Analysis of the expression of the Serpina1 gene in SARS-CoV-2 infection: Study of a new biomarker

INTRODUCTION

The SERPINA1 gene encodes the protein Alpha-1 Antitrypsin (AAT1). Possible imbalances between the concentrations of proteases and antiproteases (AAT1) can lead to the development of serious pulmonary and extrapulmonary pathologies. In this work we study the importance of this possible imbalance in patients with COVID-19.

OBJECTIVES

To correlate the severity of the symptoms of SARS-COV-2 infection with the AAT1 concentrations at diagnosis of the disease.

METHODS

An observational, prospective, cross-sectional, non-interventional, analytical study was carried out where 181 cases with COVID-19 admitted to the "Lozano Blesa" University Clinical Hospital of Zaragoza were selected. The concentration of AAT1 was studied in all of them and this was correlated with the clinical aspects and biochemical parameters at hospital admission.

RESULTS

141 cases corresponded to patients with severe COVID and 40 patients with mild COVID. AAT1 levels were positively correlated with the days of hospitalization, severity, C-Reactive Protein, ferritin, admission to Intensive Care, and death, and presented a negative correlation with the number of lymphocytes/mm3. AAT1 concentrations higher than 237.5 mg/dL allowed the patient to be classified as "severe" (S72%; E78%) and 311.5 mg/dL were associated with the risk of admission to Intensive Care or Exitus (S67%; E79%).

CONCLUSIONS

Levels of the SERPINA1 gene expression product, AAT1, correlate with the severity of COVID-19 patients at diagnosis of the disease, being useful as a prognostic biomarker.

An association between plasma levels of α2-macroglobulin and α1-antitrypsin in PiMM and PiZZ individuals differing in COPD presentation

INTRODUCTION

Compared to normal PiMM, individuals with severe α1-antitrypsin (AAT) PiZZ (Glu342Lys) genotype deficiency are at higher risk of developing early-onset chronic obstructive pulmonary disease (COPD)/emphysema associated with Z-AAT polymers and neutrophilic inflammation. We aimed to investigate putative differences in plasma levels of acute phase proteins (APP) between PiMM and PiZZ subjects and to determine plasma Z-AAT polymer levels in PiZZ subjects.

MATERIALS AND METHODS

Nephelometric analysis of seven plasma APPs was performed in 67 PiMM and 44 PiZZ subjects, of whom 43 and 42, respectively, had stable COPD. Of the PiZZ-COPD patients, 21 received and 23 did not receive intravenous therapy with human AAT preparations (IV-AAT). Plasma levels of Z-AAT polymers were determined by Western blotting using specific mouse monoclonal antibodies (2C1 and LG96).

RESULTS

In addition to lower plasma AAT, PiZZ patients had higher α2-macroglobulin (A2MG) levels than PiMM patients. In contrast, PiZZ who received IV-AAT had higher AAT values but lower A2MG values than PiZZ without IV-AAT. Regardless of the AAT genotype, AAT levels were inversely correlated with A2MG, and the AAT/A2MG ratio was correlated with lung diffusion capacity (DCLO%). All PiZZ patients had circulating Z-AAT polymer levels that correlated directly with A2MG. In PiZZ without IV-AAT therapy polymer levels correlated inversely with the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC).

CONCLUSION

Combined measurement of plasma AAT and A2MG levels may be of clinical value in assessing the progression of COPD and requires further attention.

The association of tumor-expressed REG4, SPINK4 and alpha-1 antitrypsin with cancer-associated thrombosis in colorectal cancer

Novel biomarkers are needed to improve current imperfect risk prediction models for cancer-associated thrombosis (CAT). We recently identified an RNA-sequencing profile that associates with CAT in colorectal cancer (CRC) patients, with REG4, SPINK4, and SERPINA1 as the top-3 upregulated genes at mRNA level. In the current study, we investigated whether protein expression of REG4, SPINK4 and alpha-1 antitrypsin (A1AT, encoded by SERPINA1) in the tumor associated with CAT in an independent cohort of CRC patients. From 418 patients with resected CRC, 18 patients who developed CAT were age, sex, and tumor stage-matched to 18 CRC patients without CAT. Protein expression was detected by immunohistochemical staining and scored blindly by assessing the H-score (percentage positive cells*scoring intensity). The association with CAT was assessed by means of logistic regression, using patients with an H-score below 33 as reference group. The odds ratios (ORs) for developing CAT for patients with A1AThigh, REG4high, SPINK4high tumors were 3.5 (95%CI 0.8-14.5), 2.0 (95%CI 0.5-7.6) and 2.0 (95%CI 0.5-7.4) when compared to A1ATlow, REG4low, SPINK4low, respectively. The OR was increased to 24.0 (95%CI 1.1-505.1) when two proteins were combined (A1AThigh/REG4high). This nested case-control study shows that combined protein expression of A1AT and REG4 associate with CAT in patients with colorectal cancer. Therefore, REG4/A1AT are potential biomarkers to improve the identification of patients with CRC who may benefit from thromboprophylaxis.

[Effects of α1-antitrypsin on motor function in mice with immature brain white matter injury]

OBJECTIVES

To investigate the effects of α1-antitrypsin (AAT) on motor function in adult mice with immature brain white matter injury.

METHODS

Five-day-old C57BL/6J mice were randomly assigned to the sham surgery group (n=27), hypoxia-ischemia (HI) + saline group (n=27), and HI+AAT group (n=27). The HI white matter injury mouse model was established using HI methods. The HI+AAT group received intraperitoneal injections of AAT (50 mg/kg) 24 hours before HI, immediately after HI, and 72 hours after HI; the HI+saline group received intraperitoneal injections of the same volume of saline at the corresponding time points. Brain T2-weighted magnetic resonance imaging scans were performed at 7 and 55 days after modeling. At 2 months of age, adult mice were evaluated for static, dynamic, and coordination parameters using the Catwalk gait analysis system.

RESULTS

Compared to the sham surgery group, mice with HI injury showed high signal intensity on brain T2-weighted magnetic resonance imaging at 7 days after modeling, indicating significant white matter injury. The white matter injury persisted at 55 days after modeling. In comparison to the sham surgery group, the HI+saline group exhibited decreased paw print area, maximum contact area, average pressure, maximum pressure, paw print width, average velocity, body velocity, stride length, swing speed, percentage of gait pattern AA, and percentage of inter-limb coordination (left hind paw → left front paw) (P<0.05). The HI+saline group showed increased inter-paw distance, percentage of gait pattern AB, and percentage of phase lag (left front paw → left hind paw) compared to the sham surgery group (P<0.05). In comparison to the HI+saline group, the HI+AAT group showed increased average velocity, body velocity, stride length, and swing speed (right front paw) (P<0.05).

CONCLUSIONS

The mice with immature brain white matter injury may exhibit significant motor dysfunction in adulthood, while the use of AAT can improve some aspects of their motor function.

Purified Versus Plasma Alpha-1 Antitrypsin Effects on Cellular Activities

By adding purified exogenous alpha-1 antitrypsin (AAT) to peripheral blood mononuclear cells in 20% autologous serum and measuring AAT-induced cellular adherence, it was determined that purified AAT differs from plasma AAT. The known association of AAT with lipoproteins and the negative feedback between AAT and low-density lipoprotein (LDL) suggest that purification may separate AAT from a plasma component such as LDL that participates in their normal plasma functions.

Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin (AAT) deficiency is a common monogenic disorder in which there is a strong founder effect of a single missense mutation in SERPINA1, the gene encoding this major circulating serum anti-protease that is normally expressed primarily in hepatocytes. These features make AAT deficiency particularly attractive as a target for therapeutic gene editing using a wide variety of approaches.

Measuring the Concentration of Active Alpha-1 Antitrypsin in Serum

Active Alpha-1 antitrypsin (AAT) circulates in blood in two isoforms in dynamic equilibrium: 1) native AAT, which binds irreversibly to neutrophil elastase, and 2) thiol-modified AAT, which binds reversibly to neutrophil elastase, either of which can be inactivated by oxidation, cleavage, covalent binding, and bound antibodies. Anti-AAT antibodies used for detecting AAT in plasma bind to active and inactive protein, thereby overestimating the concentration of functional protein. Active AAT can be quantitated by measuring its inhibition of active-site titrated elastase. A method for measuring active AAT in the presence of competing proteinase inhibitors in plasma has been developed and is described herein.

