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Kaji I, Thiagarajah JR, Goldenring JR. Modeling the cell biology of monogenetic intestinal epithelial disorders. J Cell Biol 2024; 223:e202310118. [PMID: 38683247 PMCID: PMC11058565 DOI: 10.1083/jcb.202310118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/02/2024] [Accepted: 04/15/2024] [Indexed: 05/01/2024] Open
Abstract
Monogenetic variants are responsible for a range of congenital human diseases. Variants in genes that are important for intestinal epithelial function cause a group of disorders characterized by severe diarrhea and loss of nutrient absorption called congenital diarrheas and enteropathies (CODEs). CODE-causing genes include nutrient transporters, enzymes, structural proteins, and vesicular trafficking proteins in intestinal epithelial cells. Several severe CODE disorders result from the loss-of-function in key regulators of polarized endocytic trafficking such as the motor protein, Myosin VB (MYO5B), as well as STX3, STXBP2, and UNC45A. Investigations of the cell biology and pathophysiology following loss-of-function in these genes have led to an increased understanding of both homeostatic and pathological vesicular trafficking in intestinal epithelial cells. Modeling different CODEs through investigation of changes in patient tissues, coupled with the development of animal models and patient-derived enteroids, has provided critical insights into the enterocyte differentiation and function. Linking basic knowledge of cell biology with the phenotype of specific patient variants is a key step in developing effective treatments for rare monogenetic diseases. This knowledge can also be applied more broadly to our understanding of common epithelial disorders.
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Affiliation(s)
- Izumi Kaji
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jay R. Thiagarajah
- Division of Gastroenterology, Hepatology and Nutrition, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Congenital Enteropathy Program, Boston Children’s Hospital, Boston, MA, USA
- Harvard Digestive Disease Center, Boston, MA, USA
| | - James R. Goldenring
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
- Nashville VA Medical Center, Nashville, TN, USA
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2
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Avitzur Y, Jimenez L, Martincevic I, Acra S, Courtney-Martin G, Gray M, Hope K, Muise A, Prieto Jimenez PM, Taylor N, Thiagarajah JR, Martín MG. Diet management in congenital diarrheas and enteropathies - general concepts and disease-specific approach, a narrative review. Am J Clin Nutr 2024:S0002-9165(24)00466-0. [PMID: 38734141 DOI: 10.1016/j.ajcnut.2024.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 04/27/2024] [Accepted: 05/06/2024] [Indexed: 05/13/2024] Open
Abstract
Congenital diarrheas and enteropathies (CODE) are a group of rare, heterogenous, monogenic disorders that lead to chronic diarrhea in infancy. Definitive treatment is rarely available, and supportive treatment is the mainstay. Nutritional management in the form of either specialized formulas, restrictive diet, or parenteral nutrition support in CODE with poor enteral tolerance is the cornerstone of CODE treatment and long-term growth. The evidence to support the use of specific diet regimens and nutritional approaches in most CODE disorders is limited due to the rarity of these diseases and the scant published clinical experience. The goal of this review was to create a comprehensive guide for nutritional management in CODE, based on the currently available literature, disease mechanism, and the PediCODE group experience. Enteral diet management in CODE can be divided into 3 distinct conceptual frameworks: nutrient elimination, nutrient supplementation, and generalized nutrient restriction. Response to nutrient elimination or supplementation can lead to resolution or significant improvement in the chronic diarrhea of CODE and resumption of normal growth. This pattern can be seen in CODE due to carbohydrate malabsorption, defects in fat absorption, and occasionally in electrolyte transport defects. In contrast, general diet restriction is mainly supportive. However, occasionally it allows parenteral nutrition weaning or reduction over time, mainly in enteroendocrine defects and rarely in epithelial trafficking and polarity defects. Further research is required to better elucidate the role of diet in the treatment of CODE and the appropriate diet management for each disease.
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Affiliation(s)
- Yaron Avitzur
- Group for Improvement of Gastrointestinal Function and Treatment (GIFT), Transplant and Regenerative Centre, SickKids Hospital, Toronto, ON, Canada; Division of Gastroenterology, Hepatology and Nutrition, SickKids Hospital, University of Toronto, Toronto, ON, Canada.
| | - Lissette Jimenez
- Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States; Congenital Enteropathy Program, Boston Children's Hospital, Boston, MA, United States;; Harvard Digestive Disease Center, Boston MA, United States
| | - Inez Martincevic
- Division of Gastroenterology, Hepatology and Nutrition, SickKids Hospital, University of Toronto, Toronto, ON, Canada
| | - Sari Acra
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Glenda Courtney-Martin
- Group for Improvement of Gastrointestinal Function and Treatment (GIFT), Transplant and Regenerative Centre, SickKids Hospital, Toronto, ON, Canada; Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - Megan Gray
- Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Kayla Hope
- Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Aleixo Muise
- Division of Gastroenterology, Hepatology and Nutrition, SickKids Hospital, University of Toronto, Toronto, ON, Canada
| | - Paula M Prieto Jimenez
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and the David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States
| | - Nancy Taylor
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Jay R Thiagarajah
- Division of Gastroenterology, Hepatology and Nutrition, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States; Congenital Enteropathy Program, Boston Children's Hospital, Boston, MA, United States;; Harvard Digestive Disease Center, Boston MA, United States
| | - Martín G Martín
- Division of Gastroenterology and Nutrition, Department of Pediatrics, Mattel Children's Hospital and the David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States.
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Granulo N, Sosnin S, Digles D, Ecker GF. The macrocycle inhibitor landscape of SLC-transporter. Mol Inform 2024; 43:e202300287. [PMID: 38288682 DOI: 10.1002/minf.202300287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/08/2024] [Accepted: 01/29/2024] [Indexed: 03/06/2024]
Abstract
In the past years the interest in Solute Carrier Transporters (SLC) has increased due to their potential as drug targets. At the same time, macrocycles demonstrated promising activities as therapeutic agents. However, the overall macrocycle/SLC-transporter interaction landscape has not been fully revealed yet. In this study, we present a statistical analysis of macrocycles with measured activity against SLC-transporter. Using a data mining pipeline based on KNIME retrieved in total 825 bioactivity data points of macrocycles interacting with SLC-transporter. For further analysis of the SLC inhibitor profiles we developed an interactive KNIME workflow as well as an interactive map of the chemical space coverage utilizing parametric t-SNE models. The parametric t-SNE models provide a good discrimination ability among several corresponding SLC subfamilies' targets. The KNIME workflow, the dataset, and the visualization tool are freely available to the community.
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Affiliation(s)
- Nejra Granulo
- Department of Pharmaceutical Sciences, University of Vienna, Josef Holaubek Platz 2, 1090, Vienna, Austria
- Research Platform NeGeMac-Next Generation Macrocycles to Address Challenging Protein Interfaces, University of Vienna, 1090, Vienna, Austria
| | - Sergey Sosnin
- Department of Pharmaceutical Sciences, University of Vienna, Josef Holaubek Platz 2, 1090, Vienna, Austria
| | - Daniela Digles
- Department of Pharmaceutical Sciences, University of Vienna, Josef Holaubek Platz 2, 1090, Vienna, Austria
| | - Gerhard F Ecker
- Department of Pharmaceutical Sciences, University of Vienna, Josef Holaubek Platz 2, 1090, Vienna, Austria
- Research Platform NeGeMac-Next Generation Macrocycles to Address Challenging Protein Interfaces, University of Vienna, 1090, Vienna, Austria
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4
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Chen L, Yi H, Li Q, Duan T, Liu X, Li L, Wang HY, Xing C, Wang RF. T-bet Regulates Ion Channels and Transporters and Induces Apoptosis in Intestinal Epithelial Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2401654. [PMID: 38650111 DOI: 10.1002/advs.202401654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [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 Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of General Surgery, Third Xiangya Hospital, Xiangya School of Medicine, Central South University, Changsha, 410013, China
| | - Hongwei Yi
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Pharmacology, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Qingtian Li
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Tianhao Duan
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Xin Liu
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Linfeng Li
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Thoracic Surgery, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Helen Y Wang
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Changsheng Xing
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Rong-Fu Wang
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, 77030, USA
- Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90027, USA
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
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5
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Huang N, Wang Q, Bernard RB, Chen CY, Hu JM, Wang JK, Chan KS, Johnson MD, Lin CY. SPINT2 mutations in the Kunitz domain 2 found in SCSD patients inactivate HAI-2 as prostasin inhibitor via abnormal protein folding and N-glycosylation. Hum Mol Genet 2024; 33:752-767. [PMID: 38271183 PMCID: PMC11031362 DOI: 10.1093/hmg/ddae005] [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: 03/04/2023] [Revised: 11/30/2023] [Accepted: 01/05/2024] [Indexed: 01/27/2024] Open
Abstract
Mutations in the Kunitz-type serine protease inhibitor HAI-2, encoded by SPINT2, are responsible for the pathogenesis of syndromic congenital sodium diarrhea (SCSD), an intractable secretory diarrhea of infancy. Some of the mutations cause defects in the functionally required Kunitz domain 1 and/or subcellular targeting signals. Almost all SCSD patients, however, harbor SPINT2 missense mutations that affect the functionally less important Kunitz domain 2. How theses single amino acid substitutions inactivate HAI-2 was, here, investigated by the doxycycline-inducible expression of three of these mutants in HAI-2-knockout Caco-2 human colorectal adenocarcinoma cells. Examining protein expressed from these HAI-2 mutants reveals that roughly 50% of the protein is synthesized as disulfide-linked oligomers that lose protease inhibitory activity due to the distortion of the Kunitz domains by disarrayed disulfide bonding. Although the remaining protein is synthesized as monomers, its glycosylation status suggests that the HAI-2 monomer remains in the immature, lightly glycosylated form, and is not converted to the heavily glycosylated mature form. Heavily glycosylated HAI-2 possesses full anti-protease activity and appropriate subcellular targeting signals, including the one embedded in the complex-type N-glycan. As predicted, these HAI-2 mutants cannot suppress the excessive prostasin proteolysis caused by HAI-2 deletion. The oligomerization and glycosylation defects have also been observed in a colorectal adenocarcinoma line that harbors one of these SPINT2 missense mutations. Our study reveals that the abnormal protein folding and N-glycosylation can cause widespread HAI-2 inactivation in SCSD patents.
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Affiliation(s)
- Nanxi Huang
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, 3970 Reservoir Road NW W422 New Research Building, Washington DC 20057, United States
| | - Qiaochu Wang
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, 3970 Reservoir Road NW W422 New Research Building, Washington DC 20057, United States
| | - Robert B Bernard
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, 3970 Reservoir Road NW W422 New Research Building, Washington DC 20057, United States
| | - Chao-Yang Chen
- School of Medicine, National Defense Medical Center, No. 161, sec. 6, Minquan E. Road, Neihu Dist. Taipei City 11490, Taiwan, ROC
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, No. 325, Sec. 2, Chenggon Road, Neihu Dist. Taipei City 114202, Taiwan, ROC
| | - Je-Ming Hu
- School of Medicine, National Defense Medical Center, No. 161, sec. 6, Minquan E. Road, Neihu Dist. Taipei City 11490, Taiwan, ROC
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, No. 325, Sec. 2, Chenggon Road, Neihu Dist. Taipei City 114202, Taiwan, ROC
- Graduate Institute of Medical Sciences, National Defense Medical Center, No. 161, sec. 6, Minquan E. Neihu Dist. Taipei City 11490, Taiwan, ROC
| | - Jehng-Kang Wang
- Department of Biochemistry, National Defense Medical Center, No. 161, sec. 6, Minquan E. Road, Taipei City, 11490, Taiwan, ROC
| | - Khee-Siang Chan
- Department of Intensive Care Medicine, Chi Mei Medical Center, No. 901, Zhonghua Road, Yongkang Dist., Tainan City, 71004, Taiwan, ROC
| | - Michael D Johnson
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, 3970 Reservoir Road NW W422 New Research Building, Washington DC 20057, United States
| | - Chen-Yong Lin
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University, 3970 Reservoir Road NW W422 New Research Building, Washington DC 20057, United States
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6
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Mann ER, Lam YK, Uhlig HH. Short-chain fatty acids: linking diet, the microbiome and immunity. Nat Rev Immunol 2024:10.1038/s41577-024-01014-8. [PMID: 38565643 DOI: 10.1038/s41577-024-01014-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2024] [Indexed: 04/04/2024]
Abstract
The short-chain fatty acids (SCFAs) butyrate, propionate and acetate are microbial metabolites and their availability in the gut and other organs is determined by environmental factors, such as diet and use of antibiotics, that shape the diversity and metabolism of the microbiota. SCFAs regulate epithelial barrier function as well as mucosal and systemic immunity via evolutionary conserved processes that involve G protein-coupled receptor signalling or histone deacetylase activity. Indicatively, the anti-inflammatory role of butyrate is mediated through direct effects on the differentiation of intestinal epithelial cells, phagocytes, B cells and plasma cells, and regulatory and effector T cells. Intestinally derived SCFAs also directly and indirectly affect immunity at extra-intestinal sites, such as the liver, the lungs, the reproductive tract and the brain, and have been implicated in a range of disorders, including infections, intestinal inflammation, autoimmunity, food allergies, asthma and responses to cancer therapies. An ecological understanding of microbial communities and their interrelated metabolic states, as well as the engineering of butyrogenic bacteria may support SCFA-focused interventions for the prevention and treatment of immune-mediated diseases.
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Affiliation(s)
- Elizabeth R Mann
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Ying Ka Lam
- Translational Gastroenterology Unit, University of Oxford, Oxford, UK
| | - Holm H Uhlig
- Translational Gastroenterology Unit, University of Oxford, Oxford, UK.
- Department of Paediatrics, University of Oxford, Oxford, UK.
- Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.
