Rohini R. Nair

MTHFR C677T Polymorphism and Recurrent Early Pregnancy Loss Risk in North Indian Population

Recurrent early pregnancy loss (REPL) is a multifactorial disorder as both genetic and environmental factors contribute to the development of disease. Folate metabolism is an important mechanism to ensure proper fetal growth. Hyperhomocysteinemia leads to a number of disorders and REPL is one of them. In a case–control study DNA from 106 cases with the history of 3 or more REPL and 140 healthy fertile controls with successful pregnancy outcomes were genotyped for C677T single-nucleotide polymorphism (SNP) of the MTHFR (methylenetetrahydrofolate reductase) gene through polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), which was further confirmed by sequencing. Allele frequencies of REPL cases were compared with healthy controls and a statistically significant association was found between REPL and the mutant T allele (χ2 = 8.786, odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.323-3.9658, P = .003). The genotype frequencies of SNP C677T also differ significantly between these 2 groups (χ2 = 8.237, P = .016). The OR for heterozygous CT in the REPL versus controls is 1.9591 (95% CI = 1.0285-3.7318, P = .04). The OR for TT homozygous is 6.3009 (95% CI = 1.2065, P = .02). Combined odds ratio of CT and TT against the control has been calculated as 2.2194 (95% CI = 1.2029-4.0952, P = .02) which is also significant. Thus the present study clearly indicates that homozygosity and heterozygosity for the MTHFR C677T polymorphism confer a 6.3009- and 1.9591-fold increased risk of idiopathic REPL, respectively.

Reduced Myeloid‐derived Suppressor Cells in the Blood and Endometrium is Associated with Early Miscarriage

The contribution of myeloid‐derived suppressor cells (MDSC) in patients suffering from early or recurrent miscarriage is unknown. MDSC are implicated in modulation of T‐cell response in healthy pregnancies; however, the role of MDSC in patients suffering from miscarriage has not been studied. We hypothesized that MDSC play major role in inducing maternal–fetal tolerance and this tolerance is compromised in patients suffering from miscarriage.

Immune-endocrine crosstalk during pregnancy.

The success of pregnancy depends mostly on a synchronized immune-endocrine crosstalk at the maternal-fetal interface. Hormones are important in terms of maintaining the suitable environment and sufficient nutrition for the developing fetus. They also play a major role during the process of parturition and lactation. Maternal immunomodulation is important for the tolerance of semiallogeneic fetus. This is achieved in concert with a variety of endocrine stimulation. Estrogen, progesterone, and Human Chorionic Gonadotropin play a major role in immune modulation during pregnancy. Hormones modulate B cells, dendritic cells, uterine natural killer cells, macrophages, neutrophils to adopt fetal friendly immune phenotypes. Recently the use of hormones in assisted reproductive technology has been found to improve the pregnancy outcome. The present review focuses on the pregnancy-related hormones, their role in immunomodulation for successful pregnancy outcome. This also shed light on the immune-endocrine crosstalk at maternal-fetal interface during pregnancy.

A new rhodamine derivative as a single optical probe for the recognition of Cu2+ and Zn2+ ions

A bifunctional colorimetric and fluorescent chemosensor of type 3,5-dinitro-2-hydroxy benzaldehyde rhodamine hydrazone (RHDN) was synthesized by the condensation of 3,5-dinitro salicylaldehyde and rhodamine B hydrazide. It was characterized using spectroscopic techniques and single crystal studies. The chemosensor RHDN exhibited remarkably enhanced absorbance and colour changes from colourless to pink color on binding with Cu2+ ions. In contrast, Zn2+ ions were identified by their selective binding with RHDN showing OFF–ON type fluorescence, which changes from colorless to orange color in ultra violet-light. The absorbance and emission pattern of RHDN adduct separately with Cu2+ and Zn2+ ions were restored with the addition of an aqueous solution of disodium salt of ethylenediaminetetraacetic acid. Thus, RHDN was found to be very robust and reversible in its binding with Cu2+ and Zn2+ ions separately.

