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Aysola V, Abd C, Kuo AH, Gupta N. Ezrin Promotes Antigen Receptor Diversity during B Cell Development by Supporting Ig H Chain Variable Gene Recombination. Immunohorizons 2022; 6:722-729. [DOI: 10.4049/immunohorizons.2100103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
Abstract
Genome-level rearrangements of Ig genes during B cell development are critical for generation of a diverse repertoire of BCRs that bind to a multitude of foreign Ags and some self Ags. Bone marrow B cell development involves a variety of cell–cell interactions, cell migration, and receptor signaling that likely benefit from the activity of membrane-cytoskeletal reorganizing proteins. However, the specific contribution of such proteins toward BCR repertoire diversification is poorly understood. Ezrin is a membrane-cytoskeletal linker protein that regulates mature B cell activation through spatial organization of the BCR. We employed next-generation sequencing to investigate whether Ezrin plays a role in IgH rearrangements and generation of BCR diversity in developing bone marrow B cells. BCR repertoire development occurred stochastically in B cell progenitors from both control and B cell conditional Ezrin-deficient mice. However, the loss of Ezrin resulted in fewer unique CDRs (CDR3s) in the BCRs and reduced Shannon entropy. Ezrin-deficient pre-B cells revealed similar utilization of joining (J) genes but significantly fewer variable (V) genes, thereby decreasing V-J combinatorial diversity. V-J junctional diversity, measured by CDR3 length and nucleotide additions and deletions, was not altered in Ezrin-deficient pre-B cells. Mechanistically, Ezrin-deficient cells showed a marked decrease in RAG1 gene expression, indicating a less efficient DNA recombination machinery. Overall, our results demonstrate that Ezrin shapes the BCR repertoire through combinatorial diversification.
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Affiliation(s)
- Varun Aysola
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Christina Abd
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Alexander H. Kuo
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Neetu Gupta
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
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Helbling-Leclerc A, Garcin C, Rosselli F. Beyond DNA repair and chromosome instability-Fanconi anaemia as a cellular senescence-associated syndrome. Cell Death Differ 2021; 28:1159-1173. [PMID: 33723374 PMCID: PMC8026967 DOI: 10.1038/s41418-021-00764-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 02/17/2021] [Accepted: 02/24/2021] [Indexed: 02/07/2023] Open
Abstract
Fanconi anaemia (FA) is the most frequent inherited bone marrow failure syndrome, due to mutations in genes encoding proteins involved in replication fork protection, DNA interstrand crosslink repair and replication rescue through inducing double-strand break repair and homologous recombination. Clinically, FA is characterised by aplastic anaemia, congenital defects and cancer predisposition. In in vitro studies, FA cells presented hallmarks defining senescent cells, including p53-p21 axis activation, altered telomere length, mitochondrial dysfunction, chromatin alterations, and a pro-inflammatory status. Senescence is a programme leading to proliferation arrest that is involved in different physiological contexts, such as embryogenesis, tissue remodelling and repair and guarantees tumour suppression activity. However, senescence can become a driving force for developmental abnormalities, aging and cancer. Herein, we summarise the current knowledge in the field to highlight the mutual relationships between FA and senescence that lead us to consider FA not only as a DNA repair and chromosome fragility syndrome but also as a "senescence syndrome".
