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Luo S, Rollins S, Schmitz-Abe K, Tam A, Li Q, Shi J, Lin J, Wang R, Agrawal PB. The solute carrier family 26 member 9 modifies rapidly progressing cystic fibrosis associated with homozygous F508del CFTR mutation. Clin Chim Acta 2024; 561:119765. [PMID: 38852790 DOI: 10.1016/j.cca.2024.119765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/14/2024] [Accepted: 06/04/2024] [Indexed: 06/11/2024]
Abstract
BACKGROUND AND AIMS Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations to the CF transmembrane conductance regulator (CFTR). Symptoms and severity of the disease can be quite variable suggesting modifier genes play an important role. MATERIALS AND METHODS Exome sequencing was performed on six individuals carrying homozygous deltaF508 for CFTR genotype but present with rapidly progressing CF (RPCF). Data was analyzed using an unbiased genome-wide genetic burden test against 3076 controls. Single cell RNA sequencing data from LungMAP was utilized to evaluate unique and co-expression of candidate genes, and structural modeling to evaluate the deleterious effects of identified candidate variants. RESULTS We have identified solute carrier family 26 member 9 (SLC26A9) as a modifier gene to be associated with RPCF. Two rare missense SLC26A9 variants were discovered in three of six individuals deemed to have RPCF: c.229G > A; p.G77S (present in two patients), and c.1885C > T; p.P629S. Co-expression of SLC26A9 and CFTR mRNA is limited across different lung cell types, with the highest level of co-expression seen in human (6.3 %) and mouse (9.0 %) alveolar type 2 (AT2) cells. Structural modeling suggests deleterious effects of these mutations as they are in critical protein domains which might affect the anion transport capability of SLC26A9. CONCLUSION The enrichment of rare and potentially deleterious SLC26A9 mutations in patients with RPCF suggests SLC26A9 may act as an alternative anion transporter in CF and is a modifier gene associated with this lung phenotype.
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Affiliation(s)
- Shiyu Luo
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health System, Miami, FL 33136, USA; Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Stuart Rollins
- Division of Pulmonary Medicine, Boston Children's Hospital, USA; Department of Medicine, Harvard Medical School, USA
| | - Klaus Schmitz-Abe
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health System, Miami, FL 33136, USA; Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Amy Tam
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Qifei Li
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health System, Miami, FL 33136, USA; Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jiahai Shi
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jasmine Lin
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Ruobing Wang
- Division of Pulmonary Medicine, Boston Children's Hospital, USA; Department of Medicine, Harvard Medical School, USA; Center for Regenerative Medicine of Boston University and Boston Medical Center, Boston, MA 02115, USA.
| | - Pankaj B Agrawal
- Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health System, Miami, FL 33136, USA; Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Delpiano L, Rodenburg LW, Burke M, Nelson G, Amatngalim GD, Beekman JM, Gray MA. Dynamic regulation of airway surface liquid pH by TMEM16A and SLC26A4 in cystic fibrosis nasal epithelia with rare mutations. Proc Natl Acad Sci U S A 2023; 120:e2307551120. [PMID: 37967223 PMCID: PMC10666107 DOI: 10.1073/pnas.2307551120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 09/28/2023] [Indexed: 11/17/2023] Open
Abstract
In cystic fibrosis (CF), defects in the CF transmembrane conductance regulator (CFTR) channel lead to an acidic airway surface liquid (ASL), which compromises innate defence mechanisms, predisposing to pulmonary failure. Restoring ASL pH is a potential therapy for people with CF, particularly for those who cannot benefit from current highly effective modulator therapy. However, we lack a comprehensive understanding of the complex mechanisms underlying ASL pH regulation. The calcium-activated chloride channel, TMEM16A, and the anion exchanger, SLC26A4, have been proposed as targets for restoring ASL pH, but current results are contradictory and often utilise nonphysiological conditions. To provide better evidence for a role of these two proteins in ASL pH homeostasis, we developed an efficient CRISPR-Cas9-based approach to knock-out (KO) relevant transporters in primary airway basal cells lacking CFTR and then measured dynamic changes in ASL pH under thin-film conditions in fully differentiated airway cultures, which better simulate the in vivo situation. Unexpectantly, we found that both proteins regulated steady-state as well as agonist-stimulated ASL pH, but only under inflammatory conditions. Furthermore, we identified two Food and Drug Administration (FDA)-approved drugs which raised ASL pH by activating SLC26A4. While we identified a role for SLC26A4 in fluid absorption, KO had no effect on cyclic adenosine monophosphate (cAMP)-stimulated fluid secretion in airway organoids. Overall, we have identified a role of TMEM16A in ASL pH homeostasis and shown that both TMEM16A and SLC26A4 could be important alternative targets for ASL pH therapy in CF, particularly for those people who do not produce any functional CFTR.
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Affiliation(s)
- Livia Delpiano
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Lisa W Rodenburg
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Member of the European Reference Network-LUNG, Utrecht 3584 EA, The Netherlands
- Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CT, The Netherlands
| | - Matthew Burke
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Glyn Nelson
- Bioimaging Unit, Ageing Research Laboratories, Campus for Ageing and Vitality, Newcastle University, Newcastle Upon Tyne NE4 5PL, United Kingdom
| | - Gimano D Amatngalim
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Member of the European Reference Network-LUNG, Utrecht 3584 EA, The Netherlands
- Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CT, The Netherlands
| | - Jeffrey M Beekman
- Department of Pediatric Pulmonology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Member of the European Reference Network-LUNG, Utrecht 3584 EA, The Netherlands
- Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CT, The Netherlands
- Centre for Living Technologies, Alliance Eindhoven University of Technology, Wageningen University and Research, Utrecht University, University Medical Center Utrecht, Utrecht 3584 CB, The Netherlands
| | - Michael A Gray
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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3
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Kunzelmann K, Ousingsawat J, Kraus A, Park JH, Marquardt T, Schreiber R, Buchholz B. Pathogenic Relationships in Cystic Fibrosis and Renal Diseases: CFTR, SLC26A9 and Anoctamins. Int J Mol Sci 2023; 24:13278. [PMID: 37686084 PMCID: PMC10487509 DOI: 10.3390/ijms241713278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
The Cl--transporting proteins CFTR, SLC26A9, and anoctamin (ANO1; ANO6) appear to have more in common than initially suspected, as they all participate in the pathogenic process and clinical outcomes of airway and renal diseases. In the present review, we will therefore concentrate on recent findings concerning electrolyte transport in the airways and kidneys, and the role of CFTR, SLC26A9, and the anoctamins ANO1 and ANO6. Special emphasis will be placed on cystic fibrosis and asthma, as well as renal alkalosis and polycystic kidney disease. In essence, we will summarize recent evidence indicating that CFTR is the only relevant secretory Cl- channel in airways under basal (nonstimulated) conditions and after stimulation by secretagogues. Information is provided on the expressions of ANO1 and ANO6, which are important for the correct expression and function of CFTR. In addition, there is evidence that the Cl- transporter SLC26A9 expressed in the airways may have a reabsorptive rather than a Cl--secretory function. In the renal collecting ducts, bicarbonate secretion occurs through a synergistic action of CFTR and the Cl-/HCO3- transporter SLC26A4 (pendrin), which is probably supported by ANO1. Finally, in autosomal dominant polycystic kidney disease (ADPKD), the secretory function of CFTR in renal cyst formation may have been overestimated, whereas ANO1 and ANO6 have now been shown to be crucial in ADPKD and therefore represent new pharmacological targets for the treatment of polycystic kidney disease.
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Affiliation(s)
- Karl Kunzelmann
- Physiological Institute, University of Regensburg, University Street 31, 93053 Regensburg, Germany; (J.O.); (R.S.)
| | - Jiraporn Ousingsawat
- Physiological Institute, University of Regensburg, University Street 31, 93053 Regensburg, Germany; (J.O.); (R.S.)
| | - Andre Kraus
- Department of Nephrology and Hypertension, Friedrich Alexander University Erlangen Nuremberg, 91054 Erlangen, Germany; (A.K.); (B.B.)
| | - Julien H. Park
- Department of Pediatrics, University Hospital Münster, 48149 Münster, Germany; (J.H.P.); (T.M.)
| | - Thorsten Marquardt
- Department of Pediatrics, University Hospital Münster, 48149 Münster, Germany; (J.H.P.); (T.M.)
| | - Rainer Schreiber
- Physiological Institute, University of Regensburg, University Street 31, 93053 Regensburg, Germany; (J.O.); (R.S.)
| | - Björn Buchholz
- Department of Nephrology and Hypertension, Friedrich Alexander University Erlangen Nuremberg, 91054 Erlangen, Germany; (A.K.); (B.B.)
