1
|
Farinha CM, Santos L, Ferreira JF. Cell type-specific regulation of CFTR trafficking-on the verge of progress. Front Cell Dev Biol 2024; 12:1338892. [PMID: 38505263 PMCID: PMC10949533 DOI: 10.3389/fcell.2024.1338892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/21/2024] [Indexed: 03/21/2024] Open
Abstract
Trafficking of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein is a complex process that starts with its biosynthesis and folding in the endoplasmic reticulum. Exit from the endoplasmic reticulum (ER) is coupled with the acquisition of a compact structure that can be processed and traffic through the secretory pathway. Once reaching its final destination-the plasma membrane, CFTR stability is regulated through interaction with multiple protein partners that are involved in its post-translation modification, connecting the channel to several signaling pathways. The complexity of the process is further boosted when analyzed in the context of the airway epithelium. Recent advances have characterized in detail the different cell types that compose the surface epithelium and shifted the paradigm on which cells express CFTR and on their individual and combined contribution to the total expression (and function) of this chloride/bicarbonate channel. Here we review CFTR trafficking and its relationship with the knowledge on the different cell types of the airway epithelia. We explore the crosstalk between these two areas and discuss what is still to be clarified and how this can be used to develop more targeted therapies for CF.
Collapse
Affiliation(s)
- Carlos M. Farinha
- Faculty of Sciences, BioISI—Biosystems and Integrative Sciences Institute, University of Lisboa, Lisboa, Portugal
| | | | | |
Collapse
|
2
|
Cui G, Strickland KM, Vazquez Cegla AJ, McCarty NA. Comparing ATPase activity of ATP-binding cassette subfamily C member 4, lamprey CFTR, and human CFTR using an antimony-phosphomolybdate assay. Front Pharmacol 2024; 15:1363456. [PMID: 38440176 PMCID: PMC10910009 DOI: 10.3389/fphar.2024.1363456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 02/05/2024] [Indexed: 03/06/2024] Open
Abstract
Introduction: ATP-binding cassette (ABC) transporters use the hydrolysis of ATP to power the active transport of molecules, but paradoxically the cystic fibrosis transmembrane regulator (CFTR, ABCC7) forms an ion channel. We previously showed that ATP-binding cassette subfamily C member 4 (ABCC4) is the closest mammalian paralog to CFTR, compared to other ABC transporters. In addition, Lamprey CFTR (Lp-CFTR) is the oldest known CFTR ortholog and has unique structural and functional features compared to human CFTR (hCFTR). The availability of these evolutionarily distant orthologs gives us the opportunity to study the changes in ATPase activity that may be related to their disparate functions. Methods: We utilized the baculovirus expression system with Sf9 insect cells and made use of the highly sensitive antimony-phosphomolybdate assay for testing the ATPase activity of human ABCC4 (hABCC4), Lp-CFTR, and hCFTR under similar experimental conditions. This assay measures the production of inorganic phosphate (Pi) in the nanomolar range. Results: Crude plasma membranes were purified, and protein concentration, determined semi-quantitatively, of hABCC4, Lp-CFTR, and hCFTR ranged from 0.01 to 0.36 μg/μL. No significant difference in expression level was found although hABCC4 trended toward the highest level. hABCC4 was activated by ATP with the equilibrium constant (Kd) 0.55 ± 0.28 mM (n = 8). Estimated maximum ATPase rate (Vmax) for hABCC4 was about 0.2 nmol/μg/min when the protein was activated with 1 mM ATP at 37°C (n = 7). Estimated maximum ATPase rate for PKA-phosphorylated Lp-CFTR reached about half of hCFTR levels in the same conditions. Vmax for both Lp-CFTR and hCFTR were significantly increased in high PKA conditions compared to low PKA conditions. Maximum intrinsic ATPase rate of hABCC4 in the absence of substrate was twice that of hCFTR when activated in 1 mM ATP. Conclusion: The findings here suggest that while both ABCC4 and hCFTR bear one consensus and one degenerate ATPase site, the hCFTR exhibited a reduced intrinsic ATPase activity. In addition, ATPase activity in the CFTR lineage increased from Lp-CFTR to hCFTR. Finally, the studies pave the way to purify hABCC4, Lp-CFTR, and hCFTR from Sf9 cells for their structural investigation, including by cryo-EM, and for studies of evolution in the ABC transporter superfamily.
