The Expression And Significance Of Progesterone Receptor Membrane Component₁、Matrix Metalloproteinase-9 In Fetal Membranes In Premature Rupture Of Fetal Membranes

Fetal membranes is rupture prior to the onset of labour,which includes preterm premature rupture of membranes（p PROM）（<37W）and term premature rupture of membranes（t PROM）（≧37W）. Premature rupture of fetal membranes（PROM） occurs in approximately 10% of pregnancies after 37 weeks of gestation（t PROM） and in 2%-3.5% of pregnancies before 37 weeks of gestation（p PROM）. Preterm premature rupture of membranes（PROM） is an obstetrics complication and is the leading cause of perinatal mortality and morbidity. Premature rupture of membranes can cause placental abruption, umbilical cord prolapse, premature birth, postpartum hemorrhage, decrease of amniotic fluid, amniotic fluid embolism, fetal distress, intrauterine infection, including chorioamnionitis, endometritis and other complications increasing. Especially preterm premature rupture of membranes easily leads to neonatal germinal pneumonia, neonatal pulmonary hyaline membrane disease and sepsis. Though the precise mechanisms cause the rupture of fetal membranes are still incompletely understood, many researchers at home and abroad think rupture of membranes（ROM） depends on mechanical strength, extracellular matrix components imbalance and increased apoptosis. However apoptosis and degradation of the extracellular matrix（ECM） are key features. So it is essential to explore the pathogenesis of premature rupture of membranes.Some literatures reported that Progesterone receptor membrane component1（PGRMC₁） can regulate the expression of MMP-9 and the occurrence of apoptosis. Although there are many studies about premature rupture of membranes, most of the scholars are limited to random sampling and single area, and there are few literatures to study the different regions of fetal membranes. But studies have found that fetal membranes local micro environment changes can affect the collagen fiber degradation and elastic fibers. Pathology is the study of membranes revealed there was a 35% decrease in the thickness of rupture zone from premature rupture of membranes; Some scholars have found that certain factors between the site of rupture [RS] and the distance to the ruptured site [DS] of fetal membranes is inconsistent; Wang Li also found that some of the factors in the maternal peripheral blood, umbilical cord blood, amniotic fluid, the expression of fetal tissue is not completely consistent. Based on the above points of views, we hypothesized that premature rupture of membranes may be altered by the local micro environment changes and some local cytokine expression’s alterations, which leads to the composition and thickness changes of this area membrane, and finally lead to the rupture of the membranes. Therefore, this study was to explore the expression of MMP-9 and PGRMC₁ in different regions of fetal membranes from different pregnant women, and then to clarify the relationship between the expression of MMP-9 and PGRMC₁ and the occurrence of premature rupture of membranes.AimThis study aimed to investigate whether the altered expression of Progesterone receptor membrane component 1（PGRMC₁） and Matrix Metalloproteinase 9（MMP-9） in the site of rupture [RS] or the distance to the ruptured site [DS] of fetal membranes（FM） were associated with the pathogenesis of Premature rupture of membranes（PROM）.Methods1.Research object:Select 80 cases of pregnant women who delivered in obstetrics and Gynecology department from of the Third Affiliated Clinical Hospital of Zhengzhou University from July 2014 to November 2014, and divided into two groups:（1） PROM group: 40 cases of premature rupture of membranes（PROM）, pregnant week: 24-40 weeks, of which 8 cases were cesarean section and 31 cases were vaginal delivery（total stage of labor was not more than 14.5 hours）. All term premature rupture of membranes were delivered during 3 days after rupture of the membrane, and all preterm premature rupture of membranes were delivered during 2 weeks after the rupture of membrane. All pregnant women showed no any clinical symptoms（Body temperature is less than 38 degrees.）. Polyhydramnion, mechanical stimulation caused by premature rupture of membranes, twins, cervical relaxation, pregnancy with uterine malformation, pregnancy complicated with uterine fibroids and other complications were excluded.（2） Control group: 40 cases of term elective cesarean（some of they were without uterine contraction suffering from esarean secticon due to placenta previa, or due to cephalopelvic disproportion, breech.）, pregnant week: 24-40 weeks.2.Methods（1） Fetal Membranes: Two samples were taken, one was collected from the labelled site of rupture [RS] and the other was collected from an area distant to the ruptured site [DS];（2） The expression of PGRMC₁ and MMP-9 in fetal membranes was performed by immunohistochemistry.（3） Real-time PCR and Western blot was used to detect the m RNA and protein expression levels of PGRMC₁ and MMP-9 in the [RS] and [DS] of fetal membranes from the four groups.