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Angyal D, Kleinfelder K, Ciciriello F, Groeneweg TA, De Marchi G, de Pretis N, Bernardoni L, Rodella L, Tomba F, De Angelis P, Surace C, Pintani E, Alghisi F, de Jonge HR, Melotti P, Sorio C, Lucidi V, Bijvelds MJC, Frulloni L. CFTR function is impaired in a subset of patients with pancreatitis carrying rare CFTR variants. Pancreatology 2024; 24:394-403. [PMID: 38493004 DOI: 10.1016/j.pan.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 03/07/2024] [Accepted: 03/08/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND Many affected by pancreatitis harbor rare variants of the cystic fibrosis (CF) gene, CFTR, which encodes an epithelial chloride/bicarbonate channel. We investigated CFTR function and the effect of CFTR modulator drugs in pancreatitis patients carrying CFTR variants. METHODS Next-generation sequencing was performed to identify CFTR variants. Sweat tests and nasal potential difference (NPD) assays were performed to assess CFTR function in vivo. Intestinal current measurement (ICM) was performed on rectal biopsies. Patient-derived intestinal epithelial monolayers were used to evaluate chloride and bicarbonate transport and the effects of a CFTR modulator combination: elexacaftor, tezacaftor and ivacaftor (ETI). RESULTS Of 32 pancreatitis patients carrying CFTR variants, three had CF-causing mutations on both alleles and yielded CF-typical sweat test, NPD and ICM results. Fourteen subjects showed a more modest elevation in sweat chloride levels, including three that were provisionally diagnosed with CF. ICM indicated impaired CFTR function in nine out of 17 non-CF subjects tested. This group of nine included five carrying a wild type CFTR allele. In epithelial monolayers, a reduction in CFTR-dependent chloride transport was found in six out of 14 subjects tested, whereas bicarbonate secretion was reduced in only one individual. In epithelial monolayers of four of these six subjects, ETI improved CFTR function. CONCLUSIONS CFTR function is impaired in a subset of pancreatitis patients carrying CFTR variants. Mutations outside the CFTR locus may contribute to the anion transport defect. Bioassays on patient-derived intestinal tissue and organoids can be used to detect such defects and to assess the effect of CFTR modulators.
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Affiliation(s)
- Dora Angyal
- Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000, CA, Rotterdam, the Netherlands
| | - Karina Kleinfelder
- Department of Medicine, University of Verona, Division of General Pathology, Verona, Italy
| | - Fabiana Ciciriello
- Cystic Fibrosis Unit, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant'Onofrio 4, 00165, Rome, Italy
| | - Tessa A Groeneweg
- Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000, CA, Rotterdam, the Netherlands
| | - Giulia De Marchi
- Gastroenterology Unit, Department of Medicine, Borgo Roma Hospital, Piazzale L.A. Scuro 10, 37134, Verona, Italy
| | - Nicolò de Pretis
- Gastroenterology Unit, Department of Medicine, Borgo Roma Hospital, Piazzale L.A. Scuro 10, 37134, Verona, Italy
| | - Laura Bernardoni
- Gastroenterology Unit, Department of Medicine, Borgo Roma Hospital, Piazzale L.A. Scuro 10, 37134, Verona, Italy
| | - Luca Rodella
- Endoscopy Surgery Unit, Azienda Ospedaliera Universitaria Integrata Verona, 37126, Verona, Italy
| | - Francesco Tomba
- Endoscopy Surgery Unit, Azienda Ospedaliera Universitaria Integrata Verona, 37126, Verona, Italy
| | - Paola De Angelis
- Digestive Endoscopy and Surgery Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Cecilia Surace
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Emily Pintani
- Cystic Fibrosis Centre, Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Federico Alghisi
- Cystic Fibrosis Unit, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant'Onofrio 4, 00165, Rome, Italy
| | - Hugo R de Jonge
- Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000, CA, Rotterdam, the Netherlands
| | - Paola Melotti
- Cystic Fibrosis Centre, Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy
| | - Claudio Sorio
- Department of Medicine, University of Verona, Division of General Pathology, Verona, Italy
| | - Vincenzina Lucidi
- Cystic Fibrosis Unit, Bambino Gesù Children's Hospital, IRCCS, Piazza di Sant'Onofrio 4, 00165, Rome, Italy
| | - Marcel J C Bijvelds
- Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center, P.O. Box 2040, 3000, CA, Rotterdam, the Netherlands.
| | - Luca Frulloni
- Gastroenterology Unit, Department of Medicine, Borgo Roma Hospital, Piazzale L.A. Scuro 10, 37134, Verona, Italy
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2
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Becker HM, Seidler UE. Bicarbonate secretion and acid/base sensing by the intestine. Pflugers Arch 2024; 476:593-610. [PMID: 38374228 PMCID: PMC11006743 DOI: 10.1007/s00424-024-02914-3] [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: 11/16/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/21/2024]
Abstract
The transport of bicarbonate across the enterocyte cell membrane regulates the intracellular as well as the luminal pH and is an essential part of directional fluid movement in the gut. Since the first description of "active" transport of HCO3- ions against a concentration gradient in the 1970s, the fundamental role of HCO3- transport for multiple intestinal functions has been recognized. The ion transport proteins have been identified and molecularly characterized, and knockout mouse models have given insight into their individual role in a variety of functions. This review describes the progress made in the last decade regarding novel techniques and new findings in the molecular regulation of intestinal HCO3- transport in the different segments of the gut. We discuss human diseases with defects in intestinal HCO3- secretion and potential treatment strategies to increase luminal alkalinity. In the last part of the review, the cellular and organismal mechanisms for acid/base sensing in the intestinal tract are highlighted.
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Affiliation(s)
- Holger M Becker
- Department of Gastroenterology, Hannover Medical School, 30625, Hannover, Germany
| | - Ursula E Seidler
- Department of Gastroenterology, Hannover Medical School, 30625, Hannover, Germany.
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3
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Abstract
The with no lysine (K) (WNK) kinases are an evolutionarily ancient group of kinases with atypical placement of the catalytic lysine and diverse physiological roles. Recent studies have shown that WNKs are directly regulated by chloride, potassium, and osmotic pressure. Here, we review the discovery of WNKs as chloride-sensitive kinases and discuss physiological contexts in which chloride regulation of WNKs has been demonstrated. These include the kidney, pancreatic duct, neurons, and inflammatory cells. We discuss the interdependent relationship of osmotic pressure and intracellular chloride in cell volume regulation. We review the recent demonstration of potassium regulation of WNKs and speculate on possible physiological roles. Finally, structural and mechanistic aspects of intracellular ion and osmotic pressure regulation of WNKs are discussed.
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Affiliation(s)
- Elizabeth J Goldsmith
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Aylin R Rodan
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA; .,Division of Nephrology and Hypertension, Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA.,Medical Service, Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah, USA
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4
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The COPD-Associated Polymorphism Impairs the CFTR Function to Suppress Excessive IL-8 Production upon Environmental Pathogen Exposure. Int J Mol Sci 2023; 24:ijms24032305. [PMID: 36768629 PMCID: PMC9916815 DOI: 10.3390/ijms24032305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/17/2023] [Accepted: 01/21/2023] [Indexed: 01/26/2023] Open
Abstract
COPD is a lifestyle-related disease resulting from irreversible damage to respiratory tissues mostly due to chronic exposure to environmental pollutants, including cigarette smoke. Environmental pathogens and pollutants induce the acquired dysfunction of the CFTR Cl- channel, which is invoked in COPD. Despite the increased incidence of CFTR polymorphism R75Q or M470V in COPD patients, the mechanism of how the CFTR variant affects COPD pathogenesis remains unclear. Here, we investigated the impact of CFTR polymorphisms (R75Q, M470V) on the CFTR function in airway epithelial cell models. While wild-type (WT) CFTR suppressed the proinflammatory cytokine production induced by COPD-related pathogens including pyocyanin (PYO), R75Q- or M470V-CFTR failed. Mechanistically, the R75Q- or M470V-CFTR fractional PM activity (FPMA) was significantly lower than WT-CFTR in the presence of PYO. Notably, the CF drug Trikafta corrected the PM expression of R75Q- or M470V-CFTR even upon PYO exposure and consequently suppressed the excessive IL-8 production. These results suggest that R75Q or M470V polymorphism impairs the CFTR function to suppress the excessive proinflammatory response to environmental pathogens associated with COPD. Moreover, Trikafta may be useful to prevent the COPD pathogenesis associated with acquired CFTR dysfunction.
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5
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Song J, Dong L, Sun H, Luo N, Huang Q, Li K, Shen X, Jiang Z, Lv Z, Peng L, Zhang M, Wang K, Liu K, Hong J, Yi C. CRISPR-free, programmable RNA pseudouridylation to suppress premature termination codons. Mol Cell 2023; 83:139-155.e9. [PMID: 36521489 DOI: 10.1016/j.molcel.2022.11.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/03/2022] [Accepted: 11/14/2022] [Indexed: 12/15/2022]
Abstract
Nonsense mutations, accounting for >20% of disease-associated mutations, lead to premature translation termination. Replacing uridine with pseudouridine in stop codons suppresses translation termination, which could be harnessed to mediate readthrough of premature termination codons (PTCs). Here, we present RESTART, a programmable RNA base editor, to revert PTC-induced translation termination in mammalian cells. RESTART utilizes an engineered guide snoRNA (gsnoRNA) and the endogenous H/ACA box snoRNP machinery to achieve precise pseudouridylation. We also identified and optimized gsnoRNA scaffolds to increase the editing efficiency. Unexpectedly, we found that a minor isoform of pseudouridine synthase DKC1, lacking a C-terminal nuclear localization signal, greatly improved the PTC-readthrough efficiency. Although RESTART induced restricted off-target pseudouridylation, they did not change the coding information nor the expression level of off-targets. Finally, RESTART enables robust pseudouridylation in primary cells and achieves functional PTC readthrough in disease-relevant contexts. Collectively, RESTART is a promising RNA-editing tool for research and therapeutics.
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Affiliation(s)
- Jinghui Song
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Liting Dong
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC
| | - Hanxiao Sun
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Nan Luo
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Qiang Huang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Kai Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC; Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, PRC
| | - Xiaowen Shen
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC
| | - Zhe Jiang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Zhicong Lv
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Luxin Peng
- College of Chemistry and Molecular Engineering, Peking University, Beijing, PRC
| | | | - Kun Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, PRC
| | - Jiaxu Hong
- Department of Ophthalmology, Eye and Ear, Nose, Throat Hospital of Fudan University, Shanghai, PRC
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, PRC; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, PRC; Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, PRC.
