1
|
Kunzelmann K, Centeio R, Ousingsawat J, Talbi K, Seidler U, Schreiber R. SLC26A9 in airways and intestine: secretion or absorption? Channels (Austin) 2023; 17:2186434. [PMID: 36866602 PMCID: PMC9988340 DOI: 10.1080/19336950.2023.2186434] [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] [Indexed: 03/04/2023] Open
Abstract
SLC26A9 is one out of 11 proteins that belong to the SLC26A family of anion transporters. Apart from expression in the gastrointestinal tract, SLC26A9 is also found in the respiratory system, in male tissues and in the skin. SLC26A9 has gained attention because of its modifier role in the gastrointestinal manifestation of cystic fibrosis (CF). SLC26A9 appears to have an impact on the extent of intestinal obstruction caused by meconium ileus. SLC26A9 supports duodenal bicarbonate secretion, but was assumed to provide a basal Cl- secretory pathway in airways. However, recent results show that basal airway Cl- secretion is due to cystic fibrosis conductance regulator (CFTR), while SLC26A9 may rather secrete HCO3-, thereby maintaining proper airway surface liquid (ASL) pH. Moreover, SLC26A9 does not secrete but probably supports reabsorption of fluid particularly in the alveolar space, which explains early death by neonatal distress in Slc26a9-knockout animals. While the novel SLC26A9 inhibitor S9-A13 helped to unmask the role of SLC26A9 in the airways, it also provided evidence for an additional role in acid secretion by gastric parietal cells. Here we discuss recent data on the function of SLC26A9 in airways and gut, and how S9-A13 may be useful in unraveling the physiological role of SLC26A9.
Collapse
Affiliation(s)
- Karl Kunzelmann
- Institut für Physiologie, Universität, Universitätsstraße 31, Regensburg, Germany
- CONTACT Karl Kunzelmann
| | - Raquel Centeio
- Institut für Physiologie, Universität, Universitätsstraße 31, Regensburg, Germany
| | - Jiraporn Ousingsawat
- Institut für Physiologie, Universität, Universitätsstraße 31, Regensburg, Germany
| | - Khaoula Talbi
- Institut für Physiologie, Universität, Universitätsstraße 31, Regensburg, Germany
| | - Ursula Seidler
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
| | - Rainer Schreiber
- Institut für Physiologie, Universität, Universitätsstraße 31, Regensburg, Germany
| |
Collapse
|
2
|
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.
Collapse
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.)
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Mésinèle J, Ruffin M, Guillot L, Corvol H. Modifier Factors of Cystic Fibrosis Phenotypes: A Focus on Modifier Genes. Int J Mol Sci 2022; 23:ijms232214205. [PMID: 36430680 PMCID: PMC9698440 DOI: 10.3390/ijms232214205] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/07/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
Although cystic fibrosis (CF) is recognized as a monogenic disease, due to variants within the CFTR (Cystic Fibrosis Transmembrane Regulator) gene, an extreme clinical heterogeneity is described among people with CF (pwCF). Apart from the exocrine pancreatic status, most studies agree that there is little association between CFTR variants and disease phenotypes. Environmental factors have been shown to contribute to this heterogeneity, accounting for almost 50% of the variability of the lung function of pwCF. Nevertheless, pwCF with similar CFTR variants and sharing the same environment (such as in siblings) may have highly variable clinical manifestations not explained by CFTR variants, and only partly explained by environmental factors. It is recognized that genetic variants located outside the CFTR locus, named "modifier genes", influence the clinical expression of the disease. This short review discusses the latest studies that have described modifier factors associated with the various CF phenotypes as well as the response to the recent CFTR modulator therapies.
Collapse
Affiliation(s)
- Julie Mésinèle
- Sorbonne Université, Inserm U938, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France
- Inovarion, 75005 Paris, France
| | - Manon Ruffin
- Sorbonne Université, Inserm U938, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France
| | - Loïc Guillot
- Sorbonne Université, Inserm U938, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France
- Correspondence: (L.G.); (H.C.)
| | - Harriet Corvol
- Sorbonne Université, Inserm U938, Centre de Recherche Saint-Antoine (CRSA), 75012 Paris, France
- Sorbonne Université, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital Trousseau, Service de Pneumologie Pédiatrique, 75012 Paris, France
- Correspondence: (L.G.); (H.C.)
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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] [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.
Collapse
|
7
|
Li T, Stefano G, Raza GS, Sommerer I, Riederer B, Römermann D, Tan X, Tan Q, Pallagi P, Hollenbach M, Herzig K, Seidler U. Hydrokinetic pancreatic function and insulin secretion are moduled by Cl - uniporter Slc26a9 in mice. Acta Physiol (Oxf) 2022; 234:e13729. [PMID: 34525257 DOI: 10.1111/apha.13729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 09/01/2021] [Accepted: 09/04/2021] [Indexed: 11/29/2022]
Abstract
AIM Slc26a9 is a member of the Slc26 multifunctional anion transporter family. Polymorphisms in Slc26a9 are associated with an increased incidence of meconium ileus and diabetes in cystic fibrosis patients. We investigated the expression of Slc26a9 in the murine pancreatic ducts, islets and parenchyma, and elucidated its role in pancreatic ductal electrolyte and fluid secretion and endocrine function. METHODS Pancreatic Slc26a9 and CFTR mRNA expression, fluid and bicarbonate secretion were assessed in slc26a9-/- mice and their age- and sex-matched wild-type (wt) littermates. Glucose and insulin tolerance tests were performed. RESULTS Compared with stomach, the mRNA expression of Slc26a9 was low in pancreatic parenchyma, 20-fold higher in microdissected pancreatic ducts than parenchyma, and very low in islets. CFTR mRNA was ~10 fold higher than Slc26a9 mRNA expression in each pancreatic cell type. Significantly reduced pancreatic fluid secretory rates and impaired glucose tolerance were observed in female slc26a9-/- mice, whereas alterations in male mice did not reach statistical significance. No significant difference was observed in peripheral insulin resistance in slc26a9-/- compared to sex- and aged-matched wt controls. In contrast, isolated slc26a9-/- islets in short term culture displayed no difference in insulin content, but a significantly reduced glucose-stimulated insulin secretion compared to age- and sex-matched wt islets, suggesting that the impaired glucose tolerance in the absence of Slc26a9 expression these is a pancreatic defect. CONCLUSIONS Deletion of Slc26a9 is associated with a reduction in pancreatic fluid secretion and impaired glucose tolerance in female mice. The results underline the importance of Slc26a9 in pancreatic physiology.
Collapse
Affiliation(s)
- T. Li
- Department of Gastroenterology Hannover Medical School Hannover Germany
- Department of Thyroid and Breast Surgery Affiliated Hospital of Zunyi Medical University Zunyi P.R. China
| | - G. Stefano
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - G. S. Raza
- Institute of Biomedicine and Biocenter of Oulu Oulu University Oulu Finland
| | - I. Sommerer
- Department of Medicine Szeged University Szeged Hungary
| | - B. Riederer
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - D. Römermann
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - X. Tan
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - Q. Tan
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - P. Pallagi
- Department of Gastroenterology Leipzig University Leipzig Germany
| | - M. Hollenbach
- Department of Medicine Szeged University Szeged Hungary
| | - K.‐H. Herzig
- Institute of Biomedicine and Biocenter of Oulu Oulu University Oulu Finland
- Department of Gastroenterology and Metabolism Poznan University of Medical Sciences Poznan Poland
| | - U. Seidler
- Department of Gastroenterology Hannover Medical School Hannover Germany
| |
Collapse
|
8
|
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.
Collapse
|
9
|
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.
