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Kang KW, Hong KW, Lee SK. Identification of novel variants for complicating cardiac disease in the scrub typhus infection using whole genome sequencing. Korean J Intern Med 2023; 38:865-871. [PMID: 37939667 PMCID: PMC10636548 DOI: 10.3904/kjim.2023.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 11/10/2023] Open
Abstract
BACKGROUND/AIMS Scrub typhus infection has been known to complicate cardiovascular diseases mainly attributing to high mortality. Genetic susceptibility loci for complicating cardiac diseases such as atrial fibrillation, heart failure, and ischemic heart disease identified by genomic study have been limited in scrub typhus infection. Therefore, we investigated the genetic novel variants predicting complicating cardiac diseases in patients with confirmed scrub typhus infection using whole genome sequencing. METHODS We performed a prospective study for eight consecutive patients with scrub typhus infection. During follow-up, six cases were clinically diagnosed with complicating cardiac diseases and two controls without complicating cardiac diseases. The whole genomes of the all patients were sequenced, and the individual sequence variants were compared between accordcase and control patients. Variant genotypes were compared and identified as a single nucleotide polymorphism (SNP) of the different genotype distributions between six cases and two controls. RESULTS The GG genotype in SNP (rs4977397) of solute carrier 24 family member 2 (SLC24A2) gene and non-TT genotype in SNP (rs2676750) of adenosine deaminase, RNA specific, B2 (ADARB2) gene were distinctively found in the case patients with complicated cardiac disease, compared with control patents in the scrub typhus infection. CONCLUSION We suggest that the SNPs of SLC24A2 and ADARB2 might be genetic surrogate markers for complicating cardiac diseases in the scrub typhus infection. Our study show that early detection based on individual sequence variants might be feasible to predict complicating cardiac diseases in patients with scrub typhus infection, if further studies with more participants confirm these findings.
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Affiliation(s)
- Ki-Woon Kang
- Division of Cardiology, Chung-Ang University Hospital, Chung-Ang University School of Medicine, Seoul,
Korea
| | | | - Seong-Kyu Lee
- Division of Endocrinology, Department of Internal Medicine, Eulji University Hospital, Daejeon,
Korea
- Department of Biochemistry-Molecular Biology, Eulji University School of Medicine, Daejeon,
Korea
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2
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Chan B, Cheng IC, Rozita J, Gorshteyn I, Huang Y, Shaffer I, Chang C, Li W, Lytton J, Den Besten P, Zhang Y. Sodium/(calcium + potassium) exchanger NCKX4 optimizes KLK4 activity in the enamel matrix microenvironment to regulate ECM modeling. Front Physiol 2023; 14:1116091. [PMID: 36814474 PMCID: PMC9939835 DOI: 10.3389/fphys.2023.1116091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/16/2023] [Indexed: 02/09/2023] Open
Abstract
Enamel development is a process in which extracellular matrix models from a soft proteinaceous matrix to the most mineralized tissue in vertebrates. Patients with mutant NCKX4, a gene encoding a K+-dependent Na+/Ca2+-exchanger, develop a hypomineralized and hypomature enamel. How NCKX4 regulates enamel protein removal to achieve an almost protein-free enamel is unknown. We characterized the upregulation pattern of Nckx4 in the progressively differentiating enamel-forming ameloblasts by qPCR, and as well as confirmed NCKX4 protein to primarily localize at the apical surface of wild-type ruffle-ended maturation ameloblasts by immunostaining of the continuously growing mouse incisors, posing the entire developmental trajectory of enamel. In contrast to the normal mature enamel, where ECM proteins are hydrolyzed and removed, we found significant protein retention in the maturation stage of Nckx4 -/- mouse enamel. The Nckx4 -/- enamel held less Ca2+ and K+ but more Na+ than the Nckx4 +/+ enamel did, as measured by EDX. The alternating acidic and neutral pH zones at the surface of mineralizing Nckx4 +/+ enamel were replaced by a largely neutral pH matrix in the Nckx4 -/- enamel. In situ zymography revealed a reduced kallikrein-related peptidase 4 (KLK4) activity in the Nckx4 -/- enamel. We showed that KLK4 took on 90% of proteinase activity in the maturation stage of normal enamel, and that recombinant KLK4 as well as native mouse enamel KLK4 both performed less effectively in a buffer with increased [Na+] and pH, conditions found in the Nckx4 -/- developing enamel. This study, for the first time to our knowledge, provides evidence demonstrating the impaired in situ KLK4 activity in Nckx4 -/- enamel and suggests a novel function of NCKX4 in facilitating KLK4-mediated hydrolysis and removal of ECM proteins, warranting the completion of enamel matrix modeling.
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Affiliation(s)
- Barry Chan
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ieong Cheng Cheng
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jalali Rozita
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Ida Gorshteyn
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yulei Huang
- Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun-Yat-sen University, Guangzhou, China
| | - Ida Shaffer
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Chih Chang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Wu Li
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Jonathan Lytton
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Pamela Den Besten
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
| | - Yan Zhang
- Department of Orofacial Sciences, University of California, San Francisco, CA, San Francisco, United States
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3
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Al-Khannaq M, Lytton J. Regulation of K +-Dependent Na +/Ca 2+-Exchangers (NCKX). Int J Mol Sci 2022; 24:ijms24010598. [PMID: 36614039 PMCID: PMC9820825 DOI: 10.3390/ijms24010598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
Potassium-dependent sodium-calcium exchangers (NCKX) have emerged as key determinants of calcium (Ca2+) signaling and homeostasis, especially in environments where ion concentrations undergo large changes, such as excitatory cells and transport epithelia. The regulation of NCKX transporters enables them to respond to the changing cellular environment thereby helping to shape the extent and kinetics of Ca2+ signals. This review examines the current knowledge of the different ways in which NCKX activity can be modulated. These include (i) cellular and dynamic subcellular location (ii); changes in protein expression mediated at the gene, transcript, or protein level (iii); genetic changes resulting in altered protein structure or expression (iv); regulation via changes in substrate concentration (v); and post-translational modification, partner protein interactions, and allosteric regulation. Detailed mechanistic understanding of NCKX regulation is an emerging area of research with the potential to provide important new insights into transporter function, the control of Ca2+ signals, and possible interventions for dysregulated Ca2+ homeostasis.
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4
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Seymen F, Zhang H, Kasimoglu Y, Koruyucu M, Simmer JP, Hu JCC, Kim JW. Novel Mutations in GPR68 and SLC24A4 Cause Hypomaturation Amelogenesis Imperfecta. J Pers Med 2021; 12:jpm12010013. [PMID: 35055328 PMCID: PMC8781920 DOI: 10.3390/jpm12010013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a rare genetic condition affecting the quantity and/or quality of tooth enamel. Hypomaturation AI is characterized by brownish-yellow discoloration with increased opacity and poorly mineralized enamel prone to fracture and attrition. We recruited three families affected by hypomaturation AI and performed whole exome sequencing with selected individuals in each family. Bioinformatic analysis and Sanger sequencing identified and confirmed mutations and segregation in the families. Family 1 had a novel homozygous frameshift mutation in GPR68 gene (NM_003485.3:c.78_83delinsC, p.(Val27Cysfs*146)). Family 2 had a novel homozygous nonsense mutation in SLC24A4 gene (NM_153646.4:c.613C>T, NP_705932.2:p.(Arg205*)). Family 3 also had a homozygous missense mutation in SLC24A4 gene which was reported previously (c.437C>T, p.(Ala146Val)). This report not only expands the mutational spectrum of the AI-causing genes but also improves our understanding of normal and pathologic amelogenesis.
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Affiliation(s)
- Figen Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - Hong Zhang
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Yelda Kasimoglu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul 34116, Turkey; (F.S.); (Y.K.); (M.K.)
| | - James P. Simmer
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA; (H.Z.); (J.P.S.); (J.C.-C.H.)
| | - Jung-Wook Kim
- Department of Pediatric Dentistry, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea
- Department of Molecular Genetics, School of Dentistry & DRI, Seoul National University, Seoul 03080, Korea
- Correspondence:
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5
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Araujo AC, Araújo RDS, Dourado LRB, Machado JS, Bayão GFV, Amoroso L, Artoni SMB, Shimano AC, Silva Sousa KR. Analysis of performance, bone characteristics, and expression of genes involved in the balance of ionic concentrations in broilers subjected to dietary electrolyte balance levels. Br Poult Sci 2021; 63:226-234. [PMID: 34378457 DOI: 10.1080/00071668.2021.1966754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. Sodium bicarbonate (NaHCO3), potassium carbonate (K2CO3), and ammonium chloride (NH4Cl) are commonly used to correct dietary electrolyte balance (DEB) in birds. However, there are many gaps in the knowledge of their effects when used simultaneously. This study investigated the effect of DEB levels on performance, femur bone characteristics and the expression of genes related to the balance of ionic concentrations in broilers at 21 days of age.2. Male Cobb broiler chickens (n = 245), aged 1-21 d, were divided into groups based on a completely randomised design with five DEB levels (110 mEq/kg, 175 mEq/kg, 240 mEq/kg, 305 mEq/kg, and 370 mEq/kg).3. The performance characteristics measured included body weight (BW), body weight gain (BWG), feed intake (FI), feed conversion (FCR) and body weight birds slaughtered (BWS).4. The bone variables assessed in the femur were weight (WE), relative bone weight (RBWE), length (L), width (WI), maximum load supported (MLS), bone-breaking resistance (BR), and Seedor index (SI). In addition, the expression of CHP1, SLC9A1, and SLC24A3 in the livers, intestines and kidneys of birds was evaluated.5. The DEB level of 370 mEq/kg, at Na+ content of 0.48%, resulted in the highest averages for L, MLS, and BR of the femur. This DEB level increased the expression of SLC9A1 in the liver and SLC24A3 in the intestine. A 240 mEq/kg DEB level decreased the expression of CHP1 in the liver, while supplementation with 110 mEq/kg increased the expression of SLC24A3 in the kidney.6. In conclusion, 370 mEq/kg DEB improved FCR and increased the mean bone characteristics of the femur (L, MLS, and BR) and the expression of SLC9A1 and SLC24A3 in the liver and intestine, respectively. These findings should be considered in future assessments of the effects of DEB levels on broilers.
