Expression And Significance Of HO-CO In Human Endometrium And Decidua-villi Of Normal Early Pregnant Women And First Trimester Spontaneous Abortion Patients

Objective: Spontaneous abortion (SA) is a common complication of pregnancy, occurring in 10-15% of all pregnancy, more than 80% take place within the first 12 weeks, named first trimester SA. In immunological aspect, pregnancy is similar as transplantation, embryo who carrys agnate alloantigen is semiallograft for mater, and abortion is the result of graft rejection. In normal pregnancy procedure, embryo wouldn't be rejected by maternal immune system because of maternal-fetal interface balance. The study of recent years indicated that many biology active substance participate in regulating maternal-fetal interface balance and maintain pregnancy. Heme oxygenase (HO) and it's production carbon monoxide (CO) are importante for body, they express in endometrium, decidua and villus. HO decline resulting in CO downregulation is consanguineous with the first trimester SA. Our aim is to detect the changes and correlation of HO-1,HO-2 and CO in human endometrium, decidua and villi of normal early pregnant(NEP) women and the first trimester SA patients and to clarify the role of them in pregnancy maintenance and the first trimester SA. Methods: The patients were selected from outpatients and inpatients of Obstetrical and Gynecology, second Affiliated Hospital, Hebei Medical University from December 2006 to September 2007. SA group: 30 SA patients (SA≥2) with regular menstruation had bellyache or vagina bleeding after menolipsis for 47-75 days, they were prompted as embryo stopping growth by B-ultrasonic, eliminating the factors of chromatosome, anatomy, endocrine, infection and self immunity. NEP group: 20 women with regular menstruation requested artificial abortion because of pregnancy for 49-70 days with at least once normal parturition history and neither had a history of informal pregnancy nor had those above diseases. They didn't have any abortion sign and made sure embryo were alive by B-ultrasonic before artificial abortion. Normal endometrium group: 30 samples came from patients with infertility or simple ovarycyst, they all had regular menstruation and didn't take hormonal drugs within 6 monthes before operations. They didn't have a history of acute or chronic pelvic inflammatory or other disease . Endometriums were detached into proliferative phase (n=14) and secretory phase (n=16) through pathological diagnoses. The average age of all groups and average menolipsis days of SA group and NEP group didn't have statistic difference. Decidua and villi were got from normal early pregnancy people and first trimester SA patients after abortion operations, and endometriums were got at the time of diagnostic scratching operation or ovarycyst divest operation. Cleaned all samples by physiological saline. Cut every sample into two parts, One part were fixed with 4% paraformaldehyde, dehydrated them, embedded by paraffin and cut into 5um continuous pieces; the other part, took 100mg tissue from every piece and mixed it with 10% 0.1mol/L cold KH2PO4/K2HPO4 then made the mixture into serosity, 3000 turn/ min centrifugated 15 minutes and stored at -70℃refrigerator. (1)Measured HO-1 and HO-2 expression characteristic by immunohistochemistry. (2) Double-wavelength quantificational method, serosity absorbency was mensurated at 420nm and 432nm by 756M spectrophotometer, made synthetical equation according to Bill-law, educed percentage content of COHb(X%). Analysed all data using SPSS13.0 statistics software, P<0.05 was considered statistically significantly different.Results: 1.HO-1 is detected in all endometrium, decidua and villus. The staining of HO-1 is mainly located in cytoplasm and membrane of endometrium epithelia, decidua epithelia and decidua cells, villi stroma cells, syncytiotrophoblast and cytotrophoblast cells, syncytiotrophoblast has stronger staining than cytotrophoblast. There were no significant differences of HO-1 expression in secretory phase and proliferative phase endometrium, P>0.05; expression of HO-1 in decidua of NEP group and SA group are significantly higher than secretory phase endometrium, P<0.01; expression of HO-1 in villi of SA group are significantly lower than NEP group, P<0.05, but in decidua the two groups are not significantly different, P>0.05. 2. HO-2 is detected in all endometrium, decidua and villus. The staining of HO-2 is mainly located in cytoplasm and membrane of endometrium epithelia, decidua epithelia, decidua cells, syncytiotrophoblast and cytotrophoblast cells, endothelial cells, syncytiotrophoblast has stronger staining than cytotrophoblast, with weak staining of villi stroma cells. HO-2 expression of secretory phase is significantly higher than proliferative phase, P<0.01; expression of HO-2 in decidua of NEP group and SA group are significantly higher than secretory phase endometrium, P<0.01, P<0.05; expression of HO-2 in decidua and villi of SA group are significantly lower than NEP group, P<0.01. 3. COHb level of secretory phase endometrium [(0.17±0.07)%] is significantly higher than proliferative phase [(0.10±0.05)%], P<0.01; COHb level of NEP group [(0.37±0.08)%] and SA group [(0.23±0.10)%] is significantly higher than secretory phase endometrium [(0.17±0.07)%], P<0.01, P<0.05; COHb level in decidua and villi of SA group [(0.23±0.10)%, (0.31±0.12)%] are significantly lower than NEP group [(0.37±0.08)%, (0.56±0.13)%], P<0.01. 4. There are positive correlation between COHb and HO-1,HO-2 of decidua and villi.Conclusions: 1.HO-1 and HO-2 express in normal endometrium. The expression of HO-2 is higher in secretory phase than proliferative phase, and COHb level is also higher. They can keep endometrium function better, promote blood vasculars growth and relaxation, correspond with normal periodicity change of endometrium. 2. The expression of HO-1,HO-2 and COHb level in decidua are higher than endometrium, HO-CO may relate to endometrium decidualized and spiral artery recast in early days of pregnancy. These can favor for trophoblast invading decidua and the planting and growth of embryon. 3. There were no significant differences of HO-1 expression in decidua of SA group and NEP group, it may because that HO-1 can be regulated by many factories. The weak expression of HO-2 in decidua of SA patients suggest that HO-2 may play greater role in protecting decidua function. The weak expression of HO-1,HO-2 and low level of COHb in villi weaken their protection for trophoblast and endothelial cells, influence trophoblast invasive ability and vasculars relaxation, attenuate their ability for resisting inflammation, oxidation and platelet aggregation in maternal-fetal interface, it will accelerate repulsion for mother to fetal, and finally result in abortion. 4. There are positive correlation between CO and HO-1,HO-2 in decidua and villi of first trimester spontaneous abortion patients, decreasing expression of HO result in low level of CO. It suggest that CO may cooperate with HO-1 and HO-2 to result in abortion together.