Collapse
Affiliation(s)
| | | | | | - Nael A. McCarty
- Division of Pulmonology, Asthma, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children’s Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children’s Healthcare of Atlanta, Atlanta, GA, United States
| |
Collapse
|
3
|
ElNashar NT, Breitinger U, Breitinger HG, Mansour S, Tammam SN. A liposomal platform for the delivery of ion channel proteins for treatment of channelopathies - Application in therapy of cystic fibrosis. Int J Biol Macromol 2023; 253:126652. [PMID: 37673169 DOI: 10.1016/j.ijbiomac.2023.126652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/21/2023] [Accepted: 08/30/2023] [Indexed: 09/08/2023]
Abstract
Channelopathies arise from ion channel dysfunction. Successful treatment entails delivery of functional ion channels to replace dysfunctional ones. Glycine receptor (GlyR)-rich cell membrane fragments (CMF) were previously delivered to target cell membranes using fusogenic liposomes. Here, cystic fibrosis transmembrane conductance regulator (CFTR)-bearing CMF were similarly delivered to target cells. We studied the effect of lipid composition on liposomes' ability to incorporate CMF and fuse with target cell membranes to deliver functional CFTR. Four formulations were prepared using thin-film hydration out of different lecithin sources, egg and soy lecithin (EL and SL), in the presence and absence of cholesterol (CHOL): EL + CHOL, EL-CHOL, SL + CHOL, and SL-CHOL. EL liposomes incorporated more CMF than SL liposomes, with CHOL only increasing CMF incorporation in SL liposomes. SL + CHOL fused better with target cell membranes than EL + CHOL. SL + CHOL and EL + CHOL equally delivered CFTR to target cell membranes, owing to the former's superior fusogenic capacity and the latter's superior CMF-incorporation capacity. SL-CHOL and EL-CHOL delivered CFTR to a lesser extent, indicating the importance of CHOL for fusion. Patch-clamp electrophysiology and confocal laser scanning microscopy (CLSM) confirmed CFTR delivery to target cell membranes by SL + CHOL. Therefore, CMF-bearing fusogenic liposomes offer a promising universal platform for the treatment of channelopathies.
Collapse
Affiliation(s)
- Noha T ElNashar
- Department of Pharmaceutical Technology, The German University in Cairo (GUC), Cairo, Egypt
| | - Ulrike Breitinger
- Department of Biochemistry, The German University in Cairo (GUC), Cairo, Egypt
| | | | - Samar Mansour
- Department of Pharmaceutical Technology, The German University in Cairo (GUC), Cairo, Egypt
| | - Salma N Tammam
- Department of Pharmaceutical Technology, The German University in Cairo (GUC), Cairo, Egypt.
| |
Collapse
|
4
|
Zhong HL, Li PZ, Li D, Guan CX, Zhou Y. The role of vasoactive intestinal peptide in pulmonary diseases. Life Sci 2023; 332:122121. [PMID: 37742737 DOI: 10.1016/j.lfs.2023.122121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 09/12/2023] [Accepted: 09/21/2023] [Indexed: 09/26/2023]
Abstract
Vasoactive intestinal peptide (VIP) is an abundant neurotransmitter in the lungs and other organs. Its discovery dates back to 1970. And VIP gains attention again due to the potential application in COVID-19 after a research wave in the 1980s and 1990s. The diverse biological impacts of VIP extend beyond its usage in COVID-19 treatment, encompassing its involvement in various pulmonary and systemic disorders. This review centers on the function of VIP in various lung diseases, such as pulmonary arterial hypertension, chronic obstructive pulmonary disease, asthma, cystic fibrosis, acute lung injury/acute respiratory distress syndrome, pulmonary fibrosis, and lung tumors. This review also outlines two main limitations of VIP as a potential medication and gathers information on extended-release formulations and VIP analogues.
Collapse
Affiliation(s)
- Hong-Lin Zhong
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Pei-Ze Li
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Di Li
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China
| | - Cha-Xiang Guan
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
| | - Yong Zhou
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, Hunan 410078, China.
