Angiogenesis of buffalo choroid plexuses: Structural and immunocytochemical study

Abstract

Mammalian choroid plexuses (CPs) are vascularized structures involved in numerous exchange processes that supply nutrients and hormones to the brain, and that remove deleterious compounds and metabolites from the brain. Studies in the adult Mediterranean buffalo have investigated the morphology of CPs using histochemical and immunohistochemical techniques. To date, however, there have been no studies conducted on ruminants regarding this removal process which serves to repair functional vascular damage in the CPs. Each of these vascular repair processes is a very complex and none of these has not yet been completely understood. Then, the aim of the present study is to investigate the morphological processes during angiogenesis in the CPs of healthy adult buffaloes, utilizing transmission electron microscopy (TEM), scanning electron microscopy (SEM), and immunogold-labeling SEM analysis (biomarkers: angiopoietin-2 [Ang-2], vascular endothelial growth factor receptor-3 [VEGFR-3], and CD133). At TEM, the inner surface of the blood capillaries sometimes showed pillar-like cells, which in contact with endothelial cells formed prominences, which in turn formed neo-blood capillaries. With immunogold-labeling SEM analysis, the CP blood capillaries showed Ang-2 and VEGF-3, respectively, in positive particles and spheroid formations. In addition, the external surface of the blood capillaries showed spheroid formations that originated from the neo-vascular capillaries whose terminals formed a capillary network, positive to CD133. On the basis of these results, the following hypothesis can be made, namely, that these CPs are vascular structures which play a fundamental role in maintaining brain homeostasis and self-repairing of functional vascular damage, independently of the presence of rete mirabile in this species.