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Abstract
The Toxic-metabolic, Idiopathic, Genetic, Autoimmune, Recurrent and severe acute pancreatitis and Obstructive (TIGAR-O) Pancreatitis Risk/Etiology Checklist (TIGAR-O_V1) is a broad classification system that lists the major risk factors and etiologies of recurrent acute pancreatitis, chronic pancreatitis, and overlapping pancreatic disorders with or without genetic, immunologic, metabolic, nutritional, neurologic, metaplastic, or other features. New discoveries and progressive concepts since the 2001 TIGAR-O list relevant to understanding and managing complex pancreatic disorders require an update to TIGAR-O_V2 with both a short (S) and long (L) form. The revised system is designed as a hierarchical checklist for health care workers to quickly document and track specific factors that, alone or in combinations, may contribute to progressive pancreatic disease in individual patients or groups of patients and to assist in treatment selection. The rationale and key clinical considerations are summarized for each updated classification item. Familiarity with the structured format speeds up the completion process and supports thoroughness and consideration of complex or alternative diagnoses during evaluation and serves as a framework for communication. The structured approach also facilitates the new health information technologies that required high-quality data for accurate precision medicine. A use primer accompanies the TIGAR-O_V2 checklist with rationale and comments for health care workers and industries caring for patients with pancreatic diseases.
Collapse
|
13
|
Ruffin M, Mercier J, Calmel C, Mésinèle J, Bigot J, Sutanto EN, Kicic A, Corvol H, Guillot L. Update on SLC6A14 in lung and gastrointestinal physiology and physiopathology: focus on cystic fibrosis. Cell Mol Life Sci 2020; 77:3311-3323. [PMID: 32166393 PMCID: PMC7426304 DOI: 10.1007/s00018-020-03487-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/24/2020] [Accepted: 02/17/2020] [Indexed: 12/17/2022]
Abstract
The solute carrier family 6 member 14 (SLC6A14) protein imports and concentrates all neutral amino acids as well as the two cationic acids lysine and arginine into the cytoplasm of different cell types. Primarily described as involved in several cancer and colonic diseases physiopathological mechanisms, the SLC6A14 gene has been more recently identified as a genetic modifier of cystic fibrosis (CF) disease severity. It was indeed shown to have a pleiotropic effect, modulating meconium ileus occurrence, lung disease severity, and precocity of P. aeruginosa airway infection. The biological mechanisms explaining the impact of SLC6A14 on intestinal and lung phenotypes of CF patients are starting to be elucidated. This review focuses on SLC6A14 in lung and gastrointestinal physiology and physiopathology, especially its involvement in the pathophysiology of CF disease.
Collapse
Affiliation(s)
- Manon Ruffin
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France
| | - Julia Mercier
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France
| | - Claire Calmel
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France
| | - Julie Mésinèle
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France
| | - Jeanne Bigot
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France
| | - Erika N Sutanto
- Telethon Kids Institute, University of Western Australia, Nedlands, WA, Australia
- School of Public Health, Curtin University, Bentley, WA, Australia
| | - Anthony Kicic
- Telethon Kids Institute, University of Western Australia, Nedlands, WA, Australia
- School of Public Health, Curtin University, Bentley, WA, Australia
- Centre for Cell Therapy and Regenerative Medicine, Medical School, The University of Western Australia, Nedlands, WA, Australia
- Department of Respiratory and Sleep Medicine, Perth Children's Hospital, Nedlands, WA, Australia
| | - Harriet Corvol
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France.
- Pneumologie Pédiatrique, APHP, Hôpital Trousseau, Paris, France.
| | - Loic Guillot
- Sorbonne Université, INSERM UMR S 938, Centre de Recherche Saint‑Antoine (CRSA), Paris, France
| |
Collapse
|
14
|
Lam ATN, Aksit MA, Vecchio-Pagan B, Shelton CA, Osorio DL, Anzmann AF, Goff LA, Whitcomb DC, Blackman SM, Cutting GR. Increased expression of anion transporter SLC26A9 delays diabetes onset in cystic fibrosis. J Clin Invest 2020; 130:272-286. [PMID: 31581148 DOI: 10.1172/jci129833] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 09/25/2019] [Indexed: 12/16/2022] Open
Abstract
Diabetes is a common complication of cystic fibrosis (CF) that affects approximately 20% of adolescents and 40%-50% of adults with CF. The age at onset of CF-related diabetes (CFRD) (marked by clinical diagnosis and treatment initiation) is an important measure of the disease process. DNA variants associated with age at onset of CFRD reside in and near SLC26A9. Deep sequencing of the SLC26A9 gene in 762 individuals with CF revealed that 2 common DNA haplotypes formed by the risk variants account for the association with diabetes. Single-cell RNA sequencing (scRNA-Seq) indicated that SLC26A9 is predominantly expressed in pancreatic ductal cells and frequently coexpressed with CF transmembrane conductance regulator (CFTR) along with transcription factors that have binding sites 5' of SLC26A9. These findings were replicated upon reanalysis of scRNA-Seq data from 4 independent studies. DNA fragments derived from the 5' region of SLC26A9-bearing variants from the low-risk haplotype generated 12%-20% higher levels of expression in PANC-1 and CFPAC-1 cells compared with the high- risk haplotype. Taken together, our findings indicate that an increase in SLC26A9 expression in ductal cells of the pancreas delays the age at onset of diabetes, suggesting a CFTR-agnostic treatment for a major complication of CF.
Collapse
Affiliation(s)
- Anh-Thu N Lam
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Melis A Aksit
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Briana Vecchio-Pagan
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland, USA
| | - Celeste A Shelton
- University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Ariel Precision Medicine, Pittsburgh, Pennsylvania, USA
| | - Derek L Osorio
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Arianna F Anzmann
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Loyal A Goff
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - Scott M Blackman
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Garry R Cutting
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
15
|
Touré A. Importance of SLC26 Transmembrane Anion Exchangers in Sperm Post-testicular Maturation and Fertilization Potential. Front Cell Dev Biol 2019; 7:230. [PMID: 31681763 PMCID: PMC6813192 DOI: 10.3389/fcell.2019.00230] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 09/26/2019] [Indexed: 12/17/2022] Open
Abstract
In mammals, sperm cells produced within the testis are structurally differentiated but remain immotile and are unable to fertilize the oocyte unless they undergo a series of maturation events during their transit in the male and female genital tracts. This post-testicular functional maturation is known to rely on the micro-environment of both male and female genital tracts, and is tightly controlled by the pH of their luminal milieus. In particular, within the epididymis, the establishment of a low bicarbonate (HCO3–) concentration contributes to luminal acidification, which is necessary for sperm maturation and subsequent storage in a quiescent state. Following ejaculation, sperm is exposed to the basic pH of the female genital tract and bicarbonate (HCO3–), calcium (Ca2+), and chloride (Cl–) influxes induce biochemical and electrophysiological changes to the sperm cells (cytoplasmic alkalinization, increased cAMP concentration, and protein phosphorylation cascades), which are indispensable for the acquisition of fertilization potential, a process called capacitation. Solute carrier 26 (SLC26) members are conserved membranous proteins that mediate the transport of various anions across the plasma membrane of epithelial cells and constitute important regulators of pH and HCO3– concentration. Most SLC26 members were shown to physically interact and cooperate with the cystic fibrosis transmembrane conductance regulator channel (CFTR) in various epithelia, mainly by stimulating its Cl– channel activity. Among SLC26 members, the function of SLC26A3, A6, and A8 were particularly investigated in the male genital tract and the sperm cells. In this review, we will focus on SLC26s contributions to ionic- and pH-dependent processes during sperm post-testicular maturation. We will specify the current knowledge regarding their functions, based on data from the literature generated by means of in vitro and in vivo studies in knock-out mouse models together with genetic studies of infertile patients. We will also discuss the limits of those studies, the current research gaps and identify some key points for potential developments in this field.
