1
|
Fang Z, Hu C, Zhou S, Yu L. PIGW-related glycosylphosphatidylinositol deficiency: A case report and literature review. Neurol Sci 2024; 45:2253-2260. [PMID: 38055078 DOI: 10.1007/s10072-023-07225-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023]
Abstract
INTRODUCTION PIGW-related glycosylphosphatidylinositol deficiency is a rare disease that manifests heterogeneous clinical phenotypes. METHODS We describe a patient with PIGW deficiency and summarize the clinical characteristics of the case. In addition, we conducted a literature review of previously reported patients with pathogenic variants of PIGW. RESULTS A Chinese girl presented with refractory epilepsy, severe intellectual disability, recurrent respiratory infections, and hyperphosphatasia. Seizures worsened during fever and infections, making her more susceptible to epileptic status. She was found to carry a heterozygous variant of PIGW and a deletion of chromosome 17q12 containing PIGW. Only six patients with homozygous or compound heterozygous pathogenic variants of PIGW have been identified in the literature thus far. Epileptic seizures were reported in all patients, and the most common types of seizures were epileptic spasms. Distinctive facial and physical features and recurrent respiratory infections are common in these patients with developmental delays. Serum alkaline phosphatase (ALP) levels were elevated in four of the six patients. CONCLUSIONS PIGW-related glycosylphosphatidylinositol deficiency is characterized by developmental delay, epilepsy, distinctive facial features, and multiple organ anomalies. Genetic testing is an important method for diagnosing this disease, and flow cytometry and serum ALP level detection are crucial complements for genetic testing.
Collapse
Affiliation(s)
- Zhixu Fang
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Chaoping Hu
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Shuizhen Zhou
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Lifei Yu
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China.
| |
Collapse
|
2
|
Chen X, Yin W, Chen S, Zhang W, Li H, Kuang H, Zhou M, Teng Y, Zhang J, Shen G, Liang D, Li Z, Hu B, Wu L. Loss of PIGK function causes severe infantile encephalopathy and extensive neuronal apoptosis. Hum Genet 2021; 140:791-803. [PMID: 33392778 DOI: 10.1007/s00439-020-02243-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/25/2020] [Indexed: 10/22/2022]
Abstract
PIGK gene, encoding a key component of glycosylphosphatidylinositol (GPI) transamidase, was recently reported to be associated with inherited GPI deficiency disorders (IGDs). However, little is known about the specific downstream effects of PIGK on neurodevelopment due to the rarity of the disease and the lack of in vivo study. Here, we described 2 patients in a Chinese family presented with profound global developmental delay, severe hypotonia, seizures, and postnatal progressive global brain atrophy including hemisphere, cerebellar and corpus callosum atrophy. Two novel compound heterozygous variants in PIGK were identified via genetic analysis, which was proved to cause significant decrease of PIGK protein and reduced cell surface presence of GPI-APs in the patients. To explore the role of Pigk on embryonic and neuronal development, we constructed Pigk knock-down zebrafish and knock-in mouse models. Zebrafish injected with a small dose of morpholino oligonucleotides displayed severe developmental defects including small eyes, deformed head, curly spinal cord, and unconsumed yolk sac. Primary motor neuronal dysplasia and extensive neural cell apoptosis were further observed. Meanwhile, the mouse models, carrying the two variants respectively homologous with the patients, both resulted in complete embryonic lethality of the homozygotes, which suggested the intolerable effect caused by amino acid substitution of Asp204 as well as the truncated mutation. Our findings provide the in vivo evidence for the essential role of PIGK during the embryonic and neuronal development. Based on these data, we propose a basis for further study of pathological and molecular mechanisms of PIGK-related neurodevelopmental defects.
Collapse
Affiliation(s)
- Xin Chen
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Wu Yin
- Department of Geriatrics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, Anhui, China
- Anhui Provincial Key Laboratory of Tumor Immunotherapy and Nutrition Therapy, Hefei, 230001, Anhui, China
| | - Siyi Chen
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Wenyu Zhang
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Hongyan Li
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Hanzhe Kuang
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Miaojin Zhou
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Yanling Teng
- Department of Medical Genetics, Hunan Jiahui Genetics Hospital, Changsha, 410078, Hunan, China
| | - Junlong Zhang
- Hefei National Laboratory of Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, 443 Huangshan Road, Hefei, 230027, Anhui, China
| | - Guodong Shen
- Department of Geriatrics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, Anhui, China
- Anhui Provincial Key Laboratory of Tumor Immunotherapy and Nutrition Therapy, Hefei, 230001, Anhui, China
| | - Desheng Liang
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China
| | - Zhuo Li
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China.
| | - Bing Hu
- Hefei National Laboratory of Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
- CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, 443 Huangshan Road, Hefei, 230027, Anhui, China.
| | - Lingqian Wu
- Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, 110 Xiangya Road, Changsha, 410078, Hunan, China.
| |
Collapse
|
3
|
Davids M, Menezes M, Guo Y, McLean SD, Hakonarson H, Collins F, Worgan L, Billington CJ, Maric I, Littlejohn RO, Onyekweli T, Adams DR, Tifft CJ, Gahl WA, Wolfe LA, Christodoulou J, Malicdan MCV. Homozygous splice-variants in human ARV1 cause GPI-anchor synthesis deficiency. Mol Genet Metab 2020; 130:49-57. [PMID: 32165008 PMCID: PMC7303973 DOI: 10.1016/j.ymgme.2020.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/15/2020] [Accepted: 02/07/2020] [Indexed: 10/25/2022]
Abstract
BACKGROUND Mutations in the ARV1 Homolog, Fatty Acid Homeostasis Modulator (ARV1), have recently been described in association with early infantile epileptic encephalopathy 38. Affected individuals presented with epilepsy, ataxia, profound intellectual disability, visual impairment, and central hypotonia. In S. cerevisiae, Arv1 is thought to be involved in sphingolipid metabolism and glycophosphatidylinositol (GPI)-anchor synthesis. The function of ARV1 in human cells, however, has not been elucidated. METHODS Mutations were discovered through whole exome sequencing and alternate splicing was validated on the cDNA level. Expression of the variants was determined by qPCR and Western blot. Expression of GPI-anchored proteins on neutrophils and fibroblasts was analyzed by FACS and immunofluorescence microscopy, respectively. RESULTS Here we describe seven patients from two unrelated families with biallelic splice mutations in ARV1. The patients presented with early onset epilepsy, global developmental delays, profound hypotonia, delayed speech development, cortical visual impairment, and severe generalized cerebral and cerebellar atrophy. The splice variants resulted in decreased ARV1 expression and significant decreases in GPI-anchored protein on the membranes of neutrophils and fibroblasts, indicating that the loss of ARV1 results in impaired GPI-anchor synthesis. CONCLUSION Loss of GPI-anchored proteins on our patients' cells confirms that the yeast Arv1 function of GPI-anchor synthesis is conserved in humans. Overlap between the phenotypes in our patients and those reported for other GPI-anchor disorders suggests that ARV1-deficiency is a GPI-anchor synthesis disorder.
Collapse
Affiliation(s)
- Mariska Davids
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Minal Menezes
- Genetic Metabolic Disorders Research Unit, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, NSW, Australia; Discipline of Child and Adolescent Health and Genomic Medicine, Sydney Medical School, Sydney University, Sydney, NSW, Australia
| | - Yiran Guo
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Scott D McLean
- Department of Clinical Genetics, The Children's Hospital of San Antonio, San Antonio, TX, USA
| | - Hakon Hakonarson
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Felicity Collins
- Discipline of Child and Adolescent Health and Genomic Medicine, Sydney Medical School, Sydney University, Sydney, NSW, Australia; Department of Clinical Genetics, Western Sydney Genetics Program, Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Lisa Worgan
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, NSW, Australia
| | - Charles J Billington
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Irina Maric
- Hematology Service, Clinical Center, NIH, Bethesda, MD, USA
| | | | - Tito Onyekweli
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - David R Adams
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Cynthia J Tifft
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - William A Gahl
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Lynne A Wolfe
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - John Christodoulou
- Genetic Metabolic Disorders Research Unit, Western Sydney Genetics Program, The Children's Hospital at Westmead, Sydney, NSW, Australia; Discipline of Child and Adolescent Health and Genomic Medicine, Sydney Medical School, Sydney University, Sydney, NSW, Australia; Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Pediatrics, Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia.
| | - May Christine V Malicdan
- NIH Undiagnosed Diseases Program, Common Fund, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
4
|
Pode-Shakked B, Heimer G, Vilboux T, Marek-Yagel D, Ben-Zeev B, Davids M, Ferreira CR, Philosoph AM, Veber A, Pode-Shakked N, Kenet G, Soudack M, Hoffmann C, Vernitsky H, Safaniev M, Lodzki M, Lahad A, Shouval DS, Levinkopf D, Weiss B, Barg AA, Daka A, Amariglio N, Malicdan MCV, Gahl WA, Anikster Y. Cerebral and portal vein thrombosis, macrocephaly and atypical absence seizures in Glycosylphosphatidyl inositol deficiency due to a PIGM promoter mutation. Mol Genet Metab 2019; 128:151-161. [PMID: 31445883 PMCID: PMC10569059 DOI: 10.1016/j.ymgme.2019.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 10/26/2022]
Abstract
Defects of the glycosylphosphatidylinositol (GPI) biosynthesis pathway constitute an emerging subgroup of congenital disorders of glycosylation with heterogeneous phenotypes. A mutation in the promoter of PIGM, resulting in a syndrome with portal vein thrombosis and persistent absence seizures, was previously described in three patients. We now report four additional patients in two unrelated families, with further clinical, biochemical and molecular delineation of this unique entity. We also describe the first prenatal diagnosis of PIGM deficiency, allowing characterization of the natural history of the disease from birth. The patients described herein expand the phenotypic spectrum of PIGM deficiency to include macrocephaly and infantile-onset cerebrovascular thrombotic events. Finally, we offer insights regarding targeted treatment of this rare disorder with sodium phenylbutyrate.
