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Ronzoni R, Ferrarotti I, D’Acunto E, Balderacchi AM, Ottaviani S, Lomas DA, Irving JA, Miranda E, Fra A. The Importance of N186 in the Alpha-1-Antitrypsin Shutter Region Is Revealed by the Novel Bologna Deficiency Variant. Int J Mol Sci 2021; 22:5668. [PMID: 34073489 PMCID: PMC8198886 DOI: 10.3390/ijms22115668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 11/17/2022] Open
Abstract
Alpha-1-antitrypsin (AAT) deficiency causes pulmonary disease due to decreased levels of circulating AAT and consequently unbalanced protease activity in the lungs. Deposition of specific AAT variants, such as the common Z AAT, within hepatocytes may also result in liver disease. These deposits are comprised of ordered polymers of AAT formed by an inter-molecular domain swap. The discovery and characterization of rare variants of AAT and other serpins have historically played a crucial role in the dissection of the structural mechanisms leading to AAT polymer formation. Here, we report a severely deficient shutter region variant, Bologna AAT (N186Y), which was identified in five unrelated subjects with different geographical origins. We characterized the new variant by expression in cellular models in comparison with known polymerogenic AAT variants. Bologna AAT showed secretion deficiency and intracellular accumulation as detergent-insoluble polymers. Extracellular polymers were detected in both the culture media of cells expressing Bologna AAT and in the plasma of a patient homozygous for this variant. Structural modelling revealed that the mutation disrupts the hydrogen bonding network in the AAT shutter region. These data support a crucial coordinating role for asparagine 186 and the importance of this network in promoting formation of the native structure.
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Affiliation(s)
- Riccardo Ronzoni
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6JF, UK; (D.A.L.); (J.A.I.)
| | - Ilaria Ferrarotti
- Pneumology Unit, Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency, Department of Internal Medicine and Therapeutics, IRCCS San Matteo Hospital Foundation, University of Pavia, 27100 Pavia, Italy; (I.F.); (A.M.B.); (S.O.)
| | - Emanuela D’Acunto
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, 00185 Rome, Italy; (E.D.); (E.M.)
| | - Alice M. Balderacchi
- Pneumology Unit, Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency, Department of Internal Medicine and Therapeutics, IRCCS San Matteo Hospital Foundation, University of Pavia, 27100 Pavia, Italy; (I.F.); (A.M.B.); (S.O.)
| | - Stefania Ottaviani
- Pneumology Unit, Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency, Department of Internal Medicine and Therapeutics, IRCCS San Matteo Hospital Foundation, University of Pavia, 27100 Pavia, Italy; (I.F.); (A.M.B.); (S.O.)
| | - David A. Lomas
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6JF, UK; (D.A.L.); (J.A.I.)
| | - James A. Irving
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6JF, UK; (D.A.L.); (J.A.I.)
| | - Elena Miranda
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, 00185 Rome, Italy; (E.D.); (E.M.)
- Italian Pasteur Institute—Cenci Bolognetti Foundation, Sapienza University of Rome, 00185 Rome, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
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Ottaviani S, Barzon V, Buxens A, Gorrini M, Larruskain A, El Hamss R, Balderacchi AM, Corsico AG, Ferrarotti I. Molecular diagnosis of alpha1-antitrypsin deficiency: A new method based on Luminex technology. J Clin Lab Anal 2020; 34:e23279. [PMID: 32181528 PMCID: PMC7370739 DOI: 10.1002/jcla.23279] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/17/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Background Alpha1‐antitrypsin deficiency (AATD) is an under‐diagnosed hereditary disorder characterized by reduced serum levels of alpha1‐antitrypsin (AAT) and increased risk to develop lung and liver diseases at an early age. AAT is encoded by the highly polymorphic SERPINA1 gene. The most common deficiency alleles are S and Z, but more than 150 rare variants lead to low levels of the protein. To identify these pathological allelic variants, sequencing is required. Since traditional sequencing is expensive and time‐consuming, we evaluated the accuracy of A1AT Genotyping Test, a new diagnostic genotyping kit which allows to simultaneously identify and genotype 14 deficiency variants of the SERPINA1 gene based on Luminex technology. Methods A total of 418 consecutive samples with AATD suspicion and submitted to the Italian Reference laboratory between January and April 2016 were analyzed both by applying the diagnostic algorithm currently in use, and by applying A1AT Genotyping Test. Results The assay gave the following results: 101 samples (24.2%) were positive for at least one of the 14 deficiency variants, 316 (75.6%) were negative for all the variants analyzed. The identified mutations showed a 100% correlation with the results obtained with our diagnostic algorithm. Seventeen samples (4%) resulted negative for the assay but sequencing identified other rare pathological variants in SERPINA1 gene. Conclusion The A1AT Genotyping Test assay was highly reliable and robust and allowed shorter diagnostic times. In few cases, it has been necessary to sequence the SERPINA1 gene to identify other rare mutations not included in the kit.