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Affiliation(s)
- A C Araujo
- Cinobelina Elvas, Universidade Federal do Piauí - Ufpi, Bom Jesus, Brazil
| | - R D S Araújo
- Departamento de Entomologia, Universidade Federal de Viçosa - Ufv, Viçosa, Brazil
| | - L R B Dourado
- Cinobelina Elvas, Universidade Federal do Piauí - Ufpi, Bom Jesus, Brazil
| | - J S Machado
- Cinobelina Elvas, Universidade Federal do Piauí - Ufpi, Bom Jesus, Brazil
| | - G F V Bayão
- Departamento de Zootecnia, Instituto Federal de Educação, Ciência e Tecnologia do Maranhão, São Luís, Brazil
| | - L Amoroso
- Departamento de Morfologia e Fisiologia Animal, Universidade Estadual Paulista Júlio de Mesquita Filho - Unesp, Jaboticabal, Brazil
| | - S M B Artoni
- Departamento de Morfologia e Fisiologia Animal, Universidade Estadual Paulista Júlio de Mesquita Filho - Unesp, Jaboticabal, Brazil
| | - A C Shimano
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Universidade de São Paulo - Usp, Ribeirão Preto, Brazil
| | - K R Silva Sousa
- Departamento de Oceanografia e Limnologia, Universidade Federal do Maranhão - Ufma, São Luís, Brazil
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6
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Akbor MM, Kim J, Nomura M, Sugioka J, Kurosawa N, Isobe M. A candidate gene of Alzheimer diseases was mutated in senescence-accelerated mouse prone (SAMP) 8 mice. Biochem Biophys Res Commun 2021; 572:112-117. [PMID: 34364289 DOI: 10.1016/j.bbrc.2021.07.095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 07/28/2021] [Indexed: 11/25/2022]
Abstract
The senescence-accelerated mouse prone (SAMP) 8 strain exhibits age-related learning and memory deficits (LMD) at 2 months of age. We have found strong association of chromosome 12 locus with learning memory deficit (LMD) phenotype in SAMP8 strain. In the course of searching candidate gene, here we identified solute carrier family 24 sodium/potassium/calcium exchanger member 4 (Slc24a4) in SAMP8 chromosome 12 LMD possessing one single nucleotide polymorphism causing amino acid replacement of Threonine at 413 position with Methionine. Since SLC24A4 has been postulated as a candidate of late onset Alzheimer's diseases (LOAD), we further analyze the functional importance of this polymorphism. By expressing Slc24a4 protein in HEK293 cells, here we showed polymorphic SAMP8 type Slc24a4-T413 M causing significant loss of calcium ion (Ca2+) transporter activity in cells compared with that of wild type mouse (Slc24a4-WT). However, no study yet shows any functional association of human SLC24A4 polymorphism with the onset of LOAD pathogenesis. Thus, our present finding may further help to clarify the importance of this ion exchanger with age related cognitive dysfunction.
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Affiliation(s)
- Maruf Mohammad Akbor
- Laboratory of Molecular and Cellular Biology, Department of Life Sciences and Bioengineering, Faculty of Engineering, University of Toyama, Toyama, Japan
| | - Juhyon Kim
- Division of Bio-Information Engineering, Faculty of Engineering, University of Toyama, Toyama, Japan
| | - Mai Nomura
- Laboratory of Molecular and Cellular Biology, Department of Life Sciences and Bioengineering, Faculty of Engineering, University of Toyama, Toyama, Japan
| | - Juno Sugioka
- Laboratory of Molecular and Cellular Biology, Department of Life Sciences and Bioengineering, Faculty of Engineering, University of Toyama, Toyama, Japan
| | - Nobuyuki Kurosawa
- Laboratory of Molecular and Cellular Biology, Department of Life Sciences and Bioengineering, Faculty of Engineering, University of Toyama, Toyama, Japan
| | - Masaharu Isobe
- Laboratory of Molecular and Cellular Biology, Department of Life Sciences and Bioengineering, Faculty of Engineering, University of Toyama, Toyama, Japan.
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7
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Vogrinc D, Goričar K, Dolžan V. Genetic Variability in Molecular Pathways Implicated in Alzheimer's Disease: A Comprehensive Review. Front Aging Neurosci 2021; 13:646901. [PMID: 33815092 PMCID: PMC8012500 DOI: 10.3389/fnagi.2021.646901] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/16/2021] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is a complex neurodegenerative disease, affecting a significant part of the population. The majority of AD cases occur in the elderly with a typical age of onset of the disease above 65 years. AD presents a major burden for the healthcare system and since population is rapidly aging, the burden of the disease will increase in the future. However, no effective drug treatment for a full-blown disease has been developed to date. The genetic background of AD is extensively studied; numerous genome-wide association studies (GWAS) identified significant genes associated with increased risk of AD development. This review summarizes more than 100 risk loci. Many of them may serve as biomarkers of AD progression, even in the preclinical stage of the disease. Furthermore, we used GWAS data to identify key pathways of AD pathogenesis: cellular processes, metabolic processes, biological regulation, localization, transport, regulation of cellular processes, and neurological system processes. Gene clustering into molecular pathways can provide background for identification of novel molecular targets and may support the development of tailored and personalized treatment of AD.
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Affiliation(s)
| | | | - Vita Dolžan
- Pharmacogenetics Laboratory, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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8
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Tran DN, Go SM, Park SM, Jung EM, Jeung EB. Loss of Nckx3 Exacerbates Experimental DSS-Induced Colitis in Mice through p53/NF-κB Pathway. Int J Mol Sci 2021; 22:ijms22052645. [PMID: 33807999 PMCID: PMC7961925 DOI: 10.3390/ijms22052645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/01/2021] [Accepted: 03/02/2021] [Indexed: 12/20/2022] Open
Abstract
Inflammatory bowel diseases (IBDs) comprises a range of chronic inflammatory conditions of the intestinal tract. The incidence and prevalence of IBDs are increasing worldwide, but the precise etiology of these diseases is not completely understood. Calcium signaling plays a regulatory role in cellular proliferation. Nckx3, a potassium-dependent Na+/Ca2+ exchanger, is not only expressed in the brain but also in the aortic, uterine, and intestinal tissues, which contain abundant smooth muscle cells. This study investigated the role of Nckx3 in intestinal inflammation. Microarray analyses revealed the upregulation of the innate immune response-associated genes in the duodenum of Nckx3 knockout (KO) mice. The Nckx3 KO mice also showed an increase in IBD- and tumorigenesis-related genes. Using dextran sodium sulfate (DSS)-induced experimental colitis mice models, the Nckx3 KO mice showed severe colitis. Furthermore, the pathways involving p53 and NF-κB signaling were significantly upregulated by the absence of Nckx3. Overall, Nckx3 plays a critical role in the innate immune and immune response and may be central to the pathogenesis of IBD.
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Affiliation(s)
- Dinh Nam Tran
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (D.N.T.); (S.M.G.); (S.-M.P.)
| | - Seon Myeong Go
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (D.N.T.); (S.M.G.); (S.-M.P.)
| | - Seon-Mi Park
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (D.N.T.); (S.M.G.); (S.-M.P.)
| | - Eui-Man Jung
- Laboratory of Molecular Developmental Biology, Department of Molecular Biology, College of Natural Sciences, Pusan National University, Busandaehang-ro, 63beon-gil 2, Geumjeong-gu, Busan 46241, Korea;
| | - Eui-Bae Jeung
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (D.N.T.); (S.M.G.); (S.-M.P.)
- Correspondence: ; Tel.: +82-43-261-2397; Fax: +82-43-267-3150
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9
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Li Z, Ma Y, Zhou F, Jia X, Zhan J, Tan H, Wang X, Yang T, Liu Q. Identification of MicroRNA-Potassium Channel Messenger RNA Interactions in the Brain of Rats With Post-traumatic Epilepsy. Front Mol Neurosci 2021; 13:610090. [PMID: 33597846 PMCID: PMC7882489 DOI: 10.3389/fnmol.2020.610090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/21/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Dysregulated expression of microRNAs and potassium channels have been reported for their contributions to seizure onset. However, the microRNA–potassium channel gene interactions in traumatic brain injury-induced post-traumatic epilepsy (PTE) remain unknown. Methods: PTE was induced in male rats by intracranial injection with ferrous chloride (0.1 mol/L, 1 μl/min) at the right frontal cortex. Electroencephalography was recorded at 60 min, as well as day 1, 7, and 30, and the behavioral seizures were assessed before injection and at different time points after injection. Rats were killed on day 30 after injection. The right frontal cortex samples were collected and subjected to high throughput messenger RNA (mRNA) and microRNA sequencing. A network of differentially expressed potassium channel mRNAs and microRNAs was constructed using OryCun2.0 and subjected to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. The differential mRNA and microRNA expressions were verified using quantitative real-time-PCR. The microRNA–mRNA was subject to the Pearson correlation analysis. Results: A PTE rat model was successfully established, as evidenced by behavioral seizures and epileptiform discharges on electroencephalography in PTE rats compared with sham rats. Among the 91 mRNAs and 40 microRNAs that were significantly differentially expressed in the PTE rat brain, 4 mRNAs and 10 microRNAs were associated with potassium channels. Except for potassium calcium-activated channel subfamily N member 2, the other three potassium channel mRNAs were negatively correlated with seven microRNAs. These microRNA–mRNA pairs were enriched in annotations and pathways related to neuronal ion channels and neuroinflammation. Quantitative real-time-PCR and correlation analysis verified negative correlations in miR-449a-5p-KCNH2, miR-98-5p-KCNH2, miR-98-5p-KCNK15, miR-19b-3p-KCNK15, and miR-301a-3p-KCNK15 pairs. Conclusion: We identified microRNA–potassium channel mRNA interactions associated with PTE, providing potential diagnostic markers and therapeutic targets for PTE.
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Affiliation(s)
- Zheng Li
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Yixun Ma
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Fengjuan Zhou
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Xiao Jia
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Jingjing Zhan
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Huachao Tan
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Xu Wang
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Tiantong Yang
- Key Laboratory of Evidence Science, Institute of Evidence Law and Forensic Science, China University of Political Science and Law, Ministry of Education, Beijing, China.,Collaborative Innovation Center of Judicial Civilization, Beijing, China
| | - Quan Liu
- Hubei University of Police, Wuhan, China
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10
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Thibodeau S, Yang W, Sharma S, Lytton J. Calmodulin binds and modulates K +-dependent Na +/Ca 2+-exchanger isoform 4, NCKX4. J Biol Chem 2021; 296:100092. [PMID: 33199372 PMCID: PMC7949085 DOI: 10.1074/jbc.ra120.015037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/25/2020] [Accepted: 11/16/2020] [Indexed: 11/06/2022] Open
Abstract
The family of K+-dependent Na+/Ca2+-exchangers, NCKX, are important mediators of cellular Ca2+ efflux, particularly in neurons associated with sensory transduction. The NCKX family comprises five proteins, NCKX1-5, each being the product of a different SLC24 gene. NCKX4 (SLC24A4) has been found to have a critical role in termination and adaptation of visual and olfactory signals, melanocortin-dependent satiety signaling, and the maturation of dental enamel. To explore mechanisms that might influence the temporal control of NCKX4 activity, a yeast two-hybrid system was used to search for protein interaction partners. We identified calmodulin as a partner for NCKX4 and confirmed the interaction using glutathione-S-transferase fusion pull-down. Calmodulin binding to NCKX4 was demonstrated in extracts from mouse brain and in transfected HEK293 cells. Calmodulin bound in a Ca2+-dependent manner to a motif present in the central cytosolic loop of NCKX4 and was abolished by the double-mutant I328D/F334D. When cotransfected in HEK293 cells, calmodulin bound to NCKX4 under basal conditions and induced a ∼2.5-fold increase in NCKX4 abundance, but did not influence either cellular location or basal activity. When purinergic stimulation of NCKX4 was examined in these cells, coexpression of wild-type calmodulin, but not a Ca2+ binding-deficient calmodulin mutant, suppressed NCKX4 activation in a time-dependent manner. We propose that Ca2+ binding to calmodulin prepositioned on NCKX4 induces a slow conformational rearrangement that interferes with purinergic stimulation of the exchanger, possibly by obscuring T331, a previously identified potential protein kinase C site.
