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Sonic hedgehog: its expression in a healing cornea and its role in neovascularization.

Fujita K, Miyamoto T, Saika S - Mol. Vis. (2009)

Bottom Line: The effect of a topical injection of cyclopamine on cauterization-induced corneal neovascularization was then studied.This effect was counteracted by addition of cyclopamine.Cyclopamine did not affect VEGF-enhanced tube formation.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Wakayama Medical University, Kimiidera, Wakayama, Japan. kyoko@wakayama-med.ac.jp

ABSTRACT

Purpose: To examine if sonic hedgehog (Shh) is involved in tissue neovascularization by using cell culture and an animal cornea.

Methods: The effects of exogenous Shh (5.0 nM), vascular endothelial growth factor (VEGF), and/or a Shh signal inhibitor (2.5 or 10.0 muM cyclopamine) on vessel-like tube formation of vascular endothelial cells were examined in vitro. The effects of Shh on the expression of angiogenic cytokines in cultured cell types were examined in cultured cells. The expression of Shh and its receptor, Patched 1 (Ptc), was examined in a vascularized mouse cornea during post-alkali burn healing. The effect of exogenous Shh on corneal neovascularization in vivo was assayed using a rat cornea system. The effect of a topical injection of cyclopamine on cauterization-induced corneal neovascularization was then studied.

Results: Adding Shh promoted vessel-like tube formation of vascular endothelial cells. This effect was counteracted by addition of cyclopamine. Cyclopamine did not affect VEGF-enhanced tube formation. Shh did not affect the expression levels of angiogenic cytokines in cultured cell types. mRNA and protein expression levels of Shh and Ptc were under the detection limit in an uninjured cornea, but Shh but not Ptc was upregulated in a healing, alkali-burned, vascularized cornea. Exogenous Shh promoted neovascularization (NV) formation in vivo in a rat cornea. Topical cyclopmine blocked Gli signaling (blocked translocation of Gli3) and the length of neovascularization in the peripheral cornea post-cauterization as compared with the control vehicle-treated cornea.

Conclusions: Shh enhances endothelial tube formation independently through VEGF signaling in vitro. Shh signaling is involved in the development of unfavorable corneal neovascularization in animal corneas.

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Related in: MedlinePlus

Effect of exogenous Sonic hedgehog on the development of corneal neovascularization in vivo. A-D: Implantation of a polymer pellet-containing recombinant Shh induced marked NV in the stroma from limbal vessels (B) as compared with control corneas (A), indicating that Shh has a NV-promoting effect in vivo like in vitro. Pellet containing cyclopamine reduced NV formation as compared with control (C, D), indicating that endogenous Shh also has a promoting role in the development of corneal NV. Cyclopamine indeed counteracted exogenous Shh-induced NV. B shows the length of the NV developed from limbus in each group of treatment (E).
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f6: Effect of exogenous Sonic hedgehog on the development of corneal neovascularization in vivo. A-D: Implantation of a polymer pellet-containing recombinant Shh induced marked NV in the stroma from limbal vessels (B) as compared with control corneas (A), indicating that Shh has a NV-promoting effect in vivo like in vitro. Pellet containing cyclopamine reduced NV formation as compared with control (C, D), indicating that endogenous Shh also has a promoting role in the development of corneal NV. Cyclopamine indeed counteracted exogenous Shh-induced NV. B shows the length of the NV developed from limbus in each group of treatment (E).

Mentions: We first examined a direct effect of exogenous Shh on corneal NV formation. We employed implantation of a Shh-containing polymer pellet to the corneal stroma. Implantation of a polymer pellet containing recombinant Shh induced marked NV in the stroma from the limbal vessels compared with control corneas, indicating that Shh has a NV-promoting effect in vivo just as it does in vitro. A pellet containing cyclopamine reduced NV formation compared with the control, indicating that endogenous Shh also has a promoting role in the development of corneal NV. Cyclopamine indeed counteracted exogenous Shh-induced NV. (Figure 6)


Sonic hedgehog: its expression in a healing cornea and its role in neovascularization.