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6
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Bergougnoux A, Billet A, Ka C, Heller M, Degrugillier F, Vuillaume ML, Thoreau V, Sasorith S, Bareil C, Thèze C, Ferec C, Gac GL, Bienvenu T, Bieth E, Gaston V, Lalau G, Pagin A, Malinge MC, Dufernez F, Lemonnier L, Koenig M, Fergelot P, Claustres M, Taulan-Cadars M, Kitzis A, Reboul MP, Becq F, Fanen P, Mekki C, Audrezet MP, Girodon E, Raynal C. The multi-faceted nature of 15 CFTR exonic variations: Impact on their functional classification and perspectives for therapy. J Cyst Fibros 2022:S1569-1993(22)01423-0. [PMID: 36567205 DOI: 10.1016/j.jcf.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 09/30/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND The majority of variants of unknown clinical significance (VUCS) in the CFTR gene are missense variants. While change on the CFTR protein structure or function is often suspected, impact on splicing may be neglected. Such undetected splicing default of variants may complicate the interpretation of genetic analyses and the use of an appropriate pharmacotherapy. METHODS We selected 15 variants suspected to impact CFTR splicing after in silico predictions on 319 missense variants (214 VUCS), reported in the CFTR-France database. Six specialized laboratories assessed the impact of nucleotide substitutions on splicing (minigenes), mRNA expression levels (quantitative PCR), synthesis and maturation (western blot), cellular localization (immunofluorescence) and channel function (patch clamp) of the CFTR protein. We also studied maturation and function of the truncated protein, consecutive to in-frame aberrant splicing, on additional plasmid constructs. RESULTS Six of the 15 variants had a major impact on CFTR splicing by in-frame (n = 3) or out-of-frame (n = 3) exon skipping. We reclassified variants into: splicing variants; variants causing a splicing defect and the impairment of CFTR folding and/or function related to the amino acid substitution; deleterious missense variants that impair CFTR folding and/or function; and variants with no consequence on the different processes tested. CONCLUSION The 15 variants have been reclassified by our comprehensive approach of in vitro experiments that should be used to properly interpret very rare exonic variants of the CFTR gene. Targeted therapies may thus be adapted to the molecular defects regarding the results of laboratory experiments.
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Affiliation(s)
- A Bergougnoux
- Génétique Moléculaire, CHU Montpellier, Montpellier, France; PhyMedExp, INSERM, CNRS UMR, Montpellier, France; Université de Montpellier, Montpellier, France
| | - A Billet
- Laboratoire STIM, Université de Poitiers, Poitiers, France
| | - C Ka
- Service de génétique moléculaire, CHRU Brest, Brest, France; Université de Brest, Inserm, UMR 1078, GGB, Brest, France
| | - M Heller
- Service de Médecine Génomique des Maladies de Système et d'Organe, APHP Centre - Université de Paris, Hôpital Cochin, Paris, France
| | - F Degrugillier
- Université Paris-Est Créteil, INSERM, IMRB, Créteil F-94010, France
| | - M-L Vuillaume
- Génétique Moléculaire, CHU Bordeaux, Bordeaux, France
| | - V Thoreau
- Laboratoire NEUVACOD-3808, Université de Poitiers, Poitiers, France
| | - S Sasorith
- Génétique Moléculaire, CHU Montpellier, Montpellier, France; PhyMedExp, INSERM, CNRS UMR, Montpellier, France
| | - C Bareil
- Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - C Thèze
- Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - C Ferec
- Université de Brest, Inserm, UMR 1078, GGB, Brest, France
| | - G Le Gac
- Service de génétique moléculaire, CHRU Brest, Brest, France; Université de Brest, Inserm, UMR 1078, GGB, Brest, France
| | - T Bienvenu
- Service de Médecine Génomique des Maladies de Système et d'Organe, APHP Centre - Université de Paris, Hôpital Cochin, Paris, France
| | - E Bieth
- Génétique Médicale, CHU Toulouse, Toulouse, France
| | - V Gaston
- Génétique Médicale, CHU Toulouse, Toulouse, France
| | - G Lalau
- Biochimie et Biologie Moléculaire, CHU Lille, Lille, France
| | - A Pagin
- Biochimie et Biologie Moléculaire, CHU Lille, Lille, France
| | - M-C Malinge
- Biochimie et Génétique, CHU Angers, Angers, France
| | - F Dufernez
- Génétique, CHU Poitiers, Poitiers, France
| | - L Lemonnier
- Association Vaincre la Mucoviscidose, Paris, France
| | - M Koenig
- Génétique Moléculaire, CHU Montpellier, Montpellier, France; PhyMedExp, INSERM, CNRS UMR, Montpellier, France; Université de Montpellier, Montpellier, France
| | - P Fergelot
- MRGM, INSERM UMR 1211 Université de Bordeaux, Bordeaux, France
| | - M Claustres
- Université de Montpellier, Montpellier, France
| | - M Taulan-Cadars
- PhyMedExp, INSERM, CNRS UMR, Montpellier, France; Université de Montpellier, Montpellier, France
| | - A Kitzis
- Génétique, CHU Poitiers, Poitiers, France
| | - M-P Reboul
- Génétique Moléculaire, CHU Bordeaux, Bordeaux, France
| | - F Becq
- Laboratoire STIM, Université de Poitiers, Poitiers, France
| | - P Fanen
- AP-HP, Département de Biochimie-Biologie Moléculaire, Pharmacologie, Génétique Médicale, Hôpital Henri Mondor, Créteil F-94010, France
| | - C Mekki
- AP-HP, Département de Biochimie-Biologie Moléculaire, Pharmacologie, Génétique Médicale, Hôpital Henri Mondor, Créteil F-94010, France
| | - M-P Audrezet
- Service de génétique moléculaire, CHRU Brest, Brest, France; Université de Brest, Inserm, UMR 1078, GGB, Brest, France
| | - E Girodon
- Service de Médecine Génomique des Maladies de Système et d'Organe, APHP Centre - Université de Paris, Hôpital Cochin, Paris, France; INSERM U1151, Institut Necker Enfants Malades, Université de Paris, Paris, France
| | - C Raynal
- Génétique Moléculaire, CHU Montpellier, Montpellier, France; PhyMedExp, INSERM, CNRS UMR, Montpellier, France.
