Association between GCK gene polymorphism and gestational diabetes mellitus and its pregnancy outcomes

Effects of Auricularia auricula-judae (Bull.) Quél. polysaccharide acid hydrolysate on glucose metabolism in diabetic mice under oxidative stress

BACKGROUND

Oxidative stress can lead to uncontrolled glucose metabolism and, thus, diabetes. Auricularia auricula-judae (Bull.) Quél. polysaccharides possess biological activities, such as antioxidant and hypoglycemic effects, but their mechanism of their acid hydrolysates on oxidative stress-injured glucose metabolism disorders is unclear.

PURPOSE

Using diabetic mice, we investigated the effect of the acid hydrolysate of polysaccharides from Auricularia auricula-judae (Bull.) Quél. on improving diabetes.

STUDY DESIGN AND METHODS

The structural information of sample polysaccharides was measured by high performance gel permeation chromatography, nuclear magnetic resolution, and high performance liquid chromatography. The diabetic model was established by intraperitoneal injection of streptozotocin. For eight consecutive weeks, the mice were orally administered sample polysaccharides (100, 200, and 300 mg/kg b.w. per day) for intervention. The improvement effect of the samples on diabetes was explored by detecting the changes in biochemical indicators in mice, and the underlying mechanism was studied by transcriptomic and metabolomic analysis.

RESULTS

The results showed that acid hydrolysate of Auricularia auricula-judae (Bull.) Quél. polysaccharides consisted mainly of mannose, xylose, glucuronic acid, and glucose; its weight-averaged molecular weight was 6.3842 × 104 Dalton, its number average molecular weight was 2.9594 × 104 Dalton; and the molecule contained α-Glc(1→4)-, β-Glc(1→3)-, and β-Man(1→4)-linked glycosidic bonds. A total of 100 mg/kg b.w. per day sample was the best intervention concentration. After eight weeks of intervention, the sample polysaccharides significantly reduced dynamic blood glucose and serum lipids, enhanced antioxidant enzyme activities, promoted glucagon like peptide-1 and insulin secretion, improved insulin sensitivity and alleviated insulin resistance in diabetic mice. Transcriptomic and metabolomic analyses showed that sample polysaccharides was able to ameliorate disorders of glucose metabolism by modulating gene expression such as glucokinase; and modulate the state of oxidative stress in mice in vivo by regulating the glutathione metabolism pathway.

CONCLUSION

Acid hydrolysate of Auricularia auricula-judae (Bull.) Quél. polysaccharides improved glucose metabolism disorders by slowing down the oxidative stress injury in mice, thereby alleviating diabetes. This study provided a basis for determining the underlying mechanism of the antidiabetic effect of Auricularia auricula-judae (Bull.) Quél. polysaccharides, which would significantly improve the deep development and application of these materials in diabetes control.

Characterization of methylation profiles in spontaneous preterm birth placental villous tissue

Preterm birth is a global public health crisis which results in significant neonatal and maternal mortality. Yet little is known regarding the molecular mechanisms of idiopathic spontaneous preterm birth, and we have few diagnostic markers for adequate assessment of placental development and function. Previous studies of placental pathology and our transcriptomics studies suggest a role for placental maturity in idiopathic spontaneous preterm birth. It is known that placental DNA methylation changes over gestation. We hypothesized that if placental hypermaturity is present in our samples, we would observe a unique idiopathic spontaneous preterm birth DNA methylation profile potentially driving the gene expression differences we previously identified in our placental samples. Our results indicate the idiopathic spontaneous preterm birth DNA methylation pattern mimics the term birth methylation pattern suggesting hypermaturity. Only seven significant differentially methylated regions fitting the idiopathic spontaneous preterm birth specific (relative to the controls) profile were identified, indicating unusually high similarity in DNA methylation between idiopathic spontaneous preterm birth and term birth samples. We identified an additional 1,718 significantly methylated regions in our gestational age matched controls where the idiopathic spontaneous preterm birth DNA methylation pattern mimics the term birth methylation pattern, again indicating a striking level of similarity between the idiopathic spontaneous preterm birth and term birth samples. Pathway analysis of these regions revealed differences in genes within the WNT and Cadherin signaling pathways, both of which are essential in placental development and maturation. Taken together, these data demonstrate that the idiopathic spontaneous preterm birth samples display a hypermature methylation signature than expected given their respective gestational age which likely impacts birth timing.

Association of glucokinase gene and glucokinase regulatory protein gene polymorphisms with gestational diabetes mellitus: A case-control study

OBJECTIVES

The aim of this study was to investigate the association of glucokinase (GCK) gene, glucokinase regulatory protein (GCKR) gene polymorphisms with the susceptibility to GDM in Chinese population.

RESEARCH DESIGN AND METHODS

This case-control study included 835 GDM patients and 870 non-diabetic pregnant women who had their prenatal examinations at 24-28 gestational weeks at the Maternal and Child Health Hospital of Hubei Province from January 15, 2018 to March 31, 2019. The nurses were trained to collect clinical information and blood samples. The candidate single nucleotide polymorphism (SNPs, GCK rs1799884, rs4607517, rs10278336, rs2268574, rs730497 and GCKR rs780094, rs1260326) were genotyped on Sequenom Massarray platform. Statistical analysis including independent sample t test, chi-square test, logistic regression and one-way ANOVA were performed to evaluate the differences in allele and genotype distributions and their correlations with the odds of GDM.

RESULTS

There were statistically significant differences in age, pre-gestational BMI, education level and family history of diabetes between case and control group (P < 0.05). After adjusting for these confounders, GCK rs1799884 was still significantly associated with GDM (P < 0.05), but there were no significant associations between rs4607517, rs10278336 and rs2268574, rs780094 and rs1260326 polymorphisms and GDM odds (P > 0.05). In addition, the pregnant women with rs4607517 TT genotype had the significantly higher fasting blood glucose level than CC genotype (P < 0.05).

CONCLUSION

GCK rs1799884 mutation is associated with higher GDM odds in Chinese population. Further larger studies are needed to explore the association between GCK and GCKR polymorphisms and GDM susceptibility.