Proteasomal regulation of pulmonary fibrosis.
It is estimated that, combined, 400,000 people are diagnosed with idiopathic pulmonary fibrosis (IPF) or acute lung injury/acute respiratory distress syndrome annually in the United States, and both diseases are associated with an unacceptably high mortality rate. Although these disorders are distinct clinical entities, they share pathogenic mechanisms that may provide overlapping therapeutic targets. One example is fibroblast activation, which occurs concomitant with acute lung injury as well as in the progressive fibrosis of IPF. Both clinical entities are characterized by elevations of the profibrotic cytokine, transforming growth factor (TGF)-beta1. Protein degradation by the ubiquitin-proteasomal system modulates TGF-beta1 expression and signaling. In this review, we highlight the effects of proteasomal inhibition in various animal models of tissue fibrosis and mechanisms by which it may regulate TGF-beta1 expression and signaling. At present, there are no effective therapies for fibroproliferative acute respiratory distress syndrome or IPF, and proteasomal inhibition may provide a novel, attractive target in these devastating diseases.
Division of Pulmonary and Critical Care Medicine, Northwestern University, 240 East Huron St., Chicago, IL 60611, USA.
Curtis H
CH
Weiss
G R Scott
GR
Budinger
Gökhan M
GM
Mutlu
Manu
M
Jain
D000818:Animals; D001897:Boronic Acids / Q000494:pharmacology; D000069286:Bortezomib; D002986:Clinical Trials as Topic; D006801:Humans; D011480:Protease Inhibitors / Q000494:pharmacology*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D061988:Proteasome Inhibitors; D011658:Pulmonary Fibrosis / Q000378:metabolism / Q000473:pathology*; D011719:Pyrazines / Q000494:pharmacology; D015398:Signal Transduction; D051785:Smad Proteins / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism*
D001897:Boronic Acids; D011480:Protease Inhibitors; D061988:Proteasome Inhibitors; D011719:Pyrazines; D051785:Smad Proteins; D053773:Transforming Growth Factor beta1; D025801:Ubiquitin; D000069286:Bortezomib; D046988:Proteasome Endopeptidase Complex