| خلاصه مقاله | Successful embryo implantation requires both well endometrial receptivity and a highquality embryo. Recurrent implantation failure (RIF) refers to the implantation failure of at least 3
healthy embryos following in vitro fertilization (IVF) in a woman under the age of 40 years.
Maternal immune system’s inadequacy is convicted for implantation failure in RIF patients.
During the implantation window, high division rate of undifferentiated stem cells of epiblast,
exposes them to DNA damage. Poly (ADP-ribosyl) ation (PARylation), prevents blastocyst
apoptosis through autophagy induction. Poly (ADP-ribose) polymerase-2 (PARP-2), the major
enzyme responsible for PARylation, plays an essential role in DNA repair pathways during early
post-implantation development. Animal studies have approved its upregulation throughout the
endometrial receptivity stages at basal levels of endometrium. This study aims to evaluate PARP-
2 levels in RIF patients compared to fertile women. In this case-control study, we investigated the
expression levels of PARP-2 in peripheral blood samples of RIF patients compared to healthy
pregnant women. 24 RIF patients, whose husbands’ semen analysis and DNA fragmentation test
results were normal, and 24 individuals as a control group, from gynecology department of Tabriz
Valiasr Hospital were enrolled in the study. 10 ml of blood sample was taken from individuals at
the follicular phase of their menstrual cycle and the serum levels of PARP-2 were assessed by
Human PARP2 ELISA kit. To determine the distribution of Potential confounding variables (age,
BMI, cigarette and alcohol addiction), Shapiro-Will test was performed that showed normal
distribution. The mean level of PARP-2 and standard deviation were reported. An independentsamples t-test was conducted to compare the mean level between the groups, using SPSS Statistics
version 23.0. The mean age was 33.64 ± 3.0 in RIF patients and 32.62 ± 4.01 in control group (p
value = 0.98). A significant reduction in PARP-2 serum levels was observed in RIF patients (7.72
± 4.41 ng/ml) compared with controls (11.06 ± 5.41 ng/ml). (p value = 0.023) This result suggests
that PARP-2 probably takes part in cellular events of implantation in human uterine as explored in
animal studies to affect endometrial receptivity, embryo development and blastocyst attachment.
Additional studies can contribute to more comprehensive understanding of its underlying
mechanisms and develop it as a biomarker of uterine receptivity and stromal cell decidualization. |