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Dastoor P, Muiler C, Garrison A, Egan M, Carlos Dos Reis D, Santos A, Ameen NA. Localization and function of humanized F508del-CFTR in mouse intestine following activation of serum glucocorticoid kinase 1 and Trikafta. Eur J Pharmacol 2024; 978:176771. [PMID: 38925289 DOI: 10.1016/j.ejphar.2024.176771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 06/21/2024] [Accepted: 06/23/2024] [Indexed: 06/28/2024]
Abstract
The CFTR modulator Trikafta has markedly improved lung disease for Cystic Fibrosis (CF) patients carrying the common delta F508 (F508del-CFTR) CFTR mutation. F508del-CFTR results in an apical trafficking defect and loss of function in CFTR-expressing epithelial cells. However, Trikafta has not resulted in improved gastrointestinal function in CF patients. A humanized mouse model of F508del-CFTR was recently generated to evaluate CFTR modulators and other compounds to treat human F508del-CFTR CF intestinal disease. Short-term (4 h) treatment of rats with Dexamethasone (Dex) potently activates serum glucocorticoid kinase 1 (SGK1) and increases CFTR apical traffic and ion transport in the native intestine. This study examined CFTR localization and ion transport in intestinal segments from humanized F508del-CFTR mice following treatment with Dex in the presence/absence of Trikafta. Dex treatment improved apical CFTR localization and function but was inconsistent along intestinal segments. Combined treatment with Dex and Trikafta was superior to Dex alone but inconsistently improved CFTR localization and function. These data suggest further optimization of humanized CF mouse models will be necessary to test the efficacy of compounds to treat human CF intestinal disease.
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Affiliation(s)
- Parinaz Dastoor
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, CT, USA.
| | - Caroline Muiler
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, CT, USA
| | - Alannah Garrison
- Department of Pediatric Pulmonary Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Marie Egan
- Department of Pediatric Pulmonary Medicine, Yale School of Medicine, New Haven, CT, USA; Department of Molecular Physiology, Yale School of Medicine, New Haven, CT, USA
| | - Diego Carlos Dos Reis
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, CT, USA.
| | - Anderson Santos
- Department of Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Nadia A Ameen
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, CT, USA; Department of Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.
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2
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Zagoren E, Dias N, Smith ZD, Ameen NA, Sumigray K. A second wave of Notch signaling diversifies the intestinal secretory lineage. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.15.603542. [PMID: 39071399 PMCID: PMC11275776 DOI: 10.1101/2024.07.15.603542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
The small intestine is well known for the function of its nutrient-absorbing enterocytes; yet equally critical for the maintenance of homeostasis is a diverse set of secretory cells, all of which are presumed to differentiate from the same intestinal stem cell. Despite major roles in intestinal function and health, understanding how the full spectrum of secretory cell types arises remains a longstanding challenge, largely due to their comparative rarity. Here, we investigate the fate specification of a rare and distinct population of small intestinal epithelial cells found in rats and humans but not mice: C FTR Hi gh E xpressers (CHEs). We use pseudotime trajectory analysis of single-cell RNA-seq data from rat intestinal jejunum to provide evidence that CHEs are specified along the secretory lineage and appear to employ a second wave of Notch-based signal transduction to distinguish these cells from other secretory cell types. We further validate the general order of transcription factors that direct these cells from unspecified progenitors within the crypt and experimentally demonstrate that Notch signaling is necessary to induce CHE fate both in vivo and in vitro . Our results suggest a model in which Notch is reactivated along the secretory lineage to specify the CHE population: a rare secretory cell type with putative functions in localized coordination of luminal pH and direct relevance to cystic fibrosis pathophysiology.
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Chen L, Yi H, Li Q, Duan T, Liu X, Li L, Wang HY, Xing C, Wang R. T-bet Regulates Ion Channels and Transporters and Induces Apoptosis in Intestinal Epithelial Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2401654. [PMID: 38650111 PMCID: PMC11267362 DOI: 10.1002/advs.202401654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/22/2024] [Indexed: 04/25/2024]
Abstract
T-bet, encoded by TBX21, is extensively expressed across various immune cell types, and orchestrates critical functions in their development, survival, and physiological activities. However, the role of T-bet in non-immune compartments, notably the epithelial cells, remains obscure. Herein, a Tet-O-T-bet transgenic mouse strain is generated for doxycycline-inducible T-bet expression in adult animals. Unexpectedly, ubiquitous T-bet overexpression causes acute diarrhea, intestinal damage, and rapid mortality. Cell-type-specific analyses reveal that T-bet-driven pathology is not attributable to its overexpression in CD4+ T cells or myeloid lineages. Instead, inducible T-bet overexpression in the intestinal epithelial cells is the critical determinant of the observed lethal phenotype. Mechanistically, T-bet overexpression modulates ion channel and transporter profiles in gut epithelial cells, triggering profound fluid secretion and subsequent lethal dehydration. Furthermore, ectopic T-bet expression enhances gut epithelial cell apoptosis and markedly suppresses colon cancer development in xenograft models. Collectively, the findings unveil a previously unrecognized role of T-bet in intestinal epithelial cells for inducing apoptosis, diarrhea, and local inflammation, thus implicating its potential as a therapeutic target for the treatment of cancer and inflammatory diseases.
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Affiliation(s)
- Lang Chen
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of General SurgeryThird Xiangya HospitalXiangya School of MedicineCentral South UniversityChangsha410013China
| | - Hongwei Yi
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of PharmacologySchool of MedicineSoutheast UniversityNanjing210009China
| | - Qingtian Li
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineBaylor College of MedicineHoustonTX77030USA
| | - Tianhao Duan
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Xin Liu
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Linfeng Li
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of Thoracic SurgeryXiangya HospitalCentral South UniversityChangsha410008China
| | - Helen Y. Wang
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Changsheng Xing
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Rong‐Fu Wang
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
- Department of PediatricsChildren's Hospital Los AngelesKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90027USA
- Norris Comprehensive Cancer CenterKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
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Teng L, Dedousis N, Adeshirlarijaney A, Kanshana JS, Liu M, Hodges CA, Kohan AB. Impaired intestinal free fatty acid transport followed by chylomicron malformation, not pancreatic insufficiency, cause metabolic defects in cystic fibrosis. J Lipid Res 2024; 65:100551. [PMID: 39002195 PMCID: PMC11301217 DOI: 10.1016/j.jlr.2024.100551] [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: 12/06/2023] [Revised: 04/03/2024] [Accepted: 04/29/2024] [Indexed: 07/15/2024] Open
Abstract
Intestinal disease is one of the earliest manifestations of cystic fibrosis (CF) in children and is closely tied to deficits in growth and nutrition, both of which are directly linked to future mortality. Patients are treated aggressively with pancreatic enzyme replacement therapy and a high-fat diet to circumvent fat malabsorption, but this does not reverse growth and nutritional defects. We hypothesized that defects in chylomicron production could explain why CF body weights and nutrition are so resistant to clinical treatments. We used gold standard intestinal lipid absorption and metabolism approaches, including mouse mesenteric lymph cannulation, in vivo chylomicron secretion kinetics, transmission electron microscopy, small intestinal organoids, and chylomicron metabolism assays to test this hypothesis. In mice expressing the G542X mutation in cystic fibrosis transmembrane conductance regulator (CFTR-/- mice), we find that defective FFA trafficking across the epithelium into enterocytes drives a chylomicron formation defect. Furthermore, G542X mice secrete small, triglyceride-poor chylomicrons into the lymph and blood. These defective chylomicrons are cleared into extraintestinal tissues at ∼10-fold faster than WT chylomicrons. This defect in FFA absorption resulting in dysfunctional chylomicrons cannot be explained by steatorrhea or pancreatic insufficiency and is maintained in primary small intestinal organoids treated with micellar lipids. These studies suggest that the ultrahigh-fat diet that most people with CF are counselled to follow may instead make steatorrhea and malabsorption defects worse by overloading the absorptive capacity of the CF small intestine.
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Affiliation(s)
- Lihong Teng
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nikolaos Dedousis
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Aneseh Adeshirlarijaney
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jitendra S Kanshana
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Min Liu
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Craig A Hodges
- Department of Genetics and Genome Sciences and Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Alison B Kohan
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA; Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA.
