title: VEGF/VEGFR2 Signaling Regulates Germ Cell Proliferation in vitro and Promotes Mouse Testicular Regeneration in vivo.
abstract: Vascular endothelial growth factor (VEGF) plays fundamental roles in testicular development; however, its function on testicular regeneration remains unknown. The objective of this study was to explore the roles VEGF/VEGFR2 signaling plays in mouse germ cells and in mouse testicular regeneration. VEGF and the VEGFR2 antagonist SU5416 were added to culture medium to evaluate their effects on spermatogonial stem cell line (C18-4 cells) proliferation. Testicular cells obtained from newborn male ICR mice were grafted into the dorsal region of male BALB/c nude mice. VEGF and SU5416 were injected into the graft sites to assess the effects of the VEGF and VEGFR2 signaling pathways on testicular reconstitution. The grafts were analyzed after 8 weeks. We found that VEGF promoted C18-4 proliferation in vitro, indicating its role in germ cell survival. HE staining revealed that seminiferous tubules were reconstituted and male germ cells from spermatogonia to spermatids could be observed in testis-like tissues 8 weeks after grafting. A few advantaged male germ cells, including spermatocytes and spermatids, were found in SU5416-treated grafts. Moreover, VEGF enhanced the expression of genes specific for male germ cells and vascularization in 8-week grafts, whereas SU5416 decreased the expression of these genes. SU5416-treated grafts had a lower expression of MVH and CD31, indicating that blockade of VEGF/VEGFR2 signaling reduces the efficiency of seminiferous tubule reconstitution. Collectively, these data suggest that VEGF/VEGFR2 signaling regulates germ cell proliferation and promotes testicular regeneration via direct action on germ cells and the enhancement of vascularization.
authors.forename: Ruhui
authors.initials: R
authors.lastname: Tian
authors.forename: Shi
authors.initials: S
authors.lastname: Yang
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhu
authors.forename: Shasha
authors.initials: S
authors.lastname: Zou
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Junlong
authors.initials: J
authors.lastname: Wang
authors.forename: Zijue
authors.initials: Z
authors.lastname: Zhu
authors.forename: Yiran
authors.initials: Y
authors.lastname: Huang
authors.forename: Zuping
authors.initials: Z
authors.lastname: He
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D053487:DEAD-box RNA Helicases / Q000096:biosynthesis; D007211:Indoles / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D008819:Mice, Nude; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis; D011758:Pyrroles / Q000494:pharmacology; D011897:Random Allocation; D012038:Regeneration / Q000502:physiology*; D012671:Seminiferous Tubules / Q000098:blood supply / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013087:Spermatids / Q000166:cytology*; D013090:Spermatocytes / Q000166:cytology*; D013091:Spermatogenesis; D013093:Spermatogonia / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism* / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D007211:Indoles; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011758:Pyrroles; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; C116890:Semaxinib; C000592875:Kdr protein, mouse; D040301:Vascular Endothelial Growth Factor Receptor-2; C090864:Ddx4 protein, mouse; D053487:DEAD-box RNA Helicases