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4
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Gavioli Santos L, Villa-Nova Pereira S, Henrique Pezzo Kmit A, Cardoso Bonadia L, Silvia Bertuzzo C, Dirceu Ribeiro J, Nitsch Mazzola T, Augusto Lima Marson F. Identification of Single Nucleotide Variants in SLC26A9 Gene in Patients with Cystic Fibrosis (p.Phe508del Homozygous) and its Association to Orkambi® (Lumacaftor and Ivacaftor) Response in vitro. Gene 2023; 871:147428. [PMID: 37068695 DOI: 10.1016/j.gene.2023.147428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/28/2023] [Accepted: 04/10/2023] [Indexed: 04/19/2023]
Abstract
BACKGROUND Since patients with cystic fibrosis with different Cystic Fibrosis Transmembrane Regulator (CFTR) genotypes present a wide response variability for modulator drugs such as Orkambi®, it is important to screen variants in candidate genes with an impact on precision and personalized medicine, such as Solute Carrier Family 26, member 9 (SLC26A9) gene. METHODS Sanger sequencing for the exons and intron-exon boundary junctions of the SLC26A9 gene was employed in nine individuals with p.Phe508del homozygous genotype for the CFTR gene who were not under CFTR modulators therapy. The sequencing variants were evaluated by in silico prediction tools. The CFTR function was measured by cAMP-stimulated current (ΔIsc-eq-FSK) in polarized CFTR of human nasal epithelial cells cultured in micro-Ussing chambers with Orkambi®. RESULTS We found 24 intronic variants, three in the coding region (missense variants - rs74146719 and rs16856462 and synonymous - rs33943971), and three in the three prime untranslated region (3' UTR) region in the SLC26A9 gene. Twenty variants were considered benign according to American College of Medical Genetics and Genomics guidelines, and ten were classified as uncertain significance. Although some variants had deleterious predictions or possible alterations in splicing, the majority of predictions were benign or neutral. When we analyzed the ΔIsc-eq-FSK response to Orkambi®, there were no significant differences within the genotypes and alleles for all 30 variants in the SLC26A9 gene. CONCLUSIONS Among the nine individuals with p.Phe508del homozygous genotype for the CFTR gene, no pathogenic SLC26A9 variants were found, and we did not detect associations from the 30 SLC26A9 variants and the response to the Orkambi® in vitro.
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Affiliation(s)
- Luana Gavioli Santos
- Laboratory of Medical Genetics and Genome Medicine, Department of Medical Genetics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - Stéphanie Villa-Nova Pereira
- Laboratory of Medical Genetics and Genome Medicine, Department of Medical Genetics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - Arthur Henrique Pezzo Kmit
- Center for Investigation in Pediatrics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - Luciana Cardoso Bonadia
- Laboratory of Medical Genetics and Genome Medicine, Department of Medical Genetics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - Carmem Silvia Bertuzzo
- Laboratory of Medical Genetics and Genome Medicine, Department of Medical Genetics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - José Dirceu Ribeiro
- Center for Investigation in Pediatrics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - Taís Nitsch Mazzola
- Center for Investigation in Pediatrics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil.
| | - Fernando Augusto Lima Marson
- Laboratory of Medical Genetics and Genome Medicine, Department of Medical Genetics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil; Center for Investigation in Pediatrics, Faculty of Medical Sciences, University of Campinas, Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas 13083-887, São Paulo, Brazil; Laboratory of Human and Medical Genetics, Laboratory of Cell and Molecular Tumor Biology and Bioactive Compounds, São Francisco University, Avenida São Francisco de Assis, 218, Jardim São José, Bragança Paulista 12916-900, São Paulo, Brazil.
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5
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Jo S, Centeio R, Park J, Ousingsawat J, Jeon DK, Talbi K, Schreiber R, Ryu K, Kahlenberg K, Somoza V, Delpiano L, Gray MA, Amaral MD, Railean V, Beekman JM, Rodenburg LW, Namkung W, Kunzelmann K. The SLC26A9 inhibitor S9-A13 provides no evidence for a role of SLC26A9 in airway chloride secretion but suggests a contribution to regulation of ASL pH and gastric proton secretion. FASEB J 2022; 36:e22534. [PMID: 36183361 DOI: 10.1096/fj.202200313rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 11/11/2022]
Abstract
The solute carrier 26 family member A9 (SLC26A9) is an epithelial anion transporter that is assumed to contribute to airway chloride secretion and surface hydration. Whether SLC26A9 or CFTR is responsible for airway Cl- transport under basal conditions is still unclear, due to the lack of a specific inhibitor for SLC26A9. In the present study, we report a novel potent and specific inhibitor for SLC26A9, identified by screening of a drug-like molecule library and subsequent chemical modifications. The most potent compound S9-A13 inhibited SLC26A9 with an IC50 of 90.9 ± 13.4 nM. S9-A13 did not inhibit other members of the SLC26 family and had no effects on Cl- channels such as CFTR, TMEM16A, or VRAC. S9-A13 inhibited SLC26A9 Cl- currents in cells that lack expression of CFTR. It also inhibited proton secretion by HGT-1 human gastric cells. In contrast, S9-A13 had minimal effects on ion transport in human airway epithelia and mouse trachea, despite clear expression of SLC26A9 in the apical membrane of ciliated cells. In both tissues, basal and stimulated Cl- secretion was due to CFTR, while acidification of airway surface liquid by S9-A13 suggests a role of SLC26A9 for airway bicarbonate secretion.
