Immunohistochemical analysis of angiotensin converting enzyme in sardinian pterygium
Paolo Demurtas1, Nick Di Girolamo2, Michela Corrias1, Ignazio Zucca3, Cristina Maxia1, Andrea Diana1, Franca Piras1, Simone Lai1, Paola Sirigu1 and Maria Teresa Perra1
1Department of Cytomorphology, University of Cagliari Medical School, Cagliari, Italy, 2School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia and 3Department of Surgical Science, Eye Clinic, University of Cagliari, Italy.
Offprint requests to: Paolo Demurtas, Ph.D., Research Fellow R.A.S., Cytomorphology Department, University of Cagliari, Cittadella Universitaria, 09042 Monserrato (CA), Italy. e-mail: pdemurtas@unica.it
Summary. Pterygium is a common ocular surface disorder characterized by excessive cell proliferation, inflammation, fibrosis, angiogenesis and extracellular matrix remodeling. The Angiotensin converting enzyme (ACE or ACE I) is the major component of the Renin-angiotensin system (RAS) converting the inactive decapeptide Angiotensin I (Ang I) to the active octapeptide Angiotensin II (Ang II). Besides this ‘classical role’, it can act as transcriptional regulator in response to external stimuli that may lead to cell damage and tissue remodeling. Due to this role, it can be internalized into the nuclear compartment to act as transcriptional factor for proteins involved in the inflammatory response. The aim of the present study was to determine ACE expression and localization in pterygium and culture pterygium cells by immunohisto-chemistry. Our results are the first to demonstrate nuclear immunolocalization of ACE, more so in pterygium compared to conjunctiva epithelial cells in histological sections. ACE was not detected in the nuclei of subcultivated pterygium epithelial cells. The nuclear localization of ACE may be correlated with an anti-inflammatory path mediated by activation of its transcriptional role. Histol Histopathol 28, 759-766 (2013)
Key words: Pterygium, Renin-angiotensin system (RAS), Angiotensin converting enzyme (ACE), Tissue culture model, Immunohistochemistry
DOI: 10.14670/HH-28.759