Maternal polymorphic loci of rs1979277 serine hydroxymethyl transferase and rs1805087 5-methylenetetrahydrofolate are correlated with the development of fetal growth restriction: A case-control study

Background: Key reactions in folate-mediated single-carbon metabolism are regulated by folate cycle enzymes. Violations of the folate cycle may be associated with the occurrence of fetal growth restriction (FGR) in pregnant women. Objective: To study the relationship between polymorphisms of folate cycle genes in the mother with the development of FGR. Materials and Methods: In this case-control study, 122 pregnant women with FGR and 243 pregnant women with normal newborn weight were enrolled. The polymorphic loci of folate cycle genes including rs1805087 5-methylenetetrahydrofolate (MTR) and rs1979277 serine hydroxymethyl transferase (SHMT1) were examined. The study of polymorphisms was carried out through the TaqMan probe detection method using polymerase chain reaction. Logistic regression was used to analyze the associations of the polymorphisms. Results: It was established that the T allele rs1979277 of the SHMT1 gene was correlated with the development of FGR within the framework of the allelic (OR = 1.67, 95% CI 1.20-2.33, pperm < 0.01), additive (OR = 1.69, 95% CI 1.20-2.37, pperm < 0.01), dominant (OR = 1.81, 95% CI 1.15-2.87, pperm = 0.01) and recessive (OR = 2.34, 95% CI 1.15-4.73, pperm = 0.01) models. The association of the G rs1805087 allele of the MTR gene with the occurrence of FGR was also identified following the recessive model (OR = 3.01, 95% CI 1.05-8.68, pperm = 0.04). Conclusion: Our results indicated that maternal polymorphic loci rs1979277 SHMT1 and rs1805087 MTR may be associated with the development of FGR. Key words: Polymorphism, Associations, Fetal growth restriction, Folic acid.

The association between serine hydroxymethyl transferase 1 gene hypermethylation and ischemic stroke

This study aimed to determine the correlation between serine hydroxymethyl transferase 1 (SHMT1) gene methylation and ischemic stroke. A total of 202 age- and sex-matched individuals were included. Quantitative methylation-specific polymerase chain reaction (qMSP-PCR) was used to analyze the DNA methylation level. The plasma homocysteine (Hcy) concentration was much higher in ischemic cases than in controls (p = 0.009), while the HDL levels in stroke cases were considerably lower than in controls (p = 0.005). A significantly higher level of SHMT1 methylation was observed in the ischemic strokes (58.82 ± 17.83 %) compared to that in the controls (42.59 ± 20.76 %, p < 0.001). The SHMT1 methylation level was strongly correlated with HDL concentration in the healthy controls (r = 0.517, p < 0.001), while the high plasma level of Hcy showed strong association with SHMT1 methylation in ischemic strokes (r = 0.346, p < 0.001). Receiver operating characteristic (ROC) analysis of curve indicated that SHMT1 methylation have been an acceptable indicator for ischemic stroke in female patients [all sexes, area under the curve (AUC) = 0.71, p < 0.001; male patients AUC = 0.62, p = 0.032; and female patients AUC = 0.79, p < 0.001] and in all ages (AUC = 0.71, p < 0.001). In our samples, DNA methylation levels of the STHMI gene were significantly correlated with ischemic stroke in Han Chinese. STHMI hypermethylation was significantly associated with the high Hcy concentration in ischemic stroke and had value as a potential indicator for female ischemic stroke.

Essential Function of the Serine Hydroxymethyl Transferase (SHMT) Gene During Rapid Syncytial Cell Cycles in Drosophila

Many metabolic enzymes are evolutionarily highly conserved and serve a central function in the catabolism and anabolism of cells. The serine hydroxymethyl transferase (SHMT) catalyzing the conversion of serine and glycine and vice versa feeds into tetrahydrofolate (THF)-mediated C1 metabolism. We identified a Drosophila mutation in SHMT (CG3011) in a screen for blastoderm mutants. Embryos from SHMT mutant germline clones specifically arrest the cell cycle in interphase 13 at the time of the midblastula transition (MBT) and prior to cellularization. The phenotype is due to a loss of enzymatic activity as it cannot be rescued by an allele with a point mutation in the catalytic center but by an allele based on the SHMT coding sequence from Escherichia coli. The onset of zygotic gene expression and degradation of maternal RNAs in SHMT mutant embryos are largely similar to that in wild-type embryos. The specific timing of the defects in SHMT mutants indicates that at least one of the SHMT-dependent metabolites becomes limiting in interphase 13, if it is not produced by the embryo. Our data suggest that mutant eggs contain maternally-provided and SHMT-dependent metabolites in amounts that suffice for early development until interphase 13.