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.
Venembre
P
P
Service de Biochimie A, Hôpital Bichat, Paris, France.
Boutten
A
A
Seta
N
N
Dehoux
M S
MS
Crestani
B
B
Aubier
M
M
Durand
G
G
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