Decreased ADAM9 expression in patients with pulmonary sarcoidosis

The pathogenesis of sarcoidosis is still poorly understood. Genome-wide gene expression profiling can provide novel genetic data involved in the pathogenesis of disease. In this study, using normal bronchoalveolar lavage (BAL) and sarcoidosis BAL as models for cDNA microarray analysis, we detected an elevation of ADAM9 (a disintegrin and metalloprotease) expression on pulmonary sarcoidosis progression. This result was further confirmed by real-time quantitative RT-PCR and immunohistochemistry. It was found that ADAM9 was significantly down-regulated in pulmonary sarcoidosis in comparison to the normal tissue on mRNA level. On protein level, ADAM9 was also highly decreased in pulmonary sarcoidosis patients. The present study provides novel candidate molecules and suggests a potential local role for ADAM9 as mediators of lung damage or remodeling and as markers of disease activity.Key words: Pulmonary sarcoidosis, ADAM9, cDNA microarray, quantitative RT-PCR, immunohistochemistry