Collapse
Affiliation(s)
- Aminata Touré
- INSERM U1016, Centre National de la Recherche Scientifique, UMR 8104, Institut Cochin, Université de Paris, Paris, France
| |
Collapse
|
16
|
Walter JD, Sawicka M, Dutzler R. Cryo-EM structures and functional characterization of murine Slc26a9 reveal mechanism of uncoupled chloride transport. eLife 2019; 8:46986. [PMID: 31339488 PMCID: PMC6656431 DOI: 10.7554/elife.46986] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/21/2019] [Indexed: 12/14/2022] Open
Abstract
The epithelial anion transporter SLC26A9 contributes to airway surface hydration and gastric acid production. Colocalizing with CFTR, SLC26A9 has been proposed as a target for the treatment of cystic fibrosis. To provide molecular details of its transport mechanism, we present cryo-EM structures and a functional characterization of murine Slc26a9. These structures define the general architecture of eukaryotic SLC26 family members and reveal an unusual mode of oligomerization which relies predominantly on the cytosolic STAS domain. Our data illustrates conformational transitions of Slc26a9, supporting a rapid alternate-access mechanism which mediates uncoupled chloride transport with negligible bicarbonate or sulfate permeability. The characterization of structure-guided mutants illuminates the properties of the ion transport path, including a selective anion binding site located in the center of a mobile module within the transmembrane domain. This study thus provides a structural foundation for the understanding of the entire SLC26 family and potentially facilitates their therapeutic exploitation. Many processes in the human body are regulated by chloride and other charged particles (known as ions) moving in and out of cells. Each cell is surrounded by a membrane barrier, which prevents ions from entering or exiting. Therefore, to control the levels of ions inside the cell, specific proteins in the membrane act as channels or transporters to provide routes for the ions to pass through the membrane. Channel proteins form pores that, when open, allow a steady stream of ions to pass through the membrane. Transporter proteins, on the other hand, generally contain a pocket that is only accessible from one side of the membrane. When individual ions enter this pocket the transporter changes shape. This causes the entrance of the pocket to close and then re-open on the other side of the membrane. Inside the lung, an ion channel known as CFTR provides a route for chloride ions to move out of cells, which helps clear harmful material from the airways. Mutations affecting this protein cause the mucus lining the airways to become very sticky, leading to a severe disease known as cystic fibrosis. CFTR works together with another protein that is also found in the membrane, called SLC26A9. Previous studies have suggested that SLC26A9 also allows chloride ions to pass through the membrane. It was not clear, however, if SLC26A9 operates as an ion channel or a transporter protein, or how the protein is arranged in the membrane. Now, Walter, Sawicka and Dutzler combined two techniques known as cryo-electron microscopy and patch-clamp electrophysiology to reveal the detailed three-dimensional structure of the mouse version of SLC26A9, which is highly similar to the human form. The experiments found that mouse SLC26A9 proteins form pairs in the membrane referred to as homodimers, which arranged themselves in an unexpected way. Further investigation into the structure of these homodimers suggests that despite having many channel-like properties, SLC26A9 operates as a fast transporter, rather than a true channel. These findings help us understand the role of SLC26A9 and other similar proteins in the lung and other parts of the body. In the future it may be possible to develop drugs that target SLC26A9 to treat cystic fibrosis and other severe lung diseases.
Collapse
Affiliation(s)
- Justin D Walter
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Marta Sawicka
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Raimund Dutzler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| |
Collapse
|
17
|
Intestinal Immunomodulation and Shifts on the Gut Microbiota of BALB/c Mice Promoted by Two Bifidobacterium and Lactobacillus Strains Isolated from Human Samples. BIOMED RESEARCH INTERNATIONAL 2019; 2019:2323540. [PMID: 31119156 PMCID: PMC6500685 DOI: 10.1155/2019/2323540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/07/2019] [Indexed: 01/22/2023]
Abstract
Bifidobacterium animalis subsp. lactis IPLA 20020 and Lactobacillus gasseri IPLA 20212, two strains isolated from human samples, were evaluated for safety and influence over the intestinal microbiota and cytokine production by the intestinal tissue of adult BALB/c mice. Mice were divided into four groups receiving during 8 days PBS or a suspension of each strain, prepared fresh or lyophilized (bifidobacteria), at an amount of 4x108 viable cells/day. This dose could be comparable to the probiotic intake of a human adult who consumed about 100-200 mL of functional fermented milk per day, considering the usual level of probiotics in commercial products. No microbial translocation to liver or alterations in food intake, weight, and behavior were observed in treated mice. Intestinal content of secretory immunoglobulin A (s-IgA) was not affected, discarding any adverse effect on the mucosa-associated immunity. The profile of intestinal proinflammatory/regulatory cytokines after intervention evidenced that the microbial strain administered and its cellular state (fresh or lyophilized) as well as the host tissue analyzed (small or large intestine) influenced the immune response and suggests a moderate shift towards a T helper 1 profile (Th1) in the large intestine after the administration of both strains. Changes on relative levels of some intestinal microbial groups were evidenced after intervention. It is noteworthy that butyrate was positively associated with a balanced pro-Th1 immune response. Therefore, B. animalis subsp. lactis IPLA20020 and L. gasseri IPLA 20212 could be considered potential probiotic candidates to be included in functional foods for balancing the intestinal immune response.
Collapse
|
18
|
Genetic association and transcriptome integration identify contributing genes and tissues at cystic fibrosis modifier loci. PLoS Genet 2019; 15:e1008007. [PMID: 30807572 PMCID: PMC6407791 DOI: 10.1371/journal.pgen.1008007] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 03/08/2019] [Accepted: 02/06/2019] [Indexed: 01/09/2023] Open
Abstract
Cystic Fibrosis (CF) exhibits morbidity in several organs, including progressive lung disease in all patients and intestinal obstruction at birth (meconium ileus) in ~15%. Individuals with the same causal CFTR mutations show variable disease presentation which is partly attributed to modifier genes. With >6,500 participants from the International CF Gene Modifier Consortium, genome-wide association investigation identified a new modifier locus for meconium ileus encompassing ATP12A on chromosome 13 (min p = 3.83x10(-10)); replicated loci encompassing SLC6A14 on chromosome X and SLC26A9 on chromosome 1, (min p<2.2x10(-16), 2.81x10(-11), respectively); and replicated a suggestive locus on chromosome 7 near PRSS1 (min p = 2.55x10(-7)). PRSS1 is exclusively expressed in the exocrine pancreas and was previously associated with non-CF pancreatitis with functional characterization demonstrating impact on PRSS1 gene expression. We thus asked whether the other meconium ileus modifier loci impact gene expression and in which organ. We developed and applied a colocalization framework called the Simple Sum (SS) that integrates regulatory and genetic association information, and also contrasts colocalization evidence across tissues or genes. The associated modifier loci colocalized with expression quantitative trait loci (eQTLs) for ATP12A (p = 3.35x10(-8)), SLC6A14 (p = 1.12x10(-10)) and SLC26A9 (p = 4.48x10(-5)) in the pancreas, even though meconium ileus manifests in the intestine. The meconium ileus susceptibility locus on chromosome X appeared shifted in location from a previously identified locus for CF lung disease severity. Using the SS we integrated the lung disease association locus with eQTLs from nasal epithelia of 63 CF participants and demonstrated evidence of colocalization with airway-specific regulation of SLC6A14 (p = 2.3x10(-4)). Cystic Fibrosis is realizing the promise of personalized medicine, and identification of the contributing organ and understanding of tissue specificity for a gene modifier is essential for the next phase of personalizing therapeutic strategies.
