1
|
Affiliation(s)
- Ahmet Ozen
- From the Department of Pediatrics, Division of Allergy and Immunology, Marmara University, School of Medicine, the Istanbul Jeffrey Modell Diagnostic Center for Primary Immunodeficiency Diseases, and the Isil Berat Barlan Center for Translational Medicine - all in Istanbul, Turkey (A.O.); and the Molecular Development of the Immune System Section, Laboratory of Immune System Biology, Clinical Genomics Program, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD (M.J.L.)
| | - Michael J Lenardo
- From the Department of Pediatrics, Division of Allergy and Immunology, Marmara University, School of Medicine, the Istanbul Jeffrey Modell Diagnostic Center for Primary Immunodeficiency Diseases, and the Isil Berat Barlan Center for Translational Medicine - all in Istanbul, Turkey (A.O.); and the Molecular Development of the Immune System Section, Laboratory of Immune System Biology, Clinical Genomics Program, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD (M.J.L.)
| |
Collapse
|
2
|
Mousa J, Veres L, Mohamed A, De Graef D, Morava E. Acetazolamide treatment in late onset CDG type 1 due to biallelic pathogenic DHDDS variants. Mol Genet Metab Rep 2022; 32:100901. [PMID: 36046393 PMCID: PMC9421445 DOI: 10.1016/j.ymgmr.2022.100901] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/29/2022] Open
Abstract
Pathogenic variants in DHDDS have been associated with either autosomal recessive retinitis pigmentosa or DHDDS-CDG. Heterozygous variants in DHDDS have been described in patients with a progressive neurodegenerative disease. Here we report on an individual presenting with a multisystem CDG phenotype who was diagnosed with known homozygous pathogenic DHDDS variants, previously associated with isolated retinitis pigmentosa. An adult Ashkenazi Jewish female developed multiple symptoms of late onset type 1 CDG including seizures, ataxia, protein losing enteropathy, tremor, and titubation in association with elevated mono-oligo/di-oligo transferrin ratio in blood, and classic retinitis pigmentosa. She was diagnosed by whole exome sequencing with the common Ashkenazi Jewish, homozygous p.K42E variants in DHDDS. She was started on Acetazolamide and responded well to the treatment which improved her titubation, tremor, and generalized edema. Reviewing the literature, families with DHDDS variants and multisystem presentation were different from our patient's presentation in terms of clinical manifestations, severity, genetic defect, and mode of inheritance. In previously reported patients with neurologic symptoms including seizures, movement abnormalities, and global development delay, the phenotype was caused by heterozygous pathogenic variants in DHDDS. The infant who was reported with a multisystem phenotype and fatal type 1 CDG had compound heterozygosity for a nonsense and a splice site variant in DHDDS, resulting in DHDDS-CDG. The discovery of the novel phenotype associated with the common p.K42E pathogenic variant in DHDDS expands the spectrum of CDG and further enhances our understanding on the role of DHDDS in glycosylation beyond the retina. We report on the first individual carrying homozygous p.K42E variants in DHDDS associated with protein losing enteropathy, seizures, and ataxia. We observed familial variability in association with p.K42E and progressive ataxia in siblings with in DHDDS-CDG. The novel DHDDS-CDG patient phenotype broadens the current spectrum of CDG. Acetazolamide was successful in treating titubation and recurrent edema in our DHDDS-CDG patient of Ashkenazi Jewish descent.
Collapse
Affiliation(s)
- Jehan Mousa
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Larissa Veres
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Anab Mohamed
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | | | - Eva Morava
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
- Corresponding author at: Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
| |
Collapse
|
3
|
Albokhari D, Ng BG, Guberinic A, Daniel EJP, Engelhardt NM, Barone R, Fiumara A, Garavelli L, Trimarchi G, Wolfe L, Raymond KM, Morava E, He M, Freeze HH, Lam C, Edmondson AC. ALG8-CDG: Molecular and phenotypic expansion suggests clinical management guidelines. J Inherit Metab Dis 2022; 45:969-980. [PMID: 35716054 PMCID: PMC9474684 DOI: 10.1002/jimd.12527] [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: 02/07/2022] [Revised: 05/26/2022] [Accepted: 06/15/2022] [Indexed: 11/06/2022]
Abstract
Congenital disorders of glycosylation are a continuously expanding group of monogenic disorders of glycoprotein and glycolipid glycan biosynthesis. These disorders mostly manifest with multisystem involvement. Individuals with ALG8-CDG commonly present with hypotonia, protein-losing enteropathy, and hepatic involvement. Here, we describe seven unreported individuals diagnosed with ALG8-CDG based on biochemical and molecular testing and we identify nine novel variants in ALG8, bringing the total to 26 individuals with ALG8-CDG in the medical literature. In addition to the typical multisystem involvement documented in ALG8-CDG, our cohort includes the two oldest patients reported and further expands the phenotype of ALG8-CDG to include stable intellectual disability, autism spectrum disorder and other neuropsychiatric symptoms. We further expand the clinical features in a variety of organ systems including ocular, musculoskeletal, dermatologic, endocrine, and cardiac abnormalities and suggest a comprehensive evaluation and monitoring strategy to improve clinical management.
Collapse
Affiliation(s)
- Daniah Albokhari
- Department of Pediatrics, Division of Human Genetics, Section of Metabolism, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Taibah University College of Medicine, Medina, Saudi Arabia
| | - Bobby G Ng
- Human Genetics Program, Sanford Burnham Prebys, La Jolla, California, USA
| | - Alis Guberinic
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Earnest James Paul Daniel
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Nicole M Engelhardt
- Department of Pediatrics, Division of Human Genetics, Section of Metabolism, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rita Barone
- Department of Clinical and Experimental Medicine, Division of Child Neurology and Psychiatry, University of Catania, Catania, Italy
| | - Agata Fiumara
- Department of Clinical and Experimental Medicine, Pediatric Clinic, University of Catania, Catania, Italy
| | - Livia Garavelli
- Medical Genetics Unit, Mother and Child Department, Local Health Authority (AUSL) of Reggio Emilia Research Unit (IRCCS), Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Gabriele Trimarchi
- Medical Genetics Unit, Mother and Child Department, Local Health Authority (AUSL) of Reggio Emilia Research Unit (IRCCS), Arcispedale Santa Maria Nuova, Reggio Emilia, Italy
| | - Lynne Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, Maryland, USA
| | - Kimiyo M Raymond
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Eva Morava
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota, USA
| | - Miao He
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Hudson H Freeze
- Human Genetics Program, Sanford Burnham Prebys, La Jolla, California, USA
| | - Christina Lam
- Division of Genetic Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA
- Center of Integrated Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Andrew C Edmondson
- Department of Pediatrics, Division of Human Genetics, Section of Metabolism, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| |
Collapse
|
4
|
Sagray E, Johnson JN, Schumacher KR, West S, Lowery RE, Simpson K. Protein-losing enteropathy recurrence after pediatric heart transplantation: Multicenter case series. Pediatr Transplant 2022; 26:e14295. [PMID: 35451219 DOI: 10.1111/petr.14295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/03/2022] [Accepted: 04/09/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Protein-losing enteropathy (PLE) is a devastating complication of the Fontan circulation. Although orthotopic heart transplantation (HTx) typically results in resolution of PLE symptoms, isolated cases of PLE relapse have been described after HTx. METHODS Patients with Fontan-related PLE who had undergone HTx at participating centers and experienced relapse of PLE during follow-up were retrospectively identified. Available data related to pre- and post-HTx characteristics and PLE events were collected. RESULTS Eight patients from four different centers were identified. Median time from Fontan procedure to the development of PLE was 8 years, and median age at HTx was 17 years (range 7.7-21). In all patients, PLE resolved at a median time of 1 month after HTx (0.3-5). PLE recurrences occurred at a median time of 7.5 months after HTx (2-132). Each occurrence was associated with one or more significant clinical events; most commonly cellular- or antibody-mediated rejection; and less commonly graft dysfunction, infection, thrombosis, and posttransplant lymphoproliferative disease. PLE recurrences resolved after the successful treatment of the concomitant event, after a median time of 2 months in seven cases, while persisted and recurred in one patient in association with atypical mycobacterium infection and subsequent PTLD onset and relapses. Six patients were alive during follow-up at a median time of 4 years (1.3-22.5) after HTx. CONCLUSIONS This is the largest series of PLE recurrence after HTx. All cases were associated with one or more concomitant and significant clinical events. PLE typically resolved after resolution of the inciting clinical event.
Collapse
Affiliation(s)
- Ezequiel Sagray
- Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Jonathan N Johnson
- Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Kurt R Schumacher
- Division of Pediatric Cardiology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Shawn West
- Pediatric Cardiology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Ray E Lowery
- Division of Pediatric Cardiology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Kathleen Simpson
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Colorado, University of Colorado Denver, Aurora, Colorado, USA
| |
Collapse
|
5
|
Boyer SW, Johnsen C, Morava E. Nutrition interventions in congenital disorders of glycosylation. Trends Mol Med 2022; 28:463-481. [PMID: 35562242 DOI: 10.1016/j.molmed.2022.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/30/2022] [Accepted: 04/04/2022] [Indexed: 12/13/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a group of more than 160 inborn errors of metabolism affecting multiple pathways of protein and lipid glycosylation. Patients present with a wide range of symptoms and therapies are only available for very few subtypes. Specific nutritional treatment options for certain CDG types include oral supplementation of monosaccharide sugars, manganese, uridine, or pyridoxine. Additional management includes specific diets (i.e., complex carbohydrate or ketogenic diet), iron supplementation, and albumin infusions. We review the dietary management in CDG with a focus on two subgroups: N-linked glycosylation defects and GPI-anchor disorders.
