Pro-inflammatory cytokines are modified during the multiplication of Trypanosoma cruzi within the placental chorionic villi and are associated with the level of infection via the signaling pathway NF-κB.

PROBLEM: Congenital Trypanosoma cruzi (T. cruzi) infection has been associated with changes in the levels of TNF-α and IFN-γ during the pregnancy. Therefore, we propose to study the participation and dynamics of proinflammatory cytokines in the infection process of placental explants infected by T. cruzi in vitro. METHOD OF STUDY: Chorionic villous explants (CVE) obtained of human term placentas (n = 8) from normal pregnancies were cultured with 105 trypomastigotes/mL of Tulahuen strain DTU VI for 0, 2, 4, 16, 24, 48 and 72 h. Explants were treated with sulfasalazine (SULF) (5 mM) and N-acetyl-cysteine (NAC) (15 mM), as inhibitors molecules of NF-κB pathway, or LPS (1 µg/mL) for 24 and 72 h p.i. Motile trypomastigotes were counted in culture supernatants. Immunohistochemistry and ELISA for TNF-α, IFN-γ, IL-1ß, IL-4, and IL-10 were performed in CVE and culture supernatants respectively. The parasite load was measured by RT-qPCR. RESULTS: T. cruzi invades the chorionic villi from 4 h p.i. increasing significantly its DNA at 48 and 72 h p.i. of culture (parasite multiplication phase). They were detected in stromal cells, which was related to elevation of TNF-α, IL-1ß, IFN-γ, and IL-10. The inhibition of NF-κB activity in the explants decreased the production of the analyzed cytokines, showing elevated levels of T. cruzi DNA during the multiplication phase of the parasite. CONCLUSIONS: Placental tissue modifies the secretion of pro-inflammatory cytokines during the phase of parasite multiplication, but not during the invasion phase, which in turns modifies the level of infection via the signaling pathway NF-κB.

Eicosapentaenoic acid prevents salt sensitivity in diabetic rats and decreases oxidative stress.

OBJECTIVES: Salt sensitivity (SS) is associated with increased cardiovascular risk in patients with Type 2 diabetes mellitus (T2-DM) due to an increase in renal oxidation. ω-3 polyunsaturated fatty acids have shown antioxidant effects, but a typical Western diet contains limited content. In particular, ω-3 polyunsaturated fatty acids are able to activate nuclear factor erythroid 2-related factor 2 (Nrf-2) to prevent diabetes mellitus-related complications by mitigating oxidative stress. Therefore, we hypothesized that eicosapentaenoic acid (EPA; ω-3) modulates SS in rats with T2-DM by decreasing renal oxidative stress via Nrf-2 activation and enhancing the antiinflammatory response via interleukin (IL) 6 modulation. METHODS: Three-month-old male rats (n = 40) were fed with a Normal Na-diet (NNaD) and randomly selected into four groups: Healthy Wistar nondiabetic rats (Wi), diabetic controls (eSS), arachidonic acid-treated eSS (AA; ω-6), and EPA-treated eSS (ω-3). After 1 year, rats were placed in metabolic cages for 7 d and fed a NNaD, followed by a 7-d period with a High Na-diet (HNaD). Systolic blood pressure, body weight, serum IL-6 and reactive oxygen species (ROS) levels were determined at the end of each 7-d period. Glycated hemoglobin (HbA1c), triacylglycerol, creatinine, and cholesterol levels were determined. ROS levels and Nrf-2 expression in kidney lysates were also assayed. Histologic changes were evaluated. A t test or analysis of variance was used for the statistical analysis. RESULTS: After a HNaD, systolic blood pressure increased in both the control eSS and AA groups, but not in the EPA and Wi groups. However, HbA1c levels remained unchanged by the treatments, which suggests that the observed beneficial effect was independent of HbA1c levels. The IL-6 levels were higher in the eSS and AA groups, but remained unaltered in EPA and Wi rats after a HNaD diet. Interestingly, EPA protected against serum ROS in rats fed the HNaD, whereas AA did not. In kidney lysates, ROS decreased significantly in the EPA group compared with the eSS group, and Nrf-2 expression was consistently higher compared with the AA and eSS groups. Diabetic rats presented focal segmental sclerosis, adherence to Bowman capsule, and mild-to-moderate interstitial fibrosis. EPA and AA treatment prevented kidney damage. CONCLUSIONS: An adequate ω3-to-ω6 ratio prevents SS in diabetic rats by a mechanism that is independent of glucose metabolism but associated with the prevention of renal oxidative stress generation. These data suggest that EPA antioxidant properties may prevent the development of hypertension or kidney damage.

Early Detection of Chronic Asymptomatic Chagas Infection.

Chagas disease, also known as American trypanosomiasis, is a chronic and systemic parasitic infection which has become a serious epidemiological problem not only in endemic regions (Latin America), but also in non-endemic ones like North America, Europe, and Oceania. Subjects with the indeterminate chagasic form (ICF), a chronic asymptomatic disease stage, are the main sources of non-vectorial dissemination through blood transfusion, organ transplantation, and congenital transmission. It has been suggested that 94% of urban infections can be explained by these subjects. Under this scenario, the availability of simple and effective screening methods for ICF detection becomes crucial for both prevention of disease propagation and detection of clinical stages. Recently, a new non-invasive method has been proposed for ICF detection. It is based on surface high-resolution ECG and it could be easily adopted and included in modern ECG devices, overcoming the limitations of serological-based tests. The proposed method shows accuracy for early ICF screening, thus improving prognosis by defining the clinical stages and allowing appropriate and effective treatment.