RT Journal Article SR Electronic T1 Metalloproteases gene expression and remodeling of lung parenchyma fibers during the progression of elastase induced emphysema JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P3944 VO 44 IS Suppl 58 A1 Fabiola Santos Zambon Robertoni A1 Clarice Rosa Olivo A1 Juliana Dias Lourenço A1 Natalia Gomes Gonçalves A1 Ana Paula Pereira Velosa A1 Walcy Rosolia Teodoro A1 Chin Jia Lin A1 Milton De Arruda Martins A1 Fernanda DTQ dos Santos Lopes YR 2014 UL http://erj.ersjournals.com/content/44/Suppl_58/P3944.abstract AB We previously demonstrated an increase in gene expression of MMP-8 and MMP-13 since the first hours of the induction of emphysema in mice by porcine pancreatic elastase (PPE) and a posterior reduction in the volume ratio of collagen type I (3 days) that returned to similar values of control groups at the 21th day of the protocol. Such results suggested the importance of collagenases in emphysema progression. Objectives: To describe the importance of MMP-12, as well as the repair process of elastin and fibrillin at the beginning of the emphysema development and correlated it with previous findings. Methods: C57BL/6 mice were submitted to intranasal instillation of PPE (0,667 IU) and were euthanized at different times after that: 1 hour, 3 hours, 6 hours, 3 days and 21 days. Control groups (S) received the same treatment with saline (NaCl 0.9%). We used the Real-time RT-PCR to assess the gene expression of MMP-12 and immunohistochemistry to quantify the volume ratio of elastin and fibrillin in lungs. Results: The MMP-12 gene expression was increased since 3 hs of emphysema induction until 6 hs. Fibrillin analyses showed no difference in its parenchyma percentage at any of the PPE groups comparing to S groups. Elastin instead, presented a decrease at 3rd day after PPE instillation and a increase at 21st day compared to respective S groups. Conclusions: We attested the importance of the MMP-12 together with MMP-8 and MMP-13 activity since the first hours after the emphysema induction. Also we verified a repair process characterized by a prior reduction in quantified parenchymal fibers followed by an increase at 21th day.