The Fas/Fas-ligand pathway does not mediate the apoptosis in elastase-induced emphysema in mice.

Porcine pancreatic elastase (PPE), which induces emphysema via apoptosis, was administered to wild-type and Fas-deficient (lpr) mice. On days 3 and 28 after administration, the mean linear intercepts within lung tissues were significantly higher in PPE-treated wild-type and lpr mice than in control mice, though there were no significant differences between the PPE-treated groups. Likewise, the numbers of TUNEL-positive cells were increased in the lungs of PPE-treated wild-type and lpr mice, and again the effect was similar in the two PPE-treated groups. These findings suggest that apoptosis associated with PPE-induced emphysema is not mediated via the Fas/Fas-ligand pathway.