Fig. 1

Angiocrine factors are differentially expressed by cerebral endothelium at early stages of BBB induction and differentiation. Microarray data analysis from our previous study [4] comparing transcriptomes of lung and cortical endothelial cells at E13.5 of potential angiocrine factors, previously suggested to be involved in CNS vasculature biology [18]. a Some angiocrine factors showed similar transcripts levels in both lung and cortex ECs (Jagged2 and EphrinB2). Other angiocrine factors showed higher levels in lung ECs, of which thrombomodulin, pigment epithelium-derived factor (PEDF) and VEGF-C were statistically significant (P < 0.05). AGM transcripts levels were significantly higher in cortex ECs then in lung ECs (more than eightfold increase, P < 0.05). b Transcripts level of AGM in cortex ECs was comparable to levels of the most highly expressed BBB genes (Glut1, Tfrc, Mfsd2a). Statistically significant differential transcripts levels (P < 0.05) are unique to BBB-enriched markers. Pan-endothelial markers (VegfR2, Claudin-5 and VE-Cadherin) show similar levels in both lung and cortex ECs at this stage. N = 4 mice. All data are mean ± sem. Statistical significance determined by a non-parametric Mann–Whitney U test