TY - JOUR
T1 - Vascular endothelial growth factor and kinase domain region receptor are involved in both seminiferous cord formation and vascular development during testis morphogenesis in the rat
AU - Bott, Rebecca C.
AU - McFee, Ryann M.
AU - Clopton, Debra T.
AU - Toombs, Candice
AU - Cupp, Andrea S.
PY - 2006/7
Y1 - 2006/7
N2 - Morphological male sex determination is dependent on migration of endothelial and preperitubular cells from the adjacent mesonephros into the developing testis. Our hypothesis is that VEGFA and its receptor KDR are necessary for both testicular cord formation and neovascularization. The Vegfa gene has 8 exons with many splice variants. Vegfa120, Vegfa164, and Vegfa188 mRNA isoforms were detected on Embryonic Day (E) 13.5 (plug date = E0) in the rat. Vegfa120, Vegfa144, Vegfa164, Vegfa188, and Vegfa205 mRNA were detected at E18 and Postnatal Day 3 (P3). Kdr mRNA was present on E13.5, whereas Fms-like tyrosine kinase 1 receptor (Flt1) mRNA was not detected until E18. VEGFA protein was localized to Sertoli cells at cord formation and KDR to germ and interstitial cells. The VEGFA signaling inhibitors SU1498 (40 μM) and VEGFR-TKI (8 μM) inhibited cord formation in E13 testis cultures with 90% reduced vascular density (P < 0.01) in VEGFR-TKI-treated organs. Furthermore, Je-11 (10 μM), an antagonist to VEGFA, also perturbed cord formation and inhibited vascular density by more than 50% (P < 0.01). To determine signal transduction pathways involved in VEGFA's regulation of testis morphogenesis, E13 testis were treated with LY 294002 (15 μM), a phosphoinositide 3-kinase (P13K) pathway inhibitor, resulting in inhibition of both vascular density (46%) and cord formation. Thus, we support our hypothesis and conclude that VEGFA, secreted by the Sertoli cell, is involved in both neovascularization and cord formation and potentially acts through the P13K pathway during testis morphogenesis to elicit its effects.
AB - Morphological male sex determination is dependent on migration of endothelial and preperitubular cells from the adjacent mesonephros into the developing testis. Our hypothesis is that VEGFA and its receptor KDR are necessary for both testicular cord formation and neovascularization. The Vegfa gene has 8 exons with many splice variants. Vegfa120, Vegfa164, and Vegfa188 mRNA isoforms were detected on Embryonic Day (E) 13.5 (plug date = E0) in the rat. Vegfa120, Vegfa144, Vegfa164, Vegfa188, and Vegfa205 mRNA were detected at E18 and Postnatal Day 3 (P3). Kdr mRNA was present on E13.5, whereas Fms-like tyrosine kinase 1 receptor (Flt1) mRNA was not detected until E18. VEGFA protein was localized to Sertoli cells at cord formation and KDR to germ and interstitial cells. The VEGFA signaling inhibitors SU1498 (40 μM) and VEGFR-TKI (8 μM) inhibited cord formation in E13 testis cultures with 90% reduced vascular density (P < 0.01) in VEGFR-TKI-treated organs. Furthermore, Je-11 (10 μM), an antagonist to VEGFA, also perturbed cord formation and inhibited vascular density by more than 50% (P < 0.01). To determine signal transduction pathways involved in VEGFA's regulation of testis morphogenesis, E13 testis were treated with LY 294002 (15 μM), a phosphoinositide 3-kinase (P13K) pathway inhibitor, resulting in inhibition of both vascular density (46%) and cord formation. Thus, we support our hypothesis and conclude that VEGFA, secreted by the Sertoli cell, is involved in both neovascularization and cord formation and potentially acts through the P13K pathway during testis morphogenesis to elicit its effects.
KW - Growth factors
KW - Sertoli cells
KW - Testis
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U2 - 10.1095/biolreprod.105.047225
DO - 10.1095/biolreprod.105.047225
M3 - Article
C2 - 16672722
AN - SCOPUS:33745439265
SN - 0006-3363
VL - 75
SP - 56
EP - 67
JO - Biology of reproduction
JF - Biology of reproduction
IS - 1
ER -