1
|
NAGAO I, TSUJI K, GOTO-KOSHINO Y, TSUBOI M, CHAMBERS JK, UCHIDA K, KAMBAYASHI S, TOMIYASU H, BABA K, OKUDA M. MUC5AC and MUC5B expression in canine gallbladder mucocele epithelial cells. J Vet Med Sci 2023; 85:1269-1276. [PMID: 37899236 PMCID: PMC10788179 DOI: 10.1292/jvms.23-0174] [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: 04/22/2023] [Accepted: 10/17/2023] [Indexed: 10/31/2023] Open
Abstract
Gallbladder mucocele (GBM) is one of the most common gallbladder diseases in dogs. Its pathogenesis has not yet been clarified, but excessive accumulation of a secretory gel-forming mucin, MUC5AC in the gallbladder has been reported. This study aimed to ascertain if MUC5AC overproduction resulted in mucus accumulation in the gallbladder during GBM development. Eleven dogs undergoing cholecystectomy who were pathologically diagnosed with GBM were included, and the expression level of mucins, particularly MUC5AC and MUC5B, in their gallbladder epithelial cells was compared with those in normal gallbladder epithelial cells. On reverse transcription-quantitative polymerase chain reaction screening, there was a significant difference (P<0.05) in the mRNA expression level of MUC1, but not of other mucins including MUC5AC and MUC5B, between mucocele and normal gallbladder epithelial cells. Protein expression levels were also evaluated for MUC5AC and MUC5B using immunohistochemistry. There was little immunoreactivity for MUC5AC, whereas MUC5B showed definitive staining in gallbladder epithelial cells. There was no difference in MUC5AC and MUC5B protein expression levels between mucocele and normal gallbladder epithelial cells. These data suggest that excessive production of mucin, especially MUC5AC and MUC5B, does not occur in canine GBM, and that abnormal mucus excretion, rather than excessive mucus production, may be the cause of GBM development.
Collapse
Affiliation(s)
- Itsuma NAGAO
- Department of Veterinary Internal Medicine, Graduate School
of Agricultural and Sciences, The University of Tokyo, Tokyo, Japan
| | - Kanako TSUJI
- Laboratory of Veterinary Internal Medicine, Joint Faculty of
Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Yuko GOTO-KOSHINO
- Department of Veterinary Internal Medicine, Graduate School
of Agricultural and Sciences, The University of Tokyo, Tokyo, Japan
| | - Masaya TSUBOI
- Laboratory of Veterinary Pathology, Graduate School of
Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - James K. CHAMBERS
- Laboratory of Veterinary Pathology, Graduate School of
Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kazuyuki UCHIDA
- Laboratory of Veterinary Pathology, Graduate School of
Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Satoshi KAMBAYASHI
- Laboratory of Veterinary Internal Medicine, Joint Faculty of
Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Hirotaka TOMIYASU
- Department of Veterinary Internal Medicine, Graduate School
of Agricultural and Sciences, The University of Tokyo, Tokyo, Japan
| | - Kenji BABA
- Laboratory of Veterinary Internal Medicine, Joint Faculty of
Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| | - Masaru OKUDA
- Laboratory of Veterinary Internal Medicine, Joint Faculty of
Veterinary Medicine, Yamaguchi University, Yamaguchi, Japan
| |
Collapse
|
2
|
Zarei K, Stroik MR, Gansemer ND, Thurman AL, Ostedgaard LS, Ernst SE, Thornell IM, Powers LS, Pezzulo AA, Meyerholz DK, Stoltz DA. Early pathogenesis of cystic fibrosis gallbladder disease in a porcine model. J Transl Med 2020; 100:1388-1399. [PMID: 32719544 PMCID: PMC7578062 DOI: 10.1038/s41374-020-0474-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/30/2020] [Accepted: 07/07/2020] [Indexed: 12/13/2022] Open
Abstract
Hepatobiliary disease causes significant morbidity in people with cystic fibrosis (CF), yet this problem remains understudied. We previously found that newborn CF pigs have microgallbladders with significant luminal obstruction in the absence of infection and consistent inflammation. In this study, we sought to better understand the early pathogenesis of CF pig gallbladder disease. We hypothesized that loss of CFTR would impair gallbladder epithelium anion/liquid secretion and increase mucin production. CFTR was expressed apically in non-CF pig gallbladder epithelium but was absent in CF. CF pig gallbladders lacked cAMP-stimulated anion transport. Using a novel gallbladder epithelial organoid model, we found that Cl- or HCO3- was sufficient for non-CF organoid swelling. This response was absent for non-CF organoids in Cl-/HCO3--free conditions and in CF. Single-cell RNA-sequencing revealed a single epithelial cell type in non-CF gallbladders that coexpressed CFTR, MUC5AC, and MUC5B. Despite CF gallbladders having increased luminal MUC5AC and MUC5B accumulation, there was no significant difference in the epithelial expression of gel-forming mucins between non-CF and CF pig gallbladders. In conclusion, these data suggest that loss of CFTR-mediated anion transport and fluid secretion contribute to microgallbladder development and luminal mucus accumulation in CF.