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Malonga T, Vialaneix N, Beaumont M. BEST4 + cells in the intestinal epithelium. Am J Physiol Cell Physiol 2024; 326:C1345-C1352. [PMID: 38557358 PMCID: PMC11371329 DOI: 10.1152/ajpcell.00042.2024] [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: 01/19/2024] [Revised: 03/13/2024] [Accepted: 03/21/2024] [Indexed: 04/04/2024]
Abstract
The recent development of single-cell transcriptomics highlighted the existence of a new lineage of mature absorptive cells in the human intestinal epithelium. This subpopulation is characterized by the specific expression of Bestrophin 4 (BEST4) and of other marker genes including OTOP2, CA7, GUCA2A, GUCA2B, and SPIB. BEST4+ cells appear early in development and are present in all regions of the small and large intestine at a low abundance (<5% of all epithelial cells). Location-specific gene expression profiles in BEST4+ cells suggest their functional specialization in each gut region, as exemplified by the small intestine-specific expression of the ion channel CFTR. The putative roles of BEST4+ cells include sensing and regulation of luminal pH, tuning of guanylyl cyclase-C signaling, transport of electrolytes, hydration of mucus, and secretion of antimicrobial peptides. However, most of these hypotheses lack functional validation, notably because BEST4+ cells are absent in mice. The presence of BEST4+ cells in human intestinal organoids indicates that this in vitro model should be suitable to study their role. Recent studies showed that BEST4+ cells are also present in the intestinal epithelium of macaque, pig, and zebrafish and, here, we report their presence in rabbits, which suggests that these species could be appropriate animal models to study BEST4+ cells during the development of diseases and their interactions with environmental factors such as diet or the microbiota. In this review, we summarize the existing literature regarding BEST4+ cells and emphasize the description of their predicted roles in the intestinal epithelium in health and disease.NEW & NOTEWORTHY BEST4+ cells are a novel subtype of mature absorptive cells in the human intestinal epithelium highlighted by single-cell transcriptomics. The gene expression profile of BEST4+ cells suggests their role in pH regulation, electrolyte secretion, mucus hydration, and innate immune defense. The absence of BEST4+ cells in mice requires the use of alternative animal models or organoids to decipher the role of this novel type of intestinal epithelial cells.
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Affiliation(s)
- Tania Malonga
- GenPhySE, Université de Toulouse, INRAE, ENVT, 31326, Castanet Tolosan, France
- Université de Toulouse, INRAE, UR MIAT, Castanet-Tolosan, France
| | - Nathalie Vialaneix
- Université de Toulouse, INRAE, UR MIAT, Castanet-Tolosan, France
- Université de Toulouse, INRAE, BioinfOmics, GenoToul Bioinformatics Facility, Castanet-Tolosan, France
| | - Martin Beaumont
- GenPhySE, Université de Toulouse, INRAE, ENVT, 31326, Castanet Tolosan, France
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Lin J, Lin M, Du Q, Tu Y, Chen J. Involvement of aquaporin 5 and Na-K-2Cl cotransporter 1 in the pathogenesis of primary focal hyperhidrosis: evidence from the primary sweat gland cell culture. Am J Physiol Cell Physiol 2024; 326:C206-C213. [PMID: 38047298 DOI: 10.1152/ajpcell.00274.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/05/2023]
Abstract
People with primary focal hyperhidrosis (PFH) usually have an overactive sympathetic nervous system, which can activate the sweat glands through the chemical messenger of acetylcholine. The role of aquaporin 5 (AQP5) and Na-K-2Cl cotransporter 1 (NKCC1) in PFH is still unknown. The relative mRNA and protein levels of AQP5 and NKCC1 in the sweat gland tissues of three subtypes of patients with PFH (primary palmar hyperhidrosis, PPH; primary axillary hyperhidrosis, PAH; and primary craniofacial hyperhidrosis, PCH) were detected with real-time PCR (qPCR) and Western blot. Primary sweat gland cells from healthy controls (NPFH-SG) were incubated with different concentrations of acetylcholine, and the relative mRNA and protein expression of AQP5 and NKCC1 were also detected. NPFH-SG cells were also transfected with si-AQP5 or shNKCC1, and acetylcholine stimulation-induced calcium transients were assayed with Fluo-3 AM calcium assay. Upregulated AQP5 and NKCC1 expression were observed in sweat gland tissues, and AQP5 demonstrated a positive Pearson correlation with NKCC1 in patients with PPH (r = 0.66, P < 0.001), patients with PAH (r = 0.71, P < 0.001), and patients with PCH (r = 0.62, P < 0.001). Upregulated AQP5 and NKCC1 expression were also detected in primary sweat gland cells derived from three subtypes of patients with PFH when compared with primary sweat gland cells derived from healthy control. Acetylcholine stimulation could induce the upregulated AQP5 and NKCC1 expression in NPFH-SG cells, and AQP5 or NKCC1 inhibitions attenuated the calcium transients induced by acetylcholine stimulation in NPFH-SG cells. The dependence of ACh-stimulated calcium transients on AQP5 and NKCC1 expression may be involved in the development of PFH.NEW & NOTEWORTHY The dependence of ACh-stimulated calcium transients on AQP5 and Na-K-2Cl cotransporter 1 (NKCC1) expression may be involved in the development of primary focal hyperhidrosis (PFH).
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Affiliation(s)
- Jianbo Lin
- Department of Thoracic Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, People's Republic of China
- Department of Thoracic Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People's Republic of China
| | - Min Lin
- Department of Thoracic Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, People's Republic of China
- Department of Thoracic Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People's Republic of China
| | - Quan Du
- Department of Thoracic Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, People's Republic of China
- Department of Thoracic Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People's Republic of China
| | - Yuanrong Tu
- Department of Thoracic Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, People's Republic of China
- Department of Thoracic Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People's Republic of China
| | - Jianfeng Chen
- Department of Thoracic Surgery, First Affiliated Hospital of Fujian Medical University, Fuzhou, People's Republic of China
- Department of Thoracic Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, People's Republic of China
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Carlos dos Reis D, Dastoor P, Santos AK, Sumigray K, Ameen NA. CFTR high expresser cells in cystic fibrosis and intestinal diseases. Heliyon 2023; 9:e14568. [PMID: 36967909 PMCID: PMC10031467 DOI: 10.1016/j.heliyon.2023.e14568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 03/02/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), the Cl-/HCO3 - channel implicated in Cystic Fibrosis, is critical to the pathophysiology of many gastrointestinal diseases. Defects in CFTR lead to intestinal dysfunction, malabsorption, obstruction, infection, inflammation, and cancer that increases morbidity and reduces quality of life. This review will focus on CFTR in the intestine and the implications of the subpopulation of CFTR High Expresser Cells (CHEs) in Cystic Fibrosis (CF), intestinal physiology and pathophysiology of intestinal diseases.
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Affiliation(s)
- Diego Carlos dos Reis
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, CT, 06510, USA
| | - Parinaz Dastoor
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, CT, 06510, USA
| | - Anderson Kenedy Santos
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, CT, 06510, USA
- Department of Genetics, Yale School of Medicine, New Haven, CT, 06510, USA
| | - Kaelyn Sumigray
- Department of Genetics, Yale School of Medicine, New Haven, CT, 06510, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, 06510, USA
- Yale Cancer Center, Yale School of Medicine, New Haven, CT, 06510, USA
| | - Nadia A. Ameen
- Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, CT, 06510, USA
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT06510, USA
- Corresponding author. Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, CT, 06510, USA.
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Mariotti Zani E, Grandinetti R, Cunico D, Torelli L, Fainardi V, Pisi G, Esposito S. Nutritional Care in Children with Cystic Fibrosis. Nutrients 2023; 15:nu15030479. [PMID: 36771186 PMCID: PMC9921127 DOI: 10.3390/nu15030479] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/05/2023] [Accepted: 01/16/2023] [Indexed: 01/18/2023] Open
Abstract
Patients with cystic fibrosis (CF) are prone to malnutrition and growth failure, mostly due to malabsorption caused by the derangement in the chloride transport across epithelial surfaces. Thus, optimal nutritional care and support should be an integral part of the management of the disease, with the aim of ameliorating clinical outcomes and life expectancy. In this report, we analyzed the nutrition support across the different ages, in patients with CF, with a focus on the relationships with growth, nutritional status, disease outcomes and the use of the CF transmembrane conductance regulator (CFTR) modulators. The nutrition support goal in CF care should begin as early as possible after diagnosis and include the achievement of an optimal nutritional status to support the growth stages and puberty development in children, that will further support the maintenance of an optimal nutritional status in adult life. The cornerstone of nutrition in patients with CF is a high calorie, high-fat diet, in conjunction with a better control of malabsorption due to pancreatic enzyme replacement therapy, and attention to the adequate supplementation of fat-soluble vitamins. When the oral caloric intake is not enough for reaching the anthropometric nutritional goals, supplemental enteral feeding should be initiated to improve growth and the nutritional status. In the last decade, the therapeutic possibilities towards CF have grown in a consistent way. The positive effects of CFTR modulators on nutritional status mainly consist in the improvement in weight gain and BMI, both in children and adults, and in an amelioration in terms of the pulmonary function and reduction of exacerbations. Several challenges need to be overcome with the development of new drugs, to transform CF from a fatal disease to a treatable chronic disease with specialized multidisciplinary care.
