Secretion of alpha 1-antitrypsin by alveolar epithelial cells.
We have investigated the ability of alveolar epithelial cells (human A549 cell line and rat type-II pneumocytes) to produce alpha 1-antitrypsin (AAT). Northern blot analysis demonstrated the presence of an AAT-specific mRNA transcript in A549 cells. Unstimulated A549 cells secreted immunoreactive AAT at a rate of 0.51 +/- 0.04 ng/10(6) cells/h, with a modified glycosylation compared to serum AAT. AAT formed a complex with neutrophil elastase. Rat type-II pneumocytes secreted immunoreactive AAT. Our results suggest that alveolar epithelial cells could participate in antiprotease defense within the lung through local AAT production.
Service de Biochimie A, Hôpital Bichat, Paris, France.
P
P
Venembre
A
A
Boutten
N
N
Seta
M S
MS
Dehoux
B
B
Crestani
M
M
Aubier
G
G
Durand
D000581:Amidohydrolases / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D004848:Epithelium / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D019272:Leukocyte Elastase; D008297:Male; D008970:Molecular Weight; D010196:Pancreatic Elastase / Q000378:metabolism; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; D011650:Pulmonary Alveoli / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D000515:alpha 1-Antitrypsin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D000515:alpha 1-Antitrypsin; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D000581:Amidohydrolases; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase