Sami, Takieddine

OBJECTIVE A bileaflet aortic valve (BAV) occurs in 1–2% of the population, making it the most common cardiovascular malformation. Patients with BAV have increased risk of thoracic ascending aortic aneurysm (TAA) and dissection compared to those with trileaflet aortic valves (TAV). We have evaluated the gene expression profile of the aorta of patients with BAV and TAV with TAA. METHODS Segment of aneurysmal tissue was collected from 12 patients with BAV (age 43–68) and 19 patients with TAV (age 37–79). RNA was extracted using the Invitrogen RNA extraction Kit. RNA that was of adequate quality by the Agilent Bioanalyzer was used in the Affymetrix protocol for the U133A gene chips probing for over 16,000 genes on each chip. Real‐time RT‐PCR was used to confirm the microarray results for a subset of genes. RESULTS Data filtering (using two different statistical methods) identified significant differences in gene expression between the BAV and TAV groups. The real time RT‐PCR independently confirmed that the expression levels of osteopontin and tenascin were consistently increased in TAA with TAV. CONCLUSIONS The results indicate that many genes are involved in a complicated manner in the pathogenesis of TAA. This study also demonstrates two basic gene expression profiles in the TAA, one characteristic of patients with BAV and the other of those with TAV. Variations in the molecular mechanisms underlying different types of TAA warrant further investigation. (This work was supported by an SS‐50 award to Dr. Thoralf Sundt from the Department of Surgery, Mayo Clinic)