An obesity-related FTO variant and the risk of preeclampsia in a Finnish study population

The obesity associated FTO gene polymorphism and the risk of preeclampsia in Iranian women: A case-control study

BACKGROUND

Preeclampsia (PE) is one of the leading disorders in pregnant women with maternal and fetal complications. Obesity is considered an important risk factor for the development of PE. Genetic variations in fat mass and obesity associated (FTO) gene may play a role in the development of PE. This study aimed to investigate the possible association between FTO gene rs9939609 and PE risk in a sample of Iranian pregnant women.

MATERIAL AND METHODS

In this case-control study, 312 pregnant women were included, including 128 with PE and 184 without PE. Demographic data and blood samples were obtained from all individuals. The genotyping of rs9939609 polymorphisms was performed by the tetra-primer amplification refractory mutation system-polymerase chain reaction (TP-ARMS-PCR) method, and the results of TP-ARMS-PCR were confirmed using DNA sequencing.

RESULTS

The genotype frequency was 50%, 47.7%, and 2.3% in pregnant patients and 37%, 47.8%, and 15.2% in healthy controls for TT, AT, and AA, respectively. The risk of PE was significantly reduced in the pregnant women having the AA genotype.

CONCLUSION

Based on the results of the present study, rs9939609 polymorphism in the FTO gene may play a protective role against PE. However, further studies are warranted. [Figure: see text].

N6-methyladenosine (m6A) Modification in Preeclampsia

Recently, epitranscriptional modification of N6-methyladenosine (m6A) has received growing attention in the research on the pathogenesis of preeclampsia. Advances in m6A sequencing have revealed the molecular mechanism and importance of m6A modification. In addition, epitranscriptional modification of m6A is closely related to the metabolic processes of placental tissues and cells in preeclampsia. This article reviews the composition, mode of action, and bioinformatics analysis of m6A modification-related proteins, and their biological function in the progression of preeclampsia. The relationship between m6A modification and preeclampsia risk factors, such as diabetes, cardiovascular disease, obesity, and psychological stress, is summarized to provide new ideas for studying PE-targeting molecules.

Evaluation of the PLAC8 Gene in Mexican Women With and Without Preeclampsia and Obesity

Preeclampsia (PE) is a leading cause of maternal-fetal mortality worldwide, and obesity is an important risk factor. Genes associated with pathophysiological events common to preeclampsia and obesity, such as PLAC8, remain to be studied; therefore, the aim of the present study was to evaluate this gene in the placentas of women affected with preeclampsia and healthy pregnant women. This case-controlled study included 71 healthy and 64 preeclampsia pregnancies. Gene expression was evaluated in primary human cytotrophoblasts (PHCT) from six normal and six preeclampsia pregnancies, and protein expression was verified in placentas from five healthy and six preeclampsia pregnancies. The whole coding and 5′ regions of the PLAC8 gene were sequenced from healthy (n = 10) and preeclamptic (n = 10) pregnancies. The presence of the observed nucleotide variations was analyzed by RT-PCR in the total population. Statistical analyses were performed accordingly. Obesity was associated with severe preeclampsia (SPE) (OR = 3.34; CI 95% 1.3–8.2, p < 0.01). Significantly higher mRNA and protein expression was observed in preeclamptic vs. healthy placentas (p < 0.05). After sequencing, a single nucleotide variation was identified in 10 cases and one control (p < 0.01), which was then evaluated in the total population showing no association with preeclampsia. This preliminary study confirms the association of SPE with obesity and suggests higher expression of PLAC8 mRNA and protein in placentas from preeclampsia. No differences in nucleotide variations between cases and controls of the whole population were observed. Further research is required to evaluate the implications of higher gene/protein expression in preeclampsia and the causes of such variation.

Maternal genetic contribution to pre-pregnancy obesity, gestational weight gain, and gestational diabetes mellitus

INTRODUCTION

Pre-pregnancy obesity, gestational diabetes mellitus (GDM), and gestational weight gain (GWG) are associated with each other. This is the first study to investigate whether genetic variants were associated with having GDM, and whether genetic variants-related GDM were associated with adiposity including pre-pregnancy obesity and excessive GWG in Turkish women.

PATIENTS AND METHODS

Women with GDM (n = 160) and without GDM (n = 145) were included in case-controlled study. Genotyping of the HNF1A gene (p.I27L rs1169288, p.98V rs1800574, p.S487N rs2464196), the VDR gene (p.BsmI rs1544410, p.ApaI rs7975232, p.TaqI rs731236, p.FokI rs2228570), and FTO gene (rs9939609) SNPs were performed by using RT-PCR.