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Affiliation(s)
- Elena Mariotti Zani
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Roberto Grandinetti
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Daniela Cunico
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Lisa Torelli
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Valentina Fainardi
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Giovanna Pisi
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
| | - Susanna Esposito
- Pediatric Clinic, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Correspondence: ; Tel.: +39-0521-903524
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9
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Levic DS, Bagnat M. Polarized transport of membrane and secreted proteins during lumen morphogenesis. Semin Cell Dev Biol 2023; 133:65-73. [PMID: 35307284 PMCID: PMC9481742 DOI: 10.1016/j.semcdb.2022.03.016] [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: 12/03/2021] [Revised: 03/09/2022] [Accepted: 03/12/2022] [Indexed: 10/18/2022]
Abstract
A ubiquitous feature of animal development is the formation of fluid-filled cavities or lumina, which transport gases and fluids across tissues and organs. Among different species, lumina vary drastically in size, scale, and complexity. However, all lumen formation processes share key morphogenetic principles that underly their development. Fundamentally, a lumen simply consists of epithelial cells that encapsulate a continuous internal space, and a common way of building a lumen is via opening and enlarging by filling it with fluid and/or macromolecules. Here, we discuss how polarized targeting of membrane and secreted proteins regulates lumen formation, mainly focusing on ion transporters in vertebrate model systems. We also discuss mechanistic differences observed among invertebrates and vertebrates and describe how the unique properties of the Na+/K+-ATPase and junctional proteins can promote polarization of immature epithelia to build lumina de novo in developing organs.
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Affiliation(s)
- Daniel S Levic
- Department of Cell Biology, Duke University, Durham, NC 27710, USA.
| | - Michel Bagnat
- Department of Cell Biology, Duke University, Durham, NC 27710, USA.
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10
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Scull CE, Luo M, Jennings S, Taylor CM, Wang G. Cftr deletion in mouse epithelial and immune cells differentially influence the intestinal microbiota. Commun Biol 2022; 5:1130. [PMID: 36289287 PMCID: PMC9605958 DOI: 10.1038/s42003-022-04101-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/11/2022] [Indexed: 11/25/2022] Open
Abstract
Cystic fibrosis (CF) is a life-threatening genetic disorder, caused by mutations in the CF transmembrane-conductance regulator gene (cftr) that encodes CFTR, a cAMP-activated chloride and bicarbonate channel. Clinically, CF lung disease dominates the adult patient population. However, its gastrointestinal illness claims the early morbidity and mortality, manifesting as intestinal dysbiosis, inflammation and obstruction. As CF is widely accepted as a disease of epithelial dysfunction, it is unknown whether CFTR loss-of-function in immune cells contributes to these clinical outcomes. Using cftr genetic knockout and bone marrow transplantation mouse models, we performed 16S rRNA gene sequencing of the intestinal microbes. Here we show that cftr deletion in both epithelial and immune cells collectively influence the intestinal microbiota. However, the immune defect is a major factor determining the dysbiosis in the small intestine, while the epithelial defect largely influences that in the large intestine. This finding revises the current concept by suggesting that CF epithelial defect and immune defect play differential roles in CF intestinal disease.
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Affiliation(s)
- Callie E Scull
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Meng Luo
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Scott Jennings
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Christopher M Taylor
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Guoshun Wang
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA.
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11
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Ahsan MK, dos Reis DC, Barbieri A, Sumigray KD, Nottoli T, Salas PJ, Ameen NA. Loss of Serum Glucocorticoid-Inducible Kinase 1 SGK1 Worsens Malabsorption and Diarrhea in Microvillus Inclusion Disease (MVID). J Clin Med 2022; 11:jcm11144179. [PMID: 35887942 PMCID: PMC9319011 DOI: 10.3390/jcm11144179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 11/16/2022] Open
Abstract
Microvillus inclusion disease (MVID), a lethal congenital diarrheal disease, results from loss of function mutations in the apical actin motor myosin VB (MYO5B). How loss of MYO5B leads to both malabsorption and fluid secretion is not well understood. Serum glucocorticoid-inducible kinase 1 (SGK1) regulates intestinal carbohydrate and ion transporters including cystic fibrosis transmembrane conductance regulator (CFTR). We hypothesized that loss of SGK1 could reduce CFTR fluid secretion and MVID diarrhea. Using CRISPR-Cas9 approaches, we generated R26CreER;MYO5Bf/f conditional single knockout (cMYO5BKO) and R26CreER;MYO5Bf/f;SGK1f/f double knockout (cSGK1/MYO5B-DKO) mice. Tamoxifen-treated cMYO5BKO mice resulted in characteristic features of human MVID including severe diarrhea, microvillus inclusions (MIs) in enterocytes, defective apical traffic, and depolarization of transporters. However, apical CFTR distribution was preserved in crypts and depolarized in villus enterocytes, and CFTR high expresser (CHE) cells were observed. cMYO5BKO mice displayed increased phosphorylation of SGK1, PDK1, and the PDK1 target PKCι in the intestine. Surprisingly, tamoxifen-treated cSGK1/MYO5B-DKO mice displayed more severe diarrhea than cMYO5BKO, with preservation of apical CFTR and CHE cells, greater fecal glucose and reduced SGLT1 and GLUT2 in the intestine. We conclude that loss of SGK1 worsens carbohydrate malabsorption and diarrhea in MVID.
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Affiliation(s)
- Md Kaimul Ahsan
- Department of Pediatrics, Gastroenterology and Hepatology, Yale University School of Medicine, New Haven, CT 06510, USA; (M.K.A.); (D.C.d.R.)
| | - Diego Carlos dos Reis
- Department of Pediatrics, Gastroenterology and Hepatology, Yale University School of Medicine, New Haven, CT 06510, USA; (M.K.A.); (D.C.d.R.)
| | - Andrea Barbieri
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510, USA;
| | - Kaelyn D. Sumigray
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA;
| | - Timothy Nottoli
- Genome Editing Center, Comparative Medicine, Yale University School of Medicine, New Haven, CT 06510, USA;
| | - Pedro J. Salas
- Department of Cell Biology, Miller School of Medicine, University of Miami, Miami, FL 33146, USA;
| | - Nadia A. Ameen
- Department of Pediatrics, Gastroenterology and Hepatology, Yale University School of Medicine, New Haven, CT 06510, USA; (M.K.A.); (D.C.d.R.)
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, USA
- Correspondence:
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12
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Li T, Stefano G, Raza GS, Sommerer I, Riederer B, Römermann D, Tan X, Tan Q, Pallagi P, Hollenbach M, Herzig K, Seidler U. Hydrokinetic pancreatic function and insulin secretion are moduled by Cl - uniporter Slc26a9 in mice. Acta Physiol (Oxf) 2022; 234:e13729. [PMID: 34525257 DOI: 10.1111/apha.13729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 09/01/2021] [Accepted: 09/04/2021] [Indexed: 11/29/2022]
Abstract
AIM Slc26a9 is a member of the Slc26 multifunctional anion transporter family. Polymorphisms in Slc26a9 are associated with an increased incidence of meconium ileus and diabetes in cystic fibrosis patients. We investigated the expression of Slc26a9 in the murine pancreatic ducts, islets and parenchyma, and elucidated its role in pancreatic ductal electrolyte and fluid secretion and endocrine function. METHODS Pancreatic Slc26a9 and CFTR mRNA expression, fluid and bicarbonate secretion were assessed in slc26a9-/- mice and their age- and sex-matched wild-type (wt) littermates. Glucose and insulin tolerance tests were performed. RESULTS Compared with stomach, the mRNA expression of Slc26a9 was low in pancreatic parenchyma, 20-fold higher in microdissected pancreatic ducts than parenchyma, and very low in islets. CFTR mRNA was ~10 fold higher than Slc26a9 mRNA expression in each pancreatic cell type. Significantly reduced pancreatic fluid secretory rates and impaired glucose tolerance were observed in female slc26a9-/- mice, whereas alterations in male mice did not reach statistical significance. No significant difference was observed in peripheral insulin resistance in slc26a9-/- compared to sex- and aged-matched wt controls. In contrast, isolated slc26a9-/- islets in short term culture displayed no difference in insulin content, but a significantly reduced glucose-stimulated insulin secretion compared to age- and sex-matched wt islets, suggesting that the impaired glucose tolerance in the absence of Slc26a9 expression these is a pancreatic defect. CONCLUSIONS Deletion of Slc26a9 is associated with a reduction in pancreatic fluid secretion and impaired glucose tolerance in female mice. The results underline the importance of Slc26a9 in pancreatic physiology.