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Affiliation(s)
- Anne Helbling-Leclerc
- grid.14925.3b0000 0001 2284 9388UMR9019-CNRS, Gustave Roussy, Villejuif, Cedex France ,grid.460789.40000 0004 4910 6535Université Paris-Saclay, Orsay, France ,Equipe labellisée “La Ligue Contre le Cancer”, Villejuif, France
| | - Cécile Garcin
- grid.14925.3b0000 0001 2284 9388UMR9019-CNRS, Gustave Roussy, Villejuif, Cedex France ,grid.460789.40000 0004 4910 6535Université Paris-Saclay, Orsay, France ,Equipe labellisée “La Ligue Contre le Cancer”, Villejuif, France
| | - Filippo Rosselli
- grid.14925.3b0000 0001 2284 9388UMR9019-CNRS, Gustave Roussy, Villejuif, Cedex France ,grid.460789.40000 0004 4910 6535Université Paris-Saclay, Orsay, France ,Equipe labellisée “La Ligue Contre le Cancer”, Villejuif, France
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Oppezzo A, Bourseguin J, Renaud E, Pawlikowska P, Rosselli F. Microphthalmia transcription factor expression contributes to bone marrow failure in Fanconi anemia. J Clin Invest 2020; 130:1377-1391. [PMID: 31877112 DOI: 10.1172/jci131540] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 12/11/2019] [Indexed: 12/20/2022] Open
Abstract
Hematopoietic stem cell (HSC) attrition is considered the key event underlying progressive BM failure (BMF) in Fanconi anemia (FA), the most frequent inherited BMF disorder in humans. However, despite major advances, how the cellular, biochemical, and molecular alterations reported in FA lead to HSC exhaustion remains poorly understood. Here, we demonstrated in human and mouse cells that loss-of-function of FANCA or FANCC, products of 2 genes affecting more than 80% of FA patients worldwide, is associated with constitutive expression of the transcription factor microphthalmia (MiTF) through the cooperative, unscheduled activation of several stress-signaling pathways, including the SMAD2/3, p38 MAPK, NF-κB, and AKT cascades. We validated the unrestrained Mitf expression downstream of p38 in Fanca-/- mice, which display hallmarks of hematopoietic stress, including loss of HSC quiescence, DNA damage accumulation in HSCs, and reduced HSC repopulation capacity. Importantly, we demonstrated that shRNA-mediated downregulation of Mitf expression or inhibition of p38 signaling rescued HSC quiescence and prevented DNA damage accumulation. Our data support the hypothesis that HSC attrition in FA is the consequence of defects in the DNA-damage response combined with chronic activation of otherwise transiently activated signaling pathways, which jointly prevent the recovery of HSC quiescence.
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Affiliation(s)
- Alessia Oppezzo
- CNRS UMR8200 Equipe Labellisée "La Ligue Contre le Cancer,".,Gustave Roussy, Villejuif, France.,Université Paris-Saclay, Orsay, France
| | - Julie Bourseguin
- CNRS UMR8200 Equipe Labellisée "La Ligue Contre le Cancer,".,Gustave Roussy, Villejuif, France.,Université Paris-Saclay, Orsay, France
| | - Emilie Renaud
- CNRS UMR8200 Equipe Labellisée "La Ligue Contre le Cancer,".,Gustave Roussy, Villejuif, France
| | - Patrycja Pawlikowska
- CNRS UMR8200 Equipe Labellisée "La Ligue Contre le Cancer,".,Gustave Roussy, Villejuif, France.,Université Paris-Saclay, Orsay, France
| | - Filippo Rosselli
- CNRS UMR8200 Equipe Labellisée "La Ligue Contre le Cancer,".,Gustave Roussy, Villejuif, France.,Université Paris-Saclay, Orsay, France
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Tao R, Liu YJ, Liu LF, Li W, Zhao Y, Li HM, Yi XL, Zhao ZY. Genetic polymorphisms of ARID5B rs7089424 and rs10994982 are associated with B-lineage ALL susceptibility in Chinese pediatric population. J Chin Med Assoc 2019; 82:562-567. [PMID: 31274788 DOI: 10.1097/jcma.0000000000000038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Several ARID5B single nucleotide polymorphisms (SNPs) were confirmed to be significantly associated with the susceptibility of childhood acute lymphoblastic leukemia (ALL) based on Caucasian populations in previous studies. Similar investigations in Asian populations were less. The aim of this study is to explore the relationship between ARID5B SNPs rs7089424, rs10994982, and the risk of ALL in Chinese pediatric population. METHODS A total of 190 pediatric ALL patients and 270 controls were enrolled in this study. PCR amplification combined with mass spectrometry were used to evaluate the genotypes of ARID5B rs7089424 and rs10994982. χ test was used in allele frequencies and genotype distributions of the SNPs for analyzing statistical differences between patients