CCM2 and CCM3 proteins contribute to vasculogenesis and angiogenesis in human placenta
Gamze Tanriover1, Yasemin Seval1, Leyla Sati1, Murat Gunel2 and Necdet Demir1
1Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey and2 Department of Neurosurgery, Yale University, School of Medicine, New Haven, CT, USA.
Offprint requests to: Necdet DEMIR, Assoc. Prof., Department of Histology and Embryology, Faculty of Medicine, Akdeniz University, 07070 Antalya, Turkey. e-mail: ndemir@akdeniz.edu.tr
Summary. Placenta as an ideal model to study angiogenic mechanisms have been established in previous studies. There are two processes, vasculogenesis and angiogenesis, involved in blood vessel formation during placental development. Therefore, blood vessel formation is a crucial issue that might cause vascular malformations. One of the vascular malformations is cerebral cavernous malformation (CCM) in the central nervous system, consisting of endothelium-lined vascular channels without intervening normal brain parenchyma. Three CCM loci have been mapped as Ccm1, Ccm2, Ccm3 genes in CCM. In order to investigate whether CCM proteins participate in blood vessel formation, we report here the expression patterns of CCM2 and CCM3 in developing and term human placenta by means of immunohistochemistry and Western blot analysis. CCM2 and CCM3 were obviously detected in the vascular endothelium during early pregnancy. Moreover, vascular endothelium of stem villi revealed a moderate immunostaining for CCM2 and, to a lesser extent, in the endothelium of mature intermediate villi in term placenta. Interestingly, CCM3 immuno-staining was weakly localized in the endothelium of mature intermediate villi and showed lesser expression going toward stem villi in term placenta. The expression patterns of the proteins were clearly identified in the vascular endothelium of human placenta, suggesting that they might play roles during angiogenesis and vasculogenesis. Furthermore, with this study, CCM2 and CCM3 have been described for the first time in the human placenta. Histol Histopathol 24, 1287-1294 (2009)
Key words: CCM2, CCM3, Placenta, Angiogenesis, Vasculogenesis
DOI: 10.14670/HH-24.1287