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Affiliation(s)
- Stephanie Thibodeau
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Weidong Yang
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sunita Sharma
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jonathan Lytton
- Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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11
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Wu G, Zhang M. A novel risk score model based on eight genes and a nomogram for predicting overall survival of patients with osteosarcoma. BMC Cancer 2020; 20:456. [PMID: 32448271 PMCID: PMC7245838 DOI: 10.1186/s12885-020-06741-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/12/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND This study aims to identify a predictive model to predict survival outcomes of osteosarcoma (OS) patients. METHODS A RNA sequencing dataset (the training set) and a microarray dataset (the validation set) were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database, respectively. Differentially expressed genes (DEGs) between metastatic and non-metastatic OS samples were identified in training set. Prognosis-related DEGs were screened and optimized by support vector machine (SVM) recursive feature elimination. A SVM classifier was built to classify metastatic and non-metastatic OS samples. Independent prognosic genes were extracted by multivariate regression analysis to build a risk score model followed by performance evaluation in two datasets by Kaplan-Meier (KM) analysis. Independent clinical prognostic indicators were identified followed by nomogram analysis. Finally, functional analyses of survival-related genes were conducted. RESULT Totally, 345 DEGs and 45 prognosis-related genes were screened. A SVM classifier could distinguish metastatic and non-metastatic OS samples. An eight-gene signature was an independent prognostic marker and used for constructing a risk score model. The risk score model could separate OS samples into high and low risk groups in two datasets (training set: log-rank p < 0.01, C-index = 0.805; validation set: log-rank p < 0.01, C-index = 0.797). Tumor metastasis and RS model status were independent prognostic factors and nomogram model exhibited accurate survival prediction for OS. Additionally, functional analyses of survival-related genes indicated they were closely associated with immune responses and cytokine-cytokine receptor interaction pathway. CONCLUSION An eight-gene predictive model and nomogram were developed to predict OS prognosis.
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Affiliation(s)
- Guangzhi Wu
- Departments of Hand Surgery, The Third Hospital of Jilin University, Changchun, Jilin Province China
| | - Minglei Zhang
- Departments of Orthopedics, The Third Hospital of Jilin University, Changchun, Jilin Province China
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12
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Khan SA, Khan MA, Muhammad N, Bashir H, Khan N, Muhammad N, Yilmaz R, Khan S, Wasif N. A novel nonsense variant in SLC24A4 causing a rare form of amelogenesis imperfecta in a Pakistani family. BMC MEDICAL GENETICS 2020; 21:97. [PMID: 32380970 PMCID: PMC7206816 DOI: 10.1186/s12881-020-01038-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 04/28/2020] [Indexed: 02/07/2023]
Abstract
Background Amelogenesis imperfecta (AI) is a highly heterogeneous group of hereditary developmental abnormalities which mainly affects the dental enamel during tooth development in terms of its thickness, structure, and composition. It appears both in syndromic as well as non-syndromic forms. In the affected individuals, the enamel is usually thin, soft, rough, brittle, pitted, chipped, and abraded, having reduced functional ability and aesthetics. It leads to severe complications in the patient, like early tooth loss, severe discomfort, pain, dental caries, chewing difficulties, and discoloration of teeth from yellow to yellowish-brown or creamy type. The study aimed to identify the disease-causing variant in a consanguineous family. Methods We recruited a consanguineous Pashtun family of Pakistani origin. Exome sequencing analysis was followed by Sanger sequencing to identify the pathogenic variant in this family. Results Clinical analysis revealed hypomaturation AI having generalized yellow-brown or creamy type of discoloration in affected members. We identified a novel nonsense sequence variant c.1192C > T (p.Gln398*) in exon-12 of SLC24A4 by using exome sequencing. Later, its co-segregation within the family was confirmed by Sanger sequencing. The human gene mutation database (HGMD, 2019) has a record of five pathogenic variants in SLC24A4, causing AI phenotype. Conclusion This nonsense sequence variant c.1192C > T (p.Gln398*) is the sixth disease-causing variant in SLC24A4, which extends its mutation spectrum and confirms the role of this gene in the morphogenesis of human tooth enamel. The identified variant highlights the critical role of SLC24A4 in causing a rare AI type in humans.
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Affiliation(s)
- Sher Alam Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Muhammad Adnan Khan
- Dental Material, Institute of Basic Medical Sciences, Khyber Medical University Peshawar, Peshawar, Pakistan
| | - Nazif Muhammad
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Hina Bashir
- Department of Biochemistry, Sharif Medical and Dental College, Lahore, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Noor Muhammad
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan
| | - Rüstem Yilmaz
- Department of Neurology, University of Ulm, Ulm, Germany
| | - Saadullah Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology (KUST), Kohat, Pakistan.
| | - Naveed Wasif
- Institute of Molecular Biology and Biotechnology (IMBB), Center for Research in Molecular Medicine (CRiMM), The University of Lahore, Lahore, Pakistan. .,Department of Human Genetics, University of Ulm, Ulm, Germany. .,Institute of Human Genetics, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
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13
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Hassan MT, Lytton J. Potassium-dependent sodium-calcium exchanger (NCKX) isoforms and neuronal function. Cell Calcium 2020; 86:102135. [DOI: 10.1016/j.ceca.2019.102135] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/16/2022]
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14
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Brown KM, Hui Q, Huang Y, Taylor JY, Prescott L, de Mendoza VB, Crusto C, Sun YV. Association Between Stress and Coping with DNA Methylation of Blood Pressure-Related Genes Among African American Women. CHRONIC STRESS 2019; 3. [PMID: 32395678 PMCID: PMC7213592 DOI: 10.1177/2470547019879088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background Exposure to psychosocial stress and employment of high effort coping
strategies have been identified as risk factors that may partially explain
the high prevalence of hypertension among African Americans. One biological
mechanism through which stress and coping may affect risk of hypertension is
via epigenetic modifications (e.g., DNA methylation) in blood
pressure-related genes; however, this area remains understudied in African
Americans. Methods We used data from the ongoing Intergenerational Blood Pressure Study, a
longitudinal study designed to investigate factors that contribute to
hypertension risk in African American women (n = 120) and their young
children, to investigate the association between stress overload,
problem-solving coping, avoidance coping, and social support coping with DNA
methylation in 25 candidate genes related to blood pressure. Multivariable
linear regression and multilevel modeling were used to conduct methylation
site-level and gene-level analyses, respectively. Results In site-level analyses, stress overload, problem-solving coping, social
support coping, and avoidance coping were associated with 47, 63, 66, and 61
sites, respectively, at p < 0.05. However, no associations were
statistically significant after multiple testing correction. There were also
no significant associations in gene-level analyses. Conclusions As human social epigenomics is an emerging, evolving area of research, there
is much to be learned from studies with statistically significant findings
as well as studies with null findings. Factors such as characteristics of
the social stressor, source of DNA, and synchronization of exposure and
outcome are likely important considerations as we move the field
forward.
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Affiliation(s)
| | - Qin Hui
- Emory University (Atlanta, Georgia)
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15
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Abstract
PURPOSE OF REVIEW Over the last decade over 40 loci have been associated with risk of Alzheimer's disease (AD). However, most studies have either focused on identifying risk loci or performing unbiased screens without a focus on protective variation in AD. Here, we provide a review of known protective variants in AD and their putative mechanisms of action. Additionally, we recommend strategies for finding new protective variants. RECENT FINDINGS Recent Genome-Wide Association Studies have identified both common and rare protective variants associated with AD. These include variants in or near APP, APOE, PLCG2, MS4A, MAPT-KANSL1, RAB10, ABCA1, CCL11, SORL1, NOCT, SCL24A4-RIN3, CASS4, EPHA1, SPPL2A, and NFIC. SUMMARY There are very few protective variants with functional evidence and a derived allele with a frequency below 20%. Additional fine mapping and multi-omic studies are needed to further validate and characterize known variants as well as specialized genome-wide scans to identify novel variants.
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Affiliation(s)
- Shea J Andrews
- Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Equal first author
| | - Brian Fulton-Howard
- Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Equal first author
| | - Alison Goate
- Icahn School of Medicine at Mount Sinai, New York, New York, USA
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16
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Takatori S, Wang W, Iguchi A, Tomita T. Genetic Risk Factors for Alzheimer Disease: Emerging Roles of Microglia in Disease Pathomechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1118:83-116. [PMID: 30747419 DOI: 10.1007/978-3-030-05542-4_5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The accumulation of aggregated amyloid β (Aβ) peptides in the brain is deeply involved in Alzheimer disease (AD) pathogenesis. Mutations in APP and presenilins play major roles in Aβ pathology in rare autosomal-dominant forms of AD, whereas pathomechanisms of sporadic AD, accounting for the majority of cases, remain unknown. In this chapter, we review current knowledge on genetic risk factors of AD, clarified by recent advances in genome analysis technology. Interestingly, TREM2 and many genes associated with disease risk are predominantly expressed in microglia, suggesting that these risk factors are involved in pathogenicity through common mechanisms involving microglia. Therefore, we focus on factors closely associated with microglia and discuss their possible roles in pathomechanisms of AD. Furthermore, we review current views on the pathological roles of microglia and emphasize the importance of microglial changes in response to Aβ deposition and mechanisms underlying the phenotypic changes. Importantly, functional outcomes of microglial activation can be both protective and deleterious to neurons. We further describe the involvement of microglia in tau pathology and the activation of other glial cells. Through these topics, we shed light on microglia as a promising target for drug development for AD and other neurological disorders.
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Affiliation(s)
- Sho Takatori
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Wenbo Wang
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Akihiro Iguchi
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
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17
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Juszczak GR, Stankiewicz AM. Glucocorticoids, genes and brain function. Prog Neuropsychopharmacol Biol Psychiatry 2018; 82:136-168. [PMID: 29180230 DOI: 10.1016/j.pnpbp.2017.11.020] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/18/2017] [Accepted: 11/23/2017] [Indexed: 01/02/2023]
Abstract
The identification of key genes in transcriptomic data constitutes a huge challenge. Our review of microarray reports revealed 88 genes whose transcription is consistently regulated by glucocorticoids (GCs), such as cortisol, corticosterone and dexamethasone, in the brain. Replicable transcriptomic data were combined with biochemical and physiological data to create an integrated view of the effects induced by GCs. The most frequently reported genes were Errfi1 and Ddit4. Their up-regulation was associated with the altered transcription of genes regulating growth factor and mTORC1 signaling (Gab1, Tsc22d3, Dusp1, Ndrg2, Ppp5c and Sesn1) and progression of the cell cycle (Ccnd1, Cdkn1a and Cables1). The GC-induced reprogramming of cell function involves changes in the mRNA level of genes responsible for the regulation of transcription (Klf9, Bcl6, Klf15, Tle3, Cxxc5, Litaf, Tle4, Jun, Sox4, Sox2, Sox9, Irf1, Sall2, Nfkbia and Id1) and the selective degradation of mRNA (Tob2). Other genes are involved in the regulation of metabolism (Gpd1, Aldoc and Pdk4), actin cytoskeleton (Myh2, Nedd9, Mical2, Rhou, Arl4d, Osbpl3, Arhgef3, Sdc4, Rdx, Wipf3, Chst1 and Hepacam), autophagy (Eva1a and Plekhf1), vesicular transport (Rhob, Ehd3, Vps37b and Scamp2), gap junctions (Gjb6), immune response (Tiparp, Mertk, Lyve1 and Il6r), signaling mediated by thyroid hormones (Thra and Sult1a1), calcium (Calm2), adrenaline/noradrenaline (Adcy9 and Adra1d), neuropeptide Y (Npy1r) and histamine (Hdc). GCs also affected genes involved in the synthesis of polyamines (Azin1) and taurine (Cdo1). The actions of GCs are restrained by feedback mechanisms depending on the transcription of Sgk1, Fkbp5 and Nr3c1. A side effect induced by GCs is increased production of reactive oxygen species. Available data show that the brain's response to GCs is part of an emergency mode characterized by inactivation of non-core activities, restrained inflammation, restriction of investments (growth), improved efficiency of energy production and the removal of unnecessary or malfunctioning cellular components to conserve energy and maintain nutrient supply during the stress response.
