Differential detection of PAS-positive inclusions formed by the Z, Siiyama, and Mmalton variants of α1-antitrypsin

Janciauskiene, Sabina; Eriksson, Sten; Callea, Francesco; Mallya, Meera; Zhou, Aiwu; Seyama, Kuniaki; Hata, Satoru; Lomas, David A.

doi:10.1002/hep.20451

Cited by 54 publications

(50 citation statements)

References 36 publications

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“…The reaction was allowed to occur at room temperature, and measurements of fluorescence were performed every 5 to 10 minutes for up to 2 to 3 hours. Conformers of A1AT were generated following established methods 22 and tested for loss of activity against elastase before caspase-3 inhibitory assays. The conformers' concentrations are given as native A1AT that was input into their generation.…”

Section: Cell-free Experimentsmentioning

confidence: 99%

“…The conformers' concentrations are given as native A1AT that was input into their generation. The proteinases used to generate cleaved conformers 22 were not removed from the modified A1AT solution, but the mixture was allowed to incubate for Ͼ3 hours, which we predict might have led to the inactivation of any remaining active proteinase. The remaining proteinase did not have any significant influence on the results, because the negative control used identically treated mixtures (minus the A1AT) as part of the caspase-3 activity assays.…”

Section: Cell-free Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

α-1 Antitrypsin Inhibits Caspase-3 Activity, Preventing Lung Endothelial Cell Apoptosis

Petrache

Fijałkowska

Medler

et al. 2006

The American Journal of Pathology

272

230

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␣-1 Antitrypsin (A1AT) is an abundant circulating serpin with a postulated function in the lung of potently inhibiting neutrophil-derived proteases. Emphysema attributable to A1AT deficiency led to the concept that a protease/anti-protease imbalance mediates cigarette smoke-induced emphysema. We hypothesized that A1AT has other pathobiological relevant functions in addition to elastase inhibition. We demonstrate a direct prosurvival effect of A1AT through inhibition of lung alveolar endothelial cell apoptosis. Primary pulmonary endothelial cells internalized human A1AT, which co-localized with and inhibited staurosporineinduced caspase-3 activation. In cell-free studies, native A1AT, but not conformers lacking an intact reactive center loop, inhibited the interaction of recombinant active caspase-3 with its specific substrate. Furthermore, overexpression of human A1AT via replication-deficient adeno-associated virus markedly attenuated alveolar wall destruction and oxidative stress caused by caspase-3 instillation in a mouse model of apoptosis-dependent emphysema. Our findings suggest that direct inhibition of active caspase-3 by A1AT may represent a novel anti-apoptotic mechanism relevant to disease processes characterized by excessive structural cell apoptosis, oxidative stress, and inflammation, such as pulmonary emphysema.

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Section: Cell-free Experimentsmentioning

confidence: 99%

Section: Cell-free Experimentsmentioning

confidence: 99%

α-1 Antitrypsin Inhibits Caspase-3 Activity, Preventing Lung Endothelial Cell Apoptosis

Petrache

Fijałkowska

Medler

et al. 2006

The American Journal of Pathology

272

230

View full text Add to dashboard Cite

show abstract

“…In the most common and severe Z α 1 AT variant, the replacement of glutamic acid 342 with a lysine residue causes the mutant protein to undergo an aberrant conformational transition, which favours the formation of polymers that tangle within the endoplasmic reticulum (ER) as periodic acid-Shiff-positive, diastase-resistant inclusions (Lomas, et al, 1992). The retention of Z α 1 AT within the hepatocytes results in a lack of circulating plasma α 1 AT and a gradual intracellular protein accumulation, which gives rise to progressive liver damage, with possible evolution to cirrhosis and hepatocellular carcinoma (Janciauskiene, et al, 2004). The significance of this pathological α 1 AT polymerization was underscored by the finding of two other deficiency variants, S iiyama (Ser52Phe) and M malton (Phe52del) which, similarly to Z, form polymers in vivo and are associated with hepatic inclusions and severe plasma deficiency (Lomas, et al, 1993;Lomas, et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization of the new defective P_bresciaalpha1-antitrypsin allele

et al. 2009

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Alpha1-antitrypsin (α 1 AT) deficiency is a hereditary disorder associated with reduced α 1 AT serum level, predisposing adults to pulmonary emphysema. Among the known mutations of the α 1 AT gene (SERPINA1) causing α 1 AT deficiency, a few alleles, particularly the Z allele, may also predispose adults to liver disease. We have characterized a new defective α 1 AT allele (c.745G>C) coding for a mutant α 1 AT (Gly225Arg), named P brescia . The P brescia α 1 AT allele was first identified in combination with the rare defective M würzburg allele in an 11-year-old boy showing significantly reduced serum α 1 AT level. Subsequently, the P brescia allele was found in the heterozygous state with the normal M or the defective Z allele in nine and three adults respectively. In cellular models of the disease, we show that the P brescia mutant is retained in the endoplasmic reticulum as ordered polymers and is secreted more slowly than the normal M α 1 AT. This behaviour recapitulates the abnormal cellular handling and fate of the Z α 1 AT and suggests that the mutation present in the P brescia α 1 AT causes a conformational change of the protein which, by favouring polymer formation, is etiologic to both severe α 1 AT deficiency in the plasma and toxic protein-overload in the liver.

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“…M-AT has not been found to polymerize in vivo (Mahadeva et al, 2005). Polymerization can occur in other variants of AT, such as Siiyama, Mmalton, I, and S Janciauskiene et al, 2004;Elliott et al, 199b). I 1 -antitrypsin and S-AT polymerize slower than Z-AT but faster than M-AT, and hence are associated with less severe plasma deficiency .…”

Section: Polymerized Formmentioning

confidence: 99%

The Role of Alpha-1 Antitrypsin in Emphysema

Alam¹,

Mahadeva²

2012

Emphysema

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Differential detection of PAS-positive inclusions formed by the Z, Siiyama, and Mmalton variants of α1-antitrypsin

Cited by 54 publications

References 36 publications

α-1 Antitrypsin Inhibits Caspase-3 Activity, Preventing Lung Endothelial Cell Apoptosis

α-1 Antitrypsin Inhibits Caspase-3 Activity, Preventing Lung Endothelial Cell Apoptosis

Molecular characterization of the new defective P_bresciaalpha1-antitrypsin allele

The Role of Alpha-1 Antitrypsin in Emphysema

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Differential detection of PAS-positive inclusions formed by the Z, Siiyama, and Mmalton variants of α1-antitrypsin

Cited by 54 publications

References 36 publications

α-1 Antitrypsin Inhibits Caspase-3 Activity, Preventing Lung Endothelial Cell Apoptosis

α-1 Antitrypsin Inhibits Caspase-3 Activity, Preventing Lung Endothelial Cell Apoptosis

Molecular characterization of the new defective Pbresciaalpha1-antitrypsin allele

The Role of Alpha-1 Antitrypsin in Emphysema

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Product

Resources

About

Molecular characterization of the new defective P_bresciaalpha1-antitrypsin allele