Genetic and Environmental Biomarkers Associated with Triglyceride Levels in Two Groups of Slovak Women

Association of the ESR1 polymorphism with menopause and MLXIPL genetic variant influence serum uric acid levels in Slovak midlife women

OBJECTIVE

This study examines associations between the ESR1 (XbaI, PvuII) and the MLXIPL (rs3812316) gene polymorphisms, and uric acid (UA) levels in Slovak midlife women, subdivided according to their menopause status.

METHODS

We assessed a total of 362 women from 38 to 65 years of age. Women were recruited from different localities in the western and middle parts of Slovakia. Participants were interviewed during their medical examination at local health centers. They were investigated with respect to a variety of aspects such as medical, anthropometrical, and lifestyle. Participants provided a blood sample for biochemical analyses and DNA genotyping. The MLXIPL gene (rs3812316 SNP variant) and ESR1 gene (PvuII and XbaI) genotypes were then detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Data were analyzed using general linear models and multiple linear regression analyses to adjust for risk factors elevating the UA level such as fat mass (FM), triglycerides (TGs) and creatinine.

RESULTS

A positive association between MLXIPL and UA level was observed in the total sample of women after control for confounding covariates, including FM, TGs, and creatinine (P = 0.027). Women with the CC genotype had higher UA levels than the G-allele carriers (261.5 μmol/L ± 68.3 vs 241.1 μmol/L ± 55.1 P = 0.013). A statistically significant association was noticed between postmenopause status and the ESR1 XbaI genotype and their effect on UA (P = 0.028). The Bonferroni pairwise comparison determined that the G-allele carriers in the postmenopausal period had higher estimated UA marginal mean (269.7 μmol/L) than the AA-allele postmenopausal women (236.5 μmol/L) (P = 0.012). The estimated UA marginal mean showed a significant increasing trend according to the MS in G allele carriers (248.5 μmol/L in pre/peri-menopausal vs 269.7 μmol/L in postmenopausal, P = 0.009). In contrast, a decreasing trend was observed in AA carriers (250.6 μmol/L in pre/perimenopausal women vs 236.5 μmol/L in postmenopausal). However, this trend was not statistically significant (P = 0.288).

CONCLUSIONS

This cross-sectional study suggests that MLXIPL (rs3812316) polymorphism is associated with higher serum UA levels and that the ESR1 (XbaI) polymorphism is associated with UA levels only in the postmenopausal cohort.

miR-1322 regulates ChREBP expression via binding a 3'-UTR variant (rs1051943)

The carbohydrate response element‐binding protein (ChREBP), also referred to as MLXIPL, plays a crucial role in the regulation of glucose and lipid metabolism. Existing studies have shown an association between genetic variations of the ChREBP gene and lipid levels, such as triglycerides and high‐density lipoprotein cholesterol. However, mechanistic studies of this association are limited. In this study, bioinformatic analysis revealed that the polymorphism rs1051943A occurs in the complementary binding sequence of miR‐1322 in the ChREBP 3′‐untranslated region (UTR). Studies of potential mechanisms showed that the A allele could facilitate miR‐1322 binding, and luciferase activity significantly decreased when co‐transfected with a ChREBP 3′‐UTR luciferase reporter vector and miR‐1322 mimics in HepG2 cells. Furthermore, miR‐1322 significantly regulated the expression of ChREBP downstream genes and reduced the synthesis of lipids. The expression of miR‐1322 was up‐regulated by glucose and palmitic acid stimulation. Population studies showed that rs1051943‐A allele was only found in the Han Chinese and Uighur ethnic groups, different from European populations (G allele frequency = 0.07). In summary, we provide evidence that the rs1051943 A allele creates a functional miR‐1322 binding site in ChREBP 3′‐UTR and post‐transcriptionally down‐regulates its expression, possibly associated with levels of plasma lipids and glucose.