MICROARRAY BASED IDENTIFICATION REVEALS ARTERIAL ANGIOTENSIN SYSTEM EXPRESSION IN HUMANAbstract
Purpose: We studied by microarray analysis the tissue angiotensin system organization. We elucidated the expression of chymase, cathepsins D, G and angiotensin-converting enzyme (ACE), potentially involved in intraparietal angiotensin II formation and atheroma. Methods: mRNA gene expression was measured by an Affymetrix Gene Chip Human Gene 1.0 ST arrays (Affymetrix, Santa Clara, CA, USA) using RNA prepared from 68 specimens of endarteriectomy from 34 patients. Results: The studied mRNAs could be measured in all patients. ACE mRNA was increased 1.2 fold (p=1.21E-07) in atheroma. A 1.4 fold increase in cathepsin D mRNA (p=2.53E-07) was observed in atheroma plaque. Concerning chymase and cathepsin G, 1.22 and 1.24 fold change (p=0.001) were observed respectively. Angiotensin type 1 receptor (AT1R) mRNA was decreased 0.7 fold (p=2.74E-06) in atheroma compared to intact tissue. Conclusion: All components required for angiotensin II formation are expressed locally in the arterial wall. The genes expression showed clear changes in ATH compared to MIT by enhancing the involvement of genes associated with Ang II production. Over expression of ACE and cathepsin D may lead to angiotensin II overproduction and contribute, to the lower amount of AT1R in atheroma. Although further evidence is needed, our results support previous data.