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Affiliation(s)
- Grzegorz R Juszczak
- Department of Animal Behavior, Institute of Genetics and Animal Breeding, Jastrzebiec, ul. Postepu 36A, 05-552 Magdalenka, Poland.
| | - Adrian M Stankiewicz
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Jastrzebiec, ul. Postepu 36A, 05-552 Magdalenka, Poland
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18
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De Maria A, Zhao H, Bassnett S. Expression of potassium-dependent sodium-calcium exchanger in the murine lens. Exp Eye Res 2017; 167:18-24. [PMID: 29128492 DOI: 10.1016/j.exer.2017.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/25/2017] [Accepted: 11/07/2017] [Indexed: 12/15/2022]
Abstract
Loss of intracellular calcium homeostasis may contribute to the opacification of lens tissue during cortical cataract formation. In healthy lenses, the concentration of intracellular calcium is maintained at levels far below electrochemical equilibrium but the identity of the calcium extrusion mechanism in lens fiber cells has remained elusive. Previous studies focused on the role of plasma membrane calcium ATPases and sodium-calcium exchangers. Here, we examined the expression of mRNA transcripts encoding potassium-dependent sodium-calcium exchangers (Nckx's, encoded by the Slc24 gene family) in the mouse lens. The most abundant of the five Slc24 family members was Slc24a4 (Nckx4). Notably, Slc24a4 was the only family member with increased expression in fiber cells. Using an antibody raised against recombinant mouse Nckx4, we showed that the protein is expressed strongly in the outer cortical fibers, consistent with results of in situ hybridization experiments and earlier mass spectrometry analysis. To test the role of Nckx4 directly, we generated mice in which Slc24a4 was deleted conditionally in lens tissue. In conditional knockout animals, the level of Nckx4 protein was reduced to background levels without a discernible effect on lens growth or transparency. Thus, despite its relative abundance in the lens, Nckx4 does not appear to have an indispensable role in the maintenance of lens clarity.
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Affiliation(s)
- Alicia De Maria
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8096, St. Louis, MO 63110, USA
| | - Haiqing Zhao
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Steven Bassnett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Ave, Campus Box 8096, St. Louis, MO 63110, USA.
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19
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Yang H, Ahn C, Shin EK, Lee JS, An BS, Jeung EB. NCKX3 was compensated by calcium transporting genes and bone resorption in a NCKX3 KO mouse model. Mol Cell Endocrinol 2017; 454:93-102. [PMID: 28602864 DOI: 10.1016/j.mce.2017.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/18/2017] [Accepted: 06/06/2017] [Indexed: 01/10/2023]
Abstract
Gene knockout is the most powerful tool for determination of gene function or permanent modification of the phenotypic characteristics of an animal. Existing methods for gene disruption are limited by their efficiency, time required for completion and potential for confounding off-target effects. In this study, a rapid single-step approach to knockout of a targeted gene in mice using zinc-finger nucleases (ZFNs) was demonstrated for generation of mutant (knockout; KO) alleles. Specifically, ZFNs to target the sodium/calcium/potassium exchanger3 (NCKX3) gene in C57bl/6j were designed using the concept of this approach. NCKX3 KO mice were generated and the phenotypic characterization and molecular regulation of active calcium transporting genes was assessed when mice were fed different calcium diets during growth. General phenotypes such as body weight and plasma ion level showed no distinct abnormalities. Thus, the potassium/sodium/calcium exchanger of NCKX3 KO mice proceeded normally in this study. As a result, the compensatory molecular regulation of this mechanism was elucidated. Renal TRPV5 mRNA of NCKX3 KO mice increased in both male and female mice. Expression of TRPV6 mRNA was only down-regulated in the duodenum of male KO mice. Renal- and duodenal expression of PTHR and VDR were not changed; however, GR mRNA expression was increased in the kidney of NCKX3 KO mice. Depletion of the NCKX3 gene in a KO mouse model showed loss of bone mineral contents and increased plasma parathyroid hormone, suggesting that NCKX3 may play a role in regulating calcium homeostasis.
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Affiliation(s)
- Hyun Yang
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea; Korean Medicine Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon 34054, Republic of Korea
| | - Changhwan Ahn
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Eun-Kyeong Shin
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Ji-Sun Lee
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea
| | - Beum-Soo An
- Department of Biomaterials Science, College of National Resources & Life Science, Pusan National University, Miryang, Gyeongsangnam-do 627-706, Republic of Korea
| | - Eui-Bae Jeung
- Laboratory of Veterinary Biochemistry and Molecular Biology, Veterinary Medical Center and College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea.
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20
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Williams RM, Winkfein RJ, Ginger RS, Green MR, Schnetkamp PP, Wheeler GN. A functional approach to understanding the role of NCKX5 in Xenopus pigmentation. PLoS One 2017; 12:e0180465. [PMID: 28692664 PMCID: PMC5503238 DOI: 10.1371/journal.pone.0180465] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/15/2017] [Indexed: 11/19/2022] Open
Abstract
NCKX5 is an ion exchanger expressed mostly in pigment cells; however, the functional role for this protein in melanogenesis is not clear. A variant allele of SLC24A5, the gene encoding NCKX5, has been shown to correlate with lighter skin pigmentation in humans, indicating a key role for SLC24A5 in determining human skin colour. SLC24A5 expression has been found to be elevated in melanoma. Knockdown analyses have shown SLC24A5 to be important for pigmentation, but to date the function of this ion exchanger in melanogenesis has not been fully established. Our data suggest NCKX5 may have an alternative activity that is key to its role in the regulation of pigmentation. Here Xenopus laevis is employed as an in vivo model system to further investigate the function of NCKX5 in pigmentation. SLC24A5 is expressed in the melanophores as they differentiate from the neural crest and develop in the RPE of the eye. Morpholino knockdown and rescue experiments were designed to elucidate key residues and regions of the NCKX5 protein. Unilateral morpholino injection at the 2 cell stage resulted in a reduction of pigmentation in the eye and epidermis of one lateral side of the tadpole. Xenopus and human SLC24A5 can rescue the morpholino effects. Further rescue experiments including the use of ion exchange inactive SLC24A5 constructs raise the possibility that full ion exchanger function of NCKX5 may not be required for rescue of pigmentation.
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Affiliation(s)
- Ruth M. Williams
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Robert J. Winkfein
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Rebecca S. Ginger
- Unilever Research and Development, Colworth Science Park, Sharnbrook, Bedfordshire, United Kingdom
| | - Martin R. Green
- Unilever Research and Development, Colworth Science Park, Sharnbrook, Bedfordshire, United Kingdom
| | - Paul P. Schnetkamp
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Grant N. Wheeler
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
- * E-mail:
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Smith CEL, Poulter JA, Antanaviciute A, Kirkham J, Brookes SJ, Inglehearn CF, Mighell AJ. Amelogenesis Imperfecta; Genes, Proteins, and Pathways. Front Physiol 2017; 8:435. [PMID: 28694781 PMCID: PMC5483479 DOI: 10.3389/fphys.2017.00435] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/08/2017] [Indexed: 01/11/2023] Open
Abstract
Amelogenesis imperfecta (AI) is the name given to a heterogeneous group of conditions characterized by inherited developmental enamel defects. AI enamel is abnormally thin, soft, fragile, pitted and/or badly discolored, with poor function and aesthetics, causing patients problems such as early tooth loss, severe embarrassment, eating difficulties, and pain. It was first described separately from diseases of dentine nearly 80 years ago, but the underlying genetic and mechanistic basis of the condition is only now coming to light. Mutations in the gene AMELX, encoding an extracellular matrix protein secreted by ameloblasts during enamel formation, were first identified as a cause of AI in 1991. Since then, mutations in at least eighteen genes have been shown to cause AI presenting in isolation of other health problems, with many more implicated in syndromic AI. Some of the encoded proteins have well documented roles in amelogenesis, acting as enamel matrix proteins or the proteases that degrade them, cell adhesion molecules or regulators of calcium homeostasis. However, for others, function is less clear and further research is needed to understand the pathways and processes essential for the development of healthy enamel. Here, we review the genes and mutations underlying AI presenting in isolation of other health problems, the proteins they encode and knowledge of their roles in amelogenesis, combining evidence from human phenotypes, inheritance patterns, mouse models, and in vitro studies. An LOVD resource (http://dna2.leeds.ac.uk/LOVD/) containing all published gene mutations for AI presenting in isolation of other health problems is described. We use this resource to identify trends in the genes and mutations reported to cause AI in the 270 families for which molecular diagnoses have been reported by 23rd May 2017. Finally we discuss the potential value of the translation of AI genetics to clinical care with improved patient pathways and speculate on the possibility of novel treatments and prevention strategies for AI.
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Affiliation(s)
- Claire E L Smith
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom.,Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - James A Poulter
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Agne Antanaviciute
- Section of Genetics, School of Medicine, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Jennifer Kirkham
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Steven J Brookes
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Chris F Inglehearn
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Alan J Mighell
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom.,Oral Medicine, School of Dentistry, University of LeedsLeeds, United Kingdom
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22
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Kitay AM, Geibel JP. Stomach and Bone. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1033:97-131. [DOI: 10.1007/978-3-319-66653-2_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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23
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Bronckers ALJJ, Jalali R, Lytton J. Reduced Protein Expression of the Na +/Ca 2++K +-Exchanger (SLC24A4) in Apical Plasma Membranes of Maturation Ameloblasts of Fluorotic Mice. Calcif Tissue Int 2017; 100:80-86. [PMID: 27752731 PMCID: PMC5215084 DOI: 10.1007/s00223-016-0197-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 10/03/2016] [Indexed: 02/07/2023]
Abstract
Exposure of forming enamel to fluoride results into formation of hypomineralized enamel. We tested whether enamel hypomineralization was caused by lower expression of the NCKX4/SLC24A4 Ca2+-transporter by ameloblasts. Three commercial antibodies against NCKX4 were tested on enamel organs of wild-type and Nckx4-null mice, one of which (a mouse monoclonal) was specific. This antibody gave a prominent staining of the apical plasma membranes of maturation ameloblasts, starting at early maturation. The layer of immuno-positive ameloblasts contained narrow gaps without immunostaining or with reduced staining. In fluorotic mouse incisors, the quantity of NCKX4 protein in ameloblasts as assessed by western blotting was not different from that in non-fluorotic ameloblasts. However, immunostaining of the apical plasma membranes of fluorotic ameloblasts was strongly reduced or absent suggesting that trafficking of NCKX4 to the apical membrane was strongly reduced. Exposure to fluoride may reduce NCKX4-mediated transport of Ca2+ by maturation stage ameloblasts which delays ameloblast modulation and reduces enamel mineralization.
