PEPTIDE INHIBITION OF LUNG EPITHELIAL APOPTOSIS AND PULMONARY FIBROSIS

摘要

During lung injury, p53 expression increases, inducing plasminogen activator inhibitor-1 (PAI-1) while inhibiting expression of urokinase-type plasminogen activator (uPA) and its receptor (uPAR), resulting in apoptosis of lung epithelial cells (LECs). In the bleomycin lung injury model, p53 and PAI-1 are induced while uPA and uPAR are inhibited. A 20 residue peptide DGIWKASFTTFTVTKYWFYR termed PP-1 (the Cav-1 scaffolding domain) or peptide NYHYLESSMTALYTLGH, termed PP 2, protected LECs from bleomycin-induced apoptosis in vitro and in vivo and prevented subsequent pulmonary fibrosis by attenuating lung epitheilial damage. Pharmaceutical compositions, peptide multimers and deliverable polypeptides comprising the above peptides are dislcosed. The peptides and functional variants, peptide multimers, cell-targeted polyepeptides and pharmaceutical compositions are used in methods for inhibiting apoptosis of injured or damaged lung epithelial cells and for treating acute lung injury and consequent pulmonary fibrosis.