The effects of placental long noncoding RNA H19 polymorphisms and promoter methylation on H19 expression in association with preeclampsia susceptibility.

The effect of DNA methylation on gene expression triggered it as a susceptibility factor in various diseases including preeclampsia (PE). The pathogenesis of PE is closely associated with the methylation status and genetic variants of relevant genes. Therefore, the aim of the study was to investigate the possible impacts of the placental DNA methylation and rs3741219, rs217727, and rs2107425 polymorphisms of the H19 gene on the PE susceptibility as well as the its mRNA expression. Moreover, eight haplotypes of three loci in the H19 gene were analyzed. In this case-control study, the placentas of 107 preeclamptic and 113 non-preeclamptic women were collected after delivery. The methylation status was assessed by methylation-specific polymerase chain reaction (PCR). The H19 polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism or amplification refractory mutation system-polymerase chain reaction methods. The quantitative real time PCR was used for mRNA expression assay. The placental H19 rs3741219 and rs2107425 polymorphisms were not associated with PE. However, H19 rs217727CT and TT genotypes might be associated with a 9.2- and 17.7-fold increased risk of PE, respectively. The Trs3741219 Crs217727 Crs2107425 and Trs3741219 Crs217727 Trs2107425 haplotypes were significantly lower, whereas the Trs3741219 Trs217727 Crs2107425 and Crs3741219 Trs217727 Crs2107425 haplotypes were significantly higher in PE women. Promoter but not upstream region hypermethylation of H19 gene could be led to decreased risk of PE (MM vs. UM + UU). No significant difference was observed in the placental mRNA expression between two groups. The H19 expression was significantly higher in women with unmethylated (UU), compared to methylated promoter (MM). The H19 expression was 17- and 15-fold higher in H19-rs2107425 CC and CT genotypes in PE women. In conclusion, the H19 rs2107425 polymorphism was associated with a higher risk of PE and increased H19 mRNA expression. The promoter hypermethylation of H19 gene was associated with a lower risk of PE and decreased H19 mRNA expression.

The possible role of maternal and placental vitamin D receptor polymorphisms and haplotypes in pathogenesis of preeclampsia.

Purpose: Vitamin D deficiency may be a main causative agent in the pathogenesis of preeclampsia (PE). The actions of the active form of vitamin D are mediated via the vitamin D receptor (VDR), which is expressed in numerous organs including placenta. Therefore, we evaluated the potential relationship between maternal and placental VDR polymorphisms and the predisposition to PE in an Iranian population.Methods: This case-control study surveyed 152 PE and 160 normotensive pregnant women. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was performed to examine the maternal and placental VDR Fok1 rs2228570, Bsm1 rs1544410, Taq1 rs731236, and Apa1 rs7975232 polymorphisms.Results: The maternal but not placental VDR FokI Ff genotype, was significantly lower in PE women (P = .02 and P = .06, respectively). The maternal and placental VDR FokI polymorphism was associated with lower PE risk in the dominant model (Ff+ff vs. FF) and these genotypes could decrease PE risk (OR, 0.5 [95% CI, 0.3-0.8], P = .007 and OR, 0.5 [95% CI, 0.3-0.9], P = .02, respectively). The haplotype analysis revealed that the maternal and placental TABf haplotype may lead to decreased risk of PE. In addition, the placental TABF haplotype was associated with higher risk of PE. No relationship was observed between PE susceptibility and the maternal and placental VDR Bsm1, Taq1 and Apa1 polymorphisms. There was also no relationship between the maternal and placental VDR polymorphisms and PE severity.Conclusions: the maternal and placental VDR FokI variant was associated with decreased risk of PE in the dominant model.

Renalase rs10887800 polymorphism is associated with severe pre-eclampsia in southeast Iranian women.

