Campos D B, Papa P C, Marques J E B, Garbelotti F, Fátima L A, Artoni L P, Birgel E H, Meirelles F V, Buratini J, Leiser R, Pfarrer C
Departamento de Cirurgia, Setor de Anatomia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brasil.
Genet Mol Res. 2010 Feb 23;9(1):309-23. doi: 10.4238/vol9-1gmr729.
Low efficiency of somatic cell cloning by nuclear transfer has been associated with alterations of placental vascular architecture. Placental growth and function depend on the growth of blood vessels; VEGF-A and bFGF are the most important factors controlling neovascularization and vascular permeability in the placenta. We hypothesize that the VEGF-A and bFGF systems are disrupted in placentomes from cloned animals, contributing to the placental abnormalities that are common in these clones. We determined mRNA expression and protein tissue localization of VEGF-A, bFGF, and their receptors in placentomes from cloned and non-cloned bovine fetuses at term. Real-time RT-PCR revealed that VEGFR-2 mRNA was increased in cloned male-derived placentomes, while mRNA of bFGF and its receptors were decreased in placentomes of cloned females. VEGF-A system proteins were found to be located in placentomal endothelial, maternal and fetal epithelial and stromal cells; there was a variable pattern of cellular distribution of these proteins in both cloned and non-cloned animals. Alterations in the expression of VEGF-A and bFGF systems suggest that angiogenic factors are involved in abnormal placental development in cloned gestations, contributing to impaired fetal development and poor survival rates.
体细胞核移植进行体细胞克隆的效率低下与胎盘血管结构的改变有关。胎盘的生长和功能依赖于血管的生长;血管内皮生长因子-A(VEGF-A)和碱性成纤维细胞生长因子(bFGF)是控制胎盘新生血管形成和血管通透性的最重要因素。我们推测,克隆动物胎盘叶中的VEGF-A和bFGF系统受到破坏,导致了这些克隆动物中常见的胎盘异常。我们测定了足月克隆和未克隆牛胎儿胎盘叶中VEGF-A、bFGF及其受体的mRNA表达和蛋白质组织定位。实时逆转录-聚合酶链反应(RT-PCR)显示,克隆雄性来源的胎盘叶中血管内皮生长因子受体-2(VEGFR-2)mRNA增加,而克隆雌性胎盘叶中bFGF及其受体的mRNA减少。发现VEGF-A系统蛋白位于胎盘叶内皮细胞、母体和胎儿上皮细胞及基质细胞中;在克隆和未克隆动物中,这些蛋白的细胞分布模式各不相同。VEGF-A和bFGF系统表达的改变表明,血管生成因子参与了克隆妊娠中胎盘的异常发育,导致胎儿发育受损和存活率低下。