1
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Zhao P, Wang C, Sun S, Wang X, Balch WE. Tracing genetic diversity captures the molecular basis of misfolding disease. Nat Commun 2024; 15:3333. [PMID: 38637533 PMCID: PMC11026414 DOI: 10.1038/s41467-024-47520-0] [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: 04/04/2023] [Accepted: 04/04/2024] [Indexed: 04/20/2024] Open
Abstract
Genetic variation in human populations can result in the misfolding and aggregation of proteins, giving rise to systemic and neurodegenerative diseases that require management by proteostasis. Here, we define the role of GRP94, the endoplasmic reticulum Hsp90 chaperone paralog, in managing alpha-1-antitrypsin deficiency on a residue-by-residue basis using Gaussian process regression-based machine learning to profile the spatial covariance relationships that dictate protein folding arising from sequence variants in the population. Covariance analysis suggests a role for the ATPase activity of GRP94 in controlling the N- to C-terminal cooperative folding of alpha-1-antitrypsin responsible for the correction of liver aggregation and lung-disease phenotypes of alpha-1-antitrypsin deficiency. Gaussian process-based spatial covariance profiling provides a standard model built on covariant principles to evaluate the role of proteostasis components in guiding information flow from genome to proteome in response to genetic variation, potentially allowing us to intervene in the onset and progression of complex multi-system human diseases.
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Affiliation(s)
- Pei Zhao
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Chao Wang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA.
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China.
| | - Shuhong Sun
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
- Department of Nutrition and Food Hygiene, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
- Institute for Brain Tumors, Collaborative Innovation Center for Cancer Personalized Medicine, and Center for Global Health, Nanjing Medical University, Nanjing, China
| | - Xi Wang
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - William E Balch
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA.
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2
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Dasí F. Alpha-1 antitrypsin deficiency. Med Clin (Barc) 2024; 162:336-342. [PMID: 37993348 DOI: 10.1016/j.medcli.2023.10.014] [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: 07/27/2023] [Revised: 10/21/2023] [Accepted: 10/24/2023] [Indexed: 11/24/2023]
Abstract
Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition caused by decreased plasma and tissue levels of alpha-1 antitrypsin (AAT) that can lead to serious lung and liver disease in children and adults. AATD patients face challenges such as under diagnosis, clinical variability, and limited treatment options for liver disease. Early detection and biomarkers for predicting outcomes are needed to improve patient outcome. Currently, the only approved pharmacological therapy is augmentation therapy, which can delay the progression of emphysema. However, alternative strategies such as gene therapy, induced pluripotent stem cells, and prevention of AAT polymerization inside hepatocytes are being investigated. This review aims to summarize and update current knowledge on AATD, identify areas of controversy, and formulate questions for further research.
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Affiliation(s)
- Francisco Dasí
- Universitat de València, Facultad de Medicina, Departamento de Fisiología, IIS INCLIVA, Valencia, Spain.
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3
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Abreu N, Pereira VM, Pestana M, Jasmins L. Future Perspectives in the Diagnosis and Treatment of Liver Disease Associated with Alpha-1 Antitrypsin Deficiency. GE PORTUGUESE JOURNAL OF GASTROENTEROLOGY 2023; 30:327-335. [PMID: 37868641 PMCID: PMC10586215 DOI: 10.1159/000528809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 11/15/2022] [Indexed: 10/24/2023]
Abstract
Alpha-1 antitrypsin deficiency (AATD) is one of the most common genetic diseases and is caused by mutations in the SERPINA1 gene. The homozygous Pi*Z variant is responsible for the majority of the classic severe form of alpha-1 antitrypsin deficiency, which is characterized by markedly decreased levels of serum alpha-1 antitrypsin (AAT) with a strong predisposition to lung and liver disease. The diagnosis and early treatment of AATD-associated liver disease are challenges in clinical practice. In this review, the authors aim to summarize the current evidence of the non-invasive methods in the assessment of liver fibrosis, as well as to elucidate the main therapeutic strategies under investigation that may emerge in the near future.
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Affiliation(s)
- Nélia Abreu
- Department of Gastroenterology, Hospital Central Do Funchal, Madeira, Portugal
| | - Vítor Magno Pereira
- Department of Gastroenterology, Hospital Central Do Funchal, Madeira, Portugal
| | - Madalena Pestana
- Department of Gastroenterology, Hospital Central Do Funchal, Madeira, Portugal
| | - Luís Jasmins
- Department of Gastroenterology, Hospital Central Do Funchal, Madeira, Portugal
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4
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Sun S, Wang C, Zhao P, Kline GM, Grandjean JMD, Jiang X, Labaudiniere R, Wiseman RL, Kelly JW, Balch WE. Capturing the conversion of the pathogenic alpha-1-antitrypsin fold by ATF6 enhanced proteostasis. Cell Chem Biol 2023; 30:22-42.e5. [PMID: 36630963 PMCID: PMC9930901 DOI: 10.1016/j.chembiol.2022.12.004] [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: 08/30/2022] [Revised: 11/07/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023]
Abstract
Genetic variation in alpha-1 antitrypsin (AAT) causes AAT deficiency (AATD) through liver aggregation-associated gain-of-toxic pathology and/or insufficient AAT activity in the lung manifesting as chronic obstructive pulmonary disease (COPD). Here, we utilize 71 AATD-associated variants as input through Gaussian process (GP)-based machine learning to study the correction of AAT folding and function at a residue-by-residue level by pharmacological activation of the ATF6 arm of the unfolded protein response (UPR). We show that ATF6 activators increase AAT neutrophil elastase (NE) inhibitory activity, while reducing polymer accumulation for the majority of AATD variants, including the prominent Z variant. GP-based profiling of the residue-by-residue response to ATF6 activators captures an unexpected role of the "gate" area in managing AAT-specific activity. Our work establishes a new spatial covariant (SCV) understanding of the convertible state of the protein fold in response to genetic perturbation and active environmental management by proteostasis enhancement for precision medicine.
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Affiliation(s)
- Shuhong Sun
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Chao Wang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Pei Zhao
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Gabe M Kline
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | | | - Xin Jiang
- Protego Biopharma, 10945 Vista Sorrento Parkway, San Diego, CA, USA
| | | | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - William E Balch
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
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5
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Liu X, Kouassi KGW, Vanbever R, Dumoulin M. Impact of the PEG length and PEGylation site on the structural, thermodynamic, thermal, and proteolytic stability of mono-PEGylated alpha-1 antitrypsin. Protein Sci 2022; 31:e4392. [PMID: 36040264 PMCID: PMC9375436 DOI: 10.1002/pro.4392] [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: 03/25/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 11/11/2022]
Abstract
Conjugation to polyethylene glycol (PEG) is a widely used approach to improve the therapeutic value of proteins essentially by prolonging their body residence time. PEGylation may however induce changes in the structure and/or the stability of proteins and thus on their function(s). The effects of PEGylation on the thermodynamic stability can either be positive (stabilization), negative (destabilization), or neutral (no effect). Moreover, various factors such as the PEG length and PEGylation site can influence the consequences of PEGylation on the structure and stability of proteins. In this study, the effects of PEGylation on the structure, stability, and polymerization of alpha1-antitrypsin (AAT) were investigated, using PEGs with different lengths, different structures (linear or 2-armed) and different linking chemistries (via amine or thiol) at two distinct positions of the sequence. The results show that whatever the size, position, and structure of PEG chains, PEGylation (a) does not induce significant changes in AAT structure (either at the secondary or tertiary level); (b) does not alter the stability of the native protein upon both chemical- and heat-induced denaturation; and (c) does not prevent AAT to fully refold and recover its activity following chemical denaturation. However, the propensity of AAT to aggregate upon heat treatment was significantly decreased by PEGylation, although PEGylation did not prevent the irreversible inactivation of the enzyme. Moreover, conjugation to PEG, especially 2-armed 40 kDa PEG, greatly improved the proteolytic resistance of AAT. PEGylation of AAT could be a promising strategy to prolong its half-life after infusion in AAT-deficient patients and thereby decrease the frequency of infusions.
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Affiliation(s)
- Xiao Liu
- Advanced Drug Delivery and BiomaterialsLouvain Drug Research Institute, Université catholique de Louvain (UCLouvain)BrusselsBelgium
| | - Kobenan G. W. Kouassi
- Advanced Drug Delivery and BiomaterialsLouvain Drug Research Institute, Université catholique de Louvain (UCLouvain)BrusselsBelgium
| | - Rita Vanbever
- Advanced Drug Delivery and BiomaterialsLouvain Drug Research Institute, Université catholique de Louvain (UCLouvain)BrusselsBelgium
| | - Mireille Dumoulin
- Department of Life SciencesInBios, Center for Protein Engineering, Nanobodies to Explore Protein Structure and Functions, University of LiègeLiègeBelgium
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6
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Rahaghi FF. Alpha-1 antitrypsin deficiency research and emerging treatment strategies: what's down the road? Ther Adv Chronic Dis 2021; 12_suppl:20406223211014025. [PMID: 34408832 PMCID: PMC8367209 DOI: 10.1177/20406223211014025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/08/2021] [Indexed: 01/29/2023] Open
Abstract
Intravenous infusion of alpha-1 antitrypsin (AAT) was approved by the United States Food and Drug Administration (FDA) to treat emphysema associated with AAT deficiency (AATD) in 1987 and there are now several FDA-approved therapy products on the market, all of which are derived from pooled human plasma. Intravenous AAT therapy has proven clinical efficacy in slowing the decline of lung function associated with AATD progression; however, it is only recommended for individuals with the most severe forms of AATD as there is a lack of evidence that this treatment is effective in treating wild-type heterozygotes (e.g., PI*MS and PI*MZ genotypes), for which the prevalence may be much higher than previously thought. There are large numbers of individuals that are currently left untreated despite displaying symptoms of AATD. Furthermore, not all countries offer AAT augmentation therapy due to its expense and inconvenience for patients. More cost-effective treatments are now being sought that show efficacy for less severe forms of AATD and many new therapeutic technologies are being investigated, such as gene repair and other interference strategies, as well as the use of chemical chaperones. New sources of AAT are also being investigated to ensure there are enough supplies to meet future demand, and new methods of assessing response to treatment are being evaluated. There is currently extensive research into AATD and its treatment, and this chapter aims to highlight important emerging treatment strategies that aim to improve the lives of patients with AATD.
