NURTIENT RESTRICTION: FETAL BABOON RENAL DEVELOPMENT

本研究的目的是确定胎儿营养供应减少的持续时间， 暴露和性别对胎儿狒狒肾脏的影响。英文名：The American Kidney 基金会估计，到2020年，2000万美国人（每9名成年人中就有1人）患有慢性肾病（CRD）。 估计达到四分之一。越来越多的流行病学和动物报告显示， 一系列母体扰动，包括妊娠期母体营养限制（MNR）， 肾脏发育，提示子宫内成分的易感性CRD。数据来源：Our 妊娠0.5（G）的狒狒模型显示，母体总营养从0.16下降到0.5 G（i）降低近端小管密度，同时降低胎肾细胞外基质mRNA表达 组分纤连蛋白、层粘连蛋白、胶原IV、整合素连接激酶、基质金属蛋白酶2和TGF β; (ii)降低胎儿肾生长因子IGF、VEGF、EGF受体（R）和PDGFR的mRNA表达;和 (iii)以胎儿性别特异性方式改变胎儿肾脏肾素-血管紧张素系统（RAS）的组分。 狒狒和人类在营养、胎盘形成和肾脏发育方面的相似之处， 为基因/环境相互作用的重要灵长类动物研究提供了一个独特的机会， 可能在人类。假设：MNR对胎儿狒狒具有暴露持续时间和性别特异性影响 主要由细胞外基质成分表达减少介导的肾脏发育， 生长因子表达、细胞因子表达和降低的营养感应途径活性。减少 胎儿的营养供应[1]减少肾单位长度，减少肾小球禀赋，增加 足月时肾小球的大小; [2]减少参与血管生成的生长因子的表达， 血管生成导致肾小管周围和肾小球毛细血管密度降低;[3]影响肾内 通过增加肾内11/MHSD 1，以性别特异性方式影响肾脏肾素-血管紧张素系统， 芳香化酶活性方法：将在0.33， 0.50、0.66和0.90 G，使用：（i）组织学和无偏体视学;（ii）QRT-PCR/ISH和Western blot/IHC 用于mRNA和蛋白质表达和定位;（iii）用于基因转录的迁移率带移位测定 调节;和（iv）在基质胶培养物和分离的近端小管中的外植体中的生长因子活性测定 细胞三维培养协同作用：所有三个项目都研究了MNR对胎儿狒狒的影响， 至少部分是通过IGF系统肽。奠定描述：我们通过更多的生物里程碑之前， 比生命中任何时候都多。我们的数据将发展我们所知道的关于肾脏发育的知识， 灵长类动物，并证明子宫内的次优条件会改变肾脏发育的轨迹。 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.