Autoantibody Recognition of Natural and Homocysteinylated Alpha-1 Antitrypsin: Indirect Enzyme-Linked Immunosorbent Assay (ELISA) Quantification in Sera

In this chapter, indirect enzyme-linked immunosorbent assays (ELISAs) to quantitatively measure autoantibodies directed to human natural and homocysteinylated alpha-1 antitrypsin (anti-AATA and anti-HAATA, respectively) in serum are described. The illustrated ELISA protocols are slightly different, since the two protein forms have different biochemical features and, consequently, different affinity for the matrix (polystyrene microplate wells), so that specific experimental conditions have to be performed for the quantification of the serum antibody recognition.These procedures can be carried out to evaluate the anti-AATA and the anti-HAATA levels, testing serum samples, for research use.

Silencing Very-Low-Density Lipoprotein Receptor Reveals Alpha-1 Antitrypsin Role in HIV Infectivity

Here we describe methods for investigating alpha-1 antitrypsin (AAT) and very-low-density lipoprotein receptor (VLDLR) interactions with infectious and non-infectious HIV-1 virions. Using silencing RNA to transiently block expression of VLDLR and the receptor-associated protein (RAP) to continuously block VLDLR activity, AAT is demonstrated to participate with VLDLR during internalization and infectivity of HIV-1 virions.

Lipoproteins in Negative Feedback with Alpha-1 Antitrypsin

Alpha-1 antitrypsin deficiency patients (AATD) have lower risk of myocardial infarction, a cardiovascular disease that is related to increased remnant cholesterol levels, but not to low-density lipoprotein (LDL) levels. However, when AAT is knocked out in mice (AAT-KO), inflammatory-related, cholesterol metabolism-related, and lipid metabolism-related gene expression in mouse liver was increased, and these data support previous evidence from clinic patients and from a small clinical trial that AAT is in negative feedback regulation with LDL. Herein is a brief summary to examine the roles of AAT in these overlapping pathways.

Molecular confirmation of alpha 1-antitrypsin deficiency in liver transplant setting: A province-wide experience

Background and Aim

Patients suspected of Alpha 1-Antitrypsin (A1AT) abnormality based on low serum concentration are routinely confirmed through polymerase chain reaction (PCR) testing of peripheral blood. Genotyping formalin-fixed paraffin-embedded (FFPE) tissue is a novel approach that could aid in detecting variant A1AT. We performed qPCR on FFPE liver explants with Periodic Acid Schiff after Diastase (PASD)- and A1AT-positive globules to confirm and estimate the frequency of A1AT deficiency in transplant cases.

Materials and Methods

Eighteen (12.68%) of 142 patients with end-stage liver disease showed PASD/A1AT positive globules. FFPE of the explants was tested through qPCR to detect S and Z alleles. A second age- and sex-matched control group consisting of five liver transplant patients with negative globules was included in the study.

Results

qPCR assay was successful with all the samples meeting QC parameters. All patients included in the study elucidated Z allele variants; 2 homozygous (11.1%) and 16 heterozygous (88.9%). The control group demonstrated normal wild-type MM allele.

Conclusion

Screening for A1AT deficiency using serum levels is not sufficiently sensitive to detect deficiency, especially in carriers. If A1AT testing was not performed preoperatively and the risk is high based on the PASD/A1AT-positive globules in the explants, then molecular testing of FFPE tissue can be a viable method for confirming the diagnosis.

Future Perspectives in the Diagnosis and Treatment of Liver Disease Associated with Alpha-1 Antitrypsin Deficiency

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.

Nebulizers effectiveness on pulmonary delivery of alpha-1 antitrypsin

The nebulization of alpha-1 antitrypsin (AAT) for its administration to the lung could be an interesting alternative to parenteral infusion for patients suffering from AAT genetic deficiency (AATD). In the case of protein therapeutics, the effect of the nebulization mode and rate on protein conformation and activity must be carefully considered. In this paper two types of nebulizers, i.e., a jet and a mesh vibrating system, were used to nebulize a commercial preparation of AAT for infusion and compared. The aerosolization performance, in terms of mass distribution, respirable fraction, and drug delivery efficiency, as well as the activity and aggregation state of AAT upon in vitro nebulization were investigated. The two nebulizers demonstrated equivalent aerosolization performances, but the mesh nebulizer provided a higher efficiency in the delivery of the dose. The activity of the protein was acceptably preserved by both nebulizers and no aggregation or changes in its conformation were identified. This suggests that nebulization of AAT represents a suitable administration strategy ready to be translated to the clinical practice for delivering the protein directly to the lungs in AATD patients, either as a support therapy to parenteral administration or for subjects with a precocious diagnosis, to prevent the onset of pulmonary symptoms.

Testing Patterns and Disparities for Alpha-1 Antitrypsin Deficiency

BACKGROUND

Alpha-1 antitrypsin deficiency is an under-recognized genetic cause of chronic lung and liver disease; it remains unclear what the testing frequency and disparities are for alpha-1 antitrypsin deficiency.

METHODS

This is a retrospective cohort study of people with newly diagnosed chronic obstructive pulmonary disease and liver disease identified at the University of Florida between January 1, 2012 and December 31, 2021. We performed incidence and prevalence analysis for alpha-1 antitrypsin (AAT) testing and point-biserial correlation analysis for tobacco use and AAT testing. We evaluated characteristics with AAT testing using adjusted multivariable logistic regression.

RESULTS

Among 75,810 subjects with newly diagnosed chronic obstructive pulmonary disease and liver disease between 2012 and 2021, 4248 (5.6%) were tested for AAT deficiency. All subjects had an AAT level performed, while 1654 (39%) had phenotype testing. Annual incidence of testing increased for subjects with newly diagnosed chronic obstructive pulmonary disease or liver disease from 2.8% and 5.4%, respectively, in 2012 to 4.1% and 11.3%, respectively, in 2021. Adjusted multivariable regression analysis showed factors favoring AAT testing were White race, and concomitant chronic obstructive pulmonary disease and liver disease. Increasing age, non-White race, current tobacco use, and being a male with chronic obstructive pulmonary disease had lower odds of AAT testing.

CONCLUSION

Although slowly improving, testing for AAT deficiency continues to have a low uptake in the clinical setting despite guidelines recommending broader testing. Individuals of White race and those with concomitant chronic obstructive pulmonary disease and liver disease are more likely to be tested, while older subjects, individuals of non-White race, current tobacco use, and men with chronic obstructive pulmonary disease are less favored to be tested.

Alpha-1 antitrypsin deficiency and Pi*S and Pi*Z SERPINA1 variants are associated with asthma exacerbations

INTRODUCTION AND OBJECTIVES

Asthma is a chronic inflammatory disease of the airways. Asthma patients may experience potentially life-threatening episodic flare-ups, known as exacerbations, which may significantly contribute to the asthma burden. The Pi*S and Pi*Z variants of the SERPINA1 gene, which usually involve alpha-1 antitrypsin (AAT) deficiency, had previously been associated with asthma. The link between AAT deficiency and asthma might be represented by the elastase/antielastase imbalance. However, their role in asthma exacerbations remains unknown. Our objective was to assess whether SERPINA1 genetic variants and reduced AAT protein levels are associated with asthma exacerbations.

MATERIALS AND METHODS

In the discovery analysis, SERPINA1 Pi*S and Pi*Z variants and serum AAT levels were analyzed in 369 subjects from La Palma (Canary Islands, Spain). As replication, genomic data from two studies focused on 525 Spaniards and publicly available data from UK Biobank, FinnGen, and GWAS Catalog (Open Targets Genetics) were analyzed. The associations between SERPINA1 Pi*S and Pi*Z variants and AAT deficiency with asthma exacerbations were analyzed with logistic regression models, including age, sex, and genotype principal components as covariates.

RESULTS

In the discovery, a significant association with asthma exacerbations was found for both Pi*S (odds ratio [OR]=2.38, 95% confidence interval [CI]= 1.40-4.04, p-value=0.001) and Pi*Z (OR=3.49, 95%CI=1.55-7.85, p-value=0.003)Likewise, AAT deficiency was associated with a higher risk for asthma exacerbations (OR=5.18, 95%CI=1.58-16.92, p-value=0.007) as well as AAT protein levels (OR= 0.72, 95%CI=0.57-0.91, p-value=0.005). The Pi*Z association with exacerbations was replicated in samples from Spaniards with two generations of Canary Islander origin (OR=3.79, p-value=0.028), and a significant association with asthma hospitalizations was found in the Finnish population (OR=1.12, p-value=0.007).