Collapse
Affiliation(s)
- Ben Pode-Shakked
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Gali Heimer
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Thierry Vilboux
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Inova Functional Laboratory, Inova Health System, Fairfax, Virginia, USA
| | - Dina Marek-Yagel
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Wohl Institute for Translational Medicine, Sheba Medical Center, Israel
| | - Bruria Ben-Zeev
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; The Wohl Institute for Translational Medicine, Sheba Medical Center, Israel
| | - Mariska Davids
- NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA
| | - Carlos R Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amit Mary Philosoph
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Alvit Veber
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Naomi Pode-Shakked
- Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Gili Kenet
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel-Hashomer, Israel
| | - Michalle Soudack
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Pediatric Imaging Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Chen Hoffmann
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Radiology, Sheba Medical Center, Tel-Hashomer, Israel
| | - Helly Vernitsky
- Hematology Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - Marina Safaniev
- Hematology Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - Maya Lodzki
- Pharmaceutical Services, Sheba Medical Center, Tel-Hashomer, Israel
| | - Avishay Lahad
- NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Dror S Shouval
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Division of Pediatric Gastroenterology, Hepatology and Nutrition, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Dana Levinkopf
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Batia Weiss
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Division of Pediatric Gastroenterology, Hepatology and Nutrition, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Assaf Arie Barg
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ayman Daka
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ninette Amariglio
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Hematology Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - May Christine V Malicdan
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA
| | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA.
| | - Yair Anikster
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Wohl Institute for Translational Medicine, Sheba Medical Center, Israel.
| |
Collapse
|
5
|
Murakami Y, Nguyen TTM, Baratang N, Raju PK, Knaus A, Ellard S, Jones G, Lace B, Rousseau J, Ajeawung NF, Kamei A, Minase G, Akasaka M, Araya N, Koshimizu E, van den Ende J, Erger F, Altmüller J, Krumina Z, Strautmanis J, Inashkina I, Stavusis J, El-Gharbawy A, Sebastian J, Puri RD, Kulshrestha S, Verma IC, Maier EM, Haack TB, Israni A, Baptista J, Gunning A, Rosenfeld JA, Liu P, Joosten M, Rocha ME, Hashem MO, Aldhalaan HM, Alkuraya FS, Miyatake S, Matsumoto N, Krawitz PM, Rossignol E, Kinoshita T, Campeau PM. Mutations in PIGB Cause an Inherited GPI Biosynthesis Defect with an Axonal Neuropathy and Metabolic Abnormality in Severe Cases. Am J Hum Genet 2019; 105:384-394. [PMID: 31256876 PMCID: PMC6698938 DOI: 10.1016/j.ajhg.2019.05.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/28/2019] [Indexed: 11/15/2022] Open
Abstract
Proteins anchored to the cell surface via glycosylphosphatidylinositol (GPI) play various key roles in the human body, particularly in development and neurogenesis. As such, many developmental disorders are caused by mutations in genes involved in the GPI biosynthesis and remodeling pathway. We describe ten unrelated families with bi-allelic mutations in PIGB, a gene that encodes phosphatidylinositol glycan class B, which transfers the third mannose to the GPI. Ten different PIGB variants were found in these individuals. Flow cytometric analysis of blood cells and fibroblasts from the affected individuals showed decreased cell surface presence of GPI-anchored proteins. Most of the affected individuals have global developmental and/or intellectual delay, all had seizures, two had polymicrogyria, and four had a peripheral neuropathy. Eight children passed away before four years old. Two of them had a clinical diagnosis of DOORS syndrome (deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures), a condition that includes sensorineural deafness, shortened terminal phalanges with small finger and toenails, intellectual disability, and seizures; this condition overlaps with the severe phenotypes associated with inherited GPI deficiency. Most individuals tested showed elevated alkaline phosphatase, which is a characteristic of the inherited GPI deficiency but not DOORS syndrome. It is notable that two severely affected individuals showed 2-oxoglutaric aciduria, which can be seen in DOORS syndrome, suggesting that severe cases of inherited GPI deficiency and DOORS syndrome might share some molecular pathway disruptions.
Collapse
Affiliation(s)
- Yoshiko Murakami
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Thi Tuyet Mai Nguyen
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Nissan Baratang
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Praveen K Raju
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Alexej Knaus
- Insitute for Genomic Statistics and Bioinformatics, University Hospital Bonn, 53127 Bonn, Germany
| | - Sian Ellard
- Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Gabriela Jones
- Clinical Genetics Department, Nottingham University Hospitals NHS Trust, Nottingham NGS 1PB, UK
| | - Baiba Lace
- Centre Hospitalier Universitaire de Québec, 2705 Boulevard Laurier, Ville de Québec, QC G1V 4G2, Canada
| | - Justine Rousseau
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Norbert Fonya Ajeawung
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Atsushi Kamei
- Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
| | - Gaku Minase
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | - Manami Akasaka
- Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
| | - Nami Araya
- Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
| | - Eriko Koshimizu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | | | - Florian Erger
- Institute of Human Genetics, University Hospital of Cologne, and Center for Molecular Medicine, University of Cologne, 50931 Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Zita Krumina
- Deparment of Biology and Microbiology, Riga Stradinš University, Riga, LV-1029, Latvia
| | | | - Inna Inashkina
- Latvian Biomedical Research and Study Centre, Ratsupites Str. 1 k-1, Riga LV-1067, Latvia
| | - Janis Stavusis
- Latvian Biomedical Research and Study Centre, Ratsupites Str. 1 k-1, Riga LV-1067, Latvia
| | - Areeg El-Gharbawy
- Department of Medical Genetics, Children's Hospital of Pittsburgh of University Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Jessica Sebastian
- Department of Medical Genetics, Children's Hospital of Pittsburgh of University Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi 110060, India
| | - Samarth Kulshrestha
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi 110060, India
| | - Ishwar C Verma
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi 110060, India
| | - Esther M Maier
- Department of Inborn Errors of Metabolism, Dr. von Hauner Children's Hospital, 80337 Munich, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72074 Tübingen, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Anil Israni
- Department of Paediatric Neurology, Leicester Royal Infirmary, Leicester LE1 5WW, UK
| | - Julia Baptista
- Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Adam Gunning
- Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Marieke Joosten
- Dept of Clinical Genetics, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, the Netherlands
| | | | - Mais O Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Hesham M Aldhalaan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Satoko Miyatake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | - Peter M Krawitz
- Insitute for Genomic Statistics and Bioinformatics, University Hospital Bonn, 53127 Bonn, Germany
| | - Elsa Rossignol
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada; Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia; Department of Neurosciences, Centre Hospitalier Universitaire Sainte-Justine and University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Taroh Kinoshita
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Philippe M Campeau
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada; Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine and University of Montreal, Montreal, QC H3T 1C5, Canada.
| |
Collapse
|
6
|
Nicklas JA, Vacek PM, Carter EW, McDiarmid M, Albertini RJ. Molecular analysis of glycosylphosphatidylinositol anchor deficient aerolysin resistant isolates in gulf war i veterans exposed to depleted uranium. Environ Mol Mutagen 2019; 60:470-493. [PMID: 30848503 DOI: 10.1002/em.22283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
During the First Gulf War (1991) over 100 servicemen sustained depleted uranium (DU) exposure through wound contamination, inhalation, and shrapnel. The Department of Veterans Affairs has a surveillance program for these Veterans which has included genotoxicity assays. The frequencies of glycosylphosphatidylinositol anchor (GPIa) negative (aerolysin resistant) cells determined by cloning assays for these Veterans are reported in Albertini RJ et al. (2019: Environ Mol Mutagen). Molecular analyses of the GPIa biosynthesis class A (PIGA) gene was performed on 862 aerolysin-resistant T-lymphocyte recovered isolates. The frequencies of different types of PIGA mutations were compared between high and low DU exposure groups. Additional molecular studies were performed on mutants that produced no PIGA mRNA or with deletions of all or part of the PIGA gene to determine deletion size and breakpoint sequence. One mutant appeared to be the result of a chromothriptic event. A significant percentage (>30%) of the aerolysin resistant isolates, which varied by sample year and Veteran, had wild-type PIGA cDNA (no mutation). As described in Albertini RJ et al. (2019: Environ Mol Mutagen), TCR gene rearrangement analysis of these isolates indicated most arose from multiple T-cell progenitors (hence the inability to find a mutation). It is likely that these isolates were the result of failure of complete selection against nonmutant cells in the cloning assays. Real-time studies of GPIa resistant isolates with no PIGA mutation but with a single TCR gene rearrangement found one clone with a PIGV deletion and several others with decreased levels of GPIa pathway gene mRNAs implying mutation in other GPIa pathway genes. Environ. Mol. Mutagen. 60:470-493, 2019. © 2019 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Janice A Nicklas
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, Vermont
| | - Pamela M Vacek
- Medical Biostatistics Unit, University of Vermont College of Medicine, Burlington, Vermont
| | - Elizabeth W Carter
- Jeffords Institute for Quality, University of Vermont Medical Center, Burlington, Vermont
| | - Melissa McDiarmid
- Occupational Health Program, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
- U.S. Department of Veterans Affairs, Washington, District of Columbia
| | - Richard J Albertini
- Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont
| |
Collapse
|
7
|
Albertini RJ, Nicklas JA, Vacek PM, Carter EW, McDiarmid M. Longitudinal study of t-cell somatic mutations conferring glycosylphosphatidylinositol-anchor deficiency in gulf war I veterans exposed to depleted uranium. Environ Mol Mutagen 2019; 60:494-504. [PMID: 30848527 DOI: 10.1002/em.22281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/01/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
Fifty Veterans of the first Gulf War in 1991 exposed to depleted uranium (DU) were studied for glycosylphosphatidylinositol-anchor (GPIa) deficient T-cell mutants on three occasions during the years 2009, 2011, and 2013. GPIa deficiency was determined in two ways: cloning assays employing aerolysin selection and cytometry using the FLAER reagent for positive staining of GPIa cell surface proteins. Subsequent molecular analyses of deficient isolates recovered from cloning assays (Nicklas JA et al. [2019]: Environ Mol Mutagen) revealed apparent incomplete selection in some cloning assays, necessitating correction of original data to afford a more realistic estimate of GPIa deficient mutant frequency (MF) values. GPIa deficient variant frequencies (VFs) determined by cytometry were determined in the years 2011 and 2013. A positive but nonsignificant association was observed between MF and VF values determined on the same blood samples during 2013. Exposure to DU had no effect on either GPIa deficient MF or VFs. Environ. Mol. Mutagen. 60:494-504, 2019. © 2019 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Richard J Albertini
- Department of Pathology, University of Vermont College of Medicine, Burlington, Vermont
| | - Janice A Nicklas
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, Vermont
| | - Pamela M Vacek
- Medical Biostatistics Unit, University of Vermont College of Medicine, Burlington, Vermont
| | - Elizabeth W Carter
- Jeffords Institute for Quality, University of Vermont Medical Center, Burlington, Vermont
| | - Melissa McDiarmid
- Occupational Health Program, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland
- U.S. Department of Veterans Affairs, Washington, DC
| |
Collapse
|
8
|
Bemis JC, Avlasevich SL, Labash C, McKinzie P, Revollo J, Dobrovolsky VN, Dertinger SD. Glycosylphosphatidylinositol (GPI) anchored protein deficiency serves as a reliable reporter of Pig-a gene Mutation: Support from an in vitro assay based on L5178Y/Tk +/- cells and the CD90.2 antigen. Environ Mol Mutagen 2018; 59:18-29. [PMID: 29115020 PMCID: PMC5771857 DOI: 10.1002/em.22154] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/11/2017] [Accepted: 10/14/2017] [Indexed: 06/07/2023]
Abstract
Lack of cell surface glycosylphosphatidylinositol (GPI)-anchored protein(s) has been used as a reporter of Pig-a gene mutation in several model systems. As an extension of this work, our laboratory initiated development of an in vitro mutation assay based on the flow cytometric assessment of CD90.2 expression on the cell surface of the mouse lymphoma cell line L5178Y/Tk+/- . Cells were exposed to mutagenic and nonmutagenic compounds for 24 hr followed by washout and incubation for an additional 7 days. Following this mutant manifestation time, cells were labeled with fluorescent antibodies against CD90.2 and CD45 antigens. These reagents indicated the presence of GPI-anchored proteins and general cell surface membrane receptor integrity, respectively. Instrument set-up was aided by parallel processing of a GPI anchor-deficient subclone. Results show that the mutagens reproducibly caused increased frequencies of mutant phenotype cells, while the nonmutagens did not. Further modifications to the method, including application of a viability dye and an isotype control for instrument set-up, were investigated. As a means to verify that the GPI-anchored protein-negative phenotype reflects bona fide Pig-a gene mutation, sequencing was performed on 38 CD90.2-negative L5178Y/Tk+/- clones derived from cultures treated with ethyl methanesulfonate. All clones were found to have mutation(s) within the Pig-a gene. The continued investigation of L5178Y/Tk+/- cells, CD90.2 labeling, and flow cytometric analysis as the basis of an in vitro mutation assay is clearly supported by this work. These data also provide evidence of the reliability of using GPI anchor-deficiency as a valid reporter of Pig-a gene mutation. Environ. Mol. Mutagen. 59:18-29, 2018. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | | | | | - Page McKinzie
- US Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas
| | - Javier Revollo
- US Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas
| | - Vasily N Dobrovolsky
- US Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas
| | | |
Collapse
|
9
|
Figueroa-Jiménez LA, González-Márquez AL, Alicea-Guevara R, Santiago-Casiano M, de la Paz-López M, Negrón-Garcia L, Báez-Dίaz L, Cáceres-Pérkins W. A Hispanic female patient with heartburn: A rare presentation of Paroxysmal Nocturnal Hemoglobinuria. Bol Asoc Med P R 2015; 107:9-12. [PMID: 26742189 PMCID: PMC5344193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a non-malignant, acquired clonal hematopoietic stem cell disease that can present with bone marrow failure, hemolytic anemia, smooth muscle dystonias, and thrombosis. We present a case of a 32 year-old-female, G2P2A0 with no past medical history of any systemic illnesses who refers approximately 2 months of progressively worsening constant heartburn with associated abdominal discomfort. CBC showed leukopenia (WBC 2.9 x 103 /µL) with neutropenia (segmented neutrophils 48%), macrocytic anemia (Hgb 6.1 g/dL, hematocrit 20%, MCV,113 fL) and thrombocytopenia (platelet count 59 x 109/L). Abdomino-pelvic CT scan revealed a superior mesenterc vein thrombosis, which was treated initially with low-molecular-weight heparih for full anticoagulation. Peripheral blood flow cytometry assays revealed diminished expression of CD55 and CD59 on the erythrocytes, granulocytes and monocytes.' Paroxysmal nocturnal hemoglobinuria is a rare, clonal, hematopoietic stem-cell disorder whose manifestations are almost entirely explained by complement-mediated intravascular hemolysis. The natural history of PNH is highly variable, ranging from indolent to life-threatening. The median survival is 10 to 15 years, but with a wide range. Thrombosis is the leading cause of death, but others may die of complications of bone marrow failure, renal failure, myelodysplastic syndrome, and leukemia. Anticoagulation is only partially effective in preventing thrombosis in PNH; thus, thrombosis is an absolute indication for initiating treatment with Eculizumab. Nevertheless, bone marrow transplantation (BMT) is still the only curative therapy for PNH but is associated with significant morbidity and mortality.