Collapse
Affiliation(s)
- Keyan Zarei
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Mallory R Stroik
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Nick D Gansemer
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Andrew L Thurman
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Lynda S Ostedgaard
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Sarah E Ernst
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Ian M Thornell
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Linda S Powers
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Alejandro A Pezzulo
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - David K Meyerholz
- Department of Pathology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
| | - David A Stoltz
- Department of Internal Medicine and Pappajohn Biomedical Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
| |
Collapse
|
3
|
Housset C, Chrétien Y, Debray D, Chignard N. Functions of the Gallbladder. Compr Physiol 2016; 6:1549-77. [PMID: 27347902 DOI: 10.1002/cphy.c150050] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The gallbladder stores and concentrates bile between meals. Gallbladder motor function is regulated by bile acids via the membrane bile acid receptor, TGR5, and by neurohormonal signals linked to digestion, for example, cholecystokinin and FGF15/19 intestinal hormones, which trigger gallbladder emptying and refilling, respectively. The cycle of gallbladder filling and emptying controls the flow of bile into the intestine and thereby the enterohepatic circulation of bile acids. The gallbladder also largely contributes to the regulation of bile composition by unique absorptive and secretory capacities. The gallbladder epithelium secretes bicarbonate and mucins, which both provide cytoprotection against bile acids. The reversal of fluid transport from absorption to secretion occurs together with bicarbonate secretion after feeding, predominantly in response to an adenosine 3',5'-cyclic monophosphate (cAMP)-dependent pathway triggered by neurohormonal factors, such as vasoactive intestinal peptide. Mucin secretion in the gallbladder is stimulated predominantly by calcium-dependent pathways that are activated by ATP present in bile, and bile acids. The gallbladder epithelium has the capacity to absorb cholesterol and provides a cholecystohepatic shunt pathway for bile acids. Changes in gallbladder motor function not only can contribute to gallstone disease, but also subserve protective functions in multiple pathological settings through the sequestration of bile acids and changes in the bile acid composition. Cholecystectomy increases the enterohepatic recirculation rates of bile acids leading to metabolic effects and an increased risk of nonalcoholic fatty liver disease, cirrhosis, and small-intestine carcinoid, independently of cholelithiasis. Among subjects with gallstones, cholecystectomy remains a priority in those at risk of gallbladder cancer, while others could benefit from gallbladder-preserving strategies. © 2016 American Physiological Society. Compr Physiol 6:1549-1577, 2016.
Collapse
Affiliation(s)
- Chantal Housset
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Centre de Référence Maladies Rares (CMR) des Maladies Inflammatoires des Voies Biliaires (MIVB), Service d'Hépatologie, Paris, France
| | - Yues Chrétien
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Centre de Référence Maladies Rares (CMR) des Maladies Inflammatoires des Voies Biliaires (MIVB), Service d'Hépatologie, Paris, France
| | - Dominique Debray
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,Assistance Publique-Hôpitaux de Paris, Hôpital Necker Enfants Malades, Medical-Surgical Center, Hepatology and Transplantation, Paris, France
| | - Nicolas Chignard
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMR_S 938, Centre de Recherche Saint-Antoine, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| |
Collapse
|
4
|
Kesimer M, Cullen J, Cao R, Radicioni G, Mathews KG, Seiler G, Gookin JL. Excess Secretion of Gel-Forming Mucins and Associated Innate Defense Proteins with Defective Mucin Un-Packaging Underpin Gallbladder Mucocele Formation in Dogs. PLoS One 2015; 10:e0138988. [PMID: 26414376 PMCID: PMC4586375 DOI: 10.1371/journal.pone.0138988] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 09/07/2015] [Indexed: 12/18/2022] Open
Abstract
Mucosal protection of the gallbladder is vital yet we know very little about the mechanisms involved. In domestic dogs, an emergent syndrome referred to as gallbladder mucocele formation is characterized by excessive secretion of abnormal mucus that results in obstruction and rupture of the gallbladder. The cause of gallbladder mucocele formation is unknown. In these first mechanistic studies of this disease, we investigated normal and mucocele-forming dog gallbladders to determine the source, identity, biophysical properties, and protein associates of the culprit mucins with aim to identify causes for abnormal mucus behavior. We established that mucocele formation involves an adoptive excess secretion of gel forming mucins with abnormal properties by the gallbladder epithelium. The mucus is characterized by a disproportionally significant increase in Muc5ac relative to Muc5b, defective mucin un-packaging, and mucin-interacting innate defense proteins that are capable of dramatically altering the physical and functional properties of mucus. These findings provide an explanation for abnormal mucus behavior and based on similarity to mucus observed in the airways of people with cystic fibrosis, suggest that abnormal mechanisms for maintenance of gallbladder epithelial hydration may be an instigating factor for mucocele formation in dogs.
