Yang Soo Jin, Uriu-Adams Janet Y, Keen Carl L, Rucker Robert B, Lanoue Louise
Department of Nutrition, University of California-Davis Department of Nutrition, Davis, CA 95616, USA.
Birth Defects Res B Dev Reprod Toxicol. 2006 Oct;77(5):445-54. doi: 10.1002/bdrb.20096.
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.
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.
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.
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.
铜缺乏会导致胚胎缺陷和卵黄囊（YS）血管系统异常。在多种模型系统中，铜处理可调节血管生成，可能是通过影响血管生成介质如血管内皮生长因子（VEGF）的活性。相反，铜螯合剂可抑制血管生成。
将来自喂食铜充足（Cu+）或铜缺乏（Cu-）饮食小鼠的妊娠第8.5天胚胎在Cu+或Cu-培养基中培养48小时。评估生长和发育情况，并测量YS血管直径。使用逆转录聚合酶链反应（RT-PCR）和免疫组织化学分析VEGF、Flt-1、Flk-1、血管生成素-1（Ang-1）和Tie-2的mRNA和蛋白表达。
Cu+/Cu+胚胎正常发育，而Cu-/Cu-胚胎出现发育异常的发生率较高。与Cu+/Cu+ YS相比，Cu-/Cu- YS中直径较大的血管比例较高。Cu-/Cu- YS中血管生成介质的mRNA表达与Cu+/Cu+ YS相似。在没有任何血管缺陷的Cu-/Cu- YS中VEGF的蛋白表达，以及在既有血管缺陷又有血岛的Cu-/Cu- YS中Tie-2的蛋白表达均显著低于Cu+/Cu+ YS。无论是否存在血管缺陷或血管缺陷类型如何，Flt-1、Flk-1和Ang-1的蛋白表达在各组之间相似。
本研究结果支持铜是YS血管系统正常发育所必需的这一概念。我们的数据表明，铜缺乏的YS血管化受损不能完全通过此处报道的血管生成生长因子蛋白表达改变来解释。