Collapse
Affiliation(s)
| | - Amy Lee González-Márquez
- Hematology–Medical Oncology Section, VA Caribbean Healthcare System and San Juan City Hospital, San Juan, Puerto Rico
| | | | - Mόnica Santiago-Casiano
- Hematology–Medical Oncology Section, VA Caribbean Healthcare System and San Juan City Hospital, San Juan, Puerto Rico
| | - Maryknoll de la Paz-López
- Hematology–Medical Oncology Section, VA Caribbean Healthcare System and San Juan City Hospital, San Juan, Puerto Rico
| | - Luis Negrón-Garcia
- Hematology–Medical Oncology Section, VA Caribbean Healthcare System and San Juan City Hospital, San Juan, Puerto Rico
| | - Luis Báez-Dίaz
- Hematology–Medical Oncology Section, VA Caribbean Healthcare System and San Juan City Hospital, San Juan, Puerto Rico
| | - William Cáceres-Pérkins
- Hematology–Medical Oncology Section, VA Caribbean Healthcare System and San Juan City Hospital, San Juan, Puerto Rico
| |
Collapse
|
10
|
Murakami Y, Kinoshita T. [Inherited GPI deficiency; a new disease with intellectual disability and epilepsy]. Nihon Rinsho 2015; 73:1227-1237. [PMID: 26165085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recently, many cases of inherited GPI deficiency(IGD) are found among individuals with intellectual disability and intractable seizures. To date, about twenty patients have been reported in Japan and up to a hundred in the world. GPI is the glycolipid which anchors 150 kinds of proteins to the plasma membrane. We have found that there are at least 26 genes involved in the biosynthesis or modification of GPI-anchored proteins. IGDs caused by mutations in 12 genes were reported until now. IGD shows a variety of symptoms according to the affected genes and the severity of the mutations. Some patients have hyperphosphatasia and most patients can be diagnosed by the flow cytometric analysis of the blood cells. Early diagnosis and treatment are desirable because the disease progresses even after birth and vitamin B6(pyridoxine) is very effective for some patients with intractable seizures.
Collapse
|
11
|
Murakami Y, Kinoshita T. [Inherited GPI deficiencies:a new disease with intellectual disability and epilepsy]. No To Hattatsu 2015; 47:5-13. [PMID: 25803904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Glycosylphosphatidylinositol (GPI) is a glycolipid, which anchors 150 or more types of proteins to the cell surface. There are at least 26 genes involved in the biosynthesis and transport of GPI-anchored proteins (GPI-APs). Many inherited GPI deficiencies (IGDs) have been recently found using whole-exome sequencing. Patients with IGD have only a partial deficiency because complete GPI deficiency causes embryonic death. The major symptoms of IGDs include intellectual disability, epilepsy, coarse facial features, and multiple organ anomalies. These symptoms vary in severity depending upon the degree of the defect and/or position in the pathway of the affected gene. We clarified a mechanism of hyperphosphatasia, which is characterized by elevated release of tissue-nonspecific alkaline phosphatase. Hyperphosphatasia is observed in some patients with IGDs, such as hyperphosphatasia mental retardation syndrome or Mabry syndrome, caused by mutations in genes in the later stage of GPI biosynthesis. The possibility of IGD should be considered in patients with seizures and intellectual disability. The presence of hyperphosphatasia is strong evidence of IGD. Flow cytometric analysis of GPI-APs on granulocytes is also useful for the detection of IGD.
Collapse
|
12
|
KINOSHITA T. Biosynthesis and deficiencies of glycosylphosphatidylinositol. Proc Jpn Acad Ser B Phys Biol Sci 2014; 90:130-43. [PMID: 24727937 PMCID: PMC4055706 DOI: 10.2183/pjab.90.130] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 02/19/2014] [Indexed: 05/18/2023]
Abstract
At least 150 different human proteins are anchored to the outer leaflet of the plasma membrane via glycosylphosphatidylinositol (GPI). GPI preassembled in the endoplasmic reticulum is attached to the protein's carboxyl-terminus as a post-translational modification by GPI transamidase. Twenty-two PIG (for Phosphatidyl Inositol Glycan) genes are involved in the biosynthesis and protein-attachment of GPI. After attachment to proteins, both lipid and glycan moieties of GPI are structurally remodeled in the endoplasmic reticulum and Golgi apparatus. Four PGAP (for Post GPI Attachment to Proteins) genes are involved in the remodeling of GPI. GPI-anchor deficiencies caused by somatic and germline mutations in the PIG and PGAP genes have been found and characterized. The characteristics of the 26 PIG and PGAP genes and the GPI deficiencies caused by mutations in these genes are reviewed.
Collapse
Affiliation(s)
- Taroh KINOSHITA
- WPI Immunology Frontier Research Center and Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
- Correspondence should be addressed: T. Kinoshita, WPI Immunology Frontier Research Center and Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan (e-mail: )
| |
Collapse
|
13
|
Yuan X, Braunstein EM, Ye Z, Liu CF, Chen G, Zou J, Cheng L, Brodsky RA. Generation of glycosylphosphatidylinositol anchor protein-deficient blood cells from human induced pluripotent stem cells. Stem Cells Transl Med 2013; 2:819-29. [PMID: 24113066 DOI: 10.5966/sctm.2013-0069] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PIG-A is an X-linked gene required for the biosynthesis of glycosylphosphatidylinositol (GPI) anchors; thus, PIG-A mutant cells have a deficiency or absence of all GPI-anchored proteins (GPI-APs). Acquired mutations in hematopoietic stem cells result in the disease paroxysmal nocturnal hemoglobinuria, and hypomorphic germline PIG-A mutations lead to severe developmental abnormalities, seizures, and early death. Human induced pluripotent stem cells (iPSCs) can differentiate into cell types derived from all three germ layers, providing a novel developmental system for modeling human diseases. Using PIG-A gene targeting and an inducible PIG-A expression system, we have established, for the first time, a conditional PIG-A knockout model in human iPSCs that allows for the production of GPI-AP-deficient blood cells. PIG-A-null iPSCs were unable to generate hematopoietic cells or any cells expressing the CD34 marker and were defective in generating mesodermal cells expressing KDR/VEGFR2 (kinase insert domain receptor) and CD56 markers. In addition, PIG-A-null iPSCs had a block in embryonic development prior to mesoderm differentiation that appears to be due to defective signaling through bone morphogenetic protein 4. However, early inducible PIG-A transgene expression allowed for the generation of GPI-AP-deficient blood cells. This conditional PIG-A knockout model should be a valuable tool for studying the importance of GPI-APs in hematopoiesis and human development.
Collapse
Affiliation(s)
- Xuan Yuan
- Division of Hematology, Department of Medicine, School of Medicine, and
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Vázquez-Fernández E, Alonso J, Pastrana MA, Ramos A, Stitz L, Vidal E, Dynin I, Petsch B, Silva CJ, Requena JR. Structural organization of mammalian prions as probed by limited proteolysis. PLoS One 2012. [PMID: 23185550 PMCID: PMC3502352 DOI: 10.1371/journal.pone.0050111] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Elucidation of the structure of PrPSc continues to be one major challenge in prion research. The mechanism of propagation of these infectious agents will not be understood until their structure is solved. Given that high resolution techniques such as NMR or X-ray crystallography cannot be used, a number of lower resolution analytical approaches have been attempted. Thus, limited proteolysis has been successfully used to pinpoint flexible regions within prion multimers (PrPSc). However, the presence of covalently attached sugar antennae and glycosylphosphatidylinositol (GPI) moieties makes mass spectrometry-based analysis impractical. In order to surmount these difficulties we analyzed PrPSc from transgenic mice expressing prion protein (PrP) lacking the GPI membrane anchor. Such animals produce prions that are devoid of the GPI anchor and sugar antennae, and, thereby, permit the detection and location of flexible, proteinase K (PK) susceptible regions by Western blot and mass spectrometry-based analysis. GPI-less PrPSc samples were digested with PK. PK-resistant peptides were identified, and found to correspond to molecules cleaved at positions 81, 85, 89, 116, 118, 133, 134, 141, 152, 153, 162, 169 and 179. The first 10 peptides (to position 153), match very well with PK cleavage sites we previously identified in wild type PrPSc. These results reinforce the hypothesis that the structure of PrPSc consists of a series of highly PK-resistant β-sheet strands connected by short flexible PK-sensitive loops and turns. A sizeable C-terminal stretch of PrPSc is highly resistant to PK and therefore perhaps also contains β-sheet secondary structure.