and controls. RESULTS There were significant differences in the risk allele frequencies of ARID5B rs7089424 and rs10994982 between B-lineage ALL (B-ALL) patients and controls (rs7089424, G allele: p = 0.001; rs10994982, A allele: p = 0.000). The genotype distributions of ARID5B rs7089424 and rs10994982 were also statistically different in B-ALL patients compared with controls (rs7089424, p = 0.004; rs10994982, p = 0.001). Further analyzing the relevance of ARID5B rs7089424 and rs10994982 genotypes to clinical risk classification of ALL showed GG genotype of rs7089424 and AA genotype of rs10994982 were strikingly correlated with the medium-risk and low-risk groups of B-ALL. Finally, GG and GT genotypes of rs7089424 and AA genotype of rs10994982 seemed to be responsible for the hyperdiploid subtype susceptibility of childhood B-ALL. CONCLUSION ARID5B rs7089424 and rs10994982 might serve as genetic susceptibility markers for B-ALL in Chinese pediatric population. Moreover, the two ARID5B SNPs are associated with the risk of B-hyperdiploid ALL, which had a better therapeutic response than other ALL subtypes.
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Affiliation(s)
- Ran Tao
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yu-Jie Liu
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Li-Fang Liu
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Li
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yun Zhao
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua-Mei Li
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao-Lian Yi
- Department of Pediatrics, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Zheng-Yan Zhao
- Laboratory Center, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, China
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Deniskin R, Sasa GS, Nandiwada SL, Rider NL. Lymphopenia With Clinical and Laboratory Features of Combined Immune Deficiency in an 11-Year-Old Female With FANCD2 Variants and Fanconi Anemia. Front Pediatr 2019; 6:390. [PMID: 30713837 PMCID: PMC6346677 DOI: 10.3389/fped.2018.00390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/27/2018] [Indexed: 11/13/2022] Open
Abstract
Fanconi anemia (FA) is an inherited bone marrow failure and cancer predisposition disorder due to mutations in DNA repair pathways proteins (FANC). The dysfunctional proteins are unable to repair DNA breaks and cause genomic instability. Mutations in many of the 19 FANC genes are well characterized biochemically and clinically. Little is known about the FANCD2 gene which acts downstream of the FA-core proteins. Here we report a 11-year-old female previously diagnosed with FA and bone marrow failure. Gene sequencing demonstrated deletion of exons 2-18 and a pathologic missense mutation (c. 2444G>A, p. Arg815Gln) in FANCD2 (Chr3). Her medical history is significant for an episode of pneumococcal sepsis despite adequate vaccination. Repeated blood samples and immunophenotyping demonstrated severe lymphopenia. There were markedly low CD4+ T-cell counts with a low CD4:CD8 ratio. Changes in the composition of the B-cell population included significantly diminished absolute total B-cells, and decreased mature cells. There was no immunogenic response to vaccination against S. pneumoniae. The NK-cell count was unaffected and demonstrated normal spontaneous and stimulated cytotoxic response. Bone marrow analysis demonstrated hypocellularity without dysplasia. The clinical and laboratory features are suggestive of combined immune deficiency. FANCD2 may be involved in the transition of immature B and T cells to mature cells, a process that requires substantial DNA recombination not observed in NK cells. Additional genetic and biochemical evaluation is needed to further characterize the novel genetic and clinical findings.
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Affiliation(s)
- Roman Deniskin
- Department of Pediatrics (Pediatrician Scientist Training and Development Program), Houston, TX, United States
| | - Ghadir S. Sasa
- Section of Hematology and Oncology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, United States
| | - Sarada L. Nandiwada
- Clinical and Diagnostic Immunology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, United States
- Section of Allergy, Immunology, and Rheumatology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, United States
| | - Nicholas L. Rider
- Section of Allergy, Immunology, and Rheumatology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, United States
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