Differential expression of Hsa-miR-517a/b in placental tissue may contribute to the pathogenesis of preeclampsia

Objective: Preeclampsia (PE) is a pregnancy hypertensive disorder that affects both maternal and fetal health. Many studies have investigated possible mechanisms in the pathogenesis of PE although the role of the placenta is undeniable. Evaluation of placental-specific microRNAs may provide additional data about the pathogenic mechanism of PE. This study compared the expression levels of Hsa-miR-517a/b in placental tissues obtained from PE patients and healthy controls. Material and Methods: One hundred tissues were obtained from fetal and maternal sides of the placenta of PE patients and healthy controls. Expression analysis was performed using quantitative real-time polymerase chain reaction. Results: Hsa-miR-517a/b level was significantly decreased in PE compared to controls (expression ratio: 0.40; p=0.007). Down-regulation of Hsa-miR-517a/b was also detected in fetal-side placental samples when compared to maternal-side in PE (expression ratio: 0.33; p=0.04). Furthermore, decreased expression of Hsa-miR-517a/b was detected in fetal-side tissue from PE cases compared to fetal-side samples from healthy pregnancies (expression ratio: 0.36; p=0.03). In maternal-side placental samples the expression level did not differ between PE and healthy pregnancies (p=0.1). Conclusion: These results demonstrate a differential expression of Hsa-miR-517a/b within placentas in pregnancies affected by PE and between placentas from PE and healthy pregnancies. Further studies are required to investigate a possible role for Hsa-miR-517a/b in the pathogenesis of PE.

CREB-binding protein (CREBBP) and preeclampsia: a new promising target gene.

Preeclampsia (PE) is a major complication of pregnancy and remains a leading cause of neonatal and maternal mortality worldwide. Several studies have revealed that the incidence of preeclampsia is high in mothers who carried a fetus with Rubinstein-Taybi Syndrome due to the mutation in CREBBP. We aimed to compare the expression level of the CERBBP gene between preeclamptic and healthy placenta in our study. The expression level of CREBBP gene was evaluated in a total of one hundred placental biopsies from PE patients and healthy pregnant women after delivery using quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, the differential expression of CREBBP was assessed between the maternal and fetal sides of the placenta. Expression of the CREBBP gene was higher in preeclampsia patients compared with the controls (Fold change = 2.158; P = 0.018). Moreover, the gene expression was slightly higher in the fetal side of the placenta, although it was not significantly different (Fold change = 1.713, P = 0.254). Our findings show a role for CREBBP in the pathogenesis of PE. Due to the important role of CREBBP in angiogenesis and hypoxia, the gene may serve as a promising target in future studies.

Contribution of long noncoding RNA HOTAIR variants to preeclampsia susceptibility in Iranian women.

Objective: To investigate the possible association of lncRNA HOTAIR rs920778 and rs874945 polymorphisms with preeclampsia risk in a sample from the Iranian population. Method: The study subjects included 250 preeclamptic women and 250 healthy women. The genotyping for rs920778 and rs874945 polymorphisms were performed using the TP-ARMS-PCR method. Results: HOTAIR rs920778 increased the risk of preeclampsia under the dominant and recessive inheritance patterns (OR = 4.84, 95% CI: 3.30-7.10, P < 0.0001; OR = 6.86, 95% CI: 3.51-13.42, P < 0.0001; respectively). Conclusion: This study confirmed the association of HOTAIR rs920778 polymorphism with preeclampsia in Iranian women. Further studies should be performed to confirm our findings.

A candidate intronic CYP24A1 gene variant affects the risk of colorectal cancer.

Aim: rs2585428 and rs4809960 polymorphisms were significantly associated with overall cancer risk, but there is no evidence regarding the overall colorectal cancer (CRC) risk. Materials & methods: A total of 505 subjects, including 246 patients with CRC and 259 noncancer controls participated in the study. The genotyping was performed using tetra-primer amplification refractory mutation systems PCR. Results: Analysis of genotypes revealed that CYP24A1 rs4809960 CC genotype decreased the risk of CRC (p = 0.009). In addition, the genotype frequencies showed a significant difference under the dominant and recessive inheritance models (p = 0.019 and p = 0.02, respectively). Conclusion: Our findings indicate that the CYP24A1 rs4809960 polymorphism decreased the risk of CRC in the studied population.

An intron variant in the FLT1 gene increases the risk of preeclampsia in Iranian women.