Collapse
Affiliation(s)
- Ester Vázquez-Fernández
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, Santiago de Compostela, Spain
- * E-mail: (EVF); (JRR)
| | - Jana Alonso
- Proteomics Unit, IDIS, Santiago de Compostela, Spain
| | - Miguel A. Pastrana
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, Santiago de Compostela, Spain
| | - Adriana Ramos
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, Santiago de Compostela, Spain
| | - Lothar Stitz
- Institute of Immunology, Friedrich Loeffler Institut, Tübingen, Germany
| | - Enric Vidal
- Priocat Laboratory, Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Barcelona, Spain
| | - Irina Dynin
- Western Regional Research Center, USDA, Albany, California, United States of America
| | - Benjamin Petsch
- Institute of Immunology, Friedrich Loeffler Institut, Tübingen, Germany
| | - Christopher J. Silva
- Western Regional Research Center, USDA, Albany, California, United States of America
| | - Jesús R. Requena
- CIMUS Biomedical Research Institute, University of Santiago de Compostela-IDIS, Santiago de Compostela, Spain
- Department of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain
- * E-mail: (EVF); (JRR)
| |
Collapse
|
15
|
Al Riyami AZ, Jacobson K, Ford J, Dalal BI. Transient appearance of GPI-deficient population in a patient with azathioprine-associated bone marrow aplasia. Ann Hematol 2012; 91:1659-61. [PMID: 22476885 DOI: 10.1007/s00277-012-1449-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 03/11/2012] [Indexed: 12/15/2022]
|
16
|
Richards SJ, Hill A, Hillmen P. Recent advances in the diagnosis, monitoring, and management of patients with paroxysmal nocturnal hemoglobinuria. Cytometry B Clin Cytom 2007; 72:291-8. [PMID: 17549742 DOI: 10.1002/cyto.b.20358] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Until recently, there has been no specific therapy for PNH with clinical management mainly supportive in terms of cytopenias and control of thrombotic risk. Currently, the only curative procedure for PNH is bone marrow transplantation although for the majority of patients the associated risks are too great to justify transplantation. The pioneering use of the therapeutic monoclonal antibody eculizumab, which binds to and prevents the activation of the complement protein C5, represents a significant advance in treatment for patients with PNH and is set to become the future standard therapy for hemolytic PNH. In both an initial pilot study and two phase III clinical trials, eculizumab has been shown to dramatically reduce intravascular hemolysis, hemoglobinuria, and transfusion requirements thus improving the quality of life in patients with PNH. As a clinical entity, PNH is synonymous with glycosylphosphatidylinositol (GPI) deficiency, and is an acquired clonal disorder associated with somatic mutations of the X-linked PIGA gene in hematopoietic stem cells. A recent study identified a novel autosomal recessively inherited form of GPI-deficiency involving a mutation in a promotor component of the pig-m gene and characterized by a thrombotic tendency and seizures. In both these developments, flow cytometry played a critical role. In the first instance, in monitoring direct response to a new therapeutic agent; second, in demonstrating the phenotypic/genotypic link in a new form of GPI deficiency.
Collapse
Affiliation(s)
- Stephen J Richards
- Haematological Malignancy Diagnostic Service, Department of Haematology, Leeds Teaching Hospitals NHS Trust, The Algernon Firth Building, Leeds General Infirmary, Leeds, LS1 3EX, United Kingdom.
| | | | | |
Collapse
|
17
|
Abstract
Congenital disorders of glycosylation (CDG) are a large family of genetic diseases resulting from defects in the synthesis of glycans and in the attachment of glycans to other compounds. These disorders cause a wide range of human diseases, with examples emanating from all medical subspecialties. Since our 2001 review on CDG ( 36 ), this field has seen substantial growth: The number of N-glycosylation defects has doubled (from 6 to 12), five new O-glycosylation defects have been added to the two previously known ones, three combined N- and O-glycosylation defects have been identified, the first lipid glycosylation defects have been discovered, and a new domain, that of the hyperglycosylation defects, has been introduced. A number of CDG are due to defects in enzymes with a putative glycosyltransferase function. There is also a growing group of patients with unidentified defects (CDG-x), some with typical clinical presentations and others with presentations not seen before in CDG. This review focuses on the clinical, biochemical, and genetic characteristics of CDG and on advances expected in their future study and clinical management.
Collapse
Affiliation(s)
- Jaak Jaeken
- Department of Pediatrics, Center for Metabolic Disease, University of Leuven, Leuven, Belgium.
| | | |
Collapse
|
18
|
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is caused by the clonal expansion of hematopoietic stem cells with mutations of the phosphatidylinositol glycan-class A gene (PIGA). PNH clones then fail to generate glycosylphosphatidylinositol (GPI) or to express a series of GPI-linked membrane proteins including complement-regulatory proteins, resulting in complement-mediated intravascular hemolysis and thrombosis. Bone marrow failure is another characteristic feature of PNH. It is currently considered that immune-mediated injury of hematopoietic cells is implicated in PNH marrow failure as well as in aplastic anemia, a well-known PNH-related disorder. There is increasing evidence that the autoimmune attack allows PNH clones to selectively survive in the injured marrow, leading to clinical manifestations characteristic of PNH. As candidate molecules that trigger the immune attack on marrow cells, stress-inducible membrane proteins and Wilms' tumor protein WT1 have been proposed. Among the stress-inducible proteins, GPI-linked proteins, such as cytomegalovirus glycoprotein UL16-binding protein, are distinct candidates that not only induce immune attack, but also allow PNH clones to survive the attack. Here, we overview the current understanding of the molecular pathogenesis of bone marrow failure in PNH.
Collapse
MESH Headings
- Anemia, Aplastic/complications
- Anemia, Aplastic/immunology
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Humanized
- Autoimmune Diseases/physiopathology
- Bone Marrow Diseases/physiopathology
- Glycosylphosphatidylinositols/deficiency
- Hemoglobinuria, Paroxysmal/complications
- Hemoglobinuria, Paroxysmal/genetics
- Hemoglobinuria, Paroxysmal/physiopathology
- Humans
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Receptors, Immunologic/physiology
- Receptors, Natural Killer Cell
Collapse
Affiliation(s)
- Tatsuya Kawaguchi
- Department of Hematology and Infectious Diseases, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan.
| | | |
Collapse
|
19
|
Abstract
Disrupted binding of the transcription factor Sp1 to the mutated promoter region of the mannosyl transferase-encoding gene PIGM causes inherited glycosylphosphatidylinositol (GPI) deficiency characterized by splanchnic vein thrombosis and epilepsy. We show that this results in histone hypoacetylation at the promoter of PIGM. The histone deacetylase inhibitor butyrate increases PIGM transcription and surface GPI expression in vitro as well as in vivo through enhanced histone acetylation in an Sp1-dependent manner. More important, the drug caused complete cessation of intractable seizures in a child with inherited GPI deficiency.
Collapse
Affiliation(s)
- Antonio M Almeida
- Department of Haematology, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Cacciapuoti C, Terrazzano G, Barone L, Sica M, Becchimanzi C, Rotoli B, Ruggiero G, Alfinito F. Glycosyl-phosphatidyl-inositol-defective granulocytes from paroxysmal nocturnal haemoglobinuria patients show increased bacterial ingestion but reduced respiratory burst induction. Am J Hematol 2007; 82:98-107. [PMID: 17013814 DOI: 10.1002/ajh.20779] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by the emergence of a GPI-defective clonal hematopoiesis. Its clinical features are hemolytic anemia, cytopenia, and thrombosis. Circulating monocytes and granulocytes are largely GPI-defective in PNH patients. This study aims to investigate the granulocyte functional properties in PNH. We analyzed bacterial-dependent intracellular ingestion and the consequent activation of oxidative burst in GPI-defective granulocytes from four neutropenic PNH patients. Our data show a significant increase in the ability of GPI-defective granulocytes to ingest opsonized bacteria. In addition, an impaired respiratory burst effectiveness in response to two independent bacterial stimuli, the N-formyl-MetLeuPhe (fMLP) synthetic bacterial peptide and E. coli, was revealed. The occurrence of neutropenia and the severe impairment of oxidative burst, occurring in chronic granulomatosis disease, were unable to significantly affect phagocytosis. Thus, additional mechanisms, able to differentially affect ingestion ability and respiratory burst effectiveness, have to be hypothesized. The reduced burst effectiveness of GPI-defective granulocytes was maintained after treatment with phorbol 12-myristate 13-acetate, a pharmacological stimulus able to extensively recruit and to trigger intracellular protein kinase C (PKC). Moreover, blocking of PKC has been observed to severely affect granulocyte respiratory burst with a mild effect on the phagocytosis. These data suggest a role for a modulation of intracellular PKC in the pathogenesis of the impaired granulocyte oxidative burst.
Collapse
Affiliation(s)
- Carmela Cacciapuoti
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli Federico II, Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Nakakuma H. [Molecular pathogenesis and clinical profile of paroxysmal nocturnal hemoglobinuria (PNH)]. Rinsho Ketsueki 2006; 47:1329-39. [PMID: 17094572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
|
22
|
Okamoto M, Shichishima T, Noji H, Ikeda K, Nakamura A, Akutsu K, Maruyama Y. High frequency of several PIG-A mutations in patients with aplastic anemia and myelodysplastic syndrome. Leukemia 2006; 20:627-34. [PMID: 16467865 DOI: 10.1038/sj.leu.2404135] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To clarify some characteristics of phosphatidylinositol glycan-class A gene (PIG-A) mutations in aplastic anemia (AA) and myelodysplastic syndrome (MDS) patients compared with those in paroxysmal nocturnal hemoglobinuria (PNH) patients, we investigated PIG-A mutations in CD59- granulocytes and CD48- monocytes from seven AA, eight MDS, and 11 PNH Japanese patients. The most frequent base or type abnormalities of the PIG-A gene in AA and MDS patients were base substitutions or missense mutations, respectively, and deletions or frameshift mutations, respectively, in PNH patients. Several PIG-A mutations, most of which were statistically minor, were found in glycosylphosphatidylinositol-negative cells from all AA and MDS patients but not from all PNH patients. However, the common PIG-A mutations during the clinical course between CD59- granulocytes and/or CD48- monocytes from each AA or MDS patient, except for Case 5, were not found. PIG-A mutations were different between the granulocytes and monocytes from five AA and five MDS patients. Our results indicate that there were some characteristics of PIG-A mutations in AA and MDS patients compared with PNH patients and that several minor PNH clones in these patients occurred at random during the clinical course. This partly explains the transformation of AA or MDS to PNH at intervals.
Collapse
Affiliation(s)
- M Okamoto
- First Department of Internal Medicine, Fukushima Medical University, Fukushima, Japan
| | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Somatic mutation in the PIG-A gene is the initial event in the pathogenesis of paroxysmal nocturnal hemoglobinuria (PNH), but the pathophysiologic mechanisms leading to clonal expansion remain unclear. The intricate association of PNH with immune-mediated bone marrow failure syndromes, including aplastic anemia (AA), suggests an immunologic selection process for the glycosylphosphatidyl-inositol (GPI)-deficient hematopoietic clone. The mechanism for the growth advantage of PNH cells may be related to the nature of the antigens targeted by the immune response or to the function of immunomodulatory GPI-anchored proteins on the surface of the hematopoietic target cells. Alternative theories of PNH evolution may include intrinsic properties of the mutated cells, but the experimental evidence is largely lacking. Elucidation of the pathogenesis of PNH may provide key information about the causes of idiopathic AA and help understand the regulation of the hematopoietic stem cell compartment.
Collapse
Affiliation(s)
- Ramon Tiu
- Experimental Hematology and Hematopoiesis Section, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
| | | |
Collapse
|
24
|
Almeida AM, Murakami Y, Layton DM, Hillmen P, Sellick GS, Maeda Y, Richards S, Patterson S, Kotsianidis I, Mollica L, Crawford DH, Baker A, Ferguson M, Roberts I, Houlston R, Kinoshita T, Karadimitris A. Hypomorphic promoter mutation in PIGM causes inherited glycosylphosphatidylinositol deficiency. Nat Med 2006; 12:846-51. [PMID: 16767100 DOI: 10.1038/nm1410] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Accepted: 04/10/2006] [Indexed: 12/22/2022]
Abstract
Attachment to the plasma membrane by linkage to a glycosylphosphatidylinositol (GPI) anchor is a mode of protein expression highly conserved from protozoa to mammals. As a clinical entity, deficiency of GPI has been recognized as paroxysmal nocturnal hemoglobinuria, an acquired clonal disorder associated with somatic mutations of the X-linked PIGA gene in hematopoietic cells. We have identified a novel disease characterized by a propensity to venous thrombosis and seizures in which deficiency of GPI is inherited in an autosomal recessive manner. In two unrelated kindreds, a point mutation (c --> g) at position -270 from the start codon of PIGM, a mannosyltransferase-encoding gene, disrupts binding of the transcription factor Sp1 to its cognate promoter motif. This mutation substantially reduces transcription of PIGM and blocks mannosylation of GPI, leading to partial but severe deficiency of GPI. These findings indicate that biosynthesis of GPI is essential to maintain homeostasis of blood coagulation and neurological function.