Collapse
Affiliation(s)
- Suzanne W Boyer
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Christin Johnsen
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Eva Morava
- Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
| |
Collapse
|
6
|
Rawat PS, Seyed Hameed AS, Meng X, Liu W. Utilization of glycosaminoglycans by the human gut microbiota: participating bacteria and their enzymatic machineries. Gut Microbes 2022; 14:2068367. [PMID: 35482895 PMCID: PMC9067506 DOI: 10.1080/19490976.2022.2068367] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Glycosaminoglycans (GAGs) are consistently present in the human colon in free forms and as part of proteoglycans. Their utilization is critical for the colonization and proliferation of gut bacteria and also the health of hosts. Hence, it is essential to determine the GAG-degrading members of the gut bacteria and their enzymatic machinery for GAG depolymerization. In this review, we have summarized the reported GAG utilizers from Bacteroides and presented their polysaccharide utilization loci (PUL) and related enzymatic machineries for the degradation of chondroitin and heparin/heparan sulfate. Although similar comprehensive knowledge of GAG degradation is not available for other gut phyla, we have specified recently isolated GAG degraders from gut Firmicutes and Proteobacteria, and analyzed their genomes for the presence of putative GAG PULs. Deciphering the precise GAG utilization mechanism for various phyla will augment our understanding of their effects on human health.
Collapse
Affiliation(s)
- Parkash Singh Rawat
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No.72 Binhai Road, Qingdao266237, P. R. China
| | - Ahkam Saddam Seyed Hameed
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No.72 Binhai Road, Qingdao266237, P. R. China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No.72 Binhai Road, Qingdao266237, P. R. China,CONTACT Xiangfeng Meng State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No.72 Binhai Road, Qingdao266237, P. R. China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No.72 Binhai Road, Qingdao266237, P. R. China
| |
Collapse
|
7
|
Gonzales GB, Njunge JM, Gichuki BM, Wen B, Ngari M, Potani I, Thitiri J, Laukens D, Voskuijl W, Bandsma R, Vanmassenhove J, Berkley JA. The role of albumin and the extracellular matrix on the pathophysiology of oedema formation in severe malnutrition. EBioMedicine 2022; 79:103991. [PMID: 35398787 PMCID: PMC9014367 DOI: 10.1016/j.ebiom.2022.103991] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 02/09/2023] Open
Abstract
BACKGROUND While fluid flows in a steady state from plasma, through interstitium, and into the lymph compartment, altered fluid distribution and oedema can result from abnormal Starling's forces, increased endothelial permeability or impaired lymphatic drainage. The mechanism of oedema formation, especially the primary role of hypoalbuminaemia, remains controversial. Here, we explored the roles of albumin and albumin-independent mechanisms in oedema formation among children with severe malnutrition (SM). METHODS We performed secondary analysis of data obtained from two independent clinical trials in Malawi and Kenya (NCT02246296 and NCT00934492). We then used an unconventional strategy of comparing children with kwashiorkor and marasmus by matching (discovery cohort, n = 144) and normalising (validation cohort, n = 98, 2 time points) for serum albumin. Untargeted proteomics was used in the discovery cohort to determine plausible albumin-independent mechanisms associated with oedema, which was validated using enzyme-linked immunosorbent assay and multiplex assays in the validation cohort. FINDINGS We demonstrated that low serum albumin is necessary but not sufficient to develop oedema in SM. We further found that markers of extracellular matrix (ECM) degradation rather than markers of EG degradation distinguished oedematous and non-oedematous children with SM. INTERPRETATION Our results show that oedema formation has both albumin-dependent and independent mechanisms. ECM integrity appears to have a greater role in oedema formation than EG shedding in SM. FUNDING Research Foundation Flanders (FWO), Thrasher Foundation (15122 and 9403), VLIR-UOS-Ghent University Global Minds Fund, Bill & Melinda Gates Foundation (OPP1131320), MRC/DfID/Wellcome Trust Global Health Trials Scheme (MR/M007367/1), Canadian Institutes of Health Research (156307), Wellcome Trust (WT083579MA).
Collapse
Affiliation(s)
- Gerard Bryan Gonzales
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University and Research, Wageningen, the Netherland,Department of Internal Medicine and Paediatrics, Laboratory of Gastroenterology, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium,VIB-UGent Center for Inflammation Research, Ghent, Belgium,Corresponding author at: Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University and Research, Wageningen, the Netherland.
| | - James M. Njunge
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya,Corresponding author at: The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya.
| | - Bonface M Gichuki
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Bijun Wen
- Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Moses Ngari
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Isabel Potani
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada,Kamuzu University of Health Sciences (Former College of Medicine), Blantyre, Malawi
| | - Johnstone Thitiri
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Debby Laukens
- Department of Internal Medicine and Paediatrics, Laboratory of Gastroenterology, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium,VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Wieger Voskuijl
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,Kamuzu University of Health Sciences (Former College of Medicine), Blantyre, Malawi,Amsterdam Centre for Global Child Health, Emma Children's Hospital, Amsterdam University Medical Centres, Amsterdam, the Netherland,Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam University Medical Centres, Amsterdam, the Netherland
| | - Robert Bandsma
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,Centre for Global Child Health, The Hospital for Sick Children, Toronto, Ontario, Canada,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada,Kamuzu University of Health Sciences (Former College of Medicine), Blantyre, Malawi
| | - Jill Vanmassenhove
- Department of Internal Medicine and Paediatrics, Renal Division, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - James A Berkley
- The Childhood Acute Illness & Nutrition (CHAIN) Network, Nairobi, Kenya,KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya,Nuffield Department of Medicine, Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| |
Collapse
|
8
|
Hassan N, Greve B, Espinoza-Sánchez NA, Götte M. Cell-surface heparan sulfate proteoglycans as multifunctional integrators of signaling in cancer. Cell Signal 2020; 77:109822. [PMID: 33152440 DOI: 10.1016/j.cellsig.2020.109822] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/15/2022]
Abstract
Proteoglycans (PGs) represent a large proportion of the components that constitute the extracellular matrix (ECM). They are a diverse group of glycoproteins characterized by a covalent link to a specific glycosaminoglycan type. As part of the ECM, heparan sulfate (HS)PGs participate in both physiological and pathological processes including cell recruitment during inflammation and the promotion of cell proliferation, adhesion and motility during development, angiogenesis, wound repair and tumor progression. A key function of HSPGs is their ability to modulate the expression and function of cytokines, chemokines, growth factors, morphogens, and adhesion molecules. This is due to their capacity to act as ligands or co-receptors for various signal-transducing receptors, affecting pathways such as FGF, VEGF, chemokines, integrins, Wnt, notch, IL-6/JAK-STAT3, and NF-κB. The activation of those pathways has been implicated in the induction, progression, and malignancy of a tumor. For many years, the study of signaling has allowed for designing specific drugs targeting these pathways for cancer treatment, with very positive results. Likewise, HSPGs have become the subject of cancer research and are increasingly recognized as important therapeutic targets. Although they have been studied in a variety of preclinical and experimental models, their mechanism of action in malignancy still needs to be more clearly defined. In this review, we discuss the role of cell-surface HSPGs as pleiotropic modulators of signaling in cancer and identify them as promising markers and targets for cancer treatment.
Collapse
Affiliation(s)
- Nourhan Hassan
- Department of Gynecology and Obstetrics, Münster University Hospital, Münster, Germany; Biotechnology Program, Department of Chemistry, Faculty of Science, Cairo University, Egypt
| | - Burkhard Greve
- Department of Radiotherapy-Radiooncology, Münster University Hospital, Albert-Schweitzer-Campus 1, A1, 48149 Münster, Germany
| | - Nancy A Espinoza-Sánchez
- Department of Gynecology and Obstetrics, Münster University Hospital, Münster, Germany; Department of Radiotherapy-Radiooncology, Münster University Hospital, Albert-Schweitzer-Campus 1, A1, 48149 Münster, Germany.
| | - Martin Götte
- Department of Gynecology and Obstetrics, Münster University Hospital, Münster, Germany.
| |
Collapse
|
9
|
Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) initially diagnosed as ALG6-CDG: Functional evidence for benignity of the ALG6 c.391T>C (p.Tyr131His) variant and further expanding the BBSOAS phenotype. Eur J Med Genet 2020; 63:103941. [PMID: 32407885 DOI: 10.1016/j.ejmg.2020.103941] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/29/2020] [Accepted: 05/02/2020] [Indexed: 11/23/2022]
Abstract
Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is a recently described autosomal dominant syndrome of developmental delay, cortical vision loss with optic nerve atrophy, epilepsy, and autism spectrum disorder. Due to its many overlapping features with congenital disorders of glycosylation (CDG), the differential diagnosis between these disorders may be difficult and relies on molecular genetic testing. We report on a 31-year-old female initially diagnosed with ALG6-CDG based on glycosylation abnormalities on transferrin isoelectrofocusing and targeted genetic testing, and later diagnosed with BBSOAS by whole-exome sequencing (WES). Functional studies on cultured fibroblasts including Western blotting and RT-qPCR, as well as mass spectrometry of glycosylated transferrin and MALDI-TOF glycan analysis in serum, demonstrated normal glycosylation in this patient. In this report, we extend the phenotype of BBSOAS with ataxia and protein-losing enteropathy. This case is illustrative of the utility of whole exome sequencing in the diagnostic odyssey, and the potential pitfalls of relying on focused genetic testing results for diagnosis of conditions with complex overlapping phenotypes.
Collapse
|
10
|
The Challenge of Modulating Heparan Sulfate Turnover by Multitarget Heparin Derivatives. Molecules 2020; 25:molecules25020390. [PMID: 31963505 PMCID: PMC7024324 DOI: 10.3390/molecules25020390] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/12/2020] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
This review comes as a part of the special issue "Emerging frontiers in GAGs and mimetics". Our interest is in the manipulation of heparan sulfate (HS) turnover by employing HS mimetics/heparin derivatives that exert pleiotropic effects and are interesting for interfering at multiple levels with pathways in which HS is implicated. Due to the important role of heparanase in HS post-biosynthetic modification and catabolism, we focus on the possibility to target heparanase, at both extracellular and intracellular levels, a strategy that can be applied to many conditions, from inflammation to cancer and neurodegeneration.