| |
Collapse
|
5
|
Dobi D, Loberto N, Bassi R, Pistocchi A, Lunghi G, Tamanini A, Aureli M. Cross-talk between CFTR and sphingolipids in cystic fibrosis. FEBS Open Bio 2023; 13:1601-1614. [PMID: 37315117 PMCID: PMC10476574 DOI: 10.1002/2211-5463.13660] [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: 04/07/2023] [Revised: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 06/16/2023] Open
Abstract
Cystic fibrosis (CF) is the most common inherited, life-limiting disorder in Caucasian populations. It is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), which lead to an impairment of protein expression and/or function. CFTR is a chloride/bicarbonate channel expressed at the apical surface of epithelial cells of different organs. Nowadays, more than 2100 CFTR genetic variants have been described, but not all of them cause CF. However, around 80-85% of the patients worldwide are characterized by the presence, at least in one allele, of the mutation F508del. CFTR mutations cause aberrant hydration and secretion of mucus in hollow organs. In the lungs, this condition favors bacterial colonization, allowing the development of chronic infections that lead to the onset of the CF lung disease, which is the main cause of death in patients. In recent years, evidence has reported that CFTR loss of function is responsible for alterations in a particular class of bioactive lipids, called sphingolipids (SL). SL are ubiquitously present in eukaryotic cells and are mainly asymmetrically located within the external leaflet of the plasma membrane, where they organize specific platforms capable of segregating a selected number of proteins. CFTR is associated with these platforms that are fundamental for its functioning. Considering the importance of SL in CFTR homeostasis, we attempt here to provide a critical overview of the literature to determine the role of these lipids in channel stability and activity, and whether their modulation in CF could be a target for new therapeutic approaches.
Collapse
Affiliation(s)
- Dorina Dobi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Nicoletta Loberto
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Rosaria Bassi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Anna Pistocchi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Giulia Lunghi
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| | - Anna Tamanini
- Section of Clinical Biochemistry, Department of Neurosciences, Biomedicine and MovementUniversity of VeronaItaly
| | - Massimo Aureli
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanItaly
| |
Collapse
|
6
|
Tse CM, Zhang Z, Lin R, Sarker R, Donowitz M, Singh V. The Air-Liquid Interface Reorganizes Membrane Lipids and Enhances the Recruitment of Slc26a3 to Lipid-Rich Domains in Human Colonoid Monolayers. Int J Mol Sci 2023; 24:8273. [PMID: 37175979 PMCID: PMC10179158 DOI: 10.3390/ijms24098273] [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: 04/11/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Cholesterol-rich membrane domains, also called lipid rafts (LRs), are specialized membrane domains that provide a platform for intracellular signal transduction. Membrane proteins often cluster in LRs that further aggregate into larger platform-like structures that are enriched in ceramides and are called ceramide-rich platforms (CRPs). The role of CRPs in the regulation of intestinal epithelial functions remains unknown. Down-regulated in adenoma (DRA) is an intestinal Cl-/HCO3- antiporter that is enriched in LRs. However, little is known regarding the mechanisms involved in the regulation of DRA activity. The air-liquid interface (ALI) was created by removing apical media for a specified number of days; from 12-14 days post-confluency, Caco-2/BBe cells or a colonoid monolayer were grown as submerged cultures. Confocal imaging was used to examine the dimensions of membrane microdomains that contained DRA. DRA expression and activity were enhanced in Caco-2/BBe cells and human colonoids using an ALI culture method. ALI causes an increase in acid sphingomyelinase (ASMase) activity, an enzyme responsible for enhancing ceramide content in the plasma membrane. ALI cultures expressed a larger number of DRA-containing platforms with dimensions >2 µm compared to cells grown as submerged cultures. ASMase inhibitor, desipramine, disrupted CRPs and reduced the ALI-induced increase in DRA expression in the apical membrane. Exposing normal human colonoid monolayers to ALI increased the ASMase activity and enhanced the differentiation of colonoids along with basal and forskolin-stimulated DRA activities. ALI increases DRA activity and expression by increasing ASMase activity and platform formation in Caco-2/BBe cells and by enhancing the differentiation of colonoids.