Collapse
Affiliation(s)
- Antonio M Almeida
- Department of Haematology, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12, 0NN, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Omidvar N, Wang ECY, Brennan P, Longhi MP, Smith RAG, Morgan BP. Expression of glycosylphosphatidylinositol-anchored CD59 on target cells enhances human NK cell-mediated cytotoxicity. J Immunol 2006; 176:2915-23. [PMID: 16493049 PMCID: PMC2843080 DOI: 10.4049/jimmunol.176.5.2915] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cell-mediated cytotoxicity of target cells is the result of a balance between the activating and inhibitory signals provided by their respective ligand-receptor interactions. In our current study, we have investigated the significance of CD59 on human target cells in modulating this process. A range of CD59 site-specific Abs were used in NK cytotoxicity blocking studies against the CD59-expressing K562 target cell line. Significantly reduced cytotoxicity was observed in the presence of Abs previously shown to lack blocking capacity for C-mediated lysis. We investigated the consequences for alternative membrane attachment modalities, namely bis-myristoylated-peptidyl (BiMP) and GPI anchoring, on CD59-negative U937 cells. Expression of GPI-anchored CD59 either via transfection or incorporation rendered U937 targets more susceptible to NK cytotoxicity, whereas incorporation of CD59 via a BiMP anchor to similar levels did not alter susceptibility to NK cytotoxicity. Localization of both BiMP- and GPI-anchored CD59 proteins was shown to be within the lipid raft microdomain. A role for the GPI anchor and independence from glycosylation status was confirmed by expression of transmembrane-anchored CD59 or unglycosylated CD59 and by testing in NK cytotoxicity assays. To investigate mechanisms, we compared the signaling capacity of the various forms of expressed and incorporated CD59 following Ab cross-linking in calcium flux assays. GPI-anchored CD59, with or without glycosylation, mediated activation events, whereas CD59 forms lacking the GPI anchor did not. The data show that the increased susceptibility of target cells expressing CD59 to NK cytotoxicity requires GPI anchor-mediating signaling events, likely mediated by interactions between GPI-anchored CD59 on targets and NK receptors.
Collapse
Affiliation(s)
- Nader Omidvar
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Eddie C. Y. Wang
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Paul Brennan
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - M. Paula Longhi
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | | | - B. Paul Morgan
- Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff, United Kingdom
- Address correspondence and reprint requests to Dr. B. Paul Morgan, Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, U.K.
| |
Collapse
|
26
|
Lewis P, Properzi F, Prodromidou K, Clarke A, Collinge J, Jackson G. Removal of the glycosylphosphatidylinositol anchor from PrP(Sc) by cathepsin D does not reduce prion infectivity. Biochem J 2006; 395:443-8. [PMID: 16441239 PMCID: PMC1422754 DOI: 10.1042/bj20051677] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
According to the protein-only hypothesis of prion propagation, prions are composed principally of PrP(Sc), an abnormal conformational isoform of the prion protein, which, like its normal cellular precursor (PrP(C)), has a GPI (glycosylphosphatidylinositol) anchor at the C-terminus. To date, elucidating the role of this anchor on the infectivity of prion preparations has not been possible because of the resistance of PrP(Sc) to the activity of PI-PLC (phosphoinositide-specific phospholipase C), an enzyme which removes the GPI moiety from PrP(C). Removal of the GPI anchor from PrP(Sc) requires denaturation before treatment with PI-PLC, a process that also abolishes infectivity. To circumvent this problem, we have removed the GPI anchor from PrP(Sc) in RML (Rocky Mountain Laboratory)-prion-infected murine brain homogenate using the aspartic endoprotease cathepsin D. This enzyme eliminates a short sequence at the C-terminal end of PrP to which the GPI anchor is attached. We found that this modification has no effect (i) on an in vitro amplification model of PrP(Sc), (ii) on the prion titre as determined by a highly sensitive N2a-cell based bioassay, or (iii) in a mouse bioassay. These results show that the GPI anchor has little or no role in either the propagation of PrP(Sc) or on prion infectivity.
Collapse
Affiliation(s)
- Patrick A. Lewis
- *MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, U.K
| | - Francesca Properzi
- *MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, U.K
| | - Kanella Prodromidou
- *MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, U.K
| | - Anthony R. Clarke
- †Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, U.K
| | - John Collinge
- *MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, U.K
| | - Graham S. Jackson
- *MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, U.K
- To whom correspondence should be addressed (email )
| |
Collapse
|
27
|
Hanaoka N, Kawaguchi T, Horikawa K, Nagakura S, Mitsuya H, Nakakuma H. Immunoselection by natural killer cells of PIGA mutant cells missing stress-inducible ULBP. Blood 2006; 107:1184-91. [PMID: 16195329 DOI: 10.1182/blood-2005-03-1337] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe mechanism by which paroxysmal nocturnal hemoglobinuria (PNH) clones expand is unknown. PNH clones harbor PIGA mutations and do not synthesize glycosylphosphatidylinositol (GPI), resulting in deficiency of GPI-linked membrane proteins. GPI-deficient blood cells often expand in patients with aplastic anemia who sustain immune-mediated marrow injury putatively induced by cytotoxic cells, hence suggesting that the injury allows PNH clones to expand selectively. We previously reported that leukemic K562 cells preferentially survived natural killer (NK) cell-mediated cytotoxicity in vitro when they acquired PIGA mutations. We herein show that the survival is ascribable to the deficiency of stress-inducible GPI-linked membrane proteins ULBP1 and ULBP2, which activate NK and T cells. The ULBPs were detected on GPI-expressing but not on GPI-deficient K562 cells. In the presence of antibodies to either the ULBPs or their receptor NKG2D on NK cells, GPI-expressing cells were as less NK sensitive as GPI-deficient cells. NK cells therefore spared ULBP-deficient cells in vitro. The ULBPs were identified only on GPI-expressing blood cells of a proportion of patients with PNH but none of healthy individuals. Granulocytes of the patients partly underwent killing by autologous cytotoxic cells, implying ULBP-associated blood cell injury. In this setting, the lack of ULBPs may allow immunoselection of PNH clones.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Anemia, Aplastic/complications
- Anemia, Aplastic/genetics
- Anemia, Aplastic/immunology
- Carrier Proteins/genetics
- Carrier Proteins/immunology
- Erythrocytes/immunology
- Female
- GPI-Linked Proteins
- Glycosylphosphatidylinositols/biosynthesis
- Glycosylphosphatidylinositols/deficiency
- Glycosylphosphatidylinositols/immunology
- Granulocytes/immunology
- Hemoglobinuria, Paroxysmal/complications
- Hemoglobinuria, Paroxysmal/genetics
- Hemoglobinuria, Paroxysmal/immunology
- Histocompatibility Antigens Class I/genetics
- Histocompatibility Antigens Class I/immunology
- Humans
- Intercellular Signaling Peptides and Proteins
- Intracellular Signaling Peptides and Proteins
- K562 Cells
- Killer Cells, Natural/immunology
- Lymphocyte Activation/immunology
- Male
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Middle Aged
- Mutation
- NK Cell Lectin-Like Receptor Subfamily K
- Receptors, Immunologic/immunology
- Receptors, Natural Killer Cell
- Stress, Physiological/genetics
- Stress, Physiological/immunology
- T-Lymphocytes/immunology
Collapse
Affiliation(s)
- Nobuyoshi Hanaoka
- Department of Hematology, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
| | | | | | | | | | | |
Collapse
|
28
|
Quirk M. Anchorless prion protein forms plaques. Lancet Neurol 2005; 4:460. [PMID: 16086494 DOI: 10.1016/s1474-4422(05)70131-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
29
|
Rungruang T, Kaneko O, Murakami Y, Tsuboi T, Hamamoto H, Akimitsu N, Sekimizu K, Kinoshita T, Torii M. Erythrocyte surface glycosylphosphatidyl inositol anchored receptor for the malaria parasite. Mol Biochem Parasitol 2005; 140:13-21. [PMID: 15694483 DOI: 10.1016/j.molbiopara.2004.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2004] [Revised: 11/03/2004] [Accepted: 11/04/2004] [Indexed: 12/01/2022]
Abstract
Parasitophorous vacuole formation is a critical step for the successful invasion of host erythrocytes by the malaria parasite. Rhoptry proteins are believed to have essential roles in vacuole formation, although their biological roles are poorly understood. To understand the molecular interactions between parasite rhoptry proteins and the erythrocyte during invasion, we have characterized the binding specificity of the high molecular mass rhoptry protein (RhopH) complex to erythrocytes using the rodent malaria parasite, Plasmodium yoelii. RhopH complex binding to erythrocytes was species-specific, observed with mouse but not rabbit or human erythrocytes. Binding is abolished following treatment of erythrocytes with trypsin or chymotrypsin. Because host cell cholesterol-rich membrane domains are recruited into the nascent parasitophorous vacuole, we evaluated a possible role of RhopH complex binding to the cholesterol-rich membrane domain-associated glycosylphosphatidyl inositol (GPI)-anchored protein. Using chimeric mice harboring GPI-deficient erythrocytes, RhopH complex binding to GPI-deficient mouse erythrocytes was undetectable, indicating involvement of GPI-anchored protein in PyRhopH complex binding. Furthermore, a significant reduction of P. yoelii parasite infection of GPI-deficient erythrocytes was observed in vivo, probably due to inefficient invasion. We conclude that the major erythrocyte receptor for PyRhopH complex is a protein attached to the erythrocyte surface via GPI-anchor and that GPI-deficient erythrocytes are resistant to P. yoelii invasion.
Collapse
Affiliation(s)
- Thanaporn Rungruang
- Department of Molecular Parasitology, Ehime University School of Medicine, Toon, Ehime 791-0295, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is caused by phosphatidylinositol glycan-class A (PIG-A) mutations in hematopoietic stem cells (HSCs). PIG-A mutations have been found in granulocytes from most healthy individuals, suggesting that these spontaneous PIG-A mutations are important in the pathogenesis of PNH. It remains unclear if these PIG-A mutations have relevance to those found in PNH. We isolated CD34+ progenitors from 4 patients with PNH and 27 controls. The frequency of PIG-A mutant progenitors was determined by assaying for colony-forming cells (CFCs) in methylcellulose containing toxic doses of aerolysin (1 x 10(-9) M). Glycosylphosphatidylinositol (GPI)-anchored proteins serve as receptors for aerolysin; thus, PNH cells are resistant to aerolysin. The frequency of aerolysin resistant CFC was 14.7 +/- 4.0 x 10(-6) in the bone marrow of healthy donors and was 57.0 +/- 6.7 x 10(-6) from mobilized peripheral blood. DNA was extracted from individual day-14 aerolysin-resistant CFCs and the PIG-A gene was sequenced to determine clonality. Aerolysin-resistant CFCs from patients with PNH exhibited clonal PIG-A mutations. In contrast, PIG-A mutations in the CFCs from controls were polyclonal, and did not involve T cells. Our data confirm the finding that PIG-A mutations are relatively common in normal hematopoiesis; however, the finding suggests that these mutations occur in differentiated progenitors rather than HSCs.
