胰岛素样生长因子-1对高胆红素血症SD大鼠幼崽脑组织Caspase-3表达的影响

Effect of insulin-like growth factor-1 on Caspase-3 expression in brain tissue of SD immature rats with hyperbilirubinemia

目的通过观察SD大鼠幼崽罹患高胆红素血症时在胰岛素样生长因子-1(IGF-1)干预的情况下脑组织中Caspase-3的表达情况,探究IGF-1在胆红素脑病防治中可能发挥的作用。方法选取7日龄的SD大鼠幼崽120只,采用随机的方法分成3个组,即对照组(A组)、高胆红素血症组(B组)、IGF-1干预组(C组),再根据处死时间点的不同(6 h、12h、24 h、48 h和72 h)将其划分成5个子组,每个子组8只。观察各组SD大鼠幼崽的异常神经行为;再依据时间点取各组SD大鼠幼崽脑组织,用HE染色法观察各组SD大鼠幼崽脑组织的病理改变,测定脑组织细胞的凋亡率选用TUNEL检测法,测定Caspase-3的表达情况选用免疫组织化学法。结果 (1)与对照组相比,高胆红素血症组SD大鼠幼崽海马区神经细胞凋亡增加,Caspase-3表达明显升高(P<0.05);与高胆红素血症组比较,IGF-1干预组SD大鼠幼崽海马区神经细胞Caspase-3蛋白表达明显降低(P<0.05),凋亡减少(P<0.05),但其表达和凋亡率仍较对照组偏高(P<0.05)。结论 SD大鼠幼崽在罹患高胆红素血症时Caspase-3可能参与了神经细胞的凋亡;IGF-1可能通过下调Caspase-3表达来抑制神经细胞凋亡,从而发挥其对脑组织的保护作用。

Objective To explore the role of insulin-like growth factor-1(IGF-1)in prevention and treatment of hyperbilirubinemia by observing the expression of Caspase-3 in brain tissue of SD immature rats with hyperbilirubinemia after IGF-1 intervention.Methods A total of 120 immature rats aged 7 days old were selected and randomly divided into group A(control group),group B(hyperbilirubinemia group),and group C(IGF-1 intervention group),40 immature rats in each group,then the immature rats in each group were divided into five subgroups according to different time points for sacrifice of immature rats(6,12,24,48,and 72 hours),8 immature rats in each subgroup.Abnormal neurobehaviors of immature rats were observed,brain tissues samples were obtained at different time points,HE staining was used to observe the pathological changes of brain tissue of immature rats,TUNEL method was used to detect the apoptotic rate of brain tissue cells,immunohistochemical method was used to detect the expression of Caspase-3.Results Compared with control group,the apoptotic rate of nerve cells in hippocampus of immature rats in hyperbilirubinemia group increased,and the expression of Caspase-3 increased significantly(P<0.05).Compared with hyperbilirubinemia group,the expression of Caspase-3 in nerve cells of hippocampus of immature rats in IGF-1 intervention group decreased significantly(P<0.05),and the apoptotic rate of nerve cells decreased significantly(P<0.05),but the expression of Caspase-3 and apoptotic rate were statistically significantly higher than those in control group(P<0.05).Conclusion Caspase-3 may be involved in apoptosis of nerve cells in immature rats with hyperbilirubinemia,IGF-1 may inhibit apoptosis of nerve cells by downregulating Caspase-3 expression,then IGF-1 can protect brain tissue.