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Affiliation(s)
- Franck F Rahaghi
- Advanced Lung Disease Clinic, Cleveland Clinic Florida, 2950 Cleveland Clinic Boulevard, Weston, FL 33331, USA
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7
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Remih K, Amzou S, Strnad P. Alpha1-antitrypsin deficiency: New therapies on the horizon. Curr Opin Pharmacol 2021; 59:149-156. [PMID: 34256305 DOI: 10.1016/j.coph.2021.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/07/2021] [Indexed: 10/20/2022]
Abstract
Alpha1-antitrypsin deficiency (AATD) is caused by mutations in the SERPINA1 gene, coding for alpha1-antitrypsin (AAT). AAT is synthesised mainly in the liver and is released into bloodstream to protect tissues (particularly lung) with its antiprotease activity. The homozygous Pi∗Z mutation (Pi∗ZZ genotype) is the predominant cause of severe AATD. It interferes with AAT secretion thereby leading to AAT accumulation in the liver and lack of AAT in the circulation and the lung. Accordingly, Pi∗ZZ individuals are strongly predisposed to lung and liver injury. The former is treated by a weekly AAT augmentation therapy, but not medicinal products exist for the liver. Our review summarises the current approaches silencing AAT production, improving protein folding and secretion or promoting AAT degradation.
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Affiliation(s)
- Katharina Remih
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Samira Amzou
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Pavel Strnad
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany; Coordinating Centre for Alpha1-Antitrypsin Deficiency-related Liver Disease of the European Reference Network (ERN) "Rare Liver" and The European Association for the Study of the Liver (EASL) Registry Group "Alpha1-Liver", Germany.
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8
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Gurevich S, Daya A, Da Silva C, Girard C, Rahaghi F. Improving Screening for Alpha-1 Antitrypsin Deficiency with Direct Testing in the Pulmonary Function Testing Laboratory. CHRONIC OBSTRUCTIVE PULMONARY DISEASES (MIAMI, FLA.) 2021; 8:190-197. [PMID: 33290644 DOI: 10.15326/jcopdf.2020.0179] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alpha-1 antitrypsin deficiency (AATD) is a common but highly underdiagnosed genetic disorder that may lead to chronic obstructive pulmonary disease (COPD), bronchiectasis, and liver disease. Early diagnosis is key to altering the course of disease as well as informing family members of potential risk. This randomized, prospective observational study compares the different testing modalities for AATD testing of at-risk patients initiated in the pulmonary function testing (PFT) laboratory. Providing a recommendation with a prescription for serologic testing, providing a finger-stick testing method (AlphaKit), and providing a buccal swab testing method (AlphaID) were compared to the community standard of referring the patient back to the PFT-ordering provider only. Results show that testing directly in the PFT laboratory has an odds ratio (OR) for completing testing of 35.14 (5.33 - 999.99), p-value of <0.0001, for buccal swab testing and an OR of 17.09 (2.58 - 729.99), p-value of 0.0002, for finger-stick testing compared to the community standard. Providing a prescription was no better than referral back to the PFT-ordering provider with an OR of 2.61(0.33 - 119.36), p-value of 0.6412. Resources needed to have testing performed by the Respiratory Therapy department were minimal with an average time of 1 to 5 minutes per patient tested. Causes of testing refusal were also identified. In conclusion, direct testing for AATD by respiratory therapists at the conclusion of PFT testing shows a significant improvement in rates of testing, especially with testing that utilizes buccal swab sample collection.
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Affiliation(s)
- Samuel Gurevich
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, United States.,Department of Pulmonary Medicine, Cleveland Clinic Florida, Weston, Florida, United States
| | - Andrew Daya
- Department of Pulmonary Medicine, Cleveland Clinic Florida, Weston, Florida, United States
| | - Cristiana Da Silva
- Department of Pulmonary Medicine, Cleveland Clinic Florida, Weston, Florida, United States
| | - Christine Girard
- Department of Pulmonary Medicine, Cleveland Clinic Florida, Weston, Florida, United States
| | - Franck Rahaghi
- Department of Pulmonary Medicine, Cleveland Clinic Florida, Weston, Florida, United States
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9
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McNulty MJ, Silberstein DZ, Kuhn BT, Padgett HS, Nandi S, McDonald KA, Cross CE. Alpha-1 antitrypsin deficiency and recombinant protein sources with focus on plant sources: Updates, challenges and perspectives. Free Radic Biol Med 2021; 163:10-30. [PMID: 33279618 DOI: 10.1016/j.freeradbiomed.2020.11.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022]
Abstract
Alpha-1 antitrypsin deficiency (A1ATD) is an autosomal recessive disease characterized by low plasma levels of A1AT, a serine protease inhibitor representing the most abundant circulating antiprotease normally present at plasma levels of 1-2 g/L. The dominant clinical manifestations include predispositions to early onset emphysema due to protease/antiprotease imbalance in distal lung parenchyma and liver disease largely due to unsecreted polymerized accumulations of misfolded mutant A1AT within the endoplasmic reticulum of hepatocytes. Since 1987, the only FDA licensed specific therapy for the emphysema component has been infusions of A1AT purified from pooled human plasma at the 2020 cost of up to US $200,000/year with the risk of intermittent shortages. In the past three decades various, potentially less expensive, recombinant forms of human A1AT have reached early stages of development, one of which is just reaching the stage of human clinical trials. The focus of this review is to update strategies for the treatment of the pulmonary component of A1ATD with some focus on perspectives for therapeutic production and regulatory approval of a recombinant product from plants. We review other competitive technologies for treating the lung disease manifestations of A1ATD, highlight strategies for the generation of data potentially helpful for securing FDA Investigational New Drug (IND) approval and present challenges in the selection of clinical trial strategies required for FDA licensing of a New Drug Approval (NDA) for this disease.
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Affiliation(s)
- Matthew J McNulty
- Department of Chemical Engineering, University of California, Davis, CA, USA
| | - David Z Silberstein
- Department of Chemical Engineering, University of California, Davis, CA, USA
| | - Brooks T Kuhn
- Department of Internal Medicine, University of California, Davis, CA, USA; University of California, Davis, Alpha-1 Deficiency Clinic, Sacramento, CA, USA
| | | | - Somen Nandi
- Department of Chemical Engineering, University of California, Davis, CA, USA; Global HealthShare Initiative®, University of California, Davis, CA, USA
| | - Karen A McDonald
- Department of Chemical Engineering, University of California, Davis, CA, USA; Global HealthShare Initiative®, University of California, Davis, CA, USA
| | - Carroll E Cross
- Department of Internal Medicine, University of California, Davis, CA, USA; University of California, Davis, Alpha-1 Deficiency Clinic, Sacramento, CA, USA; Department of Physiology and Membrane Biology, University of California, Davis, CA, USA.
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10
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Kellici TF, Pilka ES, Bodkin MJ. Small-molecule modulators of serine protease inhibitor proteins (serpins). Drug Discov Today 2020; 26:442-454. [PMID: 33259801 DOI: 10.1016/j.drudis.2020.11.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/11/2020] [Accepted: 11/10/2020] [Indexed: 02/06/2023]
Abstract
Serine protease inhibitors (serpins) are a large family of proteins that regulate and control crucial physiological processes, such as inflammation, coagulation, thrombosis and thrombolysis, and immune responses. The extraordinary impact that these proteins have on numerous crucial pathways makes them an attractive target for drug discovery. In this review, we discuss recent advances in research on small-molecule modulators of serpins, examine their mode of action, analyse the structural data from crystallised protein-ligand complexes, and highlight the potential obstacles and possible therapeutic perspectives. The application of in silico methods for rational drug discovery is also summarised. In addition, we stress the need for continued research in this field.
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11
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Narayanan P, Mistry PK. Update on Alpha-1 Antitrypsin Deficiency in Liver Disease. Clin Liver Dis (Hoboken) 2020; 15:228-235. [PMID: 32617155 PMCID: PMC7326637 DOI: 10.1002/cld.896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 10/23/2019] [Indexed: 02/04/2023] Open
Affiliation(s)
| | - Pramod K. Mistry
- Department of Digestive DiseasesYale–New Haven HospitalNew HavenCT
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12
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Post-Transcriptional Regulation of Alpha One Antitrypsin by a Proteasome Inhibitor. Int J Mol Sci 2020; 21:ijms21124318. [PMID: 32560429 PMCID: PMC7352753 DOI: 10.3390/ijms21124318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/09/2020] [Accepted: 06/16/2020] [Indexed: 12/25/2022] Open
Abstract
Alpha one antitrypsin (α1AT), a serine proteinase inhibitor primarily produced by the liver, protects pulmonary tissue from neutrophil elastase digestion. Mutations of the SERPINA1 gene results in a misfolded α1AT protein which aggregates inside hepatocytes causing cellular damage. Therefore, inhibition of mutant α1AT production is one practical strategy to alleviate liver damage. Here we show that proteasome inhibitors can selectively downregulate α1AT expression in human hepatocytes by suppressing the translation of α1AT. Translational suppression of α1AT is mediated by phosphorylation of eukaryotic translation initiation factor 2α and increased association of RNA binding proteins, especially stress granule protein Ras GAP SH3 binding protein (G3BP1), with α1AT mRNA. Treatment of human-induced pluripotent stem cell-derived hepatocytes with a proteasome inhibitor also results in translational inhibition of mutant α1AT in a similar manner. Together we revealed a previously undocumented role of proteasome inhibitors in the regulation of α1AT translation.