Collapse
|
11
|
Gougoula C, Bielfeld AP, Pour SJ, Sager M, Krüssel JS, Benten WPM, Baston-Büst DM. Metabolic and behavioral parameters of mice with reduced expression of Syndecan-1. PLoS One 2019; 14:e0219604. [PMID: 31299063 PMCID: PMC6625734 DOI: 10.1371/journal.pone.0219604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/27/2019] [Indexed: 11/19/2022] Open
Abstract
Energy balance is essential for all species. Ligand-receptor interactions mediate processes that regulate body activities like reproduction and metabolism based on the energy status. Such receptors are the heparan sulfate proteoglycans and specifically the family of syndecans. Therefore we investigated the differences of metabolic parameters of heterozygous Syndecan 1 mice (Sdc1+/-) with reduced expression of Sdc1 and the corresponding wild type mice. Sdc1+/- mice have a reduced body weight although they show increased leptin and decreased corticosterone levels. Furthermore, their food and water intake is increased. This is accompanied with less adipose tissue, smaller adipocytes and thus an increased density of adipocytes. For the detailed analysis of the metabolism the automated PhenoMaster system has been used, which allowed continuous and undisturbed recording of food and water intake, energy expenditure and movement. The reason for the lower body weight was the higher energy expenditure of these animals compared to controls. Additionally, female Sdc1+/- mice showed an increased locomotor activity. Referring to organs, the intestine in Sdc1+/- mice was heavier and longer, but no differences at the cellular level could be observed. These findings were independent of normal mating or vice versa embryo transfers of Sdc1+/- and wild type embryos in recipient females of the other genotype. Herein we showed that the reduced expression of Sdc1 led to an altered metabolism on fetal as well as on maternal side, which may play a role in the growth restriction observed in human pregnancy pathologies and in mice lacking Sdc1.
Collapse
Affiliation(s)
- Christina Gougoula
- Central Unit for Animal Research and Animal Welfare Affairs (ZETT) of the Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany
| | | | - Sarah Jean Pour
- Düsseldorf University Hospital, Department of OB/GYN and REI (UniKiD), Düsseldorf, Germany
| | - Martin Sager
- Central Unit for Animal Research and Animal Welfare Affairs (ZETT) of the Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany
| | - Jan-Steffen Krüssel
- Düsseldorf University Hospital, Department of OB/GYN and REI (UniKiD), Düsseldorf, Germany
| | - Wilhelm Peter M. Benten
- Central Unit for Animal Research and Animal Welfare Affairs (ZETT) of the Heinrich-Heine-University of Düsseldorf, Düsseldorf, Germany
| | - Dunja Maria Baston-Büst
- Düsseldorf University Hospital, Department of OB/GYN and REI (UniKiD), Düsseldorf, Germany
- * E-mail:
| |
Collapse
|
12
|
Craven MD, Washabau RJ. Comparative pathophysiology and management of protein-losing enteropathy. J Vet Intern Med 2019; 33:383-402. [PMID: 30762910 PMCID: PMC6430879 DOI: 10.1111/jvim.15406] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 11/30/2018] [Indexed: 12/17/2022] Open
Abstract
Protein‐losing enteropathy, or PLE, is not a disease but a syndrome that develops in numerous disease states of differing etiologies and often involving the lymphatic system, such as lymphangiectasia and lymphangitis in dogs. The pathophysiology of lymphatic disease is incompletely understood, and the disease is challenging to manage. Understanding of PLE mechanisms requires knowledge of lymphatic system structure and function, which are reviewed here. The mechanisms of enteric protein loss in PLE are identical in dogs and people, irrespective of the underlying cause. In people, PLE is usually associated with primary intestinal lymphangiectasia, suspected to arise from genetic susceptibility, or “idiopathic” lymphatic vascular obstruction. In dogs, PLE is most often a feature of inflammatory bowel disease (IBD), and less frequently intestinal lymphangiectasia, although it is not proven which process is the true driving defect. In cats, PLE is relatively rare. Review of the veterinary literature (1977‐2018) reveals that PLE was life‐ending in 54.2% of dogs compared to published disease‐associated deaths in IBD of <20%, implying that PLE is not merely a continuum of IBD spectrum pathophysiology. In people, diet is the cornerstone of management, whereas dogs are often treated with immunosuppression for causes of PLE including lymphangiectasia, lymphangitis, and crypt disease. Currently, however, there is no scientific, extrapolated, or evidence‐based support for an autoimmune or immune‐mediated mechanism. Moreover, people with PLE have disease‐associated loss of immune function, including lymphopenia, severe CD4+ T‐cell depletion, and negative vaccinal titers. Comparison of PLE in people and dogs is undertaken here, and theories in treatment of PLE are presented.
Collapse
Affiliation(s)
- Melanie D Craven
- Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Robert J Washabau
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota
| |
Collapse
|
13
|
Morava E, Tiemes V, Thiel C, Seta N, de Lonlay P, de Klerk H, Mulder M, Rubio-Gozalbo E, Visser G, van Hasselt P, Horovitz DDG, de Souza CFM, Schwartz IVD, Green A, Al-Owain M, Uziel G, Sigaudy S, Chabrol B, van Spronsen FJ, Steinert M, Komini E, Wurm D, Bevot A, Ayadi A, Huijben K, Dercksen M, Witters P, Jaeken J, Matthijs G, Lefeber DJ, Wevers RA. ALG6-CDG: a recognizable phenotype with epilepsy, proximal muscle weakness, ataxia and behavioral and limb anomalies. J Inherit Metab Dis 2016; 39:713-723. [PMID: 27287710 DOI: 10.1007/s10545-016-9945-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 03/17/2016] [Accepted: 05/04/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Alpha-1,3-glucosyltransferase congenital disorder of glycosylation (ALG6-CDG) is a congenital disorder of glycosylation. The original patients were described with hypotonia, developmental disability, epilepsy, and increased bleeding tendency. METHODS Based on Euroglycan database registration, we approached referring clinicians and collected comprehensive data on 41 patients. RESULTS We found hypotonia and developmental delay in all ALG6-CDG patients and epilepsy, ataxia, proximal muscle weakness, and, in the majority of cases, failure to thrive. Nine patients developed intractable seizures. Coagulation anomalies were present in <50 % of cases, without spontaneous bleedings. Facial dysmorphism was rare, but seven patients showed missing phalanges and brachydactyly. Cyclic behavioral change, with autistic features and depressive episodes, was one of the most significant complaints. Eleven children died before the age of 4 years due to protein losing enteropathy (PLE), sepsis, or seizures. The oldest patient was a 40 year-old Dutch woman. The most common pathogenic protein alterations were p.A333V and p.I299Del, without any clear genotype-phenotype correlation. DISCUSSION ALG6-CDG has been now described in 89 patients, making it the second most common type of CDG. It has a recognizable phenotype and a primary neurologic presentation.
Collapse
Affiliation(s)
- Eva Morava
- Center for Metabolic Diseases, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium.
- Tulane University Medical School, Hayward Genetics Center, New Orleans, LA, USA.
| | - Vera Tiemes
- Department of Pediatrics, Radboud University Medical Center, Nijmegen, The Netherlands
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christian Thiel
- Center for Child and Adolescent Medicine, Kinderheilkunde I, University of Heidelberg, Heidelberg, Germany
| | - Nathalie Seta
- Biochimie Métabolique Hôpital Bichat-Claude Bernard, Paris, France
| | - Pascale de Lonlay
- Reference Center of Metabolism, Necker-Enfants Malades Hospital, APHP, Imagine Institute, University Paris-Descartes, Paris, France
| | - Hans de Klerk
- Department of Pediatrics, Erasmus MC - University Medical Center Rotterdam, Emma Hospital, Rotterdam, The Netherlands
| | - Margot Mulder
- Department of Pediatrics, Free University Amsterdam, Amsterdam, The Netherlands
| | - Estela Rubio-Gozalbo
- Department of Pediatrics and Laboratory Genetic Metabolic Diseases, University of Maastricht, Maastricht, The Netherlands
| | - Gepke Visser
- Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter van Hasselt
- Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | | | - Andrew Green
- National Centre for Medical Genetics, Dublin, Ireland
| | - Mohammed Al-Owain
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | - Sabine Sigaudy
- Département de Génétique Médicale, Hôpital Timone Enfant, Marseille, France
| | - Brigitte Chabrol
- Neuropediatrics Unit, Childrens Hospital CHU Timone, Marseille, France
| | - Franc-Jan van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center of Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin Steinert
- Sozialpädiatrisches Zentrum, Neuropädiatrie, Klinik für Kinder- und Jugendmedizin, Dortmund, Germany
| | - Eleni Komini
- Kinderklinik Villingen, Schwarzwald-Baar-Klinikum, Villingen, Germany
| | - Donald Wurm
- Department of Pediatrics, Klinikum Saarbrücken, Saarbrücken, Germany
| | - Andrea Bevot
- Department of Pediatric Neurology and Developmental Medicine, Universal Children's Hospital Tübingen, Tübingen, Germany
| | - Addelkarim Ayadi
- Biochimie Métabolique Hôpital Bichat-Claude Bernard, Paris, France
| | - Karin Huijben
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marli Dercksen
- Centre for Human Metabolomics, North-West University, Potchefstroom, South Africa
| | - Peter Witters
- Center for Metabolic Diseases, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Jaak Jaeken
- Center for Metabolic Diseases, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Gert Matthijs
- Laboratory for Molecular Diagnosis, Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Dirk J Lefeber
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
| |
Collapse
|
14
|
|
15
|
Rymen D, Winter J, Van Hasselt PM, Jaeken J, Kasapkara C, Gokçay G, Haijes H, Goyens P, Tokatli A, Thiel C, Bartsch O, Hecht J, Krawitz P, Prinsen HCMT, Mildenberger E, Matthijs G, Kornak U. Key features and clinical variability of COG6-CDG. Mol Genet Metab 2015; 116:163-70. [PMID: 26260076 DOI: 10.1016/j.ymgme.2015.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 07/09/2015] [Accepted: 07/09/2015] [Indexed: 11/26/2022]
Abstract
The conserved oligomeric Golgi (COG) complex consists of eight subunits and plays a crucial role in Golgi trafficking and positioning of glycosylation enzymes. Mutations in all COG subunits, except subunit 3, have been detected in patients with congenital disorders of glycosylation (CDG) of variable severity. So far, 3 families with a total of 10 individuals with biallelic COG6 mutations have been described, showing a broad clinical spectrum. Here we present 7 additional patients with 4 novel COG6 mutations. In spite of clinical variability, we delineate the core features of COG6-CDG i.e. liver involvement (9/10), microcephaly (8/10), developmental disability (8/10), recurrent infections (7/10), early lethality (6/10), and hypohidrosis predisposing for hyperthermia (6/10) and hyperkeratosis (4/10) as ectodermal signs. Regarding all COG6-related disorders a genotype-phenotype correlation can be discerned ranging from deep intronic mutations found in Shaheen syndrome as the mildest form to loss-of-function mutations leading to early lethal CDG phenotypes. A comparison with other COG deficiencies suggests ectodermal changes to be a hallmark of COG6-related disorders. Our findings aid clinical differentiation of this complex group of disorders and imply subtle functional differences between the COG complex subunits.
