Differential expression of pro- and antiangiogenic factors in mouse strain-dependent hypoxia-induced retinal neovascularization.
Clinical observations suggest that genetic factors may influence heterogeneity of angiogenic responses in cardiovascular disease, proliferative diabetic retinopathy, and neoplasia. Experiments among mouse strains using a corneal micropocket assay indicate that extent of angiogenesis may be genetically determined. Here, we established the strain-dependence of hypoxia-induced retinal angiogenesis in multiple mouse strains which paralleled the rank order found for bFGF-induced corneal angiogenesis. Using quantitative real-time RT-PCR, strain-related gene expression differences in retina/choroid between C57BL/6J and 129S3/SvIM, inbred strains with relatively low and high levels of angiogenesis, respectively, after 0, 6, 12, 24, 48, and 96 h hypoxia were determined for vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2), angiogenic ligands potently induced by hypoxia, and for pigment epithelium-derived factor (PEDF) and thrombospondin-1 (TSP-1), endogenous broad-spectrum antiangiogenic factors. Indirect ELISA was used to correlate VEGF and PEDF protein levels with mRNA expression. At the onset of hypoxia, both PEDF and TSP-1 levels were increased over 15-fold and VEGF was increased over 10-fold compared to Ang-2 in both strains. At the onset of neovascularization (48 h), both VEGF and Ang-2 mRNA levels were increased in the more angiogenic 129S3/SvIM strain (P < 0.02), which was not observed among developmental control animals. PEDF expression was higher in the less angiogenic C57BL/6J strain at 6, 12, 24, and 96 h hypoxia (P < 0.03), while TSP-1 expression was higher in C57BL/6J throughout the entire time course of hypoxia (4 days) compared to 129S3/SvIM (P < 0.02). Among developmental control animals, PEDF and TSP-1 expression was also increased at P14 and P16 in C57BL/6J strain compared to 129S3/SvIM (P < 0.02). Strain-dependent expression of both pro- and antiangiogenic growth factors may determine heterogeneity in the angiogenic response and potentially, susceptibility to angiogenesis-dependent diseases.
Chan
Candy K
CK
Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Pham
Lucia N
LN
Zhou
Jiehao
J
Spee
Christine
C
Ryan
Stephen J
SJ
Hinton
David R
DR
D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D042501:Angiogenic Proteins / Q000235:genetics; D000818:Animals; D003315:Cornea / Q000098:blood supply*; D004797:Enzyme-Linked Immunosorbent Assay; D051379:Mice; D008806:Mice, Inbred AKR; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D018613:Microscopy, Confocal; D009389:Neovascularization, Pathologic / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D012164:Retinal Diseases / Q000473:pathology; D012171:Retinal Vessels / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
D020533:Angiogenesis Inhibitors; D042501:Angiogenic Proteins; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A