Evidence has shown that pre-eclampsia (PE) is associated with an increased level of catecholamines. Renalase is a catecholamine-metabolizing enzyme, which contributes to the occurrence of hypertension. In the current study, we aimed to assess the relation between two renalase gene ( RNLS) polymorphisms, including rs2576178 at the 5'-flanking region and rs10887800 at intron 6, near the exon/intron border and PE susceptibility. In this case-control study, 179 women with PE and 202 normotensive pregnant women were genotyped for RNLS rs2576178 and rs10887800 polymorphisms by the polymerase chain reaction-restriction fragment length polymorphism method. There was no association between RNLS rs10887800 and rs2576178 polymorphisms and PE, neither in the dominant nor in the recessive model. Although there was no association between RNLS rs10887800 polymorphism and mild PE, this polymorphism was associated with 2.2-fold higher risk of severe PE in the recessive model (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.2-4.4; P = 0.01) but not in the dominant model. The RNLS rs2576178 and rs10887800 polymorphisms were not associated with PE severity. The RNLS rs10887800 and rs2576178 GG/GG combined genotypes were associated with 8.4- and 16.7-fold higher risk of PE and severe PE, respectively (OR, 8.4; 95% CI, 1-71.1; P = 0.048 and OR, 16.7; 95% CI, 1.6-167; P = 0.018). Also, the G-G haplotype was associated with 1.7-fold risk of PE and mild PE (OR, 1.7; 95% CI, 1.1-2.4; P = 0.009 and OR, 1.7; 95% CI, 1.1-2.5; P = 0.02). The RNLS rs10887800 polymorphism was associated with severe PE. The RNLS rs10887800 and rs2576178 GG/GG combined genotypes and G-G haplotype were associated with higher risk of PE.

Genetic and epigenetic analysis of the BAX and BCL2 in the placenta of pregnant women complicated by preeclampsia.

The current study examined the effects of BAX and BCL2 polymorphisms and methylation as well as mRNA expression on susceptibility to PE. After delivery, the placentas were collected from 92 women with PE, as well as 106 normotensive pregnant women. The BAX rs4645878 and BCL2 rs2279115 polymorphisms were genotyped by the PCR-RFLP method. Methylation-specific PCR (MSP) was used for analysis of promoter methylation. mRNA expression was assayed by Quantitative RT-PCR. In addition, in silico analysis was performed by bioinformatics tools. There was no relationship between PE and placental BAX rs4645878 and BCL2 rs2279115 polymorphisms. The groups were not significantly different regarding the promoter methylation of BAX gene. Nonetheless, the MM status of BCL2 promoter had a significantly higher frequency in the PE group and was associated with 2.7-fold higher risk of PE (OR = 2.7, 95% CI = 1.3-5.6; P = 0.01). The relative mRNA expression of BCL2 was decreased in the placentas of PE women (P < 0.0001). The expression of BAX gene was not significantly different between the two groups. There was no association between placental BAX rs4645878 and BCL2 rs2279115 polymorphisms and mRNA expression levels. In silico analysis indicated that BAX rs4645878 and BCL2 rs2279115 polymorphisms were located in the core recognition site of different transcription factors and these substitutions of wild allele resulted in the loss and/ or change of these binding sites and subsequently may alter BCL2 and BAX expression. This study showed that the BAX and BCL2 polymorphisms and BAX promoter methylation were not associated with PE risk. The BCL2 promoter methylation was associated with lower BCL2 expression and higher PE susceptibility.

Impact of HOTAIR variants on preeclampsia susceptibility based on blood and placenta and in silico analysis.

HOX transcript antisense RNA (HOTAIR) as a lncRNA involves in epigenetic regulation of various genes. Several studies have been suggested the effects of HOTAIR polymorphisms on different diseases. The aim of the present study was to evaluate the effect of maternal and placental HOTAIR polymorphisms on risk of preeclampsia (PE). The maternal blood of 203 preeclamptic and 202 nonpreeclamptic pregnant women as well as the placentas of 87 of preeclamptic and 95 nonpreeclamptic pregnant women were genotyped for HOTAIR polymorphisms. There was no association between maternal and placental HOTAIR polymorphisms (rs12826786, rs920778, and rs1899663) and PE risk. However, the maternal rs4759314AG and dominant model genotypes were associated with increased risk of PE. The maternal and placental HOTAIR rs10783618 polymorphism was associated with PE risk in recessive and allelic models. Haplotype analysis showed that, the maternal CTGAT and CCTAT and placental CTGAT haplotypes were significantly higher and maternal CTGAC, TCTAT, and TTGAT and placental CTGAC haplotypes were significantly lower in PE women. In silico analysis revealed that HOTAIR rs1899663 had a main effect on the secondary structure of mRNA, however, HOTAIR rs4759314 variant had potential alteration of splicing. In conclusion, the maternal and placental HOTAIR rs10783618 polymorphism might increase PE susceptibility. © 2019 IUBMB Life, 71(9):1367-1381, 2019.

