE6KO) mouse model showed elevated Aβ in the brain, consistent with a causal effect. Increased nuclear translocation of histone deacetylase 4 (HDAC4) in ApoE4 astrocytes, compared with the nonpathogenic ApoE3 allele, suggested a mechanistic basis for transcriptional down-regulation of NHE6. HDAC inhibitors that restored NHE6 expression normalized ApoE4-specific defects in endosomal pH, LRP1 trafficking, and amyloid clearance. Thus, NHE6 is a downstream effector of ApoE4 and emerges as a promising therapeutic target in AD. These observations have prognostic implications for patients who have Christianson syndrome with loss of function mutations in NHE6 and exhibit prominent glial pathology and progressive hallmarks of neurodegeneration.
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29
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Selby LI, Aurelio L, Yuen D, Graham B, Johnston APR. Quantifying Cellular Internalization with a Fluorescent Click Sensor. ACS Sens 2018; 3:1182-1189. [PMID: 29676153 DOI: 10.1021/acssensors.8b00219] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ability to determine the amount of material endocytosed by a cell is important for our understanding of cell biology and in the design of effective carriers for drug delivery. To quantify internalization by fluorescence, the signal from material remaining on the cell surface must be differentiated from endocytosed material. Sensors for internalization offer advantages over traditional methods for achieving this as they exhibit improved sensitivity, allow for multiple fluorescent markers to be used simultaneously, and are amenable to high-throughput analysis. We have developed a small fluorescent internalization sensor, similar in size to a standard fluorescent dye, that can be conjugated to proteins and uses the rapid and highly specific bio-orthogonal reaction between a tetrazine and a trans-cyclooctene group to switch off the surface signal. The sensor can be attached to a variety of materials using simple chemistry and is compatible with flow cytometry and fluorescence microscopy, making it a useful tool to study the uptake of material into cells.
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Affiliation(s)
- Laura I. Selby
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria 3052, Australia
| | - Luigi Aurelio
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Daniel Yuen
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Bim Graham
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Angus P. R. Johnston
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University, Parkville, Victoria 3052, Australia
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30
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Fan L, Zhao L, Hu W, Li W, Novák O, Strnad M, Simon S, Friml J, Shen J, Jiang L, Qiu QS. Na + ,K + /H + antiporters regulate the pH of endoplasmic reticulum and auxin-mediated development. PLANT, CELL & ENVIRONMENT 2018; 41:850-864. [PMID: 29360148 DOI: 10.1111/pce.13153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 11/30/2017] [Accepted: 01/17/2018] [Indexed: 06/07/2023]
Abstract
AtNHX5 and AtNHX6 are endosomal Na+ ,K+ /H+ antiporters that are critical for growth and development in Arabidopsis, but the mechanism behind their action remains unknown. Here, we report that AtNHX5 and AtNHX6, functioning as H+ leak, control auxin homeostasis and auxin-mediated development. We found that nhx5 nhx6 exhibited growth variations of auxin-related defects. We further showed that nhx5 nhx6 was affected in auxin homeostasis. Genetic analysis showed that AtNHX5 and AtNHX6 were required for the function of the endoplasmic reticulum (ER)-localized auxin transporter PIN5. Although AtNHX5 and AtNHX6 were colocalized with PIN5 at ER, they did not interact directly. Instead, the conserved acidic residues in AtNHX5 and AtNHX6, which are essential for exchange activity, were required for PIN5 function. AtNHX5 and AtNHX6 regulated the pH in ER. Overall, AtNHX5 and AtNHX6 may regulate auxin transport across the ER via the pH gradient created by their transport activity. H+ -leak pathway provides a fine-tuning mechanism that controls cellular auxin fluxes.
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Affiliation(s)
- Ligang Fan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Lei Zhao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Wei Hu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Weina Li
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
| | - Ondřej Novák
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR and Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR and Palacký University, Šlechtitelů 27, CZ-78371, Olomouc, Czech Republic
| | - Sibu Simon
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic
| | - Jiří Friml
- Institute of Science and Technology (IST) Austria, Am Campus 1, 3400, Klosterneuburg, Austria
| | - Jinbo Shen
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
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Clémençon B, Lüscher BP, Hediger MA. Establishment of a novel microscale thermophoresis ligand-binding assay for characterization of SLC solute carriers using oligopeptide transporter PepT1 (SLC15 family) as a model system. J Pharmacol Toxicol Methods 2018; 92:67-76. [PMID: 29580877 DOI: 10.1016/j.vascn.2018.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 03/05/2018] [Accepted: 03/14/2018] [Indexed: 10/17/2022]
Abstract
INTRODUCTION Membrane proteins represent roughly one third of the human proteome and many of them serve as targets of therapeutic drugs. An exception is the SLC solute carrier superfamily with only a handful of approved drugs targeting SLCs. Indeed, for many of the SLCs, the natural transport substrates are still unknown. A major limitation for SLCs has been the difficulty to thoroughly characterize these multimembrane spanning proteins. The intrinsic properties of membrane proteins with alternative hydrophobic and hydrophilic domains lead to instability, making the purification tasks even more challenging compared to soluble proteins. This issue also holds true for conventional ligand-binding assays (LBAs) which usually require high-quality, pure and concentrated protein samples. Herein, we report a novel binding assay strategy to overcome these issues, taking advantage of a unique combination of yeast expression and microscale thermophoresis (MST). Following yeast overexpression of SLC15A1/PepT1 ortholog from moss Physcomitrella patens, PepTPp, which exhibits remarkable similarity to human PepT1, the approach was validated using dipeptide glycylsarcosine (Gly-Sar) and antiviral prodrug valacyclovir as test substrates. METHOD The originality of our approach is based on the comparative analysis of solubilized total membrane preparations with or without expression of the SLC target of interest, using a yeast strain (S. cerevisiae), in which the corresponding endogenous SLC homolog is depleted. MST is a recently developed technique that takes advantage of the properties of biomolecules in solution to migrate along a temperature gradient. Importantly, this migration is affected by substrate binding. It is being monitored by fluorescence using labelled SLC molecules in the presence of different ligand concentrations. RESULTS We herein report a novel MST/yeast-based method to characterize binding of ligands to SLCs without the need for a prior SLC-purification step. For validation purposes, we used a close eukaryotic homolog of the human H+-coupled oligopeptide transporter PepT1 (SLC15A1) that mediates uptake of di-tripeptides and peptide-like drugs as a test model. This approach allowed the successful confirmation of the binding of Gly-Sar at the mM range and revealed for the first time the KD of the antiviral prodrug valacyclovir to the PepT1 homolog at around 50 μM. DISCUSSION This novel LBA approach is independent of protein purification. It is suitable for drug discovery as it is upscalable to high throughput compound screening. It works well for SLC transporters which are underrepresented targets due to their difficulties to study them. Moreover, this approach could make a significant contribution toward "deorphanization" of SLCs, revealing their transport substrates.