Collapse
Affiliation(s)
- C. Ming Tse
- Division of Gastroenterology & Hepatology, Department of Medicine, School of Medicine, The Johns Hopkins University, 720 Rutland Avenue, 933 Ross Research Building, Baltimore, MD 21205, USA
| | - Zixin Zhang
- Division of Gastroenterology & Hepatology, Department of Medicine, School of Medicine, The Johns Hopkins University, 720 Rutland Avenue, 933 Ross Research Building, Baltimore, MD 21205, USA
| | - Ruxian Lin
- Division of Gastroenterology & Hepatology, Department of Medicine, School of Medicine, The Johns Hopkins University, 720 Rutland Avenue, 933 Ross Research Building, Baltimore, MD 21205, USA
| | - Rafiquel Sarker
- Division of Gastroenterology & Hepatology, Department of Medicine, School of Medicine, The Johns Hopkins University, 720 Rutland Avenue, 933 Ross Research Building, Baltimore, MD 21205, USA
| | - Mark Donowitz
- Division of Gastroenterology & Hepatology, Department of Medicine, School of Medicine, The Johns Hopkins University, 720 Rutland Avenue, 933 Ross Research Building, Baltimore, MD 21205, USA
- Department of Cellular and Molecular Physiology, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA
| | - Varsha Singh
- Division of Gastroenterology & Hepatology, Department of Medicine, School of Medicine, The Johns Hopkins University, 720 Rutland Avenue, 933 Ross Research Building, Baltimore, MD 21205, USA
| |
Collapse
|
7
|
Kim MD, Chung S, Dennis JS, Yoshida M, Aguiar C, Aller SP, Mendes ES, Schmid A, Sabater J, Baumlin N, Salathe M. Vegetable glycerin e-cigarette aerosols cause airway inflammation and ion channel dysfunction. Front Pharmacol 2022; 13:1012723. [PMID: 36225570 PMCID: PMC9549247 DOI: 10.3389/fphar.2022.1012723] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/08/2022] [Indexed: 02/02/2023] Open
Abstract
Vegetable glycerin (VG) and propylene glycol (PG) serve as delivery vehicles for nicotine and flavorings in most e-cigarette (e-cig) liquids. Here, we investigated whether VG e-cig aerosols, in the absence of nicotine and flavors, impact parameters of mucociliary function in human volunteers, a large animal model (sheep), and air-liquid interface (ALI) cultures of primary human bronchial epithelial cells (HBECs). We found that VG-containing (VG or PG/VG), but not sole PG-containing, e-cig aerosols reduced the activity of nasal cystic fibrosis transmembrane conductance regulator (CFTR) in human volunteers who vaped for seven days. Markers of inflammation, including interleukin-6 (IL6), interleukin-8 (IL8) and matrix metalloproteinase-9 (MMP9) mRNAs, as well as MMP-9 activity and mucin 5AC (MUC5AC) expression levels, were also elevated in nasal samples from volunteers who vaped VG-containing e-liquids. In sheep, exposures to VG e-cig aerosols for five days increased mucus concentrations and MMP-9 activity in tracheal secretions and plasma levels of transforming growth factor-beta 1 (TGF-β1). In vitro exposure of HBECs to VG e-cig aerosols for five days decreased ciliary beating and increased mucus concentrations. VG e-cig aerosols also reduced CFTR function in HBECs, mechanistically by reducing membrane fluidity. Although VG e-cig aerosols did not increase MMP9 mRNA expression, expression levels of IL6, IL8, TGFB1, and MUC5AC mRNAs were significantly increased in HBECs after seven days of exposure. Thus, VG e-cig aerosols can potentially cause harm in the airway by inducing inflammation and ion channel dysfunction with consequent mucus hyperconcentration.
Collapse
Affiliation(s)
- Michael D. Kim
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Samuel Chung
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - John S. Dennis
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Makoto Yoshida
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Carolina Aguiar
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Sheyla P. Aller
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Eliana S. Mendes
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Andreas Schmid
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Juan Sabater
- Department of Research, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Nathalie Baumlin
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Matthias Salathe
- Department of Internal Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS, United States,*Correspondence: Matthias Salathe,
| |
Collapse
|
8
|
Abu-Arish A, Pandžić E, Luo Y, Sato Y, Turner MJ, Wiseman PW, Hanrahan JW. Lipid-driven CFTR clustering is impaired in CF and restored by corrector drugs. J Cell Sci 2022; 135:274066. [PMID: 35060604 PMCID: PMC8976878 DOI: 10.1242/jcs.259002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/08/2022] [Indexed: 11/20/2022] Open
Abstract
Membrane proteins often cluster in nanoscale membrane domains (lipid rafts) that coalesce into ceramide-rich platforms during cell stress, however the clustering mechanisms remain uncertain. The cystic fibrosis transmembrane conductance regulator (CFTR), which is mutated in cystic fibrosis (CF), forms clusters that are cholesterol-dependent and become incorporated into long-lived platforms during hormonal stimulation. We report here that clustering does not involve known tethering interactions of CFTR with PDZ domain proteins, filamin A or the actin cytoskeleton. It also does not require CFTR palmitoylation but is critically dependent on membrane lipid order and is induced by detergents that increase the phase separation of membrane lipids. Clustering and integration of CFTR into ceramide-rich platforms are abolished by the disease mutations F508del and S13F and rescued by the CFTR modulators elexacaftor+tezacaftor. These results indicate CF therapeutics that correct mutant protein folding restore both trafficking and normal lipid interactions in the plasma membrane.
Collapse
Affiliation(s)
- Asmahan Abu-Arish
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Elvis Pandžić
- UNSW Australia, Biomedical Imaging Facility, Mark Wainwright Analytical Center, Sydney, Australia
| | - Yishan Luo
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Yukiko Sato
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Mark J. Turner
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
| | - Paul W. Wiseman
- Department of Chemistry and Department of Physics, McGill University, Montréal, QC, Canada
| | - John W. Hanrahan
- Department of Physiology, McGill University, Montréal QC H3G 1Y6, Canada
- Cystic Fibrosis Translational Research centre, McGill University, Canada
- Research Institute of the McGill University Health Centre, Canada
| |
Collapse
|
9
|
Lee H, Choi SQ. Sphingomyelinase-Mediated Multitimescale Clustering of Ganglioside GM1 in Heterogeneous Lipid Membranes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101766. [PMID: 34473415 PMCID: PMC8529493 DOI: 10.1002/advs.202101766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/19/2021] [Indexed: 05/05/2023]
Abstract
Several signaling processes in the plasma membrane are intensified by ceramides that are formed by sphingomyelinase-mediated hydrolysis of sphingomyelin. These ceramides trigger clustering of signaling-related biomolecules, but how they concentrate such biomolecules remains unclear. Here, the spatiotemporal localization of ganglioside GM1, a glycolipid receptor involved in signaling, during sphingomyelinase-mediated hydrolysis is described. Real-time visualization of the dynamic remodeling of the heterogeneous lipid membrane that occurs due to sphingomyelinase action is used to examine GM1 clustering, and unexpectedly, it is found that it is more complex than previously thought. Specifically, lipid membranes generate two distinct types of condensed GM1: 1) rapidly formed but short-lived GM1 clusters that are formed in ceramide-rich domains nucleated from the liquid-disordered phase; and 2) late-onset yet long-lasting, high-density GM1 clusters that are formed in the liquid-ordered phase. These findings suggest that multiple pathways exist in a plasma membrane to synergistically facilitate the rapid amplification and persistence of signals.
Collapse
Affiliation(s)
- Hyun‐Ro Lee
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Republic of Korea
| | - Siyoung Q. Choi
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Republic of Korea
- KAIST Institute for the NanoCenturyKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Republic of Korea
| |
Collapse
|
10
|
Cottrill KA, Peterson RJ, Lewallen CF, Koval M, Bridges RJ, McCarty NA. Sphingomyelinase decreases transepithelial anion secretion in airway epithelial cells in part by inhibiting CFTR-mediated apical conductance. Physiol Rep 2021; 9:e14928. [PMID: 34382377 PMCID: PMC8358481 DOI: 10.14814/phy2.14928] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 12/11/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel whose dysfunction causes cystic fibrosis (CF). The loss of CFTR function in pulmonary epithelial cells causes surface dehydration, mucus build-up, inflammation, and bacterial infections that lead to lung failure. Little has been done to evaluate the effects of lipid perturbation on CFTR activity, despite CFTR residing in the plasma membrane. This work focuses on the acute effects of sphingomyelinase (SMase), a bacterial virulence factor secreted by CF relevant airway bacteria which degrades sphingomyelin into ceramide and phosphocholine, on the electrical circuitry of pulmonary epithelial monolayers. We report that basolateral SMase decreases CFTR-mediated transepithelial anion secretion in both primary bronchial and tracheal epithelial cells from explant tissue, with current CFTR modulators unable to rescue this effect. Focusing on primary cells, we took a holistic ion homeostasis approach to determine a cause for reduced anion secretion following SMase treatment. Using impedance analysis, we determined that basolateral SMase inhibits apical and basolateral conductance in non-CF primary cells without affecting paracellular permeability. In CF primary airway cells, correction with clinically relevant CFTR modulators did not prevent SMase-mediated inhibition of CFTR currents. Furthermore, SMase was found to inhibit only apical conductance in these cells. Future work should determine the mechanism for SMase-mediated inhibition of CFTR currents, and further explore the clinical relevance of SMase and sphingolipid imbalances.
