Endothelial expression of TGFβ type II receptor is required to maintain vascular integrity during postnatal development of the central nervous system

• Published in: PloS one 2012-06, Vol.7 (6), p.e39336-e39336
• Main Authors: Allinson, Kathleen R, Lee, Hye Shin, Fruttiger, Marcus, McCarty, Joseph H, McCarty, Joseph, Arthur, Helen M
• Format: Article
• Language: English
• Subjects: Angiogenesis; Animal tissues; Animals; Biology; Birth defects; Brain; Cardiovascular disease; Central nervous system; Central Nervous System - growth & development; Central Nervous System - metabolism; Congenital diseases; Embryogenesis; Embryonic growth stage; Endothelial cells; Endothelial Cells - metabolism; Endothelium; Growth factors; Hemorrhage; Homeostasis; Hypothalamus; Integrity; Ligands; Medicine; Mice; Mice, Inbred C57BL; Mice, Knockout; Morphogenesis; Muscles; Mutants; Neonates; Neurogenesis; Pericytes; Protein Serine-Threonine Kinases - genetics; Protein Serine-Threonine Kinases - metabolism; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta - genetics; Receptors, Transforming Growth Factor beta - metabolism; Retina; Retina - cytology; Signaling; Smooth muscle; Tamoxifen; Tight junctions
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0039336

TGFβ signalling in endothelial cells is important for angiogenesis in early embryonic development, but little is known about its role in early postnatal life. To address this we used a tamoxifen inducible Cre-LoxP strategy in neonatal mice to deplete the TypeII TGFβ receptor (Tgfbr2) specifically in endothelial cells. This resulted in multiple micro-haemorrhages, and glomeruloid-like vascular tufts throughout the cerebral cortices and hypothalamus of the brain as well as in retinal tissues. A detailed examination of the retinal defects in these mutants revealed that endothelial adherens and tight junctions were in place, pericytes were recruited and there was no failure of vascular smooth muscle differentiation. However, the deeper retinal plexus failed to form in these mutants and the angiogenic sprouts stalled in their progress towards the inner nuclear layer. Instead the leading endothelial cells formed glomerular tufts with associated smooth muscle cells. This evidence suggests that TGFβ signalling is not required for vessel maturation, but is essential for the organised migration of endothelial cells as they begin to enter the deeper layers of the retina. Thus, TGFβ signalling is essential in vascular endothelial cells for maintaining vascular integrity at the angiogenic front as it migrates into developing neural tissues in early postnatal life.