Suppression of corneal neovascularization by curcumin inhibition of Wnt/β-catenin pathway activation.

AIM

To investigate whether curcumin suppressed corneal neovascularization (CNV) formation inhibiting activation of Wnt/β-catenin pathway.

METHODS

Suture-induced CNV was established on Sprague-Dawley (SD) rats. Curcumin were daily administrated by subconjunctival injection. Phosphorylation of low-density lipoprotein receptor-related protein 6 (LRP6) and nuclear accumulation of β-catenin, two indicators of activated Wnt/β-catenin pathway, were determined by Western-blot analysis in subconfluent/proliferating human microvascular endothelial cells (HMEC) and neovascularized corneas. Wnt3a conditioned medium (WCM) were harvested from Wnt3a expressing cells. WCM-induced cell proliferation and endothelial tubular formation capacity was measured by MTT assay and Matrigel assay, respectively.

RESULTS

Phosphorylation of LRP6 and nuclear accumulation of β-catenin was significantly increased in subconfluent/proliferating endothelial cells. Activation of Wnt/β-catenin pathway by WCM markedly promotes HMEC proliferation and tubular formation. Curcumin inhibited LRP6 phosphorylation and nuclear accumulation of β-catenin. In addition, curcumin attenuated WCM-induced HMEC proliferation and disrupted tubular structure of endothelial cells on Matrigel. Meanwhile curcumin suppressed suture-induced CNV and inhibited LRP6 phosphorylation as well as β-catenin accumulation in SD rats.

CONCLUSION

Taken together, activation of Wnt/β-catenin pathway could be involved in endothelial proliferation during suture-induced CNV formation and curcumin attenuated CNV formation inhibition of Wnt/β-catenin pathway activation.