Abbreviations: dpc = days postcoitum;
MMP = matrix metalloproteinase; RT-PCR = reverse
transcriptase-polymerase chain reaction
mice were generated that expressed collagenase matrix metalloproteinase [MMP]-1 in
the lung, and these animals developed pulmonary emphysema. These
studies not only developed an animal model of emphysema, but directly
implicated collagenase (MMP-1) in the disease process. We undertook
extensive morphometric analysis on three of the transgenic lines with
variable levels of transgene expression (Col 34, Col 50, and Col 64).
Temporal expression of the transgene demonstrated earliest
expression of the transgene in line 50 at 12 days postcoitum.
Morphometric analysis demonstrated that the lungs in all of the animals
were normal at birth, and only line 50 exhibited morphometric changes
at 5 days of age. The mice from lines 34 and 64 were normal up until 4
weeks of age, when they began to develop changes in their mean linear
intercept, which progressed over time. These animals are an ideal model
in which to study the human disease.