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Affiliation(s)
- Benjamin Clémençon
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland.
| | - Benjamin P Lüscher
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Matthias A Hediger
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland.
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32
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Karim MA, Brett CL. The Na +(K +)/H + exchanger Nhx1 controls multivesicular body-vacuolar lysosome fusion. Mol Biol Cell 2018; 29:317-325. [PMID: 29212874 PMCID: PMC5996954 DOI: 10.1091/mbc.e17-08-0496] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 11/07/2017] [Accepted: 11/28/2017] [Indexed: 01/12/2023] Open
Abstract
Loss-of-function mutations in human endosomal Na+(K+)/H+ exchangers (NHEs) NHE6 and NHE9 are implicated in neurological disorders including Christianson syndrome, autism, and attention deficit and hyperactivity disorder. These mutations disrupt retention of surface receptors within neurons and glial cells by affecting their delivery to lysosomes for degradation. However, the molecular basis of how these endosomal NHEs control endocytic trafficking is unclear. Using Saccharomyces cerevisiae as a model, we conducted cell-free organelle fusion assays to show that transport activity of the orthologous endosomal NHE Nhx1 is important for multivesicular body (MVB)-vacuolar lysosome fusion, the last step of endocytosis required for surface protein degradation. We find that deleting Nhx1 disrupts the fusogenicity of the MVB, not the vacuole, by targeting pH-sensitive machinery downstream of the Rab-GTPase Ypt7 needed for SNARE-mediated lipid bilayer merger. All contributing mechanisms are evolutionarily conserved offering new insight into the etiology of human disorders linked to loss of endosomal NHE function.
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A mouse model of autism implicates endosome pH in the regulation of presynaptic calcium entry. Nat Commun 2018; 9:330. [PMID: 29362376 PMCID: PMC5780507 DOI: 10.1038/s41467-017-02716-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/19/2017] [Indexed: 11/21/2022] Open
Abstract
Psychoactive compounds such as chloroquine and amphetamine act by dissipating the pH gradient across intracellular membranes, but the physiological mechanisms that normally regulate organelle pH remain poorly understood. Interestingly, recent human genetic studies have implicated the endosomal Na+/H+ exchanger NHE9 in both autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD). Plasma membrane NHEs regulate cytosolic pH, but the role of intracellular isoforms has remained unclear. We now find that inactivation of NHE9 in mice reproduces behavioral features of ASD including impaired social interaction, repetitive behaviors, and altered sensory processing. Physiological characterization reveals hyperacidic endosomes, a cell-autonomous defect in glutamate receptor expression and impaired neurotransmitter release due to a defect in presynaptic Ca2+ entry. Acute inhibition of synaptic vesicle acidification rescues release but without affecting the primary defect due to loss of NHE9. The Na+/H+ exchanger NHE9 is proposed to regulate the H+ electrochemical gradient across endosomal membranes. Here, the authors find that NHE9 knockout mice show autism spectrum disorder-like behaviors and disrupted synaptic vesicle exocytosis due to impaired presynaptic calcium entry.
