Expression And Significance Of HIF-1,BNIP3,NF-κB,Caspase-3 And Bcl-2 In Hypertensive Disorder Complicating Pregnancy

BackgroundHypertensive disorder complicating pregnancy is one of the main causes for the death of pregnancies and neonates,however, the etiology of hypertensive disorder complicating pregnancy remains unclear. Placenta hypoxia plays a critical role in the occurrence and progress of hypertensive disorder complicating pregnancy. Hypoxia inducible factor-1 alpha (HIF-1) is an important transcriptive factor that regulates genes involved in angiogenesis, cellular oxygen balance and energy metablossom. It is verified that HIF-1 plays a critical role in apoptosis induced by hypoxia, which induces the occurrence and development of hypertensive disorder complicating pregnancy. The Bcl-2 nineteen kilodalton interacting protein 3 (BNIP3) is a hypoxia-inducible pro-apoptotic member of the Bcl-2 family that induces cell death by associating with the mitochondria. In vitro, this expression was shown to be mediated by hypoxia. New findings show that the occurrence and progress of hypertensive disorder complicating pregnancy are correlated with apoptosis as well as hypoxia. Acceleration or insufficiency of apoptosis of the cells will lead to occurrence of illness. Recently scholars found that apoptosis of placental cells plays an important role in development of hypertensive disorder complicating pregnancy. NF-κB was found as a transcriptive factor in 1986, which play a critical role in immunity reaction , inflammation reaction and apoptosis. NF-κB pathway including NF-κB/P65 and NF-κB/P50. ObjectiveTo investigate the relation between the expressions of BNIP3 and HIF-1 in placenta and the cause of hypertensive disorder complicating pregnancy, and To investigate the relation between the expressions of the nuclear factor-kappa B (NF-κB/p65) , Caspase 3 and Bcl-2 in placenta and the cause of hypertensive disorder complicating pregnancy.Materials and methods1. Sixty women with hypertensive disorder complicating pregnancy(20 gestation hypertension,20 mild preeclampsia,20 severe preeclampsia.)and 20 women with normal pregnancy were recruited in the first affiliated hospital, the third affiliated hospital of Zhengzhou university, the Maternal and Child Health hospital as study group and control group, respectively. The two groups were matched in maternal age, parity and gestational age. First, Immunohistochemical methods SABC was used to measure the expressions of BNIP3 and HIF- 1 in placenta of normal pregnancy and hypertensive disorder complicating pregnancy. Second, immunohistochemical methods; SP was used to measure the expressions of NF-κB/p65,Caspase 3 and Bcl-2 in placenta of normal pregnancy and hypertensive disorder complicating pregnancy.2. The data was analyzed by SPSS 13.0 software wrap, Chi-Square Test and Spearman grade relation analysis are involved. Statistically significant level was considered as "alpha equals 0.05".Results1. Immunohistochemical staining for HIF-1 protein was located at the cytoplasm and nucleus of the cytotrophoblast as well as extra villous trophoblastic cells, some weak signals were showed in the cytotrophoblast. Immunohistochemical staining for HIF-1 protein was located at the cytoplasm and nucleus of the cytotrophoblast as well as syneytiotrophoblast, Immunohistochemical staining in the cytotrophoblast showed weaker than syneytiotrophoblast. The expression of HIF-1 protein in trophocyte showed significant higher in every group of hypertensive disorder complicating pregnancy(positive rate=90%) than in control group(positive rate=65%): the expression in gestation hypertension group is higher than that in control group(x²=7.55,P=0.023<0.05).the expression in mild preeclampsia group is higher than that in control group(x²=13.40,P=0.04<0.05). The expression in severe preeclampsia group is higher than that in control group(x²=8.40,P=0.038<0.05).The expression of HIF-1 protein showed significances correlated with the degree of differentiation: the expression in gestation hypertention group is lower than that in mild preeclampsia group(x²=13.80,P=0.03<0.05). The expression in mild preeclampsia group is lower than that in severe preeclampsia group (x² =15.00,P=0.02<0.05).2. Immunohistochemical staining for BNIP3 protein was located at the cytoplasm and nucleus of placental tissue . Immunohistochemical staining for BNIP3 protein was mostly located at the cytoplasm of placental tissue in study group, while the immunohistochemical staining for BNIP3 protein was mostly located at the cytoplasm of placental tissue in control group.This is the Second study