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VEGF ‐dependent continuous angiogenesis in the median eminence of adult mice
Author(s) -
Morita S.,
Ukai S.,
Miyata S.
Publication year - 2013
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.12047
Subject(s) - angiogenesis , median eminence , biology , vascular endothelial growth factor , ganglionic eminence , endocrinology , parenchyma , medicine , receptor tyrosine kinase , microbiology and biotechnology , central nervous system , cancer research , signal transduction , vegf receptors , cerebrum , botany
Brain vasculature forms the blood–brain barrier ( BBB ) that restricts the movement of molecules between the brain and blood, but the capillary of the median eminence ( ME ) lacks the BBB for secretion of adenohypophysial hormone‐releasing peptides. In the present study, we aimed to elucidate whether continuous angiogenesis occurs in the ME of adult mice. By using a mitotic marker, bromodeoxyuridine ( B r dU ), we demonstrated that new endothelial cells were born continuously in the ME of adults. Prominent expression of NG 2, platelet‐derived growth factor receptor B ( PDGFRB ), and delta‐like ligand 4 was observed at pericytes of adults, although the expression of these angiogenesis‐associated proteins has been shown to be at low or trace levels in adult mature capillary. In addition, vascular endothelial growth factor ( VEGF ), a key regulator of angiogenesis, was expressed highly in the nervous parenchyma of the ME . Expression of VEGF receptor 2 ( VEGFR 2) was observed at endothelial cells in the external zone and at somatodendrites in the internal zone. Finally, a VEGFR ‐ and PDGFR ‐associated tyrosine kinase inhibitor, SU 11248, significantly decreased the number of B r dU ‐positive proliferating endothelial cells and parenchyma cells. In conclusion, the present study demonstrates VEGF ‐dependent continuous angiogenesis in the ME of adult mouse brains under normal conditions, which provides new insight into our understanding of neurosecretion in the ME .