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Puri S, Schulte T, Chaves-Sanjuan A, Mazzini G, Caminito S, Pappone C, Anastasia L, Milani P, Merlini G, Bolognesi M, Nuvolone M, Palladini G, Ricagno S. The Cryo-EM STRUCTURE of Renal Amyloid Fibril Suggests Structurally Homogeneous Multiorgan Aggregation in AL Amyloidosis. J Mol Biol 2023; 435:168215. [PMID: 37516426 DOI: 10.1016/j.jmb.2023.168215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 07/15/2023] [Accepted: 07/24/2023] [Indexed: 07/31/2023]
Abstract
Immunoglobulin light chain amyloidosis (AL) is caused by the aberrant production of amyloidogenic light chains (LC) that accumulate as amyloid deposits in vital organs. Distinct LC sequences in each patient yield distinct amyloid structures. However different tissue microenvironments may also cause identical protein precursors to adopt distinct amyloid structures. To address the impact of the tissue environment on the structural polymorphism of amyloids, we extracted fibrils from the kidney of an AL patient (AL55) whose cardiac amyloid structure was previously determined by our group. Here we show that the 4.0 Å resolution cryo-EM structure of the renal fibril is virtually identical to that reported for the cardiac fibril. These results provide the first structural evidence that LC amyloids independently deposited in different organs of the same AL patient share a common fold.
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Affiliation(s)
- Sarita Puri
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy. https://twitter.com/@Saritapuri1504
| | - Tim Schulte
- Institute of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, 20097 Milan, Italy. https://twitter.com/@timpaul81
| | - Antonio Chaves-Sanjuan
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy; Pediatric Research Center Fondazione R.E. Invernizzi and NOLIMITS Center, Università degli Studi di Milano, Milan, Italy. https://twitter.com/@ChavesSanjuan
| | - Giulia Mazzini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Serena Caminito
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Carlo Pappone
- Institute of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, 20097 Milan, Italy; Faculty of Medicine, University of Vita-Salute San Raffaele, 20132 Milan, Italy; Arrhythmia and Electrophysiology Department, IRCCS Policlinico San Donato, San Donato, 20097 Milan, Italy
| | - Luigi Anastasia
- Institute of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, 20097 Milan, Italy; Faculty of Medicine, University of Vita-Salute San Raffaele, 20132 Milan, Italy. https://twitter.com/@skinski74
| | - Paolo Milani
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Giampaolo Merlini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Martino Bolognesi
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy; Pediatric Research Center Fondazione R.E. Invernizzi and NOLIMITS Center, Università degli Studi di Milano, Milan, Italy. https://twitter.com/@Martinobologne2
| | - Mario Nuvolone
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Giovanni Palladini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Stefano Ricagno
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy; Institute of Molecular and Translational Cardiology, IRCCS Policlinico San Donato, 20097 Milan, Italy.
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Nau A, Shen Y, Sanchorawala V, Prokaeva T, Morgan GJ. Complete variable domain sequences of monoclonal antibody light chains identified from untargeted RNA sequencing data. Front Immunol 2023; 14:1167235. [PMID: 37143670 PMCID: PMC10151772 DOI: 10.3389/fimmu.2023.1167235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/31/2023] [Indexed: 05/06/2023] Open
Abstract
Introduction Monoclonal antibody light chain proteins secreted by clonal plasma cells cause tissue damage due to amyloid deposition and other mechanisms. The unique protein sequence associated with each case contributes to the diversity of clinical features observed in patients. Extensive work has characterized many light chains associated with multiple myeloma, light chain amyloidosis and other disorders, which we have collected in the publicly accessible database, AL-Base. However, light chain sequence diversity makes it difficult to determine the contribution of specific amino acid changes to pathology. Sequences of light chains associated with multiple myeloma provide a useful comparison to study mechanisms of light chain aggregation, but relatively few monoclonal sequences have been determined. Therefore, we sought to identify complete light chain sequences from existing high throughput sequencing data. Methods We developed a computational approach using the MiXCR suite of tools to extract complete rearranged IGVL-IGJL sequences from untargeted RNA sequencing data. This method was applied to whole-transcriptome RNA sequencing data from 766 newly diagnosed patients in the Multiple Myeloma Research Foundation CoMMpass study. Results Monoclonal IGVL-IGJL sequences were defined as those where >50% of assigned IGK or IGL reads from each sample mapped to a unique sequence. Clonal light chain sequences were identified in 705/766 samples from the CoMMpass study. Of these, 685 sequences covered the complete IGVL-IGJL region. The identity of the assigned sequences is consistent with their associated clinical data and with partial sequences previously determined from the same cohort of samples. Sequences have been deposited in AL-Base. Discussion Our method allows routine identification of clonal antibody sequences from RNA sequencing data collected for gene expression studies. The sequences identified represent, to our knowledge, the largest collection of multiple myeloma-associated light chains reported to date. This work substantially increases the number of monoclonal light chains known to be associated with non-amyloid plasma cell disorders and will facilitate studies of light chain pathology.