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7
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Dominguez Rieg JA, Rieg T. New functions and roles of the Na +-H +-exchanger NHE3. Pflugers Arch 2024; 476:505-516. [PMID: 38448727 DOI: 10.1007/s00424-024-02938-9] [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: 02/05/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/08/2024]
Abstract
The sodium/proton exchanger isoform 3 (NHE3) is expressed in the intestine and the kidney, where it contributes to hydrogen secretion and sodium (re)absorption. The roles of this transporter have been studied by the use of the respective knockout mice and by using pharmacological inhibitors. Whole-body NHE3 knockout mice suffer from a high mortality rate (with only ∼30% of mice surviving into adulthood), and based on the expression of NHE3 in both intestine and kidney, some conclusions that were originally derived were based on this rather complex phenotype. In the last decade, more refined models have been developed that added temporal and spatial control of NHE3 expression. For example, novel mouse models have been developed with a knockout of NHE3 in intestinal epithelial cells, tubule/collecting duct of the kidney, proximal tubule of the kidney, and thick ascending limb of the kidney. These refined models have significantly contributed to our understanding of the role of NHE3 in a tissue/cell type-specific manner. In addition, tenapanor was developed, which is a non-absorbable, intestine-specific NHE3 inhibitor. In rat and human studies, tenapanor lowered intestinal Pi uptake and was effective in lowering plasma Pi levels in patients on hemodialysis. Of note, diarrhea is seen as a side effect of tenapanor (with its indication for the treatment of constipation) and in intestine-specific NHE3 knockout mice; however, effects on plasma Pi were not supported by this mouse model which showed enhanced and not reduced intestinal Pi uptake. Further studies indicated that the gut microbiome in mice lacking intestinal NHE3 resembles an intestinal environment favoring the competitive advantage of inflammophilic over anti-inflammatory species, something similar seen in patients with inflammatory bowel disease. This review will highlight recent developments and summarize newly gained insight from these refined models.
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Affiliation(s)
- Jessica A Dominguez Rieg
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
- James A. Haley Veterans' Hospital, Tampa, FL, 33612, USA
- Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, 33602, USA
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
- James A. Haley Veterans' Hospital, Tampa, FL, 33612, USA.
- Hypertension and Kidney Research Center, University of South Florida, Tampa, FL, 33602, USA.
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8
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Ouahed JD, Griffith A, Collen LV, Snapper SB. Breaking Down Barriers: Epithelial Contributors to Monogenic IBD Pathogenesis. Inflamm Bowel Dis 2024:izad319. [PMID: 38280053 DOI: 10.1093/ibd/izad319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Indexed: 01/29/2024]
Abstract
Monogenic causes of inflammatory bowel diseases (IBD) are increasingly being discovered. To date, much attention has been placed in those resulting from inborn errors of immunity. Therapeutic efforts have been largely focused on offering personalized immune modulation or curative bone marrow transplant for patients with IBD and underlying immune disorders. To date, less emphasis has been placed on monogenic causes of IBD that pertain to impairment of the intestinal epithelial barrier. Here, we provide a comprehensive review of monogenic causes of IBD that result in impaired intestinal epithelial barrier that are categorized into 6 important functions: (1) epithelial cell organization, (2) epithelial cell intrinsic functions, (3) epithelial cell apoptosis and necroptosis, (4) complement activation, (5) epithelial cell signaling, and (6) control of RNA degradation products. We illustrate how impairment of any of these categories can result in IBD. This work reviews the current understanding of the genes involved in maintaining the intestinal barrier, the inheritance patterns that result in dysfunction, features of IBD resulting from these disorders, and pertinent translational work in this field.
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Affiliation(s)
- Jodie D Ouahed
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Alexandra Griffith
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lauren V Collen
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Scott B Snapper
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Division of Gastroenterology, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MA, USA
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9
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Han Y, Bagchi P, Yun CC. Regulation of the intestinal Na +/H + exchanger NHE3 by AMP-activated kinase is dependent on phosphorylation of NHE3 at S555 and S563. Am J Physiol Cell Physiol 2024; 326:C50-C59. [PMID: 38047302 DOI: 10.1152/ajpcell.00540.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 12/05/2023]
Abstract
Electroneutral NaCl transport by Na+/H+ exchanger 3 (NHE3, SLC9A3) is the major Na+ absorptive mechanism in the intestine and decreased NHE3 activity contributes to diarrhea. Patients with diabetes often experience gastrointestinal adverse effects and medications are often a culprit for chronic diarrhea in type 2 diabetes (T2D). We have shown previously that metformin, the most widely prescribed drug for the treatment of T2D, induces diarrhea by inhibition of Na+/H+ exchanger 3 (NHE3) in rodent models of T2D. Metformin was shown to activate AMP-activated protein kinase (AMPK), but AMPK-independent glycemic effects of metformin are also known. The current study is undertaken to determine whether metformin inhibits NHE3 by activation of AMPK and the mechanism by which NHE3 is inhibited by AMPK. Inhibition of NHE3 by metformin was abolished by knockdown of AMPK-α1 or AMPK-α2. AMPK activation by 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) phosphorylated NHE3 at S555. S555 is the primary site of phosphorylation by protein kinase A (PKA), but AMPK phosphorylated S555 independently of PKA. Using Mass spectrometry, we found S563 as a newly recognized phosphorylation site in NHE3. Altering either S555 or S563 to Ala was sufficient to block the inhibition of NHE3 activity by AMPK. NHE3 inhibition is dependent on ubiquitination by the E3 ubiquitin ligase Nedd4-2 and metformin was shown to induce NHE3 internalization via Nedd4-2-mediated ubiquitination. AICAR did not increase NHE3 ubiquitination when S555 or S563 was mutated. We conclude that AMPK activation inhibits NHE3 activity and NHE3 inhibition is associated with phosphorylation of NHE3 at S555 and S563.NEW & NOTEWORTHY We show that AMP-activated protein kinase (AMPK) phosphorylates NHE3 at S555 and S563 to inhibit NHE3 activity in intestinal epithelial cells. Phosphorylation of NHE3 by AMPK is necessary for ubiquitination of NHE3.
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Affiliation(s)
- Yiran Han
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, Georgia, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Pritha Bagchi
- Emory Integrated Proteomics Core, Emory University, Atlanta, Georgia, United States
| | - C Chris Yun
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, Georgia, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, United States
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10
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Uhlig HH, Booth C, Cho J, Dubinsky M, Griffiths AM, Grimbacher B, Hambleton S, Huang Y, Jones K, Kammermeier J, Kanegane H, Koletzko S, Kotlarz D, Klein C, Lenardo MJ, Lo B, McGovern DPB, Özen A, de Ridder L, Ruemmele F, Shouval DS, Snapper SB, Travis SP, Turner D, Wilson DC, Muise AM. Precision medicine in monogenic inflammatory bowel disease: proposed mIBD REPORT standards. Nat Rev Gastroenterol Hepatol 2023; 20:810-828. [PMID: 37789059 DOI: 10.1038/s41575-023-00838-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 10/05/2023]
Abstract
Owing to advances in genomics that enable differentiation of molecular aetiologies, patients with monogenic inflammatory bowel disease (mIBD) potentially have access to genotype-guided precision medicine. In this Expert Recommendation, we review the therapeutic research landscape of mIBD, the reported response to therapies, the medication-related risks and systematic bias in reporting. The mIBD field is characterized by the absence of randomized controlled trials and is dominated by retrospective observational data based on case series and case reports. More than 25 off-label therapeutics (including small-molecule inhibitors and biologics) as well as cellular therapies (including haematopoietic stem cell transplantation and gene therapy) have been reported. Heterogeneous reporting of outcomes impedes the generation of robust therapeutic evidence as the basis for clinical decision making in mIBD. We discuss therapeutic goals in mIBD and recommend standardized reporting (mIBD REPORT (monogenic Inflammatory Bowel Disease Report Extended Phenotype and Outcome of Treatments) standards) to stratify patients according to a genetic diagnosis and phenotype, to assess treatment effects and to record safety signals. Implementation of these pragmatic standards should help clinicians to assess the therapy responses of individual patients in clinical practice and improve comparability between observational retrospective studies and controlled prospective trials, supporting future meta-analysis.
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Affiliation(s)
- Holm H Uhlig
- Translational Gastroenterology Unit, University of Oxford, Oxford, UK.
- Department of Paediatrics, University of Oxford, Oxford, UK.
- Biomedical Research Centre, University of Oxford, Oxford, UK.
| | - Claire Booth
- UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Paediatric Immunology and Gene Therapy, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Judy Cho
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Marla Dubinsky
- Department of Paediatric Gastroenterology, Susan and Leonard Feinstein IBD Clinical Center, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Anne M Griffiths
- SickKids Inflammatory Bowel Disease Centre and Cell Biology Program, Research Institute, Toronto, Canada
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Paediatrics, University of Toronto, Toronto, Canada
| | - Bodo Grimbacher
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency, Medical Center, Faculty of Medicine, Albert Ludwig University of Freiburg, Freiburg, Germany
- Department of Rheumatology and Clinical Immunology, Medical Center, Faculty of Medicine, Albert Ludwig University of Freiburg, Freiburg, Germany
- Institute of Immunology and Transplantation, Royal Free Hospital, University College London, London, UK
| | - Sophie Hambleton
- Primary Immunodeficiency Group, Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne, UK
| | - Ying Huang
- Department of Gastroenterology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Kelsey Jones
- Paediatric Gastroenterology, Great Ormond Street Hospital, London, UK
- Kennedy Institute, University of Oxford, Oxford, UK
| | - Jochen Kammermeier
- Gastroenterology Department, Evelina London Children's Hospital, London, UK
| | - Hirokazu Kanegane
- Department of Child Health and Development, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Sibylle Koletzko
- Dr. von Hauner Children's Hospital, Department of Paediatrics, University Hospital, LMU Munich, Munich, Germany
- Department of Paediatrics, Gastroenterology and Nutrition, School of Medicine Collegium Medicum University of Warmia and Mazury, Olsztyn, Poland
| | - Daniel Kotlarz
- Dr. von Hauner Children's Hospital, Department of Paediatrics, University Hospital, LMU Munich, Munich, Germany
- German Center for Child and Adolescent Health, Munich, Germany
- Institute of Translational Genomics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Christoph Klein
- Dr. von Hauner Children's Hospital, Department of Paediatrics, University Hospital, LMU Munich, Munich, Germany
- German Center for Child and Adolescent Health, Munich, Germany
| | - Michael J Lenardo
- Molecular Development of the Immune System Section, Laboratory of Immune System Biology, and Clinical Genomics Program, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bernice Lo
- Research Branch, Sidra Medicine, Doha, Qatar
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar
| | - Dermot P B McGovern
- F. Widjaja Foundation, Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ahmet Özen
- Marmara University Division of Allergy and Immunology, Istanbul, Turkey
| | - Lissy de Ridder
- Department of Paediatric Gastroenterology, Erasmus University Medical Center Sophia Children's Hospital, Rotterdam, Netherlands
| | - Frank Ruemmele
- Université Paris Cité, APHP, Hôpital Necker Enfants Malades, Service de Gastroentérologie pédiatrique, Paris, France
| | - Dror S Shouval
- Institute of Gastroenterology, Nutrition and Liver Diseases, Schneider Children's Medical Center of Israel, Petah Tikva, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Scott B Snapper
- Division of Gastroenterology and Nutrition, Boston Children's Hospital, Boston, MA, USA
- Department of Paediatrics and Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Simon P Travis
- Translational Gastroenterology Unit, University of Oxford, Oxford, UK
- Biomedical Research Centre, University of Oxford, Oxford, UK
- Kennedy Institute, University of Oxford, Oxford, UK
| | - Dan Turner
- Shaare Zedek Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - David C Wilson
- Child Life and Health, Centre for Inflammation Research, University of Edinburgh, Edinburgh, UK
- Department of Paediatric Gastroenterology, The Royal Hospital for Children, and Young People, Edinburgh, UK
| | - Aleixo M Muise
- SickKids Inflammatory Bowel Disease Centre and Cell Biology Program, Research Institute, Toronto, Canada
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Paediatrics, University of Toronto, Toronto, Canada
- Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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11
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Abstract
Inflammatory bowel disease (IBD) represents a spectrum of disease, which is characterized by chronic gastrointestinal inflammation. Monogenic mutations driving IBD pathogenesis are more highly represented in early-onset compared to adult-onset disease. The pathogenic genes which dysregulate host immune responses in monogenic IBD affect both the innate (ie, intestinal barrier, phagocytes) and adaptive immune systems (ie, T cells, B cells). Advanced genomic and targeted functional testing can improve clinical decision making and present increased opportunities for precision medicine approaches in this important patient population.
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Affiliation(s)
- Atiye Olcay Bilgic Dagci
- Division of Pediatric Rheumatology, University of Michigan, C.S Mott Children's Hospital, 1500 East Medical Center Drive Medical Professional Building Floor 2, Ann Arbor, MI 48109-5718, USA.
| | - Kelly Colleen Cushing
- Division of Gastroenterology, U-M Inflammatory Bowel Disease Program, University of Michigan, 3912 Taubman Center, 1500 East Medical Center Drive, SPC 5362, Ann Arbor, MI 48109-5362, USA
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12
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Thorvilson DA, Skiba CC, Muzzy JD, Grindeland CJ, Mohamed MW. Successful therapy for congenital sodium diarrhea by enteral management: A case report. Nutrition 2023; 114:112096. [PMID: 37399692 DOI: 10.1016/j.nut.2023.112096] [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: 02/26/2023] [Revised: 05/14/2023] [Accepted: 05/22/2023] [Indexed: 07/05/2023]
Abstract
BACKGROUND Congenital sodium diarrhea (CSD) is a rare disorder causing electrolyte imbalances due to excessive diarrhea. In pediatric literature, common practice for treating CSD includes parenteral nutrition (PN) for fluid, nutrient, and electrolyte support through the first year of the patient's life. The aim of this study was to report a neonate who showed common symptoms of CSD, including a distended abdomen, large amounts of clear, yellow fluid draining from the rectum, dehydration, and electrolyte abnormalities. CASE SUMMARY A diagnostic gene panel was completed and confirmed heterozygous variant GUCY2C gene associated with autosomal dominant CSD. The infant was initially treated with PN to maintain fluid, nutrient, and electrolyte status, but was subsequently transitioned to full enteral feeds, showing improvement in symptoms. Frequent therapy adjustments were required to maintain appropriate electrolyte levels during the duration of the hospital stay. At discharge, the infant followed an enteral fluid maintenance plan that provided symptomatic control through the first year of life. CONCLUSION This case demonstrated the ability to maintain electrolyte levels in a patient through enteral means while avoiding long-term use of intravenous access.