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13
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Zhang X, Santos R, Debevec G, Li D, Schutte R, Pham K, Liu C, Ostrov DA, Giulianotti M. Identification of small molecules by screening a mixture-based scaffold compound library for treatment of alpha-1 antitrypsin deficiency. Biochem Biophys Res Commun 2020; 527:317-323. [PMID: 32446387 DOI: 10.1016/j.bbrc.2020.04.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 04/10/2020] [Indexed: 12/11/2022]
Abstract
This study aimed to identify small molecules that have the potential to treat alpha1-antitrypsin deficiency (AATD) by screening compounds available from a mixture-based scaffold library. 93 scaffold libraries (total diversity of >30 million compounds in mixture format) were screened using a cell model of AATD in order to identify samples that could either reduce intracellular aggregation of Z-form AAT protein, increase extracellular secretion of Z-AAT or both. Mixture libraries containing compounds with in vitro activity, for example library 1295, were screened further to identify individual active compounds. The mixture format of the scaffold library allowed for some preliminary structure-activity relationships to be developed and also enabled the rapid selection of a promising scaffold. Utilizing this scaffold, 1295, a collection of individual "control" compounds contained in the 1295 mixture sample were then screened. A sub-library of individual "control" compounds featuring structural diversity at position R1 (1295.R1), was screened and 7 compounds were found to reduce the intracellular accumulation of Z-AAT without affecting cell viability at a concentration of 25ug/ml (about 50 μM). Screening sub-libraries featuring structural diversity at R2 and R3 (1295.R2 and 1295.R3) identified an additional 15 active compounds. Titration experiments identified 3 compounds from the 1295.R2 library that retained activity at 5ug/ml (approx. 10uM). One compound (1295.263) from 1295.R2 decreased intracellular levels of Z-AAT without affecting cell viability and wild-type AAT levels at the concentration of 5ug/ml. Molecular docking of this compound to the Z-AAT crystal structure identified a potential binding site near the C-terminal domain, an identified polymerization site. Our results indicate that screening large mixture-based compound libraries can be used to identify small molecules that may have the potential to treat AATD and other disease.
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Affiliation(s)
- Xiaojuan Zhang
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Radleigh Santos
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida, USA
| | - Ginamarie Debevec
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida, USA
| | - Danmeng Li
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Ryan Schutte
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Kien Pham
- Department of Pathology and Laboratory Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Chen Liu
- Department of Pathology and Laboratory Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - David A Ostrov
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA.
| | - Marc Giulianotti
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida, USA
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14
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Affiliation(s)
- Pavel Strnad
- From the Department of Internal Medicine III, University Hospital RWTH (Rheinisch-Westfälisch Technische Hochschule) Aachen, Aachen, Germany (P.S.); the Irish Centre for Genetic Lung Disease, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin (N.G.M.); and UCL Respiratory, Division of Medicine, Rayne Institute, University College London, London (D.A.L.)
| | - Noel G McElvaney
- From the Department of Internal Medicine III, University Hospital RWTH (Rheinisch-Westfälisch Technische Hochschule) Aachen, Aachen, Germany (P.S.); the Irish Centre for Genetic Lung Disease, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin (N.G.M.); and UCL Respiratory, Division of Medicine, Rayne Institute, University College London, London (D.A.L.)
| | - David A Lomas
- From the Department of Internal Medicine III, University Hospital RWTH (Rheinisch-Westfälisch Technische Hochschule) Aachen, Aachen, Germany (P.S.); the Irish Centre for Genetic Lung Disease, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin (N.G.M.); and UCL Respiratory, Division of Medicine, Rayne Institute, University College London, London (D.A.L.)
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15
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Alpha 1-Antitrypsin Deficiency: A Disorder of Proteostasis-Mediated Protein Folding and Trafficking Pathways. Int J Mol Sci 2020; 21:ijms21041493. [PMID: 32098273 PMCID: PMC7073043 DOI: 10.3390/ijms21041493] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/17/2020] [Accepted: 02/19/2020] [Indexed: 12/30/2022] Open
Abstract
Human cells express large amounts of different proteins continuously that must fold into well-defined structures that need to remain correctly folded and assemble in order to ensure their cellular and biological functions. The integrity of this protein balance/homeostasis, also named proteostasis, is maintained by the proteostasis network (PN). This integrated biological system, which comprises about 2000 proteins (chaperones, folding enzymes, degradation components), control and coordinate protein synthesis folding and localization, conformational maintenance, and degradation. This network is particularly challenged by mutations such as those found in genetic diseases, because of the inability of an altered peptide sequence to properly engage PN components that trigger misfolding and loss of function. Thus, deletions found in the ΔF508 variant of the Cystic Fibrosis (CF) transmembrane regulator (CFTR) triggering CF or missense mutations found in the Z variant of Alpha 1-Antitrypsin deficiency (AATD), leading to lung and liver diseases, can accelerate misfolding and/or generate aggregates. Conversely to CF variants, for which three correctors are already approved (ivacaftor, lumacaftor/ivacaftor, and most recently tezacaftor/ivacaftor), there are limited therapeutic options for AATD. Therefore, a more detailed understanding of the PN components governing AAT variant biogenesis and their manipulation by pharmacological intervention could delay, or even better, avoid the onset of AATD-related pathologies.
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Wang C, Zhao P, Sun S, Teckman J, Balch WE. Leveraging Population Genomics for Individualized Correction of the Hallmarks of Alpha-1 Antitrypsin Deficiency. CHRONIC OBSTRUCTIVE PULMONARY DISEASES-JOURNAL OF THE COPD FOUNDATION 2020; 7:224-246. [PMID: 32726074 DOI: 10.15326/jcopdf.7.3.2019.0167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Deep medicine is rapidly moving towards a high-definition approach for therapeutic management of the patient as an individual given the rapid progress of genome sequencing technologies and machine learning algorithms. While considered a monogenic disease, alpha-1 antitrypsin (AAT) deficiency (AATD) patients present with complex and variable phenotypes we refer to as the "hallmarks of AATD" that involve distinct molecular mechanisms in the liver, plasma and lung tissues, likely due to both coding and non-coding variation as well as genetic and environmental modifiers in different individuals. Herein, we briefly review the current therapeutic strategies for the management of AATD. To embrace genetic diversity in the management of AATD, we provide an overview of the disease phenotypes of AATD patients harboring different AAT variants. Linking genotypic diversity to phenotypic diversity illustrates the potential for sequence-specific regions of AAT protein fold design to play very different roles during nascent synthesis in the liver and/or function in post-liver plasma and lung environments. We illustrate how to manage diversity with recently developed machine learning (ML) approaches that bridge sequence-to-function-to-structure knowledge gaps based on the principle of spatial covariance (SCV). SCV relationships provide a deep understanding of the genotype to phenotype transformation initiated by AAT variation in the population to address the role of genetic and environmental modifiers in the individual. Embracing the complexity of AATD in the population is critical for risk management and therapeutic intervention to generate a high definition medicine approach for the patient.
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Affiliation(s)
- Chao Wang
- Department of Molecular Medicine, Scripps Research, La Jolla, California
| | - Pei Zhao
- Department of Molecular Medicine, Scripps Research, La Jolla, California
| | - Shuhong Sun
- Department of Molecular Medicine, Scripps Research, La Jolla, California
| | - Jeffrey Teckman
- Pediatrics and Biochemistry, Saint Louis University, and Cardinal Glennon Children's Medical Center, St. Louis, Missouri
| | - William E Balch
- Department of Molecular Medicine, Scripps Research, La Jolla, California
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A Novel Small Molecule Inhibits Intrahepatocellular Accumulation of Z-Variant Alpha 1-Antitrypsin In Vitro and In Vivo. Cells 2019; 8:cells8121586. [PMID: 31817705 PMCID: PMC6953066 DOI: 10.3390/cells8121586] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/01/2019] [Accepted: 12/03/2019] [Indexed: 11/30/2022] Open
Abstract
Alpha 1-antitrypsin deficiency (AATD) is the most common genetic cause of liver disease in children and is associated with early-onset chronic liver disease in adults. AATD associated liver injury is caused by hepatotoxic retention of polymerized mutant alpha 1-antitrypsin molecules within the endoplasmic reticulum. Currently, there is no curative therapy for AATD. In this study, we selected small molecules with the potential to bind mutant alpha 1-antitrypsin (Z-variant) to inhibit its accumulation in hepatocytes. We used molecular docking to select candidate compounds that were validated in cell and animal models of disease. A crystal structure of polymerized alpha 1-antitrypsin molecule was used as the basis for docking 139,735 compounds. Effects of the top scoring compounds were investigated in a cell model that stably expresses Z-variant alpha 1-antitrypsin and in PiZ mice expressing Z-variant human alpha 1-antitrypsin (Z-hAAT), encoded by SERPINA1*E342K. 4′,′5-(Methylenedioxy)-2-nitrocinnamic acid was predicted to bind cleaved alpha 1-antitrypsin at the polymerization interface, and observed to co-localize with Z-hAAT, increase Z-hAAT degradation, inhibit intracellular accumulation of Z-hAAT, and alleviate liver fibrosis.