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Affiliation(s)
- Sungwoo Jo
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea
| | - Raquel Centeio
- Physiological Institute, University of Regensburg, Regensburg, Germany
| | - Jinhong Park
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea
| | | | - Dong-Kyu Jeon
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea
| | - Khaoula Talbi
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany
| | - Rainer Schreiber
- Physiological Institute, University of Regensburg, Regensburg, Germany
| | - Kunhi Ryu
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea
| | - Kristin Kahlenberg
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany
| | - Veronika Somoza
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, Freising, Germany
| | - Livia Delpiano
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Michael A Gray
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Margarida D Amaral
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Lisbon, Portugal
| | - Violeta Railean
- BioISI-Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Lisbon, Portugal
| | - Jeffrey M Beekman
- Regenerative Medicine Utrecht, University Medical Center, Utrecht University, Utrecht, Netherlands
| | - Lisa W Rodenburg
- Regenerative Medicine Utrecht, University Medical Center, Utrecht University, Utrecht, Netherlands
| | - Wan Namkung
- College of Pharmacy, Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, South Korea
| | - Karl Kunzelmann
- Physiological Institute, University of Regensburg, Regensburg, Germany
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6
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Gong J, He G, Wang C, Bartlett C, Panjwani N, Mastromatteo S, Lin F, Keenan K, Avolio J, Halevy A, Shaw M, Esmaeili M, Côté-Maurais G, Adam D, Bégin S, Bjornson C, Chilvers M, Reisman J, Price A, Parkins M, van Wylick R, Berthiaume Y, Bilodeau L, Mateos-Corral D, Hughes D, Smith MJ, Morrison N, Brusky J, Tullis E, Stephenson AL, Quon BS, Wilcox P, Leung WM, Solomon M, Sun L, Brochiero E, Moraes TJ, Gonska T, Ratjen F, Rommens JM, Strug LJ. Genetic evidence supports the development of SLC26A9 targeting therapies for the treatment of lung disease. NPJ Genom Med 2022; 7:28. [PMID: 35396391 PMCID: PMC8993824 DOI: 10.1038/s41525-022-00299-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/04/2022] [Indexed: 12/19/2022] Open
Abstract
Over 400 variants in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) are CF-causing. CFTR modulators target variants to improve lung function, but marked variability in response exists and current therapies do not address all CF-causing variants highlighting unmet needs. Alternative epithelial ion channel/transporters such as SLC26A9 could compensate for CFTR dysfunction, providing therapeutic targets that may benefit all individuals with CF. We investigate the relationship between rs7512462, a marker of SLC26A9 activity, and lung function pre- and post-treatment with CFTR modulators in Canadian and US CF cohorts, in the general population, and in those with chronic obstructive pulmonary disease (COPD). Rs7512462 CC genotype is associated with greater lung function in CF individuals with minimal function variants (for which there are currently no approved therapies; p = 0.008); and for gating (p = 0.033) and p.Phe508del/ p.Phe508del (p = 0.006) genotypes upon treatment with CFTR modulators. In parallel, human nasal epithelia with CC and p.Phe508del/p.Phe508del after Ussing chamber analysis of a combination of approved and experimental modulator treatments show greater CFTR function (p = 0.0022). Beyond CF, rs7512462 is associated with peak expiratory flow in a meta-analysis of the UK Biobank and Spirometa Consortium (p = 2.74 × 10-44) and provides p = 0.0891 in an analysis of COPD case-control status in the UK Biobank defined by spirometry. These findings support SLC26A9 as a therapeutic target to improve lung function for all people with CF and in individuals with other obstructive lung diseases.
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Affiliation(s)
- Jiafen Gong
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Gengming He
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Biostatistics Division, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Cheng Wang
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Claire Bartlett
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Naim Panjwani
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Scott Mastromatteo
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Fan Lin
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Katherine Keenan
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Julie Avolio
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Anat Halevy
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Michelle Shaw
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mohsen Esmaeili
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Guillaume Côté-Maurais
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | - Damien Adam
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Stéphanie Bégin
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
| | | | - Mark Chilvers
- British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Joe Reisman
- The Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
| | - April Price
- The Children's Hospital, London Health Science Centre, London, ON, Canada
| | | | | | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Lara Bilodeau
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval, Québec City, QC, Canada
| | | | | | - Mary J Smith
- Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Nancy Morrison
- Queen Elizabeth II Health Sciences Centre, Halifax, NS, Canada
| | - Janna Brusky
- Department of Pediatrics, University of Saskatchewan, Saskatoon, SK, Canada
| | | | | | | | | | | | - Melinda Solomon
- Respiratory Medicine, Hospital for Sick Children, Toronto, ON, Canada
- Department of Paediatrics, University of Toronto, Toronto, ON, Canada
| | - Lei Sun
- Biostatistics Division, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada
| | - Emmanuelle Brochiero
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Theo J Moraes
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Respiratory Medicine, Hospital for Sick Children, Toronto, ON, Canada
| | - Tanja Gonska
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, ON, Canada
| | - Felix Ratjen
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Paediatrics, University of Toronto, Toronto, ON, Canada
| | - Johanna M Rommens
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Lisa J Strug
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada.