Collapse
Affiliation(s)
- Daisy Rymen
- Center for Human Genetics, University of Leuven, Leuven, Belgium; Center for Metabolic Diseases, University Hospital Gasthuisberg, Leuven, Belgium
| | - Julia Winter
- Neonatology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Peter M Van Hasselt
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jaak Jaeken
- Center for Metabolic Diseases, University Hospital Gasthuisberg, Leuven, Belgium
| | - Cigdem Kasapkara
- Department of Pediatric Metabolism and Nutrition, Dr. Sami Ulus Maternity and Children Research and Training Hospital, Ankara, Turkey
| | - Gulden Gokçay
- Department of Pediatric Nutrition and Metabolism, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Hanneke Haijes
- Department of Metabolic Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Philippe Goyens
- University Children's Hospital Queen Fabiola, Brussels, Belgium
| | - Aysegul Tokatli
- Division of Metabolism and Nutrition, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Christian Thiel
- Center for Child and Adolescent Medicine, Heidelberg, Germany
| | - Oliver Bartsch
- Institute of Human Genetics, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Jochen Hecht
- Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | - Peter Krawitz
- Institute of Medical Genetics and Human Genetics, Charité-Universitaetsmedizin Berlin, Berlin, Germany
| | - Hubertus C M T Prinsen
- Department of Medical Genetics, UMC Utrecht, Section Metabolic Diagnostics, Utrecht, The Netherlands
| | - Eva Mildenberger
- Neonatology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Gert Matthijs
- Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Uwe Kornak
- Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitaetsmedizin Berlin, Berlin, Germany; Institute of Medical Genetics and Human Genetics, Charité-Universitaetsmedizin Berlin, Berlin, Germany; Max Planck Institute for Molecular Genetics, Berlin, Germany.
| |
Collapse
|
16
|
Shrimal S, Gilmore R. Reduced expression of the oligosaccharyltransferase exacerbates protein hypoglycosylation in cells lacking the fully assembled oligosaccharide donor. Glycobiology 2015; 25:774-83. [PMID: 25792706 DOI: 10.1093/glycob/cwv018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/09/2015] [Indexed: 11/13/2022] Open
Abstract
A defect in the assembly of the oligosaccharide donor (Dol-PP-GlcNAc(2)Man(9)Glc(3)) for N-linked glycosylation causes hypoglycosylation of proteins by the oligosaccharyltransferase (OST). Mammalian cells express two OST complexes that have different catalytic subunits (STT3A or STT3B). We monitored glycosylation of proteins in asparagine-linked glycosylation 6 (ALG6) deficient cell lines that assemble Dol-PP-GlcNAc(2)Man(9) as the largest oligosaccharide donor. Based upon pulse labeling experiments, 30-40% of STT3A-dependent glycosylation sites and 20% of STT3B-dependent sites are skipped in ALG6-congenital disorders of glycosylation fibroblasts supporting previous evidence that the STT3B complex has a relaxed preference for the fully assembled oligosaccharide donor. Glycosylation of STT3B-dependent sites was more severely reduced in the ALG6 deficient MI8-5 cell line. Protein immunoblot analysis and RT-PCR revealed that MI8-5 cells express 2-fold lower levels of STT3B than the parental Chinese hamster ovary cells. The combination of reduced expression of STT3B and the lack of the optimal Dol-PP-GlcNAc(2)Man(9)Glc(3) donor synergize to cause very severe hypoglycosylation of proteins in MI8-5 cells. Thus, differences in OST subunit expression can modify the severity of hypoglycosylation displayed by cells with a primary defect in the dolichol oligosaccharide assembly pathway.
Collapse
Affiliation(s)
- Shiteshu Shrimal
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Reid Gilmore
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| |
Collapse
|
17
|
Seneff S, Swanson N, Li C. Aluminum and Glyphosate Can Synergistically Induce Pineal Gland Pathology: Connection to Gut Dysbiosis and Neurological Disease. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/as.2015.61005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
18
|
Clinical utility gene card for: ALG6 defective congenital disorder of glycosylation. Eur J Hum Genet 2014; 23:ejhg2014146. [PMID: 25052310 DOI: 10.1038/ejhg.2014.146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 06/18/2014] [Accepted: 06/25/2014] [Indexed: 12/29/2022] Open
|
19
|
Pastorelli L, De Salvo C, Mercado JR, Vecchi M, Pizarro TT. Central role of the gut epithelial barrier in the pathogenesis of chronic intestinal inflammation: lessons learned from animal models and human genetics. Front Immunol 2013; 4:280. [PMID: 24062746 PMCID: PMC3775315 DOI: 10.3389/fimmu.2013.00280] [Citation(s) in RCA: 312] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 08/29/2013] [Indexed: 12/12/2022] Open
Abstract
The gut mucosa is constantly challenged by a bombardment of foreign antigens and environmental microorganisms. As such, the precise regulation of the intestinal barrier allows the maintenance of mucosal immune homeostasis and prevents the onset of uncontrolled inflammation. In support of this concept, emerging evidence points to defects in components of the epithelial barrier as etiologic factors in the pathogenesis of inflammatory bowel diseases (IBDs). In fact, the integrity of the intestinal barrier relies on different elements, including robust innate immune responses, epithelial paracellular permeability, epithelial cell integrity, as well as the production of mucus. The purpose of this review is to systematically evaluate how alterations in the aforementioned epithelial components can lead to the disruption of intestinal immune homeostasis, and subsequent inflammation. In this regard, the wealth of data from mouse models of intestinal inflammation and human genetics are pivotal in understanding pathogenic pathways, for example, that are initiated from the specific loss of function of a single protein leading to the onset of intestinal disease. On the other hand, several recently proposed therapeutic approaches to treat human IBD are targeted at enhancing different elements of gut barrier function, further supporting a primary role of the epithelium in the pathogenesis of chronic intestinal inflammation and emphasizing the importance of maintaining a healthy and effective intestinal barrier.
Collapse
Affiliation(s)
- Luca Pastorelli
- Department of Pathology, Case Western Reserve University School of Medicine , Cleveland, OH , USA ; Department of Biomedical Sciences for Health, University of Milan , Milan , Italy ; Gastroenterology and Digestive Endoscopy Unit, IRCCS Policlinico San Donato , San Donato Milanese , Italy
| | | | | | | | | |
Collapse
|
20
|
Affiliation(s)
- Pierre Russo
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, The University of Pennsylvania Perelman School of Medicine, 324 South 34th Street, Main Building, Room 5NW16, Philadelphia, PA 19104, USA.
| |
Collapse
|
21
|
LaRue M, Gossett JG, Stewart RD, Backer CL, Mavroudis C, Jacobs ML. Plastic Bronchitis in Patients With Fontan Physiology: Review of the Literature and Preliminary Experience With Fontan Conversion and Cardiac Transplantation. World J Pediatr Congenit Heart Surg 2012; 3:364-72. [DOI: 10.1177/2150135112438107] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Madeleine LaRue
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jeffrey G. Gossett
- Division of Pediatric Cardiology, Children’s Memorial Hospital, Chicago, IL, USA
| | - Robert D. Stewart
- Department of Congenital Heart Surgery, Cleveland Clinic Children’s Hospital, Center for Pediatric and Adult Congenital Heart Disease, Cleveland, OH, USA
| | - Carl L. Backer
- Department of Surgery, Division of Cardiovascular-Thoracic Surgery, Children’s Memorial Hospital, Chicago, IL, USA
| | - Constantine Mavroudis
- Congenital Heart Institute, Walt Disney Pavilion, Florida Hospital for Children, Orlando, FL, USA
| | - Marshall L. Jacobs
- Department of Congenital Heart Surgery, Cleveland Clinic Children’s Hospital, Center for Pediatric and Adult Congenital Heart Disease, Cleveland, OH, USA
| |
Collapse
|
22
|
Dercksen M, Crutchley AC, Honey EM, Lippert MM, Matthijs G, Mienie LJ, Schuman HC, Vorster BC, Jaeken J. ALG6-CDG in South Africa: Genotype-Phenotype Description of Five Novel Patients. JIMD Rep 2012; 8:17-23. [PMID: 23430515 DOI: 10.1007/8904_2012_150] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 04/30/2012] [Accepted: 05/07/2012] [Indexed: 12/12/2022] Open
Abstract
ALG6-CDG (formerly named CDG-Ic) (phenotype OMIM 603147, genotype OMIM 604566), is caused by defective endoplasmic reticulum α-1,3-glucosyltransferase (E.C 2.4.1.267) in the N-glycan assembly pathway (Grünewald et al. 2000). It is the second most frequent N-glycosylation disorder after PMM2-CDG; some 37 patients have been reported with 21 different ALG6 gene mutations (Haeuptle & Hennet 2009; Al-Owain 2010). We report on the clinical and biochemical findings of five novel Caucasian South African patients. The first patient had a severe neuro-gastrointestinal presentation. He was compound heterozygous for the known c.998C>T (p.A333V) mutation and the novel c.1338dupA (p.V447SfsX44) mutation. Four more patients, presenting with classical neurological involvement were identified and were compound heterozygous for the known c.257 + 5G>A splice mutation and the c.680G>A (p.G227E) missense mutation. The patients belong to a semi-isolated Caucasian community that may have originated from European pioneers who colonized South Africa in the seventeenth/eighteenth centuries.