Collapse
Affiliation(s)
- Mehmet Kesimer
- Department of Pathology and Laboratory Medicine and Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - John Cullen
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Rui Cao
- Department of Pathology and Laboratory Medicine and Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Giorgia Radicioni
- Department of Pathology and Laboratory Medicine and Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kyle G. Mathews
- Department of Clinical Sciences, College of Veterinary Medicine, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Gabriela Seiler
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Jody L. Gookin
- Department of Clinical Sciences, College of Veterinary Medicine, Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
5
|
Liu J, Walker NM, Ootani A, Strubberg AM, Clarke LL. Defective goblet cell exocytosis contributes to murine cystic fibrosis-associated intestinal disease. J Clin Invest 2015; 125:1056-68. [PMID: 25642775 DOI: 10.1172/jci73193] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/18/2014] [Indexed: 01/12/2023] Open
Abstract
Cystic fibrosis (CF) intestinal disease is associated with the pathological manifestation mucoviscidosis, which is the secretion of tenacious, viscid mucus that plugs ducts and glands of epithelial-lined organs. Goblet cells are the principal cell type involved in exocytosis of mucin granules; however, little is known about the exocytotic process of goblet cells in the CF intestine. Using intestinal organoids from a CF mouse model, we determined that CF goblet cells have altered exocytotic dynamics, which involved intrathecal granule swelling that was abruptly followed by incomplete release of partially decondensated mucus. Some CF goblet cells exhibited an ectopic granule location and distorted cellular morphology, a phenotype that is consistent with retrograde intracellular granule movement during exocytosis. Increasing the luminal concentration of bicarbonate, which mimics CF transmembrane conductance regulator-mediated anion secretion, increased spontaneous degranulation in WT goblet cells and improved exocytotic dynamics in CF goblet cells; however, there was still an apparent incoordination between granule decondensation and exocytosis in the CF goblet cells. Compared with those within WT goblet cells, mucin granules within CF goblet cells had an alkaline pH, which may adversely affect the polyionic composition of the mucins. Together, these findings indicate that goblet cell dysfunction is an epithelial-autonomous defect in the CF intestine that likely contributes to the pathology of mucoviscidosis and the intestinal manifestations of obstruction and inflammation.
Collapse
|
6
|
LeSimple P, Goepp J, Palmer ML, Fahrenkrug SC, O’Grady SM, Ferraro P, Robert R, Hanrahan JW. Cystic Fibrosis Transmembrane Conductance Regulator Is Expressed in Mucin Granules from Calu-3 and Primary Human Airway Epithelial Cells. Am J Respir Cell Mol Biol 2013; 49:511-6. [DOI: 10.1165/rcmb.2012-0419rc] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
|
7
|
Song Y, Wang Q, Huang W, Xiao L, Shen L, Xu W. NF κB expression increases and CFTR and MUC1 expression decreases in the endometrium of infertile patients with hydrosalpinx: a comparative study. Reprod Biol Endocrinol 2012; 10:86. [PMID: 23061681 PMCID: PMC3551815 DOI: 10.1186/1477-7827-10-86] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 10/10/2012] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Hydrosalpinx are associated with infertility, due to reduced rates of implantation and increased abortion rates. The aims of this study were to investigate the expression of cystic fibrosis transmembrane conductance regulator (CFTR), nuclear factor kappa B (NF KappaB) and mucin-1 (MUC-1), and analyze the correlation between the expression of CFTR and NF KappaB or MUC1, in the endometrium of infertile women with and without hydrosalpinx. METHODS Thirty-one infertile women with laparoscopy-confirmed unilateral or bilateral hydrosalpinx and 20 infertile women without hydrosalpinx or pelvic inflammatory disease (control group) were recruited. Endometrial biopsy samples were collected and the expression of CFTR, NF KappaB and MUC1 were analyzed using immunohistochemistry and quantitative real-time PCR. RESULTS CFTR, NF KappaB and MUC1 mRNA and protein expression tended to increase in the secretory phase compared to the proliferative phase in both groups; however, these differences were not significantly different. The endometrium of infertile patients with hydrosalpinx had significantly higher NF KappaB mRNA and protein expression, and significantly lower CFTR and MUC1 mRNA and protein expression, compared to control infertile patients. A positive correlation was observed between CFTR and MUC1 mRNA expression (r = 0.65, P < 0.05); a negative correlation was observed between CFTR mRNA and NF KappaB mRNA expression (r = -0.59, P < 0.05). CONCLUSIONS Increased NF KappaB expression and decreased CFTR and MUC1 expression in the endometrium of infertile patients with hydrosalpinx reinforce the involvement of a molecular mechanism in the regulation of endometrial receptivity.
Collapse
Affiliation(s)
- Yong Song
- Department of Gynecology and Obstetrics, West China Second University Hospital of Sichuan University, Sichuan, China
| | - Qiushi Wang
- Department of Gynecology and Obstetrics, West China Second University Hospital of Sichuan University, Sichuan, China
| | - Wei Huang
- Department of Gynecology and Obstetrics, West China Second University Hospital of Sichuan University, Sichuan, China
| | - Li Xiao
- Department of Gynecology and Obstetrics, West China Second University Hospital of Sichuan University, Sichuan, China
| | - Licong Shen
- Department of Gynecology and Obstetrics, West China Second University Hospital of Sichuan University, Sichuan, China
| | - Wenming Xu
- The Chinese University of Hong Kong Joint Laboratory for Reproductive Medicine, Key Laboratory of Obstetric, Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital of Sichuan University, Sichuan, China
| |
Collapse
|
8
|
Chen EYT, Yang N, Quinton PM, Chin WC. A new role for bicarbonate in mucus formation. Am J Physiol Lung Cell Mol Physiol 2010; 299:L542-9. [PMID: 20693315 DOI: 10.1152/ajplung.00180.2010] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The impact of small anions on the physical properties of gel-forming mucin has been almost overlooked relative to that of cations. Recently, based on the coincident abnormalities in HCO(3)(-) secretion and abnormal mucus formed in the hereditary disease cystic fibrosis (CF), HCO(3)(-) was hypothesized to be critical in the formation of normal mucus by virtue of its ability to sequester Ca(2+) from condensed mucins being discharged from cells. However, direct evidence of the impact of HCO(3)(-) on mucus properties is lacking. Herein, we demonstrate for the first time that mucin diffusivity (∼1/viscosity) increases as a function of [HCO(3)(-)]. Direct measurements of exocytosed mucin-swelling kinetics from airway cells showed that mucin diffusivity increases by ∼300% with 20 mM extracellular HCO(3)(-) concentration. Supporting data indicate that HCO(3)(-) reduces free Ca(2+) concentration and decreases the amount of Ca(2+) that remains associated with mucins. The results demonstrate that HCO(3)(-) enhances mucin swelling and hydration by reducing Ca(2+) cross-linking in mucins, thereby decreasing its viscosity and likely increasing its transportability. In addition, HCO(3)(-) can function as a Ca(2+) chelator like EGTA to disperse mucin aggregates. This study indicates that poor HCO(3)(-) availability in CF may explain why secreted mucus remains aggregated and more viscous in affected organs. These insights bear on not only the fundamental pathogenesis in CF, but also on the process of gel mucus formation and release in general.
Collapse
Affiliation(s)
- Eric Y T Chen
- Bioengineering, Univ. of California at Merced, 95343, USA
| | | | | | | |
Collapse
|
9
|
|
10
|
Garcia MAS, Yang N, Quinton PM. Normal mouse intestinal mucus release requires cystic fibrosis transmembrane regulator-dependent bicarbonate secretion. J Clin Invest 2009; 119:2613-22. [PMID: 19726884 DOI: 10.1172/jci38662] [Citation(s) in RCA: 217] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 07/01/2009] [Indexed: 12/16/2022] Open
Abstract
The mechanisms underlying mucus-associated pathologies in cystic fibrosis (CF) remain obscure. However, recent studies indicate that CF transmembrane conductance regulator (CFTR) is required for bicarbonate (HCO3-) transport and that HCO3- is critical for normal mucus formation. We therefore investigated the role of HCO3- in mucus secretion using mouse small intestine segments ex vivo. Basal rates of mucus release in the presence or absence of HCO3- were similar. However, in the absence of HCO3-, mucus release stimulated by either PGE2 or 5-hydroxytryptamine (5-HT) was approximately half that stimulated by these molecules in the presence of HCO3-. Inhibition of HCO3- and fluid transport markedly reduced stimulated mucus release. However, neither absence of HCO3- nor inhibition of HCO3- transport affected fluid secretion rates, indicating that the effect of HCO3- removal on mucus release was not due to decreased fluid secretion. In a mouse model of CF (mice homozygous for the most common human CFTR mutation), intestinal mucus release was minimal when stimulated with either PGE2 or 5-HT in the presence or absence of HCO3-. These data suggest that normal mucus release requires concurrent HCO3- secretion and that the characteristically aggregated mucus observed in mucin-secreting organs in individuals with CF may be a consequence of defective HCO3- transport.