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Affiliation(s)
- T. Li
- Department of Gastroenterology Hannover Medical School Hannover Germany
- Department of Thyroid and Breast Surgery Affiliated Hospital of Zunyi Medical University Zunyi P.R. China
| | - G. Stefano
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - G. S. Raza
- Institute of Biomedicine and Biocenter of Oulu Oulu University Oulu Finland
| | - I. Sommerer
- Department of Medicine Szeged University Szeged Hungary
| | - B. Riederer
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - D. Römermann
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - X. Tan
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - Q. Tan
- Department of Gastroenterology Hannover Medical School Hannover Germany
| | - P. Pallagi
- Department of Gastroenterology Leipzig University Leipzig Germany
| | - M. Hollenbach
- Department of Medicine Szeged University Szeged Hungary
| | - K.‐H. Herzig
- Institute of Biomedicine and Biocenter of Oulu Oulu University Oulu Finland
- Department of Gastroenterology and Metabolism Poznan University of Medical Sciences Poznan Poland
| | - U. Seidler
- Department of Gastroenterology Hannover Medical School Hannover Germany
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13
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James KR, Elmentaite R, Teichmann SA, Hold GL. Redefining intestinal immunity with single-cell transcriptomics. Mucosal Immunol 2022; 15:531-541. [PMID: 34848830 PMCID: PMC8630196 DOI: 10.1038/s41385-021-00470-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/27/2021] [Accepted: 11/03/2021] [Indexed: 02/04/2023]
Abstract
The intestinal immune system represents the largest collection of immune cells in the body and is continually exposed to antigens from food and the microbiota. Here we discuss the contribution of single-cell transcriptomics in shaping our understanding of this complex system. We consider the impact on resolving early intestine development, engagement with the neighbouring microbiota, diversity of intestinal immune cells, compartmentalisation within the intestines and interactions with non-immune cells. Finally, we offer a perspective on open questions about gut immunity that evolving single-cell technologies are well placed to address.
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Affiliation(s)
- Kylie Renee James
- grid.415306.50000 0000 9983 6924Garvan-Weizmann Centre for Cellular Genomics, Garvan Institute of Medical Research, Sydney, NSW 2010 Australia ,grid.1005.40000 0004 4902 0432School of Medical Sciences, University of New South Wales, Sydney, NSW 2006 Australia
| | - Rasa Elmentaite
- grid.10306.340000 0004 0606 5382Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA UK
| | - Sarah Amalia Teichmann
- grid.10306.340000 0004 0606 5382Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA UK ,grid.5335.00000000121885934Theory of Condensed Matter Group, Cavendish Laboratory/Department of Physics, University of Cambridge, Cambridge, NSW CB3 0HE UK
| | - Georgina Louise Hold
- grid.1005.40000 0004 4902 0432University of New South Wales Microbiome Research Centre, Sydney, NSW 2217 Australia
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14
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Zhao Q, Chen YY, Xu DQ, Yue SJ, Fu RJ, Yang J, Xing LM, Tang YP. Action Mode of Gut Motility, Fluid and Electrolyte Transport in Chronic Constipation. Front Pharmacol 2021; 12:630249. [PMID: 34385914 PMCID: PMC8353128 DOI: 10.3389/fphar.2021.630249] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 06/28/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic constipation is a common gastrointestinal disorder, with a worldwide incidence of 14–30%. It negatively affects quality of life and is associated with a considerable economic burden. As a disease with multiple etiologies and risk factors, it is important to understand the pathophysiology of chronic constipation. The purpose of this review is to discuss latest findings on the roles of gut motility, fluid, and electrolyte transport that contribute to chronic constipation, and the main drugs available for treating patients. We conducted searches on PubMed and Google Scholar up to 9 February 2021. MeSH keywords “constipation”, “gastrointestinal motility”, “peristalsis”, “electrolytes”, “fluid”, “aquaporins”, and “medicine” were included. The reference lists of searched articles were reviewed to identify further eligible articles. Studies focusing on opioid-induced constipation, evaluation, and clinic management of constipation were excluded. The occurrence of constipation is inherently connected to disorders of gut motility as well as fluid and electrolyte transport, which involve the nervous system, endocrine signaling, the gastrointestinal microbiota, ion channels, and aquaporins. The mechanisms of action and application of the main drugs are summarized; a better understanding of ion channels and aquaporins may be helpful for new drug development. This review aims to provide a scientific basis that can guide future research on the etiology and treatment of constipation.
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Affiliation(s)
- Qi Zhao
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Yan-Yan Chen
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Ding-Qiao Xu
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Shi-Jun Yue
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Rui-Jia Fu
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Jie Yang
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Li-Ming Xing
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
| | - Yu-Ping Tang
- Key Laboratory of Shaanxi Administration of Traditional Chinese Medicine for TCM Compatibility, and State Key Laboratory of Research and Development of Characteristic Qin Medicine Resources (Cultivation), and Shaanxi Key Laboratory of Chinese Medicine Fundamentals and New Drugs Research, Shaanxi University of Chinese Medicine, Xi'an, China
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15
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Wen J, Mercado GP, Volland A, Doden HL, Lickwar CR, Crooks T, Kakiyama G, Kelly C, Cocchiaro JL, Ridlon JM, Rawls JF. Fxr signaling and microbial metabolism of bile salts in the zebrafish intestine. SCIENCE ADVANCES 2021; 7:eabg1371. [PMID: 34301599 PMCID: PMC8302129 DOI: 10.1126/sciadv.abg1371] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 06/07/2021] [Indexed: 05/02/2023]
Abstract
Bile salt synthesis, secretion into the intestinal lumen, and resorption in the ileum occur in all vertebrate classes. In mammals, bile salt composition is determined by host and microbial enzymes, affecting signaling through the bile salt-binding transcription factor farnesoid X receptor (Fxr). However, these processes in other vertebrate classes remain poorly understood. We show that key components of hepatic bile salt synthesis and ileal transport pathways are conserved and under control of Fxr in zebrafish. Zebrafish bile salts consist primarily of a C27 bile alcohol and a C24 bile acid that undergo multiple microbial modifications including bile acid deconjugation that augments Fxr activity. Using single-cell RNA sequencing, we provide a cellular atlas of the zebrafish intestinal epithelium and uncover roles for Fxr in transcriptional and differentiation programs in ileal and other cell types. These results establish zebrafish as a nonmammalian vertebrate model for studying bile salt metabolism and Fxr signaling.
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Affiliation(s)
- Jia Wen
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC, USA
| | - Gilberto Padilla Mercado
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC, USA
| | - Alyssa Volland
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Heidi L Doden
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
- Department of Animal Sciences, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Colin R Lickwar
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC, USA
| | - Taylor Crooks
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Genta Kakiyama
- Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Cecelia Kelly
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC, USA
| | - Jordan L Cocchiaro
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC, USA
| | - Jason M Ridlon
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana Champaign, Urbana, IL, USA.
- Department of Animal Sciences, University of Illinois at Urbana Champaign, Urbana, IL, USA
- Division of Nutritional Sciences, University of Illinois at Urbana Champaign, Urbana, IL, USA
- Cancer Center of Illinois, Urbana, IL, USA
| | - John F Rawls
- Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, Durham, NC, USA.
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16
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Takei Y. The digestive tract as an essential organ for water acquisition in marine teleosts: lessons from euryhaline eels. ZOOLOGICAL LETTERS 2021; 7:10. [PMID: 34154668 PMCID: PMC8215749 DOI: 10.1186/s40851-021-00175-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 04/16/2021] [Indexed: 05/17/2023]
Abstract
Adaptation to a hypertonic marine environment is one of the major topics in animal physiology research. Marine teleosts lose water osmotically from the gills and compensate for this loss by drinking surrounding seawater and absorbing water from the intestine. This situation is in contrast to that in mammals, which experience a net osmotic loss of water after drinking seawater. Water absorption in fishes is made possible by (1) removal of monovalent ions (desalinization) by the esophagus, (2) removal of divalent ions as carbonate (Mg/CaCO3) precipitates promoted by HCO3- secretion, and (3) facilitation of NaCl and water absorption from diluted seawater by the intestine using a suite of unique transporters. As a result, 70-85% of ingested seawater is absorbed during its passage through the digestive tract. Thus, the digestive tract is an essential organ for marine teleost survival in the hypertonic seawater environment. The eel is a species that has been frequently used for osmoregulation research in laboratories worldwide. The eel possesses many advantages as an experimental animal for osmoregulation studies, one of which is its outstanding euryhalinity, which enables researchers to examine changes in the structure and function of the digestive tract after direct transfer from freshwater to seawater. In recent years, the molecular mechanisms of ion and water transport across epithelial cells (the transcellular route) and through tight junctions (the paracellular route) have been elucidated for the esophagus and intestine. Thanks to the rapid progress in analytical methods for genome databases on teleosts, including the eel, the molecular identities of transporters, channels, pumps and junctional proteins have been clarified at the isoform level. As 10 y have passed since the previous reviews on this subject, it seems relevant and timely to summarize recent progress in research on the molecular mechanisms of water and ion transport in the digestive tract in eels and to compare the mechanisms with those of other teleosts and mammals from comparative and evolutionary viewpoints. We also propose future directions for this research field to achieve integrative understanding of the role of the digestive tract in adaptation to seawater with regard to pathways/mechanisms including the paracellular route, divalent ion absorption, metabolon formation and cellular trafficking of transporters. Notably, some of these have already attracted practical attention in laboratories.
