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, 9 (1), 18885

Metabolic Syndrome Agravates Cardiovascular, Oxidative and Inflammatory Dysfunction During the Acute Phase of Trypanosoma Cruzi Infection in Mice

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Metabolic Syndrome Agravates Cardiovascular, Oxidative and Inflammatory Dysfunction During the Acute Phase of Trypanosoma Cruzi Infection in Mice

Bruno Fernando Cruz Lucchetti et al. Sci Rep.

Abstract

We evaluated the influence of metabolic syndrome (MS) on acute Trypanosoma cruzi infection. Obese Swiss mice, 70 days of age, were subjected to intraperitoneal infection with 5 × 102 trypomastigotes of the Y strain. Cardiovascular, oxidative, inflammatory, and metabolic parameters were evaluated in infected and non-infected mice. We observed higher parasitaemia in the infected obese group (IOG) than in the infected control group (ICG) 13 and 15 days post-infection. All IOG animals died by 19 days post-infection (dpi), whereas 87.5% of the ICG survived to 30 days. Increased plasma nitrite levels in adipose tissue and the aorta were observed in the IOG. Higher INF-γ and MCP-1 concentrations and lower IL-10 concentrations were observed in the IOG compared to those in the ICG. Decreased insulin sensitivity was observed in obese animals, which was accentuated after infection. Higher parasitic loads were found in adipose and hepatic tissue, and increases in oxidative stress in cardiac, hepatic, and adipose tissues were characteristics of the IOG group. Thus, MS exacerbates experimental Chagas disease, resulting in greater damage and decreased survival in infected animals, and might be a warning sign that MS can influence other pathologies.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Experimental Design. Swiss mice in first day of life begin treatment with monosodium glutamate (4 mg/g) during five consecutive days. After thirty days the mice was weaning and the male mice was separated. From the 30th to the 70th day of life the mice had the cardiovascular parameters evaluated. On 70th day the mice were infected with 5 × 10² tripomastigotes (Y strain). In the 7th day after infection we started the evaluation of cardiovascular parameters and parasitaemia until day 30 post infection. In 13th day a part of group of mice was euthanized for perform other experiments.
Figure 2
Figure 2
Cardiovascular parameters during development of obesity. The analysis of cardiovascular parameters began in 30th of life of mouse and repeated every 10 days until 70th of life, using the Coda Platform. The mean arterial pressure (A) was expressed in millimeters of mercury (mmHg) and the heart rate (B) was expressed in beats per minute. Data show mean ± SEM. ****p < 0.0001 when compared control group vs obese group. The number of animals used was: 30 control and 23 obese mice.
Figure 3
Figure 3
Effect of obesity on time course of T. cruzi infection in mice. Parasitemia and survival were determined after infection. The parasitaemia (A) started on 7th day and ended on 30th day after infection. Data show mean ± SEM. ****p < 0.0001 when compared control infected vs obese infected mice. The survival rates (B) was evaluated on the same mice used in parasitaemia and was determined by Gehan-Breslow-Wilcoxon test. *p < 0.05 comparing control infected with obese infected group. For this experiment were used 15 mice per group.
Figure 4
Figure 4
Obesity modulate the tissue parasitism in infected mice. The tissue parasitism was determined in heart tissue (A), retroperitoneal adipose tissue (B) and liver tissue (C) in 13th day post infection. Representative microphotographs (original magnification X 200) are shown. Black arrows indicate amastigote nests. The results were expressed in numbers of amastigotes nests per square millimeter (mm²). Bars represent mean ± SEM of six mice per group. **p < 0.01 comparing control infected vs obese infected. For this experiment we used six animals per group.
Figure 5
Figure 5
Effect of obesity in lipid profile. The levels of triglycerides (A) and total cholesterol (B) was determined in serum of mice in 13th day post infection. The results were expressed in milligram per deciliter (mg/dL). *p < 0.05, **p < 0.01 and ****p < 0.0001 when compared between groups. For this experiment, we use eight mice per group.
Figure 6
Figure 6
Effect of obesity in cardiovascular parameters during acute phase of T. cruzi infection. The cardiovascular parameter was measured using the Coda Platform and began in 7th day and finished in 30th day post infection or until death of infected mice. The mean arterial pressure (A) was expressed in millimeter of mercury. **p < 0.01, ***p < 0.001 and ****p < 0.0001 when compared obese group vs obese infected group. The heart rate (B) was expressed in beats per minute (bpm), no statistical difference was found between the groups. For this experiment was used ten mice per group.