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Gomez Zubieta DM, Hamood MA, Beydoun R, Pall AE, Kondapalli KC. MicroRNA-135a regulates NHE9 to inhibit proliferation and migration of glioblastoma cells. Cell Commun Signal 2017; 15:55. [PMID: 29268774 PMCID: PMC5740897 DOI: 10.1186/s12964-017-0209-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 12/08/2017] [Indexed: 12/13/2022] Open
Abstract
Background Glioblastoma multiformae (GBM) is the most aggressive type of malignant brain tumor with complex molecular profile. Overexpression of Na+/H+ Exchanger isoform 9 (NHE9) promotes tumor progression and correlates positively with insensitivity to radiochemotherapy and poor prognosis. However, molecular mechanisms responsible for increase in NHE9 levels beyond a critical threshold have not been identified. Methods Bioinformatics analysis, luciferase reporter assays, real-time PCR and western blotting were conducted to examine the expression profiles and identify microRNAs (miRNA) that target NHE9. Cell proliferation and migration assays were conducted in U87 glioblastoma cells to determine the consequence of miRNA mediated targeting of NHE9. Endosomal pH measurements, immunofluorescence microscopy and surface biotinylation experiments were conducted to characterize the mechanistic basis of regulation. Results We show that microRNA 135a (miR-135a) targets NHE9 to downregulate its expression in U87 cells. MiR-135a levels are significantly lower in glioblastoma cells compared to normal brain tissue. Downregulation of NHE9 expression by miR-135a affects proliferative and migratory capacity of U87 cells. Selectively increasing NHE9 expression in these cells restored their ability to proliferate and migrate. We demonstrate that miR-135a takes a two-pronged approach affecting epidermal growth factor receptors (EGFRs) to suppress tumor cell growth and migration. EGFR activity is a potent stimulator of oncogenic signaling. While miR-135a targets EGFR transcripts to decrease the total number of receptors made, by targeting NHE9 it routes the few EGFRs made away from the plasma membrane to dampen oncogenic signaling. NHE9 is localized to sorting endosomes in glioblastoma cells where it alkalinizes the endosome lumen by leaking protons. Downregulation of NHE9 expression by miR-135a acidifies sorting endosomes limiting EGFR trafficking to the glioblastoma cell membrane. Conclusions We propose downregulation of miR-135a as a potential mechanism underlying the high NHE9 expression observed in subset of glioblastomas. Future studies should explore miR-135a as a potential therapeutic for glioblastomas with NHE9 overexpression. Electronic supplementary material The online version of this article (10.1186/s12964-017-0209-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniela M Gomez Zubieta
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, SFC # 207, Dearborn, MI, 48128, USA
| | - Mohamed A Hamood
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, SFC # 207, Dearborn, MI, 48128, USA
| | - Rami Beydoun
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, SFC # 207, Dearborn, MI, 48128, USA
| | - Ashley E Pall
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, SFC # 207, Dearborn, MI, 48128, USA
| | - Kalyan C Kondapalli
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Road, SFC # 207, Dearborn, MI, 48128, USA.
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Nishizawa D, Mieda T, Tsujita M, Nakagawa H, Yamaguchi S, Kasai S, Hasegawa J, Fukuda KI, Kitamura A, Hayashida M, Ikeda K. Genome-wide scan identifies candidate loci related to remifentanil requirements during laparoscopic-assisted colectomy. Pharmacogenomics 2017; 19:113-127. [PMID: 29207912 DOI: 10.2217/pgs-2017-0109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
AIM Opioids are widely used as effective analgesics, but opioid sensitivity is well known to vary widely among individuals. We explored the genetic factors that contribute to individual differences in intraoperative opioid sensitivity by performing a genome-wide association study. PATIENTS & METHODS We conducted a multistage genome-wide association study in subjects who underwent laparoscopic-assisted colectomy. RESULTS A nonsynonymous SNP, rs199670311, within the TMEM8A gene region and intronic SNPs, including rs4839603, within the SLC9A9 gene region were significantly associated with intraoperative opioid requirements (p = 3.409 × 10-8 in the dominant model for rs199670311; p = 4.162 × 10-6 and p = 4.229 × 10-6 in the additive and recessive models, respectively, for rs4839603). The A and T alleles of the rs199670311 and rs4839603 SNPs, respectively, were associated with lower opioid sensitivity in patients. CONCLUSION Our findings provide valuable information for personalized pain treatment during laparoscopic-assisted colectomy.
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Affiliation(s)
- Daisuke Nishizawa
- Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Tsutomu Mieda
- Department of Anesthesiology, Saitama Medical University Hospital, 38, Morohongo Moroyama-machi, Iruma-gun, Saitama 350-0495, Japan
| | - Miki Tsujita
- Department of Anesthesiology, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan
| | - Hideyuki Nakagawa
- Department of Anesthesiology, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan
| | - Shigeki Yamaguchi
- Department of Gastroenterological Surgery, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan
| | - Shinya Kasai
- Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Junko Hasegawa
- Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Ken-Ichi Fukuda
- Department of Oral Health & Clinical Science, Tokyo Dental College, 2-9-18, Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan
| | - Akira Kitamura
- Department of Anesthesiology, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan
| | - Masakazu Hayashida
- Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.,Department of Anesthesiology, Saitama Medical University International Medical Center, 1397-1, Yamane, Hidaka, Saitama 350-1298, Japan.,Department of Anesthesiology & Pain Medicine, Juntendo University School of Medicine, 2-1-1, Hongou, Bunkyou-ku, Tokyo 113-8421, Japan
| | - Kazutaka Ikeda
- Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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Chen X, Long F, Cai B, Chen X, Chen G. A novel relationship for schizophrenia, bipolar and major depressive disorder Part 3: Evidence from chromosome 3 high density association screen. J Comp Neurol 2017; 526:59-79. [PMID: 28856687 DOI: 10.1002/cne.24311] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 12/30/2022]
Abstract
Familial clustering of schizophrenia (SCZ), bipolar disorder (BPD), and major depressive disorder (MDD) was systematically reported (Aukes et al, Genet Med 2012, 14, 338-341) and convergent evidence from genetics, symptomatology, and psychopharmacology imply that there are intrinsic connections between these three major psychiatric disorders, for example, any two or even three of these disorders could co-exist in some families. A total of 60, 838 single-nucleotide polymorphisms (SNPs) on chromosome 3 were genotyped by Affymetrix Genome-Wide Human SNP array 6.0 on 119 SCZ, 253 BPD (type-I), 177 MDD patients and 1,000 controls. The population of Shandong province was formed in 14 century and believed that it belongs to homogenous population. Associated SNPs were systematically revealed and outstanding susceptibility genes (CADPS, GRM7,KALRN, LSAMP, NLGN1, PRICKLE2, ROBO2) were identified. Unexpectedly, flanking genes for the associated SNPs distinctive for BPD and/or MDD were replicated in an enlarged cohort of 986 SCZ patients. The evidence from this chromosome 3 analysis supports the notion that both of bipolar and MDD might be subtypes of schizophrenia rather than independent disease entity. Also, a similar finding was detected on chromosome 5, 6, 7, and 8 (Chen et al. Am J Transl Res 2017;9 (5):2473-2491; Curr Mol Med 2016;16(9):840-854; Behav Brain Res 2015;293:241-251; Mol Neurobiol 2016. doi: 10.1007/s12035-016-0102-1). Furthermore, PRICKLE2 play an important role in the pathogenesis of three major psychoses in this population.