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Affiliation(s)
- Dana A Thorvilson
- North Dakota State University College of Pharmacy Nursing and Allied Sciences, Fargo, North Dakota, United States.
| | - Caleb C Skiba
- North Dakota State University College of Pharmacy Nursing and Allied Sciences, Fargo, North Dakota, United States
| | - Julia D Muzzy
- Sanford Children's Hospital, Fargo, North Dakota, United States; Department of Pharmacy Practice, North Dakota State University, Fargo, North Dakota, United States
| | | | - Mohamed W Mohamed
- Department of Pediatrics, Sanford Children's Hospital, Fargo, North Dakota, United States
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13
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Han Y, Srinivasan S, Yun CC. Inhibition of protein kinase C-α and activation of ezrin by Lactobacillus acidophilus restore Na +/H + exchange activity and fluid absorption in db/db mice. Am J Physiol Endocrinol Metab 2023; 325:E214-E226. [PMID: 37467022 PMCID: PMC10511175 DOI: 10.1152/ajpendo.00145.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/03/2023] [Accepted: 07/03/2023] [Indexed: 07/20/2023]
Abstract
Gastrointestinal (GI) complications, including diarrhea, constipation, and gastroparesis, are common in patients with diabetes. Dysregulation of the Na+/H+ exchanger NHE3 in the intestine is linked to diarrhea and constipation, and recent studies showed that NHE3 expression is reduced in type 1 diabetes and metformin causes diarrhea in the db/db mouse model of type 2 diabetes (T2D) via inhibition of NHE3. In this study, we investigated whether NHE3 expression is altered in type 2 diabetic intestine and the underlying mechanism that dysregulates NHE3. NHE3 expression in the brush border membrane (BBM) of the intestine of diabetic mice and humans was decreased. Protein kinase C (PKC) activation is associated with pathologies of diabetes, and immunofluorescence (IF) analysis revealed increased BBM PKCα abundance. Inhibition of PKCα increased NHE3 BBM abundance and NHE3-mediated intestinal fluid absorption in db/db mice. Previous studies have shown that Lactobacillus acidophilus (LA) stimulates intestinal ion transporters. LA increased NHE3 BBM expression and mitigated metformin-mediated inhibition of NHE3 in vitro and in vivo. To understand the underlying mechanism of LA-mediated stimulation of NHE3, we used Caco-2bbe cells overexpressing PKCα that mimic the elevated state of PKCα in T2D. LA diminished PKCα BBM expression, increased phosphorylation of ezrin, and the interaction of NHE3 with NHE regulatory factor 2 (NHERF2). In addition, inhibition of PKCι blocked phosphorylation of ezrin and activation of NHE3 by LA. These findings demonstrate that NHE3 is downregulated in T2D, and LA restores NHE3 expression via regulation of PKCα, PKCι, and ezrin.NEW & NOTEWORTHY We used mouse models of type 2 diabetes (T2D) and human patient-derived samples to show that Na+/H+ exchanger 3 (NHE3) expression is decreased in T2D. We show that protein kinase C-α (PKCα) is activated in diabetes and inhibition of PKCα increased NHE3 expression and mitigates diarrhea. We show that Lactobacillus acidophilus (LA) stimulates NHE3 via inhibition of PKCα and phosphorylation of ezrin.
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Affiliation(s)
- Yiran Han
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, Georgia, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Shanthi Srinivasan
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, Georgia, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
| | - C Chris Yun
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, Georgia, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, United States
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14
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Berger DS, Tancioco V, Shrivastava VK. Congenital Sodium Diarrhea: Antenatal Diagnosis May Prevent Unnecessary Surgery in the Neonate. AJP Rep 2023; 13:e61-e64. [PMID: 37937268 PMCID: PMC10627711 DOI: 10.1055/s-0043-1776148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 08/08/2023] [Indexed: 11/09/2023] Open
Abstract
Congenital sodium diarrhea (CSD) is a rare, life-threatening condition characterized by intractable diarrhea, hyponatremia, and metabolic acidosis. It presents similarly to other congenital disorders and, therefore, is often misdiagnosed and mistreated. We present a case of CSD that presented with dilated loops of bowel and polyhydramnios at 18 weeks and was thought to be a congenital bowel obstruction. The patient was therefore managed surgically after birth with a diverting ileostomy, however was later found to have elevated stool sodium levels and metabolic derangements consistent with CSD. Our case demonstrates the need for high index of suspicion for congenital diarrheal disorders to prevent unnecessary surgery and a delay in appropriate medical management of this rare condition.
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Affiliation(s)
- Dana S. Berger
- Department of Obstetrics and Gynecology, University of California, Irvine, Orange, California
| | - Virginia Tancioco
- Department of Obstetrics and Gynecology, University of California, Irvine, Orange, California
| | - Vineet K. Shrivastava
- Department of Obstetrics and Gynecology, Miller Children's and Women's Hospital, Long Beach, California
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15
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Abtahi S, Sailer A, Roland JT, Haest X, Chanez-Paredes SD, Ahmad K, Sadiq K, Iqbal NT, Ali SA, Turner JR. Intestinal Epithelial Digestive, Transport, and Barrier Protein Expression Is Increased in Environmental Enteric Dysfunction. J Transl Med 2023; 103:100036. [PMID: 36870290 PMCID: PMC10121737 DOI: 10.1016/j.labinv.2022.100036] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 01/11/2023] Open
Abstract
Environmental enteric dysfunction (EED) is characterized by malabsorption and diarrhea that result in irreversible deficits in physical and intellectual growth. We sought to define the expression of transport and tight junction proteins by quantitative analysis of duodenal biopsies from patients with EED. Biopsies from Pakistani children with confirmed EED diagnoses were compared to those from age-matched North American healthy controls, patients with celiac disease, and patients with nonceliac disease with villous atrophy or intraepithelial lymphocytosis. Expression of brush border digestive and transport proteins and paracellular (tight junction) proteins was assessed by quantitative multiplex immunofluorescence microscopy. EED was characterized by partial villous atrophy and marked intraepithelial lymphocytosis. Epithelial proliferation and enteroendocrine, tuft, and Paneth cell numbers were unchanged, but there was significant goblet cell expansion in EED biopsies. Expression of proteins involved in nutrient and water absorption and that of the basolateral Cl- transport protein NKCC1 were also increased in EED. Finally, the barrier-forming tight junction protein claudin-4 (CLDN4) was significantly upregulated in EED, particularly within villous enterocytes. In contrast, expression of CFTR, CLDN2, CLDN15, JAM-A, occludin, ZO-1, and E-cadherin was unchanged. Upregulation of a barrier-forming tight junction protein and brush border and basolateral membrane proteins that support nutrient and water transport in EED is paradoxical, as their increased expression would be expected to be correlated with increased intestinal barrier function and enhanced absorption, respectively. These data suggest that EED activates adaptive intestinal epithelial responses to enhance nutrient absorption but that these changes are insufficient to restore health.
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Affiliation(s)
- Shabnam Abtahi
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Anne Sailer
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Joseph T Roland
- Epithelial Biology Center, Vanderbilt University Medical Center; Nashville, Tennessee
| | - Xenia Haest
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sandra D Chanez-Paredes
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Kumail Ahmad
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Kamran Sadiq
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Najeeha Talat Iqbal
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - S Asad Ali
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Jerrold R Turner
- Laboratory of Mucosal Barrier Pathobiology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Pathology, University of Chicago, Chicago, Illinois.
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16
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Peritore-Galve FC, Kaji I, Smith A, Walker LM, Shupe JA, Washington MK, Algood HMS, Dudeja PK, Goldenring JR, Lacy DB. Increased intestinal permeability and downregulation of absorptive ion transporters Nhe3, Dra, and Sglt1 contribute to diarrhea during Clostridioides difficile infection. Gut Microbes 2023; 15:2225841. [PMID: 37350393 PMCID: PMC10291935 DOI: 10.1080/19490976.2023.2225841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 06/09/2023] [Indexed: 06/24/2023] Open
Abstract
BACKGROUND & AIM Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea and pseudomembranous colitis. Two protein toxins, TcdA and TcdB, produced by C. difficile are the major determinants of disease. However, the pathophysiological causes of diarrhea during CDI are not well understood. Here, we investigated the effects of C. difficile toxins on paracellular permeability and apical ion transporters in the context of an acute physiological infection. METHODS We studied intestinal permeability and apical membrane transporters in female C57BL/6J mice. Üssing chambers were used to measure paracellular permeability and ion transporter function across the intestinal tract. Infected intestinal tissues were analyzed by immunofluorescence microscopy and RNA-sequencing to uncover mechanisms of transporter dysregulation. RESULTS Intestinal permeability was increased through the size-selective leak pathway in vivo during acute CDI in a 2-day-post infection model. Chloride secretory activity was reduced in the cecum and distal colon during infection by decreased CaCC and CFTR function, respectively. SGLT1 activity was significantly reduced in the cecum and colon, accompanied by ablated SGLT1 expression in colonocytes and increased luminal glucose concentrations. SGLT1 and DRA expression was ablated by either TcdA or TcdB during acute infection, but NHE3 was decreased in a TcdB-dependent manner. The localization of key proteins that link filamentous actin to the ion transporters in the apical plasma membrane was unchanged. However, Sglt1, Nhe3, and Dra were drastically reduced at the transcript level, implicating downregulation of ion transporters in the mechanism of diarrhea during CDI. CONCLUSIONS CDI increases intestinal permeability and decreases apical abundance of NHE3, SGLT1, and DRA. This combination likely leads to dysfunctional water and solute absorption in the large bowel, causing osmotic diarrhea. These findings provide insights into the pathophysiological mechanisms underlying diarrhea and may open novel avenues for attenuating CDI-associated diarrhea.
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Affiliation(s)
- F. Christopher Peritore-Galve
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Izumi Kaji
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Anna Smith
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lauren M. Walker
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John A. Shupe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M. Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Holly M. Scott Algood
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Pradeep K. Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
- Department of Veterans Affairs, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
| | - James R. Goldenring
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
- Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
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17
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Anbazhagan AN, Priyamvada S, Kumar A, Jayawardena D, Borthakur A, Gill RK, Alrefai WA, Dudeja PK, Saksena S. Downregulation of NHE-3 (SLC9A3) expression by MicroRNAs in intestinal epithelial cells. Am J Physiol Cell Physiol 2022; 323:C1720-C1727. [PMID: 36189974 PMCID: PMC9722255 DOI: 10.1152/ajpcell.00294.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 11/22/2022]
Abstract
Na+/H+ exchanger-3 (NHE-3) is the major apical membrane transporter involved in vectorial Na+ absorption in the intestine. Dysregulation of NHE-3 expression and/or function has been implicated in pathophysiology of diarrhea associated with gut inflammation and infections. Therefore, it is critical to understand the mechanisms involved in the regulation of NHE-3 expression. MicroRNAs (miRNAs) are highly conserved small RNAs that can regulate gene expression at the posttranscriptional level. To date, however, very little is known about the regulation of NHE-3 expression by microRNAs. Therefore, current studies were undertaken to examine the potential miRNA candidates that can regulate the expression of NHE-3 in intestinal epithelial cells. In silico analysis, using different algorithms, predicted several miRNAs that target NHE-3. MicroRNAs with highest context and target score, miR-326, miR-744-5p, and miR-330-5p, were selected for the current study. Human NHE-3 gene 3' untranslated region [3'UTR; 160 base pair (bp)] was cloned into pmirGLO vector upstream of luciferase reporter and transiently transfected with mimics of miR-326, miR-744-5p, and miR-330-5p into Caco-2, HT-29, and SK-CO15 cells. Cotransfection of NHE-3 3' UTR with miR-326 and -miR-330-5p mimics resulted in a significant decrease in relative luciferase activity. Transfection of miR-326 and -330-5p mimics into SK-CO15 cells significantly decreased the NHE-3 protein expression, with no change in NHE-3 messenger ribonucleic acid (mRNA) levels. Our findings demonstrate a novel mechanism for posttranscriptional regulation of NHE-3 by miR-326 and -330-5p by translational repression. We speculate that miR-326 and -330-5p dependent pathways may be involved in modulating NHE-3 expression under physiological and pathophysiological conditions.
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Affiliation(s)
- Arivarasu N Anbazhagan
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Shubha Priyamvada
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Anoop Kumar
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown VA Medical Center, Chicago, Illinois
| | - Dulari Jayawardena
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Alip Borthakur
- Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia
| | - Ravinder K Gill
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Waddah A Alrefai
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown VA Medical Center, Chicago, Illinois
| | - Pradeep K Dudeja
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown VA Medical Center, Chicago, Illinois
| | - Seema Saksena
- Division of Gastroenterology & Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
- Jesse Brown VA Medical Center, Chicago, Illinois
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18
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The genetics of monogenic intestinal epithelial disorders. Hum Genet 2022; 142:613-654. [PMID: 36422736 PMCID: PMC10182130 DOI: 10.1007/s00439-022-02501-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 10/23/2022] [Indexed: 11/27/2022]
Abstract
Monogenic intestinal epithelial disorders, also known as congenital diarrheas and enteropathies (CoDEs), are a group of rare diseases that result from mutations in genes that primarily affect intestinal epithelial cell function. Patients with CoDE disorders generally present with infantile-onset diarrhea and poor growth, and often require intensive fluid and nutritional management. CoDE disorders can be classified into several categories that relate to broad areas of epithelial function, structure, and development. The advent of accessible and low-cost genetic sequencing has accelerated discovery in the field with over 45 different genes now associated with CoDE disorders. Despite this increasing knowledge in the causal genetics of disease, the underlying cellular pathophysiology remains incompletely understood for many disorders. Consequently, clinical management options for CoDE disorders are currently limited and there is an urgent need for new and disorder-specific therapies. In this review, we provide a general overview of CoDE disorders, including a historical perspective of the field and relationship to other monogenic disorders of the intestine. We describe the genetics, clinical presentation, and known pathophysiology for specific disorders. Lastly, we describe the major challenges relating to CoDE disorders, briefly outline key areas that need further study, and provide a perspective on the future genetic and therapeutic landscape.
