Expression and regulatory mechanism of microRNA-155 in the villi of patients with unexplained recurrent spontaneous abortion patients

Abstract

To study the expression and the mechanism of miR-155in the villi of patients with unexplained recurrent spontaneous abortion (URSA). The expression of miR-155 in the villi of 36 cases with URSA (URSA group) and 25 women with normal early pregnancy (control group) were detected by stem-loop real-time reverse transcription (RT) qPCR.Expression of hypoxia inducible factor-1 (HIF-1α), vascular endothelial cell growth factor (VEGF) and micro lymphatic vessel density (MVD) in the villi of were measured by immnohistochemical staining among two groups. (1)miR-155 expression:the mean miR-155 expression were 1.456 (0.489, 2.459) in URSA group and 2.833 (1.740, 3.794) in control group, which reached statistical difference (P < 0.05). The mean expression of miR-155 of 1.683 (0.902, 2.459) in URSA group with abortion times ( ≤ 3) was significantly higher than 1.229 (0.489, 1.719) in URSA group with more than 4 times abortion (P < 0.05). (2) Indexes :the expression of HIF-1α, VEGF and MVD value were 121 ± 12, 134 ± 12, 36 ± 6 in URSA group and 99 ± 10, 109 ± 10, 28 ± 4 in control group, which reached statistical difference (P < 0.01). The expression of HIF-1α, VEGF and MVD value of 119 ± 12, 134 ± 12, 35 ± 5 in URSA group with less than 3 times abortion was significantly lower than 128 ± 12, 138 ± 12, 43 ± 6 in URSA group with more than 4 times abortion (P < 0.01). The expression of miR-155 and HIF-1α is topically stimulated by oxygen signal.HIF-1α adjusts the transcription and translation of VEGF, which together involved in placental trophoblast invasion and placental angiogenesis. The low expression of miR-155 could interfere with expression of HIF-1α and VEGF, which might be involved in villous vascular dysplasia in URSA.