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Affiliation(s)
- Xing Chen
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
| | - Feng Long
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
| | - Bin Cai
- CapitalBio corporation, Beijing, People's Republic of China
| | - Xiaohong Chen
- CapitalBio corporation, Beijing, People's Republic of China
| | - Gang Chen
- Department of Medical Genetics, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan, Shandong, People's Republic of China
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Ma L, Ouyang Q, Werthmann GC, Thompson HM, Morrow EM. Live-cell Microscopy and Fluorescence-based Measurement of Luminal pH in Intracellular Organelles. Front Cell Dev Biol 2017; 5:71. [PMID: 28871281 PMCID: PMC5566985 DOI: 10.3389/fcell.2017.00071] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 08/04/2017] [Indexed: 11/16/2022] Open
Abstract
Luminal pH is an important functional feature of intracellular organelles. Acidification of the lumen of organelles such as endosomes, lysosomes, and the Golgi apparatus plays a critical role in fundamental cellular processes. As such, measurement of the luminal pH of these organelles has relevance to both basic research and translational research. At the same time, accurate measurement of intraorganellar pH in living cells can be challenging and may be a limiting hurdle for research in some areas. Here, we describe three powerful methods to measure rigorously the luminal pH of different intracellular organelles, focusing on endosomes, lysosomes, and the Golgi apparatus. The described methods are based on live imaging of pH-sensitive fluorescent probes and include: (1) A protocol based on quantitative, ratiometric measurement of endocytosis of pH-sensitive and pH-insensitive fluorescent conjugates of transferrin; (2) A protocol for the use of proteins tagged with a ratiometric variant of the pH-sensitive intrinsically fluorescent protein pHluorin; and (3) A protocol using the fluorescent dye LysoSensor™. We describe necessary reagents, key procedures, and methods and equipment for data acquisition and analysis. Examples of implementation of the protocols are provided for cultured cells derived from a cancer cell line and for primary cultures of mouse hippocampal neurons. In addition, we present strengths and weaknesses of the different described intraorganellar pH measurement methods. These protocols are likely to be of benefit to many researchers, from basic scientists to those conducting translational research with a focus on diseases in patient-derived cells.
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Affiliation(s)
- Li Ma
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidence, RI, United States.,Brown Institute for Brain Science, Brown UniversityProvidence, RI, United States
| | - Qing Ouyang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidence, RI, United States.,Brown Institute for Brain Science, Brown UniversityProvidence, RI, United States
| | - Gordon C Werthmann
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidence, RI, United States
| | - Heather M Thompson
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidence, RI, United States.,Brown Institute for Brain Science, Brown UniversityProvidence, RI, United States.,Hassenfeld Child Health Innovation Institute, Brown UniversityProvidence, RI, United States
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidence, RI, United States.,Brown Institute for Brain Science, Brown UniversityProvidence, RI, United States.,Hassenfeld Child Health Innovation Institute, Brown UniversityProvidence, RI, United States
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38
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Lu Q, Powles RL, Abdallah S, Ou D, Wang Q, Hu Y, Lu Y, Liu W, Li B, Mukherjee S, Crane PK, Zhao H. Systematic tissue-specific functional annotation of the human genome highlights immune-related DNA elements for late-onset Alzheimer's disease. PLoS Genet 2017; 13:e1006933. [PMID: 28742084 PMCID: PMC5546707 DOI: 10.1371/journal.pgen.1006933] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 08/07/2017] [Accepted: 07/18/2017] [Indexed: 12/31/2022] Open
Abstract
Continuing efforts from large international consortia have made genome-wide epigenomic and transcriptomic annotation data publicly available for a variety of cell and tissue types. However, synthesis of these datasets into effective summary metrics to characterize the functional non-coding genome remains a challenge. Here, we present GenoSkyline-Plus, an extension of our previous work through integration of an expanded set of epigenomic and transcriptomic annotations to produce high-resolution, single tissue annotations. After validating our annotations with a catalog of tissue-specific non-coding elements previously identified in the literature, we apply our method using data from 127 different cell and tissue types to present an atlas of heritability enrichment across 45 different GWAS traits. We show that broader organ system categories (e.g. immune system) increase statistical power in identifying biologically relevant tissue types for complex diseases while annotations of individual cell types (e.g. monocytes or B-cells) provide deeper insights into disease etiology. Additionally, we use our GenoSkyline-Plus annotations in an in-depth case study of late-onset Alzheimer's disease (LOAD). Our analyses suggest a strong connection between LOAD heritability and genetic variants contained in regions of the genome functional in monocytes. Furthermore, we show that LOAD shares a similar localization of SNPs to monocyte-functional regions with Parkinson's disease. Overall, we demonstrate that integrated genome annotations at the single tissue level provide a valuable tool for understanding the etiology of complex human diseases. Our GenoSkyline-Plus annotations are freely available at http://genocanyon.med.yale.edu/GenoSkyline.