Collapse
Affiliation(s)
- M Dercksen
- Centre for Human Metabonomics, North-West University, Potchefstroom, South Africa,
| | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Johnson JN, Driscoll DJ, O'Leary PW. Protein-losing enteropathy and the Fontan operation. Nutr Clin Pract 2012; 27:375-84. [PMID: 22516942 DOI: 10.1177/0884533612444532] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Protein-losing enteropathy (PLE) is a complex disorder characterized by enteric protein loss and often is associated with cardiovascular abnormalities, particularly those with elevated central venous pressure. The Fontan operation is a surgical procedure used to palliate patients with a functional single ventricle. Although the Fontan operation eliminates cyanosis and decreases the workload of the functionally single ventricle, it also elevates central venous pressure. This can result in hepatic and enteric congestion as well as PLE. Despite the universal elevation in central venous pressure, only a fraction of patients who have had a Fontan operation develop PLE. However, PLE is associated with significant morbidity and mortality. Presenting signs and symptoms of PLE include abdominal bloating, diarrhea, edema, pleural effusions, ascites, and failure to thrive. In this review, the authors discuss the diagnosis and prevalence of PLE after the Fontan operation and review currently available therapeutic strategies.
Collapse
Affiliation(s)
- Jonathan N Johnson
- Department of Pediatrics, Division of Pediatric Cardiology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | | | | |
Collapse
|
24
|
Lecca MR, Maag C, Berger EG, Hennet T. Fibrotic response in fibroblasts from congenital disorders of glycosylation. J Cell Mol Med 2012; 15:1788-96. [PMID: 21029365 PMCID: PMC4373368 DOI: 10.1111/j.1582-4934.2010.01187.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Congenital disorders of glycosylation (CDG) are characterized by a generalized underglycosylation of proteins. CDG is associated with multiple symptoms such as psychomotor retardation, hypotonia, hormonal disturbances, liver fibrosis and coagulopathies. The molecular basis of these symptoms is poorly understood considering the large extent of affected glycoproteins. To better understand the cellular responses to protein underglycosylation in CDG, we have investigated the differences in gene expression between healthy control and CDG fibroblasts by transcriptome comparison. This analysis revealed a strong induction of several genes encoding components of the extracellular matrix, such as collagens, COMP, IGFBP5 and biglycan. The extent of this response was confirmed at the protein level by showing increased production of collagen type-I for example. This fibrotic response of CDG fibroblasts was not paralleled by a differentiation to myofibroblasts and by increased TGF-β signalling. We could show that the addition of recombinant IGFBP5, one of the induced proteins in CDG, to healthy control fibroblasts increased the production of collagen type-I to levels similar to those found in CDG fibroblasts. The fibrotic response identified in CDG fibroblasts may account for the elevated tissue fibrosis, which is often encountered in CDG patients.
Collapse
Affiliation(s)
- M Rita Lecca
- Institute of Physiology and Zürich Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland
| | | | | | | |
Collapse
|
25
|
Protein-losing enteropathy: integrating a new disease paradigm into recommendations for prevention and treatment. Cardiol Young 2011; 21:363-77. [PMID: 21349233 DOI: 10.1017/s1047951111000102] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Protein-losing enteropathy is a relatively uncommon complication of Fontan procedures for palliation of complex congenital cardiac disease. However, the relative infrequency of protein-losing enteropathy belies the tremendous medical, psychosocial and financial burdens it places upon afflicted patients, their families and the healthcare system that supports them. Unfortunately, because of the complexity and rarity of this disease process, the pathogenesis and pathophysiology of protein-losing enteropathy remain poorly understood, and attempts at treatment seldom yield long-term success. The most comprehensive analyses of protein-losing enteropathy in this patient population are now over a decade old, and re-evaluation of the prevalence and progress in treatment of this disease is needed. This report describes a single institution experience with the evaluation, management, and treatment of protein-losing enteropathy in patients with congenital cardiac disease in the current era, follows with a comprehensive review of protein-losing enteropathy, focused upon what is known and not known about the pathophysiology of protein-losing enteropathy in this patient population, and concludes with suggestions for prevention and treatment.
Collapse
|
26
|
Sarrazin S, Lamanna WC, Esko JD. Heparan sulfate proteoglycans. Cold Spring Harb Perspect Biol 2011; 3:cshperspect.a004952. [PMID: 21690215 DOI: 10.1101/cshperspect.a004952] [Citation(s) in RCA: 1012] [Impact Index Per Article: 77.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Heparan sulfate proteoglycans are found at the cell surface and in the extracellular matrix, where they interact with a plethora of ligands. Over the last decade, new insights have emerged regarding the mechanism and biological significance of these interactions. Here, we discuss changing views on the specificity of protein-heparan sulfate binding and the activity of HSPGs as receptors and coreceptors. Although few in number, heparan sulfate proteoglycans have profound effects at the cellular, tissue, and organismal level.
Collapse
Affiliation(s)
- Stephane Sarrazin
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California 92093, USA
| | | | | |
Collapse
|
27
|
Abstract
Heparan sulfate proteoglycans are found at the cell surface and in the extracellular matrix, where they interact with a plethora of ligands. Over the last decade, new insights have emerged regarding the mechanism and biological significance of these interactions. Here, we discuss changing views on the specificity of protein-heparan sulfate binding and the activity of HSPGs as receptors and coreceptors. Although few in number, heparan sulfate proteoglycans have profound effects at the cellular, tissue, and organismal level.
Collapse
Affiliation(s)
- Stephane Sarrazin
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California 92093, USA
| | | | | |
Collapse
|
28
|
Radtke AL, Wilson JW, Sarker S, Nickerson CA. Analysis of interactions of Salmonella type three secretion mutants with 3-D intestinal epithelial cells. PLoS One 2010; 5:e15750. [PMID: 21206750 PMCID: PMC3012082 DOI: 10.1371/journal.pone.0015750] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 11/28/2010] [Indexed: 02/07/2023] Open
Abstract
The prevailing paradigm of Salmonella enteropathogenesis based on monolayers asserts that Salmonella pathogenicity island-1 Type Three Secretion System (SPI-1 T3SS) is required for bacterial invasion into intestinal epithelium. However, little is known about the role of SPI-1 in mediating gastrointestinal disease in humans. Recently, SPI-1 deficient nontyphoidal Salmonella strains were isolated from infected humans and animals, indicating that SPI-1 is not required to cause enteropathogenesis and demonstrating the need for more in vivo-like models. Here, we utilized a previously characterized 3-D organotypic model of human intestinal epithelium to elucidate the role of all characterized Salmonella enterica T3SSs. Similar to in vivo reports, the Salmonella SPI-1 T3SS was not required to invade 3-D intestinal cells. Additionally, Salmonella strains carrying single (SPI-1 or SPI-2), double (SPI-1/2) and complete T3SS knockout (SPI-1/SPI-2: flhDC) also invaded 3-D intestinal cells to wildtype levels. Invasion of wildtype and TTSS mutants was a Salmonella active process, whereas non-invasive bacterial strains, bacterial size beads, and heat-killed Salmonella did not invade 3-D cells. Wildtype and T3SS mutants did not preferentially target different cell types identified within the 3-D intestinal aggregates, including M-cells/M-like cells, enterocytes, or Paneth cells. Moreover, each T3SS was necessary for substantial intracellular bacterial replication within 3-D cells. Collectively, these results indicate that T3SSs are dispensable for Salmonella invasion into highly differentiated 3-D models of human intestinal epithelial cells, but are required for intracellular bacterial growth, paralleling in vivo infection observations and demonstrating the utility of these models in predicting in vivo-like pathogenic mechanisms.
Collapse
Affiliation(s)
- Andrea L. Radtke
- School of Life Sciences, Center for Infectious Diseases and Vaccinology, The Biodesign Institute at Arizona State University, Tempe, Arizona, United States of America
| | - James W. Wilson
- School of Life Sciences, Center for Infectious Diseases and Vaccinology, The Biodesign Institute at Arizona State University, Tempe, Arizona, United States of America
- Department of Biology, Villanova University, Villanova, Pennsylvania, United States of America
| | - Shameema Sarker
- School of Life Sciences, Center for Infectious Diseases and Vaccinology, The Biodesign Institute at Arizona State University, Tempe, Arizona, United States of America
| | - Cheryl A. Nickerson
- School of Life Sciences, Center for Infectious Diseases and Vaccinology, The Biodesign Institute at Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
| |
Collapse
|
29
|
Abstract
Intestinal biopsies constitute an ever-increasing portion of the pathologist's workload, accounting for nearly two-thirds of specimens accessioned yearly by the pathology department at The Children's Hospital of Philadelphia. The widespread use of endoscopy and gastrointestinal biopsies in current clinical practice presents the pathologist with a diversity of intestinal mucosal appearances corresponding to disease states of variable clinical severity, requiring close collaboration between clinician and pathologist for optimal interpretation. Many of the entities resulting in severe diarrhea of infancy have been recognized only in the last several decades, and although rare, the study of these disorders, especially when combined with the powerful methods of present-day genetics and molecular biology, has afforded important insights into enterocyte development and function, and intestinal immunity and tolerance. Other conditions once considered infrequent, such as celiac disease, have now been recognized to be much more common and can present with a wide range of pathologic features.
Collapse
Affiliation(s)
- Pierre Russo
- Department of Pathology and Laboratory Medicine, The University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
| |
Collapse
|
30
|
Haeuptle MA, Hennet T. Congenital disorders of glycosylation: an update on defects affecting the biosynthesis of dolichol-linked oligosaccharides. Hum Mutat 2010; 30:1628-41. [PMID: 19862844 DOI: 10.1002/humu.21126] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Defects in the biosynthesis of the oligosaccharide precursor for N-glycosylation lead to decreased occupancy of glycosylation sites and thereby to diseases known as congenital disorders of glycosylation (CDG). In the last 20 years, approximately 1,000 CDG patients have been identified presenting with multiple organ dysfunctions. This review sets the state of the art by listing all mutations identified in the 15 genes (PMM2, MPI, DPAGT1, ALG1, ALG2, ALG3, ALG9, ALG12, ALG6, ALG8, DOLK, DPM1, DPM3, MPDU1, and RFT1) that yield a deficiency of dolichol-linked oligosaccharide biosynthesis. The present analysis shows that most mutations lead to substitutions of strongly conserved amino acid residues across eukaryotes. Furthermore, the comparison between the different forms of CDG affecting dolichol-linked oligosaccharide biosynthesis shows that the severity of the disease does not relate to the position of the mutated gene along this biosynthetic pathway.