Figure 7
Figure 7
Obesity modulate nitric oxide production. The nitric oxide (NO) was estimated by production of nitrite through cadmium/Griess technique and was measured in plasma (A), aorta (B), heart tissue (C) and adipose tissue from retroperitoneal region (D) on 13th day post infection. The levels of NO were expressed in NO micromolar (NO2µM). Bars represent mean ± SEM of eight mice per group. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001 when compared between groups.
Figure 8
Figure 8
The obesity stimulates production of pro-inflammatory cytokines and decrease anti-inflammatory cytokines in T. cruzi infection. (A) TNF-α, (B) INF-γ (C) IL-10 (D) MCP-1, and (E) IL-6 plasma levels were quantified using the BD CBA mouse inflammation kit for a flow cytometer. The data show the mean ± SEM of five mice per group. Bars represent mean ± SEM of eight mice per group. *p < 0.05, ***p < 0.001 and ****p < 0.0001 when compared between groups. (ND) means not identified the cytokines in plasma.
Figure 9
Figure 9
Effect of obesity in oxidative stress. To measure the oxidative stress and anti-oxidant capacity of heart tissue, liver tissue and adipose tissue from retroperitoneal region was used the assay ABTS, which evaluates the total antioxidant capacity, the FRAP assay, which evaluates the total antioxidant power, NBT assay which evaluates the production of the superoxide anion and the evaluation of lipid peroxidation that was determined by the levels of thiobarbituric acid reactive substances (TBARS). We used 6 mice per group. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001.
Figure 10
Figure 10
Effect of obesity in glucose metabolism of T. cruzi infection. The basal blood glucose (A) was measured in 2 µL of blood in tail of mice. The blood glucose was expressed in milligram per deciliter (mg/dL), after that was administrate 0,75U/g of insulin, and collected the blood at times 15, 30, 60, 90 and 120 minutes post injection of insulin for performs the insulin test tolerance (ITT) (B), with this measure we calculate the glucose decay constant (Kitt) (C) *p < 0.05, **p < 0.01 and ****p < 0.0001. For this experiment it was utilized nine mice per group.
Figure 11
Figure 11
T. cruzi infection and obesity alters liver tissue. The degree of inflammation (B) was graded using a 4-stage classification scale, where 0 = without inflammatory infiltrate and 3 = intense inflammatory infiltrate, in 10 fields per section of tissue (magnification 100×). Hepatic steatosis (A) was evaluated in the same 10 fields. To classify the intensity of steatosis a scale with score of 0 to 4 was used. Representative microphotographs (C) (original magnification X 200) of liver tissues of mice are shown, red arrows indicates inflammatory infiltrate. For this experiment it was utilized six mice per group. The aspartate aminotransferase (AST) (D) and alanine aminotransferase (E) (ALT) was evaluated in serum. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001.
Figure 12
Figure 12
Obese mice infected with T. cruzi reduces hepatic glycogen. We utilized blades stained in the reaction periodic acid-Schiff for analyze and quantification of hepatic glycogen in mice liver. The degree of hepatic glycogen (A) was graded using a positive hepatocyte quantity scale from 0 to 4+, under light microscope with increase in 200×. *p < 0.05, **p < 0.01, ***p < 0.001 and ****p < 0.0001 when compared between groups. Representative photomicrographs (B) (original magnification X 200) of liver tissues of mice of different groups are shown. For this experiment it was utilized six mice per group.

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References

    1. Perez-Molina JA, Molina I. Chagas disease. Lancet. 2018;391:82–94. doi: 10.1016/s0140-6736(17)31612-4. - DOI - PubMed
    1. TDR Disease Reference Group on Chagas Disease, H. A. T. & Leishmaniasis. Research Priorities for Chagas Disease, Human African Trypanosomiasis and Leishmaniasis: Technical Report of the TDR Disease Reference Group on Chagas Disease, Human African Trypanosomiasis and Leishmaniasis. (World Health Organization, 2012).
    1. Garcia MN, et al. Molecular identification and genotyping of Trypanosoma cruzi DNA in autochthonous Chagas disease patients from Texas, USA. Infection, Genetics and Evolution. 2017;49:151–156. doi: 10.1016/j.meegid.2017.01.016. - DOI - PubMed
    1. Schijman AG. Molecular diagnosis of Trypanosoma cruzi. Acta Trop. 2018 doi: 10.1016/j.actatropica.2018.02.019. - DOI - PubMed
    1. WHO, W. H. O. Chagas disease (American trypanosomiasis), http://www.who.int/mediacentre/factsheets/fs340/en/ (2017).
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