Lane R H, Flozak A S, Ogata E S, Bell G I, Simmons R A
Howard Hughes Medical Institute, The University of Chicago, Illinois 60614, USA.
Pediatr Res. 1996 Mar;39(3):390-4. doi: 10.1203/00006450-199603000-00003.
Intrauterine growth retardation (IUGR) resulting from placental insufficiency is a common complication of pregnancy. Bilateral uterine artery ligation of the pregnant rat is a model which mimics intrauterine growth retardation in the human. IUGR rat fetuses have altered hepatic energy and redox states, with reduced fetal hepatic ATP/ADP ratio, increased cytosolic NAD+/NADH ratio, and decreased mitochondrial NAD+/NADH ratio. These critical changes in energy metabolism contribute to IUGR. The effects of these changes at the molecular level are largely unknown. To address these effects we compared hepatic mRNA populations of IUGR and normal fetuses and neonates using mRNA differential display, a polymerase chain reaction-based method for assaying transcriptional differences under various conditions. We isolated and sequenced 18 cDNA products whose mRNA levels were elevated in IUGR compared with normal fetal and neonatal liver. These analyses demonstrated that NADH-ubiquinone oxireductase subunit 4L mRNA (ND-4L) was significantly increased in liver of IUGR fetuses and neonates. This suggested that IUGR may be associated with altered expression of genes involved in the generation of ATP and NADH. Therefore, we measured mRNA levels of adenine-nucleotide translocator-2 (ANT-2), glucose-6-phosphate dehydrogenase (G6PD), mitochondrial malate dehydrogenase (MMD), ornithine transcarbamylase (OTC), and phosphofructokinase-2 (PFK-2) using a semiquantitative reverse transcriptase-polymerase chain reaction-based technique. In the IUGR fetus, ND-4L, ANT-2, G6PD, and MMD mRNA levels were significantly elevated; PFK-2 mRNA levels were unchanged, and OTC levels were decreased. In the IUGR newborn rat, mRNA levels of all 6 enzymes were increased suggesting that the metabolic state of the growth retarded newborn remains abnormal after birth. Uteroplacental insufficiency affects the immediate and long-term metabolic milieu of the growth retarded animal, and forces specific adjustments, including the expression of mRNA encoding enzymes involved with hepatic energy production.
胎盘功能不全导致的胎儿宫内生长受限（IUGR）是一种常见的妊娠并发症。对妊娠大鼠进行双侧子宫动脉结扎是一种模拟人类胎儿宫内生长受限的模型。IUGR大鼠胎儿的肝脏能量和氧化还原状态发生改变，胎儿肝脏ATP/ADP比值降低，胞质NAD+/NADH比值升高，线粒体NAD+/NADH比值降低。这些能量代谢的关键变化导致了IUGR。这些变化在分子水平上的影响很大程度上尚不清楚。为了研究这些影响，我们使用mRNA差异显示技术（一种基于聚合酶链反应的方法，用于检测各种条件下的转录差异）比较了IUGR胎儿和正常胎儿及新生儿的肝脏mRNA群体。我们分离并测序了18种cDNA产物，与正常胎儿和新生儿肝脏相比，它们在IUGR中的mRNA水平升高。这些分析表明，NADH-泛醌氧化还原酶亚基4L mRNA（ND-4L）在IUGR胎儿和新生儿的肝脏中显著增加。这表明IUGR可能与参与ATP和NADH生成的基因表达改变有关。因此，我们使用基于半定量逆转录酶-聚合酶链反应的技术测量了腺嘌呤核苷酸转位酶-2（ANT-2）、葡萄糖-6-磷酸脱氢酶（G6PD）、线粒体苹果酸脱氢酶（MMD）、鸟氨酸转氨甲酰酶（OTC）和磷酸果糖激酶-2（PFK-2）的mRNA水平。在IUGR胎儿中，ND-4L、ANT-2、G6PD和MMD的mRNA水平显著升高；PFK-2的mRNA水平未改变，OTC水平降低。在IUGR新生大鼠中，所有6种酶的mRNA水平均升高，这表明生长受限的新生大鼠出生后的代谢状态仍保持异常。子宫胎盘功能不全影响生长受限动物的即时和长期代谢环境，并迫使进行特定的调整，包括参与肝脏能量产生的酶的mRNA表达。
