Identification of a lipocalin in mucosal glands of the human tracheobronchial tree and its enhanced secretion in cystic fibrosis.

摘要: Members of the lipocalin protein family are characterized by their ability to bind small hydrophobic molecules. Some them known be produced various glands and secretory cells. Under certain conditions, these proteins would ideally suited for clearance lipophilic, potentially harmful substances might also act as protection factors in airway secretions. We therefore used RT-PCR analysis with a set oligonucleotide primers deduced from conserved regions members identify specific RNA isolated human trachea. With two primers, positive result was obtained. Sequencing products revealed that DNA fragments were identical 1 (LCN1) encoding cDNA. LCN1 is an unusual member binds variety lipophilic compounds exhibits cysteine proteinase inhibitor antimicrobial activities. The local production topographic distribution tracheobronchial tree then investigated immunoperoxidase staining on thin-layer sections using antiserum. detectable acini serous mucosal sometimes within glandular lumen, suggesting excretion protein. latter finding tested verified Western blot bronchial secretions healthy individuals. Furthermore, results SDS-PAGE patients cystic fibrosis (CF), which usually increase lipids, suggested secretion enhanced. Northern normal trachea tracheal biopsies CF indicated induced due up-regulated expression gene. Thus, our investigations present first clear evidence infection or inflammation support idea this functions physiologic factor epithelia vivo.