Collapse
Affiliation(s)
- Mary Abigail S Garcia
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California School of Medicine, San Diego, California 92093-0831, USA
| | | | | |
Collapse
|
11
|
Delavoie F, Molinari M, Milliot M, Zahm JM, Coraux C, Michel J, Balossier G. Salmeterol restores secretory functions in cystic fibrosis airway submucosal gland serous cells. Am J Respir Cell Mol Biol 2008; 40:388-97. [PMID: 18931328 DOI: 10.1165/rcmb.2008-0037oc] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The activity of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) can be mediated by surface G protein-coupled receptors such as the beta(2)-adrenergic receptor. In this study, we explored the effect of a long-acting beta(2)-adrenergic agonist, salmeterol, on the CFTR-dependent secretory capacity of a human CF tracheal gland serous cell line (CF-KM4), homozygous for the delF508 mutation. We showed that, compared with the untreated CF serous cells, a 24-hour pre-incubation period with 200 nM salmeterol induced an 83% increase in delF508-CFTR-mediated chloride efflux. The restoration of the bioelectric properties is associated with increased apical surface pool of delF508-CFTR. Salmeterol induced a decrease in ion concentration and an increase in the level of hydration of the mucus packaged inside the CF secretory granules. The effects of salmeterol are not associated with a persistent production of cAMP. Western blotting on isolated secretory granules demonstrated immunoreactivity for CFTR and lysozyme. In parallel, we measured by atomic force microscopy an increased size of secretory granules isolated from CF serous cells compared with non-CF serous cells (MM39 cell line) and showed that salmeterol was able to restore a CF cell granule size similar to that of non-CF cells. To demonstrate that the salmeterol effect was a CFTR-dependent mechanism, we showed that the incubation of salmeterol-treated CF serous cells with CFTR-inh172 suppressed the restoration of normal secretory functions. The capacity of salmeterol to restore the secretory capacity of glandular serous cells suggests that it could also improve the airway mucociliary clearance in patients with CF.
Collapse
Affiliation(s)
- Franck Delavoie
- INSERM UMRS 926, Laboratoire de Microscopie Electronique Analytique, 21 rue Clément Ader, B.P. 138, 51685 Reims Cedex 2, France.
| | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
Mucus secretions have played a central role in the evolution of multicellular organisms, enabling adaptation to widely differing environments. In vertebrates, mucus covers and protects the epithelial cells in the respiratory, gastrointestinal, urogenital, visual, and auditory systems, amphibian's epidermis, and the gills in fishes. Deregulation of mucus production and/or composition has important consequences for human health. For example, mucus obstruction of small airways is observed in chronic airway diseases, including chronic obstructive pulmonary disease, asthma, and cystic fibrosis. The major protein component in the mucus is a family of large, disulfide-bonded glycoproteins known as gel-forming mucins. These proteins are accumulated in large, regulated secretory granules (the mucin granules) that occupy most of the apical cytoplasm of specialized cells known as mucous/goblet cells. Since mucin oligomers have contour dimensions larger than the mucin granule average diameter, the question arises how these highly hydrophilic macromolecules are organized within these organelles. I review here the intraluminal organization of the mucin granule in view of our knowledge on the structure, biosynthesis, and biophysical properties of gel-forming mucins, and novel imaging studies in living mucous/goblet cells. The emerging concept is that the mucin granule lumen comprises a partially condensed matrix meshwork embedded in a fluid phase where proteins slowly diffuse.
Collapse
Affiliation(s)
- Juan Perez-Vilar
- Cystic Fibrosis/Pulmonary Research and Treatment Center, School of Medicine, University of North Carolina at Chapel Hill, NC 27599-7248, USA.
| |
Collapse
|