Mitogenic functions of endocrine gland-derived vascular b

ble, et S nité Bv8/PK2, and their receptors (PKR1 and PKR2) in the adrenal cortex and checked for new biological functions of also increased the phosphorylation of Akt in endocrine cells of the adrenal cortex. EG-VEGF/PK1 and Bv8/PK2 thus factors play an important role in the homeostasis and the which may also be expressed in the adrenal cortex and sequence is totally different from those of VEGF and the other prokineticin-2 (PK2), the mammalian homolog of the frog 473Journal of Endocrinology (2008) 196, 473–482participate in the regulation of its vascularization. Recently, a novel family of secreted proteins comprising about 80 amino acids and possessing the N-terminal amino skin peptide Bv8. The expression of Bv8/PK2 is somewhat different from that of EG-VEGF/PK1 with major sites of expression in the central nervous system where it promotes DOI: 10.1677/JOE-07-0255hormonal control of the microvasculature (Shweiki et al. 1993). Our team has previously established that VEGF expression is under the hormonal control of adrenocortico-tropin (ACTH) both in primary cultures of bovine steroidogenic adrenocortical cells in vitro and in mouse adrenal gland in vivo (Gaillard et al. 2000, Thomas et al. 2004, Cherradi et al. 2006). However, besides VEGF, a number of other angiogenic factors have been described, known angiogenic factors, was found to be expressed in the steroidogenic cell compartment of ovary, testis, placenta, and adrenal glands and to a much lower level in non-steroidogenic organs including prostate and spleen (LeCouter et al. 2001, Zhang et al. 2003). EG-VEGF is identical to prokineticin-1 (PK1) which was initially identified as a stimulant of gastrointestinal smooth muscle contraction (Li et al. 2001). EG-VEGF/PK1 shares 44 % amino acid identity withexpression of angiogenic factors, such as vascular endothelial growth factor-A (VEGF-A), is high in these organs despite the absence of active angiogenesis, suggesting that these motogenic, and prosurvival activities for endocrine gland-derived endothelial cells (LeCouter & Ferrara 2003, Ferrara et al. 2004). In humans, EG-VEGF, whose amino acidand immunostaining analyses revealed that glomerulosa and fasciculata cells express both factors and both receptors