Collapse
|
19
|
Kunzelmann K, Ousingsawat J, Cabrita I, Doušová T, Bähr A, Janda M, Schreiber R, Benedetto R. TMEM16A in Cystic Fibrosis: Activating or Inhibiting? Front Pharmacol 2019; 10:3. [PMID: 30761000 PMCID: PMC6362895 DOI: 10.3389/fphar.2019.00003] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 01/04/2019] [Indexed: 12/26/2022] Open
Abstract
The inflammatory airway disease cystic fibrosis (CF) is characterized by airway obstruction due to mucus hypersecretion, airway plugging, and bronchoconstriction. The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is dysfunctional in CF, leading to defects in epithelial transport. Although CF pathogenesis is still disputed, activation of alternative Cl- channels is assumed to improve lung function in CF. Two suitable non-CFTR Cl- channels are present in the airway epithelium, the Ca2+ activated channel TMEM16A and SLC26A9. Activation of these channels is thought to be feasible to improve hydration of the airway mucus and to increase mucociliary clearance. Interestingly, both channels are upregulated during inflammatory lung disease. They are assumed to support fluid secretion, necessary to hydrate excess mucus and to maintain mucus clearance. During inflammation, however, TMEM16A is upregulated particularly in mucus producing cells, with only little expression in ciliated cells. Recently it was shown that knockout of TMEM16A in ciliated cells strongly compromises Cl- conductance and attenuated mucus secretion, but does not lead to a CF-like lung disease and airway plugging. Along this line, activation of TMEM16A by denufosol, a stable purinergic ligand, failed to demonstrate any benefit to CF patients in earlier studies. It rather induced adverse effects such as cough. A number of studies suggest that TMEM16A is essential for mucus secretion and possibly also for mucus production. Evidence is now provided for a crucial role of TMEM16A in fusion of mucus-filled granules with the apical plasma membrane and cellular exocytosis. This is probably due to local Ca2+ signals facilitated by TMEM16A. Taken together, TMEM16A supports fluid secretion by ciliated airway epithelial cells, but also maintains excessive mucus secretion during inflammatory airway disease. Because TMEM16A also supports airway smooth muscle contraction, inhibition rather than activation of TMEM16A might be the appropriate treatment for CF lung disease, asthma and COPD. As a number of FDA-approved and well-tolerated drugs have been shown to inhibit TMEM16A, evaluation in clinical trials appears timely.
Collapse
Affiliation(s)
- Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | | | - Inês Cabrita
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | - Tereza Doušová
- Department of Pediatrics, Second Faculty of Medicine, University Hospital Motol, Charles University in Prague, Prague, Czechia
| | - Andrea Bähr
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians-Universität München, Munich, Germany
- Innere Medizin I, Klinikum Rechts der Isar der TU München, München, Germany
| | - Melanie Janda
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | - Roberta Benedetto
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| |
Collapse
|
20
|
Balázs A, Mall MA. Role of the SLC26A9 Chloride Channel as Disease Modifier and Potential Therapeutic Target in Cystic Fibrosis. Front Pharmacol 2018; 9:1112. [PMID: 30327603 PMCID: PMC6174851 DOI: 10.3389/fphar.2018.01112] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 09/10/2018] [Indexed: 12/13/2022] Open
Abstract
The solute carrier family 26, member 9 (SLC26A9) is an epithelial chloride channel that is expressed in several organs affected in patients with cystic fibrosis (CF) including the lungs, the pancreas, and the intestine. Emerging evidence suggests SLC26A9 as a modulator of wild-type and mutant CFTR function, and as a potential alternative target to circumvent the basic ion transport defect caused by deficient CFTR-mediated chloride transport in CF. In this review, we summarize in vitro studies that revealed multifaceted molecular and functional interactions between SLC26A9 and CFTR that may be implicated in normal transepithelial chloride secretion in health, as well as impaired chloride/fluid transport in CF. Further, we focus on recent genetic association studies and investigations utilizing genetically modified mouse models that identified SLC26A9 as a disease modifier and supported an important role of this alternative chloride channel in the pathophysiology of several organ manifestations in CF, as well as other chronic lung diseases such as asthma and non-CF bronchiectasis. Collectively, these findings and the overlapping endogenous expression with CFTR suggest SLC26A9 an attractive novel therapeutic target that may be exploited to restore epithelial chloride secretion in patients with CF irrespective of their CFTR genotype. In addition, pharmacological activation of SLC26A9 may help to augment the effect of CFTR modulator therapies in patients with CF carrying responsive mutations such as the most common disease-causing mutation F508del-CFTR. However, future research and development including the identification of compounds that activate SLC26A9-mediated chloride transport are needed to explore this alternative chloride channel as a therapeutic target in CF and potentially other muco-obstructive lung diseases.
Collapse
Affiliation(s)
- Anita Balázs
- Department of Pediatric Pulmonology, Immunology and Intensive Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,German Center for Lung Research, Giessen, Germany
| | - Marcus A Mall
- Department of Pediatric Pulmonology, Immunology and Intensive Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany.,German Center for Lung Research, Giessen, Germany
| |
Collapse
|
21
|
Strug LJ. The evidential statistical paradigm in genetics. Genet Epidemiol 2018; 42:590-607. [PMID: 30120797 PMCID: PMC6284518 DOI: 10.1002/gepi.22151] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/24/2018] [Accepted: 07/02/2018] [Indexed: 01/20/2023]
Abstract
Concerns over reproducibility in research has reinvigorated the discourse on P-values as measures of statistical evidence. In a position statement by the American Statistical Association board of directors, they warn of P-value misuse and refer to the availability of alternatives. Despite the common practice of comparing P-values across different hypothesis tests in genetics, it is well-appreciated that P-values must be interpreted alongside the sample size and experimental design used for their computation. Here, we discuss the evidential statistical paradigm (EP), an alternative to Bayesian and Frequentist paradigms, that has been implemented in human genetics studies. Using applications in Cystic Fibrosis genetic association analyses, and describing recent theoretical developments, we review how to measure statistical evidence using the EP in the presence of covariates, model misspecification, and for composite hypotheses. Novel graphical displays are presented, and software for their computation is highlighted. The implications of multiple hypothesis testing for the EP are delineated in the analyses, demonstrating a view more consistent with scientific reasoning; the EP provides a theoretical justification for replication that is a requirement in genetic association studies. As genetic studies grow in size and complexity, a fresh look at measures of statistical evidence that are sensible amid the analysis of big data are required.
Collapse
Affiliation(s)
- Lisa J. Strug
- Program in Genetics and Genome Biology, The Hospital for Sick Children, The Centre for Applied Genomics, The Hospital for Sick Children, Division of Biostatistics and Department of Statistical SciencesUniversity of TorontoTorontoOntarioCanada
| |
Collapse
|
22
|
Liu X, Li T, Tuo B. Physiological and Pathophysiological Relevance of the Anion Transporter Slc26a9 in Multiple Organs. Front Physiol 2018; 9:1197. [PMID: 30233393 PMCID: PMC6127633 DOI: 10.3389/fphys.2018.01197] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 08/08/2018] [Indexed: 02/05/2023] Open
Abstract
Transepithelial Cl- and HCO3- transport is crucial for the function of all epithelia, and HCO3- is a biological buffer that maintains acid-base homeostasis. In most epithelia, a series of Cl-/HCO3- exchangers and Cl- channels that mediate Cl- absorption and HCO3- secretion have been detected in the luminal and basolateral membranes. Slc26a9 belongs to the solute carrier 26 (Slc26) family of anion transporters expressed in the epithelia of multiple organs. This review summarizes the expression pattern and functional diversity of Slc26a9 in different systems based on all investigations performed thus far. Furthermore, the physical and functional interactions between Slc26a9 and cystic fibrosis transmembrane conductance regulator (CFTR) are discussed due to their overlapping expression pattern in multiple organs. Finally, we focus on the relationship between slc26a9 mutations and disease onset. An understanding of the physiological and pathophysiological relevance of Slc26a9 in multiple organs offers new possibilities for disease therapy.
Collapse
Affiliation(s)
- Xuemei Liu
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
| | - Taolang Li
- Department of Thyroid and Breast Surgery, Affiliated Hospital, Zunyi Medical University, Zunyi, China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital, Zunyi Medical University, Zunyi, China.,Digestive Disease Institute of Guizhou Province, Zunyi, China
| |
Collapse
|
23
|
Strug LJ, Stephenson AL, Panjwani N, Harris A. Recent advances in developing therapeutics for cystic fibrosis. Hum Mol Genet 2018; 27:R173-R186. [PMID: 30060192 PMCID: PMC6061831 DOI: 10.1093/hmg/ddy188] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 05/07/2018] [Accepted: 05/10/2018] [Indexed: 12/23/2022] Open
Abstract
Despite hope that a cure was imminent when the causative gene was cloned nearly 30 years ago, cystic fibrosis (CF [MIM: 219700]) remains a life-shortening disease affecting more than 70 000 individuals worldwide. However, within the last 6 years the Food and Drug Administration's approval of Ivacaftor, the first drug that corrects the defective cystic fibrosis transmembrane conductance regulator protein [CFTR (MIM: 602421)] in patients with the G551D mutation, marks a watershed in the development of novel therapeutics for this devastating disease. Here we review recent progress in diverse research areas, which all focus on curing CF at the genetic, biochemical or physiological level. In the near future it seems probable that development of mutation-specific therapies will be the focus, since it is unlikely that any one approach will be efficient in correcting the more than 2000 disease-associated variants. We discuss the new drugs and combinations of drugs that either enhance delivery of misfolded CFTR protein to the cell membrane, where it functions as an ion channel, or that activate channel opening. Next we consider approaches to correct the causative genetic lesion at the DNA or RNA level, through repressing stop mutations and nonsense-mediated decay, modulating splice mutations, fixing errors by gene editing or using novel routes to gene replacement. Finally, we explore how modifier genes, loci elsewhere in the genome that modify CF disease severity, may be used to restore a normal phenotype. Progress in all of these areas has been dramatic, generating enthusiasm that CF may soon become a broadly treatable disease.
Collapse
Affiliation(s)
- Lisa J Strug
- Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Anne L Stephenson
- Department of Respirology, Adult Cystic Fibrosis Program, St. Michael’s Hospital, Toronto, ON, Canada
- Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - Naim Panjwani
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ann Harris
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| |
Collapse
|
24
|
Corvol H, Mésinèle J, Douksieh IH, Strug LJ, Boëlle PY, Guillot L. SLC26A9 Gene Is Associated With Lung Function Response to Ivacaftor in Patients With Cystic Fibrosis. Front Pharmacol 2018; 9:828. [PMID: 30140228 PMCID: PMC6095007 DOI: 10.3389/fphar.2018.00828] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/09/2018] [Indexed: 11/23/2022] Open
Abstract
Ivacaftor is a drug used to treat cystic fibrosis (CF) patients carrying specific gating CFTR mutations. Interpatient variability in the lung response has been shown to be partly explained by rs7512462 in the Solute Carrier Family 26 Member 9 (SLC26A9) gene. In an independent and larger cohort, we aimed to evaluate whether SLC26A9 variants contribute to the variability of the lung phenotype and if they influence the lung response to ivacaftor. We genotyped the French CF Gene Modifier Study cohort (n = 4,840) to investigate whether SLC26A9 variants were involved in the lung phenotype heterogeneity. Their influence in the response to ivacaftor was tested in the 30 treated patients who met the inclusion criteria: older than 6 years of age, percent-predicted forced expiratory volume measured in 1 s (FEV1pp) in the 3 months before treatment initiation ranging between 40 and 90%. Response to treatment was determined by the change in FEV1pp from baseline, averaged in 15–75 days, and the 1st-year post-treatment. We observed that SLC26A9 variants were not associated with lung function variability in untreated patients and that gain of lung function in patients treated with ivacaftor was similar to clinical trials. We confirmed that rs7512462 was associated with variability in ivacaftor-lung response, with a significant reduction in lung function improvement for patients with the C allele. Other SLC26A9 SNPs also contributed to the ivacaftor-response. Interindividual variability in lung response to ivacaftor is associated with SLC26A9 variants in French CF patients. Pharmacogenomics and personalized medicine will soon be part of CF patient care.
Collapse
Affiliation(s)
- Harriet Corvol
- Centre de Recherche Saint-Antoine (CRSA), Sorbonne Université, UPMC Univ Paris 06, INSERM, Paris, France.,Pneumologie Pédiatrique, APHP, Hôpital Trousseau, Paris, France
| | - Julie Mésinèle
- Centre de Recherche Saint-Antoine (CRSA), Sorbonne Université, UPMC Univ Paris 06, INSERM, Paris, France
| | - Isman-Hassan Douksieh
- Centre de Recherche Saint-Antoine (CRSA), Sorbonne Université, UPMC Univ Paris 06, INSERM, Paris, France.,INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Université, UPMC Univ Paris 06, Paris, France
| | - Lisa J Strug
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Pierre-Yves Boëlle
- INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Sorbonne Université, UPMC Univ Paris 06, Paris, France
| | - Loïc Guillot
- Centre de Recherche Saint-Antoine (CRSA), Sorbonne Université, UPMC Univ Paris 06, INSERM, Paris, France
| |
Collapse
|
25
|
Abstract
OBJECTIVE Pancreatic insufficiency (PI) in cystic fibrosis (CF) patients is a crucial clinical marker for severity and disease progression. In our study, 125 modifier genes and their SNPs were associated between CF patients with PI or pancreatic sufficiency. METHODS We prospectively evaluated 214 CF patients admitted at 1 hospital for a 2-year period. The PI status was associated with clinical variables and SNPs related with inflammatory response considering CFTR mutations. Open Array technique was used to perform the SNPs identification. RESULTS For PI risk, after correction by multiple test, in CF patients and 2 CFTR mutations class I, II, and/or III, there were 6 SNPs with positive association (P < 0.005). The odds ratio amplitude was 0.087 (95% confidence interval [CI], 0.004-0.544) for rs9870255*CG (CTNNB1 gene) to 11.06 (95% CI, 1.746-252.3) for rs729302*AA (IRF5 gene). For all CF patients at the same time, 9 SNPs showed positive association. The odds ratio amplitude was 0.144 (95% CI, 0.028-0.602) for rs2348071*AA (PSMA3 gene) to 5.809 (95% CI, 1.536-37.54) for rs11702779*AA (RUNX1 gene). In our data, we observed the interaction between CFTR mutations, rs9870255*CTNNB1, rs9378805*IRF4, and rs7664617*KCNIP4 to PI status. CONCLUSIONS Multiple SNPs in inflammatory response genes showed association with PI considering the CFTR mutations screening.
