Effects of copper deficiency on mouse yolk sac vasculature and expression of angiogenic mediators.
BACKGROUND
Cu deficiency results in embryonic defects and yolk sac (YS) vasculature abnormalities. In diverse model systems, Cu treatment modulates angiogenesis, perhaps by influencing the activity of angiogenic mediators such as vascular endothelial growth factor (VEGF). Conversely, Cu chelators can suppress angiogenesis.


METHODS
Gestation day (GD) 8.5 embryos from mice fed Cu-adequate (Cu+) or Cu-deficient (Cu-) diets were cultured in Cu+ or Cu- medium for 48 hr. Growth and development were evaluated, and YS vessel diameters were measured. Using RT-PCR and immunohistochemistry, the mRNA and protein expressions of VEGF, Flt-1, Flk-1, Angiopoietin-1 (Ang-1), and Tie-2 were analyzed.


RESULTS
Cu+/Cu+ embryos developed normally, whereas Cu-/Cu- embryos showed a high incidence of developmental anomalies. Cu-/Cu- YS had a high proportion of vessels that were large in diameter compared to the Cu+/Cu+ YS. The mRNA expression of angiogenic mediators in Cu-/Cu- YS was similar to that in Cu+/Cu+ YS. The protein expression of VEGF in the Cu-/Cu- YS without any vessel defects, and Tie-2 in the Cu-/Cu- YS with both vessel defects and blood islands was significantly lower than that in the Cu+/Cu+ YS. The protein expression of Flt-1, Flk-1 and Ang-1 was similar among groups regardless of the presence, or type, of vessel defects.


CONCLUSIONS
Results from the current study support the concept that Cu is required for the normal development of YS vasculature. Our data suggest that the impaired vascularization of Cu-deficient YS cannot be explained fully by the altered protein expression of the angiogenic growth factors reported here.
Yang
Soo Jin
SJ
Department of Nutrition, University of California-Davis Department of Nutrition, Davis, CA 95616, USA.
Uriu-Adams
Janet Y
JY
Keen
Carl L
CL
Rucker
Robert B
RB
Lanoue
Louise
L
D043925:Angiogenesis Inducing Agents / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers; D001808:Blood Vessels / Q000033:anatomy & histology; D003300:Copper / Q000097:blood / Q000172:deficiency*; D047108:Embryonic Development / Q000502:physiology; D005786:Gene Expression Regulation; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015017:Yolk Sac / Q000002:abnormalities / Q000098:blood supply* / Q000166:cytology / Q000196:embryology
D043925:Angiogenesis Inducing Agents; D015415:Biomarkers; D012333:RNA, Messenger; D003300:Copper