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Affiliation(s)
- Qiongshi Lu
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Ryan L. Powles
- Program of Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut, United States of America
| | - Sarah Abdallah
- Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Derek Ou
- Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Qian Wang
- Program of Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut, United States of America
| | - Yiming Hu
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Yisi Lu
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Wei Liu
- School of Life Sciences, Peking University, Beijing, China
| | - Boyang Li
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Shubhabrata Mukherjee
- Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Paul K. Crane
- Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Hongyu Zhao
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, United States of America
- Program of Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut, United States of America
- VA Cooperative Studies Program Coordinating Center, West Haven, Connecticut, United States of America
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Prasad H, Osei-Owusu J, Rao R. Functional analysis of Na +/H + exchanger 9 variants identified in patients with autism and epilepsy. ACTA ACUST UNITED AC 2017; 2017. [PMID: 28815171 PMCID: PMC5555647 DOI: 10.19185/matters.201704000009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Na+/H+ exchanger isoform 9, NHE9, finely tunes the pH within the endosomal lumen to regulate cargo trafficking and turnover. In patients with autism, genetic approaches have revealed deletions, truncations and missense mutations in the gene encoding NHE9 (SLC9A9). To help establish causality, functional evaluation is needed to distinguish pathogenic mutations from harmless polymorphisms. Here, we evaluated three previously uncharacterized NHE9 variants, P117T, D496N, and Q609K reported in patients with autism and epilepsy. We show that NHE9-DsRed localizes to recycling endosomes in HEK293 cells where it significantly alkalinizes luminal pH, and elevates accumulation of transferrin. All three NHE9 variants were expressed and localized to endosomal compartments, similar to wild-type NHE9. In contrast to previously characterized NHE9 variants, we observed no loss-of-function with respect to endosomal pH homeostasis and transferrin endocytosis. These findings suggest that the three NHE9 substitutions analyzed in our study are either benign polymorphisms or may have a cell-type specific or regulatory function not detected in our cell culture model. Our findings highlight the importance of combining the use of cellular studies of function with sequencing technologies that capture genomic variation in patients.
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Affiliation(s)
- Hari Prasad
- Department of Physiology, The Johns Hopkins University School of Medicine 725 N. Wolfe Street Baltimore MD 21205
| | - James Osei-Owusu
- Department of Physiology, The Johns Hopkins University School of Medicine 725 N. Wolfe Street Baltimore MD 21205
| | - Rajini Rao
- Department of Physiology, The Johns Hopkins University School of Medicine 725 N. Wolfe Street Baltimore MD 21205
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40
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Oberheide K, Puchkov D, Jentsch TJ. Loss of the Na +/H + exchanger NHE8 causes male infertility in mice by disrupting acrosome formation. J Biol Chem 2017; 292:10845-10854. [PMID: 28476888 DOI: 10.1074/jbc.m117.784108] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/04/2017] [Indexed: 01/02/2023] Open
Abstract
Mammalian sperm feature a specialized secretory organelle on the anterior part of the sperm nucleus, the acrosome, which is essential for male fertility. It is formed by a fusion of Golgi-derived vesicles. We show here that the predominantly Golgi-resident Na+/H+ exchanger NHE8 localizes to the developing acrosome of spermatids. Similar to wild-type mice, Nhe8-/- mice generated Golgi-derived vesicles positive for acrosomal markers and attached to nuclei, but these vesicles failed to form large acrosomal granules and the acrosomal cap. Spermatozoa from Nhe8-/- mice completely lacked acrosomes, were round-headed, exhibited abnormal mitochondrial distribution, and displayed decreased motility, resulting in selective male infertility. Of note, similar features are also found in globozoospermia, one of the causes of male infertility in humans. Germ cell-specific, but not Sertoli cell-specific Nhe8 disruption recapitulated the globozoospermia phenotype, demonstrating that NHE8's role in spermiogenesis is germ cell-intrinsic. Our work has uncovered a crucial role of NHE8 in acrosome biogenesis and suggests that some forms of human globozoospermia might be caused by a loss of function of this Na+/H+ exchanger. It points to NHE8 as a candidate gene for human globozoospermia and a possible drug target for male contraception.