CONCLUSIONS

AAT deficiency could be a potential therapeutic target for asthma exacerbations in specific populations.

Small airways disease in patients with alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder, characterized by panacinar emphysema mainly in the lower lobes, and predisposes to chronic obstructive pulmonary disease (COPD) at a younger age, especially in patients with concomitant cigarette smoking. Alpha-1 antitrypsin (a1-AT) is a serine protease inhibitor that mainly blocks neutrophil elastase and maintains protease/antiprotease balance in the lung and AATD is caused by mutations in the SERPINA1 gene that encodes a1-AT protein. PiZZ is the most common genotype associated with severe AATD, leading to reduced circulating levels of a1-AT. Besides its antiprotease function, a1-AT has anti-inflammatory and antioxidative effects and AATD results in defective innate immunity. Protease/antiprotease imbalance affects not only the lung parenchyma but also the small airways and recent studies have shown that AATD is associated with small airway dysfunction. Alterations in small airways structure with peripheral ventilation inhomogeneities may precede emphysema formation, providing a unique opportunity to detect early disease. The aim of the present review is to summarize the current evidence for the contribution of small airways disease in AATD-associated lung disease.

Cigarette smoke exposed airway epithelial cell-derived EVs promote pro-inflammatory macrophage activation in alpha-1 antitrypsin deficiency

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder most commonly secondary to a single mutation in the SERPINA1 gene (PI*Z) that causes misfolding and accumulation of alpha-1 antitrypsin (AAT) in hepatocytes and mononuclear phagocytes which reduces plasma AAT and creates a toxic gain of function. This toxic gain of function promotes a pro-inflammatory phenotype in macrophages that contributes to lung inflammation and early-onset COPD, especially in individuals who smoke cigarettes. The aim of this study is to determine the role of cigarette exposed AATD macrophages and bronchial epithelial cells in AATD-mediated lung inflammation.

METHODS

Peripheral blood mononuclear cells from AATD and healthy individuals were differentiated into alveolar-like macrophages and exposed to air or cigarette smoke while in culture. Macrophage endoplasmic reticulum stress was quantified and secreted cytokines were measured using qPCR and cytokine ELISAs. To determine whether there is "cross talk" between epithelial cells and macrophages, macrophages were exposed to extracellular vesicles released by airway epithelial cells exposed to cigarette smoke and their inflammatory response was determined.

RESULTS

AATD macrophages spontaneously produce several-fold more pro-inflammatory cytokines as compared to normal macrophages. AATD macrophages have an enhanced inflammatory response when exposed to cigarette smoke-induced extracellular vesicles (EVs) released from airway epithelial cells. Cigarette smoke-induced EVs induce expression of GM-CSF and IL-8 in AATD macrophages but have no effect on normal macrophages. Release of AAT polymers, potent neutrophil chemo attractants, were also increased from AATD macrophages after exposure to cigarette smoke-induced EVs.

CONCLUSIONS

The expression of mutated AAT confers an inflammatory phenotype in AATD macrophages which disposes them to an exaggerated inflammatory response to cigarette smoke-induced EVs, and thus could contribute to progressive lung inflammation and damage in AATD individuals.

Lower serum alpha 1 antitrypsin levels in patients with severe COVID-19 compared with patients hospitalized due to non-COVID-19 pneumonia

INTRODUCTION

Alpha 1 antitrypsin (A1AT) is the major human blood serine protease inhibitor. Transmembrane serine protease 2 (TMPRSS2), which is crucial for SARS-CoV-2 cell entry, is inhibited by A1AT. Therefore, we hypothesized that individuals with diminished levels of A1AT may be more prone to SARS-CoV-2 infection and severe COVID-19 disease. Our aim in this study was to evaluate the level of A1AT in hospitalized COVID-19 patients in comparison to hospitalized patients with non-COVID-19 pneumonia.

METHODS

We conducted an observational prospective study between October 2020 and April 2021 in Rabin Medical Centre in Israel. A1AT levels were measured from the routine serum samples of hospitalized patients with COVID-19 and non-COVID-19 pneumonia (control group). The primary outcome was A1AT level, secondary outcomes were clinical outcomes and predictors of morality.

RESULTS

Overall, 145 patients were included in the study, 98 in the COVID-19 group and 47 in the control group. The median A1AT level was 222 mg/dL (interquartile range (IQR) 188-269) and 258 mg/dL (IQR 210-281) in the COVID-19 and control groups, respectively (p = .045). Multivariate analysis for independent risk factors for mortality among COVID-19 patients showed that diabetes mellitus (p = .02), older age (p = .04), and high A1AT levels (p = .04) were all associated with increased mortality.

CONCLUSION

Patients admitted due to severe COVID-19 had lower A1AT levels in comparison to patients admitted due to non-COVID pneumonia. This observation may suggest an association between mildly diminished A1AT and higher risk of SARS-CoV-2 infection with severe COVID-19 disease.

Alpha-1 antitrypsin: A novel biomarker and potential therapeutic approach for metabolic diseases

It is well recognized that chronic low-grade systemic inflammation and autoimmunity contribute to the pathogenesis of metabolic syndrome, its associated diseases (e.g. type 2 diabetes, non-alcoholic fatty liver disease) and type 1 diabetes, respectively. Consequently, anti-inflammatory agents might play a role in managing these immune associated metabolic diseases. Alpha-1 antitrypsin (AAT), an endogenous acute phase protein being used for treatment of AAT deficiency (a rare genetic disease), has multiple functions including anti-inflammatory, immunomodulatory, anti-apoptosis and cytoprotective effects. In this review, we summarized basic and clinical studies that reported potential therapeutic role of AAT in metabolic syndrome associated diseases and type 1 diabetes. Studies that demonstrated AAT had the possibility to be used as a novel biomarker to predict these immune associated metabolic diseases were also included.

Assessment of the circulatory concentrations of cathepsin D, cathepsin K, and alpha-1 antitrypsin in patients with knee osteoarthritis

BACKGROUND

Evidence has shown that cysteine protease enzymes, such as cathepsin D, cathepsin A, cathepsin K, and alpha-1 antitrypsin (AAT) are involved in the chronic degenerative joint process. This study aimed to determine the potential involvement of cathepsin K, cathepsin D, and AAT in patients with osteoarthritis (OA).

METHODS

This study was performed on 31 patients with knee OA and 29 age- and sex-matched healthy subjects (both with Fars ethnicity from Iran). American College of Rheumatology (ACR) criteria were used to diagnose OA patients. The clinical status of the patients was scored by Western Ontario McMaster Universities Osteoarthritis (WOMAC), and pain intensity was measured by the Visual Analog Scale (VAS). The serum level of AAT was measured using high-resolution cellulose acetate electrophoresis. Additionally, serum levels of cathepsin D and cathepsin K were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The findings showed that the serum level of cathepsin K was significantly increased in OA patients compared to healthy subjects (P = 0.01), while there was no significant difference between serum level of cathepsin D in study groups (P = 0.2). In addition, the serum concentration of AAT was significantly decreased in OA patients compared to healthy subjects (P = 0.003). There was a significant correlation between WOMAC score and age (r = 0.644, P = 0.0001) and VAS (r = 0.866, P < 0.0001) in OA patients.

CONCLUSIONS

The decreased level of AAT in OA patients and a rise in serum level of cathepsin K are involved in the pathogenesis of OA via stimulation of bone resorption and cartilage degradation.

Protease-anti-protease compartmentalization in SARS-CoV-2 ARDS: Therapeutic implications

Background

Interleukin-6 (IL-6) is elevated in SARS-CoV-2 infection. IL-6 regulates acute-phase proteins, such as alpha-1 antitrypsin (AAT), a key lung anti-protease. We investigated the protease-anti-protease balance in the circulation and pulmonary compartments in SARS-CoV-2 acute respiratory distress syndrome (ARDS) compared to non-SARS-CoV-2 ARDS (nsARDS) and the effects of tocilizumab (IL-6 receptor antagonist) on anti-protease defence in SARS-CoV-2 infection.

Methods

Levels and activity of AAT and neutrophil elastase (NE) were measured in plasma, airway tissue and tracheal secretions (TA) of people with SARS-CoV-2 ARDS or nsARDS. AAT and IL-6 levels were evaluated in people with moderate SARS-CoV-2 infection who received standard of care +/- tocilizumab.