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19
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Bernardazzi C, Sheikh IA, Xu H, Ghishan FK. The Physiological Function and Potential Role of the Ubiquitous Na +/H + Exchanger Isoform 8 (NHE8): An Overview Data. Int J Mol Sci 2022; 23:ijms231810857. [PMID: 36142772 PMCID: PMC9501935 DOI: 10.3390/ijms231810857] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/08/2022] [Accepted: 09/15/2022] [Indexed: 11/16/2022] Open
Abstract
The Na+/H+ exchanger transporters (NHE) play an important role in various biologic processes including Na+ absorption, intracellular pH homeostasis, cell volume regulation, proliferation, and apoptosis. The wide expression pattern and cellular localization of NHEs make these proteins pivotal players in virtually all human tissues and organs. In addition, recent studies suggest that NHEs may be one of the primeval transport protein forms in the history of life. Among the different isoforms, the most well-characterized NHEs are the Na+/H+ exchanger isoform 1 (NHE1) and Na+/H+ exchanger isoform 3 (NHE3). However, Na+/H+ exchanger isoform 8 (NHE8) has been receiving attention based on its recent discoveries in the gastrointestinal tract. In this review, we will discuss what is known about the physiological function and potential role of NHE8 in the main organ systems, including useful overviews that could inspire new studies on this multifaceted protein.
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20
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Laubitz D, Gurney MA, Midura-Kiela M, Clutter C, Besselsen DG, Chen H, Ghishan FK, Kiela PR. Decreased NHE3 expression in colon cancer is associated with DNA damage, increased inflammation and tumor growth. Sci Rep 2022; 12:14725. [PMID: 36042372 PMCID: PMC9427942 DOI: 10.1038/s41598-022-19091-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Dysregulation of intra- and extracellular pH in cancer contributes to extracellular matrix remodeling, favors cell migration, proliferation, and metastasis. Although the primary attention has been focused on the role of the ubiquitous Na+/H+ exchanger isoform NHE1, the role of NHE3, the predominant apical isoform in colonic surface epithelium in the pathogenesis of colon cancer has not been investigated. Here, we show that NHE3 mRNA expression is significantly reduced in colorectal cancer patients and that low NHE3 expression is associated with poorer survival. Deletion of NHE3 in ApcMin mice evaluated at 15 weeks of age (significant mortality was observed beyond this time) led to lower body weights, increased mucosal inflammation, increased colonic tumor numbers, evidence of enhanced DNA damage in tumor surface epithelium, and to significant alteration in the gut microbiota. In the absence of the inflammatory and microbial pressors, ca. 70% knockdown of NHE3 expression in SK-CO15 cells led to reduced intracellular pH, elevated apical pH, dramatic differences in their transcriptomic profile, increased susceptibility to DNA damage, increased proliferation, decreased apoptosis and reduced adhesion to extracellular matrix proteins. Our findings suggest that loss of NHE3 in the surface epithelium of colonic tumors has profound consequences for cancer progression and behavior.
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Affiliation(s)
- Daniel Laubitz
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Michael A Gurney
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Monica Midura-Kiela
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Christy Clutter
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | | | - Hao Chen
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Fayez K Ghishan
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA
| | - Pawel R Kiela
- Department of Pediatrics, Steele Children's Research Center, University of Arizona College of Medicine, 1501 N. Campbell Ave, Tucson, AZ, 85724, USA.
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, AZ, USA.
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21
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Sun Y, Leng C, van Ijzendoorn SCD. Fetal Bowel Abnormalities Suspected by Ultrasonography in Microvillus Inclusion Disease: Prevalence and Clinical Significance. J Clin Med 2022; 11:jcm11154331. [PMID: 35893420 PMCID: PMC9332086 DOI: 10.3390/jcm11154331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/28/2022] [Accepted: 07/22/2022] [Indexed: 02/01/2023] Open
Abstract
Microvillus inclusion disease (MVID) is a rare, inherited, congenital, diarrheal disorder that is invariably fatal if left untreated. Within days after birth, MVID presents as a life-threatening emergency characterized by severe dehydration, metabolic acidosis, and weight loss. Diagnosis is cumbersome and can take a long time. Whether MVID could be diagnosed before birth is not known. Anecdotal reports of MVID-associated fetal bowel abnormalities suspected by ultrasonography (that is, dilated bowel loops and polyhydramnios) have been published. These are believed to be rare, but their prevalence in MVID has not been investigated. Here, we have performed a comprehensive retrospective study of 117 published MVID cases spanning three decades. We find that fetal bowel abnormalities in MVID occurred in up to 60% of cases of MVID for which prenatal ultrasonography or pregnancy details were reported. Suspected fetal bowel abnormalities appeared in the third trimester of pregnancy and correlated with postnatal, early-onset diarrhea and case-fatality risk during infancy. Fetal bowel dilation correlated with MYO5B loss-of-function variants. In conclusion, MVID has already started during fetal life in a significant number of cases. Genetic testing for MVID-causing gene variants in cases where fetal bowel abnormalities are suspected by ultrasonography may allow for the prenatal diagnosis of MVID in a significant percentage of cases, enabling optimal preparation for neonatal intensive care.
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Affiliation(s)
- Yue Sun
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9713 AV Groningen, The Netherlands; (Y.S.); (C.L.)
- Center for Liver, Digestive & Metabolic Disease, University of Groningen, University Medical Center Groningen, 9700 AD Groningen, The Netherlands
| | - Changsen Leng
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9713 AV Groningen, The Netherlands; (Y.S.); (C.L.)
- Center for Liver, Digestive & Metabolic Disease, University of Groningen, University Medical Center Groningen, 9700 AD Groningen, The Netherlands
- State Key Laboratory of Oncology in South China, Collaborative Innovation Centre for Cancer Medicine, Guangdong Esophageal Cancer Institute, Department of Thoracic Surgery, Sun Yat-sen University Cancer Centre, Guangzhou 510060, China
| | - Sven C. D. van Ijzendoorn
- Department of Biomedical Sciences of Cells and Systems, Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen, 9713 AV Groningen, The Netherlands; (Y.S.); (C.L.)
- Center for Liver, Digestive & Metabolic Disease, University of Groningen, University Medical Center Groningen, 9700 AD Groningen, The Netherlands
- Correspondence:
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22
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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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23
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Bogdanic E, Müller T, Heinz-Erian P, Garczarczyk-Asim D, Janecke AR, Rückel A. Further delineation of SLC9A3-related congenital sodium diarrhea. Mol Genet Genomic Med 2022; 10:e2000. [PMID: 35775128 PMCID: PMC9356552 DOI: 10.1002/mgg3.2000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/06/2022] [Accepted: 05/13/2022] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Congenital sodium diarrhea (CSD) is a rare enteropathy displaying both broad variability in clinical severity and genetic locus and allelic heterogeneity. Eleven CSD patients were reported so far with SLC9A3 variants that impair the function of the encoded intestinal sodium-proton exchanger 3 (NHE3). METHODS We report a 4-year-old patient, born prematurely in the 35th week of gestation, with antenatal polyhydramnios and dilated intestinal loops, and with diarrhea of congenital onset, 2-6 times a day, and with polydipsia. She thrived age-appropriately under a normal family diet. Serum sodium levels were repeatedly normal but urinary sodium excretion was low. Exome sequencing revealed compound heterozygous variants in SLC9A3 as the likely cause of the congenital diarrhea. RESULTS While exome sequencing did not reveal pathogenic or likely pathogenic variants in other genes that cause syndromic or non-syndromic forms of congenital and intractable diarrheas, we identified novel compound heterozygous variants in SLC9A3, a complex allele with two missense changes, NP_004165.2:p.[Ser331Leu;Val449Ile] and in-trans the missense variant p.(Phe451Ser). CONCLUSION The clinical phenotype here appears to localize to the milder end of the known CSD spectrum, and the identified variants suggest that this is the twelfth patient reported to date with CSD due to mutations in SLC9A3.
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Affiliation(s)
- Ema Bogdanic
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Heinz-Erian
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Andreas R Janecke
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria.,Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Aline Rückel
- Department of Pediatrics, University of Erlangen, Erlangen, Germany
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24
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Xue J, Dominguez Rieg JA, Thomas L, White JR, Rieg T. Intestine-Specific NHE3 Deletion in Adulthood Causes Microbial Dysbiosis. Front Cell Infect Microbiol 2022; 12:896309. [PMID: 35719363 PMCID: PMC9204535 DOI: 10.3389/fcimb.2022.896309] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
In the intestine, the Na+/H+ exchanger 3 (NHE3) plays a critical role for Na+ and fluid absorption. NHE3 deficiency predisposes patients to inflammatory bowel disease (IBD). In mice, selective deletion of intestinal NHE3 causes various local and systemic pathologies due to dramatic changes in the intestinal environment, which can influence microbiota colonization. By using metagenome shotgun sequencing, we determined the effect of inducible intestinal epithelial cell-specific deletion of NHE3 (NHE3IEC-KO) in adulthood on the gut microbiome in mice. Compared with control mice, NHE3IEC-KO mice show a significantly different gut microbiome signature, with an unexpected greater diversity. At the phylum level, NHE3IEC-KO mice showed a significant expansion in Proteobacteria and a tendency for lower Firmicutes/Bacteroidetes (F/B) ratio, an indicator of dysbiosis. At the family level, NHE3IEC-KO mice showed significant expansions in Bacteroidaceae, Rikenellaceae, Tannerellaceae, Flavobacteriaceae and Erysipelotrichaceae, but had contractions in Lachnospiraceae, Prevotellaceae and Eubacteriaceae. At the species level, after removing those with lowest occurrence and abundance, we identified 23 species that were significantly expanded (several of which are established pro-inflammatory pathobionts); whereas another 23 species were found to be contracted (some of which are potential anti-inflammatory probiotics) in NHE3IEC-KO mice. These results reveal that intestinal NHE3 deletion creates an intestinal environment favoring the competitive advantage of inflammophilic over anti-inflammatory species, which is commonly featured in conventional NHE3 knockout mice and patients with IBD. In conclusion, our study emphasizes the importance of intestinal NHE3 for gut microbiota homeostasis, and provides a deeper understanding regarding interactions between NHE3, dysbiosis, and IBD.
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Affiliation(s)
- Jianxiang Xue
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, United States
| | - Jessica A Dominguez Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States
| | - Linto Thomas
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, United States
| | - James R White
- Resphera Biosciences LLC, Baltimore, MD, United States
| | - Timo Rieg
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, United States.,James A. Haley Veterans' Hospital, Tampa, FL, United States.,Center for Hypertension and Kidney Research, University of South Florida, Tampa, FL, United States
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25
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Wedenoja S, Saarikivi A, Mälkönen J, Leskinen S, Lehto M, Adeshara K, Tuokkola J, Nikkonen A, Merras-Salmio L, Höyhtyä M, Hörkkö S, Haaramo A, Salonen A, de Vos WM, Korpela K, Kolho KL. Fecal microbiota in congenital chloride diarrhea and inflammatory bowel disease. PLoS One 2022; 17:e0269561. [PMID: 35679312 PMCID: PMC9182261 DOI: 10.1371/journal.pone.0269561] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 05/24/2022] [Indexed: 11/21/2022] Open
Abstract
Background and aims Subjects with congenital chloride diarrhea (CLD; a defect in solute carrier family 26 member 3 (SLC26A3)) are prone to inflammatory bowel disease (IBD). We investigated fecal microbiota in CLD and CLD-associated IBD. We also tested whether microbiota is modulated by supplementation with the short-chain fatty acid butyrate. Subjects and methods We recruited 30 patients with CLD for an observational 3-week follow-up study. Thereafter, 16 consented to oral butyrate substitution for a 3-week observational period. Fecal samples, collected once a week, were assayed for calprotectin and potential markers of inflammation, and studied by 16S ribosomal ribonucleic acid (rRNA) gene amplicon sequencing and compared to that of 19 healthy controls and 43 controls with Crohn’s disease. Data on intestinal symptoms, diet and quality of life were collected. Results Patients with CLD had increased abundances of Proteobacteria, Veillonella, and Prevotella, and lower abundances of normally dominant taxa Ruminococcaceae and Lachnospiraceae when compared with healthy controls and Crohn´s disease. No major differences in fecal microbiota were found between CLD and CLD-associated IBD (including two with yet untreated IBD). Butyrate was poorly tolerated and showed no major effects on fecal microbiota or biomarkers in CLD. Conclusions Fecal microbiota in CLD is different from that of healthy subjects or Crohn´s disease. Unexpectedly, no changes in the microbiota or fecal markers characterized CLD-associated IBD, an entity with high frequency among patients with CLD.