Collapse
|
26
|
Translational research to enable personalized treatment of cystic fibrosis. J Cyst Fibros 2017; 17:S46-S51. [PMID: 29275953 DOI: 10.1016/j.jcf.2017.10.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 12/16/2022]
Abstract
Translational research efforts in cystic fibrosis (CF) aim to develop therapies for all subjects with CF. To reach this goal new therapies need to be developed that target multiple aspects of the disease. To enable individuals to benefit maximally from these treatments will require improved methods to tailor these therapies specifically to individuals who suffer from CF. This report highlights current examples of translational CF research efforts to reach this goal. The use of intestinal organoids and genetics to better understand individual assessment of CFTR modulator treatment effects to ultimately enable a better personalized treatment for CF subjects will be discussed. In addition, development of viral vectors and non-viral synthetic nanoparticles for delivery of mRNA, sgRNA and DNA will be highlighted. New approaches to restore function of CFTR with early premature termination codons using nanoparticle delivery of suppressor tRNAs and new insights into mechanisms of airway epithelial repair will be reviewed as well. The state-of-the-art approaches that are discussed in this review demonstrate significant progress towards the development of optimal individual therapies for CF patients, but also reveal that remaining challenges still lie ahead.
Collapse
|
27
|
Li H, Salomon JJ, Sheppard DN, Mall MA, Galietta LJ. Bypassing CFTR dysfunction in cystic fibrosis with alternative pathways for anion transport. Curr Opin Pharmacol 2017; 34:91-97. [PMID: 29065356 DOI: 10.1016/j.coph.2017.10.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/20/2017] [Accepted: 10/04/2017] [Indexed: 12/20/2022]
Abstract
One therapeutic strategy for cystic fibrosis (CF) seeks to restore anion transport to affected epithelia by targeting other apical membrane Cl- channels to bypass dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. The properties and regulation of the Ca2+-activated Cl- channel TMEM16A argue that long-acting small molecules which target directly TMEM16A are required to overcome CFTR loss. Through genetic studies of lung diseases, SLC26A9, a member of the solute carrier 26 family of anion transporters, has emerged as a promising target to bypass CFTR dysfunction. An alternative strategy to circumvent CFTR dysfunction is to deliver to CF epithelia artificial anion transporters that shuttle Cl- across the apical membrane. Recently, powerful, non-toxic, biologically-active artificial anion transporters have emerged.
Collapse
Affiliation(s)
- Hongyu Li
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Johanna J Salomon
- Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics, University Hospital Heidelberg, Heidelberg, Germany; Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - David N Sheppard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Marcus A Mall
- Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Department of Pediatrics, University Hospital Heidelberg, Heidelberg, Germany; Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Luis Jv Galietta
- Telethon Institute for Genetics and Medicine (Tigem), Pozzuoli, Italy.
| |
Collapse
|
28
|
Pereira SVN, Ribeiro JD, Bertuzzo CS, Marson FAL. Association of clinical severity of cystic fibrosis with variants in the SLC gene family (SLC6A14, SLC26A9, SLC11A1 and SLC9A3). Gene 2017; 629:117-126. [PMID: 28756021 DOI: 10.1016/j.gene.2017.07.068] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/15/2017] [Accepted: 07/25/2017] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Cystic fibrosis (CF) manifests with clinical and histopathological variability depending on environmental and genetic factors. Moreover, the genes encoding ion channels[rs3788766(SLC6A14), rs7512462(SLC26A9), rs17235416(SLC11A1) and rs17563161(SLC9A3)] have been insufficiently studied as modifier genes. Then, our objective was associate the variants in the genes of SLC family with 43 CF severity markers. METHODS The variants were identified by real-time-PCR in 188 CF patients considering the CFTR genotype. Statistical analyses were performed by parametric and nonparametric tests. The correction by multiple testing was performed by the False Rate Discovery test, alpha=0.05. RESULTS Depending on the CFTR mutations, we found association of: (i) rs3788766*CC with mucoid Pseudomonas aeruginosa (OR=0.171; 95%CI=0.029-0.696), non-mucoid P. aeruginosa (OR=0.283; 95%CI=0.094-0.853) and Staphyloccocus aureus (OR=4.443; 95%CI=1.019-40.64), largest FEFmax(p=0.041) and best response to bronchodilator for FEF50%(p=0.033) and FEV1/FVC(p=0.044); (ii) rs3788766*CT with early start of pulmonary symptom (OR=3.524; 95%CI=1.229-10.1) and osteoporosis (OR=0.203; 95%CI=0.022-0.883); (iii) rs3788766*TT with lowest body mass index (OR=4.242; 95%CI=1.505-11.95), presence of mucoid P. aeruginosa (OR=3.176; 95%CI=1.29-7.819) and S. aureus (OR=0.116; 95%CI=0.004-0.881), highest Bhalla score (p=0.047) and lowest FEFmax(p=0.028) and FEF25%(p=0.031) values; (iv) rs7512462*CC with highest Shwachman-Kulczycki score (p=0.019), FVC(p=0.043), FEV1(p=0.047), FEV1/FVC(p=0.022), FEF50%(p=0.038) and FEF25-75%(p=0.016); (v) rs7512462*CT with lowest values of FVC(p=0.034), FEV1(p=0.047), FEV1/FVC(p=0.022), FEF25%(p=0.012), FEF50%(p=0.038), FEF75%(p=0.008), FEF25-75%(p=0.016) and ERV(p=0.023); (vi) rs7512462*TT with best response to the inhaled bronchodilator for FEV1(p=0.011), FEF50%(p=0.019), FEF75%(p=0.036) and FEF25-75%(p=0.008); (vii) rs17234516*Normal allele with lowest value of SaO2 (p=0.010) and S. aureus (OR=3.333; 95%CI=1.085-10.24); (viii) rs17563161*GG with lowest age for onset of digestive symptoms (OR=2.564; 95%CI=1.234-5.33). CONCLUSIONS The clinical and laboratory variability of CF were associated with the variants in the genes of SLC family in our sample.
Collapse
Affiliation(s)
- Stéphanie Villa-Nova Pereira
- Department of Medical Genetics, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil.
| | - José Dirceu Ribeiro
- Department of Pediatrics, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil; Laboratory of Pulmonary Physiology, Center for Pediatrics Investigation, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil
| | - Carmen Sílvia Bertuzzo
- Department of Medical Genetics, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil.
| | - Fernando Augusto Lima Marson
- Department of Medical Genetics, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil; Department of Pediatrics, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil; Laboratory of Pulmonary Physiology, Center for Pediatrics Investigation, Faculty of Medical Sciences, State University of Campinas, Tessália Vieira de Camargo, 126, Barão Geraldo, Cidade Universitária Zeferino Vaz, 13083-887 Campinas, São Paulo, Brazil.
| |
Collapse
|
29
|
Bertrand CA, Mitra S, Mishra SK, Wang X, Zhao Y, Pilewski JM, Madden DR, Frizzell RA. The CFTR trafficking mutation F508del inhibits the constitutive activity of SLC26A9. Am J Physiol Lung Cell Mol Physiol 2017; 312:L912-L925. [PMID: 28360110 PMCID: PMC5495941 DOI: 10.1152/ajplung.00178.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 03/22/2017] [Accepted: 03/22/2017] [Indexed: 11/22/2022] Open
Abstract
Several members of the SLC26A family of anion transporters associate with CFTR, forming complexes in which CFTR and SLC26A functions are reciprocally regulated. These associations are thought to be facilitated by PDZ scaffolding interactions. CFTR has been shown to be positively regulated by NHERF-1, and negatively regulated by CAL in airway epithelia. However, it is unclear which PDZ-domain protein(s) interact with SLC26A9, a SLC26A family member found in airway epithelia. We have previously shown that primary, human bronchial epithelia (HBE) from non-CF donors exhibit constitutive anion secretion attributable to SLC26A9. However, constitutive anion secretion is absent in HBE from CF donors. We examined whether changes in SLC26A9 constitutive activity could be attributed to a loss of CFTR trafficking, and what role PDZ interactions played. HEK293 coexpressing SLC26A9 with the trafficking mutant F508del CFTR exhibited a significant reduction in constitutive current compared with cells coexpressing SLC26A9 and wt CFTR. We found that SLC26A9 exhibits complex glycosylation when coexpressed with F508del CFTR, but its expression at the plasma membrane is decreased. SLC26A9 interacted with both NHERF-1 and CAL, and its interaction with both significantly increased with coexpression of wt CFTR. However, coexpression with F508del CFTR only increased SLC26A9's interaction with CAL. Mutation of SLC26A9's PDZ motif decreased this association with CAL, and restored its constitutive activity. Correcting aberrant F508del CFTR trafficking in CF HBE with corrector VX-809 also restored SLC26A9 activity. We conclude that when SLC26A9 is coexpressed with F508del CFTR, its trafficking defect leads to a PDZ motif-sensitive intracellular retention of SLC26A9.