Findings

AAT plasma levels doubled in SARS-CoV-2 ARDS. In lung parenchyma AAT levels were increased, as was the percentage of neutrophils involved in NET formation. A protease-anti-protease imbalance was detected in TA with active NE and no active AAT. The airway anti-protease, secretory leukoprotease inhibitor was decreased in SARS-CoV-2-infected lungs and cleaved in TA. In nsARDS, plasma AAT levels were elevated but TA samples had less AAT cleavage, with no detectable active NE in most samples

Induction of AAT in ARDS occurred mainly through IL-6. Tocilizumab down-regulated AAT during SARS-CoV-2 infection.

Interpretation

There is a protease-anti-protease imbalance in the airways of SARS-CoV-2-ARDS patients. This imbalance is a target for anti-protease therapy.

Ceruletide and Alpha-1 Antitrypsin as a Novel Combination Therapy for Ischemic Stroke

Ischemic stroke is a primary cause of morbidity and mortality worldwide. Beyond the approved thrombolytic therapies, there is no effective treatment to mitigate its progression. Drug repositioning combinational therapies are becoming promising approaches to identify new uses of existing drugs to synergically target multiple disease-response mechanisms underlying complex pathologies. Here, we used a systems biology-based approach based on artificial intelligence and pattern recognition tools to generate in silico mathematical models mimicking the ischemic stroke pathology. Combinational treatments were acquired by screening these models with more than 5 million two-by-two combinations of drugs. A drug combination (CA) formed by ceruletide and alpha-1 antitrypsin showing a predicted value of neuroprotection of 92% was evaluated for their synergic neuroprotective effects in a mouse pre-clinical stroke model. The administration of both drugs in combination was safe and effective in reducing by 39.42% the infarct volume 24 h after cerebral ischemia. This neuroprotection was not observed when drugs were given individually. Importantly, potential incompatibilities of the drug combination with tPA thrombolysis were discarded in vitro and in vivo by using a mouse thromboembolic stroke model with t-PA-induced reperfusion, revealing an improvement in the forepaw strength 72 h after stroke in CA-treated mice. Finally, we identified the predicted mechanisms of action of ceruletide and alpha-1 antitrypsin and we demonstrated that CA modulates EGFR and ANGPT-1 levels in circulation within the acute phase after stroke. In conclusion, we have identified a promising combinational treatment with neuroprotective effects for the treatment of ischemic stroke.

Production and characterization of mono-PEGylated alpha-1 antitrypsin for augmentation therapy

Alpha-1 antitrypsin (AAT) is an endogenous inhibitor of serine proteases which, in physiological conditions, neutralizes the excess of neutrophil elastase and other serine proteases in tissues and especially the lungs. Weekly intravenous infusion of plasma-purified human AAT is used to treat AAT deficiency-associated lung disease. However, only 2 % of the AAT dose reach the lungs after intravenous infusion. Inhalation of AAT might offer an alternative route of administration. Yet, the rapid clearance of AAT from the respiratory tract results in high and frequent dosing by inhalation and limited efficacy. In the present study, we produced and characterized in vitro a PEGylated version of AAT which could offer a prolonged body residence time and thereby be useful for augmentation therapy by the intravenous and inhalation routes. Two PEGylation reactions - N-terminal and thiol PEGylation - and three polyethylene glycol (PEG) chains - linear 30 kDa, linear 40 kDa and 2-armed 40 kDa - were used. The yields of mono-PEGylated AAT following purification by anion exchange chromatography were 40-50 % for N-terminal PEGylation and 60-70% for thiol PEGylation. The PEG-AAT conjugates preserved the ability to form a protease-inhibitor complex with neutrophil elastase and proteinase 3 as well as the full inhibitory capacity to neutralize neutrophil elastase activity. These results open up interesting prospects for PEGylated AAT to achieve a prolonged half-life and an improved therapeutic efficacy in vivo.

Clinical and functional characteristics of individuals with alpha-1 antitrypsin deficiency: EARCO international registry

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is a rare disease that is associated with an increased risk of pulmonary emphysema. The European AATD Research Collaboration (EARCO) international registry was founded with the objective of characterising the individuals with AATD and investigating their natural history.

METHODS

The EARCO registry is an international, observational and prospective study of individuals with AATD, defined as AAT serum levels < 11 μM and/or proteinase inhibitor genotypes PI*ZZ, PI*SZ and compound heterozygotes or homozygotes of other rare deficient variants. We describe the characteristics of the individuals included from February 2020 to May 2022.

RESULTS

A total of 1044 individuals from 15 countries were analysed. The most frequent genotype was PI*ZZ (60.2%), followed by PI*SZ (29.2%). Among PI*ZZ patients, emphysema was the most frequent lung disease (57.2%) followed by COPD (57.2%) and bronchiectasis (22%). Up to 76.4% had concordant values of FEV1(%) and KCO(%). Those with impairment in FEV1(%) alone had more frequently bronchiectasis and asthma and those with impairment in KCO(%) alone had more frequent emphysema and liver disease. Multivariate analysis showed that advanced age, male sex, exacerbations, increased blood platelets and neutrophils, augmentation and lower AAT serum levels were associated with worse FEV1(%).

CONCLUSIONS

EARCO has recruited > 1000 individuals with AATD from 15 countries in its first 2 years. Baseline cross sectional data provide relevant information about the clinical phenotypes of the disease, the patterns of functional impairment and factors associated with poor lung function. Trial registration www.

CLINICALTRIALS

gov (ID: NCT04180319).

The spectrum of clinical sequelae associated with alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin (AAT) deficiency (AATD) is an autosomal co-dominant condition that predisposes to the development of lung disease, primarily emphysema. Emphysema results from the breakdown of lung matrix elastin by proteases, including neutrophil elastase, a protease normally inhibited by AAT. AATD also predisposes to liver (cirrhosis) and skin (panniculitis) disease, and to vasculitis. The prevalence of AATD is estimated to be approximately 1 in 3,500 individuals in the United States. However, lack of awareness of AATD among some physicians, misperceptions regarding the absence of effective therapy, and the close overlap in symptoms with asthma and non-AATD chronic obstructive pulmonary disease are thought to contribute to under-recognition of the disease. In patients with AATD, treatment with intravenous AAT augmentation therapy is the only currently available treatment known to slow the progression of emphysema. Moreover, smoking cessation and other lifestyle interventions also help improve outcomes. Early diagnosis and intervention are of key importance due to the irreversible nature of the resultant emphysema. Liver disease is the second leading cause of death among patients with AATD and a minority of patients present with panniculitis or antineutrophil cytoplasmic antibody-associated vasculitis, thought to be directly related to AATD. Though no randomized trial has assessed the effectiveness of augmentation therapy for AATD-associated panniculitis, clinical experience and case series suggest there is a benefit. Other diseases putatively linked to AATD include aneurysmal disease and multiple neurological conditions, although these associations remain speculative in nature.

Protective role of the alpha-1-antitrypsin in intervertebral disc degeneration

BACKGROUND

Intervertebral disc degeneration is a complex disease with high prevalence. It suggests that cell death, senescence, and extracellular matrix degradation are involved in the pathogenesis. Alpha-1 antitrypsin (AAT), a serine protease inhibitor, was previously correlated with inflammation-related diseases. However, its function on intervertebral disc degeneration remains unclear.

METHODS

A latex-enhanced immunoturbidimetric assay measured the serum level of AAT. Real-time polymerase chain reaction (RT-qPCR) and western blot were used to testify the expression of RNA and proteins related to cell apoptosis and the Wnt/β-catenin pathway. The animal model for intervertebral disc degeneration was built by disc puncture. The degeneration grades were analyzed by safranin o staining.

RESULTS

We showed that alpha-1 antitrypsin could ameliorate intervertebral disc degeneration in vitro and in vivo. We also found that the serum alpha-1 antitrypsin level in Intervertebral disc degeneration patients is negative related to the severity of intervertebral disc degeneration. Moreover, alpha-1 antitrypsin was also showed to suppress tumor necrosis factor-alpha (TNF-α) induced WNT/β-catenin signaling pathway activation in human nucleus pulposus cells.

CONCLUSIONS

Our study provides evidence for AAT to serve as a potential therapeutic reagent for the treatment of intervertebral disc degeneration.

