RT Journal Article
SR Electronic
T1 LSC - 2020 - Investigating the effect of Z alpha-1 antitrypsin expression on mitochondrial injury
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 3704
DO 10.1183/13993003.congress-2020.3704
VO 56
IS suppl 64
YR 2020
UL http://erj.ersjournals.com/content/56/suppl_64/3704.abstract
AB Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder caused by mutations in the SERPINA1 gene coding for alpha-1 antitrypsin (AAT), a key serine antiprotease. The most frequent disease-associated mutation, the Z allele, leads to an accumulation of misfolded ZAAT protein, which polymerises in the endoplasmic reticulum (ER) of the cell, triggering ER stress. Whilst the liver is the main site of AAT synthesis, AAT is also produced by epithelial cells in the lung. Emerging evidence suggests that mitochondrial injury is a feature of AATD, however detailed studies on this are lacking. Damaged or dysfunctional mitochondria release a variety of pro-inflammatory signals known as mitochondrial danger-associated molecular patterns (mtDAMPs). We hypothesise that ZAAT expression in type II alveolar epithelial cells induces mitochondrial injury and subsequent release of mtDAMPs, thereby triggering pro-inflammatory signalling pathways. In this work, we transfected A549 cells with empty plasmid, or plasmid expressing wild-type (MAAT) or mutant AAT (ZAAT). Induction of AAT expression was confirmed by qPCR. The mitochondrial gene nicotinamide adenine dinucleotide dehydrogenase (NADH) was detected at increased levels in cell lysates and supernatants of ZAAT transfected cells relative to MAAT and/or empty plasmid transfected cells by qPCR. Decreased mitochondrial membrane potential in ZAAT transfected cells was observed using a tetramethylrhodamine ethyl ester (TMRE) assay. Ongoing studies using the Seahorse XF Cell Mito Stress Test are testing the effects of ZAAT on cellular respiration. Taken together the data suggest that ZAAT expression may cause mitochondrial injury in alveolar epithelial cells.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 3704.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).