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Affiliation(s)
- Satu Wedenoja
- Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Stem Cells and Metabolism Research Program, University of Helsinki, and Folkhälsan Research Center, Helsinki, Finland
| | - Aki Saarikivi
- Children’s Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Jani Mälkönen
- Children’s Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Saara Leskinen
- Department of Pediatrics, University of Kuopio and Kuopio University Hospital, Kuopio, Finland
| | - Markku Lehto
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Abdominal Center, Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Clinical and Molecular Metabolism, Faculty of Medicine Research Programs, University of Helsinki, Helsinki, Finland
| | - Krishna Adeshara
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Abdominal Center, Nephrology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Clinical and Molecular Metabolism, Faculty of Medicine Research Programs, University of Helsinki, Helsinki, Finland
| | - Jetta Tuokkola
- Children’s Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Anne Nikkonen
- Children’s Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Laura Merras-Salmio
- Children’s Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Miikka Höyhtyä
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Sohvi Hörkkö
- Medical Microbiology and Immunology, Research Unit of Biomedicine, University of Oulu, Oulu, Finland
- Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
| | - Anu Haaramo
- Department of Otorhinolaryngology, Helsinki University Hospital, Helsinki, Finland
| | - Anne Salonen
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Willem M. de Vos
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands
| | - Katri Korpela
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kaija-Leena Kolho
- Children’s Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- * E-mail:
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26
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Malabsorption Syndromes and Food Intolerance. Clin Perinatol 2022; 49:537-555. [PMID: 35659102 DOI: 10.1016/j.clp.2022.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Feeding intolerance is ubiquitous in neonatal intensive care units with as many signs and symptoms as possible diagnoses. Optimizing nutrition is paramount in both preterm and term infants. Determining the cause of feeding intolerance and adjusting nutrition interventions is an important part of the daily care of newborns. This review discusses the role of malabsorption and food intolerance as possible causes of nutrition difficulties in the newborn.
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27
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Dong Y, Li H, Ilie A, Gao Y, Boucher A, Zhang XC, Orlowski J, Zhao Y. Structural basis of autoinhibition of the human NHE3-CHP1 complex. SCIENCE ADVANCES 2022; 8:eabn3925. [PMID: 35613257 PMCID: PMC9132474 DOI: 10.1126/sciadv.abn3925] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/11/2022] [Indexed: 06/15/2023]
Abstract
Sodium-proton exchanger 3 (NHE3/SLC9A3) located in the apical membrane of renal and gastrointestinal epithelia mediates salt and fluid absorption and regulates pH homeostasis. As an auxiliary regulatory factor of NHE proteins, calcineurin B homologous protein 1 (CHP1) facilitates NHE3 maturation, plasmalemmal expression, and pH sensitivity. Dysfunctions of NHE3 are associated with renal and digestive system disorders. Here, we report the cryo-electron microscopy structure of the human NHE3-CHP1 complex in its inward-facing conformation. We found that a cytosolic helix-loop-helix motif in NHE3 blocks the intracellular cavity formed between the core and dimerization domains, functioning as an autoinhibitory element and hindering substrate transport. Furthermore, two phosphatidylinositol molecules are found to bind to the peripheric juxtamembrane sides of the complex, function as anchors to stabilize the complex, and may thus enhance its transport activity.
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Affiliation(s)
- Yanli Dong
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hang Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Alina Ilie
- Department of Physiology, McGill University, Montreal, Canada
| | - Yiwei Gao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Annie Boucher
- Department of Physiology, McGill University, Montreal, Canada
| | - Xuejun Cai Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - John Orlowski
- Department of Physiology, McGill University, Montreal, Canada
| | - Yan Zhao
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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28
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Han Y, Yun CC. Metformin Inhibits Na +/H + Exchanger NHE3 Resulting in Intestinal Water Loss. Front Physiol 2022; 13:867244. [PMID: 35444557 PMCID: PMC9014215 DOI: 10.3389/fphys.2022.867244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/07/2022] [Indexed: 11/14/2022] Open
Abstract
Glycemic control is the key to the management of type 2 diabetes. Metformin is an effective, widely used drug for controlling plasma glucose levels in diabetes, but it is often the culprit of gastrointestinal adverse effects such as abdominal pain, nausea, indigestion, vomiting, and diarrhea. Diarrhea is a complex disease and altered intestinal transport of electrolytes and fluid is a common cause of diarrhea. Na+/H+ exchanger 3 (NHE3, SLC9A3) is the major Na+ absorptive mechanism in the intestine and our previous study has demonstrated that decreased NHE3 contributes to diarrhea associated with type 1 diabetes. The goal of this study is to investigate whether metformin regulates NHE3 and inhibition of NHE3 contributes to metformin-induced diarrhea. We first determined whether metformin alters intestinal water loss, the hallmark of diarrhea, in type 2 diabetic db/db mice. We found that metformin decreased intestinal water absorption mediated by NHE3. Metformin increased fecal water content although mice did not develop watery diarrhea. To determine the mechanism of metformin-mediated regulation of NHE3, we used intestinal epithelial cells. Metformin inhibited NHE3 activity and the effect of metformin on NHE3 was mimicked by a 5'-AMP-activated protein kinase (AMPK) activator and blocked by pharmacological inhibition of AMPK. Metformin increased phosphorylation and ubiquitination of NHE3, resulting in retrieval of NHE3 from the plasma membrane. Previous studies have demonstrated the role of neural precursor cell expressed, developmentally down-regulated 4-2 (Nedd4-2) in regulation of human NHE3. Silencing of Nedd4-2 mitigated NHE3 inhibition and ubiquitination by metformin. Our findings suggest that metformin-induced diarrhea in type 2 diabetes is in part caused by reduced Na+ and water absorption that is associated with NHE3 inhibition, probably by AMPK.
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Affiliation(s)
- Yiran Han
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, GA, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States
| | - C. Chris Yun
- Gastroenterology Research, Atlanta Veterans Administration Medical Center, Decatur, GA, United States
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, United States
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29
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Molecular mechanisms altering tubular calcium reabsorption. Pediatr Nephrol 2022; 37:707-718. [PMID: 33796889 DOI: 10.1007/s00467-021-05049-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/12/2021] [Accepted: 03/09/2021] [Indexed: 12/09/2022]
Abstract
The majority of calcium filtered by the glomerulus is reabsorbed along the nephron. Most is reabsorbed from the proximal tubule (> 60%) via a paracellular pathway composed of the tight junction proteins claudins-2 and -12, a process driven by sodium and consequently water reabsorption. The thick ascending limb reabsorbs the next greatest amount of calcium (20-25%), also by a paracellular pathway composed of claudins-16 and -19. This pathway is regulated by the CaSR, whose activity increases the expression of claudin-14, a protein that blocks paracellular calcium reabsorption. The fine tuning of urinary calcium excretion occurs in the distal convoluted and connecting tubule by a transcellular pathway composed of the apical calcium channel TRPV5, the calcium shuttling protein calbindin-D28K and the basolateral proteins PMCA1b and the sodium calcium exchanger, NCX. Not surprisingly, mutations in a subset of these genes cause monogenic disorders with hypercalciuria as a part of the phenotype. More commonly, "idiopathic" hypercalciuria is encountered clinically with genetic variations in CLDN14, the CASR and TRPV5 associating with kidney stones and increased urinary calcium excretion. An understanding of the molecular pathways conferring kidney tubular calcium reabsorption is employed in this review to help explain how dietary and medical interventions for this disorder lower urinary calcium excretion.
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30
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Vuyyuru SK, Kedia S, Sahu P, Ahuja V. Immune‐mediated inflammatory diseases of the gastrointestinal tract: Beyond Crohn's disease and ulcerative colitis. JGH OPEN 2022; 6:100-111. [PMID: 35155819 PMCID: PMC8829105 DOI: 10.1002/jgh3.12706] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 12/26/2021] [Accepted: 12/29/2021] [Indexed: 12/17/2022]
Abstract
Immune‐mediated inflammatory diseases (IMIDs) are a diverse group of complex inflammatory diseases that result from dysregulated immune pathways and can involve any system of the human body. Inflammatory bowel disease (IBD) is one such disease involving the gastrointestinal (GI) system. With high prevalence in the West and increasing incidence in newly industrialized countries, IBD poses a significant burden on health care. IMIDs of the GI system other than IBD can have similar clinical features, causing diagnostic and therapeutic challenges. Although these disorders share a common pathophysiology, the defects can occur anywhere in the complex network of cytokines, inflammatory mediators, and innate and adaptive systems, leading to unregulated inflammation. Precise knowledge about them will help determine the possible targeted therapy. Thus, it is essential to distinguish these disorders from IBD. This review describes various IMIDs of the GI tract that mimic IBD.
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Affiliation(s)
- Sudheer K Vuyyuru
- Department of Gastroenterology All India Institute of Medical Sciences New Delhi India
| | - Saurabh Kedia
- Department of Gastroenterology All India Institute of Medical Sciences New Delhi India
| | - Pabitra Sahu
- Department of Gastroenterology All India Institute of Medical Sciences New Delhi India
| | - Vineet Ahuja
- Department of Gastroenterology All India Institute of Medical Sciences New Delhi India
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Prasad H, Mathew JKK, Visweswariah SS. Receptor Guanylyl Cyclase C and Cyclic GMP in Health and Disease: Perspectives and Therapeutic Opportunities. Front Endocrinol (Lausanne) 2022; 13:911459. [PMID: 35846281 PMCID: PMC9276936 DOI: 10.3389/fendo.2022.911459] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 05/26/2022] [Indexed: 11/13/2022] Open
Abstract
Receptor Guanylyl Cyclase C (GC-C) was initially characterized as an important regulator of intestinal fluid and ion homeostasis. Recent findings demonstrate that GC-C is also causally linked to intestinal inflammation, dysbiosis, and tumorigenesis. These advances have been fueled in part by identifying mutations or changes in gene expression in GC-C or its ligands, that disrupt the delicate balance of intracellular cGMP levels and are associated with a wide range of clinical phenotypes. In this review, we highlight aspects of the current knowledge of the GC-C signaling pathway in homeostasis and disease, emphasizing recent advances in the field. The review summarizes extra gastrointestinal functions for GC-C signaling, such as appetite control, energy expenditure, visceral nociception, and behavioral processes. Recent research has expanded the homeostatic role of GC-C and implicated it in regulating the ion-microbiome-immune axis, which acts as a mechanistic driver in inflammatory bowel disease. The development of transgenic and knockout mouse models allowed for in-depth studies of GC-C and its relationship to whole-animal physiology. A deeper understanding of the various aspects of GC-C biology and their relationships with pathologies such as inflammatory bowel disease, colorectal cancer, and obesity can be leveraged to devise novel therapeutics.
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Affiliation(s)
- Hari Prasad
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | | | - Sandhya S. Visweswariah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
- Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India
- *Correspondence: Sandhya S. Visweswariah,
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32
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Kovesdy CP, Adebiyi A, Rosenbaum D, Jacobs JW, Quarles LD. Novel Treatments from Inhibition of the Intestinal Sodium-Hydrogen Exchanger 3. Int J Nephrol Renovasc Dis 2021; 14:411-420. [PMID: 34880650 PMCID: PMC8646223 DOI: 10.2147/ijnrd.s334024] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/11/2021] [Indexed: 12/31/2022] Open
Abstract
Plasma membrane sodium–hydrogen exchangers (NHE) transport Na+ into cells in exchange for H+. While there are nine isoforms of NHE in humans, this review focuses on the NHE3 isoform, which is abundantly expressed in the gastrointestinal tract, where it plays a key role in acid–base balance and water homeostasis. NHE3 inhibition in the small intestine results in luminal sodium and water retention, leading to a general decrease in paracellular water flux and diffusional driving force, reduced intestinal sodium absorption, and increased stool sodium excretion. The resulting softer and more frequent stools are the rationale for the development of tenapanor as a novel, first-in-class NHE3 inhibitor to treat irritable bowel syndrome with constipation. NHE3 also has additional therapeutic implications in nephrology. Inhibition of intestinal NHE3 also lowers blood pressure by reducing intestinal sodium absorption. Perhaps, the most novel effect is its ability to decrease intestinal phosphate absorption by inhibiting the paracellular phosphate absorption pathway. Therefore, selective pharmacological inhibition of NHE3 could be a potential therapeutic strategy to treat not only heart failure and hypertension but also hyperphosphatemia. This review presents an overview of the molecular and physiological functions of NHE3 and discusses how these functions translate to potential clinical applications in nephrology.
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Affiliation(s)
- Csaba P Kovesdy
- Division of Nephrology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Adebowale Adebiyi
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | | | | | - L Darryl Quarles
- Division of Nephrology, University of Tennessee Health Science Center, Memphis, TN, USA
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Jenkin KA, Han Y, Lin S, He P, Yun CC. Nedd4-2-dependent Ubiquitination Potentiates the Inhibition of Human NHE3 by Cholera Toxin and Enteropathogenic Escherichia coli. Cell Mol Gastroenterol Hepatol 2021; 13:695-716. [PMID: 34823064 PMCID: PMC8789535 DOI: 10.1016/j.jcmgh.2021.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Diarrhea is one of the most common illnesses and is often caused by bacterial infection. Recently, we have shown that human Na+/H+ exchanger NHE3 (hNHE3), but not non-human NHE3s, interacts with the E3 ubiquitin ligase Nedd4-2. We hypothesize that this property of hNHE3 contributes to the increased severity of diarrhea in humans. METHODS We used humanized mice expressing hNHE3 in the intestine (hNHE3int) to compare the contribution of hNHE3 and mouse NHE3 to diarrhea induced by cholera toxin (CTX) and enteropathogenic Escherichia coli (EPEC). We measured Na+/H+ exchange activity and fluid absorption. The role of Nedd4-2 on hNHE3 activity and ubiquitination was determined by knockdown in Caco-2bbe cells. The effects of protein kinase A (PKA), the primary mediator of CTX-induced diarrhea, on Nedd4-2 and hNHE3 phosphorylation and their interaction were determined. RESULTS The effects of CTX and EPEC were greater in hNHE3int mice than in control wild-type (WT) mice, resulting in greater inhibition of NHE3 activity and increased fluid accumulation in the intestine, the hallmark of diarrhea. Activation of PKA increased ubiquitination of hNHE3 and enhanced interaction of Nedd4-2 with hNHE3 via phosphorylation of Nedd4-2 at S342. S342A mutation mitigated the Nedd4-2-hNHE3 interaction and blocked PKA-induced inhibition of hNHE3. Unlike non-human NHE3s, inhibition of hNHE3 by PKA is independent of NHE3 phosphorylation, suggesting a distinct mechanism of hNHE3 regulation. CONCLUSIONS The effects of CTX and EPEC on hNHE3 are amplified, and the unique properties of hNHE3 may contribute to diarrheal symptoms occurring in humans.