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Affiliation(s)
- Yoshio Takei
- Laboratory of Physiology, Department of Marine Bioscience, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan.
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17
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Busslinger GA, Weusten BLA, Bogte A, Begthel H, Brosens LAA, Clevers H. Human gastrointestinal epithelia of the esophagus, stomach, and duodenum resolved at single-cell resolution. Cell Rep 2021; 34:108819. [PMID: 33691112 DOI: 10.1016/j.celrep.2021.108819] [Citation(s) in RCA: 137] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 12/23/2020] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
The upper gastrointestinal tract, consisting of the esophagus, stomach, and duodenum, controls food transport, digestion, nutrient uptake, and hormone production. By single-cell analysis of healthy epithelia of these human organs, we molecularly define their distinct cell types. We identify a quiescent COL17A1high KRT15high stem/progenitor cell population in the most basal cell layer of the esophagus and detect substantial gene expression differences between identical cell types of the human and mouse stomach. Selective expression of BEST4, CFTR, guanylin, and uroguanylin identifies a rare duodenal cell type, referred to as BCHE cell, which likely mediates high-volume fluid secretion because of continual activation of the CFTR channel by guanylin/uroguanylin-mediated autocrine signaling. Serotonin-producing enterochromaffin cells in the antral stomach significantly differ in gene expression from duodenal enterochromaffin cells. We, furthermore, discover that the histamine-producing enterochromaffin-like cells in the oxyntic stomach express the luteinizing hormone, yet another member of the enteroendocrine hormone family.
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Affiliation(s)
- Georg A Busslinger
- Hubrecht Institute and Oncode Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), Utrecht, the Netherlands; Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands
| | - Bas L A Weusten
- Department of Gastroenterology and Hepatology, UMC Utrecht, University of Utrecht, Utrecht, the Netherlands
| | - Auke Bogte
- Department of Gastroenterology and Hepatology, UMC Utrecht, University of Utrecht, Utrecht, the Netherlands
| | - Harry Begthel
- Hubrecht Institute and Oncode Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), Utrecht, the Netherlands
| | - Lodewijk A A Brosens
- Department of Pathology, UMC Utrecht, University of Utrecht, Utrecht, the Netherlands
| | - Hans Clevers
- Hubrecht Institute and Oncode Institute, Royal Netherlands Academy of Arts and Sciences (KNAW), Utrecht, the Netherlands; Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands.
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18
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de Jonge HR, Ardelean MC, Bijvelds MJC, Vergani P. Strategies for cystic fibrosis transmembrane conductance regulator inhibition: from molecular mechanisms to treatment for secretory diarrhoeas. FEBS Lett 2020; 594:4085-4108. [PMID: 33113586 PMCID: PMC7756540 DOI: 10.1002/1873-3468.13971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/22/2020] [Accepted: 10/15/2020] [Indexed: 02/06/2023]
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) is an unusual ABC transporter. It acts as an anion‐selective channel that drives osmotic fluid transport across many epithelia. In the gut, CFTR is crucial for maintaining fluid and acid‐base homeostasis, and its activity is tightly controlled by multiple neuro‐endocrine factors. However, microbial toxins can disrupt this intricate control mechanism and trigger protracted activation of CFTR. This results in the massive faecal water loss, metabolic acidosis and dehydration that characterize secretory diarrhoeas, a major cause of malnutrition and death of children under 5 years of age. Compounds that inhibit CFTR could improve emergency treatment of diarrhoeal disease. Drawing on recent structural and functional insight, we discuss how existing CFTR inhibitors function at the molecular and cellular level. We compare their mechanisms of action to those of inhibitors of related ABC transporters, revealing some unexpected features of drug action on CFTR. Although challenges remain, especially relating to the practical effectiveness of currently available CFTR inhibitors, we discuss how recent technological advances might help develop therapies to better address this important global health need.
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Affiliation(s)
- Hugo R. de Jonge
- Department of Gastroenterology & HepatologyErasmus University Medical CenterRotterdamThe Netherlands
| | - Maria C. Ardelean
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonUK
- Department of Natural SciencesUniversity College LondonUK
| | - Marcel J. C. Bijvelds
- Department of Gastroenterology & HepatologyErasmus University Medical CenterRotterdamThe Netherlands
| | - Paola Vergani
- Department of Neuroscience, Physiology and PharmacologyUniversity College LondonUK
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19
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Scott P, Anderson K, Singhania M, Cormier R. Cystic Fibrosis, CFTR, and Colorectal Cancer. Int J Mol Sci 2020; 21:E2891. [PMID: 32326161 PMCID: PMC7215855 DOI: 10.3390/ijms21082891] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/17/2020] [Accepted: 04/19/2020] [Indexed: 02/06/2023] Open
Abstract
Cystic fibrosis (CF), caused by biallelic inactivating mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, has recently been categorized as a familial colorectal cancer (CRC) syndrome. CF patients are highly susceptible to early, aggressive colorectal tumor development. Endoscopic screening studies have revealed that by the age of forty 50% of CF patients will develop adenomas, with 25% developing aggressive advanced adenomas, some of which will have already advanced to adenocarcinomas. This enhanced risk has led to new CF colorectal cancer screening recommendations, lowering the initiation of endoscopic screening to age forty in CF patients, and to age thirty in organ transplant recipients. The enhanced risk for CRC also extends to the millions of people (more than 10 million in the US) who are heterozygous carriers of CFTR gene mutations. Further, lowered expression of CFTR is reported in sporadic CRC, where downregulation of CFTR is associated with poor survival. Mechanisms underlying the actions of CFTR as a tumor suppressor are not clearly understood. Dysregulation of Wnt/β-catenin signaling and disruption of intestinal stem cell homeostasis and intestinal barrier integrity, as well as intestinal dysbiosis, immune cell infiltration, stress responses, and intestinal inflammation have all been reported in human CF patients and in animal models. Notably, the development of new drug modalities to treat non-gastrointestinal pathologies in CF patients, especially pulmonary disease, offers hope that these drugs could be repurposed for gastrointestinal cancers.
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Affiliation(s)
| | | | | | - Robert Cormier
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA; (P.S.); (K.A.); (M.S.)
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20
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What Is the Impact of Diet on Nutritional Diarrhea Associated with Gut Microbiota in Weaning Piglets: A System Review. BIOMED RESEARCH INTERNATIONAL 2019; 2019:6916189. [PMID: 31976326 PMCID: PMC6949732 DOI: 10.1155/2019/6916189] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/19/2019] [Accepted: 12/03/2019] [Indexed: 12/11/2022]
Abstract
Piglets experience severe growth challenges and diarrhea after weaning due to nutritional, social, psychological, environmental, and physiological changes. Among these changes, the nutritional factor plays a key role in postweaning health. Dietary protein, fibre, starch, and electrolyte levels are highly associated with postweaning nutrition diarrhea (PWND). In this review, we mainly discuss the high protein, fibre, resistant starch, and electrolyte imbalance in diets that induce PWND, with a focus on potential mechanisms in weaned piglets.
