The influence of different diets on metabolism and atherosclerosis processes—A porcine model: Blood serum, urine and tissues 1H NMR metabolomics targeted analysis

The global epidemic of cardiovascular diseases leads to increased morbidity and mortality caused mainly by myocardial infarction and stroke. Atherosclerosis is the major pathological process behind this epidemic. We designed a novel model of atherosclerosis in swine. Briefly, the first group (11 pigs) received normal pig feed (balanced diet group-BDG) for 12 months, the second group (9 pigs) was fed a Western high-calorie diet (unbalanced diet group-UDG) for 12 months, the third group (8 pigs) received a Western type high-calorie diet for 9 months later replaced by a normal diet for 3 months (regression group-RG). Clinical measurements included zoometric data, arterial blood pressure, heart rate and ultrasonographic evaluation of femoral arteries. Then, the animals were sacrificed and the blood serum, urine and skeletal muscle tissue were collected and 1H NMR based metabolomics studies with the application of fingerprinting PLS-DA and univariate analysis were done. Our results have shown that the molecular disturbances might overlap with other diseases such as onset of diabetes, sleep apnea and other obesity accompanied diseases. Moreover, we revealed that once initiated, molecular changes did not return to homeostatic equilibrium, at least for the duration of this experiment

Analysis of the Model of Atherosclerosis Formation in Pig Hearts as a Result of Impaired Activity of DNA Repair Enzymes

Excessive consumption of food rich in saturated fatty acids and carbohydrates can lead to metabolic disturbances and cardiovascular disease. Hyperlipidemia is a significant risk factor for acute cardiac events due to its association with oxidative stress. This leads to arterial wall remodeling, including an increase in the thickness of the intima media complex (IMT), and endothelial dysfunction leading to plaque formation. The decreased nitric oxide synthesis and accumulation of lipids in the wall result in a reduction in the vasodilating potential of the vessel. This study aimed to establish a clear relationship between markers of endothelial dysfunction and the activity of repair enzymes in cardiac tissue from a pig model of early atherosclerosis. The study was conducted on 28 female Polish Landrace pigs, weighing 40 kg (approximately 3.5 months old), which were divided into three groups. The control group (n = 11) was fed a standard, commercial, balanced diet (BDG) for 12 months. The second group (n = 9) was fed an unbalanced, high-calorie Western-type diet (UDG). The third group (n = 8) was fed a Western-type diet for nine months and then switched to a standard, balanced diet (regression group, RG). Control examinations, including blood and urine sampling, were conducted every three months under identical conditions with food restriction for 12 h and water restriction for four hours before general anesthesia. The study analyzed markers of oxidative stress formed during lipid peroxidation processes, including etheno DNA adducts, ADMA, and NEFA. These markers play a crucial role in reactive oxygen species analysis in ischemia–reperfusion and atherosclerosis in mammalian tissue. Essential genes involved in oxidative-stress-induced DNA demethylation like OGG1 (8-oxoguanine DNA glycosylase), MPG (N-Methylpurine DNA Glycosylase), TDG (Thymine-DNA glycosylase), APEX (apurinic/apirymidinic endodeoxyribonuclease 1), PTGS2 (prostaglandin-endoperoxide synthase 2), and ALOX (Arachidonate Lipoxygenase) were measured using the Real-Time RT-PCR method. The data suggest that high oxidative stress, as indicated by TBARS levels, is associated with high levels of DNA repair enzymes and depends on the expression of genes involved in the repair pathway. In all analyzed groups of heart tissue homogenates, the highest enzyme activity and gene expression values were observed for the OGG1 protein recognizing the modified 8oxoG. Conclusion: With the long-term use of an unbalanced diet, the levels of all DNA repair genes are increased, especially (significantly) Apex, Alox, and Ptgs, which strongly supports the hypothesis that an unbalanced diet induces oxidative stress that deregulates DNA repair mechanisms and may contribute to genome instability and tissue damage

Changes in the level of statistically significant^* and VIP selected tissue metabolites.

<p>The listed metabolites are important at least in one comparison.</p

Ultrasound measured Intima-Media complex thickness (IMT) and the mean thickness of intima, media and adventitia obtained from a histological analysis of femoral arteries at the same location as ultrasound measurements in all study groups.

<p>Ultrasound measured Intima-Media complex thickness (IMT) and the mean thickness of intima, media and adventitia obtained from a histological analysis of femoral arteries at the same location as ultrasound measurements in all study groups.</p

The median spectrum ¹H NMR obtained from tissue samples in the balanced diet group.

<p>The following metabolites are identified: 1, L1; 2, Leucine; 3, Valine; 4, Isoleucine; 5, Unk_1; 6, Unk_2; 7, L2; 8, Lactate; 9, Unk_3; 10, Alanine; 11, L3; 12, Methionine; 13, L4; 14, Pyruvate; 15, Succinate; 16, Carnosine; 17, Creatine; 18, Malonate; 19, Betaine; 20, Methanol; 21, Glycine; 22, <i>N</i>,<i>N</i>-Dimethylglycine; 23, Glucose; 24, Histidine; 25, Methylhistidine; 26, IMP.</p

Changes in the level of statistically significant^* and VIP selected urine metabolites.

<p>The listed metabolites are important at least in one comparison.</p

The median spectrum ¹H NMR obtained from urine samples in the balanced diet group.

<p>The following metabolites are identified: 1, Isovalerate; 2, Isopropanol; 3, Threonine; 4, 2-Hydroxyisobutyrate; 5, Alanine; 6, Unk_1 δ 2.3 ppm; 7, β-Alanine 8, Dimethylamine (DMA); 9, <i>N</i>,<i>N</i>-Dimethylglycine; 10, Creatinine; 11, Unk_2 δ 5.23 ppm; 12, Allantoin; 13, Unk_3 δ 6.91 ppm; 14, Unk_4 δ 7.02 ppm; 15, Unk_5 δ 7.22 ppm; 16, <i>N</i>-Phenylacetylglutamine; 17, Hippurate; 18, Unk_6 δ 8.22 ppm; 19, Formate.</p

Changes in the level of statistically significant^* and VIP selected serum metabolites.

<p>The listed metabolites are important at least in one comparison.</p

Clinical laboratory data in the three study groups at the start and at the end (12 month) of the study.

<p>Clinical laboratory data in the three study groups at the start and at the end (12 month) of the study.</p