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Pye A, Turner AM. Experimental and investigational drugs for the treatment of alpha-1 antitrypsin deficiency. Expert Opin Investig Drugs 2019; 28:891-902. [PMID: 31550938 DOI: 10.1080/13543784.2019.1672656] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Introduction: Alpha-1 antitrypsin deficiency (AATD) is most often associated with chronic lung disease, early onset emphysema, and liver disease. The standard of care in lung disease due to AATD is alpha-1 antitrypsin augmentation but there are several new and emerging treatment options under investigation for both lung and liver manifestations. Areas covered: We review therapeutic approaches to lung and liver disease in alpha-1 antitrypsin deficiency (AATD) and the agents in clinical development according to their mode of action. The focus is on products in clinical trials, but data from pre-clinical studies are described where relevant, particularly where progression to trials appears likely. Expert opinion: Clinical trials directed at lung and liver disease separately are now taking place. Multimodality treatment may be the future, but this could be limited by treatment costs. The next 5-10 years may reveal new guidance on when to use therapeutics for slowing disease progression with personalized treatment regimes coming to the forefront.
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Affiliation(s)
- Anita Pye
- Institute of Applied Health Research, University of Birmingham , Birmingham , UK
| | - Alice M Turner
- Institute of Applied Health Research, University of Birmingham , Birmingham , UK
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19
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Recent Developments in mRNA-Based Protein Supplementation Therapy to Target Lung Diseases. Mol Ther 2019; 27:803-823. [PMID: 30905577 DOI: 10.1016/j.ymthe.2019.02.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/25/2019] [Accepted: 02/25/2019] [Indexed: 12/20/2022] Open
Abstract
Protein supplementation therapy using in vitro-transcribed (IVT) mRNA for genetic diseases contains huge potential as a new class of therapy. From the early ages of synthetic mRNA discovery, a great number of studies showed the versatile use of IVT mRNA as a novel approach to supplement faulty or absent protein and also as a vaccine. Many modifications have been made to produce high expressions of mRNA causing less immunogenicity and more stability. Recent advancements in the in vivo lung delivery of mRNA complexed with various carriers encouraged the whole mRNA community to tackle various genetic lung diseases. This review gives a comprehensive overview of cells associated with various lung diseases and recent advancements in mRNA-based protein replacement therapy. This review also covers a brief summary of developments in mRNA modifications and nanocarriers toward clinical translation.
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Lomas DA. New Therapeutic Targets for Alpha-1 Antitrypsin Deficiency. CHRONIC OBSTRUCTIVE PULMONARY DISEASES-JOURNAL OF THE COPD FOUNDATION 2018; 5:233-243. [PMID: 30723781 DOI: 10.15326/jcopdf.5.4.2017.0165] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Alpha-1antitrypsin deficiency (AATD) results from the intracellular polymerization and retention of mutant alpha-1antitrypsin (AAT) within the endoplasmic reticulum of hepatocytes. This causes cirrhosis whilst the deficiency of circulating AAT predisposes to early onset emphysema. This is an exciting time for researchers in the field with the development of novel therapies based on understanding the pathobiology of disease. I review here augmentation therapy to prevent the progression of lung disease and a range of approaches to treat the liver disease associated with the accumulation of mutant AAT: modifying proteostasis networks that are activated by Z AAT polymers, stimulating autophagy, small interfering RNA and small molecules to block intracellular polymerization, and stem cell technology to correct the genetic defect that underlies AATD.
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Affiliation(s)
- David A Lomas
- UCL Respiratory, Division of Medicine, University College London, United Kingdom
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21
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Pan J, Cao D, Gong J. The endoplasmic reticulum co-chaperone ERdj3/DNAJB11 promotes hepatocellular carcinoma progression through suppressing AATZ degradation. Future Oncol 2018; 14:3001-3013. [PMID: 29992839 DOI: 10.2217/fon-2018-0401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
AIM The co-chaperone ERdj3/DNAJB11 is involved in the endoplasmic reticulum stress response observed in cancer cells. We hypothesized that ERdj3 functions as a hepatocellular carcinoma (HCC) oncogene by inhibiting AATZ degradation. MATERIALS & METHODS ERdj3 and AATZ expressions were analyzed in 84 HCC patients. Cell proliferation, epithelial-mesenchymal transition marker expression, migration and invasiveness were assessed in HepG2 and Huh-7 cells. A murine xenograft tumor model was constructed. RESULTS ERdj3 is upregulated in HCC tumors and cell lines. Tumor ERdj3 levels are positively associated with cirrhosis, enhanced HCC status, inferior survival outcomes and AATZ levels. ERdj3 suppresses AATZ degradation. ERdj3 overexpression enhances proliferation, epithelial-mesenchymal transition marker expression, migration, invasiveness and xenograft tumor growth in an AATZ-dependent manner. CONCLUSION ERdj3 enhances HCC progression through suppressing AATZ degradation.
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Affiliation(s)
- Junjiang Pan
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
| | - Ding Cao
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
| | - Jianping Gong
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
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22
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Torres-Durán M, Lopez-Campos JL, Barrecheguren M, Miravitlles M, Martinez-Delgado B, Castillo S, Escribano A, Baloira A, Navarro-Garcia MM, Pellicer D, Bañuls L, Magallón M, Casas F, Dasí F. Alpha-1 antitrypsin deficiency: outstanding questions and future directions. Orphanet J Rare Dis 2018; 13:114. [PMID: 29996870 PMCID: PMC6042212 DOI: 10.1186/s13023-018-0856-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/26/2018] [Indexed: 12/14/2022] Open
Abstract
Background Alpha-1 antitrypsin deficiency (AATD) is a rare hereditary condition that leads to decreased circulating alpha-1 antitrypsin (AAT) levels, significantly increasing the risk of serious lung and/or liver disease in children and adults, in which some aspects remain unresolved. Methods In this review, we summarise and update current knowledge on alpha-1 antitrypsin deficiency in order to identify and discuss areas of controversy and formulate questions that need further research. Results 1) AATD is a highly underdiagnosed condition. Over 120,000 European individuals are estimated to have severe AATD and more than 90% of them are underdiagnosed. Conclusions 2) Several clinical and etiological aspects of the disease are yet to be resolved. New strategies for early detection and biomarkers for patient outcome prediction are needed to reduce morbidity and mortality in these patients; 3) Augmentation therapy is the only specific approved therapy that has shown clinical efficacy in delaying the progression of emphysema. Regrettably, some countries reject registration and reimbursement for this treatment because of the lack of larger randomised, placebo-controlled trials. 4) Alternative strategies are currently being investigated, including the use of gene therapy or induced pluripotent stem cells, and non-augmentation strategies to prevent AAT polymerisation inside hepatocytes.
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Affiliation(s)
- María Torres-Durán
- Pulmonary Department, Hospital Álvaro Cunqueiro EOXI, Vigo, Spain.,NeumoVigo I+i Research Group, IIS Galicia Sur, Vigo, Spain
| | - José Luis Lopez-Campos
- Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio, Universidad de Sevilla, Sevilla, Spain.,CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Miriam Barrecheguren
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.,Pneumology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Marc Miravitlles
- CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.,Pneumology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Beatriz Martinez-Delgado
- Molecular Genetics Unit, Instituto de Investigación de Enfermedades Raras (IIER), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Silvia Castillo
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Amparo Escribano
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Paediatrics, Obstetrics and Gynaecology, University of Valencia, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Adolfo Baloira
- Pneumology Department, Complejo Hospitalario Universitario de Pontevedra, Pontevedra, Spain
| | - María Mercedes Navarro-Garcia
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Daniel Pellicer
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Lucía Bañuls
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - María Magallón
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain.,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain
| | - Francisco Casas
- Pneumology Department, Hospital Universitario San Cecilio, Granada, Spain
| | - Francisco Dasí
- Fundación Investigación Hospital Clínico Valencia, Instituto de Investigación Sanitaria INCLIVA, c/Menéndez y Pelayo, 4, 46010, Valencia, Spain. .,School of Medicine, Department of Physiology, Research group on Rare Respiratory Diseases (ERR), University of Valencia, Valencia, Spain.
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Abstract
Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is estimated to become the third leading cause of death in 2020. The ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) study, funded by GlaxoSmithKline, is an observational study designed to define outcomes that can be used as endpoints in clinical trials in individuals with COPD. It allowed us to describe the heterogeneity of COPD, the stability of the exacerbation phenotype, and the factors associated with a progressive decline in lung function and the progression of emphysema on computed tomography scans. The cohort was also used to define genetic factors and biomarkers associated with COPD and disease progression. This review considers how the results from ECLIPSE can inform our understanding of the lung disease associated with alpha-1 antitrypsin deficiency.
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24
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Mitchell EL, Khan Z. Liver Disease in Alpha-1 Antitrypsin Deficiency: Current Approaches and Future Directions. CURRENT PATHOBIOLOGY REPORTS 2017; 5:243-252. [PMID: 29399420 PMCID: PMC5780543 DOI: 10.1007/s40139-017-0147-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Purpose of Review The aim of the study is to review the liver disease caused by alpha-1 antitrypsin deficiency (A1ATD), including pathogenesis, epidemiology, diagnostic testing, and recent therapeutic developments. Recent Findings Therapeutic approaches target several intracellular pathways to reduce the cytotoxic effects of the misfolded mutant globular protein (ATZ) on the hepatocyte. These include promoting ATZ transport out of the endoplasmic reticulum (ER), enhancing ATZ degradation, and preventing ATZ globule-aggregation. Summary A1ATD is the leading genetic cause of liver disease among children. It is a protein-folding disorder in which toxic insoluble ATZ proteins aggregate in the ER of hepatocytes leading to inflammation, fibrosis, cirrhosis, and increased risk of hepatocellular carcinoma. The absence of the normal A1AT serum protein also predisposes patients to pan lobar emphysema as adults. At this time, the only approved therapy for A1ATD-associated liver disease is orthotopic liver transplantation, which is curative. However, there has been significant recent progress in the development of small molecule therapies with potential both to preserve the native liver and prevent hepatotoxicity.