Collapse
Affiliation(s)
- Rong Hu
- Johns Hopkins University, School of Medicine, Division of Hematology, Baltimore, MD 21205, USA
| | | | | | | | | | | |
Collapse
|
31
|
Risitano AM, Maciejewski JP, Muranski P, Wlodarski M, O'Keefe C, Sloand EM, Young NS. Large granular lymphocyte (LGL)-like clonal expansions in paroxysmal nocturnal hemoglobinuria (PNH) patients. Leukemia 2005; 19:217-22. [PMID: 15668701 DOI: 10.1038/sj.leu.2403617] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In paroxysmal nocturnal hemoglobinuria (PNH), clonal expansion of glycosylphosphatidylinositol-anchored proteins (GPI-AP)-deficient cells leads to a syndrome characterized by hemolytic anemia, marrow failure, and venous thrombosis. PNH is closely related to aplastic anemia and may share its immune pathophysiology. In vivo expansion of dominant T-cell clones can reflect an antigen-driven immune response but may also represent autonomous proliferation, such as in large granular lymphocytic (LGL)-leukemia. T-cell clonality can be assessed by a combination of T-cell receptor (TCR) flow cytometry and complementarity-determining-region-3 (CDR3) molecular analysis. We studied 24 PNH patients for evidence of in vivo dominant T-cell responses by flow cytometry; TCR-Vbeta-specific expansions were identified in all patients. In four cases, extreme expansions of one Vbeta-subset of CD8+/CD28-/CD56+ (effector) phenotype mimicked subclinical LGL-disease. The monoclonality of these expansions was inferred from unique CDR3-size peak distributions and sequencing of dominant clonotypes. We conclude that the molecular analysis of TCR-beta chain may demonstrate clonal LGL-like expansions at unexpected frequency in PNH patients. Our observations blur the classical boundaries between different bone marrow failure syndromes such as AA, PNH, and LGL, and support the hypothesis that in PNH, the mutant clone may expand as a result of an immune-escape from antigen-driven lymphocyte attack on hematopoietic progenitors.
Collapse
Affiliation(s)
- A M Risitano
- Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | | | | | | | | | | | | |
Collapse
|
32
|
Hazenbos WLW, Murakami Y, Nishimura JI, Takeda J, Kinoshita T. Enhanced responses of glycosylphosphatidylinositol anchor-deficient T lymphocytes. J Immunol 2004; 173:3810-5. [PMID: 15356128 DOI: 10.4049/jimmunol.173.6.3810] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The functions of GPI-anchored proteins in T lymphocyte activation have been controversial. This issue was addressed by studying the responses of T lymphocytes from T lymphocyte-specific GPI anchor-deficient mice to different stimuli that normally allow coligation of TCR and GPI-anchored proteins. Stimulation of GPI anchor-deficient T lymphocytes with ConA induced 2-fold higher proliferative responses than did normal cells. In response to allogeneic stimulation, proliferation of GPI anchor-deficient T lymphocytes was enhanced 2- to 3-fold. The response to ConA of a GPI anchor-deficient anti-OVA T lymphocyte clone generated from these mice was approximately 3-fold higher than that of cells from the same clone in which GPI anchor expression was restored by retroviral transduction. The response of the GPI anchor-deficient cloned anti-OVA T lymphocytes to antigenic stimulation was similar to that of the retrovirally restored cells. These results indicate that coligation with GPI-anchored proteins counteracts the response to TCR stimulation by ConA or alloantigen but not protein Ag.
Collapse
Affiliation(s)
- Wouter L W Hazenbos
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | | | | | | | | |
Collapse
|
33
|
Abstract
Glycosylphosphatidylinositols (GPIs) serve as membrane anchors of polysaccharides and proteins in the protozoan parasite Leishmania major. Free GPIs that are not attached to macromolecules are present in L. major as intermediates of protein-GPI and polysaccharide-GPI synthesis or as terminal glycolipids. The importance of the intracellular location of GPIs in vivo for functions of the glycolipids is not appreciated. To examine the roles of intracellular free GPI pools for attachment to polypeptide, a GPI-specific phospholipase C (GPI-PLCp) from Trypanosoma brucei was used to probe trafficking of GPI pools inside L. major. The locations of GPIs were determined, and their catabolism by GPI-PLCp was analyzed with respect to the intracellular location of the enzyme. GPIs accumulated on the endo-lysosomal system, where GPI-PLCp was also detected. A peptide motif [CS][CS]-x(0,2)-G-x(1)-C-x(2,3)-S-x(3)-L formed part of an endosome targeting signal for GPI-PLCp. Mutations of the endosome targeting motif caused GPI-PLCp to associate with glycosomes (peroxisomes). Endosomal GPI-PLCp caused a deficiency of protein-GPI in L. major, whereas glycosomal GPI-PLCp failed to produce the GPI deficiency. We surmise that (i) endo-lysosomal GPIs are important for biogenesis of GPI-anchored proteins in L. major; (ii) sequestration of GPI-PLCp to glycosomes protects free protein-GPIs from cleavage by the phospholipase. In T. brucei, protein-GPIs are concentrated at the endoplasmic reticulum, separated from GPI-PLCp. These observations support a model in which glycosome sequestration of a catabolic GPI-PLCp preserves free protein-GPIs in vivo.
Collapse
Affiliation(s)
- Zhifeng Zheng
- Department of Cellular Biology, the University of Georgia, Athens, Georgia 30602, USA
| | | | | | | |
Collapse
|
34
|
Abstract
Signaling by transmembrane immunoglobulin G (IgG)-Fc receptors (FcgammaRs) in response to ligand involves association with membrane microdomains that contain glycosyl phosphatidylinositol (GPI)-anchored proteins. Recent in vitro studies showed enhancement of FcgammaR signaling by forced monoclonal antibody-mediated cocrosslinking with various GPI-anchored proteins. Here, the possibility that GPI-anchored proteins are involved in normal physiologic FcgammaR effector functions in response to a model ligand was studied using myeloid-specific GPI-anchor-deficient mice, generated by Cre-loxP conditional targeting. GPI-anchor-deficient primary myeloid cells exhibited normal FcgammaR expression and binding or endocytosis of IgG-immune complexes (IgG-ICs). Strikingly, after stimulation with IgG-ICs, tumor necrosis factor-alpha release, dendritic cell maturation, and antigen presentation were strongly reduced by GPI-anchor deficiency. Tyrosine phosphorylation of the FcR gamma-chain in response to IgG-IC was impaired in GPI-anchor-deficient cells. Myeloid GPI-anchor deficiency resulted in attenuated in vivo inflammatory processes during IgG-IC-mediated alveolitis. This study provides the first genetic evidence for an essential role of GPI-anchored proteins in physiologic FcgammaR effector functions in vitro and in vivo.
Collapse
Affiliation(s)
- Wouter L W Hazenbos
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | | | | | | |
Collapse
|
35
|
Ruggiero G, Terrazzano G, Becchimanzi C, Sica M, Andretta C, Masci AM, Racioppi L, Rotoli B, Zappacosta S, Alfinito F. GPI-defective monocytes from paroxysmal nocturnal hemoglobinuria patients show impaired in vitro dendritic cell differentiation. J Leukoc Biol 2004; 76:634-40. [PMID: 15197238 DOI: 10.1189/jlb.1203607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal, acquired hematopoietic disorder characterized by a phosphatidylinositol (PI) glycan-A gene mutation, which impairs the synthesis of the glycosyl-PI (GPI) anchor, thus causing the absence of all GPI-linked proteins on the membrane of the clonal-defective cells. The presence of a consistent GPI-defective monocyte compartment is a common feature in PNH patients. To investigate the functional behavior of this population, we analyzed its in vitro differentiation ability toward functional dendritic cells (DCs). Our data indicate that GPI-defective monocytes from PNH patients are unable to undergo full DC differentiation in vitro after granulocyte macrophage-colony stimulating factor and recombinant interleukin (IL)-4 treatment. In this context, the GPI-defective DC population shows mannose receptor expression, high levels of the CD86 molecule, and impaired CD1a up-regulation. The analysis of lipopolysaccharide and CD40-dependent, functional pathways in these DCs revealed a strong decrease in tumor necrosis factor alpha and IL-12 production. Finally, GPI-defective DCs showed a severe impairment in delivering accessory signals for T cell receptor-dependent T cell proliferation.
Collapse
MESH Headings
- Adult
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Antigens, CD1/immunology
- Antigens, CD1/metabolism
- B7-2 Antigen
- CD40 Antigens/immunology
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Division/immunology
- Dendritic Cells/cytology
- Dendritic Cells/immunology
- Female
- Glycosylphosphatidylinositols/deficiency
- Glycosylphosphatidylinositols/genetics
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Hemoglobinuria, Paroxysmal/blood
- Hemoglobinuria, Paroxysmal/genetics
- Hemoglobinuria, Paroxysmal/immunology
- Humans
- Interleukin-12/immunology
- Interleukin-12/metabolism
- Interleukin-4/pharmacology
- Lectins, C-Type/immunology
- Lectins, C-Type/metabolism
- Lipopolysaccharides/immunology
- Male
- Mannose Receptor
- Mannose-Binding Lectins/immunology
- Mannose-Binding Lectins/metabolism
- Membrane Glycoproteins/immunology
- Membrane Glycoproteins/metabolism
- Monocytes/cytology
- Monocytes/immunology
- Mutation/genetics
- Receptors, Cell Surface/immunology
- Receptors, Cell Surface/metabolism
- T-Lymphocytes/immunology
- Tumor Necrosis Factor-alpha/immunology
- Tumor Necrosis Factor-alpha/metabolism
- Up-Regulation/drug effects
- Up-Regulation/immunology
Collapse
Affiliation(s)
- Giuseppina Ruggiero
- Cattera di Immunologia, Dipartimento di Biologia e Patologia Cellulare e Molecolare, Universitá Frederico II, Naples, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Chen G, Zeng W, Green S, Young NS. Frequent HPRT mutations in paroxysmal nocturnal haemoglobinuria reflect T cell clonal expansion, not genomic instability. Br J Haematol 2004; 125:383-91. [PMID: 15086421 DOI: 10.1111/j.1365-2141.2004.04912.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Paroxysmal nocturnal haemoglobinuria (PNH) results from acquired mutations in the PIG-A gene of an haematopoietic stem cell, leading to defective biosynthesis of glycosylphosphatidylinositol (GPI) anchors and deficient expression of GPI-anchored proteins on the surface of the cell's progeny. Some laboratory and clinical findings have suggested genomic instability to be intrinsic in PNH; this possibility has been supported by mutation analysis of hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene abnormalities. However, the HPRT assay examines lymphocytes in peripheral blood (PB), and T cells may be related to the pathophysiology of PNH. We analysed the molecular and functional features of HPRT mutants in PB mononuclear cells from eleven PNH patients. CD8 T cells predominated in these samples; approximately half of the CD8 cells lacked GPI-anchored protein expression, while only a small proportion of CD4 cells appeared to derive from the PNH clone. The HPRT mutant frequency (Mf) in T lymphocytes from PNH patients was significantly higher than in healthy controls. The majority of the mutant T lymphocyte clones were of CD4 phenotype, and they had phenotypically normal GPI-anchored protein expression. In PNH patients, the majority of HPRT mutant clones were contained within the Vbeta2 T cell receptor (TCR) subfamily, which was oligoclonal by complementarity-determining region three (CDR3) size analysis. Our results are more consistent with detection of uniform populations of expanded T cell clones, which presumably acquired HPRT mutations during antigen-driven cell proliferation, and not due to an increased Mf in PNH. HPRT mutant analysis does not support underlying genomic instability in PNH.