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Affiliation(s)
- Karina Oberheide
- From the Leibniz-Forschungsinstitut für Molekulare Pharmakologie, D-13125 Berlin and.,Max-Delbrück-Centrum für Molekulare Medizin, D-13125 Berlin, Germany
| | - Dmytro Puchkov
- From the Leibniz-Forschungsinstitut für Molekulare Pharmakologie, D-13125 Berlin and
| | - Thomas J Jentsch
- From the Leibniz-Forschungsinstitut für Molekulare Pharmakologie, D-13125 Berlin and .,Max-Delbrück-Centrum für Molekulare Medizin, D-13125 Berlin, Germany
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41
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Beydoun R, Hamood MA, Gomez Zubieta DM, Kondapalli KC. Na +/H + Exchanger 9 Regulates Iron Mobilization at the Blood-Brain Barrier in Response to Iron Starvation. J Biol Chem 2017; 292:4293-4301. [PMID: 28130443 DOI: 10.1074/jbc.m116.769240] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/24/2017] [Indexed: 12/21/2022] Open
Abstract
Iron is essential for brain function, with loss of iron homeostasis in the brain linked to neurological diseases ranging from rare syndromes to more common disorders, such as Parkinson's and Alzheimer's diseases. Iron entry into the brain is regulated by the blood-brain barrier (BBB). Molecular mechanisms regulating this transport are poorly understood. Using an in vitro model of the BBB, we identify NHE9, an endosomal cation/proton exchanger, as a novel regulator of this system. Human brain microvascular endothelial cells (hBMVECs) that constitute the BBB receive brain iron status information via paracrine signals from ensheathing astrocytes. In hBMVECs, we show that NHE9 expression is up-regulated very early in a physiological response invoked by paracrine signals from iron-starved astrocytes. Ectopic expression of NHE9 in hBMVECs without external cues induced up-regulation of the transferrin receptor (TfR) and down-regulation of ferritin, leading to an increase in iron uptake. Mechanistically, we demonstrate that NHE9 localizes to recycling endosomes in hBMVECs where it raises the endosomal pH. The ensuing alkalization of the endosomal lumen increased translocation of TfRs to the hBMVEC membrane. TfRs on the membrane were previously shown to facilitate both recycling-dependent and -independent iron uptake. We propose that NHE9 regulates TfR-dependent, recycling-independent iron uptake in hBMVECs by fine-tuning the endosomal pH in response to paracrine signals and is therefore an important regulator in iron mobilization pathway at the BBB.
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Affiliation(s)
- Rami Beydoun
- From the Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128
| | - Mohamed A Hamood
- From the Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128
| | - Daniela M Gomez Zubieta
- From the Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128
| | - Kalyan C Kondapalli
- From the Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan 48128
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Liu G, Zhang F, Hu Y, Jiang Y, Gong Z, Liu S, Chen X, Jiang Q, Hao J. Genetic Variants and Multiple Sclerosis Risk Gene SLC9A9 Expression in Distinct Human Brain Regions. Mol Neurobiol 2016; 54:6820-6826. [PMID: 27766536 DOI: 10.1007/s12035-016-0208-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/11/2016] [Indexed: 01/10/2023]
Abstract
A recent genome-wide association study reported a significant association between rs9828519 (G) and nonresponsiveness to interferon-beta (IFN-β) treatment and dysregulation of SLC9A9 expression in multiple sclerosis (MS) cases. We hypothesize that disease-relevant tissues are necessary to detect the effects of rs9828519-tagged SNPs on SLC9A9 expression. Here, we investigated whether SLC9A9 expression is regulated by rs9828519-tagged SNPs in human brain tissue. We used HaploReg to identify the proxy SNPs of the rs9828519 variant based on linkage disequilibrium information from the 1000 Genomes Project. We evaluated the potential association between these SNPs and SLC9A9 expression using multiple expression quantitative trait loci datasets including 10 brain regions of 134 individuals from Braineac, 2 brain regions of 773 samples from brain expression GWAS datasets, and 12 brain regions from the GTEx. We discovered differential SLC9A9 expression in different brain regions and identified 15 rs9828519-tagged SNPs that significantly regulated SLC9A9 expression only in occipital cortex, intralobular white matter, and substantia nigra. Our results advance the understanding of the involvement of SLC9A9 and rs9828519 mechanisms in MS.
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Affiliation(s)
- Guiyou Liu
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.,School of Life Science and Technology, Harbin Institute of Technology, Room 415, Building 2E, Science Park, Yikuang Street, Nangang District, Harbin, 150080, China
| | - Fang Zhang
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yang Hu
- School of Life Science and Technology, Harbin Institute of Technology, Room 415, Building 2E, Science Park, Yikuang Street, Nangang District, Harbin, 150080, China
| | - Yongshuai Jiang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, China
| | - Zhongying Gong
- Department of Neurology, Tianjin First Central Hospital, Tianjin, China
| | - Shoufeng Liu
- Department of Neurology, Tianjin HuanHu Hospital, Tianjin, China
| | - Xiuju Chen
- Department of Neurology, Tianjin NanKai Hospital, Tianjin, China
| | - Qinghua Jiang
- School of Life Science and Technology, Harbin Institute of Technology, Room 415, Building 2E, Science Park, Yikuang Street, Nangang District, Harbin, 150080, China.
| | - Junwei Hao
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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Abstract
Several members of the SLC9A family of Na+/H+ exchangers are expressed in the gut, with varying expression patterns and cellular localization. Not only do they participate in the regulation of basic epithelial cell functions, including control of transepithelial Na+ absorption, intracellular pH (pH i ), cell volume, and nutrient absorption, but also in cellular proliferation, migration, and apoptosis. Additionally, they modulate the extracellular milieu in order to facilitate other nutrient absorption and to regulate the intestinal microbial microenvironment. Na+/H+ exchangers are frequent targets of inhibition in gastrointestinal pathologies, either by intrinsic factors (e.g. bile acids, inflammatory mediators) or infectious agents and associated microbial toxins. Based on emerging evidence, disruption of NHE activity via impaired expression or function of respective isoforms may contribute not only to local and systemic electrolyte imbalance, but also to the disease severity via multiple mechanisms. Here, we review the current state of knowledge about the roles Na+/H+ exchangers play in the pathogenesis of disorders of diverse origin and affecting a range of GI tissues.