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Affiliation(s)
- Allison Nau
- Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
| | - Yun Shen
- Research Computing Services, Boston University, Boston, MA, United States
| | - Vaishali Sanchorawala
- Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
- Section of Hematology and Medical Oncology, Department of Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
| | - Tatiana Prokaeva
- Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
| | - Gareth J. Morgan
- Amyloidosis Center, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
- Section of Hematology and Medical Oncology, Department of Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
- Department of Pathology and Laboratory Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, United States
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Nevone A, Lattarulo F, Russo M, Panno G, Milani P, Basset M, Avanzini MA, Merlini G, Palladini G, Nuvolone M. A Strategy for the Selection of RT-qPCR Reference Genes Based on Publicly Available Transcriptomic Datasets. Biomedicines 2023; 11:biomedicines11041079. [PMID: 37189697 DOI: 10.3390/biomedicines11041079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 04/05/2023] Open
Abstract
In the next-generation sequencing era, RT-qPCR is still widely employed to quantify levels of nucleic acids of interest due to its popularity, versatility, and limited costs. The measurement of transcriptional levels through RT-qPCR critically depends on reference genes used for normalization. Here, we devised a strategy to select appropriate reference genes for a specific clinical/experimental setting based on publicly available transcriptomic datasets and a pipeline for RT-qPCR assay design and validation. As a proof-of-principle, we applied this strategy to identify and validate reference genes for transcriptional studies of bone-marrow plasma cells from patients with AL amyloidosis. We performed a systematic review of published literature to compile a list of 163 candidate reference genes for RT-qPCR experiments employing human samples. Next, we interrogated the Gene Expression Omnibus to assess expression levels of these genes in published transcriptomic studies on bone-marrow plasma cells from patients with different plasma cell dyscrasias and identified the most stably expressed genes as candidate normalizing genes. Experimental validation on bone-marrow plasma cells showed the superiority of candidate reference genes identified through this strategy over commonly employed “housekeeping” genes. The strategy presented here may apply to other clinical and experimental settings for which publicly available transcriptomic datasets are available.
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Affiliation(s)
- Alice Nevone
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Francesca Lattarulo
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Monica Russo
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Giada Panno
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Paolo Milani
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Marco Basset
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Maria Antonietta Avanzini
- Pediatric Hematology Oncology, Cell Factory, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Giampaolo Merlini
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Giovanni Palladini
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Mario Nuvolone
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Amyloidosis Research and Treatment Center, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
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Monoclonal Gammopathies of Clinical Significance: A Critical Appraisal. Cancers (Basel) 2022; 14:cancers14215247. [PMID: 36358666 PMCID: PMC9659226 DOI: 10.3390/cancers14215247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/15/2022] [Accepted: 10/24/2022] [Indexed: 11/26/2022] Open
Abstract
Simple Summary Monoclonal gammopathy of clinical significance (MGCS) refers to a recently coined term describing a complex and heterogeneous group of nonmalignant monoclonal gammopathies. These patients are characterized by the presence of a commonly small clone and the occurrence of symptoms that may be associated with the clone or with the monoclonal protein through diverse mechanisms. This is an evolving, challenging, and rapidly changing field. Patients are classified according to the key organ or system involved, with kidneys, skin, nerves, and eyes being the most frequently affected. However, multiorgan involvement may be the most relevant clinical feature at the presentation or during the course. This review delves into the definition, history, differential diagnosis, classification, prognosis, and treatment of this group of entities by analyzing the evidence accumulated to date from a critical perspective. Abstract Monoclonal gammopathies of clinical significance (MGCSs) represent a group of diseases featuring the association of a nonmalignant B cells or plasma cells clone, the production of an M-protein, and singularly, the existence of organ damage. They present a current framework that is difficult to approach from a practical clinical perspective. Several points should be addressed in order to move further toward a better understanding. Overall, these entities are only partially included in the international classifications of diseases. Its definition and classification remain ambiguous. Remarkably, its real incidence is unknown, provided that a diagnostic biopsy is mandatory in most cases. In fact, amyloidosis AL is the final diagnosis in a large percentage of patients with renal significance. On the other hand, many of these young entities are syndromes that are based on a dynamic set of diagnostic criteria, challenging a timely diagnosis. Moreover, a specific risk score for progression is lacking. Despite the key role of the clinical laboratory in the diagnosis and prognosis of these patients, information about laboratory biomarkers is limited. Besides, the evidence accumulated for many of these entities is scarce. Hence, national and international registries are stimulated. In particular, IgM MGCS deserves special attention. Until now, therapy is far from being standardized, and it should be planned on a risk and patient-adapted basis. Finally, a comprehensive and coordinated multidisciplinary approach is needed, and specific clinical trials are encouraged.
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