Analysis of polymorphisms, promoter methylation, and mRNA expression profile of maternal and placental P53 and P21 genes in preeclamptic and normotensive pregnant women.

BACKGROUND: Preeclampsia (PE), as a multisystem disorder, is associated with maternal hypertension and proteinuria. Apoptosis seems to be involved in the pathophysiology of PE, although its precise pathogenic mechanisms are not well established. In this study, we aimed to identify the association between maternal TP53-rs1042522, P21-rs1801270, and P21-rs1059234 polymorphisms and PE. In addition, we examined the effects of promoter methylation and TP53 and P21 polymorphisms on placental mRNA expression in PE women. METHODS: The blood of 226 PE women and 228 normotensive pregnant women was examined in this study. In addition, the placentas were genotyped in 109 PE and 112 control women. The methylation status was assessed by a methylation-specific PCR assay, while mRNA expression was examined via Quantitative Real Time PCR. RESULTS: The maternal and placental P21-rs1801270 CA genotype had a significant association with the reduced risk of PE. In the dominant, recessive, and allelic models, maternal/placental P21-rs1059234 polymorphism had no statistically significant association with the risk of PE. On the other hand, the reduced risk of PE was associated with maternal, but not placental TP53-rs1042522 polymorphism in the dominant and recessive models. The maternal and placental P21-rs1801270 polymorphism was associated with PE risk. The maternal P21 Trs1059234Crs1801270 haplotype was associated with 3.4-fold increase in PE risk, However the maternal P21 Trs1059234Ars 1801270 haplotype and placental Crs1059234CA rs1801270 haplotype led to 0.5 and 0.4-fold decrease in PE risk, respectively. PE women showed 5.6 times higher levels of placental mRNA expression of TP53 gene, although it was not associated with rs1042522 polymorphism. The relative placental mRNA expression of P21 gene was 0.2 in PE women. It was also 2.4 times higher in individuals with rs1801270CA genotype than those with AA genotype. The hyper-methylation of P21 and TP53 genes in the promoter region was associated with a 3.4-fold and 3-fold increase in PE risk, respectively. However, no association was found between P21 and TP53 mRNA expression and promoter methylation. CONCLUSION: In conclusion, P21-rs1801270 and TP53-rs1042522 polymorphisms were involved in reduced risk of PE. P21-rs1801270 was associated with decreased P21 mRNA expression. The hyper-methylation of P21 and TP53 genes in the promoter region was associated with a higher PE risk.

Association of HOTAIR gene polymorphisms and haplotypes with uterine leiomyoma susceptibility in southeast of Iran.

Uterine leiomyoma (UL) is the most common benign tumor of the uterus. HOX transcript antisense RNA (HOTAIR) as a lncRNAs is the product of HOXC gene that plays a major role in the invasion and development of different tumors. Several lines of evidence have been suggested the effects of HOTAIR polymorphisms on cancer risk. The aim of the present study was to analyze the effects of HOTAIR polymorphisms (rs12826786, rs920778, rs4759314 and rs1899663) on UL in southeast of Iran. A total of 152 women with UL and 182 age-matched healthy women were selected in the case-control study. The PCR-RFLP and ARMS-PCR methods were used for genotyping. HOTAIR rs920778 polymorphism was associated with a lower risk of UL in dominant [OR, 0.5 (95% CI, 0.3-0.9); P = 0.03], recessive [OR, 0.6 (95% CI, 0.4-0.9; P = 0.016] and allelic models [OR, 0.6(95% CI, 0.5-0.9); P = 0.004]. However, HOTAIR rs12826786 polymorphism was associated with a higher risk of UL in dominant [OR, 2.6 (95% CI, 1.6-4.1); P = 0.0001], recessive [OR, 1.9 (95% CI, 1-3.6); P = 0.04] and allelic models [OR, 1.8 (95% CI, 1.3-2.4); P = 0.0003]. There was no association between HOTAIR rs4759314 and rs1899663 polymorphisms and UL susceptibility. The frequency of CTGA haplotype was lower in UL women; however, the CCGA, TCGA, TTTA, and TTGA haplotypes were more frequent in UL women. Our results indicated that HOTAIR rs12826786 and rs920778 polymorphisms had a significant effect on UL susceptibility. The HOTAIR haplotypes could affect UL susceptibility.

