The Expression And Clinical Significance Of FK506 Binding Protein (FKBP) In Chorionic Villi Of Patients With Recurrent Spontaneous Abortion

Objective:Recurrent spontaneous abortion (RSA) is one of the clinical common outcomes in abnormal early pregnancy. Currently there is no effective prevention measures for this disease, because of various etiology and complex pathogenesis. Our current study aims to investigate the mRNA and protein expression of human FKBPs, including FKBP-12、FKBP-13、FKBP-25、 FKBP、FKBP-38、FKBP-51、FKBP-52 and FKBP-135, in the chorionic villi of patients with early RSA, and explore the relationships about FKBP and pregnancy, FKBP and RSA, which may provide additional information regarding the causes of RSA and aid in its management.Methods:A total of 30 patients of RSA who suffered early embryo growth arrest in our hospital were enrolled into the case group (RSA group) and 30 women who had artificial abortion for normal early pregnancy served as a control group (normal group). Fresh chorionic villus tissues were collected from the two groups. The mRNA and protein expression levels of FKBP family (FKBP-12、FKBP-13、FKBP-25、FKBP-36、FKBP-38、FKBP-51、FKBP-52 and FKBP-135) were detected by semiquantitative reverse transcription polymerase chain reaction and immunohistochemistry, respectively.Results:Among eight members of the human FKBP family, FKBP-12、 FKBP-13、FKBP-25、FKBP-36、FKBP-38、FKBP-51 and FKBP-135 were not detected in the chorionic villi of RSA patients and normal early pregnant women; Only FKBP52 is expressed in chorionic villi samples of RSA patients and normal early pregnant women. RSA patients exhibited significantly lower FKBP52 mRNA expression levels (1.109 ± 0.292) compared with those in normal pregnancies (1.484±0.198), and the difference was statistically significant (P<0.05). FKBP52 immunoreactivity in chorionic villi was mainly observed in the cytoplasm and nucleus of trophoblastic cells. However, the protein expression level of FKBP52 in the chorionic villi of RSA patients (IOD: 93.802±5.310) was significantly lower than in normal early pregnancy (IOD: 66.203±8.412), and the difference was statistically significant (P<0.05).Conclusion:Among eight members of the human FKBP family, FKBP-12、FKBP-13、FKBP-25、FKBP-36、FKBP-38、FKBP-51 and FKBP-135 were not associated with pregnancy and RSA. But FKBP52 gene and protein levels in the chorionic villi of RSA patients were significantly lower than in normal pregnancy group, which indicate that the abnormal expression of FKBP52 may be associated with pregnancy and RSA. Its mechanism may be that the decrease in FKBP52 of RSA patients is unable to maintain normal pregnancy process, affects embryonic development and even leads to abortion by impairing the function of progesterone receptor complex.