Collapse
Affiliation(s)
- Guibin Chen
- Haematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1652, USA
| | | | | | | |
Collapse
|
37
|
Jasinski M, Pantazopoulos P, Rother RP, van Rooijen N, Song WC, Molina H, Bessler M. A novel mechanism of complement-independent clearance of red cells deficient in glycosyl phosphatidylinositol–linked proteins. Blood 2004; 103:2827-34. [PMID: 14645002 DOI: 10.1182/blood-2003-09-3057] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia characterized by the increased sensitivity of red blood cells (RBCs) to complement, leading to intravascular hemolysis and hemoglobinuria. PNH is due to the expansion of a cell clone that has acquired a mutation in the PIGA gene. Mice with targeted Piga gene inactivation genetically mimic the human disease and have phosphatidylinositol glycan class A-negative (PIGA-) RBCs with a reduced half-life in circulation. Although PIGA-RBCs are hypersensitive to complement in vitro, their complement sensitivity in vivo is barely detectable. Here we show that the shortened survival of PIGA- RBCs is independent of complement either by using inhibitory C5 antibodies or by transfusion into C5-, C4-, C3-, or factor B-deficient mice. Splenectomy or high-dose cortisone treatment had no effect on the shorter survival of PIGA- RBCs. However, treatment with liposome-encapsulated clodronate, an agent that depletes macrophages in vivo, normalized the half-life of PIGA- RBCs. This indicates that the shortened survival of PIGA- RBCs is due to a novel pathway of PIGA- RBC clearance that is mediated by macrophages, but occurs independently of complement. Future investigations will show whether this novel pathway of PIGA- RBC destruction identified in mice may also operate in patients with PNH. (Blood. 2004;103:2827-2834)
Collapse
Affiliation(s)
- Marek Jasinski
- Division of Hematology, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematologic disorder which is manifest by complement-mediated hemolysis, venous thrombosis, and bone marrow failure. Complement-mediated hemolysis in PNH is explained by the deficiency of glycosylphosphatidylinositol (GPI)-anchored proteins, CD55 and CD59 on erythrocyte surfaces. All the PNH patients had phosphatidylinositol glycan-class A (PIG-A) gene abnormalities in various cell types, indicating that PIG-A gene mutations cause the defects in GPI-anchored proteins that are essential for the pathogenesis of PNH. In addition, a PIG-A gene abnormality results in a PNH clone. Bone marrow failure causes cytopenias associated with a proliferative decrease of its hematopoietic stem cells and appears to be related to a pre-leukemic state. Although it is unclear how a PNH clone expands in bone marrow, it is considered that the most important hypothesis implicates negative selection of a PNH clone, but it does not explain the changes in the clinical features at the terminal stage of PNH. Recently, it has been suggested that an immune mechanism, in an HLA-restricted manner, plays an important role in the occurrence or selection of a PNH clone and GPI may be a target for cytotoxic-T lymphocytes. Also, it has been indicated that the Wilms' tumor gene (WT1) product is related to a PNH clone, but the significance of WT1 expression is not clear because of the functional diversity of the gene. To elucidate this problem, it is important to know the pathophysiology of bone marrow failure in detail and how bone marrow failure affects hematopoietic stem cells and immune mechanisms in bone marrow failure syndromes.
Collapse
Affiliation(s)
- Tsutomu Shichishima
- First Department of Internal Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan
| | | |
Collapse
|
39
|
Plasilova M, Risitano AM, O'Keefe CL, Rodriguez A, Wlodarski M, Young NS, Maciejewski J. Shared and individual specificities of immunodominant cytotoxic T-cell clones in paroxysmal nocturnal hemoglobinuria as determined by molecular analysis. Exp Hematol 2004; 32:261-9. [PMID: 15003311 DOI: 10.1016/j.exphem.2003.11.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Revised: 09/23/2003] [Accepted: 11/20/2003] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Similar immune mechanisms have been suggested to operate in aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH), and the presence of PNH clones in AA may indicate that an immune reaction directed against hematopoietic stem cells may be responsible for the immune selection pressure leading to PNH evolution. We previously described expansions of selective cytotoxic T-lymphocyte (CTL) clones in AA patients. MATERIALS AND METHODS We applied a molecular analysis of the T-cell receptor repertoire to study the characteristics of CTL response in patients with various forms of PNH. Immunodominant T-cell clones were detected using combined flow cytometric and molecular analysis of the variable beta (VB) chain and CDR3 representation, followed by determination of the frequency of individual CDR3 clonotypes. Clonotypic polymerase chain reaction (PCR) was performed to establish clonotypic utilization pattern. RESULTS In patients with a past history of AA, and when subgrouped by current blood counts as "hypoproliferative" PNH patients (in contrast to purely hemolytic form of PNH), more pronounced skewing of VB family utilization was found, consistent with T-cell responses involving several immunodominant CTL clones. Sequences of the PNH-derived clonotypes were used to design PCR-based assays for the utilization analysis of individual clones in PNH patients. The clonotypic distribution pattern established by this PCR method indicated that immunodominant T-cell specificities were shared between some patients but also may be found at low frequencies in controls. CONCLUSION Analysis of the CDR3 sequence pattern as a marker for expanded immunodominant clonotypes may have an application in the study of T-cell responses in PNH.
Collapse
MESH Headings
- Adult
- Aged
- Anemia, Aplastic/complications
- Anemia, Aplastic/immunology
- Autoimmune Diseases/immunology
- Clone Cells/immunology
- Complementarity Determining Regions/genetics
- DNA, Complementary/genetics
- Disease Progression
- Female
- Gene Rearrangement, beta-Chain T-Cell Antigen Receptor
- Glycosylphosphatidylinositols/deficiency
- Hemoglobinuria, Paroxysmal/complications
- Hemoglobinuria, Paroxysmal/genetics
- Hemoglobinuria, Paroxysmal/immunology
- Humans
- Immunodominant Epitopes/immunology
- Male
- Membrane Proteins/genetics
- Middle Aged
- Polymerase Chain Reaction
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- T-Lymphocytes, Cytotoxic/immunology
Collapse
Affiliation(s)
- Magdalena Plasilova
- Experimental Hematology and Hematopoiesis Section, Taussig Cancer Center, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Lalanne E, Honys D, Johnson A, Borner GHH, Lilley KS, Dupree P, Grossniklaus U, Twell D. SETH1 and SETH2, two components of the glycosylphosphatidylinositol anchor biosynthetic pathway, are required for pollen germination and tube growth in Arabidopsis. Plant Cell 2004; 16:229-40. [PMID: 14671020 PMCID: PMC301407 DOI: 10.1105/tpc.014407] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2003] [Accepted: 10/23/2003] [Indexed: 05/17/2023]
Abstract
Glycosylphosphatidylinositol (GPI) anchoring provides an alternative to transmembrane domains for anchoring proteins to the cell surface in eukaryotes. GPI anchors are synthesized in the endoplasmic reticulum via the sequential addition of monosaccharides, fatty acids, and phosphoethanolamines to phosphatidylinositol. Deficiencies in GPI biosynthesis lead to embryonic lethality in animals and to conditional lethality in eukaryotic microbes by blocking cell growth, cell division, or morphogenesis. We report the genetic and phenotypic analysis of insertional mutations disrupting SETH1 and SETH2, which encode Arabidopsis homologs of two conserved proteins involved in the first step of the GPI biosynthetic pathway. seth1 and seth2 mutations specifically block male transmission and pollen function. This results from reduced pollen germination and tube growth, which are associated with abnormal callose deposition. This finding suggests an essential role for GPI anchor biosynthesis in pollen tube wall deposition or metabolism. Using transcriptomic and proteomic approaches, we identified 47 genes that encode potential GPI-anchored proteins that are expressed in pollen and demonstrated that at least 11 of these proteins are associated with pollen membranes by GPI anchoring. Many of the identified candidate proteins are homologous with proteins involved in cell wall synthesis and remodeling or intercellular signaling and adhesion, and they likely play important roles in the establishment and maintenance of polarized pollen tube growth.
Collapse
Affiliation(s)
- Eric Lalanne
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Elebute MO, Rizzo S, Tooze JA, Marsh JCW, Gordon-Smith EC, Gibson FM. Evaluation of the haemopoietic reservoir in de novo haemolytic paroxysmal nocturnal haemoglobinuria. Br J Haematol 2003; 123:552-60. [PMID: 14617024 DOI: 10.1046/j.1365-2141.2003.04590.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder of the haemopoietic stem cell (HSC). The pathogenetic link with bone marrow failure is well recognized; however, the process of clonal expansion of the glycosylphosphatidylinositol (GPI)-deficient cells over normal haemopoiesis remains unclear. We have carried out detailed analysis of the stem cell population in 10 patients with de novo haemolytic PNH using the long-term culture-initiating cells (LTC-IC) assay in parallel with measurements of CD34+ cells and mature haemopoietic progenitors, granulocyte-macrophage colony-forming unit (CFU-GM) and CFU-erythroid [burst-forming units erythroid (BFU-E) + CFU granulocyte/erythroid/macrophage/megakaryocyte (GEMM)]. All patients had hypercellular bone marrows with erythroid hyperplasia, normal blood counts or mild peripheral blood cytopenias, increased reticulocyte counts and evidence of deficient GPI-anchored proteins. We found a significant reduction in the LTC-IC frequency in the CD34+ compartment of PNH patients (mean 2, range 1.3-3.0; n=6) compared with normal donors (mean 13, range 5.2-45.5; n=21) (P<0.0001). Furthermore, there was a significant reduction in the erythroid compartment [CFU-E/105 bone marrow mononuclear cells (BMMC) and CFU-E/105 CD34+ cells] of PNH patients, but no significant difference in the granulocyte-monocyte precursors (CFU-GM/105 BMMC or CFU-GM/105 CD34+ cells) compared with normal donors, suggesting that there is a defect in the early stem cell pool in PNH patients without clinical or haematological evidence of bone marrow failure.
Collapse
Affiliation(s)
- Modupe O Elebute
- Department of Haematology, St George's Hospital Medical School, London, UK.
| | | | | | | | | | | |
Collapse
|
42
|
Karadimitris A, Araten DJ, Luzzatto L, Notaro R. Severe telomere shortening in patients with paroxysmal nocturnal hemoglobinuria affects both GPI- and GPI+ hematopoiesis. Blood 2003; 102:514-6. [PMID: 12623835 DOI: 10.1182/blood-2003-01-0128] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A most distinctive feature of paroxysmal nocturnal hemoglobinuria (PNH) is that in each patient glycosylphosphatidylinositol-negative (GPI-) and GPI+ hematopoietic stem cells (HSCs) coexist, and both contribute to hematopoiesis. Telomere size correlates inversely with the cell division history of HSCs. In 10 patients with hemolytic PNH the telomeres in sorted GPI- granulocytes were shorter than in sorted GPI+ granulocytes in 4 cases, comparable in 2 cases, and longer in the remaining 4 cases. Furthermore, the telomeres of both GPI- and GPI+ hematopoietic cells were markedly shortened compared with age-matched controls. The short telomeres in the GPI- cells probably reflect the large number of cell divisions required for the progeny of a single cell to contribute a large proportion of hematopoiesis. The short telomeres of the GPI+ cells indicate that the residual hematopoiesis contributed by these cells is not normal. This epigenetic change is an additional feature shared by PNH and aplastic anemia.
Collapse
|
43
|
Abstract
We have previously demonstrated that glycosylphosphatidylinositol (GPI) anchors strongly influence protein trafficking in the procyclic insect stage of Trypanosoma brucei (M. A. McDowell, D. A. Ransom, and J. D. Bangs, Biochem. J. 335:681-689, 1998), where GPI-minus variant surface glycoprotein (VSG) reporters have greatly reduced rates of endoplasmic reticulum (ER) exit but are ultimately secreted. We now demonstrate that GPI-dependent trafficking also occurs in pathogenic bloodstream trypanosomes. However, unlike in procyclic trypanosomes, truncated VSGs lacking C-terminal GPI-addition signals are not secreted but are mistargeted to the lysosome and degraded. Failure to export these reporters is not due to a deficiency in secretion of these cells since the N-terminal ATPase domain of the endogenous ER protein BiP is efficiently secreted from transgenic cell lines. Velocity sedimentation experiments indicate that GPI-minus VSG dimerizes similarly to wild-type VSG, suggesting that degradation is not due to ER quality control mechanisms. However, GPI-minus VSGs are fully protected from degradation by the cysteine protease inhibitor FMK024, a potent inhibitor of the major lysosomal protease trypanopain. Immunofluorescence of cells incubated with FMK024 demonstrates that GPI-minus VSG colocalizes with p67, a lysosomal marker. These data suggest that in the absence of a GPI anchor, VSG is mistargeted to the lysosome and subsequently degraded. Our findings indicate that GPI-dependent transport is a general feature of secretory trafficking in both stages of the life cycle. A working model is proposed in which GPI valence regulates progression in the secretory pathway of bloodstream stage trypanosomes.
Collapse
Affiliation(s)
- Veronica P Triggs
- Department of Biomolecular Chemistry, University of Wisconsin-Madison Medical School, Madison, Wisconsin 53706, USA
| | | |
Collapse
|
44
|
Abstract
Hemolysis, a characteristic of paroxysmal nocturnal hemoglobinuria (PNH), is caused by the expansion of an affected stem cell with a mutation of the PIG-A gene. Increasing evidence has shown that the presence of the PIG-A mutation alone does not induce the expansion. Two theories have been proposed. One, the growth advantage hypothesis, is supported by current data indicating the presence of several intrinsic alterations that might confer a proliferative advantage to PNH clones over normal cells. Alternatively, the PIG-A mutation might confer a relative survival advantage to PNH clones. This theory is supported by clinical observation indicating that PIG-A mutant cells survive immune-mediated bone marrow injury in patients with aplastic anemia, PNH, and myelodysplastic syndromes. The latter theory is also supported by current experimental data indicating that PIG-A mutant cells are relatively resistant to cytotoxic attack by natural killer cells and cytotoxic T-lymphocytes. The 2 theories appear complementary rather than mutually exclusive. Rapid progress in this field can be expected in the near future.
Collapse
Affiliation(s)
- Hideki Nakakuma
- Second Department of Internal Medicine, Kumamoto University School of Medicine, Kumamoto, Japan.
| | | |
Collapse
|
45
|
Wang J, Liu HL, Xu CM, Yang Y, Lv ZJ, Pang HZ, Zhang ZN. Detection of erythrocytes deficient in glycosylphosphatidyl-inositol anchored membrane proteins in patients with paroxysmal nocturnal hemoglobinuria by the toxin HEC secreted by Aeromonas hydrophila J-1. Hematology 2003; 8:41-6. [PMID: 12623426 DOI: 10.1080/1024533021000059447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
OBJECTIVE To study the feasibility of diagnosing paroxysmal nocturnal hemoglobinuria (PNH) with toxin HEC, the abbreviation of hemolytic, entreotoxigenicity and cytotoxity secreted by Aeromonas hydrophila J-1. METHODS The crude toxin HEC was extracted from the culture medium of Aeromonas hydrophila J-1 by precipitating with saturated (NH(4))(2)SO(4) and then purified through DEAE52. Purified toxin HEC is different from Aerolysin in molecular weight and necessity of activation. Crude toxin is prepared possessed same effect as purified ones. This crude toxin was used to act on red blood cells (RBCs) from patients with PNH, non-PNH anemia, and normal persons. Absorbance at 630 nm was measured to quantitate the extent of hemolysis. Toxin HEC treated and untreated RBCs were both stained with anti-CD59 monoclonal antibody and FITC labeled goat-anti-mouse IgG. The percentage of CD59(+) cells was detected by flow cytometry (FCM). RESULTS After toxin HEC treatment, RBCs from PNH patients showed resistance to the toxin hemolysis, which was negatively related to the percentage of CD59(+) cells, while RBCs from normal persons and non-PNH anemic patient were nearly totally lysed. CONCLUSION Detection of RBCs resistance to toxin HEC can be used for the diagnosis of PNH.
Collapse
Affiliation(s)
- Jian Wang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
46
|
Abstract
Paroxysmal nocturnal haemoglobinuria (PNH) is unique because it is an acquired haemolytic anaemia, resulting from an intrinsic red cell membrane disorder. The disease has been shown to be due to a somatic mutation of the phosphatidylinositol glycan complementation class A (pig-a) gene at the level of the haemopoietic stem cell. The defect in synthesis of the glycosylphosphatidylinositol (GPI) anchor results in a deficiency of all proteins that are GPI-bound to red cell, leucocyte and platelet membranes. The function of these proteins is extremely varied but a critical role is the protection of the cell from complement and it is the unopposed action of the complement cascade that results in the intravascular haemolysis and venous thrombosis which are hallmarks of the disease. The relationship between PNH and aplastic anaemia remains intriguing. It appears likely that an insult to a haemopoietic progenitor alters it in such a way that it becomes vulnerable to immune-mediated attack by cytotoxic T cells and/or cytokines. This attack requires one or more GPI-anchored molecules to be effective. Thus a GPI-negative clone would be at a relative advantage, and it is the balance between bone marrow impairment and proliferation of the GPI-negative clone(s) that determines the clinical picture. Prospects for molecular therapy continue to improve. Cell-to-cell transfer of GPI-linked proteins has been demonstrated in murine studies and recombinant CD59 has been expressed on GPI-deficient lymphocytes in vitro. Gene therapy remains a tantalising possibility, although a greater understanding of the pathophysiology of PNH is required, as well as advances in gene therapy techniques, before such an approach can be seriously considered.
Collapse
Affiliation(s)
- Claire Hall
- Haematological Malignancy Diagnostic Service, Leeds General Infirmary, Leeds, UK.
| | | | | |
Collapse
|
47
|
Risitano AM, Holada K, Chen G, Simak J, Vostal JG, Young NS, Maciejewski JP. CD34+ cells from paroxysmal nocturnal hemoglobinuria (PNH) patients are deficient in surface expression of cellular prion protein (PrPc). Exp Hematol 2003; 31:65-72. [PMID: 12543108 DOI: 10.1016/s0301-472x(02)01011-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cellular prion protein (PrP(c)) is a glycosylphosphatidylinositol (GPI)-anchored protein (GPI-AP) constitutively expressed by neurons but also in hematopoietic cells. In trasmissible spongiform encephalopathies, the protease-resistant form of prion (PrP (s c)) converts the host PrP(c) into the pathologic form. We have investigated PrP(c) expression in hematopoietic cells from paroxysmal nocturnal hemoglobinuria (PNH). In this disease, due to somatic mutations in PIG-A gene, biosynthesis of the (GPI)-anchor is impaired and affected cells lack membrane expression of all GPI-AP. Normal and PNH hematopoietic progenitors and paired wild-type (WT) and PIG-A mutant cell lines were used for analysis of intracellular and surface PrP(c) expression using flow cytometry and Western blot.By flow cytometry, PrP(c) was constitutively present on normal CD34(+) cells, including more immature CD38(dim) cells, as well as hematopoietic cell lines. Similar results were obtained in purified CD34(+). Phospholipase C treatment confirmed that PrP(c) was expressed on the membrane via the GPI-anchor. In PNH patients, GPI-AP-deficient CD34(+) cells lacked PrP(c) membrane expression. PIG-A-mutated cell lines (Jurkat, K562, C(EBV), A(EBV)), in contrast to their normal counterparts, did not express surface PrP(c). However, we detected intracellular PrP(c) at approximately equivalent levels in both normal and PIG-A-mutated cells using intracellular flow cytometry and Western blotting. Cells and cell lines with PNH phenotype together with their normal counterparts may be a suitable system to explore the function of membrane PrP(c) in the hematopoietic system. Conversely, PrP(c) is a good model to elucidate the fate of GPI-AP in PIG-A-deficient cells.
Collapse
Affiliation(s)
- Antonio M Risitano
- Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | | |
Collapse
|
48
|
Murakami Y, Kosaka H, Maeda Y, Nishimura JI, Inoue N, Ohishi K, Okabe M, Takeda J, Kinoshita T. Inefficient response of T lymphocytes to glycosylphosphatidylinositol anchor-negative cells: implications for paroxysmal nocturnal hemoglobinuria. Blood 2002; 100:4116-22. [PMID: 12393537 DOI: 10.1182/blood-2002-06-1669] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a hematopoietic stem cell disorder in which clonal cells defective in glycosylphosphatidylinositol (GPI) biosynthesis are expanded, leading to complement-mediated hemolysis. PNH is often associated with bone marrow suppressive conditions, such as aplastic anemia. One hypothetical mechanism for the clonal expansion of GPI(-) cells in PNH is that the mutant cells escape attack by autoreactive cytotoxic cells that are thought to be responsible for aplastic anemia. Here we studied 2 model systems. First, we made pairs of GPI(+) and GPI(-) EL4 cells that expressed major histocompatibility complex (MHC) class II molecules and various types of ovalbumin. When the GPI-anchored form of ovalbumin was expressed on GPI(+) and GPI(-) cells, only the GPI(+) cells presented ovalbumin to ovalbumin-specific CD4(+) T cells, indicating that if a putative autoantigen recognized by cytotoxic cells is a GPI-anchored protein, GPI(-) cells are less sensitive to cytotoxic cells. Second, antigen-specific as well as alloreactive CD4(+) T cells responded less efficiently to GPI(-) than GPI(+) cells in proliferation assays. In vivo, when GPI(-) and GPI(+) fetal liver cells, and CD4(+) T cells alloreactive to them, were cotransplanted into irradiated hosts, the contribution of GPI(-) cells in peripheral blood cells was significantly higher than that of GPI(+) cells. The results obtained with the second model suggest that certain GPI-anchored protein on target cells is important for recognition by T cells. These results provide the first experimental evidence for the hypothesis that GPI(-) cells escape from immunologic attack.
Collapse
Affiliation(s)
- Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Kulkarni S, Bessler M. The effect of GPI-anchor deficiency on apoptosis in mice carrying a Piga gene mutation in hematopoietic cells. J Leukoc Biol 2002; 72:1228-33. [PMID: 12488505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
Glycosyl phosphatidylinositol (GPI) anchors are used by a variety of proteins to link to the cell surface. GPI-anchored proteins are deficient on a proportion of blood cells from patients with paroxysmal nocturnal hemoglobinuria. This is caused by the expansion of a cell clone that has acquired a mutation in a gene, PIGA, which is essential in the synthesis of GPI anchors. The nature of the growth/survival advantage permitting the expansion of PIGA(-) cells is unknown. A decreased susceptibility to apoptosis has been found in blood cells from patients, but the contribution of the PIGA gene mutation to this finding remained controversial. Therefore, we investigated apoptosis in mice that harbor a targeted Piga gene mutation in hematopoietic cells. When exposed to a variety of apoptotic stimuli, apoptosis in PIGA(-) thymocytes, granulocytes, and hematopoietic progenitor cells was similar to apoptosis induced in PIGA(+) cells from the same mouse or from wild-type controls. Similarly, whole-body gamma-irradiation did not produce an in vivo survival advantage of PIGA(-) hematopoietic stem cells. Our findings imply that a Piga gene mutation does not alter susceptibility to cell death, indicating that other factors in addition to the PIGA gene mutation are necessary to promote the clonal outgrowth of PIGA(-) cells.
Collapse
Affiliation(s)
- Shashikant Kulkarni
- Department of Internal Medicine, Division of Hematology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | |
Collapse
|
50
|
Kitani T. [Progress in the field of hematology in the last 100 years: Medical history of paroxysmal nocturnal hemoglobinuria]. Nihon Naika Gakkai Zasshi 2002; 91:2078-83. [PMID: 12187681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
|