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Affiliation(s)
- Michael A. Gurney
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona
| | - Daniel Laubitz
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona
| | - Fayez K. Ghishan
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona
| | - Pawel R. Kiela
- Department of Pediatrics, Steele Children’s Research Center, University of Arizona, Tucson, Arizona,Department of Immunobiology, University of Arizona, Tucson, Arizona,Correspondence Address correspondence to: Pawel R. Kiela, DVM, PhD, Department of Pediatrics, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724. fax: (520) 626-4141.Department of Pediatrics, University of Arizona1501 North Campbell AvenueTucsonArizona 85724
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Interplay between hydrophobicity and the positive-inside rule in determining membrane-protein topology. Proc Natl Acad Sci U S A 2016; 113:10340-5. [PMID: 27562165 DOI: 10.1073/pnas.1605888113] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The energetics of membrane-protein interactions determine protein topology and structure: hydrophobicity drives the insertion of helical segments into the membrane, and positive charges orient the protein with respect to the membrane plane according to the positive-inside rule. Until recently, however, quantifying these contributions met with difficulty, precluding systematic analysis of the energetic basis for membrane-protein topology. We recently developed the dsTβL method, which uses deep sequencing and in vitro selection of segments inserted into the bacterial plasma membrane to infer insertion-energy profiles for each amino acid residue across the membrane, and quantified the insertion contribution from hydrophobicity and the positive-inside rule. Here, we present a topology-prediction algorithm called TopGraph, which is based on a sequence search for minimum dsTβL insertion energy. Whereas the average insertion energy assigned by previous experimental scales was positive (unfavorable), the average assigned by TopGraph in a nonredundant set is -6.9 kcal/mol. By quantifying contributions from both hydrophobicity and the positive-inside rule we further find that in about half of large membrane proteins polar segments are inserted into the membrane to position more positive charges in the cytoplasm, suggesting an interplay between these two energy contributions. Because membrane-embedded polar residues are crucial for substrate binding and conformational change, the results implicate the positive-inside rule in determining the architectures of membrane-protein functional sites. This insight may aid structure prediction, engineering, and design of membrane proteins. TopGraph is available online (topgraph.weizmann.ac.il).
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Patak J, Hess JL, Zhang-James Y, Glatt SJ, Faraone SV. SLC9A9 Co-expression modules in autism-associated brain regions. Autism Res 2016; 10:414-429. [PMID: 27439572 DOI: 10.1002/aur.1670] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 05/27/2016] [Accepted: 06/13/2016] [Indexed: 12/16/2022]
Abstract
SLC9A9 is a sodium hydrogen exchanger present in the recycling endosome and highly expressed in the brain. It is implicated in neuropsychiatric disorders, including autism spectrum disorders (ASDs). Little research concerning its gene expression patterns and biological pathways has been conducted. We sought to investigate its possible biological roles in autism-associated brain regions throughout development. We conducted a weighted gene co-expression network analysis on RNA-seq data downloaded from Brainspan. We compared prenatal and postnatal gene expression networks for three ASD-associated brain regions known to have high SLC9A9 gene expression. We also performed an ASD-associated single nucleotide polymorphism enrichment analysis and a cell signature enrichment analysis. The modules showed differences in gene constituents (membership), gene number, and connectivity throughout time. SLC9A9 was highly associated with immune system functions, metabolism, apoptosis, endocytosis, and signaling cascades. Gene list comparison with co-immunoprecipitation data was significant for multiple modules. We found a disproportionately high autism risk signal among genes constituting the prenatal hippocampal module. The modules were enriched with astrocyte and oligodendrocyte markers. SLC9A9 is potentially involved in the pathophysiology of ASDs. Our investigation confirmed proposed functions for SLC9A9, such as endocytosis and immune regulation, while also revealing potential roles in mTOR signaling and cell survival.. By providing a concise molecular map and interactions, evidence of cell type and implicated brain regions we hope this will guide future research on SLC9A9. Autism Res 2017, 10: 414-429. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.
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Affiliation(s)
- Jameson Patak
- Department of Neuroscience and Physiology, Upstate Medical University, Syracuse, New York
| | - Jonathan L Hess
- Department of Neuroscience and Physiology, Upstate Medical University, Syracuse, New York
| | - Yanli Zhang-James
- Department of Psychiatry, Upstate Medical University, Syracuse, New York
| | - Stephen J Glatt
- Department of Neuroscience and Physiology, Upstate Medical University, Syracuse, New York.,Department of Psychiatry, Upstate Medical University, Syracuse, New York
| | - Stephen V Faraone
- Department of Neuroscience and Physiology, Upstate Medical University, Syracuse, New York.,Department of Psychiatry, Upstate Medical University, Syracuse, New York.,Department of Biomedicine, K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway
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Skatchkov SN, Antonov SM, Eaton MJ. Glia and glial polyamines. Role in brain function in health and disease. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2016. [DOI: 10.1134/s1990747816010116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Patak J, Zhang-James Y, Faraone SV. Endosomal system genetics and autism spectrum disorders: A literature review. Neurosci Biobehav Rev 2016; 65:95-112. [PMID: 27048963 PMCID: PMC4866511 DOI: 10.1016/j.neubiorev.2016.03.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 03/25/2016] [Accepted: 03/27/2016] [Indexed: 01/01/2023]
Abstract
Autism spectrum disorders (ASDs) are a group of debilitating neurodevelopmental disorders thought to have genetic etiology, due to their high heritability. The endosomal system has become increasingly implicated in ASD pathophysiology. In an attempt to summarize the association between endosomal system genes and ASDs we performed a systematic review of the literature. We searched PubMed for relevant articles. Simons Foundation Autism Research Initiative (SFARI) gene database was used to exclude articles regarding genes with less than minimal evidence for association with ASDs. Our search retained 55 articles reviewed in two categories: genes that regulate and genes that are regulated by the endosomal system. Our review shows that the endosomal system is a novel pathway implicated in ASDs as well as other neuropsychiatric disorders. It plays a central role in aspects of cellular physiology on which neurons and glial cells are particularly reliant, due to their unique metabolic and functional demands. The system shows potential for biomarkers and pharmacological intervention and thus more research into this pathway is warranted.
