Pravastatin alleviates oxidative stress and decreases placental trophoblastic cell apoptosis through IL-6/STAT3 signaling pathway in preeclampsia rats.

OBJECTIVE

The aim of this study was to explore the effects of pravastatin on oxidative stress and placental trophoblastic cell apoptosis in preeclampsia rats via the interleukin (IL)-6/signal transducer and activator of transcription 3 (STAT3) signaling pathway.

MATERIALS AND METHODS

Experimental rats were randomly assigned into three groups, including control group (C group), model group (M group) and pravastatin group (P group). The rat model of preeclampsia was successfully established. Blood pressure, urinary protein and nitric oxide (NO) as well as oxidative stress indicators in rats were detected at 7, 14 and 21 d, respectively. The content of serum IL-6 was determined via enzyme-linked immunosorbent assay (ELISA). The messenger ribonucleic acid (mRNA) expression of IL-6 in the placenta of rats in each group was detected using quantitative polymerase chain reaction (qPCR). Western blotting (WB) was used to determine the protein expression level of STATs in the placental tissues of rats. In addition, cell counting kit (CCK)-8 assay was conducted to detect the proliferation of rat placental trophoblasts.

RESULTS

The content of serum NO was (14.32±2.32) μM in M group, (28.37±3.32) μM in C group and (22.54±3.12) μM in P group, respectively. It was significantly elevated in P group compared with M group (p<0.05). Blood pressure in M group was evidently higher than that in C group at 14 and 21 d (p<0.05). However, P group exhibited distinctly lower blood pressure than M group (p<0.05). No statistically significant differences were observed in the urinary protein of rats among all the three groups at 7 d (p>0.05). At 14 and 21 d, the content of urinary protein in M group was considerably higher than that in C group (p<0.05). However, P group had distinctly lower urinary protein content than M group (p<0.05). Compared with C group, the content of malondialdehyde (MDA) and advanced oxidation protein products (AOPP) rose significantly in M group, whereas the content of superoxide dismutase (SOD) declined remarkably (p<0.05). In comparison with M group, P group exhibited declined MDA and AOPP content and increased SOD content, with statistically significant differences between the two groups (p<0.05). The expression level of serum IL-6 in rats in M group was markedly higher than that in C group (p<0.05). Meanwhile, the expression level of serum IL-6 evidently declined in P group compared with M group (p<0.05). Compared with C group, the protein expressions of phosphorylated STAT1 (p-STAT1) and p-STAT3 were considerably up-regulated in M group (p<0.01). However, they decreased prominently in P group in comparison with M group (p<0.01). C group exhibited a remarkably worse proliferation ability of rat placental trophoblasts than C group (p<0.01). In comparison with M group, the proliferation ability of rat placental trophoblasts was evidently enhanced in P group (p<0.05). Flow cytometry results indicated that the apoptosis of trophoblastic cells increased significantly in M group compared with that in C group (p<0.01). However, it significantly declined in P group in comparison with M group (p<0.05).

CONCLUSIONS

Pravastatin can repress the IL-6/STAT3 signaling pathway to alleviate oxidative stress, improve preeclampsia and decrease the apoptosis of placental trophoblastic cells in preeclampsia rats.