Predicting the Role of SERPINA1 DNA Methylation in Chronic Obstructive Pulmonary Disease and Anaemia and Identification of 3 Novel Methylation Sites

ABSTRACT Anaemia and chronic obstructive pulmonary disease (COPD) are the common blood and respiratory disorders respectively. The proper lung function is maintained by the SERPINA1 gene predominantly that encodes for alpha 1 antitrypsin protein, which also regulates the iron homeostasis of the human body, whereas imbalance in the iron homeostasis may result in the anaemic condition. The altitudinal variations influence anaemia and COPD. DNA methylation is involved in the early developmental processes, which influences the gene functioning without altering the sequence. The current study has been aimed at analyzing the inter-relationship between anaemia and COPD with DNA methylation of the SERPINA1 gene under altitudinal changes. The methodology involves the DNA isolation, bisulfite conversion and sequencing of the SERPINA1 gene. The results of the current study have shown that SERPINA1 DNA methylation did not significantly involve anaemia and COPD irrespective altitudes, but 3 novel CpG sites cg94377701, cg94389678 and cg94389930 were identified in the SERPINA1 gene of anaemia and COPD patients.

Correlation between α1-Antitrypsin Deficiency and SARS-CoV-2 Infection: Epidemiological Data and Pathogenetic Hypotheses

The most common hereditary disorder in adults, α1-antitrypsin deficiency (AATD), is characterized by reduced plasma levels or the abnormal functioning of α1-antitrypsin (AAT), a major human blood serine protease inhibitor, which is encoded by the SERine Protein INhibitor-A1 (SERPINA1) gene and produced in the liver. Recently, it has been hypothesized that the geographic differences in COVID-19 infection and fatality rates may be partially explained by ethnic differences in SERPINA1 allele frequencies. In our review, we examined epidemiological data on the correlation between the distribution of AATD, SARS-CoV-2 infection, and COVID-19 mortality rates. Moreover, we described shared pathogenetic pathways that may provide a theoretical basis for our epidemiological findings. We also considered the potential use of AAT augmentation therapy in patients with COVID-19.

Small molecule screen employing patient-derived iPS hepatocytes identifies LRRK2 as a novel therapeutic target for Alpha1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency is a life-threatening condition caused by inheritance of the SERPINA1 gene Z variant. This single base pair mutation leads to protein misfolding, ER entrapment and gain of toxic function. Despite the significant unmet medical need presented by this disorder, there remain no approved medicines and the only curative option is liver transplantation. We hypothesized that an unbiased screen of human hepatocytes harbouring the Z mutation (ATZ) using small molecules targeted against protein degradation pathways would uncover novel biological insights of therapeutic relevance. Here we report the results of that screen performed in a patient-derived iPSC model of ATZ. Starting from 1,041 compounds we identified 14 targets capable of reducing polymer burden, including Leucine-rich repeat kinase-2 (LRRK2), a well-studied target in Parkinsons. Genetic deletion of LRRK2 in ATZ mice reduced polymers and associated fibrotic liver disease leading us to test a library of commercially available LRRK2 kinase inhibitors in both patient iPSC and CHO cell models. One of the molecules tested, CZC-25146, reduced polymer load, increased normal AAT secretion and reduced inflammatory cytokines with pharmacokinetic properties supporting its potential use for treating liver diseases. We therefore tested CZC-25146 in the ATZ mouse model and confirmed its efficacy for polymer reduction without signs of toxicity. Mechanistically, in both human and mouse models, our data show CZC-25146 inhibits LRRK2 kinase activity and induces autophagy. Cumulatively, these findings support the use of CZC-25146 and LRRK2 inhibitors in general in hepatic proteopathy disease research and as potential new treatment approaches for patients.