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Affiliation(s)
- Ellen L Mitchell
- 1Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Pittsburgh of UPMC, 4401 Penn Avenue, Faculty Pavilion 6th Fl, Pittsburgh, PA 15224-1334 USA.,2Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Zahida Khan
- 1Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Pittsburgh of UPMC, 4401 Penn Avenue, Faculty Pavilion 6th Fl, Pittsburgh, PA 15224-1334 USA.,2Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA USA.,3Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA.,4McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA USA.,5Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
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25
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Andersen OJ, Risør MW, Poulsen EC, Nielsen NC, Miao Y, Enghild JJ, Schiøtt B. Reactive Center Loop Insertion in α-1-Antitrypsin Captured by Accelerated Molecular Dynamics Simulation. Biochemistry 2017; 56:634-646. [PMID: 27995800 DOI: 10.1021/acs.biochem.6b00839] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protease inhibition by metastable serine protease inhibitors (serpins) is mediated by one of the largest functional intradomain conformational changes known in biology. In this extensive structural rearrangement, protease-serpin complex formation triggers cleavage of the serpin reactive center loop (RCL), its subsequent insertion into central β-sheet A, and covalent trapping of the target protease. In this study, we present the first detailed accelerated molecular dynamics simulation of the insertion of the fully cleaved RCL in α-1-antitrypsin (α1AT), the archetypal member of the family of human serpins. Our results reveal internal water pathways that allow the initial incorporation of side chains of RCL residues into the protein interior. We observed structural plasticity of the helix F (hF) element that blocks the RCL path in the native state, which is in excellent agreement with previous experimental reports. Furthermore, the simulation suggested a novel role of hF and the connected turn (thFs3A) as chaperones that support the insertion process by reducing the conformational space available to the RCL. Transient electrostatic interactions of RCL residues potentially fine-tune the serpin inhibitory activity. On the basis of our simulation, we generated the α1AT mutants K168E, E346K, and K168E/E346K and analyzed their inhibitory activity along with their intrinsic stability and heat-induced polymerization. Remarkably, the E346K mutation exhibited enhanced inhibitory activity along with an increased rate of premature structural collapse (polymerization), suggesting a significant role of E346 in the gatekeeping of the strain in the metastable native state.
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Affiliation(s)
- Ole Juul Andersen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Chemistry, Aarhus University , Aarhus, Denmark
| | - Michael Wulff Risør
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Emil Christian Poulsen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Niels Chr Nielsen
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Chemistry, Aarhus University , Aarhus, Denmark
| | - Yinglong Miao
- Howard Hughes Medical Institute and Department of Pharmacology, University of California at San Diego , La Jolla, California 92093, United States
| | - Jan J Enghild
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Molecular Biology and Genetics, Aarhus University , Aarhus, Denmark
| | - Birgit Schiøtt
- Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Aarhus University , Aarhus, Denmark.,Department of Chemistry, Aarhus University , Aarhus, Denmark
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Faull SV, Brown AE, Haq I, Irving JA. Electrophoresis- and FRET-Based Measures of Serpin Polymerization. Methods Mol Biol 2017; 1639:235-248. [PMID: 28752464 DOI: 10.1007/978-1-4939-7163-3_24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Many serpinopathies, including alpha-1 antitrypsin (A1AT) deficiency, are associated with the formation of unbranched polymer chains of mutant serpins. In vivo, this deficiency is the result of mutations that cause kinetic or thermodynamic destabilization of the molecule. However, polymerization can also be induced in vitro from mutant or wild-type serpins under destabilizing conditions. The characteristics of the resulting polymers are dependent upon induction conditions. Due to their relationship to disease, serpin polymers, mainly those formed from A1AT, have been widely studied. Here, we describe Förster resonance energy transfer (FRET) and gel-based approaches for their characterization.
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Affiliation(s)
- Sarah V Faull
- Division of Structural Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Anwen E Brown
- UCL Respiratory, University College London, London, WC1E 6JF, UK
| | - Imran Haq
- UCL Respiratory, University College London, London, WC1E 6JF, UK
| | - James A Irving
- UCL Respiratory, University College London, London, WC1E 6JF, UK.
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27
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Salahuddin P, Siddiqi MK, Khan S, Abdelhameed AS, Khan RH. Mechanisms of protein misfolding: Novel therapeutic approaches to protein-misfolding diseases. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.06.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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28
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Motamedi-Shad N, Jagger AM, Liedtke M, Faull SV, Nanda AS, Salvadori E, Wort JL, Kay CW, Heyer-Chauhan N, Miranda E, Perez J, Ordóñez A, Haq I, Irving JA, Lomas DA. An antibody that prevents serpin polymerisation acts by inducing a novel allosteric behaviour. Biochem J 2016; 473:3269-90. [PMID: 27407165 PMCID: PMC5264506 DOI: 10.1042/bcj20160159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 11/30/2022]
Abstract
Serpins are important regulators of proteolytic pathways with an antiprotease activity that involves a conformational transition from a metastable to a hyperstable state. Certain mutations permit the transition to occur in the absence of a protease; when associated with an intermolecular interaction, this yields linear polymers of hyperstable serpin molecules, which accumulate at the site of synthesis. This is the basis of many pathologies termed the serpinopathies. We have previously identified a monoclonal antibody (mAb4B12) that, in single-chain form, blocks α1-antitrypsin (α1-AT) polymerisation in cells. Here, we describe the structural basis for this activity. The mAb4B12 epitope was found to encompass residues Glu32, Glu39 and His43 on helix A and Leu306 on helix I. This is not a region typically associated with the serpin mechanism of conformational change, and correspondingly the epitope was present in all tested structural forms of the protein. Antibody binding rendered β-sheet A - on the opposite face of the molecule - more liable to adopt an 'open' state, mediated by changes distal to the breach region and proximal to helix F. The allosteric propagation of induced changes through the molecule was evidenced by an increased rate of peptide incorporation and destabilisation of a preformed serpin-enzyme complex following mAb4B12 binding. These data suggest that prematurely shifting the β-sheet A equilibrium towards the 'open' state out of sequence with other changes suppresses polymer formation. This work identifies a region potentially exploitable for a rational design of ligands that is able to dynamically influence α1-AT polymerisation.
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Affiliation(s)
- Neda Motamedi-Shad
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Alistair M. Jagger
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Maximilian Liedtke
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
| | - Sarah V. Faull
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Arjun Scott Nanda
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Enrico Salvadori
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
- London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, U.K
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Joshua L. Wort
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Christopher W.M. Kay
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
- London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, U.K
| | - Narinder Heyer-Chauhan
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - Elena Miranda
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, Rome 00185, Italy
| | - Juan Perez
- Departamento de Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Campus Teatinos, Universidad de Malaga, Malaga 29071, Spain
| | - Adriana Ordóñez
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, U.K
| | - Imran Haq
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - James A. Irving
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
| | - David A. Lomas
- Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K
- Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K
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29
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Historical role of alpha-1-antitrypsin deficiency in respiratory and hepatic complications. Gene 2016; 589:118-22. [DOI: 10.1016/j.gene.2016.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/11/2015] [Accepted: 01/03/2016] [Indexed: 12/14/2022]
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Perlmutter DH. α1-antitrypsin Deficiency: A Misfolded Secretory Protein Variant with Unique Effects on the Endoplasmic Reticulum. ENDOPLASMIC RETICULUM STRESS IN DISEASES 2016; 3:63-72. [PMID: 28217691 PMCID: PMC5310618 DOI: 10.1515/ersc-2016-0004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the classical form of α1-antitrypsin deficiency (ATD) a point mutation leads to accumulation of a misfolded secretory glycoprotein in the endoplasmic reticulum (ER) of liver cells and so ATD has come to be considered a prototypical ER storage disease. It is associated with two major types of clinical disorders, chronic obstructive pulmonary disease (COPD) by loss-of-function mechanisms and hepatic cirrhosis and carcinogenesis by gain-of-function mechanisms. The lung disease predominantly results from proteolytic damage to the pulmonary connective tissue matrix because of reduced levels of protease inhibitor activity of α1-anitrypsin (AT) in the circulating blood and body fluids. Cigarette smoking is a powerful disease-promoting modifier but other modifiers are known to exist because variation in the lung disease phenotype is still found in smoking and non-smoking homozygotes. The liver disease is highly likely to be caused by the proteotoxic effects of intracellular misfolded protein accumulation and a high degree of variation in the hepatic phenotype among affected homozygotes has been hypothetically attributed to genetic and environmental modifiers that alter proteostasis responses. Liver biopsies of homozygotes show intrahepatocytic inclusions with dilation and expansion of the ER and recent studies of iPS-derived hepatocyte-like cells from individuals with ATD indicate that the changes in the ER directly vary with the hepatic phenotype i.e there is much lesser alteration in the ER in cells derived from homozygotes that do not have clinically significant liver disease. From a signaling perspective, studies in mammalian cell line and animal models expressing the classical α1-antitrypsin Z variant (ATZ) have found that ER signaling is perturbed in a relatively unique way with powerful activation of autophagy and the NFκB pathway but relatively limited, if any, UPR signaling. It is still not known how much these unique structural and functional changes and the variation among affected homozygotes relate to the tendency of this variant to polymerize and aggregate and/or to the repertoire of proteostasis mechanisms that are activated.
