Ultrastructure of the Bacteriocytes in the Midgut of the Carpenter ant Camponotus rufipes: Endosymbiont Control by Autophagy.

The carpenter ant Camponotus rufipes has intracellular bacteria in bacteriocytes scattered in the midgut epithelium, which have different amounts of endosymbionts, according to the developmental stages. However, there are no detailed data about the midgut cells in adult workers. The present work aimed to evaluate the morphology and cellular events that coordinate the abundance of endosymbionts in the midgut cells in C. rufipes workers. The midgut epithelium has digestive cells, bacteriocytes, and cells with intermediate morphology. The latter is similar to bacteriocytes, due to the abundance of endosymbionts, and similar to digestive cells, due to their microvilli. The digestive and intermediate cells are rich in autophagosomes and autolysosomes, both with bacteria debris in the lumen. These findings suggest that midgut cells of C. rufipes control the endosymbiont level by the autophagy pathway.

Morphology and Morphometry of the Midgut in the Stingless Bee Friesella schrottkyi (Hymenoptera: Apidae).

Friesella schrottkyi is a small stingless bee (3-mm long) important for agricultural and native forest pollination. This study describes the morphology and morphometry of the midgut in F. schrottkyi forager workers. The F. schrottkyi midgut presents a single-layered epithelium with digestive, regenerative and endocrine cells. The digestive cells are similar along the entire midgut length with a spherical nucleus, apex with long striated border, cytoplasmic granules in the apical region and well-developed basal labyrinth associated with mitochondria, suggesting they are multifunctional, synthesizing digestive enzymes and peritrophic matrix compounds and absorbing nutrients. Regenerative cells are located around the basal region organized in nests with some cells with a spherical nucleus. Phe-Met-Arg-Phe-NH2-amide (FMRFamide) positive endocrine cells are restricted to the posterior midgut region, suggesting a paracrine function in the midgut. This is the first morphological description of the F. schrottkyi midgut contributing to the comprehension of the digestive process of this bee.

Nonsteroidal anti-inflammatory is more effective than anti-oxidant therapy in counteracting oxidative/nitrosative stress and heart disease in T. cruzi-infected mice.

We compared the relevance of ibuprofen, vitamins C and E to control oxidative/nitrosative stress and heart disease in mice infected by Trypanosoma cruzi. Swiss mice were randomized into five groups: control, uninfected; infected without treatment; and infected treated with vitamins C, E or ibuprofen. Animals were inoculated with 2000 trypomastigote forms of T. cruzi. After 20 days, infected mice presented reduced vitamin C and E tissue levels, high cytokines (interferon gamma, tumour necrosis factor-α, interleukin 10 and chemokine ligand 2), prostaglandin F2α (PGF2α ) and nitric oxide (NO) cardiac production, intense myocarditis and reactive tissue damage, which was directly correlated with the intensity of the inflammatory infiltrate and the degree of pathological cardiac remodelling. Vitamins C and E supplementation were irrelevant to counteract reactive tissue damage and myocarditis in infected animals. Conversely, ibuprofen reduced tissue levels of cytokines, PGF2α and NO, as well as lipid and protein oxidation, antioxidant enzyme activity and the cardiac damage, without interfering with heart parasitism. Our results do not support the applicability of vitamin C and E supplementation in the management of acute Chagas cardiomyopathy. By controlling the inflammatory infiltrate, anti-inflammatory-based therapy proved to be a more rational strategy than a direct antioxidant therapy in attenuating oxidative/nitrosative stress and cardiac damage.

Modulation of oxidative and inflammatory cardiac response by nonselective 1- and 2-cyclooxygenase inhibitor and benznidazole in mice.

OBJECTIVES: This study investigated the combined effects of benznidazole (BZ) and ibuprofen (IB) on the oxidative and inflammatory status of the cardiac tissue in vivo. METHODS: Swiss mice were randomized in groups receiving BZ (100 mg/kg) and IB (400 mg/kg) alone or combined (BZ + IB 200 or 400 mg/kg). Control animals were concurrently treated with 1% carboxymethyl cellulose. All treatments were administered orally for 7 days. KEY FINDINGS: BZ treatment increased cardiac production of nitrogen/oxygen-reactive species, malondialdeyde, carbonyl proteins, prostaglandins as well as the activities of catalase, superoxide dismutase and glutathione peroxidase. These parameters were attenuated by IB, with the best results at higher dose. Individually, BZ and IB significantly reduced the tissue levels of chemokine ligand 2, tumour necrosis factor-α and IL-10, but no reduction was observed when the treatments were combined. CONCLUSIONS: BZ triggers an oxidative and nitrosative route, which is associated with increased prostaglandin synthesis and marked damages to the lipids and proteins of the cardiac tissue. IB treatment attenuated reactive stresses triggered by BZ, which was an independent effects of this drug on the endogenous antioxidant enzymes. Individually, but not together, BZ and IB reduced the cardiac inflammatory status, indicating a beneficial and complex drug interaction.