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Rehman T, Karp PH, Thurman AL, Mather SE, Jain A, Cooney AL, Sinn PL, Pezzulo AA, Duffey ME, Welsh MJ. WNK Inhibition Increases Surface Liquid pH and Host Defense in Cystic Fibrosis Airway Epithelia. Am J Respir Cell Mol Biol 2022; 67:491-502. [PMID: 35849656 PMCID: PMC9564924 DOI: 10.1165/rcmb.2022-0172oc] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/18/2022] [Indexed: 02/05/2023] Open
Abstract
In cystic fibrosis (CF), reduced HCO3- secretion acidifies the airway surface liquid (ASL), and the acidic pH disrupts host defenses. Thus, understanding the control of ASL pH (pHASL) in CF may help identify novel targets and facilitate therapeutic development. In diverse epithelia, the WNK (with-no-lysine [K]) kinases coordinate HCO3- and Cl- transport, but their functions in airway epithelia are poorly understood. Here, we tested the hypothesis that WNK kinases regulate CF pHASL. In primary cultures of differentiated human airway epithelia, inhibiting WNK kinases acutely increased both CF and non-CF pHASL. This response was HCO3- dependent and involved downstream SPAK/OSR1 (Ste20/SPS1-related proline-alanine-rich protein kinase/oxidative stress responsive 1 kinase). Importantly, WNK inhibition enhanced key host defenses otherwise impaired in CF. Human airway epithelia expressed two WNK isoforms in secretory cells and ionocytes, and knockdown of either WNK1 or WNK2 increased CF pHASL. WNK inhibition decreased Cl- secretion and the response to bumetanide, an NKCC1 (sodium-potassium-chloride cotransporter 1) inhibitor. Surprisingly, bumetanide alone or basolateral Cl- substitution also alkalinized CF pHASL. These data suggest that WNK kinases influence the balance between transepithelial Cl- versus HCO3- secretion. Moreover, reducing basolateral Cl- entry may increase HCO3- secretion and raise pHASL, thereby improving CF host defenses.
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Affiliation(s)
| | - Philip H. Karp
- Department of Internal Medicine and
- Howard Hughes Medical Institute, University of Iowa, Iowa City, Iowa; and
| | | | | | | | | | | | | | - Michael E. Duffey
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York
| | - Michael J. Welsh
- Department of Internal Medicine and
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, and
- Howard Hughes Medical Institute, University of Iowa, Iowa City, Iowa; and
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8
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Differential CFTR-Interactome Proximity Labeling Procedures Identify Enrichment in Multiple SLC Transporters. Int J Mol Sci 2022; 23:ijms23168937. [PMID: 36012204 PMCID: PMC9408702 DOI: 10.3390/ijms23168937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Proteins interacting with CFTR and its mutants have been intensively studied using different experimental approaches. These studies provided information on the cellular processes leading to proper protein folding, routing to the plasma membrane, recycling, activation and degradation. Recently, new approaches have been developed based on the proximity labeling of protein partners or proteins in close vicinity and their subsequent identification by mass spectrometry. In this study, we evaluated TurboID- and APEX2-based proximity labeling of WT CFTR and compared the obtained data to those reported in databases. The CFTR-WT interactome was then compared to that of two CFTR (G551D and W1282X) mutants and the structurally unrelated potassium channel KCNK3. The two proximity labeling approaches identified both known and additional CFTR protein partners, including multiple SLC transporters. Proximity labeling approaches provided a more comprehensive picture of the CFTR interactome and improved our knowledge of the CFTR environment.
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9
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Noh SH, Kim YJ, Lee MG. Autophagy-Related Pathways in Vesicular Unconventional Protein Secretion. Front Cell Dev Biol 2022; 10:892450. [PMID: 35774225 PMCID: PMC9237382 DOI: 10.3389/fcell.2022.892450] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/26/2022] [Indexed: 12/14/2022] Open
Abstract
Cellular proteins directed to the plasma membrane or released into the extracellular space can undergo a number of different pathways. Whereas the molecular mechanisms that underlie conventional ER-to-Golgi trafficking are well established, those associated with the unconventional protein secretion (UPS) pathways remain largely elusive. A pathway with an emerging role in UPS is autophagy. Although originally known as a degradative process for maintaining intracellular homeostasis, recent studies suggest that autophagy has diverse biological roles besides its disposal function and that it is mechanistically involved in the UPS of various secretory cargos including both leaderless soluble and Golgi-bypassing transmembrane proteins. Here, we summarize current knowledge of the autophagy-related UPS pathways, describing and comparing diverse features in the autophagy-related UPS cargos and autophagy machineries utilized in UPS. Additionally, we also suggest potential directions that further research in this field can take.
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Affiliation(s)
- Shin Hye Noh
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Shin Hye Noh, ; Min Goo Lee,
| | - Ye Jin Kim
- Department of Pharmacology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - Min Goo Lee
- Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea
- Department of Pharmacology, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Shin Hye Noh, ; Min Goo Lee,
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10
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Angyal D, Bijvelds MJC, Bruno MJ, Peppelenbosch MP, de Jonge HR. Bicarbonate Transport in Cystic Fibrosis and Pancreatitis. Cells 2021; 11:cells11010054. [PMID: 35011616 PMCID: PMC8750324 DOI: 10.3390/cells11010054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/12/2022] Open
Abstract
CFTR, the cystic fibrosis (CF) gene-encoded epithelial anion channel, has a prominent role in driving chloride, bicarbonate and fluid secretion in the ductal cells of the exocrine pancreas. Whereas severe mutations in CFTR cause fibrosis of the pancreas in utero, CFTR mutants with residual function, or CFTR variants with a normal chloride but defective bicarbonate permeability (CFTRBD), are associated with an enhanced risk of pancreatitis. Recent studies indicate that CFTR function is not only compromised in genetic but also in selected patients with an acquired form of pancreatitis induced by alcohol, bile salts or smoking. In this review, we summarize recent insights into the mechanism and regulation of CFTR-mediated and modulated bicarbonate secretion in the pancreatic duct, including the role of the osmotic stress/chloride sensor WNK1 and the scaffolding protein IRBIT, and current knowledge about the role of CFTR in genetic and acquired forms of pancreatitis. Furthermore, we discuss the perspectives for CFTR modulator therapy in the treatment of exocrine pancreatic insufficiency and pancreatitis and introduce pancreatic organoids as a promising model system to study CFTR function in the human pancreas, its role in the pathology of pancreatitis and its sensitivity to CFTR modulators on a personalized basis.
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Fűr G, Bálint ER, Orján EM, Balla Z, Kormányos ES, Czira B, Szűcs A, Kovács DP, Pallagi P, Maléth J, Venglovecz V, Hegyi P, Kiss L, Rakonczay Z. Mislocalization of CFTR expression in acute pancreatitis and the beneficial effect of VX-661 + VX-770 treatment on disease severity. J Physiol 2021; 599:4955-4971. [PMID: 34587656 DOI: 10.1113/jp281765] [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: 04/15/2021] [Accepted: 09/24/2021] [Indexed: 01/15/2023] Open
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) has an essential role in maintaining pancreatic ductal function. Impaired CFTR function can trigger acute pancreatitis (AP) and exacerbate disease severity. We aimed to investigate the localization and expression of CFTR during AP, and determined the effects of a CFTR corrector (VX-661) and potentiator (VX-770) on disease severity. AP was induced in FVB/n mice by 6-10 hourly intraperitoneal injections of 50 μg/kg cerulein. Some mice were pre-treated with five to six daily injections of 2 mg/kg VX-661 + VX-770. Control animals were administered physiological saline instead of cerulein and dimethyl sulfoxide instead of VX compounds. AP severity was determined by measuring laboratory and histological parameters; CFTR and CK19 expression was measured. Activity of ion transporters was followed by intracellular pH or fluid secretion measurement of isolated pancreatic intra-/interlobular ducts. Cerulein-induced AP severity was greatest between 12 and 24 h. CFTR mRNA expression was significantly increased 24 h after AP induction. Immunohistochemistry demonstrated disturbed staining morphology of CFTR and CK19 proteins in AP. Mislocalization of CFTR protein was observed from 6 h, while expression increased at 24 h compared to control. Ductal HCO3 - transport activity was significantly increased 6 h after AP induction. AP mice pre-treatment with VX-661 + VX-770 significantly reduced the extent of tissue damage by about 20-30%, but other parameters were unchanged. Interestingly, VX-661 + VX-770 in vitro administration significantly increased the fluid secretion of ducts derived from AP animals. This study described the course of the CFTR expression and mislocalization in cerulein-induced AP. Our results suggest that the beneficial effects of CFTR correctors and potentiators should be further investigated in AP. KEY POINTS: Cystic fibrosis transmembrane conductance regulator (CFTR) is an important ion channel in epithelial cells. Its malfunction has several serious consequences, like developing or aggravating acute pancreatitis (AP). Here, the localization and expression of CFTR during cerulein-induced AP in mice were investigated and the effects of CFTR corrector (VX-661) and a potentiator (VX-770) on disease severity were determined. CFTR mRNA expression was significantly increased and mislocalization of CFTR protein was observed in AP compared to the control group. Interestingly, pre-treatment of AP mice with VX-661 + VX-770 significantly reduced the extent of pancreatic tissue damage by 20-30%. In vitro administration of VX-661 + VX-770 significantly increased the fluid secretion of ducts derived from AP animals. Based on these results, the utilization of CFTR correctors and potentiators should be further investigated in AP.
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Affiliation(s)
- Gabriella Fűr
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Emese Réka Bálint
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Erik Márk Orján
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Zsolt Balla
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | | | - Beáta Czira
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Attila Szűcs
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | | | - Petra Pallagi
- First Department of Medicine, University of Szeged, Szeged, Hungary.,Momentum Epithelial Cell Signalling and Secretion Research Group, Hungarian Academy of Sciences-University of Szeged, Szeged, Hungary
| | - József Maléth
- First Department of Medicine, University of Szeged, Szeged, Hungary.,Momentum Epithelial Cell Signalling and Secretion Research Group, Hungarian Academy of Sciences-University of Szeged, Szeged, Hungary
| | - Viktória Venglovecz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Péter Hegyi
- Institute for Translational Medicine and First Department of Medicine, University of Pécs, Pécs, Hungary.,Momentum Translational Gastroenterology Research Group, Hungarian Academy of Sciences-University of Szeged, Szeged, Hungary.,Szentágothai Research Centre, University of Pécs, Pécs, Hungary
| | - Lóránd Kiss
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Zoltán Rakonczay
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
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12
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Kalayarasan R, Narayanan S, Sahoo J, Mohan P. Impact of surgery for chronic pancreatitis on the risk of pancreatic cancer: Untying the Gordian knot. World J Gastroenterol 2021; 27:4371-4382. [PMID: 34366610 PMCID: PMC8316902 DOI: 10.3748/wjg.v27.i27.4371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/10/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Pancreatic ductal adenocarcinoma is an aggressive tumor with poor long-term outcomes. Chronic pancreatitis (CP) is considered a risk factor for the development of pancreatic cancer (PC). Persistent pancreatic inflammation and activation of pancreatic stellate cells play a crucial role in the pathogenesis of CP-related PC by activating the oncogene pathway. While genetic mutations increase the possibility of recurrent and persistent pancreatic inflammation, they are not directly associated with the development of PC. Recent studies suggest that early surgical intervention for CP might have a protective role in the development of CP-related PC. Hence, the physician faces the clinical question of whether early surgical intervention should be recommended in patients with CP to prevent the development of PC. However, the varying relative risk of PC in different subsets of CP underlines the complex gene-environment interactions in the disease pathogenesis. Hence, it is essential to stratify the risk of PC in each individual patient. This review focuses on the complex relationship between CP and PC and the impact of surgical intervention on PC risk. The proposed risk stratification based on the genetic and environmental factors could guide future research and select patients for prophylactic surgery.