- Biostatistics Division, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada.
- The Centre for Applied Genomics, Hospital for Sick Children, Toronto, ON, Canada.
- Department of Computer Science, University of Toronto, Toronto, ON, Canada.
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7
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Ousingsawat J, Centeio R, Schreiber R, Kunzelmann K. Expression of SLC26A9 in Airways and Its Potential Role in Asthma. Int J Mol Sci 2022; 23:ijms23062998. [PMID: 35328418 PMCID: PMC8950296 DOI: 10.3390/ijms23062998] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/05/2022] [Accepted: 03/07/2022] [Indexed: 02/05/2023] Open
Abstract
SLC26A9 is an epithelial anion transporter with a poorly defined function in airways. It is assumed to contribute to airway chloride secretion and airway surface hydration. However, immunohistochemistry showing precise localization of SLC26A9 in airways is missing. Some studies report localization near tight junctions, which is difficult to reconcile with a chloride secretory function of SLC26A9. We therefore performed immunocytochemistry of SLC26A9 in sections of human and porcine lungs. Obvious apical localization of SLC26A9 was detected in human and porcine superficial airway epithelia, whereas submucosal glands did not express SLC26A9. The anion transporter was located exclusively in ciliated epithelial cells. Highly differentiated BCi-NS1 human airway epithelial cells grown on permeable supports also expressed SLC26A9 in the apical membrane of ciliated epithelial cells. BCi-NS1 cells expressed the major Cl− transporting proteins CFTR, TMEM16A and SLC26A9 in about equal proportions and produced short-circuit currents activated by increases in intracellular cAMP or Ca2+. Both CFTR and SLC26A9 contribute to basal chloride currents in non-stimulated BCi-NS1 airway epithelia, with CFTR being the dominating Cl− conductance. In wtCFTR-expressing CFBE human airway epithelial cells, SLC26A9 was partially located in the plasma membrane, whereas CFBE cells expressing F508del-CFTR showed exclusive cytosolic localization of SLC26A9. Membrane localization of SLC26A9 and basal chloride currents were augmented by interleukin 13 in wild-type CFTR-expressing cells, but not in cells expressing the most common disease-causing mutant F508del-CFTR. The data suggest an upregulation of SLC26A9-dependent chloride secretion in asthma, but not in the presence of F508del-CFTR.
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Affiliation(s)
| | | | | | - Karl Kunzelmann
- Correspondence: ; Tel.: +49-(0)941-943-4302; Fax: +49-(0)941-943-4315
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SLC26A9 as a Potential Modifier and Therapeutic Target in Cystic Fibrosis Lung Disease. Biomolecules 2022; 12:biom12020202. [PMID: 35204703 PMCID: PMC8961553 DOI: 10.3390/biom12020202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 01/21/2022] [Accepted: 01/22/2022] [Indexed: 11/16/2022] Open
Abstract
SLC26A9 belongs to the solute carrier family 26 (SLC26), which comprises membrane proteins involved in ion transport mechanisms. On the basis of different preliminary findings, including the phenotype of SlC26A9-deficient mice and its possible role as a gene modifier of the human phenotype and treatment response, SLC26A9 has emerged as one of the most interesting alternative targets for the treatment of cystic fibrosis (CF). However, despite relevant clues, some open issues and controversies remain. The lack of specific pharmacological modulators, the elusive expression reported in the airways, and its complex relationships with CFTR and the CF phenotype prevent us from conclusively understanding the contribution of SLC26A9 in human lung physiology and its real potential as a therapeutic target in CF. In this review, we summarized the various studies dealing with SLC26A9 expression, molecular structure, and function as an anion channel or transporter; its interaction and functional relationships with CFTR; and its role as a gene modifier and tried to reconcile them in order to highlight the current understanding and the gap in knowledge regarding the contribution of SLC26A9 to human lung physiology and CF disease and treatment.