Collapse
Affiliation(s)
- Kirsten A. Cottrill
- Molecular and Systems Pharmacology PhD ProgramEmory UniversityAtlantaGeorgiaUSA
| | - Raven J. Peterson
- Biochemistry, Cell, and Developmental Biology PhD ProgramEmory UniversityAtlantaGeorgiaUSA
| | - Colby F. Lewallen
- Georgia Institute of TechnologyG.W. Woodruff School of Mechanical EngineeringAtlantaGeorgiaUSA
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep MedicineDepartment of MedicineEmory UniversityAtlantaGeorgiaUSA
- Department of Cell BiologyEmory UniversityAtlantaGeorgiaUSA
| | - Robert J. Bridges
- Department of Physiology and BiophysicsCenter for Genetic DiseasesChicago Medical SchoolNorth Chicago, IllinoisUSA
| | - Nael A. McCarty
- Molecular and Systems Pharmacology PhD ProgramEmory UniversityAtlantaGeorgiaUSA
- Department of Pediatrics and Children’s Healthcare of AtlantaCenter for Cystic Fibrosis and Airways Disease ResearchEmory University School of MedicineAtlantaGeorgiaUSA
| |
Collapse
|
11
|
Cui G, Cottrill KA, Strickland KM, Mashburn SA, Koval M, McCarty NA. Alteration of Membrane Cholesterol Content Plays a Key Role in Regulation of Cystic Fibrosis Transmembrane Conductance Regulator Channel Activity. Front Physiol 2021; 12:652513. [PMID: 34163370 PMCID: PMC8215275 DOI: 10.3389/fphys.2021.652513] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/23/2021] [Indexed: 11/30/2022] Open
Abstract
Altered cholesterol homeostasis in cystic fibrosis patients has been reported, although controversy remains. As a major membrane lipid component, cholesterol modulates the function of multiple ion channels by complicated mechanisms. However, whether cholesterol directly modulates cystic fibrosis transmembrane conductance regulator (CFTR) channel function remains unknown. To answer this question, we determined the effects of changing plasma membrane cholesterol levels on CFTR channel function utilizing polarized fischer rat thyroid (FRT) cells and primary human bronchial epithelial (HBE) cells. Treatment with methyl-β-cyclodextrin (MβCD) significantly reduced total cholesterol content in FRT cells, which significantly decreased forskolin (FSK)-mediated activation of both wildtype (WT-) and P67L-CFTR. This effect was also seen in HBE cells expressing WT-CFTR. Cholesterol modification by cholesterol oxidase and cholesterol esterase also distinctly affected activation of CFTR by FSK. In addition, alteration of cholesterol increased the potency of VX-770, a clinically used potentiator of CFTR, when both WT- and P67L-CFTR channels were activated at low FSK concentrations; this likely reflects the apparent shift in the sensitivity of WT-CFTR to FSK after alteration of membrane cholesterol. These results demonstrate that changes in the plasma membrane cholesterol level significantly modulate CFTR channel function and consequently may affect sensitivity to clinical therapeutics in CF patients.
Collapse
Affiliation(s)
- Guiying Cui
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Kirsten A Cottrill
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Kerry M Strickland
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Sarah A Mashburn
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Michael Koval
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Nael A McCarty
- Division of Pulmonology, Allergy/Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory + Children's Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, United States
| |
Collapse
|
12
|
Turner MJ, Abbott-Banner K, Thomas DY, Hanrahan JW. Cyclic nucleotide phosphodiesterase inhibitors as therapeutic interventions for cystic fibrosis. Pharmacol Ther 2021; 224:107826. [PMID: 33662448 DOI: 10.1016/j.pharmthera.2021.107826] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/05/2021] [Accepted: 02/22/2021] [Indexed: 12/13/2022]
Abstract
Cystic Fibrosis (CF) lung disease results from mutations in the CFTR anion channel that reduce anion and fluid secretion by airway epithelia. Impaired secretion compromises airway innate defence mechanisms and leads to bacterial colonization, excessive inflammation and tissue damage; thus, restoration of CFTR function is the goal of many CF therapies. CFTR channels are activated by cyclic nucleotide-dependent protein kinases. The second messengers 3'5'-cAMP and 3'5'-cGMP are hydrolysed by a large family of cyclic nucleotide phosphodiesterases that provide subcellular spatial and temporal control of cyclic nucleotide-dependent signalling. Selective inhibition of these enzymes elevates cyclic nucleotide levels, leading to activation of CFTR and other downstream effectors. Here we examine members of the PDE family that are likely to regulate CFTR-dependent ion and fluid secretion in the airways and discuss other actions of PDE inhibitors that can influence cyclic nucleotide-regulated mucociliary transport, inflammation and bronchodilation. Finally, we review PDE inhibitors and the potential benefits they could provide as CF therapeutics.