Prevalence and clinical characteristics of alpha-1 antitrypsin deficiency in liver explants in a Mexican cohort

INTRODUCTION

Alpha-1 antitrypsin deficiency (AATD) is a risk factor for liver disease. PASD-positive inclusions have been found unexpectedly in approximately 10% of liver explants in patients with no previous diagnosis of AATD, particularly, in patients with non-alcoholic steatohepatitis (NASH), supporting a synergistic mechanism of liver injury between AATD and environmental factors. We aimed to determine the clinical characteristics of mestizo patients in which AATD was diagnosed before or after liver transplantation.

METHODS

Liver explants of patients with cryptogenic, alcoholic, and NAFLD/NASH cirrhosis undergoing orthotopic liver transplantation (OLT) were included. Liver histopathology was assessed by two expert pathologists. Hematoxylin and eosin staining, PASD staining, and confirmatory AAT immunohistochemistry were performed. In explants with positive histopathology, genotyping for SERPINA1 was performed.

RESULTS

A total of 180 liver transplants were performed during the study period. Of these, 44 patients with cryptogenic cirrhosis, NASH, and alcoholic cirrhosis were included. Of these patients, two liver explants (4.5%) had PASD-positive inclusions stain and confirmatory immunochemistry. During the period evaluated, another two patients with a diagnosis of AATD before the OLT were also included. The four patients had overweight or obesity, three had type 2 diabetes mellitus, and two developed liver steatosis after the OLT.

CONCLUSION

AATD was found to be an infrequent finding in patients with cryptogenic, NASH/NAFLD, and alcoholic cirrhosis in our population. However, it is important to consider this entity as it may represent an additional factor in the appearance and progression of liver fibrosis in patients with metabolic syndrome.

Alpha-1 antitrypsin deficiency in the elderly: a case report

BACKGROUND

Generally, alpha-1 antitrypsin deficiency (AATD) is suspected in young patients with pulmonary emphysema or chronic obstructive pulmonary disease (COPD). Patients often suffer from diagnostic gaps and are misdiagnosed with chronic obstructive pulmonary disease (COPD), asthma, and airway hyperresponsiveness (AHR), as AATD may present with nonspecific respiratory symptoms. It is never too late to suspect AATD, especially in a patient with an unusual medical history. In recent years, evidence is beginning to emerge that there may be value in identifying and treating patients who do not already have deterioration of functional parameters.

CASE PRESENTATION

We describe a case of a 69-year-old Caucasian female patient, late diagnosis of AATD, with both severe bronchial hyperreactivity and numerous exacerbations due to the peculiar clinical history and the presence of a rare mutation; although not presenting forced expiratory volume in 1 second (FEV₁) between 30 and 65%, the patient was treated with alpha-1 antitrypsin (AAT) augmentation therapy and achieved clinical and functional improvement.

CONCLUSION

AATD should always be suspected. The Alpha-1 Foundation recommendations for the diagnosis and management of AATD in adult patients indicate that treatment should be provided for patients with FEV₁ between 30 and 65%. It may be useful to evaluate and treat patients based on clinical symptoms, even outside the established parameters, in particular cases.

Impact of serine protease inhibitor alpha1-antitrypsin on expression of endoplasmic reticulum stress-induced proinflammatory factors in adipocytes

Obesity-induced endoplasmic reticulum (ER) stress contributes to low-grade chronic inflammation in adipose tissue and may cause metabolic disorders such as diabetes mellitus and dyslipidemia. Identification of high serpina A1 (alpha-1 antitrypsin, A1AT) expression in mouse adipose tissue and adipocytes prompted us to explore the role of A1AT in the inflammatory response of adipocytes under ER stress. We aimed to determine the role of A1AT expression in adipocytes with ER stress during regulation of adipocyte homeostasis and inflammation. To this end, we chemically induced ER stress in A1AT small interfering RNA-transfected differentiating adipocytes using thapsigargin. Induction of CCAAT-enhancer-binding protein homologous protein (CHOP), an ER stress marker, by thapsigargin was lower in A1AT-deficient SW872 adipocytes. Thapsigargin or the proinflammatory cytokine tumor necrosis factor (TNF)α increased basal expression of cytokines such as interleukin (IL)-1β and IL-8 in both SW872 and primary omental adipocytes. This thapsigargin- or TNFα-induced expression of proinflammatory genes was increased by A1AT deficiency. These findings indicate that adipose A1AT may suppress the ER stress response to block excessive expression of proinflammatory factors, which suggests that A1AT protects against adipose tissue dysfunction associated with ER stress activation.

•

Bip and CHOP expression responded to chemical ER stressor fluctuates in A1AT-silenced adipocytes.

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Chemical ER stressor- and TNFα-induced proinflammatory factor expression is increased by silencing of adipose A1AT expression.

•

A1AT may protect against adipose tissue dysfunction through ER stress activation.

New insights into oxidative stress and immune mechanisms involved in age-related macular degeneration tackled by novel therapies

The prevalence of age-related macular degeneration (AMD) has increased in the last years. Although anti-VEGF agents have improved the prognosis of exudative AMD, dry AMD has still devastating effects on elderly people vision. Oxidative stress and inflammation are mechanisms involved in AMD pathogenesis and its progression. Molecular pathways involving epidermal growth factor receptor (EGFR), bone morphogenetic protein (BMP4) and the nuclear erythroid related factor 2 (Nrf2) are behind oxidative stress in AMD due to their participation in antioxidant cellular pathways. As a consequence of the disbalance produced in the antioxidant mechanisms, there is an activation of innate and adaptative immune response with cell recruitment, changes in complement factors expression, and modification of cellular milieu. Different therapies are being studied to treat dry AMD based on the possible effects on antioxidant molecular pathways or their action on the immune response. There is a wide range of treatments presented in this review, from natural antioxidant compounds to cell and gene therapy, based on their mechanisms. Finally, we hypothesize that alpha-1-antitrypsin (AAT), an anti-inflammatory and immunomodulatory molecule that can also modulate antioxidant cellular defenses, could be a good candidate for testing in AMD. This article is part of the special ssue on 'The Quest for Disease-Modifying Therapies for Neurodegenerative Disorders'.

A new electrochemical impedance biosensor based on aromatic thiol for alpha-1 antitrypsin determination

Alpha-1 antitrypsin (A1AT) is one of the acute phase proteins which are synthesized in the liver. A1AT inhibits the activity of many proteases, but its main task is to protect the lungs from the attack of neutrophil elastase. In an autosomal hereditary disease known as alpha-1 antitrypsin deficiency, the A1AT level in blood serum decreases, increasing the risk of developing emphysema, liver apoptosis, and liver cancer. Thus, the detection of A1AT concentration in blood serum is very important. In this study, an impedimetric biosensor was developed, forming an SAM (self-assembled monolayer) with 4-mercaptophenylacetic acid (4MPA) on the surface of the gold electrode. An A1AT biosensor was constructed using immobilization of an A1AT-specific antibody (anti-A1AT) after activating the carboxyl groups of 4MPA with EDC/NHS. Each immobilization stage was characterized by using electrochemical impedance spectroscopy, cyclic voltammetry, and scanning electron microscopy with energy dispersive X-ray spectroscopy. With the designed biosensor, precise and highly reproducible results were obtained for A1AT concentrations in the range of 100-600 µg/mL. A1AT detection was also successfully carried out in artificial serum solutions spiked with A1AT.

Alpha-1 antitrypsin for cystic fibrosis complicated by severe cytokinemic COVID-19

BACKGROUND

The clinical course of severe COVID-19 in cystic fibrosis (CF) is incompletely understood. We describe the use of alpha-1 antitrypsin (AAT) as a salvage therapy in a critically unwell patient with CF (PWCF) who developed COVID-19 while awaiting lung transplantation.

METHODS

IV AAT was administered at 120 mg/kg/week for 4 consecutive weeks. Levels of interleukin (IL)-1β, IL-6, IL-8, and soluble TNF receptor 1 (sTNFR1) were assessed at regular intervals in plasma, with IL-1β, IL-6, IL-8 and neutrophil elastase (NE) activity measured in airway secretions. Levels were compared to baseline and historic severe exacerbation measurements.

RESULTS

Systemic and airway inflammatory markers were increased compared to both prior exacerbation and baseline levels, in particular IL-6, IL-1β and NE activity. Following each AAT dose, rapid decreases in each inflammatory parameter were observed. These were matched by marked clinical and radiographic improvement.