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Affiliation(s)
- Raja Kalayarasan
- Department of Surgical Gastroenterology, JIPMER, Puducherry 605006, India
| | - Sankar Narayanan
- Department of Surgical Gastroenterology, JIPMER, Puducherry 605006, India
| | | | - Pazhanivel Mohan
- Department of Medical Gastroenterology, JIPMER, Puducherry 605006, India
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13
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Berg P, Svendsen SL, Sorensen MV, Schreiber R, Kunzelmann K, Leipziger J. The molecular mechanism of CFTR- and secretin-dependent renal bicarbonate excretion. J Physiol 2021; 599:3003-3011. [PMID: 33963548 DOI: 10.1113/jp281285] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/12/2021] [Indexed: 11/08/2022] Open
Abstract
This review summarizes the newly discovered molecular mechanism of secretin-stimulated urine HCO3 - excretion and the role of cystic fibrosis transmembrane conductance regulator (CFTR) in renal HCO3 - excretion. The secretin receptor is functionally expressed in the basolateral membrane of the HCO3 - -secreting β-intercalated cells of the collecting duct. Here it activates a fast and efficient secretion of HCO3 - into the urine serving to normalize metabolic alkalosis. The ability to acutely increase renal base excretion is entirely dependent on functional pendrin (SLC26A4) and CFTR, and both proteins localize to the apical membrane of the β-intercalated cells. In cystic fibrosis mice and patients, this function is absent or markedly reduced. We discuss that the alkaline tide, namely the transient urine alkalinity after a meal, has now received a clear physiological explanation.
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Affiliation(s)
- Peder Berg
- Department of Biomedicine, Physiology, Health, Aarhus University, Aarhus, Denmark
| | - Samuel L Svendsen
- Department of Biomedicine, Physiology, Health, Aarhus University, Aarhus, Denmark
| | - Mads Vaarby Sorensen
- Department of Biomedicine, Physiology, Health, Aarhus University, Aarhus, Denmark
| | - Rainer Schreiber
- Department of Physiology, University of Regensburg, Regensburg, Germany
| | - Karl Kunzelmann
- Department of Physiology, University of Regensburg, Regensburg, Germany
| | - Jens Leipziger
- Department of Biomedicine, Physiology, Health, Aarhus University, Aarhus, Denmark
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14
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Zajac M, Dreano E, Edwards A, Planelles G, Sermet-Gaudelus I. Airway Surface Liquid pH Regulation in Airway Epithelium Current Understandings and Gaps in Knowledge. Int J Mol Sci 2021; 22:3384. [PMID: 33806154 PMCID: PMC8037888 DOI: 10.3390/ijms22073384] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/08/2021] [Accepted: 03/08/2021] [Indexed: 12/22/2022] Open
Abstract
Knowledge on the mechanisms of acid and base secretion in airways has progressed recently. The aim of this review is to summarize the known mechanisms of airway surface liquid (ASL) pH regulation and their implication in lung diseases. Normal ASL is slightly acidic relative to the interstitium, and defects in ASL pH regulation are associated with various respiratory diseases, such as cystic fibrosis. Basolateral bicarbonate (HCO3-) entry occurs via the electrogenic, coupled transport of sodium (Na+) and HCO3-, and, together with carbonic anhydrase enzymatic activity, provides HCO3- for apical secretion. The latter mainly involves CFTR, the apical chloride/bicarbonate exchanger pendrin and paracellular transport. Proton (H+) secretion into ASL is crucial to maintain its relative acidity compared to the blood. This is enabled by H+ apical secretion, mainly involving H+/K+ ATPase and vacuolar H+-ATPase that carry H+ against the electrochemical potential gradient. Paracellular HCO3- transport, the direction of which depends on the ASL pH value, acts as an ASL protective buffering mechanism. How the transepithelial transport of H+ and HCO3- is coordinated to tightly regulate ASL pH remains poorly understood, and should be the focus of new studies.
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Affiliation(s)
- Miroslaw Zajac
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences, 02-776 Warsaw, Poland;
| | - Elise Dreano
- Institut Necker Enfants Malades, INSERM U1151, 75015 Paris, France;
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris, 75006 Paris, France;
| | - Aurelie Edwards
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA;
| | - Gabrielle Planelles
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris, 75006 Paris, France;
- Laboratoire de Physiologie rénale et Tubulopathies, CNRS ERL 8228, 75006 Paris, France
| | - Isabelle Sermet-Gaudelus
- Institut Necker Enfants Malades, INSERM U1151, 75015 Paris, France;
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris, 75006 Paris, France;
- Centre de Référence Maladies Rares, Mucoviscidose et Maladies de CFTR, Hôpital Necker Enfants Malades, 75015 Paris, France
- Clinical Trial Network, European Cystic Fibrosis Society, BT2 Belfast, Ireland
- European Respiratory Network Lung, 75006 Paris, France
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15
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Trapp S, Aghdassi AA, Glaubitz J, Sendler M, Weiss FU, Kühn JP, Kromrey ML, Mahajan UM, Pallagi P, Rakonczay Z, Venglovecz V, Lerch MM, Hegyi P, Mayerle J. Pancreatitis severity in mice with impaired CFTR function but pancreatic sufficiency is mediated via ductal and inflammatory cells-Not acinar cells. J Cell Mol Med 2021; 25:4658-4670. [PMID: 33682322 PMCID: PMC8107082 DOI: 10.1111/jcmm.16404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 02/06/2023] Open
Abstract
Mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR) are an established risk factor for cystic fibrosis (CF) and chronic pancreatitis. Whereas patients with CF usually develop complete exocrine pancreatic insufficiency, pancreatitis patients with CFTR mutations have mostly preserved exocrine pancreatic function. We therefore used a strain of transgenic mice with significant residual CFTR function (CFTRtm1HGU ) to induce pancreatitis experimentally by serial caerulein injections. Protease activation and necrosis were investigated in isolated acini, disease severity over 24h, pancreatic function by MRI, isolated duct stimulation and faecal chymotrypsin, and leucocyte function by ex vivo lipopolysaccharide (LPS) stimulation. Pancreatic and lung injury were more severe in CFTRtm1HGU but intrapancreatic trypsin and serum enzyme activities higher than in wild-type controls only at 8h, a time interval previously attributed to leucocyte infiltration. CCK-induced trypsin activation and necrosis in acini from CFTRtm1HGU did not differ from controls. Fluid and bicarbonate secretion were greatly impaired, whereas faecal chymotrypsin remained unchanged. LPS stimulation of splenocytes from CFTRtm1HGU resulted in increased INF-γ and IL-6, but decreased IL-10 secretion. CFTR mutations that preserve residual pancreatic function significantly increase the severity of experimental pancreatitis-mostly via impairing duct cell function and a shift towards a pro-inflammatory phenotype, not by rendering acinar cells more susceptible to pathological stimuli.