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Affiliation(s)
- A L J J Bronckers
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081LA, Amsterdam, The Netherlands.
| | - R Jalali
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), MOVE Research Institute, University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081LA, Amsterdam, The Netherlands
| | - J Lytton
- Department of Biochemistry and Molecular Biology, Hotchkiss Brain Institute and Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 4Z6, Canada
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24
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Szerencsei RT, Ginger RS, Green MR, Schnetkamp PPM. Identification and Characterization of K+-Dependent Na+-Ca2+ Exchange Transport in Pigmented MEB4 Cells Mediated by NCKX4. Biochemistry 2016; 55:2704-12. [DOI: 10.1021/acs.biochem.6b00017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Robert T. Szerencsei
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary T2N 4N1, Canada
| | - Rebecca S. Ginger
- Unilever R&D, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, U.K
| | - Martin R. Green
- Unilever R&D, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, U.K
| | - Paul P. M. Schnetkamp
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary T2N 4N1, Canada
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Taylor JY, Wright ML, Crusto CA, Sun YV. The Intergenerational Impact of Genetic and Psychological Factors on Blood Pressure (InterGEN) Study: Design and Methods for Complex DNA Analysis. Biol Res Nurs 2016; 18:521-30. [PMID: 27118148 DOI: 10.1177/1099800416645399] [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: 01/11/2023]
Abstract
The Intergenerational Impact of Genetic and Psychological Factors on Blood Pressure (InterGEN) study aims to delineate the independent and interaction effects of genomic (genetic and epigenetic) and psychological-environmental (maternally perceived racial discrimination, mental health, and parenting behavior) factors on blood pressure (BP) among African American mother-child dyads over time. The purpose of this article is to describe the two-step genetic and epigenetic approach that will be executed to explore Gene × Environment interactions on BP using a longitudinal cohort design. Procedure for the single collection of DNA at Time 1 includes the use of the Oragene 500-format saliva sample collection tube, which provides enough DNA for both the Illumina Multi-Ethnic Genotyping and 850K EPIC methylation analyses. BP readings, height, weight, percentage of body fat, and percentage of body water will be measured on all participants every 6 months for 2 years for a total of 4 time points. Genomic data analyses to be completed include multivariate modeling, assessment of population admixture and structure, and extended analyses including Bonferroni correction, false discovery rate methods, Monte Carlo approach, EIGENSTRAT methods, and so on, to determine relationships among both main and interaction effects of genetic, epigenetic, and psychological environmental factors on BP.
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Affiliation(s)
| | | | - Cindy A Crusto
- School of Medicine, Yale University, New Haven, CT, USA Department of Psychology, University of Pretoria, Pretoria, South Africa
| | - Yan V Sun
- School of Medicine, Emory University, Atlanta, GA, USA
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Jalloul AH, Rogasevskaia TP, Szerencsei RT, Schnetkamp PPM. A Functional Study of Mutations in K+-dependent Na+-Ca2+ Exchangers Associated with Amelogenesis Imperfecta and Non-syndromic Oculocutaneous Albinism. J Biol Chem 2016; 291:13113-23. [PMID: 27129268 DOI: 10.1074/jbc.m116.728824] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Indexed: 12/20/2022] Open
Abstract
K(+)-dependent Na(+)/Ca(2+) exchangers belong to the solute carrier 24 (SLC24A1-5) gene family of membrane transporters. Five different gene products (NCKX1-5) have been identified in humans, which play key roles in biological processes including vision, olfaction, and skin pigmentation. NCKXs are bi-directional membrane transporters that transport 1 Ca(2+)+K(+) ions in exchange for 4 Na(+) ions. Recent studies have linked mutations in the SLC24A4 (NCKX4) and SLC24A5 (NCKX5) genes to amylogenesis imperfecta (AI) and non-syndromic oculocutaneous albinism (OCA6), respectively. Here, we introduced mutations found in patients with AI and OCA6 into human SLC24A4 (NCKX4) cDNA leading to single residue substitutions in the mutant NCKX4 proteins. We measured NCKX-mediated Ca(2+) transport activity of WT and mutant NCKX4 proteins expressed in HEK293 cells. Three mutant NCKX4 cDNAs represent mutations found in the SCL24A4 gene and three represent mutations found in the SCL24A5 gene involving residues conserved between NCKX4 and NCKX5. Five mutant proteins had no observable NCKX activity, whereas one mutation resulted in a 78% reduction in transport activity. Total protein expression and trafficking to the plasma membrane (the latter with one exception) were not affected in the HEK293 cell expression system. We also analyzed two mutations in a Drosophila NCKX gene that have been reported to result in an increased susceptibility for seizures, and found that both resulted in mutant proteins with significantly reduced but observable NCKX activity. The data presented here support the genetic analyses that mutations in SLC24A4 and SLC24A5 are responsible for the phenotypic defects observed in human patients.
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Affiliation(s)
- Ali H Jalloul
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Tatiana P Rogasevskaia
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Robert T Szerencsei
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Paul P M Schnetkamp
- From the Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Inactivation of C4orf26 in toothless placental mammals. Mol Phylogenet Evol 2015; 95:34-45. [PMID: 26596502 DOI: 10.1016/j.ympev.2015.11.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/22/2015] [Accepted: 11/03/2015] [Indexed: 01/11/2023]
Abstract
Previous studies have reported inactivated copies of six enamel-related genes (AMBN, AMEL, AMTN, ENAM, KLK4, MMP20) and one dentin-related gene (DSPP) in one or more toothless vertebrates and/or vertebrates with enamelless teeth, thereby providing evidence that these genes are enamel or tooth-specific with respect to their critical functions that are maintained by natural selection. Here, we employ available genome sequences for edentulous and enamelless mammals to evaluate the enamel specificity of four genes (WDR72, SLC24A4, FAM83H, C4orf26) that have been implicated in amelogenesis imperfecta, a condition in which proper enamel formation is abrogated during tooth development. Coding sequences for WDR72, SCL24A4, and FAM83H are intact in four edentulous taxa (Chinese pangolin, three baleen whales) and three taxa (aardvark, nine-banded armadillo, Hoffmann's two-toed sloth) with enamelless teeth, suggesting that these genes have critical functions beyond their involvement in tooth development. By contrast, genomic data for C4orf26 reveal inactivating mutations in pangolin and bowhead whale as well as evidence for deletion of this gene in two minke whale species. Hybridization capture of exonic regions and PCR screens provide evidence for inactivation of C4orf26 in eight additional baleen whale species. However, C4orf26 is intact in all three species with enamelless teeth that were surveyed, as well as in 95 additional mammalian species with enamel-capped teeth. Estimates of selection intensity suggest that dN/dS ratios on branches leading to taxa with enamelless teeth are similar to the dN/dS ratio on branches leading to taxa with enamel-capped teeth. Based on these results, we conclude that C4orf26 is tooth-specific, but not enamel-specific, with respect to its essential functions that are maintained by natural selection. A caveat is that an alternative splice site variant, which translates exon 3 in a different reading frame, is putatively functional in Catarrhini and may have evolved an additional role in this primate clade.
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Lin BD, Mbarek H, Willemsen G, Dolan CV, Fedko IO, Abdellaoui A, de Geus EJ, Boomsma DI, Hottenga JJ. Heritability and Genome-Wide Association Studies for Hair Color in a Dutch Twin Family Based Sample. Genes (Basel) 2015; 6:559-76. [PMID: 26184321 PMCID: PMC4584317 DOI: 10.3390/genes6030559] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 01/19/2023] Open
Abstract
Hair color is one of the most visible and heritable traits in humans. Here, we estimated heritability by structural equation modeling (N = 20,142), and performed a genome wide association (GWA) analysis (N = 7091) and a GCTA study (N = 3340) on hair color within a large cohort of twins, their parents and siblings from the Netherlands Twin Register (NTR). Self-reported hair color was analyzed as five binary phenotypes, namely “blond versus non-blond”, “red versus non-red”, “brown versus non-brown”, “black versus non-black”, and “light versus dark”. The broad-sense heritability of hair color was estimated between 73% and 99% and the genetic component included non-additive genetic variance. Assortative mating for hair color was significant, except for red and black hair color. From GCTA analyses, at most 24.6% of the additive genetic variance in hair color was explained by 1000G well-imputed SNPs. Genome-wide association analysis for each hair color showed that SNPs in the MC1R region were significantly associated with red, brown and black hair, and also with light versus dark hair color. Five other known genes (HERC2, TPCN2, SLC24A4, IRF4, and KITLG) gave genome-wide significant hits for blond, brown and light versus dark hair color. We did not find and replicate any new loci for hair color.
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Affiliation(s)
- Bochao Danae Lin
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Hamdi Mbarek
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Gonneke Willemsen
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Conor V Dolan
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Iryna O Fedko
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Abdel Abdellaoui
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Eco J de Geus
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Dorret I Boomsma
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
| | - Jouke-Jan Hottenga
- Department of Biological Psychology, VU University, Amsterdam 1081 BT, The Netherlands.
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Haering C, Kanageswaran N, Bouvain P, Scholz P, Altmüller J, Becker C, Gisselmann G, Wäring-Bischof J, Hatt H. Ion transporter NKCC1, modulator of neurogenesis in murine olfactory neurons. J Biol Chem 2015; 290:9767-79. [PMID: 25713142 DOI: 10.1074/jbc.m115.640656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Indexed: 12/28/2022] Open
Abstract
Olfaction is one of the most crucial senses for vertebrates regarding foraging and social behavior. Therefore, it is of particular interest to investigate the sense of smell, its function on a molecular level, the signaling proteins involved in the process and the mechanism of required ion transport. In recent years, the precise role of the ion transporter NKCC1 in olfactory sensory neuron (OSN) chloride accumulation has been a controversial subject. NKCC1 is expressed in OSNs and is involved in chloride accumulation of dissociated neurons, but it had not been shown to play a role in mouse odorant sensation. Here, we present electro-olfactogram recordings (EOG) demonstrating that NKCC1-deficient mice exhibit significant defects in perception of a complex odorant mixture (Henkel100) in both air-phase and submerged approaches. Using next generation sequencing (NGS) and RT-PCR experiments of NKCC1-deficient and wild type mouse transcriptomes, we confirmed the absence of a highly expressed ion transporter that could compensate for NKCC1. Additional histological investigations demonstrated a reduced number of cells in the olfactory epithelium (OE), resulting in a thinner neuronal layer. Therefore, we conclude that NKCC1 is an important transporter involved in chloride ion accumulation in the olfactory epithelium, but it is also involved in OSN neurogenesis.