CONCLUSIONS

The results support further investigation of AAT as a COVID-19 therapeutic, and re-exploration of its use in CF.

Alpha-1 antitrypsin deficient individuals have circulating extracellular vesicles with profibrogenic cargo

Background

Alpha-1 antitrypsin deficiency (AATD)-mediated liver disease is a toxic “gain-of-function” inflammation in the liver associated with intracellular retention of mutant alpha-1 antitrypsin. The clinical presentation of the disease includes fibrosis, cirrhosis and liver failure. However, the pathogenic mechanism of AATD-mediated liver disease is not well understood. Here, we investigated the role of plasma extracellular vesicles (EVs) in progression of AATD-mediated liver disease.

Methods

EVs were isolated from plasma of AATD individuals with liver disease and healthy controls. Their cytokines and miRNA content were examined by multiplex assay and small RNA sequencing. The bioactivity of EVs was assessed by qPCR, western blot analysis and immunofluorescent experiments using human hepatic stellate cells (HSCs) treated with EVs isolated from control or AATD plasma samples.

Results

We have found that AATD individuals have a distinct population of EVs with pathological cytokine and miRNA contents. When HSCs were cultured with AATD plasma derived-EVs, the expression of genes related to the development of fibrosis were significantly amplified compared to those treated with healthy control plasma EVs.

Conclusion

AATD individuals have a distinct population of EVs with abnormal cytokine and miRNA contents and the capacity to activate HSCs and mediate fibrosis. Better understanding of the components which cause liver inflammation and fibrogenesis, leading to further liver injury, has the potential to lead to the development of new treatments or preventive strategies to prevent AATD-mediated liver disease.

Human-Derived α1-Antitrypsin is Still Efficacious in Heavily Pretreated Patients with Steroid-Resistant Gastrointestinal Graft-versus-Host Disease

Almost one-half of patients developing graft-versus-host disease (GVHD) will not respond to standard first-line steroid treatment. Alpha-1 antitrypsin (AAT) is able to induce tolerance in preclinical models of GVHD. AAT alters the cytokine milieu, promotes a tolerogenic shift of dendritic cells, and skews effector T cells toward regulatory T cells. Gastrointestinal steroid-refractory (SR)-GVHD is a protein-losing enteropathy that might represent the optimal setting in which to use AAT. Here we analyze the outcomes of 16 patients treated with human-derived AAT in advanced-stage gut SR-GVHD, with two-thirds of the patients having failed at least 1 treatment for SR-GVHD. The overall response rate (ORR) was 44%, with a complete response (CR) rate of 27%. Gastrointestinal response was observed in 61% of patients. The median time to best response was 21 days (range, 6 to 26 days). At day 56 after AAT treatment, all CRs were maintained, and the ORR was 39%. The 1-year overall survival was 48% (95% confidence interval, 26% to 74%). Ancillary studies showed that AAT serum levels were in the normal range at the beginning of treatment, whereas fecal loss was elevated. AAT levels consistently rose after exogenous administration, but no correlation was found between serum levels and response. REG3α and IL-33 levels were associated with response while, in contrast to previous reports, regulatory T cells decreased during AAT treatment. This retrospective analysis supports a previous report of AAT as a promising agent in the management of gut SR-GVHD and should prompt its evaluation at an earlier stage.

Identification of small molecules by screening a mixture-based scaffold compound library for treatment of alpha-1 antitrypsin deficiency

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.

Rethinking fibrinogen storage disease of the liver: ground glass and globular inclusions do not represent a congenital metabolic disorder but acquired collective retention of proteins

Three types of intracytoplasmic inclusions immunoreactive to fibrinogen are collectively diagnosed as hepatic fibrinogen storage disease. This study aimed to better characterize ground glass (type II) and globular (type III) fibrinogen inclusions by the pathological examination of 3 cases and a literature review. Three adults (age: 32-64 years; male/female = 2:1) were unexpectedly found to have fibrinogen-positive ground glass changes (type II inclusions) by liver needle biopsy, against a background of acute hepatitis E, resolving acute cholangitis, or severe lobular hepatitis of unknown etiology. One patient also had fibrinogen-positive intracytoplasmic globules (type III inclusions) in the first biopsy, but they were not present in a second biopsy. None had coagulation abnormalities or hypofibrinogenemia. On immunostaining, both inclusions were strongly positive for not only fibrinogen but also C-reactive protein and C4d. Ultrastructurally, ground glass changes corresponded to membrane-bound cytoplasmic inclusions containing amorphous, granular material. The pathological features of type II fibrinogen inclusions were identical to those of pale bodies in hepatocellular carcinoma. The literature review suggested that type I fibrinogen inclusions characterized by a polygonal appearance are strongly associated with mutations in fibrinogen genes, coagulopathy, and family history, whereas type II/III inclusions are immunoreactive to multiple proteins and typically develop in cases of other unrelated liver diseases. In conclusion, type II and III fibrinogen inclusions do not represent a true hereditary storage disease but instead the collective retention of multiple proteins. Given the lack of clinical significance, a less specific name (e.g., pale body) may be more appropriate for those inclusions.

Serum alpha-1 antitrypsin in acute ischemic stroke: A prospective pilot study

BACKGROUND

Alpha-1 antitrypsin (AAT) is a potent anti-protease enzyme which may play a role in arterial wall stability. A variant of its encoding gene has been recently linked to ischemic stroke due to large artery atherosclerosis (LAA). We sought to explore potential relationships between ischemic stroke mechanisms, atherosclerosis burden and serum AAT levels.

METHODS

We performed a prospective observational study of consecutive patients with acute ischemic stroke who were admitted to an academic comprehensive stroke center over a three-month period. Blood samples were collected within 24 h of hospital admission, and stroke subtype classification was determined based on modified TOAST criteria. Modified Woodcock scoring system was used to quantify calcification of major cervico-cranial arteries as a surrogate for atherosclerosis burden. Linear regression analysis was used to assess the association between serum AAT levels and calcification scores, both as continuous variables.

RESULTS

Among eighteen patients met our inclusion criteria and were enrolled in our study, 10 patients (56%) were men; mean age was 66 (SD 12.5); median NIH stroke scale was 4 (IQR 9.5); 8 patients (44%) had stroke due to LAA. The median serum level of AAT was 140 mg/dl (IQR 41.7) for patients with LAA-related stroke, and 148.5 mg/dl (IQR 37.7) for patients with other stroke mechanisms (p = 0.26). Higher serum AAT levels was associated with lower modified Woodcock calcification scores. (p-value = 0.038) CONCLUSIONS: Measurement of AAT levels in patients with acute stroke is feasible, and there may be associations between AAT levels and stroke mechanism that warrant further study in larger samples.

Alpha-1 Antitrypsin Deficiency and Pregnancy

Alpha-1 Antitrypsin Deficiency (A1AD) is a hereditary condition characterized by low levels of circulating alpha-antitrypsin (AAT) in plasma. It is the best understood genetic risk factor for the development of chronic obstructive pulmonary disease (COPD). The diagnosis of A1AD is under-recognized. While there is a significant heterogeneity in disease presentation in relation to the severity of symptoms and prognosis, it is not uncommon for young individuals, including pregnant women to already have moderate to advanced lung disease at the time of diagnosis. Reductions in AAT levels may have unique implications for a gravid patient beyond that of lung disease. Care of the pregnant A1AD patient with chronic lung disease follows the principles of care for the management of airways disease in general with control of symptoms and reduction in exacerbation risk the main tenets of treatment. The effect of A1AD and augmentation in pregnancy has not been studied and thus care is reliant on expert opinion and clinical experience. Providers caring for pregnant patients with A1AD should consider referral to health care systems and providers with specific expertise in A1AD. Ultimately the decision is left to the individual patient and their physician to weigh the risk benefit of cessation or continuation of therapies. In this review, we present the perinatal course of a woman with A1AD and review the available literature pertaining to AAT and pregnancy and discuss the clinical implications.

Detection of alpha-1 antitrypsin deficiency: the past, present and future

Background

Most patients with alpha-1 antitrypsin deficiency remain undiagnosed and therefore do not benefit from current therapies or become eligible for research studies of new treatments under development. Improving the detection rate for AATD is therefore a high priority for the Alpha-1 Foundation. A workshop was held on June 23, 2019 in Orlando, Florida during which stakeholders from the research, pharmaceutical, and patient communities focused on the topic of alpha-1 antitrypsin deficiency detection.