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Affiliation(s)
- Kayte A. Jenkin
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Yiran Han
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Songbai Lin
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Peijian He
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - C. Chris Yun
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia,Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia,Correspondence Address correspondence to: Chris Yun, PhD, Division of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia 30324. fax: (404) 727-5767.
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34
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van Vugt AH, Bijvelds MJ, de Jonge HR, Meijsen KF, Restin T, Bryant MB, Ballauff A, Koot B, Müller T, Houwen RH, Janecke AR, Middendorp S. A Potential Treatment of Congenital Sodium Diarrhea in Patients With Activating GUCY2C Mutations. Clin Transl Gastroenterol 2021; 12:e00427. [PMID: 34797252 PMCID: PMC8604003 DOI: 10.14309/ctg.0000000000000427] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 09/23/2021] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Gain-of-function mutations in guanylyl cyclase C (GCC) result in persistent diarrhea with perinatal onset. We investigated a specific GCC inhibitor, SSP2518, for its potential to treat this disorder. METHODS We investigated the effect of SSP2518 on GCC-mediated intracellular cyclic guanosine monophosphate (cGMP) levels and on GCC-mediated chloride secretion in intestinal organoids from 3 patients with distinct activating GCC mutations and from controls, with and without stimulation of GCC with heat-stable enterotoxin. RESULTS Patient-derived organoids had significantly higher basal cGMP levels than control organoids, which were lowered by SSP2518 to levels found in control organoids. In addition, SSP2518 significantly reduced cGMP levels and chloride secretion in patient-derived and control organoids (P < 0.05 for all comparisons) after heat-stable enterotoxin stimulation. DISCUSSION We reported in this study that the GCC inhibitor SSP2518 normalizes cGMP levels in intestinal organoids derived from patients with GCC gain-of-function mutations and markedly reduces cystic fibrosis transmembrane conductance regulator-dependent chloride secretion, the driver of persistent diarrhea.
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Affiliation(s)
- Anke H.M. van Vugt
- Division of Pediatrics, Department of Pediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Center Utrecht (UMCU), Utrecht University (UU), Utrecht, the Netherlands;
- Regenerative Medicine Center, UMCU, UU, Utrecht, the Netherlands;
| | - Marcel J.C. Bijvelds
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands;
| | - Hugo R. de Jonge
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands;
| | - Kelly F. Meijsen
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands;
| | - Tanja Restin
- Newborn Research Zürich, Department of Neonatology, University Hospital Zurich and University of Zurich, Zurich, Switzerland;
- Institute of Physiology, University of Zurich, Zurich, Switzerland;
| | - Manuel B. Bryant
- Newborn Research Zürich, Department of Neonatology, University Hospital Zurich and University of Zurich, Zurich, Switzerland;
| | - Antje Ballauff
- Kinder- und Jugendmedizin, Helios Klinikum, Krefeld, Germany;
| | - Bart Koot
- Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Pediatric Gastroenterology, Amsterdam, the Netherlands;
| | - Thomas Müller
- Department of Pediatrics I, Medical University Innsbruck, Innsbruck, Austria;
| | - Roderick H.J. Houwen
- Division of Pediatrics, Department of Pediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Center Utrecht (UMCU), Utrecht University (UU), Utrecht, the Netherlands;
| | - Andreas R. Janecke
- Department of Pediatrics I, Medical University Innsbruck, Innsbruck, Austria;
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Sabine Middendorp
- Division of Pediatrics, Department of Pediatric Gastroenterology, Wilhelmina Children's Hospital, University Medical Center Utrecht (UMCU), Utrecht University (UU), Utrecht, the Netherlands;
- Regenerative Medicine Center, UMCU, UU, Utrecht, the Netherlands;
- Current affiliation: Gadeta BV, Utrecht, the Netherlands.
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35
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Mishra V, Bose A, Kiran S, Banerjee S, Shah IA, Chaukimath P, Reshi MM, Srinivas S, Barman A, Visweswariah SS. Gut-associated cGMP mediates colitis and dysbiosis in a mouse model of an activating mutation in GUCY2C. J Exp Med 2021; 218:212653. [PMID: 34546338 PMCID: PMC8480670 DOI: 10.1084/jem.20210479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/30/2021] [Accepted: 09/01/2021] [Indexed: 12/13/2022] Open
Abstract
Activating mutations in receptor guanylyl cyclase C (GC-C), the target of gastrointestinal peptide hormones guanylin and uroguanylin, and bacterial heat-stable enterotoxins cause early-onset diarrhea and chronic inflammatory bowel disease (IBD). GC-C regulates ion and fluid secretion in the gut via cGMP production and activation of cGMP-dependent protein kinase II. We characterize a novel mouse model harboring an activating mutation in Gucy2c equivalent to that seen in an affected Norwegian family. Mutant mice demonstrated elevated intestinal cGMP levels and enhanced fecal water and sodium content. Basal and linaclotide-mediated small intestinal transit was higher in mutant mice, and they were more susceptible to DSS-induced colitis. Fecal microbiome and gene expression analyses of colonic tissue revealed dysbiosis, up-regulation of IFN-stimulated genes, and misregulation of genes associated with human IBD and animal models of colitis. This novel mouse model thus provides molecular insights into the multiple roles of intestinal epithelial cell cGMP, which culminate in dysbiosis and the induction of inflammation in the gut.
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Affiliation(s)
- Vishwas Mishra
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Avipsa Bose
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Shashi Kiran
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Sanghita Banerjee
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Idrees A Shah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Pooja Chaukimath
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Mudasir M Reshi
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Swarna Srinivas
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Anaxee Barman
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Sandhya S Visweswariah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
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Abstract
Nephrolithiasis is a worldwide problem with increasing prevalence, enormous costs, and significant morbidity. Calcium-containing kidney stones are by far the most common kidney stones encountered in clinical practice. Consequently, hypercalciuria is the greatest risk factor for kidney stone formation. Hypercalciuria can result from enhanced intestinal absorption, increased bone resorption, or altered renal tubular transport. Kidney stone formation is complex and driven by high concentrations of calcium-oxalate or calcium-phosphate in the urine. After discussing the mechanism mediating renal calcium salt precipitation, we review recent discoveries in renal tubular calcium transport from the proximal tubule, thick ascending limb, and distal convolution. Furthermore, we address how calcium is absorbed from the intestine and mobilized from bone. The effect of acidosis on bone calcium resorption and urinary calcium excretion is also considered. Although recent discoveries provide insight into these processes, much remains to be understood in order to provide improved therapies for hypercalciuria and prevent kidney stone formation. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- R T Alexander
- Departments of Physiology and Pediatrics, University of Alberta, Edmonton, Canada; .,Membrane Protein Disease Research Group, University of Alberta, Edmonton, Canada
| | - D G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - H Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Nephrology, Odense University Hospital, Odense, Denmark
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37
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De La Vega FM, Chowdhury S, Moore B, Frise E, McCarthy J, Hernandez EJ, Wong T, James K, Guidugli L, Agrawal PB, Genetti CA, Brownstein CA, Beggs AH, Löscher BS, Franke A, Boone B, Levy SE, Õunap K, Pajusalu S, Huentelman M, Ramsey K, Naymik M, Narayanan V, Veeraraghavan N, Billings P, Reese MG, Yandell M, Kingsmore SF. Artificial intelligence enables comprehensive genome interpretation and nomination of candidate diagnoses for rare genetic diseases. Genome Med 2021; 13:153. [PMID: 34645491 PMCID: PMC8515723 DOI: 10.1186/s13073-021-00965-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 08/27/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Clinical interpretation of genetic variants in the context of the patient's phenotype is becoming the largest component of cost and time expenditure for genome-based diagnosis of rare genetic diseases. Artificial intelligence (AI) holds promise to greatly simplify and speed genome interpretation by integrating predictive methods with the growing knowledge of genetic disease. Here we assess the diagnostic performance of Fabric GEM, a new, AI-based, clinical decision support tool for expediting genome interpretation. METHODS We benchmarked GEM in a retrospective cohort of 119 probands, mostly NICU infants, diagnosed with rare genetic diseases, who received whole-genome or whole-exome sequencing (WGS, WES). We replicated our analyses in a separate cohort of 60 cases collected from five academic medical centers. For comparison, we also analyzed these cases with current state-of-the-art variant prioritization tools. Included in the comparisons were trio, duo, and singleton cases. Variants underpinning diagnoses spanned diverse modes of inheritance and types, including structural variants (SVs). Patient phenotypes were extracted from clinical notes by two means: manually and using an automated clinical natural language processing (CNLP) tool. Finally, 14 previously unsolved cases were reanalyzed. RESULTS GEM ranked over 90% of the causal genes among the top or second candidate and prioritized for review a median of 3 candidate genes per case, using either manually curated or CNLP-derived phenotype descriptions. Ranking of trios and duos was unchanged when analyzed as singletons. In 17 of 20 cases with diagnostic SVs, GEM identified the causal SVs as the top candidate and in 19/20 within the top five, irrespective of whether SV calls were provided or inferred ab initio by GEM using its own internal SV detection algorithm. GEM showed similar performance in absence of parental genotypes. Analysis of 14 previously unsolved cases resulted in a novel finding for one case, candidates ultimately not advanced upon manual review for 3 cases, and no new findings for 10 cases. CONCLUSIONS GEM enabled diagnostic interpretation inclusive of all variant types through automated nomination of a very short list of candidate genes and disorders for final review and reporting. In combination with deep phenotyping by CNLP, GEM enables substantial automation of genetic disease diagnosis, potentially decreasing cost and expediting case review.
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Affiliation(s)
- Francisco M. De La Vega
- Fabric Genomics Inc., Oakland, CA USA
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA USA
- Current Address: Tempus Labs Inc., Redwood City, CA 94065 USA
| | - Shimul Chowdhury
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Barry Moore
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT USA
| | | | | | - Edgar Javier Hernandez
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT USA
| | - Terence Wong
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Kiely James
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Lucia Guidugli
- Rady Children’s Institute for Genomic Medicine, San Diego, CA USA
| | - Pankaj B. Agrawal
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA USA
| | - Casie A. Genetti
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
| | - Catherine A. Brownstein
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
| | - Alan H. Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children’s Hospital, Harvard Medical School, Boston, MA USA
| | - Britt-Sabina Löscher
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel & University Hospital Schleswig-Holstein, Kiel, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel & University Hospital Schleswig-Holstein, Kiel, Germany
| | - Braden Boone
- HudsonAlpha Institute for Biotechnology, Huntsville, AL USA
| | - Shawn E. Levy
- HudsonAlpha Institute for Biotechnology, Huntsville, AL USA
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Sander Pajusalu
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - Matt Huentelman
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | - Marcus Naymik
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ USA
| | | | | | | | - Mark Yandell
- Fabric Genomics Inc., Oakland, CA USA
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT USA
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Norsa L, Berni Canani R, Duclaux-Loras R, Bequet E, Köglmeier J, Russell RK, Uhlig HH, Travis S, Hollis J, Koletzko S, Grimaldi G, Castaldo G, Rodrigues A, Deflandre J, Dembinski L, Shah N, Heinz-Erian P, Janecke A, Leskinen S, Wedenoja S, Koskela R, Lachaux A, Kolho KL, Ruemmele FM. Inflammatory Bowel Disease in Patients with Congenital Chloride Diarrhoea. J Crohns Colitis 2021; 15:1679-1685. [PMID: 33770165 DOI: 10.1093/ecco-jcc/jjab056] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Congenital chloride diarrhoea [CLD] is a rare autosomal recessive disease caused by mutations in the solute family carrier 26 member 3 [SLC26A3] gene. Patients suffer from life-long watery diarrhoea and chloride loss. Inflammatory bowel disease [IBD] has been reported in individual patients with CLD and in scl26a3-deficient mice. METHODS We performed an international multicentre analysis to build a CLD cohort and to identify cases with IBD. We assessed clinical and genetic characteristics of subjects and studied the cumulative incidence of CLD-associated IBD. RESULTS In a cohort of 72 patients with CLD caused by 17 different SLC26A3 mutations, we identified 12 patients [17%] diagnosed with IBD. Nine patients had Crohn's disease, two ulcerative colitis and one IBD-unclassified [IBD-U]. The prevalence of IBD in our cohort of CLD was higher than the highest prevalence of IBD in Europe [p < 0.0001]. The age of onset was variable [13.5 years, interquartile range: 8.5-23.5 years]. Patients with CLD and IBD had lower z-score for height than those without IBD. Four of 12 patients had required surgery [ileostomy formation n = 2, ileocaecal resection due to ileocaecal valve stenosis n = 1 and colectomy due to stage II transverse colon cancer n = 1]. At last follow-up, 5/12 were on biologics [adalimumab, infliximab or vedolizumab], 5/12 on immunosuppressants [azathioprine or mercaptopurine], one on 5-ASA and one off-treatment. CONCLUSIONS A substantial proportion of patients with CLD develop IBD. This suggests the potential involvement of SL26A3-mediated anion transport in IBD pathogenesis. Patients with CLD-associated IBD may require surgery for treatment failure or colon cancer.