to show that the pro-apoptotic protein BNIP3 are expressed in the human placenta in the word. The expression of BNIP3 protein in the cytoplasm of trophocyte showed significant higher in every group of hypertensive disorder complicating pregnancy (positive rate=98%) than in control group (positive rate=95%): the expression in gestation hypertension group is higher than that in control group(x²=22.20,P=0.000<0.01).the expression in mild preeclampsia group is higher than that in control group(x²= 14.60,P =0.002<0.05). the expression in severe preeclampsia group is higher than that in control group(x²=14.60,P=0.002<0.05).The expression of BNIP3 protein showed significances correlated with the degree of differentiation: the expression in gestation hypertension group is lower than that in mild preeclampsia group(x² =16.40,P=0.03<0.05). The expression in mild preeclampsia group is lower than that in severe preeclampsia group (x²=15.00,P=0.02<0.05).3. Positive correlation between the HIF-1 and BNIP3 was found both in study group (R=0.638,P=0.02<0.05) and control group(R=0.630,P=0.03<0.P5).4. The expression of NF-κB/p65 protein in the trophocyte showed significant higher in every group of hypertensive disorder complicating pregnancy(positive rate =88%) than in control group(positive rate=65%): the expression in gestation hypertension group is higher than that in control group(x²=7.55,P=0.023<0.05).The expression in mild preeclampsia group is higher than that in control group(x²=13.00,P =0.005<0.05). The expression in severe preeclampsia group is lower higher that in control group(x²=8.40,P=0.038<0.05).The expression of NF-κB/p65 protein showed significances correlated with the degree of differentiation: the expression in gestation hypertension group is lower than that in mild preeclampsia group(x₁²;=13.80,P₁=0.003<0.05). The expression in mild preeclampsia group is lower than that in severe preeclampsia group (x² =14.60,P=0.02<0.05).5. The expression of Caspase-3 protein in the trophocyte showed significant higher in every group of hypertensive disorder complicating pregnancy(positive rate=95%) than in control group(positive rate=70%): the expression in gestation hypertension group is higher than that in control group(x²=13.40,P=0.004<0.05).The expression in mild preeclampsia group is higher than that in control group(x²=13.20,P =0.004<0.05). The expression in severe preeclampsia group is higher than that in control group(x²=14.60,P=0.002<0.05).The expression of Caspase-3 protein showed significances correlated with the degree of differentiation: the expression in gestation hypertension group is lower than that in mild preeclampsia group(x₁²=20.60,P₁=0.00<0.05). The expression in mild preeclampsia group is lower than that in severe preeclampsia group (x²=23.00,.P=0.002<0.05).6. The expression of Bcl-2 protein in the trophocyte showed significant lower in every group of hypertensive disorder complicating pregnancy(positive rate=83%) than in control group(positive rate=100ï¼…): the expression in gestation hypertension group is lower than that in control group(x²=15.00,P=0.002<0.05).The expression in mild preeclampsia group is lower than that in control group(x²=13.00,P =0.005<0.05).The expression in severe preeclampsia group is lower than that in control group(x²=14.60,P=0.014<0.05).The expression of Bcl-2 protein showed significances correlated with the degree of differentiation: the expression in gestation hypertension group is lower than that in mild preeclampsia group(x₁² =26.00,P₁=0.00<0.05).The expression in mild preeclampsia group is lower than that in severe preeclampsia group (x²=12.60, P=0.02<0.05). 7. Positive correlation between the Caspase-3 and NF-κB/p65 was found both in stud y group( R=0.749, P=0.00<0.05)and in control group(R=0.533,P=0.016<0.05). There was no significant negative correlation between the Bcl-2 and NF-κB/p65 was found both in study group(R=-1.732, P=0.083>0.05) and in control group (R=-1.897,P=0.058>0.05). Negative correlation between the Caspase-3 and Bcl-2 was found both in study group (R=-0.579, P=0.008<0.05) and in control group(R=-0.614, P=0.004<0.05)Conclusion1. The high expression and the location of HIF-1 protein and BNIP3 protein indicates that they are the key genes, which may induce the occurrence and development of hypertensive disorder complicating pregnancy. The expression of BNIP3 can be induced by hypoxia and regulated by HIF-1.2. Elevation of the NF-κB in placenta may be related to hypertensive disorder complicating pregnancy. Apoptosis may which induces the occurrence and development of hypertensive disorder complicating pregnancy.