Correlations of MMP-9 and PPARγ gene polymorphisms with occurrence of preeclampsia

The aim of this study was to investigate the expressions of matrix metalloproteinase-9 (MMP-9) and peroxisome proliferator-activated receptor gamma (PPARγ) in the placenta of patients with preeclampsia and to elucidate the associations of their polymorphisms with the occurrence of preeclampsia.

A total of 200 patients with preeclampsia (Preeclampsia group) and 100 pregnant women with normal delivery (Control group) were enrolled as research subjects. The expressions of MMP-9 and PPARγ in placentae of Preeclampsia group and Control group were measured by Western blotting. Conformation-difference gel electrophoresis was adopted for typing single nucleotide polymorphisms (SNPs) rs101201 and rs23102 in the promoter region of MMP-9 gene and rs201018 and rs102934 in the promoter region of PPARγ gene. Chi-square test was conducted to analyze whether the distribution frequency of MMP-9 and PPARγ genotypes was consistent with the law of genetic equilibrium. The correlations of the alleles and polymorphisms of MMP-9 and PPARγ with the occurrence of preeclampsia were analyzed. In addition, the associations of rs101201 genotype GG of MMP-9 gene and rs201018 genotype TT of PPARγ gene with the clinicopathological features of preeclampsia were analyzed.

Compared with Control group, the protein expression level of MMP-9 was significantly down-regulated (p<0.05), while the protein expression level of PPARγ was significantly up-regulated in placental tissues of Preeclampsia group (p<0.05). Based on Hardy-Weinberg equilibrium analysis, the two polymorphisms of both MMP-9 and PPARγ were consistent with the genetic equilibrium distribution (p>0.05). Gene correlation analysis showed that rs101201 polymorphism and its alleles in the promoter region of MMP-9 gene and rs201018 polymorphism and its alleles in the promoter region of PPARγ gene were correlated with the occurrence of preeclampsia (p<0.05). Besides, body mass index (BMI) value, gestational age, systolic blood pressure, and serum creatinine level in preeclampsia patients with the genotype GG of rs101201 in the promoter region of MMP-9 gene were not statistically significantly different from those in Control group (p>0.05). Furthermore, no statistically significant differences were observed in gravidity, parity, gestational age, systolic blood pressure, serum creatinine level, and plasma albumin level between preeclampsia patients with the genotype TT of rs201018 in the promoter region of PPARγ gene and those in Control group (p>0.05).

PPARγ and MMP-9 are abnormally expressed in the placenta of patients with preeclampsia. Moreover, rs201018 polymorphism in the promoter region of PPARγ gene and rs101201 polymorphism in the promoter region of MMP-9 gene are correlated with the occurrence of preeclampsia.