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Affiliation(s)
- Lorenzo Norsa
- Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Pediatric Gastroenterology Hepatology and Nutrition, Paris, France.,Pediatric Gastroenterology Hepatology and Transplantation, ASST Papa Giovanni XXIII, Bergamo, Italy.,Université de Paris, Faculté de Médecine, Paris, France
| | - Roberto Berni Canani
- Department of Translational Medical Science - Pediatric Section, University 'Federico II', Naples, Italy.,CEINGE Advanced Biotechnologies, University Federico II, Naples, Italy.,European Laboratory for the Investigation of Food Induced Diseases, University 'Federico II', Naples, Italy
| | - Remi Duclaux-Loras
- Department of Paediatric Gastroenterology Hepatology and Nutrition, Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Bron, France.,CIRI unité Inserm U1111, ENS Lyon, France
| | - Emeline Bequet
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, University Hospital Liège, Belgium
| | - Jutta Köglmeier
- Pediatric Gastroenterology Hepatology and Nutrition, Great Ormond Street Hospital for Sick Children, London, UK
| | - Richard K Russell
- Pediatric Gastroenterology Hepatology and Nutrition, Royal Hospital for Children, Glasgow, UK
| | - Holm H Uhlig
- Translational Gastroenterology Unit and Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Simon Travis
- Translational Gastroenterology Unit and Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Jennifer Hollis
- Translational Gastroenterology Unit and Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Sibylle Koletzko
- Division of Gastroenterology and Hepatology, Dr. von Hauner Children's Hospital, University Hospital, LMU Munich, Munich, Germany.,Department of Paediatrics, School of Medicine Collegium Medicum University of Warmia and Mazury, Olsztyn, Poland
| | - Giusi Grimaldi
- Department of Translational Medical Science - Pediatric Section, University 'Federico II', Naples, Italy
| | - Giuseppe Castaldo
- CEINGE Advanced Biotechnologies, University Federico II, Naples, Italy
| | - Astor Rodrigues
- Translational Gastroenterology Unit and Biomedical Research Centre, University of Oxford, Oxford, UK
| | | | - Lukasz Dembinski
- Department of Paediatrics, Gastroenterology and Nutrition, Medical University of Warsaw, Warsaw, Poland
| | - Neil Shah
- Pediatric Gastroenterology Hepatology and Nutrition, Great Ormond Street Hospital for Sick Children, London, UK
| | - Peter Heinz-Erian
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Andreas Janecke
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Saara Leskinen
- Department of Paediatric Gastroenterology, Kuopio University Hospital, Kuopio, Finland
| | - Satu Wedenoja
- Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Ritva Koskela
- Department of Internal Medicine, Oulu University Hospital, Oulu, Finland
| | - Alain Lachaux
- Department of Paediatric Gastroenterology Hepatology and Nutrition, Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Bron, France
| | - Kaija-Leena Kolho
- Department of Paediatric Gastroenterology, Children's Hospital and University of Helsinki, Helsinki, Finland and Tampere University, Tampere, Finland
| | - Frank M Ruemmele
- Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Pediatric Gastroenterology Hepatology and Nutrition, Paris, France
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Wolfe RM, Mohsen AW, Walsh Vockley C, Bertrand CA, Nicholls RD, Heiman P, Seibold LM, Vockley J, Ghaloul-Gonzalez L. Novel GUCY2C variant causing familial diarrhea in a Mennonite kindred and a potential therapeutic approach. Am J Med Genet A 2021; 185:2046-2055. [PMID: 33949097 PMCID: PMC8251925 DOI: 10.1002/ajmg.a.62207] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 03/11/2021] [Accepted: 03/24/2021] [Indexed: 12/31/2022]
Abstract
Guanylate cyclase 2C (GC‐C), encoded by the GUCY2C gene, is implicated in hereditary early onset chronic diarrhea. Several families with chronic diarrhea symptoms have been identified with autosomal dominant, gain‐of‐function mutations in GUCY2C. We have identified a Mennonite patient with a novel GUCY2C variant (c.2381A > T; p.Asp794Val) with chronic diarrhea and an extensive maternal family history of chronic diarrhea and bowel dilatation. Functional studies including co‐segregation analysis showed that all family members who were heterozygous for this variant had GI‐related symptoms. HEK‐293 T cells expressing the Asp794Val GC‐C variant showed increased cGMP production when stimulated with Escherichia coli heat‐stable enterotoxin STp (HST), which was reversed when 5‐(3‐Bromophenyl)‐5,11‐dihydro‐1,3‐dimethyl‐1H‐indeno[2′,1′:5,6]pyrido[2,3‐d]pyrimidine‐2,4,6(3H)‐trione (BPIPP; a GC‐C inhibitor) was used. In addition, cystic fibrosis transmembrane conductance regulator (CFTR) activity measured with SPQ fluorescence assay was increased in these cells after treatment with HST, indicating a crucial role for CFTR activity in the pathogenesis of this disorder. These results support pathogenicity of the GC‐C Asp794Val variant as a cause of chronic diarrhea in this family. Furthermore, this work identifies potential candidate drug, GC‐C inhibitor BPIPP, to treat diarrhea caused by this syndrome.
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Affiliation(s)
- Rachel M Wolfe
- University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Al-Walid Mohsen
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Cate Walsh Vockley
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Carol A Bertrand
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Robert D Nicholls
- University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Paige Heiman
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Leah M Seibold
- Division of Gastroenterology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jerry Vockley
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lina Ghaloul-Gonzalez
- Division of Genetic and Genomic Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Downie ML, Lopez Garcia SC, Kleta R, Bockenhauer D. Inherited Tubulopathies of the Kidney: Insights from Genetics. Clin J Am Soc Nephrol 2021; 16:620-630. [PMID: 32238367 PMCID: PMC8092065 DOI: 10.2215/cjn.14481119] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The kidney tubules provide homeostasis by maintaining the external milieu that is critical for proper cellular function. Without homeostasis, there would be no heartbeat, no muscle movement, no thought, sensation, or emotion. The task is achieved by an orchestra of proteins, directly or indirectly involved in the tubular transport of water and solutes. Inherited tubulopathies are characterized by impaired function of one or more of these specific transport molecules. The clinical consequences can range from isolated alterations in the concentration of specific solutes in blood or urine to serious and life-threatening disorders of homeostasis. In this review, we focus on genetic aspects of the tubulopathies and how genetic investigations and kidney physiology have crossfertilized each other and facilitated the identification of these disorders and their molecular basis. In turn, clinical investigations of genetically defined patients have shaped our understanding of kidney physiology.
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Affiliation(s)
- Mallory L. Downie
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Sergio C. Lopez Garcia
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Robert Kleta
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Detlef Bockenhauer
- Department of Renal Medicine, University College London, London, United Kingdom,Department of Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
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Impaired Intestinal Sodium Transport in Inflammatory Bowel Disease: From the Passenger to the Driver's Seat. Cell Mol Gastroenterol Hepatol 2021; 12:277-292. [PMID: 33744482 PMCID: PMC8165433 DOI: 10.1016/j.jcmgh.2021.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/22/2022]
Abstract
Although impaired intestinal sodium transport has been described for decades as a ubiquitous feature of inflammatory bowel disease (IBD), whether and how it plays a pivotal role in the ailment has remained uncertain. Our identification of dominant mutations in receptor guanylyl cyclase 2C as a cause of IBD-associated familial diarrhea syndrome brought a shift in the way we envision impaired sodium transport. Is this just a passive collateral effect resulting from intestinal inflammation, or is it a crucial regulator of IBD pathogenesis? This review summarizes the mutational spectrum and underlying mechanisms of monogenic IBD associated with congenital sodium diarrhea. We constructed a model proposing that impaired sodium transport is an upstream pathogenic factor in IBD. The review also synthesized emerging insights from microbiome and animal studies to suggest how sodium malabsorption can serve as a unifying mediator of downstream pathophysiology. Further investigations into the mechanisms underlying salt and water transport in the intestine will provide newer approaches for understanding the ion-microbiome-immune cross-talk that serves as a driver of IBD. Model systems, such as patient-derived enteroids or induced pluripotent stem cell models, are warranted to unravel the role of individual genes regulating sodium transport and to develop more effective epithelial rescue and repair therapies.
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Yin J, Sunuwar L, Kasendra M, Yu H, Tse CM, Talbot CC, Boronina T, Cole R, Karalis K, Donowitz M. Fluid shear stress enhances differentiation of jejunal human enteroids in Intestine-Chip. Am J Physiol Gastrointest Liver Physiol 2021; 320:G258-G271. [PMID: 33074011 PMCID: PMC8202237 DOI: 10.1152/ajpgi.00282.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is increasing evidence that the study of normal human enteroids duplicates many known aspects of human intestinal physiology. However, this epithelial cell-only model lacks the many nonepithelial intestinal cells present in the gastrointestinal tract and exposure to the mechanical forces to which the intestine is exposed. We tested the hypothesis that physical shear forces produced by luminal and blood flow would provide an intestinal model more closely resembling normal human jejunum. Jejunal enteroid monolayers were studied in the Emulate, Inc. Intestine-Chip under conditions of constant luminal and basolateral flow that was designed to mimic normal intestinal fluid flow, with human umbilical vein endothelial cells (HUVECs) on the basolateral surface and with Wnt3A, R-spondin, and Noggin only on the luminal surface. The jejunal enteroids formed monolayers that remained confluent for 6-8 days, began differentiating at least as early as day 2 post plating, and demonstrated continuing differentiation over the entire time of the study, as shown by quantitative real-time polymerase chain reaction and Western blot analysis. Differentiation impacted villus genes and proteins differently with early expression of regenerating family member 1α (REG1A), early reduction to a low but constant level of expression of Na+-K+-2Cl- cotransporter 1 (NKCC1), and increasing expression of sucrase-isomaltase (SI) and downregulated in adenoma (DRA). These results were consistent with continual differentiation, as was shown to occur in mouse villus enterocytes. Compared with differentiated enteroid monolayers grown on Transwell inserts, enteroids exposed to flow were more differentiated but exhibited increased apoptosis and reduced carbohydrate metabolism, as shown by proteomic analysis. This study of human jejunal enteroids-on-chip suggests that luminal and basolateral flow produce a model of continual differentiation over time and NaCl absorption that mimics normal intestine and should provide new insights in intestinal physiology.NEW & NOTEWORTHY This study showed that polarized enteroid models in which there is no basolateral Wnt3a, are differentiated, regardless of the Wnt3a status of the apical media. The study supports the concept that in the human intestine villus differentiation is not an all or none phenomenon, demonstrating that at different days after lack of basolateral Wnt exposure, clusters of genes and proteins exist geographically along the villus with different domains having different functions.
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Affiliation(s)
- Jianyi Yin
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Laxmi Sunuwar
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Huimin Yu
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chung-Ming Tse
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - C. Conover Talbot
- 3Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Tatiana Boronina
- 4Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Robert Cole
- 4Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Katia Karalis
- 2Emulate, Inc., Boston, Massachusetts,5Biomedical Sciences Research Center (BSRC) Alexander Fleming, Vari, Greece,7Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mark Donowitz
- 1Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland,7Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Macraigne L, Allaf B, Buffat C, Spaggiari E, Dimitrov G, Fabre A, Rosenblatt J, Dreux S. Prenatal biochemical diagnosis of two forms of congenital diarrheal disorders (congenital chloride diarrhea and congenital sodium diarrhea): A series of 12 cases. Prenat Diagn 2021; 41:434-439. [PMID: 33350492 DOI: 10.1002/pd.5878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/04/2020] [Accepted: 12/02/2020] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Congenital diarrheal disorders (CDDs) are a group of rare diseases among which some present as inherited disorders of intestinal electrolyte transportation: congenital chloride diarrhea (CCD) and congenital sodium diarrhea (CSD) with prenatal manifestations, mainly polyhydramnios, leading to premature delivery. Affected neonates present with watery stools, sometimes mistaken as urine, leading to a misdiagnosis of Bartter syndrome. The aim of this study was to study the value of a prenatal biochemical pattern in the case of suspected CDD. METHODS We retrospectively studied 12 amniotic fluids of CDD-affected fetuses prenatally suspected and confirmed after birth. Digestive enzymes, proteins, and electrolytes were assayed and showed abnormal biochemical patterns. RESULTS The 12 infants (eight CCD- and four CSD-affected) were born prematurely with a normal birth weight. Electrolytes and the Bartter index were normal for all cases. Amniotic fluid enzyme patterns were abnormal: anal leakage for nine, as expected, but vomiting of bile was observed for three infants, for whom an occlusive syndrome required surgery, and thereafter severe complications appeared with a poor prognosis. CONCLUSION Amniotic fluid biochemical patterns differentiate CDD from Bartter syndrome. If a vomiting bile pattern is observed, postnatal management should take into account the hypothesis of a most severe complication.
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Affiliation(s)
- Laure Macraigne
- Unité de Biochimie Prénatale, Laboratoire de Biochimie-Hormonologie, Hôpital Robert Debré, AP-HP, Paris, France
| | - Bichr Allaf
- Unité de Biochimie Prénatale, Laboratoire de Biochimie-Hormonologie, Hôpital Robert Debré, AP-HP, Paris, France
| | - Christophe Buffat
- Département de Génétique Médicale, Hôpital Timone Enfants, AP-HM, Marseille, France
| | - Emmanuel Spaggiari
- Department of Obstetrics and Maternal-Fetal Medicine, AP-HP, Necker Enfants-Malades Hospital, Paris, France
| | | | - Alexandre Fabre
- Pediatric Gastroenterology and Nutrition, Hospital La Timone, AP-HM, Marseille, France
| | - Jonathan Rosenblatt
- Department of Gynecology and Obstetrics, AP-HP, Robert Debré Hospital, University Paris Diderot and Paris Sorbonne-Cité, Paris, France
| | - Sophie Dreux
- Unité de Biochimie Prénatale, Laboratoire de Biochimie-Hormonologie, Hôpital Robert Debré, AP-HP, Paris, France
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Quade BN, Parker MD, Occhipinti R. The therapeutic importance of acid-base balance. Biochem Pharmacol 2021; 183:114278. [PMID: 33039418 PMCID: PMC7544731 DOI: 10.1016/j.bcp.2020.114278] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023]
Abstract
Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple cider vinegar are miracles cures for everything from cancer to COVID-19. Despite these specious claims, the therapeutic value of controlling acid-base balance is indisputable and is the basis of Food and Drug Administration-approved treatments for constipation, epilepsy, metabolic acidosis, and peptic ulcers. In this narrative review, we present evidence in support of the current and potential therapeutic value of countering local and systemic acid-base imbalances, several of which do in fact involve the administration of baking soda (sodium bicarbonate). Furthermore, we discuss the side effects of pharmaceuticals on acid-base balance as well as the influence of acid-base status on the pharmacokinetic properties of drugs. Our review considers all major organ systems as well as information relevant to several clinical specialties such as anesthesiology, infectious disease, oncology, dentistry, and surgery.