The effect of miR-146a rs2910164 and miR-149 rs2292832 polymorphisms on preeclampsia susceptibility.

Preeclampsia (PE) is a gestational disorder and genetic and epigenetic alterations can affect its pathogenesis. Some evidences showed that the altered expression of miRNAs in the placentas complicated by PE. The blood samples from 219 PE and 242 normotensive pregnant women and placental tissue samples from 111 PE and 119 normotensive women were collected. MiR-146a and miR-149 polymorphisms were genotyped in blood samples and placentas using PCR-RFLP method. The frequencies of maternal miR-146a rs2910164 GC and CC genotypes did not differ between PE and control groups. However, the miR-146a rs2910164 G/C polymorphism was associated with an increased risk of PE in dominant (OR 1.5, 95% CI 1-2.1; P = 0.04) and allelic (OR 1.4, 95% CI 1-1.9; P = 0.04) but not recessive models. Moreover, the maternal GC and CC genotypes were associated with a 1.9- and 3.4-fold increased risk of severe PE (OR 1.9, 95% CI 1.1-3.2; P = 0.02 and OR 3.4, 95% CI 1.3-9; P = 0.01, respectively) and miR-146a rs2910164 polymorphism could increase risk of severe PE in dominant and recessive models (OR 2.1, 95% CI 1.3-3.4; P = 0.004 and OR 2.6, 95% CI 1-6.7; P = 0.04). The placental miR-146a rs2910164 polymorphism was associated with PE susceptibility in dominant (OR 1.8, 95% CI 1.1-3; P = 0.03) and allelic models (OR 1.7, 95% CI 1.1-2.5; P = 0.02). The frequencies of maternal and placental miR-149 rs2292832 genotypes were not different between two groups and these genotypes were not associated with PE or severe PE risk. In conclusion, according to logistic regression analysis the maternal/placental miR-146a rs2910164 G/C polymorphism was associated with PE and/or severe PE risk.

The effect of GPx-1 rs1050450 and MnSOD rs4880 polymorphisms on PE susceptibility: a case- control study.

Preeclampsia (PE) is a serious pregnancy complication whose etiology is not fully understood. However, previous reports have suggested that oxidative stress and genetic variants may contribute to the development of PE. This study aimed to examine the relationship between the Glutathione peroxidase-1(GPx-1) and Manganese Superoxide dismutase (MnSOD) polymorphisms and preeclampsia (PE) risk in Iranian women. Genotyping of the studied women, including 179 preeclamptic cases and 202 controls, for GPx-1 rs1050450 and MnSOD rs4880 polymorphisms was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our results showed a 1.7- to 1.6-fold increased risk of PE in the rs1050450 CT and CT + TT (dominant model) genotypes compared to CC genotype (OR = 1.7, 95%CI 1.1-2.7; P = 0.01 and OR = 1.6, 95%CI 1.1-2.4; P = 0.02; respectively). We also found a marked correlation between TC and CC genotypes of MnSOD rs4880 polymorphism and a 1.9- to 2.3-fold increase risk of PE (OR = 1.9, 95%CI 1.2-2.9; P = 0.005 and OR = 2.3, 95%CI 1-5.1; P = 0.04, respectively). The rs4880 MnSOD polymorphism was correlated with increased risk of PE in the allelic and dominant models (OR = 1.8, 95% CI 1.2-2.5, P = 0.002; OR = 1.9, 95%CI 1.3-3, P = 0.002, respectively). High frequency of TC/CC genotype of MnSOD rs4880 and CT genotypes of rs1050450 polymorphism in PE patients compared to controls showed the contribution of these variants to PE susceptibility.

Association of the placental VEGF promoter polymorphisms and VEGF mRNA expression with preeclampsia.

