Fumaric acid and succinic acid treat gestational hypertension by downregulating the expression of KCNMB1 and TET1

The present study hypothesized that fumaric acid and succinic acid may exhibit therapeutic effects on gestational hypertension. During pregnancy, estrogen upregulates ten-eleven translocation 1 (TET1) expression, which subsequently increases calcium-activated potassium channel subunit β1 (KCNMB1) expression. KCNMB1 is associated with hypertension. Fumaric acid and succinic acid are understood to inhibit TET. Therefore, the present study investigated whether fumaric acid and succinic acid exhibit therapeutic effects on gestational hypertension and whether these effects are mediated by TET1 and KCNMB1. Nω-Nitro-L-arginine methyl ester hydrochloride was injected into rats to establish a gestational hypertension model. Dimethyl fumarate (DMF) and succinic acid were administrated into rats to treat gestational hypertension. Rats were divided into five groups: i) Control; ii) model; iii) DMF; iv) succinic acid; and v) DMF + succinic acid. Blood pressure was monitored by a noninvasive meter and urinary protein was determined using a urinary protein kit. Placenta pathology was examined by hematoxylin-eosin staining. Compared with the control group, urinary protein and blood pressure in the model group increased significantly. The placental cells in the control group were arranged orderly. However, in the model group, decidual cellular edema of placenta and vacuolar degeneration were observed, and the intervascular membrane was markedly thicker with plenty of fibrin deposition. These results indicate successful establishment of a gestational hypertension model. However, compared with the model group, urinary protein, blood pressure, edema, vacuoles and fibrin deposition were markedly reduced in the DMF, succinic acid and DMF + succinic acid groups. mRNA and protein levels of TET1 and KCNMB1 in placenta were evaluated by immunohistochemical analysis, reverse transcription-quantitative polymerase chain reaction and western blotting. The TET1 and KCNMB1 levels in the model group were markedly increased compared with those in the control group. However, compared with the model group, the expression levels were markedly downregulated in the DMF, succinic acid and DMF + succinic acid groups. In conclusion, fumaric acid and succinic acid may treat gestational hypertension by downregulating the expression of KCNMB1 and TET1.