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Affiliation(s)
- Claudia Haering
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
| | - Ninthujah Kanageswaran
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
| | - Pascal Bouvain
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
| | - Paul Scholz
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
| | - Janine Altmüller
- the University of Köln, Cologne Center for Genomics, Köln, Germany
| | - Christian Becker
- the University of Köln, Cologne Center for Genomics, Köln, Germany
| | - Günter Gisselmann
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
| | - Janine Wäring-Bischof
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
| | - Hanns Hatt
- From Cell Physiology, Ruhr-University Bochum, Universitaetsstr.150, 44780 Bochum, Germany and
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Hypomaturation amelogenesis imperfecta caused by a novel SLC24A4 mutation. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 119:e77-81. [PMID: 25442250 DOI: 10.1016/j.oooo.2014.09.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 01/22/2023]
Abstract
In this case report of autosomal recessive pigmented hypomaturation amelogenesis imperfecta (AI), we identify a novel homozygous missense mutation (g.165151 T>G; c.1317 T>G; p.Leu436 Arg) in SLC24A4, a gene encoding a potassium-dependent sodium-calcium exchanger that is critical for hardening dental enamel during tooth development.
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31
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Medway C, Morgan K. Review: The genetics of Alzheimer's disease; putting flesh on the bones. Neuropathol Appl Neurobiol 2014; 40:97-105. [PMID: 24443964 PMCID: PMC4282344 DOI: 10.1111/nan.12101] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 11/21/2013] [Indexed: 01/14/2023]
Abstract
For two decades the search for genes involved in Alzheimer's disease brought little reward; it was not until the advent of genome-wide association studies (GWAS) that genetic associations started to be revealed. Since 2009 increasingly large GWAS have revealed 20 loci, which in itself is a substantial increase in our understanding, but perhaps the more important feature is that these studies have highlighted novel pathways that are potentially involved in the disease process. This commentary assembles our latest knowledge while acknowledging that the casual functional variants, and undoubtedly, other genes are still yet to be discovered. This is the challenge that remains and the promise of next-generation sequencing is anticipated as there are a number of large initiatives which themselves should start to yield information before long.
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Affiliation(s)
- C Medway
- Translation Cell Sciences - Human Genetics, School of Life Sciences, Queens Medical Centre, Nottingham, UK
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32
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Li XF, Lytton J. An essential role for the K+-dependent Na+/Ca2+-exchanger, NCKX4, in melanocortin-4-receptor-dependent satiety. J Biol Chem 2014; 289:25445-59. [PMID: 25096581 DOI: 10.1074/jbc.m114.564450] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
K(+)-dependent Na(+)/Ca(2+)-exchangers are broadly expressed in various tissues, and particularly enriched in neurons of the brain. The distinct physiological roles for the different members of this Ca(2+) transporter family are, however, not well described. Here we show that gene-targeted mice lacking the K(+)-dependent Na(+)/Ca(2+)-exchanger, NCKX4 (gene slc24a4 or Nckx4), display a remarkable anorexia with severe hypophagia and weight loss. Feeding and satiety are coordinated centrally by melanocortin-4 receptors (MC4R) in neurons of the hypothalamic paraventricular nucleus (PVN). The hypophagic response of Nckx4 knock-out mice is accompanied by hyperactivation of neurons in the PVN, evidenced by high levels of c-Fos expression. The activation of PVN neurons in both fasted Nckx4 knock-out and glucose-injected wild-type animals is blocked by Ca(2+) removal and MC4R antagonists. In cultured hypothalamic neurons, melanocyte stimulating hormone induces an MC4R-dependent and sustained Ca(2+) signal, which requires phospholipase C activity and plasma membrane Ca(2+) entry. The Ca(2+) signal is enhanced in hypothalamic neurons from Nckx4 knock-out animals, and is depressed in cells in which NCKX4 is overexpressed. Finally, MC4R-dependent oxytocin expression in the PVN, a key essential step in satiety, is prevented by blocking phospholipase C activation or Ca(2+) entry. These findings highlight an essential, and to our knowledge previously unknown, role for Ca(2+) signaling in the MC4R pathway that leads to satiety, and a novel non-redundant role for NCKX4-mediated Ca(2+) extrusion in controlling MC4R signaling and feeding behavior. Together, these findings highlight a novel pathway that potentially could be exploited to develop much needed new therapeutics to tackle eating disorders and obesity.
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Affiliation(s)
- Xiao-Fang Li
- From the Department of Biochemistry and Molecular Biology, Hotchkiss Brain Institute and Libin Cardiovascular Institute of Alberta, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada
| | - Jonathan Lytton
- From the Department of Biochemistry and Molecular Biology, Hotchkiss Brain Institute and Libin Cardiovascular Institute of Alberta, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4Z6, Canada
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Seymen F, Lee KE, Tran Le C, Yildirim M, Gencay K, Lee Z, Kim JW. Exonal Deletion of SLC24A4 Causes Hypomaturation Amelogenesis Imperfecta. J Dent Res 2014; 93:366-70. [DOI: 10.1177/0022034514523786] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Amelogenesis imperfecta is a heterogeneous group of genetic conditions affecting enamel formation. Recently, mutations in solute carrier family 24 member 4 ( SLC24A4) have been identified to cause autosomal recessive hypomaturation amelogenesis imperfecta. We recruited a consanguineous family with hypomaturation amelogenesis imperfecta with generalized brown discoloration. Sequencing of the candidate genes identified a 10-kb deletion, including exons 15, 16, and most of the last exon of the SLC24A4 gene. Interestingly, this deletion was caused by homologous recombination between two 354-bp-long homologous sequences located in intron 14 and the 3′ UTR. This is the first report of exonal deletion in SLC24A4 providing confirmatory evidence that the function of SLC24A4 in calcium transport has a crucial role in the maturation stage of amelogenesis.
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Affiliation(s)
- F. Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - K.-E. Lee
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - C.G. Tran Le
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - M. Yildirim
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - K. Gencay
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - Z.H. Lee
- Department of Cell and Developmental Biology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - J.-W. Kim
- Department of Pediatric Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
- Department of Molecular Genetics and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
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Sharma V, O'Halloran DM. Recent structural and functional insights into the family of sodium calcium exchangers. Genesis 2013; 52:93-109. [PMID: 24376088 DOI: 10.1002/dvg.22735] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 12/04/2013] [Accepted: 12/08/2013] [Indexed: 01/08/2023]
Abstract
Maintenance of calcium homeostasis is necessary for the development and survival of all animals. Calcium ions modulate excitability and bind effectors capable of initiating many processes such as muscular contraction and neurotransmission. However, excessive amounts of calcium in the cytosol or within intracellular calcium stores can trigger apoptotic pathways in cells that have been implicated in cardiac and neuronal pathologies. Accordingly, it is critical for cells to rapidly and effectively regulate calcium levels. The Na(+) /Ca(2+) exchangers (NCX), Na(+) /Ca(2+) /K(+) exchangers (NCKX), and Ca(2+) /Cation exchangers (CCX) are the three classes of sodium calcium antiporters found in animals. These exchanger proteins utilize an electrochemical gradient to extrude calcium. Although they have been studied for decades, much is still unknown about these proteins. In this review, we examine current knowledge about the structure, function, and physiology and also discuss their implication in various developmental disorders. Finally, we highlight recent data characterizing the family of sodium calcium exchangers in the model system, Caenorhabditis elegans, and propose that C. elegans may be an ideal model to complement other systems and help fill gaps in our knowledge of sodium calcium exchange biology.
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Affiliation(s)
- Vishal Sharma
- Department of Biological Sciences, The George Washington University, Washington, DC; Institute for Neuroscience, The George Washington University, Washington, DC
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36
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Schnetkamp PPM. The SLC24 gene family of Na⁺/Ca²⁺-K⁺ exchangers: from sight and smell to memory consolidation and skin pigmentation. Mol Aspects Med 2013; 34:455-64. [PMID: 23506883 DOI: 10.1016/j.mam.2012.07.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 03/09/2012] [Indexed: 01/28/2023]
Abstract
Members of the SLC24 gene family encode K(+)-dependent Na(+)/Ca(2+) exchangers (NCKX) that utilize both the inward Na(+) and outward K(+) gradients to extrude Ca(2+) from cells. There are five human SLC24 genes that play a role in biological process as diverse as vision in retinal rod and cone photoreceptors, olfaction, skin pigmentation and at least three of the five genes are also widely expressed in the brain. Here I review the functional, physiological and structural features of NCKX proteins that have emerged in the past few years.
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Affiliation(s)
- Paul P M Schnetkamp
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, Canada AB T2N 4N1.
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Hart KL, Kimura SL, Mushailov V, Budimlija ZM, Prinz M, Wurmbach E. Improved eye- and skin-color prediction based on 8 SNPs. Croat Med J 2013; 54:248-56. [PMID: 23771755 PMCID: PMC3694299 DOI: 10.3325/cmj.2013.54.248] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Aim To improve the 7-plex system to predict eye and skin color by increasing precision and detailed phenotypic descriptions. Methods Analysis of an eighth single nucleotide polymorphism (SNP), rs12896399 (SLC24A4), showed a statistically significant association with human eye color (P = 0.007) but a rather poor strength of agreement (κ = 0.063). This SNP was added to the 7-plex system (rs12913832 at HERC2, rs1545397 at OCA2, rs16891982 at SLC45A2, rs1426654 at SLC24A5, rs885479 at MC1R, rs6119471 at ASIP, and rs12203592 at IRF4). Further, the instruction guidelines on the interpretation of genotypes were changed to create a new 8-plex system. This was based on the analysis of an 803-sample training set of various populations. The newly developed 8-plex system can predict the eye colors brown, green, and blue, and skin colors light, not dark, and not light. It is superior to the 7-plex system with its additional ability to predict blue eye and light skin color. Results The 8-plex system was tested on an additional 212 samples, the test set. Analysis showed that the number of positive descriptions for eye colors as being brown, green, or blue increased significantly (P = 6.98e-15, z-score: -7.786). The error rate for eye-color prediction was low, at approximately 5%, while the skin color prediction showed no error in the test set (1% in training set). Conclusions We can conclude that the new 8-plex system for the prediction of eye and skin color substantially enhances its former version.