BACKGROUND: Preeclampsia (PE), is a pregnancy-specific complication with the placental origin which associated with altered expression of angiogenic factors. Vascular Endothelial Growth Factor (VEGF), is a growth and hypoxia-induced factor which contributes to the regulation of various processes. The present study has investigated the association of the placental VEGF -634G/C (rs2010963), -1154G/A (rs1570360), and -2549 I/D (18bpindel) polymorphisms in the promoter region with VEGF mRNA expression in PE women and control group. METHODS: This case-control study was performed on the placenta of 84 PE women and 103 controls after delivery. Genotyping of the VEGF polymorphisms was done by PCR or PCR, PCR-RFLP or sequencing methods. The mRNA expression levels were measured by Quantitative Real-Time PCR. RESULTS: The relative mRNA expression of VEGF gene was significantly higher in PE women compared to controls. The relative mRNA expression of VEGF gene was significantly higher in women with -634CC genotype compared to CG + GG genotypes in PE women and total studied women but not in control women. However, there was no association between the placental VEGF -1154G/A and -2549 I/D polymorphisms and VEGF mRNA expression neither in PE nor in control groups. CONCLUSION: The current study found higher mRNA expression of placental VEGF gene in PE women. The mRNA expression of the placental VEGF gene has been up-regulated in the placenta of women with -634CC genotype. No association was found between the placental VEGF -1154G/A and -2549 I/D polymorphisms and VEGF mRNA expression.

The association of pri-miRNA- 26a1 rs7372209 polymorphism and Preeclampsia susceptibility.

MicroRNAs (miRNAs) are a class of noncoding small RNAs which regulate gene expression through post-transcriptional repression or degradation of messenger RNA. They play very important roles in various biological processes including growth, differentiation, and proliferation, as well as apoptosis, angiogenesis, and metabolism. Therefore, in the present study, we evaluated the possible effect of functional rs7372209C/T polymorphism in the 5'- region of pri-miRNA- 26a1gene on preeclampsia(PE) susceptibility. This case-control study was conducted on 219 PE women and 204 unrelated healthy controls. The amplification refractory mutation system-polymerase chain reaction method was used for rs7372209C/T genotyping. The pri-miRNA- 26a1 rs7372209CT genotype was associated with decreased PE risk (OR, 0.5 [95% CI, 0.3-0.8], P = 0.001). The frequency of rs7372209TT genotype did not differ between two groups. In addition, the pri-miRNA- 26a1 rs7372209 polymorphism was associated with lower risk of PE in dominant model (CT+TT vs CC) (OR, 0.5 [95% CI, 0.4-0.8], P = 0.002). Although there was no significant difference between mild and severe PE women according to rs7372209CT genotype, the differences between mild and severe PE groups with controls remained significant. The frequency of pri-miRNA-26a1 rs7372209CT genotype was not different between late-onset PE and early onset PE groups. The present study showed for the first time that the pri-miRNA- 26a1 rs7372209 polymorphism was associated with lower risk of mild and severe PE in the dominant model and this polymorphism could be a protective factor for PE susceptibility.

Association between miRNA-152 polymorphism and risk of preeclampsia susceptibility.

BACKGROUND: Preeclampsia (PE) is one of the main causes of death among the pregnant women as well as newborns. Although the etiological cause of preeclampsia is not yet clear, a range of risk factors has been suggested. MicroRNAs (like miRNA-152) are small non-coding molecules that play a role in a wide spectrum of biological processes, such as cell proliferation and angiogenesis. This study aimed to investigate the possible relationship of miRNA-152 rs12940701 polymorphism and the risk of preeclampsia among the pregnant women as compared with the control group. METHODS: Genotyping of miRNA-152 rs12940701 polymorphism was performed using blood and placenta samples of 223 preeclampsia women and 229 normotensive pregnant women by a polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The results obtained from maternal blood showed an increase in T alleles for PE women, that there was no significant difference between the PE and control group (OR = 1.7, P = 0.19). In addition, no significant difference was found in the TT genotype between the two groups (11.6% vs. 7%, OR = 1.4, P = 0.3). Similarly, the results obtained from placental samples were identical. CONCLUSIONS: A lack of relationship between the polymorphism of miRNA-152 rs12940701 gene and preeclampsia development has been shown.

The long non-coding RNA H19 rs217727 polymorphism is associated with PE susceptibility.