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Affiliation(s)
- Stefania Ottaviani
- Center for Diagnosis of Inherited Alpha1-antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute for Respiratory Disease, Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Valentina Barzon
- Center for Diagnosis of Inherited Alpha1-antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute for Respiratory Disease, Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Amaya Buxens
- Progenika Biopharma, A Grifols Company, Derio, Spain
| | - Marina Gorrini
- Center for Diagnosis of Inherited Alpha1-antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute for Respiratory Disease, Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | | | | | - Alice M Balderacchi
- Center for Diagnosis of Inherited Alpha1-antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute for Respiratory Disease, Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Angelo G Corsico
- Center for Diagnosis of Inherited Alpha1-antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute for Respiratory Disease, Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Ilaria Ferrarotti
- Center for Diagnosis of Inherited Alpha1-antitrypsin Deficiency, Laboratory of Biochemistry and Genetics, Institute for Respiratory Disease, Department of Internal Medicine and Therapeutics, University of Pavia, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
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Benning LN, Whisstock JC, Sun J, Bird PI, Bottomley SP. The human serpin proteinase inhibitor-9 self-associates at physiological temperatures. Protein Sci 2005; 13:1859-64. [PMID: 15215529 PMCID: PMC2279926 DOI: 10.1110/ps.04715304] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The metastable serpin architecture is perturbed by extremes of temperature, pH, or changes in primary sequence resulting in the formation of inactive, polymeric conformations. Polymerization of a number of human serpins in vivo leads to diseases such as emphysema, thrombosis, and dementia, and in these cases mutations are present within the gene encoding the aggregating protein. Here we show that aggregation of the human serpin, proteinase inhibitor-9 (PI-9), occurs under physiological conditions, and forms aggregates that are morphologically distinct from previously characterized serpin polymers. Incubation of monomeric PI-9 at 37 degrees C leads to the rapid formation of aggregated PI-9. Using a variety of spectroscopic methods we analyzed the nature of the structures formed after incubation at 37 degrees C. Electron microscopy showed that PI-9 forms ordered circular and elongated-type aggregates, which also bind the fluorescent dye Thioflavin T. Our data show that in vitro wild-type PI-9 forms aggregates at physiological temperatures. The biological implications of PI-9 aggregates at physiological temperatures are discussed.
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Affiliation(s)
- Lauren N Benning
- Department of Biochemistry and Molecular Biology, Monash University, P.O. Box 13D, Clayton, Victoria 3800, Australia
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Kwok JSY, Lawton JWM, Yew WW, Chau CH, Lee J, Wong PC. Protease inhibitor phenotypes and serum alpha-1-antitrypsin levels in patients with COPD: A study from Hong Kong. Respirology 2004; 9:265-70. [PMID: 15182280 DOI: 10.1111/j.1440-1843.2004.00560.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Many studies have suggested that an imbalance of protease activation and inhibition might result in COPD with emphysema. Levels of alpha-1-antitrypsin (alpha1-AT), the key protease inhibitor, are genetically determined by alleles that present in many phenotypes/subtypes, some of which are associated with deficiency of the protein. We prospectively evaluated the prevalence of the protease inhibitor (Pi) alleles and phenotypes together with the serum alpha1-AT levels in Chinese patients with COPD. METHODOLOGY The study population comprised 356 patients with COPD. The male-to-female ratio was 4 : 1 with a mean age of 72.4 years (range 44-93 years). Isoelectric focusing was used for Pi phenotyping/subtyping. The frequencies of Pi alleles and phenotypes were compared with the frequencies in 1085 healthy unrelated Chinese control subjects. The serum alpha1-AT levels were measured by the Cobas Fara assay. RESULTS PiZ was not detected. No significant difference in distribution of PiM phenotypes/subtypes between patients with COPD and healthy controls was observed, except for M1M3 and M2M3. There was also a significant difference in the proportion of variant S and F alleles between the disease group and the control population. CONCLUSION The low prevalence of deficiency Pi phenotypes/subtypes suggests a lack of contribution of alpha1-AT deficiency to the pathogenesis of COPD in Chinese patients. The strategy of launching an alpha1-AT deficiency detection program among COPD patients, based on the recommendation of the World Health Organization, may not be readily applicable in our local setting.
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Nakade O, Kasai K, Satoh M, Yamamura M, Kakiuchi H, Kaku T, Mori M. Alpha1-antitrypsin deficiency and toxic shock: a Japanese autopsy case. Pathol Int 1999; 49:79-84. [PMID: 10227729 DOI: 10.1046/j.1440-1827.1999.00826.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A 74-year-old Japanese female presented with the sudden appearance of hemorrhagic purpuric ecchymoses on her lower extremities and with fever and chills, and died on the fifth day of hospitalization. A diagnosis of alpha1-antitrypsin (AT) deficiency was made postmortem. The liver weighed 1260 g. Histological sections from the liver revealed rather severe fatty changes of the hepatocytic parenchyma and partial loss of the normal hepatic architecture with fibrosis. The hepatocytes contained periodic acid-Schiff (PAS)-positive, diastase-resistant and alpha1-AT-positive intracytoplasmic globules. There was markedly increased inflammatory infiltration with severe edema and congestion, accompanied by fibrous, thickened pulmonary alveolar walls with fibrin deposition in the lungs (right, 410 g; left, 280 g), which suggest findings similar to those seen in multiple organ failure. Mild pulmonary emphysema was also present in the upper lobes of the lungs. Histological sections from the hemorrhagic necrotic ecchymoses of the skin showed marked neutrophil infiltration over the subcutaneous tissue with bleeding and blistering. A finding of thrombophlebitis was also found in the subcutaneous tissue. No bacteria were detected in the ecchymoses, the urine or the blood. Plasma protein analysis revealed a lower level (9.5 micromol/L) of alpha1-AT and a higher level (330 U) of anti-streptolysin O (ASO). These findings suggest that the patient died of toxic shock-like syndrome and that alpha1-AT deficiency might have facilitated the development of the toxic shock. To our knowledge, this is the first case of toxic shock associated with alpha1-AT deficiency.
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Affiliation(s)
- O Nakade
- Department of Oral Pathology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan.
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