1. Won't You Be My Neighbor? Local Induction of Arteriogenesis
Patricia A. D'Amore, Yin-Shan Ng 
Cell 
Volume 110, Issue 3, Pages (August 2002)
DOI: /S (02)

2. Figure 1 Shh/VEGF/Notch in the Arterial Vasculature
Sonic hedgehog (Shh) binding to the receptor complex formed by Patched (Ptc) and Smoothened (Smo) can release the inhibition of Smo by Ptc. The derepressed Smo in turn activates the Gli family of transcription factors. Shh can upregulate the expression of VEGF by mesenchymal cells, but whether the Ptc/Smo/Gli pathway is involved in this Shh-mediated VEGF production is still unclear. VEGF acts on its specific receptors, including Flk-1 and neuropilin-1 (NP-1) and induces arterial-specific EphrinB2 expression on endothelial cells (EC). However, VEGF-induced EphrinB2 expression is dependent on the Notch signaling pathway, and it is unclear (?) if VEGF can activate the Notch pathway in arterial ECs directly. Both the Notch receptor family and their ligand (Delta and Jagged) families are expressed by the EC and smooth muscle cell (SMC)/pericyte in vivo.
Cell  , DOI: ( /S (02) )

3. Figure 2 Local Regulation of Vessel Assembly
(Left) Peripheral nerve produces the freely diffusible VEGF120, which may then induce arterial differentiation and direct the patterning of the arteriole nearby. Such peripheral nerve-directed arteriole differentiation results in a loose alignment of the nerve and artery, likely a consequence of the nonlocalized nature of the VEGF120 isoform. It is unclear whether the Schwann cell or the axon, or both are responsible for VEGF production in vivo. Also, the inductive signal for VEGF production by the nerve in vivo has not been identified (?).
(Right) On the other hand, the association between the pulmonary microcirculation and alveolar epithelium is extremely tight, possibly due to the production of the highly localized VEGF188 isoform by the pulmonary epithelium. Such tight association between the epithelium and the vessels is required for the normal function of the air-blood barrier of the alveolus.
Cell  , DOI: ( /S (02) )