Effects of Klotho polymorphisms on Preeclampsia risk in a case-control study

Klotho-mediated activation of the anti-oxidant Nrf2/ARE signal pathway affects cell apoptosis, senescence and mobility in hypoxic human trophoblasts: involvement of Klotho in the pathogenesis of preeclampsia

The anti-aging gene Klotho is implicated in the pathogenesis of preeclampsia (PE), which is a pregnancy disease characterized by hypertension and proteinuria. Oxidative stress is closely associated with the worse outcomes in PE, and Klotho can eliminate Reactive Oxygen Species (ROS), but it is still unclear whether Klotho regulates PE pathogenesis through modulating oxidative damages. Here, by analyzing the clinical data, we found that Klotho was aberrantly downregulated in PE umbilical cord serum and placental tissues, compared to their normal counterparts. In in vitro experiments, the human trophoblasts were subjected to hypoxic pressure to establish the PE models, and we confirmed that hypoxia also decreased the expression levels of Klotho in those trophoblasts. In addition, through performing functional experiments, we confirmed that hypoxia promoted oxidative damages, cell apoptosis and senescence, whereas suppressed cell invasion in human trophoblasts, which were all reversed overexpressing Klotho. The following mechanical experiments verified that Klotho increased the levels of nuclear Nrf2, total Nrf2, SOD2 and NQO1 to activate the anti-oxidant Nrf2/ARE signal pathway, and silencing of Nrf2 abrogated the protective effects of Klotho overexpression on hypoxic human trophoblasts. Consistently, in in vivo experiments, Klotho overexpression restrained oxidative damages and facilitated cell mitosis in PE rats' placental tissues. In conclusion, this study validated that Klotho activated the Nrf2/ARE signal pathway to eliminate hypoxia-induced oxidative damages, cell apoptosis and senescence to recover normal cellular functions in human trophoblasts, and our data supported that Klotho could be used as novel biomarker for PE diagnosis and treatment.

The association of the prothrombin G20210A single-nucleotide polymorphism and the risk of preeclampsia: Systematic review and meta-analysis

OBJECTIVE

We conducted this systematic review and meta-analysis to assess the association between the risk of preeclampsia and the prothrombin G20210A single-nucleotide polymorphism.

STUDY DESIGN

We followed the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" guidelines. Relevant published studies were searched in the data base. The retrieved studies were assessed for quality by using the Modified Newcastle-Ottawa Scale for quality assessment. OpenMeta Analyst software was used for the statistics.

RESULTS

Twenty-eight case-control studies enrolling 3821 cases and 4808 controls were included in this systematic review and meta-analysis. We found a significantly increased preeclampsia risk associated with the G20210A polymorphism in three models: allele contrast (A vs. G), OR 2.183, 95 % CI 1.665-2.862; heterozygote (AG vs. GG), OR 2.233, 95 % CI 1.690-2.95; and the dominant model (AA + AG vs. GG) OR 2.240, 95 % CI 1.700-2.950. However, the association was not observed in the homozygote (AA vs. GG) OR 1.310, 95 % CI = 0.632-2.713 r recessive model (AA vs. AG + GG), OR 1.315, 95 % CI = 0.642-2.695.

CONCLUSIONS

In this meta-analysis, the prothrombin G20210A single-nucleotide polymorphism was associated with an increased risk of preeclampsia.

Value of ABCG2 Q141K and Q126X genotyping in predicting risk of preeclampsia in Chinese Han women population

Hyperuricemia (HUA) in women with preeclampsia (PE) not only indicates a reminder of severity but also contributes directly to the pathogenesis of PE. ATP-binding cassette subfamily G member 2 (ABCG2) has a very strong effect on the serum urate concentrations. Our aim was to investigate the association between polymorphisms of ABCG2 with PE in Chinese Han female population. A cohort of 793 preeclamptic women (466 PE with HUA and 327 PE without HUA) and 744 normal pregnant women recruited in this study were genotyped for genetic distribution of Q141K (rs2231142) and Q126X (72552713) in ABCG2 by the TaqMan allelic discrimination real-time PCR. There was no statistically significant difference of genotypic and allelic frequencies between PE and the normal pregnant women in Q141K (Χ² = 1.11, P = 0.58 by genotype; Χ² = 0.32, P = 0.57 by allele) and Q126X (P = 0.33 by genotype; P = 0.33 by allele), and no significant difference was found in the genetic distribution of Q141K and Q126X between PE with HUA, PE without HUA and controls. Additionally, this study observed no significant difference in genotypic and allelic distribution between early/late-onset PE with/without HUA or mild/severe PE with/without HUA and control subgroups. Based on our findings, the ABCG2 Q141K and Q126X polymorphisms may not be associated with PE in Chinese Han women.