Fujita K, Miyamoto T, Saika S - Mol. Vis. (2009)

Effect of exogenous Sonic hedgehog on the development of corneal neovascularization in vivo. A-D: Implantation of a polymer pellet-containing recombinant Shh induced marked NV in the stroma from limbal vessels (B) as compared with control corneas (A), indicating that Shh has a NV-promoting effect in vivo like in vitro. Pellet containing cyclopamine reduced NV formation as compared with control (C, D), indicating that endogenous Shh also has a promoting role in the development of corneal NV. Cyclopamine indeed counteracted exogenous Shh-induced NV. B shows the length of the NV developed from limbus in each group of treatment (E).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2684749&req=5

f6: Effect of exogenous Sonic hedgehog on the development of corneal neovascularization in vivo. A-D: Implantation of a polymer pellet-containing recombinant Shh induced marked NV in the stroma from limbal vessels (B) as compared with control corneas (A), indicating that Shh has a NV-promoting effect in vivo like in vitro. Pellet containing cyclopamine reduced NV formation as compared with control (C, D), indicating that endogenous Shh also has a promoting role in the development of corneal NV. Cyclopamine indeed counteracted exogenous Shh-induced NV. B shows the length of the NV developed from limbus in each group of treatment (E).
Mentions: We first examined a direct effect of exogenous Shh on corneal NV formation. We employed implantation of a Shh-containing polymer pellet to the corneal stroma. Implantation of a polymer pellet containing recombinant Shh induced marked NV in the stroma from the limbal vessels compared with control corneas, indicating that Shh has a NV-promoting effect in vivo just as it does in vitro. A pellet containing cyclopamine reduced NV formation compared with the control, indicating that endogenous Shh also has a promoting role in the development of corneal NV. Cyclopamine indeed counteracted exogenous Shh-induced NV. (Figure 6)

Bottom Line: The effect of a topical injection of cyclopamine on cauterization-induced corneal neovascularization was then studied.This effect was counteracted by addition of cyclopamine.Cyclopamine did not affect VEGF-enhanced tube formation.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Wakayama Medical University, Kimiidera, Wakayama, Japan. kyoko@wakayama-med.ac.jp

ABSTRACT

Purpose: To examine if sonic hedgehog (Shh) is involved in tissue neovascularization by using cell culture and an animal cornea.

Methods: The effects of exogenous Shh (5.0 nM), vascular endothelial growth factor (VEGF), and/or a Shh signal inhibitor (2.5 or 10.0 muM cyclopamine) on vessel-like tube formation of vascular endothelial cells were examined in vitro. The effects of Shh on the expression of angiogenic cytokines in cultured cell types were examined in cultured cells. The expression of Shh and its receptor, Patched 1 (Ptc), was examined in a vascularized mouse cornea during post-alkali burn healing. The effect of exogenous Shh on corneal neovascularization in vivo was assayed using a rat cornea system. The effect of a topical injection of cyclopamine on cauterization-induced corneal neovascularization was then studied.

Results: Adding Shh promoted vessel-like tube formation of vascular endothelial cells. This effect was counteracted by addition of cyclopamine. Cyclopamine did not affect VEGF-enhanced tube formation. Shh did not affect the expression levels of angiogenic cytokines in cultured cell types. mRNA and protein expression levels of Shh and Ptc were under the detection limit in an uninjured cornea, but Shh but not Ptc was upregulated in a healing, alkali-burned, vascularized cornea. Exogenous Shh promoted neovascularization (NV) formation in vivo in a rat cornea. Topical cyclopmine blocked Gli signaling (blocked translocation of Gli3) and the length of neovascularization in the peripheral cornea post-cauterization as compared with the control vehicle-treated cornea.

Conclusions: Shh enhances endothelial tube formation independently through VEGF signaling in vitro. Shh signaling is involved in the development of unfavorable corneal neovascularization in animal corneas.

Show MeSH
Related in: MedlinePlus