Background: Preeclampsia is a hypertensive disorder that affects pregnancy, mother, and fetus. Pathogenesis of preeclampsia could be associated with the angiogenesis pathways. The vascular endothelial growth factor (VEGF) family is one of the important factors for normal pregnancy and angiogenesis. Genetic variations in the gene family members may play a role in the etiology of preeclampsia. We investigated the possible association between VEGFA gene rs3025039, and VEGFR1 (FLT1) gene rs722503 polymorphisms and preeclampsia in a sample of Iranian patients. Methods: Genotyping was performed in 395 women, including, 204 pre-eclamptic pregnant women and 191 healthy normotensive pregnant women by using the PCR-RFLP method. Results: The rs722503 polymorphism was associated with preeclampsia under the dominant model (P = 0.04, OR = 1.53, 95% CI: 1.03-2.27). No significant difference was observed for the rs3025039 alleles and genotypes in the studied groups. Conclusions: Based on our study, rs722503 polymorphism in the FLT1 gene may play an important role in susceptibility to preeclampsia.

miR-30a promoter variation contributes to the increased risk of colorectal cancer in an Iranian population.

Cytochrome P450 family 24 subfamily A member 1 (CYP24A1) gene is overexpressed in many cancers including colorectal cancer (CRC) and correlated with tumor invasion, lymph node metastasis, and the reduced overall survival. We predicted that miR-30a and miR-125a regulate the CYp24A1 gene expression. Therefore, we performed a case-control study using 800 individuals, including 389 patients with CRC and 411 noncancer controls to evaluate the association between miR-30a rs2222722 and miR-125a rs12976445 polymorphisms, located at in the promoter region, and the risk of sporadic CRC in an Iranian population. The genotyping assay for both polymorphisms was performed using Tetra-primer amplification refractory mutation systems polymerase chain reaction. The results indicated that the frequency of the miR-30a rs2222722 CT genotype was significantly different in the studied groups ( P = 0.0001; odds ratio [OR] = 1.9; 95% confidence interval [CI], 1.39-2.60). Also, a significant difference was observed under the dominant inheritance model ( P = 0.0001; OR = 1.8; 95% CI, 1.33-2.43). The frequency of the miR-30a rs2222722 T allele was significantly associated with increased CRC risk in the studied population ( P = 0.0019; OR = 1.47; 95% CI, 1.15-1.89). Taken together, our study provides preliminary evidence that the rs2222722 polymorphism increases the susceptibility to CRC in an Iranian population. Therefore, the affecting factors on CYP24A1 gene expression such as microRNAs can be considered as risk factors for CRC.

ACE gene rs4343 polymorphism elevates the risk of preeclampsia in pregnant women.

The multifactorial basis of preeclampsia (PE) implies that there are several genes and risk factors that are important in the development of the disease. Therefore, the exact etiology and pathogenesis of preeclampsia remains unclear. It is suggested that inappropriate regulation of the renin-angiotensin system (RAS) is a risk factor for hypertension during pregnancy. The angiotensin I-converting enzyme (ACE) serum level, a key component of the RAS, affects the blood pressure. It is hypothesized that the ACE gene polymorphisms contribute to preeclampsia development. In a case-control study containing 296 subjects (165 PE patients and 131 normotensive controls), we aimed to examine the association of the ACE gene I/D and rs4343 polymorphisms with preeclampsia in Iranian women. Genotyping for rs4343 and ACE I/D polymorphisms was performed by using TP-ARMS-PCR and conventional PCR, respectively. The rs4343 G allele frequency was higher in the case group (OR = 1.90, 95% CI, 1.37-2.65; P = 0.0001). Besides, a significant difference was detected for the genotype frequencies between the studied groups under dominant (OR = 3.94, 95% CI, 2.05-7.56; P < 0.0001) and recessive (OR = 2.21, 95% CI, 1.22-4.01; P = 0.009) inheritance models. For the I/D polymorphism, no significant differences were detected in the genotype and allele frequencies or any of the inheritance models between PE patients and controls. To verify the current results and validate the significance of the studied genetic variations, additional studies in diverse ethnic populations are required.

The rs4846049 polymorphism in the 3'UTR region of the MTHFR gene increases the migraine susceptibility in an Iranian population.

INTRODUCTION: Migraine is a painful complex neurovascular disease characterized by recurrent moderate-to-severe headaches. Increased level of homocysteine is related to dilation of cerebral vessels and endothelial injury that could trigger migraine attacks. Functional polymorphisms in the MTHFR gene affect homocysteine metabolism and, therefore, play an important role in the etiology of the disease. OBJECTIVES: We aimed to investigate the possible association between MTHFR gene rs4846049, C677T, and A1298C polymorphisms and the risk of migraine in Iranian population. METHODS: In this genetic association study, 498 individuals were enrolled, including 223 migraine patients and 275 healthy controls. Genotyping was performed using tetra-primer ARMS-PCR for rs4846049 and PCR-restriction fragment length polymorphism for C677T and A1298C polymorphisms. RESULTS: The association between rs4846049 and C677T polymorphisms and migraine was observed. For the rs4846049 polymorphism, the association was detected under a dominant model (P=0.007; odds ratio [OR] =0.60; 95% confidence interval [CI], 0.41-0.87), and for the C677T polymorphism, the TT genotype frequency was significantly different in the studied groups (P=0.009; OR =2.48; 95% CI, 1.25-4.92). No significant differences in the genotype or allele frequencies were found for the A1298C polymorphism between the migraineurs and controls. CONCLUSION: Present data provide evidence for the association of rs4846049 and C677T polymorphisms in the MTHFR gene and migraine. Further studies are required to validate the significance of the studied genetic variations in diverse ethnic populations.