Collapse
Affiliation(s)
- Micha A Haeuptle
- Institute of Physiology, University of Zürich, Zürich, Switzerland
| | | |
Collapse
|
31
|
Amadi B, Fagbemi AO, Kelly P, Mwiya M, Torrente F, Salvestrini C, Day R, Golden MH, Eklund EA, Freeze HH, Murch SH. Reduced production of sulfated glycosaminoglycans occurs in Zambian children with kwashiorkor but not marasmus. Am J Clin Nutr 2009; 89:592-600. [PMID: 19116330 DOI: 10.3945/ajcn.2008.27092] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Kwashiorkor, a form of severe malnutrition with high mortality, is characterized by edema and systemic abnormalities. Although extremely common, its pathophysiology remains poorly understood, and its characteristic physical signs are unexplained. OBJECTIVE Because kwashiorkor can develop in protein-losing enteropathy, which is caused by a loss of enterocyte heparan sulfate proteoglycan (HSPG), and previous observations suggest abnormal sulfated glycosaminoglycan (GAG) metabolism, we examined whether intestinal GAG and HSPG are abnormal in children with kwashiorkor. DESIGN Duodenal biopsy samples collected from Zambian children with marasmus (n = 18), marasmic kwashiorkor (n = 8), and kwashiorkor (n = 15) were examined for expression of HSPG, GAGs, and immunologic markers and compared against reference samples from healthy UK control children. GAG and HSPG expression density and inflammatory cell populations were quantitated by computerized analysis. RESULTS The kwashiorkor group was less wasted and had a lower HIV incidence than did the other groups. All duodenal biopsy samples showed inflammation compared with the histologically uninflamed control samples. Biopsy samples from marasmic children had greater inflammation and greater CD3+ and HLA-DR (human leukocyte antigen DR)-positive cell densities than did samples from children with kwashiorkor. Expression of both HSPG and GAGs was similar between marasmic and well-nourished UK children but was markedly lower in children with kwashiorkor in both the epithelium and lamina propria. Although underglycosylated and undersulfated, epithelial syndecan-1 protein was normally expressed in kwashiorkor, which confirmed that abnormalities arise after core protein synthesis. CONCLUSIONS Intestinal HSPG loss occurs in kwashiorkor, which may precipitate protein-losing enteropathy to cause edema. If occurring systemically, impaired HSPG expression could cause several previously unexplained features of kwashiorkor. We speculate that a genetic predisposition to reduced HSPG biosynthesis may offer a contrasting selective advantage, by both diminishing protein catabolism during transient undernutrition and protecting against specific infectious diseases.
Collapse
Affiliation(s)
- Beatrice Amadi
- Department of Paediatrics and Child Health, University Teaching Hospital of Lusaka, Lusaka, Zambia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Glycosylation diseases: quo vadis? Biochim Biophys Acta Mol Basis Dis 2008; 1792:925-30. [PMID: 19061954 DOI: 10.1016/j.bbadis.2008.11.002] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/03/2008] [Accepted: 11/06/2008] [Indexed: 12/29/2022]
Abstract
About 250 to 500 glycogenes (genes that are directly involved in glycan assembly) are in the human genome representing about 1-2% of the total genome. Over 40 human congenital diseases associated with glycogene mutations have been described to date. It is almost certain that the causative glycogene mutations for many more congenital diseases remain to be discovered. Some glycogenes are involved in the synthesis of only a specific protein and/or a specific class of glycan whereas others play a role in the biosynthesis of more than one glycan class. Mutations in the latter type of glycogene result in complex clinical phenotypes that present difficult diagnostic problems to the clinician. In order to understand in biochemical terms the clinical signs and symptoms of a patient with a glycogene mutation, one must understand how the glycogene works. That requires, first of all, determination of the target protein or proteins of the glycogene followed by an understanding of the role, if any, of the glycogene-dependent glycan in the functions of the protein. Many glycogenes act on thousands of glycoproteins. There are unfortunately no general methods to identify all the potentially large number of glycogene target proteins and which of these proteins are responsible for the mutant phenotypes. Whereas biochemical methods have been highly successful in the discovery of glycogenes responsible for many congenital diseases, it has more recently been necessary to use other methods such as homozygosity mapping. Accurate diagnosis of many recently discovered diseases has become difficult and new diagnostic procedures must be developed. Last but not least is the lack of effective treatment for most of these children and of animal models that can be used to test new therapies.
Collapse
|
33
|
Abstract
Protein-losing enteropathy (PLE) is a poorly understood and enigmatic disease process affecting patients with single ventricle after Fontan operation. In those afflicted, PLE after Fontan operation results in significant morbidity and mortality. The pathophysiology of the disease is unknown; however, a proposed mechanism incorporates a combination of phenomena including: (1) altered hemodynamics, specifically low cardiac output; (2) increased mesenteric vascular resistance; (3) systemic inflammation; and (4) altered enterocyte basal membrane glycosaminoglycan make-up. A paradigm for the clinical management of PLE after Fontan operation is proposed.
Collapse
Affiliation(s)
- Jack Rychik
- The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
| |
Collapse
|
34
|
Bode L, Salvestrini C, Park PW, Li JP, Esko JD, Yamaguchi Y, Murch S, Freeze HH. Heparan sulfate and syndecan-1 are essential in maintaining murine and human intestinal epithelial barrier function. J Clin Invest 2008; 118:229-38. [PMID: 18064305 DOI: 10.1172/jci32335] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Accepted: 10/17/2007] [Indexed: 12/12/2022] Open
Abstract
Patients with protein-losing enteropathy (PLE) fail to maintain intestinal epithelial barrier function and develop an excessive and potentially fatal efflux of plasma proteins. PLE occurs in ostensibly unrelated diseases, but emerging commonalities in clinical observations recently led us to identify key players in PLE pathogenesis. These include elevated IFN-gamma, TNF-alpha, venous hypertension, and the specific loss of heparan sulfate proteoglycans from the basolateral surface of intestinal epithelial cells during PLE episodes. Here we show that heparan sulfate and syndecan-1, the predominant intestinal epithelial heparan sulfate proteoglycan, are essential in maintaining intestinal epithelial barrier function. Heparan sulfate- or syndecan-1-deficient mice and mice with intestinal-specific loss of heparan sulfate had increased basal protein leakage and were far more susceptible to protein loss induced by combinations of IFN-gamma, TNF-alpha, and increased venous pressure. Similarly, knockdown of syndecan-1 in human epithelial cells resulted in increased basal and cytokine-induced protein leakage. Clinical application of heparin has been known to alleviate PLE in some patients but its unknown mechanism and severe side effects due to its anticoagulant activity limit its usefulness. We demonstrate here that non-anticoagulant 2,3-de-O-sulfated heparin could prevent intestinal protein leakage in syndecan-deficient mice, suggesting that this may be a safe and effective therapy for PLE patients.
Collapse
Affiliation(s)
- Lars Bode
- Burnham Institute for Medical Research, La Jolla, California 92037, USA
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Using heparin therapy to reverse protein-losing enteropathy in a patient with CDG-Ib. ACTA ACUST UNITED AC 2008; 5:220-4. [PMID: 18285818 DOI: 10.1038/ncpgasthep1061] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 12/21/2007] [Indexed: 12/22/2022]
Abstract
BACKGROUND A 22-year-old female presented with edema, diarrhea, hypoalbuminemia and pancytopenia. She had previously been diagnosed with congenital disorder of glycosylation type Ib, and had a history of congenital hepatic fibrosis, portal hypertension and esophageal varices. In the past she had refused mannose therapy because of associated diarrhea and abdominal pain. INVESTIGATIONS Laboratory examinations, abdominal ultrasonography, bacterial and viral cultures of blood, urine and stools, double-balloon enteroscopy and fecal excretion test using 51Cr-labeled albumin. DIAGNOSIS Protein-losing enteropathy. MANAGEMENT Infusion of albumin followed by intravenous and subcutaneous therapy with unfractionated heparin.
Collapse
|
36
|
Marklová E, Albahri Z. Screening and diagnosis of congenital disorders of glycosylation. Clin Chim Acta 2007; 385:6-20. [PMID: 17716641 DOI: 10.1016/j.cca.2007.07.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 06/22/2007] [Accepted: 07/02/2007] [Indexed: 02/07/2023]
Abstract
The aim of this paper is to review the diagnostics of congenital disorders of glycosylation (CDG), an ever expanding group of diseases. Development delay, neurological, and other clinical abnormalities as well as various non-specific laboratory changes can lead to the first suspicion of the disease. Still common screening test for most CDG types, including CDG Ia, is isoelectric focusing/polyacrylamide gel electrophoresis (IEF). IEF demonstrates the hypoglycosylation of various glycoproteins, usually serum transferrin. Other methods, such as agarose electrophoresis, capillary electrophoresis, high-performance liquid chromatography, micro-column separation combined with turbidimetry, enzyme-(EIA) and radioimmunoassay (RIA) have also been used for screening. However, these methods do not recognize all CDG defects, so other approaches including analysis of membrane-linked markers and urine oligosaccharides should be taken. Confirmation of diagnosis and detailed CDG subtyping starts with thorough structure analysis of the affected lipid-linked oligosaccharide or protein-(peptide)-linked-glycan using metabolic labeling and various (possibly mass-spectrometry combined) techniques. Decreased enzyme activity in peripheral leukocytes/cultured fibroblasts or analysis of affected transporters and other functional proteins combined with identification of specific gene mutations confirm the diagnosis. Prenatal diagnosis, based on enzyme assay or mutation analysis, is also available. Peri-/post-mortem investigations of fatal cases are important for genetic counseling. Evaluation of various analytical approaches and proposed algorithms for investigation complete the review.
Collapse
Affiliation(s)
- Eliska Marklová
- Charles University, Faculty of Medicine, Department of Pediatrics, Hradec Králové, Czech Republic.
| | | |
Collapse
|
37
|
Tárnok A, Bocsi J, Lenz D, Janousek J. Protein Losing Enteropathy after Fontan Surgery – Clinical and Diagnostical Aspects. Transfus Med Hemother 2007. [DOI: 10.1159/000101373] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
38
|
Abstract
Heparan sulphate proteoglycans reside on the plasma membrane of all animal cells studied so far and are a major component of extracellular matrices. Studies of model organisms and human diseases have demonstrated their importance in development and normal physiology. A recurrent theme is the electrostatic interaction of the heparan sulphate chains with protein ligands, which affects metabolism, transport, information transfer, support and regulation in all organ systems. The importance of these interactions is exemplified by phenotypic studies of mice and humans bearing mutations in the core proteins or the biosynthetic enzymes responsible for assembling the heparan sulphate chains.
Collapse
Affiliation(s)
- Joseph R Bishop
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA.
| | | | | |
Collapse
|
39
|
Ostrow AM, Freeze H, Rychik J. Protein-losing enteropathy after fontan operation: investigations into possible pathophysiologic mechanisms. Ann Thorac Surg 2006; 82:695-700. [PMID: 16863787 DOI: 10.1016/j.athoracsur.2006.02.048] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2005] [Revised: 02/18/2006] [Accepted: 02/22/2006] [Indexed: 11/20/2022]
Abstract
BACKGROUND Protein-losing enteropathy (PLE) is an enigmatic disease with significant morbidity and mortality seen after the Fontan operation. The pathophysiology is poorly understood. The purpose of this study is to investigate the association between PLE after the Fontan operation and candidate pathophysiologic mechanisms of the disease by searching for abnormalities of the following: (1) mesenteric blood flow; (2) systemic inflammation; (3) neurohormonal activation; (4) protein glycosylation. METHODS A cross-sectional analysis of 62 patients after the Fontan operation was performed. Twenty-four hour stool sample was collected for alpha-1-antitrypsin (A1AT) clearance, to determine the presence of abnormal enteric protein loss (AEPL) defined as either an abnormal fecal A1AT clearance of greater than 27 mL/24 hours, or an abnormal fecal A1AT concentration of greater than 54 mg/dL. Subjects underwent ultrasonography of the mesenteric and celiac artery blood flow and blood draw for tumor necrosis factor-alpha (TNF-a), high sensitivity C reactive protein (CRP), brain natriuretic peptide (BNP), angiotensin II, coagulation factors protein S, protein C, and antithrombin III (AT III), and serum transferrin for determination of glycosylation defect. RESULTS Age at study was 10.9 +/- 3.4 years; 8.6 +/- 3.9 years after the Fontan operation. Seven subjects had AEPL. Mesenteric-to-celiac artery flow ratio was lower for the AEPL group, than for the non-AEPL group (p < 0.05). The TNF-a, CRP, BNP, and angiotensin II levels were elevated; however, there was no correlation with AEPL. Abnormalities in coagulation factors were present but did not correlate with AEPL. No glycosylation defects were identified. CONCLUSIONS Potential candidate mechanisms for elucidation of the pathophysiology of PLE include abnormal mesenteric vascular resistance and inflammation, conditions uniquely present after the Fontan operation. Targeted investigations of these parameters may provide clues as to the mechanism of onset of PLE after Fontan operation.
Collapse
Affiliation(s)
- Adam M Ostrow
- The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | | | | |
Collapse
|
40
|
Phillips AD. Diarrhées intraitables dues à des anomalies congénitales des entérocytes. ACTA ACUST UNITED AC 2006. [DOI: 10.1159/000093836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
41
|
Abstract
The spectrum of all glycan structures--the glycome--is immense. In humans, its size is orders of magnitude greater than the number of proteins that are encoded by the genome, one percent of which encodes proteins that make, modify, localize or bind sugar chains, which are known as glycans. In the past decade, over 30 genetic diseases have been identified that alter glycan synthesis and structure, and ultimately the function of nearly all organ systems. Many of the causal mutations affect key biosynthetic enzymes, but more recent discoveries point to defects in chaperones and Golgi-trafficking complexes that impair several glycosylation pathways. As more glycosylation disorders and patients with these disorders are identified, the functions of the glycome are starting to be revealed.
Collapse
Affiliation(s)
- Hudson H Freeze
- Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, California 92037, USA.
| |
Collapse
|
42
|
Philips AD. Diarrea intratable causada por anomalías congénitas de los enterocitos. ACTA ACUST UNITED AC 2006. [DOI: 10.1159/000091005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
43
|
Bode L, Freeze HH. Applied glycoproteomics—approaches to study genetic-environmental collisions causing protein-losing enteropathy. Biochim Biophys Acta Gen Subj 2006; 1760:547-59. [PMID: 16380211 DOI: 10.1016/j.bbagen.2005.11.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 11/04/2005] [Accepted: 11/07/2005] [Indexed: 12/31/2022]
Abstract
Protein-losing enteropathy (PLE), the loss of plasma proteins through the intestine, is a life-threatening symptom associated with seemingly unrelated conditions including Crohn's disease, congenital disorder of glycosylation, or Fontan surgery to correct univentricular hearts. Emerging commonalities between these and other disorders led us to hypothesize that PLE develops when genetic insufficiencies collide with simultaneous or sequential environmental insults. Most intriguing is the loss of heparan sulfate (HS) proteoglycans (HSPG) specifically from the basolateral surface of intestinal epithelial cells only during PLE episodes suggesting a direct link to protein leakage. Reasons for HSPG loss are unknown, but genetic insufficiencies affecting HSPG biosynthesis, trafficking, or degradation may be involved. Here, we describe cell-based assays we devised to identify key players contributing to protein leakage. Results from these assays confirm that HS loss directly causes protein leakage, but more importantly, it amplifies the effects of other factors, e.g., cytokines and increased pressure. Thus, HS loss appears to play a central role for PLE. To transfer our in vitro results back to the in vivo situation, we established methods to assess enteric protein leakage in mice and present several genetically deficient strains mimicking intestinal HS loss observed in PLE patients. Preliminary results indicate that mice with haploinsufficient genes involved in HS biosynthesis or HSPG trafficking develop intestinal protein leakage upon additional environmental stress. Our goal is to model PLE in vitro and in vivo to unravel the pathomechanisms underlying PLE, identify patients at risk, and provide them with a safe and effective therapy.
Collapse
Affiliation(s)
- Lars Bode
- Glycobiology and Carbohydrate Chemistry Program, Burnham Institute for Medical Research, La Jolla, CA 92037, USA
| | | |
Collapse
|
44
|
Mills K, Mills P, Jackson M, Worthington V, Beesley C, Mann A, Clayton P, Grunewald S, Keir G, Young L, Langridge J, Mian N, Winchester B. Diagnosis of congenital disorders of glycosylation type-I using protein chip technology. Proteomics 2006; 6:2295-304. [PMID: 16552784 DOI: 10.1002/pmic.200500682] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A method for the diagnosis of the congenital disorders of glycosylation type I (CDG-I) by SELDI-TOF-MS of serum transferrin immunocaptured on protein chip arrays is described. The underglycosylation of glycoproteins in CDG-I produces glycoforms of transferrin with masses lower than that of the normal fully glycosylated transferrin. Immobilisation of antitransferrin antibodies on reactive-surface protein chip arrays (RS100) selectively enriched transferrin by at least 100-fold and allowed the detection of patterns of transferrin glycoforms by SELDI-TOF-MS using approximately 0.3 microL of serum/plasma. Abnormal patterns of immunocaptured transferrin were detected in patients with known defects in glycosylation (CDG-Ia, CDG-Ib, CDG-Ic, CDG-If and CDG-Ih) and in patients in whom the basic defect has not yet been identified (CDG-Ix). The correction of the N-glycosylation defect in a patient with CDG-Ib after mannose therapy was readily detected. A patient who had an abnormal transferrin profile by IEF but a normal profile by SELDI-TOF-MS analysis was shown to have an amino acid polymorphism by sequencing transferrin by quadrupole-TOF MS. Complete agreement was obtained between analysis of immunocaptured transferrin by SELDI-TOF-MS and the IEF profile of transferrin, the clinical severity of the disease and the levels of aspartylglucosaminidase activity (a surrogate marker for the diagnosis of CDG-I). SELDI-TOF-MS of transferrin immunocaptured on protein chip arrays is a highly sensitive diagnostic method for CDG-I, which could be fully automated using microtitre plates and robotics.
Collapse
Affiliation(s)
- Kevin Mills
- Biochemistry, Endocrinology and Metabolism Unit, UCL Institute of Child Health, London, UK
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Bode L, Murch S, Freeze HH. Heparan Sulfate Plays a Central Role in a Dynamic in Vitro Model of Protein-losing Enteropathy. J Biol Chem 2006; 281:7809-15. [PMID: 16434407 DOI: 10.1074/jbc.m510722200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein-losing enteropathy (PLE), the loss of plasma proteins through the intestine, is a symptom in ostensibly unrelated diseases. Emerging commonalities indicate that genetic insufficiencies predispose for PLE and environmental insults, e.g. viral infections and inflammation, trigger PLE onset. The specific loss of heparan sulfate (HS) from the basolateral surface of intestinal epithelial cells only during episodes of PLE suggests a possible mechanistic link. In the first tissue culture model of PLE using a monolayer of intestinal epithelial HT29 cells, we proved that HS loss directly causes protein leakage and amplifies the effects of the proinflammatory cytokine tumor necrosis factor alpha (TNFalpha). Here, we extend our in vitro model to assess the individual and combined effects of HS loss, interferon gamma (IFNgamma), TNFalpha, and increased pressure, and find that HS plays a central role in the patho-mechanisms underlying PLE. Increased pressure, mimicking venous hypertension seen in post-Fontan PLE patients, substantially increased protein leakage, but HS loss, IFNgamma, or TNFalpha alone had only minor effects. However, IFNgamma up-regulated TNFR1 expression and amplified TNFalpha-induced protein leakage. IFNgamma and TNFalpha compromised the integrity of the HT29 monolayer and made it more susceptible to increased pressure. HS loss itself compromises the integrity of the monolayer, amplifying the effects of pressure, but also amplifies the effects of both cytokines. In the absence of HS a combination of increased pressure, IFNgamma, and TNFalpha caused maximum protein leakage. Soluble heparin fully compensated for HS loss, providing a reasonable explanation for patient favorable response to heparin therapy.
Collapse
Affiliation(s)
- Lars Bode
- Burnham Institute for Medical Research, Glycobiology and Carbohydrate Chemistry Program, La Jolla, California 92037, USA
| | | | | |
Collapse
|
46
|
Mandato C, Brive L, Miura Y, Davis JA, Di Cosmo N, Lucariello S, Pagliardini S, Seo NS, Parenti G, Vecchione R, Freeze HH, Vajro P. Cryptogenic liver disease in four children: a novel congenital disorder of glycosylation. Pediatr Res 2006; 59:293-8. [PMID: 16439595 DOI: 10.1203/01.pdr.0000196378.30165.26] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We investigated the metabolic defect(s) of four children who presented with isolated cryptogenic chronic liver disease, coagulopathy, and abnormalities of several unrelated serum glycoproteins. Analysis of the patients' serum glycoproteins and fibroblasts suggest they have a novel congenital disorder of glycosylation (CDG). All had abnormal transferrin (Tf) isoelectric focusing (IEF) profiles. More detailed analysis of Tf by electrospray ionization mass spectrometry (ESI-MS) showed a plethora of abnormal glycosylations that included loss of 1-2 sialic acids and 1-2 galactose units, typical of Group II defects. Tf from two patients also lacked 1-2 entire oligosaccharide chains, typical of Group One disorders. Total serum N-glycans were analyzed by HPLC and matrix-assisted laser desorption/ionization mass spectrometry and also showed increased proportion of neutral glycan chains lacking sialic acids and galactose units. Analysis of patient fibroblasts eliminated CDG-Ia, through CDG-Ih, -IL and CDG-IId. Our results suggest that a subset of children with clinically asymptomatic, cryptogenic hypertransaminasemia and/or liver steato-fibrosis may represent a novel type of CDG-X with an unknown defect(s). Clinicians are encouraged to test such patients for abnormal Tf glycosylation by ESI-MS.
Collapse
Affiliation(s)
- Claudia Mandato
- Department of Pediatrics, University of Naples Federico II, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Eklund EA, Sun L, Westphal V, Northrop JL, Freeze HH, Scaglia F. Congenital disorder of glycosylation (CDG)-Ih patient with a severe hepato-intestinal phenotype and evolving central nervous system pathology. J Pediatr 2005; 147:847-50. [PMID: 16356445 DOI: 10.1016/j.jpeds.2005.07.042] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 06/08/2005] [Accepted: 07/21/2005] [Indexed: 11/24/2022]
Abstract
We present the clinical, molecular, and biochemical diagnosis of a patient with congenital disorder of glycosylation (CDG)-Ih. We report significant brain dysfunction in this multisystem disease, further expanding its complex clinical spectrum.
Collapse
Affiliation(s)
- Erik A Eklund
- Glycobiology and Carbohydrate Chemistry Program, The Burnham Institute, La Jolla, California 92037, USA
| | | | | | | | | | | |
Collapse
|
48
|
Bode L, Eklund EA, Murch S, Freeze HH. Heparan sulfate depletion amplifies TNF-alpha-induced protein leakage in an in vitro model of protein-losing enteropathy. Am J Physiol Gastrointest Liver Physiol 2005; 288:G1015-23. [PMID: 15604198 DOI: 10.1152/ajpgi.00461.2004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Protein-losing enteropathy (PLE), the excessive loss of plasma proteins through the intestine, often correlates with the episodic loss of heparan sulfate (HS) proteoglycans (HSPG) from the basolateral surface of intestinal epithelial cells. PLE onset is often associated with a proinflammatory state. We investigated whether loss of HS or treatment with the proinflammatory cytokine TNF-alpha directly causes protein leakage and whether a combination of both exacerbates this process. We established the first in vitro model of PLE and measured the flux of albumin/FITC through a monolayer of intestinal HT29 or Caco-2 cells grown on transwells and determined the integrity by transepithelial electrical resistance (TER). Loss of HS from the basolateral surface, either by heparanase digestion or by inhibition of HS synthesis, increased albumin flux 1.58 +/- 0.09-fold and reduced TER by 23.4 +/- 6.5%. TNF-alpha treatment increased albumin flux 4.04 +/- 0.03-fold and reduced TER by 75.7 +/- 4.7% but only slightly decreased HS content. The combined effects of HS loss and TNF-alpha treatment were not only additive, but synergistic, with a 7.00 +/- 0.11-fold increase in albumin flux and a 83.9 +/- 8.1% reduction of TER. Coincubation of TNF-alpha with soluble HS or heparin abolished these synergistic effects. Loss of basolateral HS directly causes protein leakage and amplifies the effects of the proinflammatory cytokine TNF-alpha. Our findings imply that loss of HSPGs renders patients more susceptible to PLE and offer a potential explanation for the favorable response some PLE patients have to heparin therapy.
Collapse
Affiliation(s)
- Lars Bode
- The Burnham Institute, Glycobiology and Carbohydrate Chemistry Program, 10901 N. Torrey Pines Rd., La Jolla, California 92037, USA
| | | | | | | |
Collapse
|
49
|
Damen G, de Klerk H, Huijmans J, den Hollander J, Sinaasappel M. Gastrointestinal and other clinical manifestations in 17 children with congenital disorders of glycosylation type Ia, Ib, and Ic. J Pediatr Gastroenterol Nutr 2004; 38:282-7. [PMID: 15076627 DOI: 10.1097/00005176-200403000-00010] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES The typical signs and symptoms of congenital disorders of glycosylation (CDG) include dysmorphy, failure to thrive, and neurologic abnormalities. However, more and more children diagnosed at a young age are not dysmorphic and do not have neurologic involvement. The authors studied the gastrointestinal and other clinical manifestations of CDG type Ia, Ib, and Ic. METHODS As of January 2003, 17 children were identified with CDG at the authors' institution. The medical records of the patients were reviewed. RESULTS Five children had CDG Ia, three children CDG Ib, and nine children CDG Ic. Age at diagnosis ranged from 2 months to 15 years. Failure to thrive was present in 80% of patients with CDG Ia, in 66% of those with CDG Ib, and in 11% of those with CDG Ic. Five children had protein-losing enteropathy (two CDG Ia, two CDG Ib, and one CDG Ic). Hepatomegaly was present in 40% of patients with CDG Ia, in 66% of those with CDG Ib, and in 11% of those with CDG Ic. In CDG Ic, hepatomegaly was transient. In CDG Ia, histologic analysis of the liver showed swollen hepatocytes, steatosis, and fibrosis. In CDG Ib, hamartomatous collections of bile ducts were seen. In one patient with CDG Ib, the clinical picture was restricted to congenital hepatic fibrosis for more than a decade. CONCLUSIONS The study confirms the heterogeneity of the clinical picture in children with CDG type Ia, Ib, and Ic. Children with protein-losing enteropathy should be tested for CDG. Protein-losing enteropathy can be caused, not only by CDG Ia and Ib, but also by type Ic. Children with congenital hepatic fibrosis should be tested for CDG, even in the absence of other symptoms. In CDG Ib, histologic analysis of the liver showed hamartomatous collections of bile ducts (Meyenburg complex).
Collapse
Affiliation(s)
- Gerard Damen
- Department of Pediatric Gastroenterology, Erasmus MC/Sophia Children Hospital, Rotterdam, the Netherlands.
| | | | | | | | | |
Collapse
|
50
|
Rychik J, Spray TL. Strategies to treat protein-losing enteropathy. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2004; 5:3-11. [PMID: 11994860 DOI: 10.1053/pcsu.2002.31498] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Protein-losing enteropathy (PLE), excessive serum protein loss within the gastrointestinal tract, after Fontan operation is a poorly understood disorder. Reported to occur anywhere from weeks to years after Fontan operation, there are no identifiable risk factors for its development, and its clinical manifestations vary widely from significant morbidity and mortality to mild-to-moderate hypoproteinemia with minimal functional impairment. Treatment strategies, tailored to the severity of the disease, include symptomatic relief with diuretics and supplemental protein, attempts at halting intestinal protein leak using steroids or heparin, and alteration of cardiovascular physiology via fenestration creation, atrial pacing, or heart transplantation. A better understanding of the pathophysiology of PLE will allow the development of more effective treatment modalities. We hypothesize an abnormality of local intestinal circulation in patients with PLE that may be related to low cardiac output. Compensatory flow redistribution takes place under conditions of low cardiac output. We studied superior mesenteric artery flow using Doppler ultrasound in 40 patients after Fontan operation, 13 of whom had clinical signs of PLE, and compared them with 25 normal control patients. Diastolic velocities were lower in Fontan subjects, and the ratio of systolic-to-diastolic velocities and the resistance index were higher in Fontan patients compared with the control group. Patients with PLE after Fontan operation had higher systolic-to-diastolic velocities and resistance index than patients with Fontan and no active PLE. However, subjects with Fontan circulation but without PLE had higher indices of mesenteric resistance than the normal controls, suggesting an abnormality of the mesenteric circulation even in those without overt signs of PLE. It is plausible to postulate that activation of the renin-angiotensin system with increased levels of circulating angiotensin II may be responsible for the increase in mesenteric vascular resistance seen after Fontan operation, thereby placing these patients at risk for development of PLE.
Collapse
Affiliation(s)
- Jack Rychik
- Divisions of Cardiology and Cardiothoracic Surgery, The Cardiac Center at The Children's Hospital of Philadelphia, PA 19104, USA
| | | |
Collapse
|