1. Small molecule anti-angiogenic probes of the ubiquitin proteasome pathway: potential application to choroidal neovascularization.
- Author
-
Bargagna-Mohan P, Ravindranath PP, and Mohan R
- Subjects
- Blotting, Western, Cells, Cultured, Choroid blood supply, Endothelium, Vascular cytology, Endothelium, Vascular metabolism, Ergosterol pharmacology, Growth Substances pharmacology, Heme Oxygenase-1 metabolism, Humans, I-kappa B Proteins metabolism, NF-KappaB Inhibitor alpha, Neovascularization, Physiologic drug effects, Plant Extracts pharmacology, Plants, Medicinal, Ubiquitin metabolism, Umbilical Veins cytology, Withanolides, Angiogenesis Inhibitors pharmacology, Choroidal Neovascularization prevention & control, Endothelium, Vascular drug effects, Ergosterol analogs & derivatives, Proteasome Endopeptidase Complex metabolism
- Abstract
Purpose: To characterize the angiogenic and inflammatory responses of human choroidal endothelial cells (HCECs) to stimulators and inhibitors of the ubiquitin proteasome pathway (UPP)., Methods: The regulation of the UPP by the inhibitor withaferin A and its congener, withanolide D, two natural products derived from the medicinal plant Withania somnifera was assessed in the three-dimensional endothelial cell sprouting assay (3D-ECSA), by using HCEC- and human umbilical vein endothelial cell (HUVEC)-derived spheroids embedded in a collagen I matrix. Western blot analysis was used to investigate the effect of withanolides on IkappaB-alpha, polyubiquitination, and heme oxygenase (HO)-1 regulation in HCEC and HUVEC cultures., Results: HCECs, like HUVECs, responded to fibroblast growth factor-2, vascular endothelial growth factor, and tumor necrosis factor (TNF)-alpha stimulation and sprouted vessel-like structures in collagen I matrix. However, HCECs were slower to generate these sprouting vessels, when compared with HUVECs. The extent of inhibition of endothelial cell sprouting in 3D matrix, the blockade of TNF-alpha-induced IkappaB-alpha degradation, levels of global polyubiquitinated proteins, and induced production of HO-1 in response to treatment by the withanolides in cultured endothelial cells was similarly regulated between HCECs and HUVECs., Conclusions: HCECs share with HUVECs a similar response to UPP inhibitors, suggesting that this well-conserved pathway that regulates angioinflammatory mechanisms could be exploited for drug-targeting in the development of novel agents for CNV treatment. more...
- Published
- 2006
- Full Text
- View/download PDF