H19 is an imprinted gene transcribing a long noncoding RNA which was previously reported to be involved in some diseases. However, the association between the H19 polymorphisms and Pre-eclampsia (PE) susceptibility has remained elusive. This study aimed to evaluate the association between three H19 haplotype SNPs (rs3741219, rs217727, and rs2107425) and the risk of PE. The present case control study consisted of 193 PE women and 201 controls. The H19 rs3741219 and rs217727 polymorphisms were genotyped with PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) and the H19 rs2107425 polymorphism with ARMS-PCR (Amplification refractory mutation system) methods. The frequency of alleles and genotypes of H19 rs3741219 and rs2107425 polymorphisms did not differ between PE women and controls. The frequency of the H19 rs217727T allele was significantly higher in PE women (P < 0.0001). The H19 rs217727 polymorphism was associated with higher PE susceptibility in the Co-dominant (OR = 12.1, 95% CI = 5.7-24.5, P < 0.0001 for CT genotype and OR = 29.7, 95% CI = 12.9-68.1, P < 0.0001 for TT genotype), Dominant (OR = 15.1, 95% CI = 7.5-30.3, P = P < 0.0001), Recessive (OR = 4.5, 95% CI = 2.6-7.9, P = < 0.0001), and Over-dominant (OR = 2.1, 95% CI = 1.4-3.1, P = 0.0006) models. Furthermore, the CCC, TCT, TCC, and CCT haplotypes of H19 rs3741219, rs217727, rs2107425 were associated with lower risk of PE; however, the CTC, TTC, and TTT haplotypes were associated with higher risk of PE. In conclusion, the present study found the relationship between H19 rs217727 but not rs3741219 and rs2107425 polymorphisms and PE susceptibility. In addition, the CTC, TTC, and TTT haplotypes were associated with the higher risk of PE.

The association of the placental CASPASE-3 gene polymorphisms and preeclampsia susceptibility and in-silico analysis.

Preeclampsia is a pathologic complication of pregnancy, associated with increased apoptosis in the cytotrophoblasts as the main cause of this disorder. Caspase-3 is a key apoptosis-related enzyme that both mitochondrial and death receptor apoptotic pathways can activate. In this study, we aimed to investigate the effect of placental CASP-3 rs4647602 and rs4647610 polymorphisms on PE susceptibility. The placentas of 106 PE women and 115 normotensive pregnant women were collected. Genomic DNA was extracted from the placenta. For genotyping of CASP-3 rs4647602 and rs4647610 polymorphisms, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used. The frequencies of placental CASP-3rs4647602CA and rs4647610GA genotypes were higher in PE women; however, the differences were not statistically different (P = 0.36 and P = 0.13, respectively). In addition, the frequencies of CA-GA combined genotypes and A-A haplotype were higher in PE women compared to the control women; however, the differences were marginally non-significant (P = 0.051 and P = 0.08, respectively). In-silico analysis revealed new enhancer and silencer motifs for mutant alleles of CASP-3rs4647602 and rs4647610 polymorphisms. In conclusion, placental CASP-3rs4647602 and rs4647610 polymorphisms were not associated with PE. Further studies with higher sample size are necessary to confirm or refute these findings.

The association of the placental MTHFR 3'-UTR polymorphisms, promoter methylation, and MTHFR expression with preeclampsia.

Preeclampsia (PE) is a pregnancy specific complication arises in presence of the placenta and disappears immediately after delivery. Therefore, the aim of the present study was to investigate the possible effects of the placental 3'-UTR rs1537514C>G and rs4846049C>A polymorphisms and DNA methylation of the MTHFR gene on the MTHFR mRNA expression. The placenta of 74 PE pregnant women and 75 normotensive pregnant women were collected after delivery. The methylation status of the MTHFR promoter was assessed with Methylation Specific PCR (MSP). The rs1537514C>G and rs4846049C>A polymorphisms were genotyped using PCR-RFLP method. The mRNA expression levels were measured by Quantitative Real Time PCR. The results showed the lower MTHFR mRNA expression in the placenta of PE women. There was an association between hypermethylation and lower MTHFR mRNA expression in PE women and entire women but not normotensive pregnant women. The frequency of MTHFR rs1537514CG genotype was significantly lower in PE women; however, there was no association between MTHFR rs4846049C>A polymorphism and PE. The combination effects of MTHFR CG/AC genotypes and G-A haplotype of MTHFR rs1537514/rs4846049 polymorphisms were associated with lower risk of PE. The MTHFR rs1537514G (4869G) allele was associated with higher MTHFR mRNA expression in both groups. However, there was no relation between MTHFR rs4846049C>A polymorphism and MTHFR mRNA expression. Our findings showed lower MTHFR mRNA expression in PE women. The MTHFR rs1537514C>G polymorphism was associated with lower PE risk and MTHFR mRNA expression. Lower expression of MTHFR mRNA was observed in the women with the hypermethylated promoter.

