Associations of genetic variants of lysophosphatidylcholine metabolic enzymes with levels of serum lipids

Protective Association of APOC1/rs4420638 with Risk of Obesity: A case-control Study in Portuguese Children

The association of the rs4420638 polymorphism, near the APOC1 gene, was examined with the risk of obesity among Portuguese children. A sample of 446 Portuguese individuals (231 boys and 215 girls) of European descent, aged 3.2 to 13.7 years old (mean age: 7.98 years), were selected to conduct a case-control study. Body mass index (BMI), BMI Z-scores, and waist circumference were calculated. Genotyping was performed by real time PCR using a pre-designed TaqMan probe. Logistic regression and the nonparametric Mann-Whitney test were used to test the associations. The association results revealed a significant protective effect from the minor G-allele of SNP rs4420638 against obesity, with an odds ratio (OR) of 0.619 (95% CI 0.421-0.913; p = 0.0155) in the additive model, and OR of 0.587 (95% CI 0.383-0.9; p = 0.0145) in the dominant model. Moreover, comparing genotype groups (AA vs. AG + GG), significantly lower values (p < 0.05) for the anthropometric traits weight, height, BMI, BMI Z-score and waist circumference, were observed in the carriers of allele G. The present study provides further evidence for the APOE/APOC1 candidate-region association with the risk of obesity. This was the first study to describe the protective association of the rs4420638 minor G-allele against obesity in childhood exclusively.

Association of BMAL1 clock gene polymorphisms with fasting glucose in children

BACKGROUND

The brain and muscle Arnt-like protein-1 (BMAL1) gene is an important circadian clock gene and previous studies have found that certain polymorphisms are associated with type 2 diabetes in adults. However, it remains unknown if such polymorphisms can affect fasting glucose in children and if other factors modify the associations.

METHODS

A school-based cross-sectional study with 947 Chinese children was conducted. A multivariable linear regression model was used to analyze the association between BMAL1 gene polymorphisms and fasting glucose level.

RESULTS

After adjusting for age, sex, body mass index (BMI), physical activity, and unhealthy diet, GG genotype carriers of BMAL1 rs3789327 had higher fasting glucose than AA/GA genotype carriers (b = 0.101, SE = 0.050, P = 0.045). Adjusting for the same confounders, rs3816358 was shown to be significantly associated with fasting glucose (b = 0.060, SE = 0.028, P = 0.032). Furthermore, a significant interaction between rs3789327 and nutritional status on fasting glucose was identified (P_interaction = 0.009); rs3789327 was associated with fasting glucose in the overweight/obese subgroup (b = 0.353, SE = 0.126, P = 0.006), but not in non-overweight/non-obese children.

CONCLUSIONS

BMAL1 polymorphisms were significantly associated with the fasting glucose level in children. Additionally, the observed interaction between nutritional status and BMAL1 supports promoting an optimal BMI in children genetically predisposed to higher glucose level.

IMPACT

Polymorphisms in the essential circadian clock gene BMAL1 were associated with fasting blood glucose levels in children. Additionally, there was a significant interaction between nutritional status and BMAL1 affecting fasting glucose levels. BMAL1 rs3789327 was associated with fasting glucose only in overweight/obese children. This finding could bring novel insights into mechanisms by which nutritional status influences fasting glucose in children.

A simple preparation step to remove excess liquid lipids in white adipose tissue enabling improved detection of metabolites via MALDI-FTICR imaging MS

Matrix-assisted laser desorption ionization (MALDI) Fourier transform ion cyclotron resonance (FTICR) imaging mass spectrometry (MS) is a powerful technology used to analyze metabolites in various tissues. However, it faces significant challenges in studying adipose tissues. Poor matrix distribution and crystallization caused by excess liquid lipids on the surface of tissue sections hamper m/z species detection, an adverse effect that particularly presents in lipid-rich white adipose tissue (WAT). In this study, we integrated a simple and low-cost preparation step into the existing MALDI-FTICR imaging MS pipeline. The new method—referred to as filter paper application—is characterized by an easy sample handling and high reproducibility. The aforementioned filter paper is placed onto the tissue prior to matrix application in order to remove the layer of excess liquid lipids. Consequently, MALDI-FTICR imaging MS detection was significantly improved, resulting in a higher number of detected m/z species and higher ion intensities. After analyzing various durations of filter paper application, 30 s was found to be optimal, resulting in the detection of more than 3700 m/z species. Apart from the most common lipids found in WAT, other molecules involved in various metabolic pathways were detected, including nucleotides, carbohydrates, and amino acids. Our study is the first to propose a solution to a specific limitation of MALDI-FTICR imaging MS in investigating lipid-rich WAT. The filter paper approach can be performed quickly and is particularly effective for achieving uniform matrix distribution on fresh frozen WAT while maintaining tissue integrity. It thus helps to gain insight into the metabolism in WAT.

Synergistic Effects of Lotus Seed Resistant Starch and Sodium Lactate on Hypolipidemic Function and Serum Nontargeted Metabolites in Hyperlipidemic Rats

The synergistic effects of lotus seed resistant starch (LRS3) and sodium lactate (SL; a postbiotics of RS3) on hypolipidemic function and serum nontargeted metabolites of hyperlipidemia rats were investegated. Rats fed a high-fat diet were orally administered with LRS3 (HLRS group) or SL (HSL group) either alone or in combination (HLRSSL group) for consecutive 4 weeks. HLRSSL was found to control weight gain, regulate blood lipid levels, reduce accumulation of fat in liver cells, and improve lesions in rat cardiac arteries, liver, small intestine, and colon tissues more effectively compared to HLRS or HSL group alone. Compared to the high-fat control group (HMC), l-phenylalanine and LysoPC(22:6(4Z,7Z,10Z,13Z,16Z,19Z)) in serum were upregulated in HLRSSL rats, while aconitic acid and suberic acid were decreased. Correlation analysis showed that SM(d18:0/16:1(9Z)), taurochenodeoxycholic acid, LysoPC(22:6(4Z,7Z,10Z,13Z,16Z,19Z)), oleic acid, and retinol were negatively correlated with total cholesterol (TCHO), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) and positively correlated with high-density lipoprotein cholesterol (HDL-C). Moreover, glutamic acid and serine showed a significant positive correlation with LDL-C and negative correlation with HDL-C. These differential metabolites were associated with reducing serum lipid levels in hyperlipidemia rats potentially through metabolic pathways such as linoleic acid, glutamine and glutamate, pyruvate, citric acid cycle, and glycerophospholipid.