HIWI2 rs508485 Polymorphism Is Associated with Non-obstructive Azoospermia in Iranian Patients.

BACKGROUND: The PIWI-interacting RNA (piRNA) pathway has an essential role in transposon silencing, meiosis progression, spermatogenesis, and germline maintenance. HIWI genes are critical for piRNA biogenesis and function. Therefore, polymorphisms in HIWI genes contribute to spermatogenesis defects and can be considered as risk factors for male infertility. The aim of the present study was to investigate the association between the HIWI2 gene rs508485 polymorphism and non-obstructive azoospermia. METHODS: A total of 121 Iranian men with idiopathic azoospermia and 100 fertile controls were genotyped for HIWI2 rs508485 (T>C) polymorphism using Tetra-ARMS PCR. The presence of eight sequence-tagged site (STS) markers from the Y chromosome AZF region was also investigated by Multiplex PCR (M-PCR). RESULTS: Thirteen (10.74%) patients showed Y chromosome microdeletions and therefore were excluded from the study. rs508485 in the 3'UTR of HIWI2 was associated with increased risk of azoospermia in our studied population with a P-value of 0.035 and odds ratio of 2.00 (CI 95%: 1.04-3.86). CONCLUSIONS: We provide evidence for an association between genetic variation in the HIWI2 gene involved in the piRNA pathway and idiopathic non-obstructive azoospermia in Iranian patients. Therefore, piRNA pathway gene variants can be considered as risk factors for male infertility.

The role of parental microRNA alleles in recurrent pregnancy loss: an association study.

The medical evaluation of recurrent pregnancy loss (RPL), the occurrence of two or more consecutive pregnancy losses prior to 20th week of gestation, is mainly focused on maternal factors. However, paternally expressed genes may also play a role in implantation and placenta quality. This study aimed to investigate the possible association between parental miR-196a2C>T and miR-499aT>C polymorphisms and RPL in a case-control study including 200 RPL couples and 400 healthy men and women. Genotyping was performed using Tetra-ARMS-PCR and PCR-RFLP for miR-196a2C>T and miR-499aT>C polymorphisms, respectively. In men, the association was observed between miR-499a and RPL under dominant (P = 0.006; odds ratio [OR] = 2.36; 95% confidence interval [CI], 1.28-4.37), recessive (P < 0.0001; OR = 2.89; 95% CI, 1.92-4.36) and additive (P < 0.001; OR = 2.77; 95% CI, 1.52-5.10) models. In women, the association was found between miR-196a2 and RPL under recessive (P = 0.02; OR = 2.19; 95% CI, 1.16-4.14) and additive (P = 0.03; OR = 1.53; 95% CI, 1.04-2.27) models. Hence, evidence was provided for association of genetic variation in parental microRNA polymorphisms with RPL. Further studies are required to validate the significance of the studied genetic variations in diverse ethnic populations.

The study of MED12 gene mutations in uterine leiomyomas from Iranian patients.

Uterine leiomyomas are the most common gynecologic benign tumors of the female genital tract that cause a variety of health problems including, abnormal menstrual bleeding, pelvic pain, placenta displacement, premature labor, and miscarriages. Recently, studies showed that recurrent somatic mutations in MED12 exon 2 are the major cause of uterine leiomyomas in different ethnic groups. In order to validate these results in Iranian population, we performed mutational analysis of exon 2 and the flanking intronic regions by using single-strand conformational polymorphism (SSCP) and sequencing analyses in a series of 103 uterine leiomyomas samples. MED12 gene was mutated in 31.07 % of the uterine leiomyomas. Mutations were consisted of 20 missense (62.5 %) and 12 in-frame deletion (37.5 %) mutations and were not detected in normal myometrial tissue. Although this is the lowest mutation frequency reported so far, MED12 mutations are associated with fibroid pathogenesis in the studied population. Understanding the molecular mechanisms responsible for the pathogenesis of uterine leiomyoma will play an important role in designing new therapeutic strategies.