Transcriptional analysis of injured airway epithelial cells in Mmp7-null and wildtype mice. Mus musculus

Matrix metalloproteinase 7 (MMP7) is expressed at low levels in intact, normal airways by non-mucous-producing cells, including ciliated cells. In response to injury and infection, MMP7 expression is quickly and markedly upregulated and functions to regulate wound repair and various mucosal immune processes. We evaluated the global transcriptional response of airway epithelial cells from wild type and Mmp7-null mice cultured at an air-liquid interface. A common injury response was seen in both genotypes with up-regulation of genes associated with proliferation and migration. Analysis of differentially expressed genes between genotypes after injury revealed enrichment of functional categories associated with inflammation, cilia and differentiation. Because these analyses suggested MMP7 regulated ciliogenesis, we evaluated the recovery of the airway epithelium in wild type and Mmp7-null mice in vivo after naphthalene injury. These studies identified a new role for MMP7 in attenuating ciliogenesis during wound repair. Overall design: A total of 16 air-liquid interface cultures of mouse airway epithelial cells were studied under four conditions: 1. Mmp7-null, no injury (n = 4); 2. Mmp7-null, scratch injury (n = 4); 3. Wildtype, no injury (n =4); 4. Wiltype, scratch injury (n = 4).