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Affiliation(s)
- Simon Trapp
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany
| | - Ali A Aghdassi
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany
| | - Juliane Glaubitz
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany
| | - Matthias Sendler
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany
| | - Frank Ulrich Weiss
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany
| | - Jens Peter Kühn
- Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany
| | - Marie-Luise Kromrey
- Institute of Diagnostic Radiology and Neuroradiology, University Medicine Greifswald, Greifswald, Germany
| | - Ujjwal M Mahajan
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany.,Department of Medicine II, Ludwig-Maximilians University Munich, Munich, Germany
| | - Petra Pallagi
- First Department of Medicine, University of Szeged, Szeged, Hungary
| | - Zoltán Rakonczay
- Department of Pathophysiology, University of Szeged, Szeged, Hungary
| | - Viktória Venglovecz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | - Markus M Lerch
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany
| | - Peter Hegyi
- Department of Translational Medicine/First Department of Medicine, Medical School, Institute for Translational Medicine, Pécs, Hungary
| | - Julia Mayerle
- Department of Medicine A, University Medicine Greifswald, Greifswald, Germany.,Department of Medicine II, Ludwig-Maximilians University Munich, Munich, Germany
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16
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17
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Andrews K, Josiah SS, Zhang J. The Therapeutic Potential of Neuronal K-Cl Co-Transporter KCC2 in Huntington's Disease and Its Comorbidities. Int J Mol Sci 2020; 21:E9142. [PMID: 33266310 PMCID: PMC7730145 DOI: 10.3390/ijms21239142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/16/2020] [Accepted: 11/28/2020] [Indexed: 02/05/2023] Open
Abstract
Intracellular chloride levels in the brain are regulated primarily through the opposing effects of two cation-chloride co-transporters (CCCs), namely K+-Cl- co-transporter-2 (KCC2) and Na+-K+-Cl- co-transporter-1 (NKCC1). These CCCs are differentially expressed throughout the course of development, thereby determining the excitatory-to-inhibitory γ-aminobutyric acid (GABA) switch. GABAergic excitation (depolarisation) is important in controlling the healthy development of the nervous system; as the brain matures, GABAergic inhibition (hyperpolarisation) prevails. This developmental switch in excitability is important, as uncontrolled regulation of neuronal excitability can have implications for health. Huntington's disease (HD) is an example of a genetic disorder whereby the expression levels of KCC2 are abnormal due to mutant protein interactions. Although HD is primarily considered a motor disease, many other clinical manifestations exist; these often present in advance of any movement abnormalities. Cognitive change, in addition to sleep disorders, is prevalent in the HD population; the effect of uncontrolled KCC2 function on cognition and sleep has also been explored. Several mechanisms by which KCC2 expression is reduced have been proposed recently, thereby suggesting extensive investigation of KCC2 as a possible therapeutic target for the development of pharmacological compounds that can effectively treat HD co-morbidities. Hence, this review summarizes the role of KCC2 in the healthy and HD brain, and highlights recent advances that attest to KCC2 as a strong research and therapeutic target candidate.
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Affiliation(s)
| | | | - Jinwei Zhang
- Institute of Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK; (K.A.); (S.S.J.)
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18
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Koumangoye R, Bastarache L, Delpire E. NKCC1: Newly Found as a Human Disease-Causing Ion Transporter. FUNCTION 2020; 2:zqaa028. [PMID: 33345190 PMCID: PMC7727275 DOI: 10.1093/function/zqaa028] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 01/06/2023] Open
Abstract
Among the electroneutral Na+-dependent chloride transporters, NKCC1 had until now evaded identification as a protein causing human diseases. The closely related SLC12A transporters, NKCC2 and NCC have been identified some 25 years ago as responsible for Bartter and Gitelman syndromes: two renal-dependent salt wasting disorders. Absence of disease was most surprising since the NKCC1 knockout mouse was shown in 1999 to be viable, albeit with a wide range of deleterious phenotypes. Here we summarize the work of the past 5 years that introduced us to clinical cases involving NKCC1. The most striking cases are of 3 children with inherited mutations, who have complete absence of NKCC1 expression. These cases establish that lack of NKCC1 causes deafness; CFTR-like secretory defects with mucus accumulation in lung and intestine; severe xerostomia, hypotonia, dysmorphic facial features, and severe neurodevelopmental disorder. Another intriguing case is of a patient with a dominant deleterious SLC12A2 allele. This de novo mutation introduced a premature stop codon leading to a truncated protein. This mutant transporter seems to exert dominant-negative effect on wild-type transporter only in epithelial cells. The patient who suffers from lung, bladder, intestine, pancreas, and multiple endocrine abnormalities has, however, normal hearing and cognition. Finally, new reports substantiate the haploinsufficiency prediction of the SLC12A2 gene. Cases with single allele mutations in SLC12A2 have been linked to hearing loss and neurodevelopmental disorders.