Relationships between Dicer 1 polymorphism and expression levels in the etiopathogenesis of preeclampsia.

Preeclampsia (PE) is a pregnancy-specific complication which is a major cause of maternal and fetal morbidity and mortality. Recent studies have shown the aberrant expression of microRNAs (miRNAs) in the placenta of patients with PE. Dicer1 is a key enzyme in the generation of small noncoding RNAs including miRNAs. The aim of this study is to investigate the relationship between maternal and placental Dicer1 rs3742330 polymorphism and placental Dicer1 mRNA expression in PE and normotensive pregnant women. The blood and placenta of PE pregnant and normotensive pregnant women were collected after delivery. Dicer1 rs3742330 polymorphism was genotyped using PCR-RFLP method. The mRNA expression levels were measured using quantitative real time PCR. The maternal Dicer1 rs3742330 polymorphism was not associated with PE or PE severity; however, the placental Dicer1 rs3742330 AG genotype was associated with two fold higher risk of PE and three fold higher risk of severe PE (P = 0.018 and P = 0.005, respectively). The relative mRNA expression of Dicer1 gene in the placenta did not differ between the two groups. In addition, the relative mRNA expression of Dicer1 gene was significantly lower in the placenta of women with rs3742330 AG+GG genotypes in the total population (P = 0.028) and PE women (P = 0.004), but not in the control group. In conclusion, there was a relationship between placental but not maternal Dicer1 rs3742330 polymorphism and PE. There was no difference in Dicer1 mRNA expression between the PE and control groups; however, it was significantly lower in the placenta of women with rs3742330 AG+GG genotypes.

Genetic variants in 3'-UTRs of MTHFR in the pregnancies complicated with preeclampsia and bioinformatics analysis.

Preeclampsia (PE) as a pregnancy-specific disorder is the major cause of mortality and morbidity of mothers and fetuses. This study attempts to investigate the possible association between the 2572C>A (rs4846049) and 4869C>G (rs1537514) polymorphisms in the 3'- untranslated region of MTHFR gene and the risk of PE. A total of 198 patients diagnosed with PE and 171 unrelated, age matched healthy pregnant women, were recruited for this case-control study. The MTHFR 2572C>A and 4869C>G genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The CG genotype of MTHFR 4869C>G was associated with decreased risk of PE, and this genotype was found to be a protective factor for PE susceptibility. There was no significant difference in the genotypes of MTHFR 2572C>A polymorphism between PE patients and control group. The frequency of combined AC/CG genotypes of MTHFR 2572C>A and 4869C>G polymorphisms were less frequent in PE patients and were associated with a lower risk of PE. The C-G and A-G haplotypes of MTHFR 2572C>A and 4869C>G polymorphisms were significantly lower in PE patients. In conclusion, the CG genotype of MTHFR 4869C>G polymorphism was associated with a lower risk of PE. No association was found between MTHFR 2572C>A polymorphism and PE.

Hypomethylation of the miRNA-34a gene promoter is associated with Severe Preeclampsia.