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9
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SLC26A9 is selected for endoplasmic reticulum associated degradation (ERAD) via Hsp70-dependent targeting of the soluble STAS domain. Biochem J 2021; 478:4203-4220. [PMID: 34821356 PMCID: PMC8826537 DOI: 10.1042/bcj20210644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/24/2022]
Abstract
SLC26A9, a member of the solute carrier protein family, transports chloride ions across various epithelia. SLC26A9 also associates with other ion channels and transporters linked to human health, and in some cases these heterotypic interactions are essential to support the biogenesis of both proteins. Therefore, understanding how this complex membrane protein is initially folded might provide new therapeutic strategies to overcome deficits in the function of SLC26A9 partners, one of which is associated with Cystic Fibrosis. To this end, we developed a novel yeast expression system for SLC26A9. This facile system has been used extensively with other ion channels and transporters to screen for factors that oversee protein folding checkpoints. As commonly observed for other channels and transporters, we first noted that a substantial fraction of SLC26A9 is targeted for endoplasmic reticulum associated degradation (ERAD), which destroys folding-compromised proteins in the early secretory pathway. We next discovered that ERAD selection requires the Hsp70 chaperone, which can play a vital role in ERAD substrate selection. We then created SLC26A9 mutants and found that the transmembrane-rich domain of SLC26A9 was quite stable, whereas the soluble cytosolic STAS domain was responsible for Hsp70-dependent ERAD. To support data obtained in the yeast model, we were able to recapitulate Hsp70-facilitated ERAD of the STAS domain in human tissue culture cells. These results indicate that a critical barrier to nascent membrane protein folding can reside within a specific soluble domain, one that is monitored by components associated with the ERAD machinery.
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Synergy in Cystic Fibrosis Therapies: Targeting SLC26A9. Int J Mol Sci 2021; 22:ijms222313064. [PMID: 34884866 PMCID: PMC8658147 DOI: 10.3390/ijms222313064] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/24/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
SLC26A9, a constitutively active Cl- transporter, has gained interest over the past years as a relevant disease modifier in several respiratory disorders including Cystic Fibrosis (CF), asthma, and non-CF bronchiectasis. SLC26A9 contributes to epithelial Cl- secretion, thus preventing mucus obstruction under inflammatory conditions. Additionally, SLC26A9 was identified as a CF gene modifier, and its polymorphisms were shown to correlate with the response to drugs modulating CFTR, the defective protein in CF. Here, we aimed to investigate the relationship between SLC26A9 and CFTR, and its role in CF pathogenesis. Our data show that SLC26A9 expression contributes to enhanced CFTR expression and function. While knocking-down SLC26A9 in human bronchial cells leads to lower wt- and F508del-CFTR expression, function, and response to CFTR correctors, the opposite occurs upon its overexpression, highlighting SLC26A9 relevance for CF. Accordingly, F508del-CFTR rescue by the most efficient correctors available is further enhanced by increasing SLC26A9 expression. Interestingly, SLC26A9 overexpression does not increase the PM expression of non-F508del CFTR traffic mutants, namely those unresponsive to corrector drugs. Altogether, our data indicate that SLC26A9 stabilizes CFTR at the ER level and that the efficacy of CFTR modulator drugs may be further enhanced by increasing its expression.
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11
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Larsen MB, Choi JJ, Wang X, Myerburg MM, Frizzell RA, Bertrand CA. Separating the contributions of SLC26A9 and CFTR to anion secretion in primary human bronchial epithelia. Am J Physiol Lung Cell Mol Physiol 2021; 321:L1147-L1160. [PMID: 34668421 PMCID: PMC8715023 DOI: 10.1152/ajplung.00563.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 10/01/2021] [Accepted: 10/15/2021] [Indexed: 11/22/2022] Open
Abstract
Aberrant anion secretion across the bronchial epithelium is associated with airway disease, most notably in cystic fibrosis. Although the cystic fibrosis transmembrane conductance regulator (CFTR) is recognized as the primary source of airway anion secretion, alternative anion transport mechanisms play a contributing role. An alternative anion transporter of growing interest is SLC26A9, a constitutively active chloride channel that has been shown to interact with CFTR and may also contribute to bicarbonate secretion. Interest in SLC26A9 has been fueled by genome-wide association studies that suggest it is a significant modifier of CF disease severity. Despite this growing evidence that SLC26A9 plays an important role in the airway, its presence and function in bronchial epithelia remain poorly understood, in part, because its activity is difficult to separate from the activity of CFTR. Here, we present results using primary human bronchial epithelia (HBE) from multiple patient sources to confirm that SLC26A9 mRNA is present in HBE and that its constitutive channel activity is unaffected by knockdown of CFTR. Furthermore, SLC26A9 and CFTR show differential responses to common inhibitors of anion secretion. Finally, we assess the impact of bicarbonate on the activity of SLC26A9 and CFTR. These results confirm that SLC26A9 is the primary source of constitutive anion secretion across HBE, and should inform future studies focused on activation of SLC26A9 as an alternative anion channel in CF. These results should provide a strong foundation to investigate how single-nucleotide polymorphisms in SLC26A9 modulate airway disease.
