The Expression And Clinical Significance Of DNA Methyltransferases(DNMTs)in The Chorionic Villi Of Early Embryo Growth Arrest

Objective: 1.To detect the expression and immunohistochemical profiling of DNMT1, DNMT3 A, DNMT3 b and DNMT3 L in the chorionic villi of early embryo growth arrest.2. To analyze the differential expression of four DNMTs at m RNA and protein levels and to explore the underlying clinical significance.Methods:We randomly selected 40 women diagnosed with early embryo growth arrest by B ultrasound as observational group and accepted curettage of uterine cavity after visiting the obstetrical department of the Qingdao Municipal Hospital between January 2013 and June 2014. During the same period, we selected another 40 women who performed induced abortion with normal early pregnancy as control group. We obtained chorionic villi tissues from two groups for further research.1.Real-time quantitative PCR( RT-qRCR) was used on the normal groups and the early embryo growth arrest group to quantitatively determine DNMT1, DNMT3 B, DNMT3 B and DNMT3 L mRNA expression in the chorionic villi tissues.2. Streptavidin-Perosidase(SP) immunochemistry was used to determine the staining location of DNMT1, DNMT3 B, DNMT3 B and DNMT3 L in the villus trophoblast celltwo groups and Image-Pro Plus 6.0 was performed to detect the expression of four DNMTs proteins.3. Western Blot method was used to further detect DNMT1, DNMT3 A, DNMT3 B and DNMT3 L protein expression.4.Statistical analysis was performed using SPSS version 17.0 software. For all analysis, RT-q RCR, SP-immunochemistry and Western Blot, a P-value < 0.05 was regarded as statistically significant.Results:1.DNMT1, DNMT3 A, DNMT3 B and DNMT3 L were expressed in the two groups of chorionic villi tissues, and DNMT3 B expression was higher than other three genes whether in m RNA or Protein level.2.In m RNA level, there was no statistical significance of four DNMTs m RNA expression between the two groups(P>0.05).3.In protein level, four DNMTs presented various models of immunohistochemical staining in chorionic villi tissues of two groups, and DNMT1 and DNMT3 L located in cytoplasm, DNMT3 A and DNMT3 B located in the nucleolus. Furthermore, Image-Pro Plus 6.0 and Western Blot results showed that DNMT3 A expression of early embryo growth arrest was lower, differences between the two groups were statistical significance(P<0.05).4. There was no significant correlation among DNMT1, DNMT3 A, DNMT3 B and DNMT3L(P>0.05).Conclusion:1.The lower protein expression of the DNMT3 A might be involved in the pathogenesis of early embryo growth arrest.2.Detection of DNMTs in chorionic villi tissue probably provide a new approach for early clinical intervention and treatment on early embryo growth arrest.