Collapse
Affiliation(s)
- Mark J Turner
- Department of Physiology, McGill University, Montreal, QC, Canada; Cystic Fibrosis Translational Research Centre, McGill University, Montreal, QC, Canada.
| | | | - David Y Thomas
- Cystic Fibrosis Translational Research Centre, McGill University, Montreal, QC, Canada; Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - John W Hanrahan
- Department of Physiology, McGill University, Montreal, QC, Canada; Cystic Fibrosis Translational Research Centre, McGill University, Montreal, QC, Canada
| |
Collapse
|
13
|
Gardner AI, Haq IJ, Simpson AJ, Becker KA, Gallagher J, Saint-Criq V, Verdon B, Mavin E, Trigg A, Gray MA, Koulman A, McDonnell MJ, Fisher AJ, Kramer EL, Clancy JP, Ward C, Schuchman EH, Gulbins E, Brodlie M. Recombinant Acid Ceramidase Reduces Inflammation and Infection in Cystic Fibrosis. Am J Respir Crit Care Med 2020; 202:1133-1145. [PMID: 32569477 PMCID: PMC7560813 DOI: 10.1164/rccm.202001-0180oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Rationale: In cystic fibrosis the major cause of morbidity and mortality is lung disease characterized by inflammation and infection. The influence of sphingolipid metabolism is poorly understood with a lack of studies using human airway model systems.Objectives: To investigate sphingolipid metabolism in cystic fibrosis and the effects of treatment with recombinant human acid ceramidase on inflammation and infection.Methods: Sphingolipids were measured using mass spectrometry in fully differentiated cultures of primary human airway epithelial cells and cocultures with Pseudomonas aeruginosa. In situ activity assays, Western blotting, and quantitative PCR were used to investigate function and expression of ceramidase and sphingomyelinase. Effects of treatment with recombinant human acid ceramidase on sphingolipid profile and inflammatory mediator production were assessed in cell cultures and murine models.Measurements and Main Results: Ceramide is increased in cystic fibrosis airway epithelium owing to differential function of enzymes regulating sphingolipid metabolism. Sphingosine, a metabolite of ceramide with antimicrobial properties, is not upregulated in response to P. aeruginosa by cystic fibrosis airway epithelia. Tumor necrosis factor receptor 1 is increased in cystic fibrosis epithelia and activates NF-κB signaling, generating inflammation. Treatment with recombinant human acid ceramidase, to decrease ceramide, reduced both inflammatory mediator production and susceptibility to infection.Conclusions: Sphingolipid metabolism is altered in airway epithelial cells cultured from people with cystic fibrosis. Treatment with recombinant acid ceramidase ameliorates the two pivotal features of cystic fibrosis lung disease, inflammation and infection, and thus represents a therapeutic approach worthy of further exploration.
Collapse
Affiliation(s)
- Aaron I Gardner
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and
| | - Iram J Haq
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and.,Paediatric Respiratory Medicine, Great North Children's Hospital, and
| | - A John Simpson
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and.,Respiratory Medicine, Freeman Hospital, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Katrin A Becker
- Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany
| | - John Gallagher
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and
| | - Vinciane Saint-Criq
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Bernard Verdon
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Emily Mavin
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and
| | - Alexandra Trigg
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and
| | - Michael A Gray
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Albert Koulman
- National Institute for Health Research Biomedical Research Centre Metabolomics and Lipidomics Facility, University of Cambridge, Cambridge, United Kingdom
| | - Melissa J McDonnell
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.,Department of Respiratory Medicine, Galway University Hospital, Galway, Ireland
| | - Andrew J Fisher
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and
| | - Elizabeth L Kramer
- Department of Pediatrics and.,Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - John P Clancy
- Department of Pediatrics and.,Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Christopher Ward
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and
| | - Edward H Schuchman
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York; and
| | - Erich Gulbins
- Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany.,Department of Surgery, University of Cincinnati, Cincinnati, Ohio
| | - Malcolm Brodlie
- Translational and Clinical Research Institute, Faculty of Medical Sciences, and.,Paediatric Respiratory Medicine, Great North Children's Hospital, and
| |
Collapse
|
14
|
Liessi N, Pesce E, Braccia C, Bertozzi SM, Giraudo A, Bandiera T, Pedemonte N, Armirotti A. Distinctive lipid signatures of bronchial epithelial cells associated with cystic fibrosis drugs, including Trikafta. JCI Insight 2020; 5:138722. [PMID: 32673287 PMCID: PMC7455125 DOI: 10.1172/jci.insight.138722] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/09/2020] [Indexed: 12/11/2022] Open
Abstract
In recent years, a number of drugs have been approved for the treatment of cystic fibrosis (CF). Among them, newly released Trikafta, a combination of 3 drugs (VX-661/VX-445/VX-770), holds great promise to radically improve the quality of life for a large portion of patients with CF carrying 1 copy of F508del, the most frequent CF transmembrane conductance regulator (CFTR) mutation. Currently available disease-modifying CF drugs work by rescuing the function of the mutated CFTR anion channel. Recent research has shown that membrane lipids, and the cell lipidome in general, play a significant role in the mechanism of CFTR-defective trafficking and, on the other hand, its rescue. In this paper, by using untargeted lipidomics on CFBE41o- cells, we identified distinctive changes in the bronchial epithelial cell lipidome associated with treatment with Trikafta and other CF drugs. Particularly interesting was the reduction of levels of ceramide, a known molecular player in the induction of apoptosis, which appeared to be associated with a decrease in the susceptibility of cells to undergo apoptosis. This evidence could account for additional beneficial roles of the triple combination of drugs on CF phenotypes.
