Abstract:

BACKGROUND: The previous studies have confirmed that 100 μg/L insulin-like growth factor 1 can antagonist apoptosis in vitro induced by 30 mmol/L glucose toxicity, it can relieve harm of high glucose on maternal/fetal. But the mechanisms and molecular mechanisms to improve the nutritional environment of the early embryo development are not clear.
OBJECTIVE: To observe the effect of insulin-like growth factor 1 antagonist high glucose on mRNA expression and DNA methylation levels of the development-related imprinted genes H19/Igf-2 in mouse preimplantation embryos in vitro on the basis of preliminary work and starting from epigenetic prospect.
METHODS: The diabetic mice models were established. The acquired early period 2-cell embryos were divided into experimental group and control group: the control group was high sugar adversity cultured in KSOM culture medium containing 30 mmol/L glucose, and the experimental group was treated with 100 μg/L insulin-like growth factor 1. Until growth to the blastocyst stage, the mRNA expression level of H19/Igf-2, and the DNA methylation level in imprinting control region of H19/Igf-2 were detected.
RESULTS AND CONCLUSION: Real-time PCR analysis showed that the mRNA expression levels of H19 and Igf-2 in morulas were respectively 5.9 and 5.2 times as that of the control group (P < 0.01). Moreover, thus mRNA expression levels of H19 and Igf-2 in blastulas were separately 2.4 and 1.8 folds as that of the control group (P < 0.01). Bisulfite Sequencing PCR analysis demonstrated that the DNA methylation levels of H19 and Igf-2 in mouse morulas and blastulas of the experimental group were respectively declined by 27.9% and 20.9% than that of the control group (P < 0.01). The insulin-like growth factor 1 antagonist high glucose can partially reduce the DNA methylation level of H19/Igf-2 in imprinting control region in order to increase the mRNA expression levels of H19 and Igf-2, and it can antagonize the damage of high glucose during early mouse embryo development.