Maternal obesity modulates sexually dimorphic epigenetic regulation and expression of leptin receptor in offspring hippocampus
BRAIN BEHAVIOR AND IMMUNITY
Authors: Glendining, K. A.; Higgins, M. B. A.; Fisher, L. C.; Jasoni, C. L.
Abstract
Maternal obesity during pregnancy is associated with a greater risk for obesity and neurodevelopmental deficits in offspring. This developmental programming of disease is proposed to involve neuroendocrine, inflammatory, and epigenetic factors during gestation that disrupt normal fetal brain development. The hormones leptin and insulin are each intrinsically linked to metabolism, inflammation, and neurodevelopment, which led us to hypothesise that maternal obesity may disrupt leptin or insulin receptor signalling in the developing brain of offspring. Using a C57BL/6 mouse model of high fat diet-induced maternal obesity (mHFD), we performed qPCR to examine leptin receptor (Lepr) and insulin receptor (Insr) gene expression in gestational day (GD) 17.5 fetal brain. We found a significant effect of maternal diet and offspring sex on Lepr regulation in the developing hippocampus, with increased Lepr expression in female mHFD offspring (p < 0.05) compared to controls. Maternal diet did not alter hippocampal Insr in the fetal brain, or Lepr or Insr in prefrontal cortex, amygdala, or hypothalamus of female or male offspring. Chromatin immunoprecipitation revealed decreased binding of his-tones possessing the repressive histone mark H3K9me3 at the Lepr promoter (p < 0.05) in hippocampus of female mHFD offspring compared to controls, but not in males. Sex-specific deregulation of Lepr could be reproduced in vitro by exposing female hippocampal neurons to the obesity related proinflammatory cytokine IL-6, but not IL-17a or IFNG. Our findings indicate that the obesity-related proinflammatory cytokine IL-6 during pregnancy leads to sexually dimorphic changes in the modifications of histones binding at the Lepr gene promoter, and concomitant changes to Lepr transcription in the developing hippocampus. This suggests that exposure of the fetus to metabolic inflammatory molecules can impact epigenetic regulation of gene expression in the developing hippocampus.
Polymorphisms of microRNA target genes IL12B, INSR, CCND1 and IL10 in gastric cancer
WORLD JOURNAL OF GASTROENTEROLOGY
Authors: Petkevicius, Vytenis; Salteniene, Violeta; Juzenas, Simonas; Wex, Thomas; Link, Alexander; Leja, Marcis; Steponaitiene, Ruta; Skieceviciene, Jurgita; Kupcinskas, Limas; Jonaitis, Laimas; Kiudelis, Gediminas; Malfertheiner, Peter; Kupcinskas, Juozas
Abstract
AIM To evaluate associations between miRNA target genes IL12B, INSR, CCND1 and IL10 polymorphisms and gastric cancer (GC) in European population. METHODS Gene polymorphisms were analyzed in 508 controls and 474 GC patients from 3 tertiary centers in Germany, Lithuania and Latvia. Controls were patients from the out-patient departments, who were referred for upper endoscopy because of dyspeptic symptoms and had no history of previous malignancy. Gastric cancer (GC) patients had histopathological verification of gastric adenocarcinoma. Genomic DNA was extracted using salting out method from peripheral blood mononuclear cells. IL12B T > G (rs1368439), INSR T > C (rs1051690), CCND1 A > C (rs7177) and IL10 T > C (rs3024498) SNPs were genotyped by the real-time polymerase chain reaction. Associations between gene polymorphism and GC were evaluated using multiple logistic regression analysis with adjustment for sex, age and country of birth. RESULTS We observed similar distribution of genotypes and allelic frequencies of all polymorphisms between GC patients and controls except of INSR rs1051690. The frequency of the T allele of INSR gene was significantly higher in GC patients than in controls (23.26% and 19.19% respectively, P = 0.028). CT genotype was also more prevalent in patients compared to control group (38.48% and 30.12% respectively, P < 0.021). Logistic regression analysis revealed that only one polymorphism (rs1051690 in INSR gene) was associated with increased risk of GC. Carriers of CT genotype had higher odds of GC when compared to CC genotype (OR = 1.45, 95% PI: 1.08-1.95, P = 0.01). Similar association was observed in a dominant model for INSR gene, where comparison of TT+ CT vs CC genotypes showed an increased risk of GC (OR = 1.44, 95% PI: 1.08-1.90, P = 0.01). Other analyzed SNPs were not associated with the presence of GC. CONCLUSION INSR rs1051690 SNP is associated with increased risk of GC, while polymorphisms in IL12B, CCND1 and IL10 genes are not linked with the presence of GC.