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Affiliation(s)
- Katie L Hart
- Office of Chief Medical Examiner, Department of Forensic Biology, 421East 26th Street, Box 12-79, New York, NY 10016, USA
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Kuroda H, Sobhan U, Sato M, Tsumura M, Ichinohe T, Tazaki M, Shibukawa Y. Sodium-calcium exchangers in rat trigeminal ganglion neurons. Mol Pain 2013; 9:22. [PMID: 23628073 PMCID: PMC3646678 DOI: 10.1186/1744-8069-9-22] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 04/19/2013] [Indexed: 01/10/2023] Open
Abstract
Background Noxious stimulation and nerve injury induce an increase in intracellular Ca2+ concentration ([Ca2+]i) via various receptors or ionic channels. While an increase in [Ca2+]i excites neurons, [Ca2+]i overload elicits cytotoxicity, resulting in cell death. Intracellular Ca2+ is essential for many signal transduction mechanisms, and its level is precisely regulated by the Ca2+ extrusion system in the plasma membrane, which includes the Na+-Ca2+ exchanger (NCX). It has been demonstrated that Ca2+-ATPase is the primary mechanism for removing [Ca2+]i following excitatory activity in trigeminal ganglion (TG) neurons; however, the role of NCXs in this process has yet to be clarified. The goal of this study was to examine the expression/localization of NCXs in TG neurons and to evaluate their functional properties. Results NCX isoforms (NCX1, NCX2, and NCX3) were expressed in primary cultured rat TG neurons. All the NCX isoforms were also expressed in A-, peptidergic C-, and non-peptidergic C-neurons, and located not only in the somata, dendrites, axons and perinuclear region, but also in axons innervating the dental pulp. Reverse NCX activity was clearly observed in TG neurons. The inactivation kinetics of voltage-dependent Na+ channels were prolonged by NCX inhibitors when [Ca2+]i in TG neurons was elevated beyond physiological levels. Conclusions Our results suggest that NCXs in TG neurons play an important role in regulating Ca2+-homeostasis and somatosensory information processing by functionally coupling with voltage-dependent Na+ channels.
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Affiliation(s)
- Hidetaka Kuroda
- Oral Health Science Center hrc8, Tokyo Dental College, Tokyo 261-8502, Japan
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Kopic S, Geibel JP. Gastric acid, calcium absorption, and their impact on bone health. Physiol Rev 2013; 93:189-268. [PMID: 23303909 DOI: 10.1152/physrev.00015.2012] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.
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Affiliation(s)
- Sascha Kopic
- Department of Surgery and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
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Parry D, Poulter J, Logan C, Brookes S, Jafri H, Ferguson C, Anwari B, Rashid Y, Zhao H, Johnson C, Inglehearn C, Mighell A. Identification of mutations in SLC24A4, encoding a potassium-dependent sodium/calcium exchanger, as a cause of amelogenesis imperfecta. Am J Hum Genet 2013; 92:307-12. [PMID: 23375655 PMCID: PMC3567274 DOI: 10.1016/j.ajhg.2013.01.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/04/2013] [Accepted: 01/07/2013] [Indexed: 12/31/2022] Open
Abstract
A combination of autozygosity mapping and exome sequencing identified a null mutation in SLC24A4 in a family with hypomineralized amelogenesis imperfect a (AI), a condition in which tooth enamel formation fails. SLC24A4 encodes a calcium transporter upregulated in ameloblasts during the maturation stage of amelogenesis. Screening of further AI families identified a missense mutation in the ion-binding site of SLC24A4 expected to severely diminish or abolish the ion transport function of the protein. Furthermore, examination of previously generated Slc24a4 null mice identified a severe defect in tooth enamel that reflects impaired amelogenesis. These findings support a key role for SLC24A4 in calcium transport during enamel formation.
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Affiliation(s)
- David A. Parry
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
| | - James A. Poulter
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
| | - Clare V. Logan
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
| | | | - Hussain Jafri
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
- Gene Tech Lab 146/1, Shadman Jail Road, Lahore 54000, Pakistan
| | - Christopher H. Ferguson
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | | | - Yasmin Rashid
- Gene Tech Lab 146/1, Shadman Jail Road, Lahore 54000, Pakistan
| | - Haiqing Zhao
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Colin A. Johnson
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
| | - Chris F. Inglehearn
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
| | - Alan J. Mighell
- Leeds Institute of Molecular Medicine, St James’s University Hospital, University of Leeds, LS9 7TF Leeds, UK
- Leeds Dental Institute, University of Leeds, LS2 9LU Leeds, UK
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Yang H, Choi KC, Jung EM, An BS, Hyun SH, Jeung EB. Expression and regulation of sodium/calcium exchangers, NCX and NCKX, in reproductive tissues: do they play a critical role in calcium transport for reproduction and development? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:109-21. [PMID: 23224874 DOI: 10.1007/978-1-4614-4756-6_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Plasma membrane sodium/calcium (Na(+)/Ca(2+)) exchangers are an important component of intracellular calcium [Ca(2+)](i) homeostasis and electrical conduction. Na(+)/Ca(2+) exchangers, NCX and NCKX, play a critical role in the transport of one [Ca(2+)](i) and potassium ion across the cell membrane in exchange for four extracellular sodium ions [Na(+)](e). Mammalian plasma membrane Na(+)/Ca(2+) exchange proteins are divided into two families: one in which Ca(2+) flux is dependent only on sodium (NCX1-3) and another in which Ca(2+) flux is also dependent on potassium (NCKX1-4). Both molecules are capable of forward- and reverse-mode exchange. In cells and tissues, Na(+)/Ca(2+) (and K(+)) gradients localize to the cell membrane; thus, the exchangers transport ions across a membrane potential. Uterine NCKX3 has been shown to be involved in the regulation of endometrial receptivity by [Ca(2+)](i). In the uterus and placenta, NCKX3 expression is regulated by the sex steroid hormone estrogen (E2) and hypoxia stress, respectively. In this chapter, we described the expression and regulation of these proteins for reproductive functions in various tissues including uterus, placenta, and kidney of humans and rodents. Evidence to date suggests that NCKX3 and NCX1 may be regulated in a tissue-specific manner. In addition, we focused on the molecular mechanism involved in the regulation of NCKX3 and NCX1 in mammals, based upon our recent results and those of others.
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Affiliation(s)
- Hyun Yang
- College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
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Hu P, Lacruz RS, Smith CE, Smith SM, Kurtz I, Paine ML. Expression of the sodium/calcium/potassium exchanger, NCKX4, in ameloblasts. Cells Tissues Organs 2012; 196:501-9. [PMID: 22677781 DOI: 10.1159/000337493] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2012] [Indexed: 11/19/2022] Open
Abstract
Transcellular calcium transport is an essential activity in mineralized tissue formation, including dental hard tissues. In many organ systems, this activity is regulated by membrane-bound sodium/calcium (Na(+)/Ca(2+)) exchangers, which include the NCX and NCKX [sodium/calcium-potassium (Na(+)/Ca(2+)-K(+)) exchanger] proteins. During enamel maturation, when crystals expand in thickness, Ca(2+) requirements vastly increase but exactly how Ca(2+) traffics through ameloblasts remains uncertain. Previous studies have shown that several NCX proteins are expressed in ameloblasts, although no significant shifts in expression were observed during maturation which pointed to the possible identification of other Ca(2+) membrane transporters. NCKX proteins are encoded by members of the solute carrier gene family, Slc24a, which include 6 different proteins (NCKX1-6). NCKX are bidirectional electrogenic transporters regulating Ca(2+) transport in and out of cells dependent on the transmembrane ion gradient. In this study we show that all NCKX mRNAs are expressed in dental tissues. Real-time PCR indicates that of all the members of the NCKX group, NCKX4 is the most highly expressed gene transcript during the late stages of amelogenesis. In situ hybridization and immunolocalization analyses clearly establish that in the enamel organ, NCKX4 is expressed primarily by ameloblasts during the maturation stage. Further, during the mid-late maturation stages of amelogenesis, the expression of NCKX4 in ameloblasts is most prominent at the apical poles and at the lateral membranes proximal to the apical ends. These data suggest that NCKX4 might be an important regulator of Ca(2+) transport during amelogenesis.
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Affiliation(s)
- Ping Hu
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90033, USA
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The Na(+)/Ca(2+) exchanger NCKX4 governs termination and adaptation of the mammalian olfactory response. Nat Neurosci 2011; 15:131-7. [PMID: 22057188 PMCID: PMC3245797 DOI: 10.1038/nn.2943] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 08/29/2011] [Indexed: 11/09/2022]
Abstract
Sensory perception requires accurate encoding of stimulus information by sensory receptor cells. We identified NCKX4, a potassium-dependent Na(+)/Ca(2+) exchanger, as being necessary for rapid response termination and proper adaptation of vertebrate olfactory sensory neurons (OSNs). Nckx4(-/-) (also known as Slc24a4) mouse OSNs displayed substantially prolonged responses and stronger adaptation. Single-cell electrophysiological analyses revealed that the majority of Na(+)-dependent Ca(2+) exchange in OSNs relevant to sensory transduction is a result of NCKX4 and that Nckx4(-/-) mouse OSNs are deficient in encoding action potentials on repeated stimulation. Olfactory-specific Nckx4(-/-) mice had lower body weights and a reduced ability to locate an odorous source. These results establish the role of NCKX4 in shaping olfactory responses and suggest that rapid response termination and proper adaptation of peripheral sensory receptor cells tune the sensory system for optimal perception.
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Yang H, Kim TH, Lee HH, Choi KC, Jeung EB. Distinct expression of the calcium exchangers, NCKX3 and NCX1, and their regulation by steroid in the human endometrium during the menstrual cycle. Reprod Sci 2011; 18:577-85. [PMID: 21321244 DOI: 10.1177/1933719110396229] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Plasma membrane sodium/calcium exchangers are an important component of intracellular calcium homeostasis and electrical conduction. The potassium-dependent sodium/calcium exchangers NCKX3 (gene SLC24A3) and NCX1 (gene SLC8A1) play a critical role in the transport of intracellular calcium across the cell membrane in exchange for extracellular sodium ions. NCKX3 and NCX1 transcripts are most abundant in the brain and smooth muscle, but many other tissues, particularly the uterus, aorta, and intestine, also express this gene at lower levels. However, the expression patterns and physiological roles of NCKX3 and NCX1 in the human endometrium during the menstrual cycle are unknown. Thus, we examined the endometrial expression of NCKX3 and NCX1 messenger RNA (mRNA) and protein throughout the different phases of the menstrual cycle. Endometrial expression of NCKX3 mRNA and protein was increased 1.5- to 2.5-fold during the early-proliferative, mid-proliferative, and early-secretory phases compared with the other phases; however, no significant alteration in NCX1 expression level was observed. The effects of the sex-steroid hormones, 17β-estradiol (E2) and progesterone (P4), on the expression of NCKX3 and NCX1 in Ishikawa cells was also investigated. NCKX3 expression was significantly increased by E2 (10(-8) mol/L). However, the expression of NCX1 was not affected by E2 and P4. Subsequent immunohistochemical analysis revealed that the uterine NCKX3 and NCX1 proteins were abundantly localized in the cytoplasm of luminal and glandular epithelial cells throughout the menstrual cycle. Taken together, these results indicate that NCKX3 is abundantly expressed within the human endometrium at the transcriptional and translational levels, and its level appears to be regulated by a steroid hormone, in particular, E2 during the human menstrual cycle.