Contribution of Genetic and Environmental Risk Factors in a Juvenile Idiopathic Arthritis Large Family With SERPINA1 Gene Mutations

Objectives Although the underlying mechanisms and mediators of arthritis in juvenile idiopathic arthritis (JIA) are not well understood, accumulated evidence supports the mixt role of genetic and environmental factors. Few reports of multiplex families with JIA were published until now. The aim of this study was to identify new genetic or environmental associations concerning the patients of a kindred with juvenile idiopathic arthritis and psoriatic features (JIAPs). Methods Here, we characterized an extended multiplex family of 5 patients with juvenile idiopathic arthritis and psoriatic features (PsA) at the clinical and genetic level, using whole exome sequencing. Results We did not confirm in our family the linkage with the genetic factors already described that might be associated with increase susceptibility to JIA. We found a carrier status of siblings who inherited a pathogenic allele of the SERPINA1 gene from their mother who herself has two heterozygous pathogenic variants in the SERPINA1 gene. Conclusions Our data showed that JIA results from pleiotropic effects of environmental background with an only minor monogenic contribution. Even that a monogenetic factor could not be proved, some genetic factor as SERPINA1 mutations which can sensitize for psoriatic arthritis development seems to be involved. Further investigation must be done to prove whether SERPINA1 mutations may have a potential JIA causality.

Identification of Variants in Alpha-1-Antitrypsin by High Resolution Melting

Background Alpha-1-antitrypsin deficiency (AATD) is one of the most common hereditary disorders occurring in populations of European origin and is due to variants in SERPINA1, which encodes a protease inhibitor of neutrophil elastase, limiting lung damage from this enzyme. The World Health Organization has recommended that individuals with chronic obstructive pulmonary disease and asthma be tested for AATD. The development of inexpensive and simple genetic testing will help to meet this goal. Methods Primers and synthetic SERPINA1 gene fragments (gBlocks) were designed for 5 AATD-associated variants. PCR was run on a CFX96 Thermal Cycler with High Resolution Melting (HRM) capacity and data analyzed using the supplied HRM-analysis software. Genomic DNA from individuals (n = 86) genotyped for the S and Z variants were used for validation. HRM-analysis was performed on 3 additional samples with low alpha-1-antitrypsin levels inconsistent with the genotype determined in our clinical laboratory. Results Unique normalized melt curve and difference curve patterns were identified for the AAT variants Z, S, I, F, and MMalton using gBlocks. Similar curve shapes were seen when these primers were used to analyze the gDNA samples. HRM identified the genotypes of the gDNA correctly with 100% concordance. The curve shapes of some samples did not match the melting patterns of the targeted variant. Sequencing was used to identify the variants, including rare AATD variants c.1108_1115delinsAAAAACA (p.Glu370Lysfs*31) and c.1130dup (p.Leu377fs). Conclusion We developed a rapid and inexpensive HRM-analysis method for genotyping of Z, S, MMalton, I, and F variants that was also capable of detecting other variants.

Post-Translational Modifications of Circulating Alpha-1-Antitrypsin Protein

Alpha-1-antitrypsin (AAT), an acute-phase protein encoded by the SERPINA1 gene, is a member of the serine protease inhibitor (SERPIN) superfamily. Its primary function is to protect tissues from enzymes released during inflammation, such as neutrophil elastase and proteinase 3. In addition to its antiprotease activity, AAT interacts with numerous other substances and has various functions, mainly arising from the conformational flexibility of normal variants of AAT. Therefore, AAT has diverse biological functions and plays a role in various pathophysiological processes. This review discusses major molecular forms of AAT, including complex, cleaved, glycosylated, oxidized, and S-nitrosylated forms, in terms of their origin and function.

Familial spontaneous pneumothorax and Machado–Joseph disease

ABSTRACT We report the first known case of a 42-year-old man diagnosed with spinocerebellar ataxia type 3, also known as Machado–Joseph disease (MJD), who presented with recurrent spontaneous pneumothorax. Six other family members affected with MJD died of the same pulmonary complication. To date, there has been no direct genetic linkage between MJD and familial spontaneous pneumothorax. However, the mutated ataxin-3 (ATXN3) gene in MJD and Serpin Family A Member 1 (SERPINA1) gene in hereditary emphysema share the same loci on chromosome 14q32.1, which is suggestive of genetic proclivity of patients with MJD to develop familial pneumothorax. Furthermore, the abnormal ataxin protein encoded by ATXN3 and the patient’s smoking history could have potentiated the dysregulation of the ubiquitin-proteasome system further aggravating his genetic predisposition to develop recurrent pneumothorax. These unexplored areas of inquiry invoke further molecular characterization to give an accent to medical knowledge as well as guide novel therapies in the future.