Results

A variety of detection strategies have been explored in the past and new approaches are emerging as technology advances. Targeted detection includes patients with chronic obstructive pulmonary disease, unexplained chronic liver disease, and family members of affected individuals. Newborn screening, electronic medical record data mining, and direct-to-consumer testing remain options for future detection strategies.

Conclusion

These meeting proceedings can serve as a basis for innovative approaches to the detection of alpha-1 antitrypsin deficiency.

Proteomic and genomic biomarkers for Non-Small Cell Lung Cancer: Peroxiredoxin, Haptoglobin, and Alpha-1 antitrypsin

Background

The development of lung cancer is a multifactorial process that involves the environmental and genetic factors. The mortality rate of this cancer is higher than breast, colorectal, and prostate cancers. In this study, we try to analyze the proteome of patients with Non‐Small Cell Lung Cancer (NSCLC) and compare it with the healthy samples.

Methods

This study has compared 30 lung tissue samples from patients with NSCLC and 30 healthy samples using proteomics and RT‐PCR. Hence, tissue samples were obtained from the surgical ward in sterile conditions, and then, protein extraction applied to them. At the next stage, two‐dimensional electrophoresis and mass spectrometry LCMS/MS were performed for protein isolation and sequencing, respectively.

Results

The proteome analysis identified more than 40 differences in proteomic pattern of normal lung tissues compared to lung tissues with NSCLC. Peroxiredoxin, Haptoglobin, and Alpha‐1 antitrypsin proteins were identified. Molecularly, it has also been shown that the two main proteins of Peroxiredoxin‐2 and Alpha‐1 antitrypsin were upregulated, and the expression of Haptoglobin protein was downregulated in cancer tissue.

Conclusion

The results of this study showed that there are some differences in term of protein content between the normal and cancerous lung tissues. Further studies are needed to evaluate these proteins that investigate whether these proteins can candidate as biomarkers to use in the early diagnosis of patients with NSCLC.

Mechanisms behind Retinal Ganglion Cell Loss in Diabetes and Therapeutic Approach

Diabetes produces several changes in the body triggered by high glycemia. Some of these changes include altered metabolism, structural changes in blood vessels and chronic inflammation. The eye and particularly the retinal ganglion cells (RGCs) are not spared, and the changes eventually lead to cell loss and visual function impairment. Understanding the mechanisms resulting in RGC damage and loss from diabetic retinopathy is essential to find an effective treatment. This review focuses mainly on the signaling pathways and molecules involved in RGC loss and the potential therapeutic approaches for the prevention of this cell death. Throughout the manuscript it became evident that multiple factors of different kind are responsible for RGC damage. This shows that new therapeutic agents targeting several factors at the same time are needed. Alpha-1 antitrypsin as an anti-inflammatory agent may become a suitable option for the treatment of RGC loss because of its beneficial interaction with several signaling pathways involved in RGC injury and inflammation. In conclusion, alpha-1 antitrypsin may become a potential therapeutic agent for the treatment of RGC loss and processes behind diabetic retinopathy.

Liver Involvement in Children with Alpha-1 Antitrypsin Deficiency: A Multicenter Study

PURPOSE

Alpha-1 antitrypsin deficiency (A1ATD) in one of the most common genetic causes of liver disease in children. We aimed to analyze the clinical characteristics and outcomes of patients with A1ATD.

METHODS

This study included patients with A1ATD from five pediatric hepatology units. Demographics, clinical findings, genetics, and outcome of the patients were recorded (n=25).

RESULTS

Eight patients (32.0%) had homozygous PiZZ genotype while 17 (68.0%) had heterozygous genotype. Patients with PiZZ genotype had lower alpha-1 antitrypsin levels than patients with PiMZ genotype (37.6±7.7 mg/dL vs. 66.5±22.7 mg/dL, p=0.0001). Patients with PiZZ genotype were diagnosed earlier than patients with PiMZ genotype, but this was not significant (13±6.8 months vs. 23.7±30.1 months, p=0.192). Follow-up revealed the death of one patient (12.5%) with a homozygous mutation, and revealed that one patient had child A cirrhosis, five patients (62.5%) had chronic hepatitis, and one patient (12.5%) was asymptomatic. Nine of the 17 patients with a heterozygous mutation had chronic hepatitis (52.9%), two (11.7%) had child A cirrhosis, and six (35.2%) were asymptomatic. Overall, 18 (72%) of the 25 children had liver pathology in the long-term.

CONCLUSION

Although prevalence is rare, patients with liver disorders should be checked for alpha-1 antitrypsin levels. Moreover, long-term follow-up is essential because most patients have a liver pathology.

Alpha-1 antitrypsin inhibits formaldehyde-induced apoptosis of human peritoneal mesothelial cells

BACKGROUND

The alpha-1 antitrypsin (AAT) protein has an important role in the anti-inflammatory and apoptotic response. AAT inhibits not only serine proteases but also cysteine and aspartic proteases. Apoptosis results from the sequential activation of cysteine proteases of the caspase family. This study aimed to evaluate the effect of AAT on formaldehyde-induced apoptosis of human peritoneal mesothelial cells (HPMCs).

METHODS

HPMCs were cultured and treated with formaldehyde (250 µM) to induce apoptosis. In the AAT group, the cultured HPMCs were pretreated with AAT (2 mg/mL) for 1 h before formaldehyde treatment. We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays to determine cell viability, and flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays to detect apoptosis. The MTT assays were used to find optimal concentrations of formaldehyde and AAT. We measured caspase-3 activity and used Western blotting to estimate Bcl-2 and Bad expression.

RESULTS

Flow cytometry and TUNEL assays revealed that formaldehyde exposure significantly increased apoptosis compared with the control treatment, but pretreatment with AAT significantly inhibited this effect. Compared with the control, caspase-3 activity was significantly increased and the ratio of Bcl-2 to Bad expression significantly decreased following treatment with formaldehyde. However, caspase-3 activity was significantly lower and the Bcl-2 to Bad expression ratio higher in the AAT group than in the formaldehyde-only group.

CONCLUSION

AAT inhibits formaldehyde-induced apoptosis of HPMCs via a caspase-mediated pathway. These data support a potential use for AAT as a therapeutic agent for the inhibition of peritoneal cell apoptosis during peritoneal dialysis.

Comparative evaluation of serum alpha-1antitrypsin levels in patients with oral squamous cell carcinoma and in subjects with tobacco habit without carcinoma

Aim/Objectives:

To evaluate serum levels of Alpha-1 antitrypsin in patients with oral squamous cell carcinoma and compare them with that of healthy subjects with and without tobacco habits.

Materials and Method:

The sample of 83 subjects was divided into three groups: 30 subjects with oral squamous cell carcinoma formed Group A. The age, sex, habit matched 23 healthy subjects with tobacco habit formed Group B and 30 healthy without history of consumption of tobacco formed Group C. Analysis of the samples was done using Alpha 1 antitrypsin kit and spectrophotometer.

Results:

There was a 2.33-fold rise in serum levels of Alpha 1 antitrypsin in Group A compared to Group B, 3.71-fold rise in Group A compared to Group C and 1.59-fold rise in Group B compared to Group C (P < 0.001). A definite rise in serum Alpha 1 antitrypsin levels in patients with oral squamous cell carcinoma as compared with healthy subjects with and without tobacco habits was observed.

Conclusion:

Alpha1-antitrypsin can be used as an adjunct to various diagnostic procedures implied for the evaluation of oral squamous cell carcinoma.

Gene Expression in Intracranial Aneurysms-Comparison Analysis of Aneurysmal Walls and Extracranial Arteries with Real-Time Polymerase Chain Reaction and Immunohistochemistry

BACKGROUND

This study was aimed at evaluating the gene expression levels of 4 genes in the intracranial aneurysm wall and comparing them with extracranial arteries. The analysis was done using real-time polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). Also, a correlation of the differential genetic expression was done with various patient clinical and radiologic factors.

METHODS

The quantitative assessment of ribonucleic acid levels was done with RT-PCR and was validated with IHC. The genes studied were collagen 1A2 (COL1A2), tissue inhibitor of metalloproteinase 4 (TIMP4), cathepsin B (CTSB), and alpha-1 antitrypsin (α-1 AT). The analysis was done on 24 aneurysm sacs and superficial temporal/occipital artery samples from patients undergoing surgical clipping.