Role of inflammatory proteins S100A8 and S100A9 in pathophysiology of recurrent early pregnancy loss

Altered expression of inflammatory molecule at the maternal fetal interface is associated with early pregnancy loss. S100A8 and S100A9 are inflammatory proteins and they exhibit cytokine like function enhancing leukocyte recruitment to the inflammatory site. Reports from mouse model suggest the role of S100A8 with the vasculature of the decidual tissue and leukocyte recruitment during early pregnancy. Hence we hypothesized that maternal overexpression of S100A8 & S100A9 might increase the recruitment of inflammatory leukocytes in maternal-fetal interface resulting in uteroplacental perfusion deficiency, development of thrombotic events, and placental hypoxia, eventually embryo abortion. In the present study we investigated altered expression of S100A8 and S100A9 in 25 recurrent early pregnancy loss (REPL) patients compared to 40 induced abortion subjects as controls. S100A8 and S100A9 mRNA were evaluated using semi-quantitative RT-PCR and quantitative real-time PCR. To determine if differential expression pattern of these transcripts is translated to protein western blot analysis was performed.S100A8 and S100A9 mRNA and protein level were significantly increased in endometrial decidua tissue (p < 0.05) of REPL patients as compared to controls. This is the first report predicting the role of inflammatory molecules S100A8 & S100A9 in REPL. It opens a new perspective for understanding significance of S100A8 and S100A9 in pregnancy maintenance and outcome.

Association of GSTT1 and GSTM1 polymorphisms with early pregnancy loss in an Indian population and a meta-analysis

Glutathione S-transferase theta 1 (GSTT1) and glutathione S-transferase Mu 1 (GSTM1) enzymes of the glutathione detoxification pathway protect the embryo from oxidative stress. This study investigated GSTT1 and GSTM1 in relation to their role in conferring genetic susceptibility to pregnancy loss. In a case-control study, 174 early pregnancy loss (EPL) patients, of which 130 were recurrent pregnancy loss (RPL) patients, and 180 healthy controls were investigated. Null genotypes of GSTT1 and GSTM1 were identified in duplex PCR reaction systems. Age-adjusted odds ratios (aOR) were calculated by logistic regression analysis. A meta-analysis was also conducted. The GSTT1 null genotype was significantly associated with EPL (aOR 4.47, P=0.004) and RPL (aOR 4.39, P=0.006). No significant association of the GSTM1 null genotype was found with RPL. In a meta-analysis study, the presence of the GSTM1 null genotype was shown to be a risk for RPL. The GSTT1 null genotype was not found to be a risk factor for pregnancy loss in the pooled population but its association with RPL was found in the Indian population. This study suggests that women carriers of GSTT1 and GSTM1 null genotypes are more often at genetic risk of pregnancy loss. Glutathione S-transferase theta 1 (GSTT1) and glutathione S-transferase mu 1 (GSTM1), enzymes of detoxification pathway, protect the embryo from oxidative stress. In the present study we have investigated GSTT1 and GSTM1 in relation to their role in conferring genetic susceptibility for early pregnancy loss (EPL) and recurrent pregnancy loss (RPL). Meta-analysis on the polymorphisms was conducted to support our findings that the presence of mutant genotypes at this site increases the risk of pregnancy loss. The GSTT1 null genotype was significantly associated with both EPL and RPL. In the meta-analysis, the overall result showed that the association between GSTM1 null genotype and risk for RPL was statistically significant. On comparing the GSTT1 studies, great heterogeneity was found between studies. A subgroup analysis was performed based on ethnicity. Our results showed a significantly increased risk with the GSTT1 null genotype in the Indian population, but no risk was found in the pooled population. In conclusion, the data of the present study clearly suggest that GSTT1 and GSTM1 polymorphisms are genetic risk factors for pregnancy loss in the study population.

