Mechanism of excessive iodine-induced apoptosis of chorionic trophoblast cells in relation to missed early miscarriage / 中华地方病学杂志

ABSTRACT

Objective:To investigate the mechanism of excessive iodine-induced apoptosis of chorionic trophoblast cells associated with missed early miscarriage.Methods:Patients with unexplained missed early miscarriage ≤12 weeks of gestation (MA group, n = 43) and normal pregnant women (control group, n = 64) who were treated at Tianjin Central Obstetrics and Gynecology Hospital from September 2019 to September 2022 were selected as the study subjects, and villous tissues were collected for proliferating cell nuclear agtigen Ki67 immunohistochemistry and apoptosis assay, while urine samples were collected for urinary iodine content assay. Different doses of iodine were used to stimulate the cultivation of human chorionic trophoblast cell line (HTR8/SVneo) for 24 h. Cell proliferation viability was detected using cell counting kit 8 (CCK8), and apoptosis was detected using flow cytometry. Results:(1) Urinary iodine values were 159.70 (114.21, 218.73) μg/L in the control group and 210.80 (143.10, 336.70) μg/L in the MA group, the difference between the two groups was statistically significant ( Z = 2.26, P = 0.024). (2) The proportion of positive and strong positive Ki67 immunohistochemical staining of the villous tissues in the MA group was significantly lower than that in the control group (χ 2 = 37.00, P < 0.001). (3) The apoptosis rate of villous tissue in the MA group was significantly higher than that in the control group [(26.24 ± 1.06)% vs (2.96 ± 1.97)%, t = 92.23, P < 0.001]. (4) The cell proliferation rates of HTR8/SVneo in the 50, 100, 300 and 500 μg iodine groups were significantly lower than that in the 0 μg iodine group ( P < 0.05), with the 500 μg iodine group below the median lethal dose (LD 50). (5) The apoptosis rates of 0, 50 and 500 μg iodine groups were (8.79 ± 0.12)%, (9.56 ± 0.08)% and (19.86 ± 0.05)%, respectively, and the differences among the three groups were statistically significant ( F = 7.32, P = 0.007); in which the 50 and 500 μg iodine groups were higher than that of the 0 μg iodine group, and the 500 μg iodine group was higher than that of the 50 μg iodine group ( P < 0.05). Conclusions:Urine iodine content significantly increases in patients with missed early miscarriage. Excessive iodine intake may lead to a decrease in the proliferation viability and an increase in cell apoptosis of chorionic trophoblast cells.