RESULTS

The FTO AA genotype was associated with an increased risk of having GDM (AA vs. AT + TT, 24.4% vs. 12.4%, OR = 2.27, 95% CI [1.23-4.19], p = 0.007). The HNF1A p.I27L GT/TT genotype was associated with increased GDM risk (GT + TT vs. GG-wild, 79.4% vs. 65.5%, OR = 2.02, 95% CI 1.21-3.38], p = 0.007). However, all VDR gene SNPs and the HNF1A p.A98V, p.S487N were not associated with having GDM (p > 0.05). The FTO AA genotype was associated with an increased risk for pre-pregnancy overweight/obesity (OR = 1.43, 95% CI [1.25-3.4], p = 0.035), but not associated with excessive GWG after adjusting for pre-pregnancy weight (p > 0.05). Pre-pregnancy weight, weight at delivery, and GWG did not differ in both VDR and HNF1A gene carriers (p > 0.05). HOMA-IR and HbA1c were increased in both p.I27L TT and FTO AA genotype carriers (p < 0.05).

CONCLUSION

The adiposity-related gene FTO is associated with GDM by the effect of FTO on pre-pregnancy obesity. The diabetes-related p.I27L gene is associated with GDM by increasing insulin resistance.

Differential body weight, blood pressure and placental inflammatory responses to normal versus high-fat diet in melanocortin-4 receptor-deficient pregnant rats

OBJECTIVES

Although obesity increases the risk for hypertensive disorders of pregnancy, the mechanisms remain unclear. Neural melanocortin-4 receptor (MC4R) deficiency causes hyperphagia and obesity. Effects of MC4R deficiency on body weight, blood pressure (BP) and placental inflammatory responses to high-fat diet (HFD) are unknown. We tested two hypotheses: MC4R deficiency results in higher body weight, BP and placental inflammation under normal-fat diet (NFD) conditions and HFD exaggerates these responses in MC4R-deficient pregnant rats.

METHODS

MC4R and MC4R rats were maintained on NFD (13% kcal fat) or HFD (40% kcal fat) for ∼15 weeks, then measurements made on gestational day 19.

RESULTS

MC4R pregnant rats had greater body mass and total body fat and visceral adipose tissue weights along with greater circulating total cholesterol (TC) and leptin levels than MC4R rats regardless of diet. On NFD, circulating adiponectin levels were lower and placental TNFα levels and BP (conscious with carotid catheter) were higher in these heavier rats. Circulating adiponectin levels were lower and placental TNFα levels and BP were higher in MC4R rats compared with NFD controls. These parameters were not affected by HFD in the already heavier and hypertensive MC4R pregnant rats.

CONCLUSION

Obesity in MC4R deficiency and HFD in MC4R rats result in higher BP and placental inflammation during pregnancy. However, HFD did not exaggerate these responses in already obese MC4R pregnant rats. These data suggest that obesity and HFD are independently related to hypertension and placental inflammation in pregnancy.

The obesity associated FTO gene variant and the risk of adverse pregnancy outcomes: Evidence from the SCOPE study

OBJECTIVE

To investigate whether the FTO rs9939609 single nucleotide polymorphism (SNP), which is a risk factor for obesity and vascular diseases, is also associated with pregnancy complications including pre-eclampsia, gestational hypertension, small for gestational age pregnancy (SGA), and spontaneous preterm birth (sPTB).

METHODS

A case-control study of 1,741 nulliparous Caucasian women, their partners, and infants was conducted. DNA was extracted from peripheral blood or saliva from parents and cord blood from infants and genotyped using the Sequenom MassARRAY system.

RESULTS

The prevalence of maternal and infant AA genotype of FTO rs9939609 was increased in the SGA group compared with the uncomplicated pregnancy group (19.2% vs. 13.4%, OR = 1.7, 95% CI = 1.1-2.6, P = 0.02 and 24.6% vs. 12.5%, OR = 2.7, 95% CI = 1.6-4.6, P = 0.0002). The prevalence of maternal and infant AA genotype of FTO rs9939609 was also increased in the sPTB group compared with the uncomplicated pregnancy group (20.8% vs. 13.4%, OR = 2.1, 95% CI = 1.2-3.8, P = 0.009 and 20.0% vs. 12.5%, OR = 2.4, 95% CI = 1.0-5.3, P = 0.03).

CONCLUSIONS

The maternal and infant AA genotype of the obesity associated FTO rs9939609 SNP associates with increased risk for SGA and sPTB. This SNP may be important in predicting the risk of these pregnancy complications and subsequent vascular diseases.