Expression and significance of let-7a and tumor necrosis factor-alpha in placenta of severe preeclampsia

Objective To investigate the expression and clinical significance of let-7a and tumor necrosis factor-alpha (TNF-alpha) in placental tissue of patients with severe preeclampsia (SPE). Methods From January 2018 to October 2019, 64 cases of puerperal delivery at the First People's Hospital of Lianyungang City, 44 cases of SPE (SPE group), and 20 cases of healthy pregnant women (NC group) were selected. QRT-PCR and Western-blot were used to detect the expression levels of let-7a, TNF-alpha mRNA, and protein in the two groups of placental tissues. The correlation and the clinical significance of the two were statistically analyzed. Results The relative expression of let-7a in the SPE group was significantly lower than that in the control group (0.06 +/- 0.02 versus 0.25 +/- 0.04, p < .05); the expression of TNF-alpha mRNA in the SPE group was significantly higher than that in the control group (0.48 +/- 0.04 versus 0.17 +/- 0.03, p < .05); TNF-alpha protein expression was significantly increased in the SPE group (1.09 +/- 0.12 versus 0.56 +/- 0.03, p < .05); let-7a and TNF-alpha were significantly negatively correlated (r = -0.41, p < .05); the blood pressure and birth weight of the pregnant women in the SPE group and the control group were significantly different [systolic blood pressure (164.27 +/- 4.62) mmHg versus (125.01 +/- 2.23)] mmHg, diastolic blood pressure (109.24 +/- 2.97) mmHg versus (75.94 +/- 2.74) mmHg, neonatal birth weight (2507.02 +/- 161.46) g versus (3592.12 +/- 153.05) g, p < .05]; the expression of TNF-alpha in placental tissue of SPE group was significantly positively correlated with systolic and diastolic blood pressure (r = 0.93 and 0.89, p < .05). Conclusion let-7a may participate in the occurrence and development of SPE by negatively regulating the expression of TNF-alpha.