Collapse
Affiliation(s)
- Carol A Bertrand
- Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania;
| | - Shalini Mitra
- Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Sanjay K Mishra
- Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Xiaohui Wang
- Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Yu Zhao
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Joseph M Pilewski
- Department of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Dean R Madden
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Raymond A Frizzell
- Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| |
Collapse
|
30
|
Strug LJ, Gonska T, He G, Keenan K, Ip W, Boëlle PY, Lin F, Panjwani N, Gong J, Li W, Soave D, Xiao B, Tullis E, Rabin H, Parkins MD, Price A, Zuberbuhler PC, Corvol H, Ratjen F, Sun L, Bear CE, Rommens JM. Cystic fibrosis gene modifier SLC26A9 modulates airway response to CFTR-directed therapeutics. Hum Mol Genet 2016; 25:4590-4600. [PMID: 28171547 PMCID: PMC5886039 DOI: 10.1093/hmg/ddw290] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/12/2016] [Accepted: 08/25/2016] [Indexed: 12/18/2022] Open
Abstract
Cystic fibrosis is realizing the promise of personalized medicine. Recent advances in drug development that target the causal CFTR directly result in lung function improvement, but variability in response is demanding better prediction of outcomes to improve management decisions. The genetic modifier SLC26A9 contributes to disease severity in the CF pancreas and intestine at birth and here we assess its relationship with disease severity and therapeutic response in the airways. SLC26A9 association with lung disease was assessed in individuals from the Canadian and French CF Gene Modifier consortia with CFTR-gating mutations and in those homozygous for the common Phe508del mutation. Variability in response to a CFTR-directed therapy attributed to SLC26A9 genotype was assessed in Canadian patients with gating mutations. A primary airway model system determined if SLC26A9 shows modification of Phe508del CFTR function upon treatment with a CFTR corrector. In those with gating mutations that retain cell surface-localized CFTR we show that SLC26A9 modifies lung function while this is not the case in individuals homozygous for Phe508del where cell surface expression is lacking. Treatment response to ivacaftor, which aims to improve CFTR-channel opening probability in patients with gating mutations, shows substantial variability in response, 28% of which can be explained by rs7512462 in SLC26A9 (P = 0.0006). When homozygous Phe508del primary bronchial cells are treated to restore surface CFTR, SLC26A9 likewise modifies treatment response (P = 0.02). Our findings indicate that SLC26A9 airway modification requires CFTR at the cell surface, and that a common variant in SLC26A9 may predict response to CFTR-directed therapeutics.
Collapse
Affiliation(s)
- Lisa J. Strug
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Ontario, Canada
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Tanja Gonska
- Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
- Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, Ontario, Canada
- Program in Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Gengming He
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Katherine Keenan
- Program in Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Wan Ip
- Program in Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Pierre-Yves Boëlle
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Paris 06, Paris, France
- Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital St. Antoine, Biostatistics Department; Inserm U1136, Paris, France
| | - Fan Lin
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Naim Panjwani
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jiafen Gong
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Weili Li
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - David Soave
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Ontario, Canada
| | - Bowei Xiao
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Elizabeth Tullis
- Department of Respiratory Medicine and Li Ka Shing Knowledge Institute, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Harvey Rabin
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
- The Department of Microbiology, Immunology and Infectious Disease, University of Calgary, Calgary, Alberta, Canada
| | - Michael D. Parkins
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada
- The Department of Microbiology, Immunology and Infectious Disease, University of Calgary, Calgary, Alberta, Canada
| | - April Price
- Division of Paediatric Respirology, Department of Paediatrics, Children's Hospital at London Health Sciences Centre, London, Ontario, Canada
| | | | - Harriet Corvol
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Paris 06, Paris, France
- AP-HP, Hôpital Trousseau, Pediatric Pulmonary Department; Institut National de la Santé et al Recherche Medicale (INSERM) U938, Paris, France
| | - Felix Ratjen
- Program in Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Respiratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Lei Sun
- Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Ontario, Canada
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Christine E. Bear
- Program in Molecular Structure and Function, The Hospital for Sick Children, Toronto, Ontario, CanadaDepartments of
- Biochemistry
- Physiology
| | - Johanna M. Rommens
- Program in Genetics and Genome Biology, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
31
|
Saint-Criq V, Gray MA. Role of CFTR in epithelial physiology. Cell Mol Life Sci 2016; 74:93-115. [PMID: 27714410 PMCID: PMC5209439 DOI: 10.1007/s00018-016-2391-y] [Citation(s) in RCA: 243] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 12/20/2022]
Abstract
Salt and fluid absorption and secretion are two processes that are fundamental to epithelial function and whole body fluid homeostasis, and as such are tightly regulated in epithelial tissues. The CFTR anion channel plays a major role in regulating both secretion and absorption in a diverse range of epithelial tissues, including the airways, the GI and reproductive tracts, sweat and salivary glands. It is not surprising then that defects in CFTR function are linked to disease, including life-threatening secretory diarrhoeas, such as cholera, as well as the inherited disease, cystic fibrosis (CF), one of the most common life-limiting genetic diseases in Caucasian populations. More recently, CFTR dysfunction has also been implicated in the pathogenesis of acute pancreatitis, chronic obstructive pulmonary disease (COPD), and the hyper-responsiveness in asthma, underscoring its fundamental role in whole body health and disease. CFTR regulates many mechanisms in epithelial physiology, such as maintaining epithelial surface hydration and regulating luminal pH. Indeed, recent studies have identified luminal pH as an important arbiter of epithelial barrier function and innate defence, particularly in the airways and GI tract. In this chapter, we will illustrate the different operational roles of CFTR in epithelial function by describing its characteristics in three different tissues: the airways, the pancreas, and the sweat gland.
Collapse
Affiliation(s)
- Vinciane Saint-Criq
- Epithelial Research Group, Institute for Cell and Molecular Biosciences, University Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH UK
| | - Michael A. Gray
- Epithelial Research Group, Institute for Cell and Molecular Biosciences, University Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH UK
| |
Collapse
|
32
|
Salomon JJ, Spahn S, Wang X, Füllekrug J, Bertrand CA, Mall MA. Generation and functional characterization of epithelial cells with stable expression of SLC26A9 Cl- channels. Am J Physiol Lung Cell Mol Physiol 2016; 310:L593-602. [PMID: 26801567 DOI: 10.1152/ajplung.00321.2015] [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] [Received: 09/08/2015] [Accepted: 01/16/2016] [Indexed: 01/01/2023] Open
Abstract
Recent studies identified the SLC26A9 Cl(-) channel as a modifier and potential therapeutic target in cystic fibrosis (CF). However, understanding of the regulation of SLC26A9 in epithelia remains limited and cellular models with stable expression for biochemical and functional studies are missing. We, therefore, generated Fisher rat thyroid (FRT) epithelial cells with stable expression of HA-tagged SLC26A9 via retroviral transfection and characterized SLC26A9 expression and function using Western blotting, immunolocalization, whole cell patch-clamp, and transepithelial bioelectric studies in Ussing chambers. We demonstrate stable expression of SLC26A9 in transfected FRT (SLC26A9-FRT) cells on the mRNA and protein level. Immunolocalization and Western blotting detected SLC26A9 in different intracellular compartments and to a lesser extent at the cell surface. Whole cell patch-clamp recordings demonstrated significantly increased constitutive Cl(-) currents in SLC26A9-FRT compared with control-transduced FRT (Control-FRT) cells (P < 0.01). Similar, transepithelial measurements showed that the basal short circuit current was significantly increased in SLC26A9-FRT vs. Control-FRT cell monolayers (P < 0.01). SLC26A9-mediated Cl(-) currents were increased by cAMP-dependent stimulation (IBMX and forskolin) and inhibited by GlyH-101, niflumic acid, DIDS, and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), as well as RNAi knockdown of WNK1 implicated in epithelial osmoregulation. Our results support that these novel epithelial cells with stable expression of SLC26A9 will be a useful model for studies of pharmacological regulation including the identification of activators of SLC26A9 Cl(-) channels that may compensate deficient cystic fibrosis transmembrane regulator (CFTR)-mediated Cl(-) secretion and serve as an alternative therapeutic target in patients with CF and potentially other muco-obstructive lung diseases.
