Presence Of Alpha 1-antitrypsin Research Articles

Z-alpha1-antitrypsin polymers and small airways disease: a new paradigm in alfa-1 anti-trypsin deficiency-related COPD development?

The presence of Alpha1-Antitrypsin (AAT) polymers, known to promote a sustained pro-inflammatory activity, has been previously demonstrated in bronchial biopsies of subjects with Z-AAT deficiency (AATD) suggesting a possible role in the development of COPD through a small airway disease impairment. The study aimed to assess the presence of small airways dysfunction and the potential correlation with the presence of Z-AAT polymers obtained by Exhaled Breath Condensate (EBC) collection in PiZZ subjects, as compared with matched healthy PiMM subjects. We enrolled 19 asymptomatic, never smoker subjects: 9 PiZZ and 10 PiMM as controls, without obstructive ventilatory defect (i.e., normal FEV1/VC% ratio). All subjects underwent complete pulmonary function tests (PFT). EBC was collected in all subjects. ELISA test was applied to search for Z-AAT polymers. The PiZZ subjects showed normal lung volumes and DLCO values. However, in comparison with PiMM subjects, the single breath test N2 wash-out revealed significant differences regarding the phase III slope (1.45±0.35 N2/L vs. 0.96±0.40 N2/L) (p<0.02) in the PiZZ subjects, while the closing volume/vital capacity ratio (14.3±4.5 % vs. 11.3±6.3 %) was not significantly increased. The ELISA test detected the presence of Z-AAT polymers in 44% of PiZZ patients. Asymptomatic, never smoker PiZZ subjects with normal spirometry and lung diffusion capacity showed airways impairment when compared to PiMM subjects. Although Z-AAT polymers were found only in 44% of PiZZ subjects, these findings suggest the possibility that chronic bronchiolitis can develop as a result of the long-term pro-inflammatory activity of Z-AAT polymers in subjects with Z-related AATD.

SMALL AIRWAYS DISEASE AND Z-ALPHA1-ANTITRYPSIN POLYMERS: IS THERE A CORRELATION?

SESSION TITLE: Late-breaking Abstract Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: The aim of the study was to assess the presence of small airways dysfunction and the potential correlation with the presence of Z-AAT polymers obtained by Exhaled Breath Condensate (EBC) collection in PiZZ subjects, comparing with matched healthy PiMM subjects. METHODS: We enrolled 17 asymptomatic non-smoker subjects: 9 PiZZ and 8 PiMM as controls, without obstructive ventilatory defect (i.e.: normal FEV1/VC ratio). All subjects underwent complete pulmonary function tests (PFT). EBC was collected in PiZZ patients. ELISA test was applied to search for Z-AAT polymers. RESULTS: The PiZZ subjects showed normal lung volumes and DLCO values. However, In comparison with PiMM subjects, the single breath test N2 wash-out revealed significant differences regarding the phase III slope (1.5±0.4 N2/L vs 1.1±0.3 N2/L) and the closing volume/vital capacity ratio (14.3±4.5 % vs 9.5±5.3 %) (p<0.05) in the PiZZ subjects. The ELISA test detected the presence of Z-AAT polymers in 4 PiZZ patients. No correlations were found between polymers levels and any functional respiratory parameter. CONCLUSIONS: PiZZ subjects showed small airways dysfunction when compared to PiMM subjects. Surprisingly, Z-AAT polymers were found only in 4 PiZZ subjects; this is probably due to the sample methodology. New studies are needed to evaluate the correlation between bronchial Z-AAT polymers and small airway impairment in subjects with Z-AAT deficiency. CLINICAL IMPLICATIONS: The presence of Alpha1-Antitrypsin (AAT) polymers that are pro-inflammatory has been previously demonstrated in bronchial biopsies of subjects with Z-AAT deficiency (Respir Res, 2014 Sep 14;15:112), suggesting a possible role in the development of COPD. DISCLOSURES: No relevant relationships by Marianna Arici, source=Web Response No relevant relationships by Jordan Franz Giordani, source=Web Response No relevant relationships by Guido Levi, source=Web Response No relevant relationships by Laura Pini, source=Web Response No relevant relationships by Chiara Rocchetti, source=Web Response No relevant relationships by Claudio Tantucci, source=Web Response No relevant relationships by Laura Tiberio, source=Web Response

Structural Changes of Alpha 1-Antitrypsin Under Osmotic Pressure and in the Presence of Lipid Membranes

Alpha 1-Antitrypsin (A1AT) is a glycoprotein that has been shown to have protective roles of lung cells against emphysema, a disease characterized by lung tissue destruction [1]. Most known glycoproteins have been shown to play a role in cellular interactions but the exact role of the glycan chains is still under investigation. Previous electrophysiological measurements show that A1AT has a strong affinity to lipid bilayers perturbing the function of ion channels present in the membrane. We have performed contrast-matching small-angle neutron scattering (SANS) experiments to study the conformational changes of the glycosylated form of A1AT for different concentrations of the osmolyte poly(ethelene glycol) (PEG) and in the presence of two different lipid membranes: POPC and POPS. We also monitor the structural changes of the lipid vesicles in the presence of A1AT by SANS. Guinier fits were used as a first approximation to obtain the radius of gyration (Rg) of A1AT. Bragg peaks were used to study structural changes of lipid vesicles. We observed that the Rg of A1AT changes as a function of PEG concentration in solution and when in the presence of lipid vesicles. The deformations monitored through changed in A1AT Rg in the presence of lipid vesicles are compared to the deformations of the glycoprotein observed under osmotic pressure and to the structural changes observed in the lipid vesicles. [1] Petrusca, et al., JBC 2010.

Alpha‐1‐‐antitrypsin in aqueous humour from patients with corneal allograft rejection

To investigate the presence and concentration of alpha1-antitrypsin in aqueous humour at the time of corneal rejection and to compare results obtained from patients with reversible and irreversible rejection. Samples of aqueous humour were obtained from 17 patients with acute corneal endothelial allograft rejection. The presence of alpha1-antitrypsin in aqueous humour was confirmed by immunoblotting and measured employing a sandwich ELISA. Total protein concentrations in aqueous humour were measured using Bradford's method. The outcome of corneal rejection episodes was determined 1 month after diagnosing corneal rejection and described as reversible or irreversible rejection. alpha1-antitrypsin was detected in aqueous humour. Patients with reversible rejection had significantly higher alpha1-antitrypsin concentration than patients with irreversible rejection (p = 0.044). There was no significant difference in total protein concentrations (p = 0.745), and no correlation was found between alpha1-antitrypsin and total protein concentrations (p = 0.368). alpha1-antitrypsin in aqueous humour seems to signal a favourable outcome of corneal rejection. The possible mechanism is discussed.

α1-antitrypsin and its C-terminal fragment attenuate effects of degranulated neutrophil-conditioned medium on lung cancer HCC cells, in vitro

BackgroundTumor microenvironment, which is largely affected by inflammatory cells, is a crucial participant in the neoplastic process through promotion of cell proliferation, survival and migration. We measured the effects of polymorphonuclear neutrophil (PMN) conditioned medium alone, and supplemented with serine proteinase inhibitor α-1 antitrypsin (AAT) or its C-terminal fragment (C-36 peptide), on cultured lung cancer cells.MethodsLung cancer HCC cells were grown in a regular medium or in a PMN-conditioned medium in the presence or absence of AAT (0.5 mg/ml) or its C-36 peptide (0.06 mg/ml) for 24 h. Cell proliferation, invasiveness and release of IL-8 and VEGF were analyzed by [3H]-thymidine incorporation, Matrigel invasion and ELISA methods, respectively.ResultsCells exposed to PMN-conditioned medium show decreased proliferation and IL-8 release by 3.9-fold, p < 0.001 and 1.3-fold, p < 0.05, respectively, and increased invasiveness by 2-fold (p < 0.001) compared to non-treated controls. In the presence of AAT, PMN-conditioned medium loses its effects on cell proliferation, invasiveness and IL-8 release, whereas VEGF is up-regulated by 3.7-fold (p < 0.001) compared to controls. Similarly, C-36 peptide abolishes the effects of PMN-conditioned medium on cell invasiveness, but does not alter its effects on cell proliferation, IL-8 and VEGF release. Direct HCC cell exposure to AAT enhances VEGF, but inhibits IL-8 release by 1.7-fold (p < 0.001) and 1.4-fold (p < 0.01) respectively, and reduces proliferation 2.5-fold (p < 0.01). In contrast, C-36 peptide alone did not affect these parameters, but inhibited cell invasiveness by 51.4% (p < 0.001), when compared with non-treated controls.ConclusionsOur data provide evidence that neutrophil derived factors decrease lung cancer HCC cell proliferation and IL-8 release, but increase cell invasiveness. These effects were found to be modulated by exogenously present serine proteinase inhibitor, AAT, and its C-terminal fragment, which points to a complexity of the relationships between tumor cell biological activities and local microenvironment.

Presence of alpha1-antitrypsin and transferrin in human follicular fluid—correlation with fertilization

We purified two proteins with molecular masses of approximately 50 kDa and 80 kDa with N-terminal sequences similar to those of alpha1-antitrypsin (a1AT) and transferrin indicating that they are identical to or highly homologous to these proteins. Proteins from human follicular fluid were purified after ammonium sulfate fractionation followed by water dialysis and High Performance Liquid Chromatography. The fraction of peak 3 showed a single band on electrophoresis and its N-terminal amino acid sequence was similar to that of human serum transferrin. The fraction of peak 10 proved to be a glycoprotein and its N-terminal amino acid sequence was similar to that of human serum a1AT. There are indications that transferrin may be involved in the fertilization process. Sperm motion was assessed employing computer-assisted semen analysis. The addition of purified protein to prepared sperm samples from normospermic men significantly increases the straight-line velocity (VSL), the amplitude of lateral head displacement (ALH) and the number of progressively motile sperm. a1AT does not seem to have a stimulatory effect on sperm motility.

Partial characterization of a tropoelastin precursor isolated from chick aorta.

Evidence is presented that indicates tropoelastin is derived from a soluble elastin with a molecular weight of 95000. Tropoelastin and its proposed precursor were isolated from the aortas of copper-deficient chicks. Although it is doubtful that the proposed precursor is an initial product of elastin translation, i.e., a proelastin, it is proposed to be at least a truncated form of proelastin that is converted to tropoelastin. The key to its isolation was the presence of alpha 1-antitrypsin at each step in the purification procedure. The first 11 amino acid residues at the NH2 terminal of the proposed tropoelastin precursor (GGVPGVAVPGGV) are the same as those for tropoelastin. Its amino acid composition is similar to that of tropoelastin, except for higher amounts of acidic amino acid residues. Further, the proposed precursor contains a limited number of aldehydic functions, presumably in the form of peptidyl allysine. This was taken as an indication that the proposed precursor serves as a substract for lysyl oxidase. Under the conditions used for the isolation, the precursor appeared to be in higher concentrations than tropoelastin in aorta extracts from copper-deficient chicks.