Modulating the hypoxia-inducible factor signaling pathway as a therapeutic modality to regulate retinal angiogenesis.
Hypoxia-inducible factor (HIF) signaling cascade plays a critical role in angiogenesis by activating the transcription of genes encoding angiogenic growth factors. This study evaluated the effects of YC-1, a HIF-1 inhibitor, on the morphological, biochemical and molecular changes in human retinal microvascular endothelial cells. We found that YC-1 suppressed vascular endothelial cell proliferation, migration and tube formation, while it significantly increased the proteasome activity. Moreover, YC-1 induced a G(0)/G(1) cell-cycle arrest, whereas it exerted only an insignificant proapoptotic effects. Under normoxia or hypoxia, YC-1 did not alter the morphology or the cell viability. Additionally, under hypoxic conditions, YC-1 downregulated HIF-2alpha, VEGF, EPO, ET-1, and MMP-9 mRNA and protein levels, this was accompanied by a significant decrease in the MMP-9 activity. YC-1 decreased the basal expression of HIF-1alpha protein under normoxia, whereas it inhibited HIF-1alpha protein synthesis, stability, and nuclear translocation mechanisms under hypoxia. Furthermore, in a 3D collagen matrix model using mouse retinal explants cultured under normoxic and hypoxic conditions, YC-1; (1) inhibited outgrowth of new vessel sprouts; (2) reduced VEGF expression; (3) dramatically decreased the vessels immunoreactivities for CD31 and von Willebrand Factor (vWF); and (4) was highly effective in reducing the vascular density within the retina, compared to controls. These findings indicate that YC-1 possesses several antiangiogenic properties, both in vitro and ex vivo, which could be exploited as valuable therapeutic potentials to inhibit formation and the growth of new retinal vessels in the hypoxic retina.
DeNiro
M
M
Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia. mdeniro@kkesh.med.sa
Alsmadi
O
O
Al-Mohanna
F
F
D021581:Active Transport, Cell Nucleus; D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D015687:Cell Hypoxia; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D004921:Erythropoietin / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007191:Indazoles / Q000494:pharmacology*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D055806:Microvessels / Q000187:drug effects / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012171:Retinal Vessels / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
D020533:Angiogenesis Inhibitors; D051792:Basic Helix-Loop-Helix Proteins; D004921:Erythropoietin; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007191:Indazoles; D020780:Matrix Metalloproteinase 9; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D046988:Proteasome Endopeptidase Complex; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D014841:von Willebrand Factor; D000099162:Endothelial PAS Domain-Containing Protein 1; C497442:HIF1A protein, human; C467484:VEGFA protein, human; C467480:vascular endothelial growth factor A, mouse; C090937:3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole