摘要目的：探讨孕鼠补充牛磺酸对生长受限胎鼠脑组织Rho-ROCK信号通路活性及突触囊泡蛋白（synaptophysin，Syp）表达的影响。方法18只Sprague-Dawley孕鼠随机分为正常对照组、胎儿生长受限（fetal growth restriction，FGR）组和牛磺酸组，每组6只。FGR组和牛磺酸组通过孕期低蛋白饮食法建立FGR模型，牛磺酸组自妊娠第12天起至分娩补充牛磺酸300 mg/（kg·d）。各组孕鼠自然分娩后，采用逆转录-聚合酶链反应技术检测各组仔鼠脑组织Rho-ROCK信号通路中关键信号分子神经生长抑制因子A（neurite growth inhibitor-A，Nogo-A）、神经生长抑制因子受体（neurite growth inhibitor receptor，NgR）、Rho-A、ROCKⅡ mRNA的表达水平（n=24）；采用Western印迹技术检测Nogo-A和NgR蛋白表达水平（n=12）；采用免疫组织化学方法检测Nogo-A、NgR及Syp蛋白表达强度（n=18）。采用单因素方差分析及LSD-t检验进行统计学分析。结果（1）mRNA表达水平：Nogo-A、NgR、Rho-A和ROCKⅡ mRNA在FGR组的表达分别为4.09±1.34、3.01±0.77、39.89±7.71和7.82±1.83，均高于正常对照组（分别为1.00±0.13、1.00±0.10、1.02±0.30和1.00±0.10，t值分别为4.735、5.204、7.682和10.675，P值均＜0.05）；牛磺酸组（分别为1.07±0.30、1.20±0.27，5.36±0.41和1.89±0.43）较FGR组降低（t值分别为4.645、4.690、6.687和9.485，P值均＜0.05），与正常对照组差异无统计学意义（P值均＞0.05）。（2）蛋白含量：Nogo-A和NgR蛋白含量在FGR组分别为1.51±0.09和0.31±0.05，在牛磺酸组分别为0.82±0.06和0.06±0.01，在正常对照组分别为1.04±0.10和0.09±0.12。FGR组高于正常对照组（t值分别为9.644和5.285，P值均＜0.05）。牛磺酸组较FGR组降低（t值分别为14.163和5.825，P值均＜0.05），与正常对照组差异无统计学意义（P值均＞0.05）。（3）蛋白阳性表达情况：Nogo-A、NgR的阳性表达强度在FGR组分别为0.28±0.06和0.11±0.02，在牛磺酸组分别为0.10±0.02和0.04±0.01，在正常对照组分别为0.07±0.01和0.04±0.01。FGR组高于正常对照组（t值分别为9.778和7.645，P值均＜0.05）；牛磺酸组较FGR组降低（t值分别为8.679和7.413，P值均＜0.05），与正常对照组差异无统计学意义（P值均＞0.05）。Syp的阳性表达强度在FGR组为0.08±0.01，低于正常对照组（0.16±0.04，t=4.600，P＜0.05）；牛磺酸组（0.14±0.36）较FGR组升高（t=3.181，P＜0.05），与正常对照组差异无统计学意义（P＞0.05）。结论孕鼠补充牛磺酸通过下调FGR胎鼠脑组织Rho-ROCK信号通路中关键信号分子的表达，促进神经再生及突触囊泡的发育。

abstractsObjectiveTo investigate the effects of prenatal taurine supplementation on the Rho-ROCK signaling pathway activity and synaptophysin (Syp) expression in brain tissues of rats with intrauterine growth restriction.MethodsEighteen pregnant Sprague-Dawley rats were randomly divided into control group, fetal growth restriction (FGR) group and taurine group, with six rats in each group. Low-protein diet was given in FGR and taurine groups to establish an FGR model. Taurine 300 mg/(kg·d) was supplemented from gestational day 12 until delivery in taurine group. The mRNA expression levels of neurite growth inhibitor-A(Nogo-A), neurite growth inhibitor receptor (NgR), Rho-A and ROCKⅡin fetal rat brain were detected using reverse transcriptase polymerase chain reaction (n=24), which are the key signaling molecules of the Rho-ROCK signal pathway. The protein expression levels of Nogo-A and NgR were detected by Western blot (n=12). The mean optical density in Nogo-A, NgR and Syp was determined by immunohistochemistry (n=18). One-way analysis of variance and LSD-t test were used for statistical analysis.Results(1) Expression of mRNA: the expression levels of Nogo-A, NgR, Rho-A and ROCKⅡ mRNA in fetal rat brain were 4.09±1.34, 3.01±0.77, 39.89±7.71 and 7.82±1.83, respectively in FGR group, and were significantly higher than in control group (1.00±0.13, 1.00±0.10, 1.02±0.30 and 1.00±0.10) (t=4.735, 5.204, 7.682 and 10.675, allP<0.05). The expressions in taurine group (1.07±0.30, 1.20±0.27, 5.36±0.41 and 1.89±0.43) were significantly lower than in FGR group (t=4.645, 4.690, 6.687 and 9.485, allP<0.05), and there was no statistical difference between taurine group and control group (allP>0.05). (2) Expression of protein by Western blot: the expressions of Nogo-A and NgR protein in fetal rat brain were 1.51±0.09 and 0.31±0.05 in FGR group, 0.82±0.06 and 0.06±0.01 in taurine group, and 1.04±0.10 and 0.09±0.12 in control group. The expression was significantly higher in FGR group than in control group (t=9.644 and 5.285, bothP<0.05). The expression was significantly lower in taurine group than in FGR group (t=14.163 and 5.825, bothP<0.05), and there was no statistical difference between taurine group and control group (allP>0.05). (3) Positive expression of protein: the positive expressions of Nogo-A and NgR protein in fetal rat brain were 0.28±0.06 and 0.11±0.02 in FGR group, 0.10±0.02 and 0.04±0.01 in taurine group, and 0.07±0.01 and 0.04±0.01 in control group. The expression was significantly higher in FGR group than in control group (t=9.778 and 7.645, bothP<0.05). The expression in taurine group was significantly lower than in FGR group (t=8.679 and 7.413, bothP<0.05), and there was no statistical difference between taurine group and control group (bothP>0.05). The positive expression of Syp protein in fetal rat brain was 0.08±0.01 in FGR group, and was significantly lower than in control group (0.16±0.04,t=4.600,P<0.05). The expression in taurine group (0.14±0.36) was significantly higher than in FGR group (t=3.181,P<0.05), and there was no statistical difference between taurine group and control group (P>0.05).ConclusionsPrenatal taurine supplementation can improve neural axon development via down-regulating the expressions of the key molecules of Rho-ROCK signal pathway in fetal rat brain tissue.