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21
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Anderson KJ, Cormier RT, Scott PM. Role of ion channels in gastrointestinal cancer. World J Gastroenterol 2019; 25:5732-5772. [PMID: 31636470 PMCID: PMC6801186 DOI: 10.3748/wjg.v25.i38.5732] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 07/26/2019] [Accepted: 09/27/2019] [Indexed: 02/06/2023] Open
Abstract
In their seminal papers Hanahan and Weinberg described oncogenic processes a normal cell undergoes to be transformed into a cancer cell. The functions of ion channels in the gastrointestinal (GI) tract influence a variety of cellular processes, many of which overlap with these hallmarks of cancer. In this review we focus on the roles of the calcium (Ca2+), sodium (Na+), potassium (K+), chloride (Cl-) and zinc (Zn2+) transporters in GI cancer, with a special emphasis on the roles of the KCNQ1 K+ channel and CFTR Cl- channel in colorectal cancer (CRC). Ca2+ is a ubiquitous second messenger, serving as a signaling molecule for a variety of cellular processes such as control of the cell cycle, apoptosis, and migration. Various members of the TRP superfamily, including TRPM8, TRPM7, TRPM6 and TRPM2, have been implicated in GI cancers, especially through overexpression in pancreatic adenocarcinomas and down-regulation in colon cancer. Voltage-gated sodium channels (VGSCs) are classically associated with the initiation and conduction of action potentials in electrically excitable cells such as neurons and muscle cells. The VGSC NaV1.5 is abundantly expressed in human colorectal CRC cell lines as well as being highly expressed in primary CRC samples. Studies have demonstrated that conductance through NaV1.5 contributes significantly to CRC cell invasiveness and cancer progression. Zn2+ transporters of the ZIP/SLC39A and ZnT/SLC30A families are dysregulated in all major GI organ cancers, in particular, ZIP4 up-regulation in pancreatic cancer (PC). More than 70 K+ channel genes, clustered in four families, are found expressed in the GI tract, where they regulate a range of cellular processes, including gastrin secretion in the stomach and anion secretion and fluid balance in the intestinal tract. Several distinct types of K+ channels are found dysregulated in the GI tract. Notable are hERG1 upregulation in PC, gastric cancer (GC) and CRC, leading to enhanced cancer angiogenesis and invasion, and KCNQ1 down-regulation in CRC, where KCNQ1 expression is associated with enhanced disease-free survival in stage II, III, and IV disease. Cl- channels are critical for a range of cellular and tissue processes in the GI tract, especially fluid balance in the colon. Most notable is CFTR, whose deficiency leads to mucus blockage, microbial dysbiosis and inflammation in the intestinal tract. CFTR is a tumor suppressor in several GI cancers. Cystic fibrosis patients are at a significant risk for CRC and low levels of CFTR expression are associated with poor overall disease-free survival in sporadic CRC. Two other classes of chloride channels that are dysregulated in GI cancers are the chloride intracellular channels (CLIC1, 3 & 4) and the chloride channel accessory proteins (CLCA1,2,4). CLIC1 & 4 are upregulated in PC, GC, gallbladder cancer, and CRC, while the CLCA proteins have been reported to be down-regulated in CRC. In summary, it is clear, from the diverse influences of ion channels, that their aberrant expression and/or activity can contribute to malignant transformation and tumor progression. Further, because ion channels are often localized to the plasma membrane and subject to multiple layers of regulation, they represent promising clinical targets for therapeutic intervention including the repurposing of current drugs.
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Affiliation(s)
- Kyle J Anderson
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, United States
| | - Robert T Cormier
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, United States
| | - Patricia M Scott
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, United States
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22
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Rao MC. Physiology of Electrolyte Transport in the Gut: Implications for Disease. Compr Physiol 2019; 9:947-1023. [PMID: 31187895 DOI: 10.1002/cphy.c180011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We now have an increased understanding of the genetics, cell biology, and physiology of electrolyte transport processes in the mammalian intestine, due to the availability of sophisticated methodologies ranging from genome wide association studies to CRISPR-CAS technology, stem cell-derived organoids, 3D microscopy, electron cryomicroscopy, single cell RNA sequencing, transgenic methodologies, and tools to manipulate cellular processes at a molecular level. This knowledge has simultaneously underscored the complexity of biological systems and the interdependence of multiple regulatory systems. In addition to the plethora of mammalian neurohumoral factors and their cross talk, advances in pyrosequencing and metagenomic analyses have highlighted the relevance of the microbiome to intestinal regulation. This article provides an overview of our current understanding of electrolyte transport processes in the small and large intestine, their regulation in health and how dysregulation at multiple levels can result in disease. Intestinal electrolyte transport is a balance of ion secretory and ion absorptive processes, all exquisitely dependent on the basolateral Na+ /K+ ATPase; when this balance goes awry, it can result in diarrhea or in constipation. The key transporters involved in secretion are the apical membrane Cl- channels and the basolateral Na+ -K+ -2Cl- cotransporter, NKCC1 and K+ channels. Absorption chiefly involves apical membrane Na+ /H+ exchangers and Cl- /HCO3 - exchangers in the small intestine and proximal colon and Na+ channels in the distal colon. Key examples of our current understanding of infectious, inflammatory, and genetic diarrheal diseases and of constipation are provided. © 2019 American Physiological Society. Compr Physiol 9:947-1023, 2019.
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Affiliation(s)
- Mrinalini C Rao
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA
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23
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Engevik AC, Kaji I, Engevik MA, Meyer AR, Weis VG, Goldstein A, Hess MW, Müller T, Koepsell H, Dudeja PK, Tyska M, Huber LA, Shub MD, Ameen N, Goldenring JR. Loss of MYO5B Leads to Reductions in Na + Absorption With Maintenance of CFTR-Dependent Cl - Secretion in Enterocytes. Gastroenterology 2018; 155:1883-1897.e10. [PMID: 30144427 PMCID: PMC6279525 DOI: 10.1053/j.gastro.2018.08.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/19/2018] [Accepted: 08/06/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND & AIMS Inactivating mutations in MYO5B cause microvillus inclusion disease (MVID), but the physiological cause of the diarrhea associated with this disease is unclear. We investigated whether loss of MYO5B results in aberrant expression of apical enterocyte transporters. METHODS We studied alterations in apical membrane transporters in MYO5B-knockout mice, as well as mice with tamoxifen-inducible, intestine-specific disruption of Myo5b (VilCreERT2;Myo5bflox/flox mice) or those not given tamoxifen (controls). Intestinal tissues were collected from mice and analyzed by immunostaining, immunoelectron microscopy, or cultured enteroids were derived. Functions of brush border transporters in intestinal mucosa were measured in Ussing chambers. We obtained duodenal biopsy specimens from individuals with MVID and individuals without MVID (controls) and compared transporter distribution by immunocytochemistry. RESULTS Compared to intestinal tissues from littermate controls, intestinal tissues from MYO5B-knockout mice had decreased apical localization of SLC9A3 (also called NHE3), SLC5A1 (also called SGLT1), aquaporin (AQP) 7, and sucrase isomaltase, and subapical localization of intestinal alkaline phosphatase and CDC42. However, CFTR was present on apical membranes of enterocytes from MYO5B knockout and control mice. Intestinal biopsies from patients with MVID had subapical localization of NHE3, SGLT1, and AQP7, but maintained apical CFTR. After tamoxifen administration, VilCreERT2;Myo5bflox/flox mice lost apical NHE3, SGLT1, DRA, and AQP7, similar to germline MYO5B knockout mice. Intestinal tissues from VilCreERT2;Myo5bflox/flox mice had increased CFTR in crypts and CFTR localized to the apical membranes of enterocytes. Intestinal mucosa from VilCreERT2;Myo5bflox/flox mice given tamoxifen did not have an intestinal barrier defect, based on Ussing chamber analysis, but did have decreased SGLT1 activity and increased CFTR activity. CONCLUSIONS Although trafficking of many apical transporters is regulated by MYO5B, trafficking of CFTR is largely independent of MYO5B. Decreased apical localization of NHE3, SGLT1, DRA, and AQP7 might be responsible for dysfunctional water absorption in enterocytes of patients with MVID. Maintenance of apical CFTR might exacerbate water loss by active secretion of chloride into the intestinal lumen.
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Affiliation(s)
- Amy C Engevik
- Departments of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Izumi Kaji
- Departments of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Melinda A Engevik
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas; Department of Pathology, Texas Children's Hospital, Houston, Texas
| | - Anne R Meyer
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee; Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Victoria G Weis
- Departments of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Anna Goldstein
- Departments of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee; Nashville Veterans Affairs Medical Center, Nashville, Tennessee
| | - Michael W Hess
- Division of Histology and Embryology, Innsbruck Medical University, Innsbruck, Austria
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Hermann Koepsell
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | - Pradeep K Dudeja
- Department of Medicine, University of Illinois, Chicago and the Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Matthew Tyska
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee; Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Lukas A Huber
- Division of Cell Biology, Biocenter and Innsbruck Medical University, Innsbruck, Austria; Austrian Drug Screening Institute, Innsbruck, Austria
| | - Mitchell D Shub
- Division of Gastroenterology and Phoenix Children's Hospital and the Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona
| | - Nadia Ameen
- Department of Pediatrics, Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
| | - James R Goldenring
- Departments of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee; Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee; Nashville Veterans Affairs Medical Center, Nashville, Tennessee.
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Ratchford TL, Teckman JH, Patel DR. Gastrointestinal pathophysiology and nutrition in cystic fibrosis. Expert Rev Gastroenterol Hepatol 2018; 12:853-862. [PMID: 30019967 DOI: 10.1080/17474124.2018.1502663] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cystic fibrosis (CF) is a severe, progressive, multisystemic disease that is caused by mutations in the cystic fibrosis transmembrane conductance regulator gene. Optimizing nutrition is critical, as higher growth parameters are associated with better pulmonary function and outcomes, but unfortunately patients with this disease are prone to malnutrition, growth failure, and vitamin deficiencies. The purpose of this review is to provide a timely highlight of the physiologic processes and outcome data to support today's management strategies, as well as review these principles themselves. Areas covered: This review covers the background of the importance of vigilant attention to nutrition and growth in these patients, the underlying physiology leading to an abnormal gastrointestinal tract and its role in CF malnutrition, and current evaluation and management strategies to address nutrition in CF. Analysis of up-to-date relevant literature was performed using PubMed. Expert commentary: Advances in research and clinical developments over the years have improved knowledge of this disease as well as patient outcomes. Of particular importance is optimizing nutrition especially in the early stages of life, as well as accounting for the markedly abnormal CF intestinal milieu when addressing the gastrointestinal and nutritional needs of these patients.
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Affiliation(s)
- Thomas L Ratchford
- a Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition , Saint Louis University School of Medicine , Saint Louis , Missouri , USA
| | - Jeffrey H Teckman
- a Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition , Saint Louis University School of Medicine , Saint Louis , Missouri , USA
| | - Dhiren R Patel
- a Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition , Saint Louis University School of Medicine , Saint Louis , Missouri , USA
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Jantarajit W, Lertsuwan K, Teerapornpuntakit J, Krishnamra N, Charoenphandhu N. CFTR-mediated anion secretion across intestinal epithelium-like Caco-2 monolayer under PTH stimulation is dependent on intermediate conductance K + channels. Am J Physiol Cell Physiol 2017; 313:C118-C129. [PMID: 28490422 DOI: 10.1152/ajpcell.00010.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 12/16/2022]
Abstract
Parathyroid hormone (PTH), a pleiotropic hormone that maintains mineral homeostasis, is also essential for controlling pH balance and ion transport across renal and intestinal epithelia. Optimization of luminal pH is important for absorption of trace elements, e.g., calcium and phosphorus. We have previously demonstrated that PTH rapidly stimulated electrogenic [Formula: see text] secretion in intestinal epithelial-like Caco-2 monolayers, but the underlying cellular mechanism, contributions of other ions, particularly Cl- and K+, and long-lasting responses are not completely understood. Herein, PTH and forskolin were confirmed to induce anion secretion, which peaked within 1-3 min (early phase), followed by an abrupt decay and plateau that lasted for 60 min (late phase). In both early and late phases, apical membrane capacitance was increased with a decrease in basolateral capacitance after PTH or forskolin exposure. PTH also induced a transient increase in apical conductance with a long-lasting decrease in basolateral conductance. Anion secretion in both phases was reduced under [Formula: see text]-free and/or Cl--free conditions or after exposure to carbonic anhydrase inhibitor (acetazolamide), CFTR inhibitor (CFTRinh-172), Na+/H+ exchanger (NHE)-3 inhibitor (tenapanor), or K+ channel inhibitors (BaCl2, clotrimazole, and TRAM-34; basolateral side), the latter of which suggested that PTH action was dependent on basolateral K+ recycling. Furthermore, early- and late-phase responses to PTH were diminished by inhibitors of PI3K (wortmannin and LY-294002) and PKA (PKI 14-22). In conclusion, PTH requires NHE3 and basolateral K+ channels to induce [Formula: see text] and Cl- secretion, thus explaining how PTH regulated luminal pH balance and pH-dependent absorption of trace minerals.
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Affiliation(s)
- Walailak Jantarajit
- Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Kornkamon Lertsuwan
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand; and
| | | | - Nateetip Krishnamra
- Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok, Thailand.,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Narattaphol Charoenphandhu
- Center of Calcium and Bone Research, Faculty of Science, Mahidol University, Bangkok, Thailand; .,Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand.,Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
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26
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Kravtsov DV, Ahsan MK, Kumari V, van Ijzendoorn SCD, Reyes-Mugica M, Kumar A, Gujral T, Dudeja PK, Ameen NA. Identification of intestinal ion transport defects in microvillus inclusion disease. Am J Physiol Gastrointest Liver Physiol 2016; 311:G142-55. [PMID: 27229121 PMCID: PMC4967175 DOI: 10.1152/ajpgi.00041.2016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 05/08/2016] [Indexed: 01/31/2023]
Abstract
Loss of function mutations in the actin motor myosin Vb (Myo5b) lead to microvillus inclusion disease (MVID) and death in newborns and children. MVID results in secretory diarrhea, brush border (BB) defects, villus atrophy, and microvillus inclusions (MVIs) in enterocytes. How loss of Myo5b results in increased stool loss of chloride (Cl(-)) and sodium (Na(+)) is unknown. The present study used Myo5b loss-of-function human MVID intestine, polarized intestinal cell models of secretory crypt (T84) and villus resembling (CaCo2BBe, C2BBe) enterocytes lacking Myo5b in conjunction with immunofluorescence confocal stimulated emission depletion (gSTED) imaging, immunohistochemical staining, transmission electron microscopy, shRNA silencing, immunoblots, and electrophysiological approaches to examine the distribution, expression, and function of the major BB ion transporters NHE3 (Na(+)), CFTR (Cl(-)), and SLC26A3 (DRA) (Cl(-)/HCO3 (-)) that control intestinal fluid transport. We hypothesized that enterocyte maturation defects lead villus atrophy with immature secretory cryptlike enterocytes in the MVID epithelium. We investigated the role of Myo5b in enterocyte maturation. NHE3 and DRA localization and function were markedly reduced on the BB membrane of human MVID enterocytes and Myo5bKD C2BBe cells, while CFTR localization was preserved. Forskolin-stimulated CFTR ion transport in Myo5bKD T84 cells resembled that of control. Loss of Myo5b led to YAP1 nuclear retention, retarded enterocyte maturation, and a cryptlike phenotype. We conclude that preservation of functional CFTR in immature enterocytes, reduced functional expression of NHE3, and DRA contribute to Cl(-) and Na(+) stool loss in MVID diarrhea.
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Affiliation(s)
- Dmitri V. Kravtsov
- 1Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, Connecticut;
| | - Md Kaimul Ahsan
- 1Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, Connecticut;
| | - Vandana Kumari
- 1Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, Connecticut;
| | - Sven C. D. van Ijzendoorn
- 2Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands;
| | | | - Anoop Kumar
- 4Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; and
| | - Tarunmeet Gujral
- 4Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; and
| | - Pradeep K. Dudeja
- 4Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; and
| | - Nadia A. Ameen
- 1Department of Pediatrics/Gastroenterology and Hepatology, Yale School of Medicine, New Haven, Connecticut; ,5Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut
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27
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Barrett KE. Endogenous and exogenous control of gastrointestinal epithelial function: building on the legacy of Bayliss and Starling. J Physiol 2016; 595:423-432. [PMID: 27284010 DOI: 10.1113/jp272227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/12/2016] [Indexed: 12/21/2022] Open
Abstract
Transport of fluid and electrolytes in the intestine allows for appropriate adjustments in luminal fluidity while reclaiming water used in digesting and absorbing a meal, and is closely regulated. This article discusses various endogenous and exogenous mechanisms whereby transport is controlled in the gut, placing these in the context of the ideas about the neurohumoral control of alimentary physiology that were promulgated by William Bayliss and Ernest Starling. The article considers three themes. First, mechanisms that intrinsically regulate chloride secretion, centred on the epidermal growth factor receptor (EGFr), are discussed. These may be important in ensuring that excessive chloride secretion, with the accompanying loss of fluid, is not normally stimulated by intestinal distension as the meal passes through the gastrointestinal tract. Second, mechanisms whereby probiotic microorganisms can impart beneficial effects on the gut are described, with a focus on targets at the level of the epithelium. These findings imply that the commensal microbiota exert important influences on the epithelium in health and disease. Finally, mechanisms that lead to diarrhoea in patients infected with an invasive pathogen, Salmonella, are considered, based on recent studies in a novel mouse model. Diarrhoea is most likely attributable to reduced expression of absorptive transporters and may not require the influx of neutrophils that accompanies infection. Overall, the goal of the article is to highlight the many ways in which critical functions of the intestinal epithelium are regulated under physiological and pathophysiological conditions, and to suggest possible targets for new therapies for digestive disease states.