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Affiliation(s)
- Hyun Yang
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
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Altimimi HF, Fung EH, Winkfein RJ, Schnetkamp PPM. Residues contributing to the Na(+)-binding pocket of the SLC24 Na(+)/Ca(2+)-K(+) Exchanger NCKX2. J Biol Chem 2010; 285:15245-15255. [PMID: 20231282 DOI: 10.1074/jbc.m109.090738] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Na(+)/Ca(2+)-K(+) exchangers (NCKX; gene family SLC24) are plasma membrane Ca(2+) transporters that mediate the extrusion of one Ca(2+) ion and one K(+) ion in exchange for four Na(+) ions. NCKX is modeled to have two sets of five transmembrane segments separated by a large cytosolic loop; within each set of transmembrane segments are regions of internal symmetry termed alpha(1) and alpha(2) repeats. The central residues that are important for Ca(2+) and K(+) liganding and transport have been identified in NCKX2, and they comprise three central acidic residues, Glu(188) in alpha(1) and Asp(548) and Asp(575) in alpha(2), as well as Ser/Thr residues one-helical turn away from these residues. In this study, we have scanned through more than 100 single-residue substitutions of NCKX2 for shifts in Na(+) affinity using a fluorescence assay to monitor changes in free Ca(2+) in HEK293 cells treated with gramicidin to control intracellular Na(+). We have identified 31 residues that, when substituted, result in shifts in Na(+) affinity, either toward higher or lower K(m) values when compared with wild type NCKX2 (K(m) for Na(+) 58 mm). These residues include the central acidic residues Glu(188), Asp(548), and Asp(575), and their neighboring residues in alpha(1) and alpha(2), in addition to a number of newly investigated residues in transmembrane segment 3. Our results relate the identification of residues important for Na(+) transport in this study to those previously identified as important in the counter-transport of Ca(2+) and K(+), lending support to the alternating access model of transmembrane transport.
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Affiliation(s)
- Haider F Altimimi
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Eric H Fung
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Robert J Winkfein
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Paul P M Schnetkamp
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
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Adeyemo A, Gerry N, Chen G, Herbert A, Doumatey A, Huang H, Zhou J, Lashley K, Chen Y, Christman M, Rotimi C. A genome-wide association study of hypertension and blood pressure in African Americans. PLoS Genet 2009; 5:e1000564. [PMID: 19609347 PMCID: PMC2702100 DOI: 10.1371/journal.pgen.1000564] [Citation(s) in RCA: 350] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 06/16/2009] [Indexed: 12/15/2022] Open
Abstract
The evidence for the existence of genetic susceptibility variants for the common form of hypertension (“essential hypertension”) remains weak and inconsistent. We sought genetic variants underlying blood pressure (BP) by conducting a genome-wide association study (GWAS) among African Americans, a population group in the United States that is disproportionately affected by hypertension and associated complications, including stroke and kidney diseases. Using a dense panel of over 800,000 SNPs in a discovery sample of 1,017 African Americans from the Washington, D.C., metropolitan region, we identified multiple SNPs reaching genome-wide significance for systolic BP in or near the genes: PMS1, SLC24A4, YWHA7, IPO7, and CACANA1H. Two of these genes, SLC24A4 (a sodium/potassium/calcium exchanger) and CACNA1H (a voltage-dependent calcium channel), are potential candidate genes for BP regulation and the latter is a drug target for a class of calcium channel blockers. No variant reached genome wide significance for association with diastolic BP (top scoring SNP rs1867226, p = 5.8×10−7) or with hypertension as a binary trait (top scoring SNP rs9791170, p = 5.1×10−7). We replicated some of the significant SNPs in a sample of West Africans. Pathway analysis revealed that genes harboring top-scoring variants cluster in pathways and networks of biologic relevance to hypertension and BP regulation. This is the first GWAS for hypertension and BP in an African American population. The findings suggests that, in addition to or in lieu of relying solely on replicated variants of moderate-to-large effect reaching genome-wide significance, pathway and network approaches may be useful in identifying and prioritizing candidate genes/loci for further experiments. Despite intense research, the genetic risk factors for essential hypertension and blood pressure (BP) regulation have not been identified with consistency. We conducted a genome wide association scan using over 800,000 genetic markers in an African American sample of 1,017 adults in the Washington, D.C., area of the United States. We found evidence to suggest that genetic variants in several genes, including PMS1, SLC24A4, YWHA7, IPO7, and CACANA1H, are significantly associated with systolic BP levels. From our previous knowledge of human physiology, two of these genes have potential roles to play in BP regulation. The evidence for genetic variants influencing diastolic BP levels and hypertension status was weaker and inconclusive. To our knowledge, this is the first study that has used a genome-wide association approach to study hypertension and BP in an African American population, a minority group that experiences hypertension more frequently and more severely than other population groups in the United States. The findings will be useful to other researchers seeking to advance our understanding of the genetic factors that influence BP with the hope that these insights will eventually translate to new and better treatment options for hypertension in African Americans and other global populations.
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Affiliation(s)
- Adebowale Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (AA); (CR)
| | - Norman Gerry
- The Coriell Institute for Biomedical Research, Camden, New Jersey, United States of America
| | - Guanjie Chen
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alan Herbert
- Department of Genetics and Genomics, Boston University, Boston, Massachusetts, United States of America
| | - Ayo Doumatey
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hanxia Huang
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jie Zhou
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kerrie Lashley
- National Human Genome Center, Howard University, Washington, D.C., United States of America
| | - Yuanxiu Chen
- National Human Genome Center, Howard University, Washington, D.C., United States of America
| | - Michael Christman
- The Coriell Institute for Biomedical Research, Camden, New Jersey, United States of America
| | - Charles Rotimi
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (AA); (CR)
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Yang H, Lee GS, Yoo YM, Choi KC, Jeung EB. Sodium/potassium/calcium exchanger 3 is regulated by the steroid hormones estrogen and progesterone in the uterus of mice during the estrous cycle. Biochem Biophys Res Commun 2009; 385:279-83. [DOI: 10.1016/j.bbrc.2009.05.076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 05/15/2009] [Indexed: 12/24/2022]
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Lee GS, Choi KC, Jeung EB. K+-dependent Na+/Ca2+ exchanger 3 is involved in renal active calcium transport and is differentially expressed in the mouse kidney. Am J Physiol Renal Physiol 2009; 297:F371-9. [PMID: 19474185 DOI: 10.1152/ajprenal.90615.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Previously, we reported that renal active calcium-transporting genes are highly expressed in female mice and suggested that renal calcium-processing genes play a critical role in normal calcium reabsorption in females (Lee GS, Lee KY, Choi KC, Ryu YH, Paik SG, Oh GT, Jeung EB. J Bone Miner Res 22: 1968-1978, 2007). In the current study, we evaluated the differential expression of renal calcium-processing genes in male and female mice. Using microarray analysis, we identified K(+)-dependent Na(+)/Ca(2+) exchanger 3 (NCKX3) as a gene that was differentially expressed in the kidneys of female and male mice. The expression levels of renal NCKX3 mRNA and protein were higher in female than in male mice, whereas there was no difference between the genders in the levels of NCKX3 expression in the brain. Renal NCKX3 localized to the basolateral layer of distal convoluted tubules, indicating that this protein participates in renal calcium reabsorption. To identify putative regulators in the gender-specific expression of NCKX3, several hormones were injected into mature female and male mice. Although any hormones did not alter NCKX3 expression, adrenal gland-secreted hormones aldosterone and hydrocortisone did downregulate renal NCKX3 mRNA expression in female mice, but they did not change its protein levels. Taken together, the results in this study suggest that a high level of renal NCKX3 expression maintain in distal convoluted tubules may play a role in active calcium transport in the kidneys of female mice.
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Affiliation(s)
- Geun-Shik Lee
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Chungbuk, Republic of Korea
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Guerini D, Coletto L, Carafoli E. Exporting calcium from cells. Cell Calcium 2008; 38:281-9. [PMID: 16102821 DOI: 10.1016/j.ceca.2005.06.032] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 01/11/2023]
Abstract
All eukaryotic cells import Ca2+ through a number of variously gated plasma membrane channels. Once inside cells, Ca2+ transmits information to a large number of (enzyme) targets. Eventually, it must be exported again, to prevent the overloading of the cytosol with Ca2+. Two systems export Ca2+ from cells: a high affinity, low capacity Ca2+-ATPase, and a lower affinity, but much larger capacity, Na+/Ca2+ exchanger. The ATPase (commonly called the Ca2+ pump) is the fine-tuner of cell Ca2+, as it functions well even if the concentration of the ion drops below the microM level. It is a large enzyme, with 10 transmembrane domains and a C-terminal cytosolic tail that contains regulatory sites, including a calmodulin-binding domain. Four distinct gene products plus a large number of splice variants have been described. Some are tissue specific, the isoform 2 being specifically expressed in the sensorial cells of the Corti organ in the inner-ear. Its genetic absence causes deafness in mice. Two different families of the Na+/Ca2+ exchanger exist, one of which, originally described in photoreceptors, transports K+ and Ca2+ in exchange for Na+. The exchanger is particularly active in excitable cells, e.g., heart, where the necessity cyclically arises to rapidly eject large amounts of Ca2+. In addition to heart, the exchanger is particularly important to neurons: the cleavage of the most important neuronal isoform (NCX3) by calpains activated by excitotoxic treatments generates Ca2+ overload and eventually cell death.
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A critical role for the potassium-dependent sodium-calcium exchanger NCKX2 in protection against focal ischemic brain damage. J Neurosci 2008; 28:2053-63. [PMID: 18305240 DOI: 10.1523/jneurosci.4912-07.2008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The superfamily of cation/Ca2+ plasma-membrane exchangers contains two branches, the K+-independent Na+-Ca2+ exchangers (NCXs) and the K+-dependent Na+-Ca2+ exchangers (NCKXs), widely expressed in mammals. NCKX2 is the major neuronally expressed isoform among NCKX members. Despite its importance in maintaining Na+, Ca2+, and K+ homeostasis in the CNS, the role of NCKX2 during cerebral ischemia, a condition characterized by an alteration of ionic concentrations, has not yet been investigated. The present study examines NCKX2 role in the development of ischemic brain damage in permanent middle cerebral artery occlusion (pMCAO) and transient middle cerebral artery occlusion. Furthermore, to evaluate the effect of nckx2 ablation on neuronal survival, nckx2-/- primary cortical neurons were subjected to oxygen glucose deprivation plus reoxygenation. NCKX2 mRNA and protein expression was evaluated in the ischemic core and surrounding ipsilesional areas, at different time points after pMCAO in rats. In ischemic core and in periinfarctual area, NCKX2 mRNA and protein expression were downregulated. In addition, NCKX2 knock-down by antisense oligodeoxynucleotide and NCKX2 knock-out by genetic disruption dramatically increased infarct volume. Accordingly, nckx2-/- primary cortical neurons displayed a higher vulnerability and a greater [Ca2+]i increase under hypoxic conditions, compared with nckx2+/+ neurons. In addition, NCKX currents both in the forward and reverse mode of operation were significantly reduced in nckx2-/- neurons compared with nckx2+/+ cells. Overall, these results indicate that NCKX2 is involved in brain ischemia, and it may represent a new potential target to be investigated in the study of the molecular mechanisms involved in cerebral ischemia.
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