NURTIENT RESTRICTION: FETAL BABOON RENAL DEVELOPMENT

这项研究的目标是确定胎儿营养素可获得性降低的持续时间 暴露和性别特定的影响对胎儿狒狒肾脏的影响。意义：美国人的肾脏 基金会估计，到2020年，有2000万美国人(每9个成年人中就有一个)患有慢性肾脏疾病(CRD) 估计达到四分之一。越来越多的流行病学和动物报告表明 母体扰动的范围，包括孕期母体营养限制(MNR)损害胎儿 肾脏发育，提示宫内因素是CRD的易感因素。初步数据：我们的 怀孕0.5天(G)的狒狒模型显示，母亲的全球营养从0.16下降到0.5 G(I)降低近曲小管密度同时降低胎儿肾细胞外基质的mRNA表达 组成纤维连接蛋白、层粘连蛋白、IV型胶原、整合素连接蛋白、基质金属蛋白酶2和转化生长因子？ (Ii)减少胎儿肾脏生长因子IGF、VEGF、EGF受体(R)和PDGFR的mRNA表达； (3)以胎儿性别特有的方式改变胎儿肾脏肾素-血管紧张素系统(RAS)的组成部分。 与人类在营养、胎盘和肾脏发育方面的相似之处导致了这一点 为基因/环境相互作用的重要灵长类研究提供一个独特的机会 在人类身上是可能的。假设：接触MNR的时间长短和性别对胎儿的影响不同 肾脏发育主要是由细胞外基质成分表达减少所介导的， 生长因子表达、细胞因子表达和营养感知通路活性降低。减少 胎儿营养可获得性[1]缩短了肾单位长度，减少了肾小球捐赠，增加了 足月肾小球大小；[2]减少参与血管生成的生长因子的表达，并 血管生成导致肾小管周围和肾小球毛细血管密度降低；以及[3]影响肾小管内 肾脏肾素-血管紧张素系统通过增加肾内11/MHSD1和 芳香酶活性。方法：在0.33℃条件下，对新鲜、冷冻和固定的胎儿肾脏进行研究。 0.50、0.66和0.90G使用：(I)组织学和无偏立体学；(Ii)QRT-PCR/ISH和Western印迹/IHC 用于mRNA和蛋白质的表达和定位；(Iii)基因转录的迁移率带移分析 (Iv)Matrigel培养的外植体和分离的近端小管中的生长因子活性测定 细胞3D培养。协同作用：这三个项目都研究了MNR对胚胎狒狒的影响。 至少在一定程度上是由IGF系统多肽引起的。外行描述：我们在经历更多的生物里程碑之后 出生的时间比生命中的任何时候都多。我们的数据将发展出关于肾脏发育的已知情况 灵长类动物，并证明子宫内的次优条件会改变肾脏的发育轨迹。 临床医生将使用这些信息来了解怀孕期间的最佳生活方式和饮食。

The goal of this study is to establish the degree to which decreased fetal nutrient availability has duration of exposure and gender-specific affects on the fetal baboon kidney. Significance: The American Kidney Foundation estimates 20 million Americans (1 in 9 adults) suffer from chronic renal disease (CRD); by 2020 the estimate reaches 1 in 4. There are an increasing number of epidemiologic and animal reports that show range of maternal perturbations including maternal nutrient restriction (MNR) in pregnancy that impair fetal renal development, suggesting an in utero component of predisposition to CRD. Preliminary data: Our baboon model at 0.5 of gestation (G) shows that a 30% decrease in maternal global nutrition from 0.16 to 0.5 G (i) decreases proximal tubule density while decreasing mRNA expression of fetal renal extracellular matrix components fibronectin, laminin, collagen IV, integrin-linked kinase, matrix metalloproteinase 2 and TGF/?; (ii) decreases mRNA expression of fetal renal growth factors IGF, VEGF, EGF receptor (R) and PDGFR; and (iii) alters components of the fetal renal renin-angiotensin system (RAS) in a fetal gender-specific manner. Similarities in nutrition, placentation and kidney development between the baboon and humans make this model a unique opportunity for significant primate studies of gene/environment interaction that are not possible in humans. Hypothesis: MNR has duration of exposure and gender specific effects on fetal baboon kidney development that are primarily mediated by decreased extracellular matrix components expression, growth factor expression, cytokine expression and decreased nutrient sensing pathway activity. Reduced fetal nutrient availability [1] decreases nephron length, decreases glomerular endowment and increases glomerular size at term; [2] decreases expression of growth factors involved in vasculogenesis and angiogenesis resulting in decreased peritubular and glomerular capillary density; and [3] impacts the intra- renal renin-angiotensin system in a gender specific manner by increasing intra-renal 11/MHSD1 and aromatase activity. Approach: Studies will be conducted on fresh, frozen and fixed fetal kidney at 0.33, 0.50, 0.66 and 0.90 G using: (i) histology and unbiased stereology; (ii)QRT-PCR/ISH and Western blot/IHC for mRNA and protein expression and localization; (iii) mobility band shift assay for gene transcriptional regulation; and (iv) growth factor activity assay in explants in Matrigel culture and isolated proximal tubule cell 3D culture. Synergy: All three projects study the effects of MNR on the fetal baboon as mediated, at least in part, by the IGF system peptides. Lay Description: We pass more biological milestones before we are born than at any other time in life. Our data will develop what is know about kidney development in the primate and demonstrate that sub-optimal conditions in utero alter the trajectory of renal development. Clinicians will use the information to understand optimal life style and diet in pregnancy.