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Affiliation(s)
- Mads B Larsen
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jeannie J Choi
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Xiaohui Wang
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Michael M Myerburg
- Department of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Raymond A Frizzell
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Carol A Bertrand
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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12
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Bratcher PE, Yadav S, Shaughnessy CA, Thornell IM, Zeitlin PL. Effect of apical chloride concentration on the measurement of responses to CFTR modulation in airway epithelia cultured from nasal brushings. Physiol Rep 2021; 8:e14603. [PMID: 33038073 PMCID: PMC7547589 DOI: 10.14814/phy2.14603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/02/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION One method for assessing the in vitro response to CFTR-modulating compounds is by analysis of epithelial monolayers in an Ussing chamber, where the apical and basolateral surfaces are isolated and the potential difference, short-circuit current, and transepithelial resistance can be monitored. The effect of a chloride ion gradient across airway epithelia on transepithelial chloride transport and the magnitude of CFTR modulator efficacy were examined. METHODS CFTR-mediated changes in the potential difference and transepithelial currents of primary human nasal epithelial cell cultures were quantified in Ussing chambers with either symmetrical solutions or reduced chloride solutions in the apical chamber. CFTR activity in homozygous F508del CFTR epithelia was rescued by treatment with VX-661, C4/C18, 4-phenylbutyrate (4-PBA) for 24 hr at 37°C or by incubation at 29°C for 48 hr. RESULTS Imposing a chloride gradient increased CFTR-mediated and CaCC-mediated ion transport. Treatment of F508del CFTR homozygous cells with CFTR modulating compounds increased CFTR activity, which was significantly more evident in the presence of a chloride gradient. This observation was recapitulated with temperature-mediated F508del CFTR correction. CONCLUSIONS Imposing a chloride gradient during Ussing chamber measurements resulted in increased CFTR-mediated ion transport in expanded non-CF and F508del CFTR homozygous epithelia. In F508del CFTR homozygous epithelia, the magnitude of response to CFTR modulating compounds or low temperature was greater when assayed with a chloride gradient compared to symmetrical chloride, resulting in an apparent increase in measured efficacy. Future work may direct which methodologies utilized to quantify CFTR modulator response in vitro are most appropriate for the estimation of in vivo efficacy.
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Affiliation(s)
- Preston E Bratcher
- Department of Pediatrics, National Jewish Health, Denver, CO, USA.,Department of Pediatrics, Anschutz Medical Center, University of Colorado Denver, Aurora, CO, USA
| | - Sangya Yadav
- Department of Pediatrics, National Jewish Health, Denver, CO, USA
| | | | - Ian M Thornell
- Dept. of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Pamela L Zeitlin
- Department of Pediatrics, National Jewish Health, Denver, CO, USA.,Department of Pediatrics, Anschutz Medical Center, University of Colorado Denver, Aurora, CO, USA
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Pinto MC, Silva IAL, Figueira MF, Amaral MD, Lopes-Pacheco M. Pharmacological Modulation of Ion Channels for the Treatment of Cystic Fibrosis. J Exp Pharmacol 2021; 13:693-723. [PMID: 34326672 PMCID: PMC8316759 DOI: 10.2147/jep.s255377] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Cystic fibrosis (CF) is a life-shortening monogenic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, an anion channel that transports chloride and bicarbonate across epithelia. Despite clinical progress in delaying disease progression with symptomatic therapies, these individuals still develop various chronic complications in lungs and other organs, which significantly restricts their life expectancy and quality of life. The development of high-throughput assays to screen drug-like compound libraries have enabled the discovery of highly effective CFTR modulator therapies. These novel therapies target the primary defect underlying CF and are now approved for clinical use for individuals with specific CF genotypes. However, the clinically approved modulators only partially reverse CFTR dysfunction and there is still a considerable number of individuals with CF carrying rare CFTR mutations who remain without any effective CFTR modulator therapy. Accordingly, additional efforts have been pursued to identify novel and more potent CFTR modulators that may benefit a larger CF population. The use of ex vivo individual-derived specimens has also become a powerful tool to evaluate novel drugs and predict their effectiveness in a personalized medicine approach. In addition to CFTR modulators, pro-drugs aiming at modulating alternative ion channels/transporters are under development to compensate for the lack of CFTR function. These therapies may restore normal mucociliary clearance through a mutation-agnostic approach (ie, independent of CFTR mutation) and include inhibitors of the epithelial sodium channel (ENaC), modulators of the calcium-activated channel transmembrane 16A (TMEM16, or anoctamin 1) or of the solute carrier family 26A member 9 (SLC26A9), and anionophores. The present review focuses on recent progress and challenges for the development of ion channel/transporter-modulating drugs for the treatment of CF.
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Affiliation(s)
- Madalena C Pinto
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Iris A L Silva
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miriam F Figueira
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
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14
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Eastman AC, Pace RG, Dang H, Aksit MA, Vecchio-Pagán B, Lam ATN, O'Neal WK, Blackman SM, Knowles MR, Cutting GR. SLC26A9 SNP rs7512462 is not associated with lung disease severity or lung function response to ivacaftor in cystic fibrosis patients with G551D-CFTR. J Cyst Fibros 2021; 20:851-856. [PMID: 33674211 DOI: 10.1016/j.jcf.2021.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/05/2021] [Accepted: 02/10/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND The CFTR modulator ivacaftor has been variably effective in treating individuals with cystic fibrosis (CF) who harbor CFTR gating variants such as G551D, as well as other classes of CFTR variants when used with other modulators. Because CFTR genotype does not fully explain this variability, defining genetic modifiers of response to modulator therapy is of particular interest to the field of individualized CF drug therapy. Previous studies have proposed that a variant in SLC26A9 (rs7512462) is associated with lung disease severity and with response to treatment with ivacaftor in individuals with CF who carry G551D or gating variants. METHODS Given the implications for CF treatment, we re-examined the reported associations in three cohorts; patients enrolled in the Twin and Siblings study at Johns Hopkins University, the CF modifier study at the University of North Carolina at Chapel Hill, and the prospective G551D Observational (GOAL) study. The GOAL study was specifically designed to measure lung function response to ivacaftor. RESULTS We find no association between SLC26A9 (rs7512462) genotype and lung disease severity (n = 272) or change in lung function at one-, three-, and six-month intervals following ivacaftor treatment(n = 141) in individuals with CF who carry at least one G551D variant. CONCLUSIONS Our inability to replicate this association indicates that rs7512462 genotype should not be used in treatment decisions.
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Affiliation(s)
- Alice C Eastman
- Department of Genetic Medicine, Johns Hopkins University (JHU), Baltimore, MD, 21205, USA
| | - Rhonda G Pace
- University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, 27599, USA
| | - Hong Dang
- University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, 27599, USA
| | - Melis Atalar Aksit
- Department of Genetic Medicine, Johns Hopkins University (JHU), Baltimore, MD, 21205, USA
| | - Briana Vecchio-Pagán
- Department of Genetic Medicine, Johns Hopkins University (JHU), Baltimore, MD, 21205, USA
| | - Anh-Thu N Lam
- Department of Genetic Medicine, Johns Hopkins University (JHU), Baltimore, MD, 21205, USA
| | - Wanda K O'Neal
- University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, 27599, USA
| | - Scott M Blackman
- Department of Genetic Medicine, Johns Hopkins University (JHU), Baltimore, MD, 21205, USA
| | - Michael R Knowles
- University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, 27599, USA.
| | - Garry R Cutting
- Department of Genetic Medicine, Johns Hopkins University (JHU), Baltimore, MD, 21205, USA.
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Choice of Differentiation Media Significantly Impacts Cell Lineage and Response to CFTR Modulators in Fully Differentiated Primary Cultures of Cystic Fibrosis Human Airway Epithelial Cells. Cells 2020; 9:cells9092137. [PMID: 32967385 PMCID: PMC7565948 DOI: 10.3390/cells9092137] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/13/2020] [Accepted: 09/16/2020] [Indexed: 12/13/2022] Open
Abstract
In vitro cultures of primary human airway epithelial cells (hAECs) grown at air–liquid interface have become a valuable tool to study airway biology under normal and pathologic conditions, and for drug discovery in lung diseases such as cystic fibrosis (CF). An increasing number of different differentiation media, are now available, making comparison of data between studies difficult. Here, we investigated the impact of two common differentiation media on phenotypic, transcriptomic, and physiological features of CF and non-CF epithelia. Cellular architecture and density were strongly impacted by the choice of medium. RNA-sequencing revealed a shift in airway cell lineage; one medium promoting differentiation into club and goblet cells whilst the other enriched the growth of ionocytes and multiciliated cells. Pathway analysis identified differential expression of genes involved in ion and fluid transport. Physiological assays (intracellular/extracellular pH, Ussing chamber) specifically showed that ATP12A and CFTR function were altered, impacting pH and transepithelial ion transport in CF hAECs. Importantly, the two media differentially affected functional responses to CFTR modulators. We argue that the effect of growth conditions should be appropriately determined depending on the scientific question and that our study can act as a guide for choosing the optimal growth medium for specific applications.
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