Collapse
Affiliation(s)
- Johanna J Salomon
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Stephan Spahn
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Xiaohui Wang
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory, Department of Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
| | - Carol A Bertrand
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Marcus A Mall
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany;
| |
Collapse
|
33
|
Levy H, Nugent M, Schneck K, Stachiw-Hietpas D, Laxova A, Lakser O, Rock M, Dahmer MK, Biller J, Nasr SZ, Baker M, McColley SA, Simpson P, Farrell PM. Refining the continuum of CFTR-associated disorders in the era of newborn screening. Clin Genet 2016; 89:539-49. [PMID: 26671754 DOI: 10.1111/cge.12711] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/25/2015] [Accepted: 12/06/2015] [Indexed: 02/01/2023]
Abstract
Clinical heterogeneity in cystic fibrosis (CF) often causes diagnostic uncertainty in infants without symptoms and in older patients with milder phenotypes. We performed a cross-sectional evaluation of a comprehensive set of clinical and laboratory descriptors in a physician-defined cohort (N = 376; Children's Hospital of Wisconsin and the American Family Children's Hospital CF centers in Milwaukee and Madison, WI, USA) to determine the robustness of categorizing CF (N = 300), cystic fibrosis transmembrane conductance regulator (CFTR)-related disorder (N = 19), and CFTR-related (CRMS) metabolic syndrome (N = 57) according to current consensus guidelines. Outcome measures included patient demographics, clinical measures, sweat chloride levels, CFTR genotype, age at diagnosis, airway microbiology, pancreatic function, infection, and nutritional status. The CF cohort had a significantly higher median sweat chloride level (105 mmol/l) than CFTR-related disorder patients (43 mmol/l) and CFTR-related metabolic syndrome patients (35 mmol/l; p ≤ 0.001). Patient groups significantly differed in pancreatic sufficiency, immunoreactive trypsinogen levels, sweat chloride values, genotype, and positive Pseudomonas aeruginosa cultures (p ≤ 0.001). An automated classification algorithm using recursive partitioning demonstrated concordance between physician diagnoses and consensus guidelines. Our analysis suggests that integrating clinical information with sweat chloride levels, CFTR genotype, and pancreatic sufficiency provides a context for continued longitudinal monitoring of patients for personalized and effective treatment.
Collapse
Affiliation(s)
- H Levy
- Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, WI, USA.,Division of Pulmonary and Sleep Medicine, Children's Hospital of Wisconsin, Milwaukee, WI, USA
| | - M Nugent
- Division of Quantitative Health Sciences, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - K Schneck
- Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, WI, USA
| | - D Stachiw-Hietpas
- Genetics Center, Children's Hospital and Health System of Wisconsin, Milwaukee, WI, USA
| | - A Laxova
- Department of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - O Lakser
- Department of Pediatrics, Section of Pulmonary Medicine, Lurie's Children's Hospital and Northwestern University, Chicago, IL, USA
| | - M Rock
- Department of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - M K Dahmer
- Children's Research Institute, Children's Hospital of Wisconsin and Medical College of Wisconsin, Milwaukee, WI, USA.,Division of Pediatric Critical Care Medicine, University of Michigan, Ann Arbor, MI, USA
| | - J Biller
- Division of Pulmonary and Sleep Medicine, Children's Hospital of Wisconsin, Milwaukee, WI, USA
| | - S Z Nasr
- Division of Pediatric Pulmonary Medicine, University of Michigan, Ann Arbor, MI, USA
| | - M Baker
- Wisconsin State Lab of Hygiene, Madison, WI, USA.,Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - S A McColley
- Department of Pediatrics, Section of Pulmonary Medicine, Lurie's Children's Hospital and Northwestern University, Chicago, IL, USA
| | - P Simpson
- Division of Quantitative Health Sciences, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - P M Farrell
- Department of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| |
Collapse
|
34
|
Novel Roles for Chloride Channels, Exchangers, and Regulators in Chronic Inflammatory Airway Diseases. Mediators Inflamm 2015; 2015:497387. [PMID: 26612971 PMCID: PMC4647060 DOI: 10.1155/2015/497387] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/13/2015] [Indexed: 01/14/2023] Open
Abstract
Chloride transport proteins play critical roles in inflammatory airway diseases, contributing to the detrimental aspects of mucus overproduction, mucus secretion, and airway constriction. However, they also play crucial roles in contributing to the innate immune properties of mucus and mucociliary clearance. In this review, we focus on the emerging novel roles for a chloride channel regulator (CLCA1), a calcium-activated chloride channel (TMEM16A), and two chloride exchangers (SLC26A4/pendrin and SLC26A9) in chronic inflammatory airway diseases.
Collapse
|
35
|
Benuzzi MLS, Pereira SV, Raba J, Messina GA. Screening for cystic fibrosis via a magnetic and microfluidic immunoassay format with electrochemical detection using a copper nanoparticle-modified gold electrode. Mikrochim Acta 2015. [DOI: 10.1007/s00604-015-1660-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
36
|
Mall MA, Galietta LJV. Targeting ion channels in cystic fibrosis. J Cyst Fibros 2015; 14:561-70. [PMID: 26115565 DOI: 10.1016/j.jcf.2015.06.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 05/28/2015] [Accepted: 06/01/2015] [Indexed: 12/12/2022]
Abstract
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause a characteristic defect in epithelial ion transport that plays a central role in the pathogenesis of cystic fibrosis (CF). Hence, pharmacological correction of this ion transport defect by targeting of mutant CFTR, or alternative ion channels that may compensate for CFTR dysfunction, has long been considered as an attractive approach to a causal therapy of this life-limiting disease. The recent introduction of the CFTR potentiator ivacaftor into the therapy of a subgroup of patients with specific CFTR mutations was a major milestone and enormous stimulus for seeking effective ion transport modulators for all patients with CF. In this review, we discuss recent breakthroughs and setbacks with CFTR modulators designed to rescue mutant CFTR including the common mutation F508del. Further, we examine the alternative chloride channels TMEM16A and SLC26A9, as well as the epithelial sodium channel ENaC as alternative targets in CF lung disease, which remains the major cause of morbidity and mortality in patients with CF. Finally, we will focus on the hurdles that still need to be overcome to make effective ion transport modulation therapies available for all patients with CF irrespective of their CFTR genotype.
Collapse
Affiliation(s)
- Marcus A Mall
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany; Division of Pediatric Pulmonology & Allergy and Cystic Fibrosis Center, Department of Pediatrics, University of Heidelberg, Heidelberg, Germany.
| | | |
Collapse
|