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Affiliation(s)
- Jameson Patak
- Dept. of Neuroscience and Physiology, Upstate Medical University, Syracuse, NY, United States.
| | - Yanli Zhang-James
- Dept of Psychiatry, Upstate Medical University, Syracuse, NY, United States.
| | - Stephen V Faraone
- Dept. of Neuroscience and Physiology, Upstate Medical University, Syracuse, NY, United States; Dept of Psychiatry, Upstate Medical University, Syracuse, NY, United States; K.G. Jebsen Centre for Neuropsychiatric Disorders, Department of Biomedicine, University of Bergen, Bergen, Norway.
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Ashkenazy H, Abadi S, Martz E, Chay O, Mayrose I, Pupko T, Ben-Tal N. ConSurf 2016: an improved methodology to estimate and visualize evolutionary conservation in macromolecules. Nucleic Acids Res 2016; 44:W344-50. [PMID: 27166375 PMCID: PMC4987940 DOI: 10.1093/nar/gkw408] [Citation(s) in RCA: 1999] [Impact Index Per Article: 249.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 05/03/2016] [Indexed: 12/12/2022] Open
Abstract
The degree of evolutionary conservation of an amino acid in a protein or a nucleic acid in DNA/RNA reflects a balance between its natural tendency to mutate and the overall need to retain the structural integrity and function of the macromolecule. The ConSurf web server (http://consurf.tau.ac.il), established over 15 years ago, analyses the evolutionary pattern of the amino/nucleic acids of the macromolecule to reveal regions that are important for structure and/or function. Starting from a query sequence or structure, the server automatically collects homologues, infers their multiple sequence alignment and reconstructs a phylogenetic tree that reflects their evolutionary relations. These data are then used, within a probabilistic framework, to estimate the evolutionary rates of each sequence position. Here we introduce several new features into ConSurf, including automatic selection of the best evolutionary model used to infer the rates, the ability to homology-model query proteins, prediction of the secondary structure of query RNA molecules from sequence, the ability to view the biological assembly of a query (in addition to the single chain), mapping of the conservation grades onto 2D RNA models and an advanced view of the phylogenetic tree that enables interactively rerunning ConSurf with the taxa of a sub-tree.
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Affiliation(s)
- Haim Ashkenazy
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shiran Abadi
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Eric Martz
- Department of Microbiology, University of Massachusetts, Amherst, MA 01003, USA
| | - Ofer Chay
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Itay Mayrose
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tal Pupko
- Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nir Ben-Tal
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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Prasad H, Rao R. Applying knowledge of autism to brain cancer management: what do we know? Future Oncol 2016; 11:1847-50. [PMID: 26161920 DOI: 10.2217/fon.15.93] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Hari Prasad
- Department of Physiology, The Johns Hopkins University School of Medicine, 725 N Wolfe Street, Baltimore, MD 21205, USA
| | - Rajini Rao
- Department of Physiology, The Johns Hopkins University School of Medicine, 725 N Wolfe Street, Baltimore, MD 21205, USA
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Yang L, Faraone SV, Zhang-James Y. Autism spectrum disorder traits in Slc9a9 knock-out mice. Am J Med Genet B Neuropsychiatr Genet 2016; 171B:363-76. [PMID: 26755066 DOI: 10.1002/ajmg.b.32415] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/22/2015] [Indexed: 11/09/2022]
Abstract
Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders which begin in childhood and persist into adulthood. They cause lifelong impairments and are associated with substantial burdens to patients, families, and society. Genetic studies have implicated the sodium/proton exchanger (NHE) nine gene, Slc9a9, to ASDs and attention-deficit/hyperactivity disorder(ADHD). Slc9a9 encodes, NHE9, a membrane protein of the late recycling endosomes. The recycling endosome plays an important role in synapse development and plasticity by regulating the trafficking of membrane neurotransmitter receptors and transporters. Here we tested the hypothesis that Slc9a9 knock-out (KO) mice would show ADHD-like and ASD-like traits. Ultrasonic vocalization (USV) recording showed that Slc9a9 KO mice emitted fewer calls and had shorter call durations, which suggest communication impairment. Slc9a9 KO mice lacked a preference for social novelty, but did not show deficits in social approach; Slc9a9 KO mice spent more time self-grooming, an indicator for restricted and repetitive behavior. We did not observe hyperactivity or other behavior impairments which are commonly comorbid with ASDs in human, such as anxiety-like behavior. Our study is the first animal behavior study that links Slc9a9 to ASDs. By eliminatingNHE9 activity, it provides strong evidence that lack of Slc9a9leads to ASD-like behaviors in mice and provides the field with a new mouse model of ASDs.
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Affiliation(s)
- Lina Yang
- Departments of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York
| | - Stephen V Faraone
- Departments of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York.,Departments of Psychiatry, SUNY Upstate Medical University, Syracuse, New York.,K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway
| | - Yanli Zhang-James
- Departments of Psychiatry, SUNY Upstate Medical University, Syracuse, New York
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