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Affiliation(s)
- Rainelli Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Lisa Bastarache
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA,Corresponding author. E-mail:
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19
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Abstract
PURPOSE OF REVIEW We describe and contrast the strengths of precision medicine with Western medicine, and complex trait genetics with Mendelian genetics. Classic genetics focuses on highly penetrant pathogenic variants in a single gene believed to cause or confer a high risk for well-defined phenotypes. However, a minority of disorders have a single gene cause. Further, even individuals with identical Mendelian disease-associated genotypes may exhibit substantial phenotypic variability indicative of genetic and environmental modifiers. Still, most diseases are considered complex traits (or complex diseases). RECENT FINDINGS New insights into the genetic underpinnings of complex traits provide opportunities for advances in diagnosis and management. Precision medicine provides the framework for integrating complex trait knowledge into clinical care through a sophisticated analysis pipeline. Multidimensional modeling of acquired diseases includes multiple genetic risks scattered over many genes and gene regulators that must be interpreted on the basis of functional evidence (e.g., genomics, transcriptomics) with structured models and expert systems; strengthened with machine learning and artificial intelligence. The choice of genotyping approaches (shotgun sequencing, single nucleotide polymorphism chips, targeted panels) is discussed. SUMMARY The result of a good precision medicine tool is clinical-decision support and guidance to tackle complex disorders such as pancreatitis, diabetes, and pancreatic cancer oncogenesis.
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Abstract
OBJECTIVES Chronic pancreatitis is the end stage of a pathologic inflammatory syndrome with multiple etiological factors, including genetic. We hypothesized that some pancreatitis etiology originates in pancreatic acinar or duct cells and requires both injury and compensatory mechanism failure. METHODS One hundred pancreatitis patients were assessed using a DNA sequencing panel for pancreatitis. Cooccurrence of variants within and between genes was measured. Gene coexpression was confirmed via published single-cell RNA sequencing. RESULTS One hundred and twenty-one variants were identified in 2 or more patients, 15 of which were enriched compared with reference populations. Single cell RNA-sequencing data verified coexpression of GGT1, CFTR, and PRSS1 in duct cells, PRSS1, CPA1, CEL, CTRC, and SPINK1 in acinar cells, and UBR1 in both. Multiple-risk variants with injury/stress effects (CEL, CFTR, CPA1, PRSS1) and impaired cell protection (CTRC, GGT1, SPINK1, UBR1) cooccur within duct cells, acinar cells, or both. CONCLUSIONS Pancreatitis is a complex disorder with genetic interactions across genes and cell types. These findings suggest a new, non-Mendelian genetic risk/etiology paradigm where a combination of nonpathogenic genetic risk variants in groups of susceptibility genes and injury/dysfunction response genes contribute to acquired pancreatic disease.
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21
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Shin DH, Kim M, Kim Y, Jun I, Jung J, Nam JH, Cheng MH, Lee MG. Bicarbonate permeation through anion channels: its role in health and disease. Pflugers Arch 2020; 472:1003-1018. [PMID: 32621085 DOI: 10.1007/s00424-020-02425-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/19/2020] [Accepted: 06/26/2020] [Indexed: 12/31/2022]
Abstract
Many anion channels, frequently referred as Cl- channels, are permeable to different anions in addition to Cl-. As the second-most abundant anion in the human body, HCO3- permeation via anion channels has many important physiological roles. In addition to its classical role as an intracellular pH regulator, HCO3- also controls the activity and stability of dissolved proteins in bodily fluids such as saliva, pancreatic juice, intestinal fluid, and airway surface liquid. Moreover, HCO3- permeation through these channels affects membrane potentials that are the driving forces for transmembrane transport of solutes and water in epithelia and affect neuronal excitability in nervous tissue. Consequently, aberrant HCO3- transport via anion channels causes a number of human diseases in respiratory, gastrointestinal, genitourinary, and neuronal systems. Notably, recent studies have shown that the HCO3- permeabilities of several anion channels are not fixed and can be altered by cellular stimuli, findings which may have both physiological and pathophysiological significance. In this review, we summarize recent progress in understanding the molecular mechanisms and the physiological roles of HCO3- permeation through anion channels. We hope that the present discussions can stimulate further research into this very important topic, which will provide the basis for human disorders associated with aberrant HCO3- transport.
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Affiliation(s)
- Dong Hoon Shin
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Minjae Kim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Yonjung Kim
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Ikhyun Jun
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Jinsei Jung
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Kyungju, 780-714, Republic of Korea
| | - Mary Hongying Cheng
- Department of Computational & Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Min Goo Lee
- Department of Pharmacology, Brain Korea 21 PLUS Project for Medical Sciences, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea.
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22
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The CFTR Mutation c.3453G > C (D1152H) Confers an Anion Selectivity Defect in Primary Airway Tissue that Can Be Rescued by Ivacaftor. J Pers Med 2020; 10:jpm10020040. [PMID: 32414100 PMCID: PMC7354675 DOI: 10.3390/jpm10020040] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 04/29/2020] [Accepted: 05/08/2020] [Indexed: 02/07/2023] Open
Abstract
The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene variant, c.3453G > C (D1152H), is associated with mild Cystic Fibrosis (CF) disease, though there is considerable clinical variability ranging from no detectable symptoms to lung disease with early acquisition of Pseudomonas aeruginosa. The approval extension of ivacaftor, the first CFTR modulator drug approved, to include D1152H was based on a positive drug response of defective CFTR-D1152H chloride channel function when expressed in FRT cells. Functional analyses of primary human nasal epithelial cells (HNE) from an individual homozygous for D1152H now revealed that while CFTR-D1152H demonstrated normal, wild-type level chloride conductance, its bicarbonate-selective conductance was impaired. Treatment with ivacaftor increased this bicarbonate-selective conductance. Extensive genetic, protein and functional analysis of the nasal cells of this D1152H/D1152H patient revealed a 90% reduction of CFTR transcripts due to the homozygous presence of the 5T polymorphism in the poly-T tract forming a complex allele with D1152H. Thus, we confirm previous observation in patient-derived tissue that 10% normal CFTR transcripts confer normal, wild-type level chloride channel activity. Together, this study highlights the benefit of patient-derived tissues to study the functional expression and pharmacological modulation of CF-causing mutations, in order to understand pathogenesis and therapeutic responses.
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