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Affiliation(s)
- David H Perlmutter
- Corresponding author: David H Perlmutter, School of Medicine, Washington University in St Louis, 660 South Euclid Boulevard, St Louis, Missouri 63130, 314-362-6827,
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Lomas DA, Hurst JR, Gooptu B. Update on alpha-1 antitrypsin deficiency: New therapies. J Hepatol 2016; 65:413-24. [PMID: 27034252 DOI: 10.1016/j.jhep.2016.03.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/16/2016] [Accepted: 03/20/2016] [Indexed: 02/07/2023]
Abstract
α1-Antitrypsin deficiency is characterised by the misfolding and intracellular polymerisation of mutant α1-antitrypsin within the endoplasmic reticulum of hepatocytes. The retention of mutant protein causes hepatic damage and cirrhosis whilst the lack of an important circulating protease inhibitor predisposes the individuals with severe α1-antitrypsin deficiency to early onset emphysema. Our work over the past 25years has led to new paradigms for the liver and lung disease associated with α1-antitrypsin deficiency. We review here the molecular pathology of the cirrhosis and emphysema associated with α1-antitrypsin deficiency and show how an understanding of this condition provided the paradigm for a wider group of disorders that we have termed the serpinopathies. The detailed understanding of the pathobiology of α1-antitrypsin deficiency has identified important disease mechanisms to target. As a result, several novel parallel and complementary therapeutic approaches are in development with some now in clinical trials. We provide an overview of these new therapies for the liver and lung disease associated with α1-antitrypsin deficiency.
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Affiliation(s)
- David A Lomas
- UCL Respiratory, Division of Medicine, Rayne Building, University College London, UK; The London Alpha-1-Antitrypsin Deficiency Service, Royal Free London NHS Foundation Trust, London, UK; Institute of Structural and Molecular Biology, UCL/Birkbeck College, University of London, London WC1E 7HX, UK.
| | - John R Hurst
- UCL Respiratory, Division of Medicine, Rayne Building, University College London, UK; The London Alpha-1-Antitrypsin Deficiency Service, Royal Free London NHS Foundation Trust, London, UK
| | - Bibek Gooptu
- The London Alpha-1-Antitrypsin Deficiency Service, Royal Free London NHS Foundation Trust, London, UK; Institute of Structural and Molecular Biology, UCL/Birkbeck College, University of London, London WC1E 7HX, UK; Division of Asthma, Allergy and Lung Biology, King's College London, Guy's Hospital, 5th Floor, Tower Wing, London, UK
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Abstract
α1-Antitrypsin deficiency (A1ATD) is an inherited disorder caused by mutations in SERPINA1, leading to liver and lung disease. It is not a rare disorder but frequently goes underdiagnosed or misdiagnosed as asthma, chronic obstructive pulmonary disease (COPD) or cryptogenic liver disease. The most frequent disease-associated mutations include the S allele and the Z allele of SERPINA1, which lead to the accumulation of misfolded α1-antitrypsin in hepatocytes, endoplasmic reticulum stress, low circulating levels of α1-antitrypsin and liver disease. Currently, there is no cure for severe liver disease and the only management option is liver transplantation when liver failure is life-threatening. A1ATD-associated lung disease predominately occurs in adults and is caused principally by inadequate protease inhibition. Treatment of A1ATD-associated lung disease includes standard therapies that are also used for the treatment of COPD, in addition to the use of augmentation therapy (that is, infusions of human plasma-derived, purified α1-antitrypsin). New therapies that target the misfolded α1-antitrypsin or attempt to correct the underlying genetic mutation are currently under development.
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Madsen JB, Andersen LM, Dupont DM, Trelle MB, Johansen JS, Jensen JK, Jørgensen TJD, Andreasen PA. An RNA Aptamer Inhibits a Mutation-Induced Inactivating Misfolding of a Serpin. Cell Chem Biol 2016; 23:700-8. [PMID: 27265748 DOI: 10.1016/j.chembiol.2016.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 04/07/2016] [Accepted: 04/11/2016] [Indexed: 12/17/2022]
Abstract
Most serpins are fast and specific inhibitors of extracellular serine proteases controlling biological processes such as blood coagulation, fibrinolysis, tissue remodeling, and inflammation. The inhibitory activity of serpins is based on a conserved metastable structure and their conversion to a more stable state during reaction with the target protease. However, the metastable state also makes serpins vulnerable to mutations, resulting in disease caused by inactive and misfolded monomeric or polymeric forms ("serpinopathy"). Misfolding can occur either intracellularly (type-I serpinopathies) or extracellularly (type-II serpinopathies). We have isolated a 2'-fluoropyrimidine-modified RNA aptamer, which inhibits a mutation-induced inactivating misfolding of the serpin α1-antichymotrypsin. It is the first agent able to stabilize a type-II mutation of a serpin without interfering with the inhibitory mechanism, thereby presenting a solution for the long-standing challenge of preventing pathogenic misfolding without compromising the inhibitory function.
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Affiliation(s)
- Jeppe B Madsen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Lisbeth M Andersen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Daniel M Dupont
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Morten B Trelle
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jesper S Johansen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Jan K Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Thomas J D Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Peter A Andreasen
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark.
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Huang X, Zheng Y, Zhang F, Wei Z, Wang Y, Carrell RW, Read RJ, Chen GQ, Zhou A. Molecular Mechanism of Z α1-Antitrypsin Deficiency. J Biol Chem 2016; 291:15674-86. [PMID: 27246852 PMCID: PMC4957051 DOI: 10.1074/jbc.m116.727826] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Indexed: 12/14/2022] Open
Abstract
The Z mutation (E342K) of α1-antitrypsin (α1-AT), carried by 4% of Northern Europeans, predisposes to early onset of emphysema due to decreased functional α1-AT in the lung and to liver cirrhosis due to accumulation of polymers in hepatocytes. However, it remains unclear why the Z mutation causes intracellular polymerization of nascent Z α1-AT and why 15% of the expressed Z α1-AT is secreted into circulation as functional, but polymerogenic, monomers. Here, we solve the crystal structure of the Z-monomer and have engineered replacements to assess the conformational role of residue Glu-342 in α1-AT. The results reveal that Z α1-AT has a labile strand 5 of the central β-sheet A (s5A) with a consequent equilibrium between a native inhibitory conformation, as in its crystal structure here, and an aberrant conformation with s5A only partially incorporated into the central β-sheet. This aberrant conformation, induced by the loss of interactions from the Glu-342 side chain, explains why Z α1-AT is prone to polymerization and readily binds to a 6-mer peptide, and it supports that annealing of s5A into the central β-sheet is a crucial step in the serpins' metastable conformational formation. The demonstration that the aberrant conformation can be rectified through stabilization of the labile s5A by binding of a small molecule opens a potential therapeutic approach for Z α1-AT deficiency.
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Affiliation(s)
- Xin Huang
- From the Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine and University of Chinese Academy of Sciences, Shanghai 200025, China
| | - Ying Zheng
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Fei Zhang
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Zhenquan Wei
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Yugang Wang
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Robin W Carrell
- the Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Randy J Read
- the Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Guo-Qiang Chen
- From the Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine and University of Chinese Academy of Sciences, Shanghai 200025, China, the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
| | - Aiwu Zhou
- the Hongqiao International Institute of Medicine, Shanghai Tongren Hospital/Faculty of Basic Medicine, Chemical Biology Division of Shanghai Universities E-Institutes, Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China, and
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Saga G, Sessa F, Barbiroli A, Santambrogio C, Russo R, Sala M, Raccosta S, Martorana V, Caccia S, Noto R, Moriconi C, Miranda E, Grandori R, Manno M, Bolognesi M, Ricagno S. Embelin binds to human neuroserpin and impairs its polymerisation. Sci Rep 2016; 6:18769. [PMID: 26732982 PMCID: PMC4702122 DOI: 10.1038/srep18769] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/26/2015] [Indexed: 01/07/2023] Open
Abstract
Neuroserpin (NS) is a serpin inhibitor of tissue plasminogen activator (tPA) in the brain. The polymerisation of NS pathologic mutants is responsible for a genetic dementia known as familial encephalopathy with neuroserpin inclusion bodies (FENIB). So far, a pharmacological treatment of FENIB, i.e. an inhibitor of NS polymerisation, remains an unmet challenge. Here, we present a biophysical characterisation of the effects caused by embelin (EMB a small natural compound) on NS conformers and NS polymerisation. EMB destabilises all known NS conformers, specifically binding to NS molecules with a 1:1 NS:EMB molar ratio without unfolding the NS fold. In particular, NS polymers disaggregate in the presence of EMB, and their formation is prevented. The NS/EMB complex does not inhibit tPA proteolytic activity. Both effects are pharmacologically relevant: firstly by inhibiting the NS polymerisation associated to FENIB, and secondly by potentially antagonizing metastatic processes facilitated by NS activity in the brain.