Collapse
Affiliation(s)
- Nara Liessi
- Analytical Chemistry Lab, Istituto Italiano di Tecnologia, Genova, Italy
| | - Emanuela Pesce
- L'Unità Operativa Complessa (UOC) Genetica Medica, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS) Giannina Gaslini, Genova, Italy
| | - Clarissa Braccia
- D3 PharmaChemistry, Istituto Italiano di Tecnologia, Genova, Italy
| | | | | | - Tiziano Bandiera
- D3 PharmaChemistry, Istituto Italiano di Tecnologia, Genova, Italy
| | - Nicoletta Pedemonte
- L'Unità Operativa Complessa (UOC) Genetica Medica, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS) Giannina Gaslini, Genova, Italy
| | - Andrea Armirotti
- Analytical Chemistry Lab, Istituto Italiano di Tecnologia, Genova, Italy
| |
Collapse
|
15
|
Abstract
Cystic Fibrosis (CF) is the most common life-shortening genetic disease among Caucasians, resulting from mutations in the gene encoding the Cystic Fibrosis Transmembrane conductance Regulator (CFTR). While work to understand this protein has resulted in new treatment strategies, it is important to emphasize that CFTR exists within a complex lipid bilayer — a concept largely overlooked when performing structural and functional studies. In this review we discuss cellular lipid imbalances in CF, mechanisms by which lipids affect membrane protein activity, and the specific impact of detergents and lipids on CFTR function. In this review, Cottrill et al. discuss how the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) interacts with the membrane into which it is inserted. They summarize recent insight into the ways lipids are imbalanced in CF epithelia and how the lipid environment affects CFTR.
Collapse
|
16
|
Cholesterol Interaction Directly Enhances Intrinsic Activity of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). Cells 2019; 8:cells8080804. [PMID: 31370288 PMCID: PMC6721619 DOI: 10.3390/cells8080804] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 07/23/2019] [Accepted: 07/29/2019] [Indexed: 12/15/2022] Open
Abstract
The recent cryo-electron microscopy structures of zebrafish and the human cystic fibrosis transmembrane conductance regulator (CFTR) provided unprecedented insights into putative mechanisms underlying gating of its anion channel activity. Interestingly, despite predictions based on channel activity measurements in biological membranes, the structure of the detergent purified, phosphorylated, and ATP-bound human CFTR protein did not reveal a stably open conduction pathway. This study tested the hypothesis that the functional properties of the detergent solubilized CFTR protein used for structural determinations are different from those exhibited by CFTR purified under conditions that retain associated lipids native to the membrane. It was found that CFTR purified together with phospholipids and cholesterol using amphipol: A8-35, exhibited higher rates of catalytic activity, phosphorylation dependent channel activation and potentiation by the therapeutic compound, ivacaftor, than did CFTR purified in detergent. The catalytic activity of phosphorylated CFTR detergent micelles was rescued by the addition of phospholipids plus cholesterol, but not by phospholipids alone, arguing for a specific role for cholesterol in modulating this function. In summary, these studies highlight the importance of lipid interactions in the intrinsic activities and pharmacological potentiation of CFTR.
Collapse
|
17
|
Sedwick C. CFTR gets together. J Gen Physiol 2019; 151:705. [PMID: 31076449 PMCID: PMC6572004 DOI: 10.1085/jgp.201912385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
JGP study shows that pro-secretory agonists prompt CFTR to assemble into large lipid platforms. JGP study shows that pro-secretory agonists prompt CFTR to assemble into large lipid platforms.
Collapse
|