PURPOSE: PE is a pregnancy-specific complication, which genetic and epigenetic factors play key roles in its pathogenesis. DNA methylation is a main epigenetic alteration with important roles in gene regulation. Micro RNAs (miRNAs) as another member of epigenetic machinery regulate the gene expression and involve in different biological pathways including apoptosis and placental development. Therefore, the present study performed to assess the association between miRNA-34a promoter methylation and PE susceptibility. METHODS: The placenta of 104 PE pregnant women and 119 normotensive pregnant women were collected after delivery. The methylation status of the miRNA-34a promoter was assessed using Methylation Specific PCR (MSP). RESULTS: The frequency of the hemi-methylated (MU) miR-34a promoter was significantly lower in PE women compared to the controls (17.3 vs. 29.4%) (OR, 0.45 [95% CI, 0.2-0.9], P = 0.016). The overall methylation rate was 23.1% in PE women and 41.2% in the control group and was significantly lower in PE women (OR, 0.4 [95% CI, 0.2-0.8], P = 0.004). The frequency of hemi-methylated (MU) and overall methylated (MU+MM) promoter of miR-34a gene was significantly lower in severe PE but not in mild PE women compared to the controls [(OR, 0.3 [95% CI, 0.1-0.8], P = 0.02) and (OR, 0.3 [95% CI, 0.1-0.7], P = 0.009), respectively]. There was an association between hemi-methylated (MU) and overall methylated (MU+MM) promoter and late onset PE [(OR, 0.4 [95% CI, 0.2-0.9], P = 0.03) and (OR, 0.4 [95% CI, 0.2-0.8], P = 0.01), respectively]. CONCLUSIONS: An association was found between hypo-methylation of the miR-34a promoter and PE and PE severity.

The Drosha rs10719 T>C polymorphism is associated with preeclampsia susceptibility.

PURPOSE: Drosha is a member of the micro RNA (miRNA) processing machinery that affects miRNA processing. Single-nucleotide polymorphisms (SNPs) in the Drosha gene might affect microRNA processing and the expression of various genes. The aim of this study is to investigate the association between SNPs in the Drosha gene and preeclampsia (PE) in the southeast of Iran. METHODS: Genotyping of Drosha rs10719 and rs6877842 was performed using blood samples from 219 PE women and 205 healthy control subjects by a polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The Drosha rs10719TC genotype was significantly associated with 1.6-fold higher risk of PE (odds ratio (OR, 1.6 [95% CI, 1.1-2.4], P = 0.026). In addition, the frequency of the Drosha rs10719CC genotype was significantly higher in PE women and was associated with threefold higher risk of PE (OR 3 [95% CI 1.4-6.3], P = 0.004). There was no association between the Drosha rs6877842 polymorphism and PE susceptibility. The CC-GG combined genotype was associated with 3.4-fold higher risk of PE (OR 3.4 [95% CI 1.4-8.1], P = 0.007). The haplotype-based association analysis showed higher frequency of C-G haplotype of Drosha rs10719 and rs6877842 polymorphisms with the increased risk of PE 1.5-fold (OR 1.5 [95% CI 1.1 - 2], P = 0.01). CONCLUSIONS: The Drosha rs10719TC and CC genotypes were associated with PE risk. The CC-GG combined genotype and C-G haplotype of Drosha rs10719 and rs6877842 polymorphisms may increase PE susceptibility.

The placental vascular endothelial growth factor polymorphisms and preeclampsia/preeclampsia severity.

Preeclampsia (PE) is a serious pregnancy-specific condition, which originates from placenta and finishes after delivery. The present study has investigated the association between placental VEGF I/D (rs35569394), -1154G/A (rs1570360), and -634G/C(rs2010963) polymorphisms and maternal VEGF -2549 I/D (rs35569394) polymorphism with PE and PE severity. In this case-control study, the maternal blood of 217 women with PE and 210 normotensive pregnant women and the placenta of 84 PE women and 103 normotensive women were collected after delivery. Genotyping was done by PCR or PCR-RFLP methods. The maternal VEGF-2549I/D genotypes were not associated with PE or PE severity. The placental VEGF -2549 I/D genotypes were not associated with PE too; however; the placental VEGF-2549 DD genotype was statistically different between women with severe PE and mild PE or the controls. The placental VEGF -634GC and CC genotypes were significantly higher in PE women and associated with 2.6 and 2-fold higher risk of PE, respectively. The VEGF -634GC and CC genotypes were associated with PE severity. No association was found between placental VEGF -1154G/A polymorphism and PE or PE severity. The placental DGC haplotype of VEGF -2549 I/D, -1154G/A, and -634G/C polymorphisms was associated with 2.9-fold higher risk of PE. However, the placental IAG haplotype was associated with 0.3-fold lower risk of PE. In conclusion, the placental VEGF -2549 DD genotype was associated with severe PE and the placental -634GC and CC genotypes were associated with PE and severe PE. No association was found between VEGF -1154G/A polymorphism and PE or PE severity.