Mouse strain-dependent heterogeneity of resting limbal vasculature.
OBJECTIVE
Heterogeneity of the extent of angiogenesis induced by exogenous growth factors may be determined by genetic influences. Because angiogenesis is the formation of new vessels from preexisting ones, strain-related influences on naïve resting limbal vessel phenotype and gene expression were determined in mice having divergently low and high angiogenic responses.


METHODS
Resting limbal vessel surface area and density and extent of bFGF-induced corneal angiogenesis were determined in C57BL/6J, BALB/cJ, F1 intercross identical with C57BL/6J X 129S3/SvIM, and 129S3/SvIM mouse strains by quantitative three-dimensional reconstruction confocal microscopy. Strain-related influences on pro- and antiangiogenic gene expression in naïve cornea were determined by quantitative real-time RT-PCR.


RESULTS
The strain-dependent rank order of resting limbal vessel surface area and resting vessel density paralleled bFGF-induced neovascularization: 129S3/SvIM > BALB/cJ, F1 > C57BL/6J (P < 0.0006). Pigment epithelium-derived factor (PEDF) was increased more than 67-fold compared to Ang-2 in resting cornea of both C57BL/6J and 129S3/SvIM strains (P < 0.0001; P < 0.0001), suggesting a strongly antiangiogenic environment. The corneas of the C57BL/6J mice demonstrated 1.8-, 1.5-, and 1.7-fold increased mRNA levels for Flt-1, VEGF, and bFGF, respectively (P < 0.02; P < 0.04; P < 0.02); however, TSP-1 expression was increased 2.4-fold compared with 129S3/SvIM (P < 0.0004).


CONCLUSIONS
Strain-dependent differences in the resting limbal vessel surface area and density correlated with heterogeneity in the extent of bFGF-induced angiogenesis. Differences in pro- and antiangiogenic gene expression levels in resting cornea may influence vascular limbal phenotype during quiescence and may predict susceptibility to angiogenesis-dependent diseases.
Chan
Candy K
CK
Department of Pathology, The Arnold and Mabel Beckman Macular Research Center at the Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.
Pham
Lucia N
LN
Chinn
Cynthia
C
Spee
Christine
C
Ryan
Stephen J
SJ
Akhurst
Rosemary J
RJ
Hinton
David R
DR
D042702:Angiopoietin-2 / Q000235:genetics; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D016510:Corneal Neovascularization / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000494:pharmacology; D018740:Genetic Heterogeneity; D016850:Limbus Corneae / Q000098:blood supply*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D018995:Myosin Heavy Chains; D009414:Nerve Growth Factors; D024501:Nonmuscle Myosin Type IIB; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015843:Serpins / Q000235:genetics; D013045:Species Specificity; D019700:Thrombospondin 1 / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D040281:Vascular Endothelial Growth Factor Receptor-1; D000099174:Pigment Epithelium-Derived Factor
D042702:Angiopoietin-2; D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D016222:Fibroblast Growth Factor 2; D018995:Myosin Heavy Chains; D009414:Nerve Growth Factors; D024501:Nonmuscle Myosin Type IIB; D011506:Proteins; D012333:RNA, Messenger; D015843:Serpins; D019700:Thrombospondin 1; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1; D000099174:Pigment Epithelium-Derived Factor; C501163:Flt1 protein, mouse; C103815:nonmuscle myosin type IIB heavy chain