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Affiliation(s)
- Bianca N Quade
- Department of Physiology and Biophysics, The State University of New York, The University at Buffalo, Buffalo, NY 14203, USA
| | - Mark D Parker
- Department of Physiology and Biophysics, The State University of New York, The University at Buffalo, Buffalo, NY 14203, USA; Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA; State University of New York Eye Institute, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Rossana Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
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45
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The E3 ubiquitin ligase UBR5 interacts with TTC7A and may be associated with very early onset inflammatory bowel disease. Sci Rep 2020; 10:18648. [PMID: 33122718 PMCID: PMC7596066 DOI: 10.1038/s41598-020-73482-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 09/17/2020] [Indexed: 11/17/2022] Open
Abstract
Very early onset inflammatory bowel disease (VEOIBD) denotes children with onset of IBD before six years of age. A number of monogenic disorders are associated with VEOIBD including tetratricopeptide repeat domain 7A (TTC7A) deficiency. TTC7A-deficiency is characterized by apoptotic colitis in milder cases with severe intestinal atresia and immunodeficiency in cases with complete loss of protein. We used whole exome sequencing in a VEOIBD patient presenting with colitis characterized by colonic apoptosis and no identified known VEOIBD variants, to identify compound heterozygous deleterious variants in the Ubiquitin protein ligase E3 component N-recognin 5 (UBR5) gene. Functional studies demonstrated that UBR5 co-immunoprecipitates with the TTC7A and the UBR5 variants had reduced interaction between UBR5 and TTC7A. Together this implicates UBR5 in regulating TTC7A signaling in VEOIBD patients with apoptotic colitis.
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Abstract
Prouroguanylin (ProUGN) in the intestine is cleaved to form uroguanylin (UGN), which stimulates guanylate cyclase C (GUCY2C), inducing cyclic guanosine monophosphate signaling. Paracrine release regulates fluid secretion, contributing to bowel function, whereas endocrine secretion evoked by eating forms a gut-brain axis, controlling appetite. Whereas hormone insufficiency contributes to hyperphagia in obesity, its contribution to the pathophysiology of constipation syndromes remains unexplored. Here, we compared circulating ProUGN and UGN in healthy subjects and in patients with chronic idiopathic constipation (CIC) and patients with irritable bowel syndrome with constipation (IBS-C).
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An inducible intestinal epithelial cell-specific NHE3 knockout mouse model mimicking congenital sodium diarrhea. Clin Sci (Lond) 2020; 134:941-953. [PMID: 32227118 PMCID: PMC8819665 DOI: 10.1042/cs20200065] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 12/13/2022]
Abstract
The sodium–hydrogen exchanger isoform 3 (NHE3, SLC9A3) is abundantly expressed in the gastrointestinal tract and is proposed to play essential roles in Na+ and fluid absorption as well as acid–base homeostasis. Mutations in the SLC9A3 gene can cause congenital sodium diarrhea (CSD). However, understanding the precise role of intestinal NHE3 has been severely hampered due to the lack of a suitable animal model. To navigate this problem and better understand the role of intestinal NHE3, we generated a tamoxifen-inducible intestinal epithelial cell-specific NHE3 knockout mouse model (NHE3IEC-KO). Before tamoxifen administration, the phenotype and blood parameters of NHE3IEC-KO were unremarkable compared with control mice. After tamoxifen administration, NHE3IEC-KO mice have undetectable levels of NHE3 in the intestine. NHE3IEC-KO mice develop watery, alkaline diarrhea in combination with a swollen small intestine, cecum and colon. The persistent diarrhea results in higher fluid intake. After 3 weeks, NHE3IEC-KO mice show a ~25% mortality rate. The contribution of intestinal NHE3 to acid–base and Na+ homeostasis under normal conditions becomes evident in NHE3IEC-KO mice that have metabolic acidosis, lower blood bicarbonate levels, hyponatremia and hyperkalemia associated with drastically elevated plasma aldosterone levels. These results demonstrate that intestinal NHE3 has a significant contribution to acid–base, Na+ and volume homeostasis, and lack of intestinal NHE3 has consequences on intestinal structural integrity. This mouse model mimics and explains the phenotype of individuals with CSD carrying SLC9A3 mutations.
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Engevik AC, Coutts AW, Kaji I, Rodriguez P, Ongaratto F, Saqui-Salces M, Medida RL, Meyer AR, Kolobova E, Engevik MA, Williams JA, Shub MD, Carlson DF, Melkamu T, Goldenring JR. Editing Myosin VB Gene to Create Porcine Model of Microvillus Inclusion Disease, With Microvillus-Lined Inclusions and Alterations in Sodium Transporters. Gastroenterology 2020; 158:2236-2249.e9. [PMID: 32112796 PMCID: PMC7282982 DOI: 10.1053/j.gastro.2020.02.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/07/2020] [Accepted: 02/17/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND & AIMS Microvillus inclusion disease (MVID) is caused by inactivating mutations in the myosin VB gene (MYO5B). MVID is a complex disorder characterized by chronic, watery, life-threatening diarrhea that usually begins in the first hours to days of life. We developed a large animal model of MVID to better understand its pathophysiology. METHODS Pigs were cloned by transfer of chromatin from swine primary fetal fibroblasts, which were edited with TALENs and single-strand oligonucleotide to introduce a P663-L663 substitution in the endogenous swine MYO5B (corresponding to the P660L mutation in human MYO5B, associated with MVID) to fertilized oocytes. We analyzed duodenal tissues from patients with MVID (with the MYO5B P660L mutation) and without (controls), and from pigs using immunohistochemistry. Enteroids were generated from pigs with MYO5B(P663L) and without the substitution (control pigs). RESULTS Duodenal tissues from patients with MVID lacked MYO5B at the base of the apical membrane of intestinal cells; instead MYO5B was intracellular. Intestinal tissues and derived enteroids from MYO5B(P663L) piglets had reduced apical levels and diffuse subapical levels of sodium hydrogen exchanger 3 and SGLT1, which regulate transport of sodium, glucose, and water, compared with tissues from control piglets. However, intestinal tissues and derived enteroids from MYO5B(P663L) piglets maintained CFTR on apical membranes, like tissues from control pigs. Liver tissues from MYO5B(P663L) piglets had alterations in bile salt export pump, a transporter that facilitates bile flow, which is normally expressed in the bile canaliculi in the liver. CONCLUSIONS We developed a large animal model of MVID that has many features of the human disease. Studies of this model could provide information about the functions of MYO5B and MVID pathogenesis, and might lead to new treatments.
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Affiliation(s)
- Amy C Engevik
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; The Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.
| | | | - Izumi Kaji
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; The Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | | | | | - Milena Saqui-Salces
- Department of Animal Science, University of Minnesota, Saint Paul, Minnesota
| | - Ramya Lekha Medida
- Department of Animal Science, University of Minnesota, Saint Paul, Minnesota
| | - Anne R Meyer
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; The Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Elena Kolobova
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; The Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Melinda A Engevik
- Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Janice A Williams
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; The Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Mitchell D Shub
- Phoenix Children's Hospital and University of Arizona College of Medicine-Phoenix, Phoenix, Arizona
| | | | | | - James R Goldenring
- Department of Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee; The 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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Ouahed J, Spencer E, Kotlarz D, Shouval DS, Kowalik M, Peng K, Field M, Grushkin-Lerner L, Pai SY, Bousvaros A, Cho J, Argmann C, Schadt E, Mcgovern DPB, Mokry M, Nieuwenhuis E, Clevers H, Powrie F, Uhlig H, Klein C, Muise A, Dubinsky M, Snapper SB. Very Early Onset Inflammatory Bowel Disease: A Clinical Approach With a Focus on the Role of Genetics and Underlying Immune Deficiencies. Inflamm Bowel Dis 2020; 26:820-842. [PMID: 31833544 PMCID: PMC7216773 DOI: 10.1093/ibd/izz259] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Indexed: 12/12/2022]
Abstract
Very early onset inflammatory bowel disease (VEO-IBD) is defined as IBD presenting before 6 years of age. When compared with IBD diagnosed in older children, VEO-IBD has some distinct characteristics such as a higher likelihood of an underlying monogenic etiology or primary immune deficiency. In addition, patients with VEO-IBD have a higher incidence of inflammatory bowel disease unclassified (IBD-U) as compared with older-onset IBD. In some populations, VEO-IBD represents the age group with the fastest growing incidence of IBD. There are contradicting reports on whether VEO-IBD is more resistant to conventional medical interventions. There is a strong need for ongoing research in the field of VEO-IBD to provide optimized management of these complex patients. Here, we provide an approach to diagnosis and management of patients with VEO-IBD. These recommendations are based on expert opinion from members of the VEO-IBD Consortium (www.VEOIBD.org). We highlight the importance of monogenic etiologies, underlying immune deficiencies, and provide a comprehensive description of monogenic etiologies identified to date that are responsible for VEO-IBD.
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Affiliation(s)
- Jodie Ouahed
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA
| | - Elizabeth Spencer
- Division of Gastroenterology, Hepatology and Nutrition, Mount Sinai Hospital, New York City, NY, USA
| | - Daniel Kotlarz
- Department of Pediatrics, Dr. Von Haunder Children’s Hospital, University Hospital, Ludwig-Maximillians-University Munich, Munich, Germany
| | - Dror S Shouval
- Pediatric Gastroenterology Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel Hashomer, Ramat-Gan, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Matthew Kowalik
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA
| | - Kaiyue Peng
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA,Department of Gastroenterology, Pediatric Inflammatory Bowel Disease Research Center, Children’s Hospital of Fudan University, Shanghai, China
| | - Michael Field
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA
| | - Leslie Grushkin-Lerner
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA
| | - Sung-Yun Pai
- Division of Hematology-Oncology, Boston Children’s Hospital, Dana-Farber Cancer Institute, Boston, MA USA
| | - Athos Bousvaros
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA
| | - Judy Cho
- Icahn School of Medicine at Mount Sinai, Dr. Henry D. Janowitz Division of Gastroenterology, New York, NY, USA
| | - Carmen Argmann
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Eric Schadt
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, USA,Sema4, Stamford, CT, USA
| | - Dermot P B Mcgovern
- F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Michal Mokry
- Division of Pediatrics, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Edward Nieuwenhuis
- Division of Pediatrics, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Hans Clevers
- Hubrecht Institute-Royal Netherlands Academy of Arts and Sciences, Utrecht, the Netherlands
| | - Fiona Powrie
- University of Oxford, Kennedy Institute of Rheumatology, Oxford, UK
| | - Holm Uhlig
- Translational Gastroenterology Unit, University of Oxford, Oxford, UK; Department of Pediatrics, University of Oxford, Oxford, UK
| | - Christoph Klein
- Pediatric Gastroenterology Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Tel Hashomer, Ramat-Gan, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Aleixo Muise
- SickKids Inflammatory Bowel Disease Center and Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON, Canada. Department of Pediatrics and Biochemistry, University of Toronto, Hospital for Sick Children, Toronto, ON, Canada
| | - Marla Dubinsky
- Division of Gastroenterology, Hepatology and Nutrition, Mount Sinai Hospital, New York City, NY, USA
| | - Scott B Snapper
- Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Boston Children’s Hospital, Boston, MA, USA,Address correspondence to: Scott B. Snapper, MD, PhD, Children's Hospital Boston, Boston, Massachusetts, USA.
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Abstract
Acid-base balance is critical for normal life. Acute and chronic disturbances impact cellular energy metabolism, endocrine signaling, ion channel activity, neuronal activity, and cardiovascular functions such as cardiac contractility and vascular blood flow. Maintenance and adaptation of acid-base homeostasis are mostly controlled by respiration and kidney. The kidney contributes to acid-base balance by reabsorbing filtered bicarbonate, regenerating bicarbonate through ammoniagenesis and generation of protons, and by excreting acid. This review focuses on acid-base disorders caused by renal processes, both inherited and acquired. Distinct rare inherited monogenic diseases affecting acid-base handling in the proximal tubule and collecting duct have been identified. In the proximal tubule, mutations of solute carrier 4A4 (SLC4A4) (electrogenic Na+/HCO3--cotransporter Na+/bicarbonate cotransporter e1 [NBCe1]) and other genes such as CLCN5 (Cl-/H+-antiporter), SLC2A2 (GLUT2 glucose transporter), or EHHADH (enoyl-CoA, hydratase/3-hydroxyacyl CoA dehydrogenase) causing more generalized proximal tubule dysfunction can cause proximal renal tubular acidosis resulting from bicarbonate wasting and reduced ammoniagenesis. Mutations in adenosine triphosphate ATP6V1 (B1 H+-ATPase subunit), ATPV0A4 (a4 H+-ATPase subunit), SLC4A1 (anion exchanger 1), and FOXI1 (forkhead transcription factor) cause distal renal tubular acidosis type I. Carbonic anhydrase II mutations affect several nephron segments and give rise to a mixed proximal and distal phenotype. Finally, mutations in genes affecting aldosterone synthesis, signaling, or downstream targets can lead to hyperkalemic variants of renal tubular acidosis (type IV). More common forms of renal acidosis are found in patients with advanced stages of chronic kidney disease and are owing, at least in part, to a reduced capacity for ammoniagenesis.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center for Competence in Research Kidney, Switzerland.
| | - Pedro H Imenez Silva
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center for Competence in Research Kidney, Switzerland
| | - Soline Bourgeois
- Institute of Physiology, University of Zurich, Zurich, Switzerland; National Center for Competence in Research Kidney, Switzerland
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