（4） All experimental results were statistically analyzed by SPSS15.0 statistical software. The enumeration data were compared with Fisher’s exact probabilities. The measurement data were compared with the standard deviation（ x ±s）. The t test was used to compare the two groups of independent samples. Use α=0.05 as inspection level.Results1. Comparison of clinical data of the pregnant women in the two groups :There are no statistically significant（P > 0.05） between PROM group and control group in the pregnant women’s age, gestational age, body mass index; 2. Immunohistochemical staining results are as follows:（1） PGRMC₁ are mainly expressed in chorion and decidua of fetal membranes by Immunohistochemistry. PGRMC₁ was mainly colored in the nucleus and partly in the cytoplasm. In the four regions of the two groups, PGRMC₁ staining is the most shallow in the rupture zone of the fetal membranes in the premature rupture of fetal membranes, and there is statistically significant（P < 0.05）.（2） MMP-9 are mainly expressed in the chorion and decidua of fetal membranes by Immunohistochemistry, and are mainly expressed in the cytoplasm and part of the nucleus. In the four regions of the two groups, MMP-9 are the deepest coloring in the rupture zone of the fetal membranes in the premature rupture of fetal membranes, and there is statistically significant（P < 0.05）.3. The Comparison of PGRMC₁ protein expression levels in the four different regions between the two groups:（1） The protein expression level of PGRMC₁（0.607±0.069）in [RS] of PROM group is significantly lower than that（1.045±0.098）in [DS] of PROM group, and there is statistically significant（P < 0.05）; But the difference expression level of PGRMC₁ in the control group between the rupture zone [RS]（1.053±0.094）and away from the broken membrane area [DS]（1.041±0.094）is not statistically significant（P > 0.05）;（2） The protein expression level of PGRMC₁（0.607±0.069）in [RS] of PROM group is significantly lower than that（1.053±0.094）in [RS] of control group, and there is statistically significant（P < 0.05）; But the difference expression level of PGRMC₁ in the away from the broken membrane area [DS]（1.045±0.098）of the PROM group and the the [DS]（1.041±0.094）of control group is not statistically significant（P > 0.05）;4. The Comparison of MMP-9 protein expression levels in the four different regions between the two groups:（1） The protein expression level of MMP-9（1.450±0.122）in [RS] of PROM group is significantly higher than that（1.009±0.064）in [DS] of PROM group, and there is statistically significant（P < 0.05）; But the difference expression level of MMP-9 in the control group between the rupture zone [RS]（1.041±0.076）and away from the broken membrane area [DS]（1.011±0.074）is not statistically significant（P > 0.05）;（2） The protein expression level of MMP-9（1.450±0.122）in [RS] of PROM group is significantly higher than that（1.041±0.076）in [RS] of control group, and there is statistically significant（P < 0.05）; But the difference expression level of higher in the away from the broken membrane area [DS]（1.009±0.064）of the PROM group and the the [DS]（1.011±0.074）of control group is not statistically significant（P > 0.05）;5. The Comparison of PGRMC₁ m RNA expression levels in the four different regions between the two groups:（1） The m RNA expression level of PGRMC₁（0.635±0.020）in [RS] of PROM group is significantly lower than that（0.903±0.004）in [DS] of PROM group, and there is statistically significant（P < 0.05）; But the difference expression level of PGRMC₁ in the control group between the rupture zone [RS]（0.926±0.020）and away from the broken membrane area [DS]（0.962±0.030）is not statistically significant（P > 0.05）;（2） The m RNA expression level of PGRMC₁（0.635±0.020）in [RS] of PROM group is significantly lower than that（0.926±0.020）in [RS] of control group, and there is statistically significant（P < 0.05）; But the difference expression level of PGRMC₁ in the away from the broken membrane area [DS]（0.903±0.004）of the PROM group and the the [DS]（0.962±0.030）of control group is not statistically significant（P > 0.05）;6. The Comparison of MMP-9 mRNA expression levels in the four different regions between the two groups:（1） The m RNA expression level of MMP-9（1.809±0.046）in [RS] of PROM group is significantly higher than that（0.919±0.011）in [DS] of PROM group, and there is statistically significant（P < 0.05）; But the difference expression level of MMP-9 in the control group between the rupture zone [RS]（1.003±0.021）and away from the broken membrane area [DS]（0.952±0.013）is not statistically significant（P > 0.05）;（2） The mRNA expression level of MMP-9（1.809±0.046）in [RS] of PROM group is significantly higher than that（1.003±0.021）in [RS] of control group, and there is statistically significant（P < 0.05）; But the difference expression level of higher in the away from the broken membrane area [DS]（0.919±0.011）of the PROM group and the the [DS]（0.952±0.013）of control group is not statistically significant（P > 0.05）;ConclusionsThese results suggest that the lower expression of PGRMC₁ and the higher expression of MMP-9 in [RS] from the PROM group may play a role in the occurrence of premature rupture of membranes.