RESULTS

The mean fold change of COL1A2 in the aneurysm sample was 8.89, that of TIMP4 was 10.16, that of CTSB was 1.02, and that of α-1 AT was 1.46 when compared with normal control vessel on PCR. On semiquantitative IHC, COL1A2 was 94.44%, α-1 AT was 77.8% overexpressed, CTSB was positive in 50%, and the expression of TIMP4 was 94.4% underexpressed in aneurysmal walls. There was no statistically significant correlation between patient profile and gene expression.

CONCLUSIONS

On RT-PCR and IHC analysis, COL1A2 and α-1 AT were overexpressed, CTSB was marginally overexpressed, and TIMP4 had equivocal expression in the aneurysmal sac when compared with the normal extracranial vessel. This is the first study of its kind in the Indian population with the largest sample size on live human patients.

Clathrin-mediated Endocytosis of Alpha-1 Antitrypsin is Essential for its Protective Function in Islet Cell Survival

Cytokine-induced pancreatic β cell death plays a pivotal role in both type 1 and type 2 diabetes. Our previous study showed that alpha-1 antitrypsin (AAT) inhibits β cell death through the suppression of cytokine-induced c-Jun N-terminal kinase (JNK) activation in an islet transplantation model. The aim of this study was to further understand how AAT impacts β cells by studying AAT endocytosis in human islets and a βTC3 murine insulinoma cell line.

Methods: In vitro, human islets and βTC3 cells were stimulated with cytokines in the presence or absence of chlorpromazine (CPZ), a drug that disrupts clathrin-mediated endocytosis. Western blot, real-time PCR and cell death ELISA were performed to investigate β cell death. The oxygen consumption rate (OCR) was measured on human islets. In vivo, islets were harvested from C57BL/6 donor mice treated with saline or human AAT and transplanted into the livers of syngeneic mice that had been rendered diabetic by streptozotocin (STZ). Islet graft survival and function were analyzed.

Results: AAT was internalized by β cells in a time- and dose-dependent manner. AAT internalization was mediated by clathrin as treatment with CPZ, profoundly decreased AAT internalization, cytokine-induced JNK activation and the downstream upregulation of c-Jun mRNA expression. Similarly, addition of CPZ attenuated cytokine-induced caspase 9 cleavage (c-casp 9) and DNA fragmentation, which was suppressed by AAT. Treatment of donor mice with AAT produced AAT internalization in islets, and resulted in a higher percentage of recipients reaching normoglycemia after syngeneic intraportal islet transplantation.

Conclusion: Our results suggest that AAT is internalized by β cells through clathrin-mediated endocytosis that leads to the suppression of caspase 9 activation. This process is required for the protective function of AAT in islets when challenged with proinflammatory cytokines or after islet transplantation.

Increased proteinase 3 and neutrophil elastase plasma concentrations are associated with non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes

Introduction

Non-alcoholic fatty liver disease (NAFLD) is becoming a major health problem worldwide. Inflammation plays an important role in disease pathogenesis and recent studies have shown a potential role for the neutrophil serine proteases (NSPs) proteinase-3 (PR3) and neutrophil elastase (NE) in NAFLD as well as an imbalance between NSPs and their natural inhibitor alpha-1 antitrypsin (AAT). The aim of this study was to investigate whether PR3 and NE plasma concentrations are associated with NAFLD and/or type 2 diabetes.

Methods

To explore this hypothesis we used several cohorts: a cohort of 271 obese individuals with liver steatosis, a cohort of 41 patients with biopsy-proven NAFLD, a cohort of 401 obese type 2 diabetes patients and a cohort of 205 lean healthy controls; and measured PR3 and NE plasma concentrations. In addition, we measured AAT plasma concentrations in order to investigate if the ratios between NSPs and their natural inhibitor were altered in NAFLD and type 2 diabetes when compared to healthy controls.

Results

Our data shows an increase in PR3 and NE concentrations and a decrease in AAT concentrations in obese patients when compared to controls. Moreover, PR3 plasma concentrations are increased in patients with liver steatosis. Furthermore, PR3 and NE concentrations in the liver are associated with the advanced stages of NAFLD characterized by NASH and/ or liver fibrosis. Additionally, PR3 and NE concentrations were up-regulated in patients with type 2 diabetes when compared to lean and obese controls.

Conclusion

We conclude that circulating levels of NSPs associate with obesity-related metabolic disorders. Further research is needed to clearly establish the role of these proteases and investigate whether they could be used as non-invasive markers for NAFLD and/or type 2 diabetes.

Electronic supplementary material

The online version of this article (10.1186/s10020-019-0084-3) contains supplementary material, which is available to authorized users.

Improving engraftment of hepatocyte transplantation using alpha-1 antitrypsin as an immune modulator

Abstract

For patients with non-cirrhotic liver-based metabolic disorders, hepatocyte transplantation can be an effective treatment. However, long-term function of transplanted hepatocytes following infusion has not been achieved due to insufficient numbers of hepatocytes reaching the liver cell plates caused by activation of the instant blood-mediated inflammatory reaction (IBMIR). Our aim was to determine if the natural immune modulator, alpha-1 antitrypsin (AAT), could improve engraftment of transplanted hepatocytes and investigate its mechanism of action. A tubing loop model was used to analyse activation of the IBMIR when human hepatocytes were in contact with ABO-matched blood and 4 mg/ml AAT. Platelet and white cell counts, complement and cytokine expression were analysed. To determine if AAT could improve short-term engraftment, female rats underwent tail vein injection of AAT (120 mg/kg) or water (control) prior to the intrasplenic transplantation of 2 × 10⁷ male hepatocytes. At 48 h and 1 week, livers were collected for analysis. In our loop model, human hepatocytes elicited a significant drop in platelet count with thrombus formation compared to controls. Loops containing AAT and hepatocytes showed no platelet consumption and no thrombus formation. Further, AAT treatment resulted in reduced IL-1β, IL-6 and IFN-γ and increased IL-1RA compared to untreated loops. In vivo, AAT significantly improved engraftment of rat hepatocytes compared to untreated at 48 h. AAT infusion may inhibit the IBMIR, thus improving short-term engraftment of donor hepatocytes and potentially improve the outcomes for patients with liver-based metabolic disease.

Key messages

• Alpha-1 antitrypsin (AAT) acts as an immune modulator to improve the efficacy of hepatocyte transplantation.

• Treatment with AAT decreased thrombus formation and pro-inflammatory cytokine expression in a tubing loop model.

• AAT significantly improved engraftment of donor hepatocytes within the first 48 h post transplantation.

Electronic supplementary material

The online version of this article (10.1007/s00109-019-01747-3) contains supplementary material, which is available to authorized users.

SERPINA1 methylation and lung function in tobacco-smoke exposed European children and adults: a meta-analysis of ALEC population-based cohorts

BACKGROUND

The pathophysiological role of SERPINA1 in respiratory health may be more strongly determined by the regulation of its expression than by common genetic variants. A family based study of predominantly smoking adults found methylation at two Cytosine-phosphate-Guanine sites (CpGs) in SERPINA1 gene to be associated with chronic obstructive pulmonary disease risk. The objective of this study was to confirm the association of lung function with SERPINA1 methylation in general population samples by testing a comprehensive set of CpGs in the SERPINA gene cluster. We considered lung function level and decline in adult smokers from three European population-based cohorts and lung function level and growth in tobacco-smoke exposed children from a birth cohort.

METHODS

DNA methylation using Illumina Infinium Human Methylation 450 k and EPIC beadchips and lung function were measured at two time points in 1076 SAPALDIA, ECRHS and NFBC adult cohort participants and 259 ALSPAC children. Associations of methylation at 119 CpG sites in the SERPINA gene cluster (PP4R4-SERPINA13P) with lung functions and circulating alpha-1-antitripsin (AAT) were assessed using multivariable cross-sectional and longitudinal regression models.

RESULTS

Methylation at cg08257009 in the SERPINA gene cluster, located 32 kb downstream of SERPINA1, not annotated to a gene, was associated with FEV1/FVC at the Bonferroni corrected level in adults, but not in children. None of the methylation signals in the SERPINA1 gene showed associations with lung function after correcting for multiple testing.

CONCLUSIONS

The results do not support a role of SERPINA1 gene methylation as determinant of lung function across the life course in the tobacco smoke exposed general population exposed.

Alpha-1 antitrypsin deficiency: outstanding questions and future directions

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.