Neural deletion of Tgfbr2 impairs angiogenesis through an altered secretome.
Bottom Line: Blood vessels exhibited an atypical, clustered appearance were less in number and displayed reduced branching.HUVEC showed reduced migration towards CM of mutants compared with controls.These findings will be useful to further elucidate neurovascular interaction in general and to understand pathologies of the blood vessel system such as intracerebral haemorrhages, hereditary haemorrhagic telangiectasia, Alzheimeŕs disease, cerebral amyloid angiopathy or tumour biology.
Affiliation: Department of Molecular Embryology, Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.Show MeSH
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Mentions: Protein levels of FGF2 were unchanged, but we observed focal accumulation predominantly in microglia (Supplementary Material, Fig. S6Ba–f, white arrowheads). Stalk cells are the trailing proliferating EC that follow the guiding tip cell during migration (45). ID-proteins influence neuro- and angio genesis (46) and are expressed in EC especially by stalk cells. They can be repressed through TGFβ (47,48). ID1 is also a downstream target of bone morphogenic protein (BMP)-signalling, which is implicated in EC migration and tube formation (49). ID1 protein levels were increased in Tgfbr2-cKO (Fig. 3D–F). Moreover, immunostainings indicated ID1-positive EC in controls and mutants as well as in EC clusters showing presence of stalk cells within these structures (Fig. 3E and F). JAG1, another stalk cell marker, as well as the tip cell marker DLL4, were normally expressed in Tgfbr2-cKO (Supplementary Material, Fig. S7a, b), although DLL4 was slightly decreased in the AP-array (Supplementary Material, Fig. S6Ca, S7c–f). We concluded that tip and stalk cells are correctly specified in Tgfbr2-cKO. THBS2 and ADAMTS1 are also known to influence angiogenesis and ECM remodelling (50–52). Expression levels of both proteins were lower in Tgfbr2-cKO compared with controls (Fig. 4). These data further corroborated a molecular basis of our EM-based findings regarding an altered ECM in Tgfbr2-cKO.Figure 3.
Affiliation: Department of Molecular Embryology, Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.