Functional SNP −1562C/T in the promoter region of MMP9 and recurrent early pregnancy loss

Angiogenesis, invasion and decidualization play an important role in uterine preparation and embryo development. Matrix metalloproteinases (MMP) are crucial for the degradation/remodelling of the extracellular matrix and are involved in spiral artery formation and invasion of endometrium during implantation. A functional single-nucleotide polymorphism (SNP) in the MMP9 promoter, 1562C/T, is known to influence expression in an allele-specific manner. The present study evaluated the association between maternal genotype of SNP 1562C/T of MMP9 and recurrent early pregnancy loss (REPL) risk. This case–control study was comprised of REPL patients (n = 106) and women having one healthy child as controls (n = 111). Genotyping for SNP 1562C/T of MMP9 was performed by PCR/restriction fragment length polymorphism followed by DNA sequencing. Allele and genotype distribution did not differ significantly between patients and controls (by allele, chi-squared 0.228, odds ratio 1.12, 95% confidence interval 0.695–1.816; by genotype, chi-squared 0.893). Thus SNP 1562C/T of MMP9 was not associated with REPL risk in this population and further study in other populations will verify whether it is associated with REPL risk or not. REPL is a multifactorial pathology and other genetic or environmental factors may be contributing to the complex aetiology of REPL.

Association of FAS −1377 G>A and FAS −670 A>G functional polymorphisms of FAS gene of cell death pathway with recurrent early pregnancy loss risk

Apoptosis during the early stages of pregnancy enables the remodeling of the uterus for proper placentation. Apoptosis in the maternal activated cytotoxic T lymphocytes allows maternal immune tolerance to pregnancy and in glandular and stromal cells it helps with trophoblastic endometrial invasion. FAS gene is expressed at the maternal-fetal interface and is involved in the regulation of immune response and implantation. Altered FAS expression may result in altered apoptosis and ultimately affects both immune response and implantation. FAS -1377 G>A and FAS -670 A>G functional polymorphisms in the promoter region of FAS gene modulate its expression at transcriptional level. In a case-control study the contribution of FAS -1377 G>A and FAS -670 A>G polymorphisms to the risk of recurrent early pregnancy loss (REPL) was evaluated. DNA from 134 cases with a history of three or more REPL and 124 healthy controls with successful pregnancy outcomes were genotyped through PCR-RFLP. DNA sequencing was used to ascertain PCR-RFLP results. The genotype and allele frequencies for FAS -1377 G>A and FAS -670 A>G polymorphisms were compared in REPL and controls. FAS -1377 AA and AG genotypes were associated with an increased risk of REPL (OR, 3.25; 95%CI, 1.52-6.98 and OR, 2.62; 95%CI, 1.48-4.64, respectively), whereas FAS -670 genotypes conferred no risk. The -1377 AA/-670 GG genotypes combination of FAS polymorphisms showed highest risk (OR, 8.15; 95%CI, 2.75-25.81). Genotype combinations -1377 GA/-670 AA and -1377 GA/-670 AG were also statistically significant, suggestive of their role in REPL risk.

Association of Increased S100A8 Serum Protein with Early Pregnancy Loss

The contribution of systemic S100A8 protein in menstrual cycle, pregnancy, and early pregnancy loss (EPL) is not known. Altered expression of S100A8 in maternal decidua is associated with recurrent early pregnancy loss. The objective of this study was to investigate the systemic level of S100A8 in different phases of menstrual cycle, different trimester of pregnancy, and in EPL.

CYP1A1 and GSTM1 genes polymorphism and its association with endometriosis : A pilot study

Abstract Objective To study the genetic association between Cytochrome P450 family 1 (CYP1A1) T6235C polymorphism and glutathione S-transferase M1 (GSTM1) null mutations and endometriosis. Methods A total of 121 unrelated women having complaints of pelvic pain, dysmenorrhea, dysuria, dyschezia, dysparenuia and infertility were enrolled. Out of these 71 consented for laparoscopy, 66 were diagnosed as endometriosis as per operative. Genomic DNA isolated from endometriosis patients and controls were subjected to polymerase chain reactions to determine the GSTM1 null genotypes whereas polymorphism of CYP1A1 T6235C was determined through PCR-RFLP. Results The GSTM1 null genotype was found to be associated with endometriosis however there was no significant difference in the frequencies of the CYP1A1 6235 CC genotype between endometriosis patients and controls. The homozygous mutant and allele frequency of CYP1A1 T6235C differed significantly between patients having endometriosis and healthy control. Conclusion The data of the present study clearly suggests that GSTM1 null allele and CYP1A1 C allele is a genetic risk factor for endometriosis in North Indian population.