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Yang Z, Tao P, Han X, Kozlova A, He T, Volchkov E, Nesterenko Z, Pershin D, Raykina E, Fatkhudinov T, Korobeynikova A, Aksentijevich I, Yang J, Shcherbina A, Zhou Q, Yu X. Characterization of a Novel Pathogenic PLCG2 Variant Leading to APLAID Syndrome Responsive to a TNF Inhibitor. Arthritis Rheumatol 2024. [PMID: 38965708 DOI: 10.1002/art.42948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 05/13/2024] [Accepted: 07/25/2024] [Indexed: 07/06/2024]
Abstract
OBJECTIVE Autoinflammation and phospholipase C (PLC) γ2-associated antibody deficiency and immune dysregulation (APLAID) syndrome is an autoinflammatory disease caused by gain-of-function variants in PLCG2. This study investigates the pathogenic mechanism of a novel variant of PLCG2 in a patient with APLAID syndrome. METHODS Whole-exome sequencing and Sanger sequencing were used to identify the pathogenic variant in the patient. Single-cell RNA sequencing, immunoblotting, luciferase assay, inositol monophosphate enzyme-linked immunosorbent assay, calcium flux assay, quantitative PCR, and immunoprecipitation were used to define inflammatory signatures and evaluate the effects of the PLCG2 variant on protein functionality and immune signaling. RESULTS We identified a novel de novo variant, PLCG2 p.D993Y, in a patient with colitis, pansinusitis, skin rash, edema, recurrent respiratory infections, B-cell deficiencies, and hypogammaglobulinemia. The single-cell transcriptome revealed exacerbated inflammatory responses in the patient's peripheral blood mononuclear cells. Expression of the D993Y variant in HEK293T, COS-7, and PLCG2 knock-out THP-1 cell lines showed heightened PLCγ2 phosphorylation; elevated inositol-1,4,5-trisphosphate production and intracellular Ca2+ release; and activation of the MAPK, NF-κB, and NFAT signaling pathways compared with control-transfected cells. In vitro experiments indicated that the D993Y variant altered amino acid properties, disrupting the interaction between the catalytic and autoinhibitory domains of PLCγ2, resulting in PLCγ2 autoactivation. CONCLUSION Our findings demonstrated that the PLCG2 D993Y variant is a gain-of-function mutation via impairing its autoinhibition, activating multiple inflammatory signaling pathways, thus leading to APLAID syndrome. This study further broadens the molecular underpinnings and phenotypic spectrum of PLCγ2-related disorders.
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Affiliation(s)
- Zhaohui Yang
- The Second Affiliated Hospital, Zhejiang University School of Medicine and Liangzhu Laboratory, Zhejiang University, Hangzhou, China
| | - Panfeng Tao
- The Second Affiliated Hospital, Zhejiang University School of Medicine and Liangzhu Laboratory, Zhejiang University, Hangzhou, China
| | - Xu Han
- The Second Affiliated Hospital, Zhejiang University School of Medicine and Liangzhu Laboratory, Zhejiang University, Hangzhou, China
| | - Anna Kozlova
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Tingyan He
- Shenzhen Children's Hospital, Shenzhen, China
| | - Egor Volchkov
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation and Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
| | - Zoya Nesterenko
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Dmitryi Pershin
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Elena Raykina
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Timur Fatkhudinov
- Peoples' Friendship University of Russia (RUDN University) and Avtsyn Research Institute of Human Morphology of Federal State Budgetary Scientific Institution "Petrovsky National Research Centre of Surgery", Moscow, Russia
| | - Anastasia Korobeynikova
- Peoples' Friendship University of Russia (RUDN University), Moscow, and Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk, Russia
| | - Ivona Aksentijevich
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Jun Yang
- Shenzhen Children's Hospital, Shenzhen, China
| | - Anna Shcherbina
- Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Qing Zhou
- The Second Affiliated Hospital, Zhejiang University School of Medicine and Liangzhu Laboratory, Zhejiang University, Hangzhou, China
| | - Xiaomin Yu
- The Second Affiliated Hospital, Zhejiang University School of Medicine and Liangzhu Laboratory, Zhejiang University, Hangzhou, China
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Bull D, Matte JC, Navarron CM, McIntyre R, Whiting P, Katan M, Ducotterd F, Magno L. The hypermorphic PLCγ2 S707Y variant dysregulates microglial cell function - Insight into PLCγ2 activation in brain health and disease, and opportunities for therapeutic modulation. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166978. [PMID: 38061598 DOI: 10.1016/j.bbadis.2023.166978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/29/2023] [Accepted: 11/27/2023] [Indexed: 12/30/2023]
Abstract
Phospholipase C-gamma 2 (PLCγ2) is highly expressed in hematopoietic and immune cells, where it is a key signalling node enabling diverse cellular functions. Within the periphery, gain-of-function (GOF) PLCγ2 variants, such as the strongly hypermorphic S707Y, cause severe immune dysregulation. The milder hypermorphic mutation PLCγ2 P522R increases longevity and confers protection in central nervous system (CNS) neurodegenerative disorders, implicating PLCγ2 as a novel therapeutic target for treating these CNS indications. Currently, nothing is known about what consequences strong PLCγ2 GOF has on CNS functionality, and more precisely on the specific biological functions of microglia. Using the PLCγ2 S707Y variant as a model of chronic activation we investigated the functional consequences of strong PLCγ2 GOF on human microglia. PLCγ2 S707Y expressing human inducible pluripotent stem cells (hiPSC)-derived microglia exhibited hypermorphic enzymatic activity under both basal and stimulated conditions, compared to PLCγ2 wild type. Despite the increase in PLCγ2 enzymatic activity, the PLCγ2 S707Y hiPSC-derived microglia display diminished functionality for key microglial processes including phagocytosis and cytokine secretion upon inflammatory challenge. RNA sequencing revealed a downregulation of genes related to innate immunity and response, providing molecular support for the phenotype observed. Our data suggests that chronic activation of PLCγ2 elicits a detrimental phenotype that is contributing to unfavourable CNS functions, and informs on the therapeutic window for targeting PLCγ2 in the CNS. Drug candidates targeting PLCγ2 will need to precisely mimic the effects of the PLCγ2 P522R variant on microglial function, but not those of the PLCγ2 S707Y variant.
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Affiliation(s)
- Daniel Bull
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, The Cruciform Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Julie C Matte
- Wellcome Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Carmen M Navarron
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, The Cruciform Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Rebecca McIntyre
- Wellcome Sanger Institute, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Paul Whiting
- Institute of Neurology, University College London, Queen Square, London WC1N 3BG, United Kingdom
| | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Fiona Ducotterd
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, The Cruciform Building, Gower Street, London WC1E 6BT, United Kingdom
| | - Lorenza Magno
- Alzheimer's Research UK UCL Drug Discovery Institute, University College London, The Cruciform Building, Gower Street, London WC1E 6BT, United Kingdom.
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Constantin M, Mătanie C, Petrescu L, Bolocan A, Andronic O, Bleotu C, Mitache MM, Tudorache S, Vrancianu CO. Landscape of Genetic Mutations in Appendiceal Cancers. Cancers (Basel) 2023; 15:3591. [PMID: 37509254 PMCID: PMC10377024 DOI: 10.3390/cancers15143591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/28/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
In appendiceal cancers, the most frequently mutated genes are (i) KRAS, which, when reactivated, restores signal transduction via the RAS-RAF-MEK-ERK signaling pathway and stimulates cell proliferation in the early stages of tumor transformation, and then angiogenesis; (ii) TP53, whose inactivation leads to the inhibition of programmed cell death; (iii) GNAS, which, when reactivated, links the cAMP pathway to the RAS-RAF-MEK-ERK signaling pathway, stimulating cell proliferation and angiogenesis; (iv) SMAD4, exhibiting typical tumor-suppressive activity, blocking the transmission of oncogenic TGFB signals via the SMAD2/SMAD3 heterodimer; and (v) BRAF, which is part of the RAS-RAF-MEK-ERK signaling pathway. Diverse mutations are reported in other genes, which are part of secondary or less critical signaling pathways for tumor progression, but which amplify the phenotypic diversity of appendiceal cancers. In this review, we will present the main genetic mutations involved in appendix tumors and their roles in cell proliferation and survival, and in tumor invasiveness, angiogenesis, and acquired resistance to anti-growth signals.
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Affiliation(s)
- Marian Constantin
- Institute of Biology of Romanian Academy, 060031 Bucharest, Romania
- The Research Institute of the University of Bucharest (ICUB), 050095 Bucharest, Romania
| | - Cristina Mătanie
- Department of Anatomy, Animal Physiology and Biophysics (DAFAB), Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
| | - Livia Petrescu
- Department of Anatomy, Animal Physiology and Biophysics (DAFAB), Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
| | - Alexandra Bolocan
- Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Octavian Andronic
- Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Coralia Bleotu
- Life, Environmental and Earth Sciences Division, The Research Institute of the University of Bucharest (ICUB), 050095 Bucharest, Romania
- Stefan S. Nicolau Institute of Virology, 030304 Bucharest, Romania
| | | | - Sorin Tudorache
- Faculty of Medicine, "Titu Maiorescu" University, 040441 Bucharest, Romania
| | - Corneliu Ovidiu Vrancianu
- The Research Institute of the University of Bucharest (ICUB), 050095 Bucharest, Romania
- Microbiology-Immunology Department, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
- National Institute of Research and Development for Biological Sciences, 060031 Bucharest, Romania
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