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Affiliation(s)
- Kim E Barrett
- Department of Medicine and Biomedical Sciences Ph.D. Program, School of Medicine, University of California, La Jolla, San Diego, CA, USA
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28
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Asghar MN, Priyamvada S, Nyström JH, Anbazhagan AN, Dudeja PK, Toivola DM. Keratin 8 knockdown leads to loss of the chloride transporter DRA in the colon. Am J Physiol Gastrointest Liver Physiol 2016; 310:G1147-54. [PMID: 27125276 PMCID: PMC4935477 DOI: 10.1152/ajpgi.00354.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/23/2016] [Indexed: 02/06/2023]
Abstract
Keratins (K) are intermediate filament proteins important in protection from stress. The roles of keratins in the intestine are not clear, but K8 knockout (K8(-/-)) mice develop a Th2-type colonic inflammation, epithelial hyperproliferation, and mild diarrhea caused by a keratin level-dependent decrease in short-circuit current and net sodium and chloride absorption in the distal colon. The lack of K8 leads to mistargeting or altered levels of membrane proteins in colonocytes; however, the main transporter responsible for the keratin-related ion transport defect is unknown. We here analyzed protein and mRNA levels of candidate ion transporters CFTR, PAT-1, NHE-3, and DRA in ileum, cecum, and proximal and distal colon. Although no differences were observed for CFTR, PAT-1, or NHE-3, DRA mRNA levels were decreased by three- to fourfold and DRA protein was almost entirely lost in K8(-/-) cecum and proximal and distal colon compared with K8(+/+), whereas the levels in ileum were normal. In K8(+/-) mice, DRA mRNA levels were unaltered, while decreased DRA protein levels were detected in the proximal colon. Immunofluorescence staining confirmed the loss of DRA in K8(-/-) distal colon, while K8(+/-) displayed a similar but more patchy apical DRA distribution compared with K8(+/+) DRA was similarly decreased when K8 was knocked down in Caco-2 cells, confirming that K8 levels modulate DRA levels in an inflammation-independent manner. Taken together, the loss of DRA in the K8(-/-) mouse colon and cecum explains the dramatic chloride transport defect and diarrheal phenotype after K8 inactivation and identifies K8 as a novel regulator of DRA.
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Affiliation(s)
- M. Nadeem Asghar
- 1Cell Biology, Biosciences, Faculty of Science and Engineering, Åbo Akademi University and Turku Center for Disease Modeling, University of Turku, Turku, Finland; and
| | - Shubha Priyamvada
- 2University of Illinois at Chicago, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Joel H. Nyström
- 1Cell Biology, Biosciences, Faculty of Science and Engineering, Åbo Akademi University and Turku Center for Disease Modeling, University of Turku, Turku, Finland; and
| | | | - Pradeep K. Dudeja
- 2University of Illinois at Chicago, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| | - Diana M. Toivola
- 1Cell Biology, Biosciences, Faculty of Science and Engineering, Åbo Akademi University and Turku Center for Disease Modeling, University of Turku, Turku, Finland; and
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29
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Xia W, Yu Q, Riederer B, Singh AK, Engelhardt R, Yeruva S, Song P, Tian DA, Soleiman M, Seidler U. The distinct roles of anion transporters Slc26a3 (DRA) and Slc26a6 (PAT-1) in fluid and electrolyte absorption in the murine small intestine. Pflugers Arch 2015; 466:1541-56. [PMID: 24233434 PMCID: PMC4092241 DOI: 10.1007/s00424-013-1381-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 01/06/2023]
Abstract
The mixing of gastric and pancreatic juice subjects the jejunum to unique ionic conditions with high luminal CO2 tension and HCO3− concentration. We investigated the role of the small intestinal apical anion exchangers PAT-1 (Slc26a6) and DRA (Slc26a3) in basal and CO2/HCO3−-stimulated jejunal fluid absorption. Single pass perfusion of jejunal segments was performed in anaesthetised wild type (WT) as well as in mice deficient in DRA, PAT-1, Na+/H+ exchanger 3 (NHE3) or NHE2, and in carbonic anhydrase II (CAII). Unbuffered saline (pH 7.4) perfusion of WT jejunum resulted in fluid absorption and acidification of the effluent. DRA-deficient jejunum absorbed less fluid than WT, and acidified the effluent more strongly, consistent with its action as a Cl−/HCO3− exchanger. PAT-1-deficient jejunum also absorbed less fluid but resulted in less effluent acidification. Switching the luminal solution to a 5 % CO2/HCO3− buffered solution (pH 7.4), resulted in a decrease in jejunal enterocyte pHi in all genotypes, an increase in luminal surface pH and a strong increase in fluid absorption in a PAT-1- and NHE3- but not DRA-, CAII, or NHE2-dependent fashion. Even in the absence of luminal Cl−, luminal CO2/HCO3− augmented fluid absorption in WT, CAII, NHE2- or DRA-deficient, but not in PAT-1- or NHE3-deficient mice, indicating the likelihood that PAT-1 serves to import HCO3− and NHE3 serves to import Na+ under these circumstances. The results suggest that PAT-1 plays an important role in jejunal Na+HCO3– reabsorption, while DRA absorbs Cl− and exports HCO3− in a partly CAII-dependent fashion. Both PAT-1 and DRA significantly contribute to intestinal fluid absorption and enterocyte acid/base balance but are activated by different ion gradients.
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30
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Digestive system dysfunction in cystic fibrosis: challenges for nutrition therapy. Dig Liver Dis 2014; 46:865-74. [PMID: 25053610 DOI: 10.1016/j.dld.2014.06.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/10/2014] [Accepted: 06/28/2014] [Indexed: 02/08/2023]
Abstract
Cystic fibrosis can affect food digestion and nutrient absorption. The underlying mutation of the cystic fibrosis trans-membrane regulator gene depletes functional cystic fibrosis trans-membrane regulator on the surface of epithelial cells lining the digestive tract and associated organs, where Cl(-) secretion and subsequently secretion of water and other ions are impaired. This alters pH and dehydrates secretions that precipitate and obstruct the lumen, causing inflammation and the eventual degradation of the pancreas, liver, gallbladder and intestine. Associated conditions include exocrine pancreatic insufficiency, impaired bicarbonate and bile acid secretion and aberrant mucus formation, commonly leading to maldigestion and malabsorption, particularly of fat and fat-soluble vitamins. Pancreatic enzyme replacement therapy is used to address this insufficiency. The susceptibility of pancreatic lipase to acidic and enzymatic inactivation and decreased bile availability often impedes its efficacy. Brush border digestive enzyme activity and intestinal uptake of certain disaccharides and amino acids await clarification. Other complications that may contribute to maldigestion/malabsorption include small intestine bacterial overgrowth, enteric circular muscle dysfunction, abnormal intestinal mucus, and intestinal inflammation. However, there is some evidence that gastric digestive enzymes, colonic microflora, correction of fatty acid abnormalities using dietary n-3 polyunsaturated fatty acid supplementation and emerging intestinal biomarkers can complement nutrition management in cystic fibrosis.
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31
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Collaco AM, Geibel P, Lee BS, Geibel JP, Ameen NA. Functional vacuolar ATPase (V-ATPase) proton pumps traffic to the enterocyte brush border membrane and require CFTR. Am J Physiol Cell Physiol 2013; 305:C981-96. [PMID: 23986201 DOI: 10.1152/ajpcell.00067.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Vacuolar ATPases (V-ATPases) are highly conserved proton pumps that regulate organelle pH. Epithelial luminal pH is also regulated by cAMP-dependent traffic of specific subunits of the V-ATPase complex from endosomes into the apical membrane. In the intestine, cAMP-dependent traffic of cystic fibrosis transmembrane conductance regulator (CFTR) channels and the sodium hydrogen exchanger (NHE3) in the brush border regulate luminal pH. V-ATPase was found to colocalize with CFTR in intestinal CFTR high expresser (CHE) cells recently. Moreover, apical traffic of V-ATPase and CFTR in rat Brunner's glands was shown to be dependent on cAMP/PKA. These observations support a functional relationship between V-ATPase and CFTR in the intestine. The current study examined V-ATPase and CFTR distribution in intestines from wild-type, CFTR(-/-) mice and polarized intestinal CaCo-2BBe cells following cAMP stimulation and inhibition of CFTR/V-ATPase function. Coimmunoprecipitation studies examined V-ATPase interaction with CFTR. The pH-sensitive dye BCECF determined proton efflux and its dependence on V-ATPase/CFTR in intestinal cells. cAMP increased V-ATPase/CFTR colocalization in the apical domain of intestinal cells and redistributed the V-ATPase Voa1 and Voa2 trafficking subunits from the basolateral membrane to the brush border membrane. Voa1 and Voa2 subunits were localized to endosomes beneath the terminal web in untreated CFTR(-/-) intestine but redistributed to the subapical cytoplasm following cAMP treatment. Inhibition of CFTR or V-ATPase significantly decreased pHi in cells, confirming their functional interdependence. These data establish that V-ATPase traffics into the brush border membrane to regulate proton efflux and this activity is dependent on CFTR in the intestine.
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Affiliation(s)
- Anne M Collaco
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
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