Expression And Significance Of HSP70 And HIF-1α In Placenta In Intrahepatic Cholestasis Of Pregnancy

Objective: To investigate the expression of the heat shock protein 70(HSP70) and hypoxia-inducible factor-1α(HIF-1α) in placental tissues of patients with intrahepatic cholestasis of pregnancy(ICP), in order to explore the role of HSP70 and HIF-1α in pathogenesis of ICP, so that we can provide a theoretical basis for further study of the pathogenesis and clinical intervention of ICP.Methods: 35 ICP patients with single fetus collected from the obstetrical department of the Affiliated Hospital of North Sichuan Medical College from December 2013 to August 2014 were selected as the experimental group. All of the 35 patients had no other medical complications or obstetrical complications except ICP, and 23 patients were mild ICP, 12 patients severe ICP. In the same period, 35 normal pregnant women with single fetus who experienced cesarean section due to cephalopelvic disproportion, social purpose, and abnormal fetal position were selected as the control group. All the patients in both groups were delivered by cesarean section. Then to detect the expression of HSP70 and HIF-1α in the placenta of the two groups by HE staining and immunohistochemistry(SP method), at the same time to analysis the relevant medical records.Results: 1. HIF-1α expressed in the cytoplasm and nuclei of syncytiotrophoblast cells and trophoblast cells in all cases, and it mainly expressed in the cytoplasm. The difference of the expression rate of the HIF-1α in the mild ICP group, the severe ICP group and the control group was not statistically significant(2c=3.107, P> 0.05); While the difference of the expression intensity in the three groups, was statistically significant(P<0.05). Furthermore, the expression intensity in the mild ICP group and the severe ICP group was significantly higher than that in the control group(P<0.05); the expression intensity in the severe ICP group was significantly higher than that in the mild ICP group(P<0.05). 2. HSP70 expressed in the placental cells, especially in the cytoplasm of the syncytiotrophoblast cells and cytotrophoblast cells in all cases. The difference of the expression rate of the HSP70 in the mild ICP group, the severe ICP group and the control group was not statistically significant(2c=4.630, P>0.05); While the the difference of expression intensity in the three groups was statistically significant(P<0.05). Furthermore, the expression intensity in the mild ICP group and the severe ICP group was significantly higher than that in the control group(P<0.05); the expression intensity in the severe ICP group was significantly higher than that in the mild ICP group(P<0.05). 3. The expression intensity of the HIF-1α in the ICP group had a positive correlation with the expression intensity of the HSP70 in the ICP group(r = 0.303, P <0.05). 4. Through comparing to amniotic fluid contamination rate in the mild ICP group, the severe ICP group and the control group, it suggested that the amniotic fluid contamination rate had a positive correlation with the aggravation of disease(r = 0.317, P = 0.008 <0.05).Conclusion: 1.The expression of the HIF-1α is increased in the placenta of the intrahepatic cholestasis of pregnancy, and it has a positive correlation with the aggravation of disease; 2.The expression of the HSP70 is also increased in the placenta of the intrahepatic cholestasis of pregnancy, and it has a positive correlation with the aggravation of disease; 3. The expression of HIF-1α and HSP70 in ICP has a positive correlation, which suggest both HIF-1α and HSP70 play roles in the process of ICP. We can speculate that HSP70 play a protective role through the functions of anti- apoptotic, antioxidative stress and chaperone function in placenta cells. In addition we should continue to detect the expressions of the HIF-1α and HSP70 in maternal serum, in order to explore the relationship between the two factors(HSP70 and HIF-1α influence) and the severity of ICP, as well as the new therapy for ICP.