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Affiliation(s)
- Giorgia Saga
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| | - Fabio Sessa
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
| | - Alberto Barbiroli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l′Ambiente, Università degli Studi di Milano, Milan, Italy
| | - Carlo Santambrogio
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Rosaria Russo
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di MilanoItaly
| | - Michela Sala
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Samuele Raccosta
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Vincenzo Martorana
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Sonia Caccia
- Dipartimento di Biotecnologie Mediche e Medicina traslazionale, Università degli Studi di Milano, Milan, Italy
| | - Rosina Noto
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Claudia Moriconi
- Dipartimento di Biologia e Biotecnologie Charles Darwin, and Istituto Pasteur – Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Elena Miranda
- Dipartimento di Biologia e Biotecnologie Charles Darwin, and Istituto Pasteur – Fondazione Cenci-Bolognetti, Sapienza Università di Roma, Rome, Italy
| | - Rita Grandori
- Dipartimento di Biotecnologie e Bioscienze, Università Milano-Bicocca, Milan, Italy
| | - Mauro Manno
- Istituto di Biofisica, National Research Council of Italy, Palermo, Italy
| | - Martino Bolognesi
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
- Istituto di Biofisica, National Research Council of Italy, c/o Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | - Stefano Ricagno
- Dipartimento di Bioscienze and CIMAINA, Università degli Studi di Milano, Milan, Italy
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37
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An antibody raised against a pathogenic serpin variant induces mutant-like behaviour in the wild-type protein. Biochem J 2015; 468:99-108. [PMID: 25738741 PMCID: PMC4422257 DOI: 10.1042/bj20141569] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A monoclonal antibody (mAb) that binds to a transient intermediate may act as a catalyst for the corresponding reaction; here we show this principle can extend on a macro molecular scale to the induction of mutant-like oligomerization in a wild-type protein. Using the common pathogenic E342K (Z) variant of α1-antitrypsin as antigen–whose native state is susceptible to the formation of a proto-oligomeric intermediate–we have produced a mAb (5E3) that increases the rate of oligomerization of the wild-type (M) variant. Employing ELISA, gel shift, thermal stability and FRET time-course experiments, we show that mAb5E3 does not bind to the native state of α1-antitrypsin, but recognizes a cryptic epitope in the vicinity of the post-helix A loop and strand 4C that is revealed upon transition to the polymerization intermediate, and which persists in the ensuing oligomer. This epitope is not shared by loop-inserted monomeric conformations. We show the increased amenity to polymerization by either the pathogenic E342K mutation or the binding of mAb5E3 occurs without affecting the energetic barrier to polymerization. As mAb5E3 also does not alter the relative stability of the monomer to intermediate, it acts in a manner similar to the E342K mutant, by facilitating the conformational interchange between these two states. We show that a monoclonal antibody can act as a ‘molecular template’ in aberrant protein oligomerization, and the transient intermediate of α1-antitrypsin, a key to the molecular mechanism of disease pathogenesis, expresses a cryptic epitope also present in the oligomer.
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Caccia S, Ricagno S, Bolognesi M. Molecular bases of neuroserpin function and pathology. Biomol Concepts 2015; 1:117-30. [PMID: 25961991 DOI: 10.1515/bmc.2010.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Serpins build a large and evolutionary widespread protein superfamily, hosting members that are mainly Ser-protease inhibitors. Typically, serpins display a conserved core domain composed of three main β-sheets and 9-10 α-helices, for a total of approximately 350 amino acids. Neuroserpin (NS) is mostly expressed in neurons and in the central and peripheral nervous systems, where it targets tissue-type plasminogen activator. NS activity is relevant for axogenesis, synaptogenesis and synaptic plasticity. Five (single amino acid) NS mutations are associated with severe neurodegenerative disease in man, leading to early onset dementia, epilepsy and neuronal death. The functional aspects of NS protease inhibition are linked to the presence of a long exposed loop (reactive center loop, RCL) that acts as bait for the incoming partner protease. Large NS conformational changes, associated with the cleavage of the RCL, trap the protease in an acyl-enzyme complex. Contrary to other serpins, this complex has a half-life of approximately 10 min. Conformational flexibility is held to be at the bases of NS polymerization leading to Collins bodies intracellular deposition and neuronal damage in the pathological NS variants. Two main general mechanisms of serpin polymerization are currently discussed. Both models require the swapping of the RCL among neighboring serpin molecules. Specific differences in the size of swapped regions, as well as differences in the folding stage at which polymerization can occur, distinguish the two models. The results provided by recent crystallographic and biophysical studies allow rationalization of the functional and pathological roles played by NS based on the analysis of four three-dimensional structures.
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Berthelier V, Harris JB, Estenson KN, Baudry J. Discovery of an inhibitor of Z-alpha1 antitrypsin polymerization. PLoS One 2015; 10:e0126256. [PMID: 25961288 PMCID: PMC4427445 DOI: 10.1371/journal.pone.0126256] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/31/2015] [Indexed: 11/25/2022] Open
Abstract
Polymerization of the Z variant alpha-1-antitrypsin (Z-α1AT) results in the most common and severe form of α1AT deficiency (α1ATD), a debilitating genetic disorder whose clinical manifestations range from asymptomatic to fatal liver and/or lung disease. As the altered conformation of Z-α1AT and its attendant aggregation are responsible for pathogenesis, the polymerization process per se has become a major target for the development of therapeutics. Based on the ability of Z-α1AT to aggregate by recruiting the reactive center loop (RCL) of another Z-α1AT into its s4A cavity, we developed a high-throughput screening assay that uses a modified 6-mer peptide mimicking the RCL to screen for inhibitors of Z-α1AT polymer growth. A subset of compounds from the Library of Pharmacologically Active Compounds (LOPAC) with molecular weights ranging from 300 to 700 Da, was used to evaluate the assay's capabilities. The inhibitor S-(4-nitrobenzyl)-6-thioguanosine was identified as a lead compound and its ability to prevent Z-α1AT polymerization confirmed by secondary assays. To further investigate the binding location of S-(4-nitrobenzyl)-6-thioguanosine, an in silico strategy was pursued and the intermediate α1AT M* state modeled to allow molecular docking simulations and explore various potential binding sites. Docking results predict that S-(4-nitrobenzyl)-6-thioguanosine can bind at the s4A cavity and at the edge of β-sheet A. The former binding site would directly block RCL insertion whereas the latter site would prevent β-sheet A from expanding between s3A/s5A, and thus indirectly impede RCL insertion. Altogether, our investigations have revealed a novel compound that inhibits the formation of Z-α1AT polymers, as well as in vitro and in silico strategies for identifying and characterizing additional blocking molecules of Z-α1AT polymerization.
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Affiliation(s)
- Valerie Berthelier
- Department of Medicine, University of Tennessee Health Science Center—Graduate School of Medicine, Knoxville, Tennessee, United States of America
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jason Brett Harris
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
- UT-ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Kasey Noel Estenson
- Department of Medicine, University of Tennessee Health Science Center—Graduate School of Medicine, Knoxville, Tennessee, United States of America
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jerome Baudry
- UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
- UT-ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
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40
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Ordóñez A, Pérez J, Tan L, Dickens JA, Motamedi-Shad N, Irving JA, Haq I, Ekeowa U, Marciniak SJ, Miranda E, Lomas DA. A single-chain variable fragment intrabody prevents intracellular polymerization of Z α1-antitrypsin while allowing its antiproteinase activity. FASEB J 2015; 29:2667-78. [PMID: 25757566 PMCID: PMC4548814 DOI: 10.1096/fj.14-267351] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/19/2015] [Indexed: 01/10/2023]
Abstract
Mutant Z α1-antitrypsin (E342K) accumulates as polymers within the endoplasmic reticulum (ER) of hepatocytes predisposing to liver disease, whereas low levels of circulating Z α1-antitrypsin lead to emphysema by loss of inhibition of neutrophil elastase. The ideal therapy should prevent polymer formation while preserving inhibitory activity. Here we used mAb technology to identify interactors with Z α1-antitrypsin that comply with both requirements. We report the generation of an mAb (4B12) that blocked α1-antitrypsin polymerization in vitro at a 1:1 molar ratio, causing a small increase of the stoichiometry of inhibition for neutrophil elastase. A single-chain variable fragment (scFv) intrabody was generated based on the sequence of mAb4B12. The expression of scFv4B12 within the ER (scFv4B12KDEL) and along the secretory pathway (scFv4B12) reduced the intracellular polymerization of Z α1-antitrypsin by 60%. The scFv4B12 intrabody also increased the secretion of Z α1-antitrypsin that retained inhibitory activity against neutrophil elastase. MAb4B12 recognized a discontinuous epitope probably located in the region of helices A/C/G/H/I and seems to act by altering protein dynamics rather than binding preferentially to the native state. This novel approach could reveal new target sites for small-molecule intervention that may block the transition to aberrant polymers without compromising the inhibitory activity of Z α1-antitrypsin.—Ordóñez, A., Pérez, J., Tan, L., Dickens, J. A., Motamedi-Shad, N., Irving, J. A., Haq, I., Ekeowa, U., Marciniak, S. J., Miranda, E., Lomas, D. A. A single-chain variable fragment intrabody prevents intracellular polymerization of Z α1-antitrypsin while allowing its antiproteinase activity.
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Affiliation(s)
- Adriana Ordóñez
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Juan Pérez
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Lu Tan
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Jennifer A Dickens
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Neda Motamedi-Shad
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - James A Irving
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Imran Haq
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Ugo Ekeowa
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Stefan J Marciniak
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - Elena Miranda
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
| | - David A Lomas
- *Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom; Department of Cell Biology, Genetics and Physiology, University of Malaga, Malaga, Spain; Wolfson Institute for Biomedical Research, University College London, London, United Kingdom; and Department of Biology and Biotechnologies, "Charles Darwin," and Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University, Rome, Italy
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McElvaney OJ, Bella AME, McElvaney NG. α-1 antitrypsin deficiency: current and future treatment options. Expert Opin Orphan Drugs 2014. [DOI: 10.1517/21678707.2015.997208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Duvoix A, Roussel B, Lomas D. Molecular pathogenesis of alpha-1-antitrypsin deficiency. Rev Mal Respir 2014; 31:992-1002. [DOI: 10.1016/j.rmr.2014.03.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/14/2014] [Indexed: 11/24/2022]
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Abstract
For a protein to function appropriately, it must first achieve its proper conformation and location within the crowded environment inside the cell. Multiple chaperone systems are required to fold proteins correctly. In addition, degradation pathways participate by destroying improperly folded proteins. The intricacy of this multisystem process provides many opportunities for error. Furthermore, mutations cause misfolded, nonfunctional forms of proteins to accumulate. As a result, many pathological conditions are fundamentally rooted in the protein-folding problem that all cells must solve to maintain their function and integrity. Here, to illustrate the breadth of this phenomenon, we describe five examples of protein-misfolding events that can lead to disease: improper degradation, mislocalization, dominant-negative mutations, structural alterations that establish novel toxic functions, and amyloid accumulation. In each case, we will highlight current therapeutic options for battling such diseases.
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Affiliation(s)
- Julie S Valastyan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
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Turner AM. Alpha-1 antitrypsin deficiency: new developments in augmentation and other therapies. BioDrugs 2014; 27:547-58. [PMID: 23771682 DOI: 10.1007/s40259-013-0042-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alpha 1 antitrypsin deficiency (AATD) is a rare cause of chronic obstructive pulmonary disease. The lung disease is thought to be caused primarily by a lack of effective protection against the harmful effects of neutrophil elastase due to the low AAT levels in the lung. Patients may also develop liver disease due to polymerisation of AAT within hepatocytes. Consequently there has been much research over the years into AAT augmentation therapy in patients with lung disease, initially intravenously, and more recently in inhaled forms. This review article will discuss the role of augmentation therapy in AATD and the current status of recombinant AAT. The potential for other therapeutic strategies, such as blocking polymer formation, enhancing autophagy, gene therapy and stem cell-based treatment, will also be discussed more briefly.
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Affiliation(s)
- Alice M Turner
- QEHB Research Labs, University of Birmingham, Mindelsohn Way, Birmingham, B15 2WB, UK,
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Therapeutic targeting of misfolding and conformational change in α1-antitrypsin deficiency. Future Med Chem 2014; 6:1047-65. [DOI: 10.4155/fmc.14.58] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Misfolding and conformational diseases are increasing in prominence and prevalence. Both misfolding and ‘postfolding’ conformational mechanisms can contribute to pathogenesis and can coexist. The different contexts of folding and native state behavior may have implications for the development of therapeutic strategies. α1-antitrypsin deficiency illustrates how these issues can be addressed with therapeutic approaches to rescue folding, ameliorate downstream consequences of aberrant polymerization and/or maintain physiological function. Small-molecule strategies have successfully targeted structural features of the native conformer. Recent developments include the capability to follow solution behavior of α1-antitrypsin in the context of disease mutations and interactions with drug-like compounds. Moreover, preclinical studies in cells and organisms support the potential of manipulating cellular response repertoires to process misfolded and polymer states.
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Ghouse R, Chu A, Wang Y, Perlmutter DH. Mysteries of α1-antitrypsin deficiency: emerging therapeutic strategies for a challenging disease. Dis Model Mech 2014; 7:411-9. [PMID: 24719116 PMCID: PMC3974452 DOI: 10.1242/dmm.014092] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The classical form of α1-antitrypsin deficiency (ATD) is an autosomal co-dominant disorder that affects ~1 in 3000 live births and is an important genetic cause of lung and liver disease. The protein affected, α1-antitrypsin (AT), is predominantly derived from the liver and has the function of inhibiting neutrophil elastase and several other destructive neutrophil proteinases. The genetic defect is a point mutation that leads to misfolding of the mutant protein, which is referred to as α1-antitrypsin Z (ATZ). Because of its misfolding, ATZ is unable to efficiently traverse the secretory pathway. Accumulation of ATZ in the endoplasmic reticulum of liver cells has a gain-of-function proteotoxic effect on the liver, resulting in fibrosis, cirrhosis and/or hepatocellular carcinoma in some individuals. Moreover, because of reduced secretion, there is a lack of anti-proteinase activity in the lung, which allows neutrophil proteases to destroy the connective tissue matrix and cause chronic obstructive pulmonary disease (COPD) by loss of function. Wide variation in the incidence and severity of liver and lung disease among individuals with ATD has made this disease one of the most challenging of the rare genetic disorders to diagnose and treat. Other than cigarette smoking, which worsens COPD in ATD, genetic and environmental modifiers that determine this phenotypic variability are unknown. A limited number of therapeutic strategies are currently available, and liver transplantation is the only treatment for severe liver disease. Although replacement therapy with purified AT corrects the loss of anti-proteinase function, COPD progresses in a substantial number of individuals with ATD and some undergo lung transplantation. Nevertheless, advances in understanding the variability in clinical phenotype and in developing novel therapeutic concepts is beginning to address the major clinical challenges of this mysterious disorder.
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Affiliation(s)
- Raafe Ghouse
- Department of Pediatrics, University of Pittsburgh School of Medicine, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
- Children’s Hospital of Pittsburgh of UPMC, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Andrew Chu
- Department of Pediatrics, University of Pittsburgh School of Medicine, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
- Children’s Hospital of Pittsburgh of UPMC, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - Yan Wang
- Department of Pediatrics, University of Pittsburgh School of Medicine, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
- Children’s Hospital of Pittsburgh of UPMC, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
| | - David H. Perlmutter
- Department of Pediatrics, University of Pittsburgh School of Medicine, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
- Children’s Hospital of Pittsburgh of UPMC, One Children’s Hospital Drive, 4401 Penn Avenue, Pittsburgh, PA 15224, USA
- Department of Cell Biology, University of Pittsburgh School of Medicine, 3500 Terrace Street, 5362 Biomedical Sciences Tower, Pittsburgh, PA 15261, USA
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Brebner JA, Stockley RA. Recent advances in α-1-antitrypsin deficiency-related lung disease. Expert Rev Respir Med 2014; 7:213-29; quiz 230. [DOI: 10.1586/ers.13.20] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Xin D, Holzenburg A, Burgess K. Small Molecule Probes That Perturb A Protein-protein Interface In Antithrombin. Chem Sci 2014; 5:4914-4921. [PMID: 25396040 DOI: 10.1039/c4sc01295j] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Small molecule probes for perturbing protein-protein interactions (PPIs) in vitro can be useful if they cause the target proteins to undergo biomedically relevant changes to their tertiary and quaternary structures. Application of the Exploring Key Orientations (EKO) strategy (J. Am. Chem. Soc., 2013, 135, 167 - 173) to a piperidinone-piperidine chemotype 1 indicated specific derivatives were candidates to perturb a protein-protein interface in the α-antithrombin dimer; those particular derivatives of 1 were prepared and tested. In the event, most of them significantly accelerated oligomerization of monomeric α-antithrombin, which is metastable in its oligomeric state. This assertion is supported by data from gel electrophoresis (non-denaturing PAGE; throughout) and probe-induced loss of α-antithrombin's inhibitor activity in a reaction catalyzed by thrombin. Kinetics of α-antithrombin oligomerization induced by the target compounds were examined. It was found that probes with O-benzyl-protected serine side-chains are the most active catalysts in the series, and reasons for this, based on modeling experiments, are proposed. Overall, this study reveals one of the first examples of small molecules designed to act at a protein-protein interface relevant to oligomerization of a serpin (ie α-antithrombin). The relevance of this to formation of oligomeric serpin fibrils, associated with the disease states known as "serpinopathies", is discussed.
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Affiliation(s)
- Dongyue Xin
- Department of Chemistry, Texas A & M University, Box 30012, College Station, TX 77842
| | - Andreas Holzenburg
- Microscopy and Imaging Center, Department of Biology, and Department of Biochemistry & Biophysics TAMU, College Station, TX 77843-2257
| | - Kevin Burgess
- Department of Chemistry, Texas A & M University, Box 30012, College Station, TX 77842
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Gooptu B, Dickens JA, Lomas DA. The molecular and cellular pathology of α₁-antitrypsin deficiency. Trends Mol Med 2013; 20:116-27. [PMID: 24374162 DOI: 10.1016/j.molmed.2013.10.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/28/2013] [Accepted: 10/31/2013] [Indexed: 12/30/2022]
Abstract
Since its discovery 50 years ago, α₁-antitrypsin deficiency has represented a case study in molecular medicine, with careful clinical characterisation guiding genetic, biochemical, biophysical, structural, cellular, and in vivo studies. Here we highlight the milestones in understanding the disease mechanisms and show how they have spurred the development of novel therapeutic strategies. α₁-Antitrypsin deficiency is an archetypal conformational disease. Its pathogenesis demonstrates the interplay between protein folding and quality control mechanisms, with aberrant conformational changes causing liver and lung disease through combined loss- and toxic gain-of-function effects. Moreover, α₁-antitrypsin exemplifies the ability of diverse proteins to self-associate into a range of morphologically distinct polymers, suggesting a mechanism for protein and cell evolution.
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Affiliation(s)
- Bibek Gooptu
- Division of Asthma, Allergy, and Lung Biology, King's College London, 5th Floor, Tower Wing, Guy's Hospital, London, SE1 9RT, UK; Institute of Structural and Molecular Biology/Crystallography, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK
| | - Jennifer A Dickens
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, CB2 0XY, UK
| | - David A Lomas
- Institute of Structural and Molecular Biology/Crystallography, Department of Biological Sciences, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK; Division of Medicine, University College London, 1st Floor, Maple House, 149, Tottenham Court Road, London, W1T 7NF, UK.
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