Ultrastructure of lung elastin and collagen in mouse models of spontaneousemphysema

The tight-skin (Tsk) and beige (bg) mutants of the C57Bl/6J strain of mouse spontaneously develop air-space enlargement reminiscent of human emphysema . To determine if this enlargement is accompanied by matrix destruction, as in the human disease, we examined the elastin and collagen matrices of the lungs of both mutants. The ultrastructure of these matrix components was s eparately visualized by scanning electron microscopy following controlled a lkali digestion, which preserves collagen, and formic acid digestion, which enables visualization of elastin. Significant elastin destruction suggesti ve of an elastolytic process was observed in the lungs of Tsk mice. Thicken ing of elastin lamellae was observed in the lungs of bg mice, suggesting th at congenital matrix remodeling may underlie air-space enlargement